block: switch bios to blk_status_t

Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index c48612e6d525..c5ea03fc7ee1 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -119,7 +119,7 @@ static void iot_io_end(struct io_tracker *iot, sector_t len)
  */
 struct continuation {
 	struct work_struct ws;
-	int input;
+	blk_status_t input;
 };
 
 static inline void init_continuation(struct continuation *k,
@@ -145,7 +145,7 @@ struct batcher {
 	/*
 	 * The operation that everyone is waiting for.
 	 */
-	int (*commit_op)(void *context);
+	blk_status_t (*commit_op)(void *context);
 	void *commit_context;
 
 	/*
@@ -171,8 +171,7 @@ struct batcher {
 static void __commit(struct work_struct *_ws)
 {
 	struct batcher *b = container_of(_ws, struct batcher, commit_work);
-
-	int r;
+	blk_status_t r;
 	unsigned long flags;
 	struct list_head work_items;
 	struct work_struct *ws, *tmp;
@@ -205,7 +204,7 @@ static void __commit(struct work_struct *_ws)
 
 	while ((bio = bio_list_pop(&bios))) {
 		if (r) {
-			bio->bi_error = r;
+			bio->bi_status = r;
 			bio_endio(bio);
 		} else
 			b->issue_op(bio, b->issue_context);
@@ -213,7 +212,7 @@ static void __commit(struct work_struct *_ws)
 }
 
 static void batcher_init(struct batcher *b,
-			 int (*commit_op)(void *),
+			 blk_status_t (*commit_op)(void *),
 			 void *commit_context,
 			 void (*issue_op)(struct bio *bio, void *),
 			 void *issue_context,
@@ -955,7 +954,7 @@ static void writethrough_endio(struct bio *bio)
 
 	dm_unhook_bio(&pb->hook_info, bio);
 
-	if (bio->bi_error) {
+	if (bio->bi_status) {
 		bio_endio(bio);
 		return;
 	}
@@ -1220,7 +1219,7 @@ static void copy_complete(int read_err, unsigned long write_err, void *context)
 	struct dm_cache_migration *mg = container_of(context, struct dm_cache_migration, k);
 
 	if (read_err || write_err)
-		mg->k.input = -EIO;
+		mg->k.input = BLK_STS_IOERR;
 
 	queue_continuation(mg->cache->wq, &mg->k);
 }
@@ -1266,8 +1265,8 @@ static void overwrite_endio(struct bio *bio)
 
 	dm_unhook_bio(&pb->hook_info, bio);
 
-	if (bio->bi_error)
-		mg->k.input = bio->bi_error;
+	if (bio->bi_status)
+		mg->k.input = bio->bi_status;
 
 	queue_continuation(mg->cache->wq, &mg->k);
 }
@@ -1323,8 +1322,10 @@ static void mg_complete(struct dm_cache_migration *mg, bool success)
 		if (mg->overwrite_bio) {
 			if (success)
 				force_set_dirty(cache, cblock);
+			else if (mg->k.input)
+				mg->overwrite_bio->bi_status = mg->k.input;
 			else
-				mg->overwrite_bio->bi_error = (mg->k.input ? : -EIO);
+				mg->overwrite_bio->bi_status = BLK_STS_IOERR;
 			bio_endio(mg->overwrite_bio);
 		} else {
 			if (success)
@@ -1504,7 +1505,7 @@ static void mg_copy(struct work_struct *ws)
 		r = copy(mg, is_policy_promote);
 		if (r) {
 			DMERR_LIMIT("%s: migration copy failed", cache_device_name(cache));
-			mg->k.input = -EIO;
+			mg->k.input = BLK_STS_IOERR;
 			mg_complete(mg, false);
 		}
 	}
@@ -1907,12 +1908,12 @@ static int commit(struct cache *cache, bool clean_shutdown)
 /*
  * Used by the batcher.
  */
-static int commit_op(void *context)
+static blk_status_t commit_op(void *context)
 {
 	struct cache *cache = context;
 
 	if (dm_cache_changed_this_transaction(cache->cmd))
-		return commit(cache, false);
+		return errno_to_blk_status(commit(cache, false));
 
 	return 0;
 }
@@ -2018,7 +2019,7 @@ static void requeue_deferred_bios(struct cache *cache)
 	bio_list_init(&cache->deferred_bios);
 
 	while ((bio = bio_list_pop(&bios))) {
-		bio->bi_error = DM_ENDIO_REQUEUE;
+		bio->bi_status = BLK_STS_DM_REQUEUE;
 		bio_endio(bio);
 	}
 }
@@ -2820,7 +2821,8 @@ static int cache_map(struct dm_target *ti, struct bio *bio)
 	return r;
 }
 
-static int cache_end_io(struct dm_target *ti, struct bio *bio, int *error)
+static int cache_end_io(struct dm_target *ti, struct bio *bio,
+		blk_status_t *error)
 {
 	struct cache *cache = ti->private;
 	unsigned long flags;