[ Upstream commit 631207314d88e9091be02fbdd1fdadb1ae2ed79a ]
journal replay failed with messages: Sep 10 19:10:43 ceph kernel: bcache: error on bb379a64-e44e-4812-b91d-a5599871a3b1: bcache: journal entries 2057493-2057567 missing! (replaying 2057493-2076601), disabling caching
The reason is in journal_reclaim(), when discard is enabled, we send discard command and reclaim those journal buckets whose seq is old than the last_seq_now, but before we write a journal with last_seq_now, the machine is restarted, so the journal with the last_seq_now is not written to the journal bucket, and the last_seq_wrote in the newest journal is old than last_seq_now which we expect to be, so when we doing replay, journals from last_seq_wrote to last_seq_now are missing.
It's hard to write a journal immediately after journal_reclaim(), and it harmless if those missed journal are caused by discarding since those journals are already wrote to btree node. So, if miss seqs are started from the beginning journal, we treat it as normal, and only print a message to show the miss journal, and point out it maybe caused by discarding.
Patch v2 add a judgement condition to ignore the missed journal only when discard enabled as Coly suggested.
(Coly Li: rebase the patch with other changes in bch_journal_replay())
Signed-off-by: Tang Junhui tang.junhui.linux@gmail.com Tested-by: Dennis Schridde devurandom@gmx.net Signed-off-by: Coly Li colyli@suse.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/md/bcache/journal.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c index cd8a82655e647..6394be5ee9a8f 100644 --- a/drivers/md/bcache/journal.c +++ b/drivers/md/bcache/journal.c @@ -310,6 +310,18 @@ void bch_journal_mark(struct cache_set *c, struct list_head *list) } }
+bool is_discard_enabled(struct cache_set *s) +{ + struct cache *ca; + unsigned int i; + + for_each_cache(ca, s, i) + if (ca->discard) + return true; + + return false; +} + int bch_journal_replay(struct cache_set *s, struct list_head *list) { int ret = 0, keys = 0, entries = 0; @@ -324,10 +336,15 @@ int bch_journal_replay(struct cache_set *s, struct list_head *list) BUG_ON(i->pin && atomic_read(i->pin) != 1);
if (n != i->j.seq) { - pr_err("bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)", - n, i->j.seq - 1, start, end); - ret = -EIO; - goto err; + if (n == start && is_discard_enabled(s)) + pr_info("bcache: journal entries %llu-%llu may be discarded! (replaying %llu-%llu)", + n, i->j.seq - 1, start, end); + else { + pr_err("bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)", + n, i->j.seq - 1, start, end); + ret = -EIO; + goto err; + } }
for (k = i->j.start;