[PATCH] kill bio->bi_set

Jens:

->bi_set is totally unnecessary bloat of struct bio.  Just define a proper
destructor for the bio and it already knows what bio_set it belongs too.

Peter:

Fixed the bugs.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 21 insertions, 11 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 1f2d4649b188..bf3ec9d2b54c 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -104,18 +104,22 @@ static inline struct bio_vec *bvec_alloc_bs(unsigned int __nocast gfp_mask, int
         return bvl;
 }
 
-/*
- * default destructor for a bio allocated with bio_alloc_bioset()
- */
-static void bio_destructor(struct bio *bio)
+void bio_free(struct bio *bio, struct bio_set *bio_set)
 {
         const int pool_idx = BIO_POOL_IDX(bio);
-        struct bio_set *bs = bio->bi_set;
 
         BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS);
 
-        mempool_free(bio->bi_io_vec, bs->bvec_pools[pool_idx]);
-        mempool_free(bio, bs->bio_pool);
+        mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]);
+        mempool_free(bio, bio_set->bio_pool);
+}
+
+/*
+ * default destructor for a bio allocated with bio_alloc_bioset()
+ */
+static void bio_fs_destructor(struct bio *bio)
+{
+        bio_free(bio, fs_bio_set);
 }
 
 inline void bio_init(struct bio *bio)
@@ -171,8 +175,6 @@ struct bio *bio_alloc_bioset(unsigned int __nocast gfp_mask, int nr_iovecs, stru
                         bio->bi_max_vecs = bvec_slabs[idx].nr_vecs;
                 }
                 bio->bi_io_vec = bvl;
-                bio->bi_destructor = bio_destructor;
-                bio->bi_set = bs;
         }
 out:
         return bio;
@@ -180,7 +182,12 @@ out:
 
 struct bio *bio_alloc(unsigned int __nocast gfp_mask, int nr_iovecs)
 {
-        return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
+        struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
+
+        if (bio)
+                bio->bi_destructor = bio_fs_destructor;
+
+        return bio;
 }
 
 void zero_fill_bio(struct bio *bio)
@@ -273,8 +280,10 @@ struct bio *bio_clone(struct bio *bio, unsigned int __nocast gfp_mask)
 {
         struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
 
-        if (b)
+        if (b) {
+                b->bi_destructor = bio_fs_destructor;
                 __bio_clone(b, bio);
+        }
 
         return b;
 }
@@ -1075,6 +1084,7 @@ subsys_initcall(init_bio);
 
 EXPORT_SYMBOL(bio_alloc);
 EXPORT_SYMBOL(bio_put);
+EXPORT_SYMBOL(bio_free);
 EXPORT_SYMBOL(bio_endio);
 EXPORT_SYMBOL(bio_init);
 EXPORT_SYMBOL(__bio_clone);