From: Kent Overstreet <koverstreet@google.com>
To: axboe@kernel.dk, tytso@mit.edu, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Cc: Kent Overstreet <koverstreet@google.com>,
Yehuda Sadeh <yehuda@inktank.com>, Alex Elder <elder@inktank.com>,
ceph-devel@vger.kernel.org
Subject: [PATCH 12/26] rbd: Refactor bio cloning, don't clone biovecs
Date: Sat, 8 Jun 2013 19:18:54 -0700 [thread overview]
Message-ID: <1370744348-15407-13-git-send-email-koverstreet@google.com> (raw)
In-Reply-To: <1370744348-15407-1-git-send-email-koverstreet@google.com>
Now that we've got drivers converted to the new immutable bvec
primitives, bio splitting becomes much easier. In a few patches,
bio_clone() will be changed to share the old bio's bvec instead of
copying it, and bio_split() will do exactly what's being done here.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
---
drivers/block/rbd.c | 64 ++---------------------------------------------------
1 file changed, 2 insertions(+), 62 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 2a27dca..ed17d33 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1170,73 +1170,13 @@ static struct bio *bio_clone_range(struct bio *bio_src,
unsigned int len,
gfp_t gfpmask)
{
- struct bio_vec bv;
- struct bvec_iter iter;
- struct bvec_iter end_iter;
- unsigned int resid;
- unsigned int voff;
- unsigned short vcnt;
struct bio *bio;
- /* Handle the easy case for the caller */
-
- if (!offset && len == bio_src->bi_iter.bi_size)
- return bio_clone(bio_src, gfpmask);
-
- if (WARN_ON_ONCE(!len))
- return NULL;
- if (WARN_ON_ONCE(len > bio_src->bi_iter.bi_size))
- return NULL;
- if (WARN_ON_ONCE(offset > bio_src->bi_iter.bi_size - len))
- return NULL;
-
- /* Find first affected segment... */
-
- resid = offset;
- bio_for_each_segment(bv, bio_src, iter) {
- if (resid < bv.bv_len)
- break;
- resid -= bv.bv_len;
- }
- voff = resid;
-
- /* ...and the last affected segment */
-
- resid += len;
- __bio_for_each_segment(bv, bio_src, end_iter, iter) {
- if (resid <= bv.bv_len)
- break;
- resid -= bv.bv_len;
- }
- vcnt = end_iter.bi_idx = iter.bi_idx + 1;
-
- /* Build the clone */
-
- bio = bio_alloc(gfpmask, (unsigned int) vcnt);
+ bio = bio_clone(bio_src, gfpmask);
if (!bio)
return NULL; /* ENOMEM */
- bio->bi_bdev = bio_src->bi_bdev;
- bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector +
- (offset >> SECTOR_SHIFT);
- bio->bi_rw = bio_src->bi_rw;
- bio->bi_flags |= 1 << BIO_CLONED;
-
- /*
- * Copy over our part of the bio_vec, then update the first
- * and last (or only) entries.
- */
- memcpy(&bio->bi_io_vec[0], &bio_src->bi_io_vec[iter.bi_idx],
- vcnt * sizeof (struct bio_vec));
- bio->bi_io_vec[0].bv_offset += voff;
- if (vcnt > 1) {
- bio->bi_io_vec[0].bv_len -= voff;
- bio->bi_io_vec[vcnt - 1].bv_len = resid;
- } else {
- bio->bi_io_vec[0].bv_len = len;
- }
-
- bio->bi_vcnt = vcnt;
+ bio_advance(bio, offset);
bio->bi_iter.bi_size = len;
return bio;
--
1.8.3.rc1
next prev parent reply other threads:[~2013-06-09 2:20 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-09 2:18 Immutable biovecs, dio rewrite Kent Overstreet
2013-06-09 2:18 ` [PATCH 01/26] bcache: Use standard utility code Kent Overstreet
2013-06-09 2:18 ` [PATCH 02/26] bcache: Kill unaligned bvec hack Kent Overstreet
2013-06-09 2:18 ` [PATCH 03/26] block: Abstract out bvec iterator Kent Overstreet
2013-06-09 2:18 ` [PATCH 04/26] dm: Use bvec_iter for dm_bio_record() Kent Overstreet
2013-06-09 2:18 ` [PATCH 05/26] block: Convert bio_iovec() to bvec_iter Kent Overstreet
2013-06-09 2:18 ` [PATCH 07/26] block: Immutable bio vecs Kent Overstreet
2013-06-09 2:18 ` [PATCH 08/26] block: Convert bio_copy_data() to bvec_iter Kent Overstreet
2013-06-09 2:18 ` [PATCH 09/26] bio-integrity: Convert " Kent Overstreet
2013-06-09 2:18 ` [PATCH 10/26] block: Convert drivers to immutable biovecs Kent Overstreet
2013-06-28 19:39 ` Ed Cashin
2013-06-09 2:18 ` [PATCH 11/26] block: Kill bio_iovec_idx(), __bio_iovec() Kent Overstreet
2013-06-09 2:18 ` Kent Overstreet [this message]
2013-06-09 2:18 ` [PATCH 13/26] dm: Refactor for new bio cloning/splitting Kent Overstreet
2013-06-09 2:18 ` [PATCH 14/26] md, bcache: Remove bi_idx hacks Kent Overstreet
2013-06-09 2:18 ` [PATCH 15/26] block: Generic bio chaining Kent Overstreet
2013-06-09 2:18 ` [PATCH 16/26] block: Rename bio_split() -> bio_pair_split() Kent Overstreet
2013-06-09 2:18 ` [PATCH 17/26] block: Introduce new bio_split() Kent Overstreet
2013-06-09 2:19 ` [PATCH 18/26] block: Kill bio_pair_split() Kent Overstreet
2013-06-09 2:19 ` [PATCH 19/26] block: Kill bio_segments() Kent Overstreet
2013-06-09 2:19 ` [PATCH 20/26] block: Don't save/copy bvec array anymore, share when cloning Kent Overstreet
2013-06-09 2:19 ` [PATCH 21/26] block: Move bouncing to generic_make_request() Kent Overstreet
2013-06-09 2:19 ` [PATCH 22/26] block: Make generic_make_request handle arbitrary sized bios Kent Overstreet
2013-06-11 17:12 ` David Sterba
2013-06-12 4:26 ` Kent Overstreet
2013-06-09 2:19 ` [PATCH 23/26] blk-lib.c: generic_make_request() handles large bios now Kent Overstreet
2013-06-09 2:19 ` [PATCH 24/26] bcache: " Kent Overstreet
2013-06-09 2:19 ` [PATCH 25/26] block: Add bio_get_user_pages() Kent Overstreet
2013-06-09 2:19 ` [PATCH 26/26] Apply fire to dio code Kent Overstreet
2013-06-09 8:34 ` Immutable biovecs, dio rewrite Geert Uytterhoeven
2013-06-09 8:55 ` Kent Overstreet
[not found] ` <1370744348-15407-7-git-send-email-koverstreet@google.com>
2013-06-09 14:21 ` [PATCH 06/26] block: Convert bio_for_each_segment() to bvec_iter Geoff Levand
2013-06-11 5:20 ` Immutable biovecs, dio rewrite Dave Chinner
2013-06-12 20:30 ` Kent Overstreet
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