path: root/drivers
diff options
authorMikulas Patocka <mpatocka@redhat.com>2015-01-08 18:52:26 -0500
committerMike Snitzer <snitzer@redhat.com>2015-01-24 14:50:08 -0500
commit96b26c8c64c7a30488b8b404f7a63346df4c3bff (patch)
treed51619d0d63ab934cee6cda089531de56ed0e283 /drivers
parenta59db67656021fa212e9b95a583f13c34eb67cd9 (diff)
dm: fix handling of multiple internal suspends
Commit ffcc393641 ("dm: enhance internal suspend and resume interface") attempted to handle multiple internal suspends on the same device, but it did that incorrectly. When these functions are called in this order on the same device the device is no longer suspended, but it should be: dm_internal_suspend_noflush dm_internal_suspend_noflush dm_internal_resume Fix this bug by maintaining an 'internal_suspend_count' and resuming the device when this count drops to zero. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers')
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b98cd9d84435..2caf5b374649 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -206,6 +206,9 @@ struct mapped_device {
/* zero-length flush that will be cloned and submitted to targets */
struct bio flush_bio;
+ /* the number of internal suspends */
+ unsigned internal_suspend_count;
struct dm_stats stats;
@@ -2928,7 +2931,7 @@ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_fla
struct dm_table *map = NULL;
- if (dm_suspended_internally_md(md))
+ if (md->internal_suspend_count++)
return; /* nested internal suspend */
if (dm_suspended_md(md)) {
@@ -2953,7 +2956,9 @@ static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_fla
static void __dm_internal_resume(struct mapped_device *md)
- if (!dm_suspended_internally_md(md))
+ BUG_ON(!md->internal_suspend_count);
+ if (--md->internal_suspend_count)
return; /* resume from nested internal suspend */
if (dm_suspended_md(md))

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