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985 lines
22 KiB
985 lines
22 KiB
/* |
|
* Copyright (C) 2002 Sistina Software (UK) Limited. |
|
* Copyright (C) 2006 Red Hat GmbH |
|
* |
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* This file is released under the GPL. |
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* |
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* Kcopyd provides a simple interface for copying an area of one |
|
* block-device to one or more other block-devices, with an asynchronous |
|
* completion notification. |
|
*/ |
|
|
|
#include <linux/types.h> |
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#include <linux/atomic.h> |
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#include <linux/blkdev.h> |
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#include <linux/fs.h> |
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#include <linux/init.h> |
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#include <linux/list.h> |
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#include <linux/mempool.h> |
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#include <linux/module.h> |
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#include <linux/pagemap.h> |
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#include <linux/slab.h> |
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#include <linux/vmalloc.h> |
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#include <linux/workqueue.h> |
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#include <linux/mutex.h> |
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#include <linux/delay.h> |
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#include <linux/device-mapper.h> |
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#include <linux/dm-kcopyd.h> |
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|
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#include "dm-core.h" |
|
|
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#define SPLIT_COUNT 8 |
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#define MIN_JOBS 8 |
|
|
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#define DEFAULT_SUB_JOB_SIZE_KB 512 |
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#define MAX_SUB_JOB_SIZE_KB 1024 |
|
|
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static unsigned kcopyd_subjob_size_kb = DEFAULT_SUB_JOB_SIZE_KB; |
|
|
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module_param(kcopyd_subjob_size_kb, uint, S_IRUGO | S_IWUSR); |
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MODULE_PARM_DESC(kcopyd_subjob_size_kb, "Sub-job size for dm-kcopyd clients"); |
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|
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static unsigned dm_get_kcopyd_subjob_size(void) |
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{ |
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unsigned sub_job_size_kb; |
|
|
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sub_job_size_kb = __dm_get_module_param(&kcopyd_subjob_size_kb, |
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DEFAULT_SUB_JOB_SIZE_KB, |
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MAX_SUB_JOB_SIZE_KB); |
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|
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return sub_job_size_kb << 1; |
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} |
|
|
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/*----------------------------------------------------------------- |
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* Each kcopyd client has its own little pool of preallocated |
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* pages for kcopyd io. |
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*---------------------------------------------------------------*/ |
|
struct dm_kcopyd_client { |
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struct page_list *pages; |
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unsigned nr_reserved_pages; |
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unsigned nr_free_pages; |
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unsigned sub_job_size; |
|
|
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struct dm_io_client *io_client; |
|
|
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wait_queue_head_t destroyq; |
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|
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mempool_t job_pool; |
|
|
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struct workqueue_struct *kcopyd_wq; |
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struct work_struct kcopyd_work; |
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|
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struct dm_kcopyd_throttle *throttle; |
|
|
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atomic_t nr_jobs; |
|
|
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/* |
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* We maintain four lists of jobs: |
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* |
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* i) jobs waiting for pages |
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* ii) jobs that have pages, and are waiting for the io to be issued. |
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* iii) jobs that don't need to do any IO and just run a callback |
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* iv) jobs that have completed. |
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* |
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* All four of these are protected by job_lock. |
|
*/ |
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spinlock_t job_lock; |
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struct list_head callback_jobs; |
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struct list_head complete_jobs; |
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struct list_head io_jobs; |
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struct list_head pages_jobs; |
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}; |
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|
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static struct page_list zero_page_list; |
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|
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static DEFINE_SPINLOCK(throttle_spinlock); |
|
|
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/* |
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* IO/IDLE accounting slowly decays after (1 << ACCOUNT_INTERVAL_SHIFT) period. |
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* When total_period >= (1 << ACCOUNT_INTERVAL_SHIFT) the counters are divided |
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* by 2. |
|
*/ |
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#define ACCOUNT_INTERVAL_SHIFT SHIFT_HZ |
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|
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/* |
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* Sleep this number of milliseconds. |
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* |
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* The value was decided experimentally. |
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* Smaller values seem to cause an increased copy rate above the limit. |
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* The reason for this is unknown but possibly due to jiffies rounding errors |
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* or read/write cache inside the disk. |
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*/ |
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#define SLEEP_MSEC 100 |
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|
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/* |
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* Maximum number of sleep events. There is a theoretical livelock if more |
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* kcopyd clients do work simultaneously which this limit avoids. |
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*/ |
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#define MAX_SLEEPS 10 |
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|
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static void io_job_start(struct dm_kcopyd_throttle *t) |
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{ |
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unsigned throttle, now, difference; |
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int slept = 0, skew; |
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|
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if (unlikely(!t)) |
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return; |
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|
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try_again: |
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spin_lock_irq(&throttle_spinlock); |
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|
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throttle = READ_ONCE(t->throttle); |
|
|
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if (likely(throttle >= 100)) |
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goto skip_limit; |
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|
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now = jiffies; |
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difference = now - t->last_jiffies; |
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t->last_jiffies = now; |
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if (t->num_io_jobs) |
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t->io_period += difference; |
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t->total_period += difference; |
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|
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/* |
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* Maintain sane values if we got a temporary overflow. |
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*/ |
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if (unlikely(t->io_period > t->total_period)) |
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t->io_period = t->total_period; |
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|
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if (unlikely(t->total_period >= (1 << ACCOUNT_INTERVAL_SHIFT))) { |
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int shift = fls(t->total_period >> ACCOUNT_INTERVAL_SHIFT); |
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t->total_period >>= shift; |
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t->io_period >>= shift; |
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} |
|
|
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skew = t->io_period - throttle * t->total_period / 100; |
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|
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if (unlikely(skew > 0) && slept < MAX_SLEEPS) { |
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slept++; |
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spin_unlock_irq(&throttle_spinlock); |
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msleep(SLEEP_MSEC); |
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goto try_again; |
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} |
|
|
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skip_limit: |
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t->num_io_jobs++; |
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|
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spin_unlock_irq(&throttle_spinlock); |
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} |
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|
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static void io_job_finish(struct dm_kcopyd_throttle *t) |
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{ |
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unsigned long flags; |
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|
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if (unlikely(!t)) |
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return; |
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|
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spin_lock_irqsave(&throttle_spinlock, flags); |
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|
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t->num_io_jobs--; |
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|
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if (likely(READ_ONCE(t->throttle) >= 100)) |
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goto skip_limit; |
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|
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if (!t->num_io_jobs) { |
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unsigned now, difference; |
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|
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now = jiffies; |
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difference = now - t->last_jiffies; |
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t->last_jiffies = now; |
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|
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t->io_period += difference; |
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t->total_period += difference; |
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|
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/* |
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* Maintain sane values if we got a temporary overflow. |
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*/ |
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if (unlikely(t->io_period > t->total_period)) |
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t->io_period = t->total_period; |
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} |
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skip_limit: |
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spin_unlock_irqrestore(&throttle_spinlock, flags); |
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} |
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|
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static void wake(struct dm_kcopyd_client *kc) |
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{ |
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queue_work(kc->kcopyd_wq, &kc->kcopyd_work); |
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} |
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|
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/* |
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* Obtain one page for the use of kcopyd. |
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*/ |
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static struct page_list *alloc_pl(gfp_t gfp) |
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{ |
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struct page_list *pl; |
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|
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pl = kmalloc(sizeof(*pl), gfp); |
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if (!pl) |
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return NULL; |
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|
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pl->page = alloc_page(gfp); |
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if (!pl->page) { |
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kfree(pl); |
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return NULL; |
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} |
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return pl; |
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} |
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|
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static void free_pl(struct page_list *pl) |
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{ |
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__free_page(pl->page); |
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kfree(pl); |
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} |
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|
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/* |
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* Add the provided pages to a client's free page list, releasing |
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* back to the system any beyond the reserved_pages limit. |
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*/ |
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static void kcopyd_put_pages(struct dm_kcopyd_client *kc, struct page_list *pl) |
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{ |
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struct page_list *next; |
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|
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do { |
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next = pl->next; |
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if (kc->nr_free_pages >= kc->nr_reserved_pages) |
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free_pl(pl); |
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else { |
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pl->next = kc->pages; |
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kc->pages = pl; |
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kc->nr_free_pages++; |
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} |
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|
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pl = next; |
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} while (pl); |
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} |
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static int kcopyd_get_pages(struct dm_kcopyd_client *kc, |
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unsigned int nr, struct page_list **pages) |
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{ |
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struct page_list *pl; |
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|
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*pages = NULL; |
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|
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do { |
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pl = alloc_pl(__GFP_NOWARN | __GFP_NORETRY | __GFP_KSWAPD_RECLAIM); |
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if (unlikely(!pl)) { |
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/* Use reserved pages */ |
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pl = kc->pages; |
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if (unlikely(!pl)) |
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goto out_of_memory; |
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kc->pages = pl->next; |
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kc->nr_free_pages--; |
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} |
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pl->next = *pages; |
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*pages = pl; |
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} while (--nr); |
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|
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return 0; |
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|
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out_of_memory: |
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if (*pages) |
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kcopyd_put_pages(kc, *pages); |
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return -ENOMEM; |
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} |
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|
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/* |
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* These three functions resize the page pool. |
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*/ |
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static void drop_pages(struct page_list *pl) |
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{ |
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struct page_list *next; |
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while (pl) { |
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next = pl->next; |
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free_pl(pl); |
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pl = next; |
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} |
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} |
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/* |
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* Allocate and reserve nr_pages for the use of a specific client. |
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*/ |
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static int client_reserve_pages(struct dm_kcopyd_client *kc, unsigned nr_pages) |
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{ |
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unsigned i; |
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struct page_list *pl = NULL, *next; |
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for (i = 0; i < nr_pages; i++) { |
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next = alloc_pl(GFP_KERNEL); |
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if (!next) { |
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if (pl) |
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drop_pages(pl); |
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return -ENOMEM; |
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} |
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next->next = pl; |
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pl = next; |
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} |
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kc->nr_reserved_pages += nr_pages; |
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kcopyd_put_pages(kc, pl); |
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|
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return 0; |
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} |
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static void client_free_pages(struct dm_kcopyd_client *kc) |
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{ |
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BUG_ON(kc->nr_free_pages != kc->nr_reserved_pages); |
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drop_pages(kc->pages); |
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kc->pages = NULL; |
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kc->nr_free_pages = kc->nr_reserved_pages = 0; |
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} |
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|
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/*----------------------------------------------------------------- |
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* kcopyd_jobs need to be allocated by the *clients* of kcopyd, |
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* for this reason we use a mempool to prevent the client from |
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* ever having to do io (which could cause a deadlock). |
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*---------------------------------------------------------------*/ |
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struct kcopyd_job { |
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struct dm_kcopyd_client *kc; |
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struct list_head list; |
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unsigned long flags; |
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|
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/* |
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* Error state of the job. |
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*/ |
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int read_err; |
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unsigned long write_err; |
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|
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/* |
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* Either READ or WRITE |
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*/ |
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int rw; |
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struct dm_io_region source; |
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|
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/* |
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* The destinations for the transfer. |
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*/ |
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unsigned int num_dests; |
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struct dm_io_region dests[DM_KCOPYD_MAX_REGIONS]; |
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struct page_list *pages; |
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/* |
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* Set this to ensure you are notified when the job has |
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* completed. 'context' is for callback to use. |
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*/ |
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dm_kcopyd_notify_fn fn; |
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void *context; |
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|
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/* |
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* These fields are only used if the job has been split |
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* into more manageable parts. |
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*/ |
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struct mutex lock; |
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atomic_t sub_jobs; |
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sector_t progress; |
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sector_t write_offset; |
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struct kcopyd_job *master_job; |
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}; |
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static struct kmem_cache *_job_cache; |
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int __init dm_kcopyd_init(void) |
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{ |
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_job_cache = kmem_cache_create("kcopyd_job", |
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sizeof(struct kcopyd_job) * (SPLIT_COUNT + 1), |
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__alignof__(struct kcopyd_job), 0, NULL); |
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if (!_job_cache) |
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return -ENOMEM; |
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zero_page_list.next = &zero_page_list; |
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zero_page_list.page = ZERO_PAGE(0); |
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|
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return 0; |
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} |
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|
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void dm_kcopyd_exit(void) |
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{ |
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kmem_cache_destroy(_job_cache); |
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_job_cache = NULL; |
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} |
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|
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/* |
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* Functions to push and pop a job onto the head of a given job |
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* list. |
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*/ |
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static struct kcopyd_job *pop_io_job(struct list_head *jobs, |
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struct dm_kcopyd_client *kc) |
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{ |
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struct kcopyd_job *job; |
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|
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/* |
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* For I/O jobs, pop any read, any write without sequential write |
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* constraint and sequential writes that are at the right position. |
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*/ |
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list_for_each_entry(job, jobs, list) { |
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if (job->rw == READ || !test_bit(DM_KCOPYD_WRITE_SEQ, &job->flags)) { |
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list_del(&job->list); |
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return job; |
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} |
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|
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if (job->write_offset == job->master_job->write_offset) { |
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job->master_job->write_offset += job->source.count; |
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list_del(&job->list); |
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return job; |
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} |
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} |
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|
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return NULL; |
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} |
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|
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static struct kcopyd_job *pop(struct list_head *jobs, |
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struct dm_kcopyd_client *kc) |
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{ |
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struct kcopyd_job *job = NULL; |
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unsigned long flags; |
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|
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spin_lock_irqsave(&kc->job_lock, flags); |
|
|
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if (!list_empty(jobs)) { |
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if (jobs == &kc->io_jobs) |
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job = pop_io_job(jobs, kc); |
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else { |
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job = list_entry(jobs->next, struct kcopyd_job, list); |
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list_del(&job->list); |
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} |
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} |
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spin_unlock_irqrestore(&kc->job_lock, flags); |
|
|
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return job; |
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} |
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|
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static void push(struct list_head *jobs, struct kcopyd_job *job) |
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{ |
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unsigned long flags; |
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struct dm_kcopyd_client *kc = job->kc; |
|
|
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spin_lock_irqsave(&kc->job_lock, flags); |
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list_add_tail(&job->list, jobs); |
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spin_unlock_irqrestore(&kc->job_lock, flags); |
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} |
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|
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|
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static void push_head(struct list_head *jobs, struct kcopyd_job *job) |
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{ |
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unsigned long flags; |
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struct dm_kcopyd_client *kc = job->kc; |
|
|
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spin_lock_irqsave(&kc->job_lock, flags); |
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list_add(&job->list, jobs); |
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spin_unlock_irqrestore(&kc->job_lock, flags); |
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} |
|
|
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/* |
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* These three functions process 1 item from the corresponding |
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* job list. |
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* |
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* They return: |
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* < 0: error |
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* 0: success |
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* > 0: can't process yet. |
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*/ |
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static int run_complete_job(struct kcopyd_job *job) |
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{ |
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void *context = job->context; |
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int read_err = job->read_err; |
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unsigned long write_err = job->write_err; |
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dm_kcopyd_notify_fn fn = job->fn; |
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struct dm_kcopyd_client *kc = job->kc; |
|
|
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if (job->pages && job->pages != &zero_page_list) |
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kcopyd_put_pages(kc, job->pages); |
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/* |
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* If this is the master job, the sub jobs have already |
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* completed so we can free everything. |
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*/ |
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if (job->master_job == job) { |
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mutex_destroy(&job->lock); |
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mempool_free(job, &kc->job_pool); |
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} |
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fn(read_err, write_err, context); |
|
|
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if (atomic_dec_and_test(&kc->nr_jobs)) |
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wake_up(&kc->destroyq); |
|
|
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cond_resched(); |
|
|
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return 0; |
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} |
|
|
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static void complete_io(unsigned long error, void *context) |
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{ |
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struct kcopyd_job *job = (struct kcopyd_job *) context; |
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struct dm_kcopyd_client *kc = job->kc; |
|
|
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io_job_finish(kc->throttle); |
|
|
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if (error) { |
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if (op_is_write(job->rw)) |
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job->write_err |= error; |
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else |
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job->read_err = 1; |
|
|
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if (!test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
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push(&kc->complete_jobs, job); |
|
wake(kc); |
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return; |
|
} |
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} |
|
|
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if (op_is_write(job->rw)) |
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push(&kc->complete_jobs, job); |
|
|
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else { |
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job->rw = WRITE; |
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push(&kc->io_jobs, job); |
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} |
|
|
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wake(kc); |
|
} |
|
|
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/* |
|
* Request io on as many buffer heads as we can currently get for |
|
* a particular job. |
|
*/ |
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static int run_io_job(struct kcopyd_job *job) |
|
{ |
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int r; |
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struct dm_io_request io_req = { |
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.bi_op = job->rw, |
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.bi_op_flags = 0, |
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.mem.type = DM_IO_PAGE_LIST, |
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.mem.ptr.pl = job->pages, |
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.mem.offset = 0, |
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.notify.fn = complete_io, |
|
.notify.context = job, |
|
.client = job->kc->io_client, |
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}; |
|
|
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/* |
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* If we need to write sequentially and some reads or writes failed, |
|
* no point in continuing. |
|
*/ |
|
if (test_bit(DM_KCOPYD_WRITE_SEQ, &job->flags) && |
|
job->master_job->write_err) { |
|
job->write_err = job->master_job->write_err; |
|
return -EIO; |
|
} |
|
|
|
io_job_start(job->kc->throttle); |
|
|
|
if (job->rw == READ) |
|
r = dm_io(&io_req, 1, &job->source, NULL); |
|
else |
|
r = dm_io(&io_req, job->num_dests, job->dests, NULL); |
|
|
|
return r; |
|
} |
|
|
|
static int run_pages_job(struct kcopyd_job *job) |
|
{ |
|
int r; |
|
unsigned nr_pages = dm_div_up(job->dests[0].count, PAGE_SIZE >> 9); |
|
|
|
r = kcopyd_get_pages(job->kc, nr_pages, &job->pages); |
|
if (!r) { |
|
/* this job is ready for io */ |
|
push(&job->kc->io_jobs, job); |
|
return 0; |
|
} |
|
|
|
if (r == -ENOMEM) |
|
/* can't complete now */ |
|
return 1; |
|
|
|
return r; |
|
} |
|
|
|
/* |
|
* Run through a list for as long as possible. Returns the count |
|
* of successful jobs. |
|
*/ |
|
static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc, |
|
int (*fn) (struct kcopyd_job *)) |
|
{ |
|
struct kcopyd_job *job; |
|
int r, count = 0; |
|
|
|
while ((job = pop(jobs, kc))) { |
|
|
|
r = fn(job); |
|
|
|
if (r < 0) { |
|
/* error this rogue job */ |
|
if (op_is_write(job->rw)) |
|
job->write_err = (unsigned long) -1L; |
|
else |
|
job->read_err = 1; |
|
push(&kc->complete_jobs, job); |
|
wake(kc); |
|
break; |
|
} |
|
|
|
if (r > 0) { |
|
/* |
|
* We couldn't service this job ATM, so |
|
* push this job back onto the list. |
|
*/ |
|
push_head(jobs, job); |
|
break; |
|
} |
|
|
|
count++; |
|
} |
|
|
|
return count; |
|
} |
|
|
|
/* |
|
* kcopyd does this every time it's woken up. |
|
*/ |
|
static void do_work(struct work_struct *work) |
|
{ |
|
struct dm_kcopyd_client *kc = container_of(work, |
|
struct dm_kcopyd_client, kcopyd_work); |
|
struct blk_plug plug; |
|
unsigned long flags; |
|
|
|
/* |
|
* The order that these are called is *very* important. |
|
* complete jobs can free some pages for pages jobs. |
|
* Pages jobs when successful will jump onto the io jobs |
|
* list. io jobs call wake when they complete and it all |
|
* starts again. |
|
*/ |
|
spin_lock_irqsave(&kc->job_lock, flags); |
|
list_splice_tail_init(&kc->callback_jobs, &kc->complete_jobs); |
|
spin_unlock_irqrestore(&kc->job_lock, flags); |
|
|
|
blk_start_plug(&plug); |
|
process_jobs(&kc->complete_jobs, kc, run_complete_job); |
|
process_jobs(&kc->pages_jobs, kc, run_pages_job); |
|
process_jobs(&kc->io_jobs, kc, run_io_job); |
|
blk_finish_plug(&plug); |
|
} |
|
|
|
/* |
|
* If we are copying a small region we just dispatch a single job |
|
* to do the copy, otherwise the io has to be split up into many |
|
* jobs. |
|
*/ |
|
static void dispatch_job(struct kcopyd_job *job) |
|
{ |
|
struct dm_kcopyd_client *kc = job->kc; |
|
atomic_inc(&kc->nr_jobs); |
|
if (unlikely(!job->source.count)) |
|
push(&kc->callback_jobs, job); |
|
else if (job->pages == &zero_page_list) |
|
push(&kc->io_jobs, job); |
|
else |
|
push(&kc->pages_jobs, job); |
|
wake(kc); |
|
} |
|
|
|
static void segment_complete(int read_err, unsigned long write_err, |
|
void *context) |
|
{ |
|
/* FIXME: tidy this function */ |
|
sector_t progress = 0; |
|
sector_t count = 0; |
|
struct kcopyd_job *sub_job = (struct kcopyd_job *) context; |
|
struct kcopyd_job *job = sub_job->master_job; |
|
struct dm_kcopyd_client *kc = job->kc; |
|
|
|
mutex_lock(&job->lock); |
|
|
|
/* update the error */ |
|
if (read_err) |
|
job->read_err = 1; |
|
|
|
if (write_err) |
|
job->write_err |= write_err; |
|
|
|
/* |
|
* Only dispatch more work if there hasn't been an error. |
|
*/ |
|
if ((!job->read_err && !job->write_err) || |
|
test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
|
/* get the next chunk of work */ |
|
progress = job->progress; |
|
count = job->source.count - progress; |
|
if (count) { |
|
if (count > kc->sub_job_size) |
|
count = kc->sub_job_size; |
|
|
|
job->progress += count; |
|
} |
|
} |
|
mutex_unlock(&job->lock); |
|
|
|
if (count) { |
|
int i; |
|
|
|
*sub_job = *job; |
|
sub_job->write_offset = progress; |
|
sub_job->source.sector += progress; |
|
sub_job->source.count = count; |
|
|
|
for (i = 0; i < job->num_dests; i++) { |
|
sub_job->dests[i].sector += progress; |
|
sub_job->dests[i].count = count; |
|
} |
|
|
|
sub_job->fn = segment_complete; |
|
sub_job->context = sub_job; |
|
dispatch_job(sub_job); |
|
|
|
} else if (atomic_dec_and_test(&job->sub_jobs)) { |
|
|
|
/* |
|
* Queue the completion callback to the kcopyd thread. |
|
* |
|
* Some callers assume that all the completions are called |
|
* from a single thread and don't race with each other. |
|
* |
|
* We must not call the callback directly here because this |
|
* code may not be executing in the thread. |
|
*/ |
|
push(&kc->complete_jobs, job); |
|
wake(kc); |
|
} |
|
} |
|
|
|
/* |
|
* Create some sub jobs to share the work between them. |
|
*/ |
|
static void split_job(struct kcopyd_job *master_job) |
|
{ |
|
int i; |
|
|
|
atomic_inc(&master_job->kc->nr_jobs); |
|
|
|
atomic_set(&master_job->sub_jobs, SPLIT_COUNT); |
|
for (i = 0; i < SPLIT_COUNT; i++) { |
|
master_job[i + 1].master_job = master_job; |
|
segment_complete(0, 0u, &master_job[i + 1]); |
|
} |
|
} |
|
|
|
void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, |
|
unsigned int num_dests, struct dm_io_region *dests, |
|
unsigned int flags, dm_kcopyd_notify_fn fn, void *context) |
|
{ |
|
struct kcopyd_job *job; |
|
int i; |
|
|
|
/* |
|
* Allocate an array of jobs consisting of one master job |
|
* followed by SPLIT_COUNT sub jobs. |
|
*/ |
|
job = mempool_alloc(&kc->job_pool, GFP_NOIO); |
|
mutex_init(&job->lock); |
|
|
|
/* |
|
* set up for the read. |
|
*/ |
|
job->kc = kc; |
|
job->flags = flags; |
|
job->read_err = 0; |
|
job->write_err = 0; |
|
|
|
job->num_dests = num_dests; |
|
memcpy(&job->dests, dests, sizeof(*dests) * num_dests); |
|
|
|
/* |
|
* If one of the destination is a host-managed zoned block device, |
|
* we need to write sequentially. If one of the destination is a |
|
* host-aware device, then leave it to the caller to choose what to do. |
|
*/ |
|
if (!test_bit(DM_KCOPYD_WRITE_SEQ, &job->flags)) { |
|
for (i = 0; i < job->num_dests; i++) { |
|
if (bdev_zoned_model(dests[i].bdev) == BLK_ZONED_HM) { |
|
set_bit(DM_KCOPYD_WRITE_SEQ, &job->flags); |
|
break; |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* If we need to write sequentially, errors cannot be ignored. |
|
*/ |
|
if (test_bit(DM_KCOPYD_WRITE_SEQ, &job->flags) && |
|
test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) |
|
clear_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags); |
|
|
|
if (from) { |
|
job->source = *from; |
|
job->pages = NULL; |
|
job->rw = READ; |
|
} else { |
|
memset(&job->source, 0, sizeof job->source); |
|
job->source.count = job->dests[0].count; |
|
job->pages = &zero_page_list; |
|
|
|
/* |
|
* Use WRITE ZEROES to optimize zeroing if all dests support it. |
|
*/ |
|
job->rw = REQ_OP_WRITE_ZEROES; |
|
for (i = 0; i < job->num_dests; i++) |
|
if (!bdev_write_zeroes_sectors(job->dests[i].bdev)) { |
|
job->rw = WRITE; |
|
break; |
|
} |
|
} |
|
|
|
job->fn = fn; |
|
job->context = context; |
|
job->master_job = job; |
|
job->write_offset = 0; |
|
|
|
if (job->source.count <= kc->sub_job_size) |
|
dispatch_job(job); |
|
else { |
|
job->progress = 0; |
|
split_job(job); |
|
} |
|
} |
|
EXPORT_SYMBOL(dm_kcopyd_copy); |
|
|
|
void dm_kcopyd_zero(struct dm_kcopyd_client *kc, |
|
unsigned num_dests, struct dm_io_region *dests, |
|
unsigned flags, dm_kcopyd_notify_fn fn, void *context) |
|
{ |
|
dm_kcopyd_copy(kc, NULL, num_dests, dests, flags, fn, context); |
|
} |
|
EXPORT_SYMBOL(dm_kcopyd_zero); |
|
|
|
void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc, |
|
dm_kcopyd_notify_fn fn, void *context) |
|
{ |
|
struct kcopyd_job *job; |
|
|
|
job = mempool_alloc(&kc->job_pool, GFP_NOIO); |
|
|
|
memset(job, 0, sizeof(struct kcopyd_job)); |
|
job->kc = kc; |
|
job->fn = fn; |
|
job->context = context; |
|
job->master_job = job; |
|
|
|
atomic_inc(&kc->nr_jobs); |
|
|
|
return job; |
|
} |
|
EXPORT_SYMBOL(dm_kcopyd_prepare_callback); |
|
|
|
void dm_kcopyd_do_callback(void *j, int read_err, unsigned long write_err) |
|
{ |
|
struct kcopyd_job *job = j; |
|
struct dm_kcopyd_client *kc = job->kc; |
|
|
|
job->read_err = read_err; |
|
job->write_err = write_err; |
|
|
|
push(&kc->callback_jobs, job); |
|
wake(kc); |
|
} |
|
EXPORT_SYMBOL(dm_kcopyd_do_callback); |
|
|
|
/* |
|
* Cancels a kcopyd job, eg. someone might be deactivating a |
|
* mirror. |
|
*/ |
|
#if 0 |
|
int kcopyd_cancel(struct kcopyd_job *job, int block) |
|
{ |
|
/* FIXME: finish */ |
|
return -1; |
|
} |
|
#endif /* 0 */ |
|
|
|
/*----------------------------------------------------------------- |
|
* Client setup |
|
*---------------------------------------------------------------*/ |
|
struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle) |
|
{ |
|
int r; |
|
unsigned reserve_pages; |
|
struct dm_kcopyd_client *kc; |
|
|
|
kc = kzalloc(sizeof(*kc), GFP_KERNEL); |
|
if (!kc) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
spin_lock_init(&kc->job_lock); |
|
INIT_LIST_HEAD(&kc->callback_jobs); |
|
INIT_LIST_HEAD(&kc->complete_jobs); |
|
INIT_LIST_HEAD(&kc->io_jobs); |
|
INIT_LIST_HEAD(&kc->pages_jobs); |
|
kc->throttle = throttle; |
|
|
|
r = mempool_init_slab_pool(&kc->job_pool, MIN_JOBS, _job_cache); |
|
if (r) |
|
goto bad_slab; |
|
|
|
INIT_WORK(&kc->kcopyd_work, do_work); |
|
kc->kcopyd_wq = alloc_workqueue("kcopyd", WQ_MEM_RECLAIM, 0); |
|
if (!kc->kcopyd_wq) { |
|
r = -ENOMEM; |
|
goto bad_workqueue; |
|
} |
|
|
|
kc->sub_job_size = dm_get_kcopyd_subjob_size(); |
|
reserve_pages = DIV_ROUND_UP(kc->sub_job_size << SECTOR_SHIFT, PAGE_SIZE); |
|
|
|
kc->pages = NULL; |
|
kc->nr_reserved_pages = kc->nr_free_pages = 0; |
|
r = client_reserve_pages(kc, reserve_pages); |
|
if (r) |
|
goto bad_client_pages; |
|
|
|
kc->io_client = dm_io_client_create(); |
|
if (IS_ERR(kc->io_client)) { |
|
r = PTR_ERR(kc->io_client); |
|
goto bad_io_client; |
|
} |
|
|
|
init_waitqueue_head(&kc->destroyq); |
|
atomic_set(&kc->nr_jobs, 0); |
|
|
|
return kc; |
|
|
|
bad_io_client: |
|
client_free_pages(kc); |
|
bad_client_pages: |
|
destroy_workqueue(kc->kcopyd_wq); |
|
bad_workqueue: |
|
mempool_exit(&kc->job_pool); |
|
bad_slab: |
|
kfree(kc); |
|
|
|
return ERR_PTR(r); |
|
} |
|
EXPORT_SYMBOL(dm_kcopyd_client_create); |
|
|
|
void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc) |
|
{ |
|
/* Wait for completion of all jobs submitted by this client. */ |
|
wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs)); |
|
|
|
BUG_ON(!list_empty(&kc->callback_jobs)); |
|
BUG_ON(!list_empty(&kc->complete_jobs)); |
|
BUG_ON(!list_empty(&kc->io_jobs)); |
|
BUG_ON(!list_empty(&kc->pages_jobs)); |
|
destroy_workqueue(kc->kcopyd_wq); |
|
dm_io_client_destroy(kc->io_client); |
|
client_free_pages(kc); |
|
mempool_exit(&kc->job_pool); |
|
kfree(kc); |
|
} |
|
EXPORT_SYMBOL(dm_kcopyd_client_destroy);
|
|
|