[PATCH 26/27] block: Add an explicit bio flag for bios that own their bvec

From: Kent Overstreet
Date: Tue Feb 19 2013 - 19:23:50 EST


This is for the new bio splitting code. When we split a bio, if the
split occured on a bvec boundry we reuse the bvec for the new bio. But
that means bio_free() can't free it, hence the explicit flag.

Signed-off-by: Kent Overstreet <koverstreet@xxxxxxxxxx>
CC: Jens Axboe <axboe@xxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
---
fs/bio.c | 4 +++-
include/linux/bio.h | 5 -----
include/linux/blk_types.h | 1 +
3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/fs/bio.c b/fs/bio.c
index e545a44..9238a54 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -252,7 +252,7 @@ static void bio_free(struct bio *bio)
__bio_free(bio);

if (bs) {
- if (bio_has_allocated_vec(bio))
+ if (bio_flagged(bio, BIO_OWNS_VEC))
bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio));

/*
@@ -451,6 +451,8 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)

if (unlikely(!bvl))
goto err_free;
+
+ bio->bi_flags |= 1 << BIO_OWNS_VEC;
} else if (nr_iovecs) {
bvl = bio->bi_inline_vecs;
}
diff --git a/include/linux/bio.h b/include/linux/bio.h
index e25378f..794bcd0 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -85,11 +85,6 @@ static inline void *bio_data(struct bio *bio)
return NULL;
}

-static inline int bio_has_allocated_vec(struct bio *bio)
-{
- return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
-}
-
/*
* will die
*/
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index c178d25..538289f 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -117,6 +117,7 @@ struct bio {
* BIO_POOL_IDX()
*/
#define BIO_RESET_BITS 12
+#define BIO_OWNS_VEC 12 /* bio_free() should free bvec */

#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))

--
1.7.12

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/