mirror of https://gitee.com/openkylin/linux.git
965 lines
22 KiB
C
965 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2019 Arrikto, Inc. All Rights Reserved.
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*/
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#include <linux/mm.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/rwsem.h>
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#include <linux/bitops.h>
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#include <linux/bitmap.h>
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#include <linux/device-mapper.h>
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#include "persistent-data/dm-bitset.h"
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#include "persistent-data/dm-space-map.h"
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#include "persistent-data/dm-block-manager.h"
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#include "persistent-data/dm-transaction-manager.h"
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#include "dm-clone-metadata.h"
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#define DM_MSG_PREFIX "clone metadata"
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#define SUPERBLOCK_LOCATION 0
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#define SUPERBLOCK_MAGIC 0x8af27f64
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#define SUPERBLOCK_CSUM_XOR 257649492
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#define DM_CLONE_MAX_CONCURRENT_LOCKS 5
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#define UUID_LEN 16
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/* Min and max dm-clone metadata versions supported */
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#define DM_CLONE_MIN_METADATA_VERSION 1
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#define DM_CLONE_MAX_METADATA_VERSION 1
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/*
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* On-disk metadata layout
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*/
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struct superblock_disk {
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__le32 csum;
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__le32 flags;
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__le64 blocknr;
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__u8 uuid[UUID_LEN];
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__le64 magic;
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__le32 version;
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__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
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__le64 region_size;
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__le64 target_size;
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__le64 bitset_root;
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} __packed;
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/*
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* Region and Dirty bitmaps.
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*
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* dm-clone logically splits the source and destination devices in regions of
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* fixed size. The destination device's regions are gradually hydrated, i.e.,
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* we copy (clone) the source's regions to the destination device. Eventually,
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* all regions will get hydrated and all I/O will be served from the
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* destination device.
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*
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* We maintain an on-disk bitmap which tracks the state of each of the
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* destination device's regions, i.e., whether they are hydrated or not.
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*
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* To save constantly doing look ups on disk we keep an in core copy of the
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* on-disk bitmap, the region_map.
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*
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* To further reduce metadata I/O overhead we use a second bitmap, the dmap
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* (dirty bitmap), which tracks the dirty words, i.e. longs, of the region_map.
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*
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* When a region finishes hydrating dm-clone calls
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* dm_clone_set_region_hydrated(), or for discard requests
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* dm_clone_cond_set_range(), which sets the corresponding bits in region_map
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* and dmap.
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*
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* During a metadata commit we scan the dmap for dirty region_map words (longs)
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* and update accordingly the on-disk metadata. Thus, we don't have to flush to
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* disk the whole region_map. We can just flush the dirty region_map words.
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*
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* We use a dirty bitmap, which is smaller than the original region_map, to
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* reduce the amount of memory accesses during a metadata commit. As dm-bitset
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* accesses the on-disk bitmap in 64-bit word granularity, there is no
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* significant benefit in tracking the dirty region_map bits with a smaller
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* granularity.
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*
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* We could update directly the on-disk bitmap, when dm-clone calls either
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* dm_clone_set_region_hydrated() or dm_clone_cond_set_range(), buts this
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* inserts significant metadata I/O overhead in dm-clone's I/O path. Also, as
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* these two functions don't block, we can call them in interrupt context,
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* e.g., in a hooked overwrite bio's completion routine, and further reduce the
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* I/O completion latency.
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*
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* We maintain two dirty bitmaps. During a metadata commit we atomically swap
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* the currently used dmap with the unused one. This allows the metadata update
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* functions to run concurrently with an ongoing commit.
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*/
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struct dirty_map {
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unsigned long *dirty_words;
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unsigned int changed;
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};
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struct dm_clone_metadata {
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/* The metadata block device */
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struct block_device *bdev;
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sector_t target_size;
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sector_t region_size;
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unsigned long nr_regions;
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unsigned long nr_words;
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/* Spinlock protecting the region and dirty bitmaps. */
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spinlock_t bitmap_lock;
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struct dirty_map dmap[2];
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struct dirty_map *current_dmap;
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/*
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* In core copy of the on-disk bitmap to save constantly doing look ups
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* on disk.
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*/
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unsigned long *region_map;
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/* Protected by bitmap_lock */
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unsigned int read_only;
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struct dm_block_manager *bm;
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struct dm_space_map *sm;
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struct dm_transaction_manager *tm;
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struct rw_semaphore lock;
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struct dm_disk_bitset bitset_info;
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dm_block_t bitset_root;
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/*
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* Reading the space map root can fail, so we read it into this
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* buffer before the superblock is locked and updated.
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*/
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__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
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bool hydration_done:1;
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bool fail_io:1;
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};
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/*---------------------------------------------------------------------------*/
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/*
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* Superblock validation.
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*/
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static void sb_prepare_for_write(struct dm_block_validator *v,
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struct dm_block *b, size_t sb_block_size)
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{
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struct superblock_disk *sb;
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u32 csum;
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sb = dm_block_data(b);
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sb->blocknr = cpu_to_le64(dm_block_location(b));
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csum = dm_bm_checksum(&sb->flags, sb_block_size - sizeof(__le32),
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SUPERBLOCK_CSUM_XOR);
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sb->csum = cpu_to_le32(csum);
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}
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static int sb_check(struct dm_block_validator *v, struct dm_block *b,
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size_t sb_block_size)
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{
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struct superblock_disk *sb;
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u32 csum, metadata_version;
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sb = dm_block_data(b);
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if (dm_block_location(b) != le64_to_cpu(sb->blocknr)) {
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DMERR("Superblock check failed: blocknr %llu, expected %llu",
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le64_to_cpu(sb->blocknr),
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(unsigned long long)dm_block_location(b));
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return -ENOTBLK;
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}
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if (le64_to_cpu(sb->magic) != SUPERBLOCK_MAGIC) {
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DMERR("Superblock check failed: magic %llu, expected %llu",
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le64_to_cpu(sb->magic),
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(unsigned long long)SUPERBLOCK_MAGIC);
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return -EILSEQ;
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}
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csum = dm_bm_checksum(&sb->flags, sb_block_size - sizeof(__le32),
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SUPERBLOCK_CSUM_XOR);
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if (sb->csum != cpu_to_le32(csum)) {
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DMERR("Superblock check failed: checksum %u, expected %u",
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csum, le32_to_cpu(sb->csum));
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return -EILSEQ;
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}
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/* Check metadata version */
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metadata_version = le32_to_cpu(sb->version);
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if (metadata_version < DM_CLONE_MIN_METADATA_VERSION ||
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metadata_version > DM_CLONE_MAX_METADATA_VERSION) {
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DMERR("Clone metadata version %u found, but only versions between %u and %u supported.",
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metadata_version, DM_CLONE_MIN_METADATA_VERSION,
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DM_CLONE_MAX_METADATA_VERSION);
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return -EINVAL;
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}
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return 0;
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}
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static struct dm_block_validator sb_validator = {
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.name = "superblock",
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.prepare_for_write = sb_prepare_for_write,
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.check = sb_check
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};
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/*
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* Check if the superblock is formatted or not. We consider the superblock to
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* be formatted in case we find non-zero bytes in it.
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*/
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static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *formatted)
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{
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int r;
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unsigned int i, nr_words;
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struct dm_block *sblock;
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__le64 *data_le, zero = cpu_to_le64(0);
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/*
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* We don't use a validator here because the superblock could be all
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* zeroes.
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*/
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r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &sblock);
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if (r) {
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DMERR("Failed to read_lock superblock");
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return r;
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}
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data_le = dm_block_data(sblock);
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*formatted = false;
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/* This assumes that the block size is a multiple of 8 bytes */
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BUG_ON(dm_bm_block_size(bm) % sizeof(__le64));
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nr_words = dm_bm_block_size(bm) / sizeof(__le64);
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for (i = 0; i < nr_words; i++) {
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if (data_le[i] != zero) {
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*formatted = true;
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break;
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}
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}
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dm_bm_unlock(sblock);
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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/*
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* Low-level metadata handling.
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*/
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static inline int superblock_read_lock(struct dm_clone_metadata *cmd,
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struct dm_block **sblock)
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{
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return dm_bm_read_lock(cmd->bm, SUPERBLOCK_LOCATION, &sb_validator, sblock);
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}
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static inline int superblock_write_lock(struct dm_clone_metadata *cmd,
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struct dm_block **sblock)
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{
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return dm_bm_write_lock(cmd->bm, SUPERBLOCK_LOCATION, &sb_validator, sblock);
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}
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static inline int superblock_write_lock_zero(struct dm_clone_metadata *cmd,
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struct dm_block **sblock)
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{
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return dm_bm_write_lock_zero(cmd->bm, SUPERBLOCK_LOCATION, &sb_validator, sblock);
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}
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static int __copy_sm_root(struct dm_clone_metadata *cmd)
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{
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int r;
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size_t root_size;
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r = dm_sm_root_size(cmd->sm, &root_size);
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if (r)
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return r;
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return dm_sm_copy_root(cmd->sm, &cmd->metadata_space_map_root, root_size);
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}
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/* Save dm-clone metadata in superblock */
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static void __prepare_superblock(struct dm_clone_metadata *cmd,
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struct superblock_disk *sb)
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{
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sb->flags = cpu_to_le32(0UL);
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/* FIXME: UUID is currently unused */
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memset(sb->uuid, 0, sizeof(sb->uuid));
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sb->magic = cpu_to_le64(SUPERBLOCK_MAGIC);
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sb->version = cpu_to_le32(DM_CLONE_MAX_METADATA_VERSION);
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/* Save the metadata space_map root */
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memcpy(&sb->metadata_space_map_root, &cmd->metadata_space_map_root,
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sizeof(cmd->metadata_space_map_root));
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sb->region_size = cpu_to_le64(cmd->region_size);
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sb->target_size = cpu_to_le64(cmd->target_size);
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sb->bitset_root = cpu_to_le64(cmd->bitset_root);
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}
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static int __open_metadata(struct dm_clone_metadata *cmd)
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{
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int r;
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struct dm_block *sblock;
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struct superblock_disk *sb;
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r = superblock_read_lock(cmd, &sblock);
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if (r) {
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DMERR("Failed to read_lock superblock");
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return r;
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}
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sb = dm_block_data(sblock);
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/* Verify that target_size and region_size haven't changed. */
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if (cmd->region_size != le64_to_cpu(sb->region_size) ||
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cmd->target_size != le64_to_cpu(sb->target_size)) {
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DMERR("Region and/or target size don't match the ones in metadata");
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r = -EINVAL;
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goto out_with_lock;
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}
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r = dm_tm_open_with_sm(cmd->bm, SUPERBLOCK_LOCATION,
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sb->metadata_space_map_root,
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sizeof(sb->metadata_space_map_root),
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&cmd->tm, &cmd->sm);
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if (r) {
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DMERR("dm_tm_open_with_sm failed");
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goto out_with_lock;
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}
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dm_disk_bitset_init(cmd->tm, &cmd->bitset_info);
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cmd->bitset_root = le64_to_cpu(sb->bitset_root);
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out_with_lock:
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dm_bm_unlock(sblock);
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return r;
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}
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static int __format_metadata(struct dm_clone_metadata *cmd)
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{
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int r;
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struct dm_block *sblock;
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struct superblock_disk *sb;
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r = dm_tm_create_with_sm(cmd->bm, SUPERBLOCK_LOCATION, &cmd->tm, &cmd->sm);
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if (r) {
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DMERR("Failed to create transaction manager");
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return r;
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}
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dm_disk_bitset_init(cmd->tm, &cmd->bitset_info);
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r = dm_bitset_empty(&cmd->bitset_info, &cmd->bitset_root);
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if (r) {
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DMERR("Failed to create empty on-disk bitset");
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goto err_with_tm;
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}
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r = dm_bitset_resize(&cmd->bitset_info, cmd->bitset_root, 0,
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cmd->nr_regions, false, &cmd->bitset_root);
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if (r) {
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DMERR("Failed to resize on-disk bitset to %lu entries", cmd->nr_regions);
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goto err_with_tm;
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}
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/* Flush to disk all blocks, except the superblock */
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r = dm_tm_pre_commit(cmd->tm);
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if (r) {
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DMERR("dm_tm_pre_commit failed");
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goto err_with_tm;
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}
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r = __copy_sm_root(cmd);
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if (r) {
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DMERR("__copy_sm_root failed");
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goto err_with_tm;
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}
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r = superblock_write_lock_zero(cmd, &sblock);
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if (r) {
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DMERR("Failed to write_lock superblock");
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goto err_with_tm;
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}
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sb = dm_block_data(sblock);
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__prepare_superblock(cmd, sb);
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r = dm_tm_commit(cmd->tm, sblock);
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if (r) {
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DMERR("Failed to commit superblock");
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goto err_with_tm;
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}
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return 0;
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err_with_tm:
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dm_sm_destroy(cmd->sm);
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dm_tm_destroy(cmd->tm);
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return r;
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}
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static int __open_or_format_metadata(struct dm_clone_metadata *cmd, bool may_format_device)
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{
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int r;
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bool formatted = false;
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r = __superblock_all_zeroes(cmd->bm, &formatted);
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if (r)
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return r;
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if (!formatted)
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return may_format_device ? __format_metadata(cmd) : -EPERM;
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return __open_metadata(cmd);
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}
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static int __create_persistent_data_structures(struct dm_clone_metadata *cmd,
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bool may_format_device)
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{
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int r;
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/* Create block manager */
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cmd->bm = dm_block_manager_create(cmd->bdev,
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DM_CLONE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
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DM_CLONE_MAX_CONCURRENT_LOCKS);
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if (IS_ERR(cmd->bm)) {
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DMERR("Failed to create block manager");
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return PTR_ERR(cmd->bm);
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}
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r = __open_or_format_metadata(cmd, may_format_device);
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if (r)
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dm_block_manager_destroy(cmd->bm);
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return r;
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}
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static void __destroy_persistent_data_structures(struct dm_clone_metadata *cmd)
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{
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dm_sm_destroy(cmd->sm);
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dm_tm_destroy(cmd->tm);
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dm_block_manager_destroy(cmd->bm);
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}
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/*---------------------------------------------------------------------------*/
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static size_t bitmap_size(unsigned long nr_bits)
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{
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return BITS_TO_LONGS(nr_bits) * sizeof(long);
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}
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static int dirty_map_init(struct dm_clone_metadata *cmd)
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{
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cmd->dmap[0].changed = 0;
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cmd->dmap[0].dirty_words = kvzalloc(bitmap_size(cmd->nr_words), GFP_KERNEL);
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if (!cmd->dmap[0].dirty_words) {
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DMERR("Failed to allocate dirty bitmap");
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return -ENOMEM;
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}
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cmd->dmap[1].changed = 0;
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cmd->dmap[1].dirty_words = kvzalloc(bitmap_size(cmd->nr_words), GFP_KERNEL);
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if (!cmd->dmap[1].dirty_words) {
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DMERR("Failed to allocate dirty bitmap");
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kvfree(cmd->dmap[0].dirty_words);
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return -ENOMEM;
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}
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cmd->current_dmap = &cmd->dmap[0];
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return 0;
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}
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static void dirty_map_exit(struct dm_clone_metadata *cmd)
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{
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kvfree(cmd->dmap[0].dirty_words);
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kvfree(cmd->dmap[1].dirty_words);
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}
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static int __load_bitset_in_core(struct dm_clone_metadata *cmd)
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{
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int r;
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unsigned long i;
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struct dm_bitset_cursor c;
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/* Flush bitset cache */
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r = dm_bitset_flush(&cmd->bitset_info, cmd->bitset_root, &cmd->bitset_root);
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if (r)
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return r;
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r = dm_bitset_cursor_begin(&cmd->bitset_info, cmd->bitset_root, cmd->nr_regions, &c);
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if (r)
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return r;
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for (i = 0; ; i++) {
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if (dm_bitset_cursor_get_value(&c))
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__set_bit(i, cmd->region_map);
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else
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__clear_bit(i, cmd->region_map);
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if (i >= (cmd->nr_regions - 1))
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break;
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r = dm_bitset_cursor_next(&c);
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if (r)
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break;
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}
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dm_bitset_cursor_end(&c);
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return r;
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|
}
|
|
|
|
struct dm_clone_metadata *dm_clone_metadata_open(struct block_device *bdev,
|
|
sector_t target_size,
|
|
sector_t region_size)
|
|
{
|
|
int r;
|
|
struct dm_clone_metadata *cmd;
|
|
|
|
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
|
|
if (!cmd) {
|
|
DMERR("Failed to allocate memory for dm-clone metadata");
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
cmd->bdev = bdev;
|
|
cmd->target_size = target_size;
|
|
cmd->region_size = region_size;
|
|
cmd->nr_regions = dm_sector_div_up(cmd->target_size, cmd->region_size);
|
|
cmd->nr_words = BITS_TO_LONGS(cmd->nr_regions);
|
|
|
|
init_rwsem(&cmd->lock);
|
|
spin_lock_init(&cmd->bitmap_lock);
|
|
cmd->read_only = 0;
|
|
cmd->fail_io = false;
|
|
cmd->hydration_done = false;
|
|
|
|
cmd->region_map = kvmalloc(bitmap_size(cmd->nr_regions), GFP_KERNEL);
|
|
if (!cmd->region_map) {
|
|
DMERR("Failed to allocate memory for region bitmap");
|
|
r = -ENOMEM;
|
|
goto out_with_md;
|
|
}
|
|
|
|
r = __create_persistent_data_structures(cmd, true);
|
|
if (r)
|
|
goto out_with_region_map;
|
|
|
|
r = __load_bitset_in_core(cmd);
|
|
if (r) {
|
|
DMERR("Failed to load on-disk region map");
|
|
goto out_with_pds;
|
|
}
|
|
|
|
r = dirty_map_init(cmd);
|
|
if (r)
|
|
goto out_with_pds;
|
|
|
|
if (bitmap_full(cmd->region_map, cmd->nr_regions))
|
|
cmd->hydration_done = true;
|
|
|
|
return cmd;
|
|
|
|
out_with_pds:
|
|
__destroy_persistent_data_structures(cmd);
|
|
|
|
out_with_region_map:
|
|
kvfree(cmd->region_map);
|
|
|
|
out_with_md:
|
|
kfree(cmd);
|
|
|
|
return ERR_PTR(r);
|
|
}
|
|
|
|
void dm_clone_metadata_close(struct dm_clone_metadata *cmd)
|
|
{
|
|
if (!cmd->fail_io)
|
|
__destroy_persistent_data_structures(cmd);
|
|
|
|
dirty_map_exit(cmd);
|
|
kvfree(cmd->region_map);
|
|
kfree(cmd);
|
|
}
|
|
|
|
bool dm_clone_is_hydration_done(struct dm_clone_metadata *cmd)
|
|
{
|
|
return cmd->hydration_done;
|
|
}
|
|
|
|
bool dm_clone_is_region_hydrated(struct dm_clone_metadata *cmd, unsigned long region_nr)
|
|
{
|
|
return dm_clone_is_hydration_done(cmd) || test_bit(region_nr, cmd->region_map);
|
|
}
|
|
|
|
bool dm_clone_is_range_hydrated(struct dm_clone_metadata *cmd,
|
|
unsigned long start, unsigned long nr_regions)
|
|
{
|
|
unsigned long bit;
|
|
|
|
if (dm_clone_is_hydration_done(cmd))
|
|
return true;
|
|
|
|
bit = find_next_zero_bit(cmd->region_map, cmd->nr_regions, start);
|
|
|
|
return (bit >= (start + nr_regions));
|
|
}
|
|
|
|
unsigned long dm_clone_nr_of_hydrated_regions(struct dm_clone_metadata *cmd)
|
|
{
|
|
return bitmap_weight(cmd->region_map, cmd->nr_regions);
|
|
}
|
|
|
|
unsigned long dm_clone_find_next_unhydrated_region(struct dm_clone_metadata *cmd,
|
|
unsigned long start)
|
|
{
|
|
return find_next_zero_bit(cmd->region_map, cmd->nr_regions, start);
|
|
}
|
|
|
|
static int __update_metadata_word(struct dm_clone_metadata *cmd, unsigned long word)
|
|
{
|
|
int r;
|
|
unsigned long index = word * BITS_PER_LONG;
|
|
unsigned long max_index = min(cmd->nr_regions, (word + 1) * BITS_PER_LONG);
|
|
|
|
while (index < max_index) {
|
|
if (test_bit(index, cmd->region_map)) {
|
|
r = dm_bitset_set_bit(&cmd->bitset_info, cmd->bitset_root,
|
|
index, &cmd->bitset_root);
|
|
|
|
if (r) {
|
|
DMERR("dm_bitset_set_bit failed");
|
|
return r;
|
|
}
|
|
}
|
|
index++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __metadata_commit(struct dm_clone_metadata *cmd)
|
|
{
|
|
int r;
|
|
struct dm_block *sblock;
|
|
struct superblock_disk *sb;
|
|
|
|
/* Flush bitset cache */
|
|
r = dm_bitset_flush(&cmd->bitset_info, cmd->bitset_root, &cmd->bitset_root);
|
|
if (r) {
|
|
DMERR("dm_bitset_flush failed");
|
|
return r;
|
|
}
|
|
|
|
/* Flush to disk all blocks, except the superblock */
|
|
r = dm_tm_pre_commit(cmd->tm);
|
|
if (r) {
|
|
DMERR("dm_tm_pre_commit failed");
|
|
return r;
|
|
}
|
|
|
|
/* Save the space map root in cmd->metadata_space_map_root */
|
|
r = __copy_sm_root(cmd);
|
|
if (r) {
|
|
DMERR("__copy_sm_root failed");
|
|
return r;
|
|
}
|
|
|
|
/* Lock the superblock */
|
|
r = superblock_write_lock_zero(cmd, &sblock);
|
|
if (r) {
|
|
DMERR("Failed to write_lock superblock");
|
|
return r;
|
|
}
|
|
|
|
/* Save the metadata in superblock */
|
|
sb = dm_block_data(sblock);
|
|
__prepare_superblock(cmd, sb);
|
|
|
|
/* Unlock superblock and commit it to disk */
|
|
r = dm_tm_commit(cmd->tm, sblock);
|
|
if (r) {
|
|
DMERR("Failed to commit superblock");
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* FIXME: Find a more efficient way to check if the hydration is done.
|
|
*/
|
|
if (bitmap_full(cmd->region_map, cmd->nr_regions))
|
|
cmd->hydration_done = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __flush_dmap(struct dm_clone_metadata *cmd, struct dirty_map *dmap)
|
|
{
|
|
int r;
|
|
unsigned long word, flags;
|
|
|
|
word = 0;
|
|
do {
|
|
word = find_next_bit(dmap->dirty_words, cmd->nr_words, word);
|
|
|
|
if (word == cmd->nr_words)
|
|
break;
|
|
|
|
r = __update_metadata_word(cmd, word);
|
|
|
|
if (r)
|
|
return r;
|
|
|
|
__clear_bit(word, dmap->dirty_words);
|
|
word++;
|
|
} while (word < cmd->nr_words);
|
|
|
|
r = __metadata_commit(cmd);
|
|
|
|
if (r)
|
|
return r;
|
|
|
|
/* Update the changed flag */
|
|
spin_lock_irqsave(&cmd->bitmap_lock, flags);
|
|
dmap->changed = 0;
|
|
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int dm_clone_metadata_commit(struct dm_clone_metadata *cmd)
|
|
{
|
|
int r = -EPERM;
|
|
unsigned long flags;
|
|
struct dirty_map *dmap, *next_dmap;
|
|
|
|
down_write(&cmd->lock);
|
|
|
|
if (cmd->fail_io || dm_bm_is_read_only(cmd->bm))
|
|
goto out;
|
|
|
|
/* Get current dirty bitmap */
|
|
dmap = cmd->current_dmap;
|
|
|
|
/* Get next dirty bitmap */
|
|
next_dmap = (dmap == &cmd->dmap[0]) ? &cmd->dmap[1] : &cmd->dmap[0];
|
|
|
|
/*
|
|
* The last commit failed, so we don't have a clean dirty-bitmap to
|
|
* use.
|
|
*/
|
|
if (WARN_ON(next_dmap->changed)) {
|
|
r = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* Swap dirty bitmaps */
|
|
spin_lock_irqsave(&cmd->bitmap_lock, flags);
|
|
cmd->current_dmap = next_dmap;
|
|
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
|
|
|
|
/*
|
|
* No one is accessing the old dirty bitmap anymore, so we can flush
|
|
* it.
|
|
*/
|
|
r = __flush_dmap(cmd, dmap);
|
|
out:
|
|
up_write(&cmd->lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
int dm_clone_set_region_hydrated(struct dm_clone_metadata *cmd, unsigned long region_nr)
|
|
{
|
|
int r = 0;
|
|
struct dirty_map *dmap;
|
|
unsigned long word, flags;
|
|
|
|
word = region_nr / BITS_PER_LONG;
|
|
|
|
spin_lock_irqsave(&cmd->bitmap_lock, flags);
|
|
|
|
if (cmd->read_only) {
|
|
r = -EPERM;
|
|
goto out;
|
|
}
|
|
|
|
dmap = cmd->current_dmap;
|
|
|
|
__set_bit(word, dmap->dirty_words);
|
|
__set_bit(region_nr, cmd->region_map);
|
|
dmap->changed = 1;
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
|
|
|
|
return r;
|
|
}
|
|
|
|
int dm_clone_cond_set_range(struct dm_clone_metadata *cmd, unsigned long start,
|
|
unsigned long nr_regions)
|
|
{
|
|
int r = 0;
|
|
struct dirty_map *dmap;
|
|
unsigned long word, region_nr, flags;
|
|
|
|
spin_lock_irqsave(&cmd->bitmap_lock, flags);
|
|
|
|
if (cmd->read_only) {
|
|
r = -EPERM;
|
|
goto out;
|
|
}
|
|
|
|
dmap = cmd->current_dmap;
|
|
for (region_nr = start; region_nr < (start + nr_regions); region_nr++) {
|
|
if (!test_bit(region_nr, cmd->region_map)) {
|
|
word = region_nr / BITS_PER_LONG;
|
|
__set_bit(word, dmap->dirty_words);
|
|
__set_bit(region_nr, cmd->region_map);
|
|
dmap->changed = 1;
|
|
}
|
|
}
|
|
out:
|
|
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* WARNING: This must not be called concurrently with either
|
|
* dm_clone_set_region_hydrated() or dm_clone_cond_set_range(), as it changes
|
|
* cmd->region_map without taking the cmd->bitmap_lock spinlock. The only
|
|
* exception is after setting the metadata to read-only mode, using
|
|
* dm_clone_metadata_set_read_only().
|
|
*
|
|
* We don't take the spinlock because __load_bitset_in_core() does I/O, so it
|
|
* may block.
|
|
*/
|
|
int dm_clone_reload_in_core_bitset(struct dm_clone_metadata *cmd)
|
|
{
|
|
int r = -EINVAL;
|
|
|
|
down_write(&cmd->lock);
|
|
|
|
if (cmd->fail_io)
|
|
goto out;
|
|
|
|
r = __load_bitset_in_core(cmd);
|
|
out:
|
|
up_write(&cmd->lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
bool dm_clone_changed_this_transaction(struct dm_clone_metadata *cmd)
|
|
{
|
|
bool r;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&cmd->bitmap_lock, flags);
|
|
r = cmd->dmap[0].changed || cmd->dmap[1].changed;
|
|
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
|
|
|
|
return r;
|
|
}
|
|
|
|
int dm_clone_metadata_abort(struct dm_clone_metadata *cmd)
|
|
{
|
|
int r = -EPERM;
|
|
|
|
down_write(&cmd->lock);
|
|
|
|
if (cmd->fail_io || dm_bm_is_read_only(cmd->bm))
|
|
goto out;
|
|
|
|
__destroy_persistent_data_structures(cmd);
|
|
|
|
r = __create_persistent_data_structures(cmd, false);
|
|
if (r) {
|
|
/* If something went wrong we can neither write nor read the metadata */
|
|
cmd->fail_io = true;
|
|
}
|
|
out:
|
|
up_write(&cmd->lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
void dm_clone_metadata_set_read_only(struct dm_clone_metadata *cmd)
|
|
{
|
|
unsigned long flags;
|
|
|
|
down_write(&cmd->lock);
|
|
|
|
spin_lock_irqsave(&cmd->bitmap_lock, flags);
|
|
cmd->read_only = 1;
|
|
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
|
|
|
|
if (!cmd->fail_io)
|
|
dm_bm_set_read_only(cmd->bm);
|
|
|
|
up_write(&cmd->lock);
|
|
}
|
|
|
|
void dm_clone_metadata_set_read_write(struct dm_clone_metadata *cmd)
|
|
{
|
|
unsigned long flags;
|
|
|
|
down_write(&cmd->lock);
|
|
|
|
spin_lock_irqsave(&cmd->bitmap_lock, flags);
|
|
cmd->read_only = 0;
|
|
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
|
|
|
|
if (!cmd->fail_io)
|
|
dm_bm_set_read_write(cmd->bm);
|
|
|
|
up_write(&cmd->lock);
|
|
}
|
|
|
|
int dm_clone_get_free_metadata_block_count(struct dm_clone_metadata *cmd,
|
|
dm_block_t *result)
|
|
{
|
|
int r = -EINVAL;
|
|
|
|
down_read(&cmd->lock);
|
|
|
|
if (!cmd->fail_io)
|
|
r = dm_sm_get_nr_free(cmd->sm, result);
|
|
|
|
up_read(&cmd->lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
int dm_clone_get_metadata_dev_size(struct dm_clone_metadata *cmd,
|
|
dm_block_t *result)
|
|
{
|
|
int r = -EINVAL;
|
|
|
|
down_read(&cmd->lock);
|
|
|
|
if (!cmd->fail_io)
|
|
r = dm_sm_get_nr_blocks(cmd->sm, result);
|
|
|
|
up_read(&cmd->lock);
|
|
|
|
return r;
|
|
}
|