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| author | Li Lingfeng <lilingfeng3@huawei.com> | 2023-06-01 14:14:23 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-06-21 16:01:02 +0200 |
| commit | d24c9658177587c0e64677691fbc35b2df79b1e8 (patch) | |
| tree | eaf6bbcca50979be31cb1bae01dbfb9d7ace4507 /drivers/md | |
| parent | 010179208c662bfb16f67869dfbb90cf8ec7d55f (diff) | |
| download | linux-stable-d24c9658177587c0e64677691fbc35b2df79b1e8.tar.gz linux-stable-d24c9658177587c0e64677691fbc35b2df79b1e8.tar.bz2 linux-stable-d24c9658177587c0e64677691fbc35b2df79b1e8.zip | |
dm: don't lock fs when the map is NULL during suspend or resume
[ Upstream commit 2760904d895279f87196f0fa9ec570c79fe6a2e4 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/md')
| -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 83aecd9250ba..6ae1c19b8243 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1151,13 +1151,10 @@ 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 24284d22f15b..acf7e7551c94 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2801,6 +2801,10 @@ 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) |