[PATCH 06/13] block: Add bio_reset()
From: <hidden>
Date: 2012-05-18 02:59:53
Also in:
dm-devel, linux-fsdevel, lkml
Subsystem:
block layer, filesystems (vfs and infrastructure), the rest · Maintainers:
Jens Axboe, Alexander Viro, Christian Brauner, Linus Torvalds
From: Kent Overstreet <redacted> Reusing bios is something that's been highly frowned upon in the past, but driver code keeps doing it anyways. If it's going to happen anyways, we should provide a generic method. This'll help with getting rid of bi_destructor. Signed-off-by: Kent Overstreet <redacted> --- fs/bio.c | 8 ++++++++ include/linux/bio.h | 1 + include/linux/blk_types.h | 6 ++++++ 3 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/fs/bio.c b/fs/bio.c
index de0733e..90e4c3a 100644
--- a/fs/bio.c
+++ b/fs/bio.c@@ -259,6 +259,14 @@ void bio_init(struct bio *bio) } EXPORT_SYMBOL(bio_init); +void bio_reset(struct bio *bio) +{ + memset(bio, 0, BIO_RESET_OFFSET); + bio->bi_flags = 1 << BIO_UPTODATE; + +} +EXPORT_SYMBOL(bio_reset); + /** * bio_alloc_bioset - allocate a bio for I/O * @gfp_mask: the GFP_ mask given to the slab allocator
diff --git a/include/linux/bio.h b/include/linux/bio.h
index b27f16b..35f7c4d 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h@@ -228,6 +228,7 @@ extern struct bio *bio_clone(struct bio *, gfp_t); struct bio *bio_clone_kmalloc(struct bio *, gfp_t); extern void bio_init(struct bio *); +extern void bio_reset(struct bio *); extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index dc0e399..4a47783 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h@@ -57,6 +57,10 @@ struct bio { unsigned int bi_seg_front_size; unsigned int bi_seg_back_size; + /* + * Everything starting with bi_max_vecs will be preserved by bio_reset() + */ + unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ atomic_t bi_cnt; /* pin count */
@@ -83,6 +87,8 @@ struct bio { struct bio_vec bi_inline_vecs[0]; }; +#define BIO_RESET_OFFSET offsetof(struct bio, bi_max_vecs) + /* * bio flags */
--
1.7.9.rc2