[PATCH 3.12 090/118] dm thin: always fallback the pool mode if commit fails

Greg Kroah-Hartman
2013-12-18T21:15:51Z

From: Joe Thornber <ejt@redhat.com>

commit 020cc3b5e28c2e24f59f53a9154faf08564f308e upstream.

Rename commit_or_fallback() to commit(). Now all previous calls to
commit() will trigger the pool mode to fallback if the commit fails.

Also, check the error returned from commit() in alloc_data_block().

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-thin.c | 37 +++++++++++++++----------------------
1 file changed, 15 insertions(+), 22 deletions(-)

--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -883,32 +883,23 @@ static void schedule_zero(struct thin_c
}
}

-static int commit(struct pool *pool)
-{
- int r;
-
- r = dm_pool_commit_metadata(pool->pmd);
- if (r)
- DMERR_LIMIT("%s: commit failed: error = %d",
- dm_device_name(pool->pool_md), r);
-
- return r;
-}
-
/*
* A non-zero return indicates read_only or fail_io mode.
* Many callers don't care about the return value.
*/
-static int commit_or_fallback(struct pool *pool)
+static int commit(struct pool *pool)
{
int r;

if (get_pool_mode(pool) != PM_WRITE)
return -EINVAL;

- r = commit(pool);
- if (r)
+ r = dm_pool_commit_metadata(pool->pmd);
+ if (r) {
+ DMERR_LIMIT("%s: dm_pool_commit_metadata failed: error = %d",
+ dm_device_name(pool->pool_md), r);
set_pool_mode(pool, PM_READ_ONLY);
+ }

return r;
}
@@ -945,7 +936,9 @@ static int alloc_data_block(struct thin_
* Try to commit to see if that will free up some
* more space.
*/
- (void) commit_or_fallback(pool);
+ r = commit(pool);
+ if (r)
+ return r;

r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
if (r)
@@ -1359,7 +1352,7 @@ static void process_deferred_bios(struct
if (bio_list_empty(&bios) && !need_commit_due_to_time(pool))
return;

- if (commit_or_fallback(pool)) {
+ if (commit(pool)) {
while ((bio = bio_list_pop(&bios)))
bio_io_error(bio);
return;
@@ -2276,7 +2269,7 @@ static int pool_preresume(struct dm_targ
return r;

if (need_commit1 || need_commit2)
- (void) commit_or_fallback(pool);
+ (void) commit(pool);

return 0;
}
@@ -2303,7 +2296,7 @@ static void pool_postsuspend(struct dm_t

cancel_delayed_work(&pool->waker);
flush_workqueue(pool->wq);
- (void) commit_or_fallback(pool);
+ (void) commit(pool);
}

static int check_arg_count(unsigned argc, unsigned args_required)
@@ -2437,7 +2430,7 @@ static int process_reserve_metadata_snap
if (r)
return r;

- (void) commit_or_fallback(pool);
+ (void) commit(pool);

r = dm_pool_reserve_metadata_snap(pool->pmd);
if (r)
@@ -2499,7 +2492,7 @@ static int pool_message(struct dm_target
DMWARN("Unrecognised thin pool target message received: %s", argv[0]);

if (!r)
- (void) commit_or_fallback(pool);
+ (void) commit(pool);

return r;
}
@@ -2554,7 +2547,7 @@ static void pool_status(struct dm_target

/* Commit to ensure statistics aren't out-of-date */
if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
- (void) commit_or_fallback(pool);
+ (void) commit(pool);

r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
if (r) {