From: Mike Snitzer <snitzer@xxxxxxxxxx>
Must mutex_lock after dm_bufio_read, before dm_bufio_read error
handling, otherwise process_entry error path will return without
volume->read_threads_mutex held. This fixes potential double
mutex_unlock.
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Susan LeGendre-McGhee <slegendr@xxxxxxxxxx>
Signed-off-by: Matthew Sakai <msakai@xxxxxxxxxx>
---
drivers/md/dm-vdo/volume.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-vdo/volume.c b/drivers/md/dm-vdo/volume.c
index 37c2ef0777e5..60416dc8a9d7 100644
--- a/drivers/md/dm-vdo/volume.c
+++ b/drivers/md/dm-vdo/volume.c
@@ -556,6 +556,7 @@ static int process_entry(struct volume *volume, struct queued_read *entry)
mutex_unlock(&volume->read_threads_mutex);
page_data = dm_bufio_read(volume->client, page_number, &page->buffer);
+ mutex_lock(&volume->read_threads_mutex);
if (IS_ERR(page_data)) {
result = -PTR_ERR(page_data);
uds_log_warning_strerror(result,
@@ -564,7 +565,6 @@ static int process_entry(struct volume *volume, struct queued_read *entry)
cancel_page_in_cache(&volume->page_cache, page_number, page);
return result;
}
- mutex_lock(&volume->read_threads_mutex);
if (entry->invalid) {
uds_log_warning("Page %u invalidated after read", page_number);
--
2.42.0
