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 <mlyle@xxxxxxxx>
Reviewed-by: Coly Li <colyli@xxxxxxx>
---
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
