Contributors: 29
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| David Howells |
207 |
21.08% |
1 |
1.19% |
| Christoph Hellwig |
198 |
20.16% |
18 |
21.43% |
| Neil Brown |
112 |
11.41% |
2 |
2.38% |
| Ming Lei |
103 |
10.49% |
8 |
9.52% |
| Linus Torvalds |
90 |
9.16% |
9 |
10.71% |
| Kent Overstreet |
74 |
7.54% |
9 |
10.71% |
| Jens Axboe |
48 |
4.89% |
6 |
7.14% |
| Linus Torvalds (pre-git) |
40 |
4.07% |
8 |
9.52% |
| Keith Busch |
20 |
2.04% |
1 |
1.19% |
| Eric Biggers |
14 |
1.43% |
1 |
1.19% |
| Mitchel Humpherys |
12 |
1.22% |
1 |
1.19% |
| Chaitanya Kulkarni |
9 |
0.92% |
1 |
1.19% |
| Hannes Reinecke |
8 |
0.81% |
1 |
1.19% |
| Christoph Lameter |
7 |
0.71% |
1 |
1.19% |
| Wang YanQing |
6 |
0.61% |
1 |
1.19% |
| David Vrabel |
6 |
0.61% |
1 |
1.19% |
| Andrew Morton |
6 |
0.61% |
2 |
2.38% |
| Arnaldo Carvalho de Melo |
5 |
0.51% |
2 |
2.38% |
| Avi Kivity |
3 |
0.31% |
1 |
1.19% |
| Michael Christie |
3 |
0.31% |
1 |
1.19% |
| Satya Tangirala |
2 |
0.20% |
1 |
1.19% |
| Li Zefan |
2 |
0.20% |
1 |
1.19% |
| Adrian Hunter |
1 |
0.10% |
1 |
1.19% |
| Shaohua Li |
1 |
0.10% |
1 |
1.19% |
| Bart Van Assche |
1 |
0.10% |
1 |
1.19% |
| Kamezawa Hiroyuki |
1 |
0.10% |
1 |
1.19% |
| Dennis Zhou |
1 |
0.10% |
1 |
1.19% |
| Paul Gortmaker |
1 |
0.10% |
1 |
1.19% |
| Greg Kroah-Hartman |
1 |
0.10% |
1 |
1.19% |
| Total |
982 |
|
84 |
|
// 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);
return bio;
err_put:
bio_put(bio);
return NULL;
}
struct bio *__blk_queue_bounce(struct bio *bio_orig, struct request_queue *q)
{
struct bio *bio;
int rw = bio_data_dir(bio_orig);
struct bio_vec *to, from;
struct bvec_iter iter;
unsigned i = 0, bytes = 0;
bool bounce = false;
int sectors;
bio_for_each_segment(from, bio_orig, iter) {
if (i++ < BIO_MAX_VECS)
bytes += from.bv_len;
if (PageHighMem(from.bv_page))
bounce = true;
}
if (!bounce)
return bio_orig;
/*
* Individual bvecs might not be logical block aligned. Round down
* the split size so that each bio is properly block size aligned,
* even if we do not use the full hardware limits.
*/
sectors = ALIGN_DOWN(bytes, queue_logical_block_size(q)) >>
SECTOR_SHIFT;
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;
return bio;
}