Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1547631
| From | Ming Lei <tom.leiming@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v1 53/54] btrfs: comment on direct access bvec table |
| Date | 2016-12-27 17:10 +0100 |
| Message-ID | <sT2u6-4eA-23@gated-at.bofh.it> (permalink) |
| References | <sT2u6-4eA-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- fs/btrfs/compression.c | 4 ++++ fs/btrfs/inode.c | 17 +++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 485a60923bba..54306dee392a 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -601,6 +601,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, /* we need the actual starting offset of this extent in the file */ read_lock(&em_tree->lock); + /* + * It is still safe to retrieve the 1st page of the bio + * in this way after supporting multipage bvec. + */ em = lookup_extent_mapping(em_tree, page_offset(bio->bi_io_vec->bv_page), PAGE_SIZE); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index fa77cb210907..d0714208495f 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7914,6 +7914,11 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio, return -EIO; } + /* + * In this case it is still correct to retrieve length + * of the 1st bvec of the bio in this way after supporting + * multipage bvec. + */ if ((bio_segments_all(failed_bio) > 1) || (failed_bio->bi_io_vec->bv_len > btrfs_inode_sectorsize(inode))) @@ -7960,6 +7965,12 @@ static void btrfs_retry_endio_nocsum(struct bio *bio) if (bio->bi_error) goto end; + /* + * WARNING: + * + * With multipage bvec, the following way of direct access to + * bvec table is only safe if the bio includes single page. + */ ASSERT(bio->bi_vcnt == 1); inode = bio->bi_io_vec->bv_page->mapping->host; ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(inode)); @@ -8045,6 +8056,12 @@ static void btrfs_retry_endio(struct bio *bio) start = done->start; + /* + * WARNING: + * + * With multipage bvec, the following way of direct access to + * bvec table is only safe if the bio includes single page. + */ ASSERT(bio->bi_vcnt == 1); inode = bio->bi_io_vec->bv_page->mapping->host; ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(inode)); -- 2.7.4
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v1 32/54] block: introduce bvec_get_last_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 53/54] btrfs: comment on direct access bvec table Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 46/54] fs: crypto: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 36/54] dm-crypt: don't clear bvec->bv_page in crypt_free_buffer_pages() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 50/54] fs/buffer.c: use bvec iterator to truncate the bio Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 54/54] block: enable multipage bvecs Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 47/54] fs/btrfs: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 33/54] block: deal with dirtying pages for multipage bvec Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 38/54] md/raid1.c: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 51/54] btrfs: avoid access to .bi_vcnt directly Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 52/54] btrfs: use bvec_get_last_sp to get the last singlepage bvec Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 39/54] fs/mpage: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 37/54] dm-crypt: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 35/54] bcache: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100
[PATCH v1 49/54] fs/iomap.c: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
[PATCH v1 44/54] f2fs: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
[PATCH v1 48/54] fs/block_dev.c: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
[PATCH v1 34/54] block: convert to singe/multi page version of bio_for_each_segment_all() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
[PATCH v1 41/54] ext4: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
[PATCH v1 43/54] gfs2: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
[PATCH v1 40/54] fs/direct-io: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
[PATCH v1 45/54] exofs: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
Re: [PATCH v1 45/54] exofs: convert to bio_for_each_segment_all_sp() Boaz Harrosh <ooo@electrozaur.com> - 2017-01-03 16:10 +0100
[PATCH v1 42/54] xfs: convert to bio_for_each_segment_all_sp() Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:20 +0100
csiph-web