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-rw-r--r--block/Makefile7
-rw-r--r--block/bio-integrity.c657
-rw-r--r--block/bio.c2038
-rw-r--r--block/blk-core.c65
-rw-r--r--block/blk-flush.c16
-rw-r--r--block/blk-iopoll.c4
-rw-r--r--block/blk-lib.c4
-rw-r--r--block/blk-mq-cpu.c12
-rw-r--r--block/blk-mq-cpumap.c16
-rw-r--r--block/blk-mq-sysfs.c50
-rw-r--r--block/blk-mq-tag.c541
-rw-r--r--block/blk-mq-tag.h62
-rw-r--r--block/blk-mq.c993
-rw-r--r--block/blk-mq.h18
-rw-r--r--block/blk-sysfs.c47
-rw-r--r--block/blk-throttle.c10
-rw-r--r--block/blk-timeout.c47
-rw-r--r--block/blk.h9
-rw-r--r--block/bounce.c287
-rw-r--r--block/cfq-iosched.c2
-rw-r--r--block/ioprio.c241
21 files changed, 4631 insertions, 495 deletions
diff --git a/block/Makefile b/block/Makefile
index 20645e88fb57..a2ce6ac935ec 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 000000000000..9e241063a616
--- /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 000000000000..96d28eee8a1e
--- /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-core.c b/block/blk-core.c
index c4269701cb4f..d87be5b4e554 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -576,12 +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;
@@ -639,8 +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;
@@ -848,6 +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.
@@ -1137,7 +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);
}
@@ -1233,12 +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;
@@ -1427,6 +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)
@@ -1436,9 +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;
@@ -1517,7 +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);
diff --git a/block/blk-flush.c b/block/blk-flush.c
index ec7a224d6733..ef608b35d9be 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, requeue_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->requeue_work, mq_flush_run);
- kblockd_schedule_work(&rq->requeue_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)
diff --git a/block/blk-iopoll.c b/block/blk-iopoll.c
index c11d24e379e2..d828b44a404b 100644
--- a/block/blk-iopoll.c
+++ b/block/blk-iopoll.c
@@ -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);
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 97a733cf3d5f..8411be3c19d3 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-mq-cpu.c b/block/blk-mq-cpu.c
index 136ef8643bba..d2c253f71b86 100644
--- a/block/blk-mq-cpu.c
+++ b/block/blk-mq-cpu.c
@@ -18,14 +18,18 @@ 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 +49,7 @@ 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 5d0f93cf358c..0daacb927be1 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -96,3 +96,19 @@ unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
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 9176a6984857..99a60a829e69 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -203,45 +203,14 @@ 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)
@@ -303,15 +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,
@@ -326,9 +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,
};
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 7a799c46c32d..0d0640d38a06 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -1,64 +1,333 @@
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/random.h>
#include <linux/blk-mq.h>
#include "blk.h"
#include "blk-mq.h"
#include "blk-mq-tag.h"
-void blk_mq_wait_for_tags(struct blk_mq_tags *tags)
+static bool bt_has_free_tags(struct blk_mq_bitmap_tags *bt)
{
- int tag = blk_mq_get_tag(tags, __GFP_WAIT, false);
- blk_mq_put_tag(tags, tag);
+ 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)
{
- return !tags ||
- percpu_ida_free_tags(&tags->free_tags, nr_cpu_ids) != 0;
+ 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);
+}
+
+/*
+ * If a previously inactive queue goes active, bump the active user count.
+ */
+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);
+
+ return true;
+}
+
+/*
+ * Wakeup all potentially sleeping on normal (non-reserved) tags
+ */
+static void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags)
+{
+ 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);
+ }
}
-static unsigned int __blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp)
+/*
+ * 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)
+{
+ 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;
+}
+
+/*
+ * 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_bitmap_tags *bt, struct blk_mq_hw_ctx *hctx,
+ unsigned int *last_tag, gfp_t gfp)
+{
+ 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 (!(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);
+
+ io_schedule();
+ } while (1);
+
+ finish_wait(&bs->wait, &wait);
+ return tag;
+}
+
+static unsigned int __blk_mq_get_tag(struct blk_mq_tags *tags,
+ struct blk_mq_hw_ctx *hctx,
+ unsigned int *last_tag, gfp_t gfp)
+{
+ int tag;
+
+ tag = bt_get(&tags->bitmap_tags, hctx, last_tag, gfp);
+ if (tag >= 0)
+ return tag + tags->nr_reserved_tags;
+
+ return BLK_MQ_TAG_FAIL;
}
static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_tags *tags,
gfp_t gfp)
{
- int tag;
+ int tag, zero = 0;
if (unlikely(!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(&tags->breserved_tags, NULL, &zero, gfp);
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_hw_ctx *hctx, unsigned int *last_tag,
+ gfp_t gfp, bool reserved)
{
if (!reserved)
- return __blk_mq_get_tag(tags, gfp);
+ return __blk_mq_get_tag(hctx->tags, hctx, last_tag, gfp);
- return __blk_mq_get_reserved_tag(tags, gfp);
+ return __blk_mq_get_reserved_tag(hctx->tags, gfp);
+}
+
+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,
@@ -66,22 +335,43 @@ 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,
@@ -95,21 +385,128 @@ 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");
@@ -120,73 +517,59 @@ 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 b602e3fa66ea..c959de58d2a5 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -1,7 +1,32 @@
#ifndef INT_BLK_MQ_TAG_H
#define INT_BLK_MQ_TAG_H
-#include <linux/percpu_ida.h>
+#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.
@@ -9,11 +34,11 @@
struct blk_mq_tags {
unsigned int nr_tags;
unsigned int nr_reserved_tags;
- unsigned int nr_batch_move;
- unsigned int nr_max_cache;
- struct percpu_ida free_tags;
- struct percpu_ida 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;
@@ -23,12 +48,12 @@ struct blk_mq_tags {
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_hw_ctx *hctx, unsigned int *last_tag, gfp_t gfp, bool reserved);
+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,
@@ -41,4 +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 ee225cc312b8..ae14749b530c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -56,39 +56,40 @@ 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->tags->rqs[tag];
- blk_rq_init(hctx->queue, rq);
- 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)
@@ -187,70 +188,109 @@ 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->cmd_flags |= rw_flags;
+ rq->cmd_type = 0;
+ /* do not touch atomic flags, it needs atomic ops against the timer */
+ rq->cpu = -1;
+ rq->__data_len = 0;
+ rq->__sector = (sector_t) -1;
+ rq->bio = NULL;
+ rq->biotail = NULL;
+ INIT_HLIST_NODE(&rq->hash);
+ RB_CLEAR_NODE(&rq->rb_node);
+ memset(&rq->flush, 0, max(sizeof(rq->flush), sizeof(rq->elv)));
+ rq->rq_disk = NULL;
+ rq->part = NULL;
rq->start_time = jiffies;
+#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->ioprio = 0;
+ rq->special = NULL;
+ /* tag was already set */
+ rq->errors = 0;
+ memset(rq->__cmd, 0, sizeof(rq->__cmd));
+ rq->cmd = rq->__cmd;
+ rq->cmd_len = BLK_MAX_CDB;
+
+ rq->extra_len = 0;
+ rq->sense_len = 0;
+ rq->resid_len = 0;
+ rq->sense = NULL;
+
+ rq->deadline = 0;
+ INIT_LIST_HEAD(&rq->timeout_list);
+ rq->timeout = 0;
+ rq->retries = 0;
+ 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 request_queue *q, struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx, int rw, gfp_t gfp, bool reserved)
{
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);
-
- rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved);
- if (rq) {
- blk_mq_rq_ctx_init(q, ctx, rq, rw);
- break;
- }
+ tag = blk_mq_get_tag(hctx, &ctx->last_tag, gfp, reserved);
+ if (tag != BLK_MQ_TAG_FAIL) {
+ rq = hctx->tags->rqs[tag];
- if (gfp & __GFP_WAIT) {
- __blk_mq_run_hw_queue(hctx);
- blk_mq_put_ctx(ctx);
- } else {
- blk_mq_put_ctx(ctx);
- break;
+ rq->cmd_flags = 0;
+ if (blk_mq_tag_busy(hctx)) {
+ rq->cmd_flags = REQ_MQ_INFLIGHT;
+ atomic_inc(&hctx->nr_active);
}
- blk_mq_wait_for_tags(hctx->tags);
- } while (1);
+ rq->tag = tag;
+ blk_mq_rq_ctx_init(q, 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;
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);
- if (blk_mq_queue_enter(q))
- return NULL;
+ rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp & ~__GFP_WAIT,
+ reserved);
+ 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);
+ rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp, reserved);
+ }
+ blk_mq_put_ctx(ctx);
return rq;
}
-EXPORT_SYMBOL(blk_mq_alloc_reserved_request);
+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)
@@ -258,7 +298,11 @@ 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_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);
}
@@ -326,15 +370,19 @@ static void __blk_mq_complete_request_remote(void *data)
void __blk_mq_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;
@@ -355,10 +403,16 @@ 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);
+ if (!blk_mark_rq_complete(rq)) {
+ if (q->softirq_done_fn)
+ __blk_mq_complete_request(rq);
+ else
+ blk_mq_end_io(rq, rq->errors);
+ }
}
EXPORT_SYMBOL(blk_mq_complete_request);
@@ -375,10 +429,22 @@ static void blk_mq_start_request(struct request *rq, bool last)
/*
* 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);
+ clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
if (q->dma_drain_size && blk_rq_bytes(rq)) {
/*
@@ -415,18 +481,72 @@ static void __blk_mq_requeue_request(struct request *rq)
void blk_mq_requeue_request(struct request *rq)
{
- struct request_queue *q = rq->q;
-
__blk_mq_requeue_request(rq);
blk_clear_rq_complete(rq);
- trace_block_rq_requeue(q, rq);
-
BUG_ON(blk_queued_rq(rq));
- blk_mq_insert_request(rq, true, true, false);
+ 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);
+
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
{
return tags->rqs[tag];
@@ -485,6 +605,28 @@ 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;
@@ -492,11 +634,24 @@ 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);
+ }
}
/*
@@ -538,9 +693,38 @@ 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);
+ }
}
/*
@@ -552,10 +736,9 @@ 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));
@@ -567,15 +750,7 @@ 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
@@ -589,13 +764,9 @@ 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;
@@ -610,11 +781,6 @@ 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);
break;
@@ -646,6 +812,30 @@ 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)))
@@ -658,13 +848,7 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
else {
unsigned int cpu;
- /*
- * It'd be great if the workqueue API had a way to pass
- * in a mask and had some smarts for more clever placement
- * than the first CPU. Or we could round-robin here. For now,
- * just queue on the first CPU.
- */
- cpu = cpumask_first(hctx->cpumask);
+ cpu = blk_mq_hctx_next_cpu(hctx);
kblockd_schedule_delayed_work_on(cpu, &hctx->run_work, 0);
}
}
@@ -771,13 +955,7 @@ void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
else {
unsigned int cpu;
- /*
- * It'd be great if the workqueue API had a way to pass
- * in a mask and had some smarts for more clever placement
- * than the first CPU. Or we could round-robin here. For now,
- * just queue on the first CPU.
- */
- cpu = cpumask_first(hctx->cpumask);
+ cpu = blk_mq_hctx_next_cpu(hctx);
kblockd_schedule_delayed_work_on(cpu, &hctx->delay_work, tmo);
}
}
@@ -794,12 +972,13 @@ 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,
@@ -930,21 +1109,161 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
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);
+
+ 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);
+ rq = __blk_mq_alloc_request(q, hctx, ctx, rw, GFP_ATOMIC, false);
+ 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);
+ rq = __blk_mq_alloc_request(q, hctx, ctx, rw,
+ __GFP_WAIT|GFP_ATOMIC, false);
+ }
+
+ 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);
+
+ /*
+ * 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);
@@ -953,33 +1272,11 @@ 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);
- 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++;
+ rq = blk_mq_map_request(q, bio, &data);
if (unlikely(is_flush_fua)) {
blk_mq_bio_to_request(rq, bio);
@@ -1004,31 +1301,23 @@ 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);
-
- /*
- * 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(ctx);
+ blk_mq_put_ctx(data.ctx);
}
/*
@@ -1041,10 +1330,10 @@ 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_tag_set *set,
- unsigned int hctx_index)
+ unsigned int hctx_index,
+ int node)
{
- return kmalloc_node(sizeof(struct blk_mq_hw_ctx),
- GFP_KERNEL | __GFP_ZERO, set->numa_node);
+ return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, node);
}
EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue);
@@ -1055,52 +1344,6 @@ void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx,
}
EXPORT_SYMBOL(blk_mq_free_single_hw_queue);
-static void blk_mq_hctx_notify(void *data, unsigned long action,
- unsigned 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.
- */
- ctx = __blk_mq_get_ctx(q, cpu);
-
- 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);
- }
- spin_unlock(&ctx->lock);
-
- if (list_empty(&tmp))
- return;
-
- ctx = blk_mq_get_ctx(q);
- spin_lock(&ctx->lock);
-
- while (!list_empty(&tmp)) {
- struct request *rq;
-
- rq = list_first_entry(&tmp, struct request, queuelist);
- rq->mq_ctx = ctx;
- list_move_tail(&rq->queuelist, &ctx->rq_list);
- }
-
- hctx = q->mq_ops->map_queue(q, ctx->cpu);
- blk_mq_hctx_mark_pending(hctx, ctx);
-
- spin_unlock(&ctx->lock);
-
- blk_mq_run_hw_queue(hctx, true);
- blk_mq_put_ctx(ctx);
-}
-
static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
struct blk_mq_tags *tags, unsigned int hctx_idx)
{
@@ -1130,12 +1373,7 @@ static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
static size_t order_to_size(unsigned int order)
{
- size_t ret = PAGE_SIZE;
-
- while (order--)
- ret *= 2;
-
- return ret;
+ return (size_t)PAGE_SIZE << order;
}
static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
@@ -1219,17 +1457,147 @@ fail:
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 request_queue *q = hctx->queue;
+ struct blk_mq_ctx *ctx;
+ LIST_HEAD(tmp);
+
+ /*
+ * Move ctx entries to new CPU, if this one is going away.
+ */
+ ctx = __blk_mq_get_ctx(q, cpu);
+
+ spin_lock(&ctx->lock);
+ if (!list_empty(&ctx->rq_list)) {
+ list_splice_init(&ctx->rq_list, &tmp);
+ blk_mq_hctx_clear_pending(hctx, ctx);
+ }
+ spin_unlock(&ctx->lock);
+
+ if (list_empty(&tmp))
+ return NOTIFY_OK;
+
+ ctx = blk_mq_get_ctx(q);
+ spin_lock(&ctx->lock);
+
+ while (!list_empty(&tmp)) {
+ struct request *rq;
+
+ rq = list_first_entry(&tmp, struct request, queuelist);
+ rq->mq_ctx = ctx;
+ list_move_tail(&rq->queuelist, &ctx->rq_list);
+ }
+
+ hctx = q->mq_ops->map_queue(q, ctx->cpu);
+ blk_mq_hctx_mark_pending(hctx, ctx);
+
+ spin_unlock(&ctx->lock);
+
+ blk_mq_run_hw_queue(hctx, true);
+ blk_mq_put_ctx(ctx);
+ return NOTIFY_OK;
+}
+
+static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu)
+{
+ struct request_queue *q = hctx->queue;
+ struct blk_mq_tag_set *set = q->tag_set;
+
+ if (set->tags[hctx->queue_num])
+ return NOTIFY_OK;
+
+ set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num);
+ if (!set->tags[hctx->queue_num])
+ return NOTIFY_STOP;
+
+ hctx->tags = set->tags[hctx->queue_num];
+ return NOTIFY_OK;
+}
+
+static int blk_mq_hctx_notify(void *data, unsigned long action,
+ unsigned int cpu)
+{
+ struct blk_mq_hw_ctx *hctx = data;
+
+ 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);
+
+ return NOTIFY_OK;
+}
+
+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) {
+ if (i == nr_queue)
+ break;
+
+ if (set->ops->exit_hctx)
+ set->ops->exit_hctx(hctx, i);
+
+ blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
+ kfree(hctx->ctxs);
+ blk_mq_free_bitmap(&hctx->ctx_map);
+ }
+
+}
+
+static void blk_mq_free_hw_queues(struct request_queue *q,
+ struct blk_mq_tag_set *set)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ free_cpumask_var(hctx->cpumask);
+ set->ops->free_hctx(hctx, i);
+ }
+}
+
static int blk_mq_init_hw_queues(struct request_queue *q,
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;
@@ -1260,13 +1628,9 @@ 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 (set->ops->init_hctx &&
@@ -1280,16 +1644,7 @@ 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 (set->ops->exit_hctx)
- set->ops->exit_hctx(hctx, j);
-
- blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
- kfree(hctx->ctxs);
- }
+ blk_mq_exit_hw_queues(q, set, i);
return 1;
}
@@ -1350,6 +1705,79 @@ static void blk_mq_map_swqueue(struct request_queue *q)
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;
+ }
+}
+
+static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set)
+{
+ struct blk_mq_hw_ctx *hctx;
+ struct request_queue *q;
+ bool shared;
+ int i;
+
+ 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);
+
+ 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);
+ }
+}
+
+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)
@@ -1357,6 +1785,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
struct blk_mq_hw_ctx **hctxs;
struct blk_mq_ctx *ctx;
struct request_queue *q;
+ unsigned int *map;
int i;
ctx = alloc_percpu(struct blk_mq_ctx);
@@ -1369,15 +1798,22 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
if (!hctxs)
goto err_percpu;
+ map = blk_mq_make_queue_map(set);
+ if (!map)
+ goto err_map;
+
for (i = 0; i < set->nr_hw_queues; i++) {
- hctxs[i] = set->ops->alloc_hctx(set, i);
+ int node = blk_mq_hw_queue_to_node(map, i);
+
+ hctxs[i] = set->ops->alloc_hctx(set, i, node);
if (!hctxs[i])
goto err_hctxs;
if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL))
goto err_hctxs;
- hctxs[i]->numa_node = NUMA_NO_NODE;
+ atomic_set(&hctxs[i]->nr_active, 0);
+ hctxs[i]->numa_node = node;
hctxs[i]->queue_num = i;
}
@@ -1385,8 +1821,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
if (!q)
goto err_hctxs;
- q->mq_map = blk_mq_make_queue_map(set);
- 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);
@@ -1394,6 +1829,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
q->nr_queues = nr_cpu_ids;
q->nr_hw_queues = set->nr_hw_queues;
+ q->mq_map = map;
q->queue_ctx = ctx;
q->queue_hw_ctx = hctxs;
@@ -1403,11 +1839,24 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
q->sg_reserved_size = INT_MAX;
- blk_queue_make_request(q, blk_mq_make_request);
- blk_queue_rq_timed_out(q, set->ops->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);
+ /*
+ * 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);
@@ -1423,27 +1872,29 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
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:
+ kfree(map);
for (i = 0; i < set->nr_hw_queues; i++) {
if (!hctxs[i])
break;
free_cpumask_var(hctxs[i]->cpumask);
set->ops->free_hctx(hctxs[i], i);
}
+err_map:
kfree(hctxs);
err_percpu:
free_percpu(ctx);
@@ -1453,18 +1904,14 @@ 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_unregister_cpu_notifier(&hctx->cpu_notifier);
- if (q->mq_ops->exit_hctx)
- q->mq_ops->exit_hctx(hctx, i);
- free_cpumask_var(hctx->cpumask);
- 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);
@@ -1503,10 +1950,10 @@ 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)
@@ -1536,7 +1983,8 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
return -EINVAL;
- set->tags = kmalloc_node(set->nr_hw_queues * sizeof(struct blk_mq_tags),
+ set->tags = kmalloc_node(set->nr_hw_queues *
+ sizeof(struct blk_mq_tags *),
GFP_KERNEL, set->numa_node);
if (!set->tags)
goto out;
@@ -1547,6 +1995,9 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
goto out_unwind;
}
+ mutex_init(&set->tag_list_lock);
+ INIT_LIST_HEAD(&set->tag_list);
+
return 0;
out_unwind:
@@ -1561,11 +2012,37 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
{
int i;
- for (i = 0; i < set->nr_hw_queues; i++)
- blk_mq_free_rq_map(set, set->tags[i], 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 5fa14f19f752..ff5e6bf0f691 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -11,7 +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];
@@ -22,7 +23,7 @@ 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);
@@ -31,13 +32,14 @@ void blk_mq_drain_queue(struct request_queue *q);
void blk_mq_free_queue(struct request_queue *q);
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);
@@ -50,7 +52,15 @@ void blk_mq_disable_hotplug(void);
*/
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);
-void blk_mq_add_timer(struct request *rq);
+/*
+ * 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;
#endif
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 7500f876dae4..23321fbab293 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 033745cd7fba..9353b4683359 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 a09e8af8186c..43e8b515806f 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;
@@ -188,15 +203,15 @@ 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)) {
@@ -214,17 +229,3 @@ void __blk_add_timer(struct request *req, struct list_head *timeout_list)
}
}
-
-/**
- * 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 1d880f1f957f..45385e9abf6f 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 000000000000..523918b8c6dc
--- /dev/null
+++ b/block/bounce.c
@@ -0,0 +1,287 @@
+/* bounce buffer handling for block devices
+ *
+ * - Split from highmem.c
+ */
+
+#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 <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);
+ printk("bounce 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);
+
+ printk("isa bounce 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/cfq-iosched.c b/block/cfq-iosched.c
index 5063a0bd831a..22dffebc7c73 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -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 000000000000..e50170ca7c33
--- /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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 09:26:33 +0000