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| author | Mike Snitzer <snitzer@redhat.com> | 2017-11-25 00:27:26 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-12-04 10:23:10 -0500 |
| commit | afc567a4977b2d798e05153dd131a3c8d4758c0c (patch) | |
| tree | 8d5abb8627ae852a7dc191ffac9dfb27c58d1635 | |
| parent | ae64f9bd1d3621b5e60d7363bc20afb46aede215 (diff) | |
| download | linux-afc567a4977b2d798e05153dd131a3c8d4758c0c.tar.gz linux-afc567a4977b2d798e05153dd131a3c8d4758c0c.tar.bz2 linux-afc567a4977b2d798e05153dd131a3c8d4758c0c.zip | |
dm table: fix regression from improper dm_dev_internal.count refcount_t conversion
Multiple refcounts are needed if the device was already added. The
micro-optimization of setting the refcount to 1 on first added (rather
than fall thru to a common refcount_inc) lost sight of the fact that the
refcount_inc is also needed for the case when the device already exists
and the mode need not be upgraded.
Fixes: 2a0b4682e0 ("dm: convert dm_dev_internal.count from atomic_t to refcount_t")
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| -rw-r--r-- | drivers/md/dm-table.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 88130b5d95f9..aaffd0c0ee9a 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -453,14 +453,15 @@ int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, refcount_set(&dd->count, 1); list_add(&dd->list, &t->devices); + goto out; } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) { r = upgrade_mode(dd, mode, t->md); if (r) return r; - refcount_inc(&dd->count); } - + refcount_inc(&dd->count); +out: *result = dd->dm_dev; return 0; } |