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![Linus Torvalds](/assets/img/avatar_default.png)
-----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlsudKcQHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgphYXEAC0G+fJcLgue64LwLNjXksDUsoldqNWjTDZ e3szwseN3Woe7t+Q9DwEUO48T421WhDYe3UY50EZF3Fz5yYLi0ggTeq4qsKgpaXx 80dUY9/STxFZUV/tKrYMz5xPjM3k5x+m8FTeGlFgyR77fbOZE6/8w9XPkpmQN/B2 ayyEPMgAR9aZKhtOU4TJY45O278b2Qdfd0s6XUsxDTwBoR1mTQqKhNnY38PrIA5s wkhtKz5YRdq5tNhKt2IwYABpJ4HJ1Hz/FE6Fo1RNx+6vfxfEhsk2/DZBn0rzzGDj kvSaVlPeQEu9SZdJGtb2sx26elVWdt5sqMORQ0zb1kVCochZiT1IO3Z81XCy2Y3u 5WVvOlgsGni9BWr/K+iiN/dc+cKoRPy0g/ib77XUiJHgIC+urUIr3XgcIiuP9GZc cgCfF+6+GvRKLatSsDZSbns5cpgueJLNogZUyhs7oUouRIECo0DD9NnDAlHmaZYB 957bRd/ykE6QOvtxEsG0TWc3tgyHjJFQQ9ukb45VmzYVB8mITKOGLpceJaqzju9c AnGyQDddK4fqOct1pgFsSA5C3V6OOVXDpUiFn3DTNoQZcu5HN2hMwEA/g/u5TnGD N2sEwcu2WCoUjzsMEWFLmX8R4w8laZUDwkNSRC5tYzQEZpVDfmAsRtRcUHJdNLl/ zPj8QMAidA== =hCgr -----END PGP SIGNATURE----- Merge tag 'for-linus-20180623' of git://git.kernel.dk/linux-block Pull block fixes from Jens Axboe: - Further timeout fixes. We aren't quite there yet, so expect another round of fixes for that to completely close some of the IRQ vs completion races. (Christoph/Bart) - Set of NVMe fixes from the usual suspects, mostly error handling - Two off-by-one fixes (Dan) - Another bdi race fix (Jan) - Fix nbd reconfigure with NBD_DISCONNECT_ON_CLOSE (Doron) * tag 'for-linus-20180623' of git://git.kernel.dk/linux-block: blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE bdi: Fix another oops in wb_workfn() lightnvm: Remove depends on HAS_DMA in case of platform dependency nvme-pci: limit max IO size and segments to avoid high order allocations nvme-pci: move nvme_kill_queues to nvme_remove_dead_ctrl nvme-fc: release io queues to allow fast fail nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag. block: sed-opal: Fix a couple off by one bugs blk-mq-debugfs: Off by one in blk_mq_rq_state_name() nvmet: reset keep alive timer in controller enable nvme-rdma: don't override opts->queue_size nvme-rdma: Fix command completion race at error recovery nvme-rdma: fix possible free of a non-allocated async event buffer nvme-rdma: fix possible double free condition when failing to create a controller Revert "block: Add warning for bi_next not NULL in bio_endio()" block: fix timeout changes for legacy request drivers
2107 lines
51 KiB
C
2107 lines
51 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/uio.h>
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#include <linux/iocontext.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/export.h>
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#include <linux/mempool.h>
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#include <linux/workqueue.h>
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#include <linux/cgroup.h>
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#include <trace/events/block.h>
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#include "blk.h"
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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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/*
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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, n) { .nr_vecs = x, .name = "biovec-"#n }
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static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = {
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BV(1, 1), BV(4, 4), BV(16, 16), BV(64, 64), BV(128, 128), BV(BIO_MAX_PAGES, max),
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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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EXPORT_SYMBOL(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, *new_bio_slabs;
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unsigned int new_bio_slab_max;
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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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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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new_bio_slab_max = bio_slab_max << 1;
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new_bio_slabs = krealloc(bio_slabs,
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new_bio_slab_max * sizeof(struct bio_slab),
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GFP_KERNEL);
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if (!new_bio_slabs)
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goto out_unlock;
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bio_slab_max = new_bio_slab_max;
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bio_slabs = new_bio_slabs;
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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, ARCH_KMALLOC_MINALIGN,
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SLAB_HWCACHE_ALIGN, NULL);
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if (!slab)
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goto out_unlock;
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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(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
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{
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if (!idx)
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return;
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idx--;
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BIO_BUG_ON(idx >= BVEC_POOL_NR);
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if (idx == BVEC_POOL_MAX) {
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mempool_free(bv, 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(gfp_t gfp_mask, int nr, unsigned long *idx,
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mempool_t *pool)
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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 == BVEC_POOL_MAX) {
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fallback:
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bvl = mempool_alloc(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_DIRECT_RECLAIM | __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_DIRECT_RECLAIM
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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_DIRECT_RECLAIM))) {
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*idx = BVEC_POOL_MAX;
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goto fallback;
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}
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}
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(*idx)++;
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return bvl;
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}
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void bio_uninit(struct bio *bio)
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{
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bio_disassociate_task(bio);
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}
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EXPORT_SYMBOL(bio_uninit);
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static void bio_free(struct bio *bio)
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{
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struct bio_set *bs = bio->bi_pool;
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void *p;
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bio_uninit(bio);
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if (bs) {
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bvec_free(&bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(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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p -= bs->front_pad;
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mempool_free(p, &bs->bio_pool);
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} else {
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/* Bio was allocated by bio_kmalloc() */
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kfree(bio);
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}
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}
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/*
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* Users of this function have their own bio allocation. Subsequently,
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* they must remember to pair any call to bio_init() with bio_uninit()
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* when IO has completed, or when the bio is released.
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*/
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void bio_init(struct bio *bio, struct bio_vec *table,
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unsigned short max_vecs)
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{
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memset(bio, 0, sizeof(*bio));
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atomic_set(&bio->__bi_remaining, 1);
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atomic_set(&bio->__bi_cnt, 1);
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bio->bi_io_vec = table;
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bio->bi_max_vecs = max_vecs;
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}
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EXPORT_SYMBOL(bio_init);
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/**
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* bio_reset - reinitialize a bio
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* @bio: bio to reset
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*
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* Description:
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* After calling bio_reset(), @bio will be in the same state as a freshly
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* allocated bio returned bio bio_alloc_bioset() - the only fields that are
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* preserved are the ones that are initialized by bio_alloc_bioset(). See
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* comment in struct bio.
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*/
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void bio_reset(struct bio *bio)
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{
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unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS);
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bio_uninit(bio);
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memset(bio, 0, BIO_RESET_BYTES);
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bio->bi_flags = flags;
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atomic_set(&bio->__bi_remaining, 1);
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}
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EXPORT_SYMBOL(bio_reset);
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static struct bio *__bio_chain_endio(struct bio *bio)
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{
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struct bio *parent = bio->bi_private;
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if (!parent->bi_status)
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parent->bi_status = bio->bi_status;
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bio_put(bio);
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return parent;
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}
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static void bio_chain_endio(struct bio *bio)
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{
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bio_endio(__bio_chain_endio(bio));
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}
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/**
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* bio_chain - chain bio completions
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* @bio: the target bio
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* @parent: the @bio's parent bio
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*
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* The caller won't have a bi_end_io called when @bio completes - instead,
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* @parent's bi_end_io won't be called until both @parent and @bio have
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* completed; the chained bio will also be freed when it completes.
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*
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* The caller must not set bi_private or bi_end_io in @bio.
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*/
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void bio_chain(struct bio *bio, struct bio *parent)
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{
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BUG_ON(bio->bi_private || bio->bi_end_io);
|
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|
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bio->bi_private = parent;
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bio->bi_end_io = bio_chain_endio;
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bio_inc_remaining(parent);
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}
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EXPORT_SYMBOL(bio_chain);
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|
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static void bio_alloc_rescue(struct work_struct *work)
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{
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struct bio_set *bs = container_of(work, struct bio_set, rescue_work);
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struct bio *bio;
|
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|
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while (1) {
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spin_lock(&bs->rescue_lock);
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bio = bio_list_pop(&bs->rescue_list);
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spin_unlock(&bs->rescue_lock);
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|
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if (!bio)
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break;
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|
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generic_make_request(bio);
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}
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}
|
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|
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static void punt_bios_to_rescuer(struct bio_set *bs)
|
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{
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struct bio_list punt, nopunt;
|
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struct bio *bio;
|
|
|
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if (WARN_ON_ONCE(!bs->rescue_workqueue))
|
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return;
|
|
/*
|
|
* In order to guarantee forward progress we must punt only bios that
|
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* were allocated from this bio_set; otherwise, if there was a bio on
|
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* there for a stacking driver higher up in the stack, processing it
|
|
* could require allocating bios from this bio_set, and doing that from
|
|
* our own rescuer would be bad.
|
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*
|
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* Since bio lists are singly linked, pop them all instead of trying to
|
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* remove from the middle of the list:
|
|
*/
|
|
|
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bio_list_init(&punt);
|
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bio_list_init(&nopunt);
|
|
|
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while ((bio = bio_list_pop(¤t->bio_list[0])))
|
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bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
|
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current->bio_list[0] = nopunt;
|
|
|
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bio_list_init(&nopunt);
|
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while ((bio = bio_list_pop(¤t->bio_list[1])))
|
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bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
|
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current->bio_list[1] = nopunt;
|
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|
|
spin_lock(&bs->rescue_lock);
|
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bio_list_merge(&bs->rescue_list, &punt);
|
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spin_unlock(&bs->rescue_lock);
|
|
|
|
queue_work(bs->rescue_workqueue, &bs->rescue_work);
|
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}
|
|
|
|
/**
|
|
* bio_alloc_bioset - allocate a bio for I/O
|
|
* @gfp_mask: the GFP_* mask given to the slab allocator
|
|
* @nr_iovecs: number of iovecs to pre-allocate
|
|
* @bs: the bio_set to allocate from.
|
|
*
|
|
* Description:
|
|
* If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is
|
|
* backed by the @bs's mempool.
|
|
*
|
|
* When @bs is not NULL, if %__GFP_DIRECT_RECLAIM is set then bio_alloc will
|
|
* always be able to allocate a bio. This is due to the mempool guarantees.
|
|
* To make this work, callers must never allocate more than 1 bio at a time
|
|
* from this pool. Callers that need to allocate more than 1 bio must always
|
|
* submit the previously allocated bio for IO before attempting to allocate
|
|
* a new one. Failure to do so can cause deadlocks under memory pressure.
|
|
*
|
|
* Note that when running under generic_make_request() (i.e. any block
|
|
* driver), bios are not submitted until after you return - see the code in
|
|
* generic_make_request() that converts recursion into iteration, to prevent
|
|
* stack overflows.
|
|
*
|
|
* This would normally mean allocating multiple bios under
|
|
* generic_make_request() would be susceptible to deadlocks, but we have
|
|
* deadlock avoidance code that resubmits any blocked bios from a rescuer
|
|
* thread.
|
|
*
|
|
* However, we do not guarantee forward progress for allocations from other
|
|
* mempools. Doing multiple allocations from the same mempool under
|
|
* generic_make_request() should be avoided - instead, use bio_set's front_pad
|
|
* for per bio allocations.
|
|
*
|
|
* RETURNS:
|
|
* Pointer to new bio on success, NULL on failure.
|
|
*/
|
|
struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
|
|
struct bio_set *bs)
|
|
{
|
|
gfp_t saved_gfp = gfp_mask;
|
|
unsigned front_pad;
|
|
unsigned inline_vecs;
|
|
struct bio_vec *bvl = NULL;
|
|
struct bio *bio;
|
|
void *p;
|
|
|
|
if (!bs) {
|
|
if (nr_iovecs > UIO_MAXIOV)
|
|
return NULL;
|
|
|
|
p = kmalloc(sizeof(struct bio) +
|
|
nr_iovecs * sizeof(struct bio_vec),
|
|
gfp_mask);
|
|
front_pad = 0;
|
|
inline_vecs = nr_iovecs;
|
|
} else {
|
|
/* should not use nobvec bioset for nr_iovecs > 0 */
|
|
if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) &&
|
|
nr_iovecs > 0))
|
|
return NULL;
|
|
/*
|
|
* generic_make_request() converts recursion to iteration; this
|
|
* means if we're running beneath it, any bios we allocate and
|
|
* submit will not be submitted (and thus freed) until after we
|
|
* return.
|
|
*
|
|
* This exposes us to a potential deadlock if we allocate
|
|
* multiple bios from the same bio_set() while running
|
|
* underneath generic_make_request(). If we were to allocate
|
|
* multiple bios (say a stacking block driver that was splitting
|
|
* bios), we would deadlock if we exhausted the mempool's
|
|
* reserve.
|
|
*
|
|
* We solve this, and guarantee forward progress, with a rescuer
|
|
* workqueue per bio_set. If we go to allocate and there are
|
|
* bios on current->bio_list, we first try the allocation
|
|
* without __GFP_DIRECT_RECLAIM; if that fails, we punt those
|
|
* bios we would be blocking to the rescuer workqueue before
|
|
* we retry with the original gfp_flags.
|
|
*/
|
|
|
|
if (current->bio_list &&
|
|
(!bio_list_empty(¤t->bio_list[0]) ||
|
|
!bio_list_empty(¤t->bio_list[1])) &&
|
|
bs->rescue_workqueue)
|
|
gfp_mask &= ~__GFP_DIRECT_RECLAIM;
|
|
|
|
p = mempool_alloc(&bs->bio_pool, gfp_mask);
|
|
if (!p && gfp_mask != saved_gfp) {
|
|
punt_bios_to_rescuer(bs);
|
|
gfp_mask = saved_gfp;
|
|
p = mempool_alloc(&bs->bio_pool, gfp_mask);
|
|
}
|
|
|
|
front_pad = bs->front_pad;
|
|
inline_vecs = BIO_INLINE_VECS;
|
|
}
|
|
|
|
if (unlikely(!p))
|
|
return NULL;
|
|
|
|
bio = p + front_pad;
|
|
bio_init(bio, NULL, 0);
|
|
|
|
if (nr_iovecs > inline_vecs) {
|
|
unsigned long idx = 0;
|
|
|
|
bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool);
|
|
if (!bvl && gfp_mask != saved_gfp) {
|
|
punt_bios_to_rescuer(bs);
|
|
gfp_mask = saved_gfp;
|
|
bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool);
|
|
}
|
|
|
|
if (unlikely(!bvl))
|
|
goto err_free;
|
|
|
|
bio->bi_flags |= idx << BVEC_POOL_OFFSET;
|
|
} else if (nr_iovecs) {
|
|
bvl = bio->bi_inline_vecs;
|
|
}
|
|
|
|
bio->bi_pool = bs;
|
|
bio->bi_max_vecs = nr_iovecs;
|
|
bio->bi_io_vec = bvl;
|
|
return bio;
|
|
|
|
err_free:
|
|
mempool_free(p, &bs->bio_pool);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(bio_alloc_bioset);
|
|
|
|
void zero_fill_bio_iter(struct bio *bio, struct bvec_iter start)
|
|
{
|
|
unsigned long flags;
|
|
struct bio_vec bv;
|
|
struct bvec_iter iter;
|
|
|
|
__bio_for_each_segment(bv, bio, iter, start) {
|
|
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_iter);
|
|
|
|
/**
|
|
* bio_put - release a reference to a bio
|
|
* @bio: bio to release reference to
|
|
*
|
|
* Description:
|
|
* Put a reference to a &struct bio, either one you have gotten with
|
|
* bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it.
|
|
**/
|
|
void bio_put(struct bio *bio)
|
|
{
|
|
if (!bio_flagged(bio, BIO_REFFED))
|
|
bio_free(bio);
|
|
else {
|
|
BIO_BUG_ON(!atomic_read(&bio->__bi_cnt));
|
|
|
|
/*
|
|
* last put frees it
|
|
*/
|
|
if (atomic_dec_and_test(&bio->__bi_cnt))
|
|
bio_free(bio);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(bio_put);
|
|
|
|
inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
|
|
{
|
|
if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
|
|
blk_recount_segments(q, bio);
|
|
|
|
return bio->bi_phys_segments;
|
|
}
|
|
EXPORT_SYMBOL(bio_phys_segments);
|
|
|
|
/**
|
|
* __bio_clone_fast - clone a bio that shares the original bio's biovec
|
|
* @bio: destination bio
|
|
* @bio_src: bio to clone
|
|
*
|
|
* Clone a &bio. Caller will own the returned bio, but not
|
|
* the actual data it points to. Reference count of returned
|
|
* bio will be one.
|
|
*
|
|
* Caller must ensure that @bio_src is not freed before @bio.
|
|
*/
|
|
void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
|
|
{
|
|
BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio));
|
|
|
|
/*
|
|
* most users will be overriding ->bi_disk with a new target,
|
|
* so we don't set nor calculate new physical/hw segment counts here
|
|
*/
|
|
bio->bi_disk = bio_src->bi_disk;
|
|
bio->bi_partno = bio_src->bi_partno;
|
|
bio_set_flag(bio, BIO_CLONED);
|
|
if (bio_flagged(bio_src, BIO_THROTTLED))
|
|
bio_set_flag(bio, BIO_THROTTLED);
|
|
bio->bi_opf = bio_src->bi_opf;
|
|
bio->bi_write_hint = bio_src->bi_write_hint;
|
|
bio->bi_iter = bio_src->bi_iter;
|
|
bio->bi_io_vec = bio_src->bi_io_vec;
|
|
|
|
bio_clone_blkcg_association(bio, bio_src);
|
|
}
|
|
EXPORT_SYMBOL(__bio_clone_fast);
|
|
|
|
/**
|
|
* bio_clone_fast - clone a bio that shares the original bio's biovec
|
|
* @bio: bio to clone
|
|
* @gfp_mask: allocation priority
|
|
* @bs: bio_set to allocate from
|
|
*
|
|
* Like __bio_clone_fast, only also allocates the returned bio
|
|
*/
|
|
struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
|
|
{
|
|
struct bio *b;
|
|
|
|
b = bio_alloc_bioset(gfp_mask, 0, bs);
|
|
if (!b)
|
|
return NULL;
|
|
|
|
__bio_clone_fast(b, bio);
|
|
|
|
if (bio_integrity(bio)) {
|
|
int ret;
|
|
|
|
ret = bio_integrity_clone(b, bio, gfp_mask);
|
|
|
|
if (ret < 0) {
|
|
bio_put(b);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
return b;
|
|
}
|
|
EXPORT_SYMBOL(bio_clone_fast);
|
|
|
|
/**
|
|
* bio_clone_bioset - clone a bio
|
|
* @bio_src: bio to clone
|
|
* @gfp_mask: allocation priority
|
|
* @bs: bio_set to allocate from
|
|
*
|
|
* Clone bio. Caller will own the returned bio, but not the actual data it
|
|
* points to. Reference count of returned bio will be one.
|
|
*/
|
|
struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
|
|
struct bio_set *bs)
|
|
{
|
|
struct bvec_iter iter;
|
|
struct bio_vec bv;
|
|
struct bio *bio;
|
|
|
|
/*
|
|
* Pre immutable biovecs, __bio_clone() used to just do a memcpy from
|
|
* bio_src->bi_io_vec to bio->bi_io_vec.
|
|
*
|
|
* We can't do that anymore, because:
|
|
*
|
|
* - The point of cloning the biovec is to produce a bio with a biovec
|
|
* the caller can modify: bi_idx and bi_bvec_done should be 0.
|
|
*
|
|
* - The original bio could've had more than BIO_MAX_PAGES biovecs; if
|
|
* we tried to clone the whole thing bio_alloc_bioset() would fail.
|
|
* But the clone should succeed as long as the number of biovecs we
|
|
* actually need to allocate is fewer than BIO_MAX_PAGES.
|
|
*
|
|
* - Lastly, bi_vcnt should not be looked at or relied upon by code
|
|
* that does not own the bio - reason being drivers don't use it for
|
|
* iterating over the biovec anymore, so expecting it to be kept up
|
|
* to date (i.e. for clones that share the parent biovec) is just
|
|
* asking for trouble and would force extra work on
|
|
* __bio_clone_fast() anyways.
|
|
*/
|
|
|
|
bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
|
|
if (!bio)
|
|
return NULL;
|
|
bio->bi_disk = bio_src->bi_disk;
|
|
bio->bi_opf = bio_src->bi_opf;
|
|
bio->bi_write_hint = bio_src->bi_write_hint;
|
|
bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
|
|
bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
|
|
|
|
switch (bio_op(bio)) {
|
|
case REQ_OP_DISCARD:
|
|
case REQ_OP_SECURE_ERASE:
|
|
case REQ_OP_WRITE_ZEROES:
|
|
break;
|
|
case REQ_OP_WRITE_SAME:
|
|
bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
|
|
break;
|
|
default:
|
|
bio_for_each_segment(bv, bio_src, iter)
|
|
bio->bi_io_vec[bio->bi_vcnt++] = bv;
|
|
break;
|
|
}
|
|
|
|
if (bio_integrity(bio_src)) {
|
|
int ret;
|
|
|
|
ret = bio_integrity_clone(bio, bio_src, gfp_mask);
|
|
if (ret < 0) {
|
|
bio_put(bio);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
bio_clone_blkcg_association(bio, bio_src);
|
|
|
|
return bio;
|
|
}
|
|
EXPORT_SYMBOL(bio_clone_bioset);
|
|
|
|
/**
|
|
* bio_add_pc_page - attempt to add page to bio
|
|
* @q: the target queue
|
|
* @bio: destination bio
|
|
* @page: page to add
|
|
* @len: vec entry length
|
|
* @offset: vec entry offset
|
|
*
|
|
* Attempt to add a page to the bio_vec maplist. This can fail for a
|
|
* number of reasons, such as the bio being full or target block device
|
|
* limitations. The target block device must allow bio's up to PAGE_SIZE,
|
|
* so it is always possible to add a single page to an empty bio.
|
|
*
|
|
* This should only be used by REQ_PC bios.
|
|
*/
|
|
int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page
|
|
*page, unsigned int len, unsigned int offset)
|
|
{
|
|
int retried_segments = 0;
|
|
struct bio_vec *bvec;
|
|
|
|
/*
|
|
* cloned bio must not modify vec list
|
|
*/
|
|
if (unlikely(bio_flagged(bio, BIO_CLONED)))
|
|
return 0;
|
|
|
|
if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q))
|
|
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;
|
|
bio->bi_iter.bi_size += len;
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* If the queue doesn't support SG gaps and adding this
|
|
* offset would create a gap, disallow it.
|
|
*/
|
|
if (bvec_gap_to_prev(q, prev, offset))
|
|
return 0;
|
|
}
|
|
|
|
if (bio_full(bio))
|
|
return 0;
|
|
|
|
/*
|
|
* 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;
|
|
bio->bi_vcnt++;
|
|
bio->bi_phys_segments++;
|
|
bio->bi_iter.bi_size += len;
|
|
|
|
/*
|
|
* Perform a recount if the number of segments is greater
|
|
* than queue_max_segments(q).
|
|
*/
|
|
|
|
while (bio->bi_phys_segments > queue_max_segments(q)) {
|
|
|
|
if (retried_segments)
|
|
goto failed;
|
|
|
|
retried_segments = 1;
|
|
blk_recount_segments(q, bio);
|
|
}
|
|
|
|
/* If we may be able to merge these biovecs, force a recount */
|
|
if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
|
|
bio_clear_flag(bio, BIO_SEG_VALID);
|
|
|
|
done:
|
|
return len;
|
|
|
|
failed:
|
|
bvec->bv_page = NULL;
|
|
bvec->bv_len = 0;
|
|
bvec->bv_offset = 0;
|
|
bio->bi_vcnt--;
|
|
bio->bi_iter.bi_size -= len;
|
|
blk_recount_segments(q, bio);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(bio_add_pc_page);
|
|
|
|
/**
|
|
* __bio_try_merge_page - try appending data to an existing bvec.
|
|
* @bio: destination bio
|
|
* @page: page to add
|
|
* @len: length of the data to add
|
|
* @off: offset of the data in @page
|
|
*
|
|
* Try to add the data at @page + @off to the last bvec of @bio. This is a
|
|
* a useful optimisation for file systems with a block size smaller than the
|
|
* page size.
|
|
*
|
|
* Return %true on success or %false on failure.
|
|
*/
|
|
bool __bio_try_merge_page(struct bio *bio, struct page *page,
|
|
unsigned int len, unsigned int off)
|
|
{
|
|
if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
|
|
return false;
|
|
|
|
if (bio->bi_vcnt > 0) {
|
|
struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
|
|
|
|
if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) {
|
|
bv->bv_len += len;
|
|
bio->bi_iter.bi_size += len;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__bio_try_merge_page);
|
|
|
|
/**
|
|
* __bio_add_page - add page to a bio in a new segment
|
|
* @bio: destination bio
|
|
* @page: page to add
|
|
* @len: length of the data to add
|
|
* @off: offset of the data in @page
|
|
*
|
|
* Add the data at @page + @off to @bio as a new bvec. The caller must ensure
|
|
* that @bio has space for another bvec.
|
|
*/
|
|
void __bio_add_page(struct bio *bio, struct page *page,
|
|
unsigned int len, unsigned int off)
|
|
{
|
|
struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt];
|
|
|
|
WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
|
|
WARN_ON_ONCE(bio_full(bio));
|
|
|
|
bv->bv_page = page;
|
|
bv->bv_offset = off;
|
|
bv->bv_len = len;
|
|
|
|
bio->bi_iter.bi_size += len;
|
|
bio->bi_vcnt++;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__bio_add_page);
|
|
|
|
/**
|
|
* bio_add_page - attempt to add page to bio
|
|
* @bio: destination bio
|
|
* @page: page to add
|
|
* @len: vec entry length
|
|
* @offset: vec entry offset
|
|
*
|
|
* Attempt to add a page to the bio_vec maplist. This will only fail
|
|
* if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio.
|
|
*/
|
|
int bio_add_page(struct bio *bio, struct page *page,
|
|
unsigned int len, unsigned int offset)
|
|
{
|
|
if (!__bio_try_merge_page(bio, page, len, offset)) {
|
|
if (bio_full(bio))
|
|
return 0;
|
|
__bio_add_page(bio, page, len, offset);
|
|
}
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL(bio_add_page);
|
|
|
|
/**
|
|
* bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio
|
|
* @bio: bio to add pages to
|
|
* @iter: iov iterator describing the region to be mapped
|
|
*
|
|
* Pins as many pages from *iter and appends them to @bio's bvec array. The
|
|
* pages will have to be released using put_page() when done.
|
|
*/
|
|
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
|
|
{
|
|
unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;
|
|
struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
|
|
struct page **pages = (struct page **)bv;
|
|
size_t offset, diff;
|
|
ssize_t size;
|
|
|
|
size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset);
|
|
if (unlikely(size <= 0))
|
|
return size ? size : -EFAULT;
|
|
nr_pages = (size + offset + PAGE_SIZE - 1) / PAGE_SIZE;
|
|
|
|
/*
|
|
* Deep magic below: We need to walk the pinned pages backwards
|
|
* because we are abusing the space allocated for the bio_vecs
|
|
* for the page array. Because the bio_vecs are larger than the
|
|
* page pointers by definition this will always work. But it also
|
|
* means we can't use bio_add_page, so any changes to it's semantics
|
|
* need to be reflected here as well.
|
|
*/
|
|
bio->bi_iter.bi_size += size;
|
|
bio->bi_vcnt += nr_pages;
|
|
|
|
diff = (nr_pages * PAGE_SIZE - offset) - size;
|
|
while (nr_pages--) {
|
|
bv[nr_pages].bv_page = pages[nr_pages];
|
|
bv[nr_pages].bv_len = PAGE_SIZE;
|
|
bv[nr_pages].bv_offset = 0;
|
|
}
|
|
|
|
bv[0].bv_offset += offset;
|
|
bv[0].bv_len -= offset;
|
|
if (diff)
|
|
bv[bio->bi_vcnt - 1].bv_len -= diff;
|
|
|
|
iov_iter_advance(iter, size);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages);
|
|
|
|
static void submit_bio_wait_endio(struct bio *bio)
|
|
{
|
|
complete(bio->bi_private);
|
|
}
|
|
|
|
/**
|
|
* submit_bio_wait - submit a bio, and wait until it completes
|
|
* @bio: The &struct bio which describes the I/O
|
|
*
|
|
* Simple wrapper around submit_bio(). Returns 0 on success, or the error from
|
|
* bio_endio() on failure.
|
|
*
|
|
* WARNING: Unlike to how submit_bio() is usually used, this function does not
|
|
* result in bio reference to be consumed. The caller must drop the reference
|
|
* on his own.
|
|
*/
|
|
int submit_bio_wait(struct bio *bio)
|
|
{
|
|
DECLARE_COMPLETION_ONSTACK_MAP(done, bio->bi_disk->lockdep_map);
|
|
|
|
bio->bi_private = &done;
|
|
bio->bi_end_io = submit_bio_wait_endio;
|
|
bio->bi_opf |= REQ_SYNC;
|
|
submit_bio(bio);
|
|
wait_for_completion_io(&done);
|
|
|
|
return blk_status_to_errno(bio->bi_status);
|
|
}
|
|
EXPORT_SYMBOL(submit_bio_wait);
|
|
|
|
/**
|
|
* bio_advance - increment/complete a bio by some number of bytes
|
|
* @bio: bio to advance
|
|
* @bytes: number of bytes to complete
|
|
*
|
|
* This updates bi_sector, bi_size and bi_idx; if the number of bytes to
|
|
* complete doesn't align with a bvec boundary, then bv_len and bv_offset will
|
|
* be updated on the last bvec as well.
|
|
*
|
|
* @bio will then represent the remaining, uncompleted portion of the io.
|
|
*/
|
|
void bio_advance(struct bio *bio, unsigned bytes)
|
|
{
|
|
if (bio_integrity(bio))
|
|
bio_integrity_advance(bio, bytes);
|
|
|
|
bio_advance_iter(bio, &bio->bi_iter, bytes);
|
|
}
|
|
EXPORT_SYMBOL(bio_advance);
|
|
|
|
void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
|
|
struct bio *src, struct bvec_iter *src_iter)
|
|
{
|
|
struct bio_vec src_bv, dst_bv;
|
|
void *src_p, *dst_p;
|
|
unsigned bytes;
|
|
|
|
while (src_iter->bi_size && dst_iter->bi_size) {
|
|
src_bv = bio_iter_iovec(src, *src_iter);
|
|
dst_bv = bio_iter_iovec(dst, *dst_iter);
|
|
|
|
bytes = min(src_bv.bv_len, dst_bv.bv_len);
|
|
|
|
src_p = kmap_atomic(src_bv.bv_page);
|
|
dst_p = kmap_atomic(dst_bv.bv_page);
|
|
|
|
memcpy(dst_p + dst_bv.bv_offset,
|
|
src_p + src_bv.bv_offset,
|
|
bytes);
|
|
|
|
kunmap_atomic(dst_p);
|
|
kunmap_atomic(src_p);
|
|
|
|
flush_dcache_page(dst_bv.bv_page);
|
|
|
|
bio_advance_iter(src, src_iter, bytes);
|
|
bio_advance_iter(dst, dst_iter, bytes);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(bio_copy_data_iter);
|
|
|
|
/**
|
|
* bio_copy_data - copy contents of data buffers from one bio to another
|
|
* @src: source bio
|
|
* @dst: destination bio
|
|
*
|
|
* Stops when it reaches the end of either @src or @dst - that is, copies
|
|
* min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios).
|
|
*/
|
|
void bio_copy_data(struct bio *dst, struct bio *src)
|
|
{
|
|
struct bvec_iter src_iter = src->bi_iter;
|
|
struct bvec_iter dst_iter = dst->bi_iter;
|
|
|
|
bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
|
|
}
|
|
EXPORT_SYMBOL(bio_copy_data);
|
|
|
|
/**
|
|
* bio_list_copy_data - copy contents of data buffers from one chain of bios to
|
|
* another
|
|
* @src: source bio list
|
|
* @dst: destination bio list
|
|
*
|
|
* Stops when it reaches the end of either the @src list or @dst list - that is,
|
|
* copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
|
|
* bios).
|
|
*/
|
|
void bio_list_copy_data(struct bio *dst, struct bio *src)
|
|
{
|
|
struct bvec_iter src_iter = src->bi_iter;
|
|
struct bvec_iter dst_iter = dst->bi_iter;
|
|
|
|
while (1) {
|
|
if (!src_iter.bi_size) {
|
|
src = src->bi_next;
|
|
if (!src)
|
|
break;
|
|
|
|
src_iter = src->bi_iter;
|
|
}
|
|
|
|
if (!dst_iter.bi_size) {
|
|
dst = dst->bi_next;
|
|
if (!dst)
|
|
break;
|
|
|
|
dst_iter = dst->bi_iter;
|
|
}
|
|
|
|
bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(bio_list_copy_data);
|
|
|
|
struct bio_map_data {
|
|
int is_our_pages;
|
|
struct iov_iter iter;
|
|
struct iovec iov[];
|
|
};
|
|
|
|
static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct bio_map_data *bmd;
|
|
if (data->nr_segs > UIO_MAXIOV)
|
|
return NULL;
|
|
|
|
bmd = kmalloc(sizeof(struct bio_map_data) +
|
|
sizeof(struct iovec) * data->nr_segs, gfp_mask);
|
|
if (!bmd)
|
|
return NULL;
|
|
memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
|
|
bmd->iter = *data;
|
|
bmd->iter.iov = bmd->iov;
|
|
return bmd;
|
|
}
|
|
|
|
/**
|
|
* bio_copy_from_iter - copy all pages from iov_iter to bio
|
|
* @bio: The &struct bio which describes the I/O as destination
|
|
* @iter: iov_iter as source
|
|
*
|
|
* Copy all pages from iov_iter to bio.
|
|
* Returns 0 on success, or error on failure.
|
|
*/
|
|
static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
|
|
{
|
|
int i;
|
|
struct bio_vec *bvec;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
ssize_t ret;
|
|
|
|
ret = copy_page_from_iter(bvec->bv_page,
|
|
bvec->bv_offset,
|
|
bvec->bv_len,
|
|
iter);
|
|
|
|
if (!iov_iter_count(iter))
|
|
break;
|
|
|
|
if (ret < bvec->bv_len)
|
|
return -EFAULT;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* bio_copy_to_iter - copy all pages from bio to iov_iter
|
|
* @bio: The &struct bio which describes the I/O as source
|
|
* @iter: iov_iter as destination
|
|
*
|
|
* Copy all pages from bio to iov_iter.
|
|
* Returns 0 on success, or error on failure.
|
|
*/
|
|
static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
|
|
{
|
|
int i;
|
|
struct bio_vec *bvec;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
ssize_t ret;
|
|
|
|
ret = copy_page_to_iter(bvec->bv_page,
|
|
bvec->bv_offset,
|
|
bvec->bv_len,
|
|
&iter);
|
|
|
|
if (!iov_iter_count(&iter))
|
|
break;
|
|
|
|
if (ret < bvec->bv_len)
|
|
return -EFAULT;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bio_free_pages(struct bio *bio)
|
|
{
|
|
struct bio_vec *bvec;
|
|
int i;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i)
|
|
__free_page(bvec->bv_page);
|
|
}
|
|
EXPORT_SYMBOL(bio_free_pages);
|
|
|
|
/**
|
|
* bio_uncopy_user - finish previously mapped bio
|
|
* @bio: bio being terminated
|
|
*
|
|
* Free pages allocated from bio_copy_user_iov() 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)) {
|
|
/*
|
|
* if we're in a workqueue, the request is orphaned, so
|
|
* don't copy into a random user address space, just free
|
|
* and return -EINTR so user space doesn't expect any data.
|
|
*/
|
|
if (!current->mm)
|
|
ret = -EINTR;
|
|
else if (bio_data_dir(bio) == READ)
|
|
ret = bio_copy_to_iter(bio, bmd->iter);
|
|
if (bmd->is_our_pages)
|
|
bio_free_pages(bio);
|
|
}
|
|
kfree(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)
|
|
* @iter: iovec iterator
|
|
* @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 iov_iter *iter,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct bio_map_data *bmd;
|
|
struct page *page;
|
|
struct bio *bio;
|
|
int i = 0, ret;
|
|
int nr_pages;
|
|
unsigned int len = iter->count;
|
|
unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
|
|
|
|
bmd = bio_alloc_map_data(iter, gfp_mask);
|
|
if (!bmd)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/*
|
|
* We need to do a deep copy of the iov_iter including the iovecs.
|
|
* The caller provided iov might point to an on-stack or otherwise
|
|
* shortlived one.
|
|
*/
|
|
bmd->is_our_pages = map_data ? 0 : 1;
|
|
|
|
nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
|
|
if (nr_pages > BIO_MAX_PAGES)
|
|
nr_pages = BIO_MAX_PAGES;
|
|
|
|
ret = -ENOMEM;
|
|
bio = bio_kmalloc(gfp_mask, nr_pages);
|
|
if (!bio)
|
|
goto out_bmd;
|
|
|
|
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 (map_data)
|
|
map_data->offset += bio->bi_iter.bi_size;
|
|
|
|
/*
|
|
* success
|
|
*/
|
|
if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) ||
|
|
(map_data && map_data->from_user)) {
|
|
ret = bio_copy_from_iter(bio, iter);
|
|
if (ret)
|
|
goto cleanup;
|
|
} else {
|
|
iov_iter_advance(iter, bio->bi_iter.bi_size);
|
|
}
|
|
|
|
bio->bi_private = bmd;
|
|
if (map_data && map_data->null_mapped)
|
|
bio_set_flag(bio, BIO_NULL_MAPPED);
|
|
return bio;
|
|
cleanup:
|
|
if (!map_data)
|
|
bio_free_pages(bio);
|
|
bio_put(bio);
|
|
out_bmd:
|
|
kfree(bmd);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
/**
|
|
* bio_map_user_iov - map user iovec into bio
|
|
* @q: the struct request_queue for the bio
|
|
* @iter: iovec iterator
|
|
* @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 iov_iter *iter,
|
|
gfp_t gfp_mask)
|
|
{
|
|
int j;
|
|
struct bio *bio;
|
|
int ret;
|
|
struct bio_vec *bvec;
|
|
|
|
if (!iov_iter_count(iter))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES));
|
|
if (!bio)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
while (iov_iter_count(iter)) {
|
|
struct page **pages;
|
|
ssize_t bytes;
|
|
size_t offs, added = 0;
|
|
int npages;
|
|
|
|
bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs);
|
|
if (unlikely(bytes <= 0)) {
|
|
ret = bytes ? bytes : -EFAULT;
|
|
goto out_unmap;
|
|
}
|
|
|
|
npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
|
|
|
|
if (unlikely(offs & queue_dma_alignment(q))) {
|
|
ret = -EINVAL;
|
|
j = 0;
|
|
} else {
|
|
for (j = 0; j < npages; j++) {
|
|
struct page *page = pages[j];
|
|
unsigned int n = PAGE_SIZE - offs;
|
|
unsigned short prev_bi_vcnt = bio->bi_vcnt;
|
|
|
|
if (n > bytes)
|
|
n = bytes;
|
|
|
|
if (!bio_add_pc_page(q, bio, page, n, offs))
|
|
break;
|
|
|
|
/*
|
|
* check if vector was merged with previous
|
|
* drop page reference if needed
|
|
*/
|
|
if (bio->bi_vcnt == prev_bi_vcnt)
|
|
put_page(page);
|
|
|
|
added += n;
|
|
bytes -= n;
|
|
offs = 0;
|
|
}
|
|
iov_iter_advance(iter, added);
|
|
}
|
|
/*
|
|
* release the pages we didn't map into the bio, if any
|
|
*/
|
|
while (j < npages)
|
|
put_page(pages[j++]);
|
|
kvfree(pages);
|
|
/* couldn't stuff something into bio? */
|
|
if (bytes)
|
|
break;
|
|
}
|
|
|
|
bio_set_flag(bio, BIO_USER_MAPPED);
|
|
|
|
/*
|
|
* subtle -- if bio_map_user_iov() 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;
|
|
|
|
out_unmap:
|
|
bio_for_each_segment_all(bvec, bio, j) {
|
|
put_page(bvec->bv_page);
|
|
}
|
|
bio_put(bio);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static void __bio_unmap_user(struct bio *bio)
|
|
{
|
|
struct bio_vec *bvec;
|
|
int i;
|
|
|
|
/*
|
|
* make sure we dirty pages we wrote to
|
|
*/
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
if (bio_data_dir(bio) == READ)
|
|
set_page_dirty_lock(bvec->bv_page);
|
|
|
|
put_page(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_iov(). Must be called from
|
|
* 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)
|
|
{
|
|
bio_put(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)
|
|
{
|
|
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) {
|
|
/* we don't support partial mappings */
|
|
bio_put(bio);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
data += bytes;
|
|
len -= bytes;
|
|
offset = 0;
|
|
}
|
|
|
|
bio->bi_end_io = bio_map_kern_endio;
|
|
return bio;
|
|
}
|
|
EXPORT_SYMBOL(bio_map_kern);
|
|
|
|
static void bio_copy_kern_endio(struct bio *bio)
|
|
{
|
|
bio_free_pages(bio);
|
|
bio_put(bio);
|
|
}
|
|
|
|
static void bio_copy_kern_endio_read(struct bio *bio)
|
|
{
|
|
char *p = bio->bi_private;
|
|
struct bio_vec *bvec;
|
|
int i;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
memcpy(p, page_address(bvec->bv_page), bvec->bv_len);
|
|
p += bvec->bv_len;
|
|
}
|
|
|
|
bio_copy_kern_endio(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)
|
|
{
|
|
unsigned long kaddr = (unsigned long)data;
|
|
unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
unsigned long start = kaddr >> PAGE_SHIFT;
|
|
struct bio *bio;
|
|
void *p = data;
|
|
int nr_pages = 0;
|
|
|
|
/*
|
|
* Overflow, abort
|
|
*/
|
|
if (end < start)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
nr_pages = end - start;
|
|
bio = bio_kmalloc(gfp_mask, nr_pages);
|
|
if (!bio)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
while (len) {
|
|
struct page *page;
|
|
unsigned int bytes = PAGE_SIZE;
|
|
|
|
if (bytes > len)
|
|
bytes = len;
|
|
|
|
page = alloc_page(q->bounce_gfp | gfp_mask);
|
|
if (!page)
|
|
goto cleanup;
|
|
|
|
if (!reading)
|
|
memcpy(page_address(page), p, bytes);
|
|
|
|
if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
|
|
break;
|
|
|
|
len -= bytes;
|
|
p += bytes;
|
|
}
|
|
|
|
if (reading) {
|
|
bio->bi_end_io = bio_copy_kern_endio_read;
|
|
bio->bi_private = data;
|
|
} else {
|
|
bio->bi_end_io = bio_copy_kern_endio;
|
|
}
|
|
|
|
return bio;
|
|
|
|
cleanup:
|
|
bio_free_pages(bio);
|
|
bio_put(bio);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
/*
|
|
* bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
|
|
* for performing direct-IO in BIOs.
|
|
*
|
|
* The problem is that we cannot run set_page_dirty() from interrupt context
|
|
* because the required locks are not interrupt-safe. So what we can do is to
|
|
* mark the pages dirty _before_ performing IO. And in interrupt context,
|
|
* check that the pages are still dirty. If so, fine. If not, redirty them
|
|
* in process context.
|
|
*
|
|
* We special-case compound pages here: normally this means reads into hugetlb
|
|
* pages. The logic in here doesn't really work right for compound pages
|
|
* because the VM does not uniformly chase down the head page in all cases.
|
|
* But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't
|
|
* handle them at all. So we skip compound pages here at an early stage.
|
|
*
|
|
* Note that this code is very hard to test under normal circumstances because
|
|
* direct-io pins the pages with get_user_pages(). This makes
|
|
* is_page_cache_freeable return false, and the VM will not clean the pages.
|
|
* But other code (eg, flusher threads) could clean the pages if they are mapped
|
|
* pagecache.
|
|
*
|
|
* Simply disabling the call to bio_set_pages_dirty() is a good way to test the
|
|
* deferred bio dirtying paths.
|
|
*/
|
|
|
|
/*
|
|
* bio_set_pages_dirty() will mark all the bio's pages as dirty.
|
|
*/
|
|
void bio_set_pages_dirty(struct bio *bio)
|
|
{
|
|
struct bio_vec *bvec;
|
|
int i;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
struct page *page = bvec->bv_page;
|
|
|
|
if (page && !PageCompound(page))
|
|
set_page_dirty_lock(page);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(bio_set_pages_dirty);
|
|
|
|
static void bio_release_pages(struct bio *bio)
|
|
{
|
|
struct bio_vec *bvec;
|
|
int i;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
struct page *page = bvec->bv_page;
|
|
|
|
if (page)
|
|
put_page(page);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
|
|
* If they are, then fine. If, however, some pages are clean then they must
|
|
* have been written out during the direct-IO read. So we take another ref on
|
|
* the BIO and the offending pages and re-dirty the pages in process context.
|
|
*
|
|
* It is expected that bio_check_pages_dirty() will wholly own the BIO from
|
|
* here on. It will run one put_page() against each page and will run one
|
|
* bio_put() against the BIO.
|
|
*/
|
|
|
|
static void bio_dirty_fn(struct work_struct *work);
|
|
|
|
static DECLARE_WORK(bio_dirty_work, bio_dirty_fn);
|
|
static DEFINE_SPINLOCK(bio_dirty_lock);
|
|
static struct bio *bio_dirty_list;
|
|
|
|
/*
|
|
* This runs in process context
|
|
*/
|
|
static void bio_dirty_fn(struct work_struct *work)
|
|
{
|
|
unsigned long flags;
|
|
struct bio *bio;
|
|
|
|
spin_lock_irqsave(&bio_dirty_lock, flags);
|
|
bio = bio_dirty_list;
|
|
bio_dirty_list = NULL;
|
|
spin_unlock_irqrestore(&bio_dirty_lock, flags);
|
|
|
|
while (bio) {
|
|
struct bio *next = bio->bi_private;
|
|
|
|
bio_set_pages_dirty(bio);
|
|
bio_release_pages(bio);
|
|
bio_put(bio);
|
|
bio = next;
|
|
}
|
|
}
|
|
|
|
void bio_check_pages_dirty(struct bio *bio)
|
|
{
|
|
struct bio_vec *bvec;
|
|
int nr_clean_pages = 0;
|
|
int i;
|
|
|
|
bio_for_each_segment_all(bvec, bio, i) {
|
|
struct page *page = bvec->bv_page;
|
|
|
|
if (PageDirty(page) || PageCompound(page)) {
|
|
put_page(page);
|
|
bvec->bv_page = NULL;
|
|
} else {
|
|
nr_clean_pages++;
|
|
}
|
|
}
|
|
|
|
if (nr_clean_pages) {
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&bio_dirty_lock, flags);
|
|
bio->bi_private = bio_dirty_list;
|
|
bio_dirty_list = bio;
|
|
spin_unlock_irqrestore(&bio_dirty_lock, flags);
|
|
schedule_work(&bio_dirty_work);
|
|
} else {
|
|
bio_put(bio);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(bio_check_pages_dirty);
|
|
|
|
void generic_start_io_acct(struct request_queue *q, int rw,
|
|
unsigned long sectors, struct hd_struct *part)
|
|
{
|
|
int cpu = part_stat_lock();
|
|
|
|
part_round_stats(q, cpu, part);
|
|
part_stat_inc(cpu, part, ios[rw]);
|
|
part_stat_add(cpu, part, sectors[rw], sectors);
|
|
part_inc_in_flight(q, part, rw);
|
|
|
|
part_stat_unlock();
|
|
}
|
|
EXPORT_SYMBOL(generic_start_io_acct);
|
|
|
|
void generic_end_io_acct(struct request_queue *q, int rw,
|
|
struct hd_struct *part, unsigned long start_time)
|
|
{
|
|
unsigned long duration = jiffies - start_time;
|
|
int cpu = part_stat_lock();
|
|
|
|
part_stat_add(cpu, part, ticks[rw], duration);
|
|
part_round_stats(q, cpu, part);
|
|
part_dec_in_flight(q, part, rw);
|
|
|
|
part_stat_unlock();
|
|
}
|
|
EXPORT_SYMBOL(generic_end_io_acct);
|
|
|
|
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
|
|
void bio_flush_dcache_pages(struct bio *bi)
|
|
{
|
|
struct bio_vec bvec;
|
|
struct bvec_iter iter;
|
|
|
|
bio_for_each_segment(bvec, bi, iter)
|
|
flush_dcache_page(bvec.bv_page);
|
|
}
|
|
EXPORT_SYMBOL(bio_flush_dcache_pages);
|
|
#endif
|
|
|
|
static inline bool bio_remaining_done(struct bio *bio)
|
|
{
|
|
/*
|
|
* If we're not chaining, then ->__bi_remaining is always 1 and
|
|
* we always end io on the first invocation.
|
|
*/
|
|
if (!bio_flagged(bio, BIO_CHAIN))
|
|
return true;
|
|
|
|
BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);
|
|
|
|
if (atomic_dec_and_test(&bio->__bi_remaining)) {
|
|
bio_clear_flag(bio, BIO_CHAIN);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* bio_endio - end I/O on a bio
|
|
* @bio: bio
|
|
*
|
|
* Description:
|
|
* bio_endio() will end I/O on the whole bio. bio_endio() is the preferred
|
|
* way to end I/O on a bio. No one should call bi_end_io() directly on a
|
|
* bio unless they own it and thus know that it has an end_io function.
|
|
*
|
|
* bio_endio() can be called several times on a bio that has been chained
|
|
* using bio_chain(). The ->bi_end_io() function will only be called the
|
|
* last time. At this point the BLK_TA_COMPLETE tracing event will be
|
|
* generated if BIO_TRACE_COMPLETION is set.
|
|
**/
|
|
void bio_endio(struct bio *bio)
|
|
{
|
|
again:
|
|
if (!bio_remaining_done(bio))
|
|
return;
|
|
if (!bio_integrity_endio(bio))
|
|
return;
|
|
|
|
/*
|
|
* Need to have a real endio function for chained bios, otherwise
|
|
* various corner cases will break (like stacking block devices that
|
|
* save/restore bi_end_io) - however, we want to avoid unbounded
|
|
* recursion and blowing the stack. Tail call optimization would
|
|
* handle this, but compiling with frame pointers also disables
|
|
* gcc's sibling call optimization.
|
|
*/
|
|
if (bio->bi_end_io == bio_chain_endio) {
|
|
bio = __bio_chain_endio(bio);
|
|
goto again;
|
|
}
|
|
|
|
if (bio->bi_disk && bio_flagged(bio, BIO_TRACE_COMPLETION)) {
|
|
trace_block_bio_complete(bio->bi_disk->queue, bio,
|
|
blk_status_to_errno(bio->bi_status));
|
|
bio_clear_flag(bio, BIO_TRACE_COMPLETION);
|
|
}
|
|
|
|
blk_throtl_bio_endio(bio);
|
|
/* release cgroup info */
|
|
bio_uninit(bio);
|
|
if (bio->bi_end_io)
|
|
bio->bi_end_io(bio);
|
|
}
|
|
EXPORT_SYMBOL(bio_endio);
|
|
|
|
/**
|
|
* bio_split - split a bio
|
|
* @bio: bio to split
|
|
* @sectors: number of sectors to split from the front of @bio
|
|
* @gfp: gfp mask
|
|
* @bs: bio set to allocate from
|
|
*
|
|
* Allocates and returns a new bio which represents @sectors from the start of
|
|
* @bio, and updates @bio to represent the remaining sectors.
|
|
*
|
|
* Unless this is a discard request the newly allocated bio will point
|
|
* to @bio's bi_io_vec; it is the caller's responsibility to ensure that
|
|
* @bio is not freed before the split.
|
|
*/
|
|
struct bio *bio_split(struct bio *bio, int sectors,
|
|
gfp_t gfp, struct bio_set *bs)
|
|
{
|
|
struct bio *split;
|
|
|
|
BUG_ON(sectors <= 0);
|
|
BUG_ON(sectors >= bio_sectors(bio));
|
|
|
|
split = bio_clone_fast(bio, gfp, bs);
|
|
if (!split)
|
|
return NULL;
|
|
|
|
split->bi_iter.bi_size = sectors << 9;
|
|
|
|
if (bio_integrity(split))
|
|
bio_integrity_trim(split);
|
|
|
|
bio_advance(bio, split->bi_iter.bi_size);
|
|
|
|
if (bio_flagged(bio, BIO_TRACE_COMPLETION))
|
|
bio_set_flag(split, BIO_TRACE_COMPLETION);
|
|
|
|
return split;
|
|
}
|
|
EXPORT_SYMBOL(bio_split);
|
|
|
|
/**
|
|
* bio_trim - trim a bio
|
|
* @bio: bio to trim
|
|
* @offset: number of sectors to trim from the front of @bio
|
|
* @size: size we want to trim @bio to, in sectors
|
|
*/
|
|
void bio_trim(struct bio *bio, int offset, int size)
|
|
{
|
|
/* 'bio' is a cloned bio which we need to trim to match
|
|
* the given offset and size.
|
|
*/
|
|
|
|
size <<= 9;
|
|
if (offset == 0 && size == bio->bi_iter.bi_size)
|
|
return;
|
|
|
|
bio_clear_flag(bio, BIO_SEG_VALID);
|
|
|
|
bio_advance(bio, offset << 9);
|
|
|
|
bio->bi_iter.bi_size = size;
|
|
|
|
if (bio_integrity(bio))
|
|
bio_integrity_trim(bio);
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(bio_trim);
|
|
|
|
/*
|
|
* create memory pools for biovec's in a bio_set.
|
|
* use the global biovec slabs created for general use.
|
|
*/
|
|
int biovec_init_pool(mempool_t *pool, int pool_entries)
|
|
{
|
|
struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX;
|
|
|
|
return mempool_init_slab_pool(pool, pool_entries, bp->slab);
|
|
}
|
|
|
|
/*
|
|
* bioset_exit - exit a bioset initialized with bioset_init()
|
|
*
|
|
* May be called on a zeroed but uninitialized bioset (i.e. allocated with
|
|
* kzalloc()).
|
|
*/
|
|
void bioset_exit(struct bio_set *bs)
|
|
{
|
|
if (bs->rescue_workqueue)
|
|
destroy_workqueue(bs->rescue_workqueue);
|
|
bs->rescue_workqueue = NULL;
|
|
|
|
mempool_exit(&bs->bio_pool);
|
|
mempool_exit(&bs->bvec_pool);
|
|
|
|
bioset_integrity_free(bs);
|
|
if (bs->bio_slab)
|
|
bio_put_slab(bs);
|
|
bs->bio_slab = NULL;
|
|
}
|
|
EXPORT_SYMBOL(bioset_exit);
|
|
|
|
/**
|
|
* bioset_init - Initialize a bio_set
|
|
* @bs: pool to initialize
|
|
* @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
|
|
* @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS
|
|
* and %BIOSET_NEED_RESCUER
|
|
*
|
|
* 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.
|
|
* If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated
|
|
* for allocating iovecs. This pool is not needed e.g. for bio_clone_fast().
|
|
* If %BIOSET_NEED_RESCUER is set, a workqueue is created which can be used to
|
|
* dispatch queued requests when the mempool runs out of space.
|
|
*
|
|
*/
|
|
int bioset_init(struct bio_set *bs,
|
|
unsigned int pool_size,
|
|
unsigned int front_pad,
|
|
int flags)
|
|
{
|
|
unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
|
|
|
|
bs->front_pad = front_pad;
|
|
|
|
spin_lock_init(&bs->rescue_lock);
|
|
bio_list_init(&bs->rescue_list);
|
|
INIT_WORK(&bs->rescue_work, bio_alloc_rescue);
|
|
|
|
bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
|
|
if (!bs->bio_slab)
|
|
return -ENOMEM;
|
|
|
|
if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab))
|
|
goto bad;
|
|
|
|
if ((flags & BIOSET_NEED_BVECS) &&
|
|
biovec_init_pool(&bs->bvec_pool, pool_size))
|
|
goto bad;
|
|
|
|
if (!(flags & BIOSET_NEED_RESCUER))
|
|
return 0;
|
|
|
|
bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
|
|
if (!bs->rescue_workqueue)
|
|
goto bad;
|
|
|
|
return 0;
|
|
bad:
|
|
bioset_exit(bs);
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL(bioset_init);
|
|
|
|
/*
|
|
* Initialize and setup a new bio_set, based on the settings from
|
|
* another bio_set.
|
|
*/
|
|
int bioset_init_from_src(struct bio_set *bs, struct bio_set *src)
|
|
{
|
|
int flags;
|
|
|
|
flags = 0;
|
|
if (src->bvec_pool.min_nr)
|
|
flags |= BIOSET_NEED_BVECS;
|
|
if (src->rescue_workqueue)
|
|
flags |= BIOSET_NEED_RESCUER;
|
|
|
|
return bioset_init(bs, src->bio_pool.min_nr, src->front_pad, flags);
|
|
}
|
|
EXPORT_SYMBOL(bioset_init_from_src);
|
|
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
|
|
/**
|
|
* bio_associate_blkcg - associate a bio with the specified blkcg
|
|
* @bio: target bio
|
|
* @blkcg_css: css of the blkcg to associate
|
|
*
|
|
* Associate @bio with the blkcg specified by @blkcg_css. Block layer will
|
|
* treat @bio as if it were issued by a task which belongs to the blkcg.
|
|
*
|
|
* This function takes an extra reference of @blkcg_css which will be put
|
|
* when @bio is released. The caller must own @bio and is responsible for
|
|
* synchronizing calls to this function.
|
|
*/
|
|
int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css)
|
|
{
|
|
if (unlikely(bio->bi_css))
|
|
return -EBUSY;
|
|
css_get(blkcg_css);
|
|
bio->bi_css = blkcg_css;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bio_associate_blkcg);
|
|
|
|
/**
|
|
* bio_disassociate_task - undo bio_associate_current()
|
|
* @bio: target bio
|
|
*/
|
|
void bio_disassociate_task(struct bio *bio)
|
|
{
|
|
if (bio->bi_ioc) {
|
|
put_io_context(bio->bi_ioc);
|
|
bio->bi_ioc = NULL;
|
|
}
|
|
if (bio->bi_css) {
|
|
css_put(bio->bi_css);
|
|
bio->bi_css = NULL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* bio_clone_blkcg_association - clone blkcg association from src to dst bio
|
|
* @dst: destination bio
|
|
* @src: source bio
|
|
*/
|
|
void bio_clone_blkcg_association(struct bio *dst, struct bio *src)
|
|
{
|
|
if (src->bi_css)
|
|
WARN_ON(bio_associate_blkcg(dst, src->bi_css));
|
|
}
|
|
EXPORT_SYMBOL_GPL(bio_clone_blkcg_association);
|
|
#endif /* CONFIG_BLK_CGROUP */
|
|
|
|
static void __init biovec_init_slabs(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < BVEC_POOL_NR; 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 = kcalloc(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();
|
|
|
|
if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS))
|
|
panic("bio: can't allocate bios\n");
|
|
|
|
if (bioset_integrity_create(&fs_bio_set, BIO_POOL_SIZE))
|
|
panic("bio: can't create integrity pool\n");
|
|
|
|
return 0;
|
|
}
|
|
subsys_initcall(init_bio);
|