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![Heinz Mauelshagen](/assets/img/avatar_default.png)
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2800 lines
70 KiB
C
2800 lines
70 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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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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#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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#include <linux/delay.h>
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#include "dm-io-tracker.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 min(0x10000000 / PAGE_SIZE, totalram_pages() / 16)
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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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#define PAUSE_WRITEBACK (HZ * 3)
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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_FS_DAX)
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#define DM_WRITECACHE_HAS_PMEM
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#endif
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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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#if BITS_PER_LONG == 64
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bool write_in_progress : 1;
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unsigned long index : 47;
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#else
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bool write_in_progress;
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unsigned long index;
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#endif
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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 long pause;
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unsigned int uncommitted_blocks;
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unsigned int autocommit_blocks;
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unsigned int 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 int 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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bool metadata_only:1;
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bool pause_set:1;
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unsigned int high_wm_percent_value;
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unsigned int low_wm_percent_value;
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unsigned int autocommit_time_value;
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unsigned int max_age_value;
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unsigned int pause_value;
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unsigned int 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_tracker iot;
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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 int dirty_bitmap_size;
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struct bio_set bio_set;
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mempool_t copy_pool;
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struct {
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unsigned long long reads;
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unsigned long long read_hits;
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unsigned long long writes;
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unsigned long long write_hits_uncommitted;
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unsigned long long write_hits_committed;
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unsigned long long writes_around;
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unsigned long long writes_allocate;
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unsigned long long writes_blocked_on_freelist;
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unsigned long long flushes;
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unsigned long long discards;
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} stats;
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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 int 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 int 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, DAX_ACCESS,
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&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,
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p - i, DAX_ACCESS, 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 int 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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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 int bitmap_bits = wc->dirty_bitmap_size * 8;
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unsigned int i = 0;
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while (1) {
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unsigned int 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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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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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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|
|
|
region.sector += wc->start_sector;
|
|
atomic_inc(&endio.count);
|
|
req.bi_opf = REQ_OP_WRITE | REQ_SYNC;
|
|
req.mem.type = DM_IO_VMA;
|
|
req.mem.ptr.vma = (char *)wc->memory_map + (size_t)i * BITMAP_GRANULARITY;
|
|
req.client = wc->dm_io;
|
|
req.notify.fn = writecache_notify_io;
|
|
req.notify.context = &endio;
|
|
|
|
/* writing via async dm-io (implied by notify.fn above) won't return an error */
|
|
(void) dm_io(&req, 1, ®ion, NULL);
|
|
i = j;
|
|
}
|
|
|
|
writecache_notify_io(0, &endio);
|
|
wait_for_completion_io(&endio.c);
|
|
|
|
if (wait_for_ios)
|
|
writecache_wait_for_ios(wc, WRITE);
|
|
|
|
writecache_disk_flush(wc, wc->ssd_dev);
|
|
|
|
memset(wc->dirty_bitmap, 0, wc->dirty_bitmap_size);
|
|
}
|
|
|
|
static void ssd_commit_superblock(struct dm_writecache *wc)
|
|
{
|
|
int r;
|
|
struct dm_io_region region;
|
|
struct dm_io_request req;
|
|
|
|
region.bdev = wc->ssd_dev->bdev;
|
|
region.sector = 0;
|
|
region.count = max(4096U, wc->block_size) >> SECTOR_SHIFT;
|
|
|
|
if (unlikely(region.sector + region.count > wc->metadata_sectors))
|
|
region.count = wc->metadata_sectors - region.sector;
|
|
|
|
region.sector += wc->start_sector;
|
|
|
|
req.bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_FUA;
|
|
req.mem.type = DM_IO_VMA;
|
|
req.mem.ptr.vma = (char *)wc->memory_map;
|
|
req.client = wc->dm_io;
|
|
req.notify.fn = NULL;
|
|
req.notify.context = NULL;
|
|
|
|
r = dm_io(&req, 1, ®ion, NULL);
|
|
if (unlikely(r))
|
|
writecache_error(wc, r, "error writing superblock");
|
|
}
|
|
|
|
static void writecache_commit_flushed(struct dm_writecache *wc, bool wait_for_ios)
|
|
{
|
|
if (WC_MODE_PMEM(wc))
|
|
pmem_wmb();
|
|
else
|
|
ssd_commit_flushed(wc, wait_for_ios);
|
|
}
|
|
|
|
static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev)
|
|
{
|
|
int r;
|
|
struct dm_io_region region;
|
|
struct dm_io_request req;
|
|
|
|
region.bdev = dev->bdev;
|
|
region.sector = 0;
|
|
region.count = 0;
|
|
req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
|
|
req.mem.type = DM_IO_KMEM;
|
|
req.mem.ptr.addr = NULL;
|
|
req.client = wc->dm_io;
|
|
req.notify.fn = NULL;
|
|
|
|
r = dm_io(&req, 1, ®ion, NULL);
|
|
if (unlikely(r))
|
|
writecache_error(wc, r, "error flushing metadata: %d", r);
|
|
}
|
|
|
|
#define WFE_RETURN_FOLLOWING 1
|
|
#define WFE_LOWEST_SEQ 2
|
|
|
|
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;
|
|
|
|
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_opf = REQ_OP_READ | 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 int 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 int 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 int 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 process_clear_stats_mesg(unsigned int argc, char **argv, struct dm_writecache *wc)
|
|
{
|
|
if (argc != 1)
|
|
return -EINVAL;
|
|
|
|
wc_lock(wc);
|
|
memset(&wc->stats, 0, sizeof(wc->stats));
|
|
wc_unlock(wc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int writecache_message(struct dm_target *ti, unsigned int argc, char **argv,
|
|
char *result, unsigned int 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 if (!strcasecmp(argv[0], "clear_stats"))
|
|
r = process_clear_stats_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 int size;
|
|
int rw = bio_data_dir(bio);
|
|
unsigned int remaining_size = wc->block_size;
|
|
|
|
do {
|
|
struct bio_vec bv = bio_iter_iovec(bio, bio->bi_iter);
|
|
|
|
buf = bvec_kmap_local(&bv);
|
|
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);
|
|
}
|
|
|
|
kunmap_local(buf);
|
|
|
|
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);
|
|
}
|
|
|
|
enum wc_map_op {
|
|
WC_MAP_SUBMIT,
|
|
WC_MAP_REMAP,
|
|
WC_MAP_REMAP_ORIGIN,
|
|
WC_MAP_RETURN,
|
|
WC_MAP_ERROR,
|
|
};
|
|
|
|
static void writecache_map_remap_origin(struct dm_writecache *wc, struct bio *bio,
|
|
struct wc_entry *e)
|
|
{
|
|
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);
|
|
}
|
|
}
|
|
|
|
static enum wc_map_op writecache_map_read(struct dm_writecache *wc, struct bio *bio)
|
|
{
|
|
enum wc_map_op map_op;
|
|
struct wc_entry *e;
|
|
|
|
read_next_block:
|
|
wc->stats.reads++;
|
|
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) {
|
|
wc->stats.read_hits++;
|
|
if (WC_MODE_PMEM(wc)) {
|
|
bio_copy_block(wc, bio, memory_data(wc, e));
|
|
if (bio->bi_iter.bi_size)
|
|
goto read_next_block;
|
|
map_op = WC_MAP_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);
|
|
map_op = WC_MAP_REMAP;
|
|
}
|
|
} else {
|
|
writecache_map_remap_origin(wc, bio, e);
|
|
wc->stats.reads += (bio->bi_iter.bi_size - wc->block_size) >> wc->block_size_bits;
|
|
map_op = WC_MAP_REMAP_ORIGIN;
|
|
}
|
|
|
|
return map_op;
|
|
}
|
|
|
|
static void writecache_bio_copy_ssd(struct dm_writecache *wc, struct bio *bio,
|
|
struct wc_entry *e, bool search_used)
|
|
{
|
|
unsigned int 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) {
|
|
if (!search_used) {
|
|
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++;
|
|
} else {
|
|
struct wc_entry *f;
|
|
struct rb_node *next = rb_next(&e->rb_node);
|
|
|
|
if (!next)
|
|
break;
|
|
f = container_of(next, struct wc_entry, rb_node);
|
|
if (f != e + 1)
|
|
break;
|
|
if (read_original_sector(wc, f) !=
|
|
read_original_sector(wc, e) + (wc->block_size >> SECTOR_SHIFT))
|
|
break;
|
|
if (unlikely(f->write_in_progress))
|
|
break;
|
|
if (writecache_entry_is_committed(wc, f))
|
|
wc->overwrote_committed = true;
|
|
e = f;
|
|
}
|
|
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);
|
|
|
|
wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits;
|
|
wc->stats.writes_allocate += (bio->bi_iter.bi_size - wc->block_size) >> wc->block_size_bits;
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
static enum wc_map_op writecache_map_write(struct dm_writecache *wc, struct bio *bio)
|
|
{
|
|
struct wc_entry *e;
|
|
|
|
do {
|
|
bool found_entry = false;
|
|
bool search_used = false;
|
|
|
|
if (writecache_has_error(wc)) {
|
|
wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits;
|
|
return WC_MAP_ERROR;
|
|
}
|
|
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, 0);
|
|
if (e) {
|
|
if (!writecache_entry_is_committed(wc, e)) {
|
|
wc->stats.write_hits_uncommitted++;
|
|
search_used = true;
|
|
goto bio_copy;
|
|
}
|
|
wc->stats.write_hits_committed++;
|
|
if (!WC_MODE_PMEM(wc) && !e->write_in_progress) {
|
|
wc->overwrote_committed = true;
|
|
search_used = true;
|
|
goto bio_copy;
|
|
}
|
|
found_entry = true;
|
|
} else {
|
|
if (unlikely(wc->cleaner) ||
|
|
(wc->metadata_only && !(bio->bi_opf & REQ_META)))
|
|
goto direct_write;
|
|
}
|
|
e = writecache_pop_from_freelist(wc, (sector_t)-1);
|
|
if (unlikely(!e)) {
|
|
if (!WC_MODE_PMEM(wc) && !found_entry) {
|
|
direct_write:
|
|
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING);
|
|
writecache_map_remap_origin(wc, bio, e);
|
|
wc->stats.writes_around += bio->bi_iter.bi_size >> wc->block_size_bits;
|
|
wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits;
|
|
return WC_MAP_REMAP_ORIGIN;
|
|
}
|
|
wc->stats.writes_blocked_on_freelist++;
|
|
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++;
|
|
wc->stats.writes_allocate++;
|
|
bio_copy:
|
|
if (WC_MODE_PMEM(wc)) {
|
|
bio_copy_block(wc, bio, memory_data(wc, e));
|
|
wc->stats.writes++;
|
|
} else {
|
|
writecache_bio_copy_ssd(wc, bio, e, search_used);
|
|
return WC_MAP_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);
|
|
|
|
return WC_MAP_SUBMIT;
|
|
}
|
|
|
|
static enum wc_map_op writecache_map_flush(struct dm_writecache *wc, struct bio *bio)
|
|
{
|
|
if (writecache_has_error(wc))
|
|
return WC_MAP_ERROR;
|
|
|
|
if (WC_MODE_PMEM(wc)) {
|
|
wc->stats.flushes++;
|
|
writecache_flush(wc);
|
|
if (writecache_has_error(wc))
|
|
return WC_MAP_ERROR;
|
|
else if (unlikely(wc->cleaner) || unlikely(wc->metadata_only))
|
|
return WC_MAP_REMAP_ORIGIN;
|
|
return WC_MAP_SUBMIT;
|
|
}
|
|
/* SSD: */
|
|
if (dm_bio_get_target_bio_nr(bio))
|
|
return WC_MAP_REMAP_ORIGIN;
|
|
wc->stats.flushes++;
|
|
writecache_offload_bio(wc, bio);
|
|
return WC_MAP_RETURN;
|
|
}
|
|
|
|
static enum wc_map_op writecache_map_discard(struct dm_writecache *wc, struct bio *bio)
|
|
{
|
|
wc->stats.discards += bio->bi_iter.bi_size >> wc->block_size_bits;
|
|
|
|
if (writecache_has_error(wc))
|
|
return WC_MAP_ERROR;
|
|
|
|
if (WC_MODE_PMEM(wc)) {
|
|
writecache_discard(wc, bio->bi_iter.bi_sector, bio_end_sector(bio));
|
|
return WC_MAP_REMAP_ORIGIN;
|
|
}
|
|
/* SSD: */
|
|
writecache_offload_bio(wc, bio);
|
|
return WC_MAP_RETURN;
|
|
}
|
|
|
|
static int writecache_map(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct dm_writecache *wc = ti->private;
|
|
enum wc_map_op map_op;
|
|
|
|
bio->bi_private = NULL;
|
|
|
|
wc_lock(wc);
|
|
|
|
if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
|
|
map_op = writecache_map_flush(wc, bio);
|
|
goto done;
|
|
}
|
|
|
|
bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
|
|
|
|
if (unlikely((((unsigned int)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);
|
|
map_op = WC_MAP_ERROR;
|
|
goto done;
|
|
}
|
|
|
|
if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) {
|
|
map_op = writecache_map_discard(wc, bio);
|
|
goto done;
|
|
}
|
|
|
|
if (bio_data_dir(bio) == READ)
|
|
map_op = writecache_map_read(wc, bio);
|
|
else
|
|
map_op = writecache_map_write(wc, bio);
|
|
done:
|
|
switch (map_op) {
|
|
case WC_MAP_REMAP_ORIGIN:
|
|
if (likely(wc->pause != 0)) {
|
|
if (bio_op(bio) == REQ_OP_WRITE) {
|
|
dm_iot_io_begin(&wc->iot, 1);
|
|
bio->bi_private = (void *)2;
|
|
}
|
|
}
|
|
bio_set_dev(bio, wc->dev->bdev);
|
|
wc_unlock(wc);
|
|
return DM_MAPIO_REMAPPED;
|
|
|
|
case WC_MAP_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;
|
|
|
|
case WC_MAP_SUBMIT:
|
|
wc_unlock(wc);
|
|
bio_endio(bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
|
|
case WC_MAP_RETURN:
|
|
wc_unlock(wc);
|
|
return DM_MAPIO_SUBMITTED;
|
|
|
|
case WC_MAP_ERROR:
|
|
wc_unlock(wc);
|
|
bio_io_error(bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
|
|
default:
|
|
BUG();
|
|
wc_unlock(wc);
|
|
return DM_MAPIO_KILL;
|
|
}
|
|
}
|
|
|
|
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 == (void *)1) {
|
|
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]);
|
|
} else if (bio->bi_private == (void *)2) {
|
|
dm_iot_io_end(&wc->iot, 1);
|
|
}
|
|
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 int 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)
|
|
{
|
|
struct dm_writecache *wc = wb->wc;
|
|
unsigned int 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 int 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(wc->dev->bdev, max_pages, REQ_OP_WRITE,
|
|
GFP_NOIO, &wc->bio_set);
|
|
wb = container_of(bio, struct writeback_struct, bio);
|
|
wb->wc = wc;
|
|
bio->bi_end_io = writecache_writeback_endio;
|
|
bio->bi_iter.bi_sector = read_original_sector(wc, e);
|
|
|
|
if (unlikely(max_pages > WB_LIST_INLINE))
|
|
wb->wc_list = kmalloc_array(max_pages, sizeof(struct wc_entry *),
|
|
GFP_NOIO | __GFP_NORETRY |
|
|
__GFP_NOMEMALLOC | __GFP_NOWARN);
|
|
|
|
if (likely(max_pages <= WB_LIST_INLINE) || unlikely(!wb->wc_list)) {
|
|
wb->wc_list = wb->wc_list_inline;
|
|
max_pages = WB_LIST_INLINE;
|
|
}
|
|
|
|
BUG_ON(!wc_add_block(wb, e));
|
|
|
|
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))
|
|
break;
|
|
wbl->size--;
|
|
list_del(&f->lru);
|
|
wb->wc_list[wb->wc_list_n++] = f;
|
|
e = f;
|
|
}
|
|
if (WC_MODE_FUA(wc))
|
|
bio->bi_opf |= 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 int 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;
|
|
|
|
if (!WC_MODE_PMEM(wc)) {
|
|
/* Wait for any active kcopyd work on behalf of ssd writeback */
|
|
dm_kcopyd_client_flush(wc->dm_kcopyd);
|
|
}
|
|
|
|
if (likely(wc->pause != 0)) {
|
|
while (1) {
|
|
unsigned long idle;
|
|
|
|
if (unlikely(wc->cleaner) || unlikely(wc->writeback_all) ||
|
|
unlikely(dm_suspended(wc->ti)))
|
|
break;
|
|
idle = dm_iot_idle_time(&wc->iot);
|
|
if (idle >= wc->pause)
|
|
break;
|
|
idle = wc->pause - idle;
|
|
if (idle > HZ)
|
|
idle = HZ;
|
|
schedule_timeout_idle(idle);
|
|
}
|
|
}
|
|
|
|
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)) {
|
|
if (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_move(&e->lru, &skipped);
|
|
cond_resched();
|
|
continue;
|
|
}
|
|
}
|
|
wc->writeback_size++;
|
|
list_move(&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_move(&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 int 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 int argc, char **argv)
|
|
{
|
|
struct dm_writecache *wc;
|
|
struct dm_arg_set as;
|
|
const char *string;
|
|
unsigned int 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, 18, "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);
|
|
|
|
dm_iot_init(&wc->iot);
|
|
|
|
raw_spin_lock_init(&wc->endio_list_lock);
|
|
INIT_LIST_HEAD(&wc->endio_list);
|
|
wc->endio_thread = kthread_run(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;
|
|
}
|
|
|
|
/*
|
|
* 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 {
|
|
wc->pause = PAUSE_WRITEBACK;
|
|
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 = bdev_nr_bytes(wc->ssd_dev->bdev);
|
|
|
|
/*
|
|
* 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 int 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 int 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 if (!strcasecmp(string, "metadata_only")) {
|
|
wc->metadata_only = true;
|
|
} else if (!strcasecmp(string, "pause_writeback") && opt_params >= 1) {
|
|
unsigned int pause_msecs;
|
|
|
|
if (WC_MODE_PMEM(wc))
|
|
goto invalid_optional;
|
|
string = dm_shift_arg(&as), opt_params--;
|
|
if (sscanf(string, "%u%c", &pause_msecs, &dummy) != 1)
|
|
goto invalid_optional;
|
|
if (pause_msecs > 60000)
|
|
goto invalid_optional;
|
|
wc->pause = msecs_to_jiffies(pause_msecs);
|
|
wc->pause_set = true;
|
|
wc->pause_value = pause_msecs;
|
|
} 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_run(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;
|
|
}
|
|
|
|
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 = WC_MODE_PMEM(wc) ? 1 : 2;
|
|
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 int status_flags, char *result, unsigned int maxlen)
|
|
{
|
|
struct dm_writecache *wc = ti->private;
|
|
unsigned int extra_args;
|
|
unsigned int sz = 0;
|
|
|
|
switch (type) {
|
|
case STATUSTYPE_INFO:
|
|
DMEMIT("%ld %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %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,
|
|
wc->stats.reads,
|
|
wc->stats.read_hits,
|
|
wc->stats.writes,
|
|
wc->stats.write_hits_uncommitted,
|
|
wc->stats.write_hits_committed,
|
|
wc->stats.writes_around,
|
|
wc->stats.writes_allocate,
|
|
wc->stats.writes_blocked_on_freelist,
|
|
wc->stats.flushes,
|
|
wc->stats.discards);
|
|
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++;
|
|
if (wc->metadata_only)
|
|
extra_args++;
|
|
if (wc->pause_set)
|
|
extra_args += 2;
|
|
|
|
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");
|
|
if (wc->metadata_only)
|
|
DMEMIT(" metadata_only");
|
|
if (wc->pause_set)
|
|
DMEMIT(" pause_writeback %u", wc->pause_value);
|
|
break;
|
|
case STATUSTYPE_IMA:
|
|
*result = '\0';
|
|
break;
|
|
}
|
|
}
|
|
|
|
static struct target_type writecache_target = {
|
|
.name = "writecache",
|
|
.version = {1, 6, 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 <dm-devel@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|