Hi,
This patchset brings multi-page bvec into block layer:
1) what is multi-page bvec?
Multipage bvecs means that one 'struct bio_bvec' can hold multiple pages
which are physically contiguous instead of one single page used in linux
kernel for long time.
2) why is multi-page bvec introduced?
Kent proposed the idea[1] first.
As system's RAM becomes much bigger than before, and huge page, transparent
huge page and memory compaction are widely used, it is a bit easy now
to see physically contiguous pages from fs in I/O. On the other hand, from
block layer's view, it isn't necessary to store intermediate pages into bvec,
and it is enough to just store the physicallly contiguous 'segment' in each
io vector.
Also huge pages are being brought to filesystem and swap [2][6], we can
do IO on a hugepage each time[3], which requires that one bio can transfer
at least one huge page one time. Turns out it isn't flexiable to change
BIO_MAX_PAGES simply[3][5]. Multipage bvec can fit in this case very well.
As we saw, if CONFIG_THP_SWAP is enabled, BIO_MAX_PAGES can be configured
as much bigger, such as 512, which requires at least two 4K pages for holding
the bvec table.
With multi-page bvec:
- Inside block layer, both bio splitting and sg map can become more
efficient than before by just traversing the physically contiguous
'segment' instead of each page.
- segment handling in block layer can be improved much in future since it
should be quite easy to convert multipage bvec into segment easily. For
example, we might just store segment in each bvec directly in future.
- bio size can be increased and it should improve some high-bandwidth IO
case in theory[4].
- there is opportunity in future to improve memory footprint of bvecs.
3) how is multi-page bvec implemented in this patchset?
Patch 1 ~ 6 parpares for supporting multi-page bvec.
Patches 7 ~ 16 implement multipage bvec in block layer:
- put all tricks into bvec/bio/rq iterators, and as far as
drivers and fs use these standard iterators, they are happy
with multipage bvec
- introduce bio_for_each_bvec() to iterate over multipage bvec for splitting
bio and mapping sg
- keep current bio_for_each_segment*() to itereate over singlepage bvec and
make sure current users won't be broken; especailly, convert to this
new helper prototype in single patch 21 given it is bascially a mechanism
conversion
- deal with iomap & xfs's sub-pagesize io vec in patch 13
- enalbe multipage bvec in patch 14
Patch 17 redefines BIO_MAX_PAGES as 256.
Patch 18 documents usages of bio iterator helpers.
Patch 19~20 kills NO_SG_MERGE.
These patches can be found in the following git tree:
git: https://github.com/ming1/linux.git for-4.21-block-mp-bvec-V12
Lots of test(blktest, xfstests, ltp io, ...) have been run with this patchset,
and not see regression.
Thanks Christoph for reviewing the early version and providing very good
suggestions, such as: introduce bio_init_with_vec_table(), remove another
unnecessary helpers for cleanup and so on.
Thanks Chritoph and Omar for reviewing V10/V11, and provides lots of helpful
comments.
V12:
- deal with non-cluster by max segment size & segment boundary limit
- rename bvec helper's name
- revert new change on bvec_iter_advance() in V11
- introduce rq_for_each_bvec()
- use simpler check on enalbing multi-page bvec
- fix Document change
V11:
- address most of reviews from Omar and christoph
- rename mp_bvec_* as segment_* helpers
- remove 'mp' parameter from bvec_iter_advance() and related helpers
- cleanup patch on bvec_split_segs() and blk_bio_segment_split(),
remove unnecessary checks
- simplify bvec_last_segment()
- drop bio_pages_all()
- introduce dedicated functions/file for handling non-cluser bio for
avoiding checking queue cluster before adding page to bio
- introduce bio_try_merge_segment() for simplifying iomap/xfs page
accounting code
- Fix Document change
V10:
- no any code change, just add more guys and list into patch's CC list,
as suggested by Christoph and Dave Chinner
V9:
- fix regression on iomap's sub-pagesize io vec, covered by patch 13
V8:
- remove prepare patches which all are merged to linus tree
- rebase on for-4.21/block
- address comments on V7
- add patches of killing NO_SG_MERGE
V7:
- include Christoph and Mike's bio_clone_bioset() patches, which is
actually prepare patches for multipage bvec
- address Christoph's comments
V6:
- avoid to introduce lots of renaming, follow Jen's suggestion of
using the name of chunk for multipage io vector
- include Christoph's three prepare patches
- decrease stack usage for using bio_for_each_chunk_segment_all()
- address Kent's comment
V5:
- remove some of prepare patches, which have been merged already
- add bio_clone_seg_bioset() to fix DM's bio clone, which
is introduced by 18a25da84354c6b (dm: ensure bio submission follows
a depth-first tree walk)
- rebase on the latest block for-v4.18
V4:
- rename bio_for_each_segment*() as bio_for_each_page*(), rename
bio_segments() as bio_pages(), rename rq_for_each_segment() as
rq_for_each_pages(), because these helpers never return real
segment, and they always return single page bvec
- introducing segment_for_each_page_all()
- introduce new bio_for_each_segment*()/rq_for_each_segment()/bio_segments()
for returning real multipage segment
- rewrite segment_last_page()
- rename bvec iterator helper as suggested by Christoph
- replace comment with applying bio helpers as suggested by Christoph
- document usage of bio iterator helpers
- redefine BIO_MAX_PAGES as 256 to make the biggest bvec table
accommodated in 4K page
- move bio_alloc_pages() into bcache as suggested by Christoph
V3:
- rebase on v4.13-rc3 with for-next of block tree
- run more xfstests: xfs/ext4 over NVMe, Sata, DM(linear),
MD(raid1), and not see regressions triggered
- add Reviewed-by on some btrfs patches
- remove two MD patches because both are merged to linus tree
already
V2:
- bvec table direct access in raid has been cleaned, so NO_MP
flag is dropped
- rebase on recent Neil Brown's change on bio and bounce code
- reorganize the patchset
V1:
- against v4.10-rc1 and some cleanup in V0 are in -linus already
- handle queue_virt_boundary() in mp bvec change and make NVMe happy
- further BTRFS cleanup
- remove QUEUE_FLAG_SPLIT_MP
- rename for two new helpers of bio_for_each_segment_all()
- fix bounce convertion
- address comments in V0
[1], http://marc.info/?l=linux-kernel&m=141680246629547&w=2
[2], https://patchwork.kernel.org/patch/9451523/
[3], http://marc.info/?t=147735447100001&r=1&w=2
[4], http://marc.info/?l=linux-mm&m=147745525801433&w=2
[5], http://marc.info/?t=149569484500007&r=1&w=2
[6], http://marc.info/?t=149820215300004&r=1&w=2
Christoph Hellwig (3):
btrfs: remove various bio_offset arguments
btrfs: look at bi_size for repair decisions
block: remove the "cluster" flag
Ming Lei (17):
block: don't use bio->bi_vcnt to figure out segment number
block: remove bvec_iter_rewind()
block: rename bvec helpers
block: introduce multi-page bvec helpers
block: introduce bio_for_each_bvec() and rq_for_each_bvec()
block: use bio_for_each_bvec() to compute multi-page bvec count
block: use bio_for_each_bvec() to map sg
block: introduce bvec_last_segment()
fs/buffer.c: use bvec iterator to truncate the bio
block: loop: pass multi-page bvec to iov_iter
bcache: avoid to use bio_for_each_segment_all() in
bch_bio_alloc_pages()
block: allow bio_for_each_segment_all() to iterate over multi-page
bvec
block: enable multipage bvecs
block: always define BIO_MAX_PAGES as 256
block: document usage of bio iterator helpers
block: kill QUEUE_FLAG_NO_SG_MERGE
block: kill BLK_MQ_F_SG_MERGE
.clang-format | 2 +-
Documentation/block/biovecs.txt | 25 +++++
block/bio.c | 49 +++++---
block/blk-merge.c | 227 ++++++++++++++++++++++++--------------
block/blk-mq-debugfs.c | 2 -
block/blk-mq.c | 3 -
block/blk-settings.c | 3 -
block/blk-sysfs.c | 5 +-
block/bounce.c | 6 +-
drivers/block/loop.c | 22 ++--
drivers/block/nbd.c | 2 +-
drivers/block/rbd.c | 2 +-
drivers/block/skd_main.c | 1 -
drivers/block/xen-blkfront.c | 2 +-
drivers/md/bcache/btree.c | 3 +-
drivers/md/bcache/util.c | 6 +-
drivers/md/dm-crypt.c | 3 +-
drivers/md/dm-integrity.c | 2 +-
drivers/md/dm-io.c | 4 +-
drivers/md/dm-rq.c | 2 +-
drivers/md/dm-table.c | 13 ---
drivers/md/raid1.c | 3 +-
drivers/mmc/core/queue.c | 3 +-
drivers/nvdimm/blk.c | 4 +-
drivers/nvdimm/btt.c | 4 +-
drivers/scsi/scsi_lib.c | 22 +++-
drivers/staging/erofs/data.c | 3 +-
drivers/staging/erofs/unzip_vle.c | 3 +-
fs/block_dev.c | 6 +-
fs/btrfs/compression.c | 3 +-
fs/btrfs/disk-io.c | 24 ++--
fs/btrfs/disk-io.h | 2 +-
fs/btrfs/extent_io.c | 20 ++--
fs/btrfs/extent_io.h | 5 +-
fs/btrfs/inode.c | 23 ++--
fs/btrfs/raid56.c | 3 +-
fs/buffer.c | 5 +-
fs/crypto/bio.c | 3 +-
fs/direct-io.c | 4 +-
fs/exofs/ore.c | 3 +-
fs/exofs/ore_raid.c | 3 +-
fs/ext4/page-io.c | 3 +-
fs/ext4/readpage.c | 3 +-
fs/f2fs/data.c | 9 +-
fs/gfs2/lops.c | 6 +-
fs/gfs2/meta_io.c | 3 +-
fs/iomap.c | 10 +-
fs/mpage.c | 3 +-
fs/xfs/xfs_aops.c | 9 +-
include/linux/bio.h | 47 ++++----
include/linux/blk-mq.h | 1 -
include/linux/blkdev.h | 11 +-
include/linux/bvec.h | 104 ++++++++++++-----
include/linux/ceph/messenger.h | 2 +-
lib/iov_iter.c | 2 +-
net/ceph/messenger.c | 14 +--
56 files changed, 460 insertions(+), 297 deletions(-)
--
2.9.5
From: Christoph Hellwig <[email protected]>
The btrfs write path passes a bio_offset argument through some deep
callchains including async offloading. In the end this is easily
calculatable using page_offset plus the bvec offset for the first
page in the bio, and only actually used by by a single function.
Just move the calculation of the offset there.
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
fs/btrfs/disk-io.c | 21 +++++----------------
fs/btrfs/disk-io.h | 2 +-
fs/btrfs/extent_io.c | 9 ++-------
fs/btrfs/extent_io.h | 5 ++---
fs/btrfs/inode.c | 17 ++++++++---------
5 files changed, 18 insertions(+), 36 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3f0b6d1936e8..169839487ac9 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -108,11 +108,6 @@ struct async_submit_bio {
struct bio *bio;
extent_submit_bio_start_t *submit_bio_start;
int mirror_num;
- /*
- * bio_offset is optional, can be used if the pages in the bio
- * can't tell us where in the file the bio should go
- */
- u64 bio_offset;
struct btrfs_work work;
blk_status_t status;
};
@@ -754,8 +749,7 @@ static void run_one_async_start(struct btrfs_work *work)
blk_status_t ret;
async = container_of(work, struct async_submit_bio, work);
- ret = async->submit_bio_start(async->private_data, async->bio,
- async->bio_offset);
+ ret = async->submit_bio_start(async->private_data, async->bio);
if (ret)
async->status = ret;
}
@@ -786,7 +780,7 @@ static void run_one_async_free(struct btrfs_work *work)
blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
int mirror_num, unsigned long bio_flags,
- u64 bio_offset, void *private_data,
+ void *private_data,
extent_submit_bio_start_t *submit_bio_start)
{
struct async_submit_bio *async;
@@ -803,8 +797,6 @@ blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
btrfs_init_work(&async->work, btrfs_worker_helper, run_one_async_start,
run_one_async_done, run_one_async_free);
- async->bio_offset = bio_offset;
-
async->status = 0;
if (op_is_sync(bio->bi_opf))
@@ -831,8 +823,7 @@ static blk_status_t btree_csum_one_bio(struct bio *bio)
return errno_to_blk_status(ret);
}
-static blk_status_t btree_submit_bio_start(void *private_data, struct bio *bio,
- u64 bio_offset)
+static blk_status_t btree_submit_bio_start(void *private_data, struct bio *bio)
{
/*
* when we're called for a write, we're already in the async
@@ -853,8 +844,7 @@ static int check_async_write(struct btrfs_inode *bi)
}
static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
- int mirror_num, unsigned long bio_flags,
- u64 bio_offset)
+ int mirror_num, unsigned long bio_flags)
{
struct inode *inode = private_data;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -882,8 +872,7 @@ static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
* checksumming can happen in parallel across all CPUs
*/
ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, 0,
- bio_offset, private_data,
- btree_submit_bio_start);
+ private_data, btree_submit_bio_start);
}
if (ret)
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 4cccba22640f..b48b3ec353fc 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -119,7 +119,7 @@ blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
enum btrfs_wq_endio_type metadata);
blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
int mirror_num, unsigned long bio_flags,
- u64 bio_offset, void *private_data,
+ void *private_data,
extent_submit_bio_start_t *submit_bio_start);
blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
int mirror_num);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d228f706ff3e..15fd46582bb2 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2397,7 +2397,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
read_mode, failrec->this_mirror, failrec->in_validation);
status = tree->ops->submit_bio_hook(tree->private_data, bio, failrec->this_mirror,
- failrec->bio_flags, 0);
+ failrec->bio_flags);
if (status) {
free_io_failure(failure_tree, tree, failrec);
bio_put(bio);
@@ -2719,18 +2719,13 @@ static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
unsigned long bio_flags)
{
blk_status_t ret = 0;
- struct bio_vec *bvec = bio_last_bvec_all(bio);
- struct page *page = bvec->bv_page;
struct extent_io_tree *tree = bio->bi_private;
- u64 start;
-
- start = page_offset(page) + bvec->bv_offset;
bio->bi_private = NULL;
if (tree->ops)
ret = tree->ops->submit_bio_hook(tree->private_data, bio,
- mirror_num, bio_flags, start);
+ mirror_num, bio_flags);
else
btrfsic_submit_bio(bio);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 369daa5d4f73..ea3e1a2206dc 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -86,11 +86,10 @@ struct btrfs_io_bio;
struct io_failure_record;
typedef blk_status_t (extent_submit_bio_hook_t)(void *private_data, struct bio *bio,
- int mirror_num, unsigned long bio_flags,
- u64 bio_offset);
+ int mirror_num, unsigned long bio_flags);
typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
- struct bio *bio, u64 bio_offset);
+ struct bio *bio);
struct extent_io_ops {
/*
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 9ea4c6f0352f..c576b3fcaea7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1920,8 +1920,7 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
-static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
- u64 bio_offset)
+static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio)
{
struct inode *inode = private_data;
blk_status_t ret = 0;
@@ -1973,8 +1972,7 @@ blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
* c-3) otherwise: async submit
*/
static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
- int mirror_num, unsigned long bio_flags,
- u64 bio_offset)
+ int mirror_num, unsigned long bio_flags)
{
struct inode *inode = private_data;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -2011,8 +2009,7 @@ static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
goto mapit;
/* we're doing a write, do the async checksumming */
ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
- bio_offset, inode,
- btrfs_submit_bio_start);
+ inode, btrfs_submit_bio_start);
goto out;
} else if (!skip_sum) {
ret = btrfs_csum_one_bio(inode, bio, 0, 0);
@@ -8123,10 +8120,13 @@ static void btrfs_endio_direct_write(struct bio *bio)
}
static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
- struct bio *bio, u64 offset)
+ struct bio *bio)
{
struct inode *inode = private_data;
+ struct bio_vec *bvec = bio_first_bvec_all(bio);
+ u64 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
blk_status_t ret;
+
ret = btrfs_csum_one_bio(inode, bio, offset, 1);
BUG_ON(ret); /* -ENOMEM */
return 0;
@@ -8225,8 +8225,7 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
goto map;
if (write && async_submit) {
- ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
- file_offset, inode,
+ ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0, inode,
btrfs_submit_bio_start_direct_io);
goto err;
} else if (write) {
--
2.9.5
It is wrong to use bio->bi_vcnt to figure out how many segments
there are in the bio even though CLONED flag isn't set on this bio,
because this bio may be splitted or advanced.
So always use bio_segments() in blk_recount_segments(), and it shouldn't
cause any performance loss now because the physical segment number is figured
out in blk_queue_split() and BIO_SEG_VALID is set meantime since
bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting").
Reviewed-by: Christoph Hellwig <[email protected]>
Fixes: 76d8137a3113 ("blk-merge: recaculate segment if it isn't less than max segments")
Signed-off-by: Ming Lei <[email protected]>
---
block/blk-merge.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index e69d8f8ba819..51ec6ca56a0a 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -367,13 +367,7 @@ void blk_recalc_rq_segments(struct request *rq)
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
- unsigned short seg_cnt;
-
- /* estimate segment number by bi_vcnt for non-cloned bio */
- if (bio_flagged(bio, BIO_CLONED))
- seg_cnt = bio_segments(bio);
- else
- seg_cnt = bio->bi_vcnt;
+ unsigned short seg_cnt = bio_segments(bio);
if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
(seg_cnt < queue_max_segments(q)))
--
2.9.5
From: Christoph Hellwig <[email protected]>
The cluster flag implements some very old SCSI behavior. As far as I
can tell the original intent was to enable or disable any kind of
segment merging. But the actually visible effect to the LLDD is that
it limits each segments to be inside a single page, which we can
also affect by setting the maximum segment size and the segment
boundary.
Signed-off-by: Christoph Hellwig <[email protected]>
Replace virt boundary with segment boundary limit.
Signed-off-by: Ming Lei <[email protected]>
---
block/blk-merge.c | 20 ++++++++------------
block/blk-settings.c | 3 ---
block/blk-sysfs.c | 5 +----
drivers/scsi/scsi_lib.c | 20 ++++++++++++++++----
include/linux/blkdev.h | 6 ------
5 files changed, 25 insertions(+), 29 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 6be04ef8da5b..e69d8f8ba819 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -195,7 +195,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
goto split;
}
- if (bvprvp && blk_queue_cluster(q)) {
+ if (bvprvp) {
if (seg_size + bv.bv_len > queue_max_segment_size(q))
goto new_segment;
if (!biovec_phys_mergeable(q, bvprvp, &bv))
@@ -295,10 +295,10 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
bool no_sg_merge)
{
struct bio_vec bv, bvprv = { NULL };
- int cluster, prev = 0;
unsigned int seg_size, nr_phys_segs;
struct bio *fbio, *bbio;
struct bvec_iter iter;
+ bool prev = false;
if (!bio)
return 0;
@@ -313,7 +313,6 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
}
fbio = bio;
- cluster = blk_queue_cluster(q);
seg_size = 0;
nr_phys_segs = 0;
for_each_bio(bio) {
@@ -325,7 +324,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
if (no_sg_merge)
goto new_segment;
- if (prev && cluster) {
+ if (prev) {
if (seg_size + bv.bv_len
> queue_max_segment_size(q))
goto new_segment;
@@ -343,7 +342,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
nr_phys_segs++;
bvprv = bv;
- prev = 1;
+ prev = true;
seg_size = bv.bv_len;
}
bbio = bio;
@@ -396,9 +395,6 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
{
struct bio_vec end_bv = { NULL }, nxt_bv;
- if (!blk_queue_cluster(q))
- return 0;
-
if (bio->bi_seg_back_size + nxt->bi_seg_front_size >
queue_max_segment_size(q))
return 0;
@@ -415,12 +411,12 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
static inline void
__blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
struct scatterlist *sglist, struct bio_vec *bvprv,
- struct scatterlist **sg, int *nsegs, int *cluster)
+ struct scatterlist **sg, int *nsegs)
{
int nbytes = bvec->bv_len;
- if (*sg && *cluster) {
+ if (*sg) {
if ((*sg)->length + nbytes > queue_max_segment_size(q))
goto new_segment;
if (!biovec_phys_mergeable(q, bvprv, bvec))
@@ -466,12 +462,12 @@ static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio,
{
struct bio_vec bvec, bvprv = { NULL };
struct bvec_iter iter;
- int cluster = blk_queue_cluster(q), nsegs = 0;
+ int nsegs = 0;
for_each_bio(bio)
bio_for_each_segment(bvec, bio, iter)
__blk_segment_map_sg(q, &bvec, sglist, &bvprv, sg,
- &nsegs, &cluster);
+ &nsegs);
return nsegs;
}
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 3abe831e92c8..3e7038e475ee 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -56,7 +56,6 @@ void blk_set_default_limits(struct queue_limits *lim)
lim->alignment_offset = 0;
lim->io_opt = 0;
lim->misaligned = 0;
- lim->cluster = 1;
lim->zoned = BLK_ZONED_NONE;
}
EXPORT_SYMBOL(blk_set_default_limits);
@@ -547,8 +546,6 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
t->io_min = max(t->io_min, b->io_min);
t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
- t->cluster &= b->cluster;
-
/* Physical block size a multiple of the logical block size? */
if (t->physical_block_size & (t->logical_block_size - 1)) {
t->physical_block_size = t->logical_block_size;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 80eef48fddc8..ef7b844a3e00 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -132,10 +132,7 @@ static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *
static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
{
- if (blk_queue_cluster(q))
- return queue_var_show(queue_max_segment_size(q), (page));
-
- return queue_var_show(PAGE_SIZE, (page));
+ return queue_var_show(queue_max_segment_size(q), page);
}
static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 0df15cb738d2..78d6d05992b0 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1810,6 +1810,8 @@ static int scsi_map_queues(struct blk_mq_tag_set *set)
void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
{
struct device *dev = shost->dma_dev;
+ unsigned max_segment_size = dma_get_max_seg_size(dev);
+ unsigned long segment_boundary = shost->dma_boundary;
/*
* this limit is imposed by hardware restrictions
@@ -1828,13 +1830,23 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
blk_queue_max_hw_sectors(q, shost->max_sectors);
if (shost->unchecked_isa_dma)
blk_queue_bounce_limit(q, BLK_BOUNCE_ISA);
- blk_queue_segment_boundary(q, shost->dma_boundary);
dma_set_seg_boundary(dev, shost->dma_boundary);
- blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
+ /*
+ * Clustering is a really old concept from the stone age of Linux
+ * SCSI support. But the basic idea is that we never give the
+ * driver a segment that spans multiple pages. For that we need
+ * to limit the segment size, and set the segment boundary so that
+ * we never merge a second segment which is no page aligned.
+ */
+ if (!shost->use_clustering) {
+ max_segment_size = min_t(unsigned, max_segment_size, PAGE_SIZE);
+ segment_boundary = min_t(unsigned, segment_boundary,
+ PAGE_SIZE - 1);
+ }
- if (!shost->use_clustering)
- q->limits.cluster = 0;
+ blk_queue_max_segment_size(q, max_segment_size);
+ blk_queue_segment_boundary(q, segment_boundary);
/*
* Set a reasonable default alignment: The larger of 32-byte (dword),
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9b53db06ad08..399a7a415609 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -341,7 +341,6 @@ struct queue_limits {
unsigned char misaligned;
unsigned char discard_misaligned;
- unsigned char cluster;
unsigned char raid_partial_stripes_expensive;
enum blk_zoned_model zoned;
};
@@ -660,11 +659,6 @@ static inline bool queue_is_mq(struct request_queue *q)
return q->mq_ops;
}
-static inline unsigned int blk_queue_cluster(struct request_queue *q)
-{
- return q->limits.cluster;
-}
-
static inline enum blk_zoned_model
blk_queue_zoned_model(struct request_queue *q)
{
--
2.9.5
We will support multi-page bvec soon, and have to deal with
single-page vs multi-page bvec. This patch follows Christoph's
suggestion to rename all the following helpers:
for_each_bvec
bvec_iter_bvec
bvec_iter_len
bvec_iter_page
bvec_iter_offset
into:
for_each_segment
segment_iter_bvec
segment_iter_len
segment_iter_page
segment_iter_offset
so that these helpers named with 'segment' only deal with single-page
bvec, or called segment. We will introduce helpers named with 'bvec'
for multi-page bvec.
bvec_iter_advance() isn't renamed becasue this helper is always operated
on real bvec even though multi-page bvec is supported.
Suggested-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
.clang-format | 2 +-
drivers/md/dm-integrity.c | 2 +-
drivers/md/dm-io.c | 4 ++--
drivers/nvdimm/blk.c | 4 ++--
drivers/nvdimm/btt.c | 4 ++--
include/linux/bio.h | 10 +++++-----
include/linux/bvec.h | 20 +++++++++++---------
include/linux/ceph/messenger.h | 2 +-
lib/iov_iter.c | 2 +-
net/ceph/messenger.c | 14 +++++++-------
10 files changed, 33 insertions(+), 31 deletions(-)
diff --git a/.clang-format b/.clang-format
index e6080f5834a3..049200fbab94 100644
--- a/.clang-format
+++ b/.clang-format
@@ -120,7 +120,7 @@ ForEachMacros:
- 'for_each_available_child_of_node'
- 'for_each_bio'
- 'for_each_board_func_rsrc'
- - 'for_each_bvec'
+ - 'for_each_segment'
- 'for_each_child_of_node'
- 'for_each_clear_bit'
- 'for_each_clear_bit_from'
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index bb3096bf2cc6..bb037ed2b4eb 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1574,7 +1574,7 @@ static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio,
char *tag_ptr = journal_entry_tag(ic, je);
if (bip) do {
- struct bio_vec biv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+ struct bio_vec biv = segment_iter_bvec(bip->bip_vec, bip->bip_iter);
unsigned tag_now = min(biv.bv_len, tag_todo);
char *tag_addr;
BUG_ON(PageHighMem(biv.bv_page));
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 81ffc59d05c9..d72ec2bdd333 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -208,8 +208,8 @@ static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offse
static void bio_get_page(struct dpages *dp, struct page **p,
unsigned long *len, unsigned *offset)
{
- struct bio_vec bvec = bvec_iter_bvec((struct bio_vec *)dp->context_ptr,
- dp->context_bi);
+ struct bio_vec bvec = segment_iter_bvec((struct bio_vec *)dp->context_ptr,
+ dp->context_bi);
*p = bvec.bv_page;
*len = bvec.bv_len;
diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index db45c6bbb7bb..dfae945216bb 100644
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -89,9 +89,9 @@ static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
struct bio_vec bv;
void *iobuf;
- bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+ bv = segment_iter_bvec(bip->bip_vec, bip->bip_iter);
/*
- * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
+ * The 'bv' obtained from segment_iter_bvec has its .bv_len and
* .bv_offset already adjusted for iter->bi_bvec_done, and we
* can use those directly
*/
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index b123b0dcf274..2bbbc90c7b91 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1154,9 +1154,9 @@ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip,
struct bio_vec bv;
void *mem;
- bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
+ bv = segment_iter_bvec(bip->bip_vec, bip->bip_iter);
/*
- * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
+ * The 'bv' obtained from segment_iter_bvec has its .bv_len and
* .bv_offset already adjusted for iter->bi_bvec_done, and we
* can use those directly
*/
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 6f6bc331a5d1..6a0ff02f4d1c 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -48,14 +48,14 @@
#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
#define bio_iter_iovec(bio, iter) \
- bvec_iter_bvec((bio)->bi_io_vec, (iter))
+ segment_iter_bvec((bio)->bi_io_vec, (iter))
#define bio_iter_page(bio, iter) \
- bvec_iter_page((bio)->bi_io_vec, (iter))
+ segment_iter_page((bio)->bi_io_vec, (iter))
#define bio_iter_len(bio, iter) \
- bvec_iter_len((bio)->bi_io_vec, (iter))
+ segment_iter_len((bio)->bi_io_vec, (iter))
#define bio_iter_offset(bio, iter) \
- bvec_iter_offset((bio)->bi_io_vec, (iter))
+ segment_iter_offset((bio)->bi_io_vec, (iter))
#define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
#define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
@@ -733,7 +733,7 @@ static inline bool bioset_initialized(struct bio_set *bs)
#if defined(CONFIG_BLK_DEV_INTEGRITY)
#define bip_for_each_vec(bvl, bip, iter) \
- for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
+ for_each_segment(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
for_each_bio(_bio) \
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index ba0ae40e77c9..716a87b26a6a 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -50,23 +50,25 @@ struct bvec_iter {
*/
#define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
-#define bvec_iter_page(bvec, iter) \
+#define segment_iter_page(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_page)
-#define bvec_iter_len(bvec, iter) \
+#define segment_iter_len(bvec, iter) \
min((iter).bi_size, \
__bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
-#define bvec_iter_offset(bvec, iter) \
+#define segment_iter_offset(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
-#define bvec_iter_bvec(bvec, iter) \
+#define segment_iter_bvec(bvec, iter) \
((struct bio_vec) { \
- .bv_page = bvec_iter_page((bvec), (iter)), \
- .bv_len = bvec_iter_len((bvec), (iter)), \
- .bv_offset = bvec_iter_offset((bvec), (iter)), \
+ .bv_page = segment_iter_page((bvec), (iter)), \
+ .bv_len = segment_iter_len((bvec), (iter)), \
+ .bv_offset = segment_iter_offset((bvec), (iter)), \
})
+#define bvec_iter_len segment_iter_len
+
static inline bool bvec_iter_advance(const struct bio_vec *bv,
struct bvec_iter *iter, unsigned bytes)
{
@@ -92,10 +94,10 @@ static inline bool bvec_iter_advance(const struct bio_vec *bv,
return true;
}
-#define for_each_bvec(bvl, bio_vec, iter, start) \
+#define for_each_segment(bvl, bio_vec, iter, start) \
for (iter = (start); \
(iter).bi_size && \
- ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
+ ((bvl = segment_iter_bvec((bio_vec), (iter))), 1); \
bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
/* for iterating one bio from start to end */
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 800a2128d411..c7e37a7229c4 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -155,7 +155,7 @@ struct ceph_bvec_iter {
\
__cur_iter = (it)->iter; \
__cur_iter.bi_size = (n); \
- for_each_bvec(bv, (it)->bvecs, __cur_iter, __cur_iter) \
+ for_each_segment(bv, (it)->bvecs, __cur_iter, __cur_iter) \
(void)(BVEC_STEP); \
}))
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 7ebccb5c1637..e34eef12740f 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -65,7 +65,7 @@
__start.bi_size = n; \
__start.bi_bvec_done = skip; \
__start.bi_idx = 0; \
- for_each_bvec(__v, i->bvec, __bi, __start) { \
+ for_each_segment(__v, i->bvec, __bi, __start) { \
if (!__v.bv_len) \
continue; \
(void)(STEP); \
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 57fcc6b4bf6e..c543426ace9f 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -889,17 +889,17 @@ static void ceph_msg_data_bvecs_cursor_init(struct ceph_msg_data_cursor *cursor,
cursor->bvec_iter = data->bvec_pos.iter;
cursor->bvec_iter.bi_size = cursor->resid;
- BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
+ BUG_ON(cursor->resid < segment_iter_len(bvecs, cursor->bvec_iter));
cursor->last_piece =
- cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
+ cursor->resid == segment_iter_len(bvecs, cursor->bvec_iter);
}
static struct page *ceph_msg_data_bvecs_next(struct ceph_msg_data_cursor *cursor,
size_t *page_offset,
size_t *length)
{
- struct bio_vec bv = bvec_iter_bvec(cursor->data->bvec_pos.bvecs,
- cursor->bvec_iter);
+ struct bio_vec bv = segment_iter_bvec(cursor->data->bvec_pos.bvecs,
+ cursor->bvec_iter);
*page_offset = bv.bv_offset;
*length = bv.bv_len;
@@ -912,7 +912,7 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
BUG_ON(bytes > cursor->resid);
- BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
+ BUG_ON(bytes > segment_iter_len(bvecs, cursor->bvec_iter));
cursor->resid -= bytes;
bvec_iter_advance(bvecs, &cursor->bvec_iter, bytes);
@@ -925,9 +925,9 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
return false; /* more bytes to process in this segment */
BUG_ON(cursor->last_piece);
- BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
+ BUG_ON(cursor->resid < segment_iter_len(bvecs, cursor->bvec_iter));
cursor->last_piece =
- cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
+ cursor->resid == segment_iter_len(bvecs, cursor->bvec_iter);
return true;
}
--
2.9.5
From: Christoph Hellwig <[email protected]>
bio_readpage_error currently uses bi_vcnt to decide if it is worth
retrying an I/O. But the vector count is mostly an implementation
artifact - it really should figure out if there is more than a
single sector worth retrying. Use bi_size for that and shift by
PAGE_SHIFT. This really should be blocks/sectors, but given that
btrfs doesn't support a sector size different from the PAGE_SIZE
using the page size keeps the changes to a minimum.
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
fs/btrfs/extent_io.c | 2 +-
include/linux/bio.h | 6 ------
2 files changed, 1 insertion(+), 7 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 15fd46582bb2..40751e86a2a9 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2368,7 +2368,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
int read_mode = 0;
blk_status_t status;
int ret;
- unsigned failed_bio_pages = bio_pages_all(failed_bio);
+ unsigned failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 056fb627edb3..6f6bc331a5d1 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -263,12 +263,6 @@ static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
bv->bv_len = iter.bi_bvec_done;
}
-static inline unsigned bio_pages_all(struct bio *bio)
-{
- WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
- return bio->bi_vcnt;
-}
-
static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
{
WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
--
2.9.5
This patch introduces helpers of 'bvec_iter_*' for multi-page bvec
support.
The introduced helpers treate one bvec as real multi-page segment,
which may include more than one pages.
The existed helpers of bvec_iter_* are interfaces for supporting current
bvec iterator which is thought as single-page by drivers, fs, dm and
etc. These introduced helpers will build single-page bvec in flight, so
this way won't break current bio/bvec users, which needn't any change.
Follows some multi-page bvec background:
- bvecs stored in bio->bi_io_vec is always multi-page style
- bvec(struct bio_vec) represents one physically contiguous I/O
buffer, now the buffer may include more than one page after
multi-page bvec is supported, and all these pages represented
by one bvec is physically contiguous. Before multi-page bvec
support, at most one page is included in one bvec, we call it
single-page bvec.
- .bv_page of the bvec points to the 1st page in the multi-page bvec
- .bv_offset of the bvec is the offset of the buffer in the bvec
The effect on the current drivers/filesystem/dm/bcache/...:
- almost everyone supposes that one bvec only includes one single
page, so we keep the sp interface not changed, for example,
bio_for_each_segment() still returns single-page bvec
- bio_for_each_segment_all() will return single-page bvec too
- during iterating, iterator variable(struct bvec_iter) is always
updated in multi-page bvec style, and bvec_iter_advance() is kept
not changed
- returned(copied) single-page bvec is built in flight by bvec
helpers from the stored multi-page bvec
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
include/linux/bvec.h | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 716a87b26a6a..babc6316c117 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -23,6 +23,7 @@
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/errno.h>
+#include <linux/mm.h>
/*
* was unsigned short, but we might as well be ready for > 64kB I/O pages
@@ -50,16 +51,32 @@ struct bvec_iter {
*/
#define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
-#define segment_iter_page(bvec, iter) \
+/* multi-page (segment) helpers */
+#define bvec_iter_page(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_page)
-#define segment_iter_len(bvec, iter) \
+#define bvec_iter_len(bvec, iter) \
min((iter).bi_size, \
__bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
-#define segment_iter_offset(bvec, iter) \
+#define bvec_iter_offset(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
+#define bvec_iter_page_idx(bvec, iter) \
+ (bvec_iter_offset((bvec), (iter)) / PAGE_SIZE)
+
+/* For building single-page bvec(segment) in flight */
+ #define segment_iter_offset(bvec, iter) \
+ (bvec_iter_offset((bvec), (iter)) % PAGE_SIZE)
+
+#define segment_iter_len(bvec, iter) \
+ min_t(unsigned, bvec_iter_len((bvec), (iter)), \
+ PAGE_SIZE - segment_iter_offset((bvec), (iter)))
+
+#define segment_iter_page(bvec, iter) \
+ nth_page(bvec_iter_page((bvec), (iter)), \
+ bvec_iter_page_idx((bvec), (iter)))
+
#define segment_iter_bvec(bvec, iter) \
((struct bio_vec) { \
.bv_page = segment_iter_page((bvec), (iter)), \
@@ -67,8 +84,6 @@ struct bvec_iter {
.bv_offset = segment_iter_offset((bvec), (iter)), \
})
-#define bvec_iter_len segment_iter_len
-
static inline bool bvec_iter_advance(const struct bio_vec *bv,
struct bvec_iter *iter, unsigned bytes)
{
--
2.9.5
bio_for_each_bvec() is used for iterating over multi-page bvec for bio
split & merge code.
rq_for_each_bvec() can be used for drivers which may handle the
multi-page bvec directly, so far loop is one perfect use case.
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
include/linux/bio.h | 10 ++++++++++
include/linux/blkdev.h | 4 ++++
include/linux/bvec.h | 7 +++++++
3 files changed, 21 insertions(+)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 6a0ff02f4d1c..46fd0e03233b 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -156,6 +156,16 @@ static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
#define bio_for_each_segment(bvl, bio, iter) \
__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
+#define __bio_for_each_bvec(bvl, bio, iter, start) \
+ for (iter = (start); \
+ (iter).bi_size && \
+ ((bvl = bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
+ bio_advance_iter((bio), &(iter), (bvl).bv_len))
+
+/* iterate over multi-page bvec */
+#define bio_for_each_bvec(bvl, bio, iter) \
+ __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
+
#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
static inline unsigned bio_segments(struct bio *bio)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 399a7a415609..fa263de3f1d1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -799,6 +799,10 @@ struct req_iterator {
__rq_for_each_bio(_iter.bio, _rq) \
bio_for_each_segment(bvl, _iter.bio, _iter.iter)
+#define rq_for_each_bvec(bvl, _rq, _iter) \
+ __rq_for_each_bio(_iter.bio, _rq) \
+ bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
+
#define rq_iter_last(bvec, _iter) \
(_iter.bio->bi_next == NULL && \
bio_iter_last(bvec, _iter.iter))
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index babc6316c117..d441486db605 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -65,6 +65,13 @@ struct bvec_iter {
#define bvec_iter_page_idx(bvec, iter) \
(bvec_iter_offset((bvec), (iter)) / PAGE_SIZE)
+#define bvec_iter_bvec(bvec, iter) \
+((struct bio_vec) { \
+ .bv_page = bvec_iter_page((bvec), (iter)), \
+ .bv_len = bvec_iter_len((bvec), (iter)), \
+ .bv_offset = bvec_iter_offset((bvec), (iter)), \
+})
+
/* For building single-page bvec(segment) in flight */
#define segment_iter_offset(bvec, iter) \
(bvec_iter_offset((bvec), (iter)) % PAGE_SIZE)
--
2.9.5
First it is more efficient to use bio_for_each_bvec() in both
blk_bio_segment_split() and __blk_recalc_rq_segments() to compute how
many multi-page bvecs there are in the bio.
Secondly once bio_for_each_bvec() is used, the bvec may need to be
splitted because its length can be very longer than max segment size,
so we have to split the big bvec into several segments.
Thirdly when splitting multi-page bvec into segments, the max segment
limit may be reached, so the bio split need to be considered under
this situation too.
Signed-off-by: Ming Lei <[email protected]>
---
block/blk-merge.c | 100 +++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 80 insertions(+), 20 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 51ec6ca56a0a..2d8f388d43de 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -161,6 +161,70 @@ static inline unsigned get_max_io_size(struct request_queue *q,
return sectors;
}
+static unsigned get_max_segment_size(struct request_queue *q,
+ unsigned offset)
+{
+ unsigned long mask = queue_segment_boundary(q);
+
+ return min_t(unsigned long, mask - (mask & offset) + 1,
+ queue_max_segment_size(q));
+}
+
+/*
+ * Split the bvec @bv into segments, and update all kinds of
+ * variables.
+ */
+static bool bvec_split_segs(struct request_queue *q, struct bio_vec *bv,
+ unsigned *nsegs, unsigned *last_seg_size,
+ unsigned *front_seg_size, unsigned *sectors)
+{
+ unsigned len = bv->bv_len;
+ unsigned total_len = 0;
+ unsigned new_nsegs = 0, seg_size = 0;
+
+ /*
+ * Multipage bvec may be too big to hold in one segment,
+ * so the current bvec has to be splitted as multiple
+ * segments.
+ */
+ while (len && new_nsegs + *nsegs < queue_max_segments(q)) {
+ seg_size = get_max_segment_size(q, bv->bv_offset + total_len);
+ seg_size = min(seg_size, len);
+
+ new_nsegs++;
+ total_len += seg_size;
+ len -= seg_size;
+
+ if ((bv->bv_offset + total_len) & queue_virt_boundary(q))
+ break;
+ }
+
+ if (!new_nsegs)
+ return !!len;
+
+ /* update front segment size */
+ if (!*nsegs) {
+ unsigned first_seg_size;
+
+ if (new_nsegs == 1)
+ first_seg_size = get_max_segment_size(q, bv->bv_offset);
+ else
+ first_seg_size = queue_max_segment_size(q);
+
+ if (*front_seg_size < first_seg_size)
+ *front_seg_size = first_seg_size;
+ }
+
+ /* update other varibles */
+ *last_seg_size = seg_size;
+ *nsegs += new_nsegs;
+ if (sectors)
+ *sectors += total_len >> 9;
+
+ /* split in the middle of the bvec if len != 0 */
+ return !!len;
+}
+
static struct bio *blk_bio_segment_split(struct request_queue *q,
struct bio *bio,
struct bio_set *bs,
@@ -174,7 +238,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
struct bio *new = NULL;
const unsigned max_sectors = get_max_io_size(q, bio);
- bio_for_each_segment(bv, bio, iter) {
+ bio_for_each_bvec(bv, bio, iter) {
/*
* If the queue doesn't support SG gaps and adding this
* offset would create a gap, disallow it.
@@ -189,8 +253,12 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
*/
if (nsegs < queue_max_segments(q) &&
sectors < max_sectors) {
- nsegs++;
- sectors = max_sectors;
+ /* split in the middle of bvec */
+ bv.bv_len = (max_sectors - sectors) << 9;
+ bvec_split_segs(q, &bv, &nsegs,
+ &seg_size,
+ &front_seg_size,
+ §ors);
}
goto split;
}
@@ -212,14 +280,12 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
if (nsegs == queue_max_segments(q))
goto split;
- if (nsegs == 1 && seg_size > front_seg_size)
- front_seg_size = seg_size;
-
- nsegs++;
bvprv = bv;
bvprvp = &bvprv;
- seg_size = bv.bv_len;
- sectors += bv.bv_len >> 9;
+
+ if (bvec_split_segs(q, &bv, &nsegs, &seg_size,
+ &front_seg_size, §ors))
+ goto split;
}
@@ -233,8 +299,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
bio = new;
}
- if (nsegs == 1 && seg_size > front_seg_size)
- front_seg_size = seg_size;
bio->bi_seg_front_size = front_seg_size;
if (seg_size > bio->bi_seg_back_size)
bio->bi_seg_back_size = seg_size;
@@ -296,6 +360,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
{
struct bio_vec bv, bvprv = { NULL };
unsigned int seg_size, nr_phys_segs;
+ unsigned front_seg_size = bio->bi_seg_front_size;
struct bio *fbio, *bbio;
struct bvec_iter iter;
bool prev = false;
@@ -316,7 +381,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
seg_size = 0;
nr_phys_segs = 0;
for_each_bio(bio) {
- bio_for_each_segment(bv, bio, iter) {
+ bio_for_each_bvec(bv, bio, iter) {
/*
* If SG merging is disabled, each bio vector is
* a segment
@@ -336,20 +401,15 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
continue;
}
new_segment:
- if (nr_phys_segs == 1 && seg_size >
- fbio->bi_seg_front_size)
- fbio->bi_seg_front_size = seg_size;
-
- nr_phys_segs++;
bvprv = bv;
prev = true;
- seg_size = bv.bv_len;
+ bvec_split_segs(q, &bv, &nr_phys_segs, &seg_size,
+ &front_seg_size, NULL);
}
bbio = bio;
}
- if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size)
- fbio->bi_seg_front_size = seg_size;
+ fbio->bi_seg_front_size = front_seg_size;
if (seg_size > bbio->bi_seg_back_size)
bbio->bi_seg_back_size = seg_size;
--
2.9.5
It is more efficient to use bio_for_each_bvec() to map sg, meantime
we have to consider splitting multipage bvec as done in blk_bio_segment_split().
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
block/blk-merge.c | 70 +++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 50 insertions(+), 20 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 2d8f388d43de..20b5b0c3e182 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -462,6 +462,54 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
return biovec_phys_mergeable(q, &end_bv, &nxt_bv);
}
+static struct scatterlist *blk_next_sg(struct scatterlist **sg,
+ struct scatterlist *sglist)
+{
+ if (!*sg)
+ return sglist;
+
+ /*
+ * If the driver previously mapped a shorter list, we could see a
+ * termination bit prematurely unless it fully inits the sg table
+ * on each mapping. We KNOW that there must be more entries here
+ * or the driver would be buggy, so force clear the termination bit
+ * to avoid doing a full sg_init_table() in drivers for each command.
+ */
+ sg_unmark_end(*sg);
+ return sg_next(*sg);
+}
+
+static unsigned blk_bvec_map_sg(struct request_queue *q,
+ struct bio_vec *bvec, struct scatterlist *sglist,
+ struct scatterlist **sg)
+{
+ unsigned nbytes = bvec->bv_len;
+ unsigned nsegs = 0, total = 0, offset = 0;
+
+ while (nbytes > 0) {
+ unsigned seg_size;
+ struct page *pg;
+ unsigned idx;
+
+ *sg = blk_next_sg(sg, sglist);
+
+ seg_size = get_max_segment_size(q, bvec->bv_offset + total);
+ seg_size = min(nbytes, seg_size);
+
+ offset = (total + bvec->bv_offset) % PAGE_SIZE;
+ idx = (total + bvec->bv_offset) / PAGE_SIZE;
+ pg = nth_page(bvec->bv_page, idx);
+
+ sg_set_page(*sg, pg, seg_size, offset);
+
+ total += seg_size;
+ nbytes -= seg_size;
+ nsegs++;
+ }
+
+ return nsegs;
+}
+
static inline void
__blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
struct scatterlist *sglist, struct bio_vec *bvprv,
@@ -479,25 +527,7 @@ __blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
(*sg)->length += nbytes;
} else {
new_segment:
- if (!*sg)
- *sg = sglist;
- else {
- /*
- * If the driver previously mapped a shorter
- * list, we could see a termination bit
- * prematurely unless it fully inits the sg
- * table on each mapping. We KNOW that there
- * must be more entries here or the driver
- * would be buggy, so force clear the
- * termination bit to avoid doing a full
- * sg_init_table() in drivers for each command.
- */
- sg_unmark_end(*sg);
- *sg = sg_next(*sg);
- }
-
- sg_set_page(*sg, bvec->bv_page, nbytes, bvec->bv_offset);
- (*nsegs)++;
+ (*nsegs) += blk_bvec_map_sg(q, bvec, sglist, sg);
}
*bvprv = *bvec;
}
@@ -519,7 +549,7 @@ static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio,
int nsegs = 0;
for_each_bio(bio)
- bio_for_each_segment(bvec, bio, iter)
+ bio_for_each_bvec(bvec, bio, iter)
__blk_segment_map_sg(q, &bvec, sglist, &bvprv, sg,
&nsegs);
--
2.9.5
Commit 7759eb23fd980 ("block: remove bio_rewind_iter()") removes
bio_rewind_iter(), then no one uses bvec_iter_rewind() any more,
so remove it.
Signed-off-by: Ming Lei <[email protected]>
---
include/linux/bvec.h | 24 ------------------------
1 file changed, 24 deletions(-)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 02c73c6aa805..ba0ae40e77c9 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -92,30 +92,6 @@ static inline bool bvec_iter_advance(const struct bio_vec *bv,
return true;
}
-static inline bool bvec_iter_rewind(const struct bio_vec *bv,
- struct bvec_iter *iter,
- unsigned int bytes)
-{
- while (bytes) {
- unsigned len = min(bytes, iter->bi_bvec_done);
-
- if (iter->bi_bvec_done == 0) {
- if (WARN_ONCE(iter->bi_idx == 0,
- "Attempted to rewind iter beyond "
- "bvec's boundaries\n")) {
- return false;
- }
- iter->bi_idx--;
- iter->bi_bvec_done = __bvec_iter_bvec(bv, *iter)->bv_len;
- continue;
- }
- bytes -= len;
- iter->bi_size += len;
- iter->bi_bvec_done -= len;
- }
- return true;
-}
-
#define for_each_bvec(bvl, bio_vec, iter, start) \
for (iter = (start); \
(iter).bi_size && \
--
2.9.5
iov_iter is implemented on bvec itererator helpers, so it is safe to pass
multi-page bvec to it, and this way is much more efficient than passing one
page in each bvec.
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
drivers/block/loop.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 176ab1f28eca..e3683211f12d 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -510,21 +510,22 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
loff_t pos, bool rw)
{
struct iov_iter iter;
+ struct req_iterator rq_iter;
struct bio_vec *bvec;
struct request *rq = blk_mq_rq_from_pdu(cmd);
struct bio *bio = rq->bio;
struct file *file = lo->lo_backing_file;
+ struct bio_vec tmp;
unsigned int offset;
- int segments = 0;
+ int nr_bvec = 0;
int ret;
+ rq_for_each_bvec(tmp, rq, rq_iter)
+ nr_bvec++;
+
if (rq->bio != rq->biotail) {
- struct req_iterator iter;
- struct bio_vec tmp;
- __rq_for_each_bio(bio, rq)
- segments += bio_segments(bio);
- bvec = kmalloc_array(segments, sizeof(struct bio_vec),
+ bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
GFP_NOIO);
if (!bvec)
return -EIO;
@@ -533,10 +534,10 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
/*
* The bios of the request may be started from the middle of
* the 'bvec' because of bio splitting, so we can't directly
- * copy bio->bi_iov_vec to new bvec. The rq_for_each_segment
+ * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec
* API will take care of all details for us.
*/
- rq_for_each_segment(tmp, rq, iter) {
+ rq_for_each_bvec(tmp, rq, rq_iter) {
*bvec = tmp;
bvec++;
}
@@ -550,11 +551,10 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
*/
offset = bio->bi_iter.bi_bvec_done;
bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
- segments = bio_segments(bio);
}
atomic_set(&cmd->ref, 2);
- iov_iter_bvec(&iter, rw, bvec, segments, blk_rq_bytes(rq));
+ iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq));
iter.iov_offset = offset;
cmd->iocb.ki_pos = pos;
--
2.9.5
Once multi-page bvec is enabled, the last bvec may include more than one
page, this patch use bvec_last_segment() to truncate the bio.
Reviewed-by: Omar Sandoval <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
fs/buffer.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 1286c2b95498..fa37ad52e962 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3032,7 +3032,10 @@ void guard_bio_eod(int op, struct bio *bio)
/* ..and clear the end of the buffer for reads */
if (op == REQ_OP_READ) {
- zero_user(bvec->bv_page, bvec->bv_offset + bvec->bv_len,
+ struct bio_vec bv;
+
+ bvec_last_segment(bvec, &bv);
+ zero_user(bv.bv_page, bv.bv_offset + bv.bv_len,
truncated_bytes);
}
}
--
2.9.5
BTRFS and guard_bio_eod() need to get the last singlepage segment
from one multipage bvec, so introduce this helper to make them happy.
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
include/linux/bvec.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index d441486db605..ca6e630f88ab 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -131,4 +131,26 @@ static inline bool bvec_iter_advance(const struct bio_vec *bv,
.bi_bvec_done = 0, \
}
+/*
+ * Get the last single-page segment from the multi-page bvec and store it
+ * in @seg
+ */
+static inline void bvec_last_segment(const struct bio_vec *bvec,
+ struct bio_vec *seg)
+{
+ unsigned total = bvec->bv_offset + bvec->bv_len;
+ unsigned last_page = (total - 1) / PAGE_SIZE;
+
+ seg->bv_page = nth_page(bvec->bv_page, last_page);
+
+ /* the whole segment is inside the last page */
+ if (bvec->bv_offset >= last_page * PAGE_SIZE) {
+ seg->bv_offset = bvec->bv_offset % PAGE_SIZE;
+ seg->bv_len = bvec->bv_len;
+ } else {
+ seg->bv_offset = 0;
+ seg->bv_len = total - last_page * PAGE_SIZE;
+ }
+}
+
#endif /* __LINUX_BVEC_ITER_H */
--
2.9.5
Now multi-page bvec is supported, some helpers may return page by
page, meantime some may return segment by segment, this patch
documents the usage.
Signed-off-by: Ming Lei <[email protected]>
---
Documentation/block/biovecs.txt | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/Documentation/block/biovecs.txt b/Documentation/block/biovecs.txt
index 25689584e6e0..ce6eccaf5df7 100644
--- a/Documentation/block/biovecs.txt
+++ b/Documentation/block/biovecs.txt
@@ -117,3 +117,28 @@ Other implications:
size limitations and the limitations of the underlying devices. Thus
there's no need to define ->merge_bvec_fn() callbacks for individual block
drivers.
+
+Usage of helpers:
+=================
+
+* The following helpers whose names have the suffix of "_all" can only be used
+on non-BIO_CLONED bio. They are usually used by filesystem code. Drivers
+shouldn't use them because the bio may have been split before it reached the
+driver.
+
+ bio_for_each_segment_all()
+ bio_first_bvec_all()
+ bio_first_page_all()
+ bio_last_bvec_all()
+
+* The following helpers iterate over single-page segment. The passed 'struct
+bio_vec' will contain a single-page IO vector during the iteration
+
+ bio_for_each_segment()
+ bio_for_each_segment_all()
+
+* The following helpers iterate over multi-page bvec. The passed 'struct
+bio_vec' will contain a multi-page IO vector during the iteration
+
+ bio_for_each_bvec()
+ rq_for_each_bvec()
--
2.9.5
Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"),
physical segment number is mainly figured out in blk_queue_split() for
fast path, and the flag of BIO_SEG_VALID is set there too.
Now only blk_recount_segments() and blk_recalc_rq_segments() use this
flag.
Basically blk_recount_segments() is bypassed in fast path given BIO_SEG_VALID
is set in blk_queue_split().
For another user of blk_recalc_rq_segments():
- run in partial completion branch of blk_update_request, which is an unusual case
- run in blk_cloned_rq_check_limits(), still not a big problem if the flag is killed
since dm-rq is the only user.
Multi-page bvec is enabled now, not doing S/G merging is rather pointless with the
current setup of the I/O path, as it isn't going to save you a significant amount
of cycles.
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
block/blk-merge.c | 31 ++++++-------------------------
block/blk-mq-debugfs.c | 1 -
block/blk-mq.c | 3 ---
drivers/md/dm-table.c | 13 -------------
include/linux/blkdev.h | 1 -
5 files changed, 6 insertions(+), 43 deletions(-)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 20b5b0c3e182..9a7fd8b1f90a 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -355,8 +355,7 @@ void blk_queue_split(struct request_queue *q, struct bio **bio)
EXPORT_SYMBOL(blk_queue_split);
static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
- struct bio *bio,
- bool no_sg_merge)
+ struct bio *bio)
{
struct bio_vec bv, bvprv = { NULL };
unsigned int seg_size, nr_phys_segs;
@@ -382,13 +381,6 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
nr_phys_segs = 0;
for_each_bio(bio) {
bio_for_each_bvec(bv, bio, iter) {
- /*
- * If SG merging is disabled, each bio vector is
- * a segment
- */
- if (no_sg_merge)
- goto new_segment;
-
if (prev) {
if (seg_size + bv.bv_len
> queue_max_segment_size(q))
@@ -418,27 +410,16 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
void blk_recalc_rq_segments(struct request *rq)
{
- bool no_sg_merge = !!test_bit(QUEUE_FLAG_NO_SG_MERGE,
- &rq->q->queue_flags);
-
- rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio,
- no_sg_merge);
+ rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio);
}
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
- unsigned short seg_cnt = bio_segments(bio);
-
- if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
- (seg_cnt < queue_max_segments(q)))
- bio->bi_phys_segments = seg_cnt;
- else {
- struct bio *nxt = bio->bi_next;
+ struct bio *nxt = bio->bi_next;
- bio->bi_next = NULL;
- bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false);
- bio->bi_next = nxt;
- }
+ bio->bi_next = NULL;
+ bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio);
+ bio->bi_next = nxt;
bio_set_flag(bio, BIO_SEG_VALID);
}
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index a32bb79d6c95..d752fe4461af 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -127,7 +127,6 @@ static const char *const blk_queue_flag_name[] = {
QUEUE_FLAG_NAME(SAME_FORCE),
QUEUE_FLAG_NAME(DEAD),
QUEUE_FLAG_NAME(INIT_DONE),
- QUEUE_FLAG_NAME(NO_SG_MERGE),
QUEUE_FLAG_NAME(POLL),
QUEUE_FLAG_NAME(WC),
QUEUE_FLAG_NAME(FUA),
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b16204df65d1..7b17191d755b 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2780,9 +2780,6 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
- if (!(set->flags & BLK_MQ_F_SG_MERGE))
- blk_queue_flag_set(QUEUE_FLAG_NO_SG_MERGE, q);
-
q->sg_reserved_size = INT_MAX;
INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 844f7d0f2ef8..a41832cf0c98 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1698,14 +1698,6 @@ static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
return q && !blk_queue_add_random(q);
}
-static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
- sector_t start, sector_t len, void *data)
-{
- struct request_queue *q = bdev_get_queue(dev->bdev);
-
- return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
-}
-
static bool dm_table_all_devices_attribute(struct dm_table *t,
iterate_devices_callout_fn func)
{
@@ -1902,11 +1894,6 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
if (!dm_table_supports_write_zeroes(t))
q->limits.max_write_zeroes_sectors = 0;
- if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
- blk_queue_flag_clear(QUEUE_FLAG_NO_SG_MERGE, q);
- else
- blk_queue_flag_set(QUEUE_FLAG_NO_SG_MERGE, q);
-
dm_table_verify_integrity(t);
/*
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index fa263de3f1d1..9c1ae3a62ed3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -589,7 +589,6 @@ struct request_queue {
#define QUEUE_FLAG_SAME_FORCE 15 /* force complete on same CPU */
#define QUEUE_FLAG_DEAD 16 /* queue tear-down finished */
#define QUEUE_FLAG_INIT_DONE 17 /* queue is initialized */
-#define QUEUE_FLAG_NO_SG_MERGE 18 /* don't attempt to merge SG segments*/
#define QUEUE_FLAG_POLL 19 /* IO polling enabled if set */
#define QUEUE_FLAG_WC 20 /* Write back caching */
#define QUEUE_FLAG_FUA 21 /* device supports FUA writes */
--
2.9.5
QUEUE_FLAG_NO_SG_MERGE has been killed, so kill BLK_MQ_F_SG_MERGE too.
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
block/blk-mq-debugfs.c | 1 -
drivers/block/loop.c | 2 +-
drivers/block/nbd.c | 2 +-
drivers/block/rbd.c | 2 +-
drivers/block/skd_main.c | 1 -
drivers/block/xen-blkfront.c | 2 +-
drivers/md/dm-rq.c | 2 +-
drivers/mmc/core/queue.c | 3 +--
drivers/scsi/scsi_lib.c | 2 +-
include/linux/blk-mq.h | 1 -
10 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index d752fe4461af..a6ec055b54fa 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -249,7 +249,6 @@ static const char *const alloc_policy_name[] = {
static const char *const hctx_flag_name[] = {
HCTX_FLAG_NAME(SHOULD_MERGE),
HCTX_FLAG_NAME(TAG_SHARED),
- HCTX_FLAG_NAME(SG_MERGE),
HCTX_FLAG_NAME(BLOCKING),
HCTX_FLAG_NAME(NO_SCHED),
};
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index e3683211f12d..4cf5486689de 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1906,7 +1906,7 @@ static int loop_add(struct loop_device **l, int i)
lo->tag_set.queue_depth = 128;
lo->tag_set.numa_node = NUMA_NO_NODE;
lo->tag_set.cmd_size = sizeof(struct loop_cmd);
- lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
lo->tag_set.driver_data = lo;
err = blk_mq_alloc_tag_set(&lo->tag_set);
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 08696f5f00bb..999c94de78e5 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1570,7 +1570,7 @@ static int nbd_dev_add(int index)
nbd->tag_set.numa_node = NUMA_NO_NODE;
nbd->tag_set.cmd_size = sizeof(struct nbd_cmd);
nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
- BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING;
+ BLK_MQ_F_BLOCKING;
nbd->tag_set.driver_data = nbd;
err = blk_mq_alloc_tag_set(&nbd->tag_set);
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 8e5140bbf241..3dfd300b5283 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3988,7 +3988,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
rbd_dev->tag_set.ops = &rbd_mq_ops;
rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
- rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
rbd_dev->tag_set.nr_hw_queues = 1;
rbd_dev->tag_set.cmd_size = sizeof(struct work_struct);
diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index a10d5736d8f7..a7040f9a1b1b 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -2843,7 +2843,6 @@ static int skd_cons_disk(struct skd_device *skdev)
skdev->sgs_per_request * sizeof(struct scatterlist);
skdev->tag_set.numa_node = NUMA_NO_NODE;
skdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
- BLK_MQ_F_SG_MERGE |
BLK_ALLOC_POLICY_TO_MQ_FLAG(BLK_TAG_ALLOC_FIFO);
skdev->tag_set.driver_data = skdev;
rc = blk_mq_alloc_tag_set(&skdev->tag_set);
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 0ed4b200fa58..d43a5677ccbc 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -977,7 +977,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
} else
info->tag_set.queue_depth = BLK_RING_SIZE(info);
info->tag_set.numa_node = NUMA_NO_NODE;
- info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
info->tag_set.cmd_size = sizeof(struct blkif_req);
info->tag_set.driver_data = info;
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 1f1fe9a618ea..afbac62a02a2 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -536,7 +536,7 @@ int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t)
md->tag_set->ops = &dm_mq_ops;
md->tag_set->queue_depth = dm_get_blk_mq_queue_depth();
md->tag_set->numa_node = md->numa_node_id;
- md->tag_set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ md->tag_set->flags = BLK_MQ_F_SHOULD_MERGE;
md->tag_set->nr_hw_queues = dm_get_blk_mq_nr_hw_queues();
md->tag_set->driver_data = md;
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 35cc138b096d..cc19e71c71d4 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -410,8 +410,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
else
mq->tag_set.queue_depth = MMC_QUEUE_DEPTH;
mq->tag_set.numa_node = NUMA_NO_NODE;
- mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE |
- BLK_MQ_F_BLOCKING;
+ mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING;
mq->tag_set.nr_hw_queues = 1;
mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
mq->tag_set.driver_data = mq;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 78d6d05992b0..f5ffb97352f7 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1902,7 +1902,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost)
shost->tag_set.queue_depth = shost->can_queue;
shost->tag_set.cmd_size = cmd_size;
shost->tag_set.numa_node = NUMA_NO_NODE;
- shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
shost->tag_set.flags |=
BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
shost->tag_set.driver_data = shost;
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 929e8abc5535..ca7389d7e04f 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -211,7 +211,6 @@ struct blk_mq_ops {
enum {
BLK_MQ_F_SHOULD_MERGE = 1 << 0,
BLK_MQ_F_TAG_SHARED = 1 << 1,
- BLK_MQ_F_SG_MERGE = 1 << 2,
BLK_MQ_F_BLOCKING = 1 << 5,
BLK_MQ_F_NO_SCHED = 1 << 6,
BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
--
2.9.5
bch_bio_alloc_pages() is always called on one new bio, so it is safe
to access the bvec table directly. Given it is the only kind of this
case, open code the bvec table access since bio_for_each_segment_all()
will be changed to support for iterating over multipage bvec.
Acked-by: Coly Li <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
drivers/md/bcache/util.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
index 20eddeac1531..62fb917f7a4f 100644
--- a/drivers/md/bcache/util.c
+++ b/drivers/md/bcache/util.c
@@ -270,7 +270,11 @@ int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
int i;
struct bio_vec *bv;
- bio_for_each_segment_all(bv, bio, i) {
+ /*
+ * This is called on freshly new bio, so it is safe to access the
+ * bvec table directly.
+ */
+ for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++, i++) {
bv->bv_page = alloc_page(gfp_mask);
if (!bv->bv_page) {
while (--bv >= bio->bi_io_vec)
--
2.9.5
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.
Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
block/bio.c | 27 ++++++++++++++++++---------
block/bounce.c | 6 ++++--
drivers/md/bcache/btree.c | 3 ++-
drivers/md/dm-crypt.c | 3 ++-
drivers/md/raid1.c | 3 ++-
drivers/staging/erofs/data.c | 3 ++-
drivers/staging/erofs/unzip_vle.c | 3 ++-
fs/block_dev.c | 6 ++++--
fs/btrfs/compression.c | 3 ++-
fs/btrfs/disk-io.c | 3 ++-
fs/btrfs/extent_io.c | 9 ++++++---
fs/btrfs/inode.c | 6 ++++--
fs/btrfs/raid56.c | 3 ++-
fs/crypto/bio.c | 3 ++-
fs/direct-io.c | 4 +++-
fs/exofs/ore.c | 3 ++-
fs/exofs/ore_raid.c | 3 ++-
fs/ext4/page-io.c | 3 ++-
fs/ext4/readpage.c | 3 ++-
fs/f2fs/data.c | 9 ++++++---
fs/gfs2/lops.c | 6 ++++--
fs/gfs2/meta_io.c | 3 ++-
fs/iomap.c | 6 ++++--
fs/mpage.c | 3 ++-
fs/xfs/xfs_aops.c | 5 +++--
include/linux/bio.h | 11 +++++++++--
include/linux/bvec.h | 30 ++++++++++++++++++++++++++++++
27 files changed, 125 insertions(+), 45 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 03895cc0d74a..75fde30af51f 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1073,8 +1073,9 @@ static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
{
int i;
struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
ssize_t ret;
ret = copy_page_from_iter(bvec->bv_page,
@@ -1104,8 +1105,9 @@ static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
{
int i;
struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
ssize_t ret;
ret = copy_page_to_iter(bvec->bv_page,
@@ -1127,8 +1129,9 @@ void bio_free_pages(struct bio *bio)
{
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
__free_page(bvec->bv_page);
}
EXPORT_SYMBOL(bio_free_pages);
@@ -1295,6 +1298,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
struct bio *bio;
int ret;
struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
if (!iov_iter_count(iter))
return ERR_PTR(-EINVAL);
@@ -1368,7 +1372,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
return bio;
out_unmap:
- bio_for_each_segment_all(bvec, bio, j) {
+ bio_for_each_segment_all(bvec, bio, j, iter_all) {
put_page(bvec->bv_page);
}
bio_put(bio);
@@ -1379,11 +1383,12 @@ static void __bio_unmap_user(struct bio *bio)
{
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
/*
* make sure we dirty pages we wrote to
*/
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
if (bio_data_dir(bio) == READ)
set_page_dirty_lock(bvec->bv_page);
@@ -1475,8 +1480,9 @@ static void bio_copy_kern_endio_read(struct bio *bio)
char *p = bio->bi_private;
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
memcpy(p, page_address(bvec->bv_page), bvec->bv_len);
p += bvec->bv_len;
}
@@ -1585,8 +1591,9 @@ void bio_set_pages_dirty(struct bio *bio)
{
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
if (!PageCompound(bvec->bv_page))
set_page_dirty_lock(bvec->bv_page);
}
@@ -1597,8 +1604,9 @@ static void bio_release_pages(struct bio *bio)
{
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
put_page(bvec->bv_page);
}
@@ -1645,8 +1653,9 @@ void bio_check_pages_dirty(struct bio *bio)
struct bio_vec *bvec;
unsigned long flags;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page))
goto defer;
}
diff --git a/block/bounce.c b/block/bounce.c
index 559c55bda040..7338041e3042 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -165,11 +165,12 @@ static void bounce_end_io(struct bio *bio, mempool_t *pool)
struct bio_vec *bvec, orig_vec;
int i;
struct bvec_iter orig_iter = bio_orig->bi_iter;
+ struct bvec_iter_all iter_all;
/*
* free up bounce indirect pages used
*/
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
orig_vec = bio_iter_iovec(bio_orig, orig_iter);
if (bvec->bv_page != orig_vec.bv_page) {
dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
@@ -293,6 +294,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
bool bounce = false;
int sectors = 0;
bool passthrough = bio_is_passthrough(*bio_orig);
+ struct bvec_iter_all iter_all;
bio_for_each_segment(from, *bio_orig, iter) {
if (i++ < BIO_MAX_PAGES)
@@ -312,7 +314,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
bio = bounce_clone_bio(*bio_orig, GFP_NOIO, passthrough ? NULL :
&bounce_bio_set);
- bio_for_each_segment_all(to, bio, i) {
+ bio_for_each_segment_all(to, bio, i, iter_all) {
struct page *page = to->bv_page;
if (page_to_pfn(page) <= q->limits.bounce_pfn)
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 3f4211b5cd33..6242ae4e2127 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -427,8 +427,9 @@ static void do_btree_node_write(struct btree *b)
int j;
struct bio_vec *bv;
void *base = (void *) ((unsigned long) i & ~(PAGE_SIZE - 1));
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bv, b->bio, j)
+ bio_for_each_segment_all(bv, b->bio, j, iter_all)
memcpy(page_address(bv->bv_page),
base + j * PAGE_SIZE, PAGE_SIZE);
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index b8eec515a003..a0dcf28c01b5 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1447,8 +1447,9 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
{
unsigned int i;
struct bio_vec *bv;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bv, clone, i) {
+ bio_for_each_segment_all(bv, clone, i, iter_all) {
BUG_ON(!bv->bv_page);
mempool_free(bv->bv_page, &cc->page_pool);
}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 1d54109071cc..6f74a3b06c7e 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2114,13 +2114,14 @@ static void process_checks(struct r1bio *r1_bio)
struct page **spages = get_resync_pages(sbio)->pages;
struct bio_vec *bi;
int page_len[RESYNC_PAGES] = { 0 };
+ struct bvec_iter_all iter_all;
if (sbio->bi_end_io != end_sync_read)
continue;
/* Now we can 'fixup' the error value */
sbio->bi_status = 0;
- bio_for_each_segment_all(bi, sbio, j)
+ bio_for_each_segment_all(bi, sbio, j, iter_all)
page_len[j] = bi->bv_len;
if (!status) {
diff --git a/drivers/staging/erofs/data.c b/drivers/staging/erofs/data.c
index 6384f73e5418..96240ceca02a 100644
--- a/drivers/staging/erofs/data.c
+++ b/drivers/staging/erofs/data.c
@@ -20,8 +20,9 @@ static inline void read_endio(struct bio *bio)
int i;
struct bio_vec *bvec;
const blk_status_t err = bio->bi_status;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
/* page is already locked */
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 79d3ba62b298..41a8a9399863 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -731,11 +731,12 @@ static inline void z_erofs_vle_read_endio(struct bio *bio)
const blk_status_t err = bio->bi_status;
unsigned int i;
struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
#ifdef EROFS_FS_HAS_MANAGED_CACHE
struct address_space *mngda = NULL;
#endif
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
bool cachemngd = false;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 64ba27b8b754..f8dbfa0b4225 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -197,6 +197,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
ssize_t ret;
blk_qc_t qc;
int i;
+ struct bvec_iter_all iter_all;
if ((pos | iov_iter_alignment(iter)) &
(bdev_logical_block_size(bdev) - 1))
@@ -248,7 +249,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
}
__set_current_state(TASK_RUNNING);
- bio_for_each_segment_all(bvec, &bio, i) {
+ bio_for_each_segment_all(bvec, &bio, i, iter_all) {
if (should_dirty && !PageCompound(bvec->bv_page))
set_page_dirty_lock(bvec->bv_page);
put_page(bvec->bv_page);
@@ -316,8 +317,9 @@ static void blkdev_bio_end_io(struct bio *bio)
} else {
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
put_page(bvec->bv_page);
bio_put(bio);
}
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 2955a4ea2fa8..602a74c645c3 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -162,13 +162,14 @@ static void end_compressed_bio_read(struct bio *bio)
} else {
int i;
struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
/*
* we have verified the checksum already, set page
* checked so the end_io handlers know about it
*/
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, cb->orig_bio, i)
+ bio_for_each_segment_all(bvec, cb->orig_bio, i, iter_all)
SetPageChecked(bvec->bv_page);
bio_endio(cb->orig_bio);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 169839487ac9..559ab016a33c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -811,9 +811,10 @@ static blk_status_t btree_csum_one_bio(struct bio *bio)
struct bio_vec *bvec;
struct btrfs_root *root;
int i, ret = 0;
+ struct bvec_iter_all iter_all;
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
root = BTRFS_I(bvec->bv_page->mapping->host)->root;
ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
if (ret)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 40751e86a2a9..87907aba2a25 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2445,9 +2445,10 @@ static void end_bio_extent_writepage(struct bio *bio)
u64 start;
u64 end;
int i;
+ struct bvec_iter_all iter_all;
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -2516,9 +2517,10 @@ static void end_bio_extent_readpage(struct bio *bio)
int mirror;
int ret;
int i;
+ struct bvec_iter_all iter_all;
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -3664,9 +3666,10 @@ static void end_bio_extent_buffer_writepage(struct bio *bio)
struct bio_vec *bvec;
struct extent_buffer *eb;
int i, done;
+ struct bvec_iter_all iter_all;
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
eb = (struct extent_buffer *)page->private;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c576b3fcaea7..47c4013f4d06 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7819,6 +7819,7 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
struct bio_vec *bvec;
struct extent_io_tree *io_tree, *failure_tree;
int i;
+ struct bvec_iter_all iter_all;
if (bio->bi_status)
goto end;
@@ -7830,7 +7831,7 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
done->uptodate = 1;
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
io_tree, done->start, bvec->bv_page,
btrfs_ino(BTRFS_I(inode)), 0);
@@ -7909,6 +7910,7 @@ static void btrfs_retry_endio(struct bio *bio)
int uptodate;
int ret;
int i;
+ struct bvec_iter_all iter_all;
if (bio->bi_status)
goto end;
@@ -7922,7 +7924,7 @@ static void btrfs_retry_endio(struct bio *bio)
failure_tree = &BTRFS_I(inode)->io_failure_tree;
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
bvec->bv_offset, done->start,
bvec->bv_len);
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index df41d7049936..e33a99871d60 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1443,10 +1443,11 @@ static void set_bio_pages_uptodate(struct bio *bio)
{
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
ASSERT(!bio_flagged(bio, BIO_CLONED));
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
SetPageUptodate(bvec->bv_page);
}
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index 0959044c5cee..5759bcd018cd 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -30,8 +30,9 @@ static void __fscrypt_decrypt_bio(struct bio *bio, bool done)
{
struct bio_vec *bv;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bv, bio, i) {
+ bio_for_each_segment_all(bv, bio, i, iter_all) {
struct page *page = bv->bv_page;
int ret = fscrypt_decrypt_page(page->mapping->host, page,
PAGE_SIZE, 0, page->index);
diff --git a/fs/direct-io.c b/fs/direct-io.c
index ea07d5a34317..5904fc2e180c 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -551,7 +551,9 @@ static blk_status_t dio_bio_complete(struct dio *dio, struct bio *bio)
if (dio->is_async && dio->op == REQ_OP_READ && dio->should_dirty) {
bio_check_pages_dirty(bio); /* transfers ownership */
} else {
- bio_for_each_segment_all(bvec, bio, i) {
+ struct bvec_iter_all iter_all;
+
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
if (dio->op == REQ_OP_READ && !PageCompound(page) &&
diff --git a/fs/exofs/ore.c b/fs/exofs/ore.c
index 5331a15a61f1..24a8e34882e9 100644
--- a/fs/exofs/ore.c
+++ b/fs/exofs/ore.c
@@ -420,8 +420,9 @@ static void _clear_bio(struct bio *bio)
{
struct bio_vec *bv;
unsigned i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bv, bio, i) {
+ bio_for_each_segment_all(bv, bio, i, iter_all) {
unsigned this_count = bv->bv_len;
if (likely(PAGE_SIZE == this_count))
diff --git a/fs/exofs/ore_raid.c b/fs/exofs/ore_raid.c
index 199590f36203..e83bab54b03e 100644
--- a/fs/exofs/ore_raid.c
+++ b/fs/exofs/ore_raid.c
@@ -468,11 +468,12 @@ static void _mark_read4write_pages_uptodate(struct ore_io_state *ios, int ret)
/* loop on all devices all pages */
for (d = 0; d < ios->numdevs; d++) {
struct bio *bio = ios->per_dev[d].bio;
+ struct bvec_iter_all iter_all;
if (!bio)
continue;
- bio_for_each_segment_all(bv, bio, i) {
+ bio_for_each_segment_all(bv, bio, i, iter_all) {
struct page *page = bv->bv_page;
SetPageUptodate(page);
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index db7590178dfc..0644b4e7d6d4 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -63,8 +63,9 @@ static void ext4_finish_bio(struct bio *bio)
{
int i;
struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct page *data_page = NULL;
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index f461d75ac049..b0d9537bc797 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -72,6 +72,7 @@ static void mpage_end_io(struct bio *bio)
{
struct bio_vec *bv;
int i;
+ struct bvec_iter_all iter_all;
if (ext4_bio_encrypted(bio)) {
if (bio->bi_status) {
@@ -81,7 +82,7 @@ static void mpage_end_io(struct bio *bio)
return;
}
}
- bio_for_each_segment_all(bv, bio, i) {
+ bio_for_each_segment_all(bv, bio, i, iter_all) {
struct page *page = bv->bv_page;
if (!bio->bi_status) {
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b293cb3e27a2..d28f482a0d52 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -87,8 +87,9 @@ static void __read_end_io(struct bio *bio)
struct page *page;
struct bio_vec *bv;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bv, bio, i) {
+ bio_for_each_segment_all(bv, bio, i, iter_all) {
page = bv->bv_page;
/* PG_error was set if any post_read step failed */
@@ -164,13 +165,14 @@ static void f2fs_write_end_io(struct bio *bio)
struct f2fs_sb_info *sbi = bio->bi_private;
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
if (time_to_inject(sbi, FAULT_WRITE_IO)) {
f2fs_show_injection_info(FAULT_WRITE_IO);
bio->bi_status = BLK_STS_IOERR;
}
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
enum count_type type = WB_DATA_TYPE(page);
@@ -347,6 +349,7 @@ static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
struct bio_vec *bvec;
struct page *target;
int i;
+ struct bvec_iter_all iter_all;
if (!io->bio)
return false;
@@ -354,7 +357,7 @@ static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
if (!inode && !page && !ino)
return true;
- bio_for_each_segment_all(bvec, io->bio, i) {
+ bio_for_each_segment_all(bvec, io->bio, i, iter_all) {
if (bvec->bv_page->mapping)
target = bvec->bv_page;
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 4c7069b8f3c1..f2f165620161 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -168,7 +168,8 @@ u64 gfs2_log_bmap(struct gfs2_sbd *sdp)
* that is pinned in the pagecache.
*/
-static void gfs2_end_log_write_bh(struct gfs2_sbd *sdp, struct bio_vec *bvec,
+static void gfs2_end_log_write_bh(struct gfs2_sbd *sdp,
+ struct bio_vec *bvec,
blk_status_t error)
{
struct buffer_head *bh, *next;
@@ -207,6 +208,7 @@ static void gfs2_end_log_write(struct bio *bio)
struct bio_vec *bvec;
struct page *page;
int i;
+ struct bvec_iter_all iter_all;
if (bio->bi_status) {
fs_err(sdp, "Error %d writing to journal, jid=%u\n",
@@ -214,7 +216,7 @@ static void gfs2_end_log_write(struct bio *bio)
wake_up(&sdp->sd_logd_waitq);
}
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
page = bvec->bv_page;
if (page_has_buffers(page))
gfs2_end_log_write_bh(sdp, bvec, bio->bi_status);
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index be9c0bf697fe..3201342404a7 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -190,8 +190,9 @@ static void gfs2_meta_read_endio(struct bio *bio)
{
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i) {
+ bio_for_each_segment_all(bvec, bio, i, iter_all) {
struct page *page = bvec->bv_page;
struct buffer_head *bh = page_buffers(page);
unsigned int len = bvec->bv_len;
diff --git a/fs/iomap.c b/fs/iomap.c
index c5df035ace6f..1f648d098a3b 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -262,8 +262,9 @@ iomap_read_end_io(struct bio *bio)
int error = blk_status_to_errno(bio->bi_status);
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
iomap_read_page_end_io(bvec, error);
bio_put(bio);
}
@@ -1541,8 +1542,9 @@ static void iomap_dio_bio_end_io(struct bio *bio)
} else {
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
put_page(bvec->bv_page);
bio_put(bio);
}
diff --git a/fs/mpage.c b/fs/mpage.c
index c820dc9bebab..3f19da75178b 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -48,8 +48,9 @@ static void mpage_end_io(struct bio *bio)
{
struct bio_vec *bv;
int i;
+ struct bvec_iter_all iter_all;
- bio_for_each_segment_all(bv, bio, i) {
+ bio_for_each_segment_all(bv, bio, i, iter_all) {
struct page *page = bv->bv_page;
page_endio(page, bio_op(bio),
blk_status_to_errno(bio->bi_status));
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 338b9d9984e0..1f1829e506e8 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -62,7 +62,7 @@ xfs_find_daxdev_for_inode(
static void
xfs_finish_page_writeback(
struct inode *inode,
- struct bio_vec *bvec,
+ struct bio_vec *bvec,
int error)
{
struct iomap_page *iop = to_iomap_page(bvec->bv_page);
@@ -98,6 +98,7 @@ xfs_destroy_ioend(
for (bio = &ioend->io_inline_bio; bio; bio = next) {
struct bio_vec *bvec;
int i;
+ struct bvec_iter_all iter_all;
/*
* For the last bio, bi_private points to the ioend, so we
@@ -109,7 +110,7 @@ xfs_destroy_ioend(
next = bio->bi_private;
/* walk each page on bio, ending page IO on them */
- bio_for_each_segment_all(bvec, bio, i)
+ bio_for_each_segment_all(bvec, bio, i, iter_all)
xfs_finish_page_writeback(inode, bvec, error);
bio_put(bio);
}
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 46fd0e03233b..c35997dd02c2 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -128,12 +128,19 @@ static inline bool bio_full(struct bio *bio)
return bio->bi_vcnt >= bio->bi_max_vecs;
}
+#define bvec_for_each_segment(bv, bvl, i, iter_all) \
+ for (bv = bvec_init_iter_all(&iter_all); \
+ (iter_all.done < (bvl)->bv_len) && \
+ (bvec_next_segment((bvl), &iter_all), 1); \
+ iter_all.done += bv->bv_len, i += 1)
+
/*
* drivers should _never_ use the all version - the bio may have been split
* before it got to the driver and the driver won't own all of it
*/
-#define bio_for_each_segment_all(bvl, bio, i) \
- for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
+#define bio_for_each_segment_all(bvl, bio, i, iter_all) \
+ for (i = 0, iter_all.idx = 0; iter_all.idx < (bio)->bi_vcnt; iter_all.idx++) \
+ bvec_for_each_segment(bvl, &((bio)->bi_io_vec[iter_all.idx]), i, iter_all)
static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
unsigned bytes)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index ca6e630f88ab..94620cf01762 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -45,6 +45,12 @@ struct bvec_iter {
current bvec */
};
+struct bvec_iter_all {
+ struct bio_vec bv;
+ int idx;
+ unsigned done;
+};
+
/*
* various member access, note that bio_data should of course not be used
* on highmem page vectors
@@ -131,6 +137,30 @@ static inline bool bvec_iter_advance(const struct bio_vec *bv,
.bi_bvec_done = 0, \
}
+static inline struct bio_vec *bvec_init_iter_all(struct bvec_iter_all *iter_all)
+{
+ iter_all->bv.bv_page = NULL;
+ iter_all->done = 0;
+
+ return &iter_all->bv;
+}
+
+static inline void bvec_next_segment(const struct bio_vec *bvec,
+ struct bvec_iter_all *iter_all)
+{
+ struct bio_vec *bv = &iter_all->bv;
+
+ if (bv->bv_page) {
+ bv->bv_page = nth_page(bv->bv_page, 1);
+ bv->bv_offset = 0;
+ } else {
+ bv->bv_page = bvec->bv_page;
+ bv->bv_offset = bvec->bv_offset;
+ }
+ bv->bv_len = min_t(unsigned int, PAGE_SIZE - bv->bv_offset,
+ bvec->bv_len - iter_all->done);
+}
+
/*
* Get the last single-page segment from the multi-page bvec and store it
* in @seg
--
2.9.5
This patch pulls the trigger for multi-page bvecs.
Signed-off-by: Ming Lei <[email protected]>
---
block/bio.c | 22 +++++++++++++++-------
fs/iomap.c | 4 ++--
fs/xfs/xfs_aops.c | 4 ++--
include/linux/bio.h | 2 +-
4 files changed, 20 insertions(+), 12 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 75fde30af51f..8bf9338d4783 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -753,6 +753,8 @@ EXPORT_SYMBOL(bio_add_pc_page);
* @page: page to add
* @len: length of the data to add
* @off: offset of the data in @page
+ * @same_page: if %true only merge if the new data is in the same physical
+ * page as the last segment of the bio.
*
* Try to add the data at @page + @off to the last bvec of @bio. This is a
* a useful optimisation for file systems with a block size smaller than the
@@ -761,19 +763,25 @@ EXPORT_SYMBOL(bio_add_pc_page);
* Return %true on success or %false on failure.
*/
bool __bio_try_merge_page(struct bio *bio, struct page *page,
- unsigned int len, unsigned int off)
+ unsigned int len, unsigned int off, bool same_page)
{
if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
return false;
if (bio->bi_vcnt > 0) {
struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
+ phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +
+ bv->bv_offset + bv->bv_len;
+ phys_addr_t page_addr = page_to_phys(page);
- if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) {
- bv->bv_len += len;
- bio->bi_iter.bi_size += len;
- return true;
- }
+ if (vec_end_addr != page_addr + off)
+ return false;
+ if (same_page && ((vec_end_addr - 1) & PAGE_MASK) != page_addr)
+ return false;
+
+ bv->bv_len += len;
+ bio->bi_iter.bi_size += len;
+ return true;
}
return false;
}
@@ -819,7 +827,7 @@ EXPORT_SYMBOL_GPL(__bio_add_page);
int bio_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
- if (!__bio_try_merge_page(bio, page, len, offset)) {
+ if (!__bio_try_merge_page(bio, page, len, offset, false)) {
if (bio_full(bio))
return 0;
__bio_add_page(bio, page, len, offset);
diff --git a/fs/iomap.c b/fs/iomap.c
index 1f648d098a3b..ec5527b0fba4 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -313,7 +313,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
*/
sector = iomap_sector(iomap, pos);
if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
- if (__bio_try_merge_page(ctx->bio, page, plen, poff))
+ if (__bio_try_merge_page(ctx->bio, page, plen, poff, true))
goto done;
is_contig = true;
}
@@ -344,7 +344,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
ctx->bio->bi_end_io = iomap_read_end_io;
}
- __bio_add_page(ctx->bio, page, plen, poff);
+ bio_add_page(ctx->bio, page, plen, poff);
done:
/*
* Move the caller beyond our range so that it keeps making progress.
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 1f1829e506e8..b9fd44168f61 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -616,12 +616,12 @@ xfs_add_to_ioend(
bdev, sector);
}
- if (!__bio_try_merge_page(wpc->ioend->io_bio, page, len, poff)) {
+ if (!__bio_try_merge_page(wpc->ioend->io_bio, page, len, poff, true)) {
if (iop)
atomic_inc(&iop->write_count);
if (bio_full(wpc->ioend->io_bio))
xfs_chain_bio(wpc->ioend, wbc, bdev, sector);
- __bio_add_page(wpc->ioend->io_bio, page, len, poff);
+ bio_add_page(wpc->ioend->io_bio, page, len, poff);
}
wpc->ioend->io_size += len;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index c35997dd02c2..5505f74aef8b 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -441,7 +441,7 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
unsigned int, unsigned int);
bool __bio_try_merge_page(struct bio *bio, struct page *page,
- unsigned int len, unsigned int off);
+ unsigned int len, unsigned int off, bool same_page);
void __bio_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int off);
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
--
2.9.5
Now multi-page bvec can cover CONFIG_THP_SWAP, so we don't need to
increase BIO_MAX_PAGES for it.
CONFIG_THP_SWAP needs to split one THP into normal pages and adds
them all to one bio. With multipage-bvec, it just takes one bvec to
hold them all.
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
include/linux/bio.h | 8 --------
1 file changed, 8 deletions(-)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 5505f74aef8b..7be48c55b14a 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -34,15 +34,7 @@
#define BIO_BUG_ON
#endif
-#ifdef CONFIG_THP_SWAP
-#if HPAGE_PMD_NR > 256
-#define BIO_MAX_PAGES HPAGE_PMD_NR
-#else
#define BIO_MAX_PAGES 256
-#endif
-#else
-#define BIO_MAX_PAGES 256
-#endif
#define bio_prio(bio) (bio)->bi_ioprio
#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
--
2.9.5
On Mon, Nov 26, 2018 at 3:20 AM Ming Lei <[email protected]> wrote:
>
> We will support multi-page bvec soon, and have to deal with
> single-page vs multi-page bvec. This patch follows Christoph's
> suggestion to rename all the following helpers:
>
> for_each_bvec
> bvec_iter_bvec
> bvec_iter_len
> bvec_iter_page
> bvec_iter_offset
>
> into:
> for_each_segment
> segment_iter_bvec
> segment_iter_len
> segment_iter_page
> segment_iter_offset
>
> so that these helpers named with 'segment' only deal with single-page
> bvec, or called segment. We will introduce helpers named with 'bvec'
> for multi-page bvec.
>
> bvec_iter_advance() isn't renamed becasue this helper is always operated
> on real bvec even though multi-page bvec is supported.
>
> Suggested-by: Christoph Hellwig <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> .clang-format | 2 +-
Acked-by: Miguel Ojeda <[email protected]>
Cheers,
Miguel
On Mon, Nov 26, 2018 at 10:17:05AM +0800, Ming Lei wrote:
> Commit 7759eb23fd980 ("block: remove bio_rewind_iter()") removes
> bio_rewind_iter(), then no one uses bvec_iter_rewind() any more,
> so remove it.
>
> Signed-off-by: Ming Lei <[email protected]>
Looks good,
Reviewed-by: Christoph Hellwig <[email protected]>
On Mon, Nov 26, 2018 at 10:17:06AM +0800, Ming Lei wrote:
> We will support multi-page bvec soon, and have to deal with
> single-page vs multi-page bvec. This patch follows Christoph's
> suggestion to rename all the following helpers:
>
> for_each_bvec
> bvec_iter_bvec
> bvec_iter_len
> bvec_iter_page
> bvec_iter_offset
>
> into:
> for_each_segment
> segment_iter_bvec
> segment_iter_len
> segment_iter_page
> segment_iter_offset
>
> so that these helpers named with 'segment' only deal with single-page
> bvec, or called segment. We will introduce helpers named with 'bvec'
> for multi-page bvec.
>
> bvec_iter_advance() isn't renamed becasue this helper is always operated
> on real bvec even though multi-page bvec is supported.
>
> Suggested-by: Christoph Hellwig <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
Looks fine,
Reviewed-by: Christoph Hellwig <[email protected]>
Looks fine,
Reviewed-by: Christoph Hellwig <[email protected]>
On Mon, Nov 26, 2018 at 10:17:08AM +0800, Ming Lei wrote:
> bio_for_each_bvec() is used for iterating over multi-page bvec for bio
> split & merge code.
>
> rq_for_each_bvec() can be used for drivers which may handle the
> multi-page bvec directly, so far loop is one perfect use case.
>
> Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
Looks fine,
Reviewed-by: Christoph Hellwig <[email protected]>
> + phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +
> + bv->bv_offset + bv->bv_len;
The name is a little confusing, as the real end addr would be -1. Maybe
throw the -1 in here, and adjust for it in the contigous check below?
On Mon, Nov 26, 2018 at 10:17:18AM +0800, Ming Lei wrote:
> Now multi-page bvec is supported, some helpers may return page by
> page, meantime some may return segment by segment, this patch
> documents the usage.
>
> Signed-off-by: Ming Lei <[email protected]>
Looks fine,
Reviewed-by: Christoph Hellwig <[email protected]>
Looks fine:
Reviewed-by: Christoph Hellwig <[email protected]>
Nitpick below:
> +{
> + unsigned len = bv->bv_len;
> + unsigned total_len = 0;
> + unsigned new_nsegs = 0, seg_size = 0;
> +
> + /*
> + * Multipage bvec may be too big to hold in one segment,
> + * so the current bvec has to be splitted as multiple
> + * segments.
> + */
Please use up all 80 chars in a line.
Looks good,
Reviewed-by: Christoph Hellwig <[email protected]>
On Mon, Nov 26, 2018 at 10:17:03AM +0800, Ming Lei wrote:
> From: Christoph Hellwig <[email protected]>
>
> The cluster flag implements some very old SCSI behavior. As far as I
> can tell the original intent was to enable or disable any kind of
> segment merging. But the actually visible effect to the LLDD is that
> it limits each segments to be inside a single page, which we can
> also affect by setting the maximum segment size and the segment
> boundary.
Reviewed-by: Omar Sandoval <[email protected]>
One comment typo below.
> Signed-off-by: Christoph Hellwig <[email protected]>
>
> Replace virt boundary with segment boundary limit.
>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> block/blk-merge.c | 20 ++++++++------------
> block/blk-settings.c | 3 ---
> block/blk-sysfs.c | 5 +----
> drivers/scsi/scsi_lib.c | 20 ++++++++++++++++----
> include/linux/blkdev.h | 6 ------
> 5 files changed, 25 insertions(+), 29 deletions(-)
>
[snip]
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 0df15cb738d2..78d6d05992b0 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1810,6 +1810,8 @@ static int scsi_map_queues(struct blk_mq_tag_set *set)
> void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
> {
> struct device *dev = shost->dma_dev;
> + unsigned max_segment_size = dma_get_max_seg_size(dev);
> + unsigned long segment_boundary = shost->dma_boundary;
>
> /*
> * this limit is imposed by hardware restrictions
> @@ -1828,13 +1830,23 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
> blk_queue_max_hw_sectors(q, shost->max_sectors);
> if (shost->unchecked_isa_dma)
> blk_queue_bounce_limit(q, BLK_BOUNCE_ISA);
> - blk_queue_segment_boundary(q, shost->dma_boundary);
> dma_set_seg_boundary(dev, shost->dma_boundary);
>
> - blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
> + /*
> + * Clustering is a really old concept from the stone age of Linux
> + * SCSI support. But the basic idea is that we never give the
> + * driver a segment that spans multiple pages. For that we need
> + * to limit the segment size, and set the segment boundary so that
> + * we never merge a second segment which is no page aligned.
Typo, "which is not page aligned".
On Mon, Nov 26, 2018 at 10:17:04AM +0800, Ming Lei wrote:
> It is wrong to use bio->bi_vcnt to figure out how many segments
> there are in the bio even though CLONED flag isn't set on this bio,
> because this bio may be splitted or advanced.
>
> So always use bio_segments() in blk_recount_segments(), and it shouldn't
> cause any performance loss now because the physical segment number is figured
> out in blk_queue_split() and BIO_SEG_VALID is set meantime since
> bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting").
>
> Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
> Fixes: 76d8137a3113 ("blk-merge: recaculate segment if it isn't less than max segments")
> Signed-off-by: Ming Lei <[email protected]>
> ---
> block/blk-merge.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/block/blk-merge.c b/block/blk-merge.c
> index e69d8f8ba819..51ec6ca56a0a 100644
> --- a/block/blk-merge.c
> +++ b/block/blk-merge.c
> @@ -367,13 +367,7 @@ void blk_recalc_rq_segments(struct request *rq)
>
> void blk_recount_segments(struct request_queue *q, struct bio *bio)
> {
> - unsigned short seg_cnt;
> -
> - /* estimate segment number by bi_vcnt for non-cloned bio */
> - if (bio_flagged(bio, BIO_CLONED))
> - seg_cnt = bio_segments(bio);
> - else
> - seg_cnt = bio->bi_vcnt;
> + unsigned short seg_cnt = bio_segments(bio);
>
> if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
> (seg_cnt < queue_max_segments(q)))
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:05AM +0800, Ming Lei wrote:
> Commit 7759eb23fd980 ("block: remove bio_rewind_iter()") removes
> bio_rewind_iter(), then no one uses bvec_iter_rewind() any more,
> so remove it.
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> include/linux/bvec.h | 24 ------------------------
> 1 file changed, 24 deletions(-)
>
> diff --git a/include/linux/bvec.h b/include/linux/bvec.h
> index 02c73c6aa805..ba0ae40e77c9 100644
> --- a/include/linux/bvec.h
> +++ b/include/linux/bvec.h
> @@ -92,30 +92,6 @@ static inline bool bvec_iter_advance(const struct bio_vec *bv,
> return true;
> }
>
> -static inline bool bvec_iter_rewind(const struct bio_vec *bv,
> - struct bvec_iter *iter,
> - unsigned int bytes)
> -{
> - while (bytes) {
> - unsigned len = min(bytes, iter->bi_bvec_done);
> -
> - if (iter->bi_bvec_done == 0) {
> - if (WARN_ONCE(iter->bi_idx == 0,
> - "Attempted to rewind iter beyond "
> - "bvec's boundaries\n")) {
> - return false;
> - }
> - iter->bi_idx--;
> - iter->bi_bvec_done = __bvec_iter_bvec(bv, *iter)->bv_len;
> - continue;
> - }
> - bytes -= len;
> - iter->bi_size += len;
> - iter->bi_bvec_done -= len;
> - }
> - return true;
> -}
> -
> #define for_each_bvec(bvl, bio_vec, iter, start) \
> for (iter = (start); \
> (iter).bi_size && \
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:06AM +0800, Ming Lei wrote:
> We will support multi-page bvec soon, and have to deal with
> single-page vs multi-page bvec. This patch follows Christoph's
> suggestion to rename all the following helpers:
>
> for_each_bvec
> bvec_iter_bvec
> bvec_iter_len
> bvec_iter_page
> bvec_iter_offset
>
> into:
> for_each_segment
> segment_iter_bvec
> segment_iter_len
> segment_iter_page
> segment_iter_offset
>
> so that these helpers named with 'segment' only deal with single-page
> bvec, or called segment. We will introduce helpers named with 'bvec'
> for multi-page bvec.
>
> bvec_iter_advance() isn't renamed becasue this helper is always operated
> on real bvec even though multi-page bvec is supported.
>
> Suggested-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> .clang-format | 2 +-
> drivers/md/dm-integrity.c | 2 +-
> drivers/md/dm-io.c | 4 ++--
> drivers/nvdimm/blk.c | 4 ++--
> drivers/nvdimm/btt.c | 4 ++--
> include/linux/bio.h | 10 +++++-----
> include/linux/bvec.h | 20 +++++++++++---------
> include/linux/ceph/messenger.h | 2 +-
> lib/iov_iter.c | 2 +-
> net/ceph/messenger.c | 14 +++++++-------
> 10 files changed, 33 insertions(+), 31 deletions(-)
On Mon, Nov 26, 2018 at 10:17:01AM +0800, Ming Lei wrote:
> From: Christoph Hellwig <[email protected]>
>
> The btrfs write path passes a bio_offset argument through some deep
> callchains including async offloading. In the end this is easily
> calculatable using page_offset plus the bvec offset for the first
> page in the bio, and only actually used by by a single function.
> Just move the calculation of the offset there.
>
> Reviewed-by: David Sterba <[email protected]>
> Signed-off-by: Christoph Hellwig <[email protected]>
> ---
> fs/btrfs/disk-io.c | 21 +++++----------------
> fs/btrfs/disk-io.h | 2 +-
> fs/btrfs/extent_io.c | 9 ++-------
> fs/btrfs/extent_io.h | 5 ++---
> fs/btrfs/inode.c | 17 ++++++++---------
> 5 files changed, 18 insertions(+), 36 deletions(-)
[snip]
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 9ea4c6f0352f..c576b3fcaea7 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -1920,8 +1920,7 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
> * At IO completion time the cums attached on the ordered extent record
> * are inserted into the btree
> */
> -static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
> - u64 bio_offset)
> +static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio)
> {
> struct inode *inode = private_data;
> blk_status_t ret = 0;
> @@ -1973,8 +1972,7 @@ blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
> * c-3) otherwise: async submit
> */
> static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
> - int mirror_num, unsigned long bio_flags,
> - u64 bio_offset)
> + int mirror_num, unsigned long bio_flags)
> {
> struct inode *inode = private_data;
> struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> @@ -2011,8 +2009,7 @@ static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
> goto mapit;
> /* we're doing a write, do the async checksumming */
> ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
> - bio_offset, inode,
> - btrfs_submit_bio_start);
> + inode, btrfs_submit_bio_start);
> goto out;
> } else if (!skip_sum) {
> ret = btrfs_csum_one_bio(inode, bio, 0, 0);
> @@ -8123,10 +8120,13 @@ static void btrfs_endio_direct_write(struct bio *bio)
> }
>
> static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
> - struct bio *bio, u64 offset)
> + struct bio *bio)
> {
> struct inode *inode = private_data;
> + struct bio_vec *bvec = bio_first_bvec_all(bio);
> + u64 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
Hm, but for direct I/O, these will be user pages (or the zero page), so
page_offset() won't be valid?
> blk_status_t ret;
> +
> ret = btrfs_csum_one_bio(inode, bio, offset, 1);
> BUG_ON(ret); /* -ENOMEM */
> return 0;
On Mon, Nov 26, 2018 at 10:17:09AM +0800, Ming Lei wrote:
> First it is more efficient to use bio_for_each_bvec() in both
> blk_bio_segment_split() and __blk_recalc_rq_segments() to compute how
> many multi-page bvecs there are in the bio.
>
> Secondly once bio_for_each_bvec() is used, the bvec may need to be
> splitted because its length can be very longer than max segment size,
> so we have to split the big bvec into several segments.
>
> Thirdly when splitting multi-page bvec into segments, the max segment
> limit may be reached, so the bio split need to be considered under
> this situation too.
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> block/blk-merge.c | 100 +++++++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 80 insertions(+), 20 deletions(-)
>
> diff --git a/block/blk-merge.c b/block/blk-merge.c
> index 51ec6ca56a0a..2d8f388d43de 100644
> --- a/block/blk-merge.c
> +++ b/block/blk-merge.c
> @@ -161,6 +161,70 @@ static inline unsigned get_max_io_size(struct request_queue *q,
> return sectors;
> }
>
> +static unsigned get_max_segment_size(struct request_queue *q,
> + unsigned offset)
> +{
> + unsigned long mask = queue_segment_boundary(q);
> +
> + return min_t(unsigned long, mask - (mask & offset) + 1,
> + queue_max_segment_size(q));
> +}
> +
> +/*
> + * Split the bvec @bv into segments, and update all kinds of
> + * variables.
> + */
> +static bool bvec_split_segs(struct request_queue *q, struct bio_vec *bv,
> + unsigned *nsegs, unsigned *last_seg_size,
> + unsigned *front_seg_size, unsigned *sectors)
> +{
> + unsigned len = bv->bv_len;
> + unsigned total_len = 0;
> + unsigned new_nsegs = 0, seg_size = 0;
> +
> + /*
> + * Multipage bvec may be too big to hold in one segment,
> + * so the current bvec has to be splitted as multiple
> + * segments.
> + */
> + while (len && new_nsegs + *nsegs < queue_max_segments(q)) {
> + seg_size = get_max_segment_size(q, bv->bv_offset + total_len);
> + seg_size = min(seg_size, len);
> +
> + new_nsegs++;
> + total_len += seg_size;
> + len -= seg_size;
> +
> + if ((bv->bv_offset + total_len) & queue_virt_boundary(q))
> + break;
> + }
> +
> + if (!new_nsegs)
> + return !!len;
> +
> + /* update front segment size */
> + if (!*nsegs) {
> + unsigned first_seg_size;
> +
> + if (new_nsegs == 1)
> + first_seg_size = get_max_segment_size(q, bv->bv_offset);
> + else
> + first_seg_size = queue_max_segment_size(q);
> +
> + if (*front_seg_size < first_seg_size)
> + *front_seg_size = first_seg_size;
> + }
> +
> + /* update other varibles */
> + *last_seg_size = seg_size;
> + *nsegs += new_nsegs;
> + if (sectors)
> + *sectors += total_len >> 9;
> +
> + /* split in the middle of the bvec if len != 0 */
> + return !!len;
> +}
> +
> static struct bio *blk_bio_segment_split(struct request_queue *q,
> struct bio *bio,
> struct bio_set *bs,
> @@ -174,7 +238,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
> struct bio *new = NULL;
> const unsigned max_sectors = get_max_io_size(q, bio);
>
> - bio_for_each_segment(bv, bio, iter) {
> + bio_for_each_bvec(bv, bio, iter) {
> /*
> * If the queue doesn't support SG gaps and adding this
> * offset would create a gap, disallow it.
> @@ -189,8 +253,12 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
> */
> if (nsegs < queue_max_segments(q) &&
> sectors < max_sectors) {
> - nsegs++;
> - sectors = max_sectors;
> + /* split in the middle of bvec */
> + bv.bv_len = (max_sectors - sectors) << 9;
> + bvec_split_segs(q, &bv, &nsegs,
> + &seg_size,
> + &front_seg_size,
> + §ors);
> }
> goto split;
> }
> @@ -212,14 +280,12 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
> if (nsegs == queue_max_segments(q))
> goto split;
>
> - if (nsegs == 1 && seg_size > front_seg_size)
> - front_seg_size = seg_size;
> -
> - nsegs++;
> bvprv = bv;
> bvprvp = &bvprv;
> - seg_size = bv.bv_len;
> - sectors += bv.bv_len >> 9;
> +
> + if (bvec_split_segs(q, &bv, &nsegs, &seg_size,
> + &front_seg_size, §ors))
> + goto split;
>
> }
>
> @@ -233,8 +299,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
> bio = new;
> }
>
> - if (nsegs == 1 && seg_size > front_seg_size)
> - front_seg_size = seg_size;
> bio->bi_seg_front_size = front_seg_size;
> if (seg_size > bio->bi_seg_back_size)
> bio->bi_seg_back_size = seg_size;
> @@ -296,6 +360,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
> {
> struct bio_vec bv, bvprv = { NULL };
> unsigned int seg_size, nr_phys_segs;
> + unsigned front_seg_size = bio->bi_seg_front_size;
> struct bio *fbio, *bbio;
> struct bvec_iter iter;
> bool prev = false;
> @@ -316,7 +381,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
> seg_size = 0;
> nr_phys_segs = 0;
> for_each_bio(bio) {
> - bio_for_each_segment(bv, bio, iter) {
> + bio_for_each_bvec(bv, bio, iter) {
> /*
> * If SG merging is disabled, each bio vector is
> * a segment
> @@ -336,20 +401,15 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
> continue;
> }
> new_segment:
> - if (nr_phys_segs == 1 && seg_size >
> - fbio->bi_seg_front_size)
> - fbio->bi_seg_front_size = seg_size;
> -
> - nr_phys_segs++;
> bvprv = bv;
> prev = true;
> - seg_size = bv.bv_len;
> + bvec_split_segs(q, &bv, &nr_phys_segs, &seg_size,
> + &front_seg_size, NULL);
> }
> bbio = bio;
> }
>
> - if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size)
> - fbio->bi_seg_front_size = seg_size;
> + fbio->bi_seg_front_size = front_seg_size;
> if (seg_size > bbio->bi_seg_back_size)
> bbio->bi_seg_back_size = seg_size;
>
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:13AM +0800, Ming Lei wrote:
> iov_iter is implemented on bvec itererator helpers, so it is safe to pass
> multi-page bvec to it, and this way is much more efficient than passing one
> page in each bvec.
>
> Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> drivers/block/loop.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index 176ab1f28eca..e3683211f12d 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -510,21 +510,22 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
> loff_t pos, bool rw)
> {
> struct iov_iter iter;
> + struct req_iterator rq_iter;
> struct bio_vec *bvec;
> struct request *rq = blk_mq_rq_from_pdu(cmd);
> struct bio *bio = rq->bio;
> struct file *file = lo->lo_backing_file;
> + struct bio_vec tmp;
> unsigned int offset;
> - int segments = 0;
> + int nr_bvec = 0;
> int ret;
>
> + rq_for_each_bvec(tmp, rq, rq_iter)
> + nr_bvec++;
> +
> if (rq->bio != rq->biotail) {
> - struct req_iterator iter;
> - struct bio_vec tmp;
>
> - __rq_for_each_bio(bio, rq)
> - segments += bio_segments(bio);
> - bvec = kmalloc_array(segments, sizeof(struct bio_vec),
> + bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
> GFP_NOIO);
> if (!bvec)
> return -EIO;
> @@ -533,10 +534,10 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
> /*
> * The bios of the request may be started from the middle of
> * the 'bvec' because of bio splitting, so we can't directly
> - * copy bio->bi_iov_vec to new bvec. The rq_for_each_segment
> + * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec
> * API will take care of all details for us.
> */
> - rq_for_each_segment(tmp, rq, iter) {
> + rq_for_each_bvec(tmp, rq, rq_iter) {
> *bvec = tmp;
> bvec++;
> }
> @@ -550,11 +551,10 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
> */
> offset = bio->bi_iter.bi_bvec_done;
> bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
> - segments = bio_segments(bio);
> }
> atomic_set(&cmd->ref, 2);
>
> - iov_iter_bvec(&iter, rw, bvec, segments, blk_rq_bytes(rq));
> + iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq));
> iter.iov_offset = offset;
>
> cmd->iocb.ki_pos = pos;
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:14AM +0800, Ming Lei wrote:
> bch_bio_alloc_pages() is always called on one new bio, so it is safe
> to access the bvec table directly. Given it is the only kind of this
> case, open code the bvec table access since bio_for_each_segment_all()
> will be changed to support for iterating over multipage bvec.
>
> Acked-by: Coly Li <[email protected]>
> Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> drivers/md/bcache/util.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
> index 20eddeac1531..62fb917f7a4f 100644
> --- a/drivers/md/bcache/util.c
> +++ b/drivers/md/bcache/util.c
> @@ -270,7 +270,11 @@ int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
> int i;
> struct bio_vec *bv;
>
> - bio_for_each_segment_all(bv, bio, i) {
> + /*
> + * This is called on freshly new bio, so it is safe to access the
> + * bvec table directly.
> + */
> + for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++, i++) {
> bv->bv_page = alloc_page(gfp_mask);
> if (!bv->bv_page) {
> while (--bv >= bio->bi_io_vec)
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:15AM +0800, Ming Lei wrote:
> This patch introduces one extra iterator variable to bio_for_each_segment_all(),
> then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.
>
> Given it is just one mechannical & simple change on all bio_for_each_segment_all()
> users, this patch does tree-wide change in one single patch, so that we can
> avoid to use a temporary helper for this conversion.
>
> Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> block/bio.c | 27 ++++++++++++++++++---------
> block/bounce.c | 6 ++++--
> drivers/md/bcache/btree.c | 3 ++-
> drivers/md/dm-crypt.c | 3 ++-
> drivers/md/raid1.c | 3 ++-
> drivers/staging/erofs/data.c | 3 ++-
> drivers/staging/erofs/unzip_vle.c | 3 ++-
> fs/block_dev.c | 6 ++++--
> fs/btrfs/compression.c | 3 ++-
> fs/btrfs/disk-io.c | 3 ++-
> fs/btrfs/extent_io.c | 9 ++++++---
> fs/btrfs/inode.c | 6 ++++--
> fs/btrfs/raid56.c | 3 ++-
> fs/crypto/bio.c | 3 ++-
> fs/direct-io.c | 4 +++-
> fs/exofs/ore.c | 3 ++-
> fs/exofs/ore_raid.c | 3 ++-
> fs/ext4/page-io.c | 3 ++-
> fs/ext4/readpage.c | 3 ++-
> fs/f2fs/data.c | 9 ++++++---
> fs/gfs2/lops.c | 6 ++++--
> fs/gfs2/meta_io.c | 3 ++-
> fs/iomap.c | 6 ++++--
> fs/mpage.c | 3 ++-
> fs/xfs/xfs_aops.c | 5 +++--
> include/linux/bio.h | 11 +++++++++--
> include/linux/bvec.h | 30 ++++++++++++++++++++++++++++++
> 27 files changed, 125 insertions(+), 45 deletions(-)
On Mon, Nov 26, 2018 at 10:17:17AM +0800, Ming Lei wrote:
> Now multi-page bvec can cover CONFIG_THP_SWAP, so we don't need to
> increase BIO_MAX_PAGES for it.
>
> CONFIG_THP_SWAP needs to split one THP into normal pages and adds
> them all to one bio. With multipage-bvec, it just takes one bvec to
> hold them all.
>
> Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> include/linux/bio.h | 8 --------
> 1 file changed, 8 deletions(-)
>
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 5505f74aef8b..7be48c55b14a 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -34,15 +34,7 @@
> #define BIO_BUG_ON
> #endif
>
> -#ifdef CONFIG_THP_SWAP
> -#if HPAGE_PMD_NR > 256
> -#define BIO_MAX_PAGES HPAGE_PMD_NR
> -#else
> #define BIO_MAX_PAGES 256
> -#endif
> -#else
> -#define BIO_MAX_PAGES 256
> -#endif
>
> #define bio_prio(bio) (bio)->bi_ioprio
> #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:18AM +0800, Ming Lei wrote:
> Now multi-page bvec is supported, some helpers may return page by
> page, meantime some may return segment by segment, this patch
> documents the usage.
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> Documentation/block/biovecs.txt | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/Documentation/block/biovecs.txt b/Documentation/block/biovecs.txt
> index 25689584e6e0..ce6eccaf5df7 100644
> --- a/Documentation/block/biovecs.txt
> +++ b/Documentation/block/biovecs.txt
> @@ -117,3 +117,28 @@ Other implications:
> size limitations and the limitations of the underlying devices. Thus
> there's no need to define ->merge_bvec_fn() callbacks for individual block
> drivers.
> +
> +Usage of helpers:
> +=================
> +
> +* The following helpers whose names have the suffix of "_all" can only be used
> +on non-BIO_CLONED bio. They are usually used by filesystem code. Drivers
> +shouldn't use them because the bio may have been split before it reached the
> +driver.
> +
> + bio_for_each_segment_all()
> + bio_first_bvec_all()
> + bio_first_page_all()
> + bio_last_bvec_all()
> +
> +* The following helpers iterate over single-page segment. The passed 'struct
> +bio_vec' will contain a single-page IO vector during the iteration
> +
> + bio_for_each_segment()
> + bio_for_each_segment_all()
> +
> +* The following helpers iterate over multi-page bvec. The passed 'struct
> +bio_vec' will contain a multi-page IO vector during the iteration
> +
> + bio_for_each_bvec()
> + rq_for_each_bvec()
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:02AM +0800, Ming Lei wrote:
> From: Christoph Hellwig <[email protected]>
>
> bio_readpage_error currently uses bi_vcnt to decide if it is worth
> retrying an I/O. But the vector count is mostly an implementation
> artifact - it really should figure out if there is more than a
> single sector worth retrying. Use bi_size for that and shift by
> PAGE_SHIFT. This really should be blocks/sectors, but given that
> btrfs doesn't support a sector size different from the PAGE_SIZE
> using the page size keeps the changes to a minimum.
>
> Reviewed-by: David Sterba <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Christoph Hellwig <[email protected]>
> ---
> fs/btrfs/extent_io.c | 2 +-
> include/linux/bio.h | 6 ------
> 2 files changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 15fd46582bb2..40751e86a2a9 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -2368,7 +2368,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
> int read_mode = 0;
> blk_status_t status;
> int ret;
> - unsigned failed_bio_pages = bio_pages_all(failed_bio);
> + unsigned failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
>
> BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
>
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 056fb627edb3..6f6bc331a5d1 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -263,12 +263,6 @@ static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
> bv->bv_len = iter.bi_bvec_done;
> }
>
> -static inline unsigned bio_pages_all(struct bio *bio)
> -{
> - WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
> - return bio->bi_vcnt;
> -}
> -
> static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
> {
> WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 10:17:16AM +0800, Ming Lei wrote:
> This patch pulls the trigger for multi-page bvecs.
Reviewed-by: Omar Sandoval <[email protected]>
> Signed-off-by: Ming Lei <[email protected]>
> ---
> block/bio.c | 22 +++++++++++++++-------
> fs/iomap.c | 4 ++--
> fs/xfs/xfs_aops.c | 4 ++--
> include/linux/bio.h | 2 +-
> 4 files changed, 20 insertions(+), 12 deletions(-)
>
> diff --git a/block/bio.c b/block/bio.c
> index 75fde30af51f..8bf9338d4783 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -753,6 +753,8 @@ EXPORT_SYMBOL(bio_add_pc_page);
> * @page: page to add
> * @len: length of the data to add
> * @off: offset of the data in @page
> + * @same_page: if %true only merge if the new data is in the same physical
> + * page as the last segment of the bio.
> *
> * Try to add the data at @page + @off to the last bvec of @bio. This is a
> * a useful optimisation for file systems with a block size smaller than the
> @@ -761,19 +763,25 @@ EXPORT_SYMBOL(bio_add_pc_page);
> * Return %true on success or %false on failure.
> */
> bool __bio_try_merge_page(struct bio *bio, struct page *page,
> - unsigned int len, unsigned int off)
> + unsigned int len, unsigned int off, bool same_page)
> {
> if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
> return false;
>
> if (bio->bi_vcnt > 0) {
> struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
> + phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +
> + bv->bv_offset + bv->bv_len;
> + phys_addr_t page_addr = page_to_phys(page);
>
> - if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) {
> - bv->bv_len += len;
> - bio->bi_iter.bi_size += len;
> - return true;
> - }
> + if (vec_end_addr != page_addr + off)
> + return false;
> + if (same_page && ((vec_end_addr - 1) & PAGE_MASK) != page_addr)
> + return false;
> +
> + bv->bv_len += len;
> + bio->bi_iter.bi_size += len;
> + return true;
> }
> return false;
> }
> @@ -819,7 +827,7 @@ EXPORT_SYMBOL_GPL(__bio_add_page);
> int bio_add_page(struct bio *bio, struct page *page,
> unsigned int len, unsigned int offset)
> {
> - if (!__bio_try_merge_page(bio, page, len, offset)) {
> + if (!__bio_try_merge_page(bio, page, len, offset, false)) {
> if (bio_full(bio))
> return 0;
> __bio_add_page(bio, page, len, offset);
> diff --git a/fs/iomap.c b/fs/iomap.c
> index 1f648d098a3b..ec5527b0fba4 100644
> --- a/fs/iomap.c
> +++ b/fs/iomap.c
> @@ -313,7 +313,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> */
> sector = iomap_sector(iomap, pos);
> if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
> - if (__bio_try_merge_page(ctx->bio, page, plen, poff))
> + if (__bio_try_merge_page(ctx->bio, page, plen, poff, true))
> goto done;
> is_contig = true;
> }
> @@ -344,7 +344,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> ctx->bio->bi_end_io = iomap_read_end_io;
> }
>
> - __bio_add_page(ctx->bio, page, plen, poff);
> + bio_add_page(ctx->bio, page, plen, poff);
> done:
> /*
> * Move the caller beyond our range so that it keeps making progress.
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index 1f1829e506e8..b9fd44168f61 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -616,12 +616,12 @@ xfs_add_to_ioend(
> bdev, sector);
> }
>
> - if (!__bio_try_merge_page(wpc->ioend->io_bio, page, len, poff)) {
> + if (!__bio_try_merge_page(wpc->ioend->io_bio, page, len, poff, true)) {
> if (iop)
> atomic_inc(&iop->write_count);
> if (bio_full(wpc->ioend->io_bio))
> xfs_chain_bio(wpc->ioend, wbc, bdev, sector);
> - __bio_add_page(wpc->ioend->io_bio, page, len, poff);
> + bio_add_page(wpc->ioend->io_bio, page, len, poff);
> }
>
> wpc->ioend->io_size += len;
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index c35997dd02c2..5505f74aef8b 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -441,7 +441,7 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
> extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
> unsigned int, unsigned int);
> bool __bio_try_merge_page(struct bio *bio, struct page *page,
> - unsigned int len, unsigned int off);
> + unsigned int len, unsigned int off, bool same_page);
> void __bio_add_page(struct bio *bio, struct page *page,
> unsigned int len, unsigned int off);
> int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
> --
> 2.9.5
>
On Mon, Nov 26, 2018 at 01:58:42PM +0100, Christoph Hellwig wrote:
> > + phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +
> > + bv->bv_offset + bv->bv_len;
>
> The name is a little confusing, as the real end addr would be -1. Maybe
> throw the -1 in here, and adjust for it in the contigous check below?
Yeah, it makes sense.
thanks,
Ming
On 11/25/18 7:17 PM, Ming Lei wrote:
> Hi,
>
> This patchset brings multi-page bvec into block layer:
>
> 1) what is multi-page bvec?
>
> Multipage bvecs means that one 'struct bio_bvec' can hold multiple pages
> which are physically contiguous instead of one single page used in linux
> kernel for long time.
>
> 2) why is multi-page bvec introduced?
>
> Kent proposed the idea[1] first.
>
> As system's RAM becomes much bigger than before, and huge page, transparent
> huge page and memory compaction are widely used, it is a bit easy now
> to see physically contiguous pages from fs in I/O. On the other hand, from
> block layer's view, it isn't necessary to store intermediate pages into bvec,
> and it is enough to just store the physicallly contiguous 'segment' in each
> io vector.
>
> Also huge pages are being brought to filesystem and swap [2][6], we can
> do IO on a hugepage each time[3], which requires that one bio can transfer
> at least one huge page one time. Turns out it isn't flexiable to change
> BIO_MAX_PAGES simply[3][5]. Multipage bvec can fit in this case very well.
> As we saw, if CONFIG_THP_SWAP is enabled, BIO_MAX_PAGES can be configured
> as much bigger, such as 512, which requires at least two 4K pages for holding
> the bvec table.
I'm pretty happy with this patchset at this point, looks like it just
needs a respin to address the last comments. My only concern is whether
it's a good idea to target this for 4.21, or if we should wait until
4.22. 4.21 has a fairly substantial amount of changes in terms of block
already, it's not the best timing for something of this magnitude too.
I'm going back and forth on those one a bit. Any concerns with
pushing this to 4.22?
--
Jens Axboe
On Wed, Nov 28, 2018 at 06:44:00AM -0700, Jens Axboe wrote:
> On 11/25/18 7:17 PM, Ming Lei wrote:
> > Hi,
> >
> > This patchset brings multi-page bvec into block layer:
> >
> > 1) what is multi-page bvec?
> >
> > Multipage bvecs means that one 'struct bio_bvec' can hold multiple pages
> > which are physically contiguous instead of one single page used in linux
> > kernel for long time.
> >
> > 2) why is multi-page bvec introduced?
> >
> > Kent proposed the idea[1] first.
> >
> > As system's RAM becomes much bigger than before, and huge page, transparent
> > huge page and memory compaction are widely used, it is a bit easy now
> > to see physically contiguous pages from fs in I/O. On the other hand, from
> > block layer's view, it isn't necessary to store intermediate pages into bvec,
> > and it is enough to just store the physicallly contiguous 'segment' in each
> > io vector.
> >
> > Also huge pages are being brought to filesystem and swap [2][6], we can
> > do IO on a hugepage each time[3], which requires that one bio can transfer
> > at least one huge page one time. Turns out it isn't flexiable to change
> > BIO_MAX_PAGES simply[3][5]. Multipage bvec can fit in this case very well.
> > As we saw, if CONFIG_THP_SWAP is enabled, BIO_MAX_PAGES can be configured
> > as much bigger, such as 512, which requires at least two 4K pages for holding
> > the bvec table.
>
> I'm pretty happy with this patchset at this point, looks like it just
> needs a respin to address the last comments. My only concern is whether
I will address the last comment from Omar on patch of '[PATCH V12 01/20] btrfs:
remove various bio_offset arguments', we may use the approach in V11 simply.
> it's a good idea to target this for 4.21, or if we should wait until
> 4.22. 4.21 has a fairly substantial amount of changes in terms of block
> already, it's not the best timing for something of this magnitude too.
Yeah, I understand.
>
> I'm going back and forth on those one a bit. Any concerns with
> pushing this to 4.22?
My only one concern is about the warning of "blk_cloned_rq_check_limits:
over max segments limit" on dm multipath, and seems Ewan and Mike is waiting
for this fix.
thanks,
Ming
On 11/28/18 6:30 PM, Ming Lei wrote:
>> I'm going back and forth on those one a bit. Any concerns with
>> pushing this to 4.22?
>
> My only one concern is about the warning of
> "blk_cloned_rq_check_limits: over max segments limit" on dm multipath,
> and seems Ewan and Mike is waiting for this fix.
Not familiar with this issue, can you post a link to it? I'd be fine
working around anything until 4.22, it's not going to be a new issue.
--
Jens Axboe
On Wed, Nov 28, 2018 at 07:20:51PM -0700, Jens Axboe wrote:
> On 11/28/18 6:30 PM, Ming Lei wrote:
> >> I'm going back and forth on those one a bit. Any concerns with
> >> pushing this to 4.22?
> >
> > My only one concern is about the warning of
> > "blk_cloned_rq_check_limits: over max segments limit" on dm multipath,
> > and seems Ewan and Mike is waiting for this fix.
>
> Not familiar with this issue, can you post a link to it? I'd be fine
> working around anything until 4.22, it's not going to be a new issue.
https://marc.info/?t=153303425700002&r=1&w=2
thanks,
Ming