Revert "Fix zvol+btrfs hang"

After the dmu_req_copy change, bi_io_vecs are not touched, so this is no
longer needed.

This reverts commit e26ade5101ba1d8e8350ff1270bfca4258e1ffe3.

Signed-off-by: Chunwei Chen <[email protected]>
Signed-off-by: Richard Yao <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Issue #2124

1 files changed, 0 insertions, 77 deletions

diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
index 81b7a870b..5d9337f65 100644
--- a/module/zfs/dmu.c
+++ b/module/zfs/dmu.c
@@ -1053,57 +1053,11 @@ out:
 	return (offset);
 }
 
-static void
-dmu_bio_put(struct bio *bio)
-{
-	struct bio *bio_next;
-
-	while (bio) {
-		bio_next = bio->bi_next;
-		bio_put(bio);
-		bio = bio_next;
-	}
-}
-
-static int
-dmu_bio_clone(struct bio *bio, struct bio **bio_copy)
-{
-	struct bio *bio_root = NULL;
-	struct bio *bio_last = NULL;
-	struct bio *bio_new;
-
-	if (bio == NULL)
-		return (EINVAL);
-
-	while (bio) {
-		bio_new = bio_clone(bio, GFP_NOIO);
-		if (bio_new == NULL) {
-			dmu_bio_put(bio_root);
-			return (ENOMEM);
-		}
-
-		if (bio_last) {
-			bio_last->bi_next = bio_new;
-			bio_last = bio_new;
-		} else {
-			bio_root = bio_new;
-			bio_last = bio_new;
-		}
-
-		bio = bio->bi_next;
-	}
-
-	*bio_copy = bio_root;
-
-	return (0);
-}
-
 int
 dmu_read_req(objset_t *os, uint64_t object, struct request *req)
 {
 	uint64_t size = blk_rq_bytes(req);
 	uint64_t offset = blk_rq_pos(req) << 9;
-	struct bio *bio_saved = req->bio;
 	dmu_buf_t **dbp;
 	int numbufs, i, err;
 	size_t req_offset;
@@ -1117,17 +1071,6 @@ dmu_read_req(objset_t *os, uint64_t object, struct request *req)
 	if (err)
 		return (err);
 
-	/*
-	 * Clone the bio list so the bv->bv_offset and bv->bv_len members
-	 * can be safely modified.  The original bio list is relinked in to
-	 * the request when the function exits.  This is required because
-	 * some file systems blindly assume that these values will remain
-	 * constant between bio_submit() and the IO completion callback.
-	 */
-	err = dmu_bio_clone(bio_saved, &req->bio);
-	if (err)
-		goto error;
-
 	req_offset = 0;
 	for (i = 0; i < numbufs; i++) {
 		int tocpy, didcpy, bufoff;
@@ -1154,10 +1097,6 @@ dmu_read_req(objset_t *os, uint64_t object, struct request *req)
 		req_offset += didcpy;
 		err = 0;
 	}
-
-	dmu_bio_put(req->bio);
-	req->bio = bio_saved;
-error:
 	dmu_buf_rele_array(dbp, numbufs, FTAG);
 
 	return (err);
@@ -1168,7 +1107,6 @@ dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx)
 {
 	uint64_t size = blk_rq_bytes(req);
 	uint64_t offset = blk_rq_pos(req) << 9;
-	struct bio *bio_saved = req->bio;
 	dmu_buf_t **dbp;
 	int numbufs, i, err;
 	size_t req_offset;
@@ -1181,17 +1119,6 @@ dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx)
 	if (err)
 		return (err);
 
-	/*
-	 * Clone the bio list so the bv->bv_offset and bv->bv_len members
-	 * can be safely modified.  The original bio list is relinked in to
-	 * the request when the function exits.  This is required because
-	 * some file systems blindly assume that these values will remain
-	 * constant between bio_submit() and the IO completion callback.
-	 */
-	err = dmu_bio_clone(bio_saved, &req->bio);
-	if (err)
-		goto error;
-
 	req_offset = 0;
 	for (i = 0; i < numbufs; i++) {
 		int tocpy, didcpy, bufoff;
@@ -1229,11 +1156,7 @@ dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx)
 		err = 0;
 	}
 
-	dmu_bio_put(req->bio);
-	req->bio = bio_saved;
-error:
 	dmu_buf_rele_array(dbp, numbufs, FTAG);
-
 	return (err);
 }