As described in commit 38d11da522aa ("dm: don't lock fs when the map is
NULL in process of resume"), deadlock may be triggered between do_resume
and do_mount.
What's more, do_suspend and do_mount can also trigger it.
So clear DM_SUSPEND_LOCKFS_FLAG in dm_suspend instead of do_resume.
Signed-off-by: Li Lingfeng <lilingfe...@huawei.com>
---
drivers/md/dm-ioctl.c | 5 +----
drivers/md/dm.c | 3 +++
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index cc77cf3d4109..7d5c9c582ed2 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 3b694ba3a106..39424a0b3cd6 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2809,6 +2809,9 @@ int dm_suspend(struct mapped_device *md, unsigned int
suspend_flags)
map = rcu_dereference_protected(md->map,
lockdep_is_held(&md->suspend_lock));
+ if (!map)
+ suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
+
r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE,
DMF_SUSPENDED);
if (r)
goto out_unlock;
--
2.31.1
--
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