[PATCH 02/22] block: Consolidate duplicated bio_trim() implementations

Kent Overstreet
2013-08-07T21:55:03Z

Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on,
we should know better than this.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
---
drivers/block/xen-blkfront.c | 53 +-------------------------------------------
drivers/md/md.c | 40 ---------------------------------
drivers/md/md.h | 1 -
drivers/md/raid1.c | 10 ++++-----
drivers/md/raid10.c | 18 +++++++--------
fs/bio.c | 46 ++++++++++++++++++++++++++++++++++++++
include/linux/bio.h | 1 +
7 files changed, 61 insertions(+), 108 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index a4660bb..8d53ed2 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1336,57 +1336,6 @@ static int blkfront_probe(struct xenbus_device *dev,
return 0;
}

-/*
- * This is a clone of md_trim_bio, used to split a bio into smaller ones
- */
-static void trim_bio(struct bio *bio, int offset, int size)
-{
- /* 'bio' is a cloned bio which we need to trim to match
- * the given offset and size.
- * This requires adjusting bi_sector, bi_size, and bi_io_vec
- */
- int i;
- struct bio_vec *bvec;
- int sofar = 0;
-
- size <<= 9;
- if (offset == 0 && size == bio->bi_size)
- return;
-
- bio->bi_sector += offset;
- bio->bi_size = size;
- offset <<= 9;
- clear_bit(BIO_SEG_VALID, &bio->bi_flags);
-
- while (bio->bi_idx < bio->bi_vcnt &&
- bio->bi_io_vec[bio->bi_idx].bv_len <= offset) {
- /* remove this whole bio_vec */
- offset -= bio->bi_io_vec[bio->bi_idx].bv_len;
- bio->bi_idx++;
- }
- if (bio->bi_idx < bio->bi_vcnt) {
- bio->bi_io_vec[bio->bi_idx].bv_offset += offset;
- bio->bi_io_vec[bio->bi_idx].bv_len -= offset;
- }
- /* avoid any complications with bi_idx being non-zero*/
- if (bio->bi_idx) {
- memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
- (bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
- bio->bi_vcnt -= bio->bi_idx;
- bio->bi_idx = 0;
- }
- /* Make sure vcnt and last bv are not too big */
- bio_for_each_segment(bvec, bio, i) {
- if (sofar + bvec->bv_len > size)
- bvec->bv_len = size - sofar;
- if (bvec->bv_len == 0) {
- bio->bi_vcnt = i;
- break;
- }
- sofar += bvec->bv_len;
- }
-}
-
static void split_bio_end(struct bio *bio, int error)
{
struct split_bio *split_bio = bio->bi_private;
@@ -1522,7 +1471,7 @@ static int blkif_recover(struct blkfront_info *info)
(unsigned int)(bio->bi_size >> 9) - offset);
cloned_bio = bio_clone(bio, GFP_NOIO);
BUG_ON(cloned_bio == NULL);
- trim_bio(cloned_bio, offset, size);
+ bio_trim(cloned_bio, offset, size);
cloned_bio->bi_private = split_bio;
cloned_bio->bi_end_io = split_bio_end;
submit_bio(cloned_bio->bi_rw, cloned_bio);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9f13e13..60e10f1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -183,46 +183,6 @@ struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
}
EXPORT_SYMBOL_GPL(bio_clone_mddev);

-void md_trim_bio(struct bio *bio, int offset, int size)
-{
- /* 'bio' is a cloned bio which we need to trim to match
- * the given offset and size.
- * This requires adjusting bi_sector, bi_size, and bi_io_vec
- */
- int i;
- struct bio_vec *bvec;
- int sofar = 0;
-
- size <<= 9;
- if (offset == 0 && size == bio->bi_size)
- return;
-
- clear_bit(BIO_SEG_VALID, &bio->bi_flags);
-
- bio_advance(bio, offset << 9);
-
- bio->bi_size = size;
-
- /* avoid any complications with bi_idx being non-zero*/
- if (bio->bi_idx) {
- memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
- (bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
- bio->bi_vcnt -= bio->bi_idx;
- bio->bi_idx = 0;
- }
- /* Make sure vcnt and last bv are not too big */
- bio_for_each_segment(bvec, bio, i) {
- if (sofar + bvec->bv_len > size)
- bvec->bv_len = size - sofar;
- if (bvec->bv_len == 0) {
- bio->bi_vcnt = i;
- break;
- }
- sofar += bvec->bv_len;
- }
-}
-EXPORT_SYMBOL_GPL(md_trim_bio);
-
/*
* We have a system wide 'event count' that is incremented
* on any 'interesting' event, and readers of /proc/mdstat
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 20f02c0..01401bc 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -613,7 +613,6 @@ extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
struct mddev *mddev);
extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
struct mddev *mddev);
-extern void md_trim_bio(struct bio *bio, int offset, int size);

extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
static inline int mddev_check_plugged(struct mddev *mddev)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d60412c..fc817ff 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1097,8 +1097,8 @@ read_again:
r1_bio->read_disk = rdisk;

read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
- max_sectors);
+ bio_trim(read_bio, r1_bio->sector - bio->bi_sector,
+ max_sectors);

r1_bio->bios[rdisk] = read_bio;

@@ -1266,7 +1266,7 @@ read_again:
continue;

mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
+ bio_trim(mbio, r1_bio->sector - bio->bi_sector, max_sectors);

if (first_clone) {
/* do behind I/O ?
@@ -2125,7 +2125,7 @@ static int narrow_write_error(struct r1bio *r1_bio, int i)
wbio->bi_sector = r1_bio->sector;
wbio->bi_size = r1_bio->sectors << 9;

- md_trim_bio(wbio, sector - r1_bio->sector, sectors);
+ bio_trim(wbio, sector - r1_bio->sector, sectors);
wbio->bi_sector += rdev->data_offset;
wbio->bi_bdev = rdev->bdev;
if (submit_bio_wait(WRITE, wbio) == 0)
@@ -2240,7 +2240,7 @@ read_more:
}
r1_bio->read_disk = disk;
bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
- md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
+ bio_trim(bio, r1_bio->sector - bio->bi_sector, max_sectors);
r1_bio->bios[r1_bio->read_disk] = bio;
rdev = conf->mirrors[disk].rdev;
printk_ratelimited(KERN_ERR
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index df7b0a0..a582235 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1302,8 +1302,8 @@ read_again:
slot = r10_bio->read_slot;

read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector,
- max_sectors);
+ bio_trim(read_bio, r10_bio->sector - bio->bi_sector,
+ max_sectors);

r10_bio->devs[slot].bio = read_bio;
r10_bio->devs[slot].rdev = rdev;
@@ -1510,8 +1510,8 @@ retry_write:
if (r10_bio->devs[i].bio) {
struct md_rdev *rdev = conf->mirrors[d].rdev;
mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
- max_sectors);
+ bio_trim(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
r10_bio->devs[i].bio = mbio;

mbio->bi_sector = (r10_bio->devs[i].addr+
@@ -1553,8 +1553,8 @@ retry_write:
rdev = conf->mirrors[d].rdev;
}
mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
- max_sectors);
+ bio_trim(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
r10_bio->devs[i].repl_bio = mbio;

mbio->bi_sector = (r10_bio->devs[i].addr +
@@ -2613,7 +2613,7 @@ static int narrow_write_error(struct r10bio *r10_bio, int i)
sectors = sect_to_write;
/* Write at 'sector' for 'sectors' */
wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(wbio, sector - bio->bi_sector, sectors);
+ bio_trim(wbio, sector - bio->bi_sector, sectors);
wbio->bi_sector = (r10_bio->devs[i].addr+
choose_data_offset(r10_bio, rdev) +
(sector - r10_bio->sector));
@@ -2686,9 +2686,7 @@ read_more:
(unsigned long long)r10_bio->sector);
bio = bio_clone_mddev(r10_bio->master_bio,
GFP_NOIO, mddev);
- md_trim_bio(bio,
- r10_bio->sector - bio->bi_sector,
- max_sectors);
+ bio_trim(bio, r10_bio->sector - bio->bi_sector, max_sectors);
r10_bio->devs[slot].bio = bio;
r10_bio->devs[slot].rdev = rdev;
bio->bi_sector = r10_bio->devs[slot].addr
diff --git a/fs/bio.c b/fs/bio.c
index 94bbc04..2b6a816 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1795,6 +1795,52 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors)
EXPORT_SYMBOL(bio_split);

/**
+ * bio_trim - trim a bio
+ * @bio: bio to trim
+ * @offset: number of sectors to trim from the front of @bio
+ * @size: size we want to trim @bio to, in sectors
+ */
+void bio_trim(struct bio *bio, int offset, int size)
+{
+ /* 'bio' is a cloned bio which we need to trim to match
+ * the given offset and size.
+ * This requires adjusting bi_sector, bi_size, and bi_io_vec
+ */
+ int i;
+ struct bio_vec *bvec;
+ int sofar = 0;
+
+ size <<= 9;
+ if (offset == 0 && size == bio->bi_size)
+ return;
+
+ clear_bit(BIO_SEG_VALID, &bio->bi_flags);
+
+ bio_advance(bio, offset << 9);
+
+ bio->bi_size = size;
+
+ /* avoid any complications with bi_idx being non-zero*/
+ if (bio->bi_idx) {
+ memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
+ (bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
+ bio->bi_vcnt -= bio->bi_idx;
+ bio->bi_idx = 0;
+ }
+ /* Make sure vcnt and last bv are not too big */
+ bio_for_each_segment(bvec, bio, i) {
+ if (sofar + bvec->bv_len > size)
+ bvec->bv_len = size - sofar;
+ if (bvec->bv_len == 0) {
+ bio->bi_vcnt = i;
+ break;
+ }
+ sofar += bvec->bv_len;
+ }
+}
+EXPORT_SYMBOL_GPL(bio_trim);
+
+/**
* bio_sector_offset - Find hardware sector offset in bio
* @bio: bio to inspect
* @index: bio_vec index
diff --git a/include/linux/bio.h b/include/linux/bio.h
index ec48bac..162036a 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -218,6 +218,7 @@ struct bio_pair {
};
extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
extern void bio_pair_release(struct bio_pair *dbio);
+extern void bio_trim(struct bio *bio, int offset, int size);

extern struct bio_set *bioset_create(unsigned int, unsigned int);
extern void bioset_free(struct bio_set *);
--
1.8.4.rc1