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| author | Li Lingfeng <lilingfeng3@huawei.com> | 2023-06-01 14:14:23 +0800 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2023-06-15 12:46:53 -0400 |
| commit | 2760904d895279f87196f0fa9ec570c79fe6a2e4 (patch) | |
| tree | ba7d9355f7adccdec86305a64483cfc86a14f4ec | |
| parent | f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6 (diff) | |
| download | linux-2760904d895279f87196f0fa9ec570c79fe6a2e4.tar.gz | |
dm: don't lock fs when the map is NULL during suspend or resume
As described in commit 38d11da522aa ("dm: don't lock fs when the map is
NULL in process of resume"), a deadlock may be triggered between
do_resume() and do_mount().
This commit preserves the fix from commit 38d11da522aa but moves it to
where it also serves to fix a similar deadlock between do_suspend()
and do_mount(). It does so, if the active map is NULL, by clearing
DM_SUSPEND_LOCKFS_FLAG in dm_suspend() which is called by both
do_suspend() and do_resume().
Fixes: 38d11da522aa ("dm: don't lock fs when the map is NULL in process of resume")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
| -rw-r--r-- | drivers/md/dm-ioctl.c | 5 | ||||
| -rw-r--r-- | drivers/md/dm.c | 4 |
2 files changed, 5 insertions, 4 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index cc77cf3d410921..7d5c9c582ed2d6 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1168,13 +1168,10 @@ static int do_resume(struct dm_ioctl *param) /* Do we need to load a new map ? */ if (new_map) { sector_t old_size, new_size; - int srcu_idx; /* Suspend if it isn't already suspended */ - old_map = dm_get_live_table(md, &srcu_idx); - if ((param->flags & DM_SKIP_LOCKFS_FLAG) || !old_map) + if (param->flags & DM_SKIP_LOCKFS_FLAG) suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; - dm_put_live_table(md, srcu_idx); if (param->flags & DM_NOFLUSH_FLAG) suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; if (!dm_suspended_md(md)) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3b694ba3a106e6..8488547fc00d36 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2808,6 +2808,10 @@ retry: } map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); + if (!map) { + /* avoid deadlock with fs/namespace.c:do_mount() */ + suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; + } r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED); if (r) |