[PATCH 3.14 22/33] dm cache: fix missing ERR_PTR returns and handling

Greg Kroah-Hartman
2015-02-03T23:18:49Z

From: Joe Thornber <ejt@redhat.com>

commit 766a78882ddf79b162243649d7dfdbac1fb6fb88 upstream.

Commit 9b1cc9f251 ("dm cache: share cache-metadata object across
inactive and active DM tables") mistakenly ignored the use of ERR_PTR
returns. Restore missing IS_ERR checks and ERR_PTR returns where
appropriate.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm-cache-metadata.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -683,7 +683,7 @@ static struct dm_cache_metadata *metadat
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
if (!cmd) {
DMERR("could not allocate metadata struct");
- return NULL;
+ return ERR_PTR(-ENOMEM);
}

atomic_set(&cmd->ref_count, 1);
@@ -745,7 +745,7 @@ static struct dm_cache_metadata *lookup_
return cmd;

cmd = metadata_open(bdev, data_block_size, may_format_device, policy_hint_size);
- if (cmd) {
+ if (!IS_ERR(cmd)) {
mutex_lock(&table_lock);
cmd2 = lookup(bdev);
if (cmd2) {
@@ -780,9 +780,10 @@ struct dm_cache_metadata *dm_cache_metad
{
struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size,
may_format_device, policy_hint_size);
- if (cmd && !same_params(cmd, data_block_size)) {
+
+ if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) {
dm_cache_metadata_close(cmd);
- return NULL;
+ return ERR_PTR(-EINVAL);
}

return cmd;