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authorJoe Thornber <ejt@redhat.com>2015-09-01 11:38:19 +0100
committerMike Snitzer <snitzer@redhat.com>2015-09-01 08:56:14 -0400
commitcc7da0ba9c96699592d0a69d7d146ac6adcc18e7 (patch)
tree84a021e91e6bb4a9e395315fcf4a80bfc3f3fd51 /drivers/md/dm-cache-target.c
parentdc9cee5db50afaf38506bc12eb479fb8ea536dba (diff)
downloadlinux-cc7da0ba9c96699592d0a69d7d146ac6adcc18e7.tar.bz2
dm cache: fix use after freeing migrations
Both free_io_migration() and issue_discard() dereference a migration that was just freed. Fix those by saving off the migrations's cache object before freeing the migration. Also cleanup needless mg->cache dereferences now that the cache object is available directly. Fixes: e44b6a5a3c ("dm cache: move wake_waker() from free_migrations() to where it is needed") Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-cache-target.c')
-rw-r--r--drivers/md/dm-cache-target.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index e13e5edf2298..f9d9cc6a094b 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1113,9 +1113,11 @@ static void cell_requeue(struct cache *cache, struct dm_bio_prison_cell *cell)
static void free_io_migration(struct dm_cache_migration *mg)
{
- dec_io_migrations(mg->cache);
+ struct cache *cache = mg->cache;
+
+ dec_io_migrations(cache);
free_migration(mg);
- wake_worker(mg->cache);
+ wake_worker(cache);
}
static void migration_failure(struct dm_cache_migration *mg)
@@ -1342,17 +1344,18 @@ static void issue_discard(struct dm_cache_migration *mg)
{
dm_dblock_t b, e;
struct bio *bio = mg->new_ocell->holder;
+ struct cache *cache = mg->cache;
- calc_discard_block_range(mg->cache, bio, &b, &e);
+ calc_discard_block_range(cache, bio, &b, &e);
while (b != e) {
- set_discard(mg->cache, b);
+ set_discard(cache, b);
b = to_dblock(from_dblock(b) + 1);
}
bio_endio(bio, 0);
- cell_defer(mg->cache, mg->new_ocell, false);
+ cell_defer(cache, mg->new_ocell, false);
free_migration(mg);
- wake_worker(mg->cache);
+ wake_worker(cache);
}
static void issue_copy_or_discard(struct dm_cache_migration *mg)