block: add private bio_set for bio integrity allocations

The integrity bio allocation needs its own bio_set to avoid violating
the mempool allocation rules and risking deadlocks.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 28 insertions, 66 deletions

diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
index fe2b1aa2464e..31c46a241bac 100644
--- a/fs/bio-integrity.c
+++ b/fs/bio-integrity.c
@@ -26,23 +26,23 @@
 #include <linux/workqueue.h>
 
 static struct kmem_cache *bio_integrity_slab __read_mostly;
+static mempool_t *bio_integrity_pool;
+static struct bio_set *integrity_bio_set;
 static struct workqueue_struct *kintegrityd_wq;
 
 /**
- * bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
+ * bio_integrity_alloc - Allocate integrity payload and attach it to bio
  * @bio:        bio to attach integrity metadata to
  * @gfp_mask:   Memory allocation mask
  * @nr_vecs:    Number of integrity metadata scatter-gather elements
- * @bs:         bio_set to allocate from
  *
  * Description: This function prepares a bio for attaching integrity
  * metadata.  nr_vecs specifies the maximum number of pages containing
  * integrity metadata that can be attached.
  */
-struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
-                                                         gfp_t gfp_mask,
-                                                         unsigned int nr_vecs,
-                                                         struct bio_set *bs)
+struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
+                                                  gfp_t gfp_mask,
+                                                  unsigned int nr_vecs)
 {
         struct bio_integrity_payload *bip;
         struct bio_vec *iv;
@@ -50,7 +50,7 @@ struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
 
         BUG_ON(bio == NULL);
 
-        bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
+        bip = mempool_alloc(bio_integrity_pool, gfp_mask);
         if (unlikely(bip == NULL)) {
                 printk(KERN_ERR "%s: could not alloc bip\n", __func__);
                 return NULL;
@@ -58,10 +58,10 @@ struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
 
         memset(bip, 0, sizeof(*bip));
 
-        iv = bvec_alloc_bs(gfp_mask, nr_vecs, &idx, bs);
+        iv = bvec_alloc_bs(gfp_mask, nr_vecs, &idx, integrity_bio_set);
         if (unlikely(iv == NULL)) {
                 printk(KERN_ERR "%s: could not alloc bip_vec\n", __func__);
-                mempool_free(bip, bs->bio_integrity_pool);
+                mempool_free(bip, bio_integrity_pool);
                 return NULL;
         }
 
@@ -72,35 +72,16 @@ struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
 
         return bip;
 }
-EXPORT_SYMBOL(bio_integrity_alloc_bioset);
-
-/**
- * bio_integrity_alloc - Allocate integrity payload and attach it to bio
- * @bio:        bio to attach integrity metadata to
- * @gfp_mask:   Memory allocation mask
- * @nr_vecs:    Number of integrity metadata scatter-gather elements
- *
- * Description: This function prepares a bio for attaching integrity
- * metadata.  nr_vecs specifies the maximum number of pages containing
- * integrity metadata that can be attached.
- */
-struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
-                                                  gfp_t gfp_mask,
-                                                  unsigned int nr_vecs)
-{
-        return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
-}
 EXPORT_SYMBOL(bio_integrity_alloc);
 
 /**
  * bio_integrity_free - Free bio integrity payload
  * @bio:        bio containing bip to be freed
- * @bs:         bio_set this bio was allocated from
  *
  * Description: Used to free the integrity portion of a bio. Usually
  * called from bio_free().
  */
-void bio_integrity_free(struct bio *bio, struct bio_set *bs)
+void bio_integrity_free(struct bio *bio)
 {
         struct bio_integrity_payload *bip = bio->bi_integrity;
 
@@ -111,8 +92,8 @@ void bio_integrity_free(struct bio *bio, struct bio_set *bs)
             && bip->bip_buf != NULL)
                 kfree(bip->bip_buf);
 
-        bvec_free_bs(bs, bip->bip_vec, bip->bip_pool);
-        mempool_free(bip, bs->bio_integrity_pool);
+        bvec_free_bs(integrity_bio_set, bip->bip_vec, bip->bip_pool);
+        mempool_free(bip, bio_integrity_pool);
 
         bio->bi_integrity = NULL;
 }
@@ -686,19 +667,17 @@ EXPORT_SYMBOL(bio_integrity_split);
  * @bio:        New bio
  * @bio_src:    Original bio
  * @gfp_mask:   Memory allocation mask
- * @bs:         bio_set to allocate bip from
  *
  * Description: Called to allocate a bip when cloning a bio
  */
-int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
-                        gfp_t gfp_mask, struct bio_set *bs)
+int bio_integrity_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp_mask)
 {
         struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
         struct bio_integrity_payload *bip;
 
         BUG_ON(bip_src == NULL);
 
-        bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
+        bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
 
         if (bip == NULL)
                 return -EIO;
@@ -714,37 +693,25 @@ int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 }
 EXPORT_SYMBOL(bio_integrity_clone);
 
-int bioset_integrity_create(struct bio_set *bs, int pool_size)
+static int __init bio_integrity_init(void)
 {
-        bs->bio_integrity_pool = mempool_create_slab_pool(pool_size,
-                                                          bio_integrity_slab);
-        if (!bs->bio_integrity_pool)
-                return -1;
-
-        return 0;
-}
-EXPORT_SYMBOL(bioset_integrity_create);
+        kintegrityd_wq = create_workqueue("kintegrityd");
 
-void bioset_integrity_free(struct bio_set *bs)
-{
-        if (bs->bio_integrity_pool)
-                mempool_destroy(bs->bio_integrity_pool);
-}
-EXPORT_SYMBOL(bioset_integrity_free);
+        if (!kintegrityd_wq)
+                panic("Failed to create kintegrityd\n");
 
-void __init bio_integrity_init_slab(void)
-{
         bio_integrity_slab = KMEM_CACHE(bio_integrity_payload,
                                         SLAB_HWCACHE_ALIGN|SLAB_PANIC);
-}
 
-static int __init integrity_init(void)
-{
-        kintegrityd_wq = create_workqueue("kintegrityd");
+        bio_integrity_pool = mempool_create_slab_pool(BIO_POOL_SIZE,
+                                                      bio_integrity_slab);
+        if (!bio_integrity_pool)
+                panic("bio_integrity: can't allocate bip pool\n");
 
-        if (!kintegrityd_wq)
-                panic("Failed to create kintegrityd\n");
+        integrity_bio_set = bioset_create(BIO_POOL_SIZE, 0);
+        if (!integrity_bio_set)
+                panic("bio_integrity: can't allocate bio_set\n");
 
         return 0;
 }
-subsys_initcall(integrity_init);
+subsys_initcall(bio_integrity_init);
diff --git a/fs/bio.c b/fs/bio.c
index 9cc1430b4495..a040cde7f6fd 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -248,7 +248,7 @@ 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, bs);
+                bio_integrity_free(bio);
 
         /*
          * If we have front padding, adjust the bio pointer before freeing
@@ -466,7 +466,7 @@ 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, fs_bio_set);
+                ret = bio_integrity_clone(b, bio, gfp_mask);
 
                 if (ret < 0) {
                         bio_put(b);
@@ -1529,7 +1529,6 @@ 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);
 
@@ -1570,9 +1569,6 @@ 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;
 
@@ -1610,7 +1606,6 @@ static int __init init_bio(void)
         if (!bio_slabs)
                 panic("bio: can't allocate bios\n");
 
-        bio_integrity_init_slab();
         biovec_init_slabs();
 
         fs_bio_set = bioset_create(BIO_POOL_SIZE, 0);