From: Kent Overstreet <koverstreet@google.com>
To: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org,
dm-devel@redhat.com
Cc: axboe@kernel.dk, Kent Overstreet <koverstreet@google.com>,
tj@kernel.org, neilb@suse.de
Subject: [PATCH v2 15/26] block: Add bio_copy_data()
Date: Mon, 10 Sep 2012 17:22:26 -0700 [thread overview]
Message-ID: <1347322957-25260-16-git-send-email-koverstreet@google.com> (raw)
In-Reply-To: <1347322957-25260-1-git-send-email-koverstreet@google.com>
This gets open coded quite a bit and it's tricky to get right, so make a
generic version and convert some existing users over to it instead.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
---
fs/bio.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/bio.h | 2 ++
2 files changed, 72 insertions(+)
diff --git a/fs/bio.c b/fs/bio.c
index 1342a16..7fb9f4e 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -827,6 +827,76 @@ void bio_advance(struct bio *bio, unsigned bytes)
}
EXPORT_SYMBOL(bio_advance);
+/**
+ * bio_copy_data - copy contents of data buffers from one chain of bios to
+ * another
+ * @src: source bio list
+ * @dst: destination bio list
+ *
+ * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats
+ * @src and @dst as linked lists of bios.
+ *
+ * Stops when it reaches the end of either @src or @dst - that is, copies
+ * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios).
+ */
+void bio_copy_data(struct bio *dst, struct bio *src)
+{
+ struct bio_vec *src_bv, *dst_bv;
+ unsigned src_offset, dst_offset, bytes;
+ void *src_p, *dst_p;
+
+ src_bv = bio_iovec(src);
+ dst_bv = bio_iovec(dst);
+
+ src_offset = src_bv->bv_offset;
+ dst_offset = dst_bv->bv_offset;
+
+ while (1) {
+ if (src_offset == src_bv->bv_offset + src_bv->bv_len) {
+ src_bv++;
+ if (src_bv == bio_iovec_idx(src, src->bi_vcnt)) {
+ src = src->bi_next;
+ if (!src)
+ break;
+
+ src_bv = bio_iovec(src);
+ }
+
+ src_offset = src_bv->bv_offset;
+ }
+
+ if (dst_offset == dst_bv->bv_offset + dst_bv->bv_len) {
+ dst_bv++;
+ if (dst_bv == bio_iovec_idx(dst, dst->bi_vcnt)) {
+ dst = dst->bi_next;
+ if (!dst)
+ break;
+
+ dst_bv = bio_iovec(dst);
+ }
+
+ dst_offset = dst_bv->bv_offset;
+ }
+
+ bytes = min(dst_bv->bv_offset + dst_bv->bv_len - dst_offset,
+ src_bv->bv_offset + src_bv->bv_len - src_offset);
+
+ src_p = kmap_atomic(src_bv->bv_page);
+ dst_p = kmap_atomic(dst_bv->bv_page);
+
+ memcpy(dst_p + dst_bv->bv_offset,
+ src_p + src_bv->bv_offset,
+ bytes);
+
+ kunmap_atomic(dst_p);
+ kunmap_atomic(src_p);
+
+ src_offset += bytes;
+ dst_offset += bytes;
+ }
+}
+EXPORT_SYMBOL(bio_copy_data);
+
struct bio_map_data {
struct bio_vec *iovecs;
struct sg_iovec *sgvecs;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 949c48a..92015ce 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -286,6 +286,8 @@ static inline void bio_flush_dcache_pages(struct bio *bi)
}
#endif
+extern void bio_copy_data(struct bio *dst, struct bio *src);
+
extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
unsigned long, unsigned int, int, gfp_t);
extern struct bio *bio_copy_user_iov(struct request_queue *,
--
1.7.12
next prev parent reply other threads:[~2012-09-11 0:23 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-11 0:22 [PATCH v2 00/26] Prep work for immutable bio vecs Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 01/26] block: Convert integrity to bvec_alloc_bs(), and a bugfix Kent Overstreet
2012-09-11 20:36 ` [dm-devel] " Vivek Goyal
2012-09-11 20:48 ` Kent Overstreet
2012-09-11 22:07 ` Kent Overstreet
2012-09-12 19:39 ` Martin K. Petersen
2012-09-17 21:08 ` Kent Overstreet
2012-09-20 21:53 ` Tejun Heo
2012-09-11 0:22 ` [PATCH v2 02/26] block: Add bio_advance() Kent Overstreet
2012-09-20 21:58 ` Tejun Heo
2012-09-20 23:13 ` Kent Overstreet
2012-09-20 23:25 ` Tejun Heo
2012-09-20 23:38 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 03/26] block: Refactor blk_update_request() Kent Overstreet
2012-09-20 23:20 ` Tejun Heo
2012-09-20 23:36 ` Kent Overstreet
2012-09-20 23:41 ` Tejun Heo
2012-09-20 23:50 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 04/26] md: Convert md_trim_bio() to use bio_advance() Kent Overstreet
2012-09-20 23:27 ` Tejun Heo
2012-09-11 0:22 ` [PATCH v2 05/26] block: Add bio_end() Kent Overstreet
2012-09-17 9:17 ` Steven Whitehouse
2012-09-20 23:32 ` Tejun Heo
2012-09-20 23:44 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 06/26] block: Use bio_sectors() more consistently Kent Overstreet
2012-09-20 23:36 ` Tejun Heo
2012-09-20 23:47 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 07/26] block: Don't use bi_idx in bio_split() or require it to be 0 Kent Overstreet
2012-09-20 23:45 ` Tejun Heo
2012-09-21 0:00 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 08/26] block: Remove bi_idx references Kent Overstreet
2012-09-20 23:49 ` Tejun Heo
2012-09-21 0:04 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 09/26] block: Remove some unnecessary bi_vcnt usage Kent Overstreet
2012-09-20 23:51 ` Tejun Heo
2012-09-11 0:22 ` [PATCH v2 10/26] block: Add submit_bio_wait(), remove from md Kent Overstreet
2012-09-20 23:56 ` Tejun Heo
2012-09-21 0:06 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 11/26] raid10: Use bio_reset() Kent Overstreet
2012-09-20 23:59 ` Tejun Heo
2012-09-11 0:22 ` [PATCH v2 12/26] raid1: use bio_reset() Kent Overstreet
2012-09-11 4:59 ` NeilBrown
2012-09-11 18:28 ` Kent Overstreet
2012-09-11 21:17 ` NeilBrown
2012-09-11 0:22 ` [PATCH v2 13/26] raid5: " Kent Overstreet
2012-09-11 5:03 ` NeilBrown
2012-09-11 19:26 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 14/26] raid1: Refactor narrow_write_error() to not use bi_idx Kent Overstreet
2012-09-11 0:22 ` Kent Overstreet [this message]
2012-09-21 0:06 ` [PATCH v2 15/26] block: Add bio_copy_data() Tejun Heo
2012-09-21 0:09 ` Kent Overstreet
2012-09-21 0:15 ` Tejun Heo
2012-09-21 0:09 ` Tejun Heo
2012-09-21 0:13 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 16/26] pktcdvd: use bio_copy_data() Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 17/26] pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 18/26] raid1: use bio_copy_data() Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 19/26] bounce: Refactor __blk_queue_bounce to not use bi_io_vec Kent Overstreet
2012-09-21 0:25 ` Tejun Heo
2012-09-21 0:29 ` Kent Overstreet
2012-09-21 0:27 ` Tejun Heo
2012-09-21 0:34 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 20/26] block: Add bio_for_each_segment_all() Kent Overstreet
2012-09-21 0:35 ` Tejun Heo
2012-09-11 0:22 ` [PATCH v2 21/26] block: Convert some code to bio_for_each_segment_all() Kent Overstreet
2012-09-21 0:38 ` Tejun Heo
2012-09-21 0:50 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 22/26] block: Add bio_alloc_pages() Kent Overstreet
2012-09-21 0:47 ` Tejun Heo
2012-09-21 4:50 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 23/26] raid1: use bio_alloc_pages() Kent Overstreet
2012-09-21 0:48 ` Tejun Heo
2012-09-21 4:51 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 24/26] block: Add an explicit bio flag for bios that own their bvec Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 25/26] bio-integrity: Add explicit field for owner of bip_buf Kent Overstreet
2012-09-12 19:41 ` Martin K. Petersen
2012-09-17 21:09 ` Kent Overstreet
2012-09-11 0:22 ` [PATCH v2 26/26] block: Add BIO_SUBMITTED flag, kill BIO_CLONED Kent Overstreet
2012-09-11 5:22 ` [PATCH v2 00/26] Prep work for immutable bio vecs NeilBrown
2012-09-20 23:22 ` Tejun Heo
2012-10-15 20:08 [PATCH v4 00/24] " Kent Overstreet
2012-10-15 20:09 ` [PATCH v2 15/26] block: Add bio_copy_data() Kent Overstreet
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