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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 13:13:57 +08:00
linux-next/block/bounce.c
Linus Torvalds 561593a048 for-5.18/write-streams-2022-03-18
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Merge tag 'for-5.18/write-streams-2022-03-18' of git://git.kernel.dk/linux-block

Pull NVMe write streams removal from Jens Axboe:
 "This removes the write streams support in NVMe. No vendor ever really
  shipped working support for this, and they are not interested in
  supporting it.

  With the NVMe support gone, we have nothing in the tree that supports
  this. Remove passing around of the hints.

  The only discussion point in this patchset imho is the fact that the
  file specific write hint setting/getting fcntl helpers will now return
  -1/EINVAL like they did before we supported write hints. No known
  applications use these functions, I only know of one prototype that I
  help do for RocksDB, and that's not used. That said, with a change
  like this, it's always a bit controversial. Alternatively, we could
  just make them return 0 and pretend it worked. It's placement based
  hints after all"

* tag 'for-5.18/write-streams-2022-03-18' of git://git.kernel.dk/linux-block:
  fs: remove fs.f_write_hint
  fs: remove kiocb.ki_hint
  block: remove the per-bio/request write hint
  nvme: remove support or stream based temperature hint
2022-03-26 11:51:46 -07:00

263 lines
6.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* bounce buffer handling for block devices
*
* - Split from highmem.c
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/swap.h>
#include <linux/gfp.h>
#include <linux/bio.h>
#include <linux/pagemap.h>
#include <linux/mempool.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/init.h>
#include <linux/hash.h>
#include <linux/highmem.h>
#include <linux/printk.h>
#include <asm/tlbflush.h>
#include <trace/events/block.h>
#include "blk.h"
#include "blk-cgroup.h"
#define POOL_SIZE 64
#define ISA_POOL_SIZE 16
static struct bio_set bounce_bio_set, bounce_bio_split;
static mempool_t page_pool;
static void init_bounce_bioset(void)
{
static bool bounce_bs_setup;
int ret;
if (bounce_bs_setup)
return;
ret = bioset_init(&bounce_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
BUG_ON(ret);
if (bioset_integrity_create(&bounce_bio_set, BIO_POOL_SIZE))
BUG_ON(1);
ret = bioset_init(&bounce_bio_split, BIO_POOL_SIZE, 0, 0);
BUG_ON(ret);
bounce_bs_setup = true;
}
static __init int init_emergency_pool(void)
{
int ret;
#ifndef CONFIG_MEMORY_HOTPLUG
if (max_pfn <= max_low_pfn)
return 0;
#endif
ret = mempool_init_page_pool(&page_pool, POOL_SIZE, 0);
BUG_ON(ret);
pr_info("pool size: %d pages\n", POOL_SIZE);
init_bounce_bioset();
return 0;
}
__initcall(init_emergency_pool);
/*
* Simple bounce buffer support for highmem pages. Depending on the
* queue gfp mask set, *to may or may not be a highmem page. kmap it
* always, it will do the Right Thing
*/
static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
{
struct bio_vec tovec, fromvec;
struct bvec_iter iter;
/*
* The bio of @from is created by bounce, so we can iterate
* its bvec from start to end, but the @from->bi_iter can't be
* trusted because it might be changed by splitting.
*/
struct bvec_iter from_iter = BVEC_ITER_ALL_INIT;
bio_for_each_segment(tovec, to, iter) {
fromvec = bio_iter_iovec(from, from_iter);
if (tovec.bv_page != fromvec.bv_page) {
/*
* fromvec->bv_offset and fromvec->bv_len might have
* been modified by the block layer, so use the original
* copy, bounce_copy_vec already uses tovec->bv_len
*/
memcpy_to_bvec(&tovec, page_address(fromvec.bv_page) +
tovec.bv_offset);
}
bio_advance_iter(from, &from_iter, tovec.bv_len);
}
}
static void bounce_end_io(struct bio *bio)
{
struct bio *bio_orig = bio->bi_private;
struct bio_vec *bvec, orig_vec;
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, 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);
mempool_free(bvec->bv_page, &page_pool);
}
bio_advance_iter(bio_orig, &orig_iter, orig_vec.bv_len);
}
bio_orig->bi_status = bio->bi_status;
bio_endio(bio_orig);
bio_put(bio);
}
static void bounce_end_io_write(struct bio *bio)
{
bounce_end_io(bio);
}
static void bounce_end_io_read(struct bio *bio)
{
struct bio *bio_orig = bio->bi_private;
if (!bio->bi_status)
copy_to_high_bio_irq(bio_orig, bio);
bounce_end_io(bio);
}
static struct bio *bounce_clone_bio(struct bio *bio_src)
{
struct bvec_iter iter;
struct bio_vec bv;
struct bio *bio;
/*
* Pre immutable biovecs, __bio_clone() used to just do a memcpy from
* bio_src->bi_io_vec to bio->bi_io_vec.
*
* We can't do that anymore, because:
*
* - The point of cloning the biovec is to produce a bio with a biovec
* the caller can modify: bi_idx and bi_bvec_done should be 0.
*
* - The original bio could've had more than BIO_MAX_VECS biovecs; if
* we tried to clone the whole thing bio_alloc_bioset() would fail.
* But the clone should succeed as long as the number of biovecs we
* actually need to allocate is fewer than BIO_MAX_VECS.
*
* - Lastly, bi_vcnt should not be looked at or relied upon by code
* that does not own the bio - reason being drivers don't use it for
* iterating over the biovec anymore, so expecting it to be kept up
* to date (i.e. for clones that share the parent biovec) is just
* asking for trouble and would force extra work.
*/
bio = bio_alloc_bioset(bio_src->bi_bdev, bio_segments(bio_src),
bio_src->bi_opf, GFP_NOIO, &bounce_bio_set);
if (bio_flagged(bio_src, BIO_REMAPPED))
bio_set_flag(bio, BIO_REMAPPED);
bio->bi_ioprio = bio_src->bi_ioprio;
bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
switch (bio_op(bio)) {
case REQ_OP_DISCARD:
case REQ_OP_SECURE_ERASE:
case REQ_OP_WRITE_ZEROES:
break;
default:
bio_for_each_segment(bv, bio_src, iter)
bio->bi_io_vec[bio->bi_vcnt++] = bv;
break;
}
if (bio_crypt_clone(bio, bio_src, GFP_NOIO) < 0)
goto err_put;
if (bio_integrity(bio_src) &&
bio_integrity_clone(bio, bio_src, GFP_NOIO) < 0)
goto err_put;
bio_clone_blkg_association(bio, bio_src);
blkcg_bio_issue_init(bio);
return bio;
err_put:
bio_put(bio);
return NULL;
}
void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
{
struct bio *bio;
int rw = bio_data_dir(*bio_orig);
struct bio_vec *to, from;
struct bvec_iter iter;
unsigned i = 0;
bool bounce = false;
int sectors = 0;
bio_for_each_segment(from, *bio_orig, iter) {
if (i++ < BIO_MAX_VECS)
sectors += from.bv_len >> 9;
if (PageHighMem(from.bv_page))
bounce = true;
}
if (!bounce)
return;
if (sectors < bio_sectors(*bio_orig)) {
bio = bio_split(*bio_orig, sectors, GFP_NOIO, &bounce_bio_split);
bio_chain(bio, *bio_orig);
submit_bio_noacct(*bio_orig);
*bio_orig = bio;
}
bio = bounce_clone_bio(*bio_orig);
/*
* Bvec table can't be updated by bio_for_each_segment_all(),
* so retrieve bvec from the table directly. This way is safe
* because the 'bio' is single-page bvec.
*/
for (i = 0, to = bio->bi_io_vec; i < bio->bi_vcnt; to++, i++) {
struct page *bounce_page;
if (!PageHighMem(to->bv_page))
continue;
bounce_page = mempool_alloc(&page_pool, GFP_NOIO);
inc_zone_page_state(bounce_page, NR_BOUNCE);
if (rw == WRITE) {
flush_dcache_page(to->bv_page);
memcpy_from_bvec(page_address(bounce_page), to);
}
to->bv_page = bounce_page;
}
trace_block_bio_bounce(*bio_orig);
bio->bi_flags |= (1 << BIO_BOUNCED);
if (rw == READ)
bio->bi_end_io = bounce_end_io_read;
else
bio->bi_end_io = bounce_end_io_write;
bio->bi_private = *bio_orig;
*bio_orig = bio;
}