diff options
| author | Yufen Yu <yuyufen@huawei.com> | 2018-04-09 09:50:44 +0800 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2018-04-09 08:41:16 -0700 |
| commit | 8c2425932398a160f687534efe71f0ec4b92833e (patch) | |
| tree | aa5015eade10a68adf26f927a06164b0d66cfb61 | |
| parent | 0ea9924abe125a0c1277484f1a3d512b3f45c320 (diff) | |
md/raid1: exit sync request if MD_RECOVERY_INTR is set
We met a sync thread stuck as follows:
raid1_sync_request+0x2c9/0xb50
md_do_sync+0x983/0xfa0
md_thread+0x11c/0x160
kthread+0x111/0x130
ret_from_fork+0x35/0x40
0xffffffffffffffff
At the same time, there is a stuck mdadm thread (mdadm --manage
/dev/md2 --add /dev/sda). It is trying to stop the sync thread:
kthread_stop+0x42/0xf0
md_unregister_thread+0x3a/0x70
md_reap_sync_thread+0x15/0x160
action_store+0x142/0x2a0
md_attr_store+0x6c/0xb0
kernfs_fop_write+0x102/0x180
__vfs_write+0x33/0x170
vfs_write+0xad/0x1a0
SyS_write+0x52/0xc0
do_syscall_64+0x6e/0x190
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Debug tools show that the sync thread is waiting in raise_barrier(),
until raid1d() end all normal IO bios into bio_end_io_list(introduced
in commit 55ce74d4bfe1). But, raid1d() cannot end these bios if
MD_CHANGE_PENDING bit is set. It needs to get mddev->reconfig_mutex lock
and then clear the bit in md_check_recovery().
However, the lock is holding by mdadm in action_store().
Thus, there is a loop:
mdadm waiting for sync thread to stop, sync thread waiting for
raid1d() to end bios, raid1d() waiting for mdadm to release
mddev->reconfig_mutex lock and then it can end bios.
Fix this by checking MD_RECOVERY_INTR while waiting in raise_barrier(),
so that sync thread can exit while mdadm is stoping the sync thread.
Fixes: 55ce74d4bfe1 ("md/raid1: ensure device failure recorded before write request returns.")
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Shaohua Li <shli@fb.com>
| -rw-r--r-- | drivers/md/raid1.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index e2943fb74056..6f624311cec2 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -854,7 +854,7 @@ static void flush_pending_writes(struct r1conf *conf) * there is no normal IO happeing. It must arrange to call * lower_barrier when the particular background IO completes. */ -static void raise_barrier(struct r1conf *conf, sector_t sector_nr) +static sector_t raise_barrier(struct r1conf *conf, sector_t sector_nr) { int idx = sector_to_idx(sector_nr); @@ -885,13 +885,23 @@ static void raise_barrier(struct r1conf *conf, sector_t sector_nr) * max resync count which allowed on current I/O barrier bucket. */ wait_event_lock_irq(conf->wait_barrier, - !conf->array_frozen && + (!conf->array_frozen && !atomic_read(&conf->nr_pending[idx]) && - atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH, + 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) @@ -2662,9 +2672,12 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr, bitmap_cond_end_sync(mddev->bitmap, sector_nr, mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high)); - r1_bio = raid1_alloc_init_r1buf(conf); - raise_barrier(conf, sector_nr); + + if (raise_barrier(conf, sector_nr)) + return 0; + + r1_bio = raid1_alloc_init_r1buf(conf); rcu_read_lock(); /* |