[PATCH 2/2] block: remove the per-bio/request write hint

Christoph Hellwig
2022-03-04T17:56:13Z

With the NVMe support for this gone, there are no consumers of these hints
left, so remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/bio.c | 2 --
block/blk-crypto-fallback.c | 1 -
block/blk-merge.c | 14 --------------
block/blk-mq-debugfs.c | 24 ------------------------
block/blk-mq.c | 1 -
block/bounce.c | 1 -
block/fops.c | 3 ---
drivers/md/raid1.c | 2 --
drivers/md/raid5-ppl.c | 28 +++-------------------------
drivers/md/raid5.c | 6 ------
fs/btrfs/extent_io.c | 1 -
fs/buffer.c | 13 +++++--------
fs/direct-io.c | 3 ---
fs/ext4/page-io.c | 5 +----
fs/f2fs/data.c | 2 --
fs/gfs2/lops.c | 1 -
fs/iomap/buffered-io.c | 2 --
fs/iomap/direct-io.c | 1 -
fs/mpage.c | 1 -
fs/zonefs/super.c | 1 -
include/linux/blk_types.h | 1 -
include/linux/blkdev.h | 3 ---
22 files changed, 9 insertions(+), 107 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index b15f5466ce084..88e63bb187482 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -257,7 +257,6 @@ void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
bio->bi_opf = opf;
bio->bi_flags = 0;
bio->bi_ioprio = 0;
- bio->bi_write_hint = 0;
bio->bi_status = 0;
bio->bi_iter.bi_sector = 0;
bio->bi_iter.bi_size = 0;
@@ -737,7 +736,6 @@ static int __bio_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp)
bio_flagged(bio_src, BIO_REMAPPED))
bio_set_flag(bio, BIO_REMAPPED);
bio->bi_ioprio = bio_src->bi_ioprio;
- bio->bi_write_hint = bio_src->bi_write_hint;
bio->bi_iter = bio_src->bi_iter;

bio_clone_blkg_association(bio, bio_src);
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index 18c8eafe20b94..7c854584b52b5 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -170,7 +170,6 @@ static struct bio *blk_crypto_fallback_clone_bio(struct bio *bio_src)
bio_set_flag(bio, BIO_REMAPPED);
bio->bi_opf = bio_src->bi_opf;
bio->bi_ioprio = bio_src->bi_ioprio;
- bio->bi_write_hint = bio_src->bi_write_hint;
bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;

diff --git a/block/blk-merge.c b/block/blk-merge.c
index f5255991b773c..0e871d4e7cb8d 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -782,13 +782,6 @@ static struct request *attempt_merge(struct request_queue *q,
!blk_write_same_mergeable(req->bio, next->bio))
return NULL;

- /*
- * Don't allow merge of different write hints, or for a hint with
- * non-hint IO.
- */
- if (req->write_hint != next->write_hint)
- return NULL;
-
if (req->ioprio != next->ioprio)
return NULL;

@@ -915,13 +908,6 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
!blk_write_same_mergeable(rq->bio, bio))
return false;

- /*
- * Don't allow merge of different write hints, or for a hint with
- * non-hint IO.
- */
- if (rq->write_hint != bio->bi_write_hint)
- return false;
-
if (rq->ioprio != bio_prio(bio))
return false;

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 3a790eb4995c6..c2904c75c160f 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -183,35 +183,11 @@ static ssize_t queue_state_write(void *data, const char __user *buf,
return count;
}

-static int queue_write_hint_show(void *data, struct seq_file *m)
-{
- struct request_queue *q = data;
- int i;
-
- for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
- seq_printf(m, "hint%d: %llu\n", i, q->write_hints[i]);
-
- return 0;
-}
-
-static ssize_t queue_write_hint_store(void *data, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- struct request_queue *q = data;
- int i;
-
- for (i = 0; i < BLK_MAX_WRITE_HINTS; i++)
- q->write_hints[i] = 0;
-
- return count;
-}
-
static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
{ "poll_stat", 0400, queue_poll_stat_show },
{ "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
{ "pm_only", 0600, queue_pm_only_show, NULL },
{ "state", 0600, queue_state_show, queue_state_write },
- { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store },
{ "zone_wlock", 0400, queue_zone_wlock_show, NULL },
{ },
};
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a05ce77250316..f28023b0a87eb 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2402,7 +2402,6 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
rq->cmd_flags |= REQ_FAILFAST_MASK;

rq->__sector = bio->bi_iter.bi_sector;
- rq->write_hint = bio->bi_write_hint;
blk_rq_bio_prep(rq, bio, nr_segs);

/* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */
diff --git a/block/bounce.c b/block/bounce.c
index 3d50d19cde72a..9db1256d57d55 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -169,7 +169,6 @@ static struct bio *bounce_clone_bio(struct bio *bio_src)
if (bio_flagged(bio_src, BIO_REMAPPED))
bio_set_flag(bio, BIO_REMAPPED);
bio->bi_ioprio = bio_src->bi_ioprio;
- bio->bi_write_hint = bio_src->bi_write_hint;
bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;

diff --git a/block/fops.c b/block/fops.c
index 3696665e586a8..037f12294c863 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -83,7 +83,6 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb));
}
bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
- bio.bi_write_hint = iocb->ki_hint;
bio.bi_private = current;
bio.bi_end_io = blkdev_bio_end_io_simple;
bio.bi_ioprio = iocb->ki_ioprio;
@@ -225,7 +224,6 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,

for (;;) {
bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
- bio->bi_write_hint = iocb->ki_hint;
bio->bi_private = dio;
bio->bi_end_io = blkdev_bio_end_io;
bio->bi_ioprio = iocb->ki_ioprio;
@@ -325,7 +323,6 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
dio->flags = 0;
dio->iocb = iocb;
bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
- bio->bi_write_hint = iocb->ki_hint;
bio->bi_end_io = blkdev_bio_end_io_async;
bio->bi_ioprio = iocb->ki_ioprio;

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index c3288d46948de..c3ce6afd60a71 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1137,8 +1137,6 @@ static void alloc_behind_master_bio(struct r1bio *r1_bio,
goto skip_copy;
}

- behind_bio->bi_write_hint = bio->bi_write_hint;
-
while (i < vcnt && size) {
struct page *page;
int len = min_t(int, PAGE_SIZE, size);
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 3446797fa0aca..282ce16ee4e1f 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -469,7 +469,6 @@ static void ppl_submit_iounit(struct ppl_io_unit *io)
bio_set_dev(bio, log->rdev->bdev);
bio->bi_iter.bi_sector = log->next_io_sector;
bio_add_page(bio, io->header_page, PAGE_SIZE, 0);
- bio->bi_write_hint = ppl_conf->write_hint;

pr_debug("%s: log->current_io_sector: %llu\n", __func__,
(unsigned long long)log->next_io_sector);
@@ -499,7 +498,6 @@ static void ppl_submit_iounit(struct ppl_io_unit *io)
bio = bio_alloc_bioset(prev->bi_bdev, BIO_MAX_VECS,
prev->bi_opf, GFP_NOIO,
&ppl_conf->bs);
- bio->bi_write_hint = prev->bi_write_hint;
bio->bi_iter.bi_sector = bio_end_sector(prev);
bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0);

@@ -1402,7 +1400,6 @@ int ppl_init_log(struct r5conf *conf)
atomic64_set(&ppl_conf->seq, 0);
INIT_LIST_HEAD(&ppl_conf->no_mem_stripes);
spin_lock_init(&ppl_conf->no_mem_stripes_lock);
- ppl_conf->write_hint = RWH_WRITE_LIFE_NOT_SET;

if (!mddev->external) {
ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid));
@@ -1501,25 +1498,13 @@ int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add)
static ssize_t
ppl_write_hint_show(struct mddev *mddev, char *buf)
{
- size_t ret = 0;
- struct r5conf *conf;
- struct ppl_conf *ppl_conf = NULL;
-
- spin_lock(&mddev->lock);
- conf = mddev->private;
- if (conf && raid5_has_ppl(conf))
- ppl_conf = conf->log_private;
- ret = sprintf(buf, "%d\n", ppl_conf ? ppl_conf->write_hint : 0);
- spin_unlock(&mddev->lock);
-
- return ret;
+ return sprintf(buf, "%d\n", 0);
}

static ssize_t
ppl_write_hint_store(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
- struct ppl_conf *ppl_conf;
int err = 0;
unsigned short new;

@@ -1533,17 +1518,10 @@ ppl_write_hint_store(struct mddev *mddev, const char *page, size_t len)
return err;

conf = mddev->private;
- if (!conf) {
+ if (!conf)
err = -ENODEV;
- } else if (raid5_has_ppl(conf)) {
- ppl_conf = conf->log_private;
- if (!ppl_conf)
- err = -EINVAL;
- else
- ppl_conf->write_hint = new;
- } else {
+ else if (!raid5_has_ppl(conf) || !conf->log_private)
err = -EINVAL;
- }

mddev_unlock(mddev);

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 8891aaba65964..78503db55ca4e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1210,9 +1210,6 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
bi->bi_io_vec[0].bv_len = RAID5_STRIPE_SIZE(conf);
bi->bi_io_vec[0].bv_offset = sh->dev[i].offset;
bi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);
- bi->bi_write_hint = sh->dev[i].write_hint;
- if (!rrdev)
- sh->dev[i].write_hint = RWH_WRITE_LIFE_NOT_SET;
/*
* If this is discard request, set bi_vcnt 0. We don't
* want to confuse SCSI because SCSI will replace payload
@@ -1264,8 +1261,6 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
rbi->bi_io_vec[0].bv_len = RAID5_STRIPE_SIZE(conf);
rbi->bi_io_vec[0].bv_offset = sh->dev[i].offset;
rbi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);
- rbi->bi_write_hint = sh->dev[i].write_hint;
- sh->dev[i].write_hint = RWH_WRITE_LIFE_NOT_SET;
/*
* If this is discard request, set bi_vcnt 0. We don't
* want to confuse SCSI because SCSI will replace payload
@@ -3416,7 +3411,6 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
(unsigned long long)sh->sector);

spin_lock_irq(&sh->stripe_lock);
- sh->dev[dd_idx].write_hint = bi->bi_write_hint;
/* Don't allow new IO added to stripes in batch list */
if (sh->batch_head)
goto overlap;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index dee86911a4bef..1412f09537c73 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3321,7 +3321,6 @@ static int alloc_new_bio(struct btrfs_inode *inode,
bio_ctrl->bio_flags = bio_flags;
bio->bi_end_io = end_io_func;
bio->bi_private = &inode->io_tree;
- bio->bi_write_hint = inode->vfs_inode.i_write_hint;
bio->bi_opf = opf;
ret = calc_bio_boundaries(bio_ctrl, inode, file_offset);
if (ret < 0)
diff --git a/fs/buffer.c b/fs/buffer.c
index a17c386a142c7..29c6c60660f61 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -53,7 +53,7 @@

static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
- enum rw_hint hint, struct writeback_control *wbc);
+ struct writeback_control *wbc);

#define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)

@@ -1806,8 +1806,7 @@ int __block_write_full_page(struct inode *inode, struct page *page,
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
- submit_bh_wbc(REQ_OP_WRITE, write_flags, bh,
- inode->i_write_hint, wbc);
+ submit_bh_wbc(REQ_OP_WRITE, write_flags, bh, wbc);
nr_underway++;
}
bh = next;
@@ -1861,8 +1860,7 @@ int __block_write_full_page(struct inode *inode, struct page *page,
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
clear_buffer_dirty(bh);
- submit_bh_wbc(REQ_OP_WRITE, write_flags, bh,
- inode->i_write_hint, wbc);
+ submit_bh_wbc(REQ_OP_WRITE, write_flags, bh, wbc);
nr_underway++;
}
bh = next;
@@ -3008,7 +3006,7 @@ static void end_bio_bh_io_sync(struct bio *bio)
}

static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
- enum rw_hint write_hint, struct writeback_control *wbc)
+ struct writeback_control *wbc)
{
struct bio *bio;

@@ -3034,7 +3032,6 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO);

bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
- bio->bi_write_hint = write_hint;

bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
BUG_ON(bio->bi_iter.bi_size != bh->b_size);
@@ -3056,7 +3053,7 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,

int submit_bh(int op, int op_flags, struct buffer_head *bh)
{
- return submit_bh_wbc(op, op_flags, bh, 0, NULL);
+ return submit_bh_wbc(op, op_flags, bh, NULL);
}
EXPORT_SYMBOL(submit_bh);

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 38bca4980a1ca..aef06e607b405 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -402,9 +402,6 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
bio->bi_end_io = dio_bio_end_aio;
else
bio->bi_end_io = dio_bio_end_io;
-
- bio->bi_write_hint = dio->iocb->ki_hint;
-
sdio->bio = bio;
sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;
}
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 1253982268730..0c31b61c7628a 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -374,7 +374,6 @@ void ext4_io_submit(struct ext4_io_submit *io)
if (bio) {
int io_op_flags = io->io_wbc->sync_mode == WB_SYNC_ALL ?
REQ_SYNC : 0;
- io->io_bio->bi_write_hint = io->io_end->inode->i_write_hint;
bio_set_op_attrs(io->io_bio, REQ_OP_WRITE, io_op_flags);
submit_bio(io->io_bio);
}
@@ -420,10 +419,8 @@ static void io_submit_add_bh(struct ext4_io_submit *io,
submit_and_retry:
ext4_io_submit(io);
}
- if (io->io_bio == NULL) {
+ if (io->io_bio == NULL)
io_submit_init_bio(io, bh);
- io->io_bio->bi_write_hint = inode->i_write_hint;
- }
ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh));
if (ret != bh->b_size)
goto submit_and_retry;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index e71dde8de0db0..20d65aa6243a1 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -403,8 +403,6 @@ static struct bio *__bio_alloc(struct f2fs_io_info *fio, int npages)
} else {
bio->bi_end_io = f2fs_write_end_io;
bio->bi_private = sbi;
- bio->bi_write_hint = f2fs_io_type_to_rw_hint(sbi,
- fio->type, fio->temp);
}
iostat_alloc_and_bind_ctx(sbi, bio, NULL);

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 4ae1eefae616d..6ba51cbb94cf2 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -491,7 +491,6 @@ static struct bio *gfs2_chain_bio(struct bio *prev, unsigned int nr_iovecs)
new = bio_alloc(prev->bi_bdev, nr_iovecs, prev->bi_opf, GFP_NOIO);
bio_clone_blkg_association(new, prev);
new->bi_iter.bi_sector = bio_end_sector(prev);
- new->bi_write_hint = prev->bi_write_hint;
bio_chain(new, prev);
submit_bio(prev);
return new;
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 491534e908615..fedca4de5f6b9 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1199,7 +1199,6 @@ iomap_alloc_ioend(struct inode *inode, struct iomap_writepage_ctx *wpc,
REQ_OP_WRITE | wbc_to_write_flags(wbc),
GFP_NOFS, &iomap_ioend_bioset);
bio->bi_iter.bi_sector = sector;
- bio->bi_write_hint = inode->i_write_hint;
wbc_init_bio(wbc, bio);

ioend = container_of(bio, struct iomap_ioend, io_inline_bio);
@@ -1228,7 +1227,6 @@ iomap_chain_bio(struct bio *prev)
new = bio_alloc(prev->bi_bdev, BIO_MAX_VECS, prev->bi_opf, GFP_NOFS);
bio_clone_blkg_association(new, prev);
new->bi_iter.bi_sector = bio_end_sector(prev);
- new->bi_write_hint = prev->bi_write_hint;

bio_chain(prev, new);
bio_get(prev); /* for iomap_finish_ioend */
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index e2ba13645ef28..a434b1829545d 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -309,7 +309,6 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,

bio = bio_alloc(iomap->bdev, nr_pages, bio_opf, GFP_KERNEL);
bio->bi_iter.bi_sector = iomap_sector(iomap, pos);
- bio->bi_write_hint = dio->iocb->ki_hint;
bio->bi_ioprio = dio->iocb->ki_ioprio;
bio->bi_private = dio;
bio->bi_end_io = iomap_dio_bio_end_io;
diff --git a/fs/mpage.c b/fs/mpage.c
index dbfc02e23d97f..89eeef275a235 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -590,7 +590,6 @@ static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
bio->bi_iter.bi_sector = blocks[0] << (blkbits - 9);

wbc_init_bio(wbc, bio);
- bio->bi_write_hint = inode->i_write_hint;
}

/*
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index d331b52592a0a..b71a23dd12556 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -695,7 +695,6 @@ static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from)
bio = bio_alloc(bdev, nr_pages,
REQ_OP_ZONE_APPEND | REQ_SYNC | REQ_IDLE, GFP_NOFS);
bio->bi_iter.bi_sector = zi->i_zsector;
- bio->bi_write_hint = iocb->ki_hint;
bio->bi_ioprio = iocb->ki_ioprio;
if (iocb->ki_flags & IOCB_DSYNC)
bio->bi_opf |= REQ_FUA;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 5561e58d158ac..ba8cfa57255f3 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -250,7 +250,6 @@ struct bio {
*/
unsigned short bi_flags; /* BIO_* below */
unsigned short bi_ioprio;
- unsigned short bi_write_hint;
blk_status_t bi_status;
atomic_t __bi_remaining;

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e19947d84f128..bb6d5ee02c070 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -518,9 +518,6 @@ struct request_queue {

bool mq_sysfs_init_done;

-#define BLK_MAX_WRITE_HINTS 5
- u64 write_hints[BLK_MAX_WRITE_HINTS];
-
/*
* Independent sector access ranges. This is always NULL for
* devices that do not have multiple independent access ranges.
--
2.30.2