From: Kent Overstreet <koverstreet@google.com>
To: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org,
dm-devel@redhat.com
Cc: Kent Overstreet <koverstreet@google.com>,
tj@kernel.org, axboe@kernel.dk, neilb@suse.de, vgoyal@redhat.com
Subject: [PATCH v3 16/26] block: Add bio_copy_data()
Date: Mon, 24 Sep 2012 15:34:56 -0700 [thread overview]
Message-ID: <1348526106-17074-17-git-send-email-koverstreet@google.com> (raw)
In-Reply-To: <1348526106-17074-1-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 9a30dcf..d433825 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 3bf696b..467e101 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -289,6 +289,8 @@ 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:[~2012-09-24 22:34 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-24 22:34 [PATCH v3 00/26] Prep work for immutable bio vecs Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 01/26] block: Fix a buffer overrun in bio_integrity_split() Kent Overstreet
[not found] ` <1348526106-17074-2-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-01 21:23 ` [dm-devel] " Vivek Goyal
[not found] ` <20121001212336.GA17165-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-01 21:36 ` Kent Overstreet
2012-10-01 21:42 ` Kent Overstreet
[not found] ` <20121001214241.GE26488-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 14:08 ` Vivek Goyal
[not found] ` <20121002140847.GD758-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:26 ` Kent Overstreet
[not found] ` <20121002202643.GQ26488-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:32 ` Vivek Goyal
2012-10-02 21:01 ` Kent Overstreet
[not found] ` <20121002210143.GT26488-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 21:58 ` [dm-devel] " Vivek Goyal
[not found] ` <20121002215845.GB14471-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 22:07 ` Kent Overstreet
2012-10-02 22:30 ` Martin K. Petersen
2012-09-24 22:34 ` [PATCH v3 02/26] block: Convert integrity to bvec_alloc_bs() Kent Overstreet
2012-10-02 15:12 ` [dm-devel] " Vivek Goyal
2012-10-02 20:52 ` Kent Overstreet
[not found] ` <20121002205249.GR26488-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 22:05 ` [dm-devel] " Vivek Goyal
2012-10-02 22:17 ` Kent Overstreet
[not found] ` <1348526106-17074-3-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 15:37 ` Vivek Goyal
2012-10-02 21:00 ` Kent Overstreet
[not found] ` <20121002210006.GS26488-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 22:02 ` Vivek Goyal
2012-09-24 22:34 ` [PATCH v3 03/26] block: Add bio_advance() Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 04/26] block: Refactor blk_update_request() Kent Overstreet
2012-10-02 18:43 ` [dm-devel] " Vivek Goyal
[not found] ` <20121002184359.GC3283-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:10 ` Kent Overstreet
2012-10-02 20:14 ` Vivek Goyal
[not found] ` <20121002201451.GH758-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:25 ` Kent Overstreet
2012-10-02 18:59 ` Vivek Goyal
[not found] ` <20121002185955.GD3283-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:09 ` [dm-devel] " Kent Overstreet
[not found] ` <1348526106-17074-1-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-09-24 22:34 ` [PATCH v3 05/26] md: Convert md_trim_bio() to use bio_advance() Kent Overstreet
[not found] ` <1348526106-17074-6-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-09-26 0:38 ` NeilBrown
[not found] ` <20120926103827.4d880cf4-wvvUuzkyo1EYVZTmpyfIwg@public.gmane.org>
2012-09-27 4:41 ` Kent Overstreet
2012-09-24 22:35 ` [PATCH v3 23/26] block: Add bio_alloc_pages() Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 06/26] block: Add bio_end_sector() Kent Overstreet
[not found] ` <1348526106-17074-7-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-09-25 11:54 ` Lars Ellenberg
[not found] ` <20120925115452.GF8143-w1SgEEioFePxa46PmUWvFg@public.gmane.org>
2012-09-25 22:06 ` [Drbd-dev] " Kent Overstreet
[not found] ` <20120925220624.GC22647-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-09-26 15:16 ` Lars Ellenberg
2012-10-02 18:10 ` [dm-devel] " Vivek Goyal
[not found] ` <20121002181001.GB3283-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:20 ` Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 07/26] block: Use bio_sectors() more consistently Kent Overstreet
[not found] ` <1348526106-17074-8-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-09-24 23:04 ` Jim Paris
[not found] ` <20120924230449.GA2040-SRSuHwkuBJlaX0KmTac7FA@public.gmane.org>
2012-09-24 23:09 ` Kent Overstreet
2012-09-25 0:54 ` Ed Cashin
2012-09-24 22:34 ` [PATCH v3 08/26] block: Change bio_split() to respect the current value of bi_idx Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 09/26] block: Remove bi_idx references Kent Overstreet
[not found] ` <1348526106-17074-10-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 19:24 ` [dm-devel] " Vivek Goyal
2012-10-02 20:16 ` Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 10/26] block: Remove some unnecessary bi_vcnt usage Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 11/26] block: Add submit_bio_wait(), remove from md Kent Overstreet
[not found] ` <1348526106-17074-12-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-09-25 5:51 ` [dm-devel] " Hannes Reinecke
2012-09-25 22:15 ` Kent Overstreet
2012-10-02 19:41 ` Vivek Goyal
[not found] ` <20121002194132.GF3283-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:11 ` Kent Overstreet
[not found] ` <20121002201105.GL26488-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:16 ` Vivek Goyal
[not found] ` <20121002201630.GI758-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-10-02 20:22 ` Kent Overstreet
2012-10-04 6:07 ` Hannes Reinecke
2012-09-24 22:34 ` [PATCH v3 12/26] raid10: Use bio_reset() Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 13/26] raid1: use bio_reset() Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 14/26] raid5: " Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 15/26] raid1: Refactor narrow_write_error() to not use bi_idx Kent Overstreet
2012-09-24 22:34 ` Kent Overstreet [this message]
2012-09-24 22:34 ` [PATCH v3 17/26] pktcdvd: use bio_copy_data() Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 18/26] pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage Kent Overstreet
2012-09-24 22:34 ` [PATCH v3 19/26] raid1: use bio_copy_data() Kent Overstreet
2012-09-24 22:35 ` [PATCH v3 20/26] bounce: Refactor __blk_queue_bounce to not use bi_io_vec Kent Overstreet
2012-09-24 22:35 ` [PATCH v3 21/26] block: Add bio_for_each_segment_all() Kent Overstreet
2012-09-24 22:35 ` [PATCH v3 22/26] block: Convert some code to bio_for_each_segment_all() Kent Overstreet
2012-09-24 22:35 ` [PATCH v3 24/26] block: Add an explicit bio flag for bios that own their bvec Kent Overstreet
2012-09-24 22:35 ` [PATCH v3 25/26] bio-integrity: Add explicit field for owner of bip_buf Kent Overstreet
2012-09-24 22:35 ` [PATCH v3 26/26] block: Add BIO_SUBMITTED flag, kill BIO_CLONED Kent Overstreet
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