verity: use atomic_set instead of atomic_cmpxchg in read_completed
When moving from the PENDING to READY state it is sufficient to use
an atomic_set since we know the previous state MUST have been
PENDING. In addition, there is a BUG_ON which verifies this.
BUG=9752
TEST=Ran tests in verity.git. Ran platform_DMVerityCorruption on H/W.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
kernel.git Review URL: http://codereview.chromium.org/6677048
TBRing. Already LGTMed and committed to kernel.git
Change-Id: I1a199fc8f27f315bd98baa98f5fca0bb0fb4a556
R=wad@chromium.org,taysom@chromium.org,ups@chromium.org
Review URL: http://codereview.chromium.org/6721019
diff --git a/dm-bht.c b/dm-bht.c
index 38849d6..71e3b04 100644
--- a/dm-bht.c
+++ b/dm-bht.c
@@ -441,7 +441,6 @@
*/
void dm_bht_read_completed(struct dm_bht_entry *entry, int status)
{
- int state;
if (status) {
/* TODO(wad) add retry support */
DMCRIT("an I/O error occurred while reading entry");
@@ -449,13 +448,8 @@
/* entry->nodes will be freed later */
return;
}
- state = atomic_cmpxchg(&entry->state,
- DM_BHT_ENTRY_PENDING,
- DM_BHT_ENTRY_READY);
- if (state != DM_BHT_ENTRY_PENDING) {
- DMCRIT("state changed on entry out from under io");
- BUG();
- }
+ BUG_ON(atomic_read(&entry->state) != DM_BHT_ENTRY_PENDING);
+ atomic_set(&entry->state, DM_BHT_ENTRY_READY);
}
EXPORT_SYMBOL(dm_bht_read_completed);
