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![Jens Axboe](/assets/img/avatar_default.png)
Since commit 63a4cc2486
, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.
No intended functional changes in this commit.
Signed-off-by: Jens Axboe <axboe@fb.com>
2750 lines
62 KiB
C
2750 lines
62 KiB
C
/*
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* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
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* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the GPL.
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*/
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#include "dm-core.h"
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#include "dm-rq.h"
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#include "dm-uevent.h"
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/blkpg.h>
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#include <linux/bio.h>
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#include <linux/mempool.h>
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#include <linux/slab.h>
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#include <linux/idr.h>
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#include <linux/hdreg.h>
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#include <linux/delay.h>
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#include <linux/wait.h>
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#include <linux/pr.h>
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#define DM_MSG_PREFIX "core"
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#ifdef CONFIG_PRINTK
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/*
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* ratelimit state to be used in DMXXX_LIMIT().
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*/
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DEFINE_RATELIMIT_STATE(dm_ratelimit_state,
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DEFAULT_RATELIMIT_INTERVAL,
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DEFAULT_RATELIMIT_BURST);
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EXPORT_SYMBOL(dm_ratelimit_state);
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#endif
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/*
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* Cookies are numeric values sent with CHANGE and REMOVE
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* uevents while resuming, removing or renaming the device.
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*/
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#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
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#define DM_COOKIE_LENGTH 24
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static const char *_name = DM_NAME;
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static unsigned int major = 0;
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static unsigned int _major = 0;
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static DEFINE_IDR(_minor_idr);
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static DEFINE_SPINLOCK(_minor_lock);
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static void do_deferred_remove(struct work_struct *w);
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static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
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static struct workqueue_struct *deferred_remove_workqueue;
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/*
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* One of these is allocated per bio.
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*/
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struct dm_io {
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struct mapped_device *md;
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int error;
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atomic_t io_count;
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struct bio *bio;
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unsigned long start_time;
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spinlock_t endio_lock;
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struct dm_stats_aux stats_aux;
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};
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#define MINOR_ALLOCED ((void *)-1)
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/*
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* Bits for the md->flags field.
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*/
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#define DMF_BLOCK_IO_FOR_SUSPEND 0
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#define DMF_SUSPENDED 1
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#define DMF_FROZEN 2
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#define DMF_FREEING 3
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#define DMF_DELETING 4
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#define DMF_NOFLUSH_SUSPENDING 5
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#define DMF_DEFERRED_REMOVE 6
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#define DMF_SUSPENDED_INTERNALLY 7
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#define DM_NUMA_NODE NUMA_NO_NODE
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static int dm_numa_node = DM_NUMA_NODE;
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/*
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* For mempools pre-allocation at the table loading time.
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*/
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struct dm_md_mempools {
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mempool_t *io_pool;
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mempool_t *rq_pool;
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struct bio_set *bs;
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};
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struct table_device {
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struct list_head list;
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atomic_t count;
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struct dm_dev dm_dev;
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};
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static struct kmem_cache *_io_cache;
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static struct kmem_cache *_rq_tio_cache;
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static struct kmem_cache *_rq_cache;
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/*
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* Bio-based DM's mempools' reserved IOs set by the user.
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*/
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#define RESERVED_BIO_BASED_IOS 16
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static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
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static int __dm_get_module_param_int(int *module_param, int min, int max)
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{
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int param = ACCESS_ONCE(*module_param);
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int modified_param = 0;
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bool modified = true;
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if (param < min)
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modified_param = min;
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else if (param > max)
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modified_param = max;
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else
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modified = false;
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if (modified) {
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(void)cmpxchg(module_param, param, modified_param);
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param = modified_param;
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}
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return param;
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}
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unsigned __dm_get_module_param(unsigned *module_param,
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unsigned def, unsigned max)
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{
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unsigned param = ACCESS_ONCE(*module_param);
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unsigned modified_param = 0;
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if (!param)
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modified_param = def;
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else if (param > max)
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modified_param = max;
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if (modified_param) {
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(void)cmpxchg(module_param, param, modified_param);
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param = modified_param;
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}
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return param;
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}
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unsigned dm_get_reserved_bio_based_ios(void)
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{
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return __dm_get_module_param(&reserved_bio_based_ios,
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RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
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}
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EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
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static unsigned dm_get_numa_node(void)
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{
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return __dm_get_module_param_int(&dm_numa_node,
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DM_NUMA_NODE, num_online_nodes() - 1);
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}
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static int __init local_init(void)
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{
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int r = -ENOMEM;
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/* allocate a slab for the dm_ios */
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_io_cache = KMEM_CACHE(dm_io, 0);
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if (!_io_cache)
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return r;
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_rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
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if (!_rq_tio_cache)
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goto out_free_io_cache;
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_rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
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__alignof__(struct request), 0, NULL);
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if (!_rq_cache)
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goto out_free_rq_tio_cache;
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r = dm_uevent_init();
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if (r)
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goto out_free_rq_cache;
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deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
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if (!deferred_remove_workqueue) {
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r = -ENOMEM;
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goto out_uevent_exit;
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}
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_major = major;
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r = register_blkdev(_major, _name);
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if (r < 0)
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goto out_free_workqueue;
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if (!_major)
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_major = r;
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return 0;
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out_free_workqueue:
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destroy_workqueue(deferred_remove_workqueue);
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out_uevent_exit:
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dm_uevent_exit();
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out_free_rq_cache:
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kmem_cache_destroy(_rq_cache);
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out_free_rq_tio_cache:
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kmem_cache_destroy(_rq_tio_cache);
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out_free_io_cache:
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kmem_cache_destroy(_io_cache);
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return r;
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}
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static void local_exit(void)
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{
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flush_scheduled_work();
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destroy_workqueue(deferred_remove_workqueue);
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kmem_cache_destroy(_rq_cache);
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kmem_cache_destroy(_rq_tio_cache);
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kmem_cache_destroy(_io_cache);
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unregister_blkdev(_major, _name);
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dm_uevent_exit();
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_major = 0;
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DMINFO("cleaned up");
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}
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static int (*_inits[])(void) __initdata = {
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local_init,
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dm_target_init,
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dm_linear_init,
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dm_stripe_init,
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dm_io_init,
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dm_kcopyd_init,
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dm_interface_init,
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dm_statistics_init,
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};
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static void (*_exits[])(void) = {
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local_exit,
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dm_target_exit,
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dm_linear_exit,
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dm_stripe_exit,
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dm_io_exit,
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dm_kcopyd_exit,
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dm_interface_exit,
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dm_statistics_exit,
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};
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static int __init dm_init(void)
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{
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const int count = ARRAY_SIZE(_inits);
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int r, i;
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for (i = 0; i < count; i++) {
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r = _inits[i]();
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if (r)
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goto bad;
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}
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return 0;
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bad:
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while (i--)
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_exits[i]();
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return r;
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}
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static void __exit dm_exit(void)
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{
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int i = ARRAY_SIZE(_exits);
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while (i--)
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_exits[i]();
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/*
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* Should be empty by this point.
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*/
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idr_destroy(&_minor_idr);
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}
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/*
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* Block device functions
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*/
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int dm_deleting_md(struct mapped_device *md)
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{
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return test_bit(DMF_DELETING, &md->flags);
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}
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static int dm_blk_open(struct block_device *bdev, fmode_t mode)
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{
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struct mapped_device *md;
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spin_lock(&_minor_lock);
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md = bdev->bd_disk->private_data;
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if (!md)
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goto out;
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if (test_bit(DMF_FREEING, &md->flags) ||
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dm_deleting_md(md)) {
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md = NULL;
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goto out;
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}
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dm_get(md);
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atomic_inc(&md->open_count);
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out:
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spin_unlock(&_minor_lock);
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return md ? 0 : -ENXIO;
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}
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static void dm_blk_close(struct gendisk *disk, fmode_t mode)
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{
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struct mapped_device *md;
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spin_lock(&_minor_lock);
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md = disk->private_data;
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if (WARN_ON(!md))
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goto out;
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if (atomic_dec_and_test(&md->open_count) &&
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(test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
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queue_work(deferred_remove_workqueue, &deferred_remove_work);
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dm_put(md);
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out:
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spin_unlock(&_minor_lock);
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}
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int dm_open_count(struct mapped_device *md)
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{
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return atomic_read(&md->open_count);
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}
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/*
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* Guarantees nothing is using the device before it's deleted.
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*/
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int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
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{
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int r = 0;
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spin_lock(&_minor_lock);
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if (dm_open_count(md)) {
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r = -EBUSY;
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if (mark_deferred)
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set_bit(DMF_DEFERRED_REMOVE, &md->flags);
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} else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
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r = -EEXIST;
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else
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set_bit(DMF_DELETING, &md->flags);
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spin_unlock(&_minor_lock);
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return r;
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}
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int dm_cancel_deferred_remove(struct mapped_device *md)
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{
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int r = 0;
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spin_lock(&_minor_lock);
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if (test_bit(DMF_DELETING, &md->flags))
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r = -EBUSY;
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else
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clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
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spin_unlock(&_minor_lock);
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return r;
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}
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static void do_deferred_remove(struct work_struct *w)
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{
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dm_deferred_remove();
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}
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sector_t dm_get_size(struct mapped_device *md)
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{
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return get_capacity(md->disk);
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}
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struct request_queue *dm_get_md_queue(struct mapped_device *md)
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{
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return md->queue;
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}
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struct dm_stats *dm_get_stats(struct mapped_device *md)
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{
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return &md->stats;
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}
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static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
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{
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struct mapped_device *md = bdev->bd_disk->private_data;
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return dm_get_geometry(md, geo);
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}
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static int dm_grab_bdev_for_ioctl(struct mapped_device *md,
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struct block_device **bdev,
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fmode_t *mode)
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{
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struct dm_target *tgt;
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struct dm_table *map;
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int srcu_idx, r;
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retry:
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r = -ENOTTY;
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map = dm_get_live_table(md, &srcu_idx);
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if (!map || !dm_table_get_size(map))
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goto out;
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/* We only support devices that have a single target */
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if (dm_table_get_num_targets(map) != 1)
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goto out;
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tgt = dm_table_get_target(map, 0);
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if (!tgt->type->prepare_ioctl)
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goto out;
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if (dm_suspended_md(md)) {
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r = -EAGAIN;
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goto out;
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}
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r = tgt->type->prepare_ioctl(tgt, bdev, mode);
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if (r < 0)
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goto out;
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bdgrab(*bdev);
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dm_put_live_table(md, srcu_idx);
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return r;
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|
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out:
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dm_put_live_table(md, srcu_idx);
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if (r == -ENOTCONN && !fatal_signal_pending(current)) {
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msleep(10);
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goto retry;
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}
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return r;
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}
|
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|
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static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
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unsigned int cmd, unsigned long arg)
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{
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struct mapped_device *md = bdev->bd_disk->private_data;
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int r;
|
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r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
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if (r < 0)
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return r;
|
|
|
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if (r > 0) {
|
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/*
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* Target determined this ioctl is being issued against
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* a logical partition of the parent bdev; so extra
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* validation is needed.
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*/
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r = scsi_verify_blk_ioctl(NULL, cmd);
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if (r)
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goto out;
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}
|
|
|
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r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
|
|
out:
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bdput(bdev);
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return r;
|
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}
|
|
|
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static struct dm_io *alloc_io(struct mapped_device *md)
|
|
{
|
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return mempool_alloc(md->io_pool, GFP_NOIO);
|
|
}
|
|
|
|
static void free_io(struct mapped_device *md, struct dm_io *io)
|
|
{
|
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mempool_free(io, md->io_pool);
|
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}
|
|
|
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static void free_tio(struct dm_target_io *tio)
|
|
{
|
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bio_put(&tio->clone);
|
|
}
|
|
|
|
int md_in_flight(struct mapped_device *md)
|
|
{
|
|
return atomic_read(&md->pending[READ]) +
|
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atomic_read(&md->pending[WRITE]);
|
|
}
|
|
|
|
static void start_io_acct(struct dm_io *io)
|
|
{
|
|
struct mapped_device *md = io->md;
|
|
struct bio *bio = io->bio;
|
|
int cpu;
|
|
int rw = bio_data_dir(bio);
|
|
|
|
io->start_time = jiffies;
|
|
|
|
cpu = part_stat_lock();
|
|
part_round_stats(cpu, &dm_disk(md)->part0);
|
|
part_stat_unlock();
|
|
atomic_set(&dm_disk(md)->part0.in_flight[rw],
|
|
atomic_inc_return(&md->pending[rw]));
|
|
|
|
if (unlikely(dm_stats_used(&md->stats)))
|
|
dm_stats_account_io(&md->stats, bio_data_dir(bio),
|
|
bio->bi_iter.bi_sector, bio_sectors(bio),
|
|
false, 0, &io->stats_aux);
|
|
}
|
|
|
|
static void end_io_acct(struct dm_io *io)
|
|
{
|
|
struct mapped_device *md = io->md;
|
|
struct bio *bio = io->bio;
|
|
unsigned long duration = jiffies - io->start_time;
|
|
int pending;
|
|
int rw = bio_data_dir(bio);
|
|
|
|
generic_end_io_acct(rw, &dm_disk(md)->part0, io->start_time);
|
|
|
|
if (unlikely(dm_stats_used(&md->stats)))
|
|
dm_stats_account_io(&md->stats, bio_data_dir(bio),
|
|
bio->bi_iter.bi_sector, bio_sectors(bio),
|
|
true, duration, &io->stats_aux);
|
|
|
|
/*
|
|
* After this is decremented the bio must not be touched if it is
|
|
* a flush.
|
|
*/
|
|
pending = atomic_dec_return(&md->pending[rw]);
|
|
atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
|
|
pending += atomic_read(&md->pending[rw^0x1]);
|
|
|
|
/* nudge anyone waiting on suspend queue */
|
|
if (!pending)
|
|
wake_up(&md->wait);
|
|
}
|
|
|
|
/*
|
|
* Add the bio to the list of deferred io.
|
|
*/
|
|
static void queue_io(struct mapped_device *md, struct bio *bio)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&md->deferred_lock, flags);
|
|
bio_list_add(&md->deferred, bio);
|
|
spin_unlock_irqrestore(&md->deferred_lock, flags);
|
|
queue_work(md->wq, &md->work);
|
|
}
|
|
|
|
/*
|
|
* Everyone (including functions in this file), should use this
|
|
* function to access the md->map field, and make sure they call
|
|
* dm_put_live_table() when finished.
|
|
*/
|
|
struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
|
|
{
|
|
*srcu_idx = srcu_read_lock(&md->io_barrier);
|
|
|
|
return srcu_dereference(md->map, &md->io_barrier);
|
|
}
|
|
|
|
void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
|
|
{
|
|
srcu_read_unlock(&md->io_barrier, srcu_idx);
|
|
}
|
|
|
|
void dm_sync_table(struct mapped_device *md)
|
|
{
|
|
synchronize_srcu(&md->io_barrier);
|
|
synchronize_rcu_expedited();
|
|
}
|
|
|
|
/*
|
|
* A fast alternative to dm_get_live_table/dm_put_live_table.
|
|
* The caller must not block between these two functions.
|
|
*/
|
|
static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
|
|
{
|
|
rcu_read_lock();
|
|
return rcu_dereference(md->map);
|
|
}
|
|
|
|
static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
|
|
{
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/*
|
|
* Open a table device so we can use it as a map destination.
|
|
*/
|
|
static int open_table_device(struct table_device *td, dev_t dev,
|
|
struct mapped_device *md)
|
|
{
|
|
static char *_claim_ptr = "I belong to device-mapper";
|
|
struct block_device *bdev;
|
|
|
|
int r;
|
|
|
|
BUG_ON(td->dm_dev.bdev);
|
|
|
|
bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr);
|
|
if (IS_ERR(bdev))
|
|
return PTR_ERR(bdev);
|
|
|
|
r = bd_link_disk_holder(bdev, dm_disk(md));
|
|
if (r) {
|
|
blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
|
|
return r;
|
|
}
|
|
|
|
td->dm_dev.bdev = bdev;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Close a table device that we've been using.
|
|
*/
|
|
static void close_table_device(struct table_device *td, struct mapped_device *md)
|
|
{
|
|
if (!td->dm_dev.bdev)
|
|
return;
|
|
|
|
bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
|
|
blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
|
|
td->dm_dev.bdev = NULL;
|
|
}
|
|
|
|
static struct table_device *find_table_device(struct list_head *l, dev_t dev,
|
|
fmode_t mode) {
|
|
struct table_device *td;
|
|
|
|
list_for_each_entry(td, l, list)
|
|
if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
|
|
return td;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
|
|
struct dm_dev **result) {
|
|
int r;
|
|
struct table_device *td;
|
|
|
|
mutex_lock(&md->table_devices_lock);
|
|
td = find_table_device(&md->table_devices, dev, mode);
|
|
if (!td) {
|
|
td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
|
|
if (!td) {
|
|
mutex_unlock(&md->table_devices_lock);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
td->dm_dev.mode = mode;
|
|
td->dm_dev.bdev = NULL;
|
|
|
|
if ((r = open_table_device(td, dev, md))) {
|
|
mutex_unlock(&md->table_devices_lock);
|
|
kfree(td);
|
|
return r;
|
|
}
|
|
|
|
format_dev_t(td->dm_dev.name, dev);
|
|
|
|
atomic_set(&td->count, 0);
|
|
list_add(&td->list, &md->table_devices);
|
|
}
|
|
atomic_inc(&td->count);
|
|
mutex_unlock(&md->table_devices_lock);
|
|
|
|
*result = &td->dm_dev;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_table_device);
|
|
|
|
void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
|
|
{
|
|
struct table_device *td = container_of(d, struct table_device, dm_dev);
|
|
|
|
mutex_lock(&md->table_devices_lock);
|
|
if (atomic_dec_and_test(&td->count)) {
|
|
close_table_device(td, md);
|
|
list_del(&td->list);
|
|
kfree(td);
|
|
}
|
|
mutex_unlock(&md->table_devices_lock);
|
|
}
|
|
EXPORT_SYMBOL(dm_put_table_device);
|
|
|
|
static void free_table_devices(struct list_head *devices)
|
|
{
|
|
struct list_head *tmp, *next;
|
|
|
|
list_for_each_safe(tmp, next, devices) {
|
|
struct table_device *td = list_entry(tmp, struct table_device, list);
|
|
|
|
DMWARN("dm_destroy: %s still exists with %d references",
|
|
td->dm_dev.name, atomic_read(&td->count));
|
|
kfree(td);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get the geometry associated with a dm device
|
|
*/
|
|
int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
|
|
{
|
|
*geo = md->geometry;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set the geometry of a device.
|
|
*/
|
|
int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
|
|
{
|
|
sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
|
|
|
|
if (geo->start > sz) {
|
|
DMWARN("Start sector is beyond the geometry limits.");
|
|
return -EINVAL;
|
|
}
|
|
|
|
md->geometry = *geo;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*-----------------------------------------------------------------
|
|
* CRUD START:
|
|
* A more elegant soln is in the works that uses the queue
|
|
* merge fn, unfortunately there are a couple of changes to
|
|
* the block layer that I want to make for this. So in the
|
|
* interests of getting something for people to use I give
|
|
* you this clearly demarcated crap.
|
|
*---------------------------------------------------------------*/
|
|
|
|
static int __noflush_suspending(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
}
|
|
|
|
/*
|
|
* Decrements the number of outstanding ios that a bio has been
|
|
* cloned into, completing the original io if necc.
|
|
*/
|
|
static void dec_pending(struct dm_io *io, int error)
|
|
{
|
|
unsigned long flags;
|
|
int io_error;
|
|
struct bio *bio;
|
|
struct mapped_device *md = io->md;
|
|
|
|
/* Push-back supersedes any I/O errors */
|
|
if (unlikely(error)) {
|
|
spin_lock_irqsave(&io->endio_lock, flags);
|
|
if (!(io->error > 0 && __noflush_suspending(md)))
|
|
io->error = error;
|
|
spin_unlock_irqrestore(&io->endio_lock, flags);
|
|
}
|
|
|
|
if (atomic_dec_and_test(&io->io_count)) {
|
|
if (io->error == DM_ENDIO_REQUEUE) {
|
|
/*
|
|
* Target requested pushing back the I/O.
|
|
*/
|
|
spin_lock_irqsave(&md->deferred_lock, flags);
|
|
if (__noflush_suspending(md))
|
|
bio_list_add_head(&md->deferred, io->bio);
|
|
else
|
|
/* noflush suspend was interrupted. */
|
|
io->error = -EIO;
|
|
spin_unlock_irqrestore(&md->deferred_lock, flags);
|
|
}
|
|
|
|
io_error = io->error;
|
|
bio = io->bio;
|
|
end_io_acct(io);
|
|
free_io(md, io);
|
|
|
|
if (io_error == DM_ENDIO_REQUEUE)
|
|
return;
|
|
|
|
if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) {
|
|
/*
|
|
* Preflush done for flush with data, reissue
|
|
* without REQ_PREFLUSH.
|
|
*/
|
|
bio->bi_opf &= ~REQ_PREFLUSH;
|
|
queue_io(md, bio);
|
|
} else {
|
|
/* done with normal IO or empty flush */
|
|
trace_block_bio_complete(md->queue, bio, io_error);
|
|
bio->bi_error = io_error;
|
|
bio_endio(bio);
|
|
}
|
|
}
|
|
}
|
|
|
|
void disable_write_same(struct mapped_device *md)
|
|
{
|
|
struct queue_limits *limits = dm_get_queue_limits(md);
|
|
|
|
/* device doesn't really support WRITE SAME, disable it */
|
|
limits->max_write_same_sectors = 0;
|
|
}
|
|
|
|
static void clone_endio(struct bio *bio)
|
|
{
|
|
int error = bio->bi_error;
|
|
int r = error;
|
|
struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
|
|
struct dm_io *io = tio->io;
|
|
struct mapped_device *md = tio->io->md;
|
|
dm_endio_fn endio = tio->ti->type->end_io;
|
|
|
|
if (endio) {
|
|
r = endio(tio->ti, bio, error);
|
|
if (r < 0 || r == DM_ENDIO_REQUEUE)
|
|
/*
|
|
* error and requeue request are handled
|
|
* in dec_pending().
|
|
*/
|
|
error = r;
|
|
else if (r == DM_ENDIO_INCOMPLETE)
|
|
/* The target will handle the io */
|
|
return;
|
|
else if (r) {
|
|
DMWARN("unimplemented target endio return value: %d", r);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
if (unlikely(r == -EREMOTEIO && (bio_op(bio) == REQ_OP_WRITE_SAME) &&
|
|
!bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors))
|
|
disable_write_same(md);
|
|
|
|
free_tio(tio);
|
|
dec_pending(io, error);
|
|
}
|
|
|
|
/*
|
|
* Return maximum size of I/O possible at the supplied sector up to the current
|
|
* target boundary.
|
|
*/
|
|
static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
|
|
{
|
|
sector_t target_offset = dm_target_offset(ti, sector);
|
|
|
|
return ti->len - target_offset;
|
|
}
|
|
|
|
static sector_t max_io_len(sector_t sector, struct dm_target *ti)
|
|
{
|
|
sector_t len = max_io_len_target_boundary(sector, ti);
|
|
sector_t offset, max_len;
|
|
|
|
/*
|
|
* Does the target need to split even further?
|
|
*/
|
|
if (ti->max_io_len) {
|
|
offset = dm_target_offset(ti, sector);
|
|
if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
|
|
max_len = sector_div(offset, ti->max_io_len);
|
|
else
|
|
max_len = offset & (ti->max_io_len - 1);
|
|
max_len = ti->max_io_len - max_len;
|
|
|
|
if (len > max_len)
|
|
len = max_len;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
|
|
{
|
|
if (len > UINT_MAX) {
|
|
DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
|
|
(unsigned long long)len, UINT_MAX);
|
|
ti->error = "Maximum size of target IO is too large";
|
|
return -EINVAL;
|
|
}
|
|
|
|
ti->max_io_len = (uint32_t) len;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
|
|
|
|
static long dm_blk_direct_access(struct block_device *bdev, sector_t sector,
|
|
void **kaddr, pfn_t *pfn, long size)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
struct dm_table *map;
|
|
struct dm_target *ti;
|
|
int srcu_idx;
|
|
long len, ret = -EIO;
|
|
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
if (!map)
|
|
goto out;
|
|
|
|
ti = dm_table_find_target(map, sector);
|
|
if (!dm_target_is_valid(ti))
|
|
goto out;
|
|
|
|
len = max_io_len(sector, ti) << SECTOR_SHIFT;
|
|
size = min(len, size);
|
|
|
|
if (ti->type->direct_access)
|
|
ret = ti->type->direct_access(ti, sector, kaddr, pfn, size);
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
return min(ret, size);
|
|
}
|
|
|
|
/*
|
|
* A target may call dm_accept_partial_bio only from the map routine. It is
|
|
* allowed for all bio types except REQ_PREFLUSH.
|
|
*
|
|
* dm_accept_partial_bio informs the dm that the target only wants to process
|
|
* additional n_sectors sectors of the bio and the rest of the data should be
|
|
* sent in a next bio.
|
|
*
|
|
* A diagram that explains the arithmetics:
|
|
* +--------------------+---------------+-------+
|
|
* | 1 | 2 | 3 |
|
|
* +--------------------+---------------+-------+
|
|
*
|
|
* <-------------- *tio->len_ptr --------------->
|
|
* <------- bi_size ------->
|
|
* <-- n_sectors -->
|
|
*
|
|
* Region 1 was already iterated over with bio_advance or similar function.
|
|
* (it may be empty if the target doesn't use bio_advance)
|
|
* Region 2 is the remaining bio size that the target wants to process.
|
|
* (it may be empty if region 1 is non-empty, although there is no reason
|
|
* to make it empty)
|
|
* The target requires that region 3 is to be sent in the next bio.
|
|
*
|
|
* If the target wants to receive multiple copies of the bio (via num_*bios, etc),
|
|
* the partially processed part (the sum of regions 1+2) must be the same for all
|
|
* copies of the bio.
|
|
*/
|
|
void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
|
|
{
|
|
struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
|
|
unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
|
|
BUG_ON(bio->bi_opf & REQ_PREFLUSH);
|
|
BUG_ON(bi_size > *tio->len_ptr);
|
|
BUG_ON(n_sectors > bi_size);
|
|
*tio->len_ptr -= bi_size - n_sectors;
|
|
bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
|
|
|
|
static void __map_bio(struct dm_target_io *tio)
|
|
{
|
|
int r;
|
|
sector_t sector;
|
|
struct bio *clone = &tio->clone;
|
|
struct dm_target *ti = tio->ti;
|
|
|
|
clone->bi_end_io = clone_endio;
|
|
|
|
/*
|
|
* Map the clone. If r == 0 we don't need to do
|
|
* anything, the target has assumed ownership of
|
|
* this io.
|
|
*/
|
|
atomic_inc(&tio->io->io_count);
|
|
sector = clone->bi_iter.bi_sector;
|
|
r = ti->type->map(ti, clone);
|
|
if (r == DM_MAPIO_REMAPPED) {
|
|
/* the bio has been remapped so dispatch it */
|
|
|
|
trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone,
|
|
tio->io->bio->bi_bdev->bd_dev, sector);
|
|
|
|
generic_make_request(clone);
|
|
} else if (r < 0 || r == DM_MAPIO_REQUEUE) {
|
|
/* error the io and bail out, or requeue it if needed */
|
|
dec_pending(tio->io, r);
|
|
free_tio(tio);
|
|
} else if (r != DM_MAPIO_SUBMITTED) {
|
|
DMWARN("unimplemented target map return value: %d", r);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
struct clone_info {
|
|
struct mapped_device *md;
|
|
struct dm_table *map;
|
|
struct bio *bio;
|
|
struct dm_io *io;
|
|
sector_t sector;
|
|
unsigned sector_count;
|
|
};
|
|
|
|
static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
|
|
{
|
|
bio->bi_iter.bi_sector = sector;
|
|
bio->bi_iter.bi_size = to_bytes(len);
|
|
}
|
|
|
|
/*
|
|
* Creates a bio that consists of range of complete bvecs.
|
|
*/
|
|
static int clone_bio(struct dm_target_io *tio, struct bio *bio,
|
|
sector_t sector, unsigned len)
|
|
{
|
|
struct bio *clone = &tio->clone;
|
|
|
|
__bio_clone_fast(clone, bio);
|
|
|
|
if (bio_integrity(bio)) {
|
|
int r = bio_integrity_clone(clone, bio, GFP_NOIO);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
|
|
clone->bi_iter.bi_size = to_bytes(len);
|
|
|
|
if (bio_integrity(bio))
|
|
bio_integrity_trim(clone, 0, len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct dm_target_io *alloc_tio(struct clone_info *ci,
|
|
struct dm_target *ti,
|
|
unsigned target_bio_nr)
|
|
{
|
|
struct dm_target_io *tio;
|
|
struct bio *clone;
|
|
|
|
clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
|
|
tio = container_of(clone, struct dm_target_io, clone);
|
|
|
|
tio->io = ci->io;
|
|
tio->ti = ti;
|
|
tio->target_bio_nr = target_bio_nr;
|
|
|
|
return tio;
|
|
}
|
|
|
|
static void __clone_and_map_simple_bio(struct clone_info *ci,
|
|
struct dm_target *ti,
|
|
unsigned target_bio_nr, unsigned *len)
|
|
{
|
|
struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr);
|
|
struct bio *clone = &tio->clone;
|
|
|
|
tio->len_ptr = len;
|
|
|
|
__bio_clone_fast(clone, ci->bio);
|
|
if (len)
|
|
bio_setup_sector(clone, ci->sector, *len);
|
|
|
|
__map_bio(tio);
|
|
}
|
|
|
|
static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
|
|
unsigned num_bios, unsigned *len)
|
|
{
|
|
unsigned target_bio_nr;
|
|
|
|
for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
|
|
__clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
|
|
}
|
|
|
|
static int __send_empty_flush(struct clone_info *ci)
|
|
{
|
|
unsigned target_nr = 0;
|
|
struct dm_target *ti;
|
|
|
|
BUG_ON(bio_has_data(ci->bio));
|
|
while ((ti = dm_table_get_target(ci->map, target_nr++)))
|
|
__send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
|
|
sector_t sector, unsigned *len)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
struct dm_target_io *tio;
|
|
unsigned target_bio_nr;
|
|
unsigned num_target_bios = 1;
|
|
int r = 0;
|
|
|
|
/*
|
|
* Does the target want to receive duplicate copies of the bio?
|
|
*/
|
|
if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
|
|
num_target_bios = ti->num_write_bios(ti, bio);
|
|
|
|
for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
|
|
tio = alloc_tio(ci, ti, target_bio_nr);
|
|
tio->len_ptr = len;
|
|
r = clone_bio(tio, bio, sector, *len);
|
|
if (r < 0) {
|
|
free_tio(tio);
|
|
break;
|
|
}
|
|
__map_bio(tio);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
|
|
|
|
static unsigned get_num_discard_bios(struct dm_target *ti)
|
|
{
|
|
return ti->num_discard_bios;
|
|
}
|
|
|
|
static unsigned get_num_write_same_bios(struct dm_target *ti)
|
|
{
|
|
return ti->num_write_same_bios;
|
|
}
|
|
|
|
typedef bool (*is_split_required_fn)(struct dm_target *ti);
|
|
|
|
static bool is_split_required_for_discard(struct dm_target *ti)
|
|
{
|
|
return ti->split_discard_bios;
|
|
}
|
|
|
|
static int __send_changing_extent_only(struct clone_info *ci,
|
|
get_num_bios_fn get_num_bios,
|
|
is_split_required_fn is_split_required)
|
|
{
|
|
struct dm_target *ti;
|
|
unsigned len;
|
|
unsigned num_bios;
|
|
|
|
do {
|
|
ti = dm_table_find_target(ci->map, ci->sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return -EIO;
|
|
|
|
/*
|
|
* Even though the device advertised support for this type of
|
|
* request, that does not mean every target supports it, and
|
|
* reconfiguration might also have changed that since the
|
|
* check was performed.
|
|
*/
|
|
num_bios = get_num_bios ? get_num_bios(ti) : 0;
|
|
if (!num_bios)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (is_split_required && !is_split_required(ti))
|
|
len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
|
|
else
|
|
len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
|
|
|
|
__send_duplicate_bios(ci, ti, num_bios, &len);
|
|
|
|
ci->sector += len;
|
|
} while (ci->sector_count -= len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __send_discard(struct clone_info *ci)
|
|
{
|
|
return __send_changing_extent_only(ci, get_num_discard_bios,
|
|
is_split_required_for_discard);
|
|
}
|
|
|
|
static int __send_write_same(struct clone_info *ci)
|
|
{
|
|
return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
|
|
}
|
|
|
|
/*
|
|
* Select the correct strategy for processing a non-flush bio.
|
|
*/
|
|
static int __split_and_process_non_flush(struct clone_info *ci)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
struct dm_target *ti;
|
|
unsigned len;
|
|
int r;
|
|
|
|
if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
|
|
return __send_discard(ci);
|
|
else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
|
|
return __send_write_same(ci);
|
|
|
|
ti = dm_table_find_target(ci->map, ci->sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return -EIO;
|
|
|
|
len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
|
|
|
|
r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ci->sector += len;
|
|
ci->sector_count -= len;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Entry point to split a bio into clones and submit them to the targets.
|
|
*/
|
|
static void __split_and_process_bio(struct mapped_device *md,
|
|
struct dm_table *map, struct bio *bio)
|
|
{
|
|
struct clone_info ci;
|
|
int error = 0;
|
|
|
|
if (unlikely(!map)) {
|
|
bio_io_error(bio);
|
|
return;
|
|
}
|
|
|
|
ci.map = map;
|
|
ci.md = md;
|
|
ci.io = alloc_io(md);
|
|
ci.io->error = 0;
|
|
atomic_set(&ci.io->io_count, 1);
|
|
ci.io->bio = bio;
|
|
ci.io->md = md;
|
|
spin_lock_init(&ci.io->endio_lock);
|
|
ci.sector = bio->bi_iter.bi_sector;
|
|
|
|
start_io_acct(ci.io);
|
|
|
|
if (bio->bi_opf & REQ_PREFLUSH) {
|
|
ci.bio = &ci.md->flush_bio;
|
|
ci.sector_count = 0;
|
|
error = __send_empty_flush(&ci);
|
|
/* dec_pending submits any data associated with flush */
|
|
} else {
|
|
ci.bio = bio;
|
|
ci.sector_count = bio_sectors(bio);
|
|
while (ci.sector_count && !error)
|
|
error = __split_and_process_non_flush(&ci);
|
|
}
|
|
|
|
/* drop the extra reference count */
|
|
dec_pending(ci.io, error);
|
|
}
|
|
/*-----------------------------------------------------------------
|
|
* CRUD END
|
|
*---------------------------------------------------------------*/
|
|
|
|
/*
|
|
* The request function that just remaps the bio built up by
|
|
* dm_merge_bvec.
|
|
*/
|
|
static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
int rw = bio_data_dir(bio);
|
|
struct mapped_device *md = q->queuedata;
|
|
int srcu_idx;
|
|
struct dm_table *map;
|
|
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
|
|
generic_start_io_acct(rw, bio_sectors(bio), &dm_disk(md)->part0);
|
|
|
|
/* if we're suspended, we have to queue this io for later */
|
|
if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
|
|
dm_put_live_table(md, srcu_idx);
|
|
|
|
if (!(bio->bi_opf & REQ_RAHEAD))
|
|
queue_io(md, bio);
|
|
else
|
|
bio_io_error(bio);
|
|
return BLK_QC_T_NONE;
|
|
}
|
|
|
|
__split_and_process_bio(md, map, bio);
|
|
dm_put_live_table(md, srcu_idx);
|
|
return BLK_QC_T_NONE;
|
|
}
|
|
|
|
static int dm_any_congested(void *congested_data, int bdi_bits)
|
|
{
|
|
int r = bdi_bits;
|
|
struct mapped_device *md = congested_data;
|
|
struct dm_table *map;
|
|
|
|
if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
|
|
if (dm_request_based(md)) {
|
|
/*
|
|
* With request-based DM we only need to check the
|
|
* top-level queue for congestion.
|
|
*/
|
|
r = md->queue->backing_dev_info.wb.state & bdi_bits;
|
|
} else {
|
|
map = dm_get_live_table_fast(md);
|
|
if (map)
|
|
r = dm_table_any_congested(map, bdi_bits);
|
|
dm_put_live_table_fast(md);
|
|
}
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
/*-----------------------------------------------------------------
|
|
* An IDR is used to keep track of allocated minor numbers.
|
|
*---------------------------------------------------------------*/
|
|
static void free_minor(int minor)
|
|
{
|
|
spin_lock(&_minor_lock);
|
|
idr_remove(&_minor_idr, minor);
|
|
spin_unlock(&_minor_lock);
|
|
}
|
|
|
|
/*
|
|
* See if the device with a specific minor # is free.
|
|
*/
|
|
static int specific_minor(int minor)
|
|
{
|
|
int r;
|
|
|
|
if (minor >= (1 << MINORBITS))
|
|
return -EINVAL;
|
|
|
|
idr_preload(GFP_KERNEL);
|
|
spin_lock(&_minor_lock);
|
|
|
|
r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
idr_preload_end();
|
|
if (r < 0)
|
|
return r == -ENOSPC ? -EBUSY : r;
|
|
return 0;
|
|
}
|
|
|
|
static int next_free_minor(int *minor)
|
|
{
|
|
int r;
|
|
|
|
idr_preload(GFP_KERNEL);
|
|
spin_lock(&_minor_lock);
|
|
|
|
r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
idr_preload_end();
|
|
if (r < 0)
|
|
return r;
|
|
*minor = r;
|
|
return 0;
|
|
}
|
|
|
|
static const struct block_device_operations dm_blk_dops;
|
|
|
|
static void dm_wq_work(struct work_struct *work);
|
|
|
|
void dm_init_md_queue(struct mapped_device *md)
|
|
{
|
|
/*
|
|
* Request-based dm devices cannot be stacked on top of bio-based dm
|
|
* devices. The type of this dm device may not have been decided yet.
|
|
* The type is decided at the first table loading time.
|
|
* To prevent problematic device stacking, clear the queue flag
|
|
* for request stacking support until then.
|
|
*
|
|
* This queue is new, so no concurrency on the queue_flags.
|
|
*/
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
|
|
|
|
/*
|
|
* Initialize data that will only be used by a non-blk-mq DM queue
|
|
* - must do so here (in alloc_dev callchain) before queue is used
|
|
*/
|
|
md->queue->queuedata = md;
|
|
md->queue->backing_dev_info.congested_data = md;
|
|
}
|
|
|
|
void dm_init_normal_md_queue(struct mapped_device *md)
|
|
{
|
|
md->use_blk_mq = false;
|
|
dm_init_md_queue(md);
|
|
|
|
/*
|
|
* Initialize aspects of queue that aren't relevant for blk-mq
|
|
*/
|
|
md->queue->backing_dev_info.congested_fn = dm_any_congested;
|
|
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
|
|
}
|
|
|
|
static void cleanup_mapped_device(struct mapped_device *md)
|
|
{
|
|
if (md->wq)
|
|
destroy_workqueue(md->wq);
|
|
if (md->kworker_task)
|
|
kthread_stop(md->kworker_task);
|
|
mempool_destroy(md->io_pool);
|
|
mempool_destroy(md->rq_pool);
|
|
if (md->bs)
|
|
bioset_free(md->bs);
|
|
|
|
cleanup_srcu_struct(&md->io_barrier);
|
|
|
|
if (md->disk) {
|
|
spin_lock(&_minor_lock);
|
|
md->disk->private_data = NULL;
|
|
spin_unlock(&_minor_lock);
|
|
del_gendisk(md->disk);
|
|
put_disk(md->disk);
|
|
}
|
|
|
|
if (md->queue)
|
|
blk_cleanup_queue(md->queue);
|
|
|
|
if (md->bdev) {
|
|
bdput(md->bdev);
|
|
md->bdev = NULL;
|
|
}
|
|
|
|
dm_mq_cleanup_mapped_device(md);
|
|
}
|
|
|
|
/*
|
|
* Allocate and initialise a blank device with a given minor.
|
|
*/
|
|
static struct mapped_device *alloc_dev(int minor)
|
|
{
|
|
int r, numa_node_id = dm_get_numa_node();
|
|
struct mapped_device *md;
|
|
void *old_md;
|
|
|
|
md = kzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
|
|
if (!md) {
|
|
DMWARN("unable to allocate device, out of memory.");
|
|
return NULL;
|
|
}
|
|
|
|
if (!try_module_get(THIS_MODULE))
|
|
goto bad_module_get;
|
|
|
|
/* get a minor number for the dev */
|
|
if (minor == DM_ANY_MINOR)
|
|
r = next_free_minor(&minor);
|
|
else
|
|
r = specific_minor(minor);
|
|
if (r < 0)
|
|
goto bad_minor;
|
|
|
|
r = init_srcu_struct(&md->io_barrier);
|
|
if (r < 0)
|
|
goto bad_io_barrier;
|
|
|
|
md->numa_node_id = numa_node_id;
|
|
md->use_blk_mq = dm_use_blk_mq_default();
|
|
md->init_tio_pdu = false;
|
|
md->type = DM_TYPE_NONE;
|
|
mutex_init(&md->suspend_lock);
|
|
mutex_init(&md->type_lock);
|
|
mutex_init(&md->table_devices_lock);
|
|
spin_lock_init(&md->deferred_lock);
|
|
atomic_set(&md->holders, 1);
|
|
atomic_set(&md->open_count, 0);
|
|
atomic_set(&md->event_nr, 0);
|
|
atomic_set(&md->uevent_seq, 0);
|
|
INIT_LIST_HEAD(&md->uevent_list);
|
|
INIT_LIST_HEAD(&md->table_devices);
|
|
spin_lock_init(&md->uevent_lock);
|
|
|
|
md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
|
|
if (!md->queue)
|
|
goto bad;
|
|
|
|
dm_init_md_queue(md);
|
|
|
|
md->disk = alloc_disk_node(1, numa_node_id);
|
|
if (!md->disk)
|
|
goto bad;
|
|
|
|
atomic_set(&md->pending[0], 0);
|
|
atomic_set(&md->pending[1], 0);
|
|
init_waitqueue_head(&md->wait);
|
|
INIT_WORK(&md->work, dm_wq_work);
|
|
init_waitqueue_head(&md->eventq);
|
|
init_completion(&md->kobj_holder.completion);
|
|
md->kworker_task = NULL;
|
|
|
|
md->disk->major = _major;
|
|
md->disk->first_minor = minor;
|
|
md->disk->fops = &dm_blk_dops;
|
|
md->disk->queue = md->queue;
|
|
md->disk->private_data = md;
|
|
sprintf(md->disk->disk_name, "dm-%d", minor);
|
|
add_disk(md->disk);
|
|
format_dev_t(md->name, MKDEV(_major, minor));
|
|
|
|
md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
|
|
if (!md->wq)
|
|
goto bad;
|
|
|
|
md->bdev = bdget_disk(md->disk, 0);
|
|
if (!md->bdev)
|
|
goto bad;
|
|
|
|
bio_init(&md->flush_bio);
|
|
md->flush_bio.bi_bdev = md->bdev;
|
|
bio_set_op_attrs(&md->flush_bio, REQ_OP_WRITE, WRITE_FLUSH);
|
|
|
|
dm_stats_init(&md->stats);
|
|
|
|
/* Populate the mapping, nobody knows we exist yet */
|
|
spin_lock(&_minor_lock);
|
|
old_md = idr_replace(&_minor_idr, md, minor);
|
|
spin_unlock(&_minor_lock);
|
|
|
|
BUG_ON(old_md != MINOR_ALLOCED);
|
|
|
|
return md;
|
|
|
|
bad:
|
|
cleanup_mapped_device(md);
|
|
bad_io_barrier:
|
|
free_minor(minor);
|
|
bad_minor:
|
|
module_put(THIS_MODULE);
|
|
bad_module_get:
|
|
kfree(md);
|
|
return NULL;
|
|
}
|
|
|
|
static void unlock_fs(struct mapped_device *md);
|
|
|
|
static void free_dev(struct mapped_device *md)
|
|
{
|
|
int minor = MINOR(disk_devt(md->disk));
|
|
|
|
unlock_fs(md);
|
|
|
|
cleanup_mapped_device(md);
|
|
|
|
free_table_devices(&md->table_devices);
|
|
dm_stats_cleanup(&md->stats);
|
|
free_minor(minor);
|
|
|
|
module_put(THIS_MODULE);
|
|
kfree(md);
|
|
}
|
|
|
|
static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
|
|
{
|
|
struct dm_md_mempools *p = dm_table_get_md_mempools(t);
|
|
|
|
if (md->bs) {
|
|
/* The md already has necessary mempools. */
|
|
if (dm_table_bio_based(t)) {
|
|
/*
|
|
* Reload bioset because front_pad may have changed
|
|
* because a different table was loaded.
|
|
*/
|
|
bioset_free(md->bs);
|
|
md->bs = p->bs;
|
|
p->bs = NULL;
|
|
}
|
|
/*
|
|
* There's no need to reload with request-based dm
|
|
* because the size of front_pad doesn't change.
|
|
* Note for future: If you are to reload bioset,
|
|
* prep-ed requests in the queue may refer
|
|
* to bio from the old bioset, so you must walk
|
|
* through the queue to unprep.
|
|
*/
|
|
goto out;
|
|
}
|
|
|
|
BUG_ON(!p || md->io_pool || md->rq_pool || md->bs);
|
|
|
|
md->io_pool = p->io_pool;
|
|
p->io_pool = NULL;
|
|
md->rq_pool = p->rq_pool;
|
|
p->rq_pool = NULL;
|
|
md->bs = p->bs;
|
|
p->bs = NULL;
|
|
|
|
out:
|
|
/* mempool bind completed, no longer need any mempools in the table */
|
|
dm_table_free_md_mempools(t);
|
|
}
|
|
|
|
/*
|
|
* Bind a table to the device.
|
|
*/
|
|
static void event_callback(void *context)
|
|
{
|
|
unsigned long flags;
|
|
LIST_HEAD(uevents);
|
|
struct mapped_device *md = (struct mapped_device *) context;
|
|
|
|
spin_lock_irqsave(&md->uevent_lock, flags);
|
|
list_splice_init(&md->uevent_list, &uevents);
|
|
spin_unlock_irqrestore(&md->uevent_lock, flags);
|
|
|
|
dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
|
|
|
|
atomic_inc(&md->event_nr);
|
|
wake_up(&md->eventq);
|
|
}
|
|
|
|
/*
|
|
* Protected by md->suspend_lock obtained by dm_swap_table().
|
|
*/
|
|
static void __set_size(struct mapped_device *md, sector_t size)
|
|
{
|
|
set_capacity(md->disk, size);
|
|
|
|
i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
|
|
}
|
|
|
|
/*
|
|
* Returns old map, which caller must destroy.
|
|
*/
|
|
static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
|
|
struct queue_limits *limits)
|
|
{
|
|
struct dm_table *old_map;
|
|
struct request_queue *q = md->queue;
|
|
sector_t size;
|
|
|
|
size = dm_table_get_size(t);
|
|
|
|
/*
|
|
* Wipe any geometry if the size of the table changed.
|
|
*/
|
|
if (size != dm_get_size(md))
|
|
memset(&md->geometry, 0, sizeof(md->geometry));
|
|
|
|
__set_size(md, size);
|
|
|
|
dm_table_event_callback(t, event_callback, md);
|
|
|
|
/*
|
|
* The queue hasn't been stopped yet, if the old table type wasn't
|
|
* for request-based during suspension. So stop it to prevent
|
|
* I/O mapping before resume.
|
|
* This must be done before setting the queue restrictions,
|
|
* because request-based dm may be run just after the setting.
|
|
*/
|
|
if (dm_table_request_based(t)) {
|
|
dm_stop_queue(q);
|
|
/*
|
|
* Leverage the fact that request-based DM targets are
|
|
* immutable singletons and establish md->immutable_target
|
|
* - used to optimize both dm_request_fn and dm_mq_queue_rq
|
|
*/
|
|
md->immutable_target = dm_table_get_immutable_target(t);
|
|
}
|
|
|
|
__bind_mempools(md, t);
|
|
|
|
old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
rcu_assign_pointer(md->map, (void *)t);
|
|
md->immutable_target_type = dm_table_get_immutable_target_type(t);
|
|
|
|
dm_table_set_restrictions(t, q, limits);
|
|
if (old_map)
|
|
dm_sync_table(md);
|
|
|
|
return old_map;
|
|
}
|
|
|
|
/*
|
|
* Returns unbound table for the caller to free.
|
|
*/
|
|
static struct dm_table *__unbind(struct mapped_device *md)
|
|
{
|
|
struct dm_table *map = rcu_dereference_protected(md->map, 1);
|
|
|
|
if (!map)
|
|
return NULL;
|
|
|
|
dm_table_event_callback(map, NULL, NULL);
|
|
RCU_INIT_POINTER(md->map, NULL);
|
|
dm_sync_table(md);
|
|
|
|
return map;
|
|
}
|
|
|
|
/*
|
|
* Constructor for a new device.
|
|
*/
|
|
int dm_create(int minor, struct mapped_device **result)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
md = alloc_dev(minor);
|
|
if (!md)
|
|
return -ENXIO;
|
|
|
|
dm_sysfs_init(md);
|
|
|
|
*result = md;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Functions to manage md->type.
|
|
* All are required to hold md->type_lock.
|
|
*/
|
|
void dm_lock_md_type(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->type_lock);
|
|
}
|
|
|
|
void dm_unlock_md_type(struct mapped_device *md)
|
|
{
|
|
mutex_unlock(&md->type_lock);
|
|
}
|
|
|
|
void dm_set_md_type(struct mapped_device *md, unsigned type)
|
|
{
|
|
BUG_ON(!mutex_is_locked(&md->type_lock));
|
|
md->type = type;
|
|
}
|
|
|
|
unsigned dm_get_md_type(struct mapped_device *md)
|
|
{
|
|
return md->type;
|
|
}
|
|
|
|
struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
|
|
{
|
|
return md->immutable_target_type;
|
|
}
|
|
|
|
/*
|
|
* The queue_limits are only valid as long as you have a reference
|
|
* count on 'md'.
|
|
*/
|
|
struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
|
|
{
|
|
BUG_ON(!atomic_read(&md->holders));
|
|
return &md->queue->limits;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_queue_limits);
|
|
|
|
/*
|
|
* Setup the DM device's queue based on md's type
|
|
*/
|
|
int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
|
|
{
|
|
int r;
|
|
unsigned type = dm_get_md_type(md);
|
|
|
|
switch (type) {
|
|
case DM_TYPE_REQUEST_BASED:
|
|
r = dm_old_init_request_queue(md);
|
|
if (r) {
|
|
DMERR("Cannot initialize queue for request-based mapped device");
|
|
return r;
|
|
}
|
|
break;
|
|
case DM_TYPE_MQ_REQUEST_BASED:
|
|
r = dm_mq_init_request_queue(md, t);
|
|
if (r) {
|
|
DMERR("Cannot initialize queue for request-based dm-mq mapped device");
|
|
return r;
|
|
}
|
|
break;
|
|
case DM_TYPE_BIO_BASED:
|
|
case DM_TYPE_DAX_BIO_BASED:
|
|
dm_init_normal_md_queue(md);
|
|
blk_queue_make_request(md->queue, dm_make_request);
|
|
/*
|
|
* DM handles splitting bios as needed. Free the bio_split bioset
|
|
* since it won't be used (saves 1 process per bio-based DM device).
|
|
*/
|
|
bioset_free(md->queue->bio_split);
|
|
md->queue->bio_split = NULL;
|
|
|
|
if (type == DM_TYPE_DAX_BIO_BASED)
|
|
queue_flag_set_unlocked(QUEUE_FLAG_DAX, md->queue);
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct mapped_device *dm_get_md(dev_t dev)
|
|
{
|
|
struct mapped_device *md;
|
|
unsigned minor = MINOR(dev);
|
|
|
|
if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
|
|
return NULL;
|
|
|
|
spin_lock(&_minor_lock);
|
|
|
|
md = idr_find(&_minor_idr, minor);
|
|
if (md) {
|
|
if ((md == MINOR_ALLOCED ||
|
|
(MINOR(disk_devt(dm_disk(md))) != minor) ||
|
|
dm_deleting_md(md) ||
|
|
test_bit(DMF_FREEING, &md->flags))) {
|
|
md = NULL;
|
|
goto out;
|
|
}
|
|
dm_get(md);
|
|
}
|
|
|
|
out:
|
|
spin_unlock(&_minor_lock);
|
|
|
|
return md;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_md);
|
|
|
|
void *dm_get_mdptr(struct mapped_device *md)
|
|
{
|
|
return md->interface_ptr;
|
|
}
|
|
|
|
void dm_set_mdptr(struct mapped_device *md, void *ptr)
|
|
{
|
|
md->interface_ptr = ptr;
|
|
}
|
|
|
|
void dm_get(struct mapped_device *md)
|
|
{
|
|
atomic_inc(&md->holders);
|
|
BUG_ON(test_bit(DMF_FREEING, &md->flags));
|
|
}
|
|
|
|
int dm_hold(struct mapped_device *md)
|
|
{
|
|
spin_lock(&_minor_lock);
|
|
if (test_bit(DMF_FREEING, &md->flags)) {
|
|
spin_unlock(&_minor_lock);
|
|
return -EBUSY;
|
|
}
|
|
dm_get(md);
|
|
spin_unlock(&_minor_lock);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_hold);
|
|
|
|
const char *dm_device_name(struct mapped_device *md)
|
|
{
|
|
return md->name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_device_name);
|
|
|
|
static void __dm_destroy(struct mapped_device *md, bool wait)
|
|
{
|
|
struct dm_table *map;
|
|
int srcu_idx;
|
|
|
|
might_sleep();
|
|
|
|
spin_lock(&_minor_lock);
|
|
idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
|
|
set_bit(DMF_FREEING, &md->flags);
|
|
spin_unlock(&_minor_lock);
|
|
|
|
if (dm_request_based(md) && md->kworker_task)
|
|
flush_kthread_worker(&md->kworker);
|
|
|
|
/*
|
|
* Take suspend_lock so that presuspend and postsuspend methods
|
|
* do not race with internal suspend.
|
|
*/
|
|
mutex_lock(&md->suspend_lock);
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
if (!dm_suspended_md(md)) {
|
|
dm_table_presuspend_targets(map);
|
|
dm_table_postsuspend_targets(map);
|
|
}
|
|
/* dm_put_live_table must be before msleep, otherwise deadlock is possible */
|
|
dm_put_live_table(md, srcu_idx);
|
|
mutex_unlock(&md->suspend_lock);
|
|
|
|
/*
|
|
* Rare, but there may be I/O requests still going to complete,
|
|
* for example. Wait for all references to disappear.
|
|
* No one should increment the reference count of the mapped_device,
|
|
* after the mapped_device state becomes DMF_FREEING.
|
|
*/
|
|
if (wait)
|
|
while (atomic_read(&md->holders))
|
|
msleep(1);
|
|
else if (atomic_read(&md->holders))
|
|
DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
|
|
dm_device_name(md), atomic_read(&md->holders));
|
|
|
|
dm_sysfs_exit(md);
|
|
dm_table_destroy(__unbind(md));
|
|
free_dev(md);
|
|
}
|
|
|
|
void dm_destroy(struct mapped_device *md)
|
|
{
|
|
__dm_destroy(md, true);
|
|
}
|
|
|
|
void dm_destroy_immediate(struct mapped_device *md)
|
|
{
|
|
__dm_destroy(md, false);
|
|
}
|
|
|
|
void dm_put(struct mapped_device *md)
|
|
{
|
|
atomic_dec(&md->holders);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_put);
|
|
|
|
static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
|
|
{
|
|
int r = 0;
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
|
|
add_wait_queue(&md->wait, &wait);
|
|
|
|
while (1) {
|
|
set_current_state(interruptible);
|
|
|
|
if (!md_in_flight(md))
|
|
break;
|
|
|
|
if (interruptible == TASK_INTERRUPTIBLE &&
|
|
signal_pending(current)) {
|
|
r = -EINTR;
|
|
break;
|
|
}
|
|
|
|
io_schedule();
|
|
}
|
|
set_current_state(TASK_RUNNING);
|
|
|
|
remove_wait_queue(&md->wait, &wait);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Process the deferred bios
|
|
*/
|
|
static void dm_wq_work(struct work_struct *work)
|
|
{
|
|
struct mapped_device *md = container_of(work, struct mapped_device,
|
|
work);
|
|
struct bio *c;
|
|
int srcu_idx;
|
|
struct dm_table *map;
|
|
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
|
|
while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
|
|
spin_lock_irq(&md->deferred_lock);
|
|
c = bio_list_pop(&md->deferred);
|
|
spin_unlock_irq(&md->deferred_lock);
|
|
|
|
if (!c)
|
|
break;
|
|
|
|
if (dm_request_based(md))
|
|
generic_make_request(c);
|
|
else
|
|
__split_and_process_bio(md, map, c);
|
|
}
|
|
|
|
dm_put_live_table(md, srcu_idx);
|
|
}
|
|
|
|
static void dm_queue_flush(struct mapped_device *md)
|
|
{
|
|
clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
smp_mb__after_atomic();
|
|
queue_work(md->wq, &md->work);
|
|
}
|
|
|
|
/*
|
|
* Swap in a new table, returning the old one for the caller to destroy.
|
|
*/
|
|
struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
|
|
{
|
|
struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
|
|
struct queue_limits limits;
|
|
int r;
|
|
|
|
mutex_lock(&md->suspend_lock);
|
|
|
|
/* device must be suspended */
|
|
if (!dm_suspended_md(md))
|
|
goto out;
|
|
|
|
/*
|
|
* If the new table has no data devices, retain the existing limits.
|
|
* This helps multipath with queue_if_no_path if all paths disappear,
|
|
* then new I/O is queued based on these limits, and then some paths
|
|
* reappear.
|
|
*/
|
|
if (dm_table_has_no_data_devices(table)) {
|
|
live_map = dm_get_live_table_fast(md);
|
|
if (live_map)
|
|
limits = md->queue->limits;
|
|
dm_put_live_table_fast(md);
|
|
}
|
|
|
|
if (!live_map) {
|
|
r = dm_calculate_queue_limits(table, &limits);
|
|
if (r) {
|
|
map = ERR_PTR(r);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
map = __bind(md, table, &limits);
|
|
|
|
out:
|
|
mutex_unlock(&md->suspend_lock);
|
|
return map;
|
|
}
|
|
|
|
/*
|
|
* Functions to lock and unlock any filesystem running on the
|
|
* device.
|
|
*/
|
|
static int lock_fs(struct mapped_device *md)
|
|
{
|
|
int r;
|
|
|
|
WARN_ON(md->frozen_sb);
|
|
|
|
md->frozen_sb = freeze_bdev(md->bdev);
|
|
if (IS_ERR(md->frozen_sb)) {
|
|
r = PTR_ERR(md->frozen_sb);
|
|
md->frozen_sb = NULL;
|
|
return r;
|
|
}
|
|
|
|
set_bit(DMF_FROZEN, &md->flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void unlock_fs(struct mapped_device *md)
|
|
{
|
|
if (!test_bit(DMF_FROZEN, &md->flags))
|
|
return;
|
|
|
|
thaw_bdev(md->bdev, md->frozen_sb);
|
|
md->frozen_sb = NULL;
|
|
clear_bit(DMF_FROZEN, &md->flags);
|
|
}
|
|
|
|
/*
|
|
* If __dm_suspend returns 0, the device is completely quiescent
|
|
* now. There is no request-processing activity. All new requests
|
|
* are being added to md->deferred list.
|
|
*
|
|
* Caller must hold md->suspend_lock
|
|
*/
|
|
static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
|
|
unsigned suspend_flags, int interruptible,
|
|
int dmf_suspended_flag)
|
|
{
|
|
bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
|
|
bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
|
|
int r;
|
|
|
|
/*
|
|
* DMF_NOFLUSH_SUSPENDING must be set before presuspend.
|
|
* This flag is cleared before dm_suspend returns.
|
|
*/
|
|
if (noflush)
|
|
set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
|
|
/*
|
|
* This gets reverted if there's an error later and the targets
|
|
* provide the .presuspend_undo hook.
|
|
*/
|
|
dm_table_presuspend_targets(map);
|
|
|
|
/*
|
|
* Flush I/O to the device.
|
|
* Any I/O submitted after lock_fs() may not be flushed.
|
|
* noflush takes precedence over do_lockfs.
|
|
* (lock_fs() flushes I/Os and waits for them to complete.)
|
|
*/
|
|
if (!noflush && do_lockfs) {
|
|
r = lock_fs(md);
|
|
if (r) {
|
|
dm_table_presuspend_undo_targets(map);
|
|
return r;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Here we must make sure that no processes are submitting requests
|
|
* to target drivers i.e. no one may be executing
|
|
* __split_and_process_bio. This is called from dm_request and
|
|
* dm_wq_work.
|
|
*
|
|
* To get all processes out of __split_and_process_bio in dm_request,
|
|
* we take the write lock. To prevent any process from reentering
|
|
* __split_and_process_bio from dm_request and quiesce the thread
|
|
* (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
|
|
* flush_workqueue(md->wq).
|
|
*/
|
|
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
if (map)
|
|
synchronize_srcu(&md->io_barrier);
|
|
|
|
/*
|
|
* Stop md->queue before flushing md->wq in case request-based
|
|
* dm defers requests to md->wq from md->queue.
|
|
*/
|
|
if (dm_request_based(md)) {
|
|
dm_stop_queue(md->queue);
|
|
if (md->kworker_task)
|
|
flush_kthread_worker(&md->kworker);
|
|
}
|
|
|
|
flush_workqueue(md->wq);
|
|
|
|
/*
|
|
* At this point no more requests are entering target request routines.
|
|
* We call dm_wait_for_completion to wait for all existing requests
|
|
* to finish.
|
|
*/
|
|
r = dm_wait_for_completion(md, interruptible);
|
|
if (!r)
|
|
set_bit(dmf_suspended_flag, &md->flags);
|
|
|
|
if (noflush)
|
|
clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
if (map)
|
|
synchronize_srcu(&md->io_barrier);
|
|
|
|
/* were we interrupted ? */
|
|
if (r < 0) {
|
|
dm_queue_flush(md);
|
|
|
|
if (dm_request_based(md))
|
|
dm_start_queue(md->queue);
|
|
|
|
unlock_fs(md);
|
|
dm_table_presuspend_undo_targets(map);
|
|
/* pushback list is already flushed, so skip flush */
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* We need to be able to change a mapping table under a mounted
|
|
* filesystem. For example we might want to move some data in
|
|
* the background. Before the table can be swapped with
|
|
* dm_bind_table, dm_suspend must be called to flush any in
|
|
* flight bios and ensure that any further io gets deferred.
|
|
*/
|
|
/*
|
|
* Suspend mechanism in request-based dm.
|
|
*
|
|
* 1. Flush all I/Os by lock_fs() if needed.
|
|
* 2. Stop dispatching any I/O by stopping the request_queue.
|
|
* 3. Wait for all in-flight I/Os to be completed or requeued.
|
|
*
|
|
* To abort suspend, start the request_queue.
|
|
*/
|
|
int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
|
|
{
|
|
struct dm_table *map = NULL;
|
|
int r = 0;
|
|
|
|
retry:
|
|
mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
|
|
|
|
if (dm_suspended_md(md)) {
|
|
r = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (dm_suspended_internally_md(md)) {
|
|
/* already internally suspended, wait for internal resume */
|
|
mutex_unlock(&md->suspend_lock);
|
|
r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
|
|
if (r)
|
|
return r;
|
|
goto retry;
|
|
}
|
|
|
|
map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
|
|
r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
|
|
if (r)
|
|
goto out_unlock;
|
|
|
|
dm_table_postsuspend_targets(map);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&md->suspend_lock);
|
|
return r;
|
|
}
|
|
|
|
static int __dm_resume(struct mapped_device *md, struct dm_table *map)
|
|
{
|
|
if (map) {
|
|
int r = dm_table_resume_targets(map);
|
|
if (r)
|
|
return r;
|
|
}
|
|
|
|
dm_queue_flush(md);
|
|
|
|
/*
|
|
* Flushing deferred I/Os must be done after targets are resumed
|
|
* so that mapping of targets can work correctly.
|
|
* Request-based dm is queueing the deferred I/Os in its request_queue.
|
|
*/
|
|
if (dm_request_based(md))
|
|
dm_start_queue(md->queue);
|
|
|
|
unlock_fs(md);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int dm_resume(struct mapped_device *md)
|
|
{
|
|
int r = -EINVAL;
|
|
struct dm_table *map = NULL;
|
|
|
|
retry:
|
|
mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
|
|
|
|
if (!dm_suspended_md(md))
|
|
goto out;
|
|
|
|
if (dm_suspended_internally_md(md)) {
|
|
/* already internally suspended, wait for internal resume */
|
|
mutex_unlock(&md->suspend_lock);
|
|
r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
|
|
if (r)
|
|
return r;
|
|
goto retry;
|
|
}
|
|
|
|
map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
if (!map || !dm_table_get_size(map))
|
|
goto out;
|
|
|
|
r = __dm_resume(md, map);
|
|
if (r)
|
|
goto out;
|
|
|
|
clear_bit(DMF_SUSPENDED, &md->flags);
|
|
|
|
r = 0;
|
|
out:
|
|
mutex_unlock(&md->suspend_lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Internal suspend/resume works like userspace-driven suspend. It waits
|
|
* until all bios finish and prevents issuing new bios to the target drivers.
|
|
* It may be used only from the kernel.
|
|
*/
|
|
|
|
static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
|
|
{
|
|
struct dm_table *map = NULL;
|
|
|
|
if (md->internal_suspend_count++)
|
|
return; /* nested internal suspend */
|
|
|
|
if (dm_suspended_md(md)) {
|
|
set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
|
|
return; /* nest suspend */
|
|
}
|
|
|
|
map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
|
|
/*
|
|
* Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
|
|
* supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
|
|
* would require changing .presuspend to return an error -- avoid this
|
|
* until there is a need for more elaborate variants of internal suspend.
|
|
*/
|
|
(void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
|
|
DMF_SUSPENDED_INTERNALLY);
|
|
|
|
dm_table_postsuspend_targets(map);
|
|
}
|
|
|
|
static void __dm_internal_resume(struct mapped_device *md)
|
|
{
|
|
BUG_ON(!md->internal_suspend_count);
|
|
|
|
if (--md->internal_suspend_count)
|
|
return; /* resume from nested internal suspend */
|
|
|
|
if (dm_suspended_md(md))
|
|
goto done; /* resume from nested suspend */
|
|
|
|
/*
|
|
* NOTE: existing callers don't need to call dm_table_resume_targets
|
|
* (which may fail -- so best to avoid it for now by passing NULL map)
|
|
*/
|
|
(void) __dm_resume(md, NULL);
|
|
|
|
done:
|
|
clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
|
|
smp_mb__after_atomic();
|
|
wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
|
|
}
|
|
|
|
void dm_internal_suspend_noflush(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->suspend_lock);
|
|
__dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
|
|
mutex_unlock(&md->suspend_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
|
|
|
|
void dm_internal_resume(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->suspend_lock);
|
|
__dm_internal_resume(md);
|
|
mutex_unlock(&md->suspend_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_resume);
|
|
|
|
/*
|
|
* Fast variants of internal suspend/resume hold md->suspend_lock,
|
|
* which prevents interaction with userspace-driven suspend.
|
|
*/
|
|
|
|
void dm_internal_suspend_fast(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->suspend_lock);
|
|
if (dm_suspended_md(md) || dm_suspended_internally_md(md))
|
|
return;
|
|
|
|
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
synchronize_srcu(&md->io_barrier);
|
|
flush_workqueue(md->wq);
|
|
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
|
|
|
|
void dm_internal_resume_fast(struct mapped_device *md)
|
|
{
|
|
if (dm_suspended_md(md) || dm_suspended_internally_md(md))
|
|
goto done;
|
|
|
|
dm_queue_flush(md);
|
|
|
|
done:
|
|
mutex_unlock(&md->suspend_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
|
|
|
|
/*-----------------------------------------------------------------
|
|
* Event notification.
|
|
*---------------------------------------------------------------*/
|
|
int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
|
|
unsigned cookie)
|
|
{
|
|
char udev_cookie[DM_COOKIE_LENGTH];
|
|
char *envp[] = { udev_cookie, NULL };
|
|
|
|
if (!cookie)
|
|
return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
|
|
else {
|
|
snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
|
|
DM_COOKIE_ENV_VAR_NAME, cookie);
|
|
return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
|
|
action, envp);
|
|
}
|
|
}
|
|
|
|
uint32_t dm_next_uevent_seq(struct mapped_device *md)
|
|
{
|
|
return atomic_add_return(1, &md->uevent_seq);
|
|
}
|
|
|
|
uint32_t dm_get_event_nr(struct mapped_device *md)
|
|
{
|
|
return atomic_read(&md->event_nr);
|
|
}
|
|
|
|
int dm_wait_event(struct mapped_device *md, int event_nr)
|
|
{
|
|
return wait_event_interruptible(md->eventq,
|
|
(event_nr != atomic_read(&md->event_nr)));
|
|
}
|
|
|
|
void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&md->uevent_lock, flags);
|
|
list_add(elist, &md->uevent_list);
|
|
spin_unlock_irqrestore(&md->uevent_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* The gendisk is only valid as long as you have a reference
|
|
* count on 'md'.
|
|
*/
|
|
struct gendisk *dm_disk(struct mapped_device *md)
|
|
{
|
|
return md->disk;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_disk);
|
|
|
|
struct kobject *dm_kobject(struct mapped_device *md)
|
|
{
|
|
return &md->kobj_holder.kobj;
|
|
}
|
|
|
|
struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
|
|
|
|
if (test_bit(DMF_FREEING, &md->flags) ||
|
|
dm_deleting_md(md))
|
|
return NULL;
|
|
|
|
dm_get(md);
|
|
return md;
|
|
}
|
|
|
|
int dm_suspended_md(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_SUSPENDED, &md->flags);
|
|
}
|
|
|
|
int dm_suspended_internally_md(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
|
|
}
|
|
|
|
int dm_test_deferred_remove_flag(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
|
|
}
|
|
|
|
int dm_suspended(struct dm_target *ti)
|
|
{
|
|
return dm_suspended_md(dm_table_get_md(ti->table));
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_suspended);
|
|
|
|
int dm_noflush_suspending(struct dm_target *ti)
|
|
{
|
|
return __noflush_suspending(dm_table_get_md(ti->table));
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_noflush_suspending);
|
|
|
|
struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type,
|
|
unsigned integrity, unsigned per_io_data_size)
|
|
{
|
|
struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
|
|
struct kmem_cache *cachep = NULL;
|
|
unsigned int pool_size = 0;
|
|
unsigned int front_pad;
|
|
|
|
if (!pools)
|
|
return NULL;
|
|
|
|
switch (type) {
|
|
case DM_TYPE_BIO_BASED:
|
|
case DM_TYPE_DAX_BIO_BASED:
|
|
cachep = _io_cache;
|
|
pool_size = dm_get_reserved_bio_based_ios();
|
|
front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
|
|
break;
|
|
case DM_TYPE_REQUEST_BASED:
|
|
cachep = _rq_tio_cache;
|
|
pool_size = dm_get_reserved_rq_based_ios();
|
|
pools->rq_pool = mempool_create_slab_pool(pool_size, _rq_cache);
|
|
if (!pools->rq_pool)
|
|
goto out;
|
|
/* fall through to setup remaining rq-based pools */
|
|
case DM_TYPE_MQ_REQUEST_BASED:
|
|
if (!pool_size)
|
|
pool_size = dm_get_reserved_rq_based_ios();
|
|
front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
|
|
/* per_io_data_size is used for blk-mq pdu at queue allocation */
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
if (cachep) {
|
|
pools->io_pool = mempool_create_slab_pool(pool_size, cachep);
|
|
if (!pools->io_pool)
|
|
goto out;
|
|
}
|
|
|
|
pools->bs = bioset_create_nobvec(pool_size, front_pad);
|
|
if (!pools->bs)
|
|
goto out;
|
|
|
|
if (integrity && bioset_integrity_create(pools->bs, pool_size))
|
|
goto out;
|
|
|
|
return pools;
|
|
|
|
out:
|
|
dm_free_md_mempools(pools);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void dm_free_md_mempools(struct dm_md_mempools *pools)
|
|
{
|
|
if (!pools)
|
|
return;
|
|
|
|
mempool_destroy(pools->io_pool);
|
|
mempool_destroy(pools->rq_pool);
|
|
|
|
if (pools->bs)
|
|
bioset_free(pools->bs);
|
|
|
|
kfree(pools);
|
|
}
|
|
|
|
struct dm_pr {
|
|
u64 old_key;
|
|
u64 new_key;
|
|
u32 flags;
|
|
bool fail_early;
|
|
};
|
|
|
|
static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
|
|
void *data)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
struct dm_table *table;
|
|
struct dm_target *ti;
|
|
int ret = -ENOTTY, srcu_idx;
|
|
|
|
table = dm_get_live_table(md, &srcu_idx);
|
|
if (!table || !dm_table_get_size(table))
|
|
goto out;
|
|
|
|
/* We only support devices that have a single target */
|
|
if (dm_table_get_num_targets(table) != 1)
|
|
goto out;
|
|
ti = dm_table_get_target(table, 0);
|
|
|
|
ret = -EINVAL;
|
|
if (!ti->type->iterate_devices)
|
|
goto out;
|
|
|
|
ret = ti->type->iterate_devices(ti, fn, data);
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* For register / unregister we need to manually call out to every path.
|
|
*/
|
|
static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
|
|
sector_t start, sector_t len, void *data)
|
|
{
|
|
struct dm_pr *pr = data;
|
|
const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
|
|
|
|
if (!ops || !ops->pr_register)
|
|
return -EOPNOTSUPP;
|
|
return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
|
|
}
|
|
|
|
static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
|
|
u32 flags)
|
|
{
|
|
struct dm_pr pr = {
|
|
.old_key = old_key,
|
|
.new_key = new_key,
|
|
.flags = flags,
|
|
.fail_early = true,
|
|
};
|
|
int ret;
|
|
|
|
ret = dm_call_pr(bdev, __dm_pr_register, &pr);
|
|
if (ret && new_key) {
|
|
/* unregister all paths if we failed to register any path */
|
|
pr.old_key = new_key;
|
|
pr.new_key = 0;
|
|
pr.flags = 0;
|
|
pr.fail_early = false;
|
|
dm_call_pr(bdev, __dm_pr_register, &pr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
|
|
u32 flags)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_reserve)
|
|
r = ops->pr_reserve(bdev, key, type, flags);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_release)
|
|
r = ops->pr_release(bdev, key, type);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
|
|
enum pr_type type, bool abort)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_preempt)
|
|
r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static int dm_pr_clear(struct block_device *bdev, u64 key)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_clear)
|
|
r = ops->pr_clear(bdev, key);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static const struct pr_ops dm_pr_ops = {
|
|
.pr_register = dm_pr_register,
|
|
.pr_reserve = dm_pr_reserve,
|
|
.pr_release = dm_pr_release,
|
|
.pr_preempt = dm_pr_preempt,
|
|
.pr_clear = dm_pr_clear,
|
|
};
|
|
|
|
static const struct block_device_operations dm_blk_dops = {
|
|
.open = dm_blk_open,
|
|
.release = dm_blk_close,
|
|
.ioctl = dm_blk_ioctl,
|
|
.direct_access = dm_blk_direct_access,
|
|
.getgeo = dm_blk_getgeo,
|
|
.pr_ops = &dm_pr_ops,
|
|
.owner = THIS_MODULE
|
|
};
|
|
|
|
/*
|
|
* module hooks
|
|
*/
|
|
module_init(dm_init);
|
|
module_exit(dm_exit);
|
|
|
|
module_param(major, uint, 0);
|
|
MODULE_PARM_DESC(major, "The major number of the device mapper");
|
|
|
|
module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
|
|
|
|
module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " driver");
|
|
MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|