On Wed, May 09, 2012 at 11:08:34PM -0400, Kent Overstreet wrote: > 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.
Ok, that will explain BIO_HAS_POOL flag. Why to replace bio_has_allocated_vec() with BIO_HAS_VEC flag? Thanks Vivek > > Signed-off-by: Kent Overstreet <[email protected]> > --- > 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 > > -- > dm-devel mailing list > [email protected] > https://www.redhat.com/mailman/listinfo/dm-devel -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
