/fs/bio.c
C | 1323 lines | 1025 code | 271 blank | 27 comment | 169 complexity | 02fde33f71fd992fc75f1c2dc561fd27 MD5 | raw file
Possible License(s): GPL-2.0
- /*
- * 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/slab.h>
- #include <linux/init.h>
- #include <linux/kernel.h>
- #include <linux/export.h>
- #include <linux/mempool.h>
- #include <linux/workqueue.h>
- #include <scsi/sg.h>
- #include <trace/events/block.h>
- #define BIO_INLINE_VECS 4
- static mempool_t *bio_split_pool __read_mostly;
- #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
- struct bio_set *fs_bio_set;
- 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;
- 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) {
- bio_slab_max <<= 1;
- bio_slabs = krealloc(bio_slabs,
- bio_slab_max * sizeof(struct bio_slab),
- GFP_KERNEL);
- if (!bio_slabs)
- goto out_unlock;
- }
- 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;
- printk(KERN_INFO "bio: create slab <%s> at %d\n", bslab->name, entry);
- 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_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx)
- {
- BIO_BUG_ON(idx >= BIOVEC_NR_POOLS);
- if (idx == BIOVEC_MAX_IDX)
- mempool_free(bv, bs->bvec_pool);
- else {
- struct biovec_slab *bvs = bvec_slabs + idx;
- kmem_cache_free(bvs->slab, bv);
- }
- }
- struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx,
- struct bio_set *bs)
- {
- struct bio_vec *bvl;
- 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;
- }
- if (*idx == BIOVEC_MAX_IDX) {
- fallback:
- bvl = mempool_alloc(bs->bvec_pool, gfp_mask);
- } else {
- struct biovec_slab *bvs = bvec_slabs + *idx;
- gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
- __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
- bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
- if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) {
- *idx = BIOVEC_MAX_IDX;
- goto fallback;
- }
- }
- return bvl;
- }
- void bio_free(struct bio *bio, struct bio_set *bs)
- {
- void *p;
- if (bio_has_allocated_vec(bio))
- bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
- if (bio_integrity(bio))
- bio_integrity_free(bio, bs);
- p = bio;
- if (bs->front_pad)
- p -= bs->front_pad;
- mempool_free(p, bs->bio_pool);
- }
- EXPORT_SYMBOL(bio_free);
- void bio_init(struct bio *bio)
- {
- memset(bio, 0, sizeof(*bio));
- bio->bi_flags = 1 << BIO_UPTODATE;
- atomic_set(&bio->bi_cnt, 1);
- }
- EXPORT_SYMBOL(bio_init);
- struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
- {
- unsigned long idx = BIO_POOL_NONE;
- struct bio_vec *bvl = NULL;
- struct bio *bio;
- void *p;
- p = mempool_alloc(bs->bio_pool, gfp_mask);
- if (unlikely(!p))
- return NULL;
- bio = p + bs->front_pad;
- bio_init(bio);
- if (unlikely(!nr_iovecs))
- goto out_set;
- if (nr_iovecs <= BIO_INLINE_VECS) {
- bvl = bio->bi_inline_vecs;
- nr_iovecs = BIO_INLINE_VECS;
- } else {
- bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
- if (unlikely(!bvl))
- goto err_free;
- nr_iovecs = bvec_nr_vecs(idx);
- }
- out_set:
- 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);
- static void bio_fs_destructor(struct bio *bio)
- {
- bio_free(bio, fs_bio_set);
- }
- struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
- {
- struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
- if (bio)
- bio->bi_destructor = bio_fs_destructor;
- return bio;
- }
- EXPORT_SYMBOL(bio_alloc);
- static void bio_kmalloc_destructor(struct bio *bio)
- {
- if (bio_integrity(bio))
- bio_integrity_free(bio, fs_bio_set);
- kfree(bio);
- }
- struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
- {
- struct bio *bio;
- if (nr_iovecs > UIO_MAXIOV)
- return NULL;
- bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec),
- gfp_mask);
- if (unlikely(!bio))
- return NULL;
- bio_init(bio);
- bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET;
- bio->bi_max_vecs = nr_iovecs;
- bio->bi_io_vec = bio->bi_inline_vecs;
- bio->bi_destructor = bio_kmalloc_destructor;
- return bio;
- }
- EXPORT_SYMBOL(bio_kmalloc);
- void zero_fill_bio(struct bio *bio)
- {
- unsigned long flags;
- struct bio_vec *bv;
- int i;
- bio_for_each_segment(bv, bio, i) {
- 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);
- void bio_put(struct bio *bio)
- {
- BIO_BUG_ON(!atomic_read(&bio->bi_cnt));
- if (atomic_dec_and_test(&bio->bi_cnt)) {
- bio->bi_next = NULL;
- bio->bi_destructor(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);
- void __bio_clone(struct bio *bio, struct bio *bio_src)
- {
- memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
- bio_src->bi_max_vecs * sizeof(struct bio_vec));
- bio->bi_sector = bio_src->bi_sector;
- bio->bi_bdev = bio_src->bi_bdev;
- bio->bi_flags |= 1 << BIO_CLONED;
- bio->bi_rw = bio_src->bi_rw;
- bio->bi_vcnt = bio_src->bi_vcnt;
- bio->bi_size = bio_src->bi_size;
- bio->bi_idx = bio_src->bi_idx;
- }
- EXPORT_SYMBOL(__bio_clone);
- struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
- {
- struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
- if (!b)
- return NULL;
- b->bi_destructor = bio_fs_destructor;
- __bio_clone(b, bio);
- if (bio_integrity(bio)) {
- int ret;
- ret = bio_integrity_clone(b, bio, gfp_mask, fs_bio_set);
- if (ret < 0) {
- bio_put(b);
- return NULL;
- }
- }
- return b;
- }
- EXPORT_SYMBOL(bio_clone);
- 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 short max_sectors)
- {
- int retried_segments = 0;
- struct bio_vec *bvec;
- if (unlikely(bio_flagged(bio, BIO_CLONED)))
- return 0;
- if (((bio->bi_size + len) >> 9) > max_sectors)
- return 0;
- 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 = {
- .bi_bdev = bio->bi_bdev,
- .bi_sector = bio->bi_sector,
- .bi_size = bio->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;
- while (bio->bi_phys_segments >= queue_max_segments(q)) {
- if (retried_segments)
- return 0;
- retried_segments = 1;
- blk_recount_segments(q, bio);
- }
- bvec = &bio->bi_io_vec[bio->bi_vcnt];
- bvec->bv_page = page;
- bvec->bv_len = len;
- bvec->bv_offset = offset;
- if (q->merge_bvec_fn) {
- struct bvec_merge_data bvm = {
- .bi_bdev = bio->bi_bdev,
- .bi_sector = bio->bi_sector,
- .bi_size = bio->bi_size,
- .bi_rw = bio->bi_rw,
- };
- 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 (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_size += len;
- return len;
- }
- 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);
- 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 bio_map_data {
- struct bio_vec *iovecs;
- struct sg_iovec *sgvecs;
- int nr_sgvecs;
- int is_our_pages;
- };
- static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
- struct sg_iovec *iov, int iov_count,
- int is_our_pages)
- {
- memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt);
- 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 void bio_free_map_data(struct bio_map_data *bmd)
- {
- kfree(bmd->iovecs);
- kfree(bmd->sgvecs);
- kfree(bmd);
- }
- static struct bio_map_data *bio_alloc_map_data(int nr_segs,
- unsigned int iov_count,
- gfp_t gfp_mask)
- {
- struct bio_map_data *bmd;
- if (iov_count > UIO_MAXIOV)
- return NULL;
- bmd = kmalloc(sizeof(*bmd), gfp_mask);
- if (!bmd)
- return NULL;
- bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask);
- if (!bmd->iovecs) {
- kfree(bmd);
- return NULL;
- }
- bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask);
- if (bmd->sgvecs)
- return bmd;
- kfree(bmd->iovecs);
- kfree(bmd);
- return NULL;
- }
- static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
- 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(bvec, bio, i, 0) {
- char *bv_addr = page_address(bvec->bv_page);
- unsigned int bv_len = iovecs[i].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;
- }
- int bio_uncopy_user(struct bio *bio)
- {
- struct bio_map_data *bmd = bio->bi_private;
- int ret = 0;
- if (!bio_flagged(bio, BIO_NULL_MAPPED))
- ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
- bmd->nr_sgvecs, bio_data_dir(bio) == READ,
- 0, bmd->is_our_pages);
- bio_free_map_data(bmd);
- bio_put(bio);
- return ret;
- }
- EXPORT_SYMBOL(bio_uncopy_user);
- struct bio *bio_copy_user_iov(struct request_queue *q,
- struct rq_map_data *map_data,
- 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;
- 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(nr_pages, 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;
- if ((!write_to_vm && (!map_data || !map_data->null_mapped)) ||
- (map_data && map_data->from_user)) {
- ret = __bio_copy_iov(bio, bio->bi_io_vec, 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(bvec, bio, i)
- __free_page(bvec->bv_page);
- bio_put(bio);
- out_bmd:
- bio_free_map_data(bmd);
- return ERR_PTR(ret);
- }
- 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,
- 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;
- if (end < start)
- return ERR_PTR(-EINVAL);
- nr_pages += end - start;
- 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;
- if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
- bytes)
- break;
- len -= bytes;
- offset = 0;
- }
- cur_page = j;
- while (j < page_limit)
- page_cache_release(pages[j++]);
- }
- kfree(pages);
- 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);
- }
- 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);
- struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
- 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;
- bio_get(bio);
- return bio;
- }
- static void __bio_unmap_user(struct bio *bio)
- {
- struct bio_vec *bvec;
- int i;
- __bio_for_each_segment(bvec, bio, i, 0) {
- if (bio_data_dir(bio) == READ)
- set_page_dirty_lock(bvec->bv_page);
- page_cache_release(bvec->bv_page);
- }
- bio_put(bio);
- }
- 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;
- }
- 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_size == len)
- return bio;
- 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(bvec, bio, i, 0) {
- char *addr = page_address(bvec->bv_page);
- int len = bmd->iovecs[i].bv_len;
- if (read)
- memcpy(p, addr, len);
- __free_page(bvec->bv_page);
- p += len;
- }
- bio_free_map_data(bmd);
- bio_put(bio);
- }
- 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(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);
- void bio_set_pages_dirty(struct bio *bio)
- {
- struct bio_vec *bvec = bio->bi_io_vec;
- int i;
- for (i = 0; i < bio->bi_vcnt; i++) {
- struct page *page = bvec[i].bv_page;
- if (page && !PageCompound(page))
- set_page_dirty_lock(page);
- }
- }
- static void bio_release_pages(struct bio *bio)
- {
- struct bio_vec *bvec = bio->bi_io_vec;
- int i;
- for (i = 0; i < bio->bi_vcnt; i++) {
- struct page *page = bvec[i].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;
- 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 = bio->bi_io_vec;
- int nr_clean_pages = 0;
- int i;
- for (i = 0; i < bio->bi_vcnt; i++) {
- struct page *page = bvec[i].bv_page;
- if (PageDirty(page) || PageCompound(page)) {
- page_cache_release(page);
- bvec[i].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)
- {
- int i;
- struct bio_vec *bvec;
- bio_for_each_segment(bvec, bi, i)
- flush_dcache_page(bvec->bv_page);
- }
- EXPORT_SYMBOL(bio_flush_dcache_pages);
- #endif
- void bio_endio(struct bio *bio, int error)
- {
- if (error)
- clear_bit(BIO_UPTODATE, &bio->bi_flags);
- else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
- error = -EIO;
- if (bio->bi_end_io)
- bio->bi_end_io(bio, error);
- }
- EXPORT_SYMBOL(bio_endio);
- void bio_pair_release(struct bio_pair *bp)
- {
- if (atomic_dec_and_test(&bp->cnt)) {
- struct bio *master = bp->bio1.bi_private;
- bio_endio(master, bp->error);
- mempool_free(bp, bp->bio2.bi_private);
- }
- }
- EXPORT_SYMBOL(bio_pair_release);
- static void bio_pair_end_1(struct bio *bi, int err)
- {
- struct bio_pair *bp = container_of(bi, struct bio_pair, bio1);
- if (err)
- bp->error = err;
- bio_pair_release(bp);
- }
- static void bio_pair_end_2(struct bio *bi, int err)
- {
- struct bio_pair *bp = container_of(bi, struct bio_pair, bio2);
- if (err)
- bp->error = err;
- bio_pair_release(bp);
- }
- struct bio_pair *bio_split(struct bio *bi, int first_sectors)
- {
- struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO);
- if (!bp)
- return bp;
- trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
- bi->bi_sector + first_sectors);
- BUG_ON(bi->bi_vcnt != 1);
- BUG_ON(bi->bi_idx != 0);
- atomic_set(&bp->cnt, 3);
- bp->error = 0;
- bp->bio1 = *bi;
- bp->bio2 = *bi;
- bp->bio2.bi_sector += first_sectors;
- bp->bio2.bi_size -= first_sectors << 9;
- bp->bio1.bi_size = first_sectors << 9;
- bp->bv1 = bi->bi_io_vec[0];
- bp->bv2 = bi->bi_io_vec[0];
- bp->bv2.bv_offset += first_sectors << 9;
- bp->bv2.bv_len -= first_sectors << 9;
- bp->bv1.bv_len = first_sectors << 9;
- bp->bio1.bi_io_vec = &bp->bv1;
- bp->bio2.bi_io_vec = &bp->bv2;
- bp->bio1.bi_max_vecs = 1;
- bp->bio2.bi_max_vecs = 1;
- bp->bio1.bi_end_io = bio_pair_end_1;
- bp->bio2.bi_end_io = bio_pair_end_2;
- bp->bio1.bi_private = bi;
- bp->bio2.bi_private = bio_split_pool;
- if (bio_integrity(bi))
- bio_integrity_split(bi, bp, first_sectors);
- return bp;
- }
- EXPORT_SYMBOL(bio_split);
- sector_t bio_sector_offset(struct bio *bio, unsigned short index,
- unsigned int offset)
- {
- unsigned int sector_sz;
- struct bio_vec *bv;
- sector_t sectors;
- int i;
- sector_sz = queue_logical_block_size(bio->bi_bdev->bd_disk->queue);
- sectors = 0;
- if (index >= bio->bi_idx)
- index = bio->bi_vcnt - 1;
- __bio_for_each_segment(bv, bio, i, 0) {
- if (i == index) {
- if (offset > bv->bv_offset)
- sectors += (offset - bv->bv_offset) / sector_sz;
- break;
- }
- sectors += bv->bv_len / sector_sz;
- }
- return sectors;
- }
- EXPORT_SYMBOL(bio_sector_offset);
- static int biovec_create_pools(struct bio_set *bs, int pool_entries)
- {
- struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX;
- bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab);
- if (!bs->bvec_pool)
- return -ENOMEM;
- return 0;
- }
- static void biovec_free_pools(struct bio_set *bs)
- {
- mempool_destroy(bs->bvec_pool);
- }
- void bioset_free(struct bio_set *bs)
- {
- if (bs->bio_pool)
- mempool_destroy(bs->bio_pool);
- bioset_integrity_free(bs);
- biovec_free_pools(bs);
- bio_put_slab(bs);
- kfree(bs);
- }
- EXPORT_SYMBOL(bioset_free);
- 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;
- 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;
- if (!biovec_create_pools(bs, pool_size))
- return bs;
- bad:
- bioset_free(bs);
- return NULL;
- }
- EXPORT_SYMBOL(bioset_create);
- 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");
- bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES,
- sizeof(struct bio_pair));
- if (!bio_split_pool)
- panic("bio: can't create split pool\n");
- return 0;
- }
- subsys_initcall(init_bio);