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authorKent Overstreet <koverstreet@google.com>2012-09-10 14:30:37 -0700
committerKent Overstreet <koverstreet@google.com>2013-03-23 14:26:26 -0700
commit6bc454d150047fcfbf53346412e64cdf3bf61a79 (patch)
tree149f1c376d000053244867e3f72d48ef1bf1c563 /mm/bounce.c
parentd3b45c2a056c5df443d1ddf27fbfada65f234af1 (diff)
downloadlinux-sh-6bc454d150047fcfbf53346412e64cdf3bf61a79.tar.gz
bounce: Refactor __blk_queue_bounce to not use bi_io_vec
A bunch of what __blk_queue_bounce() was doing was problematic for the immutable bvec work; this cleans that up and the code is quite a bit smaller, too. The __bio_for_each_segment() in copy_to_high_bio_irq() was changed because that one's looping over the original bio, not the bounce bio - a later patch renames __bio_for_each_segment() -> bio_for_each_segment_all(), and documents that bio_for_each_segment_all() is only for code that owns the bio. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'mm/bounce.c')
-rw-r--r--mm/bounce.c73
1 files changed, 19 insertions, 54 deletions
diff --git a/mm/bounce.c b/mm/bounce.c
index 5f8901768602..55f512af50c7 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -101,7 +101,7 @@ static void copy_to_high_bio_irq(struct bio *to, struct bio *from)
struct bio_vec *tovec, *fromvec;
int i;
- __bio_for_each_segment(tovec, to, i, 0) {
+ bio_for_each_segment(tovec, to, i) {
fromvec = from->bi_io_vec + i;
/*
@@ -218,78 +218,43 @@ static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio)
static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
mempool_t *pool, int force)
{
- struct page *page;
- struct bio *bio = NULL;
- int i, rw = bio_data_dir(*bio_orig);
+ struct bio *bio;
+ int rw = bio_data_dir(*bio_orig);
struct bio_vec *to, *from;
+ unsigned i;
- bio_for_each_segment(from, *bio_orig, i) {
- page = from->bv_page;
+ bio_for_each_segment(from, *bio_orig, i)
+ if (page_to_pfn(from->bv_page) > queue_bounce_pfn(q))
+ goto bounce;
- /*
- * is destination page below bounce pfn?
- */
- if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force)
- continue;
+ return;
+bounce:
+ bio = bio_clone_bioset(*bio_orig, GFP_NOIO, fs_bio_set);
- /*
- * irk, bounce it
- */
- if (!bio) {
- unsigned int cnt = (*bio_orig)->bi_vcnt;
-
- bio = bio_alloc(GFP_NOIO, cnt);
- memset(bio->bi_io_vec, 0, cnt * sizeof(struct bio_vec));
- }
-
+ bio_for_each_segment(to, bio, i) {
+ struct page *page = to->bv_page;
- to = bio->bi_io_vec + i;
+ if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force)
+ continue;
- to->bv_page = mempool_alloc(pool, q->bounce_gfp);
- to->bv_len = from->bv_len;
- to->bv_offset = from->bv_offset;
inc_zone_page_state(to->bv_page, NR_BOUNCE);
+ to->bv_page = mempool_alloc(pool, q->bounce_gfp);
if (rw == WRITE) {
char *vto, *vfrom;
- flush_dcache_page(from->bv_page);
+ flush_dcache_page(page);
+
vto = page_address(to->bv_page) + to->bv_offset;
- vfrom = kmap(from->bv_page) + from->bv_offset;
+ vfrom = kmap_atomic(page) + to->bv_offset;
memcpy(vto, vfrom, to->bv_len);
- kunmap(from->bv_page);
+ kunmap_atomic(vfrom);
}
}
- /*
- * no pages bounced
- */
- if (!bio)
- return;
-
trace_block_bio_bounce(q, *bio_orig);
- /*
- * at least one page was bounced, fill in possible non-highmem
- * pages
- */
- __bio_for_each_segment(from, *bio_orig, i, 0) {
- to = bio_iovec_idx(bio, i);
- if (!to->bv_page) {
- to->bv_page = from->bv_page;
- to->bv_len = from->bv_len;
- to->bv_offset = from->bv_offset;
- }
- }
-
- bio->bi_bdev = (*bio_orig)->bi_bdev;
bio->bi_flags |= (1 << BIO_BOUNCED);
- bio->bi_sector = (*bio_orig)->bi_sector;
- bio->bi_rw = (*bio_orig)->bi_rw;
-
- bio->bi_vcnt = (*bio_orig)->bi_vcnt;
- bio->bi_idx = (*bio_orig)->bi_idx;
- bio->bi_size = (*bio_orig)->bi_size;
if (pool == page_pool) {
bio->bi_end_io = bounce_end_io_write;