When too many I/O errors happen on cache set and CACHE_SET_IO_DISABLE bit is set, bch_journal() may continue to work because the journaling bkey might be still in write set yet. The caller of bch_journal() may believe the journal still work but the truth is in-memory journal write set won't be written into cache device any more. This behavior may introduce potential inconsistent metadata status.
This patch checks CACHE_SET_IO_DISABLE bit at the head of bch_journal(), if the bit is set, bch_journal() returns NULL immediately to notice caller to know journal does not work. Signed-off-by: Coly Li <[email protected]> --- drivers/md/bcache/journal.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c index 12dae9348147..d4b9817f2237 100644 --- a/drivers/md/bcache/journal.c +++ b/drivers/md/bcache/journal.c @@ -811,6 +811,10 @@ atomic_t *bch_journal(struct cache_set *c, struct journal_write *w; atomic_t *ret; + /* No journaling if CACHE_SET_IO_DISABLE set already */ + if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &c->flags))) + return NULL; + if (!CACHE_SYNC(&c->sb)) return NULL; -- 2.16.4
