Release 4.18 block/bounce.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/bootmem.h>
#include <linux/printk.h>
#include <asm/tlbflush.h>
#include <trace/events/block.h>
#include "blk.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, isa_page_pool;
#if defined(CONFIG_HIGHMEM)
static __init int init_emergency_pool(void)
{
int ret;
#if defined(CONFIG_HIGHMEM) && !defined(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);
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);
return 0;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Neil Brown | 40 | 34.78% | 1 | 14.29% |
David Howells | 34 | 29.57% | 1 | 14.29% |
Kent Overstreet | 21 | 18.26% | 1 | 14.29% |
Chris Metcalf | 11 | 9.57% | 1 | 14.29% |
David Vrabel | 6 | 5.22% | 1 | 14.29% |
Mitchel Humpherys | 2 | 1.74% | 1 | 14.29% |
Jens Axboe | 1 | 0.87% | 1 | 14.29% |
Total | 115 | 100.00% | 7 | 100.00% |
__initcall(init_emergency_pool);
#endif
#ifdef CONFIG_HIGHMEM
/*
* highmem version, map in to vec
*/
static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom)
{
unsigned char *vto;
vto = kmap_atomic(to->bv_page);
memcpy(vto + to->bv_offset, vfrom, to->bv_len);
kunmap_atomic(vto);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 50 | 100.00% | 1 | 100.00% |
Total | 50 | 100.00% | 1 | 100.00% |
#else /* CONFIG_HIGHMEM */
#define bounce_copy_vec(to, vfrom) \
memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len)
#endif /* CONFIG_HIGHMEM */
/*
* allocate pages in the DMA region for the ISA pool
*/
static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data)
{
return mempool_alloc_pages(gfp_mask | GFP_DMA, data);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 24 | 100.00% | 1 | 100.00% |
Total | 24 | 100.00% | 1 | 100.00% |
/*
* gets called "every" time someone init's a queue with BLK_BOUNCE_ISA
* as the max address, so check if the pool has already been created.
*/
int init_emergency_isa_pool(void)
{
int ret;
if (mempool_initialized(&isa_page_pool))
return 0;
ret = mempool_init(&isa_page_pool, ISA_POOL_SIZE, mempool_alloc_pages_isa,
mempool_free_pages, (void *) 0);
BUG_ON(ret);
pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE);
return 0;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 41 | 73.21% | 1 | 33.33% |
Kent Overstreet | 13 | 23.21% | 1 | 33.33% |
Mitchel Humpherys | 2 | 3.57% | 1 | 33.33% |
Total | 56 | 100.00% | 3 | 100.00% |
/*
* 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)
{
unsigned char *vfrom;
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
*/
vfrom = page_address(fromvec.bv_page) +
tovec.bv_offset;
bounce_copy_vec(&tovec, vfrom);
flush_dcache_page(tovec.bv_page);
}
bio_advance_iter(from, &from_iter, tovec.bv_len);
}
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 62 | 56.36% | 1 | 20.00% |
Ming Lei | 29 | 26.36% | 1 | 20.00% |
Kent Overstreet | 14 | 12.73% | 2 | 40.00% |
Gary King | 5 | 4.55% | 1 | 20.00% |
Total | 110 | 100.00% | 5 | 100.00% |
static void bounce_end_io(struct bio *bio, mempool_t *pool)
{
struct bio *bio_orig = bio->bi_private;
struct bio_vec *bvec, orig_vec;
int i;
struct bvec_iter orig_iter = bio_orig->bi_iter;
/*
* free up bounce indirect pages used
*/
bio_for_each_segment_all(bvec, bio, i) {
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, 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);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 81 | 66.39% | 1 | 16.67% |
Ming Lei | 32 | 26.23% | 2 | 33.33% |
Christoph Hellwig | 8 | 6.56% | 2 | 33.33% |
Kent Overstreet | 1 | 0.82% | 1 | 16.67% |
Total | 122 | 100.00% | 6 | 100.00% |
static void bounce_end_io_write(struct bio *bio)
{
bounce_end_io(bio, &page_pool);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 17 | 89.47% | 1 | 33.33% |
Kent Overstreet | 1 | 5.26% | 1 | 33.33% |
Neil Brown | 1 | 5.26% | 1 | 33.33% |
Total | 19 | 100.00% | 3 | 100.00% |
static void bounce_end_io_write_isa(struct bio *bio)
{
bounce_end_io(bio, &isa_page_pool);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 17 | 89.47% | 1 | 33.33% |
Neil Brown | 1 | 5.26% | 1 | 33.33% |
Kent Overstreet | 1 | 5.26% | 1 | 33.33% |
Total | 19 | 100.00% | 3 | 100.00% |
static void __bounce_end_io_read(struct bio *bio, mempool_t *pool)
{
struct bio *bio_orig = bio->bi_private;
if (!bio->bi_status)
copy_to_high_bio_irq(bio_orig, bio);
bounce_end_io(bio, pool);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 43 | 95.56% | 1 | 33.33% |
Christoph Hellwig | 2 | 4.44% | 2 | 66.67% |
Total | 45 | 100.00% | 3 | 100.00% |
static void bounce_end_io_read(struct bio *bio)
{
__bounce_end_io_read(bio, &page_pool);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 17 | 89.47% | 1 | 33.33% |
Kent Overstreet | 1 | 5.26% | 1 | 33.33% |
Neil Brown | 1 | 5.26% | 1 | 33.33% |
Total | 19 | 100.00% | 3 | 100.00% |
static void bounce_end_io_read_isa(struct bio *bio)
{
__bounce_end_io_read(bio, &isa_page_pool);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 17 | 89.47% | 1 | 33.33% |
Kent Overstreet | 1 | 5.26% | 1 | 33.33% |
Neil Brown | 1 | 5.26% | 1 | 33.33% |
Total | 19 | 100.00% | 3 | 100.00% |
static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
mempool_t *pool)
{
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;
bool passthrough = bio_is_passthrough(*bio_orig);
bio_for_each_segment(from, *bio_orig, iter) {
if (i++ < BIO_MAX_PAGES)
sectors += from.bv_len >> 9;
if (page_to_pfn(from.bv_page) > q->limits.bounce_pfn)
bounce = true;
}
if (!bounce)
return;
if (!passthrough && sectors < bio_sectors(*bio_orig)) {
bio = bio_split(*bio_orig, sectors, GFP_NOIO, &bounce_bio_split);
bio_chain(bio, *bio_orig);
generic_make_request(*bio_orig);
*bio_orig = bio;
}
bio = bio_clone_bioset(*bio_orig, GFP_NOIO, passthrough ? NULL :
&bounce_bio_set);
bio_for_each_segment_all(to, bio, i) {
struct page *page = to->bv_page;
if (page_to_pfn(page) <= q->limits.bounce_pfn)
continue;
to->bv_page = mempool_alloc(pool, q->bounce_gfp);
inc_zone_page_state(to->bv_page, NR_BOUNCE);
if (rw == WRITE) {
char *vto, *vfrom;
flush_dcache_page(page);
vto = page_address(to->bv_page) + to->bv_offset;
vfrom = kmap_atomic(page) + to->bv_offset;
memcpy(vto, vfrom, to->bv_len);
kunmap_atomic(vfrom);
}
}
trace_block_bio_bounce(q, *bio_orig);
bio->bi_flags |= (1 << BIO_BOUNCED);
if (pool == &page_pool) {
bio->bi_end_io = bounce_end_io_write;
if (rw == READ)
bio->bi_end_io = bounce_end_io_read;
} else {
bio->bi_end_io = bounce_end_io_write_isa;
if (rw == READ)
bio->bi_end_io = bounce_end_io_read_isa;
}
bio->bi_private = *bio_orig;
*bio_orig = bio;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 196 | 51.72% | 1 | 7.69% |
Neil Brown | 83 | 21.90% | 1 | 7.69% |
Kent Overstreet | 50 | 13.19% | 4 | 30.77% |
Ming Lei | 16 | 4.22% | 1 | 7.69% |
Jens Axboe | 16 | 4.22% | 3 | 23.08% |
Wang YanQing | 9 | 2.37% | 1 | 7.69% |
Christoph Hellwig | 8 | 2.11% | 1 | 7.69% |
Arnaldo Carvalho de Melo | 1 | 0.26% | 1 | 7.69% |
Total | 379 | 100.00% | 13 | 100.00% |
void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
{
mempool_t *pool;
/*
* Data-less bio, nothing to bounce
*/
if (!bio_has_data(*bio_orig))
return;
/*
* for non-isa bounce case, just check if the bounce pfn is equal
* to or bigger than the highest pfn in the system -- in that case,
* don't waste time iterating over bio segments
*/
if (!(q->bounce_gfp & GFP_DMA)) {
if (q->limits.bounce_pfn >= blk_max_pfn)
return;
pool = &page_pool;
} else {
BUG_ON(!mempool_initialized(&isa_page_pool));
pool = &isa_page_pool;
}
/*
* slow path
*/
__blk_queue_bounce(q, bio_orig, pool);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 66 | 74.16% | 1 | 16.67% |
Jens Axboe | 13 | 14.61% | 3 | 50.00% |
Kent Overstreet | 6 | 6.74% | 1 | 16.67% |
Christoph Hellwig | 4 | 4.49% | 1 | 16.67% |
Total | 89 | 100.00% | 6 | 100.00% |
Overall Contributors
Person | Tokens | Prop | Commits | CommitProp |
David Howells | 737 | 62.30% | 1 | 2.94% |
Neil Brown | 133 | 11.24% | 2 | 5.88% |
Kent Overstreet | 109 | 9.21% | 5 | 14.71% |
Ming Lei | 77 | 6.51% | 4 | 11.76% |
Jens Axboe | 30 | 2.54% | 6 | 17.65% |
Christoph Hellwig | 25 | 2.11% | 4 | 11.76% |
Chris Metcalf | 21 | 1.78% | 1 | 2.94% |
Mitchel Humpherys | 14 | 1.18% | 1 | 2.94% |
Wang YanQing | 9 | 0.76% | 1 | 2.94% |
David Vrabel | 9 | 0.76% | 1 | 2.94% |
Tejun Heo | 6 | 0.51% | 2 | 5.88% |
Gary King | 5 | 0.42% | 1 | 2.94% |
Arnaldo Carvalho de Melo | 3 | 0.25% | 1 | 2.94% |
Li Zefan | 2 | 0.17% | 1 | 2.94% |
Greg Kroah-Hartman | 1 | 0.08% | 1 | 2.94% |
Bart Van Assche | 1 | 0.08% | 1 | 2.94% |
Paul Gortmaker | 1 | 0.08% | 1 | 2.94% |
Jan Kara | | 0.00% | 0 | 0.00% |
Total | 1183 | 100.00% | 34 | 100.00% |
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