v4.19.13 snapshot.
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
new file mode 100644
index 0000000..f4405e4
--- /dev/null
+++ b/fs/btrfs/volumes.c
@@ -0,0 +1,7532 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ */
+
+#include <linux/sched.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+#include <linux/blkdev.h>
+#include <linux/ratelimit.h>
+#include <linux/kthread.h>
+#include <linux/raid/pq.h>
+#include <linux/semaphore.h>
+#include <linux/uuid.h>
+#include <linux/list_sort.h>
+#include "ctree.h"
+#include "extent_map.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "print-tree.h"
+#include "volumes.h"
+#include "raid56.h"
+#include "async-thread.h"
+#include "check-integrity.h"
+#include "rcu-string.h"
+#include "math.h"
+#include "dev-replace.h"
+#include "sysfs.h"
+
+const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
+ [BTRFS_RAID_RAID10] = {
+ .sub_stripes = 2,
+ .dev_stripes = 1,
+ .devs_max = 0, /* 0 == as many as possible */
+ .devs_min = 4,
+ .tolerated_failures = 1,
+ .devs_increment = 2,
+ .ncopies = 2,
+ .raid_name = "raid10",
+ .bg_flag = BTRFS_BLOCK_GROUP_RAID10,
+ .mindev_error = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET,
+ },
+ [BTRFS_RAID_RAID1] = {
+ .sub_stripes = 1,
+ .dev_stripes = 1,
+ .devs_max = 2,
+ .devs_min = 2,
+ .tolerated_failures = 1,
+ .devs_increment = 2,
+ .ncopies = 2,
+ .raid_name = "raid1",
+ .bg_flag = BTRFS_BLOCK_GROUP_RAID1,
+ .mindev_error = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET,
+ },
+ [BTRFS_RAID_DUP] = {
+ .sub_stripes = 1,
+ .dev_stripes = 2,
+ .devs_max = 1,
+ .devs_min = 1,
+ .tolerated_failures = 0,
+ .devs_increment = 1,
+ .ncopies = 2,
+ .raid_name = "dup",
+ .bg_flag = BTRFS_BLOCK_GROUP_DUP,
+ .mindev_error = 0,
+ },
+ [BTRFS_RAID_RAID0] = {
+ .sub_stripes = 1,
+ .dev_stripes = 1,
+ .devs_max = 0,
+ .devs_min = 2,
+ .tolerated_failures = 0,
+ .devs_increment = 1,
+ .ncopies = 1,
+ .raid_name = "raid0",
+ .bg_flag = BTRFS_BLOCK_GROUP_RAID0,
+ .mindev_error = 0,
+ },
+ [BTRFS_RAID_SINGLE] = {
+ .sub_stripes = 1,
+ .dev_stripes = 1,
+ .devs_max = 1,
+ .devs_min = 1,
+ .tolerated_failures = 0,
+ .devs_increment = 1,
+ .ncopies = 1,
+ .raid_name = "single",
+ .bg_flag = 0,
+ .mindev_error = 0,
+ },
+ [BTRFS_RAID_RAID5] = {
+ .sub_stripes = 1,
+ .dev_stripes = 1,
+ .devs_max = 0,
+ .devs_min = 2,
+ .tolerated_failures = 1,
+ .devs_increment = 1,
+ .ncopies = 2,
+ .raid_name = "raid5",
+ .bg_flag = BTRFS_BLOCK_GROUP_RAID5,
+ .mindev_error = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET,
+ },
+ [BTRFS_RAID_RAID6] = {
+ .sub_stripes = 1,
+ .dev_stripes = 1,
+ .devs_max = 0,
+ .devs_min = 3,
+ .tolerated_failures = 2,
+ .devs_increment = 1,
+ .ncopies = 3,
+ .raid_name = "raid6",
+ .bg_flag = BTRFS_BLOCK_GROUP_RAID6,
+ .mindev_error = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET,
+ },
+};
+
+const char *get_raid_name(enum btrfs_raid_types type)
+{
+ if (type >= BTRFS_NR_RAID_TYPES)
+ return NULL;
+
+ return btrfs_raid_array[type].raid_name;
+}
+
+static int init_first_rw_device(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info);
+static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info);
+static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
+static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
+static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
+static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
+ enum btrfs_map_op op,
+ u64 logical, u64 *length,
+ struct btrfs_bio **bbio_ret,
+ int mirror_num, int need_raid_map);
+
+/*
+ * Device locking
+ * ==============
+ *
+ * There are several mutexes that protect manipulation of devices and low-level
+ * structures like chunks but not block groups, extents or files
+ *
+ * uuid_mutex (global lock)
+ * ------------------------
+ * protects the fs_uuids list that tracks all per-fs fs_devices, resulting from
+ * the SCAN_DEV ioctl registration or from mount either implicitly (the first
+ * device) or requested by the device= mount option
+ *
+ * the mutex can be very coarse and can cover long-running operations
+ *
+ * protects: updates to fs_devices counters like missing devices, rw devices,
+ * seeding, structure cloning, openning/closing devices at mount/umount time
+ *
+ * global::fs_devs - add, remove, updates to the global list
+ *
+ * does not protect: manipulation of the fs_devices::devices list!
+ *
+ * btrfs_device::name - renames (write side), read is RCU
+ *
+ * fs_devices::device_list_mutex (per-fs, with RCU)
+ * ------------------------------------------------
+ * protects updates to fs_devices::devices, ie. adding and deleting
+ *
+ * simple list traversal with read-only actions can be done with RCU protection
+ *
+ * may be used to exclude some operations from running concurrently without any
+ * modifications to the list (see write_all_supers)
+ *
+ * balance_mutex
+ * -------------
+ * protects balance structures (status, state) and context accessed from
+ * several places (internally, ioctl)
+ *
+ * chunk_mutex
+ * -----------
+ * protects chunks, adding or removing during allocation, trim or when a new
+ * device is added/removed
+ *
+ * cleaner_mutex
+ * -------------
+ * a big lock that is held by the cleaner thread and prevents running subvolume
+ * cleaning together with relocation or delayed iputs
+ *
+ *
+ * Lock nesting
+ * ============
+ *
+ * uuid_mutex
+ * volume_mutex
+ * device_list_mutex
+ * chunk_mutex
+ * balance_mutex
+ *
+ *
+ * Exclusive operations, BTRFS_FS_EXCL_OP
+ * ======================================
+ *
+ * Maintains the exclusivity of the following operations that apply to the
+ * whole filesystem and cannot run in parallel.
+ *
+ * - Balance (*)
+ * - Device add
+ * - Device remove
+ * - Device replace (*)
+ * - Resize
+ *
+ * The device operations (as above) can be in one of the following states:
+ *
+ * - Running state
+ * - Paused state
+ * - Completed state
+ *
+ * Only device operations marked with (*) can go into the Paused state for the
+ * following reasons:
+ *
+ * - ioctl (only Balance can be Paused through ioctl)
+ * - filesystem remounted as read-only
+ * - filesystem unmounted and mounted as read-only
+ * - system power-cycle and filesystem mounted as read-only
+ * - filesystem or device errors leading to forced read-only
+ *
+ * BTRFS_FS_EXCL_OP flag is set and cleared using atomic operations.
+ * During the course of Paused state, the BTRFS_FS_EXCL_OP remains set.
+ * A device operation in Paused or Running state can be canceled or resumed
+ * either by ioctl (Balance only) or when remounted as read-write.
+ * BTRFS_FS_EXCL_OP flag is cleared when the device operation is canceled or
+ * completed.
+ */
+
+DEFINE_MUTEX(uuid_mutex);
+static LIST_HEAD(fs_uuids);
+struct list_head *btrfs_get_fs_uuids(void)
+{
+ return &fs_uuids;
+}
+
+/*
+ * alloc_fs_devices - allocate struct btrfs_fs_devices
+ * @fsid: if not NULL, copy the uuid to fs_devices::fsid
+ *
+ * Return a pointer to a new struct btrfs_fs_devices on success, or ERR_PTR().
+ * The returned struct is not linked onto any lists and can be destroyed with
+ * kfree() right away.
+ */
+static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
+{
+ struct btrfs_fs_devices *fs_devs;
+
+ fs_devs = kzalloc(sizeof(*fs_devs), GFP_KERNEL);
+ if (!fs_devs)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&fs_devs->device_list_mutex);
+
+ INIT_LIST_HEAD(&fs_devs->devices);
+ INIT_LIST_HEAD(&fs_devs->resized_devices);
+ INIT_LIST_HEAD(&fs_devs->alloc_list);
+ INIT_LIST_HEAD(&fs_devs->fs_list);
+ if (fsid)
+ memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
+
+ return fs_devs;
+}
+
+void btrfs_free_device(struct btrfs_device *device)
+{
+ rcu_string_free(device->name);
+ bio_put(device->flush_bio);
+ kfree(device);
+}
+
+static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct btrfs_device *device;
+ WARN_ON(fs_devices->opened);
+ while (!list_empty(&fs_devices->devices)) {
+ device = list_entry(fs_devices->devices.next,
+ struct btrfs_device, dev_list);
+ list_del(&device->dev_list);
+ btrfs_free_device(device);
+ }
+ kfree(fs_devices);
+}
+
+static void btrfs_kobject_uevent(struct block_device *bdev,
+ enum kobject_action action)
+{
+ int ret;
+
+ ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
+ if (ret)
+ pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
+ action,
+ kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
+ &disk_to_dev(bdev->bd_disk)->kobj);
+}
+
+void __exit btrfs_cleanup_fs_uuids(void)
+{
+ struct btrfs_fs_devices *fs_devices;
+
+ while (!list_empty(&fs_uuids)) {
+ fs_devices = list_entry(fs_uuids.next,
+ struct btrfs_fs_devices, fs_list);
+ list_del(&fs_devices->fs_list);
+ free_fs_devices(fs_devices);
+ }
+}
+
+/*
+ * Returns a pointer to a new btrfs_device on success; ERR_PTR() on error.
+ * Returned struct is not linked onto any lists and must be destroyed using
+ * btrfs_free_device.
+ */
+static struct btrfs_device *__alloc_device(void)
+{
+ struct btrfs_device *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Preallocate a bio that's always going to be used for flushing device
+ * barriers and matches the device lifespan
+ */
+ dev->flush_bio = bio_alloc_bioset(GFP_KERNEL, 0, NULL);
+ if (!dev->flush_bio) {
+ kfree(dev);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ INIT_LIST_HEAD(&dev->dev_list);
+ INIT_LIST_HEAD(&dev->dev_alloc_list);
+ INIT_LIST_HEAD(&dev->resized_list);
+
+ spin_lock_init(&dev->io_lock);
+
+ atomic_set(&dev->reada_in_flight, 0);
+ atomic_set(&dev->dev_stats_ccnt, 0);
+ btrfs_device_data_ordered_init(dev);
+ INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+ INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+
+ return dev;
+}
+
+/*
+ * Find a device specified by @devid or @uuid in the list of @fs_devices, or
+ * return NULL.
+ *
+ * If devid and uuid are both specified, the match must be exact, otherwise
+ * only devid is used.
+ */
+static struct btrfs_device *find_device(struct btrfs_fs_devices *fs_devices,
+ u64 devid, const u8 *uuid)
+{
+ struct btrfs_device *dev;
+
+ list_for_each_entry(dev, &fs_devices->devices, dev_list) {
+ if (dev->devid == devid &&
+ (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
+ return dev;
+ }
+ }
+ return NULL;
+}
+
+static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
+{
+ struct btrfs_fs_devices *fs_devices;
+
+ list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
+ if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
+ return fs_devices;
+ }
+ return NULL;
+}
+
+static int
+btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
+ int flush, struct block_device **bdev,
+ struct buffer_head **bh)
+{
+ int ret;
+
+ *bdev = blkdev_get_by_path(device_path, flags, holder);
+
+ if (IS_ERR(*bdev)) {
+ ret = PTR_ERR(*bdev);
+ goto error;
+ }
+
+ if (flush)
+ filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
+ ret = set_blocksize(*bdev, BTRFS_BDEV_BLOCKSIZE);
+ if (ret) {
+ blkdev_put(*bdev, flags);
+ goto error;
+ }
+ invalidate_bdev(*bdev);
+ *bh = btrfs_read_dev_super(*bdev);
+ if (IS_ERR(*bh)) {
+ ret = PTR_ERR(*bh);
+ blkdev_put(*bdev, flags);
+ goto error;
+ }
+
+ return 0;
+
+error:
+ *bdev = NULL;
+ *bh = NULL;
+ return ret;
+}
+
+static void requeue_list(struct btrfs_pending_bios *pending_bios,
+ struct bio *head, struct bio *tail)
+{
+
+ struct bio *old_head;
+
+ old_head = pending_bios->head;
+ pending_bios->head = head;
+ if (pending_bios->tail)
+ tail->bi_next = old_head;
+ else
+ pending_bios->tail = tail;
+}
+
+/*
+ * we try to collect pending bios for a device so we don't get a large
+ * number of procs sending bios down to the same device. This greatly
+ * improves the schedulers ability to collect and merge the bios.
+ *
+ * But, it also turns into a long list of bios to process and that is sure
+ * to eventually make the worker thread block. The solution here is to
+ * make some progress and then put this work struct back at the end of
+ * the list if the block device is congested. This way, multiple devices
+ * can make progress from a single worker thread.
+ */
+static noinline void run_scheduled_bios(struct btrfs_device *device)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct bio *pending;
+ struct backing_dev_info *bdi;
+ struct btrfs_pending_bios *pending_bios;
+ struct bio *tail;
+ struct bio *cur;
+ int again = 0;
+ unsigned long num_run;
+ unsigned long batch_run = 0;
+ unsigned long last_waited = 0;
+ int force_reg = 0;
+ int sync_pending = 0;
+ struct blk_plug plug;
+
+ /*
+ * this function runs all the bios we've collected for
+ * a particular device. We don't want to wander off to
+ * another device without first sending all of these down.
+ * So, setup a plug here and finish it off before we return
+ */
+ blk_start_plug(&plug);
+
+ bdi = device->bdev->bd_bdi;
+
+loop:
+ spin_lock(&device->io_lock);
+
+loop_lock:
+ num_run = 0;
+
+ /* take all the bios off the list at once and process them
+ * later on (without the lock held). But, remember the
+ * tail and other pointers so the bios can be properly reinserted
+ * into the list if we hit congestion
+ */
+ if (!force_reg && device->pending_sync_bios.head) {
+ pending_bios = &device->pending_sync_bios;
+ force_reg = 1;
+ } else {
+ pending_bios = &device->pending_bios;
+ force_reg = 0;
+ }
+
+ pending = pending_bios->head;
+ tail = pending_bios->tail;
+ WARN_ON(pending && !tail);
+
+ /*
+ * if pending was null this time around, no bios need processing
+ * at all and we can stop. Otherwise it'll loop back up again
+ * and do an additional check so no bios are missed.
+ *
+ * device->running_pending is used to synchronize with the
+ * schedule_bio code.
+ */
+ if (device->pending_sync_bios.head == NULL &&
+ device->pending_bios.head == NULL) {
+ again = 0;
+ device->running_pending = 0;
+ } else {
+ again = 1;
+ device->running_pending = 1;
+ }
+
+ pending_bios->head = NULL;
+ pending_bios->tail = NULL;
+
+ spin_unlock(&device->io_lock);
+
+ while (pending) {
+
+ rmb();
+ /* we want to work on both lists, but do more bios on the
+ * sync list than the regular list
+ */
+ if ((num_run > 32 &&
+ pending_bios != &device->pending_sync_bios &&
+ device->pending_sync_bios.head) ||
+ (num_run > 64 && pending_bios == &device->pending_sync_bios &&
+ device->pending_bios.head)) {
+ spin_lock(&device->io_lock);
+ requeue_list(pending_bios, pending, tail);
+ goto loop_lock;
+ }
+
+ cur = pending;
+ pending = pending->bi_next;
+ cur->bi_next = NULL;
+
+ BUG_ON(atomic_read(&cur->__bi_cnt) == 0);
+
+ /*
+ * if we're doing the sync list, record that our
+ * plug has some sync requests on it
+ *
+ * If we're doing the regular list and there are
+ * sync requests sitting around, unplug before
+ * we add more
+ */
+ if (pending_bios == &device->pending_sync_bios) {
+ sync_pending = 1;
+ } else if (sync_pending) {
+ blk_finish_plug(&plug);
+ blk_start_plug(&plug);
+ sync_pending = 0;
+ }
+
+ btrfsic_submit_bio(cur);
+ num_run++;
+ batch_run++;
+
+ cond_resched();
+
+ /*
+ * we made progress, there is more work to do and the bdi
+ * is now congested. Back off and let other work structs
+ * run instead
+ */
+ if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
+ fs_info->fs_devices->open_devices > 1) {
+ struct io_context *ioc;
+
+ ioc = current->io_context;
+
+ /*
+ * the main goal here is that we don't want to
+ * block if we're going to be able to submit
+ * more requests without blocking.
+ *
+ * This code does two great things, it pokes into
+ * the elevator code from a filesystem _and_
+ * it makes assumptions about how batching works.
+ */
+ if (ioc && ioc->nr_batch_requests > 0 &&
+ time_before(jiffies, ioc->last_waited + HZ/50UL) &&
+ (last_waited == 0 ||
+ ioc->last_waited == last_waited)) {
+ /*
+ * we want to go through our batch of
+ * requests and stop. So, we copy out
+ * the ioc->last_waited time and test
+ * against it before looping
+ */
+ last_waited = ioc->last_waited;
+ cond_resched();
+ continue;
+ }
+ spin_lock(&device->io_lock);
+ requeue_list(pending_bios, pending, tail);
+ device->running_pending = 1;
+
+ spin_unlock(&device->io_lock);
+ btrfs_queue_work(fs_info->submit_workers,
+ &device->work);
+ goto done;
+ }
+ }
+
+ cond_resched();
+ if (again)
+ goto loop;
+
+ spin_lock(&device->io_lock);
+ if (device->pending_bios.head || device->pending_sync_bios.head)
+ goto loop_lock;
+ spin_unlock(&device->io_lock);
+
+done:
+ blk_finish_plug(&plug);
+}
+
+static void pending_bios_fn(struct btrfs_work *work)
+{
+ struct btrfs_device *device;
+
+ device = container_of(work, struct btrfs_device, work);
+ run_scheduled_bios(device);
+}
+
+/*
+ * Search and remove all stale (devices which are not mounted) devices.
+ * When both inputs are NULL, it will search and release all stale devices.
+ * path: Optional. When provided will it release all unmounted devices
+ * matching this path only.
+ * skip_dev: Optional. Will skip this device when searching for the stale
+ * devices.
+ */
+static void btrfs_free_stale_devices(const char *path,
+ struct btrfs_device *skip_device)
+{
+ struct btrfs_fs_devices *fs_devices, *tmp_fs_devices;
+ struct btrfs_device *device, *tmp_device;
+
+ list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) {
+ mutex_lock(&fs_devices->device_list_mutex);
+ if (fs_devices->opened) {
+ mutex_unlock(&fs_devices->device_list_mutex);
+ continue;
+ }
+
+ list_for_each_entry_safe(device, tmp_device,
+ &fs_devices->devices, dev_list) {
+ int not_found = 0;
+
+ if (skip_device && skip_device == device)
+ continue;
+ if (path && !device->name)
+ continue;
+
+ rcu_read_lock();
+ if (path)
+ not_found = strcmp(rcu_str_deref(device->name),
+ path);
+ rcu_read_unlock();
+ if (not_found)
+ continue;
+
+ /* delete the stale device */
+ fs_devices->num_devices--;
+ list_del(&device->dev_list);
+ btrfs_free_device(device);
+
+ if (fs_devices->num_devices == 0)
+ break;
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+ if (fs_devices->num_devices == 0) {
+ btrfs_sysfs_remove_fsid(fs_devices);
+ list_del(&fs_devices->fs_list);
+ free_fs_devices(fs_devices);
+ }
+ }
+}
+
+static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
+ struct btrfs_device *device, fmode_t flags,
+ void *holder)
+{
+ struct request_queue *q;
+ struct block_device *bdev;
+ struct buffer_head *bh;
+ struct btrfs_super_block *disk_super;
+ u64 devid;
+ int ret;
+
+ if (device->bdev)
+ return -EINVAL;
+ if (!device->name)
+ return -EINVAL;
+
+ ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
+ &bdev, &bh);
+ if (ret)
+ return ret;
+
+ disk_super = (struct btrfs_super_block *)bh->b_data;
+ devid = btrfs_stack_device_id(&disk_super->dev_item);
+ if (devid != device->devid)
+ goto error_brelse;
+
+ if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE))
+ goto error_brelse;
+
+ device->generation = btrfs_super_generation(disk_super);
+
+ if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
+ clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
+ fs_devices->seeding = 1;
+ } else {
+ if (bdev_read_only(bdev))
+ clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
+ else
+ set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
+ }
+
+ q = bdev_get_queue(bdev);
+ if (!blk_queue_nonrot(q))
+ fs_devices->rotating = 1;
+
+ device->bdev = bdev;
+ clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
+ device->mode = flags;
+
+ fs_devices->open_devices++;
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
+ device->devid != BTRFS_DEV_REPLACE_DEVID) {
+ fs_devices->rw_devices++;
+ list_add_tail(&device->dev_alloc_list, &fs_devices->alloc_list);
+ }
+ brelse(bh);
+
+ return 0;
+
+error_brelse:
+ brelse(bh);
+ blkdev_put(bdev, flags);
+
+ return -EINVAL;
+}
+
+/*
+ * Add new device to list of registered devices
+ *
+ * Returns:
+ * device pointer which was just added or updated when successful
+ * error pointer when failed
+ */
+static noinline struct btrfs_device *device_list_add(const char *path,
+ struct btrfs_super_block *disk_super,
+ bool *new_device_added)
+{
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *fs_devices;
+ struct rcu_string *name;
+ u64 found_transid = btrfs_super_generation(disk_super);
+ u64 devid = btrfs_stack_device_id(&disk_super->dev_item);
+
+ fs_devices = find_fsid(disk_super->fsid);
+ if (!fs_devices) {
+ fs_devices = alloc_fs_devices(disk_super->fsid);
+ if (IS_ERR(fs_devices))
+ return ERR_CAST(fs_devices);
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_add(&fs_devices->fs_list, &fs_uuids);
+
+ device = NULL;
+ } else {
+ mutex_lock(&fs_devices->device_list_mutex);
+ device = find_device(fs_devices, devid,
+ disk_super->dev_item.uuid);
+ }
+
+ if (!device) {
+ if (fs_devices->opened) {
+ mutex_unlock(&fs_devices->device_list_mutex);
+ return ERR_PTR(-EBUSY);
+ }
+
+ device = btrfs_alloc_device(NULL, &devid,
+ disk_super->dev_item.uuid);
+ if (IS_ERR(device)) {
+ mutex_unlock(&fs_devices->device_list_mutex);
+ /* we can safely leave the fs_devices entry around */
+ return device;
+ }
+
+ name = rcu_string_strdup(path, GFP_NOFS);
+ if (!name) {
+ btrfs_free_device(device);
+ mutex_unlock(&fs_devices->device_list_mutex);
+ return ERR_PTR(-ENOMEM);
+ }
+ rcu_assign_pointer(device->name, name);
+
+ list_add_rcu(&device->dev_list, &fs_devices->devices);
+ fs_devices->num_devices++;
+
+ device->fs_devices = fs_devices;
+ *new_device_added = true;
+
+ if (disk_super->label[0])
+ pr_info("BTRFS: device label %s devid %llu transid %llu %s\n",
+ disk_super->label, devid, found_transid, path);
+ else
+ pr_info("BTRFS: device fsid %pU devid %llu transid %llu %s\n",
+ disk_super->fsid, devid, found_transid, path);
+
+ } else if (!device->name || strcmp(device->name->str, path)) {
+ /*
+ * When FS is already mounted.
+ * 1. If you are here and if the device->name is NULL that
+ * means this device was missing at time of FS mount.
+ * 2. If you are here and if the device->name is different
+ * from 'path' that means either
+ * a. The same device disappeared and reappeared with
+ * different name. or
+ * b. The missing-disk-which-was-replaced, has
+ * reappeared now.
+ *
+ * We must allow 1 and 2a above. But 2b would be a spurious
+ * and unintentional.
+ *
+ * Further in case of 1 and 2a above, the disk at 'path'
+ * would have missed some transaction when it was away and
+ * in case of 2a the stale bdev has to be updated as well.
+ * 2b must not be allowed at all time.
+ */
+
+ /*
+ * For now, we do allow update to btrfs_fs_device through the
+ * btrfs dev scan cli after FS has been mounted. We're still
+ * tracking a problem where systems fail mount by subvolume id
+ * when we reject replacement on a mounted FS.
+ */
+ if (!fs_devices->opened && found_transid < device->generation) {
+ /*
+ * That is if the FS is _not_ mounted and if you
+ * are here, that means there is more than one
+ * disk with same uuid and devid.We keep the one
+ * with larger generation number or the last-in if
+ * generation are equal.
+ */
+ mutex_unlock(&fs_devices->device_list_mutex);
+ return ERR_PTR(-EEXIST);
+ }
+
+ name = rcu_string_strdup(path, GFP_NOFS);
+ if (!name) {
+ mutex_unlock(&fs_devices->device_list_mutex);
+ return ERR_PTR(-ENOMEM);
+ }
+ rcu_string_free(device->name);
+ rcu_assign_pointer(device->name, name);
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) {
+ fs_devices->missing_devices--;
+ clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
+ }
+ }
+
+ /*
+ * Unmount does not free the btrfs_device struct but would zero
+ * generation along with most of the other members. So just update
+ * it back. We need it to pick the disk with largest generation
+ * (as above).
+ */
+ if (!fs_devices->opened)
+ device->generation = found_transid;
+
+ fs_devices->total_devices = btrfs_super_num_devices(disk_super);
+
+ mutex_unlock(&fs_devices->device_list_mutex);
+ return device;
+}
+
+static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
+{
+ struct btrfs_fs_devices *fs_devices;
+ struct btrfs_device *device;
+ struct btrfs_device *orig_dev;
+
+ fs_devices = alloc_fs_devices(orig->fsid);
+ if (IS_ERR(fs_devices))
+ return fs_devices;
+
+ mutex_lock(&orig->device_list_mutex);
+ fs_devices->total_devices = orig->total_devices;
+
+ /* We have held the volume lock, it is safe to get the devices. */
+ list_for_each_entry(orig_dev, &orig->devices, dev_list) {
+ struct rcu_string *name;
+
+ device = btrfs_alloc_device(NULL, &orig_dev->devid,
+ orig_dev->uuid);
+ if (IS_ERR(device))
+ goto error;
+
+ /*
+ * This is ok to do without rcu read locked because we hold the
+ * uuid mutex so nothing we touch in here is going to disappear.
+ */
+ if (orig_dev->name) {
+ name = rcu_string_strdup(orig_dev->name->str,
+ GFP_KERNEL);
+ if (!name) {
+ btrfs_free_device(device);
+ goto error;
+ }
+ rcu_assign_pointer(device->name, name);
+ }
+
+ list_add(&device->dev_list, &fs_devices->devices);
+ device->fs_devices = fs_devices;
+ fs_devices->num_devices++;
+ }
+ mutex_unlock(&orig->device_list_mutex);
+ return fs_devices;
+error:
+ mutex_unlock(&orig->device_list_mutex);
+ free_fs_devices(fs_devices);
+ return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * After we have read the system tree and know devids belonging to
+ * this filesystem, remove the device which does not belong there.
+ */
+void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step)
+{
+ struct btrfs_device *device, *next;
+ struct btrfs_device *latest_dev = NULL;
+
+ mutex_lock(&uuid_mutex);
+again:
+ /* This is the initialized path, it is safe to release the devices. */
+ list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
+ if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
+ &device->dev_state)) {
+ if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
+ &device->dev_state) &&
+ (!latest_dev ||
+ device->generation > latest_dev->generation)) {
+ latest_dev = device;
+ }
+ continue;
+ }
+
+ if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
+ /*
+ * In the first step, keep the device which has
+ * the correct fsid and the devid that is used
+ * for the dev_replace procedure.
+ * In the second step, the dev_replace state is
+ * read from the device tree and it is known
+ * whether the procedure is really active or
+ * not, which means whether this device is
+ * used or whether it should be removed.
+ */
+ if (step == 0 || test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
+ &device->dev_state)) {
+ continue;
+ }
+ }
+ if (device->bdev) {
+ blkdev_put(device->bdev, device->mode);
+ device->bdev = NULL;
+ fs_devices->open_devices--;
+ }
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
+ list_del_init(&device->dev_alloc_list);
+ clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
+ if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
+ &device->dev_state))
+ fs_devices->rw_devices--;
+ }
+ list_del_init(&device->dev_list);
+ fs_devices->num_devices--;
+ btrfs_free_device(device);
+ }
+
+ if (fs_devices->seed) {
+ fs_devices = fs_devices->seed;
+ goto again;
+ }
+
+ fs_devices->latest_bdev = latest_dev->bdev;
+
+ mutex_unlock(&uuid_mutex);
+}
+
+static void free_device_rcu(struct rcu_head *head)
+{
+ struct btrfs_device *device;
+
+ device = container_of(head, struct btrfs_device, rcu);
+ btrfs_free_device(device);
+}
+
+static void btrfs_close_bdev(struct btrfs_device *device)
+{
+ if (!device->bdev)
+ return;
+
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
+ sync_blockdev(device->bdev);
+ invalidate_bdev(device->bdev);
+ }
+
+ blkdev_put(device->bdev, device->mode);
+}
+
+static void btrfs_close_one_device(struct btrfs_device *device)
+{
+ struct btrfs_fs_devices *fs_devices = device->fs_devices;
+ struct btrfs_device *new_device;
+ struct rcu_string *name;
+
+ if (device->bdev)
+ fs_devices->open_devices--;
+
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
+ device->devid != BTRFS_DEV_REPLACE_DEVID) {
+ list_del_init(&device->dev_alloc_list);
+ fs_devices->rw_devices--;
+ }
+
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
+ fs_devices->missing_devices--;
+
+ btrfs_close_bdev(device);
+
+ new_device = btrfs_alloc_device(NULL, &device->devid,
+ device->uuid);
+ BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
+
+ /* Safe because we are under uuid_mutex */
+ if (device->name) {
+ name = rcu_string_strdup(device->name->str, GFP_NOFS);
+ BUG_ON(!name); /* -ENOMEM */
+ rcu_assign_pointer(new_device->name, name);
+ }
+
+ list_replace_rcu(&device->dev_list, &new_device->dev_list);
+ new_device->fs_devices = device->fs_devices;
+
+ call_rcu(&device->rcu, free_device_rcu);
+}
+
+static int close_fs_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct btrfs_device *device, *tmp;
+
+ if (--fs_devices->opened > 0)
+ return 0;
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) {
+ btrfs_close_one_device(device);
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ WARN_ON(fs_devices->open_devices);
+ WARN_ON(fs_devices->rw_devices);
+ fs_devices->opened = 0;
+ fs_devices->seeding = 0;
+
+ return 0;
+}
+
+int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct btrfs_fs_devices *seed_devices = NULL;
+ int ret;
+
+ mutex_lock(&uuid_mutex);
+ ret = close_fs_devices(fs_devices);
+ if (!fs_devices->opened) {
+ seed_devices = fs_devices->seed;
+ fs_devices->seed = NULL;
+ }
+ mutex_unlock(&uuid_mutex);
+
+ while (seed_devices) {
+ fs_devices = seed_devices;
+ seed_devices = fs_devices->seed;
+ close_fs_devices(fs_devices);
+ free_fs_devices(fs_devices);
+ }
+ return ret;
+}
+
+static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
+ fmode_t flags, void *holder)
+{
+ struct btrfs_device *device;
+ struct btrfs_device *latest_dev = NULL;
+ int ret = 0;
+
+ flags |= FMODE_EXCL;
+
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ /* Just open everything we can; ignore failures here */
+ if (btrfs_open_one_device(fs_devices, device, flags, holder))
+ continue;
+
+ if (!latest_dev ||
+ device->generation > latest_dev->generation)
+ latest_dev = device;
+ }
+ if (fs_devices->open_devices == 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+ fs_devices->opened = 1;
+ fs_devices->latest_bdev = latest_dev->bdev;
+ fs_devices->total_rw_bytes = 0;
+out:
+ return ret;
+}
+
+static int devid_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct btrfs_device *dev1, *dev2;
+
+ dev1 = list_entry(a, struct btrfs_device, dev_list);
+ dev2 = list_entry(b, struct btrfs_device, dev_list);
+
+ if (dev1->devid < dev2->devid)
+ return -1;
+ else if (dev1->devid > dev2->devid)
+ return 1;
+ return 0;
+}
+
+int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
+ fmode_t flags, void *holder)
+{
+ int ret;
+
+ lockdep_assert_held(&uuid_mutex);
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ if (fs_devices->opened) {
+ fs_devices->opened++;
+ ret = 0;
+ } else {
+ list_sort(NULL, &fs_devices->devices, devid_cmp);
+ ret = open_fs_devices(fs_devices, flags, holder);
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ return ret;
+}
+
+static void btrfs_release_disk_super(struct page *page)
+{
+ kunmap(page);
+ put_page(page);
+}
+
+static int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr,
+ struct page **page,
+ struct btrfs_super_block **disk_super)
+{
+ void *p;
+ pgoff_t index;
+
+ /* make sure our super fits in the device */
+ if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode))
+ return 1;
+
+ /* make sure our super fits in the page */
+ if (sizeof(**disk_super) > PAGE_SIZE)
+ return 1;
+
+ /* make sure our super doesn't straddle pages on disk */
+ index = bytenr >> PAGE_SHIFT;
+ if ((bytenr + sizeof(**disk_super) - 1) >> PAGE_SHIFT != index)
+ return 1;
+
+ /* pull in the page with our super */
+ *page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
+ index, GFP_KERNEL);
+
+ if (IS_ERR_OR_NULL(*page))
+ return 1;
+
+ p = kmap(*page);
+
+ /* align our pointer to the offset of the super block */
+ *disk_super = p + (bytenr & ~PAGE_MASK);
+
+ if (btrfs_super_bytenr(*disk_super) != bytenr ||
+ btrfs_super_magic(*disk_super) != BTRFS_MAGIC) {
+ btrfs_release_disk_super(*page);
+ return 1;
+ }
+
+ if ((*disk_super)->label[0] &&
+ (*disk_super)->label[BTRFS_LABEL_SIZE - 1])
+ (*disk_super)->label[BTRFS_LABEL_SIZE - 1] = '\0';
+
+ return 0;
+}
+
+/*
+ * Look for a btrfs signature on a device. This may be called out of the mount path
+ * and we are not allowed to call set_blocksize during the scan. The superblock
+ * is read via pagecache
+ */
+struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
+ void *holder)
+{
+ struct btrfs_super_block *disk_super;
+ bool new_device_added = false;
+ struct btrfs_device *device = NULL;
+ struct block_device *bdev;
+ struct page *page;
+ u64 bytenr;
+
+ lockdep_assert_held(&uuid_mutex);
+
+ /*
+ * we would like to check all the supers, but that would make
+ * a btrfs mount succeed after a mkfs from a different FS.
+ * So, we need to add a special mount option to scan for
+ * later supers, using BTRFS_SUPER_MIRROR_MAX instead
+ */
+ bytenr = btrfs_sb_offset(0);
+ flags |= FMODE_EXCL;
+
+ bdev = blkdev_get_by_path(path, flags, holder);
+ if (IS_ERR(bdev))
+ return ERR_CAST(bdev);
+
+ if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super)) {
+ device = ERR_PTR(-EINVAL);
+ goto error_bdev_put;
+ }
+
+ device = device_list_add(path, disk_super, &new_device_added);
+ if (!IS_ERR(device)) {
+ if (new_device_added)
+ btrfs_free_stale_devices(path, device);
+ }
+
+ btrfs_release_disk_super(page);
+
+error_bdev_put:
+ blkdev_put(bdev, flags);
+
+ return device;
+}
+
+static int contains_pending_extent(struct btrfs_transaction *transaction,
+ struct btrfs_device *device,
+ u64 *start, u64 len)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct extent_map *em;
+ struct list_head *search_list = &fs_info->pinned_chunks;
+ int ret = 0;
+ u64 physical_start = *start;
+
+ if (transaction)
+ search_list = &transaction->pending_chunks;
+again:
+ list_for_each_entry(em, search_list, list) {
+ struct map_lookup *map;
+ int i;
+
+ map = em->map_lookup;
+ for (i = 0; i < map->num_stripes; i++) {
+ u64 end;
+
+ if (map->stripes[i].dev != device)
+ continue;
+ if (map->stripes[i].physical >= physical_start + len ||
+ map->stripes[i].physical + em->orig_block_len <=
+ physical_start)
+ continue;
+ /*
+ * Make sure that while processing the pinned list we do
+ * not override our *start with a lower value, because
+ * we can have pinned chunks that fall within this
+ * device hole and that have lower physical addresses
+ * than the pending chunks we processed before. If we
+ * do not take this special care we can end up getting
+ * 2 pending chunks that start at the same physical
+ * device offsets because the end offset of a pinned
+ * chunk can be equal to the start offset of some
+ * pending chunk.
+ */
+ end = map->stripes[i].physical + em->orig_block_len;
+ if (end > *start) {
+ *start = end;
+ ret = 1;
+ }
+ }
+ }
+ if (search_list != &fs_info->pinned_chunks) {
+ search_list = &fs_info->pinned_chunks;
+ goto again;
+ }
+
+ return ret;
+}
+
+
+/*
+ * find_free_dev_extent_start - find free space in the specified device
+ * @device: the device which we search the free space in
+ * @num_bytes: the size of the free space that we need
+ * @search_start: the position from which to begin the search
+ * @start: store the start of the free space.
+ * @len: the size of the free space. that we find, or the size
+ * of the max free space if we don't find suitable free space
+ *
+ * this uses a pretty simple search, the expectation is that it is
+ * called very infrequently and that a given device has a small number
+ * of extents
+ *
+ * @start is used to store the start of the free space if we find. But if we
+ * don't find suitable free space, it will be used to store the start position
+ * of the max free space.
+ *
+ * @len is used to store the size of the free space that we find.
+ * But if we don't find suitable free space, it is used to store the size of
+ * the max free space.
+ */
+int find_free_dev_extent_start(struct btrfs_transaction *transaction,
+ struct btrfs_device *device, u64 num_bytes,
+ u64 search_start, u64 *start, u64 *len)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct btrfs_root *root = fs_info->dev_root;
+ struct btrfs_key key;
+ struct btrfs_dev_extent *dev_extent;
+ struct btrfs_path *path;
+ u64 hole_size;
+ u64 max_hole_start;
+ u64 max_hole_size;
+ u64 extent_end;
+ u64 search_end = device->total_bytes;
+ int ret;
+ int slot;
+ struct extent_buffer *l;
+
+ /*
+ * We don't want to overwrite the superblock on the drive nor any area
+ * used by the boot loader (grub for example), so we make sure to start
+ * at an offset of at least 1MB.
+ */
+ search_start = max_t(u64, search_start, SZ_1M);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ max_hole_start = search_start;
+ max_hole_size = 0;
+
+again:
+ if (search_start >= search_end ||
+ test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
+ ret = -ENOSPC;
+ goto out;
+ }
+
+ path->reada = READA_FORWARD;
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ key.objectid = device->devid;
+ key.offset = search_start;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = btrfs_previous_item(root, path, key.objectid, key.type);
+ if (ret < 0)
+ goto out;
+ }
+
+ while (1) {
+ l = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto out;
+
+ break;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.objectid < device->devid)
+ goto next;
+
+ if (key.objectid > device->devid)
+ break;
+
+ if (key.type != BTRFS_DEV_EXTENT_KEY)
+ goto next;
+
+ if (key.offset > search_start) {
+ hole_size = key.offset - search_start;
+
+ /*
+ * Have to check before we set max_hole_start, otherwise
+ * we could end up sending back this offset anyway.
+ */
+ if (contains_pending_extent(transaction, device,
+ &search_start,
+ hole_size)) {
+ if (key.offset >= search_start) {
+ hole_size = key.offset - search_start;
+ } else {
+ WARN_ON_ONCE(1);
+ hole_size = 0;
+ }
+ }
+
+ if (hole_size > max_hole_size) {
+ max_hole_start = search_start;
+ max_hole_size = hole_size;
+ }
+
+ /*
+ * If this free space is greater than which we need,
+ * it must be the max free space that we have found
+ * until now, so max_hole_start must point to the start
+ * of this free space and the length of this free space
+ * is stored in max_hole_size. Thus, we return
+ * max_hole_start and max_hole_size and go back to the
+ * caller.
+ */
+ if (hole_size >= num_bytes) {
+ ret = 0;
+ goto out;
+ }
+ }
+
+ dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+ extent_end = key.offset + btrfs_dev_extent_length(l,
+ dev_extent);
+ if (extent_end > search_start)
+ search_start = extent_end;
+next:
+ path->slots[0]++;
+ cond_resched();
+ }
+
+ /*
+ * At this point, search_start should be the end of
+ * allocated dev extents, and when shrinking the device,
+ * search_end may be smaller than search_start.
+ */
+ if (search_end > search_start) {
+ hole_size = search_end - search_start;
+
+ if (contains_pending_extent(transaction, device, &search_start,
+ hole_size)) {
+ btrfs_release_path(path);
+ goto again;
+ }
+
+ if (hole_size > max_hole_size) {
+ max_hole_start = search_start;
+ max_hole_size = hole_size;
+ }
+ }
+
+ /* See above. */
+ if (max_hole_size < num_bytes)
+ ret = -ENOSPC;
+ else
+ ret = 0;
+
+out:
+ btrfs_free_path(path);
+ *start = max_hole_start;
+ if (len)
+ *len = max_hole_size;
+ return ret;
+}
+
+int find_free_dev_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device, u64 num_bytes,
+ u64 *start, u64 *len)
+{
+ /* FIXME use last free of some kind */
+ return find_free_dev_extent_start(trans->transaction, device,
+ num_bytes, 0, start, len);
+}
+
+static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device,
+ u64 start, u64 *dev_extent_len)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct btrfs_root *root = fs_info->dev_root;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf = NULL;
+ struct btrfs_dev_extent *extent = NULL;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = device->devid;
+ key.offset = start;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+again:
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0) {
+ ret = btrfs_previous_item(root, path, key.objectid,
+ BTRFS_DEV_EXTENT_KEY);
+ if (ret)
+ goto out;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_extent);
+ BUG_ON(found_key.offset > start || found_key.offset +
+ btrfs_dev_extent_length(leaf, extent) < start);
+ key = found_key;
+ btrfs_release_path(path);
+ goto again;
+ } else if (ret == 0) {
+ leaf = path->nodes[0];
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_extent);
+ } else {
+ btrfs_handle_fs_error(fs_info, ret, "Slot search failed");
+ goto out;
+ }
+
+ *dev_extent_len = btrfs_dev_extent_length(leaf, extent);
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret) {
+ btrfs_handle_fs_error(fs_info, ret,
+ "Failed to remove dev extent item");
+ } else {
+ set_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags);
+ }
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device,
+ u64 chunk_offset, u64 start, u64 num_bytes)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct btrfs_root *root = fs_info->dev_root;
+ struct btrfs_dev_extent *extent;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+
+ WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
+ WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = device->devid;
+ key.offset = start;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(*extent));
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ extent = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_extent);
+ btrfs_set_dev_extent_chunk_tree(leaf, extent,
+ BTRFS_CHUNK_TREE_OBJECTID);
+ btrfs_set_dev_extent_chunk_objectid(leaf, extent,
+ BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+ btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
+
+ btrfs_set_dev_extent_length(leaf, extent, num_bytes);
+ btrfs_mark_buffer_dirty(leaf);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
+{
+ struct extent_map_tree *em_tree;
+ struct extent_map *em;
+ struct rb_node *n;
+ u64 ret = 0;
+
+ em_tree = &fs_info->mapping_tree.map_tree;
+ read_lock(&em_tree->lock);
+ n = rb_last(&em_tree->map);
+ if (n) {
+ em = rb_entry(n, struct extent_map, rb_node);
+ ret = em->start + em->len;
+ }
+ read_unlock(&em_tree->lock);
+
+ return ret;
+}
+
+static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
+ u64 *devid_ret)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+
+ BUG_ON(ret == 0); /* Corruption */
+
+ ret = btrfs_previous_item(fs_info->chunk_root, path,
+ BTRFS_DEV_ITEMS_OBJECTID,
+ BTRFS_DEV_ITEM_KEY);
+ if (ret) {
+ *devid_ret = 1;
+ } else {
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key,
+ path->slots[0]);
+ *devid_ret = found_key.offset + 1;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * the device information is stored in the chunk root
+ * the btrfs_device struct should be fully filled in
+ */
+static int btrfs_add_dev_item(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_dev_item *dev_item;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ unsigned long ptr;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = device->devid;
+
+ ret = btrfs_insert_empty_item(trans, trans->fs_info->chunk_root, path,
+ &key, sizeof(*dev_item));
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
+
+ btrfs_set_device_id(leaf, dev_item, device->devid);
+ btrfs_set_device_generation(leaf, dev_item, 0);
+ btrfs_set_device_type(leaf, dev_item, device->type);
+ btrfs_set_device_io_align(leaf, dev_item, device->io_align);
+ btrfs_set_device_io_width(leaf, dev_item, device->io_width);
+ btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
+ btrfs_set_device_total_bytes(leaf, dev_item,
+ btrfs_device_get_disk_total_bytes(device));
+ btrfs_set_device_bytes_used(leaf, dev_item,
+ btrfs_device_get_bytes_used(device));
+ btrfs_set_device_group(leaf, dev_item, 0);
+ btrfs_set_device_seek_speed(leaf, dev_item, 0);
+ btrfs_set_device_bandwidth(leaf, dev_item, 0);
+ btrfs_set_device_start_offset(leaf, dev_item, 0);
+
+ ptr = btrfs_device_uuid(dev_item);
+ write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
+ ptr = btrfs_device_fsid(dev_item);
+ write_extent_buffer(leaf, trans->fs_info->fsid, ptr, BTRFS_FSID_SIZE);
+ btrfs_mark_buffer_dirty(leaf);
+
+ ret = 0;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * Function to update ctime/mtime for a given device path.
+ * Mainly used for ctime/mtime based probe like libblkid.
+ */
+static void update_dev_time(const char *path_name)
+{
+ struct file *filp;
+
+ filp = filp_open(path_name, O_RDWR, 0);
+ if (IS_ERR(filp))
+ return;
+ file_update_time(filp);
+ filp_close(filp, NULL);
+}
+
+static int btrfs_rm_dev_item(struct btrfs_fs_info *fs_info,
+ struct btrfs_device *device)
+{
+ struct btrfs_root *root = fs_info->chunk_root;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_trans_handle *trans;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ btrfs_free_path(path);
+ return PTR_ERR(trans);
+ }
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = device->devid;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret) {
+ if (ret > 0)
+ ret = -ENOENT;
+ btrfs_abort_transaction(trans, ret);
+ btrfs_end_transaction(trans);
+ goto out;
+ }
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ btrfs_end_transaction(trans);
+ }
+
+out:
+ btrfs_free_path(path);
+ if (!ret)
+ ret = btrfs_commit_transaction(trans);
+ return ret;
+}
+
+/*
+ * Verify that @num_devices satisfies the RAID profile constraints in the whole
+ * filesystem. It's up to the caller to adjust that number regarding eg. device
+ * replace.
+ */
+static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
+ u64 num_devices)
+{
+ u64 all_avail;
+ unsigned seq;
+ int i;
+
+ do {
+ seq = read_seqbegin(&fs_info->profiles_lock);
+
+ all_avail = fs_info->avail_data_alloc_bits |
+ fs_info->avail_system_alloc_bits |
+ fs_info->avail_metadata_alloc_bits;
+ } while (read_seqretry(&fs_info->profiles_lock, seq));
+
+ for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
+ if (!(all_avail & btrfs_raid_array[i].bg_flag))
+ continue;
+
+ if (num_devices < btrfs_raid_array[i].devs_min) {
+ int ret = btrfs_raid_array[i].mindev_error;
+
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static struct btrfs_device * btrfs_find_next_active_device(
+ struct btrfs_fs_devices *fs_devs, struct btrfs_device *device)
+{
+ struct btrfs_device *next_device;
+
+ list_for_each_entry(next_device, &fs_devs->devices, dev_list) {
+ if (next_device != device &&
+ !test_bit(BTRFS_DEV_STATE_MISSING, &next_device->dev_state)
+ && next_device->bdev)
+ return next_device;
+ }
+
+ return NULL;
+}
+
+/*
+ * Helper function to check if the given device is part of s_bdev / latest_bdev
+ * and replace it with the provided or the next active device, in the context
+ * where this function called, there should be always be another device (or
+ * this_dev) which is active.
+ */
+void btrfs_assign_next_active_device(struct btrfs_device *device,
+ struct btrfs_device *this_dev)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct btrfs_device *next_device;
+
+ if (this_dev)
+ next_device = this_dev;
+ else
+ next_device = btrfs_find_next_active_device(fs_info->fs_devices,
+ device);
+ ASSERT(next_device);
+
+ if (fs_info->sb->s_bdev &&
+ (fs_info->sb->s_bdev == device->bdev))
+ fs_info->sb->s_bdev = next_device->bdev;
+
+ if (fs_info->fs_devices->latest_bdev == device->bdev)
+ fs_info->fs_devices->latest_bdev = next_device->bdev;
+}
+
+int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
+ u64 devid)
+{
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *cur_devices;
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ u64 num_devices;
+ int ret = 0;
+
+ mutex_lock(&uuid_mutex);
+
+ num_devices = fs_devices->num_devices;
+ btrfs_dev_replace_read_lock(&fs_info->dev_replace);
+ if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
+ WARN_ON(num_devices < 1);
+ num_devices--;
+ }
+ btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+
+ ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1);
+ if (ret)
+ goto out;
+
+ ret = btrfs_find_device_by_devspec(fs_info, devid, device_path,
+ &device);
+ if (ret)
+ goto out;
+
+ if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
+ ret = BTRFS_ERROR_DEV_TGT_REPLACE;
+ goto out;
+ }
+
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
+ fs_info->fs_devices->rw_devices == 1) {
+ ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
+ goto out;
+ }
+
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
+ mutex_lock(&fs_info->chunk_mutex);
+ list_del_init(&device->dev_alloc_list);
+ device->fs_devices->rw_devices--;
+ mutex_unlock(&fs_info->chunk_mutex);
+ }
+
+ mutex_unlock(&uuid_mutex);
+ ret = btrfs_shrink_device(device, 0);
+ mutex_lock(&uuid_mutex);
+ if (ret)
+ goto error_undo;
+
+ /*
+ * TODO: the superblock still includes this device in its num_devices
+ * counter although write_all_supers() is not locked out. This
+ * could give a filesystem state which requires a degraded mount.
+ */
+ ret = btrfs_rm_dev_item(fs_info, device);
+ if (ret)
+ goto error_undo;
+
+ clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
+ btrfs_scrub_cancel_dev(fs_info, device);
+
+ /*
+ * the device list mutex makes sure that we don't change
+ * the device list while someone else is writing out all
+ * the device supers. Whoever is writing all supers, should
+ * lock the device list mutex before getting the number of
+ * devices in the super block (super_copy). Conversely,
+ * whoever updates the number of devices in the super block
+ * (super_copy) should hold the device list mutex.
+ */
+
+ /*
+ * In normal cases the cur_devices == fs_devices. But in case
+ * of deleting a seed device, the cur_devices should point to
+ * its own fs_devices listed under the fs_devices->seed.
+ */
+ cur_devices = device->fs_devices;
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_del_rcu(&device->dev_list);
+
+ cur_devices->num_devices--;
+ cur_devices->total_devices--;
+ /* Update total_devices of the parent fs_devices if it's seed */
+ if (cur_devices != fs_devices)
+ fs_devices->total_devices--;
+
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
+ cur_devices->missing_devices--;
+
+ btrfs_assign_next_active_device(device, NULL);
+
+ if (device->bdev) {
+ cur_devices->open_devices--;
+ /* remove sysfs entry */
+ btrfs_sysfs_rm_device_link(fs_devices, device);
+ }
+
+ num_devices = btrfs_super_num_devices(fs_info->super_copy) - 1;
+ btrfs_set_super_num_devices(fs_info->super_copy, num_devices);
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ /*
+ * at this point, the device is zero sized and detached from
+ * the devices list. All that's left is to zero out the old
+ * supers and free the device.
+ */
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
+ btrfs_scratch_superblocks(device->bdev, device->name->str);
+
+ btrfs_close_bdev(device);
+ call_rcu(&device->rcu, free_device_rcu);
+
+ if (cur_devices->open_devices == 0) {
+ while (fs_devices) {
+ if (fs_devices->seed == cur_devices) {
+ fs_devices->seed = cur_devices->seed;
+ break;
+ }
+ fs_devices = fs_devices->seed;
+ }
+ cur_devices->seed = NULL;
+ close_fs_devices(cur_devices);
+ free_fs_devices(cur_devices);
+ }
+
+out:
+ mutex_unlock(&uuid_mutex);
+ return ret;
+
+error_undo:
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
+ mutex_lock(&fs_info->chunk_mutex);
+ list_add(&device->dev_alloc_list,
+ &fs_devices->alloc_list);
+ device->fs_devices->rw_devices++;
+ mutex_unlock(&fs_info->chunk_mutex);
+ }
+ goto out;
+}
+
+void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev)
+{
+ struct btrfs_fs_devices *fs_devices;
+
+ lockdep_assert_held(&srcdev->fs_info->fs_devices->device_list_mutex);
+
+ /*
+ * in case of fs with no seed, srcdev->fs_devices will point
+ * to fs_devices of fs_info. However when the dev being replaced is
+ * a seed dev it will point to the seed's local fs_devices. In short
+ * srcdev will have its correct fs_devices in both the cases.
+ */
+ fs_devices = srcdev->fs_devices;
+
+ list_del_rcu(&srcdev->dev_list);
+ list_del(&srcdev->dev_alloc_list);
+ fs_devices->num_devices--;
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &srcdev->dev_state))
+ fs_devices->missing_devices--;
+
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state))
+ fs_devices->rw_devices--;
+
+ if (srcdev->bdev)
+ fs_devices->open_devices--;
+}
+
+void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
+ struct btrfs_device *srcdev)
+{
+ struct btrfs_fs_devices *fs_devices = srcdev->fs_devices;
+
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state)) {
+ /* zero out the old super if it is writable */
+ btrfs_scratch_superblocks(srcdev->bdev, srcdev->name->str);
+ }
+
+ btrfs_close_bdev(srcdev);
+ call_rcu(&srcdev->rcu, free_device_rcu);
+
+ /* if this is no devs we rather delete the fs_devices */
+ if (!fs_devices->num_devices) {
+ struct btrfs_fs_devices *tmp_fs_devices;
+
+ /*
+ * On a mounted FS, num_devices can't be zero unless it's a
+ * seed. In case of a seed device being replaced, the replace
+ * target added to the sprout FS, so there will be no more
+ * device left under the seed FS.
+ */
+ ASSERT(fs_devices->seeding);
+
+ tmp_fs_devices = fs_info->fs_devices;
+ while (tmp_fs_devices) {
+ if (tmp_fs_devices->seed == fs_devices) {
+ tmp_fs_devices->seed = fs_devices->seed;
+ break;
+ }
+ tmp_fs_devices = tmp_fs_devices->seed;
+ }
+ fs_devices->seed = NULL;
+ close_fs_devices(fs_devices);
+ free_fs_devices(fs_devices);
+ }
+}
+
+void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev)
+{
+ struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices;
+
+ WARN_ON(!tgtdev);
+ mutex_lock(&fs_devices->device_list_mutex);
+
+ btrfs_sysfs_rm_device_link(fs_devices, tgtdev);
+
+ if (tgtdev->bdev)
+ fs_devices->open_devices--;
+
+ fs_devices->num_devices--;
+
+ btrfs_assign_next_active_device(tgtdev, NULL);
+
+ list_del_rcu(&tgtdev->dev_list);
+
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ /*
+ * The update_dev_time() with in btrfs_scratch_superblocks()
+ * may lead to a call to btrfs_show_devname() which will try
+ * to hold device_list_mutex. And here this device
+ * is already out of device list, so we don't have to hold
+ * the device_list_mutex lock.
+ */
+ btrfs_scratch_superblocks(tgtdev->bdev, tgtdev->name->str);
+
+ btrfs_close_bdev(tgtdev);
+ call_rcu(&tgtdev->rcu, free_device_rcu);
+}
+
+static int btrfs_find_device_by_path(struct btrfs_fs_info *fs_info,
+ const char *device_path,
+ struct btrfs_device **device)
+{
+ int ret = 0;
+ struct btrfs_super_block *disk_super;
+ u64 devid;
+ u8 *dev_uuid;
+ struct block_device *bdev;
+ struct buffer_head *bh;
+
+ *device = NULL;
+ ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
+ fs_info->bdev_holder, 0, &bdev, &bh);
+ if (ret)
+ return ret;
+ disk_super = (struct btrfs_super_block *)bh->b_data;
+ devid = btrfs_stack_device_id(&disk_super->dev_item);
+ dev_uuid = disk_super->dev_item.uuid;
+ *device = btrfs_find_device(fs_info, devid, dev_uuid, disk_super->fsid);
+ brelse(bh);
+ if (!*device)
+ ret = -ENOENT;
+ blkdev_put(bdev, FMODE_READ);
+ return ret;
+}
+
+int btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
+ const char *device_path,
+ struct btrfs_device **device)
+{
+ *device = NULL;
+ if (strcmp(device_path, "missing") == 0) {
+ struct list_head *devices;
+ struct btrfs_device *tmp;
+
+ devices = &fs_info->fs_devices->devices;
+ list_for_each_entry(tmp, devices, dev_list) {
+ if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
+ &tmp->dev_state) && !tmp->bdev) {
+ *device = tmp;
+ break;
+ }
+ }
+
+ if (!*device)
+ return BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
+
+ return 0;
+ } else {
+ return btrfs_find_device_by_path(fs_info, device_path, device);
+ }
+}
+
+/*
+ * Lookup a device given by device id, or the path if the id is 0.
+ */
+int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
+ const char *devpath,
+ struct btrfs_device **device)
+{
+ int ret;
+
+ if (devid) {
+ ret = 0;
+ *device = btrfs_find_device(fs_info, devid, NULL, NULL);
+ if (!*device)
+ ret = -ENOENT;
+ } else {
+ if (!devpath || !devpath[0])
+ return -EINVAL;
+
+ ret = btrfs_find_device_missing_or_by_path(fs_info, devpath,
+ device);
+ }
+ return ret;
+}
+
+/*
+ * does all the dirty work required for changing file system's UUID.
+ */
+static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct btrfs_fs_devices *old_devices;
+ struct btrfs_fs_devices *seed_devices;
+ struct btrfs_super_block *disk_super = fs_info->super_copy;
+ struct btrfs_device *device;
+ u64 super_flags;
+
+ lockdep_assert_held(&uuid_mutex);
+ if (!fs_devices->seeding)
+ return -EINVAL;
+
+ seed_devices = alloc_fs_devices(NULL);
+ if (IS_ERR(seed_devices))
+ return PTR_ERR(seed_devices);
+
+ old_devices = clone_fs_devices(fs_devices);
+ if (IS_ERR(old_devices)) {
+ kfree(seed_devices);
+ return PTR_ERR(old_devices);
+ }
+
+ list_add(&old_devices->fs_list, &fs_uuids);
+
+ memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
+ seed_devices->opened = 1;
+ INIT_LIST_HEAD(&seed_devices->devices);
+ INIT_LIST_HEAD(&seed_devices->alloc_list);
+ mutex_init(&seed_devices->device_list_mutex);
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
+ synchronize_rcu);
+ list_for_each_entry(device, &seed_devices->devices, dev_list)
+ device->fs_devices = seed_devices;
+
+ mutex_lock(&fs_info->chunk_mutex);
+ list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
+ mutex_unlock(&fs_info->chunk_mutex);
+
+ fs_devices->seeding = 0;
+ fs_devices->num_devices = 0;
+ fs_devices->open_devices = 0;
+ fs_devices->missing_devices = 0;
+ fs_devices->rotating = 0;
+ fs_devices->seed = seed_devices;
+
+ generate_random_uuid(fs_devices->fsid);
+ memcpy(fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+ memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ super_flags = btrfs_super_flags(disk_super) &
+ ~BTRFS_SUPER_FLAG_SEEDING;
+ btrfs_set_super_flags(disk_super, super_flags);
+
+ return 0;
+}
+
+/*
+ * Store the expected generation for seed devices in device items.
+ */
+static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root = fs_info->chunk_root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_dev_item *dev_item;
+ struct btrfs_device *device;
+ struct btrfs_key key;
+ u8 fs_uuid[BTRFS_FSID_SIZE];
+ u8 dev_uuid[BTRFS_UUID_SIZE];
+ u64 devid;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.offset = 0;
+ key.type = BTRFS_DEV_ITEM_KEY;
+
+ while (1) {
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0)
+ goto error;
+
+ leaf = path->nodes[0];
+next_slot:
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret > 0)
+ break;
+ if (ret < 0)
+ goto error;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ btrfs_release_path(path);
+ continue;
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
+ key.type != BTRFS_DEV_ITEM_KEY)
+ break;
+
+ dev_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_dev_item);
+ devid = btrfs_device_id(leaf, dev_item);
+ read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
+ BTRFS_UUID_SIZE);
+ read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
+ BTRFS_FSID_SIZE);
+ device = btrfs_find_device(fs_info, devid, dev_uuid, fs_uuid);
+ BUG_ON(!device); /* Logic error */
+
+ if (device->fs_devices->seeding) {
+ btrfs_set_device_generation(leaf, dev_item,
+ device->generation);
+ btrfs_mark_buffer_dirty(leaf);
+ }
+
+ path->slots[0]++;
+ goto next_slot;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path)
+{
+ struct btrfs_root *root = fs_info->dev_root;
+ struct request_queue *q;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_device *device;
+ struct block_device *bdev;
+ struct super_block *sb = fs_info->sb;
+ struct rcu_string *name;
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ u64 orig_super_total_bytes;
+ u64 orig_super_num_devices;
+ int seeding_dev = 0;
+ int ret = 0;
+ bool unlocked = false;
+
+ if (sb_rdonly(sb) && !fs_devices->seeding)
+ return -EROFS;
+
+ bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
+ fs_info->bdev_holder);
+ if (IS_ERR(bdev))
+ return PTR_ERR(bdev);
+
+ if (fs_devices->seeding) {
+ seeding_dev = 1;
+ down_write(&sb->s_umount);
+ mutex_lock(&uuid_mutex);
+ }
+
+ filemap_write_and_wait(bdev->bd_inode->i_mapping);
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ if (device->bdev == bdev) {
+ ret = -EEXIST;
+ mutex_unlock(
+ &fs_devices->device_list_mutex);
+ goto error;
+ }
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ device = btrfs_alloc_device(fs_info, NULL, NULL);
+ if (IS_ERR(device)) {
+ /* we can safely leave the fs_devices entry around */
+ ret = PTR_ERR(device);
+ goto error;
+ }
+
+ name = rcu_string_strdup(device_path, GFP_KERNEL);
+ if (!name) {
+ ret = -ENOMEM;
+ goto error_free_device;
+ }
+ rcu_assign_pointer(device->name, name);
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto error_free_device;
+ }
+
+ q = bdev_get_queue(bdev);
+ set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
+ device->generation = trans->transid;
+ device->io_width = fs_info->sectorsize;
+ device->io_align = fs_info->sectorsize;
+ device->sector_size = fs_info->sectorsize;
+ device->total_bytes = round_down(i_size_read(bdev->bd_inode),
+ fs_info->sectorsize);
+ device->disk_total_bytes = device->total_bytes;
+ device->commit_total_bytes = device->total_bytes;
+ device->fs_info = fs_info;
+ device->bdev = bdev;
+ set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
+ clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
+ device->mode = FMODE_EXCL;
+ device->dev_stats_valid = 1;
+ set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
+
+ if (seeding_dev) {
+ sb->s_flags &= ~SB_RDONLY;
+ ret = btrfs_prepare_sprout(fs_info);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto error_trans;
+ }
+ }
+
+ device->fs_devices = fs_devices;
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ mutex_lock(&fs_info->chunk_mutex);
+ list_add_rcu(&device->dev_list, &fs_devices->devices);
+ list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
+ fs_devices->num_devices++;
+ fs_devices->open_devices++;
+ fs_devices->rw_devices++;
+ fs_devices->total_devices++;
+ fs_devices->total_rw_bytes += device->total_bytes;
+
+ atomic64_add(device->total_bytes, &fs_info->free_chunk_space);
+
+ if (!blk_queue_nonrot(q))
+ fs_devices->rotating = 1;
+
+ orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
+ btrfs_set_super_total_bytes(fs_info->super_copy,
+ round_down(orig_super_total_bytes + device->total_bytes,
+ fs_info->sectorsize));
+
+ orig_super_num_devices = btrfs_super_num_devices(fs_info->super_copy);
+ btrfs_set_super_num_devices(fs_info->super_copy,
+ orig_super_num_devices + 1);
+
+ /* add sysfs device entry */
+ btrfs_sysfs_add_device_link(fs_devices, device);
+
+ /*
+ * we've got more storage, clear any full flags on the space
+ * infos
+ */
+ btrfs_clear_space_info_full(fs_info);
+
+ mutex_unlock(&fs_info->chunk_mutex);
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ if (seeding_dev) {
+ mutex_lock(&fs_info->chunk_mutex);
+ ret = init_first_rw_device(trans, fs_info);
+ mutex_unlock(&fs_info->chunk_mutex);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto error_sysfs;
+ }
+ }
+
+ ret = btrfs_add_dev_item(trans, device);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto error_sysfs;
+ }
+
+ if (seeding_dev) {
+ char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
+
+ ret = btrfs_finish_sprout(trans, fs_info);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto error_sysfs;
+ }
+
+ /* Sprouting would change fsid of the mounted root,
+ * so rename the fsid on the sysfs
+ */
+ snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
+ fs_info->fsid);
+ if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
+ btrfs_warn(fs_info,
+ "sysfs: failed to create fsid for sprout");
+ }
+
+ ret = btrfs_commit_transaction(trans);
+
+ if (seeding_dev) {
+ mutex_unlock(&uuid_mutex);
+ up_write(&sb->s_umount);
+ unlocked = true;
+
+ if (ret) /* transaction commit */
+ return ret;
+
+ ret = btrfs_relocate_sys_chunks(fs_info);
+ if (ret < 0)
+ btrfs_handle_fs_error(fs_info, ret,
+ "Failed to relocate sys chunks after device initialization. This can be fixed using the \"btrfs balance\" command.");
+ trans = btrfs_attach_transaction(root);
+ if (IS_ERR(trans)) {
+ if (PTR_ERR(trans) == -ENOENT)
+ return 0;
+ ret = PTR_ERR(trans);
+ trans = NULL;
+ goto error_sysfs;
+ }
+ ret = btrfs_commit_transaction(trans);
+ }
+
+ /* Update ctime/mtime for libblkid */
+ update_dev_time(device_path);
+ return ret;
+
+error_sysfs:
+ btrfs_sysfs_rm_device_link(fs_devices, device);
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ mutex_lock(&fs_info->chunk_mutex);
+ list_del_rcu(&device->dev_list);
+ list_del(&device->dev_alloc_list);
+ fs_info->fs_devices->num_devices--;
+ fs_info->fs_devices->open_devices--;
+ fs_info->fs_devices->rw_devices--;
+ fs_info->fs_devices->total_devices--;
+ fs_info->fs_devices->total_rw_bytes -= device->total_bytes;
+ atomic64_sub(device->total_bytes, &fs_info->free_chunk_space);
+ btrfs_set_super_total_bytes(fs_info->super_copy,
+ orig_super_total_bytes);
+ btrfs_set_super_num_devices(fs_info->super_copy,
+ orig_super_num_devices);
+ mutex_unlock(&fs_info->chunk_mutex);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+error_trans:
+ if (seeding_dev)
+ sb->s_flags |= SB_RDONLY;
+ if (trans)
+ btrfs_end_transaction(trans);
+error_free_device:
+ btrfs_free_device(device);
+error:
+ blkdev_put(bdev, FMODE_EXCL);
+ if (seeding_dev && !unlocked) {
+ mutex_unlock(&uuid_mutex);
+ up_write(&sb->s_umount);
+ }
+ return ret;
+}
+
+static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device)
+{
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_root *root = device->fs_info->chunk_root;
+ struct btrfs_dev_item *dev_item;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.type = BTRFS_DEV_ITEM_KEY;
+ key.offset = device->devid;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
+
+ btrfs_set_device_id(leaf, dev_item, device->devid);
+ btrfs_set_device_type(leaf, dev_item, device->type);
+ btrfs_set_device_io_align(leaf, dev_item, device->io_align);
+ btrfs_set_device_io_width(leaf, dev_item, device->io_width);
+ btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
+ btrfs_set_device_total_bytes(leaf, dev_item,
+ btrfs_device_get_disk_total_bytes(device));
+ btrfs_set_device_bytes_used(leaf, dev_item,
+ btrfs_device_get_bytes_used(device));
+ btrfs_mark_buffer_dirty(leaf);
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_grow_device(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device, u64 new_size)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct btrfs_super_block *super_copy = fs_info->super_copy;
+ struct btrfs_fs_devices *fs_devices;
+ u64 old_total;
+ u64 diff;
+
+ if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
+ return -EACCES;
+
+ new_size = round_down(new_size, fs_info->sectorsize);
+
+ mutex_lock(&fs_info->chunk_mutex);
+ old_total = btrfs_super_total_bytes(super_copy);
+ diff = round_down(new_size - device->total_bytes, fs_info->sectorsize);
+
+ if (new_size <= device->total_bytes ||
+ test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
+ mutex_unlock(&fs_info->chunk_mutex);
+ return -EINVAL;
+ }
+
+ fs_devices = fs_info->fs_devices;
+
+ btrfs_set_super_total_bytes(super_copy,
+ round_down(old_total + diff, fs_info->sectorsize));
+ device->fs_devices->total_rw_bytes += diff;
+
+ btrfs_device_set_total_bytes(device, new_size);
+ btrfs_device_set_disk_total_bytes(device, new_size);
+ btrfs_clear_space_info_full(device->fs_info);
+ if (list_empty(&device->resized_list))
+ list_add_tail(&device->resized_list,
+ &fs_devices->resized_devices);
+ mutex_unlock(&fs_info->chunk_mutex);
+
+ return btrfs_update_device(trans, device);
+}
+
+static int btrfs_free_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_root *root = fs_info->chunk_root;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = chunk_offset;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0) { /* Logic error or corruption */
+ btrfs_handle_fs_error(fs_info, -ENOENT,
+ "Failed lookup while freeing chunk.");
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret < 0)
+ btrfs_handle_fs_error(fs_info, ret,
+ "Failed to delete chunk item.");
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int btrfs_del_sys_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
+{
+ struct btrfs_super_block *super_copy = fs_info->super_copy;
+ struct btrfs_disk_key *disk_key;
+ struct btrfs_chunk *chunk;
+ u8 *ptr;
+ int ret = 0;
+ u32 num_stripes;
+ u32 array_size;
+ u32 len = 0;
+ u32 cur;
+ struct btrfs_key key;
+
+ mutex_lock(&fs_info->chunk_mutex);
+ array_size = btrfs_super_sys_array_size(super_copy);
+
+ ptr = super_copy->sys_chunk_array;
+ cur = 0;
+
+ while (cur < array_size) {
+ disk_key = (struct btrfs_disk_key *)ptr;
+ btrfs_disk_key_to_cpu(&key, disk_key);
+
+ len = sizeof(*disk_key);
+
+ if (key.type == BTRFS_CHUNK_ITEM_KEY) {
+ chunk = (struct btrfs_chunk *)(ptr + len);
+ num_stripes = btrfs_stack_chunk_num_stripes(chunk);
+ len += btrfs_chunk_item_size(num_stripes);
+ } else {
+ ret = -EIO;
+ break;
+ }
+ if (key.objectid == BTRFS_FIRST_CHUNK_TREE_OBJECTID &&
+ key.offset == chunk_offset) {
+ memmove(ptr, ptr + len, array_size - (cur + len));
+ array_size -= len;
+ btrfs_set_super_sys_array_size(super_copy, array_size);
+ } else {
+ ptr += len;
+ cur += len;
+ }
+ }
+ mutex_unlock(&fs_info->chunk_mutex);
+ return ret;
+}
+
+static struct extent_map *get_chunk_map(struct btrfs_fs_info *fs_info,
+ u64 logical, u64 length)
+{
+ struct extent_map_tree *em_tree;
+ struct extent_map *em;
+
+ em_tree = &fs_info->mapping_tree.map_tree;
+ read_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, logical, length);
+ read_unlock(&em_tree->lock);
+
+ if (!em) {
+ btrfs_crit(fs_info, "unable to find logical %llu length %llu",
+ logical, length);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (em->start > logical || em->start + em->len < logical) {
+ btrfs_crit(fs_info,
+ "found a bad mapping, wanted %llu-%llu, found %llu-%llu",
+ logical, length, em->start, em->start + em->len);
+ free_extent_map(em);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* callers are responsible for dropping em's ref. */
+ return em;
+}
+
+int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct extent_map *em;
+ struct map_lookup *map;
+ u64 dev_extent_len = 0;
+ int i, ret = 0;
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+
+ em = get_chunk_map(fs_info, chunk_offset, 1);
+ if (IS_ERR(em)) {
+ /*
+ * This is a logic error, but we don't want to just rely on the
+ * user having built with ASSERT enabled, so if ASSERT doesn't
+ * do anything we still error out.
+ */
+ ASSERT(0);
+ return PTR_ERR(em);
+ }
+ map = em->map_lookup;
+ mutex_lock(&fs_info->chunk_mutex);
+ check_system_chunk(trans, map->type);
+ mutex_unlock(&fs_info->chunk_mutex);
+
+ /*
+ * Take the device list mutex to prevent races with the final phase of
+ * a device replace operation that replaces the device object associated
+ * with map stripes (dev-replace.c:btrfs_dev_replace_finishing()).
+ */
+ mutex_lock(&fs_devices->device_list_mutex);
+ for (i = 0; i < map->num_stripes; i++) {
+ struct btrfs_device *device = map->stripes[i].dev;
+ ret = btrfs_free_dev_extent(trans, device,
+ map->stripes[i].physical,
+ &dev_extent_len);
+ if (ret) {
+ mutex_unlock(&fs_devices->device_list_mutex);
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
+
+ if (device->bytes_used > 0) {
+ mutex_lock(&fs_info->chunk_mutex);
+ btrfs_device_set_bytes_used(device,
+ device->bytes_used - dev_extent_len);
+ atomic64_add(dev_extent_len, &fs_info->free_chunk_space);
+ btrfs_clear_space_info_full(fs_info);
+ mutex_unlock(&fs_info->chunk_mutex);
+ }
+
+ if (map->stripes[i].dev) {
+ ret = btrfs_update_device(trans, map->stripes[i].dev);
+ if (ret) {
+ mutex_unlock(&fs_devices->device_list_mutex);
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
+ }
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ ret = btrfs_free_chunk(trans, chunk_offset);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
+
+ trace_btrfs_chunk_free(fs_info, map, chunk_offset, em->len);
+
+ if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ ret = btrfs_del_sys_chunk(fs_info, chunk_offset);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
+ }
+
+ ret = btrfs_remove_block_group(trans, chunk_offset, em);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
+
+out:
+ /* once for us */
+ free_extent_map(em);
+ return ret;
+}
+
+static int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
+{
+ struct btrfs_root *root = fs_info->chunk_root;
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ /*
+ * Prevent races with automatic removal of unused block groups.
+ * After we relocate and before we remove the chunk with offset
+ * chunk_offset, automatic removal of the block group can kick in,
+ * resulting in a failure when calling btrfs_remove_chunk() below.
+ *
+ * Make sure to acquire this mutex before doing a tree search (dev
+ * or chunk trees) to find chunks. Otherwise the cleaner kthread might
+ * call btrfs_remove_chunk() (through btrfs_delete_unused_bgs()) after
+ * we release the path used to search the chunk/dev tree and before
+ * the current task acquires this mutex and calls us.
+ */
+ lockdep_assert_held(&fs_info->delete_unused_bgs_mutex);
+
+ ret = btrfs_can_relocate(fs_info, chunk_offset);
+ if (ret)
+ return -ENOSPC;
+
+ /* step one, relocate all the extents inside this chunk */
+ btrfs_scrub_pause(fs_info);
+ ret = btrfs_relocate_block_group(fs_info, chunk_offset);
+ btrfs_scrub_continue(fs_info);
+ if (ret)
+ return ret;
+
+ /*
+ * We add the kobjects here (and after forcing data chunk creation)
+ * since relocation is the only place we'll create chunks of a new
+ * type at runtime. The only place where we'll remove the last
+ * chunk of a type is the call immediately below this one. Even
+ * so, we're protected against races with the cleaner thread since
+ * we're covered by the delete_unused_bgs_mutex.
+ */
+ btrfs_add_raid_kobjects(fs_info);
+
+ trans = btrfs_start_trans_remove_block_group(root->fs_info,
+ chunk_offset);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ btrfs_handle_fs_error(root->fs_info, ret, NULL);
+ return ret;
+ }
+
+ /*
+ * step two, delete the device extents and the
+ * chunk tree entries
+ */
+ ret = btrfs_remove_chunk(trans, chunk_offset);
+ btrfs_end_transaction(trans);
+ return ret;
+}
+
+static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *chunk_root = fs_info->chunk_root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_chunk *chunk;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ u64 chunk_type;
+ bool retried = false;
+ int failed = 0;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+again:
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ while (1) {
+ mutex_lock(&fs_info->delete_unused_bgs_mutex);
+ ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
+ if (ret < 0) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ goto error;
+ }
+ BUG_ON(ret == 0); /* Corruption */
+
+ ret = btrfs_previous_item(chunk_root, path, key.objectid,
+ key.type);
+ if (ret)
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ if (ret < 0)
+ goto error;
+ if (ret > 0)
+ break;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ chunk = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_chunk);
+ chunk_type = btrfs_chunk_type(leaf, chunk);
+ btrfs_release_path(path);
+
+ if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ ret = btrfs_relocate_chunk(fs_info, found_key.offset);
+ if (ret == -ENOSPC)
+ failed++;
+ else
+ BUG_ON(ret);
+ }
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+
+ if (found_key.offset == 0)
+ break;
+ key.offset = found_key.offset - 1;
+ }
+ ret = 0;
+ if (failed && !retried) {
+ failed = 0;
+ retried = true;
+ goto again;
+ } else if (WARN_ON(failed && retried)) {
+ ret = -ENOSPC;
+ }
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * return 1 : allocate a data chunk successfully,
+ * return <0: errors during allocating a data chunk,
+ * return 0 : no need to allocate a data chunk.
+ */
+static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info,
+ u64 chunk_offset)
+{
+ struct btrfs_block_group_cache *cache;
+ u64 bytes_used;
+ u64 chunk_type;
+
+ cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+ ASSERT(cache);
+ chunk_type = cache->flags;
+ btrfs_put_block_group(cache);
+
+ if (chunk_type & BTRFS_BLOCK_GROUP_DATA) {
+ spin_lock(&fs_info->data_sinfo->lock);
+ bytes_used = fs_info->data_sinfo->bytes_used;
+ spin_unlock(&fs_info->data_sinfo->lock);
+
+ if (!bytes_used) {
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ trans = btrfs_join_transaction(fs_info->tree_root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ ret = btrfs_force_chunk_alloc(trans,
+ BTRFS_BLOCK_GROUP_DATA);
+ btrfs_end_transaction(trans);
+ if (ret < 0)
+ return ret;
+
+ btrfs_add_raid_kobjects(fs_info);
+
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int insert_balance_item(struct btrfs_fs_info *fs_info,
+ struct btrfs_balance_control *bctl)
+{
+ struct btrfs_root *root = fs_info->tree_root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_balance_item *item;
+ struct btrfs_disk_balance_args disk_bargs;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ int ret, err;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ btrfs_free_path(path);
+ return PTR_ERR(trans);
+ }
+
+ key.objectid = BTRFS_BALANCE_OBJECTID;
+ key.type = BTRFS_TEMPORARY_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(*item));
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
+
+ memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item));
+
+ btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
+ btrfs_set_balance_data(leaf, item, &disk_bargs);
+ btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
+ btrfs_set_balance_meta(leaf, item, &disk_bargs);
+ btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
+ btrfs_set_balance_sys(leaf, item, &disk_bargs);
+
+ btrfs_set_balance_flags(leaf, item, bctl->flags);
+
+ btrfs_mark_buffer_dirty(leaf);
+out:
+ btrfs_free_path(path);
+ err = btrfs_commit_transaction(trans);
+ if (err && !ret)
+ ret = err;
+ return ret;
+}
+
+static int del_balance_item(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root = fs_info->tree_root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ int ret, err;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ btrfs_free_path(path);
+ return PTR_ERR(trans);
+ }
+
+ key.objectid = BTRFS_BALANCE_OBJECTID;
+ key.type = BTRFS_TEMPORARY_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = btrfs_del_item(trans, root, path);
+out:
+ btrfs_free_path(path);
+ err = btrfs_commit_transaction(trans);
+ if (err && !ret)
+ ret = err;
+ return ret;
+}
+
+/*
+ * This is a heuristic used to reduce the number of chunks balanced on
+ * resume after balance was interrupted.
+ */
+static void update_balance_args(struct btrfs_balance_control *bctl)
+{
+ /*
+ * Turn on soft mode for chunk types that were being converted.
+ */
+ if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
+ bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
+ if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
+ bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
+ if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
+ bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
+
+ /*
+ * Turn on usage filter if is not already used. The idea is
+ * that chunks that we have already balanced should be
+ * reasonably full. Don't do it for chunks that are being
+ * converted - that will keep us from relocating unconverted
+ * (albeit full) chunks.
+ */
+ if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ !(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
+ !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+ bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
+ bctl->data.usage = 90;
+ }
+ if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ !(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
+ !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+ bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
+ bctl->sys.usage = 90;
+ }
+ if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ !(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
+ !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+ bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
+ bctl->meta.usage = 90;
+ }
+}
+
+/*
+ * Clear the balance status in fs_info and delete the balance item from disk.
+ */
+static void reset_balance_state(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+ int ret;
+
+ BUG_ON(!fs_info->balance_ctl);
+
+ spin_lock(&fs_info->balance_lock);
+ fs_info->balance_ctl = NULL;
+ spin_unlock(&fs_info->balance_lock);
+
+ kfree(bctl);
+ ret = del_balance_item(fs_info);
+ if (ret)
+ btrfs_handle_fs_error(fs_info, ret, NULL);
+}
+
+/*
+ * Balance filters. Return 1 if chunk should be filtered out
+ * (should not be balanced).
+ */
+static int chunk_profiles_filter(u64 chunk_type,
+ struct btrfs_balance_args *bargs)
+{
+ chunk_type = chunk_to_extended(chunk_type) &
+ BTRFS_EXTENDED_PROFILE_MASK;
+
+ if (bargs->profiles & chunk_type)
+ return 0;
+
+ return 1;
+}
+
+static int chunk_usage_range_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
+ struct btrfs_balance_args *bargs)
+{
+ struct btrfs_block_group_cache *cache;
+ u64 chunk_used;
+ u64 user_thresh_min;
+ u64 user_thresh_max;
+ int ret = 1;
+
+ cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+ chunk_used = btrfs_block_group_used(&cache->item);
+
+ if (bargs->usage_min == 0)
+ user_thresh_min = 0;
+ else
+ user_thresh_min = div_factor_fine(cache->key.offset,
+ bargs->usage_min);
+
+ if (bargs->usage_max == 0)
+ user_thresh_max = 1;
+ else if (bargs->usage_max > 100)
+ user_thresh_max = cache->key.offset;
+ else
+ user_thresh_max = div_factor_fine(cache->key.offset,
+ bargs->usage_max);
+
+ if (user_thresh_min <= chunk_used && chunk_used < user_thresh_max)
+ ret = 0;
+
+ btrfs_put_block_group(cache);
+ return ret;
+}
+
+static int chunk_usage_filter(struct btrfs_fs_info *fs_info,
+ u64 chunk_offset, struct btrfs_balance_args *bargs)
+{
+ struct btrfs_block_group_cache *cache;
+ u64 chunk_used, user_thresh;
+ int ret = 1;
+
+ cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+ chunk_used = btrfs_block_group_used(&cache->item);
+
+ if (bargs->usage_min == 0)
+ user_thresh = 1;
+ else if (bargs->usage > 100)
+ user_thresh = cache->key.offset;
+ else
+ user_thresh = div_factor_fine(cache->key.offset,
+ bargs->usage);
+
+ if (chunk_used < user_thresh)
+ ret = 0;
+
+ btrfs_put_block_group(cache);
+ return ret;
+}
+
+static int chunk_devid_filter(struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk,
+ struct btrfs_balance_args *bargs)
+{
+ struct btrfs_stripe *stripe;
+ int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+ int i;
+
+ for (i = 0; i < num_stripes; i++) {
+ stripe = btrfs_stripe_nr(chunk, i);
+ if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
+ return 0;
+ }
+
+ return 1;
+}
+
+/* [pstart, pend) */
+static int chunk_drange_filter(struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk,
+ struct btrfs_balance_args *bargs)
+{
+ struct btrfs_stripe *stripe;
+ int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+ u64 stripe_offset;
+ u64 stripe_length;
+ int factor;
+ int i;
+
+ if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
+ return 0;
+
+ if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
+ BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
+ factor = num_stripes / 2;
+ } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
+ factor = num_stripes - 1;
+ } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
+ factor = num_stripes - 2;
+ } else {
+ factor = num_stripes;
+ }
+
+ for (i = 0; i < num_stripes; i++) {
+ stripe = btrfs_stripe_nr(chunk, i);
+ if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
+ continue;
+
+ stripe_offset = btrfs_stripe_offset(leaf, stripe);
+ stripe_length = btrfs_chunk_length(leaf, chunk);
+ stripe_length = div_u64(stripe_length, factor);
+
+ if (stripe_offset < bargs->pend &&
+ stripe_offset + stripe_length > bargs->pstart)
+ return 0;
+ }
+
+ return 1;
+}
+
+/* [vstart, vend) */
+static int chunk_vrange_filter(struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk,
+ u64 chunk_offset,
+ struct btrfs_balance_args *bargs)
+{
+ if (chunk_offset < bargs->vend &&
+ chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
+ /* at least part of the chunk is inside this vrange */
+ return 0;
+
+ return 1;
+}
+
+static int chunk_stripes_range_filter(struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk,
+ struct btrfs_balance_args *bargs)
+{
+ int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+
+ if (bargs->stripes_min <= num_stripes
+ && num_stripes <= bargs->stripes_max)
+ return 0;
+
+ return 1;
+}
+
+static int chunk_soft_convert_filter(u64 chunk_type,
+ struct btrfs_balance_args *bargs)
+{
+ if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
+ return 0;
+
+ chunk_type = chunk_to_extended(chunk_type) &
+ BTRFS_EXTENDED_PROFILE_MASK;
+
+ if (bargs->target == chunk_type)
+ return 1;
+
+ return 0;
+}
+
+static int should_balance_chunk(struct btrfs_fs_info *fs_info,
+ struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk, u64 chunk_offset)
+{
+ struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+ struct btrfs_balance_args *bargs = NULL;
+ u64 chunk_type = btrfs_chunk_type(leaf, chunk);
+
+ /* type filter */
+ if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
+ (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
+ return 0;
+ }
+
+ if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
+ bargs = &bctl->data;
+ else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
+ bargs = &bctl->sys;
+ else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
+ bargs = &bctl->meta;
+
+ /* profiles filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
+ chunk_profiles_filter(chunk_type, bargs)) {
+ return 0;
+ }
+
+ /* usage filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ chunk_usage_filter(fs_info, chunk_offset, bargs)) {
+ return 0;
+ } else if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
+ chunk_usage_range_filter(fs_info, chunk_offset, bargs)) {
+ return 0;
+ }
+
+ /* devid filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
+ chunk_devid_filter(leaf, chunk, bargs)) {
+ return 0;
+ }
+
+ /* drange filter, makes sense only with devid filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
+ chunk_drange_filter(leaf, chunk, bargs)) {
+ return 0;
+ }
+
+ /* vrange filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
+ chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
+ return 0;
+ }
+
+ /* stripes filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) &&
+ chunk_stripes_range_filter(leaf, chunk, bargs)) {
+ return 0;
+ }
+
+ /* soft profile changing mode */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
+ chunk_soft_convert_filter(chunk_type, bargs)) {
+ return 0;
+ }
+
+ /*
+ * limited by count, must be the last filter
+ */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) {
+ if (bargs->limit == 0)
+ return 0;
+ else
+ bargs->limit--;
+ } else if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)) {
+ /*
+ * Same logic as the 'limit' filter; the minimum cannot be
+ * determined here because we do not have the global information
+ * about the count of all chunks that satisfy the filters.
+ */
+ if (bargs->limit_max == 0)
+ return 0;
+ else
+ bargs->limit_max--;
+ }
+
+ return 1;
+}
+
+static int __btrfs_balance(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_balance_control *bctl = fs_info->balance_ctl;
+ struct btrfs_root *chunk_root = fs_info->chunk_root;
+ struct btrfs_root *dev_root = fs_info->dev_root;
+ struct list_head *devices;
+ struct btrfs_device *device;
+ u64 old_size;
+ u64 size_to_free;
+ u64 chunk_type;
+ struct btrfs_chunk *chunk;
+ struct btrfs_path *path = NULL;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_trans_handle *trans;
+ struct extent_buffer *leaf;
+ int slot;
+ int ret;
+ int enospc_errors = 0;
+ bool counting = true;
+ /* The single value limit and min/max limits use the same bytes in the */
+ u64 limit_data = bctl->data.limit;
+ u64 limit_meta = bctl->meta.limit;
+ u64 limit_sys = bctl->sys.limit;
+ u32 count_data = 0;
+ u32 count_meta = 0;
+ u32 count_sys = 0;
+ int chunk_reserved = 0;
+
+ /* step one make some room on all the devices */
+ devices = &fs_info->fs_devices->devices;
+ list_for_each_entry(device, devices, dev_list) {
+ old_size = btrfs_device_get_total_bytes(device);
+ size_to_free = div_factor(old_size, 1);
+ size_to_free = min_t(u64, size_to_free, SZ_1M);
+ if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) ||
+ btrfs_device_get_total_bytes(device) -
+ btrfs_device_get_bytes_used(device) > size_to_free ||
+ test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
+ continue;
+
+ ret = btrfs_shrink_device(device, old_size - size_to_free);
+ if (ret == -ENOSPC)
+ break;
+ if (ret) {
+ /* btrfs_shrink_device never returns ret > 0 */
+ WARN_ON(ret > 0);
+ goto error;
+ }
+
+ trans = btrfs_start_transaction(dev_root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ btrfs_info_in_rcu(fs_info,
+ "resize: unable to start transaction after shrinking device %s (error %d), old size %llu, new size %llu",
+ rcu_str_deref(device->name), ret,
+ old_size, old_size - size_to_free);
+ goto error;
+ }
+
+ ret = btrfs_grow_device(trans, device, old_size);
+ if (ret) {
+ btrfs_end_transaction(trans);
+ /* btrfs_grow_device never returns ret > 0 */
+ WARN_ON(ret > 0);
+ btrfs_info_in_rcu(fs_info,
+ "resize: unable to grow device after shrinking device %s (error %d), old size %llu, new size %llu",
+ rcu_str_deref(device->name), ret,
+ old_size, old_size - size_to_free);
+ goto error;
+ }
+
+ btrfs_end_transaction(trans);
+ }
+
+ /* step two, relocate all the chunks */
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ /* zero out stat counters */
+ spin_lock(&fs_info->balance_lock);
+ memset(&bctl->stat, 0, sizeof(bctl->stat));
+ spin_unlock(&fs_info->balance_lock);
+again:
+ if (!counting) {
+ /*
+ * The single value limit and min/max limits use the same bytes
+ * in the
+ */
+ bctl->data.limit = limit_data;
+ bctl->meta.limit = limit_meta;
+ bctl->sys.limit = limit_sys;
+ }
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ while (1) {
+ if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
+ atomic_read(&fs_info->balance_cancel_req)) {
+ ret = -ECANCELED;
+ goto error;
+ }
+
+ mutex_lock(&fs_info->delete_unused_bgs_mutex);
+ ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
+ if (ret < 0) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ goto error;
+ }
+
+ /*
+ * this shouldn't happen, it means the last relocate
+ * failed
+ */
+ if (ret == 0)
+ BUG(); /* FIXME break ? */
+
+ ret = btrfs_previous_item(chunk_root, path, 0,
+ BTRFS_CHUNK_ITEM_KEY);
+ if (ret) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ ret = 0;
+ break;
+ }
+
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+ if (found_key.objectid != key.objectid) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ break;
+ }
+
+ chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+ chunk_type = btrfs_chunk_type(leaf, chunk);
+
+ if (!counting) {
+ spin_lock(&fs_info->balance_lock);
+ bctl->stat.considered++;
+ spin_unlock(&fs_info->balance_lock);
+ }
+
+ ret = should_balance_chunk(fs_info, leaf, chunk,
+ found_key.offset);
+
+ btrfs_release_path(path);
+ if (!ret) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ goto loop;
+ }
+
+ if (counting) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ spin_lock(&fs_info->balance_lock);
+ bctl->stat.expected++;
+ spin_unlock(&fs_info->balance_lock);
+
+ if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
+ count_data++;
+ else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
+ count_sys++;
+ else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
+ count_meta++;
+
+ goto loop;
+ }
+
+ /*
+ * Apply limit_min filter, no need to check if the LIMITS
+ * filter is used, limit_min is 0 by default
+ */
+ if (((chunk_type & BTRFS_BLOCK_GROUP_DATA) &&
+ count_data < bctl->data.limit_min)
+ || ((chunk_type & BTRFS_BLOCK_GROUP_METADATA) &&
+ count_meta < bctl->meta.limit_min)
+ || ((chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) &&
+ count_sys < bctl->sys.limit_min)) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ goto loop;
+ }
+
+ if (!chunk_reserved) {
+ /*
+ * We may be relocating the only data chunk we have,
+ * which could potentially end up with losing data's
+ * raid profile, so lets allocate an empty one in
+ * advance.
+ */
+ ret = btrfs_may_alloc_data_chunk(fs_info,
+ found_key.offset);
+ if (ret < 0) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ goto error;
+ } else if (ret == 1) {
+ chunk_reserved = 1;
+ }
+ }
+
+ ret = btrfs_relocate_chunk(fs_info, found_key.offset);
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ if (ret && ret != -ENOSPC)
+ goto error;
+ if (ret == -ENOSPC) {
+ enospc_errors++;
+ } else {
+ spin_lock(&fs_info->balance_lock);
+ bctl->stat.completed++;
+ spin_unlock(&fs_info->balance_lock);
+ }
+loop:
+ if (found_key.offset == 0)
+ break;
+ key.offset = found_key.offset - 1;
+ }
+
+ if (counting) {
+ btrfs_release_path(path);
+ counting = false;
+ goto again;
+ }
+error:
+ btrfs_free_path(path);
+ if (enospc_errors) {
+ btrfs_info(fs_info, "%d enospc errors during balance",
+ enospc_errors);
+ if (!ret)
+ ret = -ENOSPC;
+ }
+
+ return ret;
+}
+
+/**
+ * alloc_profile_is_valid - see if a given profile is valid and reduced
+ * @flags: profile to validate
+ * @extended: if true @flags is treated as an extended profile
+ */
+static int alloc_profile_is_valid(u64 flags, int extended)
+{
+ u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
+ BTRFS_BLOCK_GROUP_PROFILE_MASK);
+
+ flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
+
+ /* 1) check that all other bits are zeroed */
+ if (flags & ~mask)
+ return 0;
+
+ /* 2) see if profile is reduced */
+ if (flags == 0)
+ return !extended; /* "0" is valid for usual profiles */
+
+ /* true if exactly one bit set */
+ return (flags & (flags - 1)) == 0;
+}
+
+static inline int balance_need_close(struct btrfs_fs_info *fs_info)
+{
+ /* cancel requested || normal exit path */
+ return atomic_read(&fs_info->balance_cancel_req) ||
+ (atomic_read(&fs_info->balance_pause_req) == 0 &&
+ atomic_read(&fs_info->balance_cancel_req) == 0);
+}
+
+/* Non-zero return value signifies invalidity */
+static inline int validate_convert_profile(struct btrfs_balance_args *bctl_arg,
+ u64 allowed)
+{
+ return ((bctl_arg->flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (!alloc_profile_is_valid(bctl_arg->target, 1) ||
+ (bctl_arg->target & ~allowed)));
+}
+
+/*
+ * Should be called with balance mutexe held
+ */
+int btrfs_balance(struct btrfs_fs_info *fs_info,
+ struct btrfs_balance_control *bctl,
+ struct btrfs_ioctl_balance_args *bargs)
+{
+ u64 meta_target, data_target;
+ u64 allowed;
+ int mixed = 0;
+ int ret;
+ u64 num_devices;
+ unsigned seq;
+
+ if (btrfs_fs_closing(fs_info) ||
+ atomic_read(&fs_info->balance_pause_req) ||
+ atomic_read(&fs_info->balance_cancel_req)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ allowed = btrfs_super_incompat_flags(fs_info->super_copy);
+ if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+ mixed = 1;
+
+ /*
+ * In case of mixed groups both data and meta should be picked,
+ * and identical options should be given for both of them.
+ */
+ allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
+ if (mixed && (bctl->flags & allowed)) {
+ if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
+ !(bctl->flags & BTRFS_BALANCE_METADATA) ||
+ memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
+ btrfs_err(fs_info,
+ "balance: mixed groups data and metadata options must be the same");
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ num_devices = fs_info->fs_devices->num_devices;
+ btrfs_dev_replace_read_lock(&fs_info->dev_replace);
+ if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
+ BUG_ON(num_devices < 1);
+ num_devices--;
+ }
+ btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+ allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE | BTRFS_BLOCK_GROUP_DUP;
+ if (num_devices > 1)
+ allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
+ if (num_devices > 2)
+ allowed |= BTRFS_BLOCK_GROUP_RAID5;
+ if (num_devices > 3)
+ allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID6);
+ if (validate_convert_profile(&bctl->data, allowed)) {
+ int index = btrfs_bg_flags_to_raid_index(bctl->data.target);
+
+ btrfs_err(fs_info,
+ "balance: invalid convert data profile %s",
+ get_raid_name(index));
+ ret = -EINVAL;
+ goto out;
+ }
+ if (validate_convert_profile(&bctl->meta, allowed)) {
+ int index = btrfs_bg_flags_to_raid_index(bctl->meta.target);
+
+ btrfs_err(fs_info,
+ "balance: invalid convert metadata profile %s",
+ get_raid_name(index));
+ ret = -EINVAL;
+ goto out;
+ }
+ if (validate_convert_profile(&bctl->sys, allowed)) {
+ int index = btrfs_bg_flags_to_raid_index(bctl->sys.target);
+
+ btrfs_err(fs_info,
+ "balance: invalid convert system profile %s",
+ get_raid_name(index));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* allow to reduce meta or sys integrity only if force set */
+ allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_RAID6;
+ do {
+ seq = read_seqbegin(&fs_info->profiles_lock);
+
+ if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (fs_info->avail_system_alloc_bits & allowed) &&
+ !(bctl->sys.target & allowed)) ||
+ ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (fs_info->avail_metadata_alloc_bits & allowed) &&
+ !(bctl->meta.target & allowed))) {
+ if (bctl->flags & BTRFS_BALANCE_FORCE) {
+ btrfs_info(fs_info,
+ "balance: force reducing metadata integrity");
+ } else {
+ btrfs_err(fs_info,
+ "balance: reduces metadata integrity, use --force if you want this");
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ } while (read_seqretry(&fs_info->profiles_lock, seq));
+
+ /* if we're not converting, the target field is uninitialized */
+ meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
+ bctl->meta.target : fs_info->avail_metadata_alloc_bits;
+ data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ?
+ bctl->data.target : fs_info->avail_data_alloc_bits;
+ if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) <
+ btrfs_get_num_tolerated_disk_barrier_failures(data_target)) {
+ int meta_index = btrfs_bg_flags_to_raid_index(meta_target);
+ int data_index = btrfs_bg_flags_to_raid_index(data_target);
+
+ btrfs_warn(fs_info,
+ "balance: metadata profile %s has lower redundancy than data profile %s",
+ get_raid_name(meta_index), get_raid_name(data_index));
+ }
+
+ ret = insert_balance_item(fs_info, bctl);
+ if (ret && ret != -EEXIST)
+ goto out;
+
+ if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
+ BUG_ON(ret == -EEXIST);
+ BUG_ON(fs_info->balance_ctl);
+ spin_lock(&fs_info->balance_lock);
+ fs_info->balance_ctl = bctl;
+ spin_unlock(&fs_info->balance_lock);
+ } else {
+ BUG_ON(ret != -EEXIST);
+ spin_lock(&fs_info->balance_lock);
+ update_balance_args(bctl);
+ spin_unlock(&fs_info->balance_lock);
+ }
+
+ ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+ set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
+ mutex_unlock(&fs_info->balance_mutex);
+
+ ret = __btrfs_balance(fs_info);
+
+ mutex_lock(&fs_info->balance_mutex);
+ clear_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
+
+ if (bargs) {
+ memset(bargs, 0, sizeof(*bargs));
+ btrfs_update_ioctl_balance_args(fs_info, bargs);
+ }
+
+ if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
+ balance_need_close(fs_info)) {
+ reset_balance_state(fs_info);
+ clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
+ }
+
+ wake_up(&fs_info->balance_wait_q);
+
+ return ret;
+out:
+ if (bctl->flags & BTRFS_BALANCE_RESUME)
+ reset_balance_state(fs_info);
+ else
+ kfree(bctl);
+ clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
+
+ return ret;
+}
+
+static int balance_kthread(void *data)
+{
+ struct btrfs_fs_info *fs_info = data;
+ int ret = 0;
+
+ mutex_lock(&fs_info->balance_mutex);
+ if (fs_info->balance_ctl) {
+ btrfs_info(fs_info, "balance: resuming");
+ ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL);
+ }
+ mutex_unlock(&fs_info->balance_mutex);
+
+ return ret;
+}
+
+int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
+{
+ struct task_struct *tsk;
+
+ mutex_lock(&fs_info->balance_mutex);
+ if (!fs_info->balance_ctl) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return 0;
+ }
+ mutex_unlock(&fs_info->balance_mutex);
+
+ if (btrfs_test_opt(fs_info, SKIP_BALANCE)) {
+ btrfs_info(fs_info, "balance: resume skipped");
+ return 0;
+ }
+
+ /*
+ * A ro->rw remount sequence should continue with the paused balance
+ * regardless of who pauses it, system or the user as of now, so set
+ * the resume flag.
+ */
+ spin_lock(&fs_info->balance_lock);
+ fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME;
+ spin_unlock(&fs_info->balance_lock);
+
+ tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
+ return PTR_ERR_OR_ZERO(tsk);
+}
+
+int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_balance_control *bctl;
+ struct btrfs_balance_item *item;
+ struct btrfs_disk_balance_args disk_bargs;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_BALANCE_OBJECTID;
+ key.type = BTRFS_TEMPORARY_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) { /* ret = -ENOENT; */
+ ret = 0;
+ goto out;
+ }
+
+ bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
+ if (!bctl) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
+
+ bctl->flags = btrfs_balance_flags(leaf, item);
+ bctl->flags |= BTRFS_BALANCE_RESUME;
+
+ btrfs_balance_data(leaf, item, &disk_bargs);
+ btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
+ btrfs_balance_meta(leaf, item, &disk_bargs);
+ btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
+ btrfs_balance_sys(leaf, item, &disk_bargs);
+ btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
+
+ /*
+ * This should never happen, as the paused balance state is recovered
+ * during mount without any chance of other exclusive ops to collide.
+ *
+ * This gives the exclusive op status to balance and keeps in paused
+ * state until user intervention (cancel or umount). If the ownership
+ * cannot be assigned, show a message but do not fail. The balance
+ * is in a paused state and must have fs_info::balance_ctl properly
+ * set up.
+ */
+ if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
+ btrfs_warn(fs_info,
+ "balance: cannot set exclusive op status, resume manually");
+
+ mutex_lock(&fs_info->balance_mutex);
+ BUG_ON(fs_info->balance_ctl);
+ spin_lock(&fs_info->balance_lock);
+ fs_info->balance_ctl = bctl;
+ spin_unlock(&fs_info->balance_lock);
+ mutex_unlock(&fs_info->balance_mutex);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
+{
+ int ret = 0;
+
+ mutex_lock(&fs_info->balance_mutex);
+ if (!fs_info->balance_ctl) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -ENOTCONN;
+ }
+
+ if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
+ atomic_inc(&fs_info->balance_pause_req);
+ mutex_unlock(&fs_info->balance_mutex);
+
+ wait_event(fs_info->balance_wait_q,
+ !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+
+ mutex_lock(&fs_info->balance_mutex);
+ /* we are good with balance_ctl ripped off from under us */
+ BUG_ON(test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+ atomic_dec(&fs_info->balance_pause_req);
+ } else {
+ ret = -ENOTCONN;
+ }
+
+ mutex_unlock(&fs_info->balance_mutex);
+ return ret;
+}
+
+int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->balance_mutex);
+ if (!fs_info->balance_ctl) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -ENOTCONN;
+ }
+
+ /*
+ * A paused balance with the item stored on disk can be resumed at
+ * mount time if the mount is read-write. Otherwise it's still paused
+ * and we must not allow cancelling as it deletes the item.
+ */
+ if (sb_rdonly(fs_info->sb)) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -EROFS;
+ }
+
+ atomic_inc(&fs_info->balance_cancel_req);
+ /*
+ * if we are running just wait and return, balance item is
+ * deleted in btrfs_balance in this case
+ */
+ if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
+ mutex_unlock(&fs_info->balance_mutex);
+ wait_event(fs_info->balance_wait_q,
+ !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+ mutex_lock(&fs_info->balance_mutex);
+ } else {
+ mutex_unlock(&fs_info->balance_mutex);
+ /*
+ * Lock released to allow other waiters to continue, we'll
+ * reexamine the status again.
+ */
+ mutex_lock(&fs_info->balance_mutex);
+
+ if (fs_info->balance_ctl) {
+ reset_balance_state(fs_info);
+ clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
+ btrfs_info(fs_info, "balance: canceled");
+ }
+ }
+
+ BUG_ON(fs_info->balance_ctl ||
+ test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+ atomic_dec(&fs_info->balance_cancel_req);
+ mutex_unlock(&fs_info->balance_mutex);
+ return 0;
+}
+
+static int btrfs_uuid_scan_kthread(void *data)
+{
+ struct btrfs_fs_info *fs_info = data;
+ struct btrfs_root *root = fs_info->tree_root;
+ struct btrfs_key key;
+ struct btrfs_path *path = NULL;
+ int ret = 0;
+ struct extent_buffer *eb;
+ int slot;
+ struct btrfs_root_item root_item;
+ u32 item_size;
+ struct btrfs_trans_handle *trans = NULL;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ key.objectid = 0;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = 0;
+
+ while (1) {
+ ret = btrfs_search_forward(root, &key, path,
+ BTRFS_OLDEST_GENERATION);
+ if (ret) {
+ if (ret > 0)
+ ret = 0;
+ break;
+ }
+
+ if (key.type != BTRFS_ROOT_ITEM_KEY ||
+ (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
+ key.objectid != BTRFS_FS_TREE_OBJECTID) ||
+ key.objectid > BTRFS_LAST_FREE_OBJECTID)
+ goto skip;
+
+ eb = path->nodes[0];
+ slot = path->slots[0];
+ item_size = btrfs_item_size_nr(eb, slot);
+ if (item_size < sizeof(root_item))
+ goto skip;
+
+ read_extent_buffer(eb, &root_item,
+ btrfs_item_ptr_offset(eb, slot),
+ (int)sizeof(root_item));
+ if (btrfs_root_refs(&root_item) == 0)
+ goto skip;
+
+ if (!btrfs_is_empty_uuid(root_item.uuid) ||
+ !btrfs_is_empty_uuid(root_item.received_uuid)) {
+ if (trans)
+ goto update_tree;
+
+ btrfs_release_path(path);
+ /*
+ * 1 - subvol uuid item
+ * 1 - received_subvol uuid item
+ */
+ trans = btrfs_start_transaction(fs_info->uuid_root, 2);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ break;
+ }
+ continue;
+ } else {
+ goto skip;
+ }
+update_tree:
+ if (!btrfs_is_empty_uuid(root_item.uuid)) {
+ ret = btrfs_uuid_tree_add(trans, root_item.uuid,
+ BTRFS_UUID_KEY_SUBVOL,
+ key.objectid);
+ if (ret < 0) {
+ btrfs_warn(fs_info, "uuid_tree_add failed %d",
+ ret);
+ break;
+ }
+ }
+
+ if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
+ ret = btrfs_uuid_tree_add(trans,
+ root_item.received_uuid,
+ BTRFS_UUID_KEY_RECEIVED_SUBVOL,
+ key.objectid);
+ if (ret < 0) {
+ btrfs_warn(fs_info, "uuid_tree_add failed %d",
+ ret);
+ break;
+ }
+ }
+
+skip:
+ if (trans) {
+ ret = btrfs_end_transaction(trans);
+ trans = NULL;
+ if (ret)
+ break;
+ }
+
+ btrfs_release_path(path);
+ if (key.offset < (u64)-1) {
+ key.offset++;
+ } else if (key.type < BTRFS_ROOT_ITEM_KEY) {
+ key.offset = 0;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ } else if (key.objectid < (u64)-1) {
+ key.offset = 0;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.objectid++;
+ } else {
+ break;
+ }
+ cond_resched();
+ }
+
+out:
+ btrfs_free_path(path);
+ if (trans && !IS_ERR(trans))
+ btrfs_end_transaction(trans);
+ if (ret)
+ btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
+ else
+ set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
+ up(&fs_info->uuid_tree_rescan_sem);
+ return 0;
+}
+
+/*
+ * Callback for btrfs_uuid_tree_iterate().
+ * returns:
+ * 0 check succeeded, the entry is not outdated.
+ * < 0 if an error occurred.
+ * > 0 if the check failed, which means the caller shall remove the entry.
+ */
+static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
+ u8 *uuid, u8 type, u64 subid)
+{
+ struct btrfs_key key;
+ int ret = 0;
+ struct btrfs_root *subvol_root;
+
+ if (type != BTRFS_UUID_KEY_SUBVOL &&
+ type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
+ goto out;
+
+ key.objectid = subid;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = (u64)-1;
+ subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(subvol_root)) {
+ ret = PTR_ERR(subvol_root);
+ if (ret == -ENOENT)
+ ret = 1;
+ goto out;
+ }
+
+ switch (type) {
+ case BTRFS_UUID_KEY_SUBVOL:
+ if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
+ ret = 1;
+ break;
+ case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
+ if (memcmp(uuid, subvol_root->root_item.received_uuid,
+ BTRFS_UUID_SIZE))
+ ret = 1;
+ break;
+ }
+
+out:
+ return ret;
+}
+
+static int btrfs_uuid_rescan_kthread(void *data)
+{
+ struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
+ int ret;
+
+ /*
+ * 1st step is to iterate through the existing UUID tree and
+ * to delete all entries that contain outdated data.
+ * 2nd step is to add all missing entries to the UUID tree.
+ */
+ ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
+ if (ret < 0) {
+ btrfs_warn(fs_info, "iterating uuid_tree failed %d", ret);
+ up(&fs_info->uuid_tree_rescan_sem);
+ return ret;
+ }
+ return btrfs_uuid_scan_kthread(data);
+}
+
+int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ struct btrfs_root *uuid_root;
+ struct task_struct *task;
+ int ret;
+
+ /*
+ * 1 - root node
+ * 1 - root item
+ */
+ trans = btrfs_start_transaction(tree_root, 2);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ uuid_root = btrfs_create_tree(trans, fs_info,
+ BTRFS_UUID_TREE_OBJECTID);
+ if (IS_ERR(uuid_root)) {
+ ret = PTR_ERR(uuid_root);
+ btrfs_abort_transaction(trans, ret);
+ btrfs_end_transaction(trans);
+ return ret;
+ }
+
+ fs_info->uuid_root = uuid_root;
+
+ ret = btrfs_commit_transaction(trans);
+ if (ret)
+ return ret;
+
+ down(&fs_info->uuid_tree_rescan_sem);
+ task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
+ if (IS_ERR(task)) {
+ /* fs_info->update_uuid_tree_gen remains 0 in all error case */
+ btrfs_warn(fs_info, "failed to start uuid_scan task");
+ up(&fs_info->uuid_tree_rescan_sem);
+ return PTR_ERR(task);
+ }
+
+ return 0;
+}
+
+int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
+{
+ struct task_struct *task;
+
+ down(&fs_info->uuid_tree_rescan_sem);
+ task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
+ if (IS_ERR(task)) {
+ /* fs_info->update_uuid_tree_gen remains 0 in all error case */
+ btrfs_warn(fs_info, "failed to start uuid_rescan task");
+ up(&fs_info->uuid_tree_rescan_sem);
+ return PTR_ERR(task);
+ }
+
+ return 0;
+}
+
+/*
+ * shrinking a device means finding all of the device extents past
+ * the new size, and then following the back refs to the chunks.
+ * The chunk relocation code actually frees the device extent
+ */
+int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ struct btrfs_root *root = fs_info->dev_root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_dev_extent *dev_extent = NULL;
+ struct btrfs_path *path;
+ u64 length;
+ u64 chunk_offset;
+ int ret;
+ int slot;
+ int failed = 0;
+ bool retried = false;
+ bool checked_pending_chunks = false;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ struct btrfs_super_block *super_copy = fs_info->super_copy;
+ u64 old_total = btrfs_super_total_bytes(super_copy);
+ u64 old_size = btrfs_device_get_total_bytes(device);
+ u64 diff;
+
+ new_size = round_down(new_size, fs_info->sectorsize);
+ diff = round_down(old_size - new_size, fs_info->sectorsize);
+
+ if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
+ return -EINVAL;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = READA_BACK;
+
+ mutex_lock(&fs_info->chunk_mutex);
+
+ btrfs_device_set_total_bytes(device, new_size);
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
+ device->fs_devices->total_rw_bytes -= diff;
+ atomic64_sub(diff, &fs_info->free_chunk_space);
+ }
+ mutex_unlock(&fs_info->chunk_mutex);
+
+again:
+ key.objectid = device->devid;
+ key.offset = (u64)-1;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+
+ do {
+ mutex_lock(&fs_info->delete_unused_bgs_mutex);
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ goto done;
+ }
+
+ ret = btrfs_previous_item(root, path, 0, key.type);
+ if (ret)
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ if (ret < 0)
+ goto done;
+ if (ret) {
+ ret = 0;
+ btrfs_release_path(path);
+ break;
+ }
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+ btrfs_item_key_to_cpu(l, &key, path->slots[0]);
+
+ if (key.objectid != device->devid) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ btrfs_release_path(path);
+ break;
+ }
+
+ dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+ length = btrfs_dev_extent_length(l, dev_extent);
+
+ if (key.offset + length <= new_size) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ btrfs_release_path(path);
+ break;
+ }
+
+ chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
+ btrfs_release_path(path);
+
+ /*
+ * We may be relocating the only data chunk we have,
+ * which could potentially end up with losing data's
+ * raid profile, so lets allocate an empty one in
+ * advance.
+ */
+ ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset);
+ if (ret < 0) {
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ goto done;
+ }
+
+ ret = btrfs_relocate_chunk(fs_info, chunk_offset);
+ mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+ if (ret && ret != -ENOSPC)
+ goto done;
+ if (ret == -ENOSPC)
+ failed++;
+ } while (key.offset-- > 0);
+
+ if (failed && !retried) {
+ failed = 0;
+ retried = true;
+ goto again;
+ } else if (failed && retried) {
+ ret = -ENOSPC;
+ goto done;
+ }
+
+ /* Shrinking succeeded, else we would be at "done". */
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto done;
+ }
+
+ mutex_lock(&fs_info->chunk_mutex);
+
+ /*
+ * We checked in the above loop all device extents that were already in
+ * the device tree. However before we have updated the device's
+ * total_bytes to the new size, we might have had chunk allocations that
+ * have not complete yet (new block groups attached to transaction
+ * handles), and therefore their device extents were not yet in the
+ * device tree and we missed them in the loop above. So if we have any
+ * pending chunk using a device extent that overlaps the device range
+ * that we can not use anymore, commit the current transaction and
+ * repeat the search on the device tree - this way we guarantee we will
+ * not have chunks using device extents that end beyond 'new_size'.
+ */
+ if (!checked_pending_chunks) {
+ u64 start = new_size;
+ u64 len = old_size - new_size;
+
+ if (contains_pending_extent(trans->transaction, device,
+ &start, len)) {
+ mutex_unlock(&fs_info->chunk_mutex);
+ checked_pending_chunks = true;
+ failed = 0;
+ retried = false;
+ ret = btrfs_commit_transaction(trans);
+ if (ret)
+ goto done;
+ goto again;
+ }
+ }
+
+ btrfs_device_set_disk_total_bytes(device, new_size);
+ if (list_empty(&device->resized_list))
+ list_add_tail(&device->resized_list,
+ &fs_info->fs_devices->resized_devices);
+
+ WARN_ON(diff > old_total);
+ btrfs_set_super_total_bytes(super_copy,
+ round_down(old_total - diff, fs_info->sectorsize));
+ mutex_unlock(&fs_info->chunk_mutex);
+
+ /* Now btrfs_update_device() will change the on-disk size. */
+ ret = btrfs_update_device(trans, device);
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ btrfs_end_transaction(trans);
+ } else {
+ ret = btrfs_commit_transaction(trans);
+ }
+done:
+ btrfs_free_path(path);
+ if (ret) {
+ mutex_lock(&fs_info->chunk_mutex);
+ btrfs_device_set_total_bytes(device, old_size);
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
+ device->fs_devices->total_rw_bytes += diff;
+ atomic64_add(diff, &fs_info->free_chunk_space);
+ mutex_unlock(&fs_info->chunk_mutex);
+ }
+ return ret;
+}
+
+static int btrfs_add_system_chunk(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *key,
+ struct btrfs_chunk *chunk, int item_size)
+{
+ struct btrfs_super_block *super_copy = fs_info->super_copy;
+ struct btrfs_disk_key disk_key;
+ u32 array_size;
+ u8 *ptr;
+
+ mutex_lock(&fs_info->chunk_mutex);
+ array_size = btrfs_super_sys_array_size(super_copy);
+ if (array_size + item_size + sizeof(disk_key)
+ > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
+ mutex_unlock(&fs_info->chunk_mutex);
+ return -EFBIG;
+ }
+
+ ptr = super_copy->sys_chunk_array + array_size;
+ btrfs_cpu_key_to_disk(&disk_key, key);
+ memcpy(ptr, &disk_key, sizeof(disk_key));
+ ptr += sizeof(disk_key);
+ memcpy(ptr, chunk, item_size);
+ item_size += sizeof(disk_key);
+ btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
+ mutex_unlock(&fs_info->chunk_mutex);
+
+ return 0;
+}
+
+/*
+ * sort the devices in descending order by max_avail, total_avail
+ */
+static int btrfs_cmp_device_info(const void *a, const void *b)
+{
+ const struct btrfs_device_info *di_a = a;
+ const struct btrfs_device_info *di_b = b;
+
+ if (di_a->max_avail > di_b->max_avail)
+ return -1;
+ if (di_a->max_avail < di_b->max_avail)
+ return 1;
+ if (di_a->total_avail > di_b->total_avail)
+ return -1;
+ if (di_a->total_avail < di_b->total_avail)
+ return 1;
+ return 0;
+}
+
+static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
+{
+ if (!(type & BTRFS_BLOCK_GROUP_RAID56_MASK))
+ return;
+
+ btrfs_set_fs_incompat(info, RAID56);
+}
+
+#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info) \
+ - sizeof(struct btrfs_chunk)) \
+ / sizeof(struct btrfs_stripe) + 1)
+
+#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE \
+ - 2 * sizeof(struct btrfs_disk_key) \
+ - 2 * sizeof(struct btrfs_chunk)) \
+ / sizeof(struct btrfs_stripe) + 1)
+
+static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
+ u64 start, u64 type)
+{
+ struct btrfs_fs_info *info = trans->fs_info;
+ struct btrfs_fs_devices *fs_devices = info->fs_devices;
+ struct btrfs_device *device;
+ struct map_lookup *map = NULL;
+ struct extent_map_tree *em_tree;
+ struct extent_map *em;
+ struct btrfs_device_info *devices_info = NULL;
+ u64 total_avail;
+ int num_stripes; /* total number of stripes to allocate */
+ int data_stripes; /* number of stripes that count for
+ block group size */
+ int sub_stripes; /* sub_stripes info for map */
+ int dev_stripes; /* stripes per dev */
+ int devs_max; /* max devs to use */
+ int devs_min; /* min devs needed */
+ int devs_increment; /* ndevs has to be a multiple of this */
+ int ncopies; /* how many copies to data has */
+ int ret;
+ u64 max_stripe_size;
+ u64 max_chunk_size;
+ u64 stripe_size;
+ u64 num_bytes;
+ int ndevs;
+ int i;
+ int j;
+ int index;
+
+ BUG_ON(!alloc_profile_is_valid(type, 0));
+
+ if (list_empty(&fs_devices->alloc_list)) {
+ if (btrfs_test_opt(info, ENOSPC_DEBUG))
+ btrfs_debug(info, "%s: no writable device", __func__);
+ return -ENOSPC;
+ }
+
+ index = btrfs_bg_flags_to_raid_index(type);
+
+ sub_stripes = btrfs_raid_array[index].sub_stripes;
+ dev_stripes = btrfs_raid_array[index].dev_stripes;
+ devs_max = btrfs_raid_array[index].devs_max;
+ devs_min = btrfs_raid_array[index].devs_min;
+ devs_increment = btrfs_raid_array[index].devs_increment;
+ ncopies = btrfs_raid_array[index].ncopies;
+
+ if (type & BTRFS_BLOCK_GROUP_DATA) {
+ max_stripe_size = SZ_1G;
+ max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
+ if (!devs_max)
+ devs_max = BTRFS_MAX_DEVS(info);
+ } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
+ /* for larger filesystems, use larger metadata chunks */
+ if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
+ max_stripe_size = SZ_1G;
+ else
+ max_stripe_size = SZ_256M;
+ max_chunk_size = max_stripe_size;
+ if (!devs_max)
+ devs_max = BTRFS_MAX_DEVS(info);
+ } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ max_stripe_size = SZ_32M;
+ max_chunk_size = 2 * max_stripe_size;
+ if (!devs_max)
+ devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;
+ } else {
+ btrfs_err(info, "invalid chunk type 0x%llx requested",
+ type);
+ BUG_ON(1);
+ }
+
+ /* we don't want a chunk larger than 10% of writeable space */
+ max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
+ max_chunk_size);
+
+ devices_info = kcalloc(fs_devices->rw_devices, sizeof(*devices_info),
+ GFP_NOFS);
+ if (!devices_info)
+ return -ENOMEM;
+
+ /*
+ * in the first pass through the devices list, we gather information
+ * about the available holes on each device.
+ */
+ ndevs = 0;
+ list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
+ u64 max_avail;
+ u64 dev_offset;
+
+ if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
+ WARN(1, KERN_ERR
+ "BTRFS: read-only device in alloc_list\n");
+ continue;
+ }
+
+ if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
+ &device->dev_state) ||
+ test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
+ continue;
+
+ if (device->total_bytes > device->bytes_used)
+ total_avail = device->total_bytes - device->bytes_used;
+ else
+ total_avail = 0;
+
+ /* If there is no space on this device, skip it. */
+ if (total_avail == 0)
+ continue;
+
+ ret = find_free_dev_extent(trans, device,
+ max_stripe_size * dev_stripes,
+ &dev_offset, &max_avail);
+ if (ret && ret != -ENOSPC)
+ goto error;
+
+ if (ret == 0)
+ max_avail = max_stripe_size * dev_stripes;
+
+ if (max_avail < BTRFS_STRIPE_LEN * dev_stripes) {
+ if (btrfs_test_opt(info, ENOSPC_DEBUG))
+ btrfs_debug(info,
+ "%s: devid %llu has no free space, have=%llu want=%u",
+ __func__, device->devid, max_avail,
+ BTRFS_STRIPE_LEN * dev_stripes);
+ continue;
+ }
+
+ if (ndevs == fs_devices->rw_devices) {
+ WARN(1, "%s: found more than %llu devices\n",
+ __func__, fs_devices->rw_devices);
+ break;
+ }
+ devices_info[ndevs].dev_offset = dev_offset;
+ devices_info[ndevs].max_avail = max_avail;
+ devices_info[ndevs].total_avail = total_avail;
+ devices_info[ndevs].dev = device;
+ ++ndevs;
+ }
+
+ /*
+ * now sort the devices by hole size / available space
+ */
+ sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
+ btrfs_cmp_device_info, NULL);
+
+ /* round down to number of usable stripes */
+ ndevs = round_down(ndevs, devs_increment);
+
+ if (ndevs < devs_min) {
+ ret = -ENOSPC;
+ if (btrfs_test_opt(info, ENOSPC_DEBUG)) {
+ btrfs_debug(info,
+ "%s: not enough devices with free space: have=%d minimum required=%d",
+ __func__, ndevs, devs_min);
+ }
+ goto error;
+ }
+
+ ndevs = min(ndevs, devs_max);
+
+ /*
+ * The primary goal is to maximize the number of stripes, so use as
+ * many devices as possible, even if the stripes are not maximum sized.
+ *
+ * The DUP profile stores more than one stripe per device, the
+ * max_avail is the total size so we have to adjust.
+ */
+ stripe_size = div_u64(devices_info[ndevs - 1].max_avail, dev_stripes);
+ num_stripes = ndevs * dev_stripes;
+
+ /*
+ * this will have to be fixed for RAID1 and RAID10 over
+ * more drives
+ */
+ data_stripes = num_stripes / ncopies;
+
+ if (type & BTRFS_BLOCK_GROUP_RAID5)
+ data_stripes = num_stripes - 1;
+
+ if (type & BTRFS_BLOCK_GROUP_RAID6)
+ data_stripes = num_stripes - 2;
+
+ /*
+ * Use the number of data stripes to figure out how big this chunk
+ * is really going to be in terms of logical address space,
+ * and compare that answer with the max chunk size
+ */
+ if (stripe_size * data_stripes > max_chunk_size) {
+ stripe_size = div_u64(max_chunk_size, data_stripes);
+
+ /* bump the answer up to a 16MB boundary */
+ stripe_size = round_up(stripe_size, SZ_16M);
+
+ /*
+ * But don't go higher than the limits we found while searching
+ * for free extents
+ */
+ stripe_size = min(devices_info[ndevs - 1].max_avail,
+ stripe_size);
+ }
+
+ /* align to BTRFS_STRIPE_LEN */
+ stripe_size = round_down(stripe_size, BTRFS_STRIPE_LEN);
+
+ map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+ if (!map) {
+ ret = -ENOMEM;
+ goto error;
+ }
+ map->num_stripes = num_stripes;
+
+ for (i = 0; i < ndevs; ++i) {
+ for (j = 0; j < dev_stripes; ++j) {
+ int s = i * dev_stripes + j;
+ map->stripes[s].dev = devices_info[i].dev;
+ map->stripes[s].physical = devices_info[i].dev_offset +
+ j * stripe_size;
+ }
+ }
+ map->stripe_len = BTRFS_STRIPE_LEN;
+ map->io_align = BTRFS_STRIPE_LEN;
+ map->io_width = BTRFS_STRIPE_LEN;
+ map->type = type;
+ map->sub_stripes = sub_stripes;
+
+ num_bytes = stripe_size * data_stripes;
+
+ trace_btrfs_chunk_alloc(info, map, start, num_bytes);
+
+ em = alloc_extent_map();
+ if (!em) {
+ kfree(map);
+ ret = -ENOMEM;
+ goto error;
+ }
+ set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
+ em->map_lookup = map;
+ em->start = start;
+ em->len = num_bytes;
+ em->block_start = 0;
+ em->block_len = em->len;
+ em->orig_block_len = stripe_size;
+
+ em_tree = &info->mapping_tree.map_tree;
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em, 0);
+ if (ret) {
+ write_unlock(&em_tree->lock);
+ free_extent_map(em);
+ goto error;
+ }
+
+ list_add_tail(&em->list, &trans->transaction->pending_chunks);
+ refcount_inc(&em->refs);
+ write_unlock(&em_tree->lock);
+
+ ret = btrfs_make_block_group(trans, 0, type, start, num_bytes);
+ if (ret)
+ goto error_del_extent;
+
+ for (i = 0; i < map->num_stripes; i++) {
+ num_bytes = map->stripes[i].dev->bytes_used + stripe_size;
+ btrfs_device_set_bytes_used(map->stripes[i].dev, num_bytes);
+ }
+
+ atomic64_sub(stripe_size * map->num_stripes, &info->free_chunk_space);
+
+ free_extent_map(em);
+ check_raid56_incompat_flag(info, type);
+
+ kfree(devices_info);
+ return 0;
+
+error_del_extent:
+ write_lock(&em_tree->lock);
+ remove_extent_mapping(em_tree, em);
+ write_unlock(&em_tree->lock);
+
+ /* One for our allocation */
+ free_extent_map(em);
+ /* One for the tree reference */
+ free_extent_map(em);
+ /* One for the pending_chunks list reference */
+ free_extent_map(em);
+error:
+ kfree(devices_info);
+ return ret;
+}
+
+int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
+ u64 chunk_offset, u64 chunk_size)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_root *extent_root = fs_info->extent_root;
+ struct btrfs_root *chunk_root = fs_info->chunk_root;
+ struct btrfs_key key;
+ struct btrfs_device *device;
+ struct btrfs_chunk *chunk;
+ struct btrfs_stripe *stripe;
+ struct extent_map *em;
+ struct map_lookup *map;
+ size_t item_size;
+ u64 dev_offset;
+ u64 stripe_size;
+ int i = 0;
+ int ret = 0;
+
+ em = get_chunk_map(fs_info, chunk_offset, chunk_size);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+
+ map = em->map_lookup;
+ item_size = btrfs_chunk_item_size(map->num_stripes);
+ stripe_size = em->orig_block_len;
+
+ chunk = kzalloc(item_size, GFP_NOFS);
+ if (!chunk) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * Take the device list mutex to prevent races with the final phase of
+ * a device replace operation that replaces the device object associated
+ * with the map's stripes, because the device object's id can change
+ * at any time during that final phase of the device replace operation
+ * (dev-replace.c:btrfs_dev_replace_finishing()).
+ */
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ for (i = 0; i < map->num_stripes; i++) {
+ device = map->stripes[i].dev;
+ dev_offset = map->stripes[i].physical;
+
+ ret = btrfs_update_device(trans, device);
+ if (ret)
+ break;
+ ret = btrfs_alloc_dev_extent(trans, device, chunk_offset,
+ dev_offset, stripe_size);
+ if (ret)
+ break;
+ }
+ if (ret) {
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ goto out;
+ }
+
+ stripe = &chunk->stripe;
+ for (i = 0; i < map->num_stripes; i++) {
+ device = map->stripes[i].dev;
+ dev_offset = map->stripes[i].physical;
+
+ btrfs_set_stack_stripe_devid(stripe, device->devid);
+ btrfs_set_stack_stripe_offset(stripe, dev_offset);
+ memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
+ stripe++;
+ }
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+ btrfs_set_stack_chunk_length(chunk, chunk_size);
+ btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
+ btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
+ btrfs_set_stack_chunk_type(chunk, map->type);
+ btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
+ btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
+ btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
+ btrfs_set_stack_chunk_sector_size(chunk, fs_info->sectorsize);
+ btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+ key.offset = chunk_offset;
+
+ ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
+ if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ /*
+ * TODO: Cleanup of inserted chunk root in case of
+ * failure.
+ */
+ ret = btrfs_add_system_chunk(fs_info, &key, chunk, item_size);
+ }
+
+out:
+ kfree(chunk);
+ free_extent_map(em);
+ return ret;
+}
+
+/*
+ * Chunk allocation falls into two parts. The first part does works
+ * that make the new allocated chunk useable, but not do any operation
+ * that modifies the chunk tree. The second part does the works that
+ * require modifying the chunk tree. This division is important for the
+ * bootstrap process of adding storage to a seed btrfs.
+ */
+int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type)
+{
+ u64 chunk_offset;
+
+ lockdep_assert_held(&trans->fs_info->chunk_mutex);
+ chunk_offset = find_next_chunk(trans->fs_info);
+ return __btrfs_alloc_chunk(trans, chunk_offset, type);
+}
+
+static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ u64 chunk_offset;
+ u64 sys_chunk_offset;
+ u64 alloc_profile;
+ int ret;
+
+ chunk_offset = find_next_chunk(fs_info);
+ alloc_profile = btrfs_metadata_alloc_profile(fs_info);
+ ret = __btrfs_alloc_chunk(trans, chunk_offset, alloc_profile);
+ if (ret)
+ return ret;
+
+ sys_chunk_offset = find_next_chunk(fs_info);
+ alloc_profile = btrfs_system_alloc_profile(fs_info);
+ ret = __btrfs_alloc_chunk(trans, sys_chunk_offset, alloc_profile);
+ return ret;
+}
+
+static inline int btrfs_chunk_max_errors(struct map_lookup *map)
+{
+ int max_errors;
+
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID5 |
+ BTRFS_BLOCK_GROUP_DUP)) {
+ max_errors = 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
+ max_errors = 2;
+ } else {
+ max_errors = 0;
+ }
+
+ return max_errors;
+}
+
+int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ int readonly = 0;
+ int miss_ndevs = 0;
+ int i;
+
+ em = get_chunk_map(fs_info, chunk_offset, 1);
+ if (IS_ERR(em))
+ return 1;
+
+ map = em->map_lookup;
+ for (i = 0; i < map->num_stripes; i++) {
+ if (test_bit(BTRFS_DEV_STATE_MISSING,
+ &map->stripes[i].dev->dev_state)) {
+ miss_ndevs++;
+ continue;
+ }
+ if (!test_bit(BTRFS_DEV_STATE_WRITEABLE,
+ &map->stripes[i].dev->dev_state)) {
+ readonly = 1;
+ goto end;
+ }
+ }
+
+ /*
+ * If the number of missing devices is larger than max errors,
+ * we can not write the data into that chunk successfully, so
+ * set it readonly.
+ */
+ if (miss_ndevs > btrfs_chunk_max_errors(map))
+ readonly = 1;
+end:
+ free_extent_map(em);
+ return readonly;
+}
+
+void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
+{
+ extent_map_tree_init(&tree->map_tree);
+}
+
+void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
+{
+ struct extent_map *em;
+
+ while (1) {
+ write_lock(&tree->map_tree.lock);
+ em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
+ if (em)
+ remove_extent_mapping(&tree->map_tree, em);
+ write_unlock(&tree->map_tree.lock);
+ if (!em)
+ break;
+ /* once for us */
+ free_extent_map(em);
+ /* once for the tree */
+ free_extent_map(em);
+ }
+}
+
+int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ int ret;
+
+ em = get_chunk_map(fs_info, logical, len);
+ if (IS_ERR(em))
+ /*
+ * We could return errors for these cases, but that could get
+ * ugly and we'd probably do the same thing which is just not do
+ * anything else and exit, so return 1 so the callers don't try
+ * to use other copies.
+ */
+ return 1;
+
+ map = em->map_lookup;
+ if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
+ ret = map->num_stripes;
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
+ ret = map->sub_stripes;
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
+ ret = 2;
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+ /*
+ * There could be two corrupted data stripes, we need
+ * to loop retry in order to rebuild the correct data.
+ *
+ * Fail a stripe at a time on every retry except the
+ * stripe under reconstruction.
+ */
+ ret = map->num_stripes;
+ else
+ ret = 1;
+ free_extent_map(em);
+
+ btrfs_dev_replace_read_lock(&fs_info->dev_replace);
+ if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) &&
+ fs_info->dev_replace.tgtdev)
+ ret++;
+ btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+
+ return ret;
+}
+
+unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
+ u64 logical)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ unsigned long len = fs_info->sectorsize;
+
+ em = get_chunk_map(fs_info, logical, len);
+
+ if (!WARN_ON(IS_ERR(em))) {
+ map = em->map_lookup;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
+ len = map->stripe_len * nr_data_stripes(map);
+ free_extent_map(em);
+ }
+ return len;
+}
+
+int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ int ret = 0;
+
+ em = get_chunk_map(fs_info, logical, len);
+
+ if(!WARN_ON(IS_ERR(em))) {
+ map = em->map_lookup;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
+ ret = 1;
+ free_extent_map(em);
+ }
+ return ret;
+}
+
+static int find_live_mirror(struct btrfs_fs_info *fs_info,
+ struct map_lookup *map, int first,
+ int dev_replace_is_ongoing)
+{
+ int i;
+ int num_stripes;
+ int preferred_mirror;
+ int tolerance;
+ struct btrfs_device *srcdev;
+
+ ASSERT((map->type &
+ (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)));
+
+ if (map->type & BTRFS_BLOCK_GROUP_RAID10)
+ num_stripes = map->sub_stripes;
+ else
+ num_stripes = map->num_stripes;
+
+ preferred_mirror = first + current->pid % num_stripes;
+
+ if (dev_replace_is_ongoing &&
+ fs_info->dev_replace.cont_reading_from_srcdev_mode ==
+ BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
+ srcdev = fs_info->dev_replace.srcdev;
+ else
+ srcdev = NULL;
+
+ /*
+ * try to avoid the drive that is the source drive for a
+ * dev-replace procedure, only choose it if no other non-missing
+ * mirror is available
+ */
+ for (tolerance = 0; tolerance < 2; tolerance++) {
+ if (map->stripes[preferred_mirror].dev->bdev &&
+ (tolerance || map->stripes[preferred_mirror].dev != srcdev))
+ return preferred_mirror;
+ for (i = first; i < first + num_stripes; i++) {
+ if (map->stripes[i].dev->bdev &&
+ (tolerance || map->stripes[i].dev != srcdev))
+ return i;
+ }
+ }
+
+ /* we couldn't find one that doesn't fail. Just return something
+ * and the io error handling code will clean up eventually
+ */
+ return preferred_mirror;
+}
+
+static inline int parity_smaller(u64 a, u64 b)
+{
+ return a > b;
+}
+
+/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
+static void sort_parity_stripes(struct btrfs_bio *bbio, int num_stripes)
+{
+ struct btrfs_bio_stripe s;
+ int i;
+ u64 l;
+ int again = 1;
+
+ while (again) {
+ again = 0;
+ for (i = 0; i < num_stripes - 1; i++) {
+ if (parity_smaller(bbio->raid_map[i],
+ bbio->raid_map[i+1])) {
+ s = bbio->stripes[i];
+ l = bbio->raid_map[i];
+ bbio->stripes[i] = bbio->stripes[i+1];
+ bbio->raid_map[i] = bbio->raid_map[i+1];
+ bbio->stripes[i+1] = s;
+ bbio->raid_map[i+1] = l;
+
+ again = 1;
+ }
+ }
+ }
+}
+
+static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes)
+{
+ struct btrfs_bio *bbio = kzalloc(
+ /* the size of the btrfs_bio */
+ sizeof(struct btrfs_bio) +
+ /* plus the variable array for the stripes */
+ sizeof(struct btrfs_bio_stripe) * (total_stripes) +
+ /* plus the variable array for the tgt dev */
+ sizeof(int) * (real_stripes) +
+ /*
+ * plus the raid_map, which includes both the tgt dev
+ * and the stripes
+ */
+ sizeof(u64) * (total_stripes),
+ GFP_NOFS|__GFP_NOFAIL);
+
+ atomic_set(&bbio->error, 0);
+ refcount_set(&bbio->refs, 1);
+
+ return bbio;
+}
+
+void btrfs_get_bbio(struct btrfs_bio *bbio)
+{
+ WARN_ON(!refcount_read(&bbio->refs));
+ refcount_inc(&bbio->refs);
+}
+
+void btrfs_put_bbio(struct btrfs_bio *bbio)
+{
+ if (!bbio)
+ return;
+ if (refcount_dec_and_test(&bbio->refs))
+ kfree(bbio);
+}
+
+/* can REQ_OP_DISCARD be sent with other REQ like REQ_OP_WRITE? */
+/*
+ * Please note that, discard won't be sent to target device of device
+ * replace.
+ */
+static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info,
+ u64 logical, u64 length,
+ struct btrfs_bio **bbio_ret)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ struct btrfs_bio *bbio;
+ u64 offset;
+ u64 stripe_nr;
+ u64 stripe_nr_end;
+ u64 stripe_end_offset;
+ u64 stripe_cnt;
+ u64 stripe_len;
+ u64 stripe_offset;
+ u64 num_stripes;
+ u32 stripe_index;
+ u32 factor = 0;
+ u32 sub_stripes = 0;
+ u64 stripes_per_dev = 0;
+ u32 remaining_stripes = 0;
+ u32 last_stripe = 0;
+ int ret = 0;
+ int i;
+
+ /* discard always return a bbio */
+ ASSERT(bbio_ret);
+
+ em = get_chunk_map(fs_info, logical, length);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+
+ map = em->map_lookup;
+ /* we don't discard raid56 yet */
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ offset = logical - em->start;
+ length = min_t(u64, em->len - offset, length);
+
+ stripe_len = map->stripe_len;
+ /*
+ * stripe_nr counts the total number of stripes we have to stride
+ * to get to this block
+ */
+ stripe_nr = div64_u64(offset, stripe_len);
+
+ /* stripe_offset is the offset of this block in its stripe */
+ stripe_offset = offset - stripe_nr * stripe_len;
+
+ stripe_nr_end = round_up(offset + length, map->stripe_len);
+ stripe_nr_end = div64_u64(stripe_nr_end, map->stripe_len);
+ stripe_cnt = stripe_nr_end - stripe_nr;
+ stripe_end_offset = stripe_nr_end * map->stripe_len -
+ (offset + length);
+ /*
+ * after this, stripe_nr is the number of stripes on this
+ * device we have to walk to find the data, and stripe_index is
+ * the number of our device in the stripe array
+ */
+ num_stripes = 1;
+ stripe_index = 0;
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID10)) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID0)
+ sub_stripes = 1;
+ else
+ sub_stripes = map->sub_stripes;
+
+ factor = map->num_stripes / sub_stripes;
+ num_stripes = min_t(u64, map->num_stripes,
+ sub_stripes * stripe_cnt);
+ stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
+ stripe_index *= sub_stripes;
+ stripes_per_dev = div_u64_rem(stripe_cnt, factor,
+ &remaining_stripes);
+ div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
+ last_stripe *= sub_stripes;
+ } else if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_DUP)) {
+ num_stripes = map->num_stripes;
+ } else {
+ stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
+ &stripe_index);
+ }
+
+ bbio = alloc_btrfs_bio(num_stripes, 0);
+ if (!bbio) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ for (i = 0; i < num_stripes; i++) {
+ bbio->stripes[i].physical =
+ map->stripes[stripe_index].physical +
+ stripe_offset + stripe_nr * map->stripe_len;
+ bbio->stripes[i].dev = map->stripes[stripe_index].dev;
+
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID10)) {
+ bbio->stripes[i].length = stripes_per_dev *
+ map->stripe_len;
+
+ if (i / sub_stripes < remaining_stripes)
+ bbio->stripes[i].length +=
+ map->stripe_len;
+
+ /*
+ * Special for the first stripe and
+ * the last stripe:
+ *
+ * |-------|...|-------|
+ * |----------|
+ * off end_off
+ */
+ if (i < sub_stripes)
+ bbio->stripes[i].length -=
+ stripe_offset;
+
+ if (stripe_index >= last_stripe &&
+ stripe_index <= (last_stripe +
+ sub_stripes - 1))
+ bbio->stripes[i].length -=
+ stripe_end_offset;
+
+ if (i == sub_stripes - 1)
+ stripe_offset = 0;
+ } else {
+ bbio->stripes[i].length = length;
+ }
+
+ stripe_index++;
+ if (stripe_index == map->num_stripes) {
+ stripe_index = 0;
+ stripe_nr++;
+ }
+ }
+
+ *bbio_ret = bbio;
+ bbio->map_type = map->type;
+ bbio->num_stripes = num_stripes;
+out:
+ free_extent_map(em);
+ return ret;
+}
+
+/*
+ * In dev-replace case, for repair case (that's the only case where the mirror
+ * is selected explicitly when calling btrfs_map_block), blocks left of the
+ * left cursor can also be read from the target drive.
+ *
+ * For REQ_GET_READ_MIRRORS, the target drive is added as the last one to the
+ * array of stripes.
+ * For READ, it also needs to be supported using the same mirror number.
+ *
+ * If the requested block is not left of the left cursor, EIO is returned. This
+ * can happen because btrfs_num_copies() returns one more in the dev-replace
+ * case.
+ */
+static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info,
+ u64 logical, u64 length,
+ u64 srcdev_devid, int *mirror_num,
+ u64 *physical)
+{
+ struct btrfs_bio *bbio = NULL;
+ int num_stripes;
+ int index_srcdev = 0;
+ int found = 0;
+ u64 physical_of_found = 0;
+ int i;
+ int ret = 0;
+
+ ret = __btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
+ logical, &length, &bbio, 0, 0);
+ if (ret) {
+ ASSERT(bbio == NULL);
+ return ret;
+ }
+
+ num_stripes = bbio->num_stripes;
+ if (*mirror_num > num_stripes) {
+ /*
+ * BTRFS_MAP_GET_READ_MIRRORS does not contain this mirror,
+ * that means that the requested area is not left of the left
+ * cursor
+ */
+ btrfs_put_bbio(bbio);
+ return -EIO;
+ }
+
+ /*
+ * process the rest of the function using the mirror_num of the source
+ * drive. Therefore look it up first. At the end, patch the device
+ * pointer to the one of the target drive.
+ */
+ for (i = 0; i < num_stripes; i++) {
+ if (bbio->stripes[i].dev->devid != srcdev_devid)
+ continue;
+
+ /*
+ * In case of DUP, in order to keep it simple, only add the
+ * mirror with the lowest physical address
+ */
+ if (found &&
+ physical_of_found <= bbio->stripes[i].physical)
+ continue;
+
+ index_srcdev = i;
+ found = 1;
+ physical_of_found = bbio->stripes[i].physical;
+ }
+
+ btrfs_put_bbio(bbio);
+
+ ASSERT(found);
+ if (!found)
+ return -EIO;
+
+ *mirror_num = index_srcdev + 1;
+ *physical = physical_of_found;
+ return ret;
+}
+
+static void handle_ops_on_dev_replace(enum btrfs_map_op op,
+ struct btrfs_bio **bbio_ret,
+ struct btrfs_dev_replace *dev_replace,
+ int *num_stripes_ret, int *max_errors_ret)
+{
+ struct btrfs_bio *bbio = *bbio_ret;
+ u64 srcdev_devid = dev_replace->srcdev->devid;
+ int tgtdev_indexes = 0;
+ int num_stripes = *num_stripes_ret;
+ int max_errors = *max_errors_ret;
+ int i;
+
+ if (op == BTRFS_MAP_WRITE) {
+ int index_where_to_add;
+
+ /*
+ * duplicate the write operations while the dev replace
+ * procedure is running. Since the copying of the old disk to
+ * the new disk takes place at run time while the filesystem is
+ * mounted writable, the regular write operations to the old
+ * disk have to be duplicated to go to the new disk as well.
+ *
+ * Note that device->missing is handled by the caller, and that
+ * the write to the old disk is already set up in the stripes
+ * array.
+ */
+ index_where_to_add = num_stripes;
+ for (i = 0; i < num_stripes; i++) {
+ if (bbio->stripes[i].dev->devid == srcdev_devid) {
+ /* write to new disk, too */
+ struct btrfs_bio_stripe *new =
+ bbio->stripes + index_where_to_add;
+ struct btrfs_bio_stripe *old =
+ bbio->stripes + i;
+
+ new->physical = old->physical;
+ new->length = old->length;
+ new->dev = dev_replace->tgtdev;
+ bbio->tgtdev_map[i] = index_where_to_add;
+ index_where_to_add++;
+ max_errors++;
+ tgtdev_indexes++;
+ }
+ }
+ num_stripes = index_where_to_add;
+ } else if (op == BTRFS_MAP_GET_READ_MIRRORS) {
+ int index_srcdev = 0;
+ int found = 0;
+ u64 physical_of_found = 0;
+
+ /*
+ * During the dev-replace procedure, the target drive can also
+ * be used to read data in case it is needed to repair a corrupt
+ * block elsewhere. This is possible if the requested area is
+ * left of the left cursor. In this area, the target drive is a
+ * full copy of the source drive.
+ */
+ for (i = 0; i < num_stripes; i++) {
+ if (bbio->stripes[i].dev->devid == srcdev_devid) {
+ /*
+ * In case of DUP, in order to keep it simple,
+ * only add the mirror with the lowest physical
+ * address
+ */
+ if (found &&
+ physical_of_found <=
+ bbio->stripes[i].physical)
+ continue;
+ index_srcdev = i;
+ found = 1;
+ physical_of_found = bbio->stripes[i].physical;
+ }
+ }
+ if (found) {
+ struct btrfs_bio_stripe *tgtdev_stripe =
+ bbio->stripes + num_stripes;
+
+ tgtdev_stripe->physical = physical_of_found;
+ tgtdev_stripe->length =
+ bbio->stripes[index_srcdev].length;
+ tgtdev_stripe->dev = dev_replace->tgtdev;
+ bbio->tgtdev_map[index_srcdev] = num_stripes;
+
+ tgtdev_indexes++;
+ num_stripes++;
+ }
+ }
+
+ *num_stripes_ret = num_stripes;
+ *max_errors_ret = max_errors;
+ bbio->num_tgtdevs = tgtdev_indexes;
+ *bbio_ret = bbio;
+}
+
+static bool need_full_stripe(enum btrfs_map_op op)
+{
+ return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS);
+}
+
+static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
+ enum btrfs_map_op op,
+ u64 logical, u64 *length,
+ struct btrfs_bio **bbio_ret,
+ int mirror_num, int need_raid_map)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ u64 offset;
+ u64 stripe_offset;
+ u64 stripe_nr;
+ u64 stripe_len;
+ u32 stripe_index;
+ int i;
+ int ret = 0;
+ int num_stripes;
+ int max_errors = 0;
+ int tgtdev_indexes = 0;
+ struct btrfs_bio *bbio = NULL;
+ struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
+ int dev_replace_is_ongoing = 0;
+ int num_alloc_stripes;
+ int patch_the_first_stripe_for_dev_replace = 0;
+ u64 physical_to_patch_in_first_stripe = 0;
+ u64 raid56_full_stripe_start = (u64)-1;
+
+ if (op == BTRFS_MAP_DISCARD)
+ return __btrfs_map_block_for_discard(fs_info, logical,
+ *length, bbio_ret);
+
+ em = get_chunk_map(fs_info, logical, *length);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+
+ map = em->map_lookup;
+ offset = logical - em->start;
+
+ stripe_len = map->stripe_len;
+ stripe_nr = offset;
+ /*
+ * stripe_nr counts the total number of stripes we have to stride
+ * to get to this block
+ */
+ stripe_nr = div64_u64(stripe_nr, stripe_len);
+
+ stripe_offset = stripe_nr * stripe_len;
+ if (offset < stripe_offset) {
+ btrfs_crit(fs_info,
+ "stripe math has gone wrong, stripe_offset=%llu, offset=%llu, start=%llu, logical=%llu, stripe_len=%llu",
+ stripe_offset, offset, em->start, logical,
+ stripe_len);
+ free_extent_map(em);
+ return -EINVAL;
+ }
+
+ /* stripe_offset is the offset of this block in its stripe*/
+ stripe_offset = offset - stripe_offset;
+
+ /* if we're here for raid56, we need to know the stripe aligned start */
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
+ raid56_full_stripe_start = offset;
+
+ /* allow a write of a full stripe, but make sure we don't
+ * allow straddling of stripes
+ */
+ raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
+ full_stripe_len);
+ raid56_full_stripe_start *= full_stripe_len;
+ }
+
+ if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+ u64 max_len;
+ /* For writes to RAID[56], allow a full stripeset across all disks.
+ For other RAID types and for RAID[56] reads, just allow a single
+ stripe (on a single disk). */
+ if ((map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
+ (op == BTRFS_MAP_WRITE)) {
+ max_len = stripe_len * nr_data_stripes(map) -
+ (offset - raid56_full_stripe_start);
+ } else {
+ /* we limit the length of each bio to what fits in a stripe */
+ max_len = stripe_len - stripe_offset;
+ }
+ *length = min_t(u64, em->len - offset, max_len);
+ } else {
+ *length = em->len - offset;
+ }
+
+ /* This is for when we're called from btrfs_merge_bio_hook() and all
+ it cares about is the length */
+ if (!bbio_ret)
+ goto out;
+
+ btrfs_dev_replace_read_lock(dev_replace);
+ dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
+ if (!dev_replace_is_ongoing)
+ btrfs_dev_replace_read_unlock(dev_replace);
+ else
+ btrfs_dev_replace_set_lock_blocking(dev_replace);
+
+ if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
+ !need_full_stripe(op) && dev_replace->tgtdev != NULL) {
+ ret = get_extra_mirror_from_replace(fs_info, logical, *length,
+ dev_replace->srcdev->devid,
+ &mirror_num,
+ &physical_to_patch_in_first_stripe);
+ if (ret)
+ goto out;
+ else
+ patch_the_first_stripe_for_dev_replace = 1;
+ } else if (mirror_num > map->num_stripes) {
+ mirror_num = 0;
+ }
+
+ num_stripes = 1;
+ stripe_index = 0;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
+ stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
+ &stripe_index);
+ if (!need_full_stripe(op))
+ mirror_num = 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
+ if (need_full_stripe(op))
+ num_stripes = map->num_stripes;
+ else if (mirror_num)
+ stripe_index = mirror_num - 1;
+ else {
+ stripe_index = find_live_mirror(fs_info, map, 0,
+ dev_replace_is_ongoing);
+ mirror_num = stripe_index + 1;
+ }
+
+ } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
+ if (need_full_stripe(op)) {
+ num_stripes = map->num_stripes;
+ } else if (mirror_num) {
+ stripe_index = mirror_num - 1;
+ } else {
+ mirror_num = 1;
+ }
+
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+ u32 factor = map->num_stripes / map->sub_stripes;
+
+ stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
+ stripe_index *= map->sub_stripes;
+
+ if (need_full_stripe(op))
+ num_stripes = map->sub_stripes;
+ else if (mirror_num)
+ stripe_index += mirror_num - 1;
+ else {
+ int old_stripe_index = stripe_index;
+ stripe_index = find_live_mirror(fs_info, map,
+ stripe_index,
+ dev_replace_is_ongoing);
+ mirror_num = stripe_index - old_stripe_index + 1;
+ }
+
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
+ /* push stripe_nr back to the start of the full stripe */
+ stripe_nr = div64_u64(raid56_full_stripe_start,
+ stripe_len * nr_data_stripes(map));
+
+ /* RAID[56] write or recovery. Return all stripes */
+ num_stripes = map->num_stripes;
+ max_errors = nr_parity_stripes(map);
+
+ *length = map->stripe_len;
+ stripe_index = 0;
+ stripe_offset = 0;
+ } else {
+ /*
+ * Mirror #0 or #1 means the original data block.
+ * Mirror #2 is RAID5 parity block.
+ * Mirror #3 is RAID6 Q block.
+ */
+ stripe_nr = div_u64_rem(stripe_nr,
+ nr_data_stripes(map), &stripe_index);
+ if (mirror_num > 1)
+ stripe_index = nr_data_stripes(map) +
+ mirror_num - 2;
+
+ /* We distribute the parity blocks across stripes */
+ div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
+ &stripe_index);
+ if (!need_full_stripe(op) && mirror_num <= 1)
+ mirror_num = 1;
+ }
+ } else {
+ /*
+ * after this, stripe_nr is the number of stripes on this
+ * device we have to walk to find the data, and stripe_index is
+ * the number of our device in the stripe array
+ */
+ stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
+ &stripe_index);
+ mirror_num = stripe_index + 1;
+ }
+ if (stripe_index >= map->num_stripes) {
+ btrfs_crit(fs_info,
+ "stripe index math went horribly wrong, got stripe_index=%u, num_stripes=%u",
+ stripe_index, map->num_stripes);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ num_alloc_stripes = num_stripes;
+ if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL) {
+ if (op == BTRFS_MAP_WRITE)
+ num_alloc_stripes <<= 1;
+ if (op == BTRFS_MAP_GET_READ_MIRRORS)
+ num_alloc_stripes++;
+ tgtdev_indexes = num_stripes;
+ }
+
+ bbio = alloc_btrfs_bio(num_alloc_stripes, tgtdev_indexes);
+ if (!bbio) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
+ bbio->tgtdev_map = (int *)(bbio->stripes + num_alloc_stripes);
+
+ /* build raid_map */
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map &&
+ (need_full_stripe(op) || mirror_num > 1)) {
+ u64 tmp;
+ unsigned rot;
+
+ bbio->raid_map = (u64 *)((void *)bbio->stripes +
+ sizeof(struct btrfs_bio_stripe) *
+ num_alloc_stripes +
+ sizeof(int) * tgtdev_indexes);
+
+ /* Work out the disk rotation on this stripe-set */
+ div_u64_rem(stripe_nr, num_stripes, &rot);
+
+ /* Fill in the logical address of each stripe */
+ tmp = stripe_nr * nr_data_stripes(map);
+ for (i = 0; i < nr_data_stripes(map); i++)
+ bbio->raid_map[(i+rot) % num_stripes] =
+ em->start + (tmp + i) * map->stripe_len;
+
+ bbio->raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+ bbio->raid_map[(i+rot+1) % num_stripes] =
+ RAID6_Q_STRIPE;
+ }
+
+
+ for (i = 0; i < num_stripes; i++) {
+ bbio->stripes[i].physical =
+ map->stripes[stripe_index].physical +
+ stripe_offset +
+ stripe_nr * map->stripe_len;
+ bbio->stripes[i].dev =
+ map->stripes[stripe_index].dev;
+ stripe_index++;
+ }
+
+ if (need_full_stripe(op))
+ max_errors = btrfs_chunk_max_errors(map);
+
+ if (bbio->raid_map)
+ sort_parity_stripes(bbio, num_stripes);
+
+ if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
+ need_full_stripe(op)) {
+ handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes,
+ &max_errors);
+ }
+
+ *bbio_ret = bbio;
+ bbio->map_type = map->type;
+ bbio->num_stripes = num_stripes;
+ bbio->max_errors = max_errors;
+ bbio->mirror_num = mirror_num;
+
+ /*
+ * this is the case that REQ_READ && dev_replace_is_ongoing &&
+ * mirror_num == num_stripes + 1 && dev_replace target drive is
+ * available as a mirror
+ */
+ if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
+ WARN_ON(num_stripes > 1);
+ bbio->stripes[0].dev = dev_replace->tgtdev;
+ bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
+ bbio->mirror_num = map->num_stripes + 1;
+ }
+out:
+ if (dev_replace_is_ongoing) {
+ btrfs_dev_replace_clear_lock_blocking(dev_replace);
+ btrfs_dev_replace_read_unlock(dev_replace);
+ }
+ free_extent_map(em);
+ return ret;
+}
+
+int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
+ u64 logical, u64 *length,
+ struct btrfs_bio **bbio_ret, int mirror_num)
+{
+ return __btrfs_map_block(fs_info, op, logical, length, bbio_ret,
+ mirror_num, 0);
+}
+
+/* For Scrub/replace */
+int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
+ u64 logical, u64 *length,
+ struct btrfs_bio **bbio_ret)
+{
+ return __btrfs_map_block(fs_info, op, logical, length, bbio_ret, 0, 1);
+}
+
+int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
+ u64 physical, u64 **logical, int *naddrs, int *stripe_len)
+{
+ struct extent_map *em;
+ struct map_lookup *map;
+ u64 *buf;
+ u64 bytenr;
+ u64 length;
+ u64 stripe_nr;
+ u64 rmap_len;
+ int i, j, nr = 0;
+
+ em = get_chunk_map(fs_info, chunk_start, 1);
+ if (IS_ERR(em))
+ return -EIO;
+
+ map = em->map_lookup;
+ length = em->len;
+ rmap_len = map->stripe_len;
+
+ if (map->type & BTRFS_BLOCK_GROUP_RAID10)
+ length = div_u64(length, map->num_stripes / map->sub_stripes);
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
+ length = div_u64(length, map->num_stripes);
+ else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ length = div_u64(length, nr_data_stripes(map));
+ rmap_len = map->stripe_len * nr_data_stripes(map);
+ }
+
+ buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS);
+ BUG_ON(!buf); /* -ENOMEM */
+
+ for (i = 0; i < map->num_stripes; i++) {
+ if (map->stripes[i].physical > physical ||
+ map->stripes[i].physical + length <= physical)
+ continue;
+
+ stripe_nr = physical - map->stripes[i].physical;
+ stripe_nr = div64_u64(stripe_nr, map->stripe_len);
+
+ if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+ stripe_nr = stripe_nr * map->num_stripes + i;
+ stripe_nr = div_u64(stripe_nr, map->sub_stripes);
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
+ stripe_nr = stripe_nr * map->num_stripes + i;
+ } /* else if RAID[56], multiply by nr_data_stripes().
+ * Alternatively, just use rmap_len below instead of
+ * map->stripe_len */
+
+ bytenr = chunk_start + stripe_nr * rmap_len;
+ WARN_ON(nr >= map->num_stripes);
+ for (j = 0; j < nr; j++) {
+ if (buf[j] == bytenr)
+ break;
+ }
+ if (j == nr) {
+ WARN_ON(nr >= map->num_stripes);
+ buf[nr++] = bytenr;
+ }
+ }
+
+ *logical = buf;
+ *naddrs = nr;
+ *stripe_len = rmap_len;
+
+ free_extent_map(em);
+ return 0;
+}
+
+static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio)
+{
+ bio->bi_private = bbio->private;
+ bio->bi_end_io = bbio->end_io;
+ bio_endio(bio);
+
+ btrfs_put_bbio(bbio);
+}
+
+static void btrfs_end_bio(struct bio *bio)
+{
+ struct btrfs_bio *bbio = bio->bi_private;
+ int is_orig_bio = 0;
+
+ if (bio->bi_status) {
+ atomic_inc(&bbio->error);
+ if (bio->bi_status == BLK_STS_IOERR ||
+ bio->bi_status == BLK_STS_TARGET) {
+ unsigned int stripe_index =
+ btrfs_io_bio(bio)->stripe_index;
+ struct btrfs_device *dev;
+
+ BUG_ON(stripe_index >= bbio->num_stripes);
+ dev = bbio->stripes[stripe_index].dev;
+ if (dev->bdev) {
+ if (bio_op(bio) == REQ_OP_WRITE)
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_WRITE_ERRS);
+ else
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_READ_ERRS);
+ if (bio->bi_opf & REQ_PREFLUSH)
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_FLUSH_ERRS);
+ }
+ }
+ }
+
+ if (bio == bbio->orig_bio)
+ is_orig_bio = 1;
+
+ btrfs_bio_counter_dec(bbio->fs_info);
+
+ if (atomic_dec_and_test(&bbio->stripes_pending)) {
+ if (!is_orig_bio) {
+ bio_put(bio);
+ bio = bbio->orig_bio;
+ }
+
+ btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
+ /* only send an error to the higher layers if it is
+ * beyond the tolerance of the btrfs bio
+ */
+ if (atomic_read(&bbio->error) > bbio->max_errors) {
+ bio->bi_status = BLK_STS_IOERR;
+ } else {
+ /*
+ * this bio is actually up to date, we didn't
+ * go over the max number of errors
+ */
+ bio->bi_status = BLK_STS_OK;
+ }
+
+ btrfs_end_bbio(bbio, bio);
+ } else if (!is_orig_bio) {
+ bio_put(bio);
+ }
+}
+
+/*
+ * see run_scheduled_bios for a description of why bios are collected for
+ * async submit.
+ *
+ * This will add one bio to the pending list for a device and make sure
+ * the work struct is scheduled.
+ */
+static noinline void btrfs_schedule_bio(struct btrfs_device *device,
+ struct bio *bio)
+{
+ struct btrfs_fs_info *fs_info = device->fs_info;
+ int should_queue = 1;
+ struct btrfs_pending_bios *pending_bios;
+
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state) ||
+ !device->bdev) {
+ bio_io_error(bio);
+ return;
+ }
+
+ /* don't bother with additional async steps for reads, right now */
+ if (bio_op(bio) == REQ_OP_READ) {
+ btrfsic_submit_bio(bio);
+ return;
+ }
+
+ WARN_ON(bio->bi_next);
+ bio->bi_next = NULL;
+
+ spin_lock(&device->io_lock);
+ if (op_is_sync(bio->bi_opf))
+ pending_bios = &device->pending_sync_bios;
+ else
+ pending_bios = &device->pending_bios;
+
+ if (pending_bios->tail)
+ pending_bios->tail->bi_next = bio;
+
+ pending_bios->tail = bio;
+ if (!pending_bios->head)
+ pending_bios->head = bio;
+ if (device->running_pending)
+ should_queue = 0;
+
+ spin_unlock(&device->io_lock);
+
+ if (should_queue)
+ btrfs_queue_work(fs_info->submit_workers, &device->work);
+}
+
+static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
+ u64 physical, int dev_nr, int async)
+{
+ struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
+ struct btrfs_fs_info *fs_info = bbio->fs_info;
+
+ bio->bi_private = bbio;
+ btrfs_io_bio(bio)->stripe_index = dev_nr;
+ bio->bi_end_io = btrfs_end_bio;
+ bio->bi_iter.bi_sector = physical >> 9;
+ btrfs_debug_in_rcu(fs_info,
+ "btrfs_map_bio: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
+ bio_op(bio), bio->bi_opf, (u64)bio->bi_iter.bi_sector,
+ (u_long)dev->bdev->bd_dev, rcu_str_deref(dev->name), dev->devid,
+ bio->bi_iter.bi_size);
+ bio_set_dev(bio, dev->bdev);
+
+ btrfs_bio_counter_inc_noblocked(fs_info);
+
+ if (async)
+ btrfs_schedule_bio(dev, bio);
+ else
+ btrfsic_submit_bio(bio);
+}
+
+static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
+{
+ atomic_inc(&bbio->error);
+ if (atomic_dec_and_test(&bbio->stripes_pending)) {
+ /* Should be the original bio. */
+ WARN_ON(bio != bbio->orig_bio);
+
+ btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
+ bio->bi_iter.bi_sector = logical >> 9;
+ if (atomic_read(&bbio->error) > bbio->max_errors)
+ bio->bi_status = BLK_STS_IOERR;
+ else
+ bio->bi_status = BLK_STS_OK;
+ btrfs_end_bbio(bbio, bio);
+ }
+}
+
+blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
+ int mirror_num, int async_submit)
+{
+ struct btrfs_device *dev;
+ struct bio *first_bio = bio;
+ u64 logical = (u64)bio->bi_iter.bi_sector << 9;
+ u64 length = 0;
+ u64 map_length;
+ int ret;
+ int dev_nr;
+ int total_devs;
+ struct btrfs_bio *bbio = NULL;
+
+ length = bio->bi_iter.bi_size;
+ map_length = length;
+
+ btrfs_bio_counter_inc_blocked(fs_info);
+ ret = __btrfs_map_block(fs_info, btrfs_op(bio), logical,
+ &map_length, &bbio, mirror_num, 1);
+ if (ret) {
+ btrfs_bio_counter_dec(fs_info);
+ return errno_to_blk_status(ret);
+ }
+
+ total_devs = bbio->num_stripes;
+ bbio->orig_bio = first_bio;
+ bbio->private = first_bio->bi_private;
+ bbio->end_io = first_bio->bi_end_io;
+ bbio->fs_info = fs_info;
+ atomic_set(&bbio->stripes_pending, bbio->num_stripes);
+
+ if ((bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
+ ((bio_op(bio) == REQ_OP_WRITE) || (mirror_num > 1))) {
+ /* In this case, map_length has been set to the length of
+ a single stripe; not the whole write */
+ if (bio_op(bio) == REQ_OP_WRITE) {
+ ret = raid56_parity_write(fs_info, bio, bbio,
+ map_length);
+ } else {
+ ret = raid56_parity_recover(fs_info, bio, bbio,
+ map_length, mirror_num, 1);
+ }
+
+ btrfs_bio_counter_dec(fs_info);
+ return errno_to_blk_status(ret);
+ }
+
+ if (map_length < length) {
+ btrfs_crit(fs_info,
+ "mapping failed logical %llu bio len %llu len %llu",
+ logical, length, map_length);
+ BUG();
+ }
+
+ for (dev_nr = 0; dev_nr < total_devs; dev_nr++) {
+ dev = bbio->stripes[dev_nr].dev;
+ if (!dev || !dev->bdev ||
+ (bio_op(first_bio) == REQ_OP_WRITE &&
+ !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
+ bbio_error(bbio, first_bio, logical);
+ continue;
+ }
+
+ if (dev_nr < total_devs - 1)
+ bio = btrfs_bio_clone(first_bio);
+ else
+ bio = first_bio;
+
+ submit_stripe_bio(bbio, bio, bbio->stripes[dev_nr].physical,
+ dev_nr, async_submit);
+ }
+ btrfs_bio_counter_dec(fs_info);
+ return BLK_STS_OK;
+}
+
+struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
+ u8 *uuid, u8 *fsid)
+{
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *cur_devices;
+
+ cur_devices = fs_info->fs_devices;
+ while (cur_devices) {
+ if (!fsid ||
+ !memcmp(cur_devices->fsid, fsid, BTRFS_FSID_SIZE)) {
+ device = find_device(cur_devices, devid, uuid);
+ if (device)
+ return device;
+ }
+ cur_devices = cur_devices->seed;
+ }
+ return NULL;
+}
+
+static struct btrfs_device *add_missing_dev(struct btrfs_fs_devices *fs_devices,
+ u64 devid, u8 *dev_uuid)
+{
+ struct btrfs_device *device;
+
+ device = btrfs_alloc_device(NULL, &devid, dev_uuid);
+ if (IS_ERR(device))
+ return device;
+
+ list_add(&device->dev_list, &fs_devices->devices);
+ device->fs_devices = fs_devices;
+ fs_devices->num_devices++;
+
+ set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
+ fs_devices->missing_devices++;
+
+ return device;
+}
+
+/**
+ * btrfs_alloc_device - allocate struct btrfs_device
+ * @fs_info: used only for generating a new devid, can be NULL if
+ * devid is provided (i.e. @devid != NULL).
+ * @devid: a pointer to devid for this device. If NULL a new devid
+ * is generated.
+ * @uuid: a pointer to UUID for this device. If NULL a new UUID
+ * is generated.
+ *
+ * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
+ * on error. Returned struct is not linked onto any lists and must be
+ * destroyed with btrfs_free_device.
+ */
+struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
+ const u64 *devid,
+ const u8 *uuid)
+{
+ struct btrfs_device *dev;
+ u64 tmp;
+
+ if (WARN_ON(!devid && !fs_info))
+ return ERR_PTR(-EINVAL);
+
+ dev = __alloc_device();
+ if (IS_ERR(dev))
+ return dev;
+
+ if (devid)
+ tmp = *devid;
+ else {
+ int ret;
+
+ ret = find_next_devid(fs_info, &tmp);
+ if (ret) {
+ btrfs_free_device(dev);
+ return ERR_PTR(ret);
+ }
+ }
+ dev->devid = tmp;
+
+ if (uuid)
+ memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
+ else
+ generate_random_uuid(dev->uuid);
+
+ btrfs_init_work(&dev->work, btrfs_submit_helper,
+ pending_bios_fn, NULL, NULL);
+
+ return dev;
+}
+
+/* Return -EIO if any error, otherwise return 0. */
+static int btrfs_check_chunk_valid(struct btrfs_fs_info *fs_info,
+ struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk, u64 logical)
+{
+ u64 length;
+ u64 stripe_len;
+ u16 num_stripes;
+ u16 sub_stripes;
+ u64 type;
+ u64 features;
+ bool mixed = false;
+
+ length = btrfs_chunk_length(leaf, chunk);
+ stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
+ num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+ sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
+ type = btrfs_chunk_type(leaf, chunk);
+
+ if (!num_stripes) {
+ btrfs_err(fs_info, "invalid chunk num_stripes: %u",
+ num_stripes);
+ return -EIO;
+ }
+ if (!IS_ALIGNED(logical, fs_info->sectorsize)) {
+ btrfs_err(fs_info, "invalid chunk logical %llu", logical);
+ return -EIO;
+ }
+ if (btrfs_chunk_sector_size(leaf, chunk) != fs_info->sectorsize) {
+ btrfs_err(fs_info, "invalid chunk sectorsize %u",
+ btrfs_chunk_sector_size(leaf, chunk));
+ return -EIO;
+ }
+ if (!length || !IS_ALIGNED(length, fs_info->sectorsize)) {
+ btrfs_err(fs_info, "invalid chunk length %llu", length);
+ return -EIO;
+ }
+ if (!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN) {
+ btrfs_err(fs_info, "invalid chunk stripe length: %llu",
+ stripe_len);
+ return -EIO;
+ }
+ if (~(BTRFS_BLOCK_GROUP_TYPE_MASK | BTRFS_BLOCK_GROUP_PROFILE_MASK) &
+ type) {
+ btrfs_err(fs_info, "unrecognized chunk type: %llu",
+ ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
+ BTRFS_BLOCK_GROUP_PROFILE_MASK) &
+ btrfs_chunk_type(leaf, chunk));
+ return -EIO;
+ }
+
+ if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) {
+ btrfs_err(fs_info, "missing chunk type flag: 0x%llx", type);
+ return -EIO;
+ }
+
+ if ((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
+ (type & (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA))) {
+ btrfs_err(fs_info,
+ "system chunk with data or metadata type: 0x%llx", type);
+ return -EIO;
+ }
+
+ features = btrfs_super_incompat_flags(fs_info->super_copy);
+ if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+ mixed = true;
+
+ if (!mixed) {
+ if ((type & BTRFS_BLOCK_GROUP_METADATA) &&
+ (type & BTRFS_BLOCK_GROUP_DATA)) {
+ btrfs_err(fs_info,
+ "mixed chunk type in non-mixed mode: 0x%llx", type);
+ return -EIO;
+ }
+ }
+
+ if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes != 2) ||
+ (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
+ (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
+ (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
+ (type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) ||
+ ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
+ num_stripes != 1)) {
+ btrfs_err(fs_info,
+ "invalid num_stripes:sub_stripes %u:%u for profile %llu",
+ num_stripes, sub_stripes,
+ type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info,
+ u64 devid, u8 *uuid, bool error)
+{
+ if (error)
+ btrfs_err_rl(fs_info, "devid %llu uuid %pU is missing",
+ devid, uuid);
+ else
+ btrfs_warn_rl(fs_info, "devid %llu uuid %pU is missing",
+ devid, uuid);
+}
+
+static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
+ struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk)
+{
+ struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+ struct map_lookup *map;
+ struct extent_map *em;
+ u64 logical;
+ u64 length;
+ u64 devid;
+ u8 uuid[BTRFS_UUID_SIZE];
+ int num_stripes;
+ int ret;
+ int i;
+
+ logical = key->offset;
+ length = btrfs_chunk_length(leaf, chunk);
+ num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+
+ ret = btrfs_check_chunk_valid(fs_info, leaf, chunk, logical);
+ if (ret)
+ return ret;
+
+ read_lock(&map_tree->map_tree.lock);
+ em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
+ read_unlock(&map_tree->map_tree.lock);
+
+ /* already mapped? */
+ if (em && em->start <= logical && em->start + em->len > logical) {
+ free_extent_map(em);
+ return 0;
+ } else if (em) {
+ free_extent_map(em);
+ }
+
+ em = alloc_extent_map();
+ if (!em)
+ return -ENOMEM;
+ map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+ if (!map) {
+ free_extent_map(em);
+ return -ENOMEM;
+ }
+
+ set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
+ em->map_lookup = map;
+ em->start = logical;
+ em->len = length;
+ em->orig_start = 0;
+ em->block_start = 0;
+ em->block_len = em->len;
+
+ map->num_stripes = num_stripes;
+ map->io_width = btrfs_chunk_io_width(leaf, chunk);
+ map->io_align = btrfs_chunk_io_align(leaf, chunk);
+ map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
+ map->type = btrfs_chunk_type(leaf, chunk);
+ map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
+ map->verified_stripes = 0;
+ for (i = 0; i < num_stripes; i++) {
+ map->stripes[i].physical =
+ btrfs_stripe_offset_nr(leaf, chunk, i);
+ devid = btrfs_stripe_devid_nr(leaf, chunk, i);
+ read_extent_buffer(leaf, uuid, (unsigned long)
+ btrfs_stripe_dev_uuid_nr(chunk, i),
+ BTRFS_UUID_SIZE);
+ map->stripes[i].dev = btrfs_find_device(fs_info, devid,
+ uuid, NULL);
+ if (!map->stripes[i].dev &&
+ !btrfs_test_opt(fs_info, DEGRADED)) {
+ free_extent_map(em);
+ btrfs_report_missing_device(fs_info, devid, uuid, true);
+ return -ENOENT;
+ }
+ if (!map->stripes[i].dev) {
+ map->stripes[i].dev =
+ add_missing_dev(fs_info->fs_devices, devid,
+ uuid);
+ if (IS_ERR(map->stripes[i].dev)) {
+ free_extent_map(em);
+ btrfs_err(fs_info,
+ "failed to init missing dev %llu: %ld",
+ devid, PTR_ERR(map->stripes[i].dev));
+ return PTR_ERR(map->stripes[i].dev);
+ }
+ btrfs_report_missing_device(fs_info, devid, uuid, false);
+ }
+ set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
+ &(map->stripes[i].dev->dev_state));
+
+ }
+
+ write_lock(&map_tree->map_tree.lock);
+ ret = add_extent_mapping(&map_tree->map_tree, em, 0);
+ write_unlock(&map_tree->map_tree.lock);
+ if (ret < 0) {
+ btrfs_err(fs_info,
+ "failed to add chunk map, start=%llu len=%llu: %d",
+ em->start, em->len, ret);
+ }
+ free_extent_map(em);
+
+ return ret;
+}
+
+static void fill_device_from_item(struct extent_buffer *leaf,
+ struct btrfs_dev_item *dev_item,
+ struct btrfs_device *device)
+{
+ unsigned long ptr;
+
+ device->devid = btrfs_device_id(leaf, dev_item);
+ device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
+ device->total_bytes = device->disk_total_bytes;
+ device->commit_total_bytes = device->disk_total_bytes;
+ device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
+ device->commit_bytes_used = device->bytes_used;
+ device->type = btrfs_device_type(leaf, dev_item);
+ device->io_align = btrfs_device_io_align(leaf, dev_item);
+ device->io_width = btrfs_device_io_width(leaf, dev_item);
+ device->sector_size = btrfs_device_sector_size(leaf, dev_item);
+ WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
+ clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
+
+ ptr = btrfs_device_uuid(dev_item);
+ read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
+}
+
+static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info,
+ u8 *fsid)
+{
+ struct btrfs_fs_devices *fs_devices;
+ int ret;
+
+ lockdep_assert_held(&uuid_mutex);
+ ASSERT(fsid);
+
+ fs_devices = fs_info->fs_devices->seed;
+ while (fs_devices) {
+ if (!memcmp(fs_devices->fsid, fsid, BTRFS_FSID_SIZE))
+ return fs_devices;
+
+ fs_devices = fs_devices->seed;
+ }
+
+ fs_devices = find_fsid(fsid);
+ if (!fs_devices) {
+ if (!btrfs_test_opt(fs_info, DEGRADED))
+ return ERR_PTR(-ENOENT);
+
+ fs_devices = alloc_fs_devices(fsid);
+ if (IS_ERR(fs_devices))
+ return fs_devices;
+
+ fs_devices->seeding = 1;
+ fs_devices->opened = 1;
+ return fs_devices;
+ }
+
+ fs_devices = clone_fs_devices(fs_devices);
+ if (IS_ERR(fs_devices))
+ return fs_devices;
+
+ ret = open_fs_devices(fs_devices, FMODE_READ, fs_info->bdev_holder);
+ if (ret) {
+ free_fs_devices(fs_devices);
+ fs_devices = ERR_PTR(ret);
+ goto out;
+ }
+
+ if (!fs_devices->seeding) {
+ close_fs_devices(fs_devices);
+ free_fs_devices(fs_devices);
+ fs_devices = ERR_PTR(-EINVAL);
+ goto out;
+ }
+
+ fs_devices->seed = fs_info->fs_devices->seed;
+ fs_info->fs_devices->seed = fs_devices;
+out:
+ return fs_devices;
+}
+
+static int read_one_dev(struct btrfs_fs_info *fs_info,
+ struct extent_buffer *leaf,
+ struct btrfs_dev_item *dev_item)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct btrfs_device *device;
+ u64 devid;
+ int ret;
+ u8 fs_uuid[BTRFS_FSID_SIZE];
+ u8 dev_uuid[BTRFS_UUID_SIZE];
+
+ devid = btrfs_device_id(leaf, dev_item);
+ read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
+ BTRFS_UUID_SIZE);
+ read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
+ BTRFS_FSID_SIZE);
+
+ if (memcmp(fs_uuid, fs_info->fsid, BTRFS_FSID_SIZE)) {
+ fs_devices = open_seed_devices(fs_info, fs_uuid);
+ if (IS_ERR(fs_devices))
+ return PTR_ERR(fs_devices);
+ }
+
+ device = btrfs_find_device(fs_info, devid, dev_uuid, fs_uuid);
+ if (!device) {
+ if (!btrfs_test_opt(fs_info, DEGRADED)) {
+ btrfs_report_missing_device(fs_info, devid,
+ dev_uuid, true);
+ return -ENOENT;
+ }
+
+ device = add_missing_dev(fs_devices, devid, dev_uuid);
+ if (IS_ERR(device)) {
+ btrfs_err(fs_info,
+ "failed to add missing dev %llu: %ld",
+ devid, PTR_ERR(device));
+ return PTR_ERR(device);
+ }
+ btrfs_report_missing_device(fs_info, devid, dev_uuid, false);
+ } else {
+ if (!device->bdev) {
+ if (!btrfs_test_opt(fs_info, DEGRADED)) {
+ btrfs_report_missing_device(fs_info,
+ devid, dev_uuid, true);
+ return -ENOENT;
+ }
+ btrfs_report_missing_device(fs_info, devid,
+ dev_uuid, false);
+ }
+
+ if (!device->bdev &&
+ !test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) {
+ /*
+ * this happens when a device that was properly setup
+ * in the device info lists suddenly goes bad.
+ * device->bdev is NULL, and so we have to set
+ * device->missing to one here
+ */
+ device->fs_devices->missing_devices++;
+ set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
+ }
+
+ /* Move the device to its own fs_devices */
+ if (device->fs_devices != fs_devices) {
+ ASSERT(test_bit(BTRFS_DEV_STATE_MISSING,
+ &device->dev_state));
+
+ list_move(&device->dev_list, &fs_devices->devices);
+ device->fs_devices->num_devices--;
+ fs_devices->num_devices++;
+
+ device->fs_devices->missing_devices--;
+ fs_devices->missing_devices++;
+
+ device->fs_devices = fs_devices;
+ }
+ }
+
+ if (device->fs_devices != fs_info->fs_devices) {
+ BUG_ON(test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state));
+ if (device->generation !=
+ btrfs_device_generation(leaf, dev_item))
+ return -EINVAL;
+ }
+
+ fill_device_from_item(leaf, dev_item, device);
+ set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
+ if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
+ !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
+ device->fs_devices->total_rw_bytes += device->total_bytes;
+ atomic64_add(device->total_bytes - device->bytes_used,
+ &fs_info->free_chunk_space);
+ }
+ ret = 0;
+ return ret;
+}
+
+int btrfs_read_sys_array(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root = fs_info->tree_root;
+ struct btrfs_super_block *super_copy = fs_info->super_copy;
+ struct extent_buffer *sb;
+ struct btrfs_disk_key *disk_key;
+ struct btrfs_chunk *chunk;
+ u8 *array_ptr;
+ unsigned long sb_array_offset;
+ int ret = 0;
+ u32 num_stripes;
+ u32 array_size;
+ u32 len = 0;
+ u32 cur_offset;
+ u64 type;
+ struct btrfs_key key;
+
+ ASSERT(BTRFS_SUPER_INFO_SIZE <= fs_info->nodesize);
+ /*
+ * This will create extent buffer of nodesize, superblock size is
+ * fixed to BTRFS_SUPER_INFO_SIZE. If nodesize > sb size, this will
+ * overallocate but we can keep it as-is, only the first page is used.
+ */
+ sb = btrfs_find_create_tree_block(fs_info, BTRFS_SUPER_INFO_OFFSET);
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
+ set_extent_buffer_uptodate(sb);
+ btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
+ /*
+ * The sb extent buffer is artificial and just used to read the system array.
+ * set_extent_buffer_uptodate() call does not properly mark all it's
+ * pages up-to-date when the page is larger: extent does not cover the
+ * whole page and consequently check_page_uptodate does not find all
+ * the page's extents up-to-date (the hole beyond sb),
+ * write_extent_buffer then triggers a WARN_ON.
+ *
+ * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
+ * but sb spans only this function. Add an explicit SetPageUptodate call
+ * to silence the warning eg. on PowerPC 64.
+ */
+ if (PAGE_SIZE > BTRFS_SUPER_INFO_SIZE)
+ SetPageUptodate(sb->pages[0]);
+
+ write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
+ array_size = btrfs_super_sys_array_size(super_copy);
+
+ array_ptr = super_copy->sys_chunk_array;
+ sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
+ cur_offset = 0;
+
+ while (cur_offset < array_size) {
+ disk_key = (struct btrfs_disk_key *)array_ptr;
+ len = sizeof(*disk_key);
+ if (cur_offset + len > array_size)
+ goto out_short_read;
+
+ btrfs_disk_key_to_cpu(&key, disk_key);
+
+ array_ptr += len;
+ sb_array_offset += len;
+ cur_offset += len;
+
+ if (key.type == BTRFS_CHUNK_ITEM_KEY) {
+ chunk = (struct btrfs_chunk *)sb_array_offset;
+ /*
+ * At least one btrfs_chunk with one stripe must be
+ * present, exact stripe count check comes afterwards
+ */
+ len = btrfs_chunk_item_size(1);
+ if (cur_offset + len > array_size)
+ goto out_short_read;
+
+ num_stripes = btrfs_chunk_num_stripes(sb, chunk);
+ if (!num_stripes) {
+ btrfs_err(fs_info,
+ "invalid number of stripes %u in sys_array at offset %u",
+ num_stripes, cur_offset);
+ ret = -EIO;
+ break;
+ }
+
+ type = btrfs_chunk_type(sb, chunk);
+ if ((type & BTRFS_BLOCK_GROUP_SYSTEM) == 0) {
+ btrfs_err(fs_info,
+ "invalid chunk type %llu in sys_array at offset %u",
+ type, cur_offset);
+ ret = -EIO;
+ break;
+ }
+
+ len = btrfs_chunk_item_size(num_stripes);
+ if (cur_offset + len > array_size)
+ goto out_short_read;
+
+ ret = read_one_chunk(fs_info, &key, sb, chunk);
+ if (ret)
+ break;
+ } else {
+ btrfs_err(fs_info,
+ "unexpected item type %u in sys_array at offset %u",
+ (u32)key.type, cur_offset);
+ ret = -EIO;
+ break;
+ }
+ array_ptr += len;
+ sb_array_offset += len;
+ cur_offset += len;
+ }
+ clear_extent_buffer_uptodate(sb);
+ free_extent_buffer_stale(sb);
+ return ret;
+
+out_short_read:
+ btrfs_err(fs_info, "sys_array too short to read %u bytes at offset %u",
+ len, cur_offset);
+ clear_extent_buffer_uptodate(sb);
+ free_extent_buffer_stale(sb);
+ return -EIO;
+}
+
+/*
+ * Check if all chunks in the fs are OK for read-write degraded mount
+ *
+ * If the @failing_dev is specified, it's accounted as missing.
+ *
+ * Return true if all chunks meet the minimal RW mount requirements.
+ * Return false if any chunk doesn't meet the minimal RW mount requirements.
+ */
+bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
+ struct btrfs_device *failing_dev)
+{
+ struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+ struct extent_map *em;
+ u64 next_start = 0;
+ bool ret = true;
+
+ read_lock(&map_tree->map_tree.lock);
+ em = lookup_extent_mapping(&map_tree->map_tree, 0, (u64)-1);
+ read_unlock(&map_tree->map_tree.lock);
+ /* No chunk at all? Return false anyway */
+ if (!em) {
+ ret = false;
+ goto out;
+ }
+ while (em) {
+ struct map_lookup *map;
+ int missing = 0;
+ int max_tolerated;
+ int i;
+
+ map = em->map_lookup;
+ max_tolerated =
+ btrfs_get_num_tolerated_disk_barrier_failures(
+ map->type);
+ for (i = 0; i < map->num_stripes; i++) {
+ struct btrfs_device *dev = map->stripes[i].dev;
+
+ if (!dev || !dev->bdev ||
+ test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) ||
+ dev->last_flush_error)
+ missing++;
+ else if (failing_dev && failing_dev == dev)
+ missing++;
+ }
+ if (missing > max_tolerated) {
+ if (!failing_dev)
+ btrfs_warn(fs_info,
+ "chunk %llu missing %d devices, max tolerance is %d for writeable mount",
+ em->start, missing, max_tolerated);
+ free_extent_map(em);
+ ret = false;
+ goto out;
+ }
+ next_start = extent_map_end(em);
+ free_extent_map(em);
+
+ read_lock(&map_tree->map_tree.lock);
+ em = lookup_extent_mapping(&map_tree->map_tree, next_start,
+ (u64)(-1) - next_start);
+ read_unlock(&map_tree->map_tree.lock);
+ }
+out:
+ return ret;
+}
+
+int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root = fs_info->chunk_root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ int ret;
+ int slot;
+ u64 total_dev = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * uuid_mutex is needed only if we are mounting a sprout FS
+ * otherwise we don't need it.
+ */
+ mutex_lock(&uuid_mutex);
+ mutex_lock(&fs_info->chunk_mutex);
+
+ /*
+ * Read all device items, and then all the chunk items. All
+ * device items are found before any chunk item (their object id
+ * is smaller than the lowest possible object id for a chunk
+ * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
+ */
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.offset = 0;
+ key.type = 0;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+ while (1) {
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto error;
+ break;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.type == BTRFS_DEV_ITEM_KEY) {
+ struct btrfs_dev_item *dev_item;
+ dev_item = btrfs_item_ptr(leaf, slot,
+ struct btrfs_dev_item);
+ ret = read_one_dev(fs_info, leaf, dev_item);
+ if (ret)
+ goto error;
+ total_dev++;
+ } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
+ struct btrfs_chunk *chunk;
+ chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+ ret = read_one_chunk(fs_info, &found_key, leaf, chunk);
+ if (ret)
+ goto error;
+ }
+ path->slots[0]++;
+ }
+
+ /*
+ * After loading chunk tree, we've got all device information,
+ * do another round of validation checks.
+ */
+ if (total_dev != fs_info->fs_devices->total_devices) {
+ btrfs_err(fs_info,
+ "super_num_devices %llu mismatch with num_devices %llu found here",
+ btrfs_super_num_devices(fs_info->super_copy),
+ total_dev);
+ ret = -EINVAL;
+ goto error;
+ }
+ if (btrfs_super_total_bytes(fs_info->super_copy) <
+ fs_info->fs_devices->total_rw_bytes) {
+ btrfs_err(fs_info,
+ "super_total_bytes %llu mismatch with fs_devices total_rw_bytes %llu",
+ btrfs_super_total_bytes(fs_info->super_copy),
+ fs_info->fs_devices->total_rw_bytes);
+ ret = -EINVAL;
+ goto error;
+ }
+ ret = 0;
+error:
+ mutex_unlock(&fs_info->chunk_mutex);
+ mutex_unlock(&uuid_mutex);
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct btrfs_device *device;
+
+ while (fs_devices) {
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_for_each_entry(device, &fs_devices->devices, dev_list)
+ device->fs_info = fs_info;
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ fs_devices = fs_devices->seed;
+ }
+}
+
+static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
+{
+ int i;
+
+ for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
+ btrfs_dev_stat_reset(dev, i);
+}
+
+int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_root *dev_root = fs_info->dev_root;
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct extent_buffer *eb;
+ int slot;
+ int ret = 0;
+ struct btrfs_device *device;
+ struct btrfs_path *path = NULL;
+ int i;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ int item_size;
+ struct btrfs_dev_stats_item *ptr;
+
+ key.objectid = BTRFS_DEV_STATS_OBJECTID;
+ key.type = BTRFS_PERSISTENT_ITEM_KEY;
+ key.offset = device->devid;
+ ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
+ if (ret) {
+ __btrfs_reset_dev_stats(device);
+ device->dev_stats_valid = 1;
+ btrfs_release_path(path);
+ continue;
+ }
+ slot = path->slots[0];
+ eb = path->nodes[0];
+ btrfs_item_key_to_cpu(eb, &found_key, slot);
+ item_size = btrfs_item_size_nr(eb, slot);
+
+ ptr = btrfs_item_ptr(eb, slot,
+ struct btrfs_dev_stats_item);
+
+ for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
+ if (item_size >= (1 + i) * sizeof(__le64))
+ btrfs_dev_stat_set(device, i,
+ btrfs_dev_stats_value(eb, ptr, i));
+ else
+ btrfs_dev_stat_reset(device, i);
+ }
+
+ device->dev_stats_valid = 1;
+ btrfs_dev_stat_print_on_load(device);
+ btrfs_release_path(path);
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+out:
+ btrfs_free_path(path);
+ return ret < 0 ? ret : 0;
+}
+
+static int update_dev_stat_item(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_root *dev_root = fs_info->dev_root;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct extent_buffer *eb;
+ struct btrfs_dev_stats_item *ptr;
+ int ret;
+ int i;
+
+ key.objectid = BTRFS_DEV_STATS_OBJECTID;
+ key.type = BTRFS_PERSISTENT_ITEM_KEY;
+ key.offset = device->devid;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
+ if (ret < 0) {
+ btrfs_warn_in_rcu(fs_info,
+ "error %d while searching for dev_stats item for device %s",
+ ret, rcu_str_deref(device->name));
+ goto out;
+ }
+
+ if (ret == 0 &&
+ btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
+ /* need to delete old one and insert a new one */
+ ret = btrfs_del_item(trans, dev_root, path);
+ if (ret != 0) {
+ btrfs_warn_in_rcu(fs_info,
+ "delete too small dev_stats item for device %s failed %d",
+ rcu_str_deref(device->name), ret);
+ goto out;
+ }
+ ret = 1;
+ }
+
+ if (ret == 1) {
+ /* need to insert a new item */
+ btrfs_release_path(path);
+ ret = btrfs_insert_empty_item(trans, dev_root, path,
+ &key, sizeof(*ptr));
+ if (ret < 0) {
+ btrfs_warn_in_rcu(fs_info,
+ "insert dev_stats item for device %s failed %d",
+ rcu_str_deref(device->name), ret);
+ goto out;
+ }
+ }
+
+ eb = path->nodes[0];
+ ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
+ for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
+ btrfs_set_dev_stats_value(eb, ptr, i,
+ btrfs_dev_stat_read(device, i));
+ btrfs_mark_buffer_dirty(eb);
+
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * called from commit_transaction. Writes all changed device stats to disk.
+ */
+int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct btrfs_device *device;
+ int stats_cnt;
+ int ret = 0;
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ stats_cnt = atomic_read(&device->dev_stats_ccnt);
+ if (!device->dev_stats_valid || stats_cnt == 0)
+ continue;
+
+
+ /*
+ * There is a LOAD-LOAD control dependency between the value of
+ * dev_stats_ccnt and updating the on-disk values which requires
+ * reading the in-memory counters. Such control dependencies
+ * require explicit read memory barriers.
+ *
+ * This memory barriers pairs with smp_mb__before_atomic in
+ * btrfs_dev_stat_inc/btrfs_dev_stat_set and with the full
+ * barrier implied by atomic_xchg in
+ * btrfs_dev_stats_read_and_reset
+ */
+ smp_rmb();
+
+ ret = update_dev_stat_item(trans, device);
+ if (!ret)
+ atomic_sub(stats_cnt, &device->dev_stats_ccnt);
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ return ret;
+}
+
+void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
+{
+ btrfs_dev_stat_inc(dev, index);
+ btrfs_dev_stat_print_on_error(dev);
+}
+
+static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
+{
+ if (!dev->dev_stats_valid)
+ return;
+ btrfs_err_rl_in_rcu(dev->fs_info,
+ "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
+ rcu_str_deref(dev->name),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
+}
+
+static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
+{
+ int i;
+
+ for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
+ if (btrfs_dev_stat_read(dev, i) != 0)
+ break;
+ if (i == BTRFS_DEV_STAT_VALUES_MAX)
+ return; /* all values == 0, suppress message */
+
+ btrfs_info_in_rcu(dev->fs_info,
+ "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
+ rcu_str_deref(dev->name),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
+ btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
+}
+
+int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
+ struct btrfs_ioctl_get_dev_stats *stats)
+{
+ struct btrfs_device *dev;
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ int i;
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ dev = btrfs_find_device(fs_info, stats->devid, NULL, NULL);
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ if (!dev) {
+ btrfs_warn(fs_info, "get dev_stats failed, device not found");
+ return -ENODEV;
+ } else if (!dev->dev_stats_valid) {
+ btrfs_warn(fs_info, "get dev_stats failed, not yet valid");
+ return -ENODEV;
+ } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
+ for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
+ if (stats->nr_items > i)
+ stats->values[i] =
+ btrfs_dev_stat_read_and_reset(dev, i);
+ else
+ btrfs_dev_stat_reset(dev, i);
+ }
+ } else {
+ for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
+ if (stats->nr_items > i)
+ stats->values[i] = btrfs_dev_stat_read(dev, i);
+ }
+ if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
+ stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
+ return 0;
+}
+
+void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path)
+{
+ struct buffer_head *bh;
+ struct btrfs_super_block *disk_super;
+ int copy_num;
+
+ if (!bdev)
+ return;
+
+ for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX;
+ copy_num++) {
+
+ if (btrfs_read_dev_one_super(bdev, copy_num, &bh))
+ continue;
+
+ disk_super = (struct btrfs_super_block *)bh->b_data;
+
+ memset(&disk_super->magic, 0, sizeof(disk_super->magic));
+ set_buffer_dirty(bh);
+ sync_dirty_buffer(bh);
+ brelse(bh);
+ }
+
+ /* Notify udev that device has changed */
+ btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
+
+ /* Update ctime/mtime for device path for libblkid */
+ update_dev_time(device_path);
+}
+
+/*
+ * Update the size of all devices, which is used for writing out the
+ * super blocks.
+ */
+void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ struct btrfs_device *curr, *next;
+
+ if (list_empty(&fs_devices->resized_devices))
+ return;
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ mutex_lock(&fs_info->chunk_mutex);
+ list_for_each_entry_safe(curr, next, &fs_devices->resized_devices,
+ resized_list) {
+ list_del_init(&curr->resized_list);
+ curr->commit_total_bytes = curr->disk_total_bytes;
+ }
+ mutex_unlock(&fs_info->chunk_mutex);
+ mutex_unlock(&fs_devices->device_list_mutex);
+}
+
+/* Must be invoked during the transaction commit */
+void btrfs_update_commit_device_bytes_used(struct btrfs_transaction *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct extent_map *em;
+ struct map_lookup *map;
+ struct btrfs_device *dev;
+ int i;
+
+ if (list_empty(&trans->pending_chunks))
+ return;
+
+ /* In order to kick the device replace finish process */
+ mutex_lock(&fs_info->chunk_mutex);
+ list_for_each_entry(em, &trans->pending_chunks, list) {
+ map = em->map_lookup;
+
+ for (i = 0; i < map->num_stripes; i++) {
+ dev = map->stripes[i].dev;
+ dev->commit_bytes_used = dev->bytes_used;
+ }
+ }
+ mutex_unlock(&fs_info->chunk_mutex);
+}
+
+void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ while (fs_devices) {
+ fs_devices->fs_info = fs_info;
+ fs_devices = fs_devices->seed;
+ }
+}
+
+void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+ while (fs_devices) {
+ fs_devices->fs_info = NULL;
+ fs_devices = fs_devices->seed;
+ }
+}
+
+/*
+ * Multiplicity factor for simple profiles: DUP, RAID1-like and RAID10.
+ */
+int btrfs_bg_type_to_factor(u64 flags)
+{
+ if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10))
+ return 2;
+ return 1;
+}
+
+
+static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
+{
+ int index = btrfs_bg_flags_to_raid_index(type);
+ int ncopies = btrfs_raid_array[index].ncopies;
+ int data_stripes;
+
+ switch (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+ case BTRFS_BLOCK_GROUP_RAID5:
+ data_stripes = num_stripes - 1;
+ break;
+ case BTRFS_BLOCK_GROUP_RAID6:
+ data_stripes = num_stripes - 2;
+ break;
+ default:
+ data_stripes = num_stripes / ncopies;
+ break;
+ }
+ return div_u64(chunk_len, data_stripes);
+}
+
+static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
+ u64 chunk_offset, u64 devid,
+ u64 physical_offset, u64 physical_len)
+{
+ struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
+ struct extent_map *em;
+ struct map_lookup *map;
+ u64 stripe_len;
+ bool found = false;
+ int ret = 0;
+ int i;
+
+ read_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, chunk_offset, 1);
+ read_unlock(&em_tree->lock);
+
+ if (!em) {
+ btrfs_err(fs_info,
+"dev extent physical offset %llu on devid %llu doesn't have corresponding chunk",
+ physical_offset, devid);
+ ret = -EUCLEAN;
+ goto out;
+ }
+
+ map = em->map_lookup;
+ stripe_len = calc_stripe_length(map->type, em->len, map->num_stripes);
+ if (physical_len != stripe_len) {
+ btrfs_err(fs_info,
+"dev extent physical offset %llu on devid %llu length doesn't match chunk %llu, have %llu expect %llu",
+ physical_offset, devid, em->start, physical_len,
+ stripe_len);
+ ret = -EUCLEAN;
+ goto out;
+ }
+
+ for (i = 0; i < map->num_stripes; i++) {
+ if (map->stripes[i].dev->devid == devid &&
+ map->stripes[i].physical == physical_offset) {
+ found = true;
+ if (map->verified_stripes >= map->num_stripes) {
+ btrfs_err(fs_info,
+ "too many dev extents for chunk %llu found",
+ em->start);
+ ret = -EUCLEAN;
+ goto out;
+ }
+ map->verified_stripes++;
+ break;
+ }
+ }
+ if (!found) {
+ btrfs_err(fs_info,
+ "dev extent physical offset %llu devid %llu has no corresponding chunk",
+ physical_offset, devid);
+ ret = -EUCLEAN;
+ }
+out:
+ free_extent_map(em);
+ return ret;
+}
+
+static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info)
+{
+ struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
+ struct extent_map *em;
+ struct rb_node *node;
+ int ret = 0;
+
+ read_lock(&em_tree->lock);
+ for (node = rb_first(&em_tree->map); node; node = rb_next(node)) {
+ em = rb_entry(node, struct extent_map, rb_node);
+ if (em->map_lookup->num_stripes !=
+ em->map_lookup->verified_stripes) {
+ btrfs_err(fs_info,
+ "chunk %llu has missing dev extent, have %d expect %d",
+ em->start, em->map_lookup->verified_stripes,
+ em->map_lookup->num_stripes);
+ ret = -EUCLEAN;
+ goto out;
+ }
+ }
+out:
+ read_unlock(&em_tree->lock);
+ return ret;
+}
+
+/*
+ * Ensure that all dev extents are mapped to correct chunk, otherwise
+ * later chunk allocation/free would cause unexpected behavior.
+ *
+ * NOTE: This will iterate through the whole device tree, which should be of
+ * the same size level as the chunk tree. This slightly increases mount time.
+ */
+int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_path *path;
+ struct btrfs_root *root = fs_info->dev_root;
+ struct btrfs_key key;
+ int ret = 0;
+
+ key.objectid = 1;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+ key.offset = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = READA_FORWARD;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_item(root, path);
+ if (ret < 0)
+ goto out;
+ /* No dev extents at all? Not good */
+ if (ret > 0) {
+ ret = -EUCLEAN;
+ goto out;
+ }
+ }
+ while (1) {
+ struct extent_buffer *leaf = path->nodes[0];
+ struct btrfs_dev_extent *dext;
+ int slot = path->slots[0];
+ u64 chunk_offset;
+ u64 physical_offset;
+ u64 physical_len;
+ u64 devid;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.type != BTRFS_DEV_EXTENT_KEY)
+ break;
+ devid = key.objectid;
+ physical_offset = key.offset;
+
+ dext = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent);
+ chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext);
+ physical_len = btrfs_dev_extent_length(leaf, dext);
+
+ ret = verify_one_dev_extent(fs_info, chunk_offset, devid,
+ physical_offset, physical_len);
+ if (ret < 0)
+ goto out;
+ ret = btrfs_next_item(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ }
+
+ /* Ensure all chunks have corresponding dev extents */
+ ret = verify_chunk_dev_extent_mapping(fs_info);
+out:
+ btrfs_free_path(path);
+ return ret;
+}