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1eb5fa849f
Could be useful for a target to return stats or other information. If a target does DMEMIT() anything to @result from its .message method then it must return 1 to the caller. Signed-off-By: Mike Snitzer <snitzer@redhat.com>
1730 lines
38 KiB
C
1730 lines
38 KiB
C
#include "dm.h"
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#include "persistent-data/dm-transaction-manager.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 <linux/dm-io.h>
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#include <linux/dm-kcopyd.h>
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#include <linux/init.h>
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#include <linux/mempool.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#define DM_MSG_PREFIX "era"
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#define SUPERBLOCK_LOCATION 0
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#define SUPERBLOCK_MAGIC 2126579579
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#define SUPERBLOCK_CSUM_XOR 146538381
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#define MIN_ERA_VERSION 1
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#define MAX_ERA_VERSION 1
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#define INVALID_WRITESET_ROOT SUPERBLOCK_LOCATION
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#define MIN_BLOCK_SIZE 8
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/*----------------------------------------------------------------
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* Writeset
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*--------------------------------------------------------------*/
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struct writeset_metadata {
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uint32_t nr_bits;
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dm_block_t root;
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};
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struct writeset {
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struct writeset_metadata md;
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/*
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* An in core copy of the bits to save constantly doing look ups on
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* disk.
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*/
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unsigned long *bits;
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};
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/*
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* This does not free off the on disk bitset as this will normally be done
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* after digesting into the era array.
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*/
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static void writeset_free(struct writeset *ws)
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{
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vfree(ws->bits);
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}
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static int setup_on_disk_bitset(struct dm_disk_bitset *info,
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unsigned nr_bits, dm_block_t *root)
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{
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int r;
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r = dm_bitset_empty(info, root);
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if (r)
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return r;
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return dm_bitset_resize(info, *root, 0, nr_bits, false, root);
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}
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static size_t bitset_size(unsigned nr_bits)
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{
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return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG);
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}
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/*
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* Allocates memory for the in core bitset.
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*/
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static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks)
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{
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ws->md.nr_bits = nr_blocks;
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ws->md.root = INVALID_WRITESET_ROOT;
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ws->bits = vzalloc(bitset_size(nr_blocks));
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if (!ws->bits) {
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DMERR("%s: couldn't allocate in memory bitset", __func__);
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return -ENOMEM;
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}
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return 0;
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}
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/*
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* Wipes the in-core bitset, and creates a new on disk bitset.
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*/
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static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws)
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{
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int r;
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memset(ws->bits, 0, bitset_size(ws->md.nr_bits));
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r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root);
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if (r) {
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DMERR("%s: setup_on_disk_bitset failed", __func__);
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return r;
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}
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return 0;
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}
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static bool writeset_marked(struct writeset *ws, dm_block_t block)
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{
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return test_bit(block, ws->bits);
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}
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static int writeset_marked_on_disk(struct dm_disk_bitset *info,
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struct writeset_metadata *m, dm_block_t block,
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bool *result)
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{
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dm_block_t old = m->root;
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/*
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* The bitset was flushed when it was archived, so we know there'll
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* be no change to the root.
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*/
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int r = dm_bitset_test_bit(info, m->root, block, &m->root, result);
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if (r) {
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DMERR("%s: dm_bitset_test_bit failed", __func__);
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return r;
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}
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BUG_ON(m->root != old);
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return r;
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}
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/*
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* Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was.
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*/
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static int writeset_test_and_set(struct dm_disk_bitset *info,
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struct writeset *ws, uint32_t block)
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{
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int r;
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if (!test_and_set_bit(block, ws->bits)) {
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r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root);
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if (r) {
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/* FIXME: fail mode */
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return r;
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}
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return 0;
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}
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return 1;
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}
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/*----------------------------------------------------------------
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* On disk metadata layout
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*--------------------------------------------------------------*/
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#define SPACE_MAP_ROOT_SIZE 128
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#define UUID_LEN 16
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struct writeset_disk {
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__le32 nr_bits;
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__le64 root;
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} __packed;
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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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__le32 data_block_size;
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__le32 metadata_block_size;
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__le32 nr_blocks;
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__le32 current_era;
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struct writeset_disk current_writeset;
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/*
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* Only these two fields are valid within the metadata snapshot.
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*/
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__le64 writeset_tree_root;
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__le64 era_array_root;
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__le64 metadata_snap;
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} __packed;
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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,
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size_t sb_block_size)
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{
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struct superblock_disk *disk = dm_block_data(b);
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disk->blocknr = cpu_to_le64(dm_block_location(b));
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disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags,
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sb_block_size - sizeof(__le32),
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SUPERBLOCK_CSUM_XOR));
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}
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static int check_metadata_version(struct superblock_disk *disk)
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{
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uint32_t metadata_version = le32_to_cpu(disk->version);
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if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) {
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DMERR("Era metadata version %u found, but only versions between %u and %u supported.",
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metadata_version, MIN_ERA_VERSION, MAX_ERA_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 int sb_check(struct dm_block_validator *v,
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struct dm_block *b,
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size_t sb_block_size)
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{
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struct superblock_disk *disk = dm_block_data(b);
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__le32 csum_le;
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if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) {
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DMERR("sb_check failed: blocknr %llu: wanted %llu",
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le64_to_cpu(disk->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(disk->magic) != SUPERBLOCK_MAGIC) {
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DMERR("sb_check failed: magic %llu: wanted %llu",
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le64_to_cpu(disk->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_le = cpu_to_le32(dm_bm_checksum(&disk->flags,
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sb_block_size - sizeof(__le32),
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SUPERBLOCK_CSUM_XOR));
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if (csum_le != disk->csum) {
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DMERR("sb_check failed: csum %u: wanted %u",
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le32_to_cpu(csum_le), le32_to_cpu(disk->csum));
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return -EILSEQ;
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}
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return check_metadata_version(disk);
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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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* Low level metadata handling
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*--------------------------------------------------------------*/
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#define DM_ERA_METADATA_BLOCK_SIZE 4096
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#define ERA_MAX_CONCURRENT_LOCKS 5
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struct era_metadata {
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struct block_device *bdev;
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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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dm_block_t block_size;
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uint32_t nr_blocks;
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uint32_t current_era;
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/*
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* We preallocate 2 writesets. When an era rolls over we
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* switch between them. This means the allocation is done at
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* preresume time, rather than on the io path.
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*/
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struct writeset writesets[2];
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struct writeset *current_writeset;
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dm_block_t writeset_tree_root;
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dm_block_t era_array_root;
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struct dm_disk_bitset bitset_info;
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struct dm_btree_info writeset_tree_info;
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struct dm_array_info era_array_info;
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dm_block_t metadata_snap;
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/*
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* A flag that is set whenever a writeset has been archived.
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*/
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bool archived_writesets;
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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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};
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static int superblock_read_lock(struct era_metadata *md,
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struct dm_block **sblock)
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{
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return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION,
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&sb_validator, sblock);
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}
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static int superblock_lock_zero(struct era_metadata *md,
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struct dm_block **sblock)
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{
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return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION,
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&sb_validator, sblock);
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}
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static int superblock_lock(struct era_metadata *md,
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struct dm_block **sblock)
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{
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return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION,
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&sb_validator, sblock);
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}
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/* FIXME: duplication with cache and thin */
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static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
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{
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int r;
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unsigned i;
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struct dm_block *b;
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__le64 *data_le, zero = cpu_to_le64(0);
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unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
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/*
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* We can't use a validator here - it may be all zeroes.
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*/
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r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &b);
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if (r)
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return r;
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data_le = dm_block_data(b);
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*result = true;
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for (i = 0; i < sb_block_size; i++) {
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if (data_le[i] != zero) {
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*result = false;
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break;
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}
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}
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dm_bm_unlock(b);
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return 0;
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}
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/*----------------------------------------------------------------*/
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static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk)
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{
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disk->nr_bits = cpu_to_le32(core->nr_bits);
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disk->root = cpu_to_le64(core->root);
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}
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static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core)
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{
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core->nr_bits = le32_to_cpu(disk->nr_bits);
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core->root = le64_to_cpu(disk->root);
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}
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static void ws_inc(void *context, const void *value)
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{
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struct era_metadata *md = context;
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struct writeset_disk ws_d;
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dm_block_t b;
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memcpy(&ws_d, value, sizeof(ws_d));
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b = le64_to_cpu(ws_d.root);
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dm_tm_inc(md->tm, b);
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}
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static void ws_dec(void *context, const void *value)
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{
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struct era_metadata *md = context;
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struct writeset_disk ws_d;
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dm_block_t b;
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memcpy(&ws_d, value, sizeof(ws_d));
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b = le64_to_cpu(ws_d.root);
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dm_bitset_del(&md->bitset_info, b);
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}
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static int ws_eq(void *context, const void *value1, const void *value2)
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{
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return !memcmp(value1, value2, sizeof(struct writeset_metadata));
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}
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/*----------------------------------------------------------------*/
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static void setup_writeset_tree_info(struct era_metadata *md)
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{
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struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type;
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md->writeset_tree_info.tm = md->tm;
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md->writeset_tree_info.levels = 1;
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vt->context = md;
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vt->size = sizeof(struct writeset_disk);
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vt->inc = ws_inc;
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vt->dec = ws_dec;
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vt->equal = ws_eq;
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}
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static void setup_era_array_info(struct era_metadata *md)
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{
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struct dm_btree_value_type vt;
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vt.context = NULL;
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vt.size = sizeof(__le32);
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vt.inc = NULL;
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vt.dec = NULL;
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vt.equal = NULL;
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dm_array_info_init(&md->era_array_info, md->tm, &vt);
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}
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static void setup_infos(struct era_metadata *md)
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{
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dm_disk_bitset_init(md->tm, &md->bitset_info);
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setup_writeset_tree_info(md);
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setup_era_array_info(md);
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}
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/*----------------------------------------------------------------*/
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static int create_fresh_metadata(struct era_metadata *md)
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{
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int r;
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r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION,
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&md->tm, &md->sm);
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if (r < 0) {
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DMERR("dm_tm_create_with_sm failed");
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return r;
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}
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setup_infos(md);
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r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root);
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if (r) {
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DMERR("couldn't create new writeset tree");
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goto bad;
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}
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r = dm_array_empty(&md->era_array_info, &md->era_array_root);
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if (r) {
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DMERR("couldn't create era array");
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goto bad;
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}
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return 0;
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bad:
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dm_sm_destroy(md->sm);
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dm_tm_destroy(md->tm);
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return r;
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}
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static int save_sm_root(struct era_metadata *md)
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{
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int r;
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size_t metadata_len;
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r = dm_sm_root_size(md->sm, &metadata_len);
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if (r < 0)
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return r;
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return dm_sm_copy_root(md->sm, &md->metadata_space_map_root,
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metadata_len);
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}
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static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk)
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{
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memcpy(&disk->metadata_space_map_root,
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&md->metadata_space_map_root,
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sizeof(md->metadata_space_map_root));
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}
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/*
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* Writes a superblock, including the static fields that don't get updated
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* with every commit (possible optimisation here). 'md' should be fully
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* constructed when this is called.
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*/
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static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk)
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{
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disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC);
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disk->flags = cpu_to_le32(0ul);
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/* FIXME: can't keep blanking the uuid (uuid is currently unused though) */
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memset(disk->uuid, 0, sizeof(disk->uuid));
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disk->version = cpu_to_le32(MAX_ERA_VERSION);
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copy_sm_root(md, disk);
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disk->data_block_size = cpu_to_le32(md->block_size);
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disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
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disk->nr_blocks = cpu_to_le32(md->nr_blocks);
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disk->current_era = cpu_to_le32(md->current_era);
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ws_pack(&md->current_writeset->md, &disk->current_writeset);
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disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root);
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disk->era_array_root = cpu_to_le64(md->era_array_root);
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disk->metadata_snap = cpu_to_le64(md->metadata_snap);
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}
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static int write_superblock(struct era_metadata *md)
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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 *disk;
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r = save_sm_root(md);
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if (r) {
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DMERR("%s: save_sm_root failed", __func__);
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return r;
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}
|
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|
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r = superblock_lock_zero(md, &sblock);
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if (r)
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return r;
|
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|
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disk = dm_block_data(sblock);
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prepare_superblock(md, disk);
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|
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return dm_tm_commit(md->tm, sblock);
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}
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|
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/*
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* Assumes block_size and the infos are set.
|
|
*/
|
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static int format_metadata(struct era_metadata *md)
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{
|
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int r;
|
|
|
|
r = create_fresh_metadata(md);
|
|
if (r)
|
|
return r;
|
|
|
|
r = write_superblock(md);
|
|
if (r) {
|
|
dm_sm_destroy(md->sm);
|
|
dm_tm_destroy(md->tm);
|
|
return r;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int open_metadata(struct era_metadata *md)
|
|
{
|
|
int r;
|
|
struct dm_block *sblock;
|
|
struct superblock_disk *disk;
|
|
|
|
r = superblock_read_lock(md, &sblock);
|
|
if (r) {
|
|
DMERR("couldn't read_lock superblock");
|
|
return r;
|
|
}
|
|
|
|
disk = dm_block_data(sblock);
|
|
r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION,
|
|
disk->metadata_space_map_root,
|
|
sizeof(disk->metadata_space_map_root),
|
|
&md->tm, &md->sm);
|
|
if (r) {
|
|
DMERR("dm_tm_open_with_sm failed");
|
|
goto bad;
|
|
}
|
|
|
|
setup_infos(md);
|
|
|
|
md->block_size = le32_to_cpu(disk->data_block_size);
|
|
md->nr_blocks = le32_to_cpu(disk->nr_blocks);
|
|
md->current_era = le32_to_cpu(disk->current_era);
|
|
|
|
md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root);
|
|
md->era_array_root = le64_to_cpu(disk->era_array_root);
|
|
md->metadata_snap = le64_to_cpu(disk->metadata_snap);
|
|
md->archived_writesets = true;
|
|
|
|
dm_bm_unlock(sblock);
|
|
|
|
return 0;
|
|
|
|
bad:
|
|
dm_bm_unlock(sblock);
|
|
return r;
|
|
}
|
|
|
|
static int open_or_format_metadata(struct era_metadata *md,
|
|
bool may_format)
|
|
{
|
|
int r;
|
|
bool unformatted = false;
|
|
|
|
r = superblock_all_zeroes(md->bm, &unformatted);
|
|
if (r)
|
|
return r;
|
|
|
|
if (unformatted)
|
|
return may_format ? format_metadata(md) : -EPERM;
|
|
|
|
return open_metadata(md);
|
|
}
|
|
|
|
static int create_persistent_data_objects(struct era_metadata *md,
|
|
bool may_format)
|
|
{
|
|
int r;
|
|
|
|
md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE,
|
|
ERA_MAX_CONCURRENT_LOCKS);
|
|
if (IS_ERR(md->bm)) {
|
|
DMERR("could not create block manager");
|
|
return PTR_ERR(md->bm);
|
|
}
|
|
|
|
r = open_or_format_metadata(md, may_format);
|
|
if (r)
|
|
dm_block_manager_destroy(md->bm);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void destroy_persistent_data_objects(struct era_metadata *md)
|
|
{
|
|
dm_sm_destroy(md->sm);
|
|
dm_tm_destroy(md->tm);
|
|
dm_block_manager_destroy(md->bm);
|
|
}
|
|
|
|
/*
|
|
* This waits until all era_map threads have picked up the new filter.
|
|
*/
|
|
static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset)
|
|
{
|
|
rcu_assign_pointer(md->current_writeset, new_writeset);
|
|
synchronize_rcu();
|
|
}
|
|
|
|
/*----------------------------------------------------------------
|
|
* Writesets get 'digested' into the main era array.
|
|
*
|
|
* We're using a coroutine here so the worker thread can do the digestion,
|
|
* thus avoiding synchronisation of the metadata. Digesting a whole
|
|
* writeset in one go would cause too much latency.
|
|
*--------------------------------------------------------------*/
|
|
struct digest {
|
|
uint32_t era;
|
|
unsigned nr_bits, current_bit;
|
|
struct writeset_metadata writeset;
|
|
__le32 value;
|
|
struct dm_disk_bitset info;
|
|
|
|
int (*step)(struct era_metadata *, struct digest *);
|
|
};
|
|
|
|
static int metadata_digest_lookup_writeset(struct era_metadata *md,
|
|
struct digest *d);
|
|
|
|
static int metadata_digest_remove_writeset(struct era_metadata *md,
|
|
struct digest *d)
|
|
{
|
|
int r;
|
|
uint64_t key = d->era;
|
|
|
|
r = dm_btree_remove(&md->writeset_tree_info, md->writeset_tree_root,
|
|
&key, &md->writeset_tree_root);
|
|
if (r) {
|
|
DMERR("%s: dm_btree_remove failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
d->step = metadata_digest_lookup_writeset;
|
|
return 0;
|
|
}
|
|
|
|
#define INSERTS_PER_STEP 100
|
|
|
|
static int metadata_digest_transcribe_writeset(struct era_metadata *md,
|
|
struct digest *d)
|
|
{
|
|
int r;
|
|
bool marked;
|
|
unsigned b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits);
|
|
|
|
for (b = d->current_bit; b < e; b++) {
|
|
r = writeset_marked_on_disk(&d->info, &d->writeset, b, &marked);
|
|
if (r) {
|
|
DMERR("%s: writeset_marked_on_disk failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
if (!marked)
|
|
continue;
|
|
|
|
__dm_bless_for_disk(&d->value);
|
|
r = dm_array_set_value(&md->era_array_info, md->era_array_root,
|
|
b, &d->value, &md->era_array_root);
|
|
if (r) {
|
|
DMERR("%s: dm_array_set_value failed", __func__);
|
|
return r;
|
|
}
|
|
}
|
|
|
|
if (b == d->nr_bits)
|
|
d->step = metadata_digest_remove_writeset;
|
|
else
|
|
d->current_bit = b;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int metadata_digest_lookup_writeset(struct era_metadata *md,
|
|
struct digest *d)
|
|
{
|
|
int r;
|
|
uint64_t key;
|
|
struct writeset_disk disk;
|
|
|
|
r = dm_btree_find_lowest_key(&md->writeset_tree_info,
|
|
md->writeset_tree_root, &key);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
d->era = key;
|
|
|
|
r = dm_btree_lookup(&md->writeset_tree_info,
|
|
md->writeset_tree_root, &key, &disk);
|
|
if (r) {
|
|
if (r == -ENODATA) {
|
|
d->step = NULL;
|
|
return 0;
|
|
}
|
|
|
|
DMERR("%s: dm_btree_lookup failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
ws_unpack(&disk, &d->writeset);
|
|
d->value = cpu_to_le32(key);
|
|
|
|
d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks);
|
|
d->current_bit = 0;
|
|
d->step = metadata_digest_transcribe_writeset;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int metadata_digest_start(struct era_metadata *md, struct digest *d)
|
|
{
|
|
if (d->step)
|
|
return 0;
|
|
|
|
memset(d, 0, sizeof(*d));
|
|
|
|
/*
|
|
* We initialise another bitset info to avoid any caching side
|
|
* effects with the previous one.
|
|
*/
|
|
dm_disk_bitset_init(md->tm, &d->info);
|
|
d->step = metadata_digest_lookup_writeset;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*----------------------------------------------------------------
|
|
* High level metadata interface. Target methods should use these, and not
|
|
* the lower level ones.
|
|
*--------------------------------------------------------------*/
|
|
static struct era_metadata *metadata_open(struct block_device *bdev,
|
|
sector_t block_size,
|
|
bool may_format)
|
|
{
|
|
int r;
|
|
struct era_metadata *md = kzalloc(sizeof(*md), GFP_KERNEL);
|
|
|
|
if (!md)
|
|
return NULL;
|
|
|
|
md->bdev = bdev;
|
|
md->block_size = block_size;
|
|
|
|
md->writesets[0].md.root = INVALID_WRITESET_ROOT;
|
|
md->writesets[1].md.root = INVALID_WRITESET_ROOT;
|
|
md->current_writeset = &md->writesets[0];
|
|
|
|
r = create_persistent_data_objects(md, may_format);
|
|
if (r) {
|
|
kfree(md);
|
|
return ERR_PTR(r);
|
|
}
|
|
|
|
return md;
|
|
}
|
|
|
|
static void metadata_close(struct era_metadata *md)
|
|
{
|
|
destroy_persistent_data_objects(md);
|
|
kfree(md);
|
|
}
|
|
|
|
static bool valid_nr_blocks(dm_block_t n)
|
|
{
|
|
/*
|
|
* dm_bitset restricts us to 2^32. test_bit & co. restrict us
|
|
* further to 2^31 - 1
|
|
*/
|
|
return n < (1ull << 31);
|
|
}
|
|
|
|
static int metadata_resize(struct era_metadata *md, void *arg)
|
|
{
|
|
int r;
|
|
dm_block_t *new_size = arg;
|
|
__le32 value;
|
|
|
|
if (!valid_nr_blocks(*new_size)) {
|
|
DMERR("Invalid number of origin blocks %llu",
|
|
(unsigned long long) *new_size);
|
|
return -EINVAL;
|
|
}
|
|
|
|
writeset_free(&md->writesets[0]);
|
|
writeset_free(&md->writesets[1]);
|
|
|
|
r = writeset_alloc(&md->writesets[0], *new_size);
|
|
if (r) {
|
|
DMERR("%s: writeset_alloc failed for writeset 0", __func__);
|
|
return r;
|
|
}
|
|
|
|
r = writeset_alloc(&md->writesets[1], *new_size);
|
|
if (r) {
|
|
DMERR("%s: writeset_alloc failed for writeset 1", __func__);
|
|
return r;
|
|
}
|
|
|
|
value = cpu_to_le32(0u);
|
|
__dm_bless_for_disk(&value);
|
|
r = dm_array_resize(&md->era_array_info, md->era_array_root,
|
|
md->nr_blocks, *new_size,
|
|
&value, &md->era_array_root);
|
|
if (r) {
|
|
DMERR("%s: dm_array_resize failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
md->nr_blocks = *new_size;
|
|
return 0;
|
|
}
|
|
|
|
static int metadata_era_archive(struct era_metadata *md)
|
|
{
|
|
int r;
|
|
uint64_t keys[1];
|
|
struct writeset_disk value;
|
|
|
|
r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root,
|
|
&md->current_writeset->md.root);
|
|
if (r) {
|
|
DMERR("%s: dm_bitset_flush failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
ws_pack(&md->current_writeset->md, &value);
|
|
md->current_writeset->md.root = INVALID_WRITESET_ROOT;
|
|
|
|
keys[0] = md->current_era;
|
|
__dm_bless_for_disk(&value);
|
|
r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root,
|
|
keys, &value, &md->writeset_tree_root);
|
|
if (r) {
|
|
DMERR("%s: couldn't insert writeset into btree", __func__);
|
|
/* FIXME: fail mode */
|
|
return r;
|
|
}
|
|
|
|
md->archived_writesets = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct writeset *next_writeset(struct era_metadata *md)
|
|
{
|
|
return (md->current_writeset == &md->writesets[0]) ?
|
|
&md->writesets[1] : &md->writesets[0];
|
|
}
|
|
|
|
static int metadata_new_era(struct era_metadata *md)
|
|
{
|
|
int r;
|
|
struct writeset *new_writeset = next_writeset(md);
|
|
|
|
r = writeset_init(&md->bitset_info, new_writeset);
|
|
if (r) {
|
|
DMERR("%s: writeset_init failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
swap_writeset(md, new_writeset);
|
|
md->current_era++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int metadata_era_rollover(struct era_metadata *md)
|
|
{
|
|
int r;
|
|
|
|
if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) {
|
|
r = metadata_era_archive(md);
|
|
if (r) {
|
|
DMERR("%s: metadata_archive_era failed", __func__);
|
|
/* FIXME: fail mode? */
|
|
return r;
|
|
}
|
|
}
|
|
|
|
r = metadata_new_era(md);
|
|
if (r) {
|
|
DMERR("%s: new era failed", __func__);
|
|
/* FIXME: fail mode */
|
|
return r;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool metadata_current_marked(struct era_metadata *md, dm_block_t block)
|
|
{
|
|
bool r;
|
|
struct writeset *ws;
|
|
|
|
rcu_read_lock();
|
|
ws = rcu_dereference(md->current_writeset);
|
|
r = writeset_marked(ws, block);
|
|
rcu_read_unlock();
|
|
|
|
return r;
|
|
}
|
|
|
|
static int metadata_commit(struct era_metadata *md)
|
|
{
|
|
int r;
|
|
struct dm_block *sblock;
|
|
|
|
if (md->current_writeset->md.root != SUPERBLOCK_LOCATION) {
|
|
r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root,
|
|
&md->current_writeset->md.root);
|
|
if (r) {
|
|
DMERR("%s: bitset flush failed", __func__);
|
|
return r;
|
|
}
|
|
}
|
|
|
|
r = dm_tm_pre_commit(md->tm);
|
|
if (r) {
|
|
DMERR("%s: pre commit failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
r = save_sm_root(md);
|
|
if (r) {
|
|
DMERR("%s: save_sm_root failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
r = superblock_lock(md, &sblock);
|
|
if (r) {
|
|
DMERR("%s: superblock lock failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
prepare_superblock(md, dm_block_data(sblock));
|
|
|
|
return dm_tm_commit(md->tm, sblock);
|
|
}
|
|
|
|
static int metadata_checkpoint(struct era_metadata *md)
|
|
{
|
|
/*
|
|
* For now we just rollover, but later I want to put a check in to
|
|
* avoid this if the filter is still pretty fresh.
|
|
*/
|
|
return metadata_era_rollover(md);
|
|
}
|
|
|
|
/*
|
|
* Metadata snapshots allow userland to access era data.
|
|
*/
|
|
static int metadata_take_snap(struct era_metadata *md)
|
|
{
|
|
int r, inc;
|
|
struct dm_block *clone;
|
|
|
|
if (md->metadata_snap != SUPERBLOCK_LOCATION) {
|
|
DMERR("%s: metadata snapshot already exists", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = metadata_era_rollover(md);
|
|
if (r) {
|
|
DMERR("%s: era rollover failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
r = metadata_commit(md);
|
|
if (r) {
|
|
DMERR("%s: pre commit failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION);
|
|
if (r) {
|
|
DMERR("%s: couldn't increment superblock", __func__);
|
|
return r;
|
|
}
|
|
|
|
r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION,
|
|
&sb_validator, &clone, &inc);
|
|
if (r) {
|
|
DMERR("%s: couldn't shadow superblock", __func__);
|
|
dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION);
|
|
return r;
|
|
}
|
|
BUG_ON(!inc);
|
|
|
|
r = dm_sm_inc_block(md->sm, md->writeset_tree_root);
|
|
if (r) {
|
|
DMERR("%s: couldn't inc writeset tree root", __func__);
|
|
dm_tm_unlock(md->tm, clone);
|
|
return r;
|
|
}
|
|
|
|
r = dm_sm_inc_block(md->sm, md->era_array_root);
|
|
if (r) {
|
|
DMERR("%s: couldn't inc era tree root", __func__);
|
|
dm_sm_dec_block(md->sm, md->writeset_tree_root);
|
|
dm_tm_unlock(md->tm, clone);
|
|
return r;
|
|
}
|
|
|
|
md->metadata_snap = dm_block_location(clone);
|
|
|
|
dm_tm_unlock(md->tm, clone);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int metadata_drop_snap(struct era_metadata *md)
|
|
{
|
|
int r;
|
|
dm_block_t location;
|
|
struct dm_block *clone;
|
|
struct superblock_disk *disk;
|
|
|
|
if (md->metadata_snap == SUPERBLOCK_LOCATION) {
|
|
DMERR("%s: no snap to drop", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone);
|
|
if (r) {
|
|
DMERR("%s: couldn't read lock superblock clone", __func__);
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Whatever happens now we'll commit with no record of the metadata
|
|
* snap.
|
|
*/
|
|
md->metadata_snap = SUPERBLOCK_LOCATION;
|
|
|
|
disk = dm_block_data(clone);
|
|
r = dm_btree_del(&md->writeset_tree_info,
|
|
le64_to_cpu(disk->writeset_tree_root));
|
|
if (r) {
|
|
DMERR("%s: error deleting writeset tree clone", __func__);
|
|
dm_tm_unlock(md->tm, clone);
|
|
return r;
|
|
}
|
|
|
|
r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root));
|
|
if (r) {
|
|
DMERR("%s: error deleting era array clone", __func__);
|
|
dm_tm_unlock(md->tm, clone);
|
|
return r;
|
|
}
|
|
|
|
location = dm_block_location(clone);
|
|
dm_tm_unlock(md->tm, clone);
|
|
|
|
return dm_sm_dec_block(md->sm, location);
|
|
}
|
|
|
|
struct metadata_stats {
|
|
dm_block_t used;
|
|
dm_block_t total;
|
|
dm_block_t snap;
|
|
uint32_t era;
|
|
};
|
|
|
|
static int metadata_get_stats(struct era_metadata *md, void *ptr)
|
|
{
|
|
int r;
|
|
struct metadata_stats *s = ptr;
|
|
dm_block_t nr_free, nr_total;
|
|
|
|
r = dm_sm_get_nr_free(md->sm, &nr_free);
|
|
if (r) {
|
|
DMERR("dm_sm_get_nr_free returned %d", r);
|
|
return r;
|
|
}
|
|
|
|
r = dm_sm_get_nr_blocks(md->sm, &nr_total);
|
|
if (r) {
|
|
DMERR("dm_pool_get_metadata_dev_size returned %d", r);
|
|
return r;
|
|
}
|
|
|
|
s->used = nr_total - nr_free;
|
|
s->total = nr_total;
|
|
s->snap = md->metadata_snap;
|
|
s->era = md->current_era;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
struct era {
|
|
struct dm_target *ti;
|
|
struct dm_target_callbacks callbacks;
|
|
|
|
struct dm_dev *metadata_dev;
|
|
struct dm_dev *origin_dev;
|
|
|
|
dm_block_t nr_blocks;
|
|
uint32_t sectors_per_block;
|
|
int sectors_per_block_shift;
|
|
struct era_metadata *md;
|
|
|
|
struct workqueue_struct *wq;
|
|
struct work_struct worker;
|
|
|
|
spinlock_t deferred_lock;
|
|
struct bio_list deferred_bios;
|
|
|
|
spinlock_t rpc_lock;
|
|
struct list_head rpc_calls;
|
|
|
|
struct digest digest;
|
|
atomic_t suspended;
|
|
};
|
|
|
|
struct rpc {
|
|
struct list_head list;
|
|
|
|
int (*fn0)(struct era_metadata *);
|
|
int (*fn1)(struct era_metadata *, void *);
|
|
void *arg;
|
|
int result;
|
|
|
|
struct completion complete;
|
|
};
|
|
|
|
/*----------------------------------------------------------------
|
|
* Remapping.
|
|
*---------------------------------------------------------------*/
|
|
static bool block_size_is_power_of_two(struct era *era)
|
|
{
|
|
return era->sectors_per_block_shift >= 0;
|
|
}
|
|
|
|
static dm_block_t get_block(struct era *era, struct bio *bio)
|
|
{
|
|
sector_t block_nr = bio->bi_iter.bi_sector;
|
|
|
|
if (!block_size_is_power_of_two(era))
|
|
(void) sector_div(block_nr, era->sectors_per_block);
|
|
else
|
|
block_nr >>= era->sectors_per_block_shift;
|
|
|
|
return block_nr;
|
|
}
|
|
|
|
static void remap_to_origin(struct era *era, struct bio *bio)
|
|
{
|
|
bio_set_dev(bio, era->origin_dev->bdev);
|
|
}
|
|
|
|
/*----------------------------------------------------------------
|
|
* Worker thread
|
|
*--------------------------------------------------------------*/
|
|
static void wake_worker(struct era *era)
|
|
{
|
|
if (!atomic_read(&era->suspended))
|
|
queue_work(era->wq, &era->worker);
|
|
}
|
|
|
|
static void process_old_eras(struct era *era)
|
|
{
|
|
int r;
|
|
|
|
if (!era->digest.step)
|
|
return;
|
|
|
|
r = era->digest.step(era->md, &era->digest);
|
|
if (r < 0) {
|
|
DMERR("%s: digest step failed, stopping digestion", __func__);
|
|
era->digest.step = NULL;
|
|
|
|
} else if (era->digest.step)
|
|
wake_worker(era);
|
|
}
|
|
|
|
static void process_deferred_bios(struct era *era)
|
|
{
|
|
int r;
|
|
struct bio_list deferred_bios, marked_bios;
|
|
struct bio *bio;
|
|
bool commit_needed = false;
|
|
bool failed = false;
|
|
|
|
bio_list_init(&deferred_bios);
|
|
bio_list_init(&marked_bios);
|
|
|
|
spin_lock(&era->deferred_lock);
|
|
bio_list_merge(&deferred_bios, &era->deferred_bios);
|
|
bio_list_init(&era->deferred_bios);
|
|
spin_unlock(&era->deferred_lock);
|
|
|
|
while ((bio = bio_list_pop(&deferred_bios))) {
|
|
r = writeset_test_and_set(&era->md->bitset_info,
|
|
era->md->current_writeset,
|
|
get_block(era, bio));
|
|
if (r < 0) {
|
|
/*
|
|
* This is bad news, we need to rollback.
|
|
* FIXME: finish.
|
|
*/
|
|
failed = true;
|
|
|
|
} else if (r == 0)
|
|
commit_needed = true;
|
|
|
|
bio_list_add(&marked_bios, bio);
|
|
}
|
|
|
|
if (commit_needed) {
|
|
r = metadata_commit(era->md);
|
|
if (r)
|
|
failed = true;
|
|
}
|
|
|
|
if (failed)
|
|
while ((bio = bio_list_pop(&marked_bios)))
|
|
bio_io_error(bio);
|
|
else
|
|
while ((bio = bio_list_pop(&marked_bios)))
|
|
generic_make_request(bio);
|
|
}
|
|
|
|
static void process_rpc_calls(struct era *era)
|
|
{
|
|
int r;
|
|
bool need_commit = false;
|
|
struct list_head calls;
|
|
struct rpc *rpc, *tmp;
|
|
|
|
INIT_LIST_HEAD(&calls);
|
|
spin_lock(&era->rpc_lock);
|
|
list_splice_init(&era->rpc_calls, &calls);
|
|
spin_unlock(&era->rpc_lock);
|
|
|
|
list_for_each_entry_safe(rpc, tmp, &calls, list) {
|
|
rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg);
|
|
need_commit = true;
|
|
}
|
|
|
|
if (need_commit) {
|
|
r = metadata_commit(era->md);
|
|
if (r)
|
|
list_for_each_entry_safe(rpc, tmp, &calls, list)
|
|
rpc->result = r;
|
|
}
|
|
|
|
list_for_each_entry_safe(rpc, tmp, &calls, list)
|
|
complete(&rpc->complete);
|
|
}
|
|
|
|
static void kick_off_digest(struct era *era)
|
|
{
|
|
if (era->md->archived_writesets) {
|
|
era->md->archived_writesets = false;
|
|
metadata_digest_start(era->md, &era->digest);
|
|
}
|
|
}
|
|
|
|
static void do_work(struct work_struct *ws)
|
|
{
|
|
struct era *era = container_of(ws, struct era, worker);
|
|
|
|
kick_off_digest(era);
|
|
process_old_eras(era);
|
|
process_deferred_bios(era);
|
|
process_rpc_calls(era);
|
|
}
|
|
|
|
static void defer_bio(struct era *era, struct bio *bio)
|
|
{
|
|
spin_lock(&era->deferred_lock);
|
|
bio_list_add(&era->deferred_bios, bio);
|
|
spin_unlock(&era->deferred_lock);
|
|
|
|
wake_worker(era);
|
|
}
|
|
|
|
/*
|
|
* Make an rpc call to the worker to change the metadata.
|
|
*/
|
|
static int perform_rpc(struct era *era, struct rpc *rpc)
|
|
{
|
|
rpc->result = 0;
|
|
init_completion(&rpc->complete);
|
|
|
|
spin_lock(&era->rpc_lock);
|
|
list_add(&rpc->list, &era->rpc_calls);
|
|
spin_unlock(&era->rpc_lock);
|
|
|
|
wake_worker(era);
|
|
wait_for_completion(&rpc->complete);
|
|
|
|
return rpc->result;
|
|
}
|
|
|
|
static int in_worker0(struct era *era, int (*fn)(struct era_metadata *))
|
|
{
|
|
struct rpc rpc;
|
|
rpc.fn0 = fn;
|
|
rpc.fn1 = NULL;
|
|
|
|
return perform_rpc(era, &rpc);
|
|
}
|
|
|
|
static int in_worker1(struct era *era,
|
|
int (*fn)(struct era_metadata *, void *), void *arg)
|
|
{
|
|
struct rpc rpc;
|
|
rpc.fn0 = NULL;
|
|
rpc.fn1 = fn;
|
|
rpc.arg = arg;
|
|
|
|
return perform_rpc(era, &rpc);
|
|
}
|
|
|
|
static void start_worker(struct era *era)
|
|
{
|
|
atomic_set(&era->suspended, 0);
|
|
}
|
|
|
|
static void stop_worker(struct era *era)
|
|
{
|
|
atomic_set(&era->suspended, 1);
|
|
flush_workqueue(era->wq);
|
|
}
|
|
|
|
/*----------------------------------------------------------------
|
|
* Target methods
|
|
*--------------------------------------------------------------*/
|
|
static int dev_is_congested(struct dm_dev *dev, int bdi_bits)
|
|
{
|
|
struct request_queue *q = bdev_get_queue(dev->bdev);
|
|
return bdi_congested(q->backing_dev_info, bdi_bits);
|
|
}
|
|
|
|
static int era_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
|
|
{
|
|
struct era *era = container_of(cb, struct era, callbacks);
|
|
return dev_is_congested(era->origin_dev, bdi_bits);
|
|
}
|
|
|
|
static void era_destroy(struct era *era)
|
|
{
|
|
if (era->md)
|
|
metadata_close(era->md);
|
|
|
|
if (era->wq)
|
|
destroy_workqueue(era->wq);
|
|
|
|
if (era->origin_dev)
|
|
dm_put_device(era->ti, era->origin_dev);
|
|
|
|
if (era->metadata_dev)
|
|
dm_put_device(era->ti, era->metadata_dev);
|
|
|
|
kfree(era);
|
|
}
|
|
|
|
static dm_block_t calc_nr_blocks(struct era *era)
|
|
{
|
|
return dm_sector_div_up(era->ti->len, era->sectors_per_block);
|
|
}
|
|
|
|
static bool valid_block_size(dm_block_t block_size)
|
|
{
|
|
bool greater_than_zero = block_size > 0;
|
|
bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0;
|
|
|
|
return greater_than_zero && multiple_of_min_block_size;
|
|
}
|
|
|
|
/*
|
|
* <metadata dev> <data dev> <data block size (sectors)>
|
|
*/
|
|
static int era_ctr(struct dm_target *ti, unsigned argc, char **argv)
|
|
{
|
|
int r;
|
|
char dummy;
|
|
struct era *era;
|
|
struct era_metadata *md;
|
|
|
|
if (argc != 3) {
|
|
ti->error = "Invalid argument count";
|
|
return -EINVAL;
|
|
}
|
|
|
|
era = kzalloc(sizeof(*era), GFP_KERNEL);
|
|
if (!era) {
|
|
ti->error = "Error allocating era structure";
|
|
return -ENOMEM;
|
|
}
|
|
|
|
era->ti = ti;
|
|
|
|
r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &era->metadata_dev);
|
|
if (r) {
|
|
ti->error = "Error opening metadata device";
|
|
era_destroy(era);
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = dm_get_device(ti, argv[1], FMODE_READ | FMODE_WRITE, &era->origin_dev);
|
|
if (r) {
|
|
ti->error = "Error opening data device";
|
|
era_destroy(era);
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy);
|
|
if (r != 1) {
|
|
ti->error = "Error parsing block size";
|
|
era_destroy(era);
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = dm_set_target_max_io_len(ti, era->sectors_per_block);
|
|
if (r) {
|
|
ti->error = "could not set max io len";
|
|
era_destroy(era);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!valid_block_size(era->sectors_per_block)) {
|
|
ti->error = "Invalid block size";
|
|
era_destroy(era);
|
|
return -EINVAL;
|
|
}
|
|
if (era->sectors_per_block & (era->sectors_per_block - 1))
|
|
era->sectors_per_block_shift = -1;
|
|
else
|
|
era->sectors_per_block_shift = __ffs(era->sectors_per_block);
|
|
|
|
md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true);
|
|
if (IS_ERR(md)) {
|
|
ti->error = "Error reading metadata";
|
|
era_destroy(era);
|
|
return PTR_ERR(md);
|
|
}
|
|
era->md = md;
|
|
|
|
era->nr_blocks = calc_nr_blocks(era);
|
|
|
|
r = metadata_resize(era->md, &era->nr_blocks);
|
|
if (r) {
|
|
ti->error = "couldn't resize metadata";
|
|
era_destroy(era);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
|
|
if (!era->wq) {
|
|
ti->error = "could not create workqueue for metadata object";
|
|
era_destroy(era);
|
|
return -ENOMEM;
|
|
}
|
|
INIT_WORK(&era->worker, do_work);
|
|
|
|
spin_lock_init(&era->deferred_lock);
|
|
bio_list_init(&era->deferred_bios);
|
|
|
|
spin_lock_init(&era->rpc_lock);
|
|
INIT_LIST_HEAD(&era->rpc_calls);
|
|
|
|
ti->private = era;
|
|
ti->num_flush_bios = 1;
|
|
ti->flush_supported = true;
|
|
|
|
ti->num_discard_bios = 1;
|
|
era->callbacks.congested_fn = era_is_congested;
|
|
dm_table_add_target_callbacks(ti->table, &era->callbacks);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void era_dtr(struct dm_target *ti)
|
|
{
|
|
era_destroy(ti->private);
|
|
}
|
|
|
|
static int era_map(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct era *era = ti->private;
|
|
dm_block_t block = get_block(era, bio);
|
|
|
|
/*
|
|
* All bios get remapped to the origin device. We do this now, but
|
|
* it may not get issued until later. Depending on whether the
|
|
* block is marked in this era.
|
|
*/
|
|
remap_to_origin(era, bio);
|
|
|
|
/*
|
|
* REQ_PREFLUSH bios carry no data, so we're not interested in them.
|
|
*/
|
|
if (!(bio->bi_opf & REQ_PREFLUSH) &&
|
|
(bio_data_dir(bio) == WRITE) &&
|
|
!metadata_current_marked(era->md, block)) {
|
|
defer_bio(era, bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
return DM_MAPIO_REMAPPED;
|
|
}
|
|
|
|
static void era_postsuspend(struct dm_target *ti)
|
|
{
|
|
int r;
|
|
struct era *era = ti->private;
|
|
|
|
r = in_worker0(era, metadata_era_archive);
|
|
if (r) {
|
|
DMERR("%s: couldn't archive current era", __func__);
|
|
/* FIXME: fail mode */
|
|
}
|
|
|
|
stop_worker(era);
|
|
}
|
|
|
|
static int era_preresume(struct dm_target *ti)
|
|
{
|
|
int r;
|
|
struct era *era = ti->private;
|
|
dm_block_t new_size = calc_nr_blocks(era);
|
|
|
|
if (era->nr_blocks != new_size) {
|
|
r = in_worker1(era, metadata_resize, &new_size);
|
|
if (r)
|
|
return r;
|
|
|
|
era->nr_blocks = new_size;
|
|
}
|
|
|
|
start_worker(era);
|
|
|
|
r = in_worker0(era, metadata_new_era);
|
|
if (r) {
|
|
DMERR("%s: metadata_era_rollover failed", __func__);
|
|
return r;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Status format:
|
|
*
|
|
* <metadata block size> <#used metadata blocks>/<#total metadata blocks>
|
|
* <current era> <held metadata root | '-'>
|
|
*/
|
|
static void era_status(struct dm_target *ti, status_type_t type,
|
|
unsigned status_flags, char *result, unsigned maxlen)
|
|
{
|
|
int r;
|
|
struct era *era = ti->private;
|
|
ssize_t sz = 0;
|
|
struct metadata_stats stats;
|
|
char buf[BDEVNAME_SIZE];
|
|
|
|
switch (type) {
|
|
case STATUSTYPE_INFO:
|
|
r = in_worker1(era, metadata_get_stats, &stats);
|
|
if (r)
|
|
goto err;
|
|
|
|
DMEMIT("%u %llu/%llu %u",
|
|
(unsigned) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT),
|
|
(unsigned long long) stats.used,
|
|
(unsigned long long) stats.total,
|
|
(unsigned) stats.era);
|
|
|
|
if (stats.snap != SUPERBLOCK_LOCATION)
|
|
DMEMIT(" %llu", stats.snap);
|
|
else
|
|
DMEMIT(" -");
|
|
break;
|
|
|
|
case STATUSTYPE_TABLE:
|
|
format_dev_t(buf, era->metadata_dev->bdev->bd_dev);
|
|
DMEMIT("%s ", buf);
|
|
format_dev_t(buf, era->origin_dev->bdev->bd_dev);
|
|
DMEMIT("%s %u", buf, era->sectors_per_block);
|
|
break;
|
|
}
|
|
|
|
return;
|
|
|
|
err:
|
|
DMEMIT("Error");
|
|
}
|
|
|
|
static int era_message(struct dm_target *ti, unsigned argc, char **argv,
|
|
char *result, unsigned maxlen)
|
|
{
|
|
struct era *era = ti->private;
|
|
|
|
if (argc != 1) {
|
|
DMERR("incorrect number of message arguments");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!strcasecmp(argv[0], "checkpoint"))
|
|
return in_worker0(era, metadata_checkpoint);
|
|
|
|
if (!strcasecmp(argv[0], "take_metadata_snap"))
|
|
return in_worker0(era, metadata_take_snap);
|
|
|
|
if (!strcasecmp(argv[0], "drop_metadata_snap"))
|
|
return in_worker0(era, metadata_drop_snap);
|
|
|
|
DMERR("unsupported message '%s'", argv[0]);
|
|
return -EINVAL;
|
|
}
|
|
|
|
static sector_t get_dev_size(struct dm_dev *dev)
|
|
{
|
|
return i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT;
|
|
}
|
|
|
|
static int era_iterate_devices(struct dm_target *ti,
|
|
iterate_devices_callout_fn fn, void *data)
|
|
{
|
|
struct era *era = ti->private;
|
|
return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data);
|
|
}
|
|
|
|
static void era_io_hints(struct dm_target *ti, struct queue_limits *limits)
|
|
{
|
|
struct era *era = ti->private;
|
|
uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
|
|
|
|
/*
|
|
* If the system-determined stacked limits are compatible with the
|
|
* era device's blocksize (io_opt is a factor) do not override them.
|
|
*/
|
|
if (io_opt_sectors < era->sectors_per_block ||
|
|
do_div(io_opt_sectors, era->sectors_per_block)) {
|
|
blk_limits_io_min(limits, 0);
|
|
blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT);
|
|
}
|
|
}
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
static struct target_type era_target = {
|
|
.name = "era",
|
|
.version = {1, 0, 0},
|
|
.module = THIS_MODULE,
|
|
.ctr = era_ctr,
|
|
.dtr = era_dtr,
|
|
.map = era_map,
|
|
.postsuspend = era_postsuspend,
|
|
.preresume = era_preresume,
|
|
.status = era_status,
|
|
.message = era_message,
|
|
.iterate_devices = era_iterate_devices,
|
|
.io_hints = era_io_hints
|
|
};
|
|
|
|
static int __init dm_era_init(void)
|
|
{
|
|
int r;
|
|
|
|
r = dm_register_target(&era_target);
|
|
if (r) {
|
|
DMERR("era target registration failed: %d", r);
|
|
return r;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit dm_era_exit(void)
|
|
{
|
|
dm_unregister_target(&era_target);
|
|
}
|
|
|
|
module_init(dm_era_init);
|
|
module_exit(dm_era_exit);
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " era target");
|
|
MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|