# 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 \
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
--- /dev/null
+/*
+ * 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");
+}
--- /dev/null
+/*
+ * 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);
stack.o fs_struct.o statfs.o
ifeq ($(CONFIG_BLOCK),y)
-obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
+obj-y += buffer.o block_dev.o direct-io.o mpage.o ioprio.o
else
obj-y += no-block.o
endif
obj-$(CONFIG_PROC_FS) += proc_namespace.o
-obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
obj-y += notify/
obj-$(CONFIG_EPOLL) += eventpoll.o
obj-$(CONFIG_ANON_INODES) += anon_inodes.o
+++ /dev/null
-/*
- * 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");
-}
+++ /dev/null
-/*
- * 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);
projects / deliverable / linux.git / commitdiff
