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authorMikulas Patocka <mpatocka@redhat.com>2020-07-23 10:42:09 -0400
committerMike Snitzer <snitzer@redhat.com>2020-07-23 14:39:37 -0400
commit5df96f2b9f58a5d2dc1f30fe7de75e197f2c25f2 (patch)
tree70d70eb0c263e130f3ec662cc6c1248cc8da77e6 /drivers/md/dm.c
parent6958c1c640af8c3f40fa8a2eee3b5b905d95b677 (diff)
dm integrity: fix integrity recalculation that is improperly skipped
Commit adc0daad366b62ca1bce3e2958a40b0b71a8b8b3 ("dm: report suspended device during destroy") broke integrity recalculation. The problem is dm_suspended() returns true not only during suspend, but also during resume. So this race condition could occur: 1. dm_integrity_resume calls queue_work(ic->recalc_wq, &ic->recalc_work) 2. integrity_recalc (&ic->recalc_work) preempts the current thread 3. integrity_recalc calls if (unlikely(dm_suspended(ic->ti))) goto unlock_ret; 4. integrity_recalc exits and no recalculating is done. To fix this race condition, add a function dm_post_suspending that is only true during the postsuspend phase and use it instead of dm_suspended(). Signed-off-by: Mikulas Patocka <mpatocka redhat com> Fixes: adc0daad366b ("dm: report suspended device during destroy") Cc: stable vger kernel org # v4.18+ Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 52449afd58eb..5b9de2f71bb0 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -143,6 +143,7 @@ EXPORT_SYMBOL_GPL(dm_bio_get_target_bio_nr);
#define DMF_NOFLUSH_SUSPENDING 5
#define DMF_DEFERRED_REMOVE 6
#define DMF_SUSPENDED_INTERNALLY 7
+#define DMF_POST_SUSPENDING 8
#define DM_NUMA_NODE NUMA_NO_NODE
static int dm_numa_node = DM_NUMA_NODE;
@@ -2408,6 +2409,7 @@ static void __dm_destroy(struct mapped_device *md, bool wait)
if (!dm_suspended_md(md)) {
dm_table_presuspend_targets(map);
set_bit(DMF_SUSPENDED, &md->flags);
+ set_bit(DMF_POST_SUSPENDING, &md->flags);
dm_table_postsuspend_targets(map);
}
/* dm_put_live_table must be before msleep, otherwise deadlock is possible */
@@ -2766,7 +2768,9 @@ retry:
if (r)
goto out_unlock;
+ set_bit(DMF_POST_SUSPENDING, &md->flags);
dm_table_postsuspend_targets(map);
+ clear_bit(DMF_POST_SUSPENDING, &md->flags);
out_unlock:
mutex_unlock(&md->suspend_lock);
@@ -2863,7 +2867,9 @@ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_fla
(void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
DMF_SUSPENDED_INTERNALLY);
+ set_bit(DMF_POST_SUSPENDING, &md->flags);
dm_table_postsuspend_targets(map);
+ clear_bit(DMF_POST_SUSPENDING, &md->flags);
}
static void __dm_internal_resume(struct mapped_device *md)
@@ -3024,6 +3030,11 @@ int dm_suspended_md(struct mapped_device *md)
return test_bit(DMF_SUSPENDED, &md->flags);
}
+static int dm_post_suspending_md(struct mapped_device *md)
+{
+ return test_bit(DMF_POST_SUSPENDING, &md->flags);
+}
+
int dm_suspended_internally_md(struct mapped_device *md)
{
return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
@@ -3040,6 +3051,12 @@ int dm_suspended(struct dm_target *ti)
}
EXPORT_SYMBOL_GPL(dm_suspended);
+int dm_post_suspending(struct dm_target *ti)
+{
+ return dm_post_suspending_md(dm_table_get_md(ti->table));
+}
+EXPORT_SYMBOL_GPL(dm_post_suspending);
+
int dm_noflush_suspending(struct dm_target *ti)
{
return __noflush_suspending(dm_table_get_md(ti->table));