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authorLi Lingfeng <lilingfeng3@huawei.com>2023-06-01 14:14:23 +0800
committerMike Snitzer <snitzer@kernel.org>2023-06-15 12:46:53 -0400
commit2760904d895279f87196f0fa9ec570c79fe6a2e4 (patch)
treeba7d9355f7adccdec86305a64483cfc86a14f4ec /drivers/md/dm.c
parentf1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6 (diff)
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>
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 3b694ba3a106..8488547fc00d 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)