From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: [PATCH v4 2/2] block: Convert integrity to bvec_alloc_bs() Date: Mon, 15 Oct 2012 13:09:02 -0700 Message-ID: <1350331769-14856-29-git-send-email-koverstreet@google.com> References: <1350331769-14856-1-git-send-email-koverstreet@google.com> Return-path: In-Reply-To: <1350331769-14856-1-git-send-email-koverstreet@google.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Cc: Kent Overstreet , tj@kernel.org, axboe@kernel.dk, vgoyal@redhat.com, martin.petersen@oracle.com List-Id: linux-bcache@vger.kernel.org This adds a pointer to the bvec array to struct bio_integrity_payload, instead of the bvecs always being inline; then the bvecs are allocated with bvec_alloc_bs(). Changed bvec_alloc_bs() and bvec_free_bs() to take a pointer to a mempool instead of the bioset, so that bio integrity can use a different mempool for its bvecs, and thus avoid a potential deadlock. This is eventually for immutable bio vecs - immutable bvecs aren't useful if we still have to copy them, hence the need for the pointer. Less code is always nice too, though. Also, bio_integrity_alloc() was using fs_bio_set if no bio_set was specified. This was wrong - using the bio_set doesn't protect us from memory allocation failures, because we just used kmalloc for the bio_integrity_payload. But it does introduce the possibility of deadlock, if for some reason we weren't supposed to be using fs_bio_set. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: Martin K. Petersen --- fs/bio-integrity.c | 132 +++++++++++++++++++--------------------------------- fs/bio.c | 36 ++++++-------- include/linux/bio.h | 8 ++-- 3 files changed, 68 insertions(+), 108 deletions(-) diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c index 94fa1c5..8c4c604 100644 --- a/fs/bio-integrity.c +++ b/fs/bio-integrity.c @@ -27,48 +27,11 @@ #include #include -struct integrity_slab { - struct kmem_cache *slab; - unsigned short nr_vecs; - char name[8]; -}; - -#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) } -struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = { - IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES), -}; -#undef IS +#define BIP_INLINE_VECS 4 +static struct kmem_cache *bip_slab; static struct workqueue_struct *kintegrityd_wq; -static inline unsigned int vecs_to_idx(unsigned int nr) -{ - switch (nr) { - case 1: - return 0; - case 2 ... 4: - return 1; - case 5 ... 16: - return 2; - case 17 ... 64: - return 3; - case 65 ... 128: - return 4; - case 129 ... BIO_MAX_PAGES: - return 5; - default: - BUG(); - } -} - -static inline int use_bip_pool(unsigned int idx) -{ - if (idx == BIOVEC_MAX_IDX) - return 1; - - return 0; -} - /** * bio_integrity_alloc - Allocate integrity payload and attach it to bio * @bio: bio to attach integrity metadata to @@ -84,38 +47,41 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, unsigned int nr_vecs) { struct bio_integrity_payload *bip; - unsigned int idx = vecs_to_idx(nr_vecs); struct bio_set *bs = bio->bi_pool; - - if (!bs) - bs = fs_bio_set; - - BUG_ON(bio == NULL); - bip = NULL; - - /* Lower order allocations come straight from slab */ - if (!use_bip_pool(idx)) - bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask); - - /* Use mempool if lower order alloc failed or max vecs were requested */ - if (bip == NULL) { - idx = BIOVEC_MAX_IDX; /* so we free the payload properly later */ + unsigned long idx = BIO_POOL_NONE; + unsigned inline_vecs; + + if (!bs) { + bip = kmalloc(sizeof(struct bio_integrity_payload) + + sizeof(struct bio_vec) * nr_vecs, gfp_mask); + inline_vecs = nr_vecs; + } else { bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask); - - if (unlikely(bip == NULL)) { - printk(KERN_ERR "%s: could not alloc bip\n", __func__); - return NULL; - } + inline_vecs = BIP_INLINE_VECS; } + if (unlikely(!bip)) + return NULL; + memset(bip, 0, sizeof(*bip)); + if (nr_vecs > inline_vecs) { + bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx, + bs->bvec_integrity_pool); + if (!bip->bip_vec) + goto err; + } else { + bip->bip_vec = bip->bip_inline_vecs; + } + bip->bip_slab = idx; bip->bip_bio = bio; - bip->bip_vec = bip->bip_inline_vecs; bio->bi_integrity = bip; return bip; +err: + mempool_free(bip, bs->bio_integrity_pool); + return NULL; } EXPORT_SYMBOL(bio_integrity_alloc); @@ -131,20 +97,20 @@ void bio_integrity_free(struct bio *bio) struct bio_integrity_payload *bip = bio->bi_integrity; struct bio_set *bs = bio->bi_pool; - if (!bs) - bs = fs_bio_set; - - BUG_ON(bip == NULL); - /* A cloned bio doesn't own the integrity metadata */ if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY) && bip->bip_buf != NULL) kfree(bip->bip_buf); - if (use_bip_pool(bip->bip_slab)) + if (bs) { + if (bip->bip_slab != BIO_POOL_NONE) + bvec_free(bs->bvec_integrity_pool, bip->bip_vec, + bip->bip_slab); + mempool_free(bip, bs->bio_integrity_pool); - else - kmem_cache_free(bip_slab[bip->bip_slab].slab, bip); + } else { + kfree(bip); + } bio->bi_integrity = NULL; } @@ -747,13 +713,14 @@ EXPORT_SYMBOL(bio_integrity_clone); int bioset_integrity_create(struct bio_set *bs, int pool_size) { - unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES); - if (bs->bio_integrity_pool) return 0; - bs->bio_integrity_pool = - mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab); + bs->bio_integrity_pool = mempool_create_slab_pool(pool_size, bip_slab); + + bs->bvec_integrity_pool = biovec_create_pool(bs, pool_size); + if (!bs->bvec_integrity_pool) + return -1; if (!bs->bio_integrity_pool) return -1; @@ -766,13 +733,14 @@ void bioset_integrity_free(struct bio_set *bs) { if (bs->bio_integrity_pool) mempool_destroy(bs->bio_integrity_pool); + + if (bs->bvec_integrity_pool) + mempool_destroy(bs->bio_integrity_pool); } EXPORT_SYMBOL(bioset_integrity_free); void __init bio_integrity_init(void) { - unsigned int i; - /* * kintegrityd won't block much but may burn a lot of CPU cycles. * Make it highpri CPU intensive wq with max concurrency of 1. @@ -782,14 +750,10 @@ void __init bio_integrity_init(void) if (!kintegrityd_wq) panic("Failed to create kintegrityd\n"); - for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) { - unsigned int size; - - size = sizeof(struct bio_integrity_payload) - + bip_slab[i].nr_vecs * sizeof(struct bio_vec); - - bip_slab[i].slab = - kmem_cache_create(bip_slab[i].name, size, 0, - SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); - } + bip_slab = kmem_cache_create("bio_integrity_payload", + sizeof(struct bio_integrity_payload) + + sizeof(struct bio_vec) * BIP_INLINE_VECS, + 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + if (!bip_slab) + panic("Failed to create slab\n"); } diff --git a/fs/bio.c b/fs/bio.c index 9aa1938..f16aa6b 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -158,12 +158,12 @@ unsigned int bvec_nr_vecs(unsigned short idx) return bvec_slabs[idx].nr_vecs; } -void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx) +void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx) { BIO_BUG_ON(idx >= BIOVEC_NR_POOLS); if (idx == BIOVEC_MAX_IDX) - mempool_free(bv, bs->bvec_pool); + mempool_free(bv, pool); else { struct biovec_slab *bvs = bvec_slabs + idx; @@ -171,8 +171,8 @@ void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx) } } -struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, - struct bio_set *bs) +struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, + mempool_t *pool) { struct bio_vec *bvl; @@ -208,7 +208,7 @@ struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, */ if (*idx == BIOVEC_MAX_IDX) { fallback: - bvl = mempool_alloc(bs->bvec_pool, gfp_mask); + bvl = mempool_alloc(pool, gfp_mask); } else { struct biovec_slab *bvs = bvec_slabs + *idx; gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO); @@ -251,7 +251,7 @@ static void bio_free(struct bio *bio) if (bs) { if (bio_has_allocated_vec(bio)) - bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); + bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio)); /* * If we have front padding, adjust the bio pointer before freeing @@ -440,11 +440,11 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) bio_init(bio); if (nr_iovecs > inline_vecs) { - bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); + bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool); if (!bvl && gfp_mask != saved_gfp) { punt_bios_to_rescuer(bs); gfp_mask = saved_gfp; - bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); + bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool); } if (unlikely(!bvl)) @@ -1657,20 +1657,11 @@ EXPORT_SYMBOL(bio_sector_offset); * create memory pools for biovec's in a bio_set. * use the global biovec slabs created for general use. */ -static int biovec_create_pools(struct bio_set *bs, int pool_entries) +mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries) { struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX; - bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab); - if (!bs->bvec_pool) - return -ENOMEM; - - return 0; -} - -static void biovec_free_pools(struct bio_set *bs) -{ - mempool_destroy(bs->bvec_pool); + return mempool_create_slab_pool(pool_entries, bp->slab); } void bioset_free(struct bio_set *bs) @@ -1681,8 +1672,10 @@ void bioset_free(struct bio_set *bs) if (bs->bio_pool) mempool_destroy(bs->bio_pool); + if (bs->bvec_pool) + mempool_destroy(bs->bvec_pool); + bioset_integrity_free(bs); - biovec_free_pools(bs); bio_put_slab(bs); kfree(bs); @@ -1727,7 +1720,8 @@ struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) if (!bs->bio_pool) goto bad; - if (biovec_create_pools(bs, pool_size)) + bs->bvec_pool = biovec_create_pool(bs, pool_size); + if (!bs->bvec_pool) goto bad; bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); diff --git a/include/linux/bio.h b/include/linux/bio.h index 81004fd..669b1cb 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -213,6 +213,7 @@ extern void bio_pair_release(struct bio_pair *dbio); extern struct bio_set *bioset_create(unsigned int, unsigned int); extern void bioset_free(struct bio_set *); +extern mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries); extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *); extern void bio_put(struct bio *); @@ -288,8 +289,8 @@ extern struct bio *bio_copy_user_iov(struct request_queue *, int, int, gfp_t); extern int bio_uncopy_user(struct bio *); void zero_fill_bio(struct bio *bio); -extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *); -extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int); +extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); +extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int); extern unsigned int bvec_nr_vecs(unsigned short idx); #ifdef CONFIG_BLK_CGROUP @@ -511,10 +512,11 @@ struct bio_set { unsigned int front_pad; mempool_t *bio_pool; + mempool_t *bvec_pool; #if defined(CONFIG_BLK_DEV_INTEGRITY) mempool_t *bio_integrity_pool; + mempool_t *bvec_integrity_pool; #endif - mempool_t *bvec_pool; /* * Deadlock avoidance for stacking block drivers: see comments in -- 1.7.12