diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2020-07-23 10:42:09 -0400 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2020-07-23 14:39:37 -0400 |
| commit | 5df96f2b9f58a5d2dc1f30fe7de75e197f2c25f2 (patch) | |
| tree | 70d70eb0c263e130f3ec662cc6c1248cc8da77e6 /drivers/md/dm.c | |
| parent | 6958c1c640af8c3f40fa8a2eee3b5b905d95b677 (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.c | 17 |
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)); |