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2581 lines
64 KiB
2581 lines
64 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2018 Red Hat. 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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|
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#include <linux/device-mapper.h> |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/vmalloc.h> |
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#include <linux/kthread.h> |
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#include <linux/dm-io.h> |
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#include <linux/dm-kcopyd.h> |
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#include <linux/dax.h> |
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#include <linux/pfn_t.h> |
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#include <linux/libnvdimm.h> |
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#define DM_MSG_PREFIX "writecache" |
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#define HIGH_WATERMARK 50 |
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#define LOW_WATERMARK 45 |
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#define MAX_WRITEBACK_JOBS 0 |
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#define ENDIO_LATENCY 16 |
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#define WRITEBACK_LATENCY 64 |
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#define AUTOCOMMIT_BLOCKS_SSD 65536 |
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#define AUTOCOMMIT_BLOCKS_PMEM 64 |
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#define AUTOCOMMIT_MSEC 1000 |
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#define MAX_AGE_DIV 16 |
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#define MAX_AGE_UNSPECIFIED -1UL |
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|
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#define BITMAP_GRANULARITY 65536 |
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#if BITMAP_GRANULARITY < PAGE_SIZE |
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#undef BITMAP_GRANULARITY |
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#define BITMAP_GRANULARITY PAGE_SIZE |
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#endif |
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#if IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) |
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#define DM_WRITECACHE_HAS_PMEM |
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#endif |
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|
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#ifdef DM_WRITECACHE_HAS_PMEM |
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#define pmem_assign(dest, src) \ |
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do { \ |
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typeof(dest) uniq = (src); \ |
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memcpy_flushcache(&(dest), &uniq, sizeof(dest)); \ |
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} while (0) |
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#else |
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#define pmem_assign(dest, src) ((dest) = (src)) |
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#endif |
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#if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM) |
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#define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
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#endif |
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#define MEMORY_SUPERBLOCK_MAGIC 0x23489321 |
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#define MEMORY_SUPERBLOCK_VERSION 1 |
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struct wc_memory_entry { |
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__le64 original_sector; |
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__le64 seq_count; |
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}; |
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struct wc_memory_superblock { |
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union { |
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struct { |
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__le32 magic; |
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__le32 version; |
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__le32 block_size; |
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__le32 pad; |
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__le64 n_blocks; |
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__le64 seq_count; |
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}; |
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__le64 padding[8]; |
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}; |
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struct wc_memory_entry entries[]; |
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}; |
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struct wc_entry { |
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struct rb_node rb_node; |
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struct list_head lru; |
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unsigned short wc_list_contiguous; |
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bool write_in_progress |
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#if BITS_PER_LONG == 64 |
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:1 |
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#endif |
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; |
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unsigned long index |
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#if BITS_PER_LONG == 64 |
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:47 |
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#endif |
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; |
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unsigned long age; |
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#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
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uint64_t original_sector; |
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uint64_t seq_count; |
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#endif |
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}; |
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#ifdef DM_WRITECACHE_HAS_PMEM |
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#define WC_MODE_PMEM(wc) ((wc)->pmem_mode) |
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#define WC_MODE_FUA(wc) ((wc)->writeback_fua) |
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#else |
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#define WC_MODE_PMEM(wc) false |
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#define WC_MODE_FUA(wc) false |
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#endif |
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#define WC_MODE_SORT_FREELIST(wc) (!WC_MODE_PMEM(wc)) |
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struct dm_writecache { |
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struct mutex lock; |
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struct list_head lru; |
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union { |
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struct list_head freelist; |
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struct { |
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struct rb_root freetree; |
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struct wc_entry *current_free; |
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}; |
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}; |
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struct rb_root tree; |
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size_t freelist_size; |
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size_t writeback_size; |
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size_t freelist_high_watermark; |
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size_t freelist_low_watermark; |
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unsigned long max_age; |
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unsigned uncommitted_blocks; |
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unsigned autocommit_blocks; |
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unsigned max_writeback_jobs; |
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int error; |
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unsigned long autocommit_jiffies; |
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struct timer_list autocommit_timer; |
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struct wait_queue_head freelist_wait; |
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struct timer_list max_age_timer; |
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atomic_t bio_in_progress[2]; |
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struct wait_queue_head bio_in_progress_wait[2]; |
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struct dm_target *ti; |
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struct dm_dev *dev; |
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struct dm_dev *ssd_dev; |
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sector_t start_sector; |
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void *memory_map; |
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uint64_t memory_map_size; |
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size_t metadata_sectors; |
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size_t n_blocks; |
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uint64_t seq_count; |
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sector_t data_device_sectors; |
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void *block_start; |
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struct wc_entry *entries; |
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unsigned block_size; |
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unsigned char block_size_bits; |
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bool pmem_mode:1; |
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bool writeback_fua:1; |
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bool overwrote_committed:1; |
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bool memory_vmapped:1; |
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bool start_sector_set:1; |
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bool high_wm_percent_set:1; |
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bool low_wm_percent_set:1; |
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bool max_writeback_jobs_set:1; |
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bool autocommit_blocks_set:1; |
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bool autocommit_time_set:1; |
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bool max_age_set:1; |
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bool writeback_fua_set:1; |
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bool flush_on_suspend:1; |
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bool cleaner:1; |
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bool cleaner_set:1; |
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unsigned high_wm_percent_value; |
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unsigned low_wm_percent_value; |
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unsigned autocommit_time_value; |
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unsigned max_age_value; |
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unsigned writeback_all; |
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struct workqueue_struct *writeback_wq; |
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struct work_struct writeback_work; |
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struct work_struct flush_work; |
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struct dm_io_client *dm_io; |
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raw_spinlock_t endio_list_lock; |
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struct list_head endio_list; |
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struct task_struct *endio_thread; |
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struct task_struct *flush_thread; |
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struct bio_list flush_list; |
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struct dm_kcopyd_client *dm_kcopyd; |
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unsigned long *dirty_bitmap; |
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unsigned dirty_bitmap_size; |
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struct bio_set bio_set; |
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mempool_t copy_pool; |
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}; |
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#define WB_LIST_INLINE 16 |
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struct writeback_struct { |
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struct list_head endio_entry; |
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struct dm_writecache *wc; |
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struct wc_entry **wc_list; |
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unsigned wc_list_n; |
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struct wc_entry *wc_list_inline[WB_LIST_INLINE]; |
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struct bio bio; |
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}; |
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struct copy_struct { |
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struct list_head endio_entry; |
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struct dm_writecache *wc; |
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struct wc_entry *e; |
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unsigned n_entries; |
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int error; |
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}; |
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DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(dm_writecache_throttle, |
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"A percentage of time allocated for data copying"); |
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static void wc_lock(struct dm_writecache *wc) |
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{ |
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mutex_lock(&wc->lock); |
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} |
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static void wc_unlock(struct dm_writecache *wc) |
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{ |
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mutex_unlock(&wc->lock); |
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} |
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#ifdef DM_WRITECACHE_HAS_PMEM |
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static int persistent_memory_claim(struct dm_writecache *wc) |
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{ |
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int r; |
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loff_t s; |
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long p, da; |
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pfn_t pfn; |
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int id; |
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struct page **pages; |
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sector_t offset; |
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wc->memory_vmapped = false; |
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s = wc->memory_map_size; |
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p = s >> PAGE_SHIFT; |
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if (!p) { |
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r = -EINVAL; |
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goto err1; |
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} |
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if (p != s >> PAGE_SHIFT) { |
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r = -EOVERFLOW; |
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goto err1; |
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} |
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offset = get_start_sect(wc->ssd_dev->bdev); |
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if (offset & (PAGE_SIZE / 512 - 1)) { |
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r = -EINVAL; |
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goto err1; |
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} |
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offset >>= PAGE_SHIFT - 9; |
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id = dax_read_lock(); |
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da = dax_direct_access(wc->ssd_dev->dax_dev, offset, p, &wc->memory_map, &pfn); |
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if (da < 0) { |
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wc->memory_map = NULL; |
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r = da; |
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goto err2; |
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} |
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if (!pfn_t_has_page(pfn)) { |
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wc->memory_map = NULL; |
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r = -EOPNOTSUPP; |
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goto err2; |
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} |
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if (da != p) { |
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long i; |
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wc->memory_map = NULL; |
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pages = kvmalloc_array(p, sizeof(struct page *), GFP_KERNEL); |
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if (!pages) { |
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r = -ENOMEM; |
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goto err2; |
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} |
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i = 0; |
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do { |
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long daa; |
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daa = dax_direct_access(wc->ssd_dev->dax_dev, offset + i, p - i, |
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NULL, &pfn); |
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if (daa <= 0) { |
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r = daa ? daa : -EINVAL; |
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goto err3; |
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} |
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if (!pfn_t_has_page(pfn)) { |
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r = -EOPNOTSUPP; |
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goto err3; |
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} |
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while (daa-- && i < p) { |
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pages[i++] = pfn_t_to_page(pfn); |
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pfn.val++; |
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if (!(i & 15)) |
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cond_resched(); |
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} |
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} while (i < p); |
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wc->memory_map = vmap(pages, p, VM_MAP, PAGE_KERNEL); |
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if (!wc->memory_map) { |
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r = -ENOMEM; |
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goto err3; |
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} |
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kvfree(pages); |
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wc->memory_vmapped = true; |
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} |
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dax_read_unlock(id); |
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wc->memory_map += (size_t)wc->start_sector << SECTOR_SHIFT; |
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wc->memory_map_size -= (size_t)wc->start_sector << SECTOR_SHIFT; |
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return 0; |
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err3: |
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kvfree(pages); |
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err2: |
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dax_read_unlock(id); |
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err1: |
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return r; |
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} |
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#else |
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static int persistent_memory_claim(struct dm_writecache *wc) |
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{ |
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return -EOPNOTSUPP; |
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} |
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#endif |
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static void persistent_memory_release(struct dm_writecache *wc) |
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{ |
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if (wc->memory_vmapped) |
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vunmap(wc->memory_map - ((size_t)wc->start_sector << SECTOR_SHIFT)); |
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} |
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static struct page *persistent_memory_page(void *addr) |
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{ |
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if (is_vmalloc_addr(addr)) |
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return vmalloc_to_page(addr); |
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else |
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return virt_to_page(addr); |
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} |
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static unsigned persistent_memory_page_offset(void *addr) |
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{ |
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return (unsigned long)addr & (PAGE_SIZE - 1); |
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} |
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static void persistent_memory_flush_cache(void *ptr, size_t size) |
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{ |
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if (is_vmalloc_addr(ptr)) |
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flush_kernel_vmap_range(ptr, size); |
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} |
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static void persistent_memory_invalidate_cache(void *ptr, size_t size) |
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{ |
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if (is_vmalloc_addr(ptr)) |
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invalidate_kernel_vmap_range(ptr, size); |
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} |
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static struct wc_memory_superblock *sb(struct dm_writecache *wc) |
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{ |
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return wc->memory_map; |
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} |
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static struct wc_memory_entry *memory_entry(struct dm_writecache *wc, struct wc_entry *e) |
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{ |
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return &sb(wc)->entries[e->index]; |
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} |
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static void *memory_data(struct dm_writecache *wc, struct wc_entry *e) |
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{ |
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return (char *)wc->block_start + (e->index << wc->block_size_bits); |
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} |
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static sector_t cache_sector(struct dm_writecache *wc, struct wc_entry *e) |
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{ |
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return wc->start_sector + wc->metadata_sectors + |
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((sector_t)e->index << (wc->block_size_bits - SECTOR_SHIFT)); |
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} |
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static uint64_t read_original_sector(struct dm_writecache *wc, struct wc_entry *e) |
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{ |
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#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
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return e->original_sector; |
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#else |
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return le64_to_cpu(memory_entry(wc, e)->original_sector); |
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#endif |
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} |
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static uint64_t read_seq_count(struct dm_writecache *wc, struct wc_entry *e) |
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{ |
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#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
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return e->seq_count; |
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#else |
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return le64_to_cpu(memory_entry(wc, e)->seq_count); |
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#endif |
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} |
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static void clear_seq_count(struct dm_writecache *wc, struct wc_entry *e) |
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{ |
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#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
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e->seq_count = -1; |
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#endif |
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pmem_assign(memory_entry(wc, e)->seq_count, cpu_to_le64(-1)); |
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} |
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static void write_original_sector_seq_count(struct dm_writecache *wc, struct wc_entry *e, |
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uint64_t original_sector, uint64_t seq_count) |
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{ |
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struct wc_memory_entry me; |
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#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
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e->original_sector = original_sector; |
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e->seq_count = seq_count; |
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#endif |
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me.original_sector = cpu_to_le64(original_sector); |
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me.seq_count = cpu_to_le64(seq_count); |
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pmem_assign(*memory_entry(wc, e), me); |
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} |
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#define writecache_error(wc, err, msg, arg...) \ |
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do { \ |
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if (!cmpxchg(&(wc)->error, 0, err)) \ |
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DMERR(msg, ##arg); \ |
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wake_up(&(wc)->freelist_wait); \ |
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} while (0) |
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#define writecache_has_error(wc) (unlikely(READ_ONCE((wc)->error))) |
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static void writecache_flush_all_metadata(struct dm_writecache *wc) |
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{ |
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if (!WC_MODE_PMEM(wc)) |
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memset(wc->dirty_bitmap, -1, wc->dirty_bitmap_size); |
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} |
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static void writecache_flush_region(struct dm_writecache *wc, void *ptr, size_t size) |
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{ |
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if (!WC_MODE_PMEM(wc)) |
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__set_bit(((char *)ptr - (char *)wc->memory_map) / BITMAP_GRANULARITY, |
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wc->dirty_bitmap); |
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} |
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static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev); |
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struct io_notify { |
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struct dm_writecache *wc; |
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struct completion c; |
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atomic_t count; |
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}; |
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static void writecache_notify_io(unsigned long error, void *context) |
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{ |
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struct io_notify *endio = context; |
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|
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if (unlikely(error != 0)) |
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writecache_error(endio->wc, -EIO, "error writing metadata"); |
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BUG_ON(atomic_read(&endio->count) <= 0); |
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if (atomic_dec_and_test(&endio->count)) |
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complete(&endio->c); |
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} |
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static void writecache_wait_for_ios(struct dm_writecache *wc, int direction) |
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{ |
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wait_event(wc->bio_in_progress_wait[direction], |
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!atomic_read(&wc->bio_in_progress[direction])); |
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} |
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static void ssd_commit_flushed(struct dm_writecache *wc, bool wait_for_ios) |
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{ |
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struct dm_io_region region; |
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struct dm_io_request req; |
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struct io_notify endio = { |
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wc, |
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COMPLETION_INITIALIZER_ONSTACK(endio.c), |
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ATOMIC_INIT(1), |
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}; |
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unsigned bitmap_bits = wc->dirty_bitmap_size * 8; |
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unsigned i = 0; |
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|
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while (1) { |
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unsigned j; |
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i = find_next_bit(wc->dirty_bitmap, bitmap_bits, i); |
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if (unlikely(i == bitmap_bits)) |
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break; |
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j = find_next_zero_bit(wc->dirty_bitmap, bitmap_bits, i); |
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|
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region.bdev = wc->ssd_dev->bdev; |
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region.sector = (sector_t)i * (BITMAP_GRANULARITY >> SECTOR_SHIFT); |
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region.count = (sector_t)(j - i) * (BITMAP_GRANULARITY >> SECTOR_SHIFT); |
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|
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if (unlikely(region.sector >= wc->metadata_sectors)) |
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break; |
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if (unlikely(region.sector + region.count > wc->metadata_sectors)) |
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region.count = wc->metadata_sectors - region.sector; |
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|
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region.sector += wc->start_sector; |
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atomic_inc(&endio.count); |
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req.bi_op = REQ_OP_WRITE; |
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req.bi_op_flags = REQ_SYNC; |
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req.mem.type = DM_IO_VMA; |
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req.mem.ptr.vma = (char *)wc->memory_map + (size_t)i * BITMAP_GRANULARITY; |
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req.client = wc->dm_io; |
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req.notify.fn = writecache_notify_io; |
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req.notify.context = &endio; |
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|
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/* writing via async dm-io (implied by notify.fn above) won't return an error */ |
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(void) dm_io(&req, 1, ®ion, NULL); |
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i = j; |
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} |
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|
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writecache_notify_io(0, &endio); |
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wait_for_completion_io(&endio.c); |
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|
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if (wait_for_ios) |
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writecache_wait_for_ios(wc, WRITE); |
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|
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writecache_disk_flush(wc, wc->ssd_dev); |
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|
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memset(wc->dirty_bitmap, 0, wc->dirty_bitmap_size); |
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} |
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|
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static void ssd_commit_superblock(struct dm_writecache *wc) |
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{ |
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int r; |
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struct dm_io_region region; |
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struct dm_io_request req; |
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|
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region.bdev = wc->ssd_dev->bdev; |
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region.sector = 0; |
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region.count = PAGE_SIZE >> SECTOR_SHIFT; |
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|
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if (unlikely(region.sector + region.count > wc->metadata_sectors)) |
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region.count = wc->metadata_sectors - region.sector; |
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|
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region.sector += wc->start_sector; |
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|
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req.bi_op = REQ_OP_WRITE; |
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req.bi_op_flags = REQ_SYNC | REQ_FUA; |
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req.mem.type = DM_IO_VMA; |
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req.mem.ptr.vma = (char *)wc->memory_map; |
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req.client = wc->dm_io; |
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req.notify.fn = NULL; |
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req.notify.context = NULL; |
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|
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r = dm_io(&req, 1, ®ion, NULL); |
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if (unlikely(r)) |
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writecache_error(wc, r, "error writing superblock"); |
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} |
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|
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static void writecache_commit_flushed(struct dm_writecache *wc, bool wait_for_ios) |
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{ |
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if (WC_MODE_PMEM(wc)) |
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pmem_wmb(); |
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else |
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ssd_commit_flushed(wc, wait_for_ios); |
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} |
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|
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static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev) |
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{ |
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int r; |
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struct dm_io_region region; |
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struct dm_io_request req; |
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|
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region.bdev = dev->bdev; |
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region.sector = 0; |
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region.count = 0; |
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req.bi_op = REQ_OP_WRITE; |
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req.bi_op_flags = REQ_PREFLUSH; |
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req.mem.type = DM_IO_KMEM; |
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req.mem.ptr.addr = NULL; |
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req.client = wc->dm_io; |
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req.notify.fn = NULL; |
|
|
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r = dm_io(&req, 1, ®ion, NULL); |
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if (unlikely(r)) |
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writecache_error(wc, r, "error flushing metadata: %d", r); |
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} |
|
|
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#define WFE_RETURN_FOLLOWING 1 |
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#define WFE_LOWEST_SEQ 2 |
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|
|
static struct wc_entry *writecache_find_entry(struct dm_writecache *wc, |
|
uint64_t block, int flags) |
|
{ |
|
struct wc_entry *e; |
|
struct rb_node *node = wc->tree.rb_node; |
|
|
|
if (unlikely(!node)) |
|
return NULL; |
|
|
|
while (1) { |
|
e = container_of(node, struct wc_entry, rb_node); |
|
if (read_original_sector(wc, e) == block) |
|
break; |
|
|
|
node = (read_original_sector(wc, e) >= block ? |
|
e->rb_node.rb_left : e->rb_node.rb_right); |
|
if (unlikely(!node)) { |
|
if (!(flags & WFE_RETURN_FOLLOWING)) |
|
return NULL; |
|
if (read_original_sector(wc, e) >= block) { |
|
return e; |
|
} else { |
|
node = rb_next(&e->rb_node); |
|
if (unlikely(!node)) |
|
return NULL; |
|
e = container_of(node, struct wc_entry, rb_node); |
|
return e; |
|
} |
|
} |
|
} |
|
|
|
while (1) { |
|
struct wc_entry *e2; |
|
if (flags & WFE_LOWEST_SEQ) |
|
node = rb_prev(&e->rb_node); |
|
else |
|
node = rb_next(&e->rb_node); |
|
if (unlikely(!node)) |
|
return e; |
|
e2 = container_of(node, struct wc_entry, rb_node); |
|
if (read_original_sector(wc, e2) != block) |
|
return e; |
|
e = e2; |
|
} |
|
} |
|
|
|
static void writecache_insert_entry(struct dm_writecache *wc, struct wc_entry *ins) |
|
{ |
|
struct wc_entry *e; |
|
struct rb_node **node = &wc->tree.rb_node, *parent = NULL; |
|
|
|
while (*node) { |
|
e = container_of(*node, struct wc_entry, rb_node); |
|
parent = &e->rb_node; |
|
if (read_original_sector(wc, e) > read_original_sector(wc, ins)) |
|
node = &parent->rb_left; |
|
else |
|
node = &parent->rb_right; |
|
} |
|
rb_link_node(&ins->rb_node, parent, node); |
|
rb_insert_color(&ins->rb_node, &wc->tree); |
|
list_add(&ins->lru, &wc->lru); |
|
ins->age = jiffies; |
|
} |
|
|
|
static void writecache_unlink(struct dm_writecache *wc, struct wc_entry *e) |
|
{ |
|
list_del(&e->lru); |
|
rb_erase(&e->rb_node, &wc->tree); |
|
} |
|
|
|
static void writecache_add_to_freelist(struct dm_writecache *wc, struct wc_entry *e) |
|
{ |
|
if (WC_MODE_SORT_FREELIST(wc)) { |
|
struct rb_node **node = &wc->freetree.rb_node, *parent = NULL; |
|
if (unlikely(!*node)) |
|
wc->current_free = e; |
|
while (*node) { |
|
parent = *node; |
|
if (&e->rb_node < *node) |
|
node = &parent->rb_left; |
|
else |
|
node = &parent->rb_right; |
|
} |
|
rb_link_node(&e->rb_node, parent, node); |
|
rb_insert_color(&e->rb_node, &wc->freetree); |
|
} else { |
|
list_add_tail(&e->lru, &wc->freelist); |
|
} |
|
wc->freelist_size++; |
|
} |
|
|
|
static inline void writecache_verify_watermark(struct dm_writecache *wc) |
|
{ |
|
if (unlikely(wc->freelist_size + wc->writeback_size <= wc->freelist_high_watermark)) |
|
queue_work(wc->writeback_wq, &wc->writeback_work); |
|
} |
|
|
|
static void writecache_max_age_timer(struct timer_list *t) |
|
{ |
|
struct dm_writecache *wc = from_timer(wc, t, max_age_timer); |
|
|
|
if (!dm_suspended(wc->ti) && !writecache_has_error(wc)) { |
|
queue_work(wc->writeback_wq, &wc->writeback_work); |
|
mod_timer(&wc->max_age_timer, jiffies + wc->max_age / MAX_AGE_DIV); |
|
} |
|
} |
|
|
|
static struct wc_entry *writecache_pop_from_freelist(struct dm_writecache *wc, sector_t expected_sector) |
|
{ |
|
struct wc_entry *e; |
|
|
|
if (WC_MODE_SORT_FREELIST(wc)) { |
|
struct rb_node *next; |
|
if (unlikely(!wc->current_free)) |
|
return NULL; |
|
e = wc->current_free; |
|
if (expected_sector != (sector_t)-1 && unlikely(cache_sector(wc, e) != expected_sector)) |
|
return NULL; |
|
next = rb_next(&e->rb_node); |
|
rb_erase(&e->rb_node, &wc->freetree); |
|
if (unlikely(!next)) |
|
next = rb_first(&wc->freetree); |
|
wc->current_free = next ? container_of(next, struct wc_entry, rb_node) : NULL; |
|
} else { |
|
if (unlikely(list_empty(&wc->freelist))) |
|
return NULL; |
|
e = container_of(wc->freelist.next, struct wc_entry, lru); |
|
if (expected_sector != (sector_t)-1 && unlikely(cache_sector(wc, e) != expected_sector)) |
|
return NULL; |
|
list_del(&e->lru); |
|
} |
|
wc->freelist_size--; |
|
|
|
writecache_verify_watermark(wc); |
|
|
|
return e; |
|
} |
|
|
|
static void writecache_free_entry(struct dm_writecache *wc, struct wc_entry *e) |
|
{ |
|
writecache_unlink(wc, e); |
|
writecache_add_to_freelist(wc, e); |
|
clear_seq_count(wc, e); |
|
writecache_flush_region(wc, memory_entry(wc, e), sizeof(struct wc_memory_entry)); |
|
if (unlikely(waitqueue_active(&wc->freelist_wait))) |
|
wake_up(&wc->freelist_wait); |
|
} |
|
|
|
static void writecache_wait_on_freelist(struct dm_writecache *wc) |
|
{ |
|
DEFINE_WAIT(wait); |
|
|
|
prepare_to_wait(&wc->freelist_wait, &wait, TASK_UNINTERRUPTIBLE); |
|
wc_unlock(wc); |
|
io_schedule(); |
|
finish_wait(&wc->freelist_wait, &wait); |
|
wc_lock(wc); |
|
} |
|
|
|
static void writecache_poison_lists(struct dm_writecache *wc) |
|
{ |
|
/* |
|
* Catch incorrect access to these values while the device is suspended. |
|
*/ |
|
memset(&wc->tree, -1, sizeof wc->tree); |
|
wc->lru.next = LIST_POISON1; |
|
wc->lru.prev = LIST_POISON2; |
|
wc->freelist.next = LIST_POISON1; |
|
wc->freelist.prev = LIST_POISON2; |
|
} |
|
|
|
static void writecache_flush_entry(struct dm_writecache *wc, struct wc_entry *e) |
|
{ |
|
writecache_flush_region(wc, memory_entry(wc, e), sizeof(struct wc_memory_entry)); |
|
if (WC_MODE_PMEM(wc)) |
|
writecache_flush_region(wc, memory_data(wc, e), wc->block_size); |
|
} |
|
|
|
static bool writecache_entry_is_committed(struct dm_writecache *wc, struct wc_entry *e) |
|
{ |
|
return read_seq_count(wc, e) < wc->seq_count; |
|
} |
|
|
|
static void writecache_flush(struct dm_writecache *wc) |
|
{ |
|
struct wc_entry *e, *e2; |
|
bool need_flush_after_free; |
|
|
|
wc->uncommitted_blocks = 0; |
|
del_timer(&wc->autocommit_timer); |
|
|
|
if (list_empty(&wc->lru)) |
|
return; |
|
|
|
e = container_of(wc->lru.next, struct wc_entry, lru); |
|
if (writecache_entry_is_committed(wc, e)) { |
|
if (wc->overwrote_committed) { |
|
writecache_wait_for_ios(wc, WRITE); |
|
writecache_disk_flush(wc, wc->ssd_dev); |
|
wc->overwrote_committed = false; |
|
} |
|
return; |
|
} |
|
while (1) { |
|
writecache_flush_entry(wc, e); |
|
if (unlikely(e->lru.next == &wc->lru)) |
|
break; |
|
e2 = container_of(e->lru.next, struct wc_entry, lru); |
|
if (writecache_entry_is_committed(wc, e2)) |
|
break; |
|
e = e2; |
|
cond_resched(); |
|
} |
|
writecache_commit_flushed(wc, true); |
|
|
|
wc->seq_count++; |
|
pmem_assign(sb(wc)->seq_count, cpu_to_le64(wc->seq_count)); |
|
if (WC_MODE_PMEM(wc)) |
|
writecache_commit_flushed(wc, false); |
|
else |
|
ssd_commit_superblock(wc); |
|
|
|
wc->overwrote_committed = false; |
|
|
|
need_flush_after_free = false; |
|
while (1) { |
|
/* Free another committed entry with lower seq-count */ |
|
struct rb_node *rb_node = rb_prev(&e->rb_node); |
|
|
|
if (rb_node) { |
|
e2 = container_of(rb_node, struct wc_entry, rb_node); |
|
if (read_original_sector(wc, e2) == read_original_sector(wc, e) && |
|
likely(!e2->write_in_progress)) { |
|
writecache_free_entry(wc, e2); |
|
need_flush_after_free = true; |
|
} |
|
} |
|
if (unlikely(e->lru.prev == &wc->lru)) |
|
break; |
|
e = container_of(e->lru.prev, struct wc_entry, lru); |
|
cond_resched(); |
|
} |
|
|
|
if (need_flush_after_free) |
|
writecache_commit_flushed(wc, false); |
|
} |
|
|
|
static void writecache_flush_work(struct work_struct *work) |
|
{ |
|
struct dm_writecache *wc = container_of(work, struct dm_writecache, flush_work); |
|
|
|
wc_lock(wc); |
|
writecache_flush(wc); |
|
wc_unlock(wc); |
|
} |
|
|
|
static void writecache_autocommit_timer(struct timer_list *t) |
|
{ |
|
struct dm_writecache *wc = from_timer(wc, t, autocommit_timer); |
|
if (!writecache_has_error(wc)) |
|
queue_work(wc->writeback_wq, &wc->flush_work); |
|
} |
|
|
|
static void writecache_schedule_autocommit(struct dm_writecache *wc) |
|
{ |
|
if (!timer_pending(&wc->autocommit_timer)) |
|
mod_timer(&wc->autocommit_timer, jiffies + wc->autocommit_jiffies); |
|
} |
|
|
|
static void writecache_discard(struct dm_writecache *wc, sector_t start, sector_t end) |
|
{ |
|
struct wc_entry *e; |
|
bool discarded_something = false; |
|
|
|
e = writecache_find_entry(wc, start, WFE_RETURN_FOLLOWING | WFE_LOWEST_SEQ); |
|
if (unlikely(!e)) |
|
return; |
|
|
|
while (read_original_sector(wc, e) < end) { |
|
struct rb_node *node = rb_next(&e->rb_node); |
|
|
|
if (likely(!e->write_in_progress)) { |
|
if (!discarded_something) { |
|
if (!WC_MODE_PMEM(wc)) { |
|
writecache_wait_for_ios(wc, READ); |
|
writecache_wait_for_ios(wc, WRITE); |
|
} |
|
discarded_something = true; |
|
} |
|
if (!writecache_entry_is_committed(wc, e)) |
|
wc->uncommitted_blocks--; |
|
writecache_free_entry(wc, e); |
|
} |
|
|
|
if (unlikely(!node)) |
|
break; |
|
|
|
e = container_of(node, struct wc_entry, rb_node); |
|
} |
|
|
|
if (discarded_something) |
|
writecache_commit_flushed(wc, false); |
|
} |
|
|
|
static bool writecache_wait_for_writeback(struct dm_writecache *wc) |
|
{ |
|
if (wc->writeback_size) { |
|
writecache_wait_on_freelist(wc); |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
static void writecache_suspend(struct dm_target *ti) |
|
{ |
|
struct dm_writecache *wc = ti->private; |
|
bool flush_on_suspend; |
|
|
|
del_timer_sync(&wc->autocommit_timer); |
|
del_timer_sync(&wc->max_age_timer); |
|
|
|
wc_lock(wc); |
|
writecache_flush(wc); |
|
flush_on_suspend = wc->flush_on_suspend; |
|
if (flush_on_suspend) { |
|
wc->flush_on_suspend = false; |
|
wc->writeback_all++; |
|
queue_work(wc->writeback_wq, &wc->writeback_work); |
|
} |
|
wc_unlock(wc); |
|
|
|
drain_workqueue(wc->writeback_wq); |
|
|
|
wc_lock(wc); |
|
if (flush_on_suspend) |
|
wc->writeback_all--; |
|
while (writecache_wait_for_writeback(wc)); |
|
|
|
if (WC_MODE_PMEM(wc)) |
|
persistent_memory_flush_cache(wc->memory_map, wc->memory_map_size); |
|
|
|
writecache_poison_lists(wc); |
|
|
|
wc_unlock(wc); |
|
} |
|
|
|
static int writecache_alloc_entries(struct dm_writecache *wc) |
|
{ |
|
size_t b; |
|
|
|
if (wc->entries) |
|
return 0; |
|
wc->entries = vmalloc(array_size(sizeof(struct wc_entry), wc->n_blocks)); |
|
if (!wc->entries) |
|
return -ENOMEM; |
|
for (b = 0; b < wc->n_blocks; b++) { |
|
struct wc_entry *e = &wc->entries[b]; |
|
e->index = b; |
|
e->write_in_progress = false; |
|
cond_resched(); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int writecache_read_metadata(struct dm_writecache *wc, sector_t n_sectors) |
|
{ |
|
struct dm_io_region region; |
|
struct dm_io_request req; |
|
|
|
region.bdev = wc->ssd_dev->bdev; |
|
region.sector = wc->start_sector; |
|
region.count = n_sectors; |
|
req.bi_op = REQ_OP_READ; |
|
req.bi_op_flags = REQ_SYNC; |
|
req.mem.type = DM_IO_VMA; |
|
req.mem.ptr.vma = (char *)wc->memory_map; |
|
req.client = wc->dm_io; |
|
req.notify.fn = NULL; |
|
|
|
return dm_io(&req, 1, ®ion, NULL); |
|
} |
|
|
|
static void writecache_resume(struct dm_target *ti) |
|
{ |
|
struct dm_writecache *wc = ti->private; |
|
size_t b; |
|
bool need_flush = false; |
|
__le64 sb_seq_count; |
|
int r; |
|
|
|
wc_lock(wc); |
|
|
|
wc->data_device_sectors = bdev_nr_sectors(wc->dev->bdev); |
|
|
|
if (WC_MODE_PMEM(wc)) { |
|
persistent_memory_invalidate_cache(wc->memory_map, wc->memory_map_size); |
|
} else { |
|
r = writecache_read_metadata(wc, wc->metadata_sectors); |
|
if (r) { |
|
size_t sb_entries_offset; |
|
writecache_error(wc, r, "unable to read metadata: %d", r); |
|
sb_entries_offset = offsetof(struct wc_memory_superblock, entries); |
|
memset((char *)wc->memory_map + sb_entries_offset, -1, |
|
(wc->metadata_sectors << SECTOR_SHIFT) - sb_entries_offset); |
|
} |
|
} |
|
|
|
wc->tree = RB_ROOT; |
|
INIT_LIST_HEAD(&wc->lru); |
|
if (WC_MODE_SORT_FREELIST(wc)) { |
|
wc->freetree = RB_ROOT; |
|
wc->current_free = NULL; |
|
} else { |
|
INIT_LIST_HEAD(&wc->freelist); |
|
} |
|
wc->freelist_size = 0; |
|
|
|
r = copy_mc_to_kernel(&sb_seq_count, &sb(wc)->seq_count, |
|
sizeof(uint64_t)); |
|
if (r) { |
|
writecache_error(wc, r, "hardware memory error when reading superblock: %d", r); |
|
sb_seq_count = cpu_to_le64(0); |
|
} |
|
wc->seq_count = le64_to_cpu(sb_seq_count); |
|
|
|
#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS |
|
for (b = 0; b < wc->n_blocks; b++) { |
|
struct wc_entry *e = &wc->entries[b]; |
|
struct wc_memory_entry wme; |
|
if (writecache_has_error(wc)) { |
|
e->original_sector = -1; |
|
e->seq_count = -1; |
|
continue; |
|
} |
|
r = copy_mc_to_kernel(&wme, memory_entry(wc, e), |
|
sizeof(struct wc_memory_entry)); |
|
if (r) { |
|
writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d", |
|
(unsigned long)b, r); |
|
e->original_sector = -1; |
|
e->seq_count = -1; |
|
} else { |
|
e->original_sector = le64_to_cpu(wme.original_sector); |
|
e->seq_count = le64_to_cpu(wme.seq_count); |
|
} |
|
cond_resched(); |
|
} |
|
#endif |
|
for (b = 0; b < wc->n_blocks; b++) { |
|
struct wc_entry *e = &wc->entries[b]; |
|
if (!writecache_entry_is_committed(wc, e)) { |
|
if (read_seq_count(wc, e) != -1) { |
|
erase_this: |
|
clear_seq_count(wc, e); |
|
need_flush = true; |
|
} |
|
writecache_add_to_freelist(wc, e); |
|
} else { |
|
struct wc_entry *old; |
|
|
|
old = writecache_find_entry(wc, read_original_sector(wc, e), 0); |
|
if (!old) { |
|
writecache_insert_entry(wc, e); |
|
} else { |
|
if (read_seq_count(wc, old) == read_seq_count(wc, e)) { |
|
writecache_error(wc, -EINVAL, |
|
"two identical entries, position %llu, sector %llu, sequence %llu", |
|
(unsigned long long)b, (unsigned long long)read_original_sector(wc, e), |
|
(unsigned long long)read_seq_count(wc, e)); |
|
} |
|
if (read_seq_count(wc, old) > read_seq_count(wc, e)) { |
|
goto erase_this; |
|
} else { |
|
writecache_free_entry(wc, old); |
|
writecache_insert_entry(wc, e); |
|
need_flush = true; |
|
} |
|
} |
|
} |
|
cond_resched(); |
|
} |
|
|
|
if (need_flush) { |
|
writecache_flush_all_metadata(wc); |
|
writecache_commit_flushed(wc, false); |
|
} |
|
|
|
writecache_verify_watermark(wc); |
|
|
|
if (wc->max_age != MAX_AGE_UNSPECIFIED) |
|
mod_timer(&wc->max_age_timer, jiffies + wc->max_age / MAX_AGE_DIV); |
|
|
|
wc_unlock(wc); |
|
} |
|
|
|
static int process_flush_mesg(unsigned argc, char **argv, struct dm_writecache *wc) |
|
{ |
|
if (argc != 1) |
|
return -EINVAL; |
|
|
|
wc_lock(wc); |
|
if (dm_suspended(wc->ti)) { |
|
wc_unlock(wc); |
|
return -EBUSY; |
|
} |
|
if (writecache_has_error(wc)) { |
|
wc_unlock(wc); |
|
return -EIO; |
|
} |
|
|
|
writecache_flush(wc); |
|
wc->writeback_all++; |
|
queue_work(wc->writeback_wq, &wc->writeback_work); |
|
wc_unlock(wc); |
|
|
|
flush_workqueue(wc->writeback_wq); |
|
|
|
wc_lock(wc); |
|
wc->writeback_all--; |
|
if (writecache_has_error(wc)) { |
|
wc_unlock(wc); |
|
return -EIO; |
|
} |
|
wc_unlock(wc); |
|
|
|
return 0; |
|
} |
|
|
|
static int process_flush_on_suspend_mesg(unsigned argc, char **argv, struct dm_writecache *wc) |
|
{ |
|
if (argc != 1) |
|
return -EINVAL; |
|
|
|
wc_lock(wc); |
|
wc->flush_on_suspend = true; |
|
wc_unlock(wc); |
|
|
|
return 0; |
|
} |
|
|
|
static void activate_cleaner(struct dm_writecache *wc) |
|
{ |
|
wc->flush_on_suspend = true; |
|
wc->cleaner = true; |
|
wc->freelist_high_watermark = wc->n_blocks; |
|
wc->freelist_low_watermark = wc->n_blocks; |
|
} |
|
|
|
static int process_cleaner_mesg(unsigned argc, char **argv, struct dm_writecache *wc) |
|
{ |
|
if (argc != 1) |
|
return -EINVAL; |
|
|
|
wc_lock(wc); |
|
activate_cleaner(wc); |
|
if (!dm_suspended(wc->ti)) |
|
writecache_verify_watermark(wc); |
|
wc_unlock(wc); |
|
|
|
return 0; |
|
} |
|
|
|
static int writecache_message(struct dm_target *ti, unsigned argc, char **argv, |
|
char *result, unsigned maxlen) |
|
{ |
|
int r = -EINVAL; |
|
struct dm_writecache *wc = ti->private; |
|
|
|
if (!strcasecmp(argv[0], "flush")) |
|
r = process_flush_mesg(argc, argv, wc); |
|
else if (!strcasecmp(argv[0], "flush_on_suspend")) |
|
r = process_flush_on_suspend_mesg(argc, argv, wc); |
|
else if (!strcasecmp(argv[0], "cleaner")) |
|
r = process_cleaner_mesg(argc, argv, wc); |
|
else |
|
DMERR("unrecognised message received: %s", argv[0]); |
|
|
|
return r; |
|
} |
|
|
|
static void memcpy_flushcache_optimized(void *dest, void *source, size_t size) |
|
{ |
|
/* |
|
* clflushopt performs better with block size 1024, 2048, 4096 |
|
* non-temporal stores perform better with block size 512 |
|
* |
|
* block size 512 1024 2048 4096 |
|
* movnti 496 MB/s 642 MB/s 725 MB/s 744 MB/s |
|
* clflushopt 373 MB/s 688 MB/s 1.1 GB/s 1.2 GB/s |
|
* |
|
* We see that movnti performs better for 512-byte blocks, and |
|
* clflushopt performs better for 1024-byte and larger blocks. So, we |
|
* prefer clflushopt for sizes >= 768. |
|
* |
|
* NOTE: this happens to be the case now (with dm-writecache's single |
|
* threaded model) but re-evaluate this once memcpy_flushcache() is |
|
* enabled to use movdir64b which might invalidate this performance |
|
* advantage seen with cache-allocating-writes plus flushing. |
|
*/ |
|
#ifdef CONFIG_X86 |
|
if (static_cpu_has(X86_FEATURE_CLFLUSHOPT) && |
|
likely(boot_cpu_data.x86_clflush_size == 64) && |
|
likely(size >= 768)) { |
|
do { |
|
memcpy((void *)dest, (void *)source, 64); |
|
clflushopt((void *)dest); |
|
dest += 64; |
|
source += 64; |
|
size -= 64; |
|
} while (size >= 64); |
|
return; |
|
} |
|
#endif |
|
memcpy_flushcache(dest, source, size); |
|
} |
|
|
|
static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data) |
|
{ |
|
void *buf; |
|
unsigned long flags; |
|
unsigned size; |
|
int rw = bio_data_dir(bio); |
|
unsigned remaining_size = wc->block_size; |
|
|
|
do { |
|
struct bio_vec bv = bio_iter_iovec(bio, bio->bi_iter); |
|
buf = bvec_kmap_irq(&bv, &flags); |
|
size = bv.bv_len; |
|
if (unlikely(size > remaining_size)) |
|
size = remaining_size; |
|
|
|
if (rw == READ) { |
|
int r; |
|
r = copy_mc_to_kernel(buf, data, size); |
|
flush_dcache_page(bio_page(bio)); |
|
if (unlikely(r)) { |
|
writecache_error(wc, r, "hardware memory error when reading data: %d", r); |
|
bio->bi_status = BLK_STS_IOERR; |
|
} |
|
} else { |
|
flush_dcache_page(bio_page(bio)); |
|
memcpy_flushcache_optimized(data, buf, size); |
|
} |
|
|
|
bvec_kunmap_irq(buf, &flags); |
|
|
|
data = (char *)data + size; |
|
remaining_size -= size; |
|
bio_advance(bio, size); |
|
} while (unlikely(remaining_size)); |
|
} |
|
|
|
static int writecache_flush_thread(void *data) |
|
{ |
|
struct dm_writecache *wc = data; |
|
|
|
while (1) { |
|
struct bio *bio; |
|
|
|
wc_lock(wc); |
|
bio = bio_list_pop(&wc->flush_list); |
|
if (!bio) { |
|
set_current_state(TASK_INTERRUPTIBLE); |
|
wc_unlock(wc); |
|
|
|
if (unlikely(kthread_should_stop())) { |
|
set_current_state(TASK_RUNNING); |
|
break; |
|
} |
|
|
|
schedule(); |
|
continue; |
|
} |
|
|
|
if (bio_op(bio) == REQ_OP_DISCARD) { |
|
writecache_discard(wc, bio->bi_iter.bi_sector, |
|
bio_end_sector(bio)); |
|
wc_unlock(wc); |
|
bio_set_dev(bio, wc->dev->bdev); |
|
submit_bio_noacct(bio); |
|
} else { |
|
writecache_flush(wc); |
|
wc_unlock(wc); |
|
if (writecache_has_error(wc)) |
|
bio->bi_status = BLK_STS_IOERR; |
|
bio_endio(bio); |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void writecache_offload_bio(struct dm_writecache *wc, struct bio *bio) |
|
{ |
|
if (bio_list_empty(&wc->flush_list)) |
|
wake_up_process(wc->flush_thread); |
|
bio_list_add(&wc->flush_list, bio); |
|
} |
|
|
|
static int writecache_map(struct dm_target *ti, struct bio *bio) |
|
{ |
|
struct wc_entry *e; |
|
struct dm_writecache *wc = ti->private; |
|
|
|
bio->bi_private = NULL; |
|
|
|
wc_lock(wc); |
|
|
|
if (unlikely(bio->bi_opf & REQ_PREFLUSH)) { |
|
if (writecache_has_error(wc)) |
|
goto unlock_error; |
|
if (WC_MODE_PMEM(wc)) { |
|
writecache_flush(wc); |
|
if (writecache_has_error(wc)) |
|
goto unlock_error; |
|
goto unlock_submit; |
|
} else { |
|
writecache_offload_bio(wc, bio); |
|
goto unlock_return; |
|
} |
|
} |
|
|
|
bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector); |
|
|
|
if (unlikely((((unsigned)bio->bi_iter.bi_sector | bio_sectors(bio)) & |
|
(wc->block_size / 512 - 1)) != 0)) { |
|
DMERR("I/O is not aligned, sector %llu, size %u, block size %u", |
|
(unsigned long long)bio->bi_iter.bi_sector, |
|
bio->bi_iter.bi_size, wc->block_size); |
|
goto unlock_error; |
|
} |
|
|
|
if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) { |
|
if (writecache_has_error(wc)) |
|
goto unlock_error; |
|
if (WC_MODE_PMEM(wc)) { |
|
writecache_discard(wc, bio->bi_iter.bi_sector, bio_end_sector(bio)); |
|
goto unlock_remap_origin; |
|
} else { |
|
writecache_offload_bio(wc, bio); |
|
goto unlock_return; |
|
} |
|
} |
|
|
|
if (bio_data_dir(bio) == READ) { |
|
read_next_block: |
|
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING); |
|
if (e && read_original_sector(wc, e) == bio->bi_iter.bi_sector) { |
|
if (WC_MODE_PMEM(wc)) { |
|
bio_copy_block(wc, bio, memory_data(wc, e)); |
|
if (bio->bi_iter.bi_size) |
|
goto read_next_block; |
|
goto unlock_submit; |
|
} else { |
|
dm_accept_partial_bio(bio, wc->block_size >> SECTOR_SHIFT); |
|
bio_set_dev(bio, wc->ssd_dev->bdev); |
|
bio->bi_iter.bi_sector = cache_sector(wc, e); |
|
if (!writecache_entry_is_committed(wc, e)) |
|
writecache_wait_for_ios(wc, WRITE); |
|
goto unlock_remap; |
|
} |
|
} else { |
|
if (e) { |
|
sector_t next_boundary = |
|
read_original_sector(wc, e) - bio->bi_iter.bi_sector; |
|
if (next_boundary < bio->bi_iter.bi_size >> SECTOR_SHIFT) { |
|
dm_accept_partial_bio(bio, next_boundary); |
|
} |
|
} |
|
goto unlock_remap_origin; |
|
} |
|
} else { |
|
do { |
|
bool found_entry = false; |
|
if (writecache_has_error(wc)) |
|
goto unlock_error; |
|
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, 0); |
|
if (e) { |
|
if (!writecache_entry_is_committed(wc, e)) |
|
goto bio_copy; |
|
if (!WC_MODE_PMEM(wc) && !e->write_in_progress) { |
|
wc->overwrote_committed = true; |
|
goto bio_copy; |
|
} |
|
found_entry = true; |
|
} else { |
|
if (unlikely(wc->cleaner)) |
|
goto direct_write; |
|
} |
|
e = writecache_pop_from_freelist(wc, (sector_t)-1); |
|
if (unlikely(!e)) { |
|
if (!found_entry) { |
|
direct_write: |
|
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING); |
|
if (e) { |
|
sector_t next_boundary = read_original_sector(wc, e) - bio->bi_iter.bi_sector; |
|
BUG_ON(!next_boundary); |
|
if (next_boundary < bio->bi_iter.bi_size >> SECTOR_SHIFT) { |
|
dm_accept_partial_bio(bio, next_boundary); |
|
} |
|
} |
|
goto unlock_remap_origin; |
|
} |
|
writecache_wait_on_freelist(wc); |
|
continue; |
|
} |
|
write_original_sector_seq_count(wc, e, bio->bi_iter.bi_sector, wc->seq_count); |
|
writecache_insert_entry(wc, e); |
|
wc->uncommitted_blocks++; |
|
bio_copy: |
|
if (WC_MODE_PMEM(wc)) { |
|
bio_copy_block(wc, bio, memory_data(wc, e)); |
|
} else { |
|
unsigned bio_size = wc->block_size; |
|
sector_t start_cache_sec = cache_sector(wc, e); |
|
sector_t current_cache_sec = start_cache_sec + (bio_size >> SECTOR_SHIFT); |
|
|
|
while (bio_size < bio->bi_iter.bi_size) { |
|
struct wc_entry *f = writecache_pop_from_freelist(wc, current_cache_sec); |
|
if (!f) |
|
break; |
|
write_original_sector_seq_count(wc, f, bio->bi_iter.bi_sector + |
|
(bio_size >> SECTOR_SHIFT), wc->seq_count); |
|
writecache_insert_entry(wc, f); |
|
wc->uncommitted_blocks++; |
|
bio_size += wc->block_size; |
|
current_cache_sec += wc->block_size >> SECTOR_SHIFT; |
|
} |
|
|
|
bio_set_dev(bio, wc->ssd_dev->bdev); |
|
bio->bi_iter.bi_sector = start_cache_sec; |
|
dm_accept_partial_bio(bio, bio_size >> SECTOR_SHIFT); |
|
|
|
if (unlikely(wc->uncommitted_blocks >= wc->autocommit_blocks)) { |
|
wc->uncommitted_blocks = 0; |
|
queue_work(wc->writeback_wq, &wc->flush_work); |
|
} else { |
|
writecache_schedule_autocommit(wc); |
|
} |
|
goto unlock_remap; |
|
} |
|
} while (bio->bi_iter.bi_size); |
|
|
|
if (unlikely(bio->bi_opf & REQ_FUA || |
|
wc->uncommitted_blocks >= wc->autocommit_blocks)) |
|
writecache_flush(wc); |
|
else |
|
writecache_schedule_autocommit(wc); |
|
goto unlock_submit; |
|
} |
|
|
|
unlock_remap_origin: |
|
bio_set_dev(bio, wc->dev->bdev); |
|
wc_unlock(wc); |
|
return DM_MAPIO_REMAPPED; |
|
|
|
unlock_remap: |
|
/* make sure that writecache_end_io decrements bio_in_progress: */ |
|
bio->bi_private = (void *)1; |
|
atomic_inc(&wc->bio_in_progress[bio_data_dir(bio)]); |
|
wc_unlock(wc); |
|
return DM_MAPIO_REMAPPED; |
|
|
|
unlock_submit: |
|
wc_unlock(wc); |
|
bio_endio(bio); |
|
return DM_MAPIO_SUBMITTED; |
|
|
|
unlock_return: |
|
wc_unlock(wc); |
|
return DM_MAPIO_SUBMITTED; |
|
|
|
unlock_error: |
|
wc_unlock(wc); |
|
bio_io_error(bio); |
|
return DM_MAPIO_SUBMITTED; |
|
} |
|
|
|
static int writecache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *status) |
|
{ |
|
struct dm_writecache *wc = ti->private; |
|
|
|
if (bio->bi_private != NULL) { |
|
int dir = bio_data_dir(bio); |
|
if (atomic_dec_and_test(&wc->bio_in_progress[dir])) |
|
if (unlikely(waitqueue_active(&wc->bio_in_progress_wait[dir]))) |
|
wake_up(&wc->bio_in_progress_wait[dir]); |
|
} |
|
return 0; |
|
} |
|
|
|
static int writecache_iterate_devices(struct dm_target *ti, |
|
iterate_devices_callout_fn fn, void *data) |
|
{ |
|
struct dm_writecache *wc = ti->private; |
|
|
|
return fn(ti, wc->dev, 0, ti->len, data); |
|
} |
|
|
|
static void writecache_io_hints(struct dm_target *ti, struct queue_limits *limits) |
|
{ |
|
struct dm_writecache *wc = ti->private; |
|
|
|
if (limits->logical_block_size < wc->block_size) |
|
limits->logical_block_size = wc->block_size; |
|
|
|
if (limits->physical_block_size < wc->block_size) |
|
limits->physical_block_size = wc->block_size; |
|
|
|
if (limits->io_min < wc->block_size) |
|
limits->io_min = wc->block_size; |
|
} |
|
|
|
|
|
static void writecache_writeback_endio(struct bio *bio) |
|
{ |
|
struct writeback_struct *wb = container_of(bio, struct writeback_struct, bio); |
|
struct dm_writecache *wc = wb->wc; |
|
unsigned long flags; |
|
|
|
raw_spin_lock_irqsave(&wc->endio_list_lock, flags); |
|
if (unlikely(list_empty(&wc->endio_list))) |
|
wake_up_process(wc->endio_thread); |
|
list_add_tail(&wb->endio_entry, &wc->endio_list); |
|
raw_spin_unlock_irqrestore(&wc->endio_list_lock, flags); |
|
} |
|
|
|
static void writecache_copy_endio(int read_err, unsigned long write_err, void *ptr) |
|
{ |
|
struct copy_struct *c = ptr; |
|
struct dm_writecache *wc = c->wc; |
|
|
|
c->error = likely(!(read_err | write_err)) ? 0 : -EIO; |
|
|
|
raw_spin_lock_irq(&wc->endio_list_lock); |
|
if (unlikely(list_empty(&wc->endio_list))) |
|
wake_up_process(wc->endio_thread); |
|
list_add_tail(&c->endio_entry, &wc->endio_list); |
|
raw_spin_unlock_irq(&wc->endio_list_lock); |
|
} |
|
|
|
static void __writecache_endio_pmem(struct dm_writecache *wc, struct list_head *list) |
|
{ |
|
unsigned i; |
|
struct writeback_struct *wb; |
|
struct wc_entry *e; |
|
unsigned long n_walked = 0; |
|
|
|
do { |
|
wb = list_entry(list->next, struct writeback_struct, endio_entry); |
|
list_del(&wb->endio_entry); |
|
|
|
if (unlikely(wb->bio.bi_status != BLK_STS_OK)) |
|
writecache_error(wc, blk_status_to_errno(wb->bio.bi_status), |
|
"write error %d", wb->bio.bi_status); |
|
i = 0; |
|
do { |
|
e = wb->wc_list[i]; |
|
BUG_ON(!e->write_in_progress); |
|
e->write_in_progress = false; |
|
INIT_LIST_HEAD(&e->lru); |
|
if (!writecache_has_error(wc)) |
|
writecache_free_entry(wc, e); |
|
BUG_ON(!wc->writeback_size); |
|
wc->writeback_size--; |
|
n_walked++; |
|
if (unlikely(n_walked >= ENDIO_LATENCY)) { |
|
writecache_commit_flushed(wc, false); |
|
wc_unlock(wc); |
|
wc_lock(wc); |
|
n_walked = 0; |
|
} |
|
} while (++i < wb->wc_list_n); |
|
|
|
if (wb->wc_list != wb->wc_list_inline) |
|
kfree(wb->wc_list); |
|
bio_put(&wb->bio); |
|
} while (!list_empty(list)); |
|
} |
|
|
|
static void __writecache_endio_ssd(struct dm_writecache *wc, struct list_head *list) |
|
{ |
|
struct copy_struct *c; |
|
struct wc_entry *e; |
|
|
|
do { |
|
c = list_entry(list->next, struct copy_struct, endio_entry); |
|
list_del(&c->endio_entry); |
|
|
|
if (unlikely(c->error)) |
|
writecache_error(wc, c->error, "copy error"); |
|
|
|
e = c->e; |
|
do { |
|
BUG_ON(!e->write_in_progress); |
|
e->write_in_progress = false; |
|
INIT_LIST_HEAD(&e->lru); |
|
if (!writecache_has_error(wc)) |
|
writecache_free_entry(wc, e); |
|
|
|
BUG_ON(!wc->writeback_size); |
|
wc->writeback_size--; |
|
e++; |
|
} while (--c->n_entries); |
|
mempool_free(c, &wc->copy_pool); |
|
} while (!list_empty(list)); |
|
} |
|
|
|
static int writecache_endio_thread(void *data) |
|
{ |
|
struct dm_writecache *wc = data; |
|
|
|
while (1) { |
|
struct list_head list; |
|
|
|
raw_spin_lock_irq(&wc->endio_list_lock); |
|
if (!list_empty(&wc->endio_list)) |
|
goto pop_from_list; |
|
set_current_state(TASK_INTERRUPTIBLE); |
|
raw_spin_unlock_irq(&wc->endio_list_lock); |
|
|
|
if (unlikely(kthread_should_stop())) { |
|
set_current_state(TASK_RUNNING); |
|
break; |
|
} |
|
|
|
schedule(); |
|
|
|
continue; |
|
|
|
pop_from_list: |
|
list = wc->endio_list; |
|
list.next->prev = list.prev->next = &list; |
|
INIT_LIST_HEAD(&wc->endio_list); |
|
raw_spin_unlock_irq(&wc->endio_list_lock); |
|
|
|
if (!WC_MODE_FUA(wc)) |
|
writecache_disk_flush(wc, wc->dev); |
|
|
|
wc_lock(wc); |
|
|
|
if (WC_MODE_PMEM(wc)) { |
|
__writecache_endio_pmem(wc, &list); |
|
} else { |
|
__writecache_endio_ssd(wc, &list); |
|
writecache_wait_for_ios(wc, READ); |
|
} |
|
|
|
writecache_commit_flushed(wc, false); |
|
|
|
wc_unlock(wc); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static bool wc_add_block(struct writeback_struct *wb, struct wc_entry *e, gfp_t gfp) |
|
{ |
|
struct dm_writecache *wc = wb->wc; |
|
unsigned block_size = wc->block_size; |
|
void *address = memory_data(wc, e); |
|
|
|
persistent_memory_flush_cache(address, block_size); |
|
|
|
if (unlikely(bio_end_sector(&wb->bio) >= wc->data_device_sectors)) |
|
return true; |
|
|
|
return bio_add_page(&wb->bio, persistent_memory_page(address), |
|
block_size, persistent_memory_page_offset(address)) != 0; |
|
} |
|
|
|
struct writeback_list { |
|
struct list_head list; |
|
size_t size; |
|
}; |
|
|
|
static void __writeback_throttle(struct dm_writecache *wc, struct writeback_list *wbl) |
|
{ |
|
if (unlikely(wc->max_writeback_jobs)) { |
|
if (READ_ONCE(wc->writeback_size) - wbl->size >= wc->max_writeback_jobs) { |
|
wc_lock(wc); |
|
while (wc->writeback_size - wbl->size >= wc->max_writeback_jobs) |
|
writecache_wait_on_freelist(wc); |
|
wc_unlock(wc); |
|
} |
|
} |
|
cond_resched(); |
|
} |
|
|
|
static void __writecache_writeback_pmem(struct dm_writecache *wc, struct writeback_list *wbl) |
|
{ |
|
struct wc_entry *e, *f; |
|
struct bio *bio; |
|
struct writeback_struct *wb; |
|
unsigned max_pages; |
|
|
|
while (wbl->size) { |
|
wbl->size--; |
|
e = container_of(wbl->list.prev, struct wc_entry, lru); |
|
list_del(&e->lru); |
|
|
|
max_pages = e->wc_list_contiguous; |
|
|
|
bio = bio_alloc_bioset(GFP_NOIO, max_pages, &wc->bio_set); |
|
wb = container_of(bio, struct writeback_struct, bio); |
|
wb->wc = wc; |
|
bio->bi_end_io = writecache_writeback_endio; |
|
bio_set_dev(bio, wc->dev->bdev); |
|
bio->bi_iter.bi_sector = read_original_sector(wc, e); |
|
if (max_pages <= WB_LIST_INLINE || |
|
unlikely(!(wb->wc_list = kmalloc_array(max_pages, sizeof(struct wc_entry *), |
|
GFP_NOIO | __GFP_NORETRY | |
|
__GFP_NOMEMALLOC | __GFP_NOWARN)))) { |
|
wb->wc_list = wb->wc_list_inline; |
|
max_pages = WB_LIST_INLINE; |
|
} |
|
|
|
BUG_ON(!wc_add_block(wb, e, GFP_NOIO)); |
|
|
|
wb->wc_list[0] = e; |
|
wb->wc_list_n = 1; |
|
|
|
while (wbl->size && wb->wc_list_n < max_pages) { |
|
f = container_of(wbl->list.prev, struct wc_entry, lru); |
|
if (read_original_sector(wc, f) != |
|
read_original_sector(wc, e) + (wc->block_size >> SECTOR_SHIFT)) |
|
break; |
|
if (!wc_add_block(wb, f, GFP_NOWAIT | __GFP_NOWARN)) |
|
break; |
|
wbl->size--; |
|
list_del(&f->lru); |
|
wb->wc_list[wb->wc_list_n++] = f; |
|
e = f; |
|
} |
|
bio_set_op_attrs(bio, REQ_OP_WRITE, WC_MODE_FUA(wc) * REQ_FUA); |
|
if (writecache_has_error(wc)) { |
|
bio->bi_status = BLK_STS_IOERR; |
|
bio_endio(bio); |
|
} else if (unlikely(!bio_sectors(bio))) { |
|
bio->bi_status = BLK_STS_OK; |
|
bio_endio(bio); |
|
} else { |
|
submit_bio(bio); |
|
} |
|
|
|
__writeback_throttle(wc, wbl); |
|
} |
|
} |
|
|
|
static void __writecache_writeback_ssd(struct dm_writecache *wc, struct writeback_list *wbl) |
|
{ |
|
struct wc_entry *e, *f; |
|
struct dm_io_region from, to; |
|
struct copy_struct *c; |
|
|
|
while (wbl->size) { |
|
unsigned n_sectors; |
|
|
|
wbl->size--; |
|
e = container_of(wbl->list.prev, struct wc_entry, lru); |
|
list_del(&e->lru); |
|
|
|
n_sectors = e->wc_list_contiguous << (wc->block_size_bits - SECTOR_SHIFT); |
|
|
|
from.bdev = wc->ssd_dev->bdev; |
|
from.sector = cache_sector(wc, e); |
|
from.count = n_sectors; |
|
to.bdev = wc->dev->bdev; |
|
to.sector = read_original_sector(wc, e); |
|
to.count = n_sectors; |
|
|
|
c = mempool_alloc(&wc->copy_pool, GFP_NOIO); |
|
c->wc = wc; |
|
c->e = e; |
|
c->n_entries = e->wc_list_contiguous; |
|
|
|
while ((n_sectors -= wc->block_size >> SECTOR_SHIFT)) { |
|
wbl->size--; |
|
f = container_of(wbl->list.prev, struct wc_entry, lru); |
|
BUG_ON(f != e + 1); |
|
list_del(&f->lru); |
|
e = f; |
|
} |
|
|
|
if (unlikely(to.sector + to.count > wc->data_device_sectors)) { |
|
if (to.sector >= wc->data_device_sectors) { |
|
writecache_copy_endio(0, 0, c); |
|
continue; |
|
} |
|
from.count = to.count = wc->data_device_sectors - to.sector; |
|
} |
|
|
|
dm_kcopyd_copy(wc->dm_kcopyd, &from, 1, &to, 0, writecache_copy_endio, c); |
|
|
|
__writeback_throttle(wc, wbl); |
|
} |
|
} |
|
|
|
static void writecache_writeback(struct work_struct *work) |
|
{ |
|
struct dm_writecache *wc = container_of(work, struct dm_writecache, writeback_work); |
|
struct blk_plug plug; |
|
struct wc_entry *f, *g, *e = NULL; |
|
struct rb_node *node, *next_node; |
|
struct list_head skipped; |
|
struct writeback_list wbl; |
|
unsigned long n_walked; |
|
|
|
wc_lock(wc); |
|
restart: |
|
if (writecache_has_error(wc)) { |
|
wc_unlock(wc); |
|
return; |
|
} |
|
|
|
if (unlikely(wc->writeback_all)) { |
|
if (writecache_wait_for_writeback(wc)) |
|
goto restart; |
|
} |
|
|
|
if (wc->overwrote_committed) { |
|
writecache_wait_for_ios(wc, WRITE); |
|
} |
|
|
|
n_walked = 0; |
|
INIT_LIST_HEAD(&skipped); |
|
INIT_LIST_HEAD(&wbl.list); |
|
wbl.size = 0; |
|
while (!list_empty(&wc->lru) && |
|
(wc->writeback_all || |
|
wc->freelist_size + wc->writeback_size <= wc->freelist_low_watermark || |
|
(jiffies - container_of(wc->lru.prev, struct wc_entry, lru)->age >= |
|
wc->max_age - wc->max_age / MAX_AGE_DIV))) { |
|
|
|
n_walked++; |
|
if (unlikely(n_walked > WRITEBACK_LATENCY) && |
|
likely(!wc->writeback_all) && likely(!dm_suspended(wc->ti))) { |
|
queue_work(wc->writeback_wq, &wc->writeback_work); |
|
break; |
|
} |
|
|
|
if (unlikely(wc->writeback_all)) { |
|
if (unlikely(!e)) { |
|
writecache_flush(wc); |
|
e = container_of(rb_first(&wc->tree), struct wc_entry, rb_node); |
|
} else |
|
e = g; |
|
} else |
|
e = container_of(wc->lru.prev, struct wc_entry, lru); |
|
BUG_ON(e->write_in_progress); |
|
if (unlikely(!writecache_entry_is_committed(wc, e))) { |
|
writecache_flush(wc); |
|
} |
|
node = rb_prev(&e->rb_node); |
|
if (node) { |
|
f = container_of(node, struct wc_entry, rb_node); |
|
if (unlikely(read_original_sector(wc, f) == |
|
read_original_sector(wc, e))) { |
|
BUG_ON(!f->write_in_progress); |
|
list_del(&e->lru); |
|
list_add(&e->lru, &skipped); |
|
cond_resched(); |
|
continue; |
|
} |
|
} |
|
wc->writeback_size++; |
|
list_del(&e->lru); |
|
list_add(&e->lru, &wbl.list); |
|
wbl.size++; |
|
e->write_in_progress = true; |
|
e->wc_list_contiguous = 1; |
|
|
|
f = e; |
|
|
|
while (1) { |
|
next_node = rb_next(&f->rb_node); |
|
if (unlikely(!next_node)) |
|
break; |
|
g = container_of(next_node, struct wc_entry, rb_node); |
|
if (unlikely(read_original_sector(wc, g) == |
|
read_original_sector(wc, f))) { |
|
f = g; |
|
continue; |
|
} |
|
if (read_original_sector(wc, g) != |
|
read_original_sector(wc, f) + (wc->block_size >> SECTOR_SHIFT)) |
|
break; |
|
if (unlikely(g->write_in_progress)) |
|
break; |
|
if (unlikely(!writecache_entry_is_committed(wc, g))) |
|
break; |
|
|
|
if (!WC_MODE_PMEM(wc)) { |
|
if (g != f + 1) |
|
break; |
|
} |
|
|
|
n_walked++; |
|
//if (unlikely(n_walked > WRITEBACK_LATENCY) && likely(!wc->writeback_all)) |
|
// break; |
|
|
|
wc->writeback_size++; |
|
list_del(&g->lru); |
|
list_add(&g->lru, &wbl.list); |
|
wbl.size++; |
|
g->write_in_progress = true; |
|
g->wc_list_contiguous = BIO_MAX_VECS; |
|
f = g; |
|
e->wc_list_contiguous++; |
|
if (unlikely(e->wc_list_contiguous == BIO_MAX_VECS)) { |
|
if (unlikely(wc->writeback_all)) { |
|
next_node = rb_next(&f->rb_node); |
|
if (likely(next_node)) |
|
g = container_of(next_node, struct wc_entry, rb_node); |
|
} |
|
break; |
|
} |
|
} |
|
cond_resched(); |
|
} |
|
|
|
if (!list_empty(&skipped)) { |
|
list_splice_tail(&skipped, &wc->lru); |
|
/* |
|
* If we didn't do any progress, we must wait until some |
|
* writeback finishes to avoid burning CPU in a loop |
|
*/ |
|
if (unlikely(!wbl.size)) |
|
writecache_wait_for_writeback(wc); |
|
} |
|
|
|
wc_unlock(wc); |
|
|
|
blk_start_plug(&plug); |
|
|
|
if (WC_MODE_PMEM(wc)) |
|
__writecache_writeback_pmem(wc, &wbl); |
|
else |
|
__writecache_writeback_ssd(wc, &wbl); |
|
|
|
blk_finish_plug(&plug); |
|
|
|
if (unlikely(wc->writeback_all)) { |
|
wc_lock(wc); |
|
while (writecache_wait_for_writeback(wc)); |
|
wc_unlock(wc); |
|
} |
|
} |
|
|
|
static int calculate_memory_size(uint64_t device_size, unsigned block_size, |
|
size_t *n_blocks_p, size_t *n_metadata_blocks_p) |
|
{ |
|
uint64_t n_blocks, offset; |
|
struct wc_entry e; |
|
|
|
n_blocks = device_size; |
|
do_div(n_blocks, block_size + sizeof(struct wc_memory_entry)); |
|
|
|
while (1) { |
|
if (!n_blocks) |
|
return -ENOSPC; |
|
/* Verify the following entries[n_blocks] won't overflow */ |
|
if (n_blocks >= ((size_t)-sizeof(struct wc_memory_superblock) / |
|
sizeof(struct wc_memory_entry))) |
|
return -EFBIG; |
|
offset = offsetof(struct wc_memory_superblock, entries[n_blocks]); |
|
offset = (offset + block_size - 1) & ~(uint64_t)(block_size - 1); |
|
if (offset + n_blocks * block_size <= device_size) |
|
break; |
|
n_blocks--; |
|
} |
|
|
|
/* check if the bit field overflows */ |
|
e.index = n_blocks; |
|
if (e.index != n_blocks) |
|
return -EFBIG; |
|
|
|
if (n_blocks_p) |
|
*n_blocks_p = n_blocks; |
|
if (n_metadata_blocks_p) |
|
*n_metadata_blocks_p = offset >> __ffs(block_size); |
|
return 0; |
|
} |
|
|
|
static int init_memory(struct dm_writecache *wc) |
|
{ |
|
size_t b; |
|
int r; |
|
|
|
r = calculate_memory_size(wc->memory_map_size, wc->block_size, &wc->n_blocks, NULL); |
|
if (r) |
|
return r; |
|
|
|
r = writecache_alloc_entries(wc); |
|
if (r) |
|
return r; |
|
|
|
for (b = 0; b < ARRAY_SIZE(sb(wc)->padding); b++) |
|
pmem_assign(sb(wc)->padding[b], cpu_to_le64(0)); |
|
pmem_assign(sb(wc)->version, cpu_to_le32(MEMORY_SUPERBLOCK_VERSION)); |
|
pmem_assign(sb(wc)->block_size, cpu_to_le32(wc->block_size)); |
|
pmem_assign(sb(wc)->n_blocks, cpu_to_le64(wc->n_blocks)); |
|
pmem_assign(sb(wc)->seq_count, cpu_to_le64(0)); |
|
|
|
for (b = 0; b < wc->n_blocks; b++) { |
|
write_original_sector_seq_count(wc, &wc->entries[b], -1, -1); |
|
cond_resched(); |
|
} |
|
|
|
writecache_flush_all_metadata(wc); |
|
writecache_commit_flushed(wc, false); |
|
pmem_assign(sb(wc)->magic, cpu_to_le32(MEMORY_SUPERBLOCK_MAGIC)); |
|
writecache_flush_region(wc, &sb(wc)->magic, sizeof sb(wc)->magic); |
|
writecache_commit_flushed(wc, false); |
|
|
|
return 0; |
|
} |
|
|
|
static void writecache_dtr(struct dm_target *ti) |
|
{ |
|
struct dm_writecache *wc = ti->private; |
|
|
|
if (!wc) |
|
return; |
|
|
|
if (wc->endio_thread) |
|
kthread_stop(wc->endio_thread); |
|
|
|
if (wc->flush_thread) |
|
kthread_stop(wc->flush_thread); |
|
|
|
bioset_exit(&wc->bio_set); |
|
|
|
mempool_exit(&wc->copy_pool); |
|
|
|
if (wc->writeback_wq) |
|
destroy_workqueue(wc->writeback_wq); |
|
|
|
if (wc->dev) |
|
dm_put_device(ti, wc->dev); |
|
|
|
if (wc->ssd_dev) |
|
dm_put_device(ti, wc->ssd_dev); |
|
|
|
vfree(wc->entries); |
|
|
|
if (wc->memory_map) { |
|
if (WC_MODE_PMEM(wc)) |
|
persistent_memory_release(wc); |
|
else |
|
vfree(wc->memory_map); |
|
} |
|
|
|
if (wc->dm_kcopyd) |
|
dm_kcopyd_client_destroy(wc->dm_kcopyd); |
|
|
|
if (wc->dm_io) |
|
dm_io_client_destroy(wc->dm_io); |
|
|
|
vfree(wc->dirty_bitmap); |
|
|
|
kfree(wc); |
|
} |
|
|
|
static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) |
|
{ |
|
struct dm_writecache *wc; |
|
struct dm_arg_set as; |
|
const char *string; |
|
unsigned opt_params; |
|
size_t offset, data_size; |
|
int i, r; |
|
char dummy; |
|
int high_wm_percent = HIGH_WATERMARK; |
|
int low_wm_percent = LOW_WATERMARK; |
|
uint64_t x; |
|
struct wc_memory_superblock s; |
|
|
|
static struct dm_arg _args[] = { |
|
{0, 16, "Invalid number of feature args"}, |
|
}; |
|
|
|
as.argc = argc; |
|
as.argv = argv; |
|
|
|
wc = kzalloc(sizeof(struct dm_writecache), GFP_KERNEL); |
|
if (!wc) { |
|
ti->error = "Cannot allocate writecache structure"; |
|
r = -ENOMEM; |
|
goto bad; |
|
} |
|
ti->private = wc; |
|
wc->ti = ti; |
|
|
|
mutex_init(&wc->lock); |
|
wc->max_age = MAX_AGE_UNSPECIFIED; |
|
writecache_poison_lists(wc); |
|
init_waitqueue_head(&wc->freelist_wait); |
|
timer_setup(&wc->autocommit_timer, writecache_autocommit_timer, 0); |
|
timer_setup(&wc->max_age_timer, writecache_max_age_timer, 0); |
|
|
|
for (i = 0; i < 2; i++) { |
|
atomic_set(&wc->bio_in_progress[i], 0); |
|
init_waitqueue_head(&wc->bio_in_progress_wait[i]); |
|
} |
|
|
|
wc->dm_io = dm_io_client_create(); |
|
if (IS_ERR(wc->dm_io)) { |
|
r = PTR_ERR(wc->dm_io); |
|
ti->error = "Unable to allocate dm-io client"; |
|
wc->dm_io = NULL; |
|
goto bad; |
|
} |
|
|
|
wc->writeback_wq = alloc_workqueue("writecache-writeback", WQ_MEM_RECLAIM, 1); |
|
if (!wc->writeback_wq) { |
|
r = -ENOMEM; |
|
ti->error = "Could not allocate writeback workqueue"; |
|
goto bad; |
|
} |
|
INIT_WORK(&wc->writeback_work, writecache_writeback); |
|
INIT_WORK(&wc->flush_work, writecache_flush_work); |
|
|
|
raw_spin_lock_init(&wc->endio_list_lock); |
|
INIT_LIST_HEAD(&wc->endio_list); |
|
wc->endio_thread = kthread_create(writecache_endio_thread, wc, "writecache_endio"); |
|
if (IS_ERR(wc->endio_thread)) { |
|
r = PTR_ERR(wc->endio_thread); |
|
wc->endio_thread = NULL; |
|
ti->error = "Couldn't spawn endio thread"; |
|
goto bad; |
|
} |
|
wake_up_process(wc->endio_thread); |
|
|
|
/* |
|
* Parse the mode (pmem or ssd) |
|
*/ |
|
string = dm_shift_arg(&as); |
|
if (!string) |
|
goto bad_arguments; |
|
|
|
if (!strcasecmp(string, "s")) { |
|
wc->pmem_mode = false; |
|
} else if (!strcasecmp(string, "p")) { |
|
#ifdef DM_WRITECACHE_HAS_PMEM |
|
wc->pmem_mode = true; |
|
wc->writeback_fua = true; |
|
#else |
|
/* |
|
* If the architecture doesn't support persistent memory or |
|
* the kernel doesn't support any DAX drivers, this driver can |
|
* only be used in SSD-only mode. |
|
*/ |
|
r = -EOPNOTSUPP; |
|
ti->error = "Persistent memory or DAX not supported on this system"; |
|
goto bad; |
|
#endif |
|
} else { |
|
goto bad_arguments; |
|
} |
|
|
|
if (WC_MODE_PMEM(wc)) { |
|
r = bioset_init(&wc->bio_set, BIO_POOL_SIZE, |
|
offsetof(struct writeback_struct, bio), |
|
BIOSET_NEED_BVECS); |
|
if (r) { |
|
ti->error = "Could not allocate bio set"; |
|
goto bad; |
|
} |
|
} else { |
|
r = mempool_init_kmalloc_pool(&wc->copy_pool, 1, sizeof(struct copy_struct)); |
|
if (r) { |
|
ti->error = "Could not allocate mempool"; |
|
goto bad; |
|
} |
|
} |
|
|
|
/* |
|
* Parse the origin data device |
|
*/ |
|
string = dm_shift_arg(&as); |
|
if (!string) |
|
goto bad_arguments; |
|
r = dm_get_device(ti, string, dm_table_get_mode(ti->table), &wc->dev); |
|
if (r) { |
|
ti->error = "Origin data device lookup failed"; |
|
goto bad; |
|
} |
|
|
|
/* |
|
* Parse cache data device (be it pmem or ssd) |
|
*/ |
|
string = dm_shift_arg(&as); |
|
if (!string) |
|
goto bad_arguments; |
|
|
|
r = dm_get_device(ti, string, dm_table_get_mode(ti->table), &wc->ssd_dev); |
|
if (r) { |
|
ti->error = "Cache data device lookup failed"; |
|
goto bad; |
|
} |
|
wc->memory_map_size = i_size_read(wc->ssd_dev->bdev->bd_inode); |
|
|
|
/* |
|
* Parse the cache block size |
|
*/ |
|
string = dm_shift_arg(&as); |
|
if (!string) |
|
goto bad_arguments; |
|
if (sscanf(string, "%u%c", &wc->block_size, &dummy) != 1 || |
|
wc->block_size < 512 || wc->block_size > PAGE_SIZE || |
|
(wc->block_size & (wc->block_size - 1))) { |
|
r = -EINVAL; |
|
ti->error = "Invalid block size"; |
|
goto bad; |
|
} |
|
if (wc->block_size < bdev_logical_block_size(wc->dev->bdev) || |
|
wc->block_size < bdev_logical_block_size(wc->ssd_dev->bdev)) { |
|
r = -EINVAL; |
|
ti->error = "Block size is smaller than device logical block size"; |
|
goto bad; |
|
} |
|
wc->block_size_bits = __ffs(wc->block_size); |
|
|
|
wc->max_writeback_jobs = MAX_WRITEBACK_JOBS; |
|
wc->autocommit_blocks = !WC_MODE_PMEM(wc) ? AUTOCOMMIT_BLOCKS_SSD : AUTOCOMMIT_BLOCKS_PMEM; |
|
wc->autocommit_jiffies = msecs_to_jiffies(AUTOCOMMIT_MSEC); |
|
|
|
/* |
|
* Parse optional arguments |
|
*/ |
|
r = dm_read_arg_group(_args, &as, &opt_params, &ti->error); |
|
if (r) |
|
goto bad; |
|
|
|
while (opt_params) { |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (!strcasecmp(string, "start_sector") && opt_params >= 1) { |
|
unsigned long long start_sector; |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (sscanf(string, "%llu%c", &start_sector, &dummy) != 1) |
|
goto invalid_optional; |
|
wc->start_sector = start_sector; |
|
wc->start_sector_set = true; |
|
if (wc->start_sector != start_sector || |
|
wc->start_sector >= wc->memory_map_size >> SECTOR_SHIFT) |
|
goto invalid_optional; |
|
} else if (!strcasecmp(string, "high_watermark") && opt_params >= 1) { |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (sscanf(string, "%d%c", &high_wm_percent, &dummy) != 1) |
|
goto invalid_optional; |
|
if (high_wm_percent < 0 || high_wm_percent > 100) |
|
goto invalid_optional; |
|
wc->high_wm_percent_value = high_wm_percent; |
|
wc->high_wm_percent_set = true; |
|
} else if (!strcasecmp(string, "low_watermark") && opt_params >= 1) { |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (sscanf(string, "%d%c", &low_wm_percent, &dummy) != 1) |
|
goto invalid_optional; |
|
if (low_wm_percent < 0 || low_wm_percent > 100) |
|
goto invalid_optional; |
|
wc->low_wm_percent_value = low_wm_percent; |
|
wc->low_wm_percent_set = true; |
|
} else if (!strcasecmp(string, "writeback_jobs") && opt_params >= 1) { |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (sscanf(string, "%u%c", &wc->max_writeback_jobs, &dummy) != 1) |
|
goto invalid_optional; |
|
wc->max_writeback_jobs_set = true; |
|
} else if (!strcasecmp(string, "autocommit_blocks") && opt_params >= 1) { |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (sscanf(string, "%u%c", &wc->autocommit_blocks, &dummy) != 1) |
|
goto invalid_optional; |
|
wc->autocommit_blocks_set = true; |
|
} else if (!strcasecmp(string, "autocommit_time") && opt_params >= 1) { |
|
unsigned autocommit_msecs; |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (sscanf(string, "%u%c", &autocommit_msecs, &dummy) != 1) |
|
goto invalid_optional; |
|
if (autocommit_msecs > 3600000) |
|
goto invalid_optional; |
|
wc->autocommit_jiffies = msecs_to_jiffies(autocommit_msecs); |
|
wc->autocommit_time_value = autocommit_msecs; |
|
wc->autocommit_time_set = true; |
|
} else if (!strcasecmp(string, "max_age") && opt_params >= 1) { |
|
unsigned max_age_msecs; |
|
string = dm_shift_arg(&as), opt_params--; |
|
if (sscanf(string, "%u%c", &max_age_msecs, &dummy) != 1) |
|
goto invalid_optional; |
|
if (max_age_msecs > 86400000) |
|
goto invalid_optional; |
|
wc->max_age = msecs_to_jiffies(max_age_msecs); |
|
wc->max_age_set = true; |
|
wc->max_age_value = max_age_msecs; |
|
} else if (!strcasecmp(string, "cleaner")) { |
|
wc->cleaner_set = true; |
|
wc->cleaner = true; |
|
} else if (!strcasecmp(string, "fua")) { |
|
if (WC_MODE_PMEM(wc)) { |
|
wc->writeback_fua = true; |
|
wc->writeback_fua_set = true; |
|
} else goto invalid_optional; |
|
} else if (!strcasecmp(string, "nofua")) { |
|
if (WC_MODE_PMEM(wc)) { |
|
wc->writeback_fua = false; |
|
wc->writeback_fua_set = true; |
|
} else goto invalid_optional; |
|
} else { |
|
invalid_optional: |
|
r = -EINVAL; |
|
ti->error = "Invalid optional argument"; |
|
goto bad; |
|
} |
|
} |
|
|
|
if (high_wm_percent < low_wm_percent) { |
|
r = -EINVAL; |
|
ti->error = "High watermark must be greater than or equal to low watermark"; |
|
goto bad; |
|
} |
|
|
|
if (WC_MODE_PMEM(wc)) { |
|
if (!dax_synchronous(wc->ssd_dev->dax_dev)) { |
|
r = -EOPNOTSUPP; |
|
ti->error = "Asynchronous persistent memory not supported as pmem cache"; |
|
goto bad; |
|
} |
|
|
|
r = persistent_memory_claim(wc); |
|
if (r) { |
|
ti->error = "Unable to map persistent memory for cache"; |
|
goto bad; |
|
} |
|
} else { |
|
size_t n_blocks, n_metadata_blocks; |
|
uint64_t n_bitmap_bits; |
|
|
|
wc->memory_map_size -= (uint64_t)wc->start_sector << SECTOR_SHIFT; |
|
|
|
bio_list_init(&wc->flush_list); |
|
wc->flush_thread = kthread_create(writecache_flush_thread, wc, "dm_writecache_flush"); |
|
if (IS_ERR(wc->flush_thread)) { |
|
r = PTR_ERR(wc->flush_thread); |
|
wc->flush_thread = NULL; |
|
ti->error = "Couldn't spawn flush thread"; |
|
goto bad; |
|
} |
|
wake_up_process(wc->flush_thread); |
|
|
|
r = calculate_memory_size(wc->memory_map_size, wc->block_size, |
|
&n_blocks, &n_metadata_blocks); |
|
if (r) { |
|
ti->error = "Invalid device size"; |
|
goto bad; |
|
} |
|
|
|
n_bitmap_bits = (((uint64_t)n_metadata_blocks << wc->block_size_bits) + |
|
BITMAP_GRANULARITY - 1) / BITMAP_GRANULARITY; |
|
/* this is limitation of test_bit functions */ |
|
if (n_bitmap_bits > 1U << 31) { |
|
r = -EFBIG; |
|
ti->error = "Invalid device size"; |
|
goto bad; |
|
} |
|
|
|
wc->memory_map = vmalloc(n_metadata_blocks << wc->block_size_bits); |
|
if (!wc->memory_map) { |
|
r = -ENOMEM; |
|
ti->error = "Unable to allocate memory for metadata"; |
|
goto bad; |
|
} |
|
|
|
wc->dm_kcopyd = dm_kcopyd_client_create(&dm_kcopyd_throttle); |
|
if (IS_ERR(wc->dm_kcopyd)) { |
|
r = PTR_ERR(wc->dm_kcopyd); |
|
ti->error = "Unable to allocate dm-kcopyd client"; |
|
wc->dm_kcopyd = NULL; |
|
goto bad; |
|
} |
|
|
|
wc->metadata_sectors = n_metadata_blocks << (wc->block_size_bits - SECTOR_SHIFT); |
|
wc->dirty_bitmap_size = (n_bitmap_bits + BITS_PER_LONG - 1) / |
|
BITS_PER_LONG * sizeof(unsigned long); |
|
wc->dirty_bitmap = vzalloc(wc->dirty_bitmap_size); |
|
if (!wc->dirty_bitmap) { |
|
r = -ENOMEM; |
|
ti->error = "Unable to allocate dirty bitmap"; |
|
goto bad; |
|
} |
|
|
|
r = writecache_read_metadata(wc, wc->block_size >> SECTOR_SHIFT); |
|
if (r) { |
|
ti->error = "Unable to read first block of metadata"; |
|
goto bad; |
|
} |
|
} |
|
|
|
r = copy_mc_to_kernel(&s, sb(wc), sizeof(struct wc_memory_superblock)); |
|
if (r) { |
|
ti->error = "Hardware memory error when reading superblock"; |
|
goto bad; |
|
} |
|
if (!le32_to_cpu(s.magic) && !le32_to_cpu(s.version)) { |
|
r = init_memory(wc); |
|
if (r) { |
|
ti->error = "Unable to initialize device"; |
|
goto bad; |
|
} |
|
r = copy_mc_to_kernel(&s, sb(wc), |
|
sizeof(struct wc_memory_superblock)); |
|
if (r) { |
|
ti->error = "Hardware memory error when reading superblock"; |
|
goto bad; |
|
} |
|
} |
|
|
|
if (le32_to_cpu(s.magic) != MEMORY_SUPERBLOCK_MAGIC) { |
|
ti->error = "Invalid magic in the superblock"; |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
|
|
if (le32_to_cpu(s.version) != MEMORY_SUPERBLOCK_VERSION) { |
|
ti->error = "Invalid version in the superblock"; |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
|
|
if (le32_to_cpu(s.block_size) != wc->block_size) { |
|
ti->error = "Block size does not match superblock"; |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
|
|
wc->n_blocks = le64_to_cpu(s.n_blocks); |
|
|
|
offset = wc->n_blocks * sizeof(struct wc_memory_entry); |
|
if (offset / sizeof(struct wc_memory_entry) != le64_to_cpu(sb(wc)->n_blocks)) { |
|
overflow: |
|
ti->error = "Overflow in size calculation"; |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
offset += sizeof(struct wc_memory_superblock); |
|
if (offset < sizeof(struct wc_memory_superblock)) |
|
goto overflow; |
|
offset = (offset + wc->block_size - 1) & ~(size_t)(wc->block_size - 1); |
|
data_size = wc->n_blocks * (size_t)wc->block_size; |
|
if (!offset || (data_size / wc->block_size != wc->n_blocks) || |
|
(offset + data_size < offset)) |
|
goto overflow; |
|
if (offset + data_size > wc->memory_map_size) { |
|
ti->error = "Memory area is too small"; |
|
r = -EINVAL; |
|
goto bad; |
|
} |
|
|
|
wc->metadata_sectors = offset >> SECTOR_SHIFT; |
|
wc->block_start = (char *)sb(wc) + offset; |
|
|
|
x = (uint64_t)wc->n_blocks * (100 - high_wm_percent); |
|
x += 50; |
|
do_div(x, 100); |
|
wc->freelist_high_watermark = x; |
|
x = (uint64_t)wc->n_blocks * (100 - low_wm_percent); |
|
x += 50; |
|
do_div(x, 100); |
|
wc->freelist_low_watermark = x; |
|
|
|
if (wc->cleaner) |
|
activate_cleaner(wc); |
|
|
|
r = writecache_alloc_entries(wc); |
|
if (r) { |
|
ti->error = "Cannot allocate memory"; |
|
goto bad; |
|
} |
|
|
|
ti->num_flush_bios = 1; |
|
ti->flush_supported = true; |
|
ti->num_discard_bios = 1; |
|
|
|
if (WC_MODE_PMEM(wc)) |
|
persistent_memory_flush_cache(wc->memory_map, wc->memory_map_size); |
|
|
|
return 0; |
|
|
|
bad_arguments: |
|
r = -EINVAL; |
|
ti->error = "Bad arguments"; |
|
bad: |
|
writecache_dtr(ti); |
|
return r; |
|
} |
|
|
|
static void writecache_status(struct dm_target *ti, status_type_t type, |
|
unsigned status_flags, char *result, unsigned maxlen) |
|
{ |
|
struct dm_writecache *wc = ti->private; |
|
unsigned extra_args; |
|
unsigned sz = 0; |
|
|
|
switch (type) { |
|
case STATUSTYPE_INFO: |
|
DMEMIT("%ld %llu %llu %llu", writecache_has_error(wc), |
|
(unsigned long long)wc->n_blocks, (unsigned long long)wc->freelist_size, |
|
(unsigned long long)wc->writeback_size); |
|
break; |
|
case STATUSTYPE_TABLE: |
|
DMEMIT("%c %s %s %u ", WC_MODE_PMEM(wc) ? 'p' : 's', |
|
wc->dev->name, wc->ssd_dev->name, wc->block_size); |
|
extra_args = 0; |
|
if (wc->start_sector_set) |
|
extra_args += 2; |
|
if (wc->high_wm_percent_set) |
|
extra_args += 2; |
|
if (wc->low_wm_percent_set) |
|
extra_args += 2; |
|
if (wc->max_writeback_jobs_set) |
|
extra_args += 2; |
|
if (wc->autocommit_blocks_set) |
|
extra_args += 2; |
|
if (wc->autocommit_time_set) |
|
extra_args += 2; |
|
if (wc->max_age_set) |
|
extra_args += 2; |
|
if (wc->cleaner_set) |
|
extra_args++; |
|
if (wc->writeback_fua_set) |
|
extra_args++; |
|
|
|
DMEMIT("%u", extra_args); |
|
if (wc->start_sector_set) |
|
DMEMIT(" start_sector %llu", (unsigned long long)wc->start_sector); |
|
if (wc->high_wm_percent_set) |
|
DMEMIT(" high_watermark %u", wc->high_wm_percent_value); |
|
if (wc->low_wm_percent_set) |
|
DMEMIT(" low_watermark %u", wc->low_wm_percent_value); |
|
if (wc->max_writeback_jobs_set) |
|
DMEMIT(" writeback_jobs %u", wc->max_writeback_jobs); |
|
if (wc->autocommit_blocks_set) |
|
DMEMIT(" autocommit_blocks %u", wc->autocommit_blocks); |
|
if (wc->autocommit_time_set) |
|
DMEMIT(" autocommit_time %u", wc->autocommit_time_value); |
|
if (wc->max_age_set) |
|
DMEMIT(" max_age %u", wc->max_age_value); |
|
if (wc->cleaner_set) |
|
DMEMIT(" cleaner"); |
|
if (wc->writeback_fua_set) |
|
DMEMIT(" %sfua", wc->writeback_fua ? "" : "no"); |
|
break; |
|
} |
|
} |
|
|
|
static struct target_type writecache_target = { |
|
.name = "writecache", |
|
.version = {1, 4, 0}, |
|
.module = THIS_MODULE, |
|
.ctr = writecache_ctr, |
|
.dtr = writecache_dtr, |
|
.status = writecache_status, |
|
.postsuspend = writecache_suspend, |
|
.resume = writecache_resume, |
|
.message = writecache_message, |
|
.map = writecache_map, |
|
.end_io = writecache_end_io, |
|
.iterate_devices = writecache_iterate_devices, |
|
.io_hints = writecache_io_hints, |
|
}; |
|
|
|
static int __init dm_writecache_init(void) |
|
{ |
|
int r; |
|
|
|
r = dm_register_target(&writecache_target); |
|
if (r < 0) { |
|
DMERR("register failed %d", r); |
|
return r; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void __exit dm_writecache_exit(void) |
|
{ |
|
dm_unregister_target(&writecache_target); |
|
} |
|
|
|
module_init(dm_writecache_init); |
|
module_exit(dm_writecache_exit); |
|
|
|
MODULE_DESCRIPTION(DM_NAME " writecache target"); |
|
MODULE_AUTHOR("Mikulas Patocka <[email protected]>"); |
|
MODULE_LICENSE("GPL");
|
|
|