When you allocate a bio from a bio pool, to free it you have to know
where it came from; this adds a flag which, if set, means bi_destructor
is the pointer to the pool and bio_put() can do the right thing.
This is used in bcache, so we can cleanly use per device bio pools.
Signed-off-by: Kent Overstreet <koverstreet@xxxxxxxxxx>
---
fs/bio.c | 9 +++++++--
include/linux/blk_types.h | 2 ++
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/bio.c b/fs/bio.c
index a965b89..6a967fc 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -235,7 +235,7 @@ void bio_free(struct bio *bio, struct bio_set *bs)
{
void *p;
- if (bio_has_allocated_vec(bio))
+ if (bio_flagged(bio, BIO_HAS_VEC))
bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
if (bio_integrity(bio))
@@ -301,6 +301,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
goto err_free;
nr_iovecs = bvec_nr_vecs(idx);
+ bio->bi_flags |= 1 << BIO_HAS_VEC;
}
out_set:
bio->bi_flags |= idx << BIO_POOL_OFFSET;
@@ -417,7 +418,11 @@ void bio_put(struct bio *bio)
*/
if (atomic_dec_and_test(&bio->bi_cnt)) {
bio->bi_next = NULL;
- bio->bi_destructor(bio);
+
+ if (bio_flagged(bio, BIO_HAS_POOL))
+ bio_free(bio, (void *) bio->bi_destructor);
+ else
+ bio->bi_destructor(bio);
}
}
EXPORT_SYMBOL(bio_put);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 4053cbd..a0be8b3 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -95,6 +95,8 @@ struct bio {
#define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */
#define BIO_QUIET 10 /* Make BIO Quiet */
#define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */
+#define BIO_HAS_POOL 12 /* bi_destructor points to bio_pool */
+#define BIO_HAS_VEC 13 /* bio_free() should free bvec */
#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
/*
--
1.7.9.rc2
--
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