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>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 7c0f6bd..36fe820 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -58,12 +58,12 @@ static void f2fs_read_end_io(struct bio *bio)
 #ifdef CONFIG_F2FS_FAULT_INJECTION
 	if (time_to_inject(F2FS_P_SB(bio->bi_io_vec->bv_page), FAULT_IO)) {
 		f2fs_show_injection_info(FAULT_IO);
-		bio->bi_error = -EIO;
+		bio->bi_status = BLK_STS_IOERR;
 	}
 #endif
 
 	if (f2fs_bio_encrypted(bio)) {
-		if (bio->bi_error) {
+		if (bio->bi_status) {
 			fscrypt_release_ctx(bio->bi_private);
 		} else {
 			fscrypt_decrypt_bio_pages(bio->bi_private, bio);
@@ -74,7 +74,7 @@ static void f2fs_read_end_io(struct bio *bio)
 	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 
-		if (!bio->bi_error) {
+		if (!bio->bi_status) {
 			if (!PageUptodate(page))
 				SetPageUptodate(page);
 		} else {
@@ -102,14 +102,14 @@ static void f2fs_write_end_io(struct bio *bio)
 			unlock_page(page);
 			mempool_free(page, sbi->write_io_dummy);
 
-			if (unlikely(bio->bi_error))
+			if (unlikely(bio->bi_status))
 				f2fs_stop_checkpoint(sbi, true);
 			continue;
 		}
 
 		fscrypt_pullback_bio_page(&page, true);
 
-		if (unlikely(bio->bi_error)) {
+		if (unlikely(bio->bi_status)) {
 			mapping_set_error(page->mapping, -EIO);
 			f2fs_stop_checkpoint(sbi, true);
 		}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9684585..ea9f455 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -749,7 +749,7 @@ static void f2fs_submit_discard_endio(struct bio *bio)
 {
 	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
 
-	dc->error = bio->bi_error;
+	dc->error = blk_status_to_errno(bio->bi_status);
 	dc->state = D_DONE;
 	complete(&dc->wait);
 	bio_put(bio);