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69838727bc
st driver uses blk_rq_map_user() in order to just build a request out of page frames. In this case, map_data->offset is a non zero value and iov[0].iov_base is NULL. We need to increase nr_pages for that. Cc: stable@kernel.org Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
1658 lines
39 KiB
C
1658 lines
39 KiB
C
/*
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* Copyright (C) 2001 Jens Axboe <axboe@kernel.dk>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public Licens
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
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*
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*/
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mempool.h>
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#include <linux/workqueue.h>
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#include <linux/blktrace_api.h>
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#include <trace/block.h>
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#include <scsi/sg.h> /* for struct sg_iovec */
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DEFINE_TRACE(block_split);
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/*
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* Test patch to inline a certain number of bi_io_vec's inside the bio
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* itself, to shrink a bio data allocation from two mempool calls to one
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*/
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#define BIO_INLINE_VECS 4
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static mempool_t *bio_split_pool __read_mostly;
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/*
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* if you change this list, also change bvec_alloc or things will
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* break badly! cannot be bigger than what you can fit into an
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* unsigned short
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*/
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#define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
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struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
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BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
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};
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#undef BV
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/*
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* fs_bio_set is the bio_set containing bio and iovec memory pools used by
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* IO code that does not need private memory pools.
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*/
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struct bio_set *fs_bio_set;
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/*
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* Our slab pool management
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*/
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struct bio_slab {
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struct kmem_cache *slab;
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unsigned int slab_ref;
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unsigned int slab_size;
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char name[8];
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};
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static DEFINE_MUTEX(bio_slab_lock);
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static struct bio_slab *bio_slabs;
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static unsigned int bio_slab_nr, bio_slab_max;
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static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
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{
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unsigned int sz = sizeof(struct bio) + extra_size;
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struct kmem_cache *slab = NULL;
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struct bio_slab *bslab;
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unsigned int i, entry = -1;
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mutex_lock(&bio_slab_lock);
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i = 0;
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while (i < bio_slab_nr) {
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struct bio_slab *bslab = &bio_slabs[i];
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if (!bslab->slab && entry == -1)
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entry = i;
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else if (bslab->slab_size == sz) {
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slab = bslab->slab;
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bslab->slab_ref++;
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break;
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}
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i++;
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}
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if (slab)
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goto out_unlock;
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if (bio_slab_nr == bio_slab_max && entry == -1) {
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bio_slab_max <<= 1;
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bio_slabs = krealloc(bio_slabs,
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bio_slab_max * sizeof(struct bio_slab),
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GFP_KERNEL);
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if (!bio_slabs)
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goto out_unlock;
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}
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if (entry == -1)
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entry = bio_slab_nr++;
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bslab = &bio_slabs[entry];
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snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry);
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slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL);
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if (!slab)
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goto out_unlock;
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printk("bio: create slab <%s> at %d\n", bslab->name, entry);
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bslab->slab = slab;
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bslab->slab_ref = 1;
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bslab->slab_size = sz;
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out_unlock:
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mutex_unlock(&bio_slab_lock);
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return slab;
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}
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static void bio_put_slab(struct bio_set *bs)
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{
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struct bio_slab *bslab = NULL;
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unsigned int i;
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mutex_lock(&bio_slab_lock);
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for (i = 0; i < bio_slab_nr; i++) {
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if (bs->bio_slab == bio_slabs[i].slab) {
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bslab = &bio_slabs[i];
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break;
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}
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}
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if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n"))
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goto out;
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WARN_ON(!bslab->slab_ref);
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if (--bslab->slab_ref)
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goto out;
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kmem_cache_destroy(bslab->slab);
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bslab->slab = NULL;
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out:
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mutex_unlock(&bio_slab_lock);
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}
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unsigned int bvec_nr_vecs(unsigned short idx)
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{
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return bvec_slabs[idx].nr_vecs;
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}
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void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx)
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{
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BIO_BUG_ON(idx >= BIOVEC_NR_POOLS);
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if (idx == BIOVEC_MAX_IDX)
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mempool_free(bv, bs->bvec_pool);
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else {
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struct biovec_slab *bvs = bvec_slabs + idx;
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kmem_cache_free(bvs->slab, bv);
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}
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}
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struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx,
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struct bio_set *bs)
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{
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struct bio_vec *bvl;
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/*
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* see comment near bvec_array define!
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*/
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switch (nr) {
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case 1:
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*idx = 0;
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break;
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case 2 ... 4:
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*idx = 1;
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break;
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case 5 ... 16:
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*idx = 2;
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break;
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case 17 ... 64:
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*idx = 3;
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break;
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case 65 ... 128:
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*idx = 4;
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break;
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case 129 ... BIO_MAX_PAGES:
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*idx = 5;
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break;
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default:
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return NULL;
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}
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/*
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* idx now points to the pool we want to allocate from. only the
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* 1-vec entry pool is mempool backed.
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*/
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if (*idx == BIOVEC_MAX_IDX) {
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fallback:
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bvl = mempool_alloc(bs->bvec_pool, gfp_mask);
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} else {
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struct biovec_slab *bvs = bvec_slabs + *idx;
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gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
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/*
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* Make this allocation restricted and don't dump info on
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* allocation failures, since we'll fallback to the mempool
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* in case of failure.
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*/
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__gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
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/*
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* Try a slab allocation. If this fails and __GFP_WAIT
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* is set, retry with the 1-entry mempool
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*/
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bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
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if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) {
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*idx = BIOVEC_MAX_IDX;
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goto fallback;
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}
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}
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return bvl;
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}
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void bio_free(struct bio *bio, struct bio_set *bs)
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{
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void *p;
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if (bio_has_allocated_vec(bio))
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bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
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if (bio_integrity(bio))
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bio_integrity_free(bio);
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/*
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* If we have front padding, adjust the bio pointer before freeing
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*/
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p = bio;
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if (bs->front_pad)
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p -= bs->front_pad;
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mempool_free(p, bs->bio_pool);
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}
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void bio_init(struct bio *bio)
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{
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memset(bio, 0, sizeof(*bio));
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bio->bi_flags = 1 << BIO_UPTODATE;
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bio->bi_comp_cpu = -1;
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atomic_set(&bio->bi_cnt, 1);
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}
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/**
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* bio_alloc_bioset - allocate a bio for I/O
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* @gfp_mask: the GFP_ mask given to the slab allocator
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* @nr_iovecs: number of iovecs to pre-allocate
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* @bs: the bio_set to allocate from. If %NULL, just use kmalloc
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*
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* Description:
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* bio_alloc_bioset will first try its own mempool to satisfy the allocation.
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* If %__GFP_WAIT is set then we will block on the internal pool waiting
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* for a &struct bio to become free. If a %NULL @bs is passed in, we will
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* fall back to just using @kmalloc to allocate the required memory.
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*
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* Note that the caller must set ->bi_destructor on succesful return
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* of a bio, to do the appropriate freeing of the bio once the reference
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* count drops to zero.
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**/
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struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
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{
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unsigned long idx = BIO_POOL_NONE;
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struct bio_vec *bvl = NULL;
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struct bio *bio;
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void *p;
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p = mempool_alloc(bs->bio_pool, gfp_mask);
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if (unlikely(!p))
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return NULL;
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bio = p + bs->front_pad;
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bio_init(bio);
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if (unlikely(!nr_iovecs))
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goto out_set;
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if (nr_iovecs <= BIO_INLINE_VECS) {
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bvl = bio->bi_inline_vecs;
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nr_iovecs = BIO_INLINE_VECS;
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} else {
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bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
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if (unlikely(!bvl))
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goto err_free;
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nr_iovecs = bvec_nr_vecs(idx);
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}
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out_set:
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bio->bi_flags |= idx << BIO_POOL_OFFSET;
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bio->bi_max_vecs = nr_iovecs;
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bio->bi_io_vec = bvl;
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return bio;
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err_free:
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mempool_free(p, bs->bio_pool);
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return NULL;
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}
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static void bio_fs_destructor(struct bio *bio)
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{
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bio_free(bio, fs_bio_set);
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}
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/**
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* bio_alloc - allocate a new bio, memory pool backed
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* @gfp_mask: allocation mask to use
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* @nr_iovecs: number of iovecs
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*
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* Allocate a new bio with @nr_iovecs bvecs. If @gfp_mask
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* contains __GFP_WAIT, the allocation is guaranteed to succeed.
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*
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* RETURNS:
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* Pointer to new bio on success, NULL on failure.
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*/
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struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
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{
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struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
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if (bio)
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bio->bi_destructor = bio_fs_destructor;
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return bio;
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}
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static void bio_kmalloc_destructor(struct bio *bio)
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{
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if (bio_integrity(bio))
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bio_integrity_free(bio);
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kfree(bio);
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}
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/**
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* bio_alloc - allocate a bio for I/O
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* @gfp_mask: the GFP_ mask given to the slab allocator
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* @nr_iovecs: number of iovecs to pre-allocate
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*
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* Description:
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* bio_alloc will allocate a bio and associated bio_vec array that can hold
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* at least @nr_iovecs entries. Allocations will be done from the
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* fs_bio_set. Also see @bio_alloc_bioset.
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*
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* If %__GFP_WAIT is set, then bio_alloc will always be able to allocate
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* a bio. This is due to the mempool guarantees. To make this work, callers
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* must never allocate more than 1 bio at the time from this pool. Callers
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* that need to allocate more than 1 bio must always submit the previously
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* allocate bio for IO before attempting to allocate a new one. Failure to
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* do so can cause livelocks under memory pressure.
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*
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**/
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struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
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{
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struct bio *bio;
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bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec),
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gfp_mask);
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if (unlikely(!bio))
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return NULL;
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bio_init(bio);
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bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET;
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bio->bi_max_vecs = nr_iovecs;
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bio->bi_io_vec = bio->bi_inline_vecs;
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bio->bi_destructor = bio_kmalloc_destructor;
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return bio;
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}
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void zero_fill_bio(struct bio *bio)
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{
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unsigned long flags;
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struct bio_vec *bv;
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int i;
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bio_for_each_segment(bv, bio, i) {
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char *data = bvec_kmap_irq(bv, &flags);
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memset(data, 0, bv->bv_len);
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flush_dcache_page(bv->bv_page);
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bvec_kunmap_irq(data, &flags);
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}
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}
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EXPORT_SYMBOL(zero_fill_bio);
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/**
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* bio_put - release a reference to a bio
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* @bio: bio to release reference to
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*
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* Description:
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* Put a reference to a &struct bio, either one you have gotten with
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* bio_alloc or bio_get. The last put of a bio will free it.
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**/
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void bio_put(struct bio *bio)
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{
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BIO_BUG_ON(!atomic_read(&bio->bi_cnt));
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/*
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* last put frees it
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*/
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if (atomic_dec_and_test(&bio->bi_cnt)) {
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bio->bi_next = NULL;
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bio->bi_destructor(bio);
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}
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}
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inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
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{
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if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
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blk_recount_segments(q, bio);
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return bio->bi_phys_segments;
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}
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/**
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* __bio_clone - clone a bio
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* @bio: destination bio
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* @bio_src: bio to clone
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*
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* Clone a &bio. Caller will own the returned bio, but not
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* the actual data it points to. Reference count of returned
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* bio will be one.
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*/
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void __bio_clone(struct bio *bio, struct bio *bio_src)
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{
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memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
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bio_src->bi_max_vecs * sizeof(struct bio_vec));
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|
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/*
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* most users will be overriding ->bi_bdev with a new target,
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* so we don't set nor calculate new physical/hw segment counts here
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*/
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bio->bi_sector = bio_src->bi_sector;
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bio->bi_bdev = bio_src->bi_bdev;
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bio->bi_flags |= 1 << BIO_CLONED;
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bio->bi_rw = bio_src->bi_rw;
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bio->bi_vcnt = bio_src->bi_vcnt;
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bio->bi_size = bio_src->bi_size;
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bio->bi_idx = bio_src->bi_idx;
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}
|
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|
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/**
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* bio_clone - clone a bio
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* @bio: bio to clone
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* @gfp_mask: allocation priority
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*
|
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* Like __bio_clone, only also allocates the returned bio
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*/
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struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
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{
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struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
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|
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if (!b)
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return NULL;
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|
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b->bi_destructor = bio_fs_destructor;
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__bio_clone(b, bio);
|
|
|
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if (bio_integrity(bio)) {
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int ret;
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|
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ret = bio_integrity_clone(b, bio, gfp_mask);
|
|
|
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if (ret < 0) {
|
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bio_put(b);
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return NULL;
|
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}
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}
|
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|
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return b;
|
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}
|
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|
|
/**
|
|
* 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.
|
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* There's no guarantee that you will be able to fit this number of pages
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* into a bio, it does not account for dynamic restrictions that vary
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* on offset.
|
|
*/
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int bio_get_nr_vecs(struct block_device *bdev)
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|
{
|
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struct request_queue *q = bdev_get_queue(bdev);
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int nr_pages;
|
|
|
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nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
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if (nr_pages > q->max_phys_segments)
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nr_pages = q->max_phys_segments;
|
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if (nr_pages > q->max_hw_segments)
|
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nr_pages = q->max_hw_segments;
|
|
|
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return nr_pages;
|
|
}
|
|
|
|
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;
|
|
|
|
/*
|
|
* cloned bio must not modify vec list
|
|
*/
|
|
if (unlikely(bio_flagged(bio, BIO_CLONED)))
|
|
return 0;
|
|
|
|
if (((bio->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) {
|
|
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,
|
|
.bi_rw = bio->bi_rw,
|
|
};
|
|
|
|
if (q->merge_bvec_fn(q, &bvm, prev) < 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 >= q->max_phys_segments
|
|
|| bio->bi_phys_segments >= q->max_hw_segments) {
|
|
|
|
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_sector,
|
|
.bi_size = bio->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) < 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_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
|
|
* smaller than 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, q->max_hw_sectors);
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
* smaller than 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, q->max_sectors);
|
|
}
|
|
|
|
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, int iov_count,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct bio_map_data *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 uncopy,
|
|
int do_free_page)
|
|
{
|
|
int ret = 0, i;
|
|
struct bio_vec *bvec;
|
|
int iov_idx = 0;
|
|
unsigned int iov_off = 0;
|
|
int read = bio_data_dir(bio) == READ;
|
|
|
|
__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 *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 (!read && !uncopy)
|
|
ret = copy_from_user(bv_addr, iov_addr,
|
|
bytes);
|
|
if (read && uncopy)
|
|
ret = copy_to_user(iov_addr, bv_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;
|
|
int ret = 0;
|
|
|
|
if (!bio_flagged(bio, BIO_NULL_MAPPED))
|
|
ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
|
|
bmd->nr_sgvecs, 1, bmd->is_our_pages);
|
|
bio_free_map_data(bmd);
|
|
bio_put(bio);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* 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,
|
|
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;
|
|
|
|
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;
|
|
|
|
bio->bi_rw |= (!write_to_vm << BIO_RW);
|
|
|
|
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)) {
|
|
ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 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);
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
|
|
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;
|
|
|
|
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 |= (1 << BIO_RW);
|
|
|
|
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);
|
|
}
|
|
|
|
/**
|
|
* 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,
|
|
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(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);
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
|
|
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_size == len)
|
|
return bio;
|
|
|
|
/*
|
|
* Don't support partial mappings.
|
|
*/
|
|
bio_put(bio);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
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 && !err)
|
|
memcpy(p, addr, len);
|
|
|
|
__free_page(bvec->bv_page);
|
|
p += len;
|
|
}
|
|
|
|
bio_free_map_data(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(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;
|
|
}
|
|
|
|
/*
|
|
* 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, pdflush) 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 = 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;
|
|
|
|
/*
|
|
* 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 = 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);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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. Noone 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)
|
|
{
|
|
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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* split a bio - only worry about a bio with a single page in its iovec
|
|
*/
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* bio_sector_offset - Find hardware sector offset in bio
|
|
* @bio: bio to inspect
|
|
* @index: bio_vec index
|
|
* @offset: offset in bv_page
|
|
*
|
|
* Return the number of hardware sectors between beginning of bio
|
|
* and an end point indicated by a bio_vec index and an offset
|
|
* within that vector's page.
|
|
*/
|
|
sector_t bio_sector_offset(struct bio *bio, unsigned short index,
|
|
unsigned int offset)
|
|
{
|
|
unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue);
|
|
struct bio_vec *bv;
|
|
sector_t sectors;
|
|
int i;
|
|
|
|
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);
|
|
|
|
/*
|
|
* create memory pools for biovec's in a bio_set.
|
|
* use the global biovec slabs created for general use.
|
|
*/
|
|
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);
|
|
|
|
biovec_free_pools(bs);
|
|
bio_put_slab(bs);
|
|
|
|
kfree(bs);
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
|
|
#ifndef CONFIG_BLK_DEV_INTEGRITY
|
|
if (bvs->nr_vecs <= BIO_INLINE_VECS) {
|
|
bvs->slab = NULL;
|
|
continue;
|
|
}
|
|
#endif
|
|
|
|
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");
|
|
|
|
biovec_init_slabs();
|
|
|
|
fs_bio_set = bioset_create(BIO_POOL_SIZE, 0);
|
|
if (!fs_bio_set)
|
|
panic("bio: can't allocate bios\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);
|
|
|
|
EXPORT_SYMBOL(bio_alloc);
|
|
EXPORT_SYMBOL(bio_kmalloc);
|
|
EXPORT_SYMBOL(bio_put);
|
|
EXPORT_SYMBOL(bio_free);
|
|
EXPORT_SYMBOL(bio_endio);
|
|
EXPORT_SYMBOL(bio_init);
|
|
EXPORT_SYMBOL(__bio_clone);
|
|
EXPORT_SYMBOL(bio_clone);
|
|
EXPORT_SYMBOL(bio_phys_segments);
|
|
EXPORT_SYMBOL(bio_add_page);
|
|
EXPORT_SYMBOL(bio_add_pc_page);
|
|
EXPORT_SYMBOL(bio_get_nr_vecs);
|
|
EXPORT_SYMBOL(bio_map_user);
|
|
EXPORT_SYMBOL(bio_unmap_user);
|
|
EXPORT_SYMBOL(bio_map_kern);
|
|
EXPORT_SYMBOL(bio_copy_kern);
|
|
EXPORT_SYMBOL(bio_pair_release);
|
|
EXPORT_SYMBOL(bio_split);
|
|
EXPORT_SYMBOL(bio_copy_user);
|
|
EXPORT_SYMBOL(bio_uncopy_user);
|
|
EXPORT_SYMBOL(bioset_create);
|
|
EXPORT_SYMBOL(bioset_free);
|
|
EXPORT_SYMBOL(bio_alloc_bioset);
|