diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c index af8940145fee..e6e5d24a79f5 100644 --- a/drivers/md/dm-clone-target.c +++ b/drivers/md/dm-clone-target.c @@ -86,6 +86,12 @@ struct clone { struct dm_clone_metadata *cmd; + /* + * bio used to flush the destination device, before committing the + * metadata. + */ + struct bio flush_bio; + /* Region hydration hash table */ struct hash_table_bucket *ht; @@ -1106,10 +1112,13 @@ static bool need_commit_due_to_time(struct clone *clone) /* * A non-zero return indicates read-only or fail mode. */ -static int commit_metadata(struct clone *clone) +static int commit_metadata(struct clone *clone, bool *dest_dev_flushed) { int r = 0; + if (dest_dev_flushed) + *dest_dev_flushed = false; + mutex_lock(&clone->commit_lock); if (!dm_clone_changed_this_transaction(clone->cmd)) @@ -1126,6 +1135,19 @@ static int commit_metadata(struct clone *clone) goto out; } + bio_reset(&clone->flush_bio); + bio_set_dev(&clone->flush_bio, clone->dest_dev->bdev); + clone->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; + + r = submit_bio_wait(&clone->flush_bio); + if (unlikely(r)) { + __metadata_operation_failed(clone, "flush destination device", r); + goto out; + } + + if (dest_dev_flushed) + *dest_dev_flushed = true; + r = dm_clone_metadata_commit(clone->cmd); if (unlikely(r)) { __metadata_operation_failed(clone, "dm_clone_metadata_commit", r); @@ -1199,6 +1221,7 @@ static void process_deferred_flush_bios(struct clone *clone) { struct bio *bio; unsigned long flags; + bool dest_dev_flushed; struct bio_list bios = BIO_EMPTY_LIST; struct bio_list bio_completions = BIO_EMPTY_LIST; @@ -1218,7 +1241,7 @@ static void process_deferred_flush_bios(struct clone *clone) !(dm_clone_changed_this_transaction(clone->cmd) && need_commit_due_to_time(clone))) return; - if (commit_metadata(clone)) { + if (commit_metadata(clone, &dest_dev_flushed)) { bio_list_merge(&bios, &bio_completions); while ((bio = bio_list_pop(&bios))) @@ -1232,8 +1255,17 @@ static void process_deferred_flush_bios(struct clone *clone) while ((bio = bio_list_pop(&bio_completions))) bio_endio(bio); - while ((bio = bio_list_pop(&bios))) - generic_make_request(bio); + while ((bio = bio_list_pop(&bios))) { + if ((bio->bi_opf & REQ_PREFLUSH) && dest_dev_flushed) { + /* We just flushed the destination device as part of + * the metadata commit, so there is no reason to send + * another flush. + */ + bio_endio(bio); + } else { + generic_make_request(bio); + } + } } static void do_worker(struct work_struct *work) @@ -1405,7 +1437,7 @@ static void clone_status(struct dm_target *ti, status_type_t type, /* Commit to ensure statistics aren't out-of-date */ if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) - (void) commit_metadata(clone); + (void) commit_metadata(clone, NULL); r = dm_clone_get_free_metadata_block_count(clone->cmd, &nr_free_metadata_blocks); @@ -1839,6 +1871,7 @@ static int clone_ctr(struct dm_target *ti, unsigned int argc, char **argv) bio_list_init(&clone->deferred_flush_completions); clone->hydration_offset = 0; atomic_set(&clone->hydrations_in_flight, 0); + bio_init(&clone->flush_bio, NULL, 0); clone->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0); if (!clone->wq) { @@ -1912,6 +1945,7 @@ static void clone_dtr(struct dm_target *ti) struct clone *clone = ti->private; mutex_destroy(&clone->commit_lock); + bio_uninit(&clone->flush_bio); for (i = 0; i < clone->nr_ctr_args; i++) kfree(clone->ctr_args[i]); @@ -1966,7 +2000,7 @@ static void clone_postsuspend(struct dm_target *ti) wait_event(clone->hydration_stopped, !atomic_read(&clone->hydrations_in_flight)); flush_workqueue(clone->wq); - (void) commit_metadata(clone); + (void) commit_metadata(clone, NULL); } static void clone_resume(struct dm_target *ti)