On 2019/3/25 10:55 上午, Junhui Tang wrote: > From 6e23ea6fb81df1cfea23ef7a37b8a5732d691caf Mon Sep 17 00:00:00 2001 > From: Tang Junhui <tang.junhui.linux@xxxxxxxxx > <mailto:tang.junhui.linux@xxxxxxxxx>> > Date: Wed, 12 Sep 2018 04:42:14 +0800 > Subject: [PATCH] [v2] bcache: fix failure in journal relplay > > 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(), 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. > > Signed-off-by: Tang Junhui <tang.junhui.linux@xxxxxxxxx > <mailto:tang.junhui.linux@xxxxxxxxx>> Hi Junhui, It is good to me, I will add it into my for-test directory. Thanks. Coly Li > --- > drivers/md/bcache/journal.c | 21 +++++++++++++++++++-- > 1 file changed, 19 insertions(+), 2 deletions(-) > > diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c > index 10748c6..59869bb 100644 > --- a/drivers/md/bcache/journal.c > +++ b/drivers/md/bcache/journal.c > @@ -315,6 +315,17 @@ void bch_journal_mark(struct cache_set *c, struct > list_head *list) > } > } > > +bool is_discard_enabled(struct cache_set *s) > +{ > +struct cache *ca; > +unsigned 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; > @@ -328,9 +339,15 @@ int bch_journal_replay(struct cache_set *s, struct > list_head *list) > list_for_each_entry(i, list, list) { > BUG_ON(i->pin && atomic_read(i->pin) != 1); > > -cache_set_err_on(n != i->j.seq, s, > -"bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)", > +if (n != i->j.seq && > + 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 > +cache_set_err_on(n != i->j.seq, s, > + "bcache: journal entries %llu-%llu missing! (replaying %llu-%llu)", > + n, i->j.seq - 1, start, end); > > for (k = i->j.start; > k < bset_bkey_last(&i->j); > -- > 1.8.3.1 > -- Coly Li
