linux/drivers/md/persistent-data/dm-space-map-common.c
Andy Shevchenko 5cc9cdf631 dm: Avoid namespace collision with bitmap API
bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.

On the other hand DM bitmap API is special case.
Adding 'dm' prefix to it to avoid potential name space collision.

No functional changes intended.

Suggested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-08-01 15:49:38 -07:00

758 lines
17 KiB
C

/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-space-map-common.h"
#include "dm-transaction-manager.h"
#include <linux/bitops.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "space map common"
/*----------------------------------------------------------------*/
/*
* Index validator.
*/
#define INDEX_CSUM_XOR 160478
static void index_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_metadata_index *mi_le = dm_block_data(b);
mi_le->blocknr = cpu_to_le64(dm_block_location(b));
mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
block_size - sizeof(__le32),
INDEX_CSUM_XOR));
}
static int index_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_metadata_index *mi_le = dm_block_data(b);
__le32 csum_disk;
if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
DMERR_LIMIT("index_check failed: blocknr %llu != wanted %llu",
le64_to_cpu(mi_le->blocknr), dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
block_size - sizeof(__le32),
INDEX_CSUM_XOR));
if (csum_disk != mi_le->csum) {
DMERR_LIMIT("index_check failed: csum %u != wanted %u",
le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator index_validator = {
.name = "index",
.prepare_for_write = index_prepare_for_write,
.check = index_check
};
/*----------------------------------------------------------------*/
/*
* Bitmap validator
*/
#define BITMAP_CSUM_XOR 240779
static void dm_bitmap_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_bitmap_header *disk_header = dm_block_data(b);
disk_header->blocknr = cpu_to_le64(dm_block_location(b));
disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
block_size - sizeof(__le32),
BITMAP_CSUM_XOR));
}
static int dm_bitmap_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_bitmap_header *disk_header = dm_block_data(b);
__le32 csum_disk;
if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
le64_to_cpu(disk_header->blocknr), dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
block_size - sizeof(__le32),
BITMAP_CSUM_XOR));
if (csum_disk != disk_header->csum) {
DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator dm_sm_bitmap_validator = {
.name = "sm_bitmap",
.prepare_for_write = dm_bitmap_prepare_for_write,
.check = dm_bitmap_check,
};
/*----------------------------------------------------------------*/
#define ENTRIES_PER_WORD 32
#define ENTRIES_SHIFT 5
static void *dm_bitmap_data(struct dm_block *b)
{
return dm_block_data(b) + sizeof(struct disk_bitmap_header);
}
#define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
static unsigned dm_bitmap_word_used(void *addr, unsigned b)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
uint64_t bits = le64_to_cpu(*w_le);
uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
return !(~bits & mask);
}
static unsigned sm_lookup_bitmap(void *addr, unsigned b)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
unsigned hi, lo;
b = (b & (ENTRIES_PER_WORD - 1)) << 1;
hi = !!test_bit_le(b, (void *) w_le);
lo = !!test_bit_le(b + 1, (void *) w_le);
return (hi << 1) | lo;
}
static void sm_set_bitmap(void *addr, unsigned b, unsigned val)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
b = (b & (ENTRIES_PER_WORD - 1)) << 1;
if (val & 2)
__set_bit_le(b, (void *) w_le);
else
__clear_bit_le(b, (void *) w_le);
if (val & 1)
__set_bit_le(b + 1, (void *) w_le);
else
__clear_bit_le(b + 1, (void *) w_le);
}
static int sm_find_free(void *addr, unsigned begin, unsigned end,
unsigned *result)
{
while (begin < end) {
if (!(begin & (ENTRIES_PER_WORD - 1)) &&
dm_bitmap_word_used(addr, begin)) {
begin += ENTRIES_PER_WORD;
continue;
}
if (!sm_lookup_bitmap(addr, begin)) {
*result = begin;
return 0;
}
begin++;
}
return -ENOSPC;
}
/*----------------------------------------------------------------*/
static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
ll->tm = tm;
ll->bitmap_info.tm = tm;
ll->bitmap_info.levels = 1;
/*
* Because the new bitmap blocks are created via a shadow
* operation, the old entry has already had its reference count
* decremented and we don't need the btree to do any bookkeeping.
*/
ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
ll->bitmap_info.value_type.inc = NULL;
ll->bitmap_info.value_type.dec = NULL;
ll->bitmap_info.value_type.equal = NULL;
ll->ref_count_info.tm = tm;
ll->ref_count_info.levels = 1;
ll->ref_count_info.value_type.size = sizeof(uint32_t);
ll->ref_count_info.value_type.inc = NULL;
ll->ref_count_info.value_type.dec = NULL;
ll->ref_count_info.value_type.equal = NULL;
ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
if (ll->block_size > (1 << 30)) {
DMERR("block size too big to hold bitmaps");
return -EINVAL;
}
ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
ENTRIES_PER_BYTE;
ll->nr_blocks = 0;
ll->bitmap_root = 0;
ll->ref_count_root = 0;
ll->bitmap_index_changed = false;
return 0;
}
int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
{
int r;
dm_block_t i, nr_blocks, nr_indexes;
unsigned old_blocks, blocks;
nr_blocks = ll->nr_blocks + extra_blocks;
old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
if (nr_indexes > ll->max_entries(ll)) {
DMERR("space map too large");
return -EINVAL;
}
/*
* We need to set this before the dm_tm_new_block() call below.
*/
ll->nr_blocks = nr_blocks;
for (i = old_blocks; i < blocks; i++) {
struct dm_block *b;
struct disk_index_entry idx;
r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
if (r < 0)
return r;
idx.blocknr = cpu_to_le64(dm_block_location(b));
dm_tm_unlock(ll->tm, b);
idx.nr_free = cpu_to_le32(ll->entries_per_block);
idx.none_free_before = 0;
r = ll->save_ie(ll, i, &idx);
if (r < 0)
return r;
}
return 0;
}
int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
{
int r;
dm_block_t index = b;
struct disk_index_entry ie_disk;
struct dm_block *blk;
b = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ie_disk);
if (r < 0)
return r;
r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &blk);
if (r < 0)
return r;
*result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
dm_tm_unlock(ll->tm, blk);
return 0;
}
static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
uint32_t *result)
{
__le32 le_rc;
int r;
r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
if (r < 0)
return r;
*result = le32_to_cpu(le_rc);
return r;
}
int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
{
int r = sm_ll_lookup_bitmap(ll, b, result);
if (r)
return r;
if (*result != 3)
return r;
return sm_ll_lookup_big_ref_count(ll, b, result);
}
int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
dm_block_t end, dm_block_t *result)
{
int r;
struct disk_index_entry ie_disk;
dm_block_t i, index_begin = begin;
dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
/*
* FIXME: Use shifts
*/
begin = do_div(index_begin, ll->entries_per_block);
end = do_div(end, ll->entries_per_block);
for (i = index_begin; i < index_end; i++, begin = 0) {
struct dm_block *blk;
unsigned position;
uint32_t bit_end;
r = ll->load_ie(ll, i, &ie_disk);
if (r < 0)
return r;
if (le32_to_cpu(ie_disk.nr_free) == 0)
continue;
r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &blk);
if (r < 0)
return r;
bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
r = sm_find_free(dm_bitmap_data(blk),
max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
bit_end, &position);
if (r == -ENOSPC) {
/*
* This might happen because we started searching
* part way through the bitmap.
*/
dm_tm_unlock(ll->tm, blk);
continue;
} else if (r < 0) {
dm_tm_unlock(ll->tm, blk);
return r;
}
dm_tm_unlock(ll->tm, blk);
*result = i * ll->entries_per_block + (dm_block_t) position;
return 0;
}
return -ENOSPC;
}
static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
int (*mutator)(void *context, uint32_t old, uint32_t *new),
void *context, enum allocation_event *ev)
{
int r;
uint32_t bit, old, ref_count;
struct dm_block *nb;
dm_block_t index = b;
struct disk_index_entry ie_disk;
void *bm_le;
int inc;
bit = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ie_disk);
if (r < 0)
return r;
r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &nb, &inc);
if (r < 0) {
DMERR("dm_tm_shadow_block() failed");
return r;
}
ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
bm_le = dm_bitmap_data(nb);
old = sm_lookup_bitmap(bm_le, bit);
if (old > 2) {
r = sm_ll_lookup_big_ref_count(ll, b, &old);
if (r < 0) {
dm_tm_unlock(ll->tm, nb);
return r;
}
}
r = mutator(context, old, &ref_count);
if (r) {
dm_tm_unlock(ll->tm, nb);
return r;
}
if (ref_count <= 2) {
sm_set_bitmap(bm_le, bit, ref_count);
dm_tm_unlock(ll->tm, nb);
if (old > 2) {
r = dm_btree_remove(&ll->ref_count_info,
ll->ref_count_root,
&b, &ll->ref_count_root);
if (r)
return r;
}
} else {
__le32 le_rc = cpu_to_le32(ref_count);
sm_set_bitmap(bm_le, bit, 3);
dm_tm_unlock(ll->tm, nb);
__dm_bless_for_disk(&le_rc);
r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
&b, &le_rc, &ll->ref_count_root);
if (r < 0) {
DMERR("ref count insert failed");
return r;
}
}
if (ref_count && !old) {
*ev = SM_ALLOC;
ll->nr_allocated++;
le32_add_cpu(&ie_disk.nr_free, -1);
if (le32_to_cpu(ie_disk.none_free_before) == bit)
ie_disk.none_free_before = cpu_to_le32(bit + 1);
} else if (old && !ref_count) {
*ev = SM_FREE;
ll->nr_allocated--;
le32_add_cpu(&ie_disk.nr_free, 1);
ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
} else
*ev = SM_NONE;
return ll->save_ie(ll, index, &ie_disk);
}
static int set_ref_count(void *context, uint32_t old, uint32_t *new)
{
*new = *((uint32_t *) context);
return 0;
}
int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
uint32_t ref_count, enum allocation_event *ev)
{
return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
}
static int inc_ref_count(void *context, uint32_t old, uint32_t *new)
{
*new = old + 1;
return 0;
}
int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
{
return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
}
static int dec_ref_count(void *context, uint32_t old, uint32_t *new)
{
if (!old) {
DMERR_LIMIT("unable to decrement a reference count below 0");
return -EINVAL;
}
*new = old - 1;
return 0;
}
int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
{
return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
}
int sm_ll_commit(struct ll_disk *ll)
{
int r = 0;
if (ll->bitmap_index_changed) {
r = ll->commit(ll);
if (!r)
ll->bitmap_index_changed = false;
}
return r;
}
/*----------------------------------------------------------------*/
static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
return 0;
}
static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
ll->bitmap_index_changed = true;
memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
return 0;
}
static int metadata_ll_init_index(struct ll_disk *ll)
{
int r;
struct dm_block *b;
r = dm_tm_new_block(ll->tm, &index_validator, &b);
if (r < 0)
return r;
ll->bitmap_root = dm_block_location(b);
dm_tm_unlock(ll->tm, b);
return 0;
}
static int metadata_ll_open(struct ll_disk *ll)
{
int r;
struct dm_block *block;
r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
&index_validator, &block);
if (r)
return r;
memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
dm_tm_unlock(ll->tm, block);
return 0;
}
static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
{
return MAX_METADATA_BITMAPS;
}
static int metadata_ll_commit(struct ll_disk *ll)
{
int r, inc;
struct dm_block *b;
r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
if (r)
return r;
memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
ll->bitmap_root = dm_block_location(b);
dm_tm_unlock(ll->tm, b);
return 0;
}
int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
int r;
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = metadata_ll_load_ie;
ll->save_ie = metadata_ll_save_ie;
ll->init_index = metadata_ll_init_index;
ll->open_index = metadata_ll_open;
ll->max_entries = metadata_ll_max_entries;
ll->commit = metadata_ll_commit;
ll->nr_blocks = 0;
ll->nr_allocated = 0;
r = ll->init_index(ll);
if (r < 0)
return r;
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
if (r < 0)
return r;
return 0;
}
int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct disk_sm_root smr;
if (len < sizeof(struct disk_sm_root)) {
DMERR("sm_metadata root too small");
return -ENOMEM;
}
/*
* We don't know the alignment of the root_le buffer, so need to
* copy into a new structure.
*/
memcpy(&smr, root_le, sizeof(smr));
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = metadata_ll_load_ie;
ll->save_ie = metadata_ll_save_ie;
ll->init_index = metadata_ll_init_index;
ll->open_index = metadata_ll_open;
ll->max_entries = metadata_ll_max_entries;
ll->commit = metadata_ll_commit;
ll->nr_blocks = le64_to_cpu(smr.nr_blocks);
ll->nr_allocated = le64_to_cpu(smr.nr_allocated);
ll->bitmap_root = le64_to_cpu(smr.bitmap_root);
ll->ref_count_root = le64_to_cpu(smr.ref_count_root);
return ll->open_index(ll);
}
/*----------------------------------------------------------------*/
static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
}
static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
__dm_bless_for_disk(ie);
return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
&index, ie, &ll->bitmap_root);
}
static int disk_ll_init_index(struct ll_disk *ll)
{
return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
}
static int disk_ll_open(struct ll_disk *ll)
{
/* nothing to do */
return 0;
}
static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
{
return -1ULL;
}
static int disk_ll_commit(struct ll_disk *ll)
{
return 0;
}
int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
int r;
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = disk_ll_load_ie;
ll->save_ie = disk_ll_save_ie;
ll->init_index = disk_ll_init_index;
ll->open_index = disk_ll_open;
ll->max_entries = disk_ll_max_entries;
ll->commit = disk_ll_commit;
ll->nr_blocks = 0;
ll->nr_allocated = 0;
r = ll->init_index(ll);
if (r < 0)
return r;
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
if (r < 0)
return r;
return 0;
}
int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct disk_sm_root *smr = root_le;
if (len < sizeof(struct disk_sm_root)) {
DMERR("sm_metadata root too small");
return -ENOMEM;
}
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = disk_ll_load_ie;
ll->save_ie = disk_ll_save_ie;
ll->init_index = disk_ll_init_index;
ll->open_index = disk_ll_open;
ll->max_entries = disk_ll_max_entries;
ll->commit = disk_ll_commit;
ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
return ll->open_index(ll);
}
/*----------------------------------------------------------------*/