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![Darrick J. Wong](/assets/img/avatar_default.png)
The "force" parameter in __blk_queue_bounce was being ignored, which
means that stable page snapshots are not always happening (on ext3).
This of course leads to DIF disks reporting checksum errors, so fix this
regression.
The regression was introduced in commit 6bc454d150
("bounce: Refactor
__blk_queue_bounce to not use bi_io_vec")
Reported-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
289 lines
6.4 KiB
C
289 lines
6.4 KiB
C
/* bounce buffer handling for block devices
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*
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* - Split from highmem.c
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*/
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#include <linux/mm.h>
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#include <linux/export.h>
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#include <linux/swap.h>
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#include <linux/gfp.h>
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#include <linux/bio.h>
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#include <linux/pagemap.h>
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#include <linux/mempool.h>
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#include <linux/blkdev.h>
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#include <linux/init.h>
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#include <linux/hash.h>
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#include <linux/highmem.h>
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#include <linux/bootmem.h>
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#include <asm/tlbflush.h>
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#include <trace/events/block.h>
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#define POOL_SIZE 64
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#define ISA_POOL_SIZE 16
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static mempool_t *page_pool, *isa_page_pool;
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#if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL)
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static __init int init_emergency_pool(void)
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{
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#if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG)
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if (max_pfn <= max_low_pfn)
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return 0;
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#endif
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page_pool = mempool_create_page_pool(POOL_SIZE, 0);
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BUG_ON(!page_pool);
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printk("bounce pool size: %d pages\n", POOL_SIZE);
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return 0;
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}
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__initcall(init_emergency_pool);
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#endif
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#ifdef CONFIG_HIGHMEM
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/*
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* highmem version, map in to vec
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*/
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static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom)
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{
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unsigned long flags;
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unsigned char *vto;
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local_irq_save(flags);
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vto = kmap_atomic(to->bv_page);
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memcpy(vto + to->bv_offset, vfrom, to->bv_len);
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kunmap_atomic(vto);
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local_irq_restore(flags);
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}
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#else /* CONFIG_HIGHMEM */
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#define bounce_copy_vec(to, vfrom) \
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memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len)
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#endif /* CONFIG_HIGHMEM */
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/*
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* allocate pages in the DMA region for the ISA pool
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*/
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static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data)
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{
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return mempool_alloc_pages(gfp_mask | GFP_DMA, data);
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}
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/*
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* gets called "every" time someone init's a queue with BLK_BOUNCE_ISA
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* as the max address, so check if the pool has already been created.
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*/
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int init_emergency_isa_pool(void)
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{
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if (isa_page_pool)
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return 0;
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isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa,
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mempool_free_pages, (void *) 0);
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BUG_ON(!isa_page_pool);
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printk("isa bounce pool size: %d pages\n", ISA_POOL_SIZE);
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return 0;
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}
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/*
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* Simple bounce buffer support for highmem pages. Depending on the
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* queue gfp mask set, *to may or may not be a highmem page. kmap it
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* always, it will do the Right Thing
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*/
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static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
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{
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unsigned char *vfrom;
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struct bio_vec *tovec, *fromvec;
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int i;
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bio_for_each_segment(tovec, to, i) {
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fromvec = from->bi_io_vec + i;
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/*
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* not bounced
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*/
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if (tovec->bv_page == fromvec->bv_page)
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continue;
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/*
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* fromvec->bv_offset and fromvec->bv_len might have been
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* modified by the block layer, so use the original copy,
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* bounce_copy_vec already uses tovec->bv_len
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*/
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vfrom = page_address(fromvec->bv_page) + tovec->bv_offset;
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bounce_copy_vec(tovec, vfrom);
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flush_dcache_page(tovec->bv_page);
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}
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}
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static void bounce_end_io(struct bio *bio, mempool_t *pool, int err)
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{
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struct bio *bio_orig = bio->bi_private;
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struct bio_vec *bvec, *org_vec;
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int i;
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if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
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set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags);
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/*
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* free up bounce indirect pages used
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*/
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bio_for_each_segment_all(bvec, bio, i) {
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org_vec = bio_orig->bi_io_vec + i;
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if (bvec->bv_page == org_vec->bv_page)
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continue;
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dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
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mempool_free(bvec->bv_page, pool);
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}
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bio_endio(bio_orig, err);
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bio_put(bio);
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}
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static void bounce_end_io_write(struct bio *bio, int err)
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{
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bounce_end_io(bio, page_pool, err);
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}
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static void bounce_end_io_write_isa(struct bio *bio, int err)
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{
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bounce_end_io(bio, isa_page_pool, err);
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}
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static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err)
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{
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struct bio *bio_orig = bio->bi_private;
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if (test_bit(BIO_UPTODATE, &bio->bi_flags))
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copy_to_high_bio_irq(bio_orig, bio);
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bounce_end_io(bio, pool, err);
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}
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static void bounce_end_io_read(struct bio *bio, int err)
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{
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__bounce_end_io_read(bio, page_pool, err);
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}
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static void bounce_end_io_read_isa(struct bio *bio, int err)
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{
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__bounce_end_io_read(bio, isa_page_pool, err);
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}
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#ifdef CONFIG_NEED_BOUNCE_POOL
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static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio)
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{
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if (bio_data_dir(bio) != WRITE)
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return 0;
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if (!bdi_cap_stable_pages_required(&q->backing_dev_info))
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return 0;
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return test_bit(BIO_SNAP_STABLE, &bio->bi_flags);
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}
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#else
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static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio)
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{
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return 0;
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}
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#endif /* CONFIG_NEED_BOUNCE_POOL */
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static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
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mempool_t *pool, int force)
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{
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struct bio *bio;
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int rw = bio_data_dir(*bio_orig);
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struct bio_vec *to, *from;
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unsigned i;
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if (force)
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goto bounce;
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bio_for_each_segment(from, *bio_orig, i)
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if (page_to_pfn(from->bv_page) > queue_bounce_pfn(q))
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goto bounce;
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return;
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bounce:
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bio = bio_clone_bioset(*bio_orig, GFP_NOIO, fs_bio_set);
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bio_for_each_segment_all(to, bio, i) {
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struct page *page = to->bv_page;
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if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force)
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continue;
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inc_zone_page_state(to->bv_page, NR_BOUNCE);
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to->bv_page = mempool_alloc(pool, q->bounce_gfp);
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if (rw == WRITE) {
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char *vto, *vfrom;
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flush_dcache_page(page);
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vto = page_address(to->bv_page) + to->bv_offset;
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vfrom = kmap_atomic(page) + to->bv_offset;
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memcpy(vto, vfrom, to->bv_len);
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kunmap_atomic(vfrom);
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}
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}
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trace_block_bio_bounce(q, *bio_orig);
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bio->bi_flags |= (1 << BIO_BOUNCED);
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if (pool == page_pool) {
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bio->bi_end_io = bounce_end_io_write;
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if (rw == READ)
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bio->bi_end_io = bounce_end_io_read;
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} else {
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bio->bi_end_io = bounce_end_io_write_isa;
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if (rw == READ)
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bio->bi_end_io = bounce_end_io_read_isa;
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}
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bio->bi_private = *bio_orig;
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*bio_orig = bio;
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}
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void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
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{
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int must_bounce;
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mempool_t *pool;
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/*
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* Data-less bio, nothing to bounce
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*/
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if (!bio_has_data(*bio_orig))
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return;
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must_bounce = must_snapshot_stable_pages(q, *bio_orig);
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/*
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* for non-isa bounce case, just check if the bounce pfn is equal
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* to or bigger than the highest pfn in the system -- in that case,
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* don't waste time iterating over bio segments
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*/
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if (!(q->bounce_gfp & GFP_DMA)) {
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if (queue_bounce_pfn(q) >= blk_max_pfn && !must_bounce)
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return;
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pool = page_pool;
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} else {
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BUG_ON(!isa_page_pool);
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pool = isa_page_pool;
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}
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/*
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* slow path
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*/
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__blk_queue_bounce(q, bio_orig, pool, must_bounce);
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}
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EXPORT_SYMBOL(blk_queue_bounce);
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