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Diffstat (limited to 'fs/bio-integrity.c')
| -rw-r--r-- | fs/bio-integrity.c | 657 |
1 files changed, 0 insertions, 657 deletions
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c deleted file mode 100644 index 9e241063a616..000000000000 --- a/fs/bio-integrity.c +++ /dev/null @@ -1,657 +0,0 @@ -/* - * bio-integrity.c - bio data integrity extensions - * - * Copyright (C) 2007, 2008, 2009 Oracle Corporation - * Written by: Martin K. Petersen <martin.petersen@oracle.com> - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License version - * 2 as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; see the file COPYING. If not, write to - * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, - * USA. - * - */ - -#include <linux/blkdev.h> -#include <linux/mempool.h> -#include <linux/export.h> -#include <linux/bio.h> -#include <linux/workqueue.h> -#include <linux/slab.h> - -#define BIP_INLINE_VECS 4 - -static struct kmem_cache *bip_slab; -static struct workqueue_struct *kintegrityd_wq; - -/** - * 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) -{ - struct bio_integrity_payload *bip; - struct bio_set *bs = bio->bi_pool; - 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); - 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; - bio->bi_integrity = bip; - - return bip; -err: - mempool_free(bip, bs->bio_integrity_pool); - return NULL; -} -EXPORT_SYMBOL(bio_integrity_alloc); - -/** - * bio_integrity_free - Free bio integrity payload - * @bio: bio containing bip to be freed - * - * Description: Used to free the integrity portion of a bio. Usually - * called from bio_free(). - */ -void bio_integrity_free(struct bio *bio) -{ - struct bio_integrity_payload *bip = bio->bi_integrity; - struct bio_set *bs = bio->bi_pool; - - if (bip->bip_owns_buf) - kfree(bip->bip_buf); - - 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 { - kfree(bip); - } - - bio->bi_integrity = NULL; -} -EXPORT_SYMBOL(bio_integrity_free); - -static inline unsigned int bip_integrity_vecs(struct bio_integrity_payload *bip) -{ - if (bip->bip_slab == BIO_POOL_NONE) - return BIP_INLINE_VECS; - - return bvec_nr_vecs(bip->bip_slab); -} - -/** - * bio_integrity_add_page - Attach integrity metadata - * @bio: bio to update - * @page: page containing integrity metadata - * @len: number of bytes of integrity metadata in page - * @offset: start offset within page - * - * Description: Attach a page containing integrity metadata to bio. - */ -int bio_integrity_add_page(struct bio *bio, struct page *page, - unsigned int len, unsigned int offset) -{ - struct bio_integrity_payload *bip = bio->bi_integrity; - struct bio_vec *iv; - - if (bip->bip_vcnt >= bip_integrity_vecs(bip)) { - printk(KERN_ERR "%s: bip_vec full\n", __func__); - return 0; - } - - iv = bip->bip_vec + bip->bip_vcnt; - - iv->bv_page = page; - iv->bv_len = len; - iv->bv_offset = offset; - bip->bip_vcnt++; - - return len; -} -EXPORT_SYMBOL(bio_integrity_add_page); - -static int bdev_integrity_enabled(struct block_device *bdev, int rw) -{ - struct blk_integrity *bi = bdev_get_integrity(bdev); - - if (bi == NULL) - return 0; - - if (rw == READ && bi->verify_fn != NULL && - (bi->flags & INTEGRITY_FLAG_READ)) - return 1; - - if (rw == WRITE && bi->generate_fn != NULL && - (bi->flags & INTEGRITY_FLAG_WRITE)) - return 1; - - return 0; -} - -/** - * bio_integrity_enabled - Check whether integrity can be passed - * @bio: bio to check - * - * Description: Determines whether bio_integrity_prep() can be called - * on this bio or not. bio data direction and target device must be - * set prior to calling. The functions honors the write_generate and - * read_verify flags in sysfs. - */ -int bio_integrity_enabled(struct bio *bio) -{ - if (!bio_is_rw(bio)) - return 0; - - /* Already protected? */ - if (bio_integrity(bio)) - return 0; - - return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio)); -} -EXPORT_SYMBOL(bio_integrity_enabled); - -/** - * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto - * @bi: blk_integrity profile for device - * @sectors: Number of 512 sectors to convert - * - * Description: The block layer calculates everything in 512 byte - * sectors but integrity metadata is done in terms of the hardware - * sector size of the storage device. Convert the block layer sectors - * to physical sectors. - */ -static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi, - unsigned int sectors) -{ - /* At this point there are only 512b or 4096b DIF/EPP devices */ - if (bi->sector_size == 4096) - return sectors >>= 3; - - return sectors; -} - -static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi, - unsigned int sectors) -{ - return bio_integrity_hw_sectors(bi, sectors) * bi->tuple_size; -} - -/** - * bio_integrity_tag_size - Retrieve integrity tag space - * @bio: bio to inspect - * - * Description: Returns the maximum number of tag bytes that can be - * attached to this bio. Filesystems can use this to determine how - * much metadata to attach to an I/O. - */ -unsigned int bio_integrity_tag_size(struct bio *bio) -{ - struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); - - BUG_ON(bio->bi_iter.bi_size == 0); - - return bi->tag_size * (bio->bi_iter.bi_size / bi->sector_size); -} -EXPORT_SYMBOL(bio_integrity_tag_size); - -static int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, - int set) -{ - struct bio_integrity_payload *bip = bio->bi_integrity; - struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); - unsigned int nr_sectors; - - BUG_ON(bip->bip_buf == NULL); - - if (bi->tag_size == 0) - return -1; - - nr_sectors = bio_integrity_hw_sectors(bi, - DIV_ROUND_UP(len, bi->tag_size)); - - if (nr_sectors * bi->tuple_size > bip->bip_iter.bi_size) { - printk(KERN_ERR "%s: tag too big for bio: %u > %u\n", __func__, - nr_sectors * bi->tuple_size, bip->bip_iter.bi_size); - return -1; - } - - if (set) - bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors); - else - bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors); - - return 0; -} - -/** - * bio_integrity_set_tag - Attach a tag buffer to a bio - * @bio: bio to attach buffer to - * @tag_buf: Pointer to a buffer containing tag data - * @len: Length of the included buffer - * - * Description: Use this function to tag a bio by leveraging the extra - * space provided by devices formatted with integrity protection. The - * size of the integrity buffer must be <= to the size reported by - * bio_integrity_tag_size(). - */ -int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len) -{ - BUG_ON(bio_data_dir(bio) != WRITE); - - return bio_integrity_tag(bio, tag_buf, len, 1); -} -EXPORT_SYMBOL(bio_integrity_set_tag); - -/** - * bio_integrity_get_tag - Retrieve a tag buffer from a bio - * @bio: bio to retrieve buffer from - * @tag_buf: Pointer to a buffer for the tag data - * @len: Length of the target buffer - * - * Description: Use this function to retrieve the tag buffer from a - * completed I/O. The size of the integrity buffer must be <= to the - * size reported by bio_integrity_tag_size(). - */ -int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len) -{ - BUG_ON(bio_data_dir(bio) != READ); - - return bio_integrity_tag(bio, tag_buf, len, 0); -} -EXPORT_SYMBOL(bio_integrity_get_tag); - -/** - * bio_integrity_generate_verify - Generate/verify integrity metadata for a bio - * @bio: bio to generate/verify integrity metadata for - * @operate: operate number, 1 for generate, 0 for verify - */ -static int bio_integrity_generate_verify(struct bio *bio, int operate) -{ - struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); - struct blk_integrity_exchg bix; - struct bio_vec *bv; - sector_t sector; - unsigned int sectors, ret = 0, i; - void *prot_buf = bio->bi_integrity->bip_buf; - - if (operate) - sector = bio->bi_iter.bi_sector; - else - sector = bio->bi_integrity->bip_iter.bi_sector; - - bix.disk_name = bio->bi_bdev->bd_disk->disk_name; - bix.sector_size = bi->sector_size; - - bio_for_each_segment_all(bv, bio, i) { - void *kaddr = kmap_atomic(bv->bv_page); - bix.data_buf = kaddr + bv->bv_offset; - bix.data_size = bv->bv_len; - bix.prot_buf = prot_buf; - bix.sector = sector; - - if (operate) - bi->generate_fn(&bix); - else { - ret = bi->verify_fn(&bix); - if (ret) { - kunmap_atomic(kaddr); - return ret; - } - } - - sectors = bv->bv_len / bi->sector_size; - sector += sectors; - prot_buf += sectors * bi->tuple_size; - - kunmap_atomic(kaddr); - } - return ret; -} - -/** - * bio_integrity_generate - Generate integrity metadata for a bio - * @bio: bio to generate integrity metadata for - * - * Description: Generates integrity metadata for a bio by calling the - * block device's generation callback function. The bio must have a - * bip attached with enough room to accommodate the generated - * integrity metadata. - */ -static void bio_integrity_generate(struct bio *bio) -{ - bio_integrity_generate_verify(bio, 1); -} - -static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi) -{ - if (bi) - return bi->tuple_size; - - return 0; -} - -/** - * bio_integrity_prep - Prepare bio for integrity I/O - * @bio: bio to prepare - * - * Description: Allocates a buffer for integrity metadata, maps the - * pages and attaches them to a bio. The bio must have data - * direction, target device and start sector set priot to calling. In - * the WRITE case, integrity metadata will be generated using the - * block device's integrity function. In the READ case, the buffer - * will be prepared for DMA and a suitable end_io handler set up. - */ -int bio_integrity_prep(struct bio *bio) -{ - struct bio_integrity_payload *bip; - struct blk_integrity *bi; - struct request_queue *q; - void *buf; - unsigned long start, end; - unsigned int len, nr_pages; - unsigned int bytes, offset, i; - unsigned int sectors; - - bi = bdev_get_integrity(bio->bi_bdev); - q = bdev_get_queue(bio->bi_bdev); - BUG_ON(bi == NULL); - BUG_ON(bio_integrity(bio)); - - sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio)); - - /* Allocate kernel buffer for protection data */ - len = sectors * blk_integrity_tuple_size(bi); - buf = kmalloc(len, GFP_NOIO | q->bounce_gfp); - if (unlikely(buf == NULL)) { - printk(KERN_ERR "could not allocate integrity buffer\n"); - return -ENOMEM; - } - - end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT; - start = ((unsigned long) buf) >> PAGE_SHIFT; - nr_pages = end - start; - - /* Allocate bio integrity payload and integrity vectors */ - bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages); - if (unlikely(bip == NULL)) { - printk(KERN_ERR "could not allocate data integrity bioset\n"); - kfree(buf); - return -EIO; - } - - bip->bip_owns_buf = 1; - bip->bip_buf = buf; - bip->bip_iter.bi_size = len; - bip->bip_iter.bi_sector = bio->bi_iter.bi_sector; - - /* Map it */ - offset = offset_in_page(buf); - for (i = 0 ; i < nr_pages ; i++) { - int ret; - bytes = PAGE_SIZE - offset; - - if (len <= 0) - break; - - if (bytes > len) - bytes = len; - - ret = bio_integrity_add_page(bio, virt_to_page(buf), - bytes, offset); - - if (ret == 0) - return 0; - - if (ret < bytes) - break; - - buf += bytes; - len -= bytes; - offset = 0; - } - - /* Install custom I/O completion handler if read verify is enabled */ - if (bio_data_dir(bio) == READ) { - bip->bip_end_io = bio->bi_end_io; - bio->bi_end_io = bio_integrity_endio; - } - - /* Auto-generate integrity metadata if this is a write */ - if (bio_data_dir(bio) == WRITE) - bio_integrity_generate(bio); - - return 0; -} -EXPORT_SYMBOL(bio_integrity_prep); - -/** - * bio_integrity_verify - Verify integrity metadata for a bio - * @bio: bio to verify - * - * Description: This function is called to verify the integrity of a - * bio. The data in the bio io_vec is compared to the integrity - * metadata returned by the HBA. - */ -static int bio_integrity_verify(struct bio *bio) -{ - return bio_integrity_generate_verify(bio, 0); -} - -/** - * bio_integrity_verify_fn - Integrity I/O completion worker - * @work: Work struct stored in bio to be verified - * - * Description: This workqueue function is called to complete a READ - * request. The function verifies the transferred integrity metadata - * and then calls the original bio end_io function. - */ -static void bio_integrity_verify_fn(struct work_struct *work) -{ - struct bio_integrity_payload *bip = - container_of(work, struct bio_integrity_payload, bip_work); - struct bio *bio = bip->bip_bio; - int error; - - error = bio_integrity_verify(bio); - - /* Restore original bio completion handler */ - bio->bi_end_io = bip->bip_end_io; - bio_endio_nodec(bio, error); -} - -/** - * bio_integrity_endio - Integrity I/O completion function - * @bio: Protected bio - * @error: Pointer to errno - * - * Description: Completion for integrity I/O - * - * Normally I/O completion is done in interrupt context. However, - * verifying I/O integrity is a time-consuming task which must be run - * in process context. This function postpones completion - * accordingly. - */ -void bio_integrity_endio(struct bio *bio, int error) -{ - struct bio_integrity_payload *bip = bio->bi_integrity; - - BUG_ON(bip->bip_bio != bio); - - /* In case of an I/O error there is no point in verifying the - * integrity metadata. Restore original bio end_io handler - * and run it. - */ - if (error) { - bio->bi_end_io = bip->bip_end_io; - bio_endio(bio, error); - - return; - } - - INIT_WORK(&bip->bip_work, bio_integrity_verify_fn); - queue_work(kintegrityd_wq, &bip->bip_work); -} -EXPORT_SYMBOL(bio_integrity_endio); - -/** - * bio_integrity_advance - Advance integrity vector - * @bio: bio whose integrity vector to update - * @bytes_done: number of data bytes that have been completed - * - * Description: This function calculates how many integrity bytes the - * number of completed data bytes correspond to and advances the - * integrity vector accordingly. - */ -void bio_integrity_advance(struct bio *bio, unsigned int bytes_done) -{ - struct bio_integrity_payload *bip = bio->bi_integrity; - struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); - unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9); - - bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes); -} -EXPORT_SYMBOL(bio_integrity_advance); - -/** - * bio_integrity_trim - Trim integrity vector - * @bio: bio whose integrity vector to update - * @offset: offset to first data sector - * @sectors: number of data sectors - * - * Description: Used to trim the integrity vector in a cloned bio. - * The ivec will be advanced corresponding to 'offset' data sectors - * and the length will be truncated corresponding to 'len' data - * sectors. - */ -void bio_integrity_trim(struct bio *bio, unsigned int offset, - unsigned int sectors) -{ - struct bio_integrity_payload *bip = bio->bi_integrity; - struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); - - bio_integrity_advance(bio, offset << 9); - bip->bip_iter.bi_size = bio_integrity_bytes(bi, sectors); -} -EXPORT_SYMBOL(bio_integrity_trim); - -/** - * bio_integrity_clone - Callback for cloning bios with integrity metadata - * @bio: New bio - * @bio_src: Original bio - * @gfp_mask: Memory allocation mask - * - * 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_integrity_payload *bip_src = bio_src->bi_integrity; - struct bio_integrity_payload *bip; - - BUG_ON(bip_src == NULL); - - bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt); - - if (bip == NULL) - return -EIO; - - memcpy(bip->bip_vec, bip_src->bip_vec, - bip_src->bip_vcnt * sizeof(struct bio_vec)); - - bip->bip_vcnt = bip_src->bip_vcnt; - bip->bip_iter = bip_src->bip_iter; - - return 0; -} -EXPORT_SYMBOL(bio_integrity_clone); - -int bioset_integrity_create(struct bio_set *bs, int pool_size) -{ - if (bs->bio_integrity_pool) - return 0; - - bs->bio_integrity_pool = mempool_create_slab_pool(pool_size, bip_slab); - if (!bs->bio_integrity_pool) - return -1; - - bs->bvec_integrity_pool = biovec_create_pool(pool_size); - if (!bs->bvec_integrity_pool) { - mempool_destroy(bs->bio_integrity_pool); - return -1; - } - - return 0; -} -EXPORT_SYMBOL(bioset_integrity_create); - -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->bvec_integrity_pool); -} -EXPORT_SYMBOL(bioset_integrity_free); - -void __init bio_integrity_init(void) -{ - /* - * kintegrityd won't block much but may burn a lot of CPU cycles. - * Make it highpri CPU intensive wq with max concurrency of 1. - */ - kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM | - WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1); - if (!kintegrityd_wq) - panic("Failed to create kintegrityd\n"); - - 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"); -} |