diff options
Diffstat (limited to 'block')
-rw-r--r-- | block/Makefile | 7 | ||||
-rw-r--r-- | block/bio-integrity.c | 657 | ||||
-rw-r--r-- | block/bio.c | 2038 | ||||
-rw-r--r-- | block/blk-cgroup.c | 15 | ||||
-rw-r--r-- | block/blk-core.c | 113 | ||||
-rw-r--r-- | block/blk-flush.c | 40 | ||||
-rw-r--r-- | block/blk-iopoll.c | 8 | ||||
-rw-r--r-- | block/blk-lib.c | 4 | ||||
-rw-r--r-- | block/blk-map.c | 3 | ||||
-rw-r--r-- | block/blk-merge.c | 28 | ||||
-rw-r--r-- | block/blk-mq-cpu.c | 17 | ||||
-rw-r--r-- | block/blk-mq-cpumap.c | 27 | ||||
-rw-r--r-- | block/blk-mq-sysfs.c | 160 | ||||
-rw-r--r-- | block/blk-mq-tag.c | 581 | ||||
-rw-r--r-- | block/blk-mq-tag.h | 71 | ||||
-rw-r--r-- | block/blk-mq.c | 1454 | ||||
-rw-r--r-- | block/blk-mq.h | 77 | ||||
-rw-r--r-- | block/blk-sysfs.c | 47 | ||||
-rw-r--r-- | block/blk-throttle.c | 10 | ||||
-rw-r--r-- | block/blk-timeout.c | 60 | ||||
-rw-r--r-- | block/blk.h | 9 | ||||
-rw-r--r-- | block/bounce.c | 290 | ||||
-rw-r--r-- | block/bsg.c | 2 | ||||
-rw-r--r-- | block/cfq-iosched.c | 4 | ||||
-rw-r--r-- | block/ioprio.c | 241 | ||||
-rw-r--r-- | block/scsi_ioctl.c | 4 |
26 files changed, 5183 insertions, 784 deletions
diff --git a/block/Makefile b/block/Makefile index 20645e8..a2ce6ac 100644 --- a/block/Makefile +++ b/block/Makefile @@ -2,13 +2,15 @@ # Makefile for the kernel block layer # -obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \ +obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-tag.o blk-sysfs.o \ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \ blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \ blk-iopoll.o blk-lib.o blk-mq.o blk-mq-tag.o \ blk-mq-sysfs.o blk-mq-cpu.o blk-mq-cpumap.o ioctl.o \ - genhd.o scsi_ioctl.o partition-generic.o partitions/ + genhd.o scsi_ioctl.o partition-generic.o ioprio.o \ + partitions/ +obj-$(CONFIG_BOUNCE) += bounce.o obj-$(CONFIG_BLK_DEV_BSG) += bsg.o obj-$(CONFIG_BLK_DEV_BSGLIB) += bsg-lib.o obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o @@ -20,3 +22,4 @@ obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o obj-$(CONFIG_BLK_CMDLINE_PARSER) += cmdline-parser.o +obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o diff --git a/block/bio-integrity.c b/block/bio-integrity.c new file mode 100644 index 0000000..9e24106 --- /dev/null +++ b/block/bio-integrity.c @@ -0,0 +1,657 @@ +/* + * 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"); +} diff --git a/block/bio.c b/block/bio.c new file mode 100644 index 0000000..96d28ee --- /dev/null +++ b/block/bio.c @@ -0,0 +1,2038 @@ +/* + * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> + * + * 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 Licens + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- + * + */ +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/uio.h> +#include <linux/iocontext.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/mempool.h> +#include <linux/workqueue.h> +#include <linux/cgroup.h> +#include <scsi/sg.h> /* for struct sg_iovec */ + +#include <trace/events/block.h> + +/* + * Test patch to inline a certain number of bi_io_vec's inside the bio + * itself, to shrink a bio data allocation from two mempool calls to one + */ +#define BIO_INLINE_VECS 4 + +/* + * if you change this list, also change bvec_alloc or things will + * break badly! cannot be bigger than what you can fit into an + * unsigned short + */ +#define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } +static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { + BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), +}; +#undef BV + +/* + * fs_bio_set is the bio_set containing bio and iovec memory pools used by + * IO code that does not need private memory pools. + */ +struct bio_set *fs_bio_set; +EXPORT_SYMBOL(fs_bio_set); + +/* + * Our slab pool management + */ +struct bio_slab { + struct kmem_cache *slab; + unsigned int slab_ref; + unsigned int slab_size; + char name[8]; +}; +static DEFINE_MUTEX(bio_slab_lock); +static struct bio_slab *bio_slabs; +static unsigned int bio_slab_nr, bio_slab_max; + +static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) +{ + unsigned int sz = sizeof(struct bio) + extra_size; + struct kmem_cache *slab = NULL; + struct bio_slab *bslab, *new_bio_slabs; + unsigned int new_bio_slab_max; + unsigned int i, entry = -1; + + mutex_lock(&bio_slab_lock); + + i = 0; + while (i < bio_slab_nr) { + bslab = &bio_slabs[i]; + + if (!bslab->slab && entry == -1) + entry = i; + else if (bslab->slab_size == sz) { + slab = bslab->slab; + bslab->slab_ref++; + break; + } + i++; + } + + if (slab) + goto out_unlock; + + if (bio_slab_nr == bio_slab_max && entry == -1) { + new_bio_slab_max = bio_slab_max << 1; + new_bio_slabs = krealloc(bio_slabs, + new_bio_slab_max * sizeof(struct bio_slab), + GFP_KERNEL); + if (!new_bio_slabs) + goto out_unlock; + bio_slab_max = new_bio_slab_max; + bio_slabs = new_bio_slabs; + } + if (entry == -1) + entry = bio_slab_nr++; + + bslab = &bio_slabs[entry]; + + snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); + slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL); + if (!slab) + goto out_unlock; + + bslab->slab = slab; + bslab->slab_ref = 1; + bslab->slab_size = sz; +out_unlock: + mutex_unlock(&bio_slab_lock); + return slab; +} + +static void bio_put_slab(struct bio_set *bs) +{ + struct bio_slab *bslab = NULL; + unsigned int i; + + mutex_lock(&bio_slab_lock); + + for (i = 0; i < bio_slab_nr; i++) { + if (bs->bio_slab == bio_slabs[i].slab) { + bslab = &bio_slabs[i]; + break; + } + } + + if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) + goto out; + + WARN_ON(!bslab->slab_ref); + + if (--bslab->slab_ref) + goto out; + + kmem_cache_destroy(bslab->slab); + bslab->slab = NULL; + +out: + mutex_unlock(&bio_slab_lock); +} + +unsigned int bvec_nr_vecs(unsigned short idx) +{ + return bvec_slabs[idx].nr_vecs; +} + +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, pool); + else { + struct biovec_slab *bvs = bvec_slabs + idx; + + kmem_cache_free(bvs->slab, bv); + } +} + +struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, + mempool_t *pool) +{ + struct bio_vec *bvl; + + /* + * see comment near bvec_array define! + */ + switch (nr) { + case 1: + *idx = 0; + break; + case 2 ... 4: + *idx = 1; + break; + case 5 ... 16: + *idx = 2; + break; + case 17 ... 64: + *idx = 3; + break; + case 65 ... 128: + *idx = 4; + break; + case 129 ... BIO_MAX_PAGES: + *idx = 5; + break; + default: + return NULL; + } + + /* + * idx now points to the pool we want to allocate from. only the + * 1-vec entry pool is mempool backed. + */ + if (*idx == BIOVEC_MAX_IDX) { +fallback: + bvl = mempool_alloc(pool, gfp_mask); + } else { + struct biovec_slab *bvs = bvec_slabs + *idx; + gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO); + + /* + * Make this allocation restricted and don't dump info on + * allocation failures, since we'll fallback to the mempool + * in case of failure. + */ + __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; + + /* + * Try a slab allocation. If this fails and __GFP_WAIT + * is set, retry with the 1-entry mempool + */ + bvl = kmem_cache_alloc(bvs->slab, __gfp_mask); + if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) { + *idx = BIOVEC_MAX_IDX; + goto fallback; + } + } + + return bvl; +} + +static void __bio_free(struct bio *bio) +{ + bio_disassociate_task(bio); + + if (bio_integrity(bio)) + bio_integrity_free(bio); +} + +static void bio_free(struct bio *bio) +{ + struct bio_set *bs = bio->bi_pool; + void *p; + + __bio_free(bio); + + if (bs) { + if (bio_flagged(bio, BIO_OWNS_VEC)) + bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio)); + + /* + * If we have front padding, adjust the bio pointer before freeing + */ + p = bio; + p -= bs->front_pad; + + mempool_free(p, bs->bio_pool); + } else { + /* Bio was allocated by bio_kmalloc() */ + kfree(bio); + } +} + +void bio_init(struct bio *bio) +{ + memset(bio, 0, sizeof(*bio)); + bio->bi_flags = 1 << BIO_UPTODATE; + atomic_set(&bio->bi_remaining, 1); + atomic_set(&bio->bi_cnt, 1); +} +EXPORT_SYMBOL(bio_init); + +/** + * bio_reset - reinitialize a bio + * @bio: bio to reset + * + * Description: + * After calling bio_reset(), @bio will be in the same state as a freshly + * allocated bio returned bio bio_alloc_bioset() - the only fields that are + * preserved are the ones that are initialized by bio_alloc_bioset(). See + * comment in struct bio. + */ +void bio_reset(struct bio *bio) +{ + unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS); + + __bio_free(bio); + + memset(bio, 0, BIO_RESET_BYTES); + bio->bi_flags = flags|(1 << BIO_UPTODATE); + atomic_set(&bio->bi_remaining, 1); +} +EXPORT_SYMBOL(bio_reset); + +static void bio_chain_endio(struct bio *bio, int error) +{ + bio_endio(bio->bi_private, error); + bio_put(bio); +} + +/** + * bio_chain - chain bio completions + * @bio: the target bio + * @parent: the @bio's parent bio + * + * The caller won't have a bi_end_io called when @bio completes - instead, + * @parent's bi_end_io won't be called until both @parent and @bio have + * completed; the chained bio will also be freed when it completes. + * + * The caller must not set bi_private or bi_end_io in @bio. + */ +void bio_chain(struct bio *bio, struct bio *parent) +{ + BUG_ON(bio->bi_private || bio->bi_end_io); + + bio->bi_private = parent; + bio->bi_end_io = bio_chain_endio; + atomic_inc(&parent->bi_remaining); +} +EXPORT_SYMBOL(bio_chain); + +static void bio_alloc_rescue(struct work_struct *work) +{ + struct bio_set *bs = container_of(work, struct bio_set, rescue_work); + struct bio *bio; + + while (1) { + spin_lock(&bs->rescue_lock); + bio = bio_list_pop(&bs->rescue_list); + spin_unlock(&bs->rescue_lock); + + if (!bio) + break; + + generic_make_request(bio); + } +} + +static void punt_bios_to_rescuer(struct bio_set *bs) +{ + struct bio_list punt, nopunt; + struct bio *bio; + + /* + * In order to guarantee forward progress we must punt only bios that + * were allocated from this bio_set; otherwise, if there was a bio on + * there for a stacking driver higher up in the stack, processing it + * could require allocating bios from this bio_set, and doing that from + * our own rescuer would be bad. + * + * Since bio lists are singly linked, pop them all instead of trying to + * remove from the middle of the list: + */ + + bio_list_init(&punt); + bio_list_init(&nopunt); + + while ((bio = bio_list_pop(current->bio_list))) + bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); + + *current->bio_list = nopunt; + + spin_lock(&bs->rescue_lock); + bio_list_merge(&bs->rescue_list, &punt); + spin_unlock(&bs->rescue_lock); + + queue_work(bs->rescue_workqueue, &bs->rescue_work); +} + +/** + * bio_alloc_bioset - allocate a bio for I/O + * @gfp_mask: the GFP_ mask given to the slab allocator + * @nr_iovecs: number of iovecs to pre-allocate + * @bs: the bio_set to allocate from. + * + * Description: + * If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is + * backed by the @bs's mempool. + * + * When @bs is not NULL, if %__GFP_WAIT is set then bio_alloc will always be + * able to allocate a bio. This is due to the mempool guarantees. To make this + * work, callers must never allocate more than 1 bio at a time from this pool. + * Callers that need to allocate more than 1 bio must always submit the + * previously allocated bio for IO before attempting to allocate a new one. + * Failure to do so can cause deadlocks under memory pressure. + * + * Note that when running under generic_make_request() (i.e. any block + * driver), bios are not submitted until after you return - see the code in + * generic_make_request() that converts recursion into iteration, to prevent + * stack overflows. + * + * This would normally mean allocating multiple bios under + * generic_make_request() would be susceptible to deadlocks, but we have + * deadlock avoidance code that resubmits any blocked bios from a rescuer + * thread. + * + * However, we do not guarantee forward progress for allocations from other + * mempools. Doing multiple allocations from the same mempool under + * generic_make_request() should be avoided - instead, use bio_set's front_pad + * for per bio allocations. + * + * RETURNS: + * Pointer to new bio on success, NULL on failure. + */ +struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) +{ + gfp_t saved_gfp = gfp_mask; + unsigned front_pad; + unsigned inline_vecs; + unsigned long idx = BIO_POOL_NONE; + struct bio_vec *bvl = NULL; + struct bio *bio; + void *p; + + if (!bs) { + if (nr_iovecs > UIO_MAXIOV) + return NULL; + + p = kmalloc(sizeof(struct bio) + + nr_iovecs * sizeof(struct bio_vec), + gfp_mask); + front_pad = 0; + inline_vecs = nr_iovecs; + } else { + /* + * generic_make_request() converts recursion to iteration; this + * means if we're running beneath it, any bios we allocate and + * submit will not be submitted (and thus freed) until after we + * return. + * + * This exposes us to a potential deadlock if we allocate + * multiple bios from the same bio_set() while running + * underneath generic_make_request(). If we were to allocate + * multiple bios (say a stacking block driver that was splitting + * bios), we would deadlock if we exhausted the mempool's + * reserve. + * + * We solve this, and guarantee forward progress, with a rescuer + * workqueue per bio_set. If we go to allocate and there are + * bios on current->bio_list, we first try the allocation + * without __GFP_WAIT; if that fails, we punt those bios we + * would be blocking to the rescuer workqueue before we retry + * with the original gfp_flags. + */ + + if (current->bio_list && !bio_list_empty(current->bio_list)) + gfp_mask &= ~__GFP_WAIT; + + p = mempool_alloc(bs->bio_pool, gfp_mask); + if (!p && gfp_mask != saved_gfp) { + punt_bios_to_rescuer(bs); + gfp_mask = saved_gfp; + p = mempool_alloc(bs->bio_pool, gfp_mask); + } + + front_pad = bs->front_pad; + inline_vecs = BIO_INLINE_VECS; + } + + if (unlikely(!p)) + return NULL; + + bio = p + front_pad; + bio_init(bio); + + if (nr_iovecs > inline_vecs) { + 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(gfp_mask, nr_iovecs, &idx, bs->bvec_pool); + } + + if (unlikely(!bvl)) + goto err_free; + + bio->bi_flags |= 1 << BIO_OWNS_VEC; + } else if (nr_iovecs) { + bvl = bio->bi_inline_vecs; + } + + bio->bi_pool = bs; + bio->bi_flags |= idx << BIO_POOL_OFFSET; + bio->bi_max_vecs = nr_iovecs; + bio->bi_io_vec = bvl; + return bio; + +err_free: + mempool_free(p, bs->bio_pool); + return NULL; +} +EXPORT_SYMBOL(bio_alloc_bioset); + +void zero_fill_bio(struct bio *bio) +{ + unsigned long flags; + struct bio_vec bv; + struct bvec_iter iter; + + bio_for_each_segment(bv, bio, iter) { + char *data = bvec_kmap_irq(&bv, &flags); + memset(data, 0, bv.bv_len); + flush_dcache_page(bv.bv_page); + bvec_kunmap_irq(data, &flags); + } +} +EXPORT_SYMBOL(zero_fill_bio); + +/** + * bio_put - release a reference to a bio + * @bio: bio to release reference to + * + * Description: + * Put a reference to a &struct bio, either one you have gotten with + * bio_alloc, bio_get or bio_clone. The last put of a bio will free it. + **/ +void bio_put(struct bio *bio) +{ + BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); + + /* + * last put frees it + */ + if (atomic_dec_and_test(&bio->bi_cnt)) + bio_free(bio); +} +EXPORT_SYMBOL(bio_put); + +inline int bio_phys_segments(struct request_queue *q, struct bio *bio) +{ + if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) + blk_recount_segments(q, bio); + + return bio->bi_phys_segments; +} +EXPORT_SYMBOL(bio_phys_segments); + +/** + * __bio_clone_fast - clone a bio that shares the original bio's biovec + * @bio: destination bio + * @bio_src: bio to clone + * + * Clone a &bio. Caller will own the returned bio, but not + * the actual data it points to. Reference count of returned + * bio will be one. + * + * Caller must ensure that @bio_src is not freed before @bio. + */ +void __bio_clone_fast(struct bio *bio, struct bio *bio_src) +{ + BUG_ON(bio->bi_pool && BIO_POOL_IDX(bio) != BIO_POOL_NONE); + + /* + * most users will be overriding ->bi_bdev with a new target, + * so we don't set nor calculate new physical/hw segment counts here + */ + bio->bi_bdev = bio_src->bi_bdev; + bio->bi_flags |= 1 << BIO_CLONED; + bio->bi_rw = bio_src->bi_rw; + bio->bi_iter = bio_src->bi_iter; + bio->bi_io_vec = bio_src->bi_io_vec; +} +EXPORT_SYMBOL(__bio_clone_fast); + +/** + * bio_clone_fast - clone a bio that shares the original bio's biovec + * @bio: bio to clone + * @gfp_mask: allocation priority + * @bs: bio_set to allocate from + * + * Like __bio_clone_fast, only also allocates the returned bio + */ +struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) +{ + struct bio *b; + + b = bio_alloc_bioset(gfp_mask, 0, bs); + if (!b) + return NULL; + + __bio_clone_fast(b, bio); + + if (bio_integrity(bio)) { + int ret; + + ret = bio_integrity_clone(b, bio, gfp_mask); + + if (ret < 0) { + bio_put(b); + return NULL; + } + } + + return b; +} +EXPORT_SYMBOL(bio_clone_fast); + +/** + * bio_clone_bioset - clone a bio + * @bio_src: bio to clone + * @gfp_mask: allocation priority + * @bs: bio_set to allocate from + * + * Clone bio. Caller will own the returned bio, but not the actual data it + * points to. Reference count of returned bio will be one. + */ +struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, + struct bio_set *bs) +{ + struct bvec_iter iter; + struct bio_vec bv; + struct bio *bio; + + /* + * Pre immutable biovecs, __bio_clone() used to just do a memcpy from + * bio_src->bi_io_vec to bio->bi_io_vec. + * + * We can't do that anymore, because: + * + * - The point of cloning the biovec is to produce a bio with a biovec + * the caller can modify: bi_idx and bi_bvec_done should be 0. + * + * - The original bio could've had more than BIO_MAX_PAGES biovecs; if + * we tried to clone the whole thing bio_alloc_bioset() would fail. + * But the clone should succeed as long as the number of biovecs we + * actually need to allocate is fewer than BIO_MAX_PAGES. + * + * - Lastly, bi_vcnt should not be looked at or relied upon by code + * that does not own the bio - reason being drivers don't use it for + * iterating over the biovec anymore, so expecting it to be kept up + * to date (i.e. for clones that share the parent biovec) is just + * asking for trouble and would force extra work on + * __bio_clone_fast() anyways. + */ + + bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs); + if (!bio) + return NULL; + + bio->bi_bdev = bio_src->bi_bdev; + bio->bi_rw = bio_src->bi_rw; + bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector; + bio->bi_iter.bi_size = bio_src->bi_iter.bi_size; + + if (bio->bi_rw & REQ_DISCARD) + goto integrity_clone; + + if (bio->bi_rw & REQ_WRITE_SAME) { + bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0]; + goto integrity_clone; + } + + bio_for_each_segment(bv, bio_src, iter) + bio->bi_io_vec[bio->bi_vcnt++] = bv; + +integrity_clone: + if (bio_integrity(bio_src)) { + int ret; + + ret = bio_integrity_clone(bio, bio_src, gfp_mask); + if (ret < 0) { + bio_put(bio); + return NULL; + } + } + + return bio; +} +EXPORT_SYMBOL(bio_clone_bioset); + +/** + * bio_get_nr_vecs - return approx number of vecs + * @bdev: I/O target + * + * Return the approximate number of pages we can send to this target. + * There's no guarantee that you will be able to fit this number of pages + * into a bio, it does not account for dynamic restrictions that vary + * on offset. + */ +int bio_get_nr_vecs(struct block_device *bdev) +{ + struct request_queue *q = bdev_get_queue(bdev); + int nr_pages; + + nr_pages = min_t(unsigned, + queue_max_segments(q), + queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1); + + return min_t(unsigned, nr_pages, BIO_MAX_PAGES); + +} +EXPORT_SYMBOL(bio_get_nr_vecs); + +static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page + *page, unsigned int len, unsigned int offset, + unsigned int max_sectors) +{ + int retried_segments = 0; + struct bio_vec *bvec; + + /* + * cloned bio must not modify vec list + */ + if (unlikely(bio_flagged(bio, BIO_CLONED))) + return 0; + + if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors) + return 0; + + /* + * For filesystems with a blocksize smaller than the pagesize + * we will often be called with the same page as last time and + * a consecutive offset. Optimize this special case. + */ + if (bio->bi_vcnt > 0) { + struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; + + if (page == prev->bv_page && + offset == prev->bv_offset + prev->bv_len) { + unsigned int prev_bv_len = prev->bv_len; + prev->bv_len += len; + + if (q->merge_bvec_fn) { + struct bvec_merge_data bvm = { + /* prev_bvec is already charged in + bi_size, discharge it in order to + simulate merging updated prev_bvec + as new bvec. */ + .bi_bdev = bio->bi_bdev, + .bi_sector = bio->bi_iter.bi_sector, + .bi_size = bio->bi_iter.bi_size - + prev_bv_len, + .bi_rw = bio->bi_rw, + }; + + if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len) { + prev->bv_len -= len; + return 0; + } + } + + goto done; + } + } + + if (bio->bi_vcnt >= bio->bi_max_vecs) + return 0; + + /* + * we might lose a segment or two here, but rather that than + * make this too complex. + */ + + while (bio->bi_phys_segments >= queue_max_segments(q)) { + + if (retried_segments) + return 0; + + retried_segments = 1; + blk_recount_segments(q, bio); + } + + /* + * setup the new entry, we might clear it again later if we + * cannot add the page + */ + bvec = &bio->bi_io_vec[bio->bi_vcnt]; + bvec->bv_page = page; + bvec->bv_len = len; + bvec->bv_offset = offset; + + /* + * if queue has other restrictions (eg varying max sector size + * depending on offset), it can specify a merge_bvec_fn in the + * queue to get further control + */ + if (q->merge_bvec_fn) { + struct bvec_merge_data bvm = { + .bi_bdev = bio->bi_bdev, + .bi_sector = bio->bi_iter.bi_sector, + .bi_size = bio->bi_iter.bi_size, + .bi_rw = bio->bi_rw, + }; + + /* + * merge_bvec_fn() returns number of bytes it can accept + * at this offset + */ + if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) { + bvec->bv_page = NULL; + bvec->bv_len = 0; + bvec->bv_offset = 0; + return 0; + } + } + + /* If we may be able to merge these biovecs, force a recount */ + if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) + bio->bi_flags &= ~(1 << BIO_SEG_VALID); + + bio->bi_vcnt++; + bio->bi_phys_segments++; + done: + bio->bi_iter.bi_size += len; + return len; +} + +/** + * bio_add_pc_page - attempt to add page to bio + * @q: the target queue + * @bio: destination bio + * @page: page to add + * @len: vec entry length + * @offset: vec entry offset + * + * Attempt to add a page to the bio_vec maplist. This can fail for a + * number of reasons, such as the bio being full or target block device + * limitations. The target block device must allow bio's up to PAGE_SIZE, + * so it is always possible to add a single page to an empty bio. + * + * This should only be used by REQ_PC bios. + */ +int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, + unsigned int len, unsigned int offset) +{ + return __bio_add_page(q, bio, page, len, offset, + queue_max_hw_sectors(q)); +} +EXPORT_SYMBOL(bio_add_pc_page); + +/** + * bio_add_page - attempt to add page to bio + * @bio: destination bio + * @page: page to add + * @len: vec entry length + * @offset: vec entry offset + * + * Attempt to add a page to the bio_vec maplist. This can fail for a + * number of reasons, such as the bio being full or target block device + * limitations. The target block device must allow bio's up to PAGE_SIZE, + * so it is always possible to add a single page to an empty bio. + */ +int bio_add_page(struct bio *bio, struct page *page, unsigned int len, + unsigned int offset) +{ + struct request_queue *q = bdev_get_queue(bio->bi_bdev); + return __bio_add_page(q, bio, page, len, offset, queue_max_sectors(q)); +} +EXPORT_SYMBOL(bio_add_page); + +struct submit_bio_ret { + struct completion event; + int error; +}; + +static void submit_bio_wait_endio(struct bio *bio, int error) +{ + struct submit_bio_ret *ret = bio->bi_private; + + ret->error = error; + complete(&ret->event); +} + +/** + * submit_bio_wait - submit a bio, and wait until it completes + * @rw: whether to %READ or %WRITE, or maybe to %READA (read ahead) + * @bio: The &struct bio which describes the I/O + * + * Simple wrapper around submit_bio(). Returns 0 on success, or the error from + * bio_endio() on failure. + */ +int submit_bio_wait(int rw, struct bio *bio) +{ + struct submit_bio_ret ret; + + rw |= REQ_SYNC; + init_completion(&ret.event); + bio->bi_private = &ret; + bio->bi_end_io = submit_bio_wait_endio; + submit_bio(rw, bio); + wait_for_completion(&ret.event); + + return ret.error; +} +EXPORT_SYMBOL(submit_bio_wait); + +/** + * bio_advance - increment/complete a bio by some number of bytes + * @bio: bio to advance + * @bytes: number of bytes to complete + * + * This updates bi_sector, bi_size and bi_idx; if the number of bytes to + * complete doesn't align with a bvec boundary, then bv_len and bv_offset will + * be updated on the last bvec as well. + * + * @bio will then represent the remaining, uncompleted portion of the io. + */ +void bio_advance(struct bio *bio, unsigned bytes) +{ + if (bio_integrity(bio)) + bio_integrity_advance(bio, bytes); + + bio_advance_iter(bio, &bio->bi_iter, bytes); +} +EXPORT_SYMBOL(bio_advance); + +/** + * bio_alloc_pages - allocates a single page for each bvec in a bio + * @bio: bio to allocate pages for + * @gfp_mask: flags for allocation + * + * Allocates pages up to @bio->bi_vcnt. + * + * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are + * freed. + */ +int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) +{ + int i; + struct bio_vec *bv; + + bio_for_each_segment_all(bv, bio, i) { + bv->bv_page = alloc_page(gfp_mask); + if (!bv->bv_page) { + while (--bv >= bio->bi_io_vec) + __free_page(bv->bv_page); + return -ENOMEM; + } + } + + return 0; +} +EXPORT_SYMBOL(bio_alloc_pages); + +/** + * bio_copy_data - copy contents of data buffers from one chain of bios to + * another + * @src: source bio list + * @dst: destination bio list + * + * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats + * @src and @dst as linked lists of bios. + * + * Stops when it reaches the end of either @src or @dst - that is, copies + * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). + */ +void bio_copy_data(struct bio *dst, struct bio *src) +{ + struct bvec_iter src_iter, dst_iter; + struct bio_vec src_bv, dst_bv; + void *src_p, *dst_p; + unsigned bytes; + + src_iter = src->bi_iter; + dst_iter = dst->bi_iter; + + while (1) { + if (!src_iter.bi_size) { + src = src->bi_next; + if (!src) + break; + + src_iter = src->bi_iter; + } + + if (!dst_iter.bi_size) { + dst = dst->bi_next; + if (!dst) + break; + + dst_iter = dst->bi_iter; + } + + src_bv = bio_iter_iovec(src, src_iter); + dst_bv = bio_iter_iovec(dst, dst_iter); + + bytes = min(src_bv.bv_len, dst_bv.bv_len); + + src_p = kmap_atomic(src_bv.bv_page); + dst_p = kmap_atomic(dst_bv.bv_page); + + memcpy(dst_p + dst_bv.bv_offset, + src_p + src_bv.bv_offset, + bytes); + + kunmap_atomic(dst_p); + kunmap_atomic(src_p); + + bio_advance_iter(src, &src_iter, bytes); + bio_advance_iter(dst, &dst_iter, bytes); + } +} +EXPORT_SYMBOL(bio_copy_data); + +struct bio_map_data { + int nr_sgvecs; + int is_our_pages; + struct sg_iovec sgvecs[]; +}; + +static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, + const struct sg_iovec *iov, int iov_count, + int is_our_pages) +{ + memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); + bmd->nr_sgvecs = iov_count; + bmd->is_our_pages = is_our_pages; + bio->bi_private = bmd; +} + +static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count, + gfp_t gfp_mask) +{ + if (iov_count > UIO_MAXIOV) + return NULL; + + return kmalloc(sizeof(struct bio_map_data) + + sizeof(struct sg_iovec) * iov_count, gfp_mask); +} + +static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_count, + int to_user, int from_user, int do_free_page) +{ + int ret = 0, i; + struct bio_vec *bvec; + int iov_idx = 0; + unsigned int iov_off = 0; + + bio_for_each_segment_all(bvec, bio, i) { + char *bv_addr = page_address(bvec->bv_page); + unsigned int bv_len = bvec->bv_len; + + while (bv_len && iov_idx < iov_count) { + unsigned int bytes; + char __user *iov_addr; + + bytes = min_t(unsigned int, + iov[iov_idx].iov_len - iov_off, bv_len); + iov_addr = iov[iov_idx].iov_base + iov_off; + + if (!ret) { + if (to_user) + ret = copy_to_user(iov_addr, bv_addr, + bytes); + + if (from_user) + ret = copy_from_user(bv_addr, iov_addr, + bytes); + + if (ret) + ret = -EFAULT; + } + + bv_len -= bytes; + bv_addr += bytes; + iov_addr += bytes; + iov_off += bytes; + + if (iov[iov_idx].iov_len == iov_off) { + iov_idx++; + iov_off = 0; + } + } + + if (do_free_page) + __free_page(bvec->bv_page); + } + + return ret; +} + +/** + * bio_uncopy_user - finish previously mapped bio + * @bio: bio being terminated + * + * Free pages allocated from bio_copy_user() and write back data + * to user space in case of a read. + */ +int bio_uncopy_user(struct bio *bio) +{ + struct bio_map_data *bmd = bio->bi_private; + struct bio_vec *bvec; + int ret = 0, i; + + if (!bio_flagged(bio, BIO_NULL_MAPPED)) { + /* + * if we're in a workqueue, the request is orphaned, so + * don't copy into a random user address space, just free. + */ + if (current->mm) + ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs, + bio_data_dir(bio) == READ, + 0, bmd->is_our_pages); + else if (bmd->is_our_pages) + bio_for_each_segment_all(bvec, bio, i) + __free_page(bvec->bv_page); + } + kfree(bmd); + bio_put(bio); + return ret; +} +EXPORT_SYMBOL(bio_uncopy_user); + +/** + * bio_copy_user_iov - copy user data to bio + * @q: destination block queue + * @map_data: pointer to the rq_map_data holding pages (if necessary) + * @iov: the iovec. + * @iov_count: number of elements in the iovec + * @write_to_vm: bool indicating writing to pages or not + * @gfp_mask: memory allocation flags + * + * Prepares and returns a bio for indirect user io, bouncing data + * to/from kernel pages as necessary. Must be paired with + * call bio_uncopy_user() on io completion. + */ +struct bio *bio_copy_user_iov(struct request_queue *q, + struct rq_map_data *map_data, + const struct sg_iovec *iov, int iov_count, + int write_to_vm, gfp_t gfp_mask) +{ + struct bio_map_data *bmd; + struct bio_vec *bvec; + struct page *page; + struct bio *bio; + int i, ret; + int nr_pages = 0; + unsigned int len = 0; + unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; + + for (i = 0; i < iov_count; i++) { + unsigned long uaddr; + unsigned long end; + unsigned long start; + + uaddr = (unsigned long)iov[i].iov_base; + end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; + start = uaddr >> PAGE_SHIFT; + + /* + * Overflow, abort + */ + if (end < start) + return ERR_PTR(-EINVAL); + + nr_pages += end - start; + len += iov[i].iov_len; + } + + if (offset) + nr_pages++; + + bmd = bio_alloc_map_data(iov_count, gfp_mask); + if (!bmd) + return ERR_PTR(-ENOMEM); + + ret = -ENOMEM; + bio = bio_kmalloc(gfp_mask, nr_pages); + if (!bio) + goto out_bmd; + + if (!write_to_vm) + bio->bi_rw |= REQ_WRITE; + + ret = 0; + + if (map_data) { + nr_pages = 1 << map_data->page_order; + i = map_data->offset / PAGE_SIZE; + } + while (len) { + unsigned int bytes = PAGE_SIZE; + + bytes -= offset; + + if (bytes > len) + bytes = len; + + if (map_data) { + if (i == map_data->nr_entries * nr_pages) { + ret = -ENOMEM; + break; + } + + page = map_data->pages[i / nr_pages]; + page += (i % nr_pages); + + i++; + } else { + page = alloc_page(q->bounce_gfp | gfp_mask); + if (!page) { + ret = -ENOMEM; + break; + } + } + + if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) + break; + + len -= bytes; + offset = 0; + } + + if (ret) + goto cleanup; + + /* + * success + */ + if ((!write_to_vm && (!map_data || !map_data->null_mapped)) || + (map_data && map_data->from_user)) { + ret = __bio_copy_iov(bio, iov, iov_count, 0, 1, 0); + if (ret) + goto cleanup; + } + + bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1); + return bio; +cleanup: + if (!map_data) + bio_for_each_segment_all(bvec, bio, i) + __free_page(bvec->bv_page); + + bio_put(bio); +out_bmd: + kfree(bmd); + return ERR_PTR(ret); +} + +/** + * bio_copy_user - copy user data to bio + * @q: destination block queue + * @map_data: pointer to the rq_map_data holding pages (if necessary) + * @uaddr: start of user address + * @len: length in bytes + * @write_to_vm: bool indicating writing to pages or not + * @gfp_mask: memory allocation flags + * + * Prepares and returns a bio for indirect user io, bouncing data + * to/from kernel pages as necessary. Must be paired with + * call bio_uncopy_user() on io completion. + */ +struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data, + unsigned long uaddr, unsigned int len, + int write_to_vm, gfp_t gfp_mask) +{ + struct sg_iovec iov; + + iov.iov_base = (void __user *)uaddr; + iov.iov_len = len; + + return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask); +} +EXPORT_SYMBOL(bio_copy_user); + +static struct bio *__bio_map_user_iov(struct request_queue *q, + struct block_device *bdev, + const struct sg_iovec *iov, int iov_count, + int write_to_vm, gfp_t gfp_mask) +{ + int i, j; + int nr_pages = 0; + struct page **pages; + struct bio *bio; + int cur_page = 0; + int ret, offset; + + for (i = 0; i < iov_count; i++) { + unsigned long uaddr = (unsigned long)iov[i].iov_base; + unsigned long len = iov[i].iov_len; + unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = uaddr >> PAGE_SHIFT; + + /* + * Overflow, abort + */ + if (end < start) + return ERR_PTR(-EINVAL); + + nr_pages += end - start; + /* + * buffer must be aligned to at least hardsector size for now + */ + if (uaddr & queue_dma_alignment(q)) + return ERR_PTR(-EINVAL); + } + + if (!nr_pages) + return ERR_PTR(-EINVAL); + + bio = bio_kmalloc(gfp_mask, nr_pages); + if (!bio) + return ERR_PTR(-ENOMEM); + + ret = -ENOMEM; + pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); + if (!pages) + goto out; + + for (i = 0; i < iov_count; i++) { + unsigned long uaddr = (unsigned long)iov[i].iov_base; + unsigned long len = iov[i].iov_len; + unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = uaddr >> PAGE_SHIFT; + const int local_nr_pages = end - start; + const int page_limit = cur_page + local_nr_pages; + + ret = get_user_pages_fast(uaddr, local_nr_pages, + write_to_vm, &pages[cur_page]); + if (ret < local_nr_pages) { + ret = -EFAULT; + goto out_unmap; + } + + offset = uaddr & ~PAGE_MASK; + for (j = cur_page; j < page_limit; j++) { + unsigned int bytes = PAGE_SIZE - offset; + + if (len <= 0) + break; + + if (bytes > len) + bytes = len; + + /* + * sorry... + */ + if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < + bytes) + break; + + len -= bytes; + offset = 0; + } + + cur_page = j; + /* + * release the pages we didn't map into the bio, if any + */ + while (j < page_limit) + page_cache_release(pages[j++]); + } + + kfree(pages); + + /* + * set data direction, and check if mapped pages need bouncing + */ + if (!write_to_vm) + bio->bi_rw |= REQ_WRITE; + + bio->bi_bdev = bdev; + bio->bi_flags |= (1 << BIO_USER_MAPPED); + return bio; + + out_unmap: + for (i = 0; i < nr_pages; i++) { + if(!pages[i]) + break; + page_cache_release(pages[i]); + } + out: + kfree(pages); + bio_put(bio); + return ERR_PTR(ret); +} + +/** + * bio_map_user - map user address into bio + * @q: the struct request_queue for the bio + * @bdev: destination block device + * @uaddr: start of user address + * @len: length in bytes + * @write_to_vm: bool indicating writing to pages or not + * @gfp_mask: memory allocation flags + * + * Map the user space address into a bio suitable for io to a block + * device. Returns an error pointer in case of error. + */ +struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, + unsigned long uaddr, unsigned int len, int write_to_vm, + gfp_t gfp_mask) +{ + struct sg_iovec iov; + + iov.iov_base = (void __user *)uaddr; + iov.iov_len = len; + + return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask); +} +EXPORT_SYMBOL(bio_map_user); + +/** + * bio_map_user_iov - map user sg_iovec table into bio + * @q: the struct request_queue for the bio + * @bdev: destination block device + * @iov: the iovec. + * @iov_count: number of elements in the iovec + * @write_to_vm: bool indicating writing to pages or not + * @gfp_mask: memory allocation flags + * + * Map the user space address into a bio suitable for io to a block + * device. Returns an error pointer in case of error. + */ +struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev, + const struct sg_iovec *iov, int iov_count, + int write_to_vm, gfp_t gfp_mask) +{ + struct bio *bio; + + bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm, + gfp_mask); + if (IS_ERR(bio)) + return bio; + + /* + * subtle -- if __bio_map_user() ended up bouncing a bio, + * it would normally disappear when its bi_end_io is run. + * however, we need it for the unmap, so grab an extra + * reference to it + */ + bio_get(bio); + + return bio; +} + +static void __bio_unmap_user(struct bio *bio) +{ + struct bio_vec *bvec; + int i; + + /* + * make sure we dirty pages we wrote to + */ + bio_for_each_segment_all(bvec, bio, i) { + if (bio_data_dir(bio) == READ) + set_page_dirty_lock(bvec->bv_page); + + page_cache_release(bvec->bv_page); + } + + bio_put(bio); +} + +/** + * bio_unmap_user - unmap a bio + * @bio: the bio being unmapped + * + * Unmap a bio previously mapped by bio_map_user(). Must be called with + * a process context. + * + * bio_unmap_user() may sleep. + */ +void bio_unmap_user(struct bio *bio) +{ + __bio_unmap_user(bio); + bio_put(bio); +} +EXPORT_SYMBOL(bio_unmap_user); + +static void bio_map_kern_endio(struct bio *bio, int err) +{ + bio_put(bio); +} + +static struct bio *__bio_map_kern(struct request_queue *q, void *data, + unsigned int len, gfp_t gfp_mask) +{ + unsigned long kaddr = (unsigned long)data; + unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = kaddr >> PAGE_SHIFT; + const int nr_pages = end - start; + int offset, i; + struct bio *bio; + + bio = bio_kmalloc(gfp_mask, nr_pages); + if (!bio) + return ERR_PTR(-ENOMEM); + + offset = offset_in_page(kaddr); + for (i = 0; i < nr_pages; i++) { + unsigned int bytes = PAGE_SIZE - offset; + + if (len <= 0) + break; + + if (bytes > len) + bytes = len; + + if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, + offset) < bytes) + break; + + data += bytes; + len -= bytes; + offset = 0; + } + + bio->bi_end_io = bio_map_kern_endio; + return bio; +} + +/** + * bio_map_kern - map kernel address into bio + * @q: the struct request_queue for the bio + * @data: pointer to buffer to map + * @len: length in bytes + * @gfp_mask: allocation flags for bio allocation + * + * Map the kernel address into a bio suitable for io to a block + * device. Returns an error pointer in case of error. + */ +struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, + gfp_t gfp_mask) +{ + struct bio *bio; + + bio = __bio_map_kern(q, data, len, gfp_mask); + if (IS_ERR(bio)) + return bio; + + if (bio->bi_iter.bi_size == len) + return bio; + + /* + * Don't support partial mappings. + */ + bio_put(bio); + return ERR_PTR(-EINVAL); +} +EXPORT_SYMBOL(bio_map_kern); + +static void bio_copy_kern_endio(struct bio *bio, int err) +{ + struct bio_vec *bvec; + const int read = bio_data_dir(bio) == READ; + struct bio_map_data *bmd = bio->bi_private; + int i; + char *p = bmd->sgvecs[0].iov_base; + + bio_for_each_segment_all(bvec, bio, i) { + char *addr = page_address(bvec->bv_page); + + if (read) + memcpy(p, addr, bvec->bv_len); + + __free_page(bvec->bv_page); + p += bvec->bv_len; + } + + kfree(bmd); + bio_put(bio); +} + +/** + * bio_copy_kern - copy kernel address into bio + * @q: the struct request_queue for the bio + * @data: pointer to buffer to copy + * @len: length in bytes + * @gfp_mask: allocation flags for bio and page allocation + * @reading: data direction is READ + * + * copy the kernel address into a bio suitable for io to a block + * device. Returns an error pointer in case of error. + */ +struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, + gfp_t gfp_mask, int reading) +{ + struct bio *bio; + struct bio_vec *bvec; + int i; + + bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask); + if (IS_ERR(bio)) + return bio; + + if (!reading) { + void *p = data; + + bio_for_each_segment_all(bvec, bio, i) { + char *addr = page_address(bvec->bv_page); + + memcpy(addr, p, bvec->bv_len); + p += bvec->bv_len; + } + } + + bio->bi_end_io = bio_copy_kern_endio; + + return bio; +} +EXPORT_SYMBOL(bio_copy_kern); + +/* + * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions + * for performing direct-IO in BIOs. + * + * The problem is that we cannot run set_page_dirty() from interrupt context + * because the required locks are not interrupt-safe. So what we can do is to + * mark the pages dirty _before_ performing IO. And in interrupt context, + * check that the pages are still dirty. If so, fine. If not, redirty them + * in process context. + * + * We special-case compound pages here: normally this means reads into hugetlb + * pages. The logic in here doesn't really work right for compound pages + * because the VM does not uniformly chase down the head page in all cases. + * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't + * handle them at all. So we skip compound pages here at an early stage. + * + * Note that this code is very hard to test under normal circumstances because + * direct-io pins the pages with get_user_pages(). This makes + * is_page_cache_freeable return false, and the VM will not clean the pages. + * But other code (eg, flusher threads) could clean the pages if they are mapped + * pagecache. + * + * Simply disabling the call to bio_set_pages_dirty() is a good way to test the + * deferred bio dirtying paths. + */ + +/* + * bio_set_pages_dirty() will mark all the bio's pages as dirty. + */ +void bio_set_pages_dirty(struct bio *bio) +{ + struct bio_vec *bvec; + int i; + + bio_for_each_segment_all(bvec, bio, i) { + struct page *page = bvec->bv_page; + + if (page && !PageCompound(page)) + set_page_dirty_lock(page); + } +} + +static void bio_release_pages(struct bio *bio) +{ + struct bio_vec *bvec; + int i; + + bio_for_each_segment_all(bvec, bio, i) { + struct page *page = bvec->bv_page; + + if (page) + put_page(page); + } +} + +/* + * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. + * If they are, then fine. If, however, some pages are clean then they must + * have been written out during the direct-IO read. So we take another ref on + * the BIO and the offending pages and re-dirty the pages in process context. + * + * It is expected that bio_check_pages_dirty() will wholly own the BIO from + * here on. It will run one page_cache_release() against each page and will + * run one bio_put() against the BIO. + */ + +static void bio_dirty_fn(struct work_struct *work); + +static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); +static DEFINE_SPINLOCK(bio_dirty_lock); +static struct bio *bio_dirty_list; + +/* + * This runs in process context + */ +static void bio_dirty_fn(struct work_struct *work) +{ + unsigned long flags; + struct bio *bio; + + spin_lock_irqsave(&bio_dirty_lock, flags); + bio = bio_dirty_list; + bio_dirty_list = NULL; + spin_unlock_irqrestore(&bio_dirty_lock, flags); + + while (bio) { + struct bio *next = bio->bi_private; + + bio_set_pages_dirty(bio); + bio_release_pages(bio); + bio_put(bio); + bio = next; + } +} + +void bio_check_pages_dirty(struct bio *bio) +{ + struct bio_vec *bvec; + int nr_clean_pages = 0; + int i; + + bio_for_each_segment_all(bvec, bio, i) { + struct page *page = bvec->bv_page; + + if (PageDirty(page) || PageCompound(page)) { + page_cache_release(page); + bvec->bv_page = NULL; + } else { + nr_clean_pages++; + } + } + + if (nr_clean_pages) { + unsigned long flags; + + spin_lock_irqsave(&bio_dirty_lock, flags); + bio->bi_private = bio_dirty_list; + bio_dirty_list = bio; + spin_unlock_irqrestore(&bio_dirty_lock, flags); + schedule_work(&bio_dirty_work); + } else { + bio_put(bio); + } +} + +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE +void bio_flush_dcache_pages(struct bio *bi) +{ + struct bio_vec bvec; + struct bvec_iter iter; + + bio_for_each_segment(bvec, bi, iter) + flush_dcache_page(bvec.bv_page); +} +EXPORT_SYMBOL(bio_flush_dcache_pages); +#endif + +/** + * bio_endio - end I/O on a bio + * @bio: bio + * @error: error, if any + * + * Description: + * bio_endio() will end I/O on the whole bio. bio_endio() is the + * preferred way to end I/O on a bio, it takes care of clearing + * BIO_UPTODATE on error. @error is 0 on success, and and one of the + * established -Exxxx (-EIO, for instance) error values in case + * something went wrong. No one should call bi_end_io() directly on a + * bio unless they own it and thus know that it has an end_io + * function. + **/ +void bio_endio(struct bio *bio, int error) +{ + while (bio) { + BUG_ON(atomic_read(&bio->bi_remaining) <= 0); + + if (error) + clear_bit(BIO_UPTODATE, &bio->bi_flags); + else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) + error = -EIO; + + if (!atomic_dec_and_test(&bio->bi_remaining)) + return; + + /* + * Need to have a real endio function for chained bios, + * otherwise various corner cases will break (like stacking + * block devices that save/restore bi_end_io) - however, we want + * to avoid unbounded recursion and blowing the stack. Tail call + * optimization would handle this, but compiling with frame + * pointers also disables gcc's sibling call optimization. + */ + if (bio->bi_end_io == bio_chain_endio) { + struct bio *parent = bio->bi_private; + bio_put(bio); + bio = parent; + } else { + if (bio->bi_end_io) + bio->bi_end_io(bio, error); + bio = NULL; + } + } +} +EXPORT_SYMBOL(bio_endio); + +/** + * bio_endio_nodec - end I/O on a bio, without decrementing bi_remaining + * @bio: bio + * @error: error, if any + * + * For code that has saved and restored bi_end_io; thing hard before using this + * function, probably you should've cloned the entire bio. + **/ +void bio_endio_nodec(struct bio *bio, int error) +{ + atomic_inc(&bio->bi_remaining); + bio_endio(bio, error); +} +EXPORT_SYMBOL(bio_endio_nodec); + +/** + * bio_split - split a bio + * @bio: bio to split + * @sectors: number of sectors to split from the front of @bio + * @gfp: gfp mask + * @bs: bio set to allocate from + * + * Allocates and returns a new bio which represents @sectors from the start of + * @bio, and updates @bio to represent the remaining sectors. + * + * The newly allocated bio will point to @bio's bi_io_vec; it is the caller's + * responsibility to ensure that @bio is not freed before the split. + */ +struct bio *bio_split(struct bio *bio, int sectors, + gfp_t gfp, struct bio_set *bs) +{ + struct bio *split = NULL; + + BUG_ON(sectors <= 0); + BUG_ON(sectors >= bio_sectors(bio)); + + split = bio_clone_fast(bio, gfp, bs); + if (!split) + return NULL; + + split->bi_iter.bi_size = sectors << 9; + + if (bio_integrity(split)) + bio_integrity_trim(split, 0, sectors); + + bio_advance(bio, split->bi_iter.bi_size); + + return split; +} +EXPORT_SYMBOL(bio_split); + +/** + * bio_trim - trim a bio + * @bio: bio to trim + * @offset: number of sectors to trim from the front of @bio + * @size: size we want to trim @bio to, in sectors + */ +void bio_trim(struct bio *bio, int offset, int size) +{ + /* 'bio' is a cloned bio which we need to trim to match + * the given offset and size. + */ + + size <<= 9; + if (offset == 0 && size == bio->bi_iter.bi_size) + return; + + clear_bit(BIO_SEG_VALID, &bio->bi_flags); + + bio_advance(bio, offset << 9); + + bio->bi_iter.bi_size = size; +} +EXPORT_SYMBOL_GPL(bio_trim); + +/* + * create memory pools for biovec's in a bio_set. + * use the global biovec slabs created for general use. + */ +mempool_t *biovec_create_pool(int pool_entries) +{ + struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX; + + return mempool_create_slab_pool(pool_entries, bp->slab); +} + +void bioset_free(struct bio_set *bs) +{ + if (bs->rescue_workqueue) + destroy_workqueue(bs->rescue_workqueue); + + if (bs->bio_pool) + mempool_destroy(bs->bio_pool); + + if (bs->bvec_pool) + mempool_destroy(bs->bvec_pool); + + bioset_integrity_free(bs); + bio_put_slab(bs); + + kfree(bs); +} +EXPORT_SYMBOL(bioset_free); + +/** + * bioset_create - Create a bio_set + * @pool_size: Number of bio and bio_vecs to cache in the mempool + * @front_pad: Number of bytes to allocate in front of the returned bio + * + * Description: + * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller + * to ask for a number of bytes to be allocated in front of the bio. + * Front pad allocation is useful for embedding the bio inside + * another structure, to avoid allocating extra data to go with the bio. + * Note that the bio must be embedded at the END of that structure always, + * or things will break badly. + */ +struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) +{ + unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); + struct bio_set *bs; + + bs = kzalloc(sizeof(*bs), GFP_KERNEL); + if (!bs) + return NULL; + + bs->front_pad = front_pad; + + spin_lock_init(&bs->rescue_lock); + bio_list_init(&bs->rescue_list); + INIT_WORK(&bs->rescue_work, bio_alloc_rescue); + + bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); + if (!bs->bio_slab) { + kfree(bs); + return NULL; + } + + bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab); + if (!bs->bio_pool) + goto bad; + + bs->bvec_pool = biovec_create_pool(pool_size); + if (!bs->bvec_pool) + goto bad; + + bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); + if (!bs->rescue_workqueue) + goto bad; + + return bs; +bad: + bioset_free(bs); + return NULL; +} +EXPORT_SYMBOL(bioset_create); + +#ifdef CONFIG_BLK_CGROUP +/** + * bio_associate_current - associate a bio with %current + * @bio: target bio + * + * Associate @bio with %current if it hasn't been associated yet. Block + * layer will treat @bio as if it were issued by %current no matter which + * task actually issues it. + * + * This function takes an extra reference of @task's io_context and blkcg + * which will be put when @bio is released. The caller must own @bio, + * ensure %current->io_context exists, and is responsible for synchronizing + * calls to this function. + */ +int bio_associate_current(struct bio *bio) +{ + struct io_context *ioc; + struct cgroup_subsys_state *css; + + if (bio->bi_ioc) + return -EBUSY; + + ioc = current->io_context; + if (!ioc) + return -ENOENT; + + /* acquire active ref on @ioc and associate */ + get_io_context_active(ioc); + bio->bi_ioc = ioc; + + /* associate blkcg if exists */ + rcu_read_lock(); + css = task_css(current, blkio_cgrp_id); + if (css && css_tryget(css)) + bio->bi_css = css; + rcu_read_unlock(); + + return 0; +} + +/** + * bio_disassociate_task - undo bio_associate_current() + * @bio: target bio + */ +void bio_disassociate_task(struct bio *bio) +{ + if (bio->bi_ioc) { + put_io_context(bio->bi_ioc); + bio->bi_ioc = NULL; + } + if (bio->bi_css) { + css_put(bio->bi_css); + bio->bi_css = NULL; + } +} + +#endif /* CONFIG_BLK_CGROUP */ + +static void __init biovec_init_slabs(void) +{ + int i; + + for (i = 0; i < BIOVEC_NR_POOLS; i++) { + int size; + struct biovec_slab *bvs = bvec_slabs + i; + + if (bvs->nr_vecs <= BIO_INLINE_VECS) { + bvs->slab = NULL; + continue; + } + + size = bvs->nr_vecs * sizeof(struct bio_vec); + bvs->slab = kmem_cache_create(bvs->name, size, 0, + SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + } +} + +static int __init init_bio(void) +{ + bio_slab_max = 2; + bio_slab_nr = 0; + bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); + 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); + if (!fs_bio_set) + panic("bio: can't allocate bios\n"); + + if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE)) + panic("bio: can't create integrity pool\n"); + + return 0; +} +subsys_initcall(init_bio); diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index e4a4145..1039fb9 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -451,7 +451,20 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css, struct blkcg_gq *blkg; int i; - mutex_lock(&blkcg_pol_mutex); + /* + * XXX: We invoke cgroup_add/rm_cftypes() under blkcg_pol_mutex + * which ends up putting cgroup's internal cgroup_tree_mutex under + * it; however, cgroup_tree_mutex is nested above cgroup file + * active protection and grabbing blkcg_pol_mutex from a cgroup + * file operation creates a possible circular dependency. cgroup + * internal locking is planned to go through further simplification + * and this issue should go away soon. For now, let's trylock + * blkcg_pol_mutex and restart the write on failure. + * + * http://lkml.kernel.org/g/5363C04B.4010400@oracle.com + */ + if (!mutex_trylock(&blkcg_pol_mutex)) + return restart_syscall(); spin_lock_irq(&blkcg->lock); /* diff --git a/block/blk-core.c b/block/blk-core.c index a0e3096..40d6548 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -146,8 +146,8 @@ void blk_dump_rq_flags(struct request *rq, char *msg) printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n", (unsigned long long)blk_rq_pos(rq), blk_rq_sectors(rq), blk_rq_cur_sectors(rq)); - printk(KERN_INFO " bio %p, biotail %p, buffer %p, len %u\n", - rq->bio, rq->biotail, rq->buffer, blk_rq_bytes(rq)); + printk(KERN_INFO " bio %p, biotail %p, len %u\n", + rq->bio, rq->biotail, blk_rq_bytes(rq)); if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { printk(KERN_INFO " cdb: "); @@ -251,8 +251,10 @@ void blk_sync_queue(struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i; - queue_for_each_hw_ctx(q, hctx, i) - cancel_delayed_work_sync(&hctx->delayed_work); + queue_for_each_hw_ctx(q, hctx, i) { + cancel_delayed_work_sync(&hctx->run_work); + cancel_delayed_work_sync(&hctx->delay_work); + } } else { cancel_delayed_work_sync(&q->delay_work); } @@ -574,12 +576,9 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) if (!q) return NULL; - if (percpu_counter_init(&q->mq_usage_counter, 0)) - goto fail_q; - q->id = ida_simple_get(&blk_queue_ida, 0, 0, gfp_mask); if (q->id < 0) - goto fail_c; + goto fail_q; q->backing_dev_info.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; @@ -637,8 +636,6 @@ fail_bdi: bdi_destroy(&q->backing_dev_info); fail_id: ida_simple_remove(&blk_queue_ida, q->id); -fail_c: - percpu_counter_destroy(&q->mq_usage_counter); fail_q: kmem_cache_free(blk_requestq_cachep, q); return NULL; @@ -846,6 +843,47 @@ static void freed_request(struct request_list *rl, unsigned int flags) __freed_request(rl, sync ^ 1); } +int blk_update_nr_requests(struct request_queue *q, unsigned int nr) +{ + struct request_list *rl; + + spin_lock_irq(q->queue_lock); + q->nr_requests = nr; + blk_queue_congestion_threshold(q); + + /* congestion isn't cgroup aware and follows root blkcg for now */ + rl = &q->root_rl; + + if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q)) + blk_set_queue_congested(q, BLK_RW_SYNC); + else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q)) + blk_clear_queue_congested(q, BLK_RW_SYNC); + + if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q)) + blk_set_queue_congested(q, BLK_RW_ASYNC); + else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q)) + blk_clear_queue_congested(q, BLK_RW_ASYNC); + + blk_queue_for_each_rl(rl, q) { + if (rl->count[BLK_RW_SYNC] >= q->nr_requests) { + blk_set_rl_full(rl, BLK_RW_SYNC); + } else { + blk_clear_rl_full(rl, BLK_RW_SYNC); + wake_up(&rl->wait[BLK_RW_SYNC]); + } + + if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) { + blk_set_rl_full(rl, BLK_RW_ASYNC); + } else { + blk_clear_rl_full(rl, BLK_RW_ASYNC); + wake_up(&rl->wait[BLK_RW_ASYNC]); + } + } + + spin_unlock_irq(q->queue_lock); + return 0; +} + /* * Determine if elevator data should be initialized when allocating the * request associated with @bio. @@ -1135,7 +1173,7 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw, struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask) { if (q->mq_ops) - return blk_mq_alloc_request(q, rw, gfp_mask); + return blk_mq_alloc_request(q, rw, gfp_mask, false); else return blk_old_get_request(q, rw, gfp_mask); } @@ -1231,12 +1269,15 @@ static void add_acct_request(struct request_queue *q, struct request *rq, static void part_round_stats_single(int cpu, struct hd_struct *part, unsigned long now) { + int inflight; + if (now == part->stamp) return; - if (part_in_flight(part)) { + inflight = part_in_flight(part); + if (inflight) { __part_stat_add(cpu, part, time_in_queue, - part_in_flight(part) * (now - part->stamp)); + inflight * (now - part->stamp)); __part_stat_add(cpu, part, io_ticks, (now - part->stamp)); } part->stamp = now; @@ -1360,7 +1401,6 @@ void blk_add_request_payload(struct request *rq, struct page *page, rq->__data_len = rq->resid_len = len; rq->nr_phys_segments = 1; - rq->buffer = bio_data(bio); } EXPORT_SYMBOL_GPL(blk_add_request_payload); @@ -1402,12 +1442,6 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req, bio->bi_next = req->bio; req->bio = bio; - /* - * may not be valid. if the low level driver said - * it didn't need a bounce buffer then it better - * not touch req->buffer either... - */ - req->buffer = bio_data(bio); req->__sector = bio->bi_iter.bi_sector; req->__data_len += bio->bi_iter.bi_size; req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); @@ -1432,6 +1466,8 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req, * added on the elevator at this point. In addition, we don't have * reliable access to the elevator outside queue lock. Only check basic * merging parameters without querying the elevator. + * + * Caller must ensure !blk_queue_nomerges(q) beforehand. */ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int *request_count) @@ -1441,9 +1477,6 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, bool ret = false; struct list_head *plug_list; - if (blk_queue_nomerges(q)) - goto out; - plug = current->plug; if (!plug) goto out; @@ -1522,7 +1555,8 @@ void blk_queue_bio(struct request_queue *q, struct bio *bio) * Check if we can merge with the plugged list before grabbing * any locks. */ - if (blk_attempt_plug_merge(q, bio, &request_count)) + if (!blk_queue_nomerges(q) && + blk_attempt_plug_merge(q, bio, &request_count)) return; spin_lock_irq(q->queue_lock); @@ -1654,7 +1688,7 @@ static int __init fail_make_request_debugfs(void) struct dentry *dir = fault_create_debugfs_attr("fail_make_request", NULL, &fail_make_request); - return IS_ERR(dir) ? PTR_ERR(dir) : 0; + return PTR_ERR_OR_ZERO(dir); } late_initcall(fail_make_request_debugfs); @@ -2434,7 +2468,6 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) } req->__data_len -= total_bytes; - req->buffer = bio_data(req->bio); /* update sector only for requests with clear definition of sector */ if (req->cmd_type == REQ_TYPE_FS) @@ -2503,7 +2536,7 @@ EXPORT_SYMBOL_GPL(blk_unprep_request); /* * queue lock must be held */ -static void blk_finish_request(struct request *req, int error) +void blk_finish_request(struct request *req, int error) { if (blk_rq_tagged(req)) blk_queue_end_tag(req->q, req); @@ -2529,6 +2562,7 @@ static void blk_finish_request(struct request *req, int error) __blk_put_request(req->q, req); } } +EXPORT_SYMBOL(blk_finish_request); /** * blk_end_bidi_request - Complete a bidi request @@ -2752,10 +2786,9 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq, /* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw */ rq->cmd_flags |= bio->bi_rw & REQ_WRITE; - if (bio_has_data(bio)) { + if (bio_has_data(bio)) rq->nr_phys_segments = bio_phys_segments(q, bio); - rq->buffer = bio_data(bio); - } + rq->__data_len = bio->bi_iter.bi_size; rq->bio = rq->biotail = bio; @@ -2831,7 +2864,7 @@ EXPORT_SYMBOL_GPL(blk_rq_unprep_clone); /* * Copy attributes of the original request to the clone request. - * The actual data parts (e.g. ->cmd, ->buffer, ->sense) are not copied. + * The actual data parts (e.g. ->cmd, ->sense) are not copied. */ static void __blk_rq_prep_clone(struct request *dst, struct request *src) { @@ -2857,7 +2890,7 @@ static void __blk_rq_prep_clone(struct request *dst, struct request *src) * * Description: * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq. - * The actual data parts of @rq_src (e.g. ->cmd, ->buffer, ->sense) + * The actual data parts of @rq_src (e.g. ->cmd, ->sense) * are not copied, and copying such parts is the caller's responsibility. * Also, pages which the original bios are pointing to are not copied * and the cloned bios just point same pages. @@ -2904,20 +2937,25 @@ free_and_out: } EXPORT_SYMBOL_GPL(blk_rq_prep_clone); -int kblockd_schedule_work(struct request_queue *q, struct work_struct *work) +int kblockd_schedule_work(struct work_struct *work) { return queue_work(kblockd_workqueue, work); } EXPORT_SYMBOL(kblockd_schedule_work); -int kblockd_schedule_delayed_work(struct request_queue *q, - struct delayed_work *dwork, unsigned long delay) +int kblockd_schedule_delayed_work(struct delayed_work *dwork, + unsigned long delay) { return queue_delayed_work(kblockd_workqueue, dwork, delay); } EXPORT_SYMBOL(kblockd_schedule_delayed_work); -#define PLUG_MAGIC 0x91827364 +int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, + unsigned long delay) +{ + return queue_delayed_work_on(cpu, kblockd_workqueue, dwork, delay); +} +EXPORT_SYMBOL(kblockd_schedule_delayed_work_on); /** * blk_start_plug - initialize blk_plug and track it inside the task_struct @@ -2937,7 +2975,6 @@ void blk_start_plug(struct blk_plug *plug) { struct task_struct *tsk = current; - plug->magic = PLUG_MAGIC; INIT_LIST_HEAD(&plug->list); INIT_LIST_HEAD(&plug->mq_list); INIT_LIST_HEAD(&plug->cb_list); @@ -3034,8 +3071,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) LIST_HEAD(list); unsigned int depth; - BUG_ON(plug->magic != PLUG_MAGIC); - flush_plug_callbacks(plug, from_schedule); if (!list_empty(&plug->mq_list)) diff --git a/block/blk-flush.c b/block/blk-flush.c index 43e6b47..8ffee4b 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -130,21 +130,13 @@ static void blk_flush_restore_request(struct request *rq) blk_clear_rq_complete(rq); } -static void mq_flush_run(struct work_struct *work) -{ - struct request *rq; - - rq = container_of(work, struct request, mq_flush_work); - - memset(&rq->csd, 0, sizeof(rq->csd)); - blk_mq_insert_request(rq, false, true, false); -} - static bool blk_flush_queue_rq(struct request *rq, bool add_front) { if (rq->q->mq_ops) { - INIT_WORK(&rq->mq_flush_work, mq_flush_run); - kblockd_schedule_work(rq->q, &rq->mq_flush_work); + struct request_queue *q = rq->q; + + blk_mq_add_to_requeue_list(rq, add_front); + blk_mq_kick_requeue_list(q); return false; } else { if (add_front) @@ -231,8 +223,10 @@ static void flush_end_io(struct request *flush_rq, int error) struct request *rq, *n; unsigned long flags = 0; - if (q->mq_ops) + if (q->mq_ops) { spin_lock_irqsave(&q->mq_flush_lock, flags); + q->flush_rq->tag = -1; + } running = &q->flush_queue[q->flush_running_idx]; BUG_ON(q->flush_pending_idx == q->flush_running_idx); @@ -306,23 +300,9 @@ static bool blk_kick_flush(struct request_queue *q) */ q->flush_pending_idx ^= 1; - if (q->mq_ops) { - struct blk_mq_ctx *ctx = first_rq->mq_ctx; - struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu); - - blk_mq_rq_init(hctx, q->flush_rq); - q->flush_rq->mq_ctx = ctx; - - /* - * Reuse the tag value from the fist waiting request, - * with blk-mq the tag is generated during request - * allocation and drivers can rely on it being inside - * the range they asked for. - */ - q->flush_rq->tag = first_rq->tag; - } else { - blk_rq_init(q, q->flush_rq); - } + blk_rq_init(q, q->flush_rq); + if (q->mq_ops) + blk_mq_clone_flush_request(q->flush_rq, first_rq); q->flush_rq->cmd_type = REQ_TYPE_FS; q->flush_rq->cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ; diff --git a/block/blk-iopoll.c b/block/blk-iopoll.c index c11d24e..0736729 100644 --- a/block/blk-iopoll.c +++ b/block/blk-iopoll.c @@ -49,7 +49,7 @@ EXPORT_SYMBOL(blk_iopoll_sched); void __blk_iopoll_complete(struct blk_iopoll *iop) { list_del(&iop->list); - smp_mb__before_clear_bit(); + smp_mb__before_atomic(); clear_bit_unlock(IOPOLL_F_SCHED, &iop->state); } EXPORT_SYMBOL(__blk_iopoll_complete); @@ -64,12 +64,12 @@ EXPORT_SYMBOL(__blk_iopoll_complete); * iopoll handler will not be invoked again before blk_iopoll_sched_prep() * is called. **/ -void blk_iopoll_complete(struct blk_iopoll *iopoll) +void blk_iopoll_complete(struct blk_iopoll *iop) { unsigned long flags; local_irq_save(flags); - __blk_iopoll_complete(iopoll); + __blk_iopoll_complete(iop); local_irq_restore(flags); } EXPORT_SYMBOL(blk_iopoll_complete); @@ -161,7 +161,7 @@ EXPORT_SYMBOL(blk_iopoll_disable); void blk_iopoll_enable(struct blk_iopoll *iop) { BUG_ON(!test_bit(IOPOLL_F_SCHED, &iop->state)); - smp_mb__before_clear_bit(); + smp_mb__before_atomic(); clear_bit_unlock(IOPOLL_F_SCHED, &iop->state); } EXPORT_SYMBOL(blk_iopoll_enable); diff --git a/block/blk-lib.c b/block/blk-lib.c index 97a733c..8411be3 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -226,8 +226,8 @@ EXPORT_SYMBOL(blkdev_issue_write_same); * Generate and issue number of bios with zerofiled pages. */ -int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, - sector_t nr_sects, gfp_t gfp_mask) +static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, + sector_t nr_sects, gfp_t gfp_mask) { int ret; struct bio *bio; diff --git a/block/blk-map.c b/block/blk-map.c index f7b22bc..f890d43 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -155,7 +155,6 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq, if (!bio_flagged(bio, BIO_USER_MAPPED)) rq->cmd_flags |= REQ_COPY_USER; - rq->buffer = NULL; return 0; unmap_rq: blk_rq_unmap_user(bio); @@ -238,7 +237,6 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, blk_queue_bounce(q, &bio); bio_get(bio); blk_rq_bio_prep(q, rq, bio); - rq->buffer = NULL; return 0; } EXPORT_SYMBOL(blk_rq_map_user_iov); @@ -325,7 +323,6 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, } blk_queue_bounce(q, &rq->bio); - rq->buffer = NULL; return 0; } EXPORT_SYMBOL(blk_rq_map_kern); diff --git a/block/blk-merge.c b/block/blk-merge.c index 6c583f9..b3bf0df 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -13,7 +13,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, struct bio *bio) { struct bio_vec bv, bvprv = { NULL }; - int cluster, high, highprv = 1; + int cluster, high, highprv = 1, no_sg_merge; unsigned int seg_size, nr_phys_segs; struct bio *fbio, *bbio; struct bvec_iter iter; @@ -35,12 +35,21 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, cluster = blk_queue_cluster(q); seg_size = 0; nr_phys_segs = 0; + no_sg_merge = test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags); + high = 0; for_each_bio(bio) { bio_for_each_segment(bv, bio, iter) { /* + * If SG merging is disabled, each bio vector is + * a segment + */ + if (no_sg_merge) + goto new_segment; + + /* * the trick here is making sure that a high page is - * never considered part of another segment, since that - * might change with the bounce page. + * never considered part of another segment, since + * that might change with the bounce page. */ high = page_to_pfn(bv.bv_page) > queue_bounce_pfn(q); if (!high && !highprv && cluster) { @@ -84,11 +93,16 @@ void blk_recalc_rq_segments(struct request *rq) void blk_recount_segments(struct request_queue *q, struct bio *bio) { - struct bio *nxt = bio->bi_next; + if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags)) + bio->bi_phys_segments = bio->bi_vcnt; + else { + struct bio *nxt = bio->bi_next; + + bio->bi_next = NULL; + bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio); + bio->bi_next = nxt; + } - bio->bi_next = NULL; - bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio); - bio->bi_next = nxt; bio->bi_flags |= (1 << BIO_SEG_VALID); } EXPORT_SYMBOL(blk_recount_segments); diff --git a/block/blk-mq-cpu.c b/block/blk-mq-cpu.c index 136ef86..bb3ed48 100644 --- a/block/blk-mq-cpu.c +++ b/block/blk-mq-cpu.c @@ -1,3 +1,8 @@ +/* + * CPU notifier helper code for blk-mq + * + * Copyright (C) 2013-2014 Jens Axboe + */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> @@ -18,14 +23,18 @@ static int blk_mq_main_cpu_notify(struct notifier_block *self, { unsigned int cpu = (unsigned long) hcpu; struct blk_mq_cpu_notifier *notify; + int ret = NOTIFY_OK; raw_spin_lock(&blk_mq_cpu_notify_lock); - list_for_each_entry(notify, &blk_mq_cpu_notify_list, list) - notify->notify(notify->data, action, cpu); + list_for_each_entry(notify, &blk_mq_cpu_notify_list, list) { + ret = notify->notify(notify->data, action, cpu); + if (ret != NOTIFY_OK) + break; + } raw_spin_unlock(&blk_mq_cpu_notify_lock); - return NOTIFY_OK; + return ret; } void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier) @@ -45,7 +54,7 @@ void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier) } void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier, - void (*fn)(void *, unsigned long, unsigned int), + int (*fn)(void *, unsigned long, unsigned int), void *data) { notifier->notify = fn; diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index 09792132..1065d7c 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -1,3 +1,8 @@ +/* + * CPU <-> hardware queue mapping helpers + * + * Copyright (C) 2013-2014 Jens Axboe + */ #include <linux/kernel.h> #include <linux/threads.h> #include <linux/module.h> @@ -80,19 +85,35 @@ int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues) return 0; } -unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg) +unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set) { unsigned int *map; /* If cpus are offline, map them to first hctx */ map = kzalloc_node(sizeof(*map) * num_possible_cpus(), GFP_KERNEL, - reg->numa_node); + set->numa_node); if (!map) return NULL; - if (!blk_mq_update_queue_map(map, reg->nr_hw_queues)) + if (!blk_mq_update_queue_map(map, set->nr_hw_queues)) return map; kfree(map); return NULL; } + +/* + * We have no quick way of doing reverse lookups. This is only used at + * queue init time, so runtime isn't important. + */ +int blk_mq_hw_queue_to_node(unsigned int *mq_map, unsigned int index) +{ + int i; + + for_each_possible_cpu(i) { + if (index == mq_map[i]) + return cpu_to_node(i); + } + + return NUMA_NO_NODE; +} diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index b0ba264..ed52178 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -203,59 +203,24 @@ static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx, return ret; } -static ssize_t blk_mq_hw_sysfs_ipi_show(struct blk_mq_hw_ctx *hctx, char *page) -{ - ssize_t ret; - - spin_lock(&hctx->lock); - ret = sprintf(page, "%u\n", !!(hctx->flags & BLK_MQ_F_SHOULD_IPI)); - spin_unlock(&hctx->lock); - - return ret; -} - -static ssize_t blk_mq_hw_sysfs_ipi_store(struct blk_mq_hw_ctx *hctx, - const char *page, size_t len) +static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page) { - struct blk_mq_ctx *ctx; - unsigned long ret; - unsigned int i; - - if (kstrtoul(page, 10, &ret)) { - pr_err("blk-mq-sysfs: invalid input '%s'\n", page); - return -EINVAL; - } - - spin_lock(&hctx->lock); - if (ret) - hctx->flags |= BLK_MQ_F_SHOULD_IPI; - else - hctx->flags &= ~BLK_MQ_F_SHOULD_IPI; - spin_unlock(&hctx->lock); - - hctx_for_each_ctx(hctx, ctx, i) - ctx->ipi_redirect = !!ret; - - return len; + return blk_mq_tag_sysfs_show(hctx->tags, page); } -static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page) +static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page) { - return blk_mq_tag_sysfs_show(hctx->tags, page); + return sprintf(page, "%u\n", atomic_read(&hctx->nr_active)); } static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page) { - unsigned int i, queue_num, first = 1; + unsigned int i, first = 1; ssize_t ret = 0; blk_mq_disable_hotplug(); - for_each_online_cpu(i) { - queue_num = hctx->queue->mq_map[i]; - if (queue_num != hctx->queue_num) - continue; - + for_each_cpu(i, hctx->cpumask) { if (first) ret += sprintf(ret + page, "%u", i); else @@ -307,15 +272,14 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = { .attr = {.name = "dispatched", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_dispatched_show, }; +static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = { + .attr = {.name = "active", .mode = S_IRUGO }, + .show = blk_mq_hw_sysfs_active_show, +}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = { .attr = {.name = "pending", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_rq_list_show, }; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_ipi = { - .attr = {.name = "ipi_redirect", .mode = S_IRUGO | S_IWUSR}, - .show = blk_mq_hw_sysfs_ipi_show, - .store = blk_mq_hw_sysfs_ipi_store, -}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = { .attr = {.name = "tags", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_tags_show, @@ -330,9 +294,9 @@ static struct attribute *default_hw_ctx_attrs[] = { &blk_mq_hw_sysfs_run.attr, &blk_mq_hw_sysfs_dispatched.attr, &blk_mq_hw_sysfs_pending.attr, - &blk_mq_hw_sysfs_ipi.attr, &blk_mq_hw_sysfs_tags.attr, &blk_mq_hw_sysfs_cpus.attr, + &blk_mq_hw_sysfs_active.attr, NULL, }; @@ -363,6 +327,42 @@ static struct kobj_type blk_mq_hw_ktype = { .release = blk_mq_sysfs_release, }; +static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx) +{ + struct blk_mq_ctx *ctx; + int i; + + if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP)) + return; + + hctx_for_each_ctx(hctx, ctx, i) + kobject_del(&ctx->kobj); + + kobject_del(&hctx->kobj); +} + +static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx) +{ + struct request_queue *q = hctx->queue; + struct blk_mq_ctx *ctx; + int i, ret; + + if (!hctx->nr_ctx || !(hctx->flags & BLK_MQ_F_SYSFS_UP)) + return 0; + + ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", hctx->queue_num); + if (ret) + return ret; + + hctx_for_each_ctx(hctx, ctx, i) { + ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu); + if (ret) + break; + } + + return ret; +} + void blk_mq_unregister_disk(struct gendisk *disk) { struct request_queue *q = disk->queue; @@ -371,11 +371,11 @@ void blk_mq_unregister_disk(struct gendisk *disk) int i, j; queue_for_each_hw_ctx(q, hctx, i) { - hctx_for_each_ctx(hctx, ctx, j) { - kobject_del(&ctx->kobj); + blk_mq_unregister_hctx(hctx); + + hctx_for_each_ctx(hctx, ctx, j) kobject_put(&ctx->kobj); - } - kobject_del(&hctx->kobj); + kobject_put(&hctx->kobj); } @@ -386,15 +386,30 @@ void blk_mq_unregister_disk(struct gendisk *disk) kobject_put(&disk_to_dev(disk)->kobj); } +static void blk_mq_sysfs_init(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + struct blk_mq_ctx *ctx; + int i, j; + + kobject_init(&q->mq_kobj, &blk_mq_ktype); + + queue_for_each_hw_ctx(q, hctx, i) { + kobject_init(&hctx->kobj, &blk_mq_hw_ktype); + + hctx_for_each_ctx(hctx, ctx, j) + kobject_init(&ctx->kobj, &blk_mq_ctx_ktype); + } +} + int blk_mq_register_disk(struct gendisk *disk) { struct device *dev = disk_to_dev(disk); struct request_queue *q = disk->queue; struct blk_mq_hw_ctx *hctx; - struct blk_mq_ctx *ctx; - int ret, i, j; + int ret, i; - kobject_init(&q->mq_kobj, &blk_mq_ktype); + blk_mq_sysfs_init(q); ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq"); if (ret < 0) @@ -403,20 +418,10 @@ int blk_mq_register_disk(struct gendisk *disk) kobject_uevent(&q->mq_kobj, KOBJ_ADD); queue_for_each_hw_ctx(q, hctx, i) { - kobject_init(&hctx->kobj, &blk_mq_hw_ktype); - ret = kobject_add(&hctx->kobj, &q->mq_kobj, "%u", i); + hctx->flags |= BLK_MQ_F_SYSFS_UP; + ret = blk_mq_register_hctx(hctx); if (ret) break; - - if (!hctx->nr_ctx) - continue; - - hctx_for_each_ctx(hctx, ctx, j) { - kobject_init(&ctx->kobj, &blk_mq_ctx_ktype); - ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu); - if (ret) - break; - } } if (ret) { @@ -426,3 +431,26 @@ int blk_mq_register_disk(struct gendisk *disk) return 0; } + +void blk_mq_sysfs_unregister(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + int i; + + queue_for_each_hw_ctx(q, hctx, i) + blk_mq_unregister_hctx(hctx); +} + +int blk_mq_sysfs_register(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + int i, ret = 0; + + queue_for_each_hw_ctx(q, hctx, i) { + ret = blk_mq_register_hctx(hctx); + if (ret) + break; + } + + return ret; +} diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 83ae96c..1aab39f 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -1,78 +1,359 @@ +/* + * Fast and scalable bitmap tagging variant. Uses sparser bitmaps spread + * over multiple cachelines to avoid ping-pong between multiple submitters + * or submitter and completer. Uses rolling wakeups to avoid falling of + * the scaling cliff when we run out of tags and have to start putting + * submitters to sleep. + * + * Uses active queue tracking to support fairer distribution of tags + * between multiple submitters when a shared tag map is used. + * + * Copyright (C) 2013-2014 Jens Axboe + */ #include <linux/kernel.h> #include <linux/module.h> -#include <linux/percpu_ida.h> +#include <linux/random.h> #include <linux/blk-mq.h> #include "blk.h" #include "blk-mq.h" #include "blk-mq-tag.h" +static bool bt_has_free_tags(struct blk_mq_bitmap_tags *bt) +{ + int i; + + for (i = 0; i < bt->map_nr; i++) { + struct blk_align_bitmap *bm = &bt->map[i]; + int ret; + + ret = find_first_zero_bit(&bm->word, bm->depth); + if (ret < bm->depth) + return true; + } + + return false; +} + +bool blk_mq_has_free_tags(struct blk_mq_tags *tags) +{ + if (!tags) + return true; + + return bt_has_free_tags(&tags->bitmap_tags); +} + +static inline void bt_index_inc(unsigned int *index) +{ + *index = (*index + 1) & (BT_WAIT_QUEUES - 1); +} + /* - * Per tagged queue (tag address space) map + * If a previously inactive queue goes active, bump the active user count. */ -struct blk_mq_tags { - unsigned int nr_tags; - unsigned int nr_reserved_tags; - unsigned int nr_batch_move; - unsigned int nr_max_cache; +bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) +{ + if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && + !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) + atomic_inc(&hctx->tags->active_queues); - struct percpu_ida free_tags; - struct percpu_ida reserved_tags; -}; + return true; +} -void blk_mq_wait_for_tags(struct blk_mq_tags *tags) +/* + * Wakeup all potentially sleeping on normal (non-reserved) tags + */ +static void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags) { - int tag = blk_mq_get_tag(tags, __GFP_WAIT, false); - blk_mq_put_tag(tags, tag); + struct blk_mq_bitmap_tags *bt; + int i, wake_index; + + bt = &tags->bitmap_tags; + wake_index = bt->wake_index; + for (i = 0; i < BT_WAIT_QUEUES; i++) { + struct bt_wait_state *bs = &bt->bs[wake_index]; + + if (waitqueue_active(&bs->wait)) + wake_up(&bs->wait); + + bt_index_inc(&wake_index); + } } -bool blk_mq_has_free_tags(struct blk_mq_tags *tags) +/* + * If a previously busy queue goes inactive, potential waiters could now + * be allowed to queue. Wake them up and check. + */ +void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) +{ + struct blk_mq_tags *tags = hctx->tags; + + if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) + return; + + atomic_dec(&tags->active_queues); + + blk_mq_tag_wakeup_all(tags); +} + +/* + * For shared tag users, we track the number of currently active users + * and attempt to provide a fair share of the tag depth for each of them. + */ +static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, + struct blk_mq_bitmap_tags *bt) +{ + unsigned int depth, users; + + if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED)) + return true; + if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) + return true; + + /* + * Don't try dividing an ant + */ + if (bt->depth == 1) + return true; + + users = atomic_read(&hctx->tags->active_queues); + if (!users) + return true; + + /* + * Allow at least some tags + */ + depth = max((bt->depth + users - 1) / users, 4U); + return atomic_read(&hctx->nr_active) < depth; +} + +static int __bt_get_word(struct blk_align_bitmap *bm, unsigned int last_tag) { - return !tags || - percpu_ida_free_tags(&tags->free_tags, nr_cpu_ids) != 0; + int tag, org_last_tag, end; + + org_last_tag = last_tag; + end = bm->depth; + do { +restart: + tag = find_next_zero_bit(&bm->word, end, last_tag); + if (unlikely(tag >= end)) { + /* + * We started with an offset, start from 0 to + * exhaust the map. + */ + if (org_last_tag && last_tag) { + end = last_tag; + last_tag = 0; + goto restart; + } + return -1; + } + last_tag = tag + 1; + } while (test_and_set_bit_lock(tag, &bm->word)); + + return tag; } -static unsigned int __blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp) +/* + * Straight forward bitmap tag implementation, where each bit is a tag + * (cleared == free, and set == busy). The small twist is using per-cpu + * last_tag caches, which blk-mq stores in the blk_mq_ctx software queue + * contexts. This enables us to drastically limit the space searched, + * without dirtying an extra shared cacheline like we would if we stored + * the cache value inside the shared blk_mq_bitmap_tags structure. On top + * of that, each word of tags is in a separate cacheline. This means that + * multiple users will tend to stick to different cachelines, at least + * until the map is exhausted. + */ +static int __bt_get(struct blk_mq_hw_ctx *hctx, struct blk_mq_bitmap_tags *bt, + unsigned int *tag_cache) { + unsigned int last_tag, org_last_tag; + int index, i, tag; + + if (!hctx_may_queue(hctx, bt)) + return -1; + + last_tag = org_last_tag = *tag_cache; + index = TAG_TO_INDEX(bt, last_tag); + + for (i = 0; i < bt->map_nr; i++) { + tag = __bt_get_word(&bt->map[index], TAG_TO_BIT(bt, last_tag)); + if (tag != -1) { + tag += (index << bt->bits_per_word); + goto done; + } + + last_tag = 0; + if (++index >= bt->map_nr) + index = 0; + } + + *tag_cache = 0; + return -1; + + /* + * Only update the cache from the allocation path, if we ended + * up using the specific cached tag. + */ +done: + if (tag == org_last_tag) { + last_tag = tag + 1; + if (last_tag >= bt->depth - 1) + last_tag = 0; + + *tag_cache = last_tag; + } + + return tag; +} + +static struct bt_wait_state *bt_wait_ptr(struct blk_mq_bitmap_tags *bt, + struct blk_mq_hw_ctx *hctx) +{ + struct bt_wait_state *bs; + + if (!hctx) + return &bt->bs[0]; + + bs = &bt->bs[hctx->wait_index]; + bt_index_inc(&hctx->wait_index); + return bs; +} + +static int bt_get(struct blk_mq_alloc_data *data, + struct blk_mq_bitmap_tags *bt, + struct blk_mq_hw_ctx *hctx, + unsigned int *last_tag) +{ + struct bt_wait_state *bs; + DEFINE_WAIT(wait); int tag; - tag = percpu_ida_alloc(&tags->free_tags, (gfp & __GFP_WAIT) ? - TASK_UNINTERRUPTIBLE : TASK_RUNNING); - if (tag < 0) - return BLK_MQ_TAG_FAIL; - return tag + tags->nr_reserved_tags; + tag = __bt_get(hctx, bt, last_tag); + if (tag != -1) + return tag; + + if (!(data->gfp & __GFP_WAIT)) + return -1; + + bs = bt_wait_ptr(bt, hctx); + do { + bool was_empty; + + was_empty = list_empty(&wait.task_list); + prepare_to_wait(&bs->wait, &wait, TASK_UNINTERRUPTIBLE); + + tag = __bt_get(hctx, bt, last_tag); + if (tag != -1) + break; + + if (was_empty) + atomic_set(&bs->wait_cnt, bt->wake_cnt); + + blk_mq_put_ctx(data->ctx); + + io_schedule(); + + data->ctx = blk_mq_get_ctx(data->q); + data->hctx = data->q->mq_ops->map_queue(data->q, + data->ctx->cpu); + if (data->reserved) { + bt = &data->hctx->tags->breserved_tags; + } else { + last_tag = &data->ctx->last_tag; + hctx = data->hctx; + bt = &hctx->tags->bitmap_tags; + } + finish_wait(&bs->wait, &wait); + bs = bt_wait_ptr(bt, hctx); + } while (1); + + finish_wait(&bs->wait, &wait); + return tag; } -static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_tags *tags, - gfp_t gfp) +static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data) { int tag; - if (unlikely(!tags->nr_reserved_tags)) { + tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx, + &data->ctx->last_tag); + if (tag >= 0) + return tag + data->hctx->tags->nr_reserved_tags; + + return BLK_MQ_TAG_FAIL; +} + +static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data) +{ + int tag, zero = 0; + + if (unlikely(!data->hctx->tags->nr_reserved_tags)) { WARN_ON_ONCE(1); return BLK_MQ_TAG_FAIL; } - tag = percpu_ida_alloc(&tags->reserved_tags, (gfp & __GFP_WAIT) ? - TASK_UNINTERRUPTIBLE : TASK_RUNNING); + tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, &zero); if (tag < 0) return BLK_MQ_TAG_FAIL; + return tag; } -unsigned int blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp, bool reserved) +unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) { - if (!reserved) - return __blk_mq_get_tag(tags, gfp); + if (!data->reserved) + return __blk_mq_get_tag(data); - return __blk_mq_get_reserved_tag(tags, gfp); + return __blk_mq_get_reserved_tag(data); +} + +static struct bt_wait_state *bt_wake_ptr(struct blk_mq_bitmap_tags *bt) +{ + int i, wake_index; + + wake_index = bt->wake_index; + for (i = 0; i < BT_WAIT_QUEUES; i++) { + struct bt_wait_state *bs = &bt->bs[wake_index]; + + if (waitqueue_active(&bs->wait)) { + if (wake_index != bt->wake_index) + bt->wake_index = wake_index; + + return bs; + } + + bt_index_inc(&wake_index); + } + + return NULL; +} + +static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag) +{ + const int index = TAG_TO_INDEX(bt, tag); + struct bt_wait_state *bs; + + /* + * The unlock memory barrier need to order access to req in free + * path and clearing tag bit + */ + clear_bit_unlock(TAG_TO_BIT(bt, tag), &bt->map[index].word); + + bs = bt_wake_ptr(bt); + if (bs && atomic_dec_and_test(&bs->wait_cnt)) { + atomic_set(&bs->wait_cnt, bt->wake_cnt); + bt_index_inc(&bt->wake_index); + wake_up(&bs->wait); + } } static void __blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag) { BUG_ON(tag >= tags->nr_tags); - percpu_ida_free(&tags->free_tags, tag - tags->nr_reserved_tags); + bt_clear_tag(&tags->bitmap_tags, tag); } static void __blk_mq_put_reserved_tag(struct blk_mq_tags *tags, @@ -80,22 +361,43 @@ static void __blk_mq_put_reserved_tag(struct blk_mq_tags *tags, { BUG_ON(tag >= tags->nr_reserved_tags); - percpu_ida_free(&tags->reserved_tags, tag); + bt_clear_tag(&tags->breserved_tags, tag); } -void blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag) +void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, + unsigned int *last_tag) { - if (tag >= tags->nr_reserved_tags) - __blk_mq_put_tag(tags, tag); - else + struct blk_mq_tags *tags = hctx->tags; + + if (tag >= tags->nr_reserved_tags) { + const int real_tag = tag - tags->nr_reserved_tags; + + __blk_mq_put_tag(tags, real_tag); + *last_tag = real_tag; + } else __blk_mq_put_reserved_tag(tags, tag); } -static int __blk_mq_tag_iter(unsigned id, void *data) +static void bt_for_each_free(struct blk_mq_bitmap_tags *bt, + unsigned long *free_map, unsigned int off) { - unsigned long *tag_map = data; - __set_bit(id, tag_map); - return 0; + int i; + + for (i = 0; i < bt->map_nr; i++) { + struct blk_align_bitmap *bm = &bt->map[i]; + int bit = 0; + + do { + bit = find_next_zero_bit(&bm->word, bm->depth, bit); + if (bit >= bm->depth) + break; + + __set_bit(bit + off, free_map); + bit++; + } while (1); + + off += (1 << bt->bits_per_word); + } } void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, @@ -109,21 +411,128 @@ void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, if (!tag_map) return; - percpu_ida_for_each_free(&tags->free_tags, __blk_mq_tag_iter, tag_map); + bt_for_each_free(&tags->bitmap_tags, tag_map, tags->nr_reserved_tags); if (tags->nr_reserved_tags) - percpu_ida_for_each_free(&tags->reserved_tags, __blk_mq_tag_iter, - tag_map); + bt_for_each_free(&tags->breserved_tags, tag_map, 0); fn(data, tag_map); kfree(tag_map); } +EXPORT_SYMBOL(blk_mq_tag_busy_iter); + +static unsigned int bt_unused_tags(struct blk_mq_bitmap_tags *bt) +{ + unsigned int i, used; + + for (i = 0, used = 0; i < bt->map_nr; i++) { + struct blk_align_bitmap *bm = &bt->map[i]; + + used += bitmap_weight(&bm->word, bm->depth); + } + + return bt->depth - used; +} + +static void bt_update_count(struct blk_mq_bitmap_tags *bt, + unsigned int depth) +{ + unsigned int tags_per_word = 1U << bt->bits_per_word; + unsigned int map_depth = depth; + + if (depth) { + int i; + + for (i = 0; i < bt->map_nr; i++) { + bt->map[i].depth = min(map_depth, tags_per_word); + map_depth -= bt->map[i].depth; + } + } + + bt->wake_cnt = BT_WAIT_BATCH; + if (bt->wake_cnt > depth / 4) + bt->wake_cnt = max(1U, depth / 4); + + bt->depth = depth; +} + +static int bt_alloc(struct blk_mq_bitmap_tags *bt, unsigned int depth, + int node, bool reserved) +{ + int i; + + bt->bits_per_word = ilog2(BITS_PER_LONG); + + /* + * Depth can be zero for reserved tags, that's not a failure + * condition. + */ + if (depth) { + unsigned int nr, tags_per_word; + + tags_per_word = (1 << bt->bits_per_word); + + /* + * If the tag space is small, shrink the number of tags + * per word so we spread over a few cachelines, at least. + * If less than 4 tags, just forget about it, it's not + * going to work optimally anyway. + */ + if (depth >= 4) { + while (tags_per_word * 4 > depth) { + bt->bits_per_word--; + tags_per_word = (1 << bt->bits_per_word); + } + } + + nr = ALIGN(depth, tags_per_word) / tags_per_word; + bt->map = kzalloc_node(nr * sizeof(struct blk_align_bitmap), + GFP_KERNEL, node); + if (!bt->map) + return -ENOMEM; + + bt->map_nr = nr; + } + + bt->bs = kzalloc(BT_WAIT_QUEUES * sizeof(*bt->bs), GFP_KERNEL); + if (!bt->bs) { + kfree(bt->map); + return -ENOMEM; + } + + for (i = 0; i < BT_WAIT_QUEUES; i++) + init_waitqueue_head(&bt->bs[i].wait); + + bt_update_count(bt, depth); + return 0; +} + +static void bt_free(struct blk_mq_bitmap_tags *bt) +{ + kfree(bt->map); + kfree(bt->bs); +} + +static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, + int node) +{ + unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; + + if (bt_alloc(&tags->bitmap_tags, depth, node, false)) + goto enomem; + if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, node, true)) + goto enomem; + + return tags; +enomem: + bt_free(&tags->bitmap_tags); + kfree(tags); + return NULL; +} struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, unsigned int reserved_tags, int node) { - unsigned int nr_tags, nr_cache; struct blk_mq_tags *tags; - int ret; if (total_tags > BLK_MQ_TAG_MAX) { pr_err("blk-mq: tag depth too large\n"); @@ -134,73 +543,59 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, if (!tags) return NULL; - nr_tags = total_tags - reserved_tags; - nr_cache = nr_tags / num_possible_cpus(); - - if (nr_cache < BLK_MQ_TAG_CACHE_MIN) - nr_cache = BLK_MQ_TAG_CACHE_MIN; - else if (nr_cache > BLK_MQ_TAG_CACHE_MAX) - nr_cache = BLK_MQ_TAG_CACHE_MAX; - tags->nr_tags = total_tags; tags->nr_reserved_tags = reserved_tags; - tags->nr_max_cache = nr_cache; - tags->nr_batch_move = max(1u, nr_cache / 2); - ret = __percpu_ida_init(&tags->free_tags, tags->nr_tags - - tags->nr_reserved_tags, - tags->nr_max_cache, - tags->nr_batch_move); - if (ret) - goto err_free_tags; + return blk_mq_init_bitmap_tags(tags, node); +} - if (reserved_tags) { - /* - * With max_cahe and batch set to 1, the allocator fallbacks to - * no cached. It's fine reserved tags allocation is slow. - */ - ret = __percpu_ida_init(&tags->reserved_tags, reserved_tags, - 1, 1); - if (ret) - goto err_reserved_tags; - } +void blk_mq_free_tags(struct blk_mq_tags *tags) +{ + bt_free(&tags->bitmap_tags); + bt_free(&tags->breserved_tags); + kfree(tags); +} - return tags; +void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *tag) +{ + unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; -err_reserved_tags: - percpu_ida_destroy(&tags->free_tags); -err_free_tags: - kfree(tags); - return NULL; + *tag = prandom_u32() % depth; } -void blk_mq_free_tags(struct blk_mq_tags *tags) +int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth) { - percpu_ida_destroy(&tags->free_tags); - percpu_ida_destroy(&tags->reserved_tags); - kfree(tags); + tdepth -= tags->nr_reserved_tags; + if (tdepth > tags->nr_tags) + return -EINVAL; + + /* + * Don't need (or can't) update reserved tags here, they remain + * static and should never need resizing. + */ + bt_update_count(&tags->bitmap_tags, tdepth); + blk_mq_tag_wakeup_all(tags); + return 0; } ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page) { char *orig_page = page; - unsigned int cpu; + unsigned int free, res; if (!tags) return 0; - page += sprintf(page, "nr_tags=%u, reserved_tags=%u, batch_move=%u," - " max_cache=%u\n", tags->nr_tags, tags->nr_reserved_tags, - tags->nr_batch_move, tags->nr_max_cache); + page += sprintf(page, "nr_tags=%u, reserved_tags=%u, " + "bits_per_word=%u\n", + tags->nr_tags, tags->nr_reserved_tags, + tags->bitmap_tags.bits_per_word); - page += sprintf(page, "nr_free=%u, nr_reserved=%u\n", - percpu_ida_free_tags(&tags->free_tags, nr_cpu_ids), - percpu_ida_free_tags(&tags->reserved_tags, nr_cpu_ids)); + free = bt_unused_tags(&tags->bitmap_tags); + res = bt_unused_tags(&tags->breserved_tags); - for_each_possible_cpu(cpu) { - page += sprintf(page, " cpu%02u: nr_free=%u\n", cpu, - percpu_ida_free_tags(&tags->free_tags, cpu)); - } + page += sprintf(page, "nr_free=%u, nr_reserved=%u\n", free, res); + page += sprintf(page, "active_queues=%u\n", atomic_read(&tags->active_queues)); return page - orig_page; } diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 947ba2c..98696a6 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -1,17 +1,59 @@ #ifndef INT_BLK_MQ_TAG_H #define INT_BLK_MQ_TAG_H -struct blk_mq_tags; +#include "blk-mq.h" + +enum { + BT_WAIT_QUEUES = 8, + BT_WAIT_BATCH = 8, +}; + +struct bt_wait_state { + atomic_t wait_cnt; + wait_queue_head_t wait; +} ____cacheline_aligned_in_smp; + +#define TAG_TO_INDEX(bt, tag) ((tag) >> (bt)->bits_per_word) +#define TAG_TO_BIT(bt, tag) ((tag) & ((1 << (bt)->bits_per_word) - 1)) + +struct blk_mq_bitmap_tags { + unsigned int depth; + unsigned int wake_cnt; + unsigned int bits_per_word; + + unsigned int map_nr; + struct blk_align_bitmap *map; + + unsigned int wake_index; + struct bt_wait_state *bs; +}; + +/* + * Tag address space map. + */ +struct blk_mq_tags { + unsigned int nr_tags; + unsigned int nr_reserved_tags; + + atomic_t active_queues; + + struct blk_mq_bitmap_tags bitmap_tags; + struct blk_mq_bitmap_tags breserved_tags; + + struct request **rqs; + struct list_head page_list; +}; + extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node); extern void blk_mq_free_tags(struct blk_mq_tags *tags); -extern unsigned int blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp, bool reserved); -extern void blk_mq_wait_for_tags(struct blk_mq_tags *tags); -extern void blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag); -extern void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data); +extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); +extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag); extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); +extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag); +extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth); enum { BLK_MQ_TAG_CACHE_MIN = 1, @@ -24,4 +66,23 @@ enum { BLK_MQ_TAG_MAX = BLK_MQ_TAG_FAIL - 1, }; +extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *); +extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *); + +static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) +{ + if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) + return false; + + return __blk_mq_tag_busy(hctx); +} + +static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) +{ + if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) + return; + + __blk_mq_tag_idle(hctx); +} + #endif diff --git a/block/blk-mq.c b/block/blk-mq.c index 1d2a9bd..4e4cd62 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1,3 +1,9 @@ +/* + * Block multiqueue core code + * + * Copyright (C) 2013-2014 Jens Axboe + * Copyright (C) 2013-2014 Christoph Hellwig + */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/backing-dev.h> @@ -27,28 +33,6 @@ static LIST_HEAD(all_q_list); static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); -static struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, - unsigned int cpu) -{ - return per_cpu_ptr(q->queue_ctx, cpu); -} - -/* - * This assumes per-cpu software queueing queues. They could be per-node - * as well, for instance. For now this is hardcoded as-is. Note that we don't - * care about preemption, since we know the ctx's are persistent. This does - * mean that we can't rely on ctx always matching the currently running CPU. - */ -static struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) -{ - return __blk_mq_get_ctx(q, get_cpu()); -} - -static void blk_mq_put_ctx(struct blk_mq_ctx *ctx) -{ - put_cpu(); -} - /* * Check if any of the ctx's have pending work in this hardware queue */ @@ -56,38 +40,40 @@ static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) { unsigned int i; - for (i = 0; i < hctx->nr_ctx_map; i++) - if (hctx->ctx_map[i]) + for (i = 0; i < hctx->ctx_map.map_size; i++) + if (hctx->ctx_map.map[i].word) return true; return false; } +static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx, + struct blk_mq_ctx *ctx) +{ + return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word]; +} + +#define CTX_TO_BIT(hctx, ctx) \ + ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1)) + /* * Mark this ctx as having pending work in this hardware queue */ static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx) { - if (!test_bit(ctx->index_hw, hctx->ctx_map)) - set_bit(ctx->index_hw, hctx->ctx_map); + struct blk_align_bitmap *bm = get_bm(hctx, ctx); + + if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word)) + set_bit(CTX_TO_BIT(hctx, ctx), &bm->word); } -static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx, - gfp_t gfp, bool reserved) +static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, + struct blk_mq_ctx *ctx) { - struct request *rq; - unsigned int tag; - - tag = blk_mq_get_tag(hctx->tags, gfp, reserved); - if (tag != BLK_MQ_TAG_FAIL) { - rq = hctx->rqs[tag]; - rq->tag = tag; - - return rq; - } + struct blk_align_bitmap *bm = get_bm(hctx, ctx); - return NULL; + clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word); } static int blk_mq_queue_enter(struct request_queue *q) @@ -186,78 +172,99 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, if (blk_queue_io_stat(q)) rw_flags |= REQ_IO_STAT; + INIT_LIST_HEAD(&rq->queuelist); + /* csd/requeue_work/fifo_time is initialized before use */ + rq->q = q; rq->mq_ctx = ctx; - rq->cmd_flags = rw_flags; - rq->start_time = jiffies; + rq->cmd_flags |= rw_flags; + /* do not touch atomic flags, it needs atomic ops against the timer */ + rq->cpu = -1; + INIT_HLIST_NODE(&rq->hash); + RB_CLEAR_NODE(&rq->rb_node); + rq->rq_disk = NULL; + rq->part = NULL; +#ifdef CONFIG_BLK_CGROUP + rq->rl = NULL; set_start_time_ns(rq); + rq->io_start_time_ns = 0; +#endif + rq->nr_phys_segments = 0; +#if defined(CONFIG_BLK_DEV_INTEGRITY) + rq->nr_integrity_segments = 0; +#endif + rq->special = NULL; + /* tag was already set */ + rq->errors = 0; + + rq->extra_len = 0; + rq->sense_len = 0; + rq->resid_len = 0; + rq->sense = NULL; + + INIT_LIST_HEAD(&rq->timeout_list); + rq->end_io = NULL; + rq->end_io_data = NULL; + rq->next_rq = NULL; + ctx->rq_dispatched[rw_is_sync(rw_flags)]++; } -static struct request *blk_mq_alloc_request_pinned(struct request_queue *q, - int rw, gfp_t gfp, - bool reserved) +static struct request * +__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw) { struct request *rq; + unsigned int tag; - do { - struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); - struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu); + tag = blk_mq_get_tag(data); + if (tag != BLK_MQ_TAG_FAIL) { + rq = data->hctx->tags->rqs[tag]; - rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved); - if (rq) { - blk_mq_rq_ctx_init(q, ctx, rq, rw); - break; + rq->cmd_flags = 0; + if (blk_mq_tag_busy(data->hctx)) { + rq->cmd_flags = REQ_MQ_INFLIGHT; + atomic_inc(&data->hctx->nr_active); } - blk_mq_put_ctx(ctx); - if (!(gfp & __GFP_WAIT)) - break; - - __blk_mq_run_hw_queue(hctx); - blk_mq_wait_for_tags(hctx->tags); - } while (1); + rq->tag = tag; + blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw); + return rq; + } - return rq; + return NULL; } -struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp) +struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, + bool reserved) { + struct blk_mq_ctx *ctx; + struct blk_mq_hw_ctx *hctx; struct request *rq; + struct blk_mq_alloc_data alloc_data; if (blk_mq_queue_enter(q)) return NULL; - rq = blk_mq_alloc_request_pinned(q, rw, gfp, false); - if (rq) - blk_mq_put_ctx(rq->mq_ctx); - return rq; -} - -struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, - gfp_t gfp) -{ - struct request *rq; + ctx = blk_mq_get_ctx(q); + hctx = q->mq_ops->map_queue(q, ctx->cpu); + blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT, + reserved, ctx, hctx); - if (blk_mq_queue_enter(q)) - return NULL; + rq = __blk_mq_alloc_request(&alloc_data, rw); + if (!rq && (gfp & __GFP_WAIT)) { + __blk_mq_run_hw_queue(hctx); + blk_mq_put_ctx(ctx); - rq = blk_mq_alloc_request_pinned(q, rw, gfp, true); - if (rq) - blk_mq_put_ctx(rq->mq_ctx); + ctx = blk_mq_get_ctx(q); + hctx = q->mq_ops->map_queue(q, ctx->cpu); + blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx, + hctx); + rq = __blk_mq_alloc_request(&alloc_data, rw); + ctx = alloc_data.ctx; + } + blk_mq_put_ctx(ctx); return rq; } -EXPORT_SYMBOL(blk_mq_alloc_reserved_request); - -/* - * Re-init and set pdu, if we have it - */ -void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq) -{ - blk_rq_init(hctx->queue, rq); - - if (hctx->cmd_size) - rq->special = blk_mq_rq_to_pdu(rq); -} +EXPORT_SYMBOL(blk_mq_alloc_request); static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct request *rq) @@ -265,9 +272,11 @@ static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, const int tag = rq->tag; struct request_queue *q = rq->q; - blk_mq_rq_init(hctx, rq); - blk_mq_put_tag(hctx->tags, tag); + if (rq->cmd_flags & REQ_MQ_INFLIGHT) + atomic_dec(&hctx->nr_active); + clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); + blk_mq_put_tag(hctx, tag, &ctx->last_tag); blk_mq_queue_exit(q); } @@ -283,20 +292,47 @@ void blk_mq_free_request(struct request *rq) __blk_mq_free_request(hctx, ctx, rq); } -bool blk_mq_end_io_partial(struct request *rq, int error, unsigned int nr_bytes) +/* + * Clone all relevant state from a request that has been put on hold in + * the flush state machine into the preallocated flush request that hangs + * off the request queue. + * + * For a driver the flush request should be invisible, that's why we are + * impersonating the original request here. + */ +void blk_mq_clone_flush_request(struct request *flush_rq, + struct request *orig_rq) { - if (blk_update_request(rq, error, blk_rq_bytes(rq))) - return true; + struct blk_mq_hw_ctx *hctx = + orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu); + flush_rq->mq_ctx = orig_rq->mq_ctx; + flush_rq->tag = orig_rq->tag; + memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), + hctx->cmd_size); +} + +inline void __blk_mq_end_io(struct request *rq, int error) +{ blk_account_io_done(rq); - if (rq->end_io) + if (rq->end_io) { rq->end_io(rq, error); - else + } else { + if (unlikely(blk_bidi_rq(rq))) + blk_mq_free_request(rq->next_rq); blk_mq_free_request(rq); - return false; + } } -EXPORT_SYMBOL(blk_mq_end_io_partial); +EXPORT_SYMBOL(__blk_mq_end_io); + +void blk_mq_end_io(struct request *rq, int error) +{ + if (blk_update_request(rq, error, blk_rq_bytes(rq))) + BUG(); + __blk_mq_end_io(rq, error); +} +EXPORT_SYMBOL(blk_mq_end_io); static void __blk_mq_complete_request_remote(void *data) { @@ -305,18 +341,22 @@ static void __blk_mq_complete_request_remote(void *data) rq->q->softirq_done_fn(rq); } -void __blk_mq_complete_request(struct request *rq) +static void blk_mq_ipi_complete_request(struct request *rq) { struct blk_mq_ctx *ctx = rq->mq_ctx; + bool shared = false; int cpu; - if (!ctx->ipi_redirect) { + if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { rq->q->softirq_done_fn(rq); return; } cpu = get_cpu(); - if (cpu != ctx->cpu && cpu_online(ctx->cpu)) { + if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) + shared = cpus_share_cache(cpu, ctx->cpu); + + if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { rq->csd.func = __blk_mq_complete_request_remote; rq->csd.info = rq; rq->csd.flags = 0; @@ -327,6 +367,16 @@ void __blk_mq_complete_request(struct request *rq) put_cpu(); } +void __blk_mq_complete_request(struct request *rq) +{ + struct request_queue *q = rq->q; + + if (!q->softirq_done_fn) + blk_mq_end_io(rq, rq->errors); + else + blk_mq_ipi_complete_request(rq); +} + /** * blk_mq_complete_request - end I/O on a request * @rq: the request being processed @@ -337,7 +387,9 @@ void __blk_mq_complete_request(struct request *rq) **/ void blk_mq_complete_request(struct request *rq) { - if (unlikely(blk_should_fake_timeout(rq->q))) + struct request_queue *q = rq->q; + + if (unlikely(blk_should_fake_timeout(q))) return; if (!blk_mark_rq_complete(rq)) __blk_mq_complete_request(rq); @@ -350,13 +402,31 @@ static void blk_mq_start_request(struct request *rq, bool last) trace_block_rq_issue(q, rq); + rq->resid_len = blk_rq_bytes(rq); + if (unlikely(blk_bidi_rq(rq))) + rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); + /* * Just mark start time and set the started bit. Due to memory * ordering, we know we'll see the correct deadline as long as - * REQ_ATOMIC_STARTED is seen. + * REQ_ATOMIC_STARTED is seen. Use the default queue timeout, + * unless one has been set in the request. + */ + if (!rq->timeout) + rq->deadline = jiffies + q->rq_timeout; + else + rq->deadline = jiffies + rq->timeout; + + /* + * Mark us as started and clear complete. Complete might have been + * set if requeue raced with timeout, which then marked it as + * complete. So be sure to clear complete again when we start + * the request, otherwise we'll ignore the completion event. */ - rq->deadline = jiffies + q->rq_timeout; - set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); + if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) + set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); + if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) + clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); if (q->dma_drain_size && blk_rq_bytes(rq)) { /* @@ -378,7 +448,7 @@ static void blk_mq_start_request(struct request *rq, bool last) rq->cmd_flags |= REQ_END; } -static void blk_mq_requeue_request(struct request *rq) +static void __blk_mq_requeue_request(struct request *rq) { struct request_queue *q = rq->q; @@ -391,6 +461,91 @@ static void blk_mq_requeue_request(struct request *rq) rq->nr_phys_segments--; } +void blk_mq_requeue_request(struct request *rq) +{ + __blk_mq_requeue_request(rq); + blk_clear_rq_complete(rq); + + BUG_ON(blk_queued_rq(rq)); + blk_mq_add_to_requeue_list(rq, true); +} +EXPORT_SYMBOL(blk_mq_requeue_request); + +static void blk_mq_requeue_work(struct work_struct *work) +{ + struct request_queue *q = + container_of(work, struct request_queue, requeue_work); + LIST_HEAD(rq_list); + struct request *rq, *next; + unsigned long flags; + + spin_lock_irqsave(&q->requeue_lock, flags); + list_splice_init(&q->requeue_list, &rq_list); + spin_unlock_irqrestore(&q->requeue_lock, flags); + + list_for_each_entry_safe(rq, next, &rq_list, queuelist) { + if (!(rq->cmd_flags & REQ_SOFTBARRIER)) + continue; + + rq->cmd_flags &= ~REQ_SOFTBARRIER; + list_del_init(&rq->queuelist); + blk_mq_insert_request(rq, true, false, false); + } + + while (!list_empty(&rq_list)) { + rq = list_entry(rq_list.next, struct request, queuelist); + list_del_init(&rq->queuelist); + blk_mq_insert_request(rq, false, false, false); + } + + blk_mq_run_queues(q, false); +} + +void blk_mq_add_to_requeue_list(struct request *rq, bool at_head) +{ + struct request_queue *q = rq->q; + unsigned long flags; + + /* + * We abuse this flag that is otherwise used by the I/O scheduler to + * request head insertation from the workqueue. + */ + BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER); + + spin_lock_irqsave(&q->requeue_lock, flags); + if (at_head) { + rq->cmd_flags |= REQ_SOFTBARRIER; + list_add(&rq->queuelist, &q->requeue_list); + } else { + list_add_tail(&rq->queuelist, &q->requeue_list); + } + spin_unlock_irqrestore(&q->requeue_lock, flags); +} +EXPORT_SYMBOL(blk_mq_add_to_requeue_list); + +void blk_mq_kick_requeue_list(struct request_queue *q) +{ + kblockd_schedule_work(&q->requeue_work); +} +EXPORT_SYMBOL(blk_mq_kick_requeue_list); + +static inline bool is_flush_request(struct request *rq, unsigned int tag) +{ + return ((rq->cmd_flags & REQ_FLUSH_SEQ) && + rq->q->flush_rq->tag == tag); +} + +struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) +{ + struct request *rq = tags->rqs[tag]; + + if (!is_flush_request(rq, tag)) + return rq; + + return rq->q->flush_rq; +} +EXPORT_SYMBOL(blk_mq_tag_to_rq); + struct blk_mq_timeout_data { struct blk_mq_hw_ctx *hctx; unsigned long *next; @@ -412,12 +567,13 @@ static void blk_mq_timeout_check(void *__data, unsigned long *free_tags) do { struct request *rq; - tag = find_next_zero_bit(free_tags, hctx->queue_depth, tag); - if (tag >= hctx->queue_depth) + tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag); + if (tag >= hctx->tags->nr_tags) break; - rq = hctx->rqs[tag++]; - + rq = blk_mq_tag_to_rq(hctx->tags, tag++); + if (rq->q != hctx->queue) + continue; if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) continue; @@ -442,6 +598,28 @@ static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx, blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data); } +static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq) +{ + struct request_queue *q = rq->q; + + /* + * We know that complete is set at this point. If STARTED isn't set + * anymore, then the request isn't active and the "timeout" should + * just be ignored. This can happen due to the bitflag ordering. + * Timeout first checks if STARTED is set, and if it is, assumes + * the request is active. But if we race with completion, then + * we both flags will get cleared. So check here again, and ignore + * a timeout event with a request that isn't active. + */ + if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) + return BLK_EH_NOT_HANDLED; + + if (!q->mq_ops->timeout) + return BLK_EH_RESET_TIMER; + + return q->mq_ops->timeout(rq); +} + static void blk_mq_rq_timer(unsigned long data) { struct request_queue *q = (struct request_queue *) data; @@ -449,11 +627,24 @@ static void blk_mq_rq_timer(unsigned long data) unsigned long next = 0; int i, next_set = 0; - queue_for_each_hw_ctx(q, hctx, i) + queue_for_each_hw_ctx(q, hctx, i) { + /* + * If not software queues are currently mapped to this + * hardware queue, there's nothing to check + */ + if (!hctx->nr_ctx || !hctx->tags) + continue; + blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set); + } - if (next_set) - mod_timer(&q->timeout, round_jiffies_up(next)); + if (next_set) { + next = blk_rq_timeout(round_jiffies_up(next)); + mod_timer(&q->timeout, next); + } else { + queue_for_each_hw_ctx(q, hctx, i) + blk_mq_tag_idle(hctx); + } } /* @@ -495,9 +686,38 @@ static bool blk_mq_attempt_merge(struct request_queue *q, return false; } -void blk_mq_add_timer(struct request *rq) +/* + * Process software queues that have been marked busy, splicing them + * to the for-dispatch + */ +static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) { - __blk_add_timer(rq, NULL); + struct blk_mq_ctx *ctx; + int i; + + for (i = 0; i < hctx->ctx_map.map_size; i++) { + struct blk_align_bitmap *bm = &hctx->ctx_map.map[i]; + unsigned int off, bit; + + if (!bm->word) + continue; + + bit = 0; + off = i * hctx->ctx_map.bits_per_word; + do { + bit = find_next_bit(&bm->word, bm->depth, bit); + if (bit >= bm->depth) + break; + + ctx = hctx->ctxs[bit + off]; + clear_bit(bit, &bm->word); + spin_lock(&ctx->lock); + list_splice_tail_init(&ctx->rq_list, list); + spin_unlock(&ctx->lock); + + bit++; + } while (1); + } } /* @@ -509,10 +729,11 @@ void blk_mq_add_timer(struct request *rq) static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) { struct request_queue *q = hctx->queue; - struct blk_mq_ctx *ctx; struct request *rq; LIST_HEAD(rq_list); - int bit, queued; + int queued; + + WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)); if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) return; @@ -522,15 +743,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) /* * Touch any software queue that has pending entries. */ - for_each_set_bit(bit, hctx->ctx_map, hctx->nr_ctx) { - clear_bit(bit, hctx->ctx_map); - ctx = hctx->ctxs[bit]; - BUG_ON(bit != ctx->index_hw); - - spin_lock(&ctx->lock); - list_splice_tail_init(&ctx->rq_list, &rq_list); - spin_unlock(&ctx->lock); - } + flush_busy_ctxs(hctx, &rq_list); /* * If we have previous entries on our dispatch list, grab them @@ -544,13 +757,9 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) } /* - * Delete and return all entries from our dispatch list - */ - queued = 0; - - /* * Now process all the entries, sending them to the driver. */ + queued = 0; while (!list_empty(&rq_list)) { int ret; @@ -565,13 +774,8 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) queued++; continue; case BLK_MQ_RQ_QUEUE_BUSY: - /* - * FIXME: we should have a mechanism to stop the queue - * like blk_stop_queue, otherwise we will waste cpu - * time - */ list_add(&rq->queuelist, &rq_list); - blk_mq_requeue_request(rq); + __blk_mq_requeue_request(rq); break; default: pr_err("blk-mq: bad return on queue: %d\n", ret); @@ -601,17 +805,44 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) } } +/* + * It'd be great if the workqueue API had a way to pass + * in a mask and had some smarts for more clever placement. + * For now we just round-robin here, switching for every + * BLK_MQ_CPU_WORK_BATCH queued items. + */ +static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) +{ + int cpu = hctx->next_cpu; + + if (--hctx->next_cpu_batch <= 0) { + int next_cpu; + + next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); + if (next_cpu >= nr_cpu_ids) + next_cpu = cpumask_first(hctx->cpumask); + + hctx->next_cpu = next_cpu; + hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; + } + + return cpu; +} + void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) { if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) return; - if (!async) + if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) __blk_mq_run_hw_queue(hctx); + else if (hctx->queue->nr_hw_queues == 1) + kblockd_schedule_delayed_work(&hctx->run_work, 0); else { - struct request_queue *q = hctx->queue; + unsigned int cpu; - kblockd_schedule_delayed_work(q, &hctx->delayed_work, 0); + cpu = blk_mq_hctx_next_cpu(hctx); + kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0); } } @@ -626,14 +857,17 @@ void blk_mq_run_queues(struct request_queue *q, bool async) test_bit(BLK_MQ_S_STOPPED, &hctx->state)) continue; + preempt_disable(); blk_mq_run_hw_queue(hctx, async); + preempt_enable(); } } EXPORT_SYMBOL(blk_mq_run_queues); void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) { - cancel_delayed_work(&hctx->delayed_work); + cancel_delayed_work(&hctx->run_work); + cancel_delayed_work(&hctx->delay_work); set_bit(BLK_MQ_S_STOPPED, &hctx->state); } EXPORT_SYMBOL(blk_mq_stop_hw_queue); @@ -651,11 +885,25 @@ EXPORT_SYMBOL(blk_mq_stop_hw_queues); void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) { clear_bit(BLK_MQ_S_STOPPED, &hctx->state); + + preempt_disable(); __blk_mq_run_hw_queue(hctx); + preempt_enable(); } EXPORT_SYMBOL(blk_mq_start_hw_queue); -void blk_mq_start_stopped_hw_queues(struct request_queue *q) +void blk_mq_start_hw_queues(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + int i; + + queue_for_each_hw_ctx(q, hctx, i) + blk_mq_start_hw_queue(hctx); +} +EXPORT_SYMBOL(blk_mq_start_hw_queues); + + +void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) { struct blk_mq_hw_ctx *hctx; int i; @@ -665,19 +913,47 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q) continue; clear_bit(BLK_MQ_S_STOPPED, &hctx->state); - blk_mq_run_hw_queue(hctx, true); + preempt_disable(); + blk_mq_run_hw_queue(hctx, async); + preempt_enable(); } } EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); -static void blk_mq_work_fn(struct work_struct *work) +static void blk_mq_run_work_fn(struct work_struct *work) { struct blk_mq_hw_ctx *hctx; - hctx = container_of(work, struct blk_mq_hw_ctx, delayed_work.work); + hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); + __blk_mq_run_hw_queue(hctx); } +static void blk_mq_delay_work_fn(struct work_struct *work) +{ + struct blk_mq_hw_ctx *hctx; + + hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); + + if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) + __blk_mq_run_hw_queue(hctx); +} + +void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) +{ + unsigned long tmo = msecs_to_jiffies(msecs); + + if (hctx->queue->nr_hw_queues == 1) + kblockd_schedule_delayed_work(&hctx->delay_work, tmo); + else { + unsigned int cpu; + + cpu = blk_mq_hctx_next_cpu(hctx); + kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo); + } +} +EXPORT_SYMBOL(blk_mq_delay_queue); + static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, bool at_head) { @@ -689,12 +965,13 @@ static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, list_add(&rq->queuelist, &ctx->rq_list); else list_add_tail(&rq->queuelist, &ctx->rq_list); + blk_mq_hctx_mark_pending(hctx, ctx); /* * We do this early, to ensure we are on the right CPU. */ - blk_mq_add_timer(rq); + blk_add_timer(rq); } void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, @@ -719,10 +996,10 @@ void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, spin_unlock(&ctx->lock); } - blk_mq_put_ctx(current_ctx); - if (run_queue) blk_mq_run_hw_queue(hctx, async); + + blk_mq_put_ctx(current_ctx); } static void blk_mq_insert_requests(struct request_queue *q, @@ -758,9 +1035,8 @@ static void blk_mq_insert_requests(struct request_queue *q, } spin_unlock(&ctx->lock); - blk_mq_put_ctx(current_ctx); - blk_mq_run_hw_queue(hctx, from_schedule); + blk_mq_put_ctx(current_ctx); } static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) @@ -823,24 +1099,175 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) { init_request_from_bio(rq, bio); - blk_account_io_start(rq, 1); + + if (blk_do_io_stat(rq)) { + rq->start_time = jiffies; + blk_account_io_start(rq, 1); + } } -static void blk_mq_make_request(struct request_queue *q, struct bio *bio) +static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, + struct blk_mq_ctx *ctx, + struct request *rq, struct bio *bio) +{ + struct request_queue *q = hctx->queue; + + if (!(hctx->flags & BLK_MQ_F_SHOULD_MERGE)) { + blk_mq_bio_to_request(rq, bio); + spin_lock(&ctx->lock); +insert_rq: + __blk_mq_insert_request(hctx, rq, false); + spin_unlock(&ctx->lock); + return false; + } else { + spin_lock(&ctx->lock); + if (!blk_mq_attempt_merge(q, ctx, bio)) { + blk_mq_bio_to_request(rq, bio); + goto insert_rq; + } + + spin_unlock(&ctx->lock); + __blk_mq_free_request(hctx, ctx, rq); + return true; + } +} + +struct blk_map_ctx { + struct blk_mq_hw_ctx *hctx; + struct blk_mq_ctx *ctx; +}; + +static struct request *blk_mq_map_request(struct request_queue *q, + struct bio *bio, + struct blk_map_ctx *data) { struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; + struct request *rq; + int rw = bio_data_dir(bio); + struct blk_mq_alloc_data alloc_data; + + if (unlikely(blk_mq_queue_enter(q))) { + bio_endio(bio, -EIO); + return NULL; + } + + ctx = blk_mq_get_ctx(q); + hctx = q->mq_ops->map_queue(q, ctx->cpu); + + if (rw_is_sync(bio->bi_rw)) + rw |= REQ_SYNC; + + trace_block_getrq(q, bio, rw); + blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx, + hctx); + rq = __blk_mq_alloc_request(&alloc_data, rw); + if (unlikely(!rq)) { + __blk_mq_run_hw_queue(hctx); + blk_mq_put_ctx(ctx); + trace_block_sleeprq(q, bio, rw); + + ctx = blk_mq_get_ctx(q); + hctx = q->mq_ops->map_queue(q, ctx->cpu); + blk_mq_set_alloc_data(&alloc_data, q, + __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx); + rq = __blk_mq_alloc_request(&alloc_data, rw); + ctx = alloc_data.ctx; + hctx = alloc_data.hctx; + } + + hctx->queued++; + data->hctx = hctx; + data->ctx = ctx; + return rq; +} + +/* + * Multiple hardware queue variant. This will not use per-process plugs, + * but will attempt to bypass the hctx queueing if we can go straight to + * hardware for SYNC IO. + */ +static void blk_mq_make_request(struct request_queue *q, struct bio *bio) +{ const int is_sync = rw_is_sync(bio->bi_rw); const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); - int rw = bio_data_dir(bio); + struct blk_map_ctx data; struct request *rq; + + blk_queue_bounce(q, &bio); + + if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { + bio_endio(bio, -EIO); + return; + } + + rq = blk_mq_map_request(q, bio, &data); + if (unlikely(!rq)) + return; + + if (unlikely(is_flush_fua)) { + blk_mq_bio_to_request(rq, bio); + blk_insert_flush(rq); + goto run_queue; + } + + if (is_sync) { + int ret; + + blk_mq_bio_to_request(rq, bio); + blk_mq_start_request(rq, true); + blk_add_timer(rq); + + /* + * For OK queue, we are done. For error, kill it. Any other + * error (busy), just add it to our list as we previously + * would have done + */ + ret = q->mq_ops->queue_rq(data.hctx, rq); + if (ret == BLK_MQ_RQ_QUEUE_OK) + goto done; + else { + __blk_mq_requeue_request(rq); + + if (ret == BLK_MQ_RQ_QUEUE_ERROR) { + rq->errors = -EIO; + blk_mq_end_io(rq, rq->errors); + goto done; + } + } + } + + if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { + /* + * For a SYNC request, send it to the hardware immediately. For + * an ASYNC request, just ensure that we run it later on. The + * latter allows for merging opportunities and more efficient + * dispatching. + */ +run_queue: + blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); + } +done: + blk_mq_put_ctx(data.ctx); +} + +/* + * Single hardware queue variant. This will attempt to use any per-process + * plug for merging and IO deferral. + */ +static void blk_sq_make_request(struct request_queue *q, struct bio *bio) +{ + const int is_sync = rw_is_sync(bio->bi_rw); + const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA); unsigned int use_plug, request_count = 0; + struct blk_map_ctx data; + struct request *rq; /* * If we have multiple hardware queues, just go directly to * one of those for sync IO. */ - use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync); + use_plug = !is_flush_fua && !is_sync; blk_queue_bounce(q, &bio); @@ -849,37 +1276,16 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio) return; } - if (use_plug && blk_attempt_plug_merge(q, bio, &request_count)) + if (use_plug && !blk_queue_nomerges(q) && + blk_attempt_plug_merge(q, bio, &request_count)) return; - if (blk_mq_queue_enter(q)) { - bio_endio(bio, -EIO); + rq = blk_mq_map_request(q, bio, &data); + if (unlikely(!rq)) return; - } - - ctx = blk_mq_get_ctx(q); - hctx = q->mq_ops->map_queue(q, ctx->cpu); - - if (is_sync) - rw |= REQ_SYNC; - trace_block_getrq(q, bio, rw); - rq = __blk_mq_alloc_request(hctx, GFP_ATOMIC, false); - if (likely(rq)) - blk_mq_rq_ctx_init(q, ctx, rq, rw); - else { - blk_mq_put_ctx(ctx); - trace_block_sleeprq(q, bio, rw); - rq = blk_mq_alloc_request_pinned(q, rw, __GFP_WAIT|GFP_ATOMIC, - false); - ctx = rq->mq_ctx; - hctx = q->mq_ops->map_queue(q, ctx->cpu); - } - - hctx->queued++; if (unlikely(is_flush_fua)) { blk_mq_bio_to_request(rq, bio); - blk_mq_put_ctx(ctx); blk_insert_flush(rq); goto run_queue; } @@ -901,31 +1307,23 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio) trace_block_plug(q); } list_add_tail(&rq->queuelist, &plug->mq_list); - blk_mq_put_ctx(ctx); + blk_mq_put_ctx(data.ctx); return; } } - spin_lock(&ctx->lock); - - if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) && - blk_mq_attempt_merge(q, ctx, bio)) - __blk_mq_free_request(hctx, ctx, rq); - else { - blk_mq_bio_to_request(rq, bio); - __blk_mq_insert_request(hctx, rq, false); + if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { + /* + * For a SYNC request, send it to the hardware immediately. For + * an ASYNC request, just ensure that we run it later on. The + * latter allows for merging opportunities and more efficient + * dispatching. + */ +run_queue: + blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); } - spin_unlock(&ctx->lock); - blk_mq_put_ctx(ctx); - - /* - * For a SYNC request, send it to the hardware immediately. For an - * ASYNC request, just ensure that we run it later on. The latter - * allows for merging opportunities and more efficient dispatching. - */ -run_queue: - blk_mq_run_hw_queue(hctx, !is_sync || is_flush_fua); + blk_mq_put_ctx(data.ctx); } /* @@ -937,32 +1335,153 @@ struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu) } EXPORT_SYMBOL(blk_mq_map_queue); -struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *reg, - unsigned int hctx_index) +static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, + struct blk_mq_tags *tags, unsigned int hctx_idx) { - return kmalloc_node(sizeof(struct blk_mq_hw_ctx), - GFP_KERNEL | __GFP_ZERO, reg->numa_node); + struct page *page; + + if (tags->rqs && set->ops->exit_request) { + int i; + + for (i = 0; i < tags->nr_tags; i++) { + if (!tags->rqs[i]) + continue; + set->ops->exit_request(set->driver_data, tags->rqs[i], + hctx_idx, i); + } + } + + while (!list_empty(&tags->page_list)) { + page = list_first_entry(&tags->page_list, struct page, lru); + list_del_init(&page->lru); + __free_pages(page, page->private); + } + + kfree(tags->rqs); + + blk_mq_free_tags(tags); } -EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue); -void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx, - unsigned int hctx_index) +static size_t order_to_size(unsigned int order) { - kfree(hctx); + return (size_t)PAGE_SIZE << order; } -EXPORT_SYMBOL(blk_mq_free_single_hw_queue); -static void blk_mq_hctx_notify(void *data, unsigned long action, - unsigned int cpu) +static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, + unsigned int hctx_idx) +{ + struct blk_mq_tags *tags; + unsigned int i, j, entries_per_page, max_order = 4; + size_t rq_size, left; + + tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, + set->numa_node); + if (!tags) + return NULL; + + INIT_LIST_HEAD(&tags->page_list); + + tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *), + GFP_KERNEL, set->numa_node); + if (!tags->rqs) { + blk_mq_free_tags(tags); + return NULL; + } + + /* + * rq_size is the size of the request plus driver payload, rounded + * to the cacheline size + */ + rq_size = round_up(sizeof(struct request) + set->cmd_size, + cache_line_size()); + left = rq_size * set->queue_depth; + + for (i = 0; i < set->queue_depth; ) { + int this_order = max_order; + struct page *page; + int to_do; + void *p; + + while (left < order_to_size(this_order - 1) && this_order) + this_order--; + + do { + page = alloc_pages_node(set->numa_node, GFP_KERNEL, + this_order); + if (page) + break; + if (!this_order--) + break; + if (order_to_size(this_order) < rq_size) + break; + } while (1); + + if (!page) + goto fail; + + page->private = this_order; + list_add_tail(&page->lru, &tags->page_list); + + p = page_address(page); + entries_per_page = order_to_size(this_order) / rq_size; + to_do = min(entries_per_page, set->queue_depth - i); + left -= to_do * rq_size; + for (j = 0; j < to_do; j++) { + tags->rqs[i] = p; + if (set->ops->init_request) { + if (set->ops->init_request(set->driver_data, + tags->rqs[i], hctx_idx, i, + set->numa_node)) + goto fail; + } + + p += rq_size; + i++; + } + } + + return tags; + +fail: + pr_warn("%s: failed to allocate requests\n", __func__); + blk_mq_free_rq_map(set, tags, hctx_idx); + return NULL; +} + +static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap) +{ + kfree(bitmap->map); +} + +static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node) +{ + unsigned int bpw = 8, total, num_maps, i; + + bitmap->bits_per_word = bpw; + + num_maps = ALIGN(nr_cpu_ids, bpw) / bpw; + bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap), + GFP_KERNEL, node); + if (!bitmap->map) + return -ENOMEM; + + bitmap->map_size = num_maps; + + total = nr_cpu_ids; + for (i = 0; i < num_maps; i++) { + bitmap->map[i].depth = min(total, bitmap->bits_per_word); + total -= bitmap->map[i].depth; + } + + return 0; +} + +static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu) { - struct blk_mq_hw_ctx *hctx = data; struct request_queue *q = hctx->queue; struct blk_mq_ctx *ctx; LIST_HEAD(tmp); - if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) - return; - /* * Move ctx entries to new CPU, if this one is going away. */ @@ -971,12 +1490,12 @@ static void blk_mq_hctx_notify(void *data, unsigned long action, spin_lock(&ctx->lock); if (!list_empty(&ctx->rq_list)) { list_splice_init(&ctx->rq_list, &tmp); - clear_bit(ctx->index_hw, hctx->ctx_map); + blk_mq_hctx_clear_pending(hctx, ctx); } spin_unlock(&ctx->lock); if (list_empty(&tmp)) - return; + return NOTIFY_OK; ctx = blk_mq_get_ctx(q); spin_lock(&ctx->lock); @@ -993,210 +1512,105 @@ static void blk_mq_hctx_notify(void *data, unsigned long action, blk_mq_hctx_mark_pending(hctx, ctx); spin_unlock(&ctx->lock); - blk_mq_put_ctx(ctx); blk_mq_run_hw_queue(hctx, true); + blk_mq_put_ctx(ctx); + return NOTIFY_OK; } -static int blk_mq_init_hw_commands(struct blk_mq_hw_ctx *hctx, - int (*init)(void *, struct blk_mq_hw_ctx *, - struct request *, unsigned int), - void *data) +static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu) { - unsigned int i; - int ret = 0; - - for (i = 0; i < hctx->queue_depth; i++) { - struct request *rq = hctx->rqs[i]; - - ret = init(data, hctx, rq, i); - if (ret) - break; - } - - return ret; -} + struct request_queue *q = hctx->queue; + struct blk_mq_tag_set *set = q->tag_set; -int blk_mq_init_commands(struct request_queue *q, - int (*init)(void *, struct blk_mq_hw_ctx *, - struct request *, unsigned int), - void *data) -{ - struct blk_mq_hw_ctx *hctx; - unsigned int i; - int ret = 0; + if (set->tags[hctx->queue_num]) + return NOTIFY_OK; - queue_for_each_hw_ctx(q, hctx, i) { - ret = blk_mq_init_hw_commands(hctx, init, data); - if (ret) - break; - } + set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num); + if (!set->tags[hctx->queue_num]) + return NOTIFY_STOP; - return ret; + hctx->tags = set->tags[hctx->queue_num]; + return NOTIFY_OK; } -EXPORT_SYMBOL(blk_mq_init_commands); -static void blk_mq_free_hw_commands(struct blk_mq_hw_ctx *hctx, - void (*free)(void *, struct blk_mq_hw_ctx *, - struct request *, unsigned int), - void *data) +static int blk_mq_hctx_notify(void *data, unsigned long action, + unsigned int cpu) { - unsigned int i; + struct blk_mq_hw_ctx *hctx = data; - for (i = 0; i < hctx->queue_depth; i++) { - struct request *rq = hctx->rqs[i]; + if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) + return blk_mq_hctx_cpu_offline(hctx, cpu); + else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) + return blk_mq_hctx_cpu_online(hctx, cpu); - free(data, hctx, rq, i); - } + return NOTIFY_OK; } -void blk_mq_free_commands(struct request_queue *q, - void (*free)(void *, struct blk_mq_hw_ctx *, - struct request *, unsigned int), - void *data) +static void blk_mq_exit_hw_queues(struct request_queue *q, + struct blk_mq_tag_set *set, int nr_queue) { struct blk_mq_hw_ctx *hctx; unsigned int i; - queue_for_each_hw_ctx(q, hctx, i) - blk_mq_free_hw_commands(hctx, free, data); -} -EXPORT_SYMBOL(blk_mq_free_commands); - -static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx) -{ - struct page *page; - - while (!list_empty(&hctx->page_list)) { - page = list_first_entry(&hctx->page_list, struct page, lru); - list_del_init(&page->lru); - __free_pages(page, page->private); - } - - kfree(hctx->rqs); + queue_for_each_hw_ctx(q, hctx, i) { + if (i == nr_queue) + break; - if (hctx->tags) - blk_mq_free_tags(hctx->tags); -} + blk_mq_tag_idle(hctx); -static size_t order_to_size(unsigned int order) -{ - size_t ret = PAGE_SIZE; + if (set->ops->exit_hctx) + set->ops->exit_hctx(hctx, i); - while (order--) - ret *= 2; + blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); + kfree(hctx->ctxs); + blk_mq_free_bitmap(&hctx->ctx_map); + } - return ret; } -static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx, - unsigned int reserved_tags, int node) +static void blk_mq_free_hw_queues(struct request_queue *q, + struct blk_mq_tag_set *set) { - unsigned int i, j, entries_per_page, max_order = 4; - size_t rq_size, left; - - INIT_LIST_HEAD(&hctx->page_list); - - hctx->rqs = kmalloc_node(hctx->queue_depth * sizeof(struct request *), - GFP_KERNEL, node); - if (!hctx->rqs) - return -ENOMEM; - - /* - * rq_size is the size of the request plus driver payload, rounded - * to the cacheline size - */ - rq_size = round_up(sizeof(struct request) + hctx->cmd_size, - cache_line_size()); - left = rq_size * hctx->queue_depth; - - for (i = 0; i < hctx->queue_depth;) { - int this_order = max_order; - struct page *page; - int to_do; - void *p; - - while (left < order_to_size(this_order - 1) && this_order) - this_order--; - - do { - page = alloc_pages_node(node, GFP_KERNEL, this_order); - if (page) - break; - if (!this_order--) - break; - if (order_to_size(this_order) < rq_size) - break; - } while (1); - - if (!page) - break; - - page->private = this_order; - list_add_tail(&page->lru, &hctx->page_list); - - p = page_address(page); - entries_per_page = order_to_size(this_order) / rq_size; - to_do = min(entries_per_page, hctx->queue_depth - i); - left -= to_do * rq_size; - for (j = 0; j < to_do; j++) { - hctx->rqs[i] = p; - blk_mq_rq_init(hctx, hctx->rqs[i]); - p += rq_size; - i++; - } - } - - if (i < (reserved_tags + BLK_MQ_TAG_MIN)) - goto err_rq_map; - else if (i != hctx->queue_depth) { - hctx->queue_depth = i; - pr_warn("%s: queue depth set to %u because of low memory\n", - __func__, i); - } + struct blk_mq_hw_ctx *hctx; + unsigned int i; - hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node); - if (!hctx->tags) { -err_rq_map: - blk_mq_free_rq_map(hctx); - return -ENOMEM; + queue_for_each_hw_ctx(q, hctx, i) { + free_cpumask_var(hctx->cpumask); + kfree(hctx); } - - return 0; } static int blk_mq_init_hw_queues(struct request_queue *q, - struct blk_mq_reg *reg, void *driver_data) + struct blk_mq_tag_set *set) { struct blk_mq_hw_ctx *hctx; - unsigned int i, j; + unsigned int i; /* * Initialize hardware queues */ queue_for_each_hw_ctx(q, hctx, i) { - unsigned int num_maps; int node; node = hctx->numa_node; if (node == NUMA_NO_NODE) - node = hctx->numa_node = reg->numa_node; + node = hctx->numa_node = set->numa_node; - INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn); + INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); + INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); spin_lock_init(&hctx->lock); INIT_LIST_HEAD(&hctx->dispatch); hctx->queue = q; hctx->queue_num = i; - hctx->flags = reg->flags; - hctx->queue_depth = reg->queue_depth; - hctx->cmd_size = reg->cmd_size; + hctx->flags = set->flags; + hctx->cmd_size = set->cmd_size; blk_mq_init_cpu_notifier(&hctx->cpu_notifier, blk_mq_hctx_notify, hctx); blk_mq_register_cpu_notifier(&hctx->cpu_notifier); - if (blk_mq_init_rq_map(hctx, reg->reserved_tags, node)) - break; + hctx->tags = set->tags[i]; /* * Allocate space for all possible cpus to avoid allocation in @@ -1207,17 +1621,13 @@ static int blk_mq_init_hw_queues(struct request_queue *q, if (!hctx->ctxs) break; - num_maps = ALIGN(nr_cpu_ids, BITS_PER_LONG) / BITS_PER_LONG; - hctx->ctx_map = kzalloc_node(num_maps * sizeof(unsigned long), - GFP_KERNEL, node); - if (!hctx->ctx_map) + if (blk_mq_alloc_bitmap(&hctx->ctx_map, node)) break; - hctx->nr_ctx_map = num_maps; hctx->nr_ctx = 0; - if (reg->ops->init_hctx && - reg->ops->init_hctx(hctx, driver_data, i)) + if (set->ops->init_hctx && + set->ops->init_hctx(hctx, set->driver_data, i)) break; } @@ -1227,17 +1637,7 @@ static int blk_mq_init_hw_queues(struct request_queue *q, /* * Init failed */ - queue_for_each_hw_ctx(q, hctx, j) { - if (i == j) - break; - - if (reg->ops->exit_hctx) - reg->ops->exit_hctx(hctx, j); - - blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); - blk_mq_free_rq_map(hctx); - kfree(hctx->ctxs); - } + blk_mq_exit_hw_queues(q, set, i); return 1; } @@ -1258,12 +1658,13 @@ static void blk_mq_init_cpu_queues(struct request_queue *q, __ctx->queue = q; /* If the cpu isn't online, the cpu is mapped to first hctx */ - hctx = q->mq_ops->map_queue(q, i); - hctx->nr_ctx++; - if (!cpu_online(i)) continue; + hctx = q->mq_ops->map_queue(q, i); + cpumask_set_cpu(i, hctx->cpumask); + hctx->nr_ctx++; + /* * Set local node, IFF we have more than one hw queue. If * not, we remain on the home node of the device @@ -1280,6 +1681,7 @@ static void blk_mq_map_swqueue(struct request_queue *q) struct blk_mq_ctx *ctx; queue_for_each_hw_ctx(q, hctx, i) { + cpumask_clear(hctx->cpumask); hctx->nr_ctx = 0; } @@ -1288,115 +1690,208 @@ static void blk_mq_map_swqueue(struct request_queue *q) */ queue_for_each_ctx(q, ctx, i) { /* If the cpu isn't online, the cpu is mapped to first hctx */ + if (!cpu_online(i)) + continue; + hctx = q->mq_ops->map_queue(q, i); + cpumask_set_cpu(i, hctx->cpumask); ctx->index_hw = hctx->nr_ctx; hctx->ctxs[hctx->nr_ctx++] = ctx; } + + queue_for_each_hw_ctx(q, hctx, i) { + /* + * If not software queues are mapped to this hardware queue, + * disable it and free the request entries + */ + if (!hctx->nr_ctx) { + struct blk_mq_tag_set *set = q->tag_set; + + if (set->tags[i]) { + blk_mq_free_rq_map(set, set->tags[i], i); + set->tags[i] = NULL; + hctx->tags = NULL; + } + continue; + } + + /* + * Initialize batch roundrobin counts + */ + hctx->next_cpu = cpumask_first(hctx->cpumask); + hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; + } } -struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg, - void *driver_data) +static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set) { - struct blk_mq_hw_ctx **hctxs; - struct blk_mq_ctx *ctx; + struct blk_mq_hw_ctx *hctx; struct request_queue *q; + bool shared; int i; - if (!reg->nr_hw_queues || - !reg->ops->queue_rq || !reg->ops->map_queue || - !reg->ops->alloc_hctx || !reg->ops->free_hctx) - return ERR_PTR(-EINVAL); + if (set->tag_list.next == set->tag_list.prev) + shared = false; + else + shared = true; + + list_for_each_entry(q, &set->tag_list, tag_set_list) { + blk_mq_freeze_queue(q); - if (!reg->queue_depth) - reg->queue_depth = BLK_MQ_MAX_DEPTH; - else if (reg->queue_depth > BLK_MQ_MAX_DEPTH) { - pr_err("blk-mq: queuedepth too large (%u)\n", reg->queue_depth); - reg->queue_depth = BLK_MQ_MAX_DEPTH; + queue_for_each_hw_ctx(q, hctx, i) { + if (shared) + hctx->flags |= BLK_MQ_F_TAG_SHARED; + else + hctx->flags &= ~BLK_MQ_F_TAG_SHARED; + } + blk_mq_unfreeze_queue(q); } +} - if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN)) - return ERR_PTR(-EINVAL); +static void blk_mq_del_queue_tag_set(struct request_queue *q) +{ + struct blk_mq_tag_set *set = q->tag_set; + + blk_mq_freeze_queue(q); + + mutex_lock(&set->tag_list_lock); + list_del_init(&q->tag_set_list); + blk_mq_update_tag_set_depth(set); + mutex_unlock(&set->tag_list_lock); + + blk_mq_unfreeze_queue(q); +} + +static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, + struct request_queue *q) +{ + q->tag_set = set; + + mutex_lock(&set->tag_list_lock); + list_add_tail(&q->tag_set_list, &set->tag_list); + blk_mq_update_tag_set_depth(set); + mutex_unlock(&set->tag_list_lock); +} + +struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) +{ + struct blk_mq_hw_ctx **hctxs; + struct blk_mq_ctx __percpu *ctx; + struct request_queue *q; + unsigned int *map; + int i; ctx = alloc_percpu(struct blk_mq_ctx); if (!ctx) return ERR_PTR(-ENOMEM); - hctxs = kmalloc_node(reg->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, - reg->numa_node); + hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL, + set->numa_node); if (!hctxs) goto err_percpu; - for (i = 0; i < reg->nr_hw_queues; i++) { - hctxs[i] = reg->ops->alloc_hctx(reg, i); + map = blk_mq_make_queue_map(set); + if (!map) + goto err_map; + + for (i = 0; i < set->nr_hw_queues; i++) { + int node = blk_mq_hw_queue_to_node(map, i); + + hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), + GFP_KERNEL, node); if (!hctxs[i]) goto err_hctxs; - hctxs[i]->numa_node = NUMA_NO_NODE; + if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL)) + goto err_hctxs; + + atomic_set(&hctxs[i]->nr_active, 0); + hctxs[i]->numa_node = node; hctxs[i]->queue_num = i; } - q = blk_alloc_queue_node(GFP_KERNEL, reg->numa_node); + q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); if (!q) goto err_hctxs; - q->mq_map = blk_mq_make_queue_map(reg); - if (!q->mq_map) + if (percpu_counter_init(&q->mq_usage_counter, 0)) goto err_map; setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q); blk_queue_rq_timeout(q, 30000); q->nr_queues = nr_cpu_ids; - q->nr_hw_queues = reg->nr_hw_queues; + q->nr_hw_queues = set->nr_hw_queues; + q->mq_map = map; q->queue_ctx = ctx; q->queue_hw_ctx = hctxs; - q->mq_ops = reg->ops; + q->mq_ops = set->ops; q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; + if (!(set->flags & BLK_MQ_F_SG_MERGE)) + q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; + q->sg_reserved_size = INT_MAX; - blk_queue_make_request(q, blk_mq_make_request); - blk_queue_rq_timed_out(q, reg->ops->timeout); - if (reg->timeout) - blk_queue_rq_timeout(q, reg->timeout); + INIT_WORK(&q->requeue_work, blk_mq_requeue_work); + INIT_LIST_HEAD(&q->requeue_list); + spin_lock_init(&q->requeue_lock); + + if (q->nr_hw_queues > 1) + blk_queue_make_request(q, blk_mq_make_request); + else + blk_queue_make_request(q, blk_sq_make_request); + + blk_queue_rq_timed_out(q, blk_mq_rq_timed_out); + if (set->timeout) + blk_queue_rq_timeout(q, set->timeout); - if (reg->ops->complete) - blk_queue_softirq_done(q, reg->ops->complete); + /* + * Do this after blk_queue_make_request() overrides it... + */ + q->nr_requests = set->queue_depth; + + if (set->ops->complete) + blk_queue_softirq_done(q, set->ops->complete); blk_mq_init_flush(q); - blk_mq_init_cpu_queues(q, reg->nr_hw_queues); + blk_mq_init_cpu_queues(q, set->nr_hw_queues); - q->flush_rq = kzalloc(round_up(sizeof(struct request) + reg->cmd_size, - cache_line_size()), GFP_KERNEL); + q->flush_rq = kzalloc(round_up(sizeof(struct request) + + set->cmd_size, cache_line_size()), + GFP_KERNEL); if (!q->flush_rq) goto err_hw; - if (blk_mq_init_hw_queues(q, reg, driver_data)) + if (blk_mq_init_hw_queues(q, set)) goto err_flush_rq; - blk_mq_map_swqueue(q); - mutex_lock(&all_q_mutex); list_add_tail(&q->all_q_node, &all_q_list); mutex_unlock(&all_q_mutex); + blk_mq_add_queue_tag_set(set, q); + + blk_mq_map_swqueue(q); + return q; err_flush_rq: kfree(q->flush_rq); err_hw: - kfree(q->mq_map); -err_map: blk_cleanup_queue(q); err_hctxs: - for (i = 0; i < reg->nr_hw_queues; i++) { + kfree(map); + for (i = 0; i < set->nr_hw_queues; i++) { if (!hctxs[i]) break; - reg->ops->free_hctx(hctxs[i], i); + free_cpumask_var(hctxs[i]->cpumask); + kfree(hctxs[i]); } +err_map: kfree(hctxs); err_percpu: free_percpu(ctx); @@ -1406,18 +1901,14 @@ EXPORT_SYMBOL(blk_mq_init_queue); void blk_mq_free_queue(struct request_queue *q) { - struct blk_mq_hw_ctx *hctx; - int i; + struct blk_mq_tag_set *set = q->tag_set; - queue_for_each_hw_ctx(q, hctx, i) { - kfree(hctx->ctx_map); - kfree(hctx->ctxs); - blk_mq_free_rq_map(hctx); - blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier); - if (q->mq_ops->exit_hctx) - q->mq_ops->exit_hctx(hctx, i); - q->mq_ops->free_hctx(hctx, i); - } + blk_mq_del_queue_tag_set(q); + + blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); + blk_mq_free_hw_queues(q, set); + + percpu_counter_destroy(&q->mq_usage_counter); free_percpu(q->queue_ctx); kfree(q->queue_hw_ctx); @@ -1437,6 +1928,8 @@ static void blk_mq_queue_reinit(struct request_queue *q) { blk_mq_freeze_queue(q); + blk_mq_sysfs_unregister(q); + blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); /* @@ -1447,6 +1940,8 @@ static void blk_mq_queue_reinit(struct request_queue *q) blk_mq_map_swqueue(q); + blk_mq_sysfs_register(q); + blk_mq_unfreeze_queue(q); } @@ -1456,10 +1951,10 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb, struct request_queue *q; /* - * Before new mapping is established, hotadded cpu might already start - * handling requests. This doesn't break anything as we map offline - * CPUs to first hardware queue. We will re-init queue below to get - * optimal settings. + * Before new mappings are established, hotadded cpu might already + * start handling requests. This doesn't break anything as we map + * offline CPUs to first hardware queue. We will re-init the queue + * below to get optimal settings. */ if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) @@ -1472,6 +1967,81 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb, return NOTIFY_OK; } +int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) +{ + int i; + + if (!set->nr_hw_queues) + return -EINVAL; + if (!set->queue_depth || set->queue_depth > BLK_MQ_MAX_DEPTH) + return -EINVAL; + if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) + return -EINVAL; + + if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue) + return -EINVAL; + + + set->tags = kmalloc_node(set->nr_hw_queues * + sizeof(struct blk_mq_tags *), + GFP_KERNEL, set->numa_node); + if (!set->tags) + goto out; + + for (i = 0; i < set->nr_hw_queues; i++) { + set->tags[i] = blk_mq_init_rq_map(set, i); + if (!set->tags[i]) + goto out_unwind; + } + + mutex_init(&set->tag_list_lock); + INIT_LIST_HEAD(&set->tag_list); + + return 0; + +out_unwind: + while (--i >= 0) + blk_mq_free_rq_map(set, set->tags[i], i); +out: + return -ENOMEM; +} +EXPORT_SYMBOL(blk_mq_alloc_tag_set); + +void blk_mq_free_tag_set(struct blk_mq_tag_set *set) +{ + int i; + + for (i = 0; i < set->nr_hw_queues; i++) { + if (set->tags[i]) + blk_mq_free_rq_map(set, set->tags[i], i); + } + + kfree(set->tags); +} +EXPORT_SYMBOL(blk_mq_free_tag_set); + +int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) +{ + struct blk_mq_tag_set *set = q->tag_set; + struct blk_mq_hw_ctx *hctx; + int i, ret; + + if (!set || nr > set->queue_depth) + return -EINVAL; + + ret = 0; + queue_for_each_hw_ctx(q, hctx, i) { + ret = blk_mq_tag_update_depth(hctx->tags, nr); + if (ret) + break; + } + + if (!ret) + q->nr_requests = nr; + + return ret; +} + void blk_mq_disable_hotplug(void) { mutex_lock(&all_q_mutex); diff --git a/block/blk-mq.h b/block/blk-mq.h index ebbe6ba..2646088 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -1,6 +1,8 @@ #ifndef INT_BLK_MQ_H #define INT_BLK_MQ_H +struct blk_mq_tag_set; + struct blk_mq_ctx { struct { spinlock_t lock; @@ -9,7 +11,8 @@ struct blk_mq_ctx { unsigned int cpu; unsigned int index_hw; - unsigned int ipi_redirect; + + unsigned int last_tag ____cacheline_aligned_in_smp; /* incremented at dispatch time */ unsigned long rq_dispatched[2]; @@ -20,21 +23,23 @@ struct blk_mq_ctx { struct request_queue *queue; struct kobject kobj; -}; +} ____cacheline_aligned_in_smp; void __blk_mq_complete_request(struct request *rq); void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); void blk_mq_init_flush(struct request_queue *q); void blk_mq_drain_queue(struct request_queue *q); void blk_mq_free_queue(struct request_queue *q); -void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq); +void blk_mq_clone_flush_request(struct request *flush_rq, + struct request *orig_rq); +int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); /* * CPU hotplug helpers */ struct blk_mq_cpu_notifier; void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier, - void (*fn)(void *, unsigned long, unsigned int), + int (*fn)(void *, unsigned long, unsigned int), void *data); void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier); void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier); @@ -45,10 +50,68 @@ void blk_mq_disable_hotplug(void); /* * CPU -> queue mappings */ -struct blk_mq_reg; -extern unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg); +extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set); extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues); +extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int); + +/* + * sysfs helpers + */ +extern int blk_mq_sysfs_register(struct request_queue *q); +extern void blk_mq_sysfs_unregister(struct request_queue *q); + +/* + * Basic implementation of sparser bitmap, allowing the user to spread + * the bits over more cachelines. + */ +struct blk_align_bitmap { + unsigned long word; + unsigned long depth; +} ____cacheline_aligned_in_smp; + +static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q, + unsigned int cpu) +{ + return per_cpu_ptr(q->queue_ctx, cpu); +} + +/* + * This assumes per-cpu software queueing queues. They could be per-node + * as well, for instance. For now this is hardcoded as-is. Note that we don't + * care about preemption, since we know the ctx's are persistent. This does + * mean that we can't rely on ctx always matching the currently running CPU. + */ +static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q) +{ + return __blk_mq_get_ctx(q, get_cpu()); +} + +static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx) +{ + put_cpu(); +} + +struct blk_mq_alloc_data { + /* input parameter */ + struct request_queue *q; + gfp_t gfp; + bool reserved; + + /* input & output parameter */ + struct blk_mq_ctx *ctx; + struct blk_mq_hw_ctx *hctx; +}; -void blk_mq_add_timer(struct request *rq); +static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data, + struct request_queue *q, gfp_t gfp, bool reserved, + struct blk_mq_ctx *ctx, + struct blk_mq_hw_ctx *hctx) +{ + data->q = q; + data->gfp = gfp; + data->reserved = reserved; + data->ctx = ctx; + data->hctx = hctx; +} #endif diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 7500f87..23321fb 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -48,11 +48,10 @@ static ssize_t queue_requests_show(struct request_queue *q, char *page) static ssize_t queue_requests_store(struct request_queue *q, const char *page, size_t count) { - struct request_list *rl; unsigned long nr; - int ret; + int ret, err; - if (!q->request_fn) + if (!q->request_fn && !q->mq_ops) return -EINVAL; ret = queue_var_store(&nr, page, count); @@ -62,40 +61,14 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count) if (nr < BLKDEV_MIN_RQ) nr = BLKDEV_MIN_RQ; - spin_lock_irq(q->queue_lock); - q->nr_requests = nr; - blk_queue_congestion_threshold(q); - - /* congestion isn't cgroup aware and follows root blkcg for now */ - rl = &q->root_rl; - - if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q)) - blk_set_queue_congested(q, BLK_RW_SYNC); - else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q)) - blk_clear_queue_congested(q, BLK_RW_SYNC); - - if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q)) - blk_set_queue_congested(q, BLK_RW_ASYNC); - else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q)) - blk_clear_queue_congested(q, BLK_RW_ASYNC); - - blk_queue_for_each_rl(rl, q) { - if (rl->count[BLK_RW_SYNC] >= q->nr_requests) { - blk_set_rl_full(rl, BLK_RW_SYNC); - } else { - blk_clear_rl_full(rl, BLK_RW_SYNC); - wake_up(&rl->wait[BLK_RW_SYNC]); - } - - if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) { - blk_set_rl_full(rl, BLK_RW_ASYNC); - } else { - blk_clear_rl_full(rl, BLK_RW_ASYNC); - wake_up(&rl->wait[BLK_RW_ASYNC]); - } - } + if (q->request_fn) + err = blk_update_nr_requests(q, nr); + else + err = blk_mq_update_nr_requests(q, nr); + + if (err) + return err; - spin_unlock_irq(q->queue_lock); return ret; } @@ -544,8 +517,6 @@ static void blk_release_queue(struct kobject *kobj) if (q->queue_tags) __blk_queue_free_tags(q); - percpu_counter_destroy(&q->mq_usage_counter); - if (q->mq_ops) blk_mq_free_queue(q); diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 033745c..9353b46 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -744,7 +744,7 @@ static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw, static bool throtl_slice_used(struct throtl_grp *tg, bool rw) { if (time_in_range(jiffies, tg->slice_start[rw], tg->slice_end[rw])) - return 0; + return false; return 1; } @@ -842,7 +842,7 @@ static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, if (tg->io_disp[rw] + 1 <= io_allowed) { if (wait) *wait = 0; - return 1; + return true; } /* Calc approx time to dispatch */ @@ -880,7 +880,7 @@ static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, if (tg->bytes_disp[rw] + bio->bi_iter.bi_size <= bytes_allowed) { if (wait) *wait = 0; - return 1; + return true; } /* Calc approx time to dispatch */ @@ -923,7 +923,7 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, if (tg->bps[rw] == -1 && tg->iops[rw] == -1) { if (wait) *wait = 0; - return 1; + return true; } /* @@ -1258,7 +1258,7 @@ out_unlock: * of throtl_data->service_queue. Those bio's are ready and issued by this * function. */ -void blk_throtl_dispatch_work_fn(struct work_struct *work) +static void blk_throtl_dispatch_work_fn(struct work_struct *work) { struct throtl_data *td = container_of(work, struct throtl_data, dispatch_work); diff --git a/block/blk-timeout.c b/block/blk-timeout.c index d96f7061..95a0959 100644 --- a/block/blk-timeout.c +++ b/block/blk-timeout.c @@ -96,11 +96,7 @@ static void blk_rq_timed_out(struct request *req) __blk_complete_request(req); break; case BLK_EH_RESET_TIMER: - if (q->mq_ops) - blk_mq_add_timer(req); - else - blk_add_timer(req); - + blk_add_timer(req); blk_clear_rq_complete(req); break; case BLK_EH_NOT_HANDLED: @@ -170,7 +166,26 @@ void blk_abort_request(struct request *req) } EXPORT_SYMBOL_GPL(blk_abort_request); -void __blk_add_timer(struct request *req, struct list_head *timeout_list) +unsigned long blk_rq_timeout(unsigned long timeout) +{ + unsigned long maxt; + + maxt = round_jiffies_up(jiffies + BLK_MAX_TIMEOUT); + if (time_after(timeout, maxt)) + timeout = maxt; + + return timeout; +} + +/** + * blk_add_timer - Start timeout timer for a single request + * @req: request that is about to start running. + * + * Notes: + * Each request has its own timer, and as it is added to the queue, we + * set up the timer. When the request completes, we cancel the timer. + */ +void blk_add_timer(struct request *req) { struct request_queue *q = req->q; unsigned long expiry; @@ -188,32 +203,29 @@ void __blk_add_timer(struct request *req, struct list_head *timeout_list) req->timeout = q->rq_timeout; req->deadline = jiffies + req->timeout; - if (timeout_list) - list_add_tail(&req->timeout_list, timeout_list); + if (!q->mq_ops) + list_add_tail(&req->timeout_list, &req->q->timeout_list); /* * If the timer isn't already pending or this timeout is earlier * than an existing one, modify the timer. Round up to next nearest * second. */ - expiry = round_jiffies_up(req->deadline); + expiry = blk_rq_timeout(round_jiffies_up(req->deadline)); if (!timer_pending(&q->timeout) || - time_before(expiry, q->timeout.expires)) - mod_timer(&q->timeout, expiry); + time_before(expiry, q->timeout.expires)) { + unsigned long diff = q->timeout.expires - expiry; -} + /* + * Due to added timer slack to group timers, the timer + * will often be a little in front of what we asked for. + * So apply some tolerance here too, otherwise we keep + * modifying the timer because expires for value X + * will be X + something. + */ + if (!timer_pending(&q->timeout) || (diff >= HZ / 2)) + mod_timer(&q->timeout, expiry); + } -/** - * blk_add_timer - Start timeout timer for a single request - * @req: request that is about to start running. - * - * Notes: - * Each request has its own timer, and as it is added to the queue, we - * set up the timer. When the request completes, we cancel the timer. - */ -void blk_add_timer(struct request *req) -{ - __blk_add_timer(req, &req->q->timeout_list); } - diff --git a/block/blk.h b/block/blk.h index 1d880f1..45385e9 100644 --- a/block/blk.h +++ b/block/blk.h @@ -9,6 +9,9 @@ /* Number of requests a "batching" process may submit */ #define BLK_BATCH_REQ 32 +/* Max future timer expiry for timeouts */ +#define BLK_MAX_TIMEOUT (5 * HZ) + extern struct kmem_cache *blk_requestq_cachep; extern struct kmem_cache *request_cachep; extern struct kobj_type blk_queue_ktype; @@ -37,9 +40,9 @@ bool __blk_end_bidi_request(struct request *rq, int error, void blk_rq_timed_out_timer(unsigned long data); void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout, unsigned int *next_set); -void __blk_add_timer(struct request *req, struct list_head *timeout_list); +unsigned long blk_rq_timeout(unsigned long timeout); +void blk_add_timer(struct request *req); void blk_delete_timer(struct request *); -void blk_add_timer(struct request *); bool bio_attempt_front_merge(struct request_queue *q, struct request *req, @@ -185,6 +188,8 @@ static inline int queue_congestion_off_threshold(struct request_queue *q) return q->nr_congestion_off; } +extern int blk_update_nr_requests(struct request_queue *, unsigned int); + /* * Contribute to IO statistics IFF: * diff --git a/block/bounce.c b/block/bounce.c new file mode 100644 index 0000000..ab21ba2 --- /dev/null +++ b/block/bounce.c @@ -0,0 +1,290 @@ +/* bounce buffer handling for block devices + * + * - Split from highmem.c + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/mm.h> +#include <linux/export.h> +#include <linux/swap.h> +#include <linux/gfp.h> +#include <linux/bio.h> +#include <linux/pagemap.h> +#include <linux/mempool.h> +#include <linux/blkdev.h> +#include <linux/init.h> +#include <linux/hash.h> +#include <linux/highmem.h> +#include <linux/bootmem.h> +#include <linux/printk.h> +#include <asm/tlbflush.h> + +#include <trace/events/block.h> + +#define POOL_SIZE 64 +#define ISA_POOL_SIZE 16 + +static mempool_t *page_pool, *isa_page_pool; + +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_NEED_BOUNCE_POOL) +static __init int init_emergency_pool(void) +{ +#if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG) + if (max_pfn <= max_low_pfn) + return 0; +#endif + + page_pool = mempool_create_page_pool(POOL_SIZE, 0); + BUG_ON(!page_pool); + pr_info("pool size: %d pages\n", POOL_SIZE); + + return 0; +} + +__initcall(init_emergency_pool); +#endif + +#ifdef CONFIG_HIGHMEM +/* + * highmem version, map in to vec + */ +static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom) +{ + unsigned long flags; + unsigned char *vto; + + local_irq_save(flags); + vto = kmap_atomic(to->bv_page); + memcpy(vto + to->bv_offset, vfrom, to->bv_len); + kunmap_atomic(vto); + local_irq_restore(flags); +} + +#else /* CONFIG_HIGHMEM */ + +#define bounce_copy_vec(to, vfrom) \ + memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len) + +#endif /* CONFIG_HIGHMEM */ + +/* + * allocate pages in the DMA region for the ISA pool + */ +static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void *data) +{ + return mempool_alloc_pages(gfp_mask | GFP_DMA, data); +} + +/* + * gets called "every" time someone init's a queue with BLK_BOUNCE_ISA + * as the max address, so check if the pool has already been created. + */ +int init_emergency_isa_pool(void) +{ + if (isa_page_pool) + return 0; + + isa_page_pool = mempool_create(ISA_POOL_SIZE, mempool_alloc_pages_isa, + mempool_free_pages, (void *) 0); + BUG_ON(!isa_page_pool); + + pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE); + return 0; +} + +/* + * Simple bounce buffer support for highmem pages. Depending on the + * queue gfp mask set, *to may or may not be a highmem page. kmap it + * always, it will do the Right Thing + */ +static void copy_to_high_bio_irq(struct bio *to, struct bio *from) +{ + unsigned char *vfrom; + struct bio_vec tovec, *fromvec = from->bi_io_vec; + struct bvec_iter iter; + + bio_for_each_segment(tovec, to, iter) { + if (tovec.bv_page != fromvec->bv_page) { + /* + * fromvec->bv_offset and fromvec->bv_len might have + * been modified by the block layer, so use the original + * copy, bounce_copy_vec already uses tovec->bv_len + */ + vfrom = page_address(fromvec->bv_page) + + tovec.bv_offset; + + bounce_copy_vec(&tovec, vfrom); + flush_dcache_page(tovec.bv_page); + } + + fromvec++; + } +} + +static void bounce_end_io(struct bio *bio, mempool_t *pool, int err) +{ + struct bio *bio_orig = bio->bi_private; + struct bio_vec *bvec, *org_vec; + int i; + + if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags)) + set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags); + + /* + * free up bounce indirect pages used + */ + bio_for_each_segment_all(bvec, bio, i) { + org_vec = bio_orig->bi_io_vec + i; + if (bvec->bv_page == org_vec->bv_page) + continue; + + dec_zone_page_state(bvec->bv_page, NR_BOUNCE); + mempool_free(bvec->bv_page, pool); + } + + bio_endio(bio_orig, err); + bio_put(bio); +} + +static void bounce_end_io_write(struct bio *bio, int err) +{ + bounce_end_io(bio, page_pool, err); +} + +static void bounce_end_io_write_isa(struct bio *bio, int err) +{ + + bounce_end_io(bio, isa_page_pool, err); +} + +static void __bounce_end_io_read(struct bio *bio, mempool_t *pool, int err) +{ + struct bio *bio_orig = bio->bi_private; + + if (test_bit(BIO_UPTODATE, &bio->bi_flags)) + copy_to_high_bio_irq(bio_orig, bio); + + bounce_end_io(bio, pool, err); +} + +static void bounce_end_io_read(struct bio *bio, int err) +{ + __bounce_end_io_read(bio, page_pool, err); +} + +static void bounce_end_io_read_isa(struct bio *bio, int err) +{ + __bounce_end_io_read(bio, isa_page_pool, err); +} + +#ifdef CONFIG_NEED_BOUNCE_POOL +static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio) +{ + if (bio_data_dir(bio) != WRITE) + return 0; + + if (!bdi_cap_stable_pages_required(&q->backing_dev_info)) + return 0; + + return test_bit(BIO_SNAP_STABLE, &bio->bi_flags); +} +#else +static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio) +{ + return 0; +} +#endif /* CONFIG_NEED_BOUNCE_POOL */ + +static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, + mempool_t *pool, int force) +{ + struct bio *bio; + int rw = bio_data_dir(*bio_orig); + struct bio_vec *to, from; + struct bvec_iter iter; + unsigned i; + + if (force) + goto bounce; + bio_for_each_segment(from, *bio_orig, iter) + if (page_to_pfn(from.bv_page) > queue_bounce_pfn(q)) + goto bounce; + + return; +bounce: + bio = bio_clone_bioset(*bio_orig, GFP_NOIO, fs_bio_set); + + bio_for_each_segment_all(to, bio, i) { + struct page *page = to->bv_page; + + if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force) + continue; + + inc_zone_page_state(to->bv_page, NR_BOUNCE); + to->bv_page = mempool_alloc(pool, q->bounce_gfp); + + if (rw == WRITE) { + char *vto, *vfrom; + + flush_dcache_page(page); + + vto = page_address(to->bv_page) + to->bv_offset; + vfrom = kmap_atomic(page) + to->bv_offset; + memcpy(vto, vfrom, to->bv_len); + kunmap_atomic(vfrom); + } + } + + trace_block_bio_bounce(q, *bio_orig); + + bio->bi_flags |= (1 << BIO_BOUNCED); + + if (pool == page_pool) { + bio->bi_end_io = bounce_end_io_write; + if (rw == READ) + bio->bi_end_io = bounce_end_io_read; + } else { + bio->bi_end_io = bounce_end_io_write_isa; + if (rw == READ) + bio->bi_end_io = bounce_end_io_read_isa; + } + + bio->bi_private = *bio_orig; + *bio_orig = bio; +} + +void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) +{ + int must_bounce; + mempool_t *pool; + + /* + * Data-less bio, nothing to bounce + */ + if (!bio_has_data(*bio_orig)) + return; + + must_bounce = must_snapshot_stable_pages(q, *bio_orig); + + /* + * for non-isa bounce case, just check if the bounce pfn is equal + * to or bigger than the highest pfn in the system -- in that case, + * don't waste time iterating over bio segments + */ + if (!(q->bounce_gfp & GFP_DMA)) { + if (queue_bounce_pfn(q) >= blk_max_pfn && !must_bounce) + return; + pool = page_pool; + } else { + BUG_ON(!isa_page_pool); + pool = isa_page_pool; + } + + /* + * slow path + */ + __blk_queue_bounce(q, bio_orig, pool, must_bounce); +} + +EXPORT_SYMBOL(blk_queue_bounce); diff --git a/block/bsg.c b/block/bsg.c index 420a5a9..e5214c1 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -1008,7 +1008,7 @@ int bsg_register_queue(struct request_queue *q, struct device *parent, /* * we need a proper transport to send commands, not a stacked device */ - if (!q->request_fn) + if (!queue_is_rq_based(q)) return 0; bcd = &q->bsg_dev; diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index e0985f1..22dffeb 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -908,7 +908,7 @@ static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) { if (cfqd->busy_queues) { cfq_log(cfqd, "schedule dispatch"); - kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); + kblockd_schedule_work(&cfqd->unplug_work); } } @@ -4460,7 +4460,7 @@ out_free: static ssize_t cfq_var_show(unsigned int var, char *page) { - return sprintf(page, "%d\n", var); + return sprintf(page, "%u\n", var); } static ssize_t diff --git a/block/ioprio.c b/block/ioprio.c new file mode 100644 index 0000000..e50170c --- /dev/null +++ b/block/ioprio.c @@ -0,0 +1,241 @@ +/* + * fs/ioprio.c + * + * Copyright (C) 2004 Jens Axboe <axboe@kernel.dk> + * + * Helper functions for setting/querying io priorities of processes. The + * system calls closely mimmick getpriority/setpriority, see the man page for + * those. The prio argument is a composite of prio class and prio data, where + * the data argument has meaning within that class. The standard scheduling + * classes have 8 distinct prio levels, with 0 being the highest prio and 7 + * being the lowest. + * + * IOW, setting BE scheduling class with prio 2 is done ala: + * + * unsigned int prio = (IOPRIO_CLASS_BE << IOPRIO_CLASS_SHIFT) | 2; + * + * ioprio_set(PRIO_PROCESS, pid, prio); + * + * See also Documentation/block/ioprio.txt + * + */ +#include <linux/gfp.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/ioprio.h> +#include <linux/blkdev.h> +#include <linux/capability.h> +#include <linux/syscalls.h> +#include <linux/security.h> +#include <linux/pid_namespace.h> + +int set_task_ioprio(struct task_struct *task, int ioprio) +{ + int err; + struct io_context *ioc; + const struct cred *cred = current_cred(), *tcred; + + rcu_read_lock(); + tcred = __task_cred(task); + if (!uid_eq(tcred->uid, cred->euid) && + !uid_eq(tcred->uid, cred->uid) && !capable(CAP_SYS_NICE)) { + rcu_read_unlock(); + return -EPERM; + } + rcu_read_unlock(); + + err = security_task_setioprio(task, ioprio); + if (err) + return err; + + ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE); + if (ioc) { + ioc->ioprio = ioprio; + put_io_context(ioc); + } + + return err; +} +EXPORT_SYMBOL_GPL(set_task_ioprio); + +SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) +{ + int class = IOPRIO_PRIO_CLASS(ioprio); + int data = IOPRIO_PRIO_DATA(ioprio); + struct task_struct *p, *g; + struct user_struct *user; + struct pid *pgrp; + kuid_t uid; + int ret; + + switch (class) { + case IOPRIO_CLASS_RT: + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + /* fall through, rt has prio field too */ + case IOPRIO_CLASS_BE: + if (data >= IOPRIO_BE_NR || data < 0) + return -EINVAL; + + break; + case IOPRIO_CLASS_IDLE: + break; + case IOPRIO_CLASS_NONE: + if (data) + return -EINVAL; + break; + default: + return -EINVAL; + } + + ret = -ESRCH; + rcu_read_lock(); + switch (which) { + case IOPRIO_WHO_PROCESS: + if (!who) + p = current; + else + p = find_task_by_vpid(who); + if (p) + ret = set_task_ioprio(p, ioprio); + break; + case IOPRIO_WHO_PGRP: + if (!who) + pgrp = task_pgrp(current); + else + pgrp = find_vpid(who); + do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { + ret = set_task_ioprio(p, ioprio); + if (ret) + break; + } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); + break; + case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); + if (!uid_valid(uid)) + break; + if (!who) + user = current_user(); + else + user = find_user(uid); + + if (!user) + break; + + do_each_thread(g, p) { + if (!uid_eq(task_uid(p), uid)) + continue; + ret = set_task_ioprio(p, ioprio); + if (ret) + goto free_uid; + } while_each_thread(g, p); +free_uid: + if (who) + free_uid(user); + break; + default: + ret = -EINVAL; + } + + rcu_read_unlock(); + return ret; +} + +static int get_task_ioprio(struct task_struct *p) +{ + int ret; + + ret = security_task_getioprio(p); + if (ret) + goto out; + ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM); + if (p->io_context) + ret = p->io_context->ioprio; +out: + return ret; +} + +int ioprio_best(unsigned short aprio, unsigned short bprio) +{ + unsigned short aclass = IOPRIO_PRIO_CLASS(aprio); + unsigned short bclass = IOPRIO_PRIO_CLASS(bprio); + + if (aclass == IOPRIO_CLASS_NONE) + aclass = IOPRIO_CLASS_BE; + if (bclass == IOPRIO_CLASS_NONE) + bclass = IOPRIO_CLASS_BE; + + if (aclass == bclass) + return min(aprio, bprio); + if (aclass > bclass) + return bprio; + else + return aprio; +} + +SYSCALL_DEFINE2(ioprio_get, int, which, int, who) +{ + struct task_struct *g, *p; + struct user_struct *user; + struct pid *pgrp; + kuid_t uid; + int ret = -ESRCH; + int tmpio; + + rcu_read_lock(); + switch (which) { + case IOPRIO_WHO_PROCESS: + if (!who) + p = current; + else + p = find_task_by_vpid(who); + if (p) + ret = get_task_ioprio(p); + break; + case IOPRIO_WHO_PGRP: + if (!who) + pgrp = task_pgrp(current); + else + pgrp = find_vpid(who); + do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { + tmpio = get_task_ioprio(p); + if (tmpio < 0) + continue; + if (ret == -ESRCH) + ret = tmpio; + else + ret = ioprio_best(ret, tmpio); + } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); + break; + case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); + if (!who) + user = current_user(); + else + user = find_user(uid); + + if (!user) + break; + + do_each_thread(g, p) { + if (!uid_eq(task_uid(p), user->uid)) + continue; + tmpio = get_task_ioprio(p); + if (tmpio < 0) + continue; + if (ret == -ESRCH) + ret = tmpio; + else + ret = ioprio_best(ret, tmpio); + } while_each_thread(g, p); + + if (who) + free_uid(user); + break; + default: + ret = -EINVAL; + } + + rcu_read_unlock(); + return ret; +} diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 2648797..9c28a5b 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -205,10 +205,6 @@ int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm) if (capable(CAP_SYS_RAWIO)) return 0; - /* if there's no filter set, assume we're filtering everything out */ - if (!filter) - return -EPERM; - /* Anybody who can open the device can do a read-safe command */ if (test_bit(cmd[0], filter->read_ok)) return 0; |