From: Kent Overstreet Date: Wed, 6 Feb 2013 20:23:11 +0000 (-0800) Subject: block: Add bio_for_each_segment_all() X-Git-Tag: v3.2.51~40 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=efd99ef3a97b5a68e7f7bc87efd62b887f77bc89;p=pandora-kernel.git block: Add bio_for_each_segment_all() commit d74c6d514fe314b8bdab58b487b25992291577ec upstream. __bio_for_each_segment() iterates bvecs from the specified index instead of bio->bv_idx. Currently, the only usage is to walk all the bvecs after the bio has been advanced by specifying 0 index. For immutable bvecs, we need to split these apart; bio_for_each_segment() is going to have a different implementation. This will also help document the intent of code that's using it - bio_for_each_segment_all() is only legal to use for code that owns the bio. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: Neil Brown CC: Boaz Harrosh [bwh: Backported to 3.2: drop inapplicable change to drivers/block/rbd.c. This is a prerequisite for commit 35dc248383bb 'sg: Fix user memory corruption when SG_IO is interrupted by a signal'] Signed-off-by: Ben Hutchings --- diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 298e02a4c934..c706a7bf5d9c 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1139,7 +1139,7 @@ read_again: * know the original bi_idx, so we just free * them all */ - __bio_for_each_segment(bvec, mbio, j, 0) + bio_for_each_segment_all(bvec, mbio, j) bvec->bv_page = r1_bio->behind_bvecs[j].bv_page; if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) atomic_inc(&r1_bio->behind_remaining); diff --git a/fs/bio.c b/fs/bio.c index 4fc4dbb079a9..27116a45cb20 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -734,7 +734,7 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs, int iov_idx = 0; unsigned int iov_off = 0; - __bio_for_each_segment(bvec, bio, i, 0) { + bio_for_each_segment_all(bvec, bio, i) { char *bv_addr = page_address(bvec->bv_page); unsigned int bv_len = iovecs[i].bv_len; @@ -916,7 +916,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, return bio; cleanup: if (!map_data) - bio_for_each_segment(bvec, bio, i) + bio_for_each_segment_all(bvec, bio, i) __free_page(bvec->bv_page); bio_put(bio); @@ -1130,7 +1130,7 @@ static void __bio_unmap_user(struct bio *bio) /* * make sure we dirty pages we wrote to */ - __bio_for_each_segment(bvec, bio, i, 0) { + bio_for_each_segment_all(bvec, bio, i) { if (bio_data_dir(bio) == READ) set_page_dirty_lock(bvec->bv_page); @@ -1236,7 +1236,7 @@ static void bio_copy_kern_endio(struct bio *bio, int err) int i; char *p = bmd->sgvecs[0].iov_base; - __bio_for_each_segment(bvec, bio, i, 0) { + bio_for_each_segment_all(bvec, bio, i) { char *addr = page_address(bvec->bv_page); int len = bmd->iovecs[i].bv_len; @@ -1276,7 +1276,7 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, if (!reading) { void *p = data; - bio_for_each_segment(bvec, bio, i) { + bio_for_each_segment_all(bvec, bio, i) { char *addr = page_address(bvec->bv_page); memcpy(addr, p, bvec->bv_len); @@ -1556,7 +1556,7 @@ sector_t bio_sector_offset(struct bio *bio, unsigned short index, if (index >= bio->bi_idx) index = bio->bi_vcnt - 1; - __bio_for_each_segment(bv, bio, i, 0) { + bio_for_each_segment_all(bv, bio, i) { if (i == index) { if (offset > bv->bv_offset) sectors += (offset - bv->bv_offset) / sector_sz; diff --git a/fs/exofs/ore.c b/fs/exofs/ore.c index 1585db1aa365..26bb512c3566 100644 --- a/fs/exofs/ore.c +++ b/fs/exofs/ore.c @@ -401,7 +401,7 @@ static void _clear_bio(struct bio *bio) struct bio_vec *bv; unsigned i; - __bio_for_each_segment(bv, bio, i, 0) { + bio_for_each_segment_all(bv, bio, i) { unsigned this_count = bv->bv_len; if (likely(PAGE_SIZE == this_count)) diff --git a/fs/exofs/ore_raid.c b/fs/exofs/ore_raid.c index fff2070c6751..2c6482629dd8 100644 --- a/fs/exofs/ore_raid.c +++ b/fs/exofs/ore_raid.c @@ -432,7 +432,7 @@ static void _mark_read4write_pages_uptodate(struct ore_io_state *ios, int ret) if (!bio) continue; - __bio_for_each_segment(bv, bio, i, 0) { + bio_for_each_segment_all(bv, bio, i) { struct page *page = bv->bv_page; SetPageUptodate(page); diff --git a/include/linux/bio.h b/include/linux/bio.h index 847994aef0e9..e8685547cfd7 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -135,16 +135,27 @@ static inline int bio_has_allocated_vec(struct bio *bio) #define bio_io_error(bio) bio_endio((bio), -EIO) /* - * drivers should not use the __ version unless they _really_ want to - * run through the entire bio and not just pending pieces + * drivers should not use the __ version unless they _really_ know what + * they're doing */ #define __bio_for_each_segment(bvl, bio, i, start_idx) \ for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \ i < (bio)->bi_vcnt; \ bvl++, i++) +/* + * drivers should _never_ use the all version - the bio may have been split + * before it got to the driver and the driver won't own all of it + */ +#define bio_for_each_segment_all(bvl, bio, i) \ + for (i = 0; \ + bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \ + i++) + #define bio_for_each_segment(bvl, bio, i) \ - __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx) + for (i = (bio)->bi_idx; \ + bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \ + i++) /* * get a reference to a bio, so it won't disappear. the intended use is diff --git a/mm/bounce.c b/mm/bounce.c index 4e9ae722af83..f71a3b347303 100644 --- a/mm/bounce.c +++ b/mm/bounce.c @@ -132,7 +132,7 @@ static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) /* * free up bounce indirect pages used */ - __bio_for_each_segment(bvec, bio, i, 0) { + bio_for_each_segment_all(bvec, bio, i) { org_vec = bio_orig->bi_io_vec + i; if (bvec->bv_page == org_vec->bv_page) continue;