From 3e44f325f6f75078cdcd44cd337f517ba3650d05 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 11 Jan 2024 08:36:55 +0100 Subject: bcachefs: fix incorrect usage of REQ_OP_FLUSH REQ_OP_FLUSH is only for internal use in the blk-mq and request based drivers. File systems and other block layer consumers must use REQ_OP_WRITE | REQ_PREFLUSH as documented in Documentation/block/writeback_cache_control.rst. While REQ_OP_FLUSH appears to work for blk-mq drivers it does not get the proper flush state machine handling, and completely fails for any bio based drivers, including all the stacking drivers. The block layer will also get a check in 6.8 to reject this use case entirely. [Note: completely untested, but as this never got fixed since the original bug report in November: https://bugzilla.kernel.org/show_bug.cgi?id=218184 and the the discussion in December: https://lore.kernel.org/all/20231221053016.72cqcfg46vxwohcj@moria.home.lan/T/ this seems to be best way to force it] Signed-off-by: Christoph Hellwig Signed-off-by: Kent Overstreet --- fs/bcachefs/journal_io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/bcachefs/journal_io.c') diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c index 04a1e79a5ed3..bfd6585e746d 100644 --- a/fs/bcachefs/journal_io.c +++ b/fs/bcachefs/journal_io.c @@ -1988,7 +1988,8 @@ CLOSURE_CALLBACK(bch2_journal_write) percpu_ref_get(&ca->io_ref); bio = ca->journal.bio; - bio_reset(bio, ca->disk_sb.bdev, REQ_OP_FLUSH); + bio_reset(bio, ca->disk_sb.bdev, + REQ_OP_WRITE|REQ_PREFLUSH); bio->bi_end_io = journal_write_endio; bio->bi_private = ca; closure_bio_submit(bio, cl); -- cgit v1.2.3