diff options
| author |   Mikulas Patocka <mpatocka@redhat.com> | 2015-01-08 18:52:26 -0500 |
|---|---|---|
| committer |   Mike Snitzer <snitzer@redhat.com> | 2015-01-24 14:50:08 -0500 |
| commit | 96b26c8c64c7a30488b8b404f7a63346df4c3bff (patch) | |
| tree | d51619d0d63ab934cee6cda089531de56ed0e283 | |
| parent | dm cache: fix problematic dual use of a single migration count variable (diff) | |
| download | linux-dev-96b26c8c64c7a30488b8b404f7a63346df4c3bff.tar.xz linux-dev-96b26c8c64c7a30488b8b404f7a63346df4c3bff.zip | |
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>
| -rw-r--r-- | drivers/md/dm.c | 9 |
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)) |