mainline inclusion from mainline-v6.4-rc8 commit 2760904d895279f87196f0fa9ec570c79fe6a2e4 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7FI78 CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h...
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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
Conflicts: drivers/md/dm-ioctl.c Signed-off-by: Li Lingfeng lilingfeng3@huawei.com --- drivers/md/dm.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3649ee4d9000..3a49fbed974a 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2602,6 +2602,10 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) }
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)