v4.19.13 snapshot.
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
new file mode 100644
index 0000000..1d54109
--- /dev/null
+++ b/drivers/md/raid1.c
@@ -0,0 +1,3363 @@
+/*
+ * raid1.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
+ *
+ * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
+ *
+ * RAID-1 management functions.
+ *
+ * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
+ *
+ * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
+ * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
+ *
+ * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
+ * bitmapped intelligence in resync:
+ *
+ * - bitmap marked during normal i/o
+ * - bitmap used to skip nondirty blocks during sync
+ *
+ * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
+ * - persistent bitmap code
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/ratelimit.h>
+
+#include <trace/events/block.h>
+
+#include "md.h"
+#include "raid1.h"
+#include "md-bitmap.h"
+
+#define UNSUPPORTED_MDDEV_FLAGS \
+ ((1L << MD_HAS_JOURNAL) | \
+ (1L << MD_JOURNAL_CLEAN) | \
+ (1L << MD_HAS_PPL) | \
+ (1L << MD_HAS_MULTIPLE_PPLS))
+
+/*
+ * Number of guaranteed r1bios in case of extreme VM load:
+ */
+#define NR_RAID1_BIOS 256
+
+/* when we get a read error on a read-only array, we redirect to another
+ * device without failing the first device, or trying to over-write to
+ * correct the read error. To keep track of bad blocks on a per-bio
+ * level, we store IO_BLOCKED in the appropriate 'bios' pointer
+ */
+#define IO_BLOCKED ((struct bio *)1)
+/* When we successfully write to a known bad-block, we need to remove the
+ * bad-block marking which must be done from process context. So we record
+ * the success by setting devs[n].bio to IO_MADE_GOOD
+ */
+#define IO_MADE_GOOD ((struct bio *)2)
+
+#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
+
+/* When there are this many requests queue to be written by
+ * the raid1 thread, we become 'congested' to provide back-pressure
+ * for writeback.
+ */
+static int max_queued_requests = 1024;
+
+static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
+static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
+
+#define raid1_log(md, fmt, args...) \
+ do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
+
+#include "raid1-10.c"
+
+/*
+ * for resync bio, r1bio pointer can be retrieved from the per-bio
+ * 'struct resync_pages'.
+ */
+static inline struct r1bio *get_resync_r1bio(struct bio *bio)
+{
+ return get_resync_pages(bio)->raid_bio;
+}
+
+static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ int size = offsetof(struct r1bio, bios[pi->raid_disks]);
+
+ /* allocate a r1bio with room for raid_disks entries in the bios array */
+ return kzalloc(size, gfp_flags);
+}
+
+static void r1bio_pool_free(void *r1_bio, void *data)
+{
+ kfree(r1_bio);
+}
+
+#define RESYNC_DEPTH 32
+#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
+#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
+#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
+#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
+#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
+
+static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ struct r1bio *r1_bio;
+ struct bio *bio;
+ int need_pages;
+ int j;
+ struct resync_pages *rps;
+
+ r1_bio = r1bio_pool_alloc(gfp_flags, pi);
+ if (!r1_bio)
+ return NULL;
+
+ rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
+ gfp_flags);
+ if (!rps)
+ goto out_free_r1bio;
+
+ /*
+ * Allocate bios : 1 for reading, n-1 for writing
+ */
+ for (j = pi->raid_disks ; j-- ; ) {
+ bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
+ if (!bio)
+ goto out_free_bio;
+ r1_bio->bios[j] = bio;
+ }
+ /*
+ * Allocate RESYNC_PAGES data pages and attach them to
+ * the first bio.
+ * If this is a user-requested check/repair, allocate
+ * RESYNC_PAGES for each bio.
+ */
+ if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
+ need_pages = pi->raid_disks;
+ else
+ need_pages = 1;
+ for (j = 0; j < pi->raid_disks; j++) {
+ struct resync_pages *rp = &rps[j];
+
+ bio = r1_bio->bios[j];
+
+ if (j < need_pages) {
+ if (resync_alloc_pages(rp, gfp_flags))
+ goto out_free_pages;
+ } else {
+ memcpy(rp, &rps[0], sizeof(*rp));
+ resync_get_all_pages(rp);
+ }
+
+ rp->raid_bio = r1_bio;
+ bio->bi_private = rp;
+ }
+
+ r1_bio->master_bio = NULL;
+
+ return r1_bio;
+
+out_free_pages:
+ while (--j >= 0)
+ resync_free_pages(&rps[j]);
+
+out_free_bio:
+ while (++j < pi->raid_disks)
+ bio_put(r1_bio->bios[j]);
+ kfree(rps);
+
+out_free_r1bio:
+ r1bio_pool_free(r1_bio, data);
+ return NULL;
+}
+
+static void r1buf_pool_free(void *__r1_bio, void *data)
+{
+ struct pool_info *pi = data;
+ int i;
+ struct r1bio *r1bio = __r1_bio;
+ struct resync_pages *rp = NULL;
+
+ for (i = pi->raid_disks; i--; ) {
+ rp = get_resync_pages(r1bio->bios[i]);
+ resync_free_pages(rp);
+ bio_put(r1bio->bios[i]);
+ }
+
+ /* resync pages array stored in the 1st bio's .bi_private */
+ kfree(rp);
+
+ r1bio_pool_free(r1bio, data);
+}
+
+static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
+{
+ int i;
+
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+ struct bio **bio = r1_bio->bios + i;
+ if (!BIO_SPECIAL(*bio))
+ bio_put(*bio);
+ *bio = NULL;
+ }
+}
+
+static void free_r1bio(struct r1bio *r1_bio)
+{
+ struct r1conf *conf = r1_bio->mddev->private;
+
+ put_all_bios(conf, r1_bio);
+ mempool_free(r1_bio, &conf->r1bio_pool);
+}
+
+static void put_buf(struct r1bio *r1_bio)
+{
+ struct r1conf *conf = r1_bio->mddev->private;
+ sector_t sect = r1_bio->sector;
+ int i;
+
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+ struct bio *bio = r1_bio->bios[i];
+ if (bio->bi_end_io)
+ rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
+ }
+
+ mempool_free(r1_bio, &conf->r1buf_pool);
+
+ lower_barrier(conf, sect);
+}
+
+static void reschedule_retry(struct r1bio *r1_bio)
+{
+ unsigned long flags;
+ struct mddev *mddev = r1_bio->mddev;
+ struct r1conf *conf = mddev->private;
+ int idx;
+
+ idx = sector_to_idx(r1_bio->sector);
+ spin_lock_irqsave(&conf->device_lock, flags);
+ list_add(&r1_bio->retry_list, &conf->retry_list);
+ atomic_inc(&conf->nr_queued[idx]);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ wake_up(&conf->wait_barrier);
+ md_wakeup_thread(mddev->thread);
+}
+
+/*
+ * raid_end_bio_io() is called when we have finished servicing a mirrored
+ * operation and are ready to return a success/failure code to the buffer
+ * cache layer.
+ */
+static void call_bio_endio(struct r1bio *r1_bio)
+{
+ struct bio *bio = r1_bio->master_bio;
+ struct r1conf *conf = r1_bio->mddev->private;
+
+ if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
+ bio->bi_status = BLK_STS_IOERR;
+
+ bio_endio(bio);
+ /*
+ * Wake up any possible resync thread that waits for the device
+ * to go idle.
+ */
+ allow_barrier(conf, r1_bio->sector);
+}
+
+static void raid_end_bio_io(struct r1bio *r1_bio)
+{
+ struct bio *bio = r1_bio->master_bio;
+
+ /* if nobody has done the final endio yet, do it now */
+ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
+ pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
+ (bio_data_dir(bio) == WRITE) ? "write" : "read",
+ (unsigned long long) bio->bi_iter.bi_sector,
+ (unsigned long long) bio_end_sector(bio) - 1);
+
+ call_bio_endio(r1_bio);
+ }
+ free_r1bio(r1_bio);
+}
+
+/*
+ * Update disk head position estimator based on IRQ completion info.
+ */
+static inline void update_head_pos(int disk, struct r1bio *r1_bio)
+{
+ struct r1conf *conf = r1_bio->mddev->private;
+
+ conf->mirrors[disk].head_position =
+ r1_bio->sector + (r1_bio->sectors);
+}
+
+/*
+ * Find the disk number which triggered given bio
+ */
+static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
+{
+ int mirror;
+ struct r1conf *conf = r1_bio->mddev->private;
+ int raid_disks = conf->raid_disks;
+
+ for (mirror = 0; mirror < raid_disks * 2; mirror++)
+ if (r1_bio->bios[mirror] == bio)
+ break;
+
+ BUG_ON(mirror == raid_disks * 2);
+ update_head_pos(mirror, r1_bio);
+
+ return mirror;
+}
+
+static void raid1_end_read_request(struct bio *bio)
+{
+ int uptodate = !bio->bi_status;
+ struct r1bio *r1_bio = bio->bi_private;
+ struct r1conf *conf = r1_bio->mddev->private;
+ struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
+
+ /*
+ * this branch is our 'one mirror IO has finished' event handler:
+ */
+ update_head_pos(r1_bio->read_disk, r1_bio);
+
+ if (uptodate)
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+ else if (test_bit(FailFast, &rdev->flags) &&
+ test_bit(R1BIO_FailFast, &r1_bio->state))
+ /* This was a fail-fast read so we definitely
+ * want to retry */
+ ;
+ else {
+ /* If all other devices have failed, we want to return
+ * the error upwards rather than fail the last device.
+ * Here we redefine "uptodate" to mean "Don't want to retry"
+ */
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (r1_bio->mddev->degraded == conf->raid_disks ||
+ (r1_bio->mddev->degraded == conf->raid_disks-1 &&
+ test_bit(In_sync, &rdev->flags)))
+ uptodate = 1;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+
+ if (uptodate) {
+ raid_end_bio_io(r1_bio);
+ rdev_dec_pending(rdev, conf->mddev);
+ } else {
+ /*
+ * oops, read error:
+ */
+ char b[BDEVNAME_SIZE];
+ pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n",
+ mdname(conf->mddev),
+ bdevname(rdev->bdev, b),
+ (unsigned long long)r1_bio->sector);
+ set_bit(R1BIO_ReadError, &r1_bio->state);
+ reschedule_retry(r1_bio);
+ /* don't drop the reference on read_disk yet */
+ }
+}
+
+static void close_write(struct r1bio *r1_bio)
+{
+ /* it really is the end of this request */
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ bio_free_pages(r1_bio->behind_master_bio);
+ bio_put(r1_bio->behind_master_bio);
+ r1_bio->behind_master_bio = NULL;
+ }
+ /* clear the bitmap if all writes complete successfully */
+ md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
+ r1_bio->sectors,
+ !test_bit(R1BIO_Degraded, &r1_bio->state),
+ test_bit(R1BIO_BehindIO, &r1_bio->state));
+ md_write_end(r1_bio->mddev);
+}
+
+static void r1_bio_write_done(struct r1bio *r1_bio)
+{
+ if (!atomic_dec_and_test(&r1_bio->remaining))
+ return;
+
+ if (test_bit(R1BIO_WriteError, &r1_bio->state))
+ reschedule_retry(r1_bio);
+ else {
+ close_write(r1_bio);
+ if (test_bit(R1BIO_MadeGood, &r1_bio->state))
+ reschedule_retry(r1_bio);
+ else
+ raid_end_bio_io(r1_bio);
+ }
+}
+
+static void raid1_end_write_request(struct bio *bio)
+{
+ struct r1bio *r1_bio = bio->bi_private;
+ int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
+ struct r1conf *conf = r1_bio->mddev->private;
+ struct bio *to_put = NULL;
+ int mirror = find_bio_disk(r1_bio, bio);
+ struct md_rdev *rdev = conf->mirrors[mirror].rdev;
+ bool discard_error;
+
+ discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
+
+ /*
+ * 'one mirror IO has finished' event handler:
+ */
+ if (bio->bi_status && !discard_error) {
+ set_bit(WriteErrorSeen, &rdev->flags);
+ if (!test_and_set_bit(WantReplacement, &rdev->flags))
+ set_bit(MD_RECOVERY_NEEDED, &
+ conf->mddev->recovery);
+
+ if (test_bit(FailFast, &rdev->flags) &&
+ (bio->bi_opf & MD_FAILFAST) &&
+ /* We never try FailFast to WriteMostly devices */
+ !test_bit(WriteMostly, &rdev->flags)) {
+ md_error(r1_bio->mddev, rdev);
+ if (!test_bit(Faulty, &rdev->flags))
+ /* This is the only remaining device,
+ * We need to retry the write without
+ * FailFast
+ */
+ set_bit(R1BIO_WriteError, &r1_bio->state);
+ else {
+ /* Finished with this branch */
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ }
+ } else
+ set_bit(R1BIO_WriteError, &r1_bio->state);
+ } else {
+ /*
+ * Set R1BIO_Uptodate in our master bio, so that we
+ * will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer
+ * fails.
+ *
+ * The 'master' represents the composite IO operation
+ * to user-side. So if something waits for IO, then it
+ * will wait for the 'master' bio.
+ */
+ sector_t first_bad;
+ int bad_sectors;
+
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ /*
+ * Do not set R1BIO_Uptodate if the current device is
+ * rebuilding or Faulty. This is because we cannot use
+ * such device for properly reading the data back (we could
+ * potentially use it, if the current write would have felt
+ * before rdev->recovery_offset, but for simplicity we don't
+ * check this here.
+ */
+ if (test_bit(In_sync, &rdev->flags) &&
+ !test_bit(Faulty, &rdev->flags))
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ /* Maybe we can clear some bad blocks. */
+ if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
+ &first_bad, &bad_sectors) && !discard_error) {
+ r1_bio->bios[mirror] = IO_MADE_GOOD;
+ set_bit(R1BIO_MadeGood, &r1_bio->state);
+ }
+ }
+
+ if (behind) {
+ if (test_bit(WriteMostly, &rdev->flags))
+ atomic_dec(&r1_bio->behind_remaining);
+
+ /*
+ * In behind mode, we ACK the master bio once the I/O
+ * has safely reached all non-writemostly
+ * disks. Setting the Returned bit ensures that this
+ * gets done only once -- we don't ever want to return
+ * -EIO here, instead we'll wait
+ */
+ if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
+ test_bit(R1BIO_Uptodate, &r1_bio->state)) {
+ /* Maybe we can return now */
+ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
+ struct bio *mbio = r1_bio->master_bio;
+ pr_debug("raid1: behind end write sectors"
+ " %llu-%llu\n",
+ (unsigned long long) mbio->bi_iter.bi_sector,
+ (unsigned long long) bio_end_sector(mbio) - 1);
+ call_bio_endio(r1_bio);
+ }
+ }
+ }
+ if (r1_bio->bios[mirror] == NULL)
+ rdev_dec_pending(rdev, conf->mddev);
+
+ /*
+ * Let's see if all mirrored write operations have finished
+ * already.
+ */
+ r1_bio_write_done(r1_bio);
+
+ if (to_put)
+ bio_put(to_put);
+}
+
+static sector_t align_to_barrier_unit_end(sector_t start_sector,
+ sector_t sectors)
+{
+ sector_t len;
+
+ WARN_ON(sectors == 0);
+ /*
+ * len is the number of sectors from start_sector to end of the
+ * barrier unit which start_sector belongs to.
+ */
+ len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
+ start_sector;
+
+ if (len > sectors)
+ len = sectors;
+
+ return len;
+}
+
+/*
+ * This routine returns the disk from which the requested read should
+ * be done. There is a per-array 'next expected sequential IO' sector
+ * number - if this matches on the next IO then we use the last disk.
+ * There is also a per-disk 'last know head position' sector that is
+ * maintained from IRQ contexts, both the normal and the resync IO
+ * completion handlers update this position correctly. If there is no
+ * perfect sequential match then we pick the disk whose head is closest.
+ *
+ * If there are 2 mirrors in the same 2 devices, performance degrades
+ * because position is mirror, not device based.
+ *
+ * The rdev for the device selected will have nr_pending incremented.
+ */
+static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
+{
+ const sector_t this_sector = r1_bio->sector;
+ int sectors;
+ int best_good_sectors;
+ int best_disk, best_dist_disk, best_pending_disk;
+ int has_nonrot_disk;
+ int disk;
+ sector_t best_dist;
+ unsigned int min_pending;
+ struct md_rdev *rdev;
+ int choose_first;
+ int choose_next_idle;
+
+ rcu_read_lock();
+ /*
+ * Check if we can balance. We can balance on the whole
+ * device if no resync is going on, or below the resync window.
+ * We take the first readable disk when above the resync window.
+ */
+ retry:
+ sectors = r1_bio->sectors;
+ best_disk = -1;
+ best_dist_disk = -1;
+ best_dist = MaxSector;
+ best_pending_disk = -1;
+ min_pending = UINT_MAX;
+ best_good_sectors = 0;
+ has_nonrot_disk = 0;
+ choose_next_idle = 0;
+ clear_bit(R1BIO_FailFast, &r1_bio->state);
+
+ if ((conf->mddev->recovery_cp < this_sector + sectors) ||
+ (mddev_is_clustered(conf->mddev) &&
+ md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
+ this_sector + sectors)))
+ choose_first = 1;
+ else
+ choose_first = 0;
+
+ for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
+ sector_t dist;
+ sector_t first_bad;
+ int bad_sectors;
+ unsigned int pending;
+ bool nonrot;
+
+ rdev = rcu_dereference(conf->mirrors[disk].rdev);
+ if (r1_bio->bios[disk] == IO_BLOCKED
+ || rdev == NULL
+ || test_bit(Faulty, &rdev->flags))
+ continue;
+ if (!test_bit(In_sync, &rdev->flags) &&
+ rdev->recovery_offset < this_sector + sectors)
+ continue;
+ if (test_bit(WriteMostly, &rdev->flags)) {
+ /* Don't balance among write-mostly, just
+ * use the first as a last resort */
+ if (best_dist_disk < 0) {
+ if (is_badblock(rdev, this_sector, sectors,
+ &first_bad, &bad_sectors)) {
+ if (first_bad <= this_sector)
+ /* Cannot use this */
+ continue;
+ best_good_sectors = first_bad - this_sector;
+ } else
+ best_good_sectors = sectors;
+ best_dist_disk = disk;
+ best_pending_disk = disk;
+ }
+ continue;
+ }
+ /* This is a reasonable device to use. It might
+ * even be best.
+ */
+ if (is_badblock(rdev, this_sector, sectors,
+ &first_bad, &bad_sectors)) {
+ if (best_dist < MaxSector)
+ /* already have a better device */
+ continue;
+ if (first_bad <= this_sector) {
+ /* cannot read here. If this is the 'primary'
+ * device, then we must not read beyond
+ * bad_sectors from another device..
+ */
+ bad_sectors -= (this_sector - first_bad);
+ if (choose_first && sectors > bad_sectors)
+ sectors = bad_sectors;
+ if (best_good_sectors > sectors)
+ best_good_sectors = sectors;
+
+ } else {
+ sector_t good_sectors = first_bad - this_sector;
+ if (good_sectors > best_good_sectors) {
+ best_good_sectors = good_sectors;
+ best_disk = disk;
+ }
+ if (choose_first)
+ break;
+ }
+ continue;
+ } else {
+ if ((sectors > best_good_sectors) && (best_disk >= 0))
+ best_disk = -1;
+ best_good_sectors = sectors;
+ }
+
+ if (best_disk >= 0)
+ /* At least two disks to choose from so failfast is OK */
+ set_bit(R1BIO_FailFast, &r1_bio->state);
+
+ nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
+ has_nonrot_disk |= nonrot;
+ pending = atomic_read(&rdev->nr_pending);
+ dist = abs(this_sector - conf->mirrors[disk].head_position);
+ if (choose_first) {
+ best_disk = disk;
+ break;
+ }
+ /* Don't change to another disk for sequential reads */
+ if (conf->mirrors[disk].next_seq_sect == this_sector
+ || dist == 0) {
+ int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
+ struct raid1_info *mirror = &conf->mirrors[disk];
+
+ best_disk = disk;
+ /*
+ * If buffered sequential IO size exceeds optimal
+ * iosize, check if there is idle disk. If yes, choose
+ * the idle disk. read_balance could already choose an
+ * idle disk before noticing it's a sequential IO in
+ * this disk. This doesn't matter because this disk
+ * will idle, next time it will be utilized after the
+ * first disk has IO size exceeds optimal iosize. In
+ * this way, iosize of the first disk will be optimal
+ * iosize at least. iosize of the second disk might be
+ * small, but not a big deal since when the second disk
+ * starts IO, the first disk is likely still busy.
+ */
+ if (nonrot && opt_iosize > 0 &&
+ mirror->seq_start != MaxSector &&
+ mirror->next_seq_sect > opt_iosize &&
+ mirror->next_seq_sect - opt_iosize >=
+ mirror->seq_start) {
+ choose_next_idle = 1;
+ continue;
+ }
+ break;
+ }
+
+ if (choose_next_idle)
+ continue;
+
+ if (min_pending > pending) {
+ min_pending = pending;
+ best_pending_disk = disk;
+ }
+
+ if (dist < best_dist) {
+ best_dist = dist;
+ best_dist_disk = disk;
+ }
+ }
+
+ /*
+ * If all disks are rotational, choose the closest disk. If any disk is
+ * non-rotational, choose the disk with less pending request even the
+ * disk is rotational, which might/might not be optimal for raids with
+ * mixed ratation/non-rotational disks depending on workload.
+ */
+ if (best_disk == -1) {
+ if (has_nonrot_disk || min_pending == 0)
+ best_disk = best_pending_disk;
+ else
+ best_disk = best_dist_disk;
+ }
+
+ if (best_disk >= 0) {
+ rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
+ if (!rdev)
+ goto retry;
+ atomic_inc(&rdev->nr_pending);
+ sectors = best_good_sectors;
+
+ if (conf->mirrors[best_disk].next_seq_sect != this_sector)
+ conf->mirrors[best_disk].seq_start = this_sector;
+
+ conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
+ }
+ rcu_read_unlock();
+ *max_sectors = sectors;
+
+ return best_disk;
+}
+
+static int raid1_congested(struct mddev *mddev, int bits)
+{
+ struct r1conf *conf = mddev->private;
+ int i, ret = 0;
+
+ if ((bits & (1 << WB_async_congested)) &&
+ conf->pending_count >= max_queued_requests)
+ return 1;
+
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ struct request_queue *q = bdev_get_queue(rdev->bdev);
+
+ BUG_ON(!q);
+
+ /* Note the '|| 1' - when read_balance prefers
+ * non-congested targets, it can be removed
+ */
+ if ((bits & (1 << WB_async_congested)) || 1)
+ ret |= bdi_congested(q->backing_dev_info, bits);
+ else
+ ret &= bdi_congested(q->backing_dev_info, bits);
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+static void flush_bio_list(struct r1conf *conf, struct bio *bio)
+{
+ /* flush any pending bitmap writes to disk before proceeding w/ I/O */
+ md_bitmap_unplug(conf->mddev->bitmap);
+ wake_up(&conf->wait_barrier);
+
+ while (bio) { /* submit pending writes */
+ struct bio *next = bio->bi_next;
+ struct md_rdev *rdev = (void *)bio->bi_disk;
+ bio->bi_next = NULL;
+ bio_set_dev(bio, rdev->bdev);
+ if (test_bit(Faulty, &rdev->flags)) {
+ bio_io_error(bio);
+ } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
+ !blk_queue_discard(bio->bi_disk->queue)))
+ /* Just ignore it */
+ bio_endio(bio);
+ else
+ generic_make_request(bio);
+ bio = next;
+ }
+}
+
+static void flush_pending_writes(struct r1conf *conf)
+{
+ /* Any writes that have been queued but are awaiting
+ * bitmap updates get flushed here.
+ */
+ spin_lock_irq(&conf->device_lock);
+
+ if (conf->pending_bio_list.head) {
+ struct blk_plug plug;
+ struct bio *bio;
+
+ bio = bio_list_get(&conf->pending_bio_list);
+ conf->pending_count = 0;
+ spin_unlock_irq(&conf->device_lock);
+
+ /*
+ * As this is called in a wait_event() loop (see freeze_array),
+ * current->state might be TASK_UNINTERRUPTIBLE which will
+ * cause a warning when we prepare to wait again. As it is
+ * rare that this path is taken, it is perfectly safe to force
+ * us to go around the wait_event() loop again, so the warning
+ * is a false-positive. Silence the warning by resetting
+ * thread state
+ */
+ __set_current_state(TASK_RUNNING);
+ blk_start_plug(&plug);
+ flush_bio_list(conf, bio);
+ blk_finish_plug(&plug);
+ } else
+ spin_unlock_irq(&conf->device_lock);
+}
+
+/* Barriers....
+ * Sometimes we need to suspend IO while we do something else,
+ * either some resync/recovery, or reconfigure the array.
+ * To do this we raise a 'barrier'.
+ * The 'barrier' is a counter that can be raised multiple times
+ * to count how many activities are happening which preclude
+ * normal IO.
+ * We can only raise the barrier if there is no pending IO.
+ * i.e. if nr_pending == 0.
+ * We choose only to raise the barrier if no-one is waiting for the
+ * barrier to go down. This means that as soon as an IO request
+ * is ready, no other operations which require a barrier will start
+ * until the IO request has had a chance.
+ *
+ * So: regular IO calls 'wait_barrier'. When that returns there
+ * is no backgroup IO happening, It must arrange to call
+ * allow_barrier when it has finished its IO.
+ * backgroup IO calls must call raise_barrier. Once that returns
+ * there is no normal IO happeing. It must arrange to call
+ * lower_barrier when the particular background IO completes.
+ */
+static sector_t raise_barrier(struct r1conf *conf, sector_t sector_nr)
+{
+ int idx = sector_to_idx(sector_nr);
+
+ spin_lock_irq(&conf->resync_lock);
+
+ /* Wait until no block IO is waiting */
+ wait_event_lock_irq(conf->wait_barrier,
+ !atomic_read(&conf->nr_waiting[idx]),
+ conf->resync_lock);
+
+ /* block any new IO from starting */
+ atomic_inc(&conf->barrier[idx]);
+ /*
+ * In raise_barrier() we firstly increase conf->barrier[idx] then
+ * check conf->nr_pending[idx]. In _wait_barrier() we firstly
+ * increase conf->nr_pending[idx] then check conf->barrier[idx].
+ * A memory barrier here to make sure conf->nr_pending[idx] won't
+ * be fetched before conf->barrier[idx] is increased. Otherwise
+ * there will be a race between raise_barrier() and _wait_barrier().
+ */
+ smp_mb__after_atomic();
+
+ /* For these conditions we must wait:
+ * A: while the array is in frozen state
+ * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
+ * existing in corresponding I/O barrier bucket.
+ * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
+ * max resync count which allowed on current I/O barrier bucket.
+ */
+ wait_event_lock_irq(conf->wait_barrier,
+ (!conf->array_frozen &&
+ !atomic_read(&conf->nr_pending[idx]) &&
+ atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
+ test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
+ conf->resync_lock);
+
+ if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
+ atomic_dec(&conf->barrier[idx]);
+ spin_unlock_irq(&conf->resync_lock);
+ wake_up(&conf->wait_barrier);
+ return -EINTR;
+ }
+
+ atomic_inc(&conf->nr_sync_pending);
+ spin_unlock_irq(&conf->resync_lock);
+
+ return 0;
+}
+
+static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
+{
+ int idx = sector_to_idx(sector_nr);
+
+ BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
+
+ atomic_dec(&conf->barrier[idx]);
+ atomic_dec(&conf->nr_sync_pending);
+ wake_up(&conf->wait_barrier);
+}
+
+static void _wait_barrier(struct r1conf *conf, int idx)
+{
+ /*
+ * We need to increase conf->nr_pending[idx] very early here,
+ * then raise_barrier() can be blocked when it waits for
+ * conf->nr_pending[idx] to be 0. Then we can avoid holding
+ * conf->resync_lock when there is no barrier raised in same
+ * barrier unit bucket. Also if the array is frozen, I/O
+ * should be blocked until array is unfrozen.
+ */
+ atomic_inc(&conf->nr_pending[idx]);
+ /*
+ * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
+ * check conf->barrier[idx]. In raise_barrier() we firstly increase
+ * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
+ * barrier is necessary here to make sure conf->barrier[idx] won't be
+ * fetched before conf->nr_pending[idx] is increased. Otherwise there
+ * will be a race between _wait_barrier() and raise_barrier().
+ */
+ smp_mb__after_atomic();
+
+ /*
+ * Don't worry about checking two atomic_t variables at same time
+ * here. If during we check conf->barrier[idx], the array is
+ * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
+ * 0, it is safe to return and make the I/O continue. Because the
+ * array is frozen, all I/O returned here will eventually complete
+ * or be queued, no race will happen. See code comment in
+ * frozen_array().
+ */
+ if (!READ_ONCE(conf->array_frozen) &&
+ !atomic_read(&conf->barrier[idx]))
+ return;
+
+ /*
+ * After holding conf->resync_lock, conf->nr_pending[idx]
+ * should be decreased before waiting for barrier to drop.
+ * Otherwise, we may encounter a race condition because
+ * raise_barrer() might be waiting for conf->nr_pending[idx]
+ * to be 0 at same time.
+ */
+ spin_lock_irq(&conf->resync_lock);
+ atomic_inc(&conf->nr_waiting[idx]);
+ atomic_dec(&conf->nr_pending[idx]);
+ /*
+ * In case freeze_array() is waiting for
+ * get_unqueued_pending() == extra
+ */
+ wake_up(&conf->wait_barrier);
+ /* Wait for the barrier in same barrier unit bucket to drop. */
+ wait_event_lock_irq(conf->wait_barrier,
+ !conf->array_frozen &&
+ !atomic_read(&conf->barrier[idx]),
+ conf->resync_lock);
+ atomic_inc(&conf->nr_pending[idx]);
+ atomic_dec(&conf->nr_waiting[idx]);
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void wait_read_barrier(struct r1conf *conf, sector_t sector_nr)
+{
+ int idx = sector_to_idx(sector_nr);
+
+ /*
+ * Very similar to _wait_barrier(). The difference is, for read
+ * I/O we don't need wait for sync I/O, but if the whole array
+ * is frozen, the read I/O still has to wait until the array is
+ * unfrozen. Since there is no ordering requirement with
+ * conf->barrier[idx] here, memory barrier is unnecessary as well.
+ */
+ atomic_inc(&conf->nr_pending[idx]);
+
+ if (!READ_ONCE(conf->array_frozen))
+ return;
+
+ spin_lock_irq(&conf->resync_lock);
+ atomic_inc(&conf->nr_waiting[idx]);
+ atomic_dec(&conf->nr_pending[idx]);
+ /*
+ * In case freeze_array() is waiting for
+ * get_unqueued_pending() == extra
+ */
+ wake_up(&conf->wait_barrier);
+ /* Wait for array to be unfrozen */
+ wait_event_lock_irq(conf->wait_barrier,
+ !conf->array_frozen,
+ conf->resync_lock);
+ atomic_inc(&conf->nr_pending[idx]);
+ atomic_dec(&conf->nr_waiting[idx]);
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void wait_barrier(struct r1conf *conf, sector_t sector_nr)
+{
+ int idx = sector_to_idx(sector_nr);
+
+ _wait_barrier(conf, idx);
+}
+
+static void _allow_barrier(struct r1conf *conf, int idx)
+{
+ atomic_dec(&conf->nr_pending[idx]);
+ wake_up(&conf->wait_barrier);
+}
+
+static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
+{
+ int idx = sector_to_idx(sector_nr);
+
+ _allow_barrier(conf, idx);
+}
+
+/* conf->resync_lock should be held */
+static int get_unqueued_pending(struct r1conf *conf)
+{
+ int idx, ret;
+
+ ret = atomic_read(&conf->nr_sync_pending);
+ for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
+ ret += atomic_read(&conf->nr_pending[idx]) -
+ atomic_read(&conf->nr_queued[idx]);
+
+ return ret;
+}
+
+static void freeze_array(struct r1conf *conf, int extra)
+{
+ /* Stop sync I/O and normal I/O and wait for everything to
+ * go quiet.
+ * This is called in two situations:
+ * 1) management command handlers (reshape, remove disk, quiesce).
+ * 2) one normal I/O request failed.
+
+ * After array_frozen is set to 1, new sync IO will be blocked at
+ * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
+ * or wait_read_barrier(). The flying I/Os will either complete or be
+ * queued. When everything goes quite, there are only queued I/Os left.
+
+ * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
+ * barrier bucket index which this I/O request hits. When all sync and
+ * normal I/O are queued, sum of all conf->nr_pending[] will match sum
+ * of all conf->nr_queued[]. But normal I/O failure is an exception,
+ * in handle_read_error(), we may call freeze_array() before trying to
+ * fix the read error. In this case, the error read I/O is not queued,
+ * so get_unqueued_pending() == 1.
+ *
+ * Therefore before this function returns, we need to wait until
+ * get_unqueued_pendings(conf) gets equal to extra. For
+ * normal I/O context, extra is 1, in rested situations extra is 0.
+ */
+ spin_lock_irq(&conf->resync_lock);
+ conf->array_frozen = 1;
+ raid1_log(conf->mddev, "wait freeze");
+ wait_event_lock_irq_cmd(
+ conf->wait_barrier,
+ get_unqueued_pending(conf) == extra,
+ conf->resync_lock,
+ flush_pending_writes(conf));
+ spin_unlock_irq(&conf->resync_lock);
+}
+static void unfreeze_array(struct r1conf *conf)
+{
+ /* reverse the effect of the freeze */
+ spin_lock_irq(&conf->resync_lock);
+ conf->array_frozen = 0;
+ spin_unlock_irq(&conf->resync_lock);
+ wake_up(&conf->wait_barrier);
+}
+
+static void alloc_behind_master_bio(struct r1bio *r1_bio,
+ struct bio *bio)
+{
+ int size = bio->bi_iter.bi_size;
+ unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ int i = 0;
+ struct bio *behind_bio = NULL;
+
+ behind_bio = bio_alloc_mddev(GFP_NOIO, vcnt, r1_bio->mddev);
+ if (!behind_bio)
+ return;
+
+ /* discard op, we don't support writezero/writesame yet */
+ if (!bio_has_data(bio)) {
+ behind_bio->bi_iter.bi_size = size;
+ goto skip_copy;
+ }
+
+ behind_bio->bi_write_hint = bio->bi_write_hint;
+
+ while (i < vcnt && size) {
+ struct page *page;
+ int len = min_t(int, PAGE_SIZE, size);
+
+ page = alloc_page(GFP_NOIO);
+ if (unlikely(!page))
+ goto free_pages;
+
+ bio_add_page(behind_bio, page, len, 0);
+
+ size -= len;
+ i++;
+ }
+
+ bio_copy_data(behind_bio, bio);
+skip_copy:
+ r1_bio->behind_master_bio = behind_bio;
+ set_bit(R1BIO_BehindIO, &r1_bio->state);
+
+ return;
+
+free_pages:
+ pr_debug("%dB behind alloc failed, doing sync I/O\n",
+ bio->bi_iter.bi_size);
+ bio_free_pages(behind_bio);
+ bio_put(behind_bio);
+}
+
+struct raid1_plug_cb {
+ struct blk_plug_cb cb;
+ struct bio_list pending;
+ int pending_cnt;
+};
+
+static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
+{
+ struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
+ cb);
+ struct mddev *mddev = plug->cb.data;
+ struct r1conf *conf = mddev->private;
+ struct bio *bio;
+
+ if (from_schedule || current->bio_list) {
+ spin_lock_irq(&conf->device_lock);
+ bio_list_merge(&conf->pending_bio_list, &plug->pending);
+ conf->pending_count += plug->pending_cnt;
+ spin_unlock_irq(&conf->device_lock);
+ wake_up(&conf->wait_barrier);
+ md_wakeup_thread(mddev->thread);
+ kfree(plug);
+ return;
+ }
+
+ /* we aren't scheduling, so we can do the write-out directly. */
+ bio = bio_list_get(&plug->pending);
+ flush_bio_list(conf, bio);
+ kfree(plug);
+}
+
+static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
+{
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = bio_sectors(bio);
+ r1_bio->state = 0;
+ r1_bio->mddev = mddev;
+ r1_bio->sector = bio->bi_iter.bi_sector;
+}
+
+static inline struct r1bio *
+alloc_r1bio(struct mddev *mddev, struct bio *bio)
+{
+ struct r1conf *conf = mddev->private;
+ struct r1bio *r1_bio;
+
+ r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
+ /* Ensure no bio records IO_BLOCKED */
+ memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
+ init_r1bio(r1_bio, mddev, bio);
+ return r1_bio;
+}
+
+static void raid1_read_request(struct mddev *mddev, struct bio *bio,
+ int max_read_sectors, struct r1bio *r1_bio)
+{
+ struct r1conf *conf = mddev->private;
+ struct raid1_info *mirror;
+ struct bio *read_bio;
+ struct bitmap *bitmap = mddev->bitmap;
+ const int op = bio_op(bio);
+ const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
+ int max_sectors;
+ int rdisk;
+ bool print_msg = !!r1_bio;
+ char b[BDEVNAME_SIZE];
+
+ /*
+ * If r1_bio is set, we are blocking the raid1d thread
+ * so there is a tiny risk of deadlock. So ask for
+ * emergency memory if needed.
+ */
+ gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
+
+ if (print_msg) {
+ /* Need to get the block device name carefully */
+ struct md_rdev *rdev;
+ rcu_read_lock();
+ rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
+ if (rdev)
+ bdevname(rdev->bdev, b);
+ else
+ strcpy(b, "???");
+ rcu_read_unlock();
+ }
+
+ /*
+ * Still need barrier for READ in case that whole
+ * array is frozen.
+ */
+ wait_read_barrier(conf, bio->bi_iter.bi_sector);
+
+ if (!r1_bio)
+ r1_bio = alloc_r1bio(mddev, bio);
+ else
+ init_r1bio(r1_bio, mddev, bio);
+ r1_bio->sectors = max_read_sectors;
+
+ /*
+ * make_request() can abort the operation when read-ahead is being
+ * used and no empty request is available.
+ */
+ rdisk = read_balance(conf, r1_bio, &max_sectors);
+
+ if (rdisk < 0) {
+ /* couldn't find anywhere to read from */
+ if (print_msg) {
+ pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
+ mdname(mddev),
+ b,
+ (unsigned long long)r1_bio->sector);
+ }
+ raid_end_bio_io(r1_bio);
+ return;
+ }
+ mirror = conf->mirrors + rdisk;
+
+ if (print_msg)
+ pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
+ mdname(mddev),
+ (unsigned long long)r1_bio->sector,
+ bdevname(mirror->rdev->bdev, b));
+
+ if (test_bit(WriteMostly, &mirror->rdev->flags) &&
+ bitmap) {
+ /*
+ * Reading from a write-mostly device must take care not to
+ * over-take any writes that are 'behind'
+ */
+ raid1_log(mddev, "wait behind writes");
+ wait_event(bitmap->behind_wait,
+ atomic_read(&bitmap->behind_writes) == 0);
+ }
+
+ if (max_sectors < bio_sectors(bio)) {
+ struct bio *split = bio_split(bio, max_sectors,
+ gfp, &conf->bio_split);
+ bio_chain(split, bio);
+ generic_make_request(bio);
+ bio = split;
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = max_sectors;
+ }
+
+ r1_bio->read_disk = rdisk;
+
+ read_bio = bio_clone_fast(bio, gfp, &mddev->bio_set);
+
+ r1_bio->bios[rdisk] = read_bio;
+
+ read_bio->bi_iter.bi_sector = r1_bio->sector +
+ mirror->rdev->data_offset;
+ bio_set_dev(read_bio, mirror->rdev->bdev);
+ read_bio->bi_end_io = raid1_end_read_request;
+ bio_set_op_attrs(read_bio, op, do_sync);
+ if (test_bit(FailFast, &mirror->rdev->flags) &&
+ test_bit(R1BIO_FailFast, &r1_bio->state))
+ read_bio->bi_opf |= MD_FAILFAST;
+ read_bio->bi_private = r1_bio;
+
+ if (mddev->gendisk)
+ trace_block_bio_remap(read_bio->bi_disk->queue, read_bio,
+ disk_devt(mddev->gendisk), r1_bio->sector);
+
+ generic_make_request(read_bio);
+}
+
+static void raid1_write_request(struct mddev *mddev, struct bio *bio,
+ int max_write_sectors)
+{
+ struct r1conf *conf = mddev->private;
+ struct r1bio *r1_bio;
+ int i, disks;
+ struct bitmap *bitmap = mddev->bitmap;
+ unsigned long flags;
+ struct md_rdev *blocked_rdev;
+ struct blk_plug_cb *cb;
+ struct raid1_plug_cb *plug = NULL;
+ int first_clone;
+ int max_sectors;
+
+ if (mddev_is_clustered(mddev) &&
+ md_cluster_ops->area_resyncing(mddev, WRITE,
+ bio->bi_iter.bi_sector, bio_end_sector(bio))) {
+
+ DEFINE_WAIT(w);
+ for (;;) {
+ prepare_to_wait(&conf->wait_barrier,
+ &w, TASK_IDLE);
+ if (!md_cluster_ops->area_resyncing(mddev, WRITE,
+ bio->bi_iter.bi_sector,
+ bio_end_sector(bio)))
+ break;
+ schedule();
+ }
+ finish_wait(&conf->wait_barrier, &w);
+ }
+
+ /*
+ * Register the new request and wait if the reconstruction
+ * thread has put up a bar for new requests.
+ * Continue immediately if no resync is active currently.
+ */
+ wait_barrier(conf, bio->bi_iter.bi_sector);
+
+ r1_bio = alloc_r1bio(mddev, bio);
+ r1_bio->sectors = max_write_sectors;
+
+ if (conf->pending_count >= max_queued_requests) {
+ md_wakeup_thread(mddev->thread);
+ raid1_log(mddev, "wait queued");
+ wait_event(conf->wait_barrier,
+ conf->pending_count < max_queued_requests);
+ }
+ /* first select target devices under rcu_lock and
+ * inc refcount on their rdev. Record them by setting
+ * bios[x] to bio
+ * If there are known/acknowledged bad blocks on any device on
+ * which we have seen a write error, we want to avoid writing those
+ * blocks.
+ * This potentially requires several writes to write around
+ * the bad blocks. Each set of writes gets it's own r1bio
+ * with a set of bios attached.
+ */
+
+ disks = conf->raid_disks * 2;
+ retry_write:
+ blocked_rdev = NULL;
+ rcu_read_lock();
+ max_sectors = r1_bio->sectors;
+ for (i = 0; i < disks; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+ atomic_inc(&rdev->nr_pending);
+ blocked_rdev = rdev;
+ break;
+ }
+ r1_bio->bios[i] = NULL;
+ if (!rdev || test_bit(Faulty, &rdev->flags)) {
+ if (i < conf->raid_disks)
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ continue;
+ }
+
+ atomic_inc(&rdev->nr_pending);
+ if (test_bit(WriteErrorSeen, &rdev->flags)) {
+ sector_t first_bad;
+ int bad_sectors;
+ int is_bad;
+
+ is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
+ &first_bad, &bad_sectors);
+ if (is_bad < 0) {
+ /* mustn't write here until the bad block is
+ * acknowledged*/
+ set_bit(BlockedBadBlocks, &rdev->flags);
+ blocked_rdev = rdev;
+ break;
+ }
+ if (is_bad && first_bad <= r1_bio->sector) {
+ /* Cannot write here at all */
+ bad_sectors -= (r1_bio->sector - first_bad);
+ if (bad_sectors < max_sectors)
+ /* mustn't write more than bad_sectors
+ * to other devices yet
+ */
+ max_sectors = bad_sectors;
+ rdev_dec_pending(rdev, mddev);
+ /* We don't set R1BIO_Degraded as that
+ * only applies if the disk is
+ * missing, so it might be re-added,
+ * and we want to know to recover this
+ * chunk.
+ * In this case the device is here,
+ * and the fact that this chunk is not
+ * in-sync is recorded in the bad
+ * block log
+ */
+ continue;
+ }
+ if (is_bad) {
+ int good_sectors = first_bad - r1_bio->sector;
+ if (good_sectors < max_sectors)
+ max_sectors = good_sectors;
+ }
+ }
+ r1_bio->bios[i] = bio;
+ }
+ rcu_read_unlock();
+
+ if (unlikely(blocked_rdev)) {
+ /* Wait for this device to become unblocked */
+ int j;
+
+ for (j = 0; j < i; j++)
+ if (r1_bio->bios[j])
+ rdev_dec_pending(conf->mirrors[j].rdev, mddev);
+ r1_bio->state = 0;
+ allow_barrier(conf, bio->bi_iter.bi_sector);
+ raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
+ md_wait_for_blocked_rdev(blocked_rdev, mddev);
+ wait_barrier(conf, bio->bi_iter.bi_sector);
+ goto retry_write;
+ }
+
+ if (max_sectors < bio_sectors(bio)) {
+ struct bio *split = bio_split(bio, max_sectors,
+ GFP_NOIO, &conf->bio_split);
+ bio_chain(split, bio);
+ generic_make_request(bio);
+ bio = split;
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = max_sectors;
+ }
+
+ atomic_set(&r1_bio->remaining, 1);
+ atomic_set(&r1_bio->behind_remaining, 0);
+
+ first_clone = 1;
+
+ for (i = 0; i < disks; i++) {
+ struct bio *mbio = NULL;
+ if (!r1_bio->bios[i])
+ continue;
+
+
+ if (first_clone) {
+ /* do behind I/O ?
+ * Not if there are too many, or cannot
+ * allocate memory, or a reader on WriteMostly
+ * is waiting for behind writes to flush */
+ if (bitmap &&
+ (atomic_read(&bitmap->behind_writes)
+ < mddev->bitmap_info.max_write_behind) &&
+ !waitqueue_active(&bitmap->behind_wait)) {
+ alloc_behind_master_bio(r1_bio, bio);
+ }
+
+ md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
+ test_bit(R1BIO_BehindIO, &r1_bio->state));
+ first_clone = 0;
+ }
+
+ if (r1_bio->behind_master_bio)
+ mbio = bio_clone_fast(r1_bio->behind_master_bio,
+ GFP_NOIO, &mddev->bio_set);
+ else
+ mbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set);
+
+ if (r1_bio->behind_master_bio) {
+ if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
+ atomic_inc(&r1_bio->behind_remaining);
+ }
+
+ r1_bio->bios[i] = mbio;
+
+ mbio->bi_iter.bi_sector = (r1_bio->sector +
+ conf->mirrors[i].rdev->data_offset);
+ bio_set_dev(mbio, conf->mirrors[i].rdev->bdev);
+ mbio->bi_end_io = raid1_end_write_request;
+ mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
+ if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) &&
+ !test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) &&
+ conf->raid_disks - mddev->degraded > 1)
+ mbio->bi_opf |= MD_FAILFAST;
+ mbio->bi_private = r1_bio;
+
+ atomic_inc(&r1_bio->remaining);
+
+ if (mddev->gendisk)
+ trace_block_bio_remap(mbio->bi_disk->queue,
+ mbio, disk_devt(mddev->gendisk),
+ r1_bio->sector);
+ /* flush_pending_writes() needs access to the rdev so...*/
+ mbio->bi_disk = (void *)conf->mirrors[i].rdev;
+
+ cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
+ if (cb)
+ plug = container_of(cb, struct raid1_plug_cb, cb);
+ else
+ plug = NULL;
+ if (plug) {
+ bio_list_add(&plug->pending, mbio);
+ plug->pending_cnt++;
+ } else {
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_add(&conf->pending_bio_list, mbio);
+ conf->pending_count++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ md_wakeup_thread(mddev->thread);
+ }
+ }
+
+ r1_bio_write_done(r1_bio);
+
+ /* In case raid1d snuck in to freeze_array */
+ wake_up(&conf->wait_barrier);
+}
+
+static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
+{
+ sector_t sectors;
+
+ if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+ md_flush_request(mddev, bio);
+ return true;
+ }
+
+ /*
+ * There is a limit to the maximum size, but
+ * the read/write handler might find a lower limit
+ * due to bad blocks. To avoid multiple splits,
+ * we pass the maximum number of sectors down
+ * and let the lower level perform the split.
+ */
+ sectors = align_to_barrier_unit_end(
+ bio->bi_iter.bi_sector, bio_sectors(bio));
+
+ if (bio_data_dir(bio) == READ)
+ raid1_read_request(mddev, bio, sectors, NULL);
+ else {
+ if (!md_write_start(mddev,bio))
+ return false;
+ raid1_write_request(mddev, bio, sectors);
+ }
+ return true;
+}
+
+static void raid1_status(struct seq_file *seq, struct mddev *mddev)
+{
+ struct r1conf *conf = mddev->private;
+ int i;
+
+ seq_printf(seq, " [%d/%d] [", conf->raid_disks,
+ conf->raid_disks - mddev->degraded);
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ seq_printf(seq, "%s",
+ rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+ }
+ rcu_read_unlock();
+ seq_printf(seq, "]");
+}
+
+static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
+{
+ char b[BDEVNAME_SIZE];
+ struct r1conf *conf = mddev->private;
+ unsigned long flags;
+
+ /*
+ * If it is not operational, then we have already marked it as dead
+ * else if it is the last working disks, ignore the error, let the
+ * next level up know.
+ * else mark the drive as failed
+ */
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (test_bit(In_sync, &rdev->flags)
+ && (conf->raid_disks - mddev->degraded) == 1) {
+ /*
+ * Don't fail the drive, act as though we were just a
+ * normal single drive.
+ * However don't try a recovery from this drive as
+ * it is very likely to fail.
+ */
+ conf->recovery_disabled = mddev->recovery_disabled;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ return;
+ }
+ set_bit(Blocked, &rdev->flags);
+ if (test_and_clear_bit(In_sync, &rdev->flags)) {
+ mddev->degraded++;
+ set_bit(Faulty, &rdev->flags);
+ } else
+ set_bit(Faulty, &rdev->flags);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ /*
+ * if recovery is running, make sure it aborts.
+ */
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ set_mask_bits(&mddev->sb_flags, 0,
+ BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
+ pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n"
+ "md/raid1:%s: Operation continuing on %d devices.\n",
+ mdname(mddev), bdevname(rdev->bdev, b),
+ mdname(mddev), conf->raid_disks - mddev->degraded);
+}
+
+static void print_conf(struct r1conf *conf)
+{
+ int i;
+
+ pr_debug("RAID1 conf printout:\n");
+ if (!conf) {
+ pr_debug("(!conf)\n");
+ return;
+ }
+ pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
+ conf->raid_disks);
+
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ char b[BDEVNAME_SIZE];
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev)
+ pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
+ i, !test_bit(In_sync, &rdev->flags),
+ !test_bit(Faulty, &rdev->flags),
+ bdevname(rdev->bdev,b));
+ }
+ rcu_read_unlock();
+}
+
+static void close_sync(struct r1conf *conf)
+{
+ int idx;
+
+ for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
+ _wait_barrier(conf, idx);
+ _allow_barrier(conf, idx);
+ }
+
+ mempool_exit(&conf->r1buf_pool);
+}
+
+static int raid1_spare_active(struct mddev *mddev)
+{
+ int i;
+ struct r1conf *conf = mddev->private;
+ int count = 0;
+ unsigned long flags;
+
+ /*
+ * Find all failed disks within the RAID1 configuration
+ * and mark them readable.
+ * Called under mddev lock, so rcu protection not needed.
+ * device_lock used to avoid races with raid1_end_read_request
+ * which expects 'In_sync' flags and ->degraded to be consistent.
+ */
+ spin_lock_irqsave(&conf->device_lock, flags);
+ for (i = 0; i < conf->raid_disks; i++) {
+ struct md_rdev *rdev = conf->mirrors[i].rdev;
+ struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
+ if (repl
+ && !test_bit(Candidate, &repl->flags)
+ && repl->recovery_offset == MaxSector
+ && !test_bit(Faulty, &repl->flags)
+ && !test_and_set_bit(In_sync, &repl->flags)) {
+ /* replacement has just become active */
+ if (!rdev ||
+ !test_and_clear_bit(In_sync, &rdev->flags))
+ count++;
+ if (rdev) {
+ /* Replaced device not technically
+ * faulty, but we need to be sure
+ * it gets removed and never re-added
+ */
+ set_bit(Faulty, &rdev->flags);
+ sysfs_notify_dirent_safe(
+ rdev->sysfs_state);
+ }
+ }
+ if (rdev
+ && rdev->recovery_offset == MaxSector
+ && !test_bit(Faulty, &rdev->flags)
+ && !test_and_set_bit(In_sync, &rdev->flags)) {
+ count++;
+ sysfs_notify_dirent_safe(rdev->sysfs_state);
+ }
+ }
+ mddev->degraded -= count;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ print_conf(conf);
+ return count;
+}
+
+static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct r1conf *conf = mddev->private;
+ int err = -EEXIST;
+ int mirror = 0;
+ struct raid1_info *p;
+ int first = 0;
+ int last = conf->raid_disks - 1;
+
+ if (mddev->recovery_disabled == conf->recovery_disabled)
+ return -EBUSY;
+
+ if (md_integrity_add_rdev(rdev, mddev))
+ return -ENXIO;
+
+ if (rdev->raid_disk >= 0)
+ first = last = rdev->raid_disk;
+
+ /*
+ * find the disk ... but prefer rdev->saved_raid_disk
+ * if possible.
+ */
+ if (rdev->saved_raid_disk >= 0 &&
+ rdev->saved_raid_disk >= first &&
+ rdev->saved_raid_disk < conf->raid_disks &&
+ conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
+ first = last = rdev->saved_raid_disk;
+
+ for (mirror = first; mirror <= last; mirror++) {
+ p = conf->mirrors+mirror;
+ if (!p->rdev) {
+
+ if (mddev->gendisk)
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+
+ p->head_position = 0;
+ rdev->raid_disk = mirror;
+ err = 0;
+ /* As all devices are equivalent, we don't need a full recovery
+ * if this was recently any drive of the array
+ */
+ if (rdev->saved_raid_disk < 0)
+ conf->fullsync = 1;
+ rcu_assign_pointer(p->rdev, rdev);
+ break;
+ }
+ if (test_bit(WantReplacement, &p->rdev->flags) &&
+ p[conf->raid_disks].rdev == NULL) {
+ /* Add this device as a replacement */
+ clear_bit(In_sync, &rdev->flags);
+ set_bit(Replacement, &rdev->flags);
+ rdev->raid_disk = mirror;
+ err = 0;
+ conf->fullsync = 1;
+ rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
+ break;
+ }
+ }
+ if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
+ blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
+ print_conf(conf);
+ return err;
+}
+
+static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
+{
+ struct r1conf *conf = mddev->private;
+ int err = 0;
+ int number = rdev->raid_disk;
+ struct raid1_info *p = conf->mirrors + number;
+
+ if (rdev != p->rdev)
+ p = conf->mirrors + conf->raid_disks + number;
+
+ print_conf(conf);
+ if (rdev == p->rdev) {
+ if (test_bit(In_sync, &rdev->flags) ||
+ atomic_read(&rdev->nr_pending)) {
+ err = -EBUSY;
+ goto abort;
+ }
+ /* Only remove non-faulty devices if recovery
+ * is not possible.
+ */
+ if (!test_bit(Faulty, &rdev->flags) &&
+ mddev->recovery_disabled != conf->recovery_disabled &&
+ mddev->degraded < conf->raid_disks) {
+ err = -EBUSY;
+ goto abort;
+ }
+ p->rdev = NULL;
+ if (!test_bit(RemoveSynchronized, &rdev->flags)) {
+ synchronize_rcu();
+ if (atomic_read(&rdev->nr_pending)) {
+ /* lost the race, try later */
+ err = -EBUSY;
+ p->rdev = rdev;
+ goto abort;
+ }
+ }
+ if (conf->mirrors[conf->raid_disks + number].rdev) {
+ /* We just removed a device that is being replaced.
+ * Move down the replacement. We drain all IO before
+ * doing this to avoid confusion.
+ */
+ struct md_rdev *repl =
+ conf->mirrors[conf->raid_disks + number].rdev;
+ freeze_array(conf, 0);
+ if (atomic_read(&repl->nr_pending)) {
+ /* It means that some queued IO of retry_list
+ * hold repl. Thus, we cannot set replacement
+ * as NULL, avoiding rdev NULL pointer
+ * dereference in sync_request_write and
+ * handle_write_finished.
+ */
+ err = -EBUSY;
+ unfreeze_array(conf);
+ goto abort;
+ }
+ clear_bit(Replacement, &repl->flags);
+ p->rdev = repl;
+ conf->mirrors[conf->raid_disks + number].rdev = NULL;
+ unfreeze_array(conf);
+ }
+
+ clear_bit(WantReplacement, &rdev->flags);
+ err = md_integrity_register(mddev);
+ }
+abort:
+
+ print_conf(conf);
+ return err;
+}
+
+static void end_sync_read(struct bio *bio)
+{
+ struct r1bio *r1_bio = get_resync_r1bio(bio);
+
+ update_head_pos(r1_bio->read_disk, r1_bio);
+
+ /*
+ * we have read a block, now it needs to be re-written,
+ * or re-read if the read failed.
+ * We don't do much here, just schedule handling by raid1d
+ */
+ if (!bio->bi_status)
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ if (atomic_dec_and_test(&r1_bio->remaining))
+ reschedule_retry(r1_bio);
+}
+
+static void end_sync_write(struct bio *bio)
+{
+ int uptodate = !bio->bi_status;
+ struct r1bio *r1_bio = get_resync_r1bio(bio);
+ struct mddev *mddev = r1_bio->mddev;
+ struct r1conf *conf = mddev->private;
+ sector_t first_bad;
+ int bad_sectors;
+ struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
+
+ if (!uptodate) {
+ sector_t sync_blocks = 0;
+ sector_t s = r1_bio->sector;
+ long sectors_to_go = r1_bio->sectors;
+ /* make sure these bits doesn't get cleared. */
+ do {
+ md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
+ s += sync_blocks;
+ sectors_to_go -= sync_blocks;
+ } while (sectors_to_go > 0);
+ set_bit(WriteErrorSeen, &rdev->flags);
+ if (!test_and_set_bit(WantReplacement, &rdev->flags))
+ set_bit(MD_RECOVERY_NEEDED, &
+ mddev->recovery);
+ set_bit(R1BIO_WriteError, &r1_bio->state);
+ } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
+ &first_bad, &bad_sectors) &&
+ !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
+ r1_bio->sector,
+ r1_bio->sectors,
+ &first_bad, &bad_sectors)
+ )
+ set_bit(R1BIO_MadeGood, &r1_bio->state);
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ int s = r1_bio->sectors;
+ if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
+ test_bit(R1BIO_WriteError, &r1_bio->state))
+ reschedule_retry(r1_bio);
+ else {
+ put_buf(r1_bio);
+ md_done_sync(mddev, s, uptodate);
+ }
+ }
+}
+
+static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
+ int sectors, struct page *page, int rw)
+{
+ if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
+ /* success */
+ return 1;
+ if (rw == WRITE) {
+ set_bit(WriteErrorSeen, &rdev->flags);
+ if (!test_and_set_bit(WantReplacement,
+ &rdev->flags))
+ set_bit(MD_RECOVERY_NEEDED, &
+ rdev->mddev->recovery);
+ }
+ /* need to record an error - either for the block or the device */
+ if (!rdev_set_badblocks(rdev, sector, sectors, 0))
+ md_error(rdev->mddev, rdev);
+ return 0;
+}
+
+static int fix_sync_read_error(struct r1bio *r1_bio)
+{
+ /* Try some synchronous reads of other devices to get
+ * good data, much like with normal read errors. Only
+ * read into the pages we already have so we don't
+ * need to re-issue the read request.
+ * We don't need to freeze the array, because being in an
+ * active sync request, there is no normal IO, and
+ * no overlapping syncs.
+ * We don't need to check is_badblock() again as we
+ * made sure that anything with a bad block in range
+ * will have bi_end_io clear.
+ */
+ struct mddev *mddev = r1_bio->mddev;
+ struct r1conf *conf = mddev->private;
+ struct bio *bio = r1_bio->bios[r1_bio->read_disk];
+ struct page **pages = get_resync_pages(bio)->pages;
+ sector_t sect = r1_bio->sector;
+ int sectors = r1_bio->sectors;
+ int idx = 0;
+ struct md_rdev *rdev;
+
+ rdev = conf->mirrors[r1_bio->read_disk].rdev;
+ if (test_bit(FailFast, &rdev->flags)) {
+ /* Don't try recovering from here - just fail it
+ * ... unless it is the last working device of course */
+ md_error(mddev, rdev);
+ if (test_bit(Faulty, &rdev->flags))
+ /* Don't try to read from here, but make sure
+ * put_buf does it's thing
+ */
+ bio->bi_end_io = end_sync_write;
+ }
+
+ while(sectors) {
+ int s = sectors;
+ int d = r1_bio->read_disk;
+ int success = 0;
+ int start;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+ do {
+ if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
+ /* No rcu protection needed here devices
+ * can only be removed when no resync is
+ * active, and resync is currently active
+ */
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev, sect, s<<9,
+ pages[idx],
+ REQ_OP_READ, 0, false)) {
+ success = 1;
+ break;
+ }
+ }
+ d++;
+ if (d == conf->raid_disks * 2)
+ d = 0;
+ } while (!success && d != r1_bio->read_disk);
+
+ if (!success) {
+ char b[BDEVNAME_SIZE];
+ int abort = 0;
+ /* Cannot read from anywhere, this block is lost.
+ * Record a bad block on each device. If that doesn't
+ * work just disable and interrupt the recovery.
+ * Don't fail devices as that won't really help.
+ */
+ pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
+ mdname(mddev), bio_devname(bio, b),
+ (unsigned long long)r1_bio->sector);
+ for (d = 0; d < conf->raid_disks * 2; d++) {
+ rdev = conf->mirrors[d].rdev;
+ if (!rdev || test_bit(Faulty, &rdev->flags))
+ continue;
+ if (!rdev_set_badblocks(rdev, sect, s, 0))
+ abort = 1;
+ }
+ if (abort) {
+ conf->recovery_disabled =
+ mddev->recovery_disabled;
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ md_done_sync(mddev, r1_bio->sectors, 0);
+ put_buf(r1_bio);
+ return 0;
+ }
+ /* Try next page */
+ sectors -= s;
+ sect += s;
+ idx++;
+ continue;
+ }
+
+ start = d;
+ /* write it back and re-read */
+ while (d != r1_bio->read_disk) {
+ if (d == 0)
+ d = conf->raid_disks * 2;
+ d--;
+ if (r1_bio->bios[d]->bi_end_io != end_sync_read)
+ continue;
+ rdev = conf->mirrors[d].rdev;
+ if (r1_sync_page_io(rdev, sect, s,
+ pages[idx],
+ WRITE) == 0) {
+ r1_bio->bios[d]->bi_end_io = NULL;
+ rdev_dec_pending(rdev, mddev);
+ }
+ }
+ d = start;
+ while (d != r1_bio->read_disk) {
+ if (d == 0)
+ d = conf->raid_disks * 2;
+ d--;
+ if (r1_bio->bios[d]->bi_end_io != end_sync_read)
+ continue;
+ rdev = conf->mirrors[d].rdev;
+ if (r1_sync_page_io(rdev, sect, s,
+ pages[idx],
+ READ) != 0)
+ atomic_add(s, &rdev->corrected_errors);
+ }
+ sectors -= s;
+ sect += s;
+ idx ++;
+ }
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+ bio->bi_status = 0;
+ return 1;
+}
+
+static void process_checks(struct r1bio *r1_bio)
+{
+ /* We have read all readable devices. If we haven't
+ * got the block, then there is no hope left.
+ * If we have, then we want to do a comparison
+ * and skip the write if everything is the same.
+ * If any blocks failed to read, then we need to
+ * attempt an over-write
+ */
+ struct mddev *mddev = r1_bio->mddev;
+ struct r1conf *conf = mddev->private;
+ int primary;
+ int i;
+ int vcnt;
+
+ /* Fix variable parts of all bios */
+ vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+ blk_status_t status;
+ struct bio *b = r1_bio->bios[i];
+ struct resync_pages *rp = get_resync_pages(b);
+ if (b->bi_end_io != end_sync_read)
+ continue;
+ /* fixup the bio for reuse, but preserve errno */
+ status = b->bi_status;
+ bio_reset(b);
+ b->bi_status = status;
+ b->bi_iter.bi_sector = r1_bio->sector +
+ conf->mirrors[i].rdev->data_offset;
+ bio_set_dev(b, conf->mirrors[i].rdev->bdev);
+ b->bi_end_io = end_sync_read;
+ rp->raid_bio = r1_bio;
+ b->bi_private = rp;
+
+ /* initialize bvec table again */
+ md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
+ }
+ for (primary = 0; primary < conf->raid_disks * 2; primary++)
+ if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
+ !r1_bio->bios[primary]->bi_status) {
+ r1_bio->bios[primary]->bi_end_io = NULL;
+ rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
+ break;
+ }
+ r1_bio->read_disk = primary;
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+ int j;
+ struct bio *pbio = r1_bio->bios[primary];
+ struct bio *sbio = r1_bio->bios[i];
+ blk_status_t status = sbio->bi_status;
+ struct page **ppages = get_resync_pages(pbio)->pages;
+ struct page **spages = get_resync_pages(sbio)->pages;
+ struct bio_vec *bi;
+ int page_len[RESYNC_PAGES] = { 0 };
+
+ if (sbio->bi_end_io != end_sync_read)
+ continue;
+ /* Now we can 'fixup' the error value */
+ sbio->bi_status = 0;
+
+ bio_for_each_segment_all(bi, sbio, j)
+ page_len[j] = bi->bv_len;
+
+ if (!status) {
+ for (j = vcnt; j-- ; ) {
+ if (memcmp(page_address(ppages[j]),
+ page_address(spages[j]),
+ page_len[j]))
+ break;
+ }
+ } else
+ j = 0;
+ if (j >= 0)
+ atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
+ if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
+ && !status)) {
+ /* No need to write to this device. */
+ sbio->bi_end_io = NULL;
+ rdev_dec_pending(conf->mirrors[i].rdev, mddev);
+ continue;
+ }
+
+ bio_copy_data(sbio, pbio);
+ }
+}
+
+static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
+{
+ struct r1conf *conf = mddev->private;
+ int i;
+ int disks = conf->raid_disks * 2;
+ struct bio *wbio;
+
+ if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
+ /* ouch - failed to read all of that. */
+ if (!fix_sync_read_error(r1_bio))
+ return;
+
+ if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+ process_checks(r1_bio);
+
+ /*
+ * schedule writes
+ */
+ atomic_set(&r1_bio->remaining, 1);
+ for (i = 0; i < disks ; i++) {
+ wbio = r1_bio->bios[i];
+ if (wbio->bi_end_io == NULL ||
+ (wbio->bi_end_io == end_sync_read &&
+ (i == r1_bio->read_disk ||
+ !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
+ continue;
+ if (test_bit(Faulty, &conf->mirrors[i].rdev->flags))
+ continue;
+
+ bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
+ if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
+ wbio->bi_opf |= MD_FAILFAST;
+
+ wbio->bi_end_io = end_sync_write;
+ atomic_inc(&r1_bio->remaining);
+ md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
+
+ generic_make_request(wbio);
+ }
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ /* if we're here, all write(s) have completed, so clean up */
+ int s = r1_bio->sectors;
+ if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
+ test_bit(R1BIO_WriteError, &r1_bio->state))
+ reschedule_retry(r1_bio);
+ else {
+ put_buf(r1_bio);
+ md_done_sync(mddev, s, 1);
+ }
+ }
+}
+
+/*
+ * This is a kernel thread which:
+ *
+ * 1. Retries failed read operations on working mirrors.
+ * 2. Updates the raid superblock when problems encounter.
+ * 3. Performs writes following reads for array synchronising.
+ */
+
+static void fix_read_error(struct r1conf *conf, int read_disk,
+ sector_t sect, int sectors)
+{
+ struct mddev *mddev = conf->mddev;
+ while(sectors) {
+ int s = sectors;
+ int d = read_disk;
+ int success = 0;
+ int start;
+ struct md_rdev *rdev;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+
+ do {
+ sector_t first_bad;
+ int bad_sectors;
+
+ rcu_read_lock();
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev &&
+ (test_bit(In_sync, &rdev->flags) ||
+ (!test_bit(Faulty, &rdev->flags) &&
+ rdev->recovery_offset >= sect + s)) &&
+ is_badblock(rdev, sect, s,
+ &first_bad, &bad_sectors) == 0) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ if (sync_page_io(rdev, sect, s<<9,
+ conf->tmppage, REQ_OP_READ, 0, false))
+ success = 1;
+ rdev_dec_pending(rdev, mddev);
+ if (success)
+ break;
+ } else
+ rcu_read_unlock();
+ d++;
+ if (d == conf->raid_disks * 2)
+ d = 0;
+ } while (!success && d != read_disk);
+
+ if (!success) {
+ /* Cannot read from anywhere - mark it bad */
+ struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
+ if (!rdev_set_badblocks(rdev, sect, s, 0))
+ md_error(mddev, rdev);
+ break;
+ }
+ /* write it back and re-read */
+ start = d;
+ while (d != read_disk) {
+ if (d==0)
+ d = conf->raid_disks * 2;
+ d--;
+ rcu_read_lock();
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev &&
+ !test_bit(Faulty, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ r1_sync_page_io(rdev, sect, s,
+ conf->tmppage, WRITE);
+ rdev_dec_pending(rdev, mddev);
+ } else
+ rcu_read_unlock();
+ }
+ d = start;
+ while (d != read_disk) {
+ char b[BDEVNAME_SIZE];
+ if (d==0)
+ d = conf->raid_disks * 2;
+ d--;
+ rcu_read_lock();
+ rdev = rcu_dereference(conf->mirrors[d].rdev);
+ if (rdev &&
+ !test_bit(Faulty, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ if (r1_sync_page_io(rdev, sect, s,
+ conf->tmppage, READ)) {
+ atomic_add(s, &rdev->corrected_errors);
+ pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(sect +
+ rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ }
+ rdev_dec_pending(rdev, mddev);
+ } else
+ rcu_read_unlock();
+ }
+ sectors -= s;
+ sect += s;
+ }
+}
+
+static int narrow_write_error(struct r1bio *r1_bio, int i)
+{
+ struct mddev *mddev = r1_bio->mddev;
+ struct r1conf *conf = mddev->private;
+ struct md_rdev *rdev = conf->mirrors[i].rdev;
+
+ /* bio has the data to be written to device 'i' where
+ * we just recently had a write error.
+ * We repeatedly clone the bio and trim down to one block,
+ * then try the write. Where the write fails we record
+ * a bad block.
+ * It is conceivable that the bio doesn't exactly align with
+ * blocks. We must handle this somehow.
+ *
+ * We currently own a reference on the rdev.
+ */
+
+ int block_sectors;
+ sector_t sector;
+ int sectors;
+ int sect_to_write = r1_bio->sectors;
+ int ok = 1;
+
+ if (rdev->badblocks.shift < 0)
+ return 0;
+
+ block_sectors = roundup(1 << rdev->badblocks.shift,
+ bdev_logical_block_size(rdev->bdev) >> 9);
+ sector = r1_bio->sector;
+ sectors = ((sector + block_sectors)
+ & ~(sector_t)(block_sectors - 1))
+ - sector;
+
+ while (sect_to_write) {
+ struct bio *wbio;
+ if (sectors > sect_to_write)
+ sectors = sect_to_write;
+ /* Write at 'sector' for 'sectors'*/
+
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ wbio = bio_clone_fast(r1_bio->behind_master_bio,
+ GFP_NOIO,
+ &mddev->bio_set);
+ } else {
+ wbio = bio_clone_fast(r1_bio->master_bio, GFP_NOIO,
+ &mddev->bio_set);
+ }
+
+ bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
+ wbio->bi_iter.bi_sector = r1_bio->sector;
+ wbio->bi_iter.bi_size = r1_bio->sectors << 9;
+
+ bio_trim(wbio, sector - r1_bio->sector, sectors);
+ wbio->bi_iter.bi_sector += rdev->data_offset;
+ bio_set_dev(wbio, rdev->bdev);
+
+ if (submit_bio_wait(wbio) < 0)
+ /* failure! */
+ ok = rdev_set_badblocks(rdev, sector,
+ sectors, 0)
+ && ok;
+
+ bio_put(wbio);
+ sect_to_write -= sectors;
+ sector += sectors;
+ sectors = block_sectors;
+ }
+ return ok;
+}
+
+static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
+{
+ int m;
+ int s = r1_bio->sectors;
+ for (m = 0; m < conf->raid_disks * 2 ; m++) {
+ struct md_rdev *rdev = conf->mirrors[m].rdev;
+ struct bio *bio = r1_bio->bios[m];
+ if (bio->bi_end_io == NULL)
+ continue;
+ if (!bio->bi_status &&
+ test_bit(R1BIO_MadeGood, &r1_bio->state)) {
+ rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
+ }
+ if (bio->bi_status &&
+ test_bit(R1BIO_WriteError, &r1_bio->state)) {
+ if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
+ md_error(conf->mddev, rdev);
+ }
+ }
+ put_buf(r1_bio);
+ md_done_sync(conf->mddev, s, 1);
+}
+
+static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
+{
+ int m, idx;
+ bool fail = false;
+
+ for (m = 0; m < conf->raid_disks * 2 ; m++)
+ if (r1_bio->bios[m] == IO_MADE_GOOD) {
+ struct md_rdev *rdev = conf->mirrors[m].rdev;
+ rdev_clear_badblocks(rdev,
+ r1_bio->sector,
+ r1_bio->sectors, 0);
+ rdev_dec_pending(rdev, conf->mddev);
+ } else if (r1_bio->bios[m] != NULL) {
+ /* This drive got a write error. We need to
+ * narrow down and record precise write
+ * errors.
+ */
+ fail = true;
+ if (!narrow_write_error(r1_bio, m)) {
+ md_error(conf->mddev,
+ conf->mirrors[m].rdev);
+ /* an I/O failed, we can't clear the bitmap */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ }
+ rdev_dec_pending(conf->mirrors[m].rdev,
+ conf->mddev);
+ }
+ if (fail) {
+ spin_lock_irq(&conf->device_lock);
+ list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
+ idx = sector_to_idx(r1_bio->sector);
+ atomic_inc(&conf->nr_queued[idx]);
+ spin_unlock_irq(&conf->device_lock);
+ /*
+ * In case freeze_array() is waiting for condition
+ * get_unqueued_pending() == extra to be true.
+ */
+ wake_up(&conf->wait_barrier);
+ md_wakeup_thread(conf->mddev->thread);
+ } else {
+ if (test_bit(R1BIO_WriteError, &r1_bio->state))
+ close_write(r1_bio);
+ raid_end_bio_io(r1_bio);
+ }
+}
+
+static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
+{
+ struct mddev *mddev = conf->mddev;
+ struct bio *bio;
+ struct md_rdev *rdev;
+
+ clear_bit(R1BIO_ReadError, &r1_bio->state);
+ /* we got a read error. Maybe the drive is bad. Maybe just
+ * the block and we can fix it.
+ * We freeze all other IO, and try reading the block from
+ * other devices. When we find one, we re-write
+ * and check it that fixes the read error.
+ * This is all done synchronously while the array is
+ * frozen
+ */
+
+ bio = r1_bio->bios[r1_bio->read_disk];
+ bio_put(bio);
+ r1_bio->bios[r1_bio->read_disk] = NULL;
+
+ rdev = conf->mirrors[r1_bio->read_disk].rdev;
+ if (mddev->ro == 0
+ && !test_bit(FailFast, &rdev->flags)) {
+ freeze_array(conf, 1);
+ fix_read_error(conf, r1_bio->read_disk,
+ r1_bio->sector, r1_bio->sectors);
+ unfreeze_array(conf);
+ } else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
+ md_error(mddev, rdev);
+ } else {
+ r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
+ }
+
+ rdev_dec_pending(rdev, conf->mddev);
+ allow_barrier(conf, r1_bio->sector);
+ bio = r1_bio->master_bio;
+
+ /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
+ r1_bio->state = 0;
+ raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
+}
+
+static void raid1d(struct md_thread *thread)
+{
+ struct mddev *mddev = thread->mddev;
+ struct r1bio *r1_bio;
+ unsigned long flags;
+ struct r1conf *conf = mddev->private;
+ struct list_head *head = &conf->retry_list;
+ struct blk_plug plug;
+ int idx;
+
+ md_check_recovery(mddev);
+
+ if (!list_empty_careful(&conf->bio_end_io_list) &&
+ !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
+ LIST_HEAD(tmp);
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
+ list_splice_init(&conf->bio_end_io_list, &tmp);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ while (!list_empty(&tmp)) {
+ r1_bio = list_first_entry(&tmp, struct r1bio,
+ retry_list);
+ list_del(&r1_bio->retry_list);
+ idx = sector_to_idx(r1_bio->sector);
+ atomic_dec(&conf->nr_queued[idx]);
+ if (mddev->degraded)
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ if (test_bit(R1BIO_WriteError, &r1_bio->state))
+ close_write(r1_bio);
+ raid_end_bio_io(r1_bio);
+ }
+ }
+
+ blk_start_plug(&plug);
+ for (;;) {
+
+ flush_pending_writes(conf);
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (list_empty(head)) {
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ break;
+ }
+ r1_bio = list_entry(head->prev, struct r1bio, retry_list);
+ list_del(head->prev);
+ idx = sector_to_idx(r1_bio->sector);
+ atomic_dec(&conf->nr_queued[idx]);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ mddev = r1_bio->mddev;
+ conf = mddev->private;
+ if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
+ if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
+ test_bit(R1BIO_WriteError, &r1_bio->state))
+ handle_sync_write_finished(conf, r1_bio);
+ else
+ sync_request_write(mddev, r1_bio);
+ } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
+ test_bit(R1BIO_WriteError, &r1_bio->state))
+ handle_write_finished(conf, r1_bio);
+ else if (test_bit(R1BIO_ReadError, &r1_bio->state))
+ handle_read_error(conf, r1_bio);
+ else
+ WARN_ON_ONCE(1);
+
+ cond_resched();
+ if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
+ md_check_recovery(mddev);
+ }
+ blk_finish_plug(&plug);
+}
+
+static int init_resync(struct r1conf *conf)
+{
+ int buffs;
+
+ buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
+ BUG_ON(mempool_initialized(&conf->r1buf_pool));
+
+ return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
+ r1buf_pool_free, conf->poolinfo);
+}
+
+static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
+{
+ struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
+ struct resync_pages *rps;
+ struct bio *bio;
+ int i;
+
+ for (i = conf->poolinfo->raid_disks; i--; ) {
+ bio = r1bio->bios[i];
+ rps = bio->bi_private;
+ bio_reset(bio);
+ bio->bi_private = rps;
+ }
+ r1bio->master_bio = NULL;
+ return r1bio;
+}
+
+/*
+ * perform a "sync" on one "block"
+ *
+ * We need to make sure that no normal I/O request - particularly write
+ * requests - conflict with active sync requests.
+ *
+ * This is achieved by tracking pending requests and a 'barrier' concept
+ * that can be installed to exclude normal IO requests.
+ */
+
+static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
+ int *skipped)
+{
+ struct r1conf *conf = mddev->private;
+ struct r1bio *r1_bio;
+ struct bio *bio;
+ sector_t max_sector, nr_sectors;
+ int disk = -1;
+ int i;
+ int wonly = -1;
+ int write_targets = 0, read_targets = 0;
+ sector_t sync_blocks;
+ int still_degraded = 0;
+ int good_sectors = RESYNC_SECTORS;
+ int min_bad = 0; /* number of sectors that are bad in all devices */
+ int idx = sector_to_idx(sector_nr);
+ int page_idx = 0;
+
+ if (!mempool_initialized(&conf->r1buf_pool))
+ if (init_resync(conf))
+ return 0;
+
+ max_sector = mddev->dev_sectors;
+ if (sector_nr >= max_sector) {
+ /* If we aborted, we need to abort the
+ * sync on the 'current' bitmap chunk (there will
+ * only be one in raid1 resync.
+ * We can find the current addess in mddev->curr_resync
+ */
+ if (mddev->curr_resync < max_sector) /* aborted */
+ md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
+ &sync_blocks, 1);
+ else /* completed sync */
+ conf->fullsync = 0;
+
+ md_bitmap_close_sync(mddev->bitmap);
+ close_sync(conf);
+
+ if (mddev_is_clustered(mddev)) {
+ conf->cluster_sync_low = 0;
+ conf->cluster_sync_high = 0;
+ }
+ return 0;
+ }
+
+ if (mddev->bitmap == NULL &&
+ mddev->recovery_cp == MaxSector &&
+ !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
+ conf->fullsync == 0) {
+ *skipped = 1;
+ return max_sector - sector_nr;
+ }
+ /* before building a request, check if we can skip these blocks..
+ * This call the bitmap_start_sync doesn't actually record anything
+ */
+ if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
+ !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+ /* We can skip this block, and probably several more */
+ *skipped = 1;
+ return sync_blocks;
+ }
+
+ /*
+ * If there is non-resync activity waiting for a turn, then let it
+ * though before starting on this new sync request.
+ */
+ if (atomic_read(&conf->nr_waiting[idx]))
+ schedule_timeout_uninterruptible(1);
+
+ /* we are incrementing sector_nr below. To be safe, we check against
+ * sector_nr + two times RESYNC_SECTORS
+ */
+
+ md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
+ mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
+
+
+ if (raise_barrier(conf, sector_nr))
+ return 0;
+
+ r1_bio = raid1_alloc_init_r1buf(conf);
+
+ rcu_read_lock();
+ /*
+ * If we get a correctably read error during resync or recovery,
+ * we might want to read from a different device. So we
+ * flag all drives that could conceivably be read from for READ,
+ * and any others (which will be non-In_sync devices) for WRITE.
+ * If a read fails, we try reading from something else for which READ
+ * is OK.
+ */
+
+ r1_bio->mddev = mddev;
+ r1_bio->sector = sector_nr;
+ r1_bio->state = 0;
+ set_bit(R1BIO_IsSync, &r1_bio->state);
+ /* make sure good_sectors won't go across barrier unit boundary */
+ good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
+
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+ struct md_rdev *rdev;
+ bio = r1_bio->bios[i];
+
+ rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev == NULL ||
+ test_bit(Faulty, &rdev->flags)) {
+ if (i < conf->raid_disks)
+ still_degraded = 1;
+ } else if (!test_bit(In_sync, &rdev->flags)) {
+ bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+ bio->bi_end_io = end_sync_write;
+ write_targets ++;
+ } else {
+ /* may need to read from here */
+ sector_t first_bad = MaxSector;
+ int bad_sectors;
+
+ if (is_badblock(rdev, sector_nr, good_sectors,
+ &first_bad, &bad_sectors)) {
+ if (first_bad > sector_nr)
+ good_sectors = first_bad - sector_nr;
+ else {
+ bad_sectors -= (sector_nr - first_bad);
+ if (min_bad == 0 ||
+ min_bad > bad_sectors)
+ min_bad = bad_sectors;
+ }
+ }
+ if (sector_nr < first_bad) {
+ if (test_bit(WriteMostly, &rdev->flags)) {
+ if (wonly < 0)
+ wonly = i;
+ } else {
+ if (disk < 0)
+ disk = i;
+ }
+ bio_set_op_attrs(bio, REQ_OP_READ, 0);
+ bio->bi_end_io = end_sync_read;
+ read_targets++;
+ } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
+ test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
+ !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
+ /*
+ * The device is suitable for reading (InSync),
+ * but has bad block(s) here. Let's try to correct them,
+ * if we are doing resync or repair. Otherwise, leave
+ * this device alone for this sync request.
+ */
+ bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+ bio->bi_end_io = end_sync_write;
+ write_targets++;
+ }
+ }
+ if (bio->bi_end_io) {
+ atomic_inc(&rdev->nr_pending);
+ bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
+ bio_set_dev(bio, rdev->bdev);
+ if (test_bit(FailFast, &rdev->flags))
+ bio->bi_opf |= MD_FAILFAST;
+ }
+ }
+ rcu_read_unlock();
+ if (disk < 0)
+ disk = wonly;
+ r1_bio->read_disk = disk;
+
+ if (read_targets == 0 && min_bad > 0) {
+ /* These sectors are bad on all InSync devices, so we
+ * need to mark them bad on all write targets
+ */
+ int ok = 1;
+ for (i = 0 ; i < conf->raid_disks * 2 ; i++)
+ if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
+ struct md_rdev *rdev = conf->mirrors[i].rdev;
+ ok = rdev_set_badblocks(rdev, sector_nr,
+ min_bad, 0
+ ) && ok;
+ }
+ set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
+ *skipped = 1;
+ put_buf(r1_bio);
+
+ if (!ok) {
+ /* Cannot record the badblocks, so need to
+ * abort the resync.
+ * If there are multiple read targets, could just
+ * fail the really bad ones ???
+ */
+ conf->recovery_disabled = mddev->recovery_disabled;
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ return 0;
+ } else
+ return min_bad;
+
+ }
+ if (min_bad > 0 && min_bad < good_sectors) {
+ /* only resync enough to reach the next bad->good
+ * transition */
+ good_sectors = min_bad;
+ }
+
+ if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
+ /* extra read targets are also write targets */
+ write_targets += read_targets-1;
+
+ if (write_targets == 0 || read_targets == 0) {
+ /* There is nowhere to write, so all non-sync
+ * drives must be failed - so we are finished
+ */
+ sector_t rv;
+ if (min_bad > 0)
+ max_sector = sector_nr + min_bad;
+ rv = max_sector - sector_nr;
+ *skipped = 1;
+ put_buf(r1_bio);
+ return rv;
+ }
+
+ if (max_sector > mddev->resync_max)
+ max_sector = mddev->resync_max; /* Don't do IO beyond here */
+ if (max_sector > sector_nr + good_sectors)
+ max_sector = sector_nr + good_sectors;
+ nr_sectors = 0;
+ sync_blocks = 0;
+ do {
+ struct page *page;
+ int len = PAGE_SIZE;
+ if (sector_nr + (len>>9) > max_sector)
+ len = (max_sector - sector_nr) << 9;
+ if (len == 0)
+ break;
+ if (sync_blocks == 0) {
+ if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
+ &sync_blocks, still_degraded) &&
+ !conf->fullsync &&
+ !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+ break;
+ if ((len >> 9) > sync_blocks)
+ len = sync_blocks<<9;
+ }
+
+ for (i = 0 ; i < conf->raid_disks * 2; i++) {
+ struct resync_pages *rp;
+
+ bio = r1_bio->bios[i];
+ rp = get_resync_pages(bio);
+ if (bio->bi_end_io) {
+ page = resync_fetch_page(rp, page_idx);
+
+ /*
+ * won't fail because the vec table is big
+ * enough to hold all these pages
+ */
+ bio_add_page(bio, page, len, 0);
+ }
+ }
+ nr_sectors += len>>9;
+ sector_nr += len>>9;
+ sync_blocks -= (len>>9);
+ } while (++page_idx < RESYNC_PAGES);
+
+ r1_bio->sectors = nr_sectors;
+
+ if (mddev_is_clustered(mddev) &&
+ conf->cluster_sync_high < sector_nr + nr_sectors) {
+ conf->cluster_sync_low = mddev->curr_resync_completed;
+ conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
+ /* Send resync message */
+ md_cluster_ops->resync_info_update(mddev,
+ conf->cluster_sync_low,
+ conf->cluster_sync_high);
+ }
+
+ /* For a user-requested sync, we read all readable devices and do a
+ * compare
+ */
+ if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+ atomic_set(&r1_bio->remaining, read_targets);
+ for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io == end_sync_read) {
+ read_targets--;
+ md_sync_acct_bio(bio, nr_sectors);
+ if (read_targets == 1)
+ bio->bi_opf &= ~MD_FAILFAST;
+ generic_make_request(bio);
+ }
+ }
+ } else {
+ atomic_set(&r1_bio->remaining, 1);
+ bio = r1_bio->bios[r1_bio->read_disk];
+ md_sync_acct_bio(bio, nr_sectors);
+ if (read_targets == 1)
+ bio->bi_opf &= ~MD_FAILFAST;
+ generic_make_request(bio);
+
+ }
+ return nr_sectors;
+}
+
+static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
+{
+ if (sectors)
+ return sectors;
+
+ return mddev->dev_sectors;
+}
+
+static struct r1conf *setup_conf(struct mddev *mddev)
+{
+ struct r1conf *conf;
+ int i;
+ struct raid1_info *disk;
+ struct md_rdev *rdev;
+ int err = -ENOMEM;
+
+ conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
+ if (!conf)
+ goto abort;
+
+ conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
+ sizeof(atomic_t), GFP_KERNEL);
+ if (!conf->nr_pending)
+ goto abort;
+
+ conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
+ sizeof(atomic_t), GFP_KERNEL);
+ if (!conf->nr_waiting)
+ goto abort;
+
+ conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
+ sizeof(atomic_t), GFP_KERNEL);
+ if (!conf->nr_queued)
+ goto abort;
+
+ conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
+ sizeof(atomic_t), GFP_KERNEL);
+ if (!conf->barrier)
+ goto abort;
+
+ conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
+ mddev->raid_disks, 2),
+ GFP_KERNEL);
+ if (!conf->mirrors)
+ goto abort;
+
+ conf->tmppage = alloc_page(GFP_KERNEL);
+ if (!conf->tmppage)
+ goto abort;
+
+ conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
+ if (!conf->poolinfo)
+ goto abort;
+ conf->poolinfo->raid_disks = mddev->raid_disks * 2;
+ err = mempool_init(&conf->r1bio_pool, NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free, conf->poolinfo);
+ if (err)
+ goto abort;
+
+ err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
+ if (err)
+ goto abort;
+
+ conf->poolinfo->mddev = mddev;
+
+ err = -EINVAL;
+ spin_lock_init(&conf->device_lock);
+ rdev_for_each(rdev, mddev) {
+ int disk_idx = rdev->raid_disk;
+ if (disk_idx >= mddev->raid_disks
+ || disk_idx < 0)
+ continue;
+ if (test_bit(Replacement, &rdev->flags))
+ disk = conf->mirrors + mddev->raid_disks + disk_idx;
+ else
+ disk = conf->mirrors + disk_idx;
+
+ if (disk->rdev)
+ goto abort;
+ disk->rdev = rdev;
+ disk->head_position = 0;
+ disk->seq_start = MaxSector;
+ }
+ conf->raid_disks = mddev->raid_disks;
+ conf->mddev = mddev;
+ INIT_LIST_HEAD(&conf->retry_list);
+ INIT_LIST_HEAD(&conf->bio_end_io_list);
+
+ spin_lock_init(&conf->resync_lock);
+ init_waitqueue_head(&conf->wait_barrier);
+
+ bio_list_init(&conf->pending_bio_list);
+ conf->pending_count = 0;
+ conf->recovery_disabled = mddev->recovery_disabled - 1;
+
+ err = -EIO;
+ for (i = 0; i < conf->raid_disks * 2; i++) {
+
+ disk = conf->mirrors + i;
+
+ if (i < conf->raid_disks &&
+ disk[conf->raid_disks].rdev) {
+ /* This slot has a replacement. */
+ if (!disk->rdev) {
+ /* No original, just make the replacement
+ * a recovering spare
+ */
+ disk->rdev =
+ disk[conf->raid_disks].rdev;
+ disk[conf->raid_disks].rdev = NULL;
+ } else if (!test_bit(In_sync, &disk->rdev->flags))
+ /* Original is not in_sync - bad */
+ goto abort;
+ }
+
+ if (!disk->rdev ||
+ !test_bit(In_sync, &disk->rdev->flags)) {
+ disk->head_position = 0;
+ if (disk->rdev &&
+ (disk->rdev->saved_raid_disk < 0))
+ conf->fullsync = 1;
+ }
+ }
+
+ err = -ENOMEM;
+ conf->thread = md_register_thread(raid1d, mddev, "raid1");
+ if (!conf->thread)
+ goto abort;
+
+ return conf;
+
+ abort:
+ if (conf) {
+ mempool_exit(&conf->r1bio_pool);
+ kfree(conf->mirrors);
+ safe_put_page(conf->tmppage);
+ kfree(conf->poolinfo);
+ kfree(conf->nr_pending);
+ kfree(conf->nr_waiting);
+ kfree(conf->nr_queued);
+ kfree(conf->barrier);
+ bioset_exit(&conf->bio_split);
+ kfree(conf);
+ }
+ return ERR_PTR(err);
+}
+
+static void raid1_free(struct mddev *mddev, void *priv);
+static int raid1_run(struct mddev *mddev)
+{
+ struct r1conf *conf;
+ int i;
+ struct md_rdev *rdev;
+ int ret;
+ bool discard_supported = false;
+
+ if (mddev->level != 1) {
+ pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
+ mdname(mddev), mddev->level);
+ return -EIO;
+ }
+ if (mddev->reshape_position != MaxSector) {
+ pr_warn("md/raid1:%s: reshape_position set but not supported\n",
+ mdname(mddev));
+ return -EIO;
+ }
+ if (mddev_init_writes_pending(mddev) < 0)
+ return -ENOMEM;
+ /*
+ * copy the already verified devices into our private RAID1
+ * bookkeeping area. [whatever we allocate in run(),
+ * should be freed in raid1_free()]
+ */
+ if (mddev->private == NULL)
+ conf = setup_conf(mddev);
+ else
+ conf = mddev->private;
+
+ if (IS_ERR(conf))
+ return PTR_ERR(conf);
+
+ if (mddev->queue) {
+ blk_queue_max_write_same_sectors(mddev->queue, 0);
+ blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
+ }
+
+ rdev_for_each(rdev, mddev) {
+ if (!mddev->gendisk)
+ continue;
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+ if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+ discard_supported = true;
+ }
+
+ mddev->degraded = 0;
+ for (i=0; i < conf->raid_disks; i++)
+ if (conf->mirrors[i].rdev == NULL ||
+ !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
+ test_bit(Faulty, &conf->mirrors[i].rdev->flags))
+ mddev->degraded++;
+
+ if (conf->raid_disks - mddev->degraded == 1)
+ mddev->recovery_cp = MaxSector;
+
+ if (mddev->recovery_cp != MaxSector)
+ pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
+ mdname(mddev));
+ pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
+ mdname(mddev), mddev->raid_disks - mddev->degraded,
+ mddev->raid_disks);
+
+ /*
+ * Ok, everything is just fine now
+ */
+ mddev->thread = conf->thread;
+ conf->thread = NULL;
+ mddev->private = conf;
+ set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
+
+ md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
+
+ if (mddev->queue) {
+ if (discard_supported)
+ blk_queue_flag_set(QUEUE_FLAG_DISCARD,
+ mddev->queue);
+ else
+ blk_queue_flag_clear(QUEUE_FLAG_DISCARD,
+ mddev->queue);
+ }
+
+ ret = md_integrity_register(mddev);
+ if (ret) {
+ md_unregister_thread(&mddev->thread);
+ raid1_free(mddev, conf);
+ }
+ return ret;
+}
+
+static void raid1_free(struct mddev *mddev, void *priv)
+{
+ struct r1conf *conf = priv;
+
+ mempool_exit(&conf->r1bio_pool);
+ kfree(conf->mirrors);
+ safe_put_page(conf->tmppage);
+ kfree(conf->poolinfo);
+ kfree(conf->nr_pending);
+ kfree(conf->nr_waiting);
+ kfree(conf->nr_queued);
+ kfree(conf->barrier);
+ bioset_exit(&conf->bio_split);
+ kfree(conf);
+}
+
+static int raid1_resize(struct mddev *mddev, sector_t sectors)
+{
+ /* no resync is happening, and there is enough space
+ * on all devices, so we can resize.
+ * We need to make sure resync covers any new space.
+ * If the array is shrinking we should possibly wait until
+ * any io in the removed space completes, but it hardly seems
+ * worth it.
+ */
+ sector_t newsize = raid1_size(mddev, sectors, 0);
+ if (mddev->external_size &&
+ mddev->array_sectors > newsize)
+ return -EINVAL;
+ if (mddev->bitmap) {
+ int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
+ if (ret)
+ return ret;
+ }
+ md_set_array_sectors(mddev, newsize);
+ if (sectors > mddev->dev_sectors &&
+ mddev->recovery_cp > mddev->dev_sectors) {
+ mddev->recovery_cp = mddev->dev_sectors;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ }
+ mddev->dev_sectors = sectors;
+ mddev->resync_max_sectors = sectors;
+ return 0;
+}
+
+static int raid1_reshape(struct mddev *mddev)
+{
+ /* We need to:
+ * 1/ resize the r1bio_pool
+ * 2/ resize conf->mirrors
+ *
+ * We allocate a new r1bio_pool if we can.
+ * Then raise a device barrier and wait until all IO stops.
+ * Then resize conf->mirrors and swap in the new r1bio pool.
+ *
+ * At the same time, we "pack" the devices so that all the missing
+ * devices have the higher raid_disk numbers.
+ */
+ mempool_t newpool, oldpool;
+ struct pool_info *newpoolinfo;
+ struct raid1_info *newmirrors;
+ struct r1conf *conf = mddev->private;
+ int cnt, raid_disks;
+ unsigned long flags;
+ int d, d2;
+ int ret;
+
+ memset(&newpool, 0, sizeof(newpool));
+ memset(&oldpool, 0, sizeof(oldpool));
+
+ /* Cannot change chunk_size, layout, or level */
+ if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
+ mddev->layout != mddev->new_layout ||
+ mddev->level != mddev->new_level) {
+ mddev->new_chunk_sectors = mddev->chunk_sectors;
+ mddev->new_layout = mddev->layout;
+ mddev->new_level = mddev->level;
+ return -EINVAL;
+ }
+
+ if (!mddev_is_clustered(mddev))
+ md_allow_write(mddev);
+
+ raid_disks = mddev->raid_disks + mddev->delta_disks;
+
+ if (raid_disks < conf->raid_disks) {
+ cnt=0;
+ for (d= 0; d < conf->raid_disks; d++)
+ if (conf->mirrors[d].rdev)
+ cnt++;
+ if (cnt > raid_disks)
+ return -EBUSY;
+ }
+
+ newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
+ if (!newpoolinfo)
+ return -ENOMEM;
+ newpoolinfo->mddev = mddev;
+ newpoolinfo->raid_disks = raid_disks * 2;
+
+ ret = mempool_init(&newpool, NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free, newpoolinfo);
+ if (ret) {
+ kfree(newpoolinfo);
+ return ret;
+ }
+ newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
+ raid_disks, 2),
+ GFP_KERNEL);
+ if (!newmirrors) {
+ kfree(newpoolinfo);
+ mempool_exit(&newpool);
+ return -ENOMEM;
+ }
+
+ freeze_array(conf, 0);
+
+ /* ok, everything is stopped */
+ oldpool = conf->r1bio_pool;
+ conf->r1bio_pool = newpool;
+
+ for (d = d2 = 0; d < conf->raid_disks; d++) {
+ struct md_rdev *rdev = conf->mirrors[d].rdev;
+ if (rdev && rdev->raid_disk != d2) {
+ sysfs_unlink_rdev(mddev, rdev);
+ rdev->raid_disk = d2;
+ sysfs_unlink_rdev(mddev, rdev);
+ if (sysfs_link_rdev(mddev, rdev))
+ pr_warn("md/raid1:%s: cannot register rd%d\n",
+ mdname(mddev), rdev->raid_disk);
+ }
+ if (rdev)
+ newmirrors[d2++].rdev = rdev;
+ }
+ kfree(conf->mirrors);
+ conf->mirrors = newmirrors;
+ kfree(conf->poolinfo);
+ conf->poolinfo = newpoolinfo;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded += (raid_disks - conf->raid_disks);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ conf->raid_disks = mddev->raid_disks = raid_disks;
+ mddev->delta_disks = 0;
+
+ unfreeze_array(conf);
+
+ set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
+
+ mempool_exit(&oldpool);
+ return 0;
+}
+
+static void raid1_quiesce(struct mddev *mddev, int quiesce)
+{
+ struct r1conf *conf = mddev->private;
+
+ if (quiesce)
+ freeze_array(conf, 0);
+ else
+ unfreeze_array(conf);
+}
+
+static void *raid1_takeover(struct mddev *mddev)
+{
+ /* raid1 can take over:
+ * raid5 with 2 devices, any layout or chunk size
+ */
+ if (mddev->level == 5 && mddev->raid_disks == 2) {
+ struct r1conf *conf;
+ mddev->new_level = 1;
+ mddev->new_layout = 0;
+ mddev->new_chunk_sectors = 0;
+ conf = setup_conf(mddev);
+ if (!IS_ERR(conf)) {
+ /* Array must appear to be quiesced */
+ conf->array_frozen = 1;
+ mddev_clear_unsupported_flags(mddev,
+ UNSUPPORTED_MDDEV_FLAGS);
+ }
+ return conf;
+ }
+ return ERR_PTR(-EINVAL);
+}
+
+static struct md_personality raid1_personality =
+{
+ .name = "raid1",
+ .level = 1,
+ .owner = THIS_MODULE,
+ .make_request = raid1_make_request,
+ .run = raid1_run,
+ .free = raid1_free,
+ .status = raid1_status,
+ .error_handler = raid1_error,
+ .hot_add_disk = raid1_add_disk,
+ .hot_remove_disk= raid1_remove_disk,
+ .spare_active = raid1_spare_active,
+ .sync_request = raid1_sync_request,
+ .resize = raid1_resize,
+ .size = raid1_size,
+ .check_reshape = raid1_reshape,
+ .quiesce = raid1_quiesce,
+ .takeover = raid1_takeover,
+ .congested = raid1_congested,
+};
+
+static int __init raid_init(void)
+{
+ return register_md_personality(&raid1_personality);
+}
+
+static void raid_exit(void)
+{
+ unregister_md_personality(&raid1_personality);
+}
+
+module_init(raid_init);
+module_exit(raid_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
+MODULE_ALIAS("md-personality-3"); /* RAID1 */
+MODULE_ALIAS("md-raid1");
+MODULE_ALIAS("md-level-1");
+
+module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);