From: Yu Kuai yukuai3@huawei.com
mainline inclusion from mainline-next-20231220 commit a448af25becf4b555660b5ba2618c7ed3c4de6da category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8T02O
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Because it's safe to accees rdev from conf: - If any spinlock is held, because synchronize_rcu() from md_kick_rdev_from_array() will prevent 'rdev' to be freed until spinlock is released; - If 'reconfig_lock' is held, because rdev can't be added or removed from array; - If there is normal IO inflight, because mddev_suspend() will prevent rdev to be added or removed from array; - If there is sync IO inflight, because 'MD_RECOVERY_RUNNING' is checked in remove_and_add_spares().
And these will cover all the scenarios in raid10.
This patch also cleanup the code to handle the case that replacement replace rdev while IO is still inflight.
Signed-off-by: Yu Kuai yukuai3@huawei.com Signed-off-by: Song Liu song@kernel.org Link: https://lore.kernel.org/r/20231125081604.3939938-3-yukuai1@huaweicloud.com Signed-off-by: Li Nan linan122@huawei.com --- drivers/md/raid10.c | 213 ++++++++++++-------------------------------- 1 file changed, 58 insertions(+), 155 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 132a79523338..375c11d6159f 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -743,7 +743,6 @@ static struct md_rdev *read_balance(struct r10conf *conf, struct geom *geo = &conf->geo;
raid10_find_phys(conf, r10_bio); - rcu_read_lock(); best_dist_slot = -1; min_pending = UINT_MAX; best_dist_rdev = NULL; @@ -775,18 +774,11 @@ static struct md_rdev *read_balance(struct r10conf *conf, if (r10_bio->devs[slot].bio == IO_BLOCKED) continue; disk = r10_bio->devs[slot].devnum; - rdev = rcu_dereference(conf->mirrors[disk].replacement); + rdev = conf->mirrors[disk].replacement; if (rdev == NULL || test_bit(Faulty, &rdev->flags) || r10_bio->devs[slot].addr + sectors > - rdev->recovery_offset) { - /* - * Read replacement first to prevent reading both rdev - * and replacement as NULL during replacement replace - * rdev. - */ - smp_mb(); - rdev = rcu_dereference(conf->mirrors[disk].rdev); - } + rdev->recovery_offset) + rdev = conf->mirrors[disk].rdev; if (rdev == NULL || test_bit(Faulty, &rdev->flags)) continue; @@ -876,7 +868,6 @@ static struct md_rdev *read_balance(struct r10conf *conf, r10_bio->read_slot = slot; } else rdev = NULL; - rcu_read_unlock(); *max_sectors = best_good_sectors;
return rdev; @@ -1198,9 +1189,8 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, */ gfp = GFP_NOIO | __GFP_HIGH;
- rcu_read_lock(); disk = r10_bio->devs[slot].devnum; - err_rdev = rcu_dereference(conf->mirrors[disk].rdev); + err_rdev = conf->mirrors[disk].rdev; if (err_rdev) snprintf(b, sizeof(b), "%pg", err_rdev->bdev); else { @@ -1208,7 +1198,6 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, /* This never gets dereferenced */ err_rdev = r10_bio->devs[slot].rdev; } - rcu_read_unlock(); }
if (!regular_request_wait(mddev, conf, bio, r10_bio->sectors)) @@ -1279,15 +1268,8 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio, int devnum = r10_bio->devs[n_copy].devnum; struct bio *mbio;
- if (replacement) { - rdev = conf->mirrors[devnum].replacement; - if (rdev == NULL) { - /* Replacement just got moved to main 'rdev' */ - smp_mb(); - rdev = conf->mirrors[devnum].rdev; - } - } else - rdev = conf->mirrors[devnum].rdev; + rdev = replacement ? conf->mirrors[devnum].replacement : + conf->mirrors[devnum].rdev;
mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO, &mddev->bio_set); if (replacement) @@ -1321,25 +1303,6 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio, } }
-static struct md_rdev *dereference_rdev_and_rrdev(struct raid10_info *mirror, - struct md_rdev **prrdev) -{ - struct md_rdev *rdev, *rrdev; - - rrdev = rcu_dereference(mirror->replacement); - /* - * Read replacement first to prevent reading both rdev and - * replacement as NULL during replacement replace rdev. - */ - smp_mb(); - rdev = rcu_dereference(mirror->rdev); - if (rdev == rrdev) - rrdev = NULL; - - *prrdev = rrdev; - return rdev; -} - static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio) { int i; @@ -1348,11 +1311,11 @@ static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
retry_wait: blocked_rdev = NULL; - rcu_read_lock(); for (i = 0; i < conf->copies; i++) { struct md_rdev *rdev, *rrdev;
- rdev = dereference_rdev_and_rrdev(&conf->mirrors[i], &rrdev); + rdev = conf->mirrors[i].rdev; + rrdev = conf->mirrors[i].replacement; if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { atomic_inc(&rdev->nr_pending); blocked_rdev = rdev; @@ -1391,7 +1354,6 @@ static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio) } } } - rcu_read_unlock();
if (unlikely(blocked_rdev)) { /* Have to wait for this device to get unblocked, then retry */ @@ -1474,14 +1436,14 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
wait_blocked_dev(mddev, r10_bio);
- rcu_read_lock(); max_sectors = r10_bio->sectors;
for (i = 0; i < conf->copies; i++) { int d = r10_bio->devs[i].devnum; struct md_rdev *rdev, *rrdev;
- rdev = dereference_rdev_and_rrdev(&conf->mirrors[d], &rrdev); + rdev = conf->mirrors[d].rdev; + rrdev = conf->mirrors[d].replacement; if (rdev && (test_bit(Faulty, &rdev->flags))) rdev = NULL; if (rrdev && (test_bit(Faulty, &rrdev->flags))) @@ -1535,7 +1497,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, atomic_inc(&rrdev->nr_pending); } } - rcu_read_unlock();
if (max_sectors < r10_bio->sectors) r10_bio->sectors = max_sectors; @@ -1625,17 +1586,8 @@ static void raid10_end_discard_request(struct bio *bio) set_bit(R10BIO_Uptodate, &r10_bio->state);
dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl); - if (repl) - rdev = conf->mirrors[dev].replacement; - if (!rdev) { - /* - * raid10_remove_disk uses smp_mb to make sure rdev is set to - * replacement before setting replacement to NULL. It can read - * rdev first without barrier protect even replacement is NULL - */ - smp_rmb(); - rdev = conf->mirrors[dev].rdev; - } + rdev = repl ? conf->mirrors[dev].replacement : + conf->mirrors[dev].rdev;
raid_end_discard_bio(r10_bio); rdev_dec_pending(rdev, conf->mddev); @@ -1785,11 +1737,11 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) * inc refcount on their rdev. Record them by setting * bios[x] to bio */ - rcu_read_lock(); for (disk = 0; disk < geo->raid_disks; disk++) { struct md_rdev *rdev, *rrdev;
- rdev = dereference_rdev_and_rrdev(&conf->mirrors[disk], &rrdev); + rdev = conf->mirrors[disk].rdev; + rrdev = conf->mirrors[disk].replacement; r10_bio->devs[disk].bio = NULL; r10_bio->devs[disk].repl_bio = NULL;
@@ -1809,7 +1761,6 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) atomic_inc(&rrdev->nr_pending); } } - rcu_read_unlock();
atomic_set(&r10_bio->remaining, 1); for (disk = 0; disk < geo->raid_disks; disk++) { @@ -1939,6 +1890,8 @@ static void raid10_status(struct seq_file *seq, struct mddev *mddev) struct r10conf *conf = mddev->private; int i;
+ lockdep_assert_held(&mddev->lock); + if (conf->geo.near_copies < conf->geo.raid_disks) seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2); if (conf->geo.near_copies > 1) @@ -1953,12 +1906,11 @@ static void raid10_status(struct seq_file *seq, struct mddev *mddev) } seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks, conf->geo.raid_disks - mddev->degraded); - rcu_read_lock(); for (i = 0; i < conf->geo.raid_disks; i++) { - struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); + struct md_rdev *rdev = READ_ONCE(conf->mirrors[i].rdev); + seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); } - rcu_read_unlock(); seq_printf(seq, "]"); }
@@ -1980,7 +1932,6 @@ static int _enough(struct r10conf *conf, int previous, int ignore) ncopies = conf->geo.near_copies; }
- rcu_read_lock(); do { int n = conf->copies; int cnt = 0; @@ -1988,7 +1939,7 @@ static int _enough(struct r10conf *conf, int previous, int ignore) while (n--) { struct md_rdev *rdev; if (this != ignore && - (rdev = rcu_dereference(conf->mirrors[this].rdev)) && + (rdev = conf->mirrors[this].rdev) && test_bit(In_sync, &rdev->flags)) cnt++; this = (this+1) % disks; @@ -1999,7 +1950,6 @@ static int _enough(struct r10conf *conf, int previous, int ignore) } while (first != 0); has_enough = 1; out: - rcu_read_unlock(); return has_enough; }
@@ -2072,8 +2022,7 @@ static void print_conf(struct r10conf *conf) pr_debug(" --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded, conf->geo.raid_disks);
- /* This is only called with ->reconfix_mutex held, so - * rcu protection of rdev is not needed */ + lockdep_assert_held(&conf->mddev->reconfig_mutex); for (i = 0; i < conf->geo.raid_disks; i++) { rdev = conf->mirrors[i].rdev; if (rdev) @@ -2190,7 +2139,7 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev) err = 0; if (rdev->saved_raid_disk != mirror) conf->fullsync = 1; - rcu_assign_pointer(p->rdev, rdev); + WRITE_ONCE(p->rdev, rdev); break; }
@@ -2204,7 +2153,7 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev) disk_stack_limits(mddev->gendisk, rdev->bdev, rdev->data_offset << 9); conf->fullsync = 1; - rcu_assign_pointer(p->replacement, rdev); + WRITE_ONCE(p->replacement, rdev); }
print_conf(conf); @@ -2246,15 +2195,12 @@ static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev) err = -EBUSY; goto abort; } - *rdevp = NULL; + WRITE_ONCE(*rdevp, NULL); if (p->replacement) { /* We must have just cleared 'rdev' */ - p->rdev = p->replacement; + WRITE_ONCE(p->rdev, p->replacement); clear_bit(Replacement, &p->replacement->flags); - smp_mb(); /* Make sure other CPUs may see both as identical - * but will never see neither -- if they are careful. - */ - p->replacement = NULL; + WRITE_ONCE(p->replacement, NULL); }
clear_bit(WantReplacement, &rdev->flags); @@ -2754,20 +2700,18 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 if (s > (PAGE_SIZE>>9)) s = PAGE_SIZE >> 9;
- rcu_read_lock(); do { sector_t first_bad; int bad_sectors;
d = r10_bio->devs[sl].devnum; - rdev = rcu_dereference(conf->mirrors[d].rdev); + rdev = conf->mirrors[d].rdev; if (rdev && test_bit(In_sync, &rdev->flags) && !test_bit(Faulty, &rdev->flags) && is_badblock(rdev, r10_bio->devs[sl].addr + sect, s, &first_bad, &bad_sectors) == 0) { atomic_inc(&rdev->nr_pending); - rcu_read_unlock(); success = sync_page_io(rdev, r10_bio->devs[sl].addr + sect, @@ -2775,7 +2719,6 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 conf->tmppage, REQ_OP_READ, false); rdev_dec_pending(rdev, mddev); - rcu_read_lock(); if (success) break; } @@ -2783,7 +2726,6 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 if (sl == conf->copies) sl = 0; } while (sl != slot); - rcu_read_unlock();
if (!success) { /* Cannot read from anywhere, just mark the block @@ -2807,20 +2749,18 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10
start = sl; /* write it back and re-read */ - rcu_read_lock(); while (sl != slot) { if (sl==0) sl = conf->copies; sl--; d = r10_bio->devs[sl].devnum; - rdev = rcu_dereference(conf->mirrors[d].rdev); + rdev = conf->mirrors[d].rdev; if (!rdev || test_bit(Faulty, &rdev->flags) || !test_bit(In_sync, &rdev->flags)) continue;
atomic_inc(&rdev->nr_pending); - rcu_read_unlock(); if (r10_sync_page_io(rdev, r10_bio->devs[sl].addr + sect, @@ -2839,7 +2779,6 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 rdev->bdev); } rdev_dec_pending(rdev, mddev); - rcu_read_lock(); } sl = start; while (sl != slot) { @@ -2847,14 +2786,13 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 sl = conf->copies; sl--; d = r10_bio->devs[sl].devnum; - rdev = rcu_dereference(conf->mirrors[d].rdev); + rdev = conf->mirrors[d].rdev; if (!rdev || test_bit(Faulty, &rdev->flags) || !test_bit(In_sync, &rdev->flags)) continue;
atomic_inc(&rdev->nr_pending); - rcu_read_unlock(); switch (r10_sync_page_io(rdev, r10_bio->devs[sl].addr + sect, @@ -2882,9 +2820,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 }
rdev_dec_pending(rdev, mddev); - rcu_read_lock(); } - rcu_read_unlock();
sectors -= s; sect += s; @@ -3358,14 +3294,13 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, /* Completed a full sync so the replacements * are now fully recovered. */ - rcu_read_lock(); for (i = 0; i < conf->geo.raid_disks; i++) { struct md_rdev *rdev = - rcu_dereference(conf->mirrors[i].replacement); + conf->mirrors[i].replacement; + if (rdev) rdev->recovery_offset = MaxSector; } - rcu_read_unlock(); } conf->fullsync = 0; } @@ -3446,9 +3381,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, struct raid10_info *mirror = &conf->mirrors[i]; struct md_rdev *mrdev, *mreplace;
- rcu_read_lock(); - mrdev = rcu_dereference(mirror->rdev); - mreplace = rcu_dereference(mirror->replacement); + mrdev = mirror->rdev; + mreplace = mirror->replacement;
if (mrdev && (test_bit(Faulty, &mrdev->flags) || test_bit(In_sync, &mrdev->flags))) @@ -3456,22 +3390,18 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, if (mreplace && test_bit(Faulty, &mreplace->flags)) mreplace = NULL;
- if (!mrdev && !mreplace) { - rcu_read_unlock(); + if (!mrdev && !mreplace) continue; - }
still_degraded = 0; /* want to reconstruct this device */ rb2 = r10_bio; sect = raid10_find_virt(conf, sector_nr, i); - if (sect >= mddev->resync_max_sectors) { + if (sect >= mddev->resync_max_sectors) /* last stripe is not complete - don't * try to recover this sector. */ - rcu_read_unlock(); continue; - } /* Unless we are doing a full sync, or a replacement * we only need to recover the block if it is set in * the bitmap @@ -3487,14 +3417,12 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, * that there will never be anything to do here */ chunks_skipped = -1; - rcu_read_unlock(); continue; } if (mrdev) atomic_inc(&mrdev->nr_pending); if (mreplace) atomic_inc(&mreplace->nr_pending); - rcu_read_unlock();
r10_bio = raid10_alloc_init_r10buf(conf); r10_bio->state = 0; @@ -3513,10 +3441,9 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, /* Need to check if the array will still be * degraded */ - rcu_read_lock(); for (j = 0; j < conf->geo.raid_disks; j++) { - struct md_rdev *rdev = rcu_dereference( - conf->mirrors[j].rdev); + struct md_rdev *rdev = conf->mirrors[j].rdev; + if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { still_degraded = 1; break; @@ -3531,8 +3458,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, int k; int d = r10_bio->devs[j].devnum; sector_t from_addr, to_addr; - struct md_rdev *rdev = - rcu_dereference(conf->mirrors[d].rdev); + struct md_rdev *rdev = conf->mirrors[d].rdev; sector_t sector, first_bad; int bad_sectors; if (!rdev || @@ -3611,7 +3537,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, atomic_inc(&r10_bio->remaining); break; } - rcu_read_unlock(); if (j == conf->copies) { /* Cannot recover, so abort the recovery or * record a bad block */ @@ -3738,12 +3663,10 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
bio = r10_bio->devs[i].bio; bio->bi_status = BLK_STS_IOERR; - rcu_read_lock(); - rdev = rcu_dereference(conf->mirrors[d].rdev); - if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { - rcu_read_unlock(); + rdev = conf->mirrors[d].rdev; + if (rdev == NULL || test_bit(Faulty, &rdev->flags)) continue; - } + sector = r10_bio->devs[i].addr; if (is_badblock(rdev, sector, max_sync, &first_bad, &bad_sectors)) { @@ -3753,7 +3676,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, bad_sectors -= (sector - first_bad); if (max_sync > bad_sectors) max_sync = bad_sectors; - rcu_read_unlock(); continue; } } @@ -3769,11 +3691,10 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, bio_set_dev(bio, rdev->bdev); count++;
- rdev = rcu_dereference(conf->mirrors[d].replacement); - if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { - rcu_read_unlock(); + rdev = conf->mirrors[d].replacement; + if (rdev == NULL || test_bit(Faulty, &rdev->flags)) continue; - } + atomic_inc(&rdev->nr_pending);
/* Need to set up for writing to the replacement */ @@ -3790,7 +3711,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, bio->bi_iter.bi_sector = sector + rdev->data_offset; bio_set_dev(bio, rdev->bdev); count++; - rcu_read_unlock(); }
if (count < 2) { @@ -4500,11 +4420,11 @@ static int calc_degraded(struct r10conf *conf) int degraded, degraded2; int i;
- rcu_read_lock(); degraded = 0; /* 'prev' section first */ for (i = 0; i < conf->prev.raid_disks; i++) { - struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); + struct md_rdev *rdev = conf->mirrors[i].rdev; + if (!rdev || test_bit(Faulty, &rdev->flags)) degraded++; else if (!test_bit(In_sync, &rdev->flags)) @@ -4514,13 +4434,12 @@ static int calc_degraded(struct r10conf *conf) */ degraded++; } - rcu_read_unlock(); if (conf->geo.raid_disks == conf->prev.raid_disks) return degraded; - rcu_read_lock(); degraded2 = 0; for (i = 0; i < conf->geo.raid_disks; i++) { - struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); + struct md_rdev *rdev = conf->mirrors[i].rdev; + if (!rdev || test_bit(Faulty, &rdev->flags)) degraded2++; else if (!test_bit(In_sync, &rdev->flags)) { @@ -4533,7 +4452,6 @@ static int calc_degraded(struct r10conf *conf) degraded2++; } } - rcu_read_unlock(); if (degraded2 > degraded) return degraded2; return degraded; @@ -4965,16 +4883,15 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, blist = read_bio; read_bio->bi_next = NULL;
- rcu_read_lock(); for (s = 0; s < conf->copies*2; s++) { struct bio *b; int d = r10_bio->devs[s/2].devnum; struct md_rdev *rdev2; if (s&1) { - rdev2 = rcu_dereference(conf->mirrors[d].replacement); + rdev2 = conf->mirrors[d].replacement; b = r10_bio->devs[s/2].repl_bio; } else { - rdev2 = rcu_dereference(conf->mirrors[d].rdev); + rdev2 = conf->mirrors[d].rdev; b = r10_bio->devs[s/2].bio; } if (!rdev2 || test_bit(Faulty, &rdev2->flags)) @@ -5008,7 +4925,6 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, sector_nr += len >> 9; nr_sectors += len >> 9; } - rcu_read_unlock(); r10_bio->sectors = nr_sectors;
/* Now submit the read */ @@ -5061,20 +4977,17 @@ static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio) struct bio *b; int d = r10_bio->devs[s/2].devnum; struct md_rdev *rdev; - rcu_read_lock(); if (s&1) { - rdev = rcu_dereference(conf->mirrors[d].replacement); + rdev = conf->mirrors[d].replacement; b = r10_bio->devs[s/2].repl_bio; } else { - rdev = rcu_dereference(conf->mirrors[d].rdev); + rdev = conf->mirrors[d].rdev; b = r10_bio->devs[s/2].bio; } - if (!rdev || test_bit(Faulty, &rdev->flags)) { - rcu_read_unlock(); + if (!rdev || test_bit(Faulty, &rdev->flags)) continue; - } + atomic_inc(&rdev->nr_pending); - rcu_read_unlock(); md_sync_acct_bio(b, r10_bio->sectors); atomic_inc(&r10_bio->remaining); b->bi_next = NULL; @@ -5145,10 +5058,9 @@ static int handle_reshape_read_error(struct mddev *mddev, if (s > (PAGE_SIZE >> 9)) s = PAGE_SIZE >> 9;
- rcu_read_lock(); while (!success) { int d = r10b->devs[slot].devnum; - struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev); + struct md_rdev *rdev = conf->mirrors[d].rdev; sector_t addr; if (rdev == NULL || test_bit(Faulty, &rdev->flags) || @@ -5157,14 +5069,12 @@ static int handle_reshape_read_error(struct mddev *mddev,
addr = r10b->devs[slot].addr + idx * PAGE_SIZE; atomic_inc(&rdev->nr_pending); - rcu_read_unlock(); success = sync_page_io(rdev, addr, s << 9, pages[idx], REQ_OP_READ, false); rdev_dec_pending(rdev, mddev); - rcu_read_lock(); if (success) break; failed: @@ -5174,7 +5084,6 @@ static int handle_reshape_read_error(struct mddev *mddev, if (slot == first_slot) break; } - rcu_read_unlock(); if (!success) { /* couldn't read this block, must give up */ set_bit(MD_RECOVERY_INTR, @@ -5200,12 +5109,8 @@ static void end_reshape_write(struct bio *bio) struct md_rdev *rdev = NULL;
d = find_bio_disk(conf, r10_bio, bio, &slot, &repl); - if (repl) - rdev = conf->mirrors[d].replacement; - if (!rdev) { - smp_mb(); - rdev = conf->mirrors[d].rdev; - } + rdev = repl ? conf->mirrors[d].replacement : + conf->mirrors[d].rdev;
if (bio->bi_status) { /* FIXME should record badblock */ @@ -5240,18 +5145,16 @@ static void raid10_finish_reshape(struct mddev *mddev) mddev->resync_max_sectors = mddev->array_sectors; } else { int d; - rcu_read_lock(); for (d = conf->geo.raid_disks ; d < conf->geo.raid_disks - mddev->delta_disks; d++) { - struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev); + struct md_rdev *rdev = conf->mirrors[d].rdev; if (rdev) clear_bit(In_sync, &rdev->flags); - rdev = rcu_dereference(conf->mirrors[d].replacement); + rdev = conf->mirrors[d].replacement; if (rdev) clear_bit(In_sync, &rdev->flags); } - rcu_read_unlock(); } mddev->layout = mddev->new_layout; mddev->chunk_sectors = 1 << conf->geo.chunk_shift;