v4.19.13 snapshot.
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
new file mode 100644
index 0000000..3be1456
--- /dev/null
+++ b/fs/btrfs/scrub.c
@@ -0,0 +1,4023 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2011, 2012 STRATO. All rights reserved.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/mm.h>
+#include "ctree.h"
+#include "volumes.h"
+#include "disk-io.h"
+#include "ordered-data.h"
+#include "transaction.h"
+#include "backref.h"
+#include "extent_io.h"
+#include "dev-replace.h"
+#include "check-integrity.h"
+#include "rcu-string.h"
+#include "raid56.h"
+
+/*
+ * This is only the first step towards a full-features scrub. It reads all
+ * extent and super block and verifies the checksums. In case a bad checksum
+ * is found or the extent cannot be read, good data will be written back if
+ * any can be found.
+ *
+ * Future enhancements:
+ * - In case an unrepairable extent is encountered, track which files are
+ * affected and report them
+ * - track and record media errors, throw out bad devices
+ * - add a mode to also read unallocated space
+ */
+
+struct scrub_block;
+struct scrub_ctx;
+
+/*
+ * the following three values only influence the performance.
+ * The last one configures the number of parallel and outstanding I/O
+ * operations. The first two values configure an upper limit for the number
+ * of (dynamically allocated) pages that are added to a bio.
+ */
+#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
+#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
+#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
+
+/*
+ * the following value times PAGE_SIZE needs to be large enough to match the
+ * largest node/leaf/sector size that shall be supported.
+ * Values larger than BTRFS_STRIPE_LEN are not supported.
+ */
+#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
+
+struct scrub_recover {
+ refcount_t refs;
+ struct btrfs_bio *bbio;
+ u64 map_length;
+};
+
+struct scrub_page {
+ struct scrub_block *sblock;
+ struct page *page;
+ struct btrfs_device *dev;
+ struct list_head list;
+ u64 flags; /* extent flags */
+ u64 generation;
+ u64 logical;
+ u64 physical;
+ u64 physical_for_dev_replace;
+ atomic_t refs;
+ struct {
+ unsigned int mirror_num:8;
+ unsigned int have_csum:1;
+ unsigned int io_error:1;
+ };
+ u8 csum[BTRFS_CSUM_SIZE];
+
+ struct scrub_recover *recover;
+};
+
+struct scrub_bio {
+ int index;
+ struct scrub_ctx *sctx;
+ struct btrfs_device *dev;
+ struct bio *bio;
+ blk_status_t status;
+ u64 logical;
+ u64 physical;
+#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
+ struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
+#else
+ struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
+#endif
+ int page_count;
+ int next_free;
+ struct btrfs_work work;
+};
+
+struct scrub_block {
+ struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
+ int page_count;
+ atomic_t outstanding_pages;
+ refcount_t refs; /* free mem on transition to zero */
+ struct scrub_ctx *sctx;
+ struct scrub_parity *sparity;
+ struct {
+ unsigned int header_error:1;
+ unsigned int checksum_error:1;
+ unsigned int no_io_error_seen:1;
+ unsigned int generation_error:1; /* also sets header_error */
+
+ /* The following is for the data used to check parity */
+ /* It is for the data with checksum */
+ unsigned int data_corrected:1;
+ };
+ struct btrfs_work work;
+};
+
+/* Used for the chunks with parity stripe such RAID5/6 */
+struct scrub_parity {
+ struct scrub_ctx *sctx;
+
+ struct btrfs_device *scrub_dev;
+
+ u64 logic_start;
+
+ u64 logic_end;
+
+ int nsectors;
+
+ u64 stripe_len;
+
+ refcount_t refs;
+
+ struct list_head spages;
+
+ /* Work of parity check and repair */
+ struct btrfs_work work;
+
+ /* Mark the parity blocks which have data */
+ unsigned long *dbitmap;
+
+ /*
+ * Mark the parity blocks which have data, but errors happen when
+ * read data or check data
+ */
+ unsigned long *ebitmap;
+
+ unsigned long bitmap[0];
+};
+
+struct scrub_ctx {
+ struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
+ struct btrfs_fs_info *fs_info;
+ int first_free;
+ int curr;
+ atomic_t bios_in_flight;
+ atomic_t workers_pending;
+ spinlock_t list_lock;
+ wait_queue_head_t list_wait;
+ u16 csum_size;
+ struct list_head csum_list;
+ atomic_t cancel_req;
+ int readonly;
+ int pages_per_rd_bio;
+
+ int is_dev_replace;
+
+ struct scrub_bio *wr_curr_bio;
+ struct mutex wr_lock;
+ int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
+ struct btrfs_device *wr_tgtdev;
+ bool flush_all_writes;
+
+ /*
+ * statistics
+ */
+ struct btrfs_scrub_progress stat;
+ spinlock_t stat_lock;
+
+ /*
+ * Use a ref counter to avoid use-after-free issues. Scrub workers
+ * decrement bios_in_flight and workers_pending and then do a wakeup
+ * on the list_wait wait queue. We must ensure the main scrub task
+ * doesn't free the scrub context before or while the workers are
+ * doing the wakeup() call.
+ */
+ refcount_t refs;
+};
+
+struct scrub_warning {
+ struct btrfs_path *path;
+ u64 extent_item_size;
+ const char *errstr;
+ u64 physical;
+ u64 logical;
+ struct btrfs_device *dev;
+};
+
+struct full_stripe_lock {
+ struct rb_node node;
+ u64 logical;
+ u64 refs;
+ struct mutex mutex;
+};
+
+static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
+static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
+static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
+static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
+ struct scrub_block *sblocks_for_recheck);
+static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock,
+ int retry_failed_mirror);
+static void scrub_recheck_block_checksum(struct scrub_block *sblock);
+static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good);
+static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good,
+ int page_num, int force_write);
+static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
+static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
+ int page_num);
+static int scrub_checksum_data(struct scrub_block *sblock);
+static int scrub_checksum_tree_block(struct scrub_block *sblock);
+static int scrub_checksum_super(struct scrub_block *sblock);
+static void scrub_block_get(struct scrub_block *sblock);
+static void scrub_block_put(struct scrub_block *sblock);
+static void scrub_page_get(struct scrub_page *spage);
+static void scrub_page_put(struct scrub_page *spage);
+static void scrub_parity_get(struct scrub_parity *sparity);
+static void scrub_parity_put(struct scrub_parity *sparity);
+static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage);
+static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u8 *csum, int force,
+ u64 physical_for_dev_replace);
+static void scrub_bio_end_io(struct bio *bio);
+static void scrub_bio_end_io_worker(struct btrfs_work *work);
+static void scrub_block_complete(struct scrub_block *sblock);
+static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
+ u64 extent_logical, u64 extent_len,
+ u64 *extent_physical,
+ struct btrfs_device **extent_dev,
+ int *extent_mirror_num);
+static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage);
+static void scrub_wr_submit(struct scrub_ctx *sctx);
+static void scrub_wr_bio_end_io(struct bio *bio);
+static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
+static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
+static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
+static void scrub_put_ctx(struct scrub_ctx *sctx);
+
+static inline int scrub_is_page_on_raid56(struct scrub_page *page)
+{
+ return page->recover &&
+ (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
+}
+
+static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
+{
+ refcount_inc(&sctx->refs);
+ atomic_inc(&sctx->bios_in_flight);
+}
+
+static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
+{
+ atomic_dec(&sctx->bios_in_flight);
+ wake_up(&sctx->list_wait);
+ scrub_put_ctx(sctx);
+}
+
+static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
+{
+ while (atomic_read(&fs_info->scrub_pause_req)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ atomic_read(&fs_info->scrub_pause_req) == 0);
+ mutex_lock(&fs_info->scrub_lock);
+ }
+}
+
+static void scrub_pause_on(struct btrfs_fs_info *fs_info)
+{
+ atomic_inc(&fs_info->scrubs_paused);
+ wake_up(&fs_info->scrub_pause_wait);
+}
+
+static void scrub_pause_off(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->scrub_lock);
+ __scrub_blocked_if_needed(fs_info);
+ atomic_dec(&fs_info->scrubs_paused);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ wake_up(&fs_info->scrub_pause_wait);
+}
+
+static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
+{
+ scrub_pause_on(fs_info);
+ scrub_pause_off(fs_info);
+}
+
+/*
+ * Insert new full stripe lock into full stripe locks tree
+ *
+ * Return pointer to existing or newly inserted full_stripe_lock structure if
+ * everything works well.
+ * Return ERR_PTR(-ENOMEM) if we failed to allocate memory
+ *
+ * NOTE: caller must hold full_stripe_locks_root->lock before calling this
+ * function
+ */
+static struct full_stripe_lock *insert_full_stripe_lock(
+ struct btrfs_full_stripe_locks_tree *locks_root,
+ u64 fstripe_logical)
+{
+ struct rb_node **p;
+ struct rb_node *parent = NULL;
+ struct full_stripe_lock *entry;
+ struct full_stripe_lock *ret;
+
+ lockdep_assert_held(&locks_root->lock);
+
+ p = &locks_root->root.rb_node;
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct full_stripe_lock, node);
+ if (fstripe_logical < entry->logical) {
+ p = &(*p)->rb_left;
+ } else if (fstripe_logical > entry->logical) {
+ p = &(*p)->rb_right;
+ } else {
+ entry->refs++;
+ return entry;
+ }
+ }
+
+ /* Insert new lock */
+ ret = kmalloc(sizeof(*ret), GFP_KERNEL);
+ if (!ret)
+ return ERR_PTR(-ENOMEM);
+ ret->logical = fstripe_logical;
+ ret->refs = 1;
+ mutex_init(&ret->mutex);
+
+ rb_link_node(&ret->node, parent, p);
+ rb_insert_color(&ret->node, &locks_root->root);
+ return ret;
+}
+
+/*
+ * Search for a full stripe lock of a block group
+ *
+ * Return pointer to existing full stripe lock if found
+ * Return NULL if not found
+ */
+static struct full_stripe_lock *search_full_stripe_lock(
+ struct btrfs_full_stripe_locks_tree *locks_root,
+ u64 fstripe_logical)
+{
+ struct rb_node *node;
+ struct full_stripe_lock *entry;
+
+ lockdep_assert_held(&locks_root->lock);
+
+ node = locks_root->root.rb_node;
+ while (node) {
+ entry = rb_entry(node, struct full_stripe_lock, node);
+ if (fstripe_logical < entry->logical)
+ node = node->rb_left;
+ else if (fstripe_logical > entry->logical)
+ node = node->rb_right;
+ else
+ return entry;
+ }
+ return NULL;
+}
+
+/*
+ * Helper to get full stripe logical from a normal bytenr.
+ *
+ * Caller must ensure @cache is a RAID56 block group.
+ */
+static u64 get_full_stripe_logical(struct btrfs_block_group_cache *cache,
+ u64 bytenr)
+{
+ u64 ret;
+
+ /*
+ * Due to chunk item size limit, full stripe length should not be
+ * larger than U32_MAX. Just a sanity check here.
+ */
+ WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
+
+ /*
+ * round_down() can only handle power of 2, while RAID56 full
+ * stripe length can be 64KiB * n, so we need to manually round down.
+ */
+ ret = div64_u64(bytenr - cache->key.objectid, cache->full_stripe_len) *
+ cache->full_stripe_len + cache->key.objectid;
+ return ret;
+}
+
+/*
+ * Lock a full stripe to avoid concurrency of recovery and read
+ *
+ * It's only used for profiles with parities (RAID5/6), for other profiles it
+ * does nothing.
+ *
+ * Return 0 if we locked full stripe covering @bytenr, with a mutex held.
+ * So caller must call unlock_full_stripe() at the same context.
+ *
+ * Return <0 if encounters error.
+ */
+static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
+ bool *locked_ret)
+{
+ struct btrfs_block_group_cache *bg_cache;
+ struct btrfs_full_stripe_locks_tree *locks_root;
+ struct full_stripe_lock *existing;
+ u64 fstripe_start;
+ int ret = 0;
+
+ *locked_ret = false;
+ bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
+ if (!bg_cache) {
+ ASSERT(0);
+ return -ENOENT;
+ }
+
+ /* Profiles not based on parity don't need full stripe lock */
+ if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
+ goto out;
+ locks_root = &bg_cache->full_stripe_locks_root;
+
+ fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
+
+ /* Now insert the full stripe lock */
+ mutex_lock(&locks_root->lock);
+ existing = insert_full_stripe_lock(locks_root, fstripe_start);
+ mutex_unlock(&locks_root->lock);
+ if (IS_ERR(existing)) {
+ ret = PTR_ERR(existing);
+ goto out;
+ }
+ mutex_lock(&existing->mutex);
+ *locked_ret = true;
+out:
+ btrfs_put_block_group(bg_cache);
+ return ret;
+}
+
+/*
+ * Unlock a full stripe.
+ *
+ * NOTE: Caller must ensure it's the same context calling corresponding
+ * lock_full_stripe().
+ *
+ * Return 0 if we unlock full stripe without problem.
+ * Return <0 for error
+ */
+static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
+ bool locked)
+{
+ struct btrfs_block_group_cache *bg_cache;
+ struct btrfs_full_stripe_locks_tree *locks_root;
+ struct full_stripe_lock *fstripe_lock;
+ u64 fstripe_start;
+ bool freeit = false;
+ int ret = 0;
+
+ /* If we didn't acquire full stripe lock, no need to continue */
+ if (!locked)
+ return 0;
+
+ bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
+ if (!bg_cache) {
+ ASSERT(0);
+ return -ENOENT;
+ }
+ if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
+ goto out;
+
+ locks_root = &bg_cache->full_stripe_locks_root;
+ fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
+
+ mutex_lock(&locks_root->lock);
+ fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
+ /* Unpaired unlock_full_stripe() detected */
+ if (!fstripe_lock) {
+ WARN_ON(1);
+ ret = -ENOENT;
+ mutex_unlock(&locks_root->lock);
+ goto out;
+ }
+
+ if (fstripe_lock->refs == 0) {
+ WARN_ON(1);
+ btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
+ fstripe_lock->logical);
+ } else {
+ fstripe_lock->refs--;
+ }
+
+ if (fstripe_lock->refs == 0) {
+ rb_erase(&fstripe_lock->node, &locks_root->root);
+ freeit = true;
+ }
+ mutex_unlock(&locks_root->lock);
+
+ mutex_unlock(&fstripe_lock->mutex);
+ if (freeit)
+ kfree(fstripe_lock);
+out:
+ btrfs_put_block_group(bg_cache);
+ return ret;
+}
+
+static void scrub_free_csums(struct scrub_ctx *sctx)
+{
+ while (!list_empty(&sctx->csum_list)) {
+ struct btrfs_ordered_sum *sum;
+ sum = list_first_entry(&sctx->csum_list,
+ struct btrfs_ordered_sum, list);
+ list_del(&sum->list);
+ kfree(sum);
+ }
+}
+
+static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
+{
+ int i;
+
+ if (!sctx)
+ return;
+
+ /* this can happen when scrub is cancelled */
+ if (sctx->curr != -1) {
+ struct scrub_bio *sbio = sctx->bios[sctx->curr];
+
+ for (i = 0; i < sbio->page_count; i++) {
+ WARN_ON(!sbio->pagev[i]->page);
+ scrub_block_put(sbio->pagev[i]->sblock);
+ }
+ bio_put(sbio->bio);
+ }
+
+ for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
+ struct scrub_bio *sbio = sctx->bios[i];
+
+ if (!sbio)
+ break;
+ kfree(sbio);
+ }
+
+ kfree(sctx->wr_curr_bio);
+ scrub_free_csums(sctx);
+ kfree(sctx);
+}
+
+static void scrub_put_ctx(struct scrub_ctx *sctx)
+{
+ if (refcount_dec_and_test(&sctx->refs))
+ scrub_free_ctx(sctx);
+}
+
+static noinline_for_stack
+struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
+{
+ struct scrub_ctx *sctx;
+ int i;
+ struct btrfs_fs_info *fs_info = dev->fs_info;
+
+ sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
+ if (!sctx)
+ goto nomem;
+ refcount_set(&sctx->refs, 1);
+ sctx->is_dev_replace = is_dev_replace;
+ sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
+ sctx->curr = -1;
+ sctx->fs_info = dev->fs_info;
+ for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
+ struct scrub_bio *sbio;
+
+ sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
+ if (!sbio)
+ goto nomem;
+ sctx->bios[i] = sbio;
+
+ sbio->index = i;
+ sbio->sctx = sctx;
+ sbio->page_count = 0;
+ btrfs_init_work(&sbio->work, btrfs_scrub_helper,
+ scrub_bio_end_io_worker, NULL, NULL);
+
+ if (i != SCRUB_BIOS_PER_SCTX - 1)
+ sctx->bios[i]->next_free = i + 1;
+ else
+ sctx->bios[i]->next_free = -1;
+ }
+ sctx->first_free = 0;
+ atomic_set(&sctx->bios_in_flight, 0);
+ atomic_set(&sctx->workers_pending, 0);
+ atomic_set(&sctx->cancel_req, 0);
+ sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
+ INIT_LIST_HEAD(&sctx->csum_list);
+
+ spin_lock_init(&sctx->list_lock);
+ spin_lock_init(&sctx->stat_lock);
+ init_waitqueue_head(&sctx->list_wait);
+
+ WARN_ON(sctx->wr_curr_bio != NULL);
+ mutex_init(&sctx->wr_lock);
+ sctx->wr_curr_bio = NULL;
+ if (is_dev_replace) {
+ WARN_ON(!fs_info->dev_replace.tgtdev);
+ sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
+ sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
+ sctx->flush_all_writes = false;
+ }
+
+ return sctx;
+
+nomem:
+ scrub_free_ctx(sctx);
+ return ERR_PTR(-ENOMEM);
+}
+
+static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
+ void *warn_ctx)
+{
+ u64 isize;
+ u32 nlink;
+ int ret;
+ int i;
+ unsigned nofs_flag;
+ struct extent_buffer *eb;
+ struct btrfs_inode_item *inode_item;
+ struct scrub_warning *swarn = warn_ctx;
+ struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
+ struct inode_fs_paths *ipath = NULL;
+ struct btrfs_root *local_root;
+ struct btrfs_key root_key;
+ struct btrfs_key key;
+
+ root_key.objectid = root;
+ root_key.type = BTRFS_ROOT_ITEM_KEY;
+ root_key.offset = (u64)-1;
+ local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
+ if (IS_ERR(local_root)) {
+ ret = PTR_ERR(local_root);
+ goto err;
+ }
+
+ /*
+ * this makes the path point to (inum INODE_ITEM ioff)
+ */
+ key.objectid = inum;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
+ if (ret) {
+ btrfs_release_path(swarn->path);
+ goto err;
+ }
+
+ eb = swarn->path->nodes[0];
+ inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
+ struct btrfs_inode_item);
+ isize = btrfs_inode_size(eb, inode_item);
+ nlink = btrfs_inode_nlink(eb, inode_item);
+ btrfs_release_path(swarn->path);
+
+ /*
+ * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
+ * uses GFP_NOFS in this context, so we keep it consistent but it does
+ * not seem to be strictly necessary.
+ */
+ nofs_flag = memalloc_nofs_save();
+ ipath = init_ipath(4096, local_root, swarn->path);
+ memalloc_nofs_restore(nofs_flag);
+ if (IS_ERR(ipath)) {
+ ret = PTR_ERR(ipath);
+ ipath = NULL;
+ goto err;
+ }
+ ret = paths_from_inode(inum, ipath);
+
+ if (ret < 0)
+ goto err;
+
+ /*
+ * we deliberately ignore the bit ipath might have been too small to
+ * hold all of the paths here
+ */
+ for (i = 0; i < ipath->fspath->elem_cnt; ++i)
+ btrfs_warn_in_rcu(fs_info,
+"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
+ swarn->errstr, swarn->logical,
+ rcu_str_deref(swarn->dev->name),
+ swarn->physical,
+ root, inum, offset,
+ min(isize - offset, (u64)PAGE_SIZE), nlink,
+ (char *)(unsigned long)ipath->fspath->val[i]);
+
+ free_ipath(ipath);
+ return 0;
+
+err:
+ btrfs_warn_in_rcu(fs_info,
+ "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
+ swarn->errstr, swarn->logical,
+ rcu_str_deref(swarn->dev->name),
+ swarn->physical,
+ root, inum, offset, ret);
+
+ free_ipath(ipath);
+ return 0;
+}
+
+static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
+{
+ struct btrfs_device *dev;
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_path *path;
+ struct btrfs_key found_key;
+ struct extent_buffer *eb;
+ struct btrfs_extent_item *ei;
+ struct scrub_warning swarn;
+ unsigned long ptr = 0;
+ u64 extent_item_pos;
+ u64 flags = 0;
+ u64 ref_root;
+ u32 item_size;
+ u8 ref_level = 0;
+ int ret;
+
+ WARN_ON(sblock->page_count < 1);
+ dev = sblock->pagev[0]->dev;
+ fs_info = sblock->sctx->fs_info;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return;
+
+ swarn.physical = sblock->pagev[0]->physical;
+ swarn.logical = sblock->pagev[0]->logical;
+ swarn.errstr = errstr;
+ swarn.dev = NULL;
+
+ ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
+ &flags);
+ if (ret < 0)
+ goto out;
+
+ extent_item_pos = swarn.logical - found_key.objectid;
+ swarn.extent_item_size = found_key.offset;
+
+ eb = path->nodes[0];
+ ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
+ item_size = btrfs_item_size_nr(eb, path->slots[0]);
+
+ if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ do {
+ ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
+ item_size, &ref_root,
+ &ref_level);
+ btrfs_warn_in_rcu(fs_info,
+"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
+ errstr, swarn.logical,
+ rcu_str_deref(dev->name),
+ swarn.physical,
+ ref_level ? "node" : "leaf",
+ ret < 0 ? -1 : ref_level,
+ ret < 0 ? -1 : ref_root);
+ } while (ret != 1);
+ btrfs_release_path(path);
+ } else {
+ btrfs_release_path(path);
+ swarn.path = path;
+ swarn.dev = dev;
+ iterate_extent_inodes(fs_info, found_key.objectid,
+ extent_item_pos, 1,
+ scrub_print_warning_inode, &swarn, false);
+ }
+
+out:
+ btrfs_free_path(path);
+}
+
+static inline void scrub_get_recover(struct scrub_recover *recover)
+{
+ refcount_inc(&recover->refs);
+}
+
+static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
+ struct scrub_recover *recover)
+{
+ if (refcount_dec_and_test(&recover->refs)) {
+ btrfs_bio_counter_dec(fs_info);
+ btrfs_put_bbio(recover->bbio);
+ kfree(recover);
+ }
+}
+
+/*
+ * scrub_handle_errored_block gets called when either verification of the
+ * pages failed or the bio failed to read, e.g. with EIO. In the latter
+ * case, this function handles all pages in the bio, even though only one
+ * may be bad.
+ * The goal of this function is to repair the errored block by using the
+ * contents of one of the mirrors.
+ */
+static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
+{
+ struct scrub_ctx *sctx = sblock_to_check->sctx;
+ struct btrfs_device *dev;
+ struct btrfs_fs_info *fs_info;
+ u64 logical;
+ unsigned int failed_mirror_index;
+ unsigned int is_metadata;
+ unsigned int have_csum;
+ struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
+ struct scrub_block *sblock_bad;
+ int ret;
+ int mirror_index;
+ int page_num;
+ int success;
+ bool full_stripe_locked;
+ static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ BUG_ON(sblock_to_check->page_count < 1);
+ fs_info = sctx->fs_info;
+ if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
+ /*
+ * if we find an error in a super block, we just report it.
+ * They will get written with the next transaction commit
+ * anyway
+ */
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.super_errors;
+ spin_unlock(&sctx->stat_lock);
+ return 0;
+ }
+ logical = sblock_to_check->pagev[0]->logical;
+ BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
+ failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
+ is_metadata = !(sblock_to_check->pagev[0]->flags &
+ BTRFS_EXTENT_FLAG_DATA);
+ have_csum = sblock_to_check->pagev[0]->have_csum;
+ dev = sblock_to_check->pagev[0]->dev;
+
+ /*
+ * For RAID5/6, race can happen for a different device scrub thread.
+ * For data corruption, Parity and Data threads will both try
+ * to recovery the data.
+ * Race can lead to doubly added csum error, or even unrecoverable
+ * error.
+ */
+ ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
+ if (ret < 0) {
+ spin_lock(&sctx->stat_lock);
+ if (ret == -ENOMEM)
+ sctx->stat.malloc_errors++;
+ sctx->stat.read_errors++;
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return ret;
+ }
+
+ /*
+ * read all mirrors one after the other. This includes to
+ * re-read the extent or metadata block that failed (that was
+ * the cause that this fixup code is called) another time,
+ * page by page this time in order to know which pages
+ * caused I/O errors and which ones are good (for all mirrors).
+ * It is the goal to handle the situation when more than one
+ * mirror contains I/O errors, but the errors do not
+ * overlap, i.e. the data can be repaired by selecting the
+ * pages from those mirrors without I/O error on the
+ * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
+ * would be that mirror #1 has an I/O error on the first page,
+ * the second page is good, and mirror #2 has an I/O error on
+ * the second page, but the first page is good.
+ * Then the first page of the first mirror can be repaired by
+ * taking the first page of the second mirror, and the
+ * second page of the second mirror can be repaired by
+ * copying the contents of the 2nd page of the 1st mirror.
+ * One more note: if the pages of one mirror contain I/O
+ * errors, the checksum cannot be verified. In order to get
+ * the best data for repairing, the first attempt is to find
+ * a mirror without I/O errors and with a validated checksum.
+ * Only if this is not possible, the pages are picked from
+ * mirrors with I/O errors without considering the checksum.
+ * If the latter is the case, at the end, the checksum of the
+ * repaired area is verified in order to correctly maintain
+ * the statistics.
+ */
+
+ sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
+ sizeof(*sblocks_for_recheck), GFP_NOFS);
+ if (!sblocks_for_recheck) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ sctx->stat.read_errors++;
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
+ goto out;
+ }
+
+ /* setup the context, map the logical blocks and alloc the pages */
+ ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
+ if (ret) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors++;
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
+ goto out;
+ }
+ BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
+ sblock_bad = sblocks_for_recheck + failed_mirror_index;
+
+ /* build and submit the bios for the failed mirror, check checksums */
+ scrub_recheck_block(fs_info, sblock_bad, 1);
+
+ if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
+ sblock_bad->no_io_error_seen) {
+ /*
+ * the error disappeared after reading page by page, or
+ * the area was part of a huge bio and other parts of the
+ * bio caused I/O errors, or the block layer merged several
+ * read requests into one and the error is caused by a
+ * different bio (usually one of the two latter cases is
+ * the cause)
+ */
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.unverified_errors++;
+ sblock_to_check->data_corrected = 1;
+ spin_unlock(&sctx->stat_lock);
+
+ if (sctx->is_dev_replace)
+ scrub_write_block_to_dev_replace(sblock_bad);
+ goto out;
+ }
+
+ if (!sblock_bad->no_io_error_seen) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors++;
+ spin_unlock(&sctx->stat_lock);
+ if (__ratelimit(&_rs))
+ scrub_print_warning("i/o error", sblock_to_check);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
+ } else if (sblock_bad->checksum_error) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.csum_errors++;
+ spin_unlock(&sctx->stat_lock);
+ if (__ratelimit(&_rs))
+ scrub_print_warning("checksum error", sblock_to_check);
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ } else if (sblock_bad->header_error) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.verify_errors++;
+ spin_unlock(&sctx->stat_lock);
+ if (__ratelimit(&_rs))
+ scrub_print_warning("checksum/header error",
+ sblock_to_check);
+ if (sblock_bad->generation_error)
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_GENERATION_ERRS);
+ else
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ }
+
+ if (sctx->readonly) {
+ ASSERT(!sctx->is_dev_replace);
+ goto out;
+ }
+
+ /*
+ * now build and submit the bios for the other mirrors, check
+ * checksums.
+ * First try to pick the mirror which is completely without I/O
+ * errors and also does not have a checksum error.
+ * If one is found, and if a checksum is present, the full block
+ * that is known to contain an error is rewritten. Afterwards
+ * the block is known to be corrected.
+ * If a mirror is found which is completely correct, and no
+ * checksum is present, only those pages are rewritten that had
+ * an I/O error in the block to be repaired, since it cannot be
+ * determined, which copy of the other pages is better (and it
+ * could happen otherwise that a correct page would be
+ * overwritten by a bad one).
+ */
+ for (mirror_index = 0; ;mirror_index++) {
+ struct scrub_block *sblock_other;
+
+ if (mirror_index == failed_mirror_index)
+ continue;
+
+ /* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
+ if (!scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
+ if (mirror_index >= BTRFS_MAX_MIRRORS)
+ break;
+ if (!sblocks_for_recheck[mirror_index].page_count)
+ break;
+
+ sblock_other = sblocks_for_recheck + mirror_index;
+ } else {
+ struct scrub_recover *r = sblock_bad->pagev[0]->recover;
+ int max_allowed = r->bbio->num_stripes -
+ r->bbio->num_tgtdevs;
+
+ if (mirror_index >= max_allowed)
+ break;
+ if (!sblocks_for_recheck[1].page_count)
+ break;
+
+ ASSERT(failed_mirror_index == 0);
+ sblock_other = sblocks_for_recheck + 1;
+ sblock_other->pagev[0]->mirror_num = 1 + mirror_index;
+ }
+
+ /* build and submit the bios, check checksums */
+ scrub_recheck_block(fs_info, sblock_other, 0);
+
+ if (!sblock_other->header_error &&
+ !sblock_other->checksum_error &&
+ sblock_other->no_io_error_seen) {
+ if (sctx->is_dev_replace) {
+ scrub_write_block_to_dev_replace(sblock_other);
+ goto corrected_error;
+ } else {
+ ret = scrub_repair_block_from_good_copy(
+ sblock_bad, sblock_other);
+ if (!ret)
+ goto corrected_error;
+ }
+ }
+ }
+
+ if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
+ goto did_not_correct_error;
+
+ /*
+ * In case of I/O errors in the area that is supposed to be
+ * repaired, continue by picking good copies of those pages.
+ * Select the good pages from mirrors to rewrite bad pages from
+ * the area to fix. Afterwards verify the checksum of the block
+ * that is supposed to be repaired. This verification step is
+ * only done for the purpose of statistic counting and for the
+ * final scrub report, whether errors remain.
+ * A perfect algorithm could make use of the checksum and try
+ * all possible combinations of pages from the different mirrors
+ * until the checksum verification succeeds. For example, when
+ * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
+ * of mirror #2 is readable but the final checksum test fails,
+ * then the 2nd page of mirror #3 could be tried, whether now
+ * the final checksum succeeds. But this would be a rare
+ * exception and is therefore not implemented. At least it is
+ * avoided that the good copy is overwritten.
+ * A more useful improvement would be to pick the sectors
+ * without I/O error based on sector sizes (512 bytes on legacy
+ * disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
+ * mirror could be repaired by taking 512 byte of a different
+ * mirror, even if other 512 byte sectors in the same PAGE_SIZE
+ * area are unreadable.
+ */
+ success = 1;
+ for (page_num = 0; page_num < sblock_bad->page_count;
+ page_num++) {
+ struct scrub_page *page_bad = sblock_bad->pagev[page_num];
+ struct scrub_block *sblock_other = NULL;
+
+ /* skip no-io-error page in scrub */
+ if (!page_bad->io_error && !sctx->is_dev_replace)
+ continue;
+
+ if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
+ /*
+ * In case of dev replace, if raid56 rebuild process
+ * didn't work out correct data, then copy the content
+ * in sblock_bad to make sure target device is identical
+ * to source device, instead of writing garbage data in
+ * sblock_for_recheck array to target device.
+ */
+ sblock_other = NULL;
+ } else if (page_bad->io_error) {
+ /* try to find no-io-error page in mirrors */
+ for (mirror_index = 0;
+ mirror_index < BTRFS_MAX_MIRRORS &&
+ sblocks_for_recheck[mirror_index].page_count > 0;
+ mirror_index++) {
+ if (!sblocks_for_recheck[mirror_index].
+ pagev[page_num]->io_error) {
+ sblock_other = sblocks_for_recheck +
+ mirror_index;
+ break;
+ }
+ }
+ if (!sblock_other)
+ success = 0;
+ }
+
+ if (sctx->is_dev_replace) {
+ /*
+ * did not find a mirror to fetch the page
+ * from. scrub_write_page_to_dev_replace()
+ * handles this case (page->io_error), by
+ * filling the block with zeros before
+ * submitting the write request
+ */
+ if (!sblock_other)
+ sblock_other = sblock_bad;
+
+ if (scrub_write_page_to_dev_replace(sblock_other,
+ page_num) != 0) {
+ btrfs_dev_replace_stats_inc(
+ &fs_info->dev_replace.num_write_errors);
+ success = 0;
+ }
+ } else if (sblock_other) {
+ ret = scrub_repair_page_from_good_copy(sblock_bad,
+ sblock_other,
+ page_num, 0);
+ if (0 == ret)
+ page_bad->io_error = 0;
+ else
+ success = 0;
+ }
+ }
+
+ if (success && !sctx->is_dev_replace) {
+ if (is_metadata || have_csum) {
+ /*
+ * need to verify the checksum now that all
+ * sectors on disk are repaired (the write
+ * request for data to be repaired is on its way).
+ * Just be lazy and use scrub_recheck_block()
+ * which re-reads the data before the checksum
+ * is verified, but most likely the data comes out
+ * of the page cache.
+ */
+ scrub_recheck_block(fs_info, sblock_bad, 1);
+ if (!sblock_bad->header_error &&
+ !sblock_bad->checksum_error &&
+ sblock_bad->no_io_error_seen)
+ goto corrected_error;
+ else
+ goto did_not_correct_error;
+ } else {
+corrected_error:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.corrected_errors++;
+ sblock_to_check->data_corrected = 1;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "fixed up error at logical %llu on dev %s",
+ logical, rcu_str_deref(dev->name));
+ }
+ } else {
+did_not_correct_error:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "unable to fixup (regular) error at logical %llu on dev %s",
+ logical, rcu_str_deref(dev->name));
+ }
+
+out:
+ if (sblocks_for_recheck) {
+ for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
+ mirror_index++) {
+ struct scrub_block *sblock = sblocks_for_recheck +
+ mirror_index;
+ struct scrub_recover *recover;
+ int page_index;
+
+ for (page_index = 0; page_index < sblock->page_count;
+ page_index++) {
+ sblock->pagev[page_index]->sblock = NULL;
+ recover = sblock->pagev[page_index]->recover;
+ if (recover) {
+ scrub_put_recover(fs_info, recover);
+ sblock->pagev[page_index]->recover =
+ NULL;
+ }
+ scrub_page_put(sblock->pagev[page_index]);
+ }
+ }
+ kfree(sblocks_for_recheck);
+ }
+
+ ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
+ if (ret < 0)
+ return ret;
+ return 0;
+}
+
+static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
+{
+ if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
+ return 2;
+ else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
+ return 3;
+ else
+ return (int)bbio->num_stripes;
+}
+
+static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
+ u64 *raid_map,
+ u64 mapped_length,
+ int nstripes, int mirror,
+ int *stripe_index,
+ u64 *stripe_offset)
+{
+ int i;
+
+ if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ /* RAID5/6 */
+ for (i = 0; i < nstripes; i++) {
+ if (raid_map[i] == RAID6_Q_STRIPE ||
+ raid_map[i] == RAID5_P_STRIPE)
+ continue;
+
+ if (logical >= raid_map[i] &&
+ logical < raid_map[i] + mapped_length)
+ break;
+ }
+
+ *stripe_index = i;
+ *stripe_offset = logical - raid_map[i];
+ } else {
+ /* The other RAID type */
+ *stripe_index = mirror;
+ *stripe_offset = 0;
+ }
+}
+
+static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
+ struct scrub_block *sblocks_for_recheck)
+{
+ struct scrub_ctx *sctx = original_sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ u64 length = original_sblock->page_count * PAGE_SIZE;
+ u64 logical = original_sblock->pagev[0]->logical;
+ u64 generation = original_sblock->pagev[0]->generation;
+ u64 flags = original_sblock->pagev[0]->flags;
+ u64 have_csum = original_sblock->pagev[0]->have_csum;
+ struct scrub_recover *recover;
+ struct btrfs_bio *bbio;
+ u64 sublen;
+ u64 mapped_length;
+ u64 stripe_offset;
+ int stripe_index;
+ int page_index = 0;
+ int mirror_index;
+ int nmirrors;
+ int ret;
+
+ /*
+ * note: the two members refs and outstanding_pages
+ * are not used (and not set) in the blocks that are used for
+ * the recheck procedure
+ */
+
+ while (length > 0) {
+ sublen = min_t(u64, length, PAGE_SIZE);
+ mapped_length = sublen;
+ bbio = NULL;
+
+ /*
+ * with a length of PAGE_SIZE, each returned stripe
+ * represents one mirror
+ */
+ btrfs_bio_counter_inc_blocked(fs_info);
+ ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
+ logical, &mapped_length, &bbio);
+ if (ret || !bbio || mapped_length < sublen) {
+ btrfs_put_bbio(bbio);
+ btrfs_bio_counter_dec(fs_info);
+ return -EIO;
+ }
+
+ recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
+ if (!recover) {
+ btrfs_put_bbio(bbio);
+ btrfs_bio_counter_dec(fs_info);
+ return -ENOMEM;
+ }
+
+ refcount_set(&recover->refs, 1);
+ recover->bbio = bbio;
+ recover->map_length = mapped_length;
+
+ BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
+
+ nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
+
+ for (mirror_index = 0; mirror_index < nmirrors;
+ mirror_index++) {
+ struct scrub_block *sblock;
+ struct scrub_page *page;
+
+ sblock = sblocks_for_recheck + mirror_index;
+ sblock->sctx = sctx;
+
+ page = kzalloc(sizeof(*page), GFP_NOFS);
+ if (!page) {
+leave_nomem:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_put_recover(fs_info, recover);
+ return -ENOMEM;
+ }
+ scrub_page_get(page);
+ sblock->pagev[page_index] = page;
+ page->sblock = sblock;
+ page->flags = flags;
+ page->generation = generation;
+ page->logical = logical;
+ page->have_csum = have_csum;
+ if (have_csum)
+ memcpy(page->csum,
+ original_sblock->pagev[0]->csum,
+ sctx->csum_size);
+
+ scrub_stripe_index_and_offset(logical,
+ bbio->map_type,
+ bbio->raid_map,
+ mapped_length,
+ bbio->num_stripes -
+ bbio->num_tgtdevs,
+ mirror_index,
+ &stripe_index,
+ &stripe_offset);
+ page->physical = bbio->stripes[stripe_index].physical +
+ stripe_offset;
+ page->dev = bbio->stripes[stripe_index].dev;
+
+ BUG_ON(page_index >= original_sblock->page_count);
+ page->physical_for_dev_replace =
+ original_sblock->pagev[page_index]->
+ physical_for_dev_replace;
+ /* for missing devices, dev->bdev is NULL */
+ page->mirror_num = mirror_index + 1;
+ sblock->page_count++;
+ page->page = alloc_page(GFP_NOFS);
+ if (!page->page)
+ goto leave_nomem;
+
+ scrub_get_recover(recover);
+ page->recover = recover;
+ }
+ scrub_put_recover(fs_info, recover);
+ length -= sublen;
+ logical += sublen;
+ page_index++;
+ }
+
+ return 0;
+}
+
+static void scrub_bio_wait_endio(struct bio *bio)
+{
+ complete(bio->bi_private);
+}
+
+static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
+ struct bio *bio,
+ struct scrub_page *page)
+{
+ DECLARE_COMPLETION_ONSTACK(done);
+ int ret;
+ int mirror_num;
+
+ bio->bi_iter.bi_sector = page->logical >> 9;
+ bio->bi_private = &done;
+ bio->bi_end_io = scrub_bio_wait_endio;
+
+ mirror_num = page->sblock->pagev[0]->mirror_num;
+ ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
+ page->recover->map_length,
+ mirror_num, 0);
+ if (ret)
+ return ret;
+
+ wait_for_completion_io(&done);
+ return blk_status_to_errno(bio->bi_status);
+}
+
+static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock)
+{
+ struct scrub_page *first_page = sblock->pagev[0];
+ struct bio *bio;
+ int page_num;
+
+ /* All pages in sblock belong to the same stripe on the same device. */
+ ASSERT(first_page->dev);
+ if (!first_page->dev->bdev)
+ goto out;
+
+ bio = btrfs_io_bio_alloc(BIO_MAX_PAGES);
+ bio_set_dev(bio, first_page->dev->bdev);
+
+ for (page_num = 0; page_num < sblock->page_count; page_num++) {
+ struct scrub_page *page = sblock->pagev[page_num];
+
+ WARN_ON(!page->page);
+ bio_add_page(bio, page->page, PAGE_SIZE, 0);
+ }
+
+ if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) {
+ bio_put(bio);
+ goto out;
+ }
+
+ bio_put(bio);
+
+ scrub_recheck_block_checksum(sblock);
+
+ return;
+out:
+ for (page_num = 0; page_num < sblock->page_count; page_num++)
+ sblock->pagev[page_num]->io_error = 1;
+
+ sblock->no_io_error_seen = 0;
+}
+
+/*
+ * this function will check the on disk data for checksum errors, header
+ * errors and read I/O errors. If any I/O errors happen, the exact pages
+ * which are errored are marked as being bad. The goal is to enable scrub
+ * to take those pages that are not errored from all the mirrors so that
+ * the pages that are errored in the just handled mirror can be repaired.
+ */
+static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock,
+ int retry_failed_mirror)
+{
+ int page_num;
+
+ sblock->no_io_error_seen = 1;
+
+ /* short cut for raid56 */
+ if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->pagev[0]))
+ return scrub_recheck_block_on_raid56(fs_info, sblock);
+
+ for (page_num = 0; page_num < sblock->page_count; page_num++) {
+ struct bio *bio;
+ struct scrub_page *page = sblock->pagev[page_num];
+
+ if (page->dev->bdev == NULL) {
+ page->io_error = 1;
+ sblock->no_io_error_seen = 0;
+ continue;
+ }
+
+ WARN_ON(!page->page);
+ bio = btrfs_io_bio_alloc(1);
+ bio_set_dev(bio, page->dev->bdev);
+
+ bio_add_page(bio, page->page, PAGE_SIZE, 0);
+ bio->bi_iter.bi_sector = page->physical >> 9;
+ bio->bi_opf = REQ_OP_READ;
+
+ if (btrfsic_submit_bio_wait(bio)) {
+ page->io_error = 1;
+ sblock->no_io_error_seen = 0;
+ }
+
+ bio_put(bio);
+ }
+
+ if (sblock->no_io_error_seen)
+ scrub_recheck_block_checksum(sblock);
+}
+
+static inline int scrub_check_fsid(u8 fsid[],
+ struct scrub_page *spage)
+{
+ struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
+ int ret;
+
+ ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+ return !ret;
+}
+
+static void scrub_recheck_block_checksum(struct scrub_block *sblock)
+{
+ sblock->header_error = 0;
+ sblock->checksum_error = 0;
+ sblock->generation_error = 0;
+
+ if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
+ scrub_checksum_data(sblock);
+ else
+ scrub_checksum_tree_block(sblock);
+}
+
+static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good)
+{
+ int page_num;
+ int ret = 0;
+
+ for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
+ int ret_sub;
+
+ ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
+ sblock_good,
+ page_num, 1);
+ if (ret_sub)
+ ret = ret_sub;
+ }
+
+ return ret;
+}
+
+static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good,
+ int page_num, int force_write)
+{
+ struct scrub_page *page_bad = sblock_bad->pagev[page_num];
+ struct scrub_page *page_good = sblock_good->pagev[page_num];
+ struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
+
+ BUG_ON(page_bad->page == NULL);
+ BUG_ON(page_good->page == NULL);
+ if (force_write || sblock_bad->header_error ||
+ sblock_bad->checksum_error || page_bad->io_error) {
+ struct bio *bio;
+ int ret;
+
+ if (!page_bad->dev->bdev) {
+ btrfs_warn_rl(fs_info,
+ "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
+ return -EIO;
+ }
+
+ bio = btrfs_io_bio_alloc(1);
+ bio_set_dev(bio, page_bad->dev->bdev);
+ bio->bi_iter.bi_sector = page_bad->physical >> 9;
+ bio->bi_opf = REQ_OP_WRITE;
+
+ ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
+ if (PAGE_SIZE != ret) {
+ bio_put(bio);
+ return -EIO;
+ }
+
+ if (btrfsic_submit_bio_wait(bio)) {
+ btrfs_dev_stat_inc_and_print(page_bad->dev,
+ BTRFS_DEV_STAT_WRITE_ERRS);
+ btrfs_dev_replace_stats_inc(
+ &fs_info->dev_replace.num_write_errors);
+ bio_put(bio);
+ return -EIO;
+ }
+ bio_put(bio);
+ }
+
+ return 0;
+}
+
+static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
+{
+ struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
+ int page_num;
+
+ /*
+ * This block is used for the check of the parity on the source device,
+ * so the data needn't be written into the destination device.
+ */
+ if (sblock->sparity)
+ return;
+
+ for (page_num = 0; page_num < sblock->page_count; page_num++) {
+ int ret;
+
+ ret = scrub_write_page_to_dev_replace(sblock, page_num);
+ if (ret)
+ btrfs_dev_replace_stats_inc(
+ &fs_info->dev_replace.num_write_errors);
+ }
+}
+
+static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
+ int page_num)
+{
+ struct scrub_page *spage = sblock->pagev[page_num];
+
+ BUG_ON(spage->page == NULL);
+ if (spage->io_error) {
+ void *mapped_buffer = kmap_atomic(spage->page);
+
+ clear_page(mapped_buffer);
+ flush_dcache_page(spage->page);
+ kunmap_atomic(mapped_buffer);
+ }
+ return scrub_add_page_to_wr_bio(sblock->sctx, spage);
+}
+
+static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage)
+{
+ struct scrub_bio *sbio;
+ int ret;
+
+ mutex_lock(&sctx->wr_lock);
+again:
+ if (!sctx->wr_curr_bio) {
+ sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
+ GFP_KERNEL);
+ if (!sctx->wr_curr_bio) {
+ mutex_unlock(&sctx->wr_lock);
+ return -ENOMEM;
+ }
+ sctx->wr_curr_bio->sctx = sctx;
+ sctx->wr_curr_bio->page_count = 0;
+ }
+ sbio = sctx->wr_curr_bio;
+ if (sbio->page_count == 0) {
+ struct bio *bio;
+
+ sbio->physical = spage->physical_for_dev_replace;
+ sbio->logical = spage->logical;
+ sbio->dev = sctx->wr_tgtdev;
+ bio = sbio->bio;
+ if (!bio) {
+ bio = btrfs_io_bio_alloc(sctx->pages_per_wr_bio);
+ sbio->bio = bio;
+ }
+
+ bio->bi_private = sbio;
+ bio->bi_end_io = scrub_wr_bio_end_io;
+ bio_set_dev(bio, sbio->dev->bdev);
+ bio->bi_iter.bi_sector = sbio->physical >> 9;
+ bio->bi_opf = REQ_OP_WRITE;
+ sbio->status = 0;
+ } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
+ spage->physical_for_dev_replace ||
+ sbio->logical + sbio->page_count * PAGE_SIZE !=
+ spage->logical) {
+ scrub_wr_submit(sctx);
+ goto again;
+ }
+
+ ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
+ if (ret != PAGE_SIZE) {
+ if (sbio->page_count < 1) {
+ bio_put(sbio->bio);
+ sbio->bio = NULL;
+ mutex_unlock(&sctx->wr_lock);
+ return -EIO;
+ }
+ scrub_wr_submit(sctx);
+ goto again;
+ }
+
+ sbio->pagev[sbio->page_count] = spage;
+ scrub_page_get(spage);
+ sbio->page_count++;
+ if (sbio->page_count == sctx->pages_per_wr_bio)
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ return 0;
+}
+
+static void scrub_wr_submit(struct scrub_ctx *sctx)
+{
+ struct scrub_bio *sbio;
+
+ if (!sctx->wr_curr_bio)
+ return;
+
+ sbio = sctx->wr_curr_bio;
+ sctx->wr_curr_bio = NULL;
+ WARN_ON(!sbio->bio->bi_disk);
+ scrub_pending_bio_inc(sctx);
+ /* process all writes in a single worker thread. Then the block layer
+ * orders the requests before sending them to the driver which
+ * doubled the write performance on spinning disks when measured
+ * with Linux 3.5 */
+ btrfsic_submit_bio(sbio->bio);
+}
+
+static void scrub_wr_bio_end_io(struct bio *bio)
+{
+ struct scrub_bio *sbio = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
+
+ sbio->status = bio->bi_status;
+ sbio->bio = bio;
+
+ btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
+ scrub_wr_bio_end_io_worker, NULL, NULL);
+ btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
+}
+
+static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
+{
+ struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
+ struct scrub_ctx *sctx = sbio->sctx;
+ int i;
+
+ WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
+ if (sbio->status) {
+ struct btrfs_dev_replace *dev_replace =
+ &sbio->sctx->fs_info->dev_replace;
+
+ for (i = 0; i < sbio->page_count; i++) {
+ struct scrub_page *spage = sbio->pagev[i];
+
+ spage->io_error = 1;
+ btrfs_dev_replace_stats_inc(&dev_replace->
+ num_write_errors);
+ }
+ }
+
+ for (i = 0; i < sbio->page_count; i++)
+ scrub_page_put(sbio->pagev[i]);
+
+ bio_put(sbio->bio);
+ kfree(sbio);
+ scrub_pending_bio_dec(sctx);
+}
+
+static int scrub_checksum(struct scrub_block *sblock)
+{
+ u64 flags;
+ int ret;
+
+ /*
+ * No need to initialize these stats currently,
+ * because this function only use return value
+ * instead of these stats value.
+ *
+ * Todo:
+ * always use stats
+ */
+ sblock->header_error = 0;
+ sblock->generation_error = 0;
+ sblock->checksum_error = 0;
+
+ WARN_ON(sblock->page_count < 1);
+ flags = sblock->pagev[0]->flags;
+ ret = 0;
+ if (flags & BTRFS_EXTENT_FLAG_DATA)
+ ret = scrub_checksum_data(sblock);
+ else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+ ret = scrub_checksum_tree_block(sblock);
+ else if (flags & BTRFS_EXTENT_FLAG_SUPER)
+ (void)scrub_checksum_super(sblock);
+ else
+ WARN_ON(1);
+ if (ret)
+ scrub_handle_errored_block(sblock);
+
+ return ret;
+}
+
+static int scrub_checksum_data(struct scrub_block *sblock)
+{
+ struct scrub_ctx *sctx = sblock->sctx;
+ u8 csum[BTRFS_CSUM_SIZE];
+ u8 *on_disk_csum;
+ struct page *page;
+ void *buffer;
+ u32 crc = ~(u32)0;
+ u64 len;
+ int index;
+
+ BUG_ON(sblock->page_count < 1);
+ if (!sblock->pagev[0]->have_csum)
+ return 0;
+
+ on_disk_csum = sblock->pagev[0]->csum;
+ page = sblock->pagev[0]->page;
+ buffer = kmap_atomic(page);
+
+ len = sctx->fs_info->sectorsize;
+ index = 0;
+ for (;;) {
+ u64 l = min_t(u64, len, PAGE_SIZE);
+
+ crc = btrfs_csum_data(buffer, crc, l);
+ kunmap_atomic(buffer);
+ len -= l;
+ if (len == 0)
+ break;
+ index++;
+ BUG_ON(index >= sblock->page_count);
+ BUG_ON(!sblock->pagev[index]->page);
+ page = sblock->pagev[index]->page;
+ buffer = kmap_atomic(page);
+ }
+
+ btrfs_csum_final(crc, csum);
+ if (memcmp(csum, on_disk_csum, sctx->csum_size))
+ sblock->checksum_error = 1;
+
+ return sblock->checksum_error;
+}
+
+static int scrub_checksum_tree_block(struct scrub_block *sblock)
+{
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_header *h;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ u8 calculated_csum[BTRFS_CSUM_SIZE];
+ u8 on_disk_csum[BTRFS_CSUM_SIZE];
+ struct page *page;
+ void *mapped_buffer;
+ u64 mapped_size;
+ void *p;
+ u32 crc = ~(u32)0;
+ u64 len;
+ int index;
+
+ BUG_ON(sblock->page_count < 1);
+ page = sblock->pagev[0]->page;
+ mapped_buffer = kmap_atomic(page);
+ h = (struct btrfs_header *)mapped_buffer;
+ memcpy(on_disk_csum, h->csum, sctx->csum_size);
+
+ /*
+ * we don't use the getter functions here, as we
+ * a) don't have an extent buffer and
+ * b) the page is already kmapped
+ */
+ if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
+ sblock->header_error = 1;
+
+ if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
+ sblock->header_error = 1;
+ sblock->generation_error = 1;
+ }
+
+ if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
+ sblock->header_error = 1;
+
+ if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
+ BTRFS_UUID_SIZE))
+ sblock->header_error = 1;
+
+ len = sctx->fs_info->nodesize - BTRFS_CSUM_SIZE;
+ mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
+ p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
+ index = 0;
+ for (;;) {
+ u64 l = min_t(u64, len, mapped_size);
+
+ crc = btrfs_csum_data(p, crc, l);
+ kunmap_atomic(mapped_buffer);
+ len -= l;
+ if (len == 0)
+ break;
+ index++;
+ BUG_ON(index >= sblock->page_count);
+ BUG_ON(!sblock->pagev[index]->page);
+ page = sblock->pagev[index]->page;
+ mapped_buffer = kmap_atomic(page);
+ mapped_size = PAGE_SIZE;
+ p = mapped_buffer;
+ }
+
+ btrfs_csum_final(crc, calculated_csum);
+ if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
+ sblock->checksum_error = 1;
+
+ return sblock->header_error || sblock->checksum_error;
+}
+
+static int scrub_checksum_super(struct scrub_block *sblock)
+{
+ struct btrfs_super_block *s;
+ struct scrub_ctx *sctx = sblock->sctx;
+ u8 calculated_csum[BTRFS_CSUM_SIZE];
+ u8 on_disk_csum[BTRFS_CSUM_SIZE];
+ struct page *page;
+ void *mapped_buffer;
+ u64 mapped_size;
+ void *p;
+ u32 crc = ~(u32)0;
+ int fail_gen = 0;
+ int fail_cor = 0;
+ u64 len;
+ int index;
+
+ BUG_ON(sblock->page_count < 1);
+ page = sblock->pagev[0]->page;
+ mapped_buffer = kmap_atomic(page);
+ s = (struct btrfs_super_block *)mapped_buffer;
+ memcpy(on_disk_csum, s->csum, sctx->csum_size);
+
+ if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
+ ++fail_cor;
+
+ if (sblock->pagev[0]->generation != btrfs_super_generation(s))
+ ++fail_gen;
+
+ if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
+ ++fail_cor;
+
+ len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
+ mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
+ p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
+ index = 0;
+ for (;;) {
+ u64 l = min_t(u64, len, mapped_size);
+
+ crc = btrfs_csum_data(p, crc, l);
+ kunmap_atomic(mapped_buffer);
+ len -= l;
+ if (len == 0)
+ break;
+ index++;
+ BUG_ON(index >= sblock->page_count);
+ BUG_ON(!sblock->pagev[index]->page);
+ page = sblock->pagev[index]->page;
+ mapped_buffer = kmap_atomic(page);
+ mapped_size = PAGE_SIZE;
+ p = mapped_buffer;
+ }
+
+ btrfs_csum_final(crc, calculated_csum);
+ if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
+ ++fail_cor;
+
+ if (fail_cor + fail_gen) {
+ /*
+ * if we find an error in a super block, we just report it.
+ * They will get written with the next transaction commit
+ * anyway
+ */
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.super_errors;
+ spin_unlock(&sctx->stat_lock);
+ if (fail_cor)
+ btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
+ BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ else
+ btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
+ BTRFS_DEV_STAT_GENERATION_ERRS);
+ }
+
+ return fail_cor + fail_gen;
+}
+
+static void scrub_block_get(struct scrub_block *sblock)
+{
+ refcount_inc(&sblock->refs);
+}
+
+static void scrub_block_put(struct scrub_block *sblock)
+{
+ if (refcount_dec_and_test(&sblock->refs)) {
+ int i;
+
+ if (sblock->sparity)
+ scrub_parity_put(sblock->sparity);
+
+ for (i = 0; i < sblock->page_count; i++)
+ scrub_page_put(sblock->pagev[i]);
+ kfree(sblock);
+ }
+}
+
+static void scrub_page_get(struct scrub_page *spage)
+{
+ atomic_inc(&spage->refs);
+}
+
+static void scrub_page_put(struct scrub_page *spage)
+{
+ if (atomic_dec_and_test(&spage->refs)) {
+ if (spage->page)
+ __free_page(spage->page);
+ kfree(spage);
+ }
+}
+
+static void scrub_submit(struct scrub_ctx *sctx)
+{
+ struct scrub_bio *sbio;
+
+ if (sctx->curr == -1)
+ return;
+
+ sbio = sctx->bios[sctx->curr];
+ sctx->curr = -1;
+ scrub_pending_bio_inc(sctx);
+ btrfsic_submit_bio(sbio->bio);
+}
+
+static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage)
+{
+ struct scrub_block *sblock = spage->sblock;
+ struct scrub_bio *sbio;
+ int ret;
+
+again:
+ /*
+ * grab a fresh bio or wait for one to become available
+ */
+ while (sctx->curr == -1) {
+ spin_lock(&sctx->list_lock);
+ sctx->curr = sctx->first_free;
+ if (sctx->curr != -1) {
+ sctx->first_free = sctx->bios[sctx->curr]->next_free;
+ sctx->bios[sctx->curr]->next_free = -1;
+ sctx->bios[sctx->curr]->page_count = 0;
+ spin_unlock(&sctx->list_lock);
+ } else {
+ spin_unlock(&sctx->list_lock);
+ wait_event(sctx->list_wait, sctx->first_free != -1);
+ }
+ }
+ sbio = sctx->bios[sctx->curr];
+ if (sbio->page_count == 0) {
+ struct bio *bio;
+
+ sbio->physical = spage->physical;
+ sbio->logical = spage->logical;
+ sbio->dev = spage->dev;
+ bio = sbio->bio;
+ if (!bio) {
+ bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio);
+ sbio->bio = bio;
+ }
+
+ bio->bi_private = sbio;
+ bio->bi_end_io = scrub_bio_end_io;
+ bio_set_dev(bio, sbio->dev->bdev);
+ bio->bi_iter.bi_sector = sbio->physical >> 9;
+ bio->bi_opf = REQ_OP_READ;
+ sbio->status = 0;
+ } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
+ spage->physical ||
+ sbio->logical + sbio->page_count * PAGE_SIZE !=
+ spage->logical ||
+ sbio->dev != spage->dev) {
+ scrub_submit(sctx);
+ goto again;
+ }
+
+ sbio->pagev[sbio->page_count] = spage;
+ ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
+ if (ret != PAGE_SIZE) {
+ if (sbio->page_count < 1) {
+ bio_put(sbio->bio);
+ sbio->bio = NULL;
+ return -EIO;
+ }
+ scrub_submit(sctx);
+ goto again;
+ }
+
+ scrub_block_get(sblock); /* one for the page added to the bio */
+ atomic_inc(&sblock->outstanding_pages);
+ sbio->page_count++;
+ if (sbio->page_count == sctx->pages_per_rd_bio)
+ scrub_submit(sctx);
+
+ return 0;
+}
+
+static void scrub_missing_raid56_end_io(struct bio *bio)
+{
+ struct scrub_block *sblock = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
+
+ if (bio->bi_status)
+ sblock->no_io_error_seen = 0;
+
+ bio_put(bio);
+
+ btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
+}
+
+static void scrub_missing_raid56_worker(struct btrfs_work *work)
+{
+ struct scrub_block *sblock = container_of(work, struct scrub_block, work);
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ u64 logical;
+ struct btrfs_device *dev;
+
+ logical = sblock->pagev[0]->logical;
+ dev = sblock->pagev[0]->dev;
+
+ if (sblock->no_io_error_seen)
+ scrub_recheck_block_checksum(sblock);
+
+ if (!sblock->no_io_error_seen) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "IO error rebuilding logical %llu for dev %s",
+ logical, rcu_str_deref(dev->name));
+ } else if (sblock->header_error || sblock->checksum_error) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "failed to rebuild valid logical %llu for dev %s",
+ logical, rcu_str_deref(dev->name));
+ } else {
+ scrub_write_block_to_dev_replace(sblock);
+ }
+
+ scrub_block_put(sblock);
+
+ if (sctx->is_dev_replace && sctx->flush_all_writes) {
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+ }
+
+ scrub_pending_bio_dec(sctx);
+}
+
+static void scrub_missing_raid56_pages(struct scrub_block *sblock)
+{
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ u64 length = sblock->page_count * PAGE_SIZE;
+ u64 logical = sblock->pagev[0]->logical;
+ struct btrfs_bio *bbio = NULL;
+ struct bio *bio;
+ struct btrfs_raid_bio *rbio;
+ int ret;
+ int i;
+
+ btrfs_bio_counter_inc_blocked(fs_info);
+ ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
+ &length, &bbio);
+ if (ret || !bbio || !bbio->raid_map)
+ goto bbio_out;
+
+ if (WARN_ON(!sctx->is_dev_replace ||
+ !(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
+ /*
+ * We shouldn't be scrubbing a missing device. Even for dev
+ * replace, we should only get here for RAID 5/6. We either
+ * managed to mount something with no mirrors remaining or
+ * there's a bug in scrub_remap_extent()/btrfs_map_block().
+ */
+ goto bbio_out;
+ }
+
+ bio = btrfs_io_bio_alloc(0);
+ bio->bi_iter.bi_sector = logical >> 9;
+ bio->bi_private = sblock;
+ bio->bi_end_io = scrub_missing_raid56_end_io;
+
+ rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
+ if (!rbio)
+ goto rbio_out;
+
+ for (i = 0; i < sblock->page_count; i++) {
+ struct scrub_page *spage = sblock->pagev[i];
+
+ raid56_add_scrub_pages(rbio, spage->page, spage->logical);
+ }
+
+ btrfs_init_work(&sblock->work, btrfs_scrub_helper,
+ scrub_missing_raid56_worker, NULL, NULL);
+ scrub_block_get(sblock);
+ scrub_pending_bio_inc(sctx);
+ raid56_submit_missing_rbio(rbio);
+ return;
+
+rbio_out:
+ bio_put(bio);
+bbio_out:
+ btrfs_bio_counter_dec(fs_info);
+ btrfs_put_bbio(bbio);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+}
+
+static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u8 *csum, int force,
+ u64 physical_for_dev_replace)
+{
+ struct scrub_block *sblock;
+ int index;
+
+ sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
+ if (!sblock) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ /* one ref inside this function, plus one for each page added to
+ * a bio later on */
+ refcount_set(&sblock->refs, 1);
+ sblock->sctx = sctx;
+ sblock->no_io_error_seen = 1;
+
+ for (index = 0; len > 0; index++) {
+ struct scrub_page *spage;
+ u64 l = min_t(u64, len, PAGE_SIZE);
+
+ spage = kzalloc(sizeof(*spage), GFP_KERNEL);
+ if (!spage) {
+leave_nomem:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_block_put(sblock);
+ return -ENOMEM;
+ }
+ BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
+ scrub_page_get(spage);
+ sblock->pagev[index] = spage;
+ spage->sblock = sblock;
+ spage->dev = dev;
+ spage->flags = flags;
+ spage->generation = gen;
+ spage->logical = logical;
+ spage->physical = physical;
+ spage->physical_for_dev_replace = physical_for_dev_replace;
+ spage->mirror_num = mirror_num;
+ if (csum) {
+ spage->have_csum = 1;
+ memcpy(spage->csum, csum, sctx->csum_size);
+ } else {
+ spage->have_csum = 0;
+ }
+ sblock->page_count++;
+ spage->page = alloc_page(GFP_KERNEL);
+ if (!spage->page)
+ goto leave_nomem;
+ len -= l;
+ logical += l;
+ physical += l;
+ physical_for_dev_replace += l;
+ }
+
+ WARN_ON(sblock->page_count == 0);
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
+ /*
+ * This case should only be hit for RAID 5/6 device replace. See
+ * the comment in scrub_missing_raid56_pages() for details.
+ */
+ scrub_missing_raid56_pages(sblock);
+ } else {
+ for (index = 0; index < sblock->page_count; index++) {
+ struct scrub_page *spage = sblock->pagev[index];
+ int ret;
+
+ ret = scrub_add_page_to_rd_bio(sctx, spage);
+ if (ret) {
+ scrub_block_put(sblock);
+ return ret;
+ }
+ }
+
+ if (force)
+ scrub_submit(sctx);
+ }
+
+ /* last one frees, either here or in bio completion for last page */
+ scrub_block_put(sblock);
+ return 0;
+}
+
+static void scrub_bio_end_io(struct bio *bio)
+{
+ struct scrub_bio *sbio = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
+
+ sbio->status = bio->bi_status;
+ sbio->bio = bio;
+
+ btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
+}
+
+static void scrub_bio_end_io_worker(struct btrfs_work *work)
+{
+ struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
+ struct scrub_ctx *sctx = sbio->sctx;
+ int i;
+
+ BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
+ if (sbio->status) {
+ for (i = 0; i < sbio->page_count; i++) {
+ struct scrub_page *spage = sbio->pagev[i];
+
+ spage->io_error = 1;
+ spage->sblock->no_io_error_seen = 0;
+ }
+ }
+
+ /* now complete the scrub_block items that have all pages completed */
+ for (i = 0; i < sbio->page_count; i++) {
+ struct scrub_page *spage = sbio->pagev[i];
+ struct scrub_block *sblock = spage->sblock;
+
+ if (atomic_dec_and_test(&sblock->outstanding_pages))
+ scrub_block_complete(sblock);
+ scrub_block_put(sblock);
+ }
+
+ bio_put(sbio->bio);
+ sbio->bio = NULL;
+ spin_lock(&sctx->list_lock);
+ sbio->next_free = sctx->first_free;
+ sctx->first_free = sbio->index;
+ spin_unlock(&sctx->list_lock);
+
+ if (sctx->is_dev_replace && sctx->flush_all_writes) {
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+ }
+
+ scrub_pending_bio_dec(sctx);
+}
+
+static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
+ unsigned long *bitmap,
+ u64 start, u64 len)
+{
+ u64 offset;
+ u64 nsectors64;
+ u32 nsectors;
+ int sectorsize = sparity->sctx->fs_info->sectorsize;
+
+ if (len >= sparity->stripe_len) {
+ bitmap_set(bitmap, 0, sparity->nsectors);
+ return;
+ }
+
+ start -= sparity->logic_start;
+ start = div64_u64_rem(start, sparity->stripe_len, &offset);
+ offset = div_u64(offset, sectorsize);
+ nsectors64 = div_u64(len, sectorsize);
+
+ ASSERT(nsectors64 < UINT_MAX);
+ nsectors = (u32)nsectors64;
+
+ if (offset + nsectors <= sparity->nsectors) {
+ bitmap_set(bitmap, offset, nsectors);
+ return;
+ }
+
+ bitmap_set(bitmap, offset, sparity->nsectors - offset);
+ bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
+}
+
+static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
+ u64 start, u64 len)
+{
+ __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
+}
+
+static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
+ u64 start, u64 len)
+{
+ __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
+}
+
+static void scrub_block_complete(struct scrub_block *sblock)
+{
+ int corrupted = 0;
+
+ if (!sblock->no_io_error_seen) {
+ corrupted = 1;
+ scrub_handle_errored_block(sblock);
+ } else {
+ /*
+ * if has checksum error, write via repair mechanism in
+ * dev replace case, otherwise write here in dev replace
+ * case.
+ */
+ corrupted = scrub_checksum(sblock);
+ if (!corrupted && sblock->sctx->is_dev_replace)
+ scrub_write_block_to_dev_replace(sblock);
+ }
+
+ if (sblock->sparity && corrupted && !sblock->data_corrected) {
+ u64 start = sblock->pagev[0]->logical;
+ u64 end = sblock->pagev[sblock->page_count - 1]->logical +
+ PAGE_SIZE;
+
+ scrub_parity_mark_sectors_error(sblock->sparity,
+ start, end - start);
+ }
+}
+
+static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
+{
+ struct btrfs_ordered_sum *sum = NULL;
+ unsigned long index;
+ unsigned long num_sectors;
+
+ while (!list_empty(&sctx->csum_list)) {
+ sum = list_first_entry(&sctx->csum_list,
+ struct btrfs_ordered_sum, list);
+ if (sum->bytenr > logical)
+ return 0;
+ if (sum->bytenr + sum->len > logical)
+ break;
+
+ ++sctx->stat.csum_discards;
+ list_del(&sum->list);
+ kfree(sum);
+ sum = NULL;
+ }
+ if (!sum)
+ return 0;
+
+ index = div_u64(logical - sum->bytenr, sctx->fs_info->sectorsize);
+ ASSERT(index < UINT_MAX);
+
+ num_sectors = sum->len / sctx->fs_info->sectorsize;
+ memcpy(csum, sum->sums + index, sctx->csum_size);
+ if (index == num_sectors - 1) {
+ list_del(&sum->list);
+ kfree(sum);
+ }
+ return 1;
+}
+
+/* scrub extent tries to collect up to 64 kB for each bio */
+static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
+ u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u64 physical_for_dev_replace)
+{
+ int ret;
+ u8 csum[BTRFS_CSUM_SIZE];
+ u32 blocksize;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
+ blocksize = map->stripe_len;
+ else
+ blocksize = sctx->fs_info->sectorsize;
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.data_extents_scrubbed++;
+ sctx->stat.data_bytes_scrubbed += len;
+ spin_unlock(&sctx->stat_lock);
+ } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
+ blocksize = map->stripe_len;
+ else
+ blocksize = sctx->fs_info->nodesize;
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.tree_extents_scrubbed++;
+ sctx->stat.tree_bytes_scrubbed += len;
+ spin_unlock(&sctx->stat_lock);
+ } else {
+ blocksize = sctx->fs_info->sectorsize;
+ WARN_ON(1);
+ }
+
+ while (len) {
+ u64 l = min_t(u64, len, blocksize);
+ int have_csum = 0;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ /* push csums to sbio */
+ have_csum = scrub_find_csum(sctx, logical, csum);
+ if (have_csum == 0)
+ ++sctx->stat.no_csum;
+ }
+ ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
+ mirror_num, have_csum ? csum : NULL, 0,
+ physical_for_dev_replace);
+ if (ret)
+ return ret;
+ len -= l;
+ logical += l;
+ physical += l;
+ physical_for_dev_replace += l;
+ }
+ return 0;
+}
+
+static int scrub_pages_for_parity(struct scrub_parity *sparity,
+ u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev,
+ u64 flags, u64 gen, int mirror_num, u8 *csum)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct scrub_block *sblock;
+ int index;
+
+ sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
+ if (!sblock) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ /* one ref inside this function, plus one for each page added to
+ * a bio later on */
+ refcount_set(&sblock->refs, 1);
+ sblock->sctx = sctx;
+ sblock->no_io_error_seen = 1;
+ sblock->sparity = sparity;
+ scrub_parity_get(sparity);
+
+ for (index = 0; len > 0; index++) {
+ struct scrub_page *spage;
+ u64 l = min_t(u64, len, PAGE_SIZE);
+
+ spage = kzalloc(sizeof(*spage), GFP_KERNEL);
+ if (!spage) {
+leave_nomem:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_block_put(sblock);
+ return -ENOMEM;
+ }
+ BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
+ /* For scrub block */
+ scrub_page_get(spage);
+ sblock->pagev[index] = spage;
+ /* For scrub parity */
+ scrub_page_get(spage);
+ list_add_tail(&spage->list, &sparity->spages);
+ spage->sblock = sblock;
+ spage->dev = dev;
+ spage->flags = flags;
+ spage->generation = gen;
+ spage->logical = logical;
+ spage->physical = physical;
+ spage->mirror_num = mirror_num;
+ if (csum) {
+ spage->have_csum = 1;
+ memcpy(spage->csum, csum, sctx->csum_size);
+ } else {
+ spage->have_csum = 0;
+ }
+ sblock->page_count++;
+ spage->page = alloc_page(GFP_KERNEL);
+ if (!spage->page)
+ goto leave_nomem;
+ len -= l;
+ logical += l;
+ physical += l;
+ }
+
+ WARN_ON(sblock->page_count == 0);
+ for (index = 0; index < sblock->page_count; index++) {
+ struct scrub_page *spage = sblock->pagev[index];
+ int ret;
+
+ ret = scrub_add_page_to_rd_bio(sctx, spage);
+ if (ret) {
+ scrub_block_put(sblock);
+ return ret;
+ }
+ }
+
+ /* last one frees, either here or in bio completion for last page */
+ scrub_block_put(sblock);
+ return 0;
+}
+
+static int scrub_extent_for_parity(struct scrub_parity *sparity,
+ u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev,
+ u64 flags, u64 gen, int mirror_num)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ int ret;
+ u8 csum[BTRFS_CSUM_SIZE];
+ u32 blocksize;
+
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
+ scrub_parity_mark_sectors_error(sparity, logical, len);
+ return 0;
+ }
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ blocksize = sparity->stripe_len;
+ } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ blocksize = sparity->stripe_len;
+ } else {
+ blocksize = sctx->fs_info->sectorsize;
+ WARN_ON(1);
+ }
+
+ while (len) {
+ u64 l = min_t(u64, len, blocksize);
+ int have_csum = 0;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ /* push csums to sbio */
+ have_csum = scrub_find_csum(sctx, logical, csum);
+ if (have_csum == 0)
+ goto skip;
+ }
+ ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
+ flags, gen, mirror_num,
+ have_csum ? csum : NULL);
+ if (ret)
+ return ret;
+skip:
+ len -= l;
+ logical += l;
+ physical += l;
+ }
+ return 0;
+}
+
+/*
+ * Given a physical address, this will calculate it's
+ * logical offset. if this is a parity stripe, it will return
+ * the most left data stripe's logical offset.
+ *
+ * return 0 if it is a data stripe, 1 means parity stripe.
+ */
+static int get_raid56_logic_offset(u64 physical, int num,
+ struct map_lookup *map, u64 *offset,
+ u64 *stripe_start)
+{
+ int i;
+ int j = 0;
+ u64 stripe_nr;
+ u64 last_offset;
+ u32 stripe_index;
+ u32 rot;
+
+ last_offset = (physical - map->stripes[num].physical) *
+ nr_data_stripes(map);
+ if (stripe_start)
+ *stripe_start = last_offset;
+
+ *offset = last_offset;
+ for (i = 0; i < nr_data_stripes(map); i++) {
+ *offset = last_offset + i * map->stripe_len;
+
+ stripe_nr = div64_u64(*offset, map->stripe_len);
+ stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
+
+ /* Work out the disk rotation on this stripe-set */
+ stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
+ /* calculate which stripe this data locates */
+ rot += i;
+ stripe_index = rot % map->num_stripes;
+ if (stripe_index == num)
+ return 0;
+ if (stripe_index < num)
+ j++;
+ }
+ *offset = last_offset + j * map->stripe_len;
+ return 1;
+}
+
+static void scrub_free_parity(struct scrub_parity *sparity)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct scrub_page *curr, *next;
+ int nbits;
+
+ nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
+ if (nbits) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors += nbits;
+ sctx->stat.uncorrectable_errors += nbits;
+ spin_unlock(&sctx->stat_lock);
+ }
+
+ list_for_each_entry_safe(curr, next, &sparity->spages, list) {
+ list_del_init(&curr->list);
+ scrub_page_put(curr);
+ }
+
+ kfree(sparity);
+}
+
+static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
+{
+ struct scrub_parity *sparity = container_of(work, struct scrub_parity,
+ work);
+ struct scrub_ctx *sctx = sparity->sctx;
+
+ scrub_free_parity(sparity);
+ scrub_pending_bio_dec(sctx);
+}
+
+static void scrub_parity_bio_endio(struct bio *bio)
+{
+ struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
+ struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
+
+ if (bio->bi_status)
+ bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
+ sparity->nsectors);
+
+ bio_put(bio);
+
+ btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
+ scrub_parity_bio_endio_worker, NULL, NULL);
+ btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
+}
+
+static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct bio *bio;
+ struct btrfs_raid_bio *rbio;
+ struct btrfs_bio *bbio = NULL;
+ u64 length;
+ int ret;
+
+ if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
+ sparity->nsectors))
+ goto out;
+
+ length = sparity->logic_end - sparity->logic_start;
+
+ btrfs_bio_counter_inc_blocked(fs_info);
+ ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
+ &length, &bbio);
+ if (ret || !bbio || !bbio->raid_map)
+ goto bbio_out;
+
+ bio = btrfs_io_bio_alloc(0);
+ bio->bi_iter.bi_sector = sparity->logic_start >> 9;
+ bio->bi_private = sparity;
+ bio->bi_end_io = scrub_parity_bio_endio;
+
+ rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
+ length, sparity->scrub_dev,
+ sparity->dbitmap,
+ sparity->nsectors);
+ if (!rbio)
+ goto rbio_out;
+
+ scrub_pending_bio_inc(sctx);
+ raid56_parity_submit_scrub_rbio(rbio);
+ return;
+
+rbio_out:
+ bio_put(bio);
+bbio_out:
+ btrfs_bio_counter_dec(fs_info);
+ btrfs_put_bbio(bbio);
+ bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
+ sparity->nsectors);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+out:
+ scrub_free_parity(sparity);
+}
+
+static inline int scrub_calc_parity_bitmap_len(int nsectors)
+{
+ return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
+}
+
+static void scrub_parity_get(struct scrub_parity *sparity)
+{
+ refcount_inc(&sparity->refs);
+}
+
+static void scrub_parity_put(struct scrub_parity *sparity)
+{
+ if (!refcount_dec_and_test(&sparity->refs))
+ return;
+
+ scrub_parity_check_and_repair(sparity);
+}
+
+static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
+ struct map_lookup *map,
+ struct btrfs_device *sdev,
+ struct btrfs_path *path,
+ u64 logic_start,
+ u64 logic_end)
+{
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_root *root = fs_info->extent_root;
+ struct btrfs_root *csum_root = fs_info->csum_root;
+ struct btrfs_extent_item *extent;
+ struct btrfs_bio *bbio = NULL;
+ u64 flags;
+ int ret;
+ int slot;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ u64 generation;
+ u64 extent_logical;
+ u64 extent_physical;
+ u64 extent_len;
+ u64 mapped_length;
+ struct btrfs_device *extent_dev;
+ struct scrub_parity *sparity;
+ int nsectors;
+ int bitmap_len;
+ int extent_mirror_num;
+ int stop_loop = 0;
+
+ nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
+ bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
+ sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
+ GFP_NOFS);
+ if (!sparity) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ sparity->stripe_len = map->stripe_len;
+ sparity->nsectors = nsectors;
+ sparity->sctx = sctx;
+ sparity->scrub_dev = sdev;
+ sparity->logic_start = logic_start;
+ sparity->logic_end = logic_end;
+ refcount_set(&sparity->refs, 1);
+ INIT_LIST_HEAD(&sparity->spages);
+ sparity->dbitmap = sparity->bitmap;
+ sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
+
+ ret = 0;
+ while (logic_start < logic_end) {
+ if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ else
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.objectid = logic_start;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = btrfs_previous_extent_item(root, path, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &key,
+ path, 0, 0);
+ if (ret < 0)
+ goto out;
+ }
+ }
+
+ stop_loop = 0;
+ while (1) {
+ u64 bytes;
+
+ 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;
+
+ stop_loop = 1;
+ break;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.type != BTRFS_EXTENT_ITEM_KEY &&
+ key.type != BTRFS_METADATA_ITEM_KEY)
+ goto next;
+
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ bytes = fs_info->nodesize;
+ else
+ bytes = key.offset;
+
+ if (key.objectid + bytes <= logic_start)
+ goto next;
+
+ if (key.objectid >= logic_end) {
+ stop_loop = 1;
+ break;
+ }
+
+ while (key.objectid >= logic_start + map->stripe_len)
+ logic_start += map->stripe_len;
+
+ extent = btrfs_item_ptr(l, slot,
+ struct btrfs_extent_item);
+ flags = btrfs_extent_flags(l, extent);
+ generation = btrfs_extent_generation(l, extent);
+
+ if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
+ (key.objectid < logic_start ||
+ key.objectid + bytes >
+ logic_start + map->stripe_len)) {
+ btrfs_err(fs_info,
+ "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
+ key.objectid, logic_start);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ goto next;
+ }
+again:
+ extent_logical = key.objectid;
+ extent_len = bytes;
+
+ if (extent_logical < logic_start) {
+ extent_len -= logic_start - extent_logical;
+ extent_logical = logic_start;
+ }
+
+ if (extent_logical + extent_len >
+ logic_start + map->stripe_len)
+ extent_len = logic_start + map->stripe_len -
+ extent_logical;
+
+ scrub_parity_mark_sectors_data(sparity, extent_logical,
+ extent_len);
+
+ mapped_length = extent_len;
+ bbio = NULL;
+ ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
+ extent_logical, &mapped_length, &bbio,
+ 0);
+ if (!ret) {
+ if (!bbio || mapped_length < extent_len)
+ ret = -EIO;
+ }
+ if (ret) {
+ btrfs_put_bbio(bbio);
+ goto out;
+ }
+ extent_physical = bbio->stripes[0].physical;
+ extent_mirror_num = bbio->mirror_num;
+ extent_dev = bbio->stripes[0].dev;
+ btrfs_put_bbio(bbio);
+
+ ret = btrfs_lookup_csums_range(csum_root,
+ extent_logical,
+ extent_logical + extent_len - 1,
+ &sctx->csum_list, 1);
+ if (ret)
+ goto out;
+
+ ret = scrub_extent_for_parity(sparity, extent_logical,
+ extent_len,
+ extent_physical,
+ extent_dev, flags,
+ generation,
+ extent_mirror_num);
+
+ scrub_free_csums(sctx);
+
+ if (ret)
+ goto out;
+
+ if (extent_logical + extent_len <
+ key.objectid + bytes) {
+ logic_start += map->stripe_len;
+
+ if (logic_start >= logic_end) {
+ stop_loop = 1;
+ break;
+ }
+
+ if (logic_start < key.objectid + bytes) {
+ cond_resched();
+ goto again;
+ }
+ }
+next:
+ path->slots[0]++;
+ }
+
+ btrfs_release_path(path);
+
+ if (stop_loop)
+ break;
+
+ logic_start += map->stripe_len;
+ }
+out:
+ if (ret < 0)
+ scrub_parity_mark_sectors_error(sparity, logic_start,
+ logic_end - logic_start);
+ scrub_parity_put(sparity);
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ btrfs_release_path(path);
+ return ret < 0 ? ret : 0;
+}
+
+static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
+ struct map_lookup *map,
+ struct btrfs_device *scrub_dev,
+ int num, u64 base, u64 length,
+ int is_dev_replace)
+{
+ struct btrfs_path *path, *ppath;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_root *root = fs_info->extent_root;
+ struct btrfs_root *csum_root = fs_info->csum_root;
+ struct btrfs_extent_item *extent;
+ struct blk_plug plug;
+ u64 flags;
+ int ret;
+ int slot;
+ u64 nstripes;
+ struct extent_buffer *l;
+ u64 physical;
+ u64 logical;
+ u64 logic_end;
+ u64 physical_end;
+ u64 generation;
+ int mirror_num;
+ struct reada_control *reada1;
+ struct reada_control *reada2;
+ struct btrfs_key key;
+ struct btrfs_key key_end;
+ u64 increment = map->stripe_len;
+ u64 offset;
+ u64 extent_logical;
+ u64 extent_physical;
+ u64 extent_len;
+ u64 stripe_logical;
+ u64 stripe_end;
+ struct btrfs_device *extent_dev;
+ int extent_mirror_num;
+ int stop_loop = 0;
+
+ physical = map->stripes[num].physical;
+ offset = 0;
+ nstripes = div64_u64(length, map->stripe_len);
+ if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
+ offset = map->stripe_len * num;
+ increment = map->stripe_len * map->num_stripes;
+ mirror_num = 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+ int factor = map->num_stripes / map->sub_stripes;
+ offset = map->stripe_len * (num / map->sub_stripes);
+ increment = map->stripe_len * factor;
+ mirror_num = num % map->sub_stripes + 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
+ increment = map->stripe_len;
+ mirror_num = num % map->num_stripes + 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
+ increment = map->stripe_len;
+ mirror_num = num % map->num_stripes + 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ get_raid56_logic_offset(physical, num, map, &offset, NULL);
+ increment = map->stripe_len * nr_data_stripes(map);
+ mirror_num = 1;
+ } else {
+ increment = map->stripe_len;
+ mirror_num = 1;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ppath = btrfs_alloc_path();
+ if (!ppath) {
+ btrfs_free_path(path);
+ return -ENOMEM;
+ }
+
+ /*
+ * work on commit root. The related disk blocks are static as
+ * long as COW is applied. This means, it is save to rewrite
+ * them to repair disk errors without any race conditions
+ */
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ ppath->search_commit_root = 1;
+ ppath->skip_locking = 1;
+ /*
+ * trigger the readahead for extent tree csum tree and wait for
+ * completion. During readahead, the scrub is officially paused
+ * to not hold off transaction commits
+ */
+ logical = base + offset;
+ physical_end = physical + nstripes * map->stripe_len;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ get_raid56_logic_offset(physical_end, num,
+ map, &logic_end, NULL);
+ logic_end += base;
+ } else {
+ logic_end = logical + increment * nstripes;
+ }
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+ scrub_blocked_if_needed(fs_info);
+
+ /* FIXME it might be better to start readahead at commit root */
+ key.objectid = logical;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = (u64)0;
+ key_end.objectid = logic_end;
+ key_end.type = BTRFS_METADATA_ITEM_KEY;
+ key_end.offset = (u64)-1;
+ reada1 = btrfs_reada_add(root, &key, &key_end);
+
+ key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key.type = BTRFS_EXTENT_CSUM_KEY;
+ key.offset = logical;
+ key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key_end.type = BTRFS_EXTENT_CSUM_KEY;
+ key_end.offset = logic_end;
+ reada2 = btrfs_reada_add(csum_root, &key, &key_end);
+
+ if (!IS_ERR(reada1))
+ btrfs_reada_wait(reada1);
+ if (!IS_ERR(reada2))
+ btrfs_reada_wait(reada2);
+
+
+ /*
+ * collect all data csums for the stripe to avoid seeking during
+ * the scrub. This might currently (crc32) end up to be about 1MB
+ */
+ blk_start_plug(&plug);
+
+ /*
+ * now find all extents for each stripe and scrub them
+ */
+ ret = 0;
+ while (physical < physical_end) {
+ /*
+ * canceled?
+ */
+ if (atomic_read(&fs_info->scrub_cancel_req) ||
+ atomic_read(&sctx->cancel_req)) {
+ ret = -ECANCELED;
+ goto out;
+ }
+ /*
+ * check to see if we have to pause
+ */
+ if (atomic_read(&fs_info->scrub_pause_req)) {
+ /* push queued extents */
+ sctx->flush_all_writes = true;
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+ sctx->flush_all_writes = false;
+ scrub_blocked_if_needed(fs_info);
+ }
+
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ ret = get_raid56_logic_offset(physical, num, map,
+ &logical,
+ &stripe_logical);
+ logical += base;
+ if (ret) {
+ /* it is parity strip */
+ stripe_logical += base;
+ stripe_end = stripe_logical + increment;
+ ret = scrub_raid56_parity(sctx, map, scrub_dev,
+ ppath, stripe_logical,
+ stripe_end);
+ if (ret)
+ goto out;
+ goto skip;
+ }
+ }
+
+ if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ else
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.objectid = logical;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = btrfs_previous_extent_item(root, path, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ /* there's no smaller item, so stick with the
+ * larger one */
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &key,
+ path, 0, 0);
+ if (ret < 0)
+ goto out;
+ }
+ }
+
+ stop_loop = 0;
+ while (1) {
+ u64 bytes;
+
+ 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;
+
+ stop_loop = 1;
+ break;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.type != BTRFS_EXTENT_ITEM_KEY &&
+ key.type != BTRFS_METADATA_ITEM_KEY)
+ goto next;
+
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ bytes = fs_info->nodesize;
+ else
+ bytes = key.offset;
+
+ if (key.objectid + bytes <= logical)
+ goto next;
+
+ if (key.objectid >= logical + map->stripe_len) {
+ /* out of this device extent */
+ if (key.objectid >= logic_end)
+ stop_loop = 1;
+ break;
+ }
+
+ extent = btrfs_item_ptr(l, slot,
+ struct btrfs_extent_item);
+ flags = btrfs_extent_flags(l, extent);
+ generation = btrfs_extent_generation(l, extent);
+
+ if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
+ (key.objectid < logical ||
+ key.objectid + bytes >
+ logical + map->stripe_len)) {
+ btrfs_err(fs_info,
+ "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
+ key.objectid, logical);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ goto next;
+ }
+
+again:
+ extent_logical = key.objectid;
+ extent_len = bytes;
+
+ /*
+ * trim extent to this stripe
+ */
+ if (extent_logical < logical) {
+ extent_len -= logical - extent_logical;
+ extent_logical = logical;
+ }
+ if (extent_logical + extent_len >
+ logical + map->stripe_len) {
+ extent_len = logical + map->stripe_len -
+ extent_logical;
+ }
+
+ extent_physical = extent_logical - logical + physical;
+ extent_dev = scrub_dev;
+ extent_mirror_num = mirror_num;
+ if (is_dev_replace)
+ scrub_remap_extent(fs_info, extent_logical,
+ extent_len, &extent_physical,
+ &extent_dev,
+ &extent_mirror_num);
+
+ ret = btrfs_lookup_csums_range(csum_root,
+ extent_logical,
+ extent_logical +
+ extent_len - 1,
+ &sctx->csum_list, 1);
+ if (ret)
+ goto out;
+
+ ret = scrub_extent(sctx, map, extent_logical, extent_len,
+ extent_physical, extent_dev, flags,
+ generation, extent_mirror_num,
+ extent_logical - logical + physical);
+
+ scrub_free_csums(sctx);
+
+ if (ret)
+ goto out;
+
+ if (extent_logical + extent_len <
+ key.objectid + bytes) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ /*
+ * loop until we find next data stripe
+ * or we have finished all stripes.
+ */
+loop:
+ physical += map->stripe_len;
+ ret = get_raid56_logic_offset(physical,
+ num, map, &logical,
+ &stripe_logical);
+ logical += base;
+
+ if (ret && physical < physical_end) {
+ stripe_logical += base;
+ stripe_end = stripe_logical +
+ increment;
+ ret = scrub_raid56_parity(sctx,
+ map, scrub_dev, ppath,
+ stripe_logical,
+ stripe_end);
+ if (ret)
+ goto out;
+ goto loop;
+ }
+ } else {
+ physical += map->stripe_len;
+ logical += increment;
+ }
+ if (logical < key.objectid + bytes) {
+ cond_resched();
+ goto again;
+ }
+
+ if (physical >= physical_end) {
+ stop_loop = 1;
+ break;
+ }
+ }
+next:
+ path->slots[0]++;
+ }
+ btrfs_release_path(path);
+skip:
+ logical += increment;
+ physical += map->stripe_len;
+ spin_lock(&sctx->stat_lock);
+ if (stop_loop)
+ sctx->stat.last_physical = map->stripes[num].physical +
+ length;
+ else
+ sctx->stat.last_physical = physical;
+ spin_unlock(&sctx->stat_lock);
+ if (stop_loop)
+ break;
+ }
+out:
+ /* push queued extents */
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ blk_finish_plug(&plug);
+ btrfs_free_path(path);
+ btrfs_free_path(ppath);
+ return ret < 0 ? ret : 0;
+}
+
+static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
+ struct btrfs_device *scrub_dev,
+ u64 chunk_offset, u64 length,
+ u64 dev_offset,
+ struct btrfs_block_group_cache *cache,
+ int is_dev_replace)
+{
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+ struct map_lookup *map;
+ struct extent_map *em;
+ int i;
+ int ret = 0;
+
+ read_lock(&map_tree->map_tree.lock);
+ em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
+ read_unlock(&map_tree->map_tree.lock);
+
+ if (!em) {
+ /*
+ * Might have been an unused block group deleted by the cleaner
+ * kthread or relocation.
+ */
+ spin_lock(&cache->lock);
+ if (!cache->removed)
+ ret = -EINVAL;
+ spin_unlock(&cache->lock);
+
+ return ret;
+ }
+
+ map = em->map_lookup;
+ if (em->start != chunk_offset)
+ goto out;
+
+ if (em->len < length)
+ goto out;
+
+ for (i = 0; i < map->num_stripes; ++i) {
+ if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
+ map->stripes[i].physical == dev_offset) {
+ ret = scrub_stripe(sctx, map, scrub_dev, i,
+ chunk_offset, length,
+ is_dev_replace);
+ if (ret)
+ goto out;
+ }
+ }
+out:
+ free_extent_map(em);
+
+ return ret;
+}
+
+static noinline_for_stack
+int scrub_enumerate_chunks(struct scrub_ctx *sctx,
+ struct btrfs_device *scrub_dev, u64 start, u64 end,
+ int is_dev_replace)
+{
+ struct btrfs_dev_extent *dev_extent = NULL;
+ struct btrfs_path *path;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_root *root = fs_info->dev_root;
+ u64 length;
+ u64 chunk_offset;
+ int ret = 0;
+ int ro_set;
+ int slot;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = READA_FORWARD;
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ key.objectid = scrub_dev->devid;
+ key.offset = 0ull;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+
+ while (1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ if (path->slots[0] >=
+ btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ } else {
+ ret = 0;
+ }
+ }
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+
+ if (found_key.objectid != scrub_dev->devid)
+ break;
+
+ if (found_key.type != BTRFS_DEV_EXTENT_KEY)
+ break;
+
+ if (found_key.offset >= end)
+ break;
+
+ if (found_key.offset < key.offset)
+ break;
+
+ dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+ length = btrfs_dev_extent_length(l, dev_extent);
+
+ if (found_key.offset + length <= start)
+ goto skip;
+
+ chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
+
+ /*
+ * get a reference on the corresponding block group to prevent
+ * the chunk from going away while we scrub it
+ */
+ cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+
+ /* some chunks are removed but not committed to disk yet,
+ * continue scrubbing */
+ if (!cache)
+ goto skip;
+
+ /*
+ * we need call btrfs_inc_block_group_ro() with scrubs_paused,
+ * to avoid deadlock caused by:
+ * btrfs_inc_block_group_ro()
+ * -> btrfs_wait_for_commit()
+ * -> btrfs_commit_transaction()
+ * -> btrfs_scrub_pause()
+ */
+ scrub_pause_on(fs_info);
+ ret = btrfs_inc_block_group_ro(cache);
+ if (!ret && is_dev_replace) {
+ /*
+ * If we are doing a device replace wait for any tasks
+ * that started dellaloc right before we set the block
+ * group to RO mode, as they might have just allocated
+ * an extent from it or decided they could do a nocow
+ * write. And if any such tasks did that, wait for their
+ * ordered extents to complete and then commit the
+ * current transaction, so that we can later see the new
+ * extent items in the extent tree - the ordered extents
+ * create delayed data references (for cow writes) when
+ * they complete, which will be run and insert the
+ * corresponding extent items into the extent tree when
+ * we commit the transaction they used when running
+ * inode.c:btrfs_finish_ordered_io(). We later use
+ * the commit root of the extent tree to find extents
+ * to copy from the srcdev into the tgtdev, and we don't
+ * want to miss any new extents.
+ */
+ btrfs_wait_block_group_reservations(cache);
+ btrfs_wait_nocow_writers(cache);
+ ret = btrfs_wait_ordered_roots(fs_info, U64_MAX,
+ cache->key.objectid,
+ cache->key.offset);
+ if (ret > 0) {
+ struct btrfs_trans_handle *trans;
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ ret = PTR_ERR(trans);
+ else
+ ret = btrfs_commit_transaction(trans);
+ if (ret) {
+ scrub_pause_off(fs_info);
+ btrfs_put_block_group(cache);
+ break;
+ }
+ }
+ }
+ scrub_pause_off(fs_info);
+
+ if (ret == 0) {
+ ro_set = 1;
+ } else if (ret == -ENOSPC) {
+ /*
+ * btrfs_inc_block_group_ro return -ENOSPC when it
+ * failed in creating new chunk for metadata.
+ * It is not a problem for scrub/replace, because
+ * metadata are always cowed, and our scrub paused
+ * commit_transactions.
+ */
+ ro_set = 0;
+ } else {
+ btrfs_warn(fs_info,
+ "failed setting block group ro: %d", ret);
+ btrfs_put_block_group(cache);
+ break;
+ }
+
+ btrfs_dev_replace_write_lock(&fs_info->dev_replace);
+ dev_replace->cursor_right = found_key.offset + length;
+ dev_replace->cursor_left = found_key.offset;
+ dev_replace->item_needs_writeback = 1;
+ btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
+ ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
+ found_key.offset, cache, is_dev_replace);
+
+ /*
+ * flush, submit all pending read and write bios, afterwards
+ * wait for them.
+ * Note that in the dev replace case, a read request causes
+ * write requests that are submitted in the read completion
+ * worker. Therefore in the current situation, it is required
+ * that all write requests are flushed, so that all read and
+ * write requests are really completed when bios_in_flight
+ * changes to 0.
+ */
+ sctx->flush_all_writes = true;
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+
+ scrub_pause_on(fs_info);
+
+ /*
+ * must be called before we decrease @scrub_paused.
+ * make sure we don't block transaction commit while
+ * we are waiting pending workers finished.
+ */
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->workers_pending) == 0);
+ sctx->flush_all_writes = false;
+
+ scrub_pause_off(fs_info);
+
+ btrfs_dev_replace_write_lock(&fs_info->dev_replace);
+ dev_replace->cursor_left = dev_replace->cursor_right;
+ dev_replace->item_needs_writeback = 1;
+ btrfs_dev_replace_write_unlock(&fs_info->dev_replace);
+
+ if (ro_set)
+ btrfs_dec_block_group_ro(cache);
+
+ /*
+ * We might have prevented the cleaner kthread from deleting
+ * this block group if it was already unused because we raced
+ * and set it to RO mode first. So add it back to the unused
+ * list, otherwise it might not ever be deleted unless a manual
+ * balance is triggered or it becomes used and unused again.
+ */
+ spin_lock(&cache->lock);
+ if (!cache->removed && !cache->ro && cache->reserved == 0 &&
+ btrfs_block_group_used(&cache->item) == 0) {
+ spin_unlock(&cache->lock);
+ btrfs_mark_bg_unused(cache);
+ } else {
+ spin_unlock(&cache->lock);
+ }
+
+ btrfs_put_block_group(cache);
+ if (ret)
+ break;
+ if (is_dev_replace &&
+ atomic64_read(&dev_replace->num_write_errors) > 0) {
+ ret = -EIO;
+ break;
+ }
+ if (sctx->stat.malloc_errors > 0) {
+ ret = -ENOMEM;
+ break;
+ }
+skip:
+ key.offset = found_key.offset + length;
+ btrfs_release_path(path);
+ }
+
+ btrfs_free_path(path);
+
+ return ret;
+}
+
+static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
+ struct btrfs_device *scrub_dev)
+{
+ int i;
+ u64 bytenr;
+ u64 gen;
+ int ret;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+
+ if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
+ return -EIO;
+
+ /* Seed devices of a new filesystem has their own generation. */
+ if (scrub_dev->fs_devices != fs_info->fs_devices)
+ gen = scrub_dev->generation;
+ else
+ gen = fs_info->last_trans_committed;
+
+ for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+ bytenr = btrfs_sb_offset(i);
+ if (bytenr + BTRFS_SUPER_INFO_SIZE >
+ scrub_dev->commit_total_bytes)
+ break;
+
+ ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
+ scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
+ NULL, 1, bytenr);
+ if (ret)
+ return ret;
+ }
+ wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+
+ return 0;
+}
+
+/*
+ * get a reference count on fs_info->scrub_workers. start worker if necessary
+ */
+static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
+ int is_dev_replace)
+{
+ unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
+ int max_active = fs_info->thread_pool_size;
+
+ if (fs_info->scrub_workers_refcnt == 0) {
+ fs_info->scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub",
+ flags, is_dev_replace ? 1 : max_active, 4);
+ if (!fs_info->scrub_workers)
+ goto fail_scrub_workers;
+
+ fs_info->scrub_wr_completion_workers =
+ btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
+ max_active, 2);
+ if (!fs_info->scrub_wr_completion_workers)
+ goto fail_scrub_wr_completion_workers;
+
+ fs_info->scrub_parity_workers =
+ btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
+ max_active, 2);
+ if (!fs_info->scrub_parity_workers)
+ goto fail_scrub_parity_workers;
+ }
+ ++fs_info->scrub_workers_refcnt;
+ return 0;
+
+fail_scrub_parity_workers:
+ btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
+fail_scrub_wr_completion_workers:
+ btrfs_destroy_workqueue(fs_info->scrub_workers);
+fail_scrub_workers:
+ return -ENOMEM;
+}
+
+static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
+{
+ if (--fs_info->scrub_workers_refcnt == 0) {
+ btrfs_destroy_workqueue(fs_info->scrub_workers);
+ btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
+ btrfs_destroy_workqueue(fs_info->scrub_parity_workers);
+ }
+ WARN_ON(fs_info->scrub_workers_refcnt < 0);
+}
+
+int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
+ u64 end, struct btrfs_scrub_progress *progress,
+ int readonly, int is_dev_replace)
+{
+ struct scrub_ctx *sctx;
+ int ret;
+ struct btrfs_device *dev;
+
+ if (btrfs_fs_closing(fs_info))
+ return -EINVAL;
+
+ if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
+ /*
+ * in this case scrub is unable to calculate the checksum
+ * the way scrub is implemented. Do not handle this
+ * situation at all because it won't ever happen.
+ */
+ btrfs_err(fs_info,
+ "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
+ fs_info->nodesize,
+ BTRFS_STRIPE_LEN);
+ return -EINVAL;
+ }
+
+ if (fs_info->sectorsize != PAGE_SIZE) {
+ /* not supported for data w/o checksums */
+ btrfs_err_rl(fs_info,
+ "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
+ fs_info->sectorsize, PAGE_SIZE);
+ return -EINVAL;
+ }
+
+ if (fs_info->nodesize >
+ PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
+ fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
+ /*
+ * would exhaust the array bounds of pagev member in
+ * struct scrub_block
+ */
+ btrfs_err(fs_info,
+ "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
+ fs_info->nodesize,
+ SCRUB_MAX_PAGES_PER_BLOCK,
+ fs_info->sectorsize,
+ SCRUB_MAX_PAGES_PER_BLOCK);
+ return -EINVAL;
+ }
+
+
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+ if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
+ !is_dev_replace)) {
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return -ENODEV;
+ }
+
+ if (!is_dev_replace && !readonly &&
+ !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
+ rcu_str_deref(dev->name));
+ return -EROFS;
+ }
+
+ mutex_lock(&fs_info->scrub_lock);
+ if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
+ test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return -EIO;
+ }
+
+ btrfs_dev_replace_read_lock(&fs_info->dev_replace);
+ if (dev->scrub_ctx ||
+ (!is_dev_replace &&
+ btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
+ btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return -EINPROGRESS;
+ }
+ btrfs_dev_replace_read_unlock(&fs_info->dev_replace);
+
+ ret = scrub_workers_get(fs_info, is_dev_replace);
+ if (ret) {
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return ret;
+ }
+
+ sctx = scrub_setup_ctx(dev, is_dev_replace);
+ if (IS_ERR(sctx)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ scrub_workers_put(fs_info);
+ return PTR_ERR(sctx);
+ }
+ sctx->readonly = readonly;
+ dev->scrub_ctx = sctx;
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+ /*
+ * checking @scrub_pause_req here, we can avoid
+ * race between committing transaction and scrubbing.
+ */
+ __scrub_blocked_if_needed(fs_info);
+ atomic_inc(&fs_info->scrubs_running);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ if (!is_dev_replace) {
+ /*
+ * by holding device list mutex, we can
+ * kick off writing super in log tree sync.
+ */
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ ret = scrub_supers(sctx, dev);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ }
+
+ if (!ret)
+ ret = scrub_enumerate_chunks(sctx, dev, start, end,
+ is_dev_replace);
+
+ wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+ atomic_dec(&fs_info->scrubs_running);
+ wake_up(&fs_info->scrub_pause_wait);
+
+ wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
+
+ if (progress)
+ memcpy(progress, &sctx->stat, sizeof(*progress));
+
+ mutex_lock(&fs_info->scrub_lock);
+ dev->scrub_ctx = NULL;
+ scrub_workers_put(fs_info);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ scrub_put_ctx(sctx);
+
+ return ret;
+}
+
+void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->scrub_lock);
+ atomic_inc(&fs_info->scrub_pause_req);
+ while (atomic_read(&fs_info->scrubs_paused) !=
+ atomic_read(&fs_info->scrubs_running)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ atomic_read(&fs_info->scrubs_paused) ==
+ atomic_read(&fs_info->scrubs_running));
+ mutex_lock(&fs_info->scrub_lock);
+ }
+ mutex_unlock(&fs_info->scrub_lock);
+}
+
+void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
+{
+ atomic_dec(&fs_info->scrub_pause_req);
+ wake_up(&fs_info->scrub_pause_wait);
+}
+
+int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->scrub_lock);
+ if (!atomic_read(&fs_info->scrubs_running)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ return -ENOTCONN;
+ }
+
+ atomic_inc(&fs_info->scrub_cancel_req);
+ while (atomic_read(&fs_info->scrubs_running)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ atomic_read(&fs_info->scrubs_running) == 0);
+ mutex_lock(&fs_info->scrub_lock);
+ }
+ atomic_dec(&fs_info->scrub_cancel_req);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ return 0;
+}
+
+int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
+ struct btrfs_device *dev)
+{
+ struct scrub_ctx *sctx;
+
+ mutex_lock(&fs_info->scrub_lock);
+ sctx = dev->scrub_ctx;
+ if (!sctx) {
+ mutex_unlock(&fs_info->scrub_lock);
+ return -ENOTCONN;
+ }
+ atomic_inc(&sctx->cancel_req);
+ while (dev->scrub_ctx) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ dev->scrub_ctx == NULL);
+ mutex_lock(&fs_info->scrub_lock);
+ }
+ mutex_unlock(&fs_info->scrub_lock);
+
+ return 0;
+}
+
+int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
+ struct btrfs_scrub_progress *progress)
+{
+ struct btrfs_device *dev;
+ struct scrub_ctx *sctx = NULL;
+
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+ if (dev)
+ sctx = dev->scrub_ctx;
+ if (sctx)
+ memcpy(progress, &sctx->stat, sizeof(*progress));
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+ return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
+}
+
+static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
+ u64 extent_logical, u64 extent_len,
+ u64 *extent_physical,
+ struct btrfs_device **extent_dev,
+ int *extent_mirror_num)
+{
+ u64 mapped_length;
+ struct btrfs_bio *bbio = NULL;
+ int ret;
+
+ mapped_length = extent_len;
+ ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
+ &mapped_length, &bbio, 0);
+ if (ret || !bbio || mapped_length < extent_len ||
+ !bbio->stripes[0].dev->bdev) {
+ btrfs_put_bbio(bbio);
+ return;
+ }
+
+ *extent_physical = bbio->stripes[0].physical;
+ *extent_mirror_num = bbio->mirror_num;
+ *extent_dev = bbio->stripes[0].dev;
+ btrfs_put_bbio(bbio);
+}