Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1706488
| From | Coly Li <i@coly.li> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v3 07/49] bcache: comment on direct access to bvec table |
| Date | 2017-08-08 14:40 +0200 |
| Message-ID | <ucbXH-8or-1@gated-at.bofh.it> (permalink) |
| References | <uc8n7-5sU-3@gated-at.bofh.it> <uc8n9-5sU-33@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 2017/8/8 下午4:45, Ming Lei wrote:
> Looks all are safe after multipage bvec is supported.
>
> Cc: linux-bcache@vger.kernel.org
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Coly Li <colyli@suse.de>
Coly Li
> ---
> drivers/md/bcache/btree.c | 1 +
> drivers/md/bcache/super.c | 6 ++++++
> drivers/md/bcache/util.c | 7 +++++++
> 3 files changed, 14 insertions(+)
>
> diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
> index 866dcf78ff8e..3da595ae565b 100644
> --- a/drivers/md/bcache/btree.c
> +++ b/drivers/md/bcache/btree.c
> @@ -431,6 +431,7 @@ static void do_btree_node_write(struct btree *b)
>
> continue_at(cl, btree_node_write_done, NULL);
> } else {
> + /* No harm for multipage bvec since the new is just allocated */
> b->bio->bi_vcnt = 0;
> bch_bio_map(b->bio, i);
>
> diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
> index 8352fad765f6..6808f548cd13 100644
> --- a/drivers/md/bcache/super.c
> +++ b/drivers/md/bcache/super.c
> @@ -208,6 +208,7 @@ static void write_bdev_super_endio(struct bio *bio)
>
> static void __write_super(struct cache_sb *sb, struct bio *bio)
> {
> + /* single page bio, safe for multipage bvec */
> struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page);
> unsigned i;
>
> @@ -1154,6 +1155,8 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
> dc->bdev->bd_holder = dc;
>
> bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1);
> +
> + /* single page bio, safe for multipage bvec */
> dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
> get_page(sb_page);
>
> @@ -1799,6 +1802,7 @@ void bch_cache_release(struct kobject *kobj)
> for (i = 0; i < RESERVE_NR; i++)
> free_fifo(&ca->free[i]);
>
> + /* single page bio, safe for multipage bvec */
> if (ca->sb_bio.bi_inline_vecs[0].bv_page)
> put_page(ca->sb_bio.bi_io_vec[0].bv_page);
>
> @@ -1854,6 +1858,8 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
> ca->bdev->bd_holder = ca;
>
> bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1);
> +
> + /* single page bio, safe for multipage bvec */
> ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
> get_page(sb_page);
>
> diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
> index 8c3a938f4bf0..11b4230ea6ad 100644
> --- a/drivers/md/bcache/util.c
> +++ b/drivers/md/bcache/util.c
> @@ -223,6 +223,13 @@ uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
> : 0;
> }
>
> +/*
> + * Generally it isn't good to access .bi_io_vec and .bi_vcnt
> + * directly, the preferred way is bio_add_page, but in
> + * this case, bch_bio_map() supposes that the bvec table
> + * is empty, so it is safe to access .bi_vcnt & .bi_io_vec
> + * in this way even after multipage bvec is supported.
> + */
> void bch_bio_map(struct bio *bio, void *base)
> {
> size_t size = bio->bi_iter.bi_size;
>
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v3 00/49] block: support multipage bvec Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 10/49] dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
Re: [PATCH v3 10/49] dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE Christoph Hellwig <hch@infradead.org> - 2017-08-10 13:30 +0200
[PATCH v3 13/49] btrfs: comment on direct access bvec table Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 08/49] block: comment on bio_alloc_pages() Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 09/49] block: comment on bio_iov_iter_get_pages() Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
Re: [PATCH v3 09/49] block: comment on bio_iov_iter_get_pages() Christoph Hellwig <hch@infradead.org> - 2017-08-10 13:30 +0200
[PATCH v3 07/49] bcache: comment on direct access to bvec table Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
Re: [PATCH v3 07/49] bcache: comment on direct access to bvec table Coly Li <i@coly.li> - 2017-08-08 14:40 +0200
Re: [PATCH v3 07/49] bcache: comment on direct access to bvec table Christoph Hellwig <hch@infradead.org> - 2017-08-10 13:30 +0200
[PATCH v3 05/49] fs/buffer: comment on direct access to bvec table Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
Re: [PATCH v3 05/49] fs/buffer: comment on direct access to bvec table Christoph Hellwig <hch@infradead.org> - 2017-08-10 13:20 +0200
[PATCH v3 12/49] btrfs: avoid to access bvec table directly for a cloned bio Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 03/49] kernel/power/swap.c: comment on direct access to bvec table Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 02/49] block: loop: comment on direct access to bvec table Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 16/49] block: bounce: don't access bio->bi_io_vec in copy_to_high_bio_irq Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 15/49] bvec_iter: introduce BVEC_ITER_ALL_INIT Ming Lei <ming.lei@redhat.com> - 2017-08-08 10:50 +0200
[PATCH v3 41/49] xfs: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 41/49] xfs: convert to bio_for_each_segment_all_sp() "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-08-08 18:40 +0200
[PATCH v3 48/49] block: enable multipage bvecs Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 33/49] bcache: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 33/49] bcache: convert to bio_for_each_segment_all_sp() Coly Li <i@coly.li> - 2017-08-08 14:40 +0200
[PATCH v3 49/49] block: bio: pass segments to bio if bio_add_page() is bypassed Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 25/49] block: use bio_for_each_segment_mp() to map sg Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 37/49] fs/mpage: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 37/49] fs/mpage: convert to bio_for_each_segment_all_sp() Christoph Hellwig <hch@infradead.org> - 2017-08-10 14:20 +0200
[PATCH v3 28/49] block: introduce bvec_get_last_page() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 34/49] md: raid1: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 26/49] block: introduce bvec_for_each_sp_bvec() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 44/49] exofs: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 35/49] dm-crypt: don't clear bvec->bv_page in crypt_free_buffer_pages() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 42/49] gfs2: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 32/49] block: convert to singe/multi page version of bio_for_each_segment_all() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 39/49] fs/iomap: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 29/49] fs/buffer.c: use bvec iterator to truncate the bio Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 21/49] blk-merge: compute bio->bi_seg_front_size efficiently Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 21/49] blk-merge: compute bio->bi_seg_front_size efficiently Christoph Hellwig <hch@infradead.org> - 2017-08-10 14:30 +0200
[PATCH v3 24/49] block: use bio_for_each_segment_mp() to compute segments count Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 43/49] f2fs: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 23/49] block: blk-merge: remove unnecessary check Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 23/49] block: blk-merge: remove unnecessary check Christoph Hellwig <hch@infradead.org> - 2017-08-10 14:20 +0200
[PATCH v3 27/49] block: bio: introduce single/multi page version of bio_for_each_segment_all() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 46/49] fs/btrfs: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 46/49] fs/btrfs: convert to bio_for_each_segment_all_sp() Filipe Manana <fdmanana@gmail.com> - 2017-08-08 11:10 +0200
[PATCH v3 38/49] fs/block: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 18/49] block: introduce multipage/single page bvec helpers Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 18/49] block: introduce multipage/single page bvec helpers Christoph Hellwig <hch@infradead.org> - 2017-08-10 14:10 +0200
[PATCH v3 47/49] fs/direct-io: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 31/49] block: deal with dirtying pages for multipage bvec Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 20/49] block: introduce bio_for_each_segment_mp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 20/49] block: introduce bio_for_each_segment_mp() Christoph Hellwig <hch@infradead.org> - 2017-08-10 14:30 +0200
[PATCH v3 45/49] fs: crypto: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 40/49] ext4: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 22/49] block: blk-merge: try to make front segments in full size Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 22/49] block: blk-merge: try to make front segments in full size Christoph Hellwig <hch@infradead.org> - 2017-08-10 14:30 +0200
[PATCH v3 30/49] btrfs: use bvec_get_last_page to get bio's last page Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 36/49] dm-crypt: convert to bio_for_each_segment_all_sp() Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
[PATCH v3 19/49] block: implement sp version of bvec iterator helpers Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:00 +0200
Re: [PATCH v3 19/49] block: implement sp version of bvec iterator helpers Christoph Hellwig <hch@infradead.org> - 2017-08-10 14:10 +0200
[PATCH v3 04/49] mm: page_io.c: comment on direct access to bvec table Ming Lei <ming.lei@redhat.com> - 2017-08-08 11:10 +0200
Re: [PATCH v3 04/49] mm: page_io.c: comment on direct access to bvec table Christoph Hellwig <hch@infradead.org> - 2017-08-10 13:20 +0200
csiph-web