block: Create bip slabs with embedded integrity vectors

This patch restores stacking ability to the block layer integrity
infrastructure by creating a set of dedicated bip slabs.  Each bip slab
has an embedded bio_vec array at the end.  This cuts down on memory
allocations and also simplifies the code compared to the original bvec
version.  Only the largest bip slab is backed by a mempool.  The pool is
contained in the bio_set so stacking drivers can ensure forward
progress.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.(none)>

1 files changed, 8 insertions, 3 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 24c914043532..1486b19fc431 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -238,7 +238,7 @@ void bio_free(struct bio *bio, struct bio_set *bs)
                 bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
 
         if (bio_integrity(bio))
-                bio_integrity_free(bio);
+                bio_integrity_free(bio, bs);
 
         /*
          * If we have front padding, adjust the bio pointer before freeing
@@ -341,7 +341,7 @@ struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
 static void bio_kmalloc_destructor(struct bio *bio)
 {
         if (bio_integrity(bio))
-                bio_integrity_free(bio);
+                bio_integrity_free(bio, fs_bio_set);
         kfree(bio);
 }
 
@@ -472,7 +472,7 @@ struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
         if (bio_integrity(bio)) {
                 int ret;
 
-                ret = bio_integrity_clone(b, bio, gfp_mask);
+                ret = bio_integrity_clone(b, bio, gfp_mask, fs_bio_set);
 
                 if (ret < 0) {
                         bio_put(b);
@@ -1539,6 +1539,7 @@ void bioset_free(struct bio_set *bs)
         if (bs->bio_pool)
                 mempool_destroy(bs->bio_pool);
 
+        bioset_integrity_free(bs);
         biovec_free_pools(bs);
         bio_put_slab(bs);
 
@@ -1579,6 +1580,9 @@ struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
         if (!bs->bio_pool)
                 goto bad;
 
+        if (bioset_integrity_create(bs, pool_size))
+                goto bad;
+
         if (!biovec_create_pools(bs, pool_size))
                 return bs;
 
@@ -1616,6 +1620,7 @@ static int __init init_bio(void)
         if (!bio_slabs)
                 panic("bio: can't allocate bios\n");
 
+        bio_integrity_init();
         biovec_init_slabs();
 
         fs_bio_set = bioset_create(BIO_POOL_SIZE, 0);