[PATCH 08/15] bcache: don't write back data if reading it failed
From: Michael Lyle <hidden>
Date: 2017-10-13 23:36:07
Also in:
linux-bcache
Subsystem:
bcache (block layer cache), the rest · Maintainers:
Coly Li, Kent Overstreet, Linus Torvalds
If an IO operation fails, and we didn't successfully read data from the cache, don't writeback invalid/partial data to the backing disk. Signed-off-by: Michael Lyle <redacted> Reviewed-by: Coly Li <redacted> --- drivers/md/bcache/writeback.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index e663ca082183..5e65a392287d 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c@@ -179,13 +179,21 @@ static void write_dirty(struct closure *cl) struct dirty_io *io = container_of(cl, struct dirty_io, cl); struct keybuf_key *w = io->bio.bi_private; - dirty_init(w); - bio_set_op_attrs(&io->bio, REQ_OP_WRITE, 0); - io->bio.bi_iter.bi_sector = KEY_START(&w->key); - bio_set_dev(&io->bio, io->dc->bdev); - io->bio.bi_end_io = dirty_endio; + /* + * IO errors are signalled using the dirty bit on the key. + * If we failed to read, we should not attempt to write to the + * backing device. Instead, immediately go to write_dirty_finish + * to clean up. + */ + if (KEY_DIRTY(&w->key)) { + dirty_init(w); + bio_set_op_attrs(&io->bio, REQ_OP_WRITE, 0); + io->bio.bi_iter.bi_sector = KEY_START(&w->key); + bio_set_dev(&io->bio, io->dc->bdev); + io->bio.bi_end_io = dirty_endio; - closure_bio_submit(&io->bio, cl); + closure_bio_submit(&io->bio, cl); + } continue_at(cl, write_dirty_finish, io->dc->writeback_write_wq); }
--
2.11.0