Commit 0e28997e authored by Kent Overstreet's avatar Kent Overstreet Committed by Jens Axboe
Browse files

btrfs: remove bio splitting and merge_bvec_fn() calls

Btrfs has been doing bio splitting from btrfs_map_bio(), by checking
device limits as well as calling ->merge_bvec_fn() etc. That is not
necessary any more, because generic_make_request() is now able to
handle arbitrarily sized bios. So clean up unnecessary code paths.

Cc: Chris Mason <>
Cc: Josef Bacik <>
Signed-off-by: default avatarKent Overstreet <>
Signed-off-by: default avatarChris Mason <>
[dpark: add more description in commit message]
Signed-off-by: default avatarDongsu Park <>
Signed-off-by: default avatarMing Lin <>
Signed-off-by: default avatarJens Axboe <>
parent 749b61da
......@@ -5870,34 +5870,6 @@ static noinline void btrfs_schedule_bio(struct btrfs_root *root,
static int bio_size_ok(struct block_device *bdev, struct bio *bio,
sector_t sector)
struct bio_vec *prev;
struct request_queue *q = bdev_get_queue(bdev);
unsigned int max_sectors = queue_max_sectors(q);
struct bvec_merge_data bvm = {
.bi_bdev = bdev,
.bi_sector = sector,
.bi_rw = bio->bi_rw,
if (WARN_ON(bio->bi_vcnt == 0))
return 1;
prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
if (bio_sectors(bio) > max_sectors)
return 0;
if (!q->merge_bvec_fn)
return 1;
bvm.bi_size = bio->bi_iter.bi_size - prev->bv_len;
if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
return 0;
return 1;
static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
struct bio *bio, u64 physical, int dev_nr,
int rw, int async)
......@@ -5931,38 +5903,6 @@ static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
btrfsic_submit_bio(rw, bio);
static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
struct bio *first_bio, struct btrfs_device *dev,
int dev_nr, int rw, int async)
struct bio_vec *bvec = first_bio->bi_io_vec;
struct bio *bio;
int nr_vecs = bio_get_nr_vecs(dev->bdev);
u64 physical = bbio->stripes[dev_nr].physical;
bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
if (!bio)
return -ENOMEM;
while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
bvec->bv_offset) < bvec->bv_len) {
u64 len = bio->bi_iter.bi_size;
submit_stripe_bio(root, bbio, bio, physical, dev_nr,
rw, async);
physical += len;
goto again;
submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
return 0;
static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
......@@ -6035,18 +5975,6 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
* Check and see if we're ok with this bio based on it's size
* and offset with the given device.
if (!bio_size_ok(dev->bdev, first_bio,
bbio->stripes[dev_nr].physical >> 9)) {
ret = breakup_stripe_bio(root, bbio, first_bio, dev,
dev_nr, rw, async_submit);
if (dev_nr < total_devs - 1) {
bio = btrfs_bio_clone(first_bio, GFP_NOFS);
BUG_ON(!bio); /* -ENOMEM */
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