block: export bio_free_pages to other modules

bio_free_pages is introduced in commit 1dfa0f68c040
("block: add a helper to free bio bounce buffer pages"),
we can reuse the func in other modules after it was
imported.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

9 files changed, 13 insertions, 36 deletions

diff --git a/block/bio.c b/block/bio.c
index a6d279e1ea9e..db85c5753a76 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1068,7 +1068,7 @@ static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
         return 0;
 }
 
-static void bio_free_pages(struct bio *bio)
+void bio_free_pages(struct bio *bio)
 {
         struct bio_vec *bvec;
         int i;
@@ -1076,6 +1076,7 @@ static void bio_free_pages(struct bio *bio)
         bio_for_each_segment_all(bvec, bio, i)
                 __free_page(bvec->bv_page);
 }
+EXPORT_SYMBOL(bio_free_pages);
 
 /**
  *      bio_uncopy_user -       finish previously mapped bio
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 76f7534d1dd1..81d3db40cd7b 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -361,12 +361,8 @@ static void __btree_node_write_done(struct closure *cl)
 static void btree_node_write_done(struct closure *cl)
 {
         struct btree *b = container_of(cl, struct btree, io);
-        struct bio_vec *bv;
-        int n;
-
-        bio_for_each_segment_all(bv, b->bio, n)
-                __free_page(bv->bv_page);
 
+        bio_free_pages(b->bio);
         __btree_node_write_done(cl);
 }
 
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index c28df164701e..333a1e5f6ae6 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -107,9 +107,8 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 {
         char name[BDEVNAME_SIZE];
         struct bio *check;
-        struct bio_vec bv, *bv2;
+        struct bio_vec bv;
         struct bvec_iter iter;
-        int i;
 
         check = bio_clone(bio, GFP_NOIO);
         if (!check)
@@ -136,8 +135,7 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio)
                 kunmap_atomic(p1);
         }
 
-        bio_for_each_segment_all(bv2, check, i)
-                __free_page(bv2->bv_page);
+        bio_free_pages(check);
 out_put:
         bio_put(check);
 }
diff --git a/drivers/md/bcache/movinggc.c b/drivers/md/bcache/movinggc.c
index 1881319f2298..5c4bddecfaf0 100644
--- a/drivers/md/bcache/movinggc.c
+++ b/drivers/md/bcache/movinggc.c
@@ -44,11 +44,8 @@ static void write_moving_finish(struct closure *cl)
 {
         struct moving_io *io = container_of(cl, struct moving_io, cl);
         struct bio *bio = &io->bio.bio;
-        struct bio_vec *bv;
-        int i;
 
-        bio_for_each_segment_all(bv, bio, i)
-                __free_page(bv->bv_page);
+        bio_free_pages(bio);
 
         if (io->op.replace_collision)
                 trace_bcache_gc_copy_collision(&io->w->key);
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 4b177fe11ebb..40ffe5e424b3 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -694,13 +694,8 @@ static void cached_dev_cache_miss_done(struct closure *cl)
         if (s->iop.replace_collision)
                 bch_mark_cache_miss_collision(s->iop.c, s->d);
 
-        if (s->iop.bio) {
-                int i;
-                struct bio_vec *bv;
-
-                bio_for_each_segment_all(bv, s->iop.bio, i)
-                        __free_page(bv->bv_page);
-        }
+        if (s->iop.bio)
+                bio_free_pages(s->iop.bio);
 
         cached_dev_bio_complete(cl);
 }
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index d9fd2a62e5f6..e51644e503a5 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -128,11 +128,8 @@ static void write_dirty_finish(struct closure *cl)
         struct dirty_io *io = container_of(cl, struct dirty_io, cl);
         struct keybuf_key *w = io->bio.bi_private;
         struct cached_dev *dc = io->dc;
-        struct bio_vec *bv;
-        int i;
 
-        bio_for_each_segment_all(bv, &io->bio, i)
-                __free_page(bv->bv_page);
+        bio_free_pages(&io->bio);
 
         /* This is kind of a dumb way of signalling errors. */
         if (KEY_DIRTY(&w->key)) {
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 4ab68033f9d1..b52404159ccf 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -149,8 +149,6 @@ static void put_io_block(struct log_writes_c *lc)
 static void log_end_io(struct bio *bio)
 {
         struct log_writes_c *lc = bio->bi_private;
-        struct bio_vec *bvec;
-        int i;
 
         if (bio->bi_error) {
                 unsigned long flags;
@@ -161,9 +159,7 @@ static void log_end_io(struct bio *bio)
                 spin_unlock_irqrestore(&lc->blocks_lock, flags);
         }
 
-        bio_for_each_segment_all(bvec, bio, i)
-                __free_page(bvec->bv_page);
-
+        bio_free_pages(bio);
         put_io_block(lc);
         bio_put(bio);
 }
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 21dc00eb1989..1961d827dbd1 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -145,12 +145,8 @@ static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
         return r1_bio;
 
 out_free_pages:
-        while (--j >= 0) {
-                struct bio_vec *bv;
-
-                bio_for_each_segment_all(bv, r1_bio->bios[j], i)
-                        __free_page(bv->bv_page);
-        }
+        while (--j >= 0)
+                bio_free_pages(r1_bio->bios[j]);
 
 out_free_bio:
         while (++j < pi->raid_disks)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index e00721a2dce1..97cb48f03dc7 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -459,6 +459,7 @@ static inline void bio_flush_dcache_pages(struct bio *bi)
 
 extern void bio_copy_data(struct bio *dst, struct bio *src);
 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
+extern void bio_free_pages(struct bio *bio);
 
 extern struct bio *bio_copy_user_iov(struct request_queue *,
                                      struct rq_map_data *,