block: Add an explicit bio flag for bios that own their bvec

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@google.com>
CC: Jens Axboe <axboe@kernel.dk>
Acked-by: Tejun Heo <tj@kernel.org>

3 files changed, 4 insertions, 6 deletions

diff --git a/fs/bio.c b/fs/bio.c
index e545a440d376..9238a54b562c 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 e25378f2f408..794bcd0c5039 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 c178d25e588b..538289ffc704 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)))