--- zzzz-none-000/linux-3.10.107/drivers/md/dm-cache-metadata.c 2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/md/dm-cache-metadata.c 2021-02-04 17:41:59.000000000 +0000
@@ -20,7 +20,13 @@
#define CACHE_SUPERBLOCK_MAGIC 06142003
#define CACHE_SUPERBLOCK_LOCATION 0
-#define CACHE_VERSION 1
+
+/*
+ * defines a range of metadata versions that this module can handle.
+ */
+#define MIN_CACHE_VERSION 1
+#define MAX_CACHE_VERSION 1
+
#define CACHE_METADATA_CACHE_SIZE 64
/*
@@ -33,6 +39,8 @@
enum superblock_flag_bits {
/* for spotting crashes that would invalidate the dirty bitset */
CLEAN_SHUTDOWN,
+ /* metadata must be checked using the tools */
+ NEEDS_CHECK,
};
/*
@@ -101,6 +109,7 @@
struct dm_disk_bitset discard_info;
struct rw_semaphore root_lock;
+ unsigned long flags;
dm_block_t root;
dm_block_t hint_root;
dm_block_t discard_root;
@@ -117,6 +126,20 @@
unsigned policy_version[CACHE_POLICY_VERSION_SIZE];
size_t policy_hint_size;
struct dm_cache_statistics stats;
+
+ /*
+ * Reading the space map root can fail, so we read it into this
+ * buffer before the superblock is locked and updated.
+ */
+ __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
+
+ /*
+ * Set if a transaction has to be aborted but the attempt to roll
+ * back to the previous (good) transaction failed. The only
+ * metadata operation permissible in this state is the closing of
+ * the device.
+ */
+ bool fail_io:1;
};
/*-------------------------------------------------------------------
@@ -137,6 +160,18 @@
SUPERBLOCK_CSUM_XOR));
}
+static int check_metadata_version(struct cache_disk_superblock *disk_super)
+{
+ uint32_t metadata_version = le32_to_cpu(disk_super->version);
+ if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) {
+ DMERR("Cache metadata version %u found, but only versions between %u and %u supported.",
+ metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int sb_check(struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
@@ -167,7 +202,7 @@
return -EILSEQ;
}
- return 0;
+ return check_metadata_version(disk_super);
}
static struct dm_block_validator sb_validator = {
@@ -201,7 +236,7 @@
/*----------------------------------------------------------------*/
-static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
+static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
{
int r;
unsigned i;
@@ -217,15 +252,17 @@
return r;
data_le = dm_block_data(b);
- *result = 1;
+ *result = true;
for (i = 0; i < sb_block_size; i++) {
if (data_le[i] != zero) {
- *result = 0;
+ *result = false;
break;
}
}
- return dm_bm_unlock(b);
+ dm_bm_unlock(b);
+
+ return 0;
}
static void __setup_mapping_info(struct dm_cache_metadata *cmd)
@@ -245,11 +282,31 @@
}
}
+static int __save_sm_root(struct dm_cache_metadata *cmd)
+{
+ int r;
+ size_t metadata_len;
+
+ r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
+ if (r < 0)
+ return r;
+
+ return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root,
+ metadata_len);
+}
+
+static void __copy_sm_root(struct dm_cache_metadata *cmd,
+ struct cache_disk_superblock *disk_super)
+{
+ memcpy(&disk_super->metadata_space_map_root,
+ &cmd->metadata_space_map_root,
+ sizeof(cmd->metadata_space_map_root));
+}
+
static int __write_initial_superblock(struct dm_cache_metadata *cmd)
{
int r;
struct dm_block *sblock;
- size_t metadata_len;
struct cache_disk_superblock *disk_super;
sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT;
@@ -257,12 +314,16 @@
if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS)
bdev_size = DM_CACHE_METADATA_MAX_SECTORS;
- r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
+ r = dm_tm_pre_commit(cmd->tm);
if (r < 0)
return r;
- r = dm_tm_pre_commit(cmd->tm);
- if (r < 0)
+ /*
+ * dm_sm_copy_root() can fail. So we need to do it before we start
+ * updating the superblock.
+ */
+ r = __save_sm_root(cmd);
+ if (r)
return r;
r = superblock_lock_zero(cmd, &sblock);
@@ -273,22 +334,19 @@
disk_super->flags = 0;
memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC);
- disk_super->version = cpu_to_le32(CACHE_VERSION);
+ disk_super->version = cpu_to_le32(MAX_CACHE_VERSION);
memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name));
memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version));
disk_super->policy_hint_size = 0;
- r = dm_sm_copy_root(cmd->metadata_sm, &disk_super->metadata_space_map_root,
- metadata_len);
- if (r < 0)
- goto bad_locked;
+ __copy_sm_root(cmd, disk_super);
disk_super->mapping_root = cpu_to_le64(cmd->root);
disk_super->hint_root = cpu_to_le64(cmd->hint_root);
disk_super->discard_root = cpu_to_le64(cmd->discard_root);
disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size);
disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks));
- disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
+ disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE);
disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
disk_super->cache_blocks = cpu_to_le32(0);
@@ -298,10 +356,6 @@
disk_super->write_misses = cpu_to_le32(0);
return dm_tm_commit(cmd->tm, sblock);
-
-bad_locked:
- dm_bm_unlock(sblock);
- return r;
}
static int __format_metadata(struct dm_cache_metadata *cmd)
@@ -413,7 +467,9 @@
dm_disk_bitset_init(cmd->tm, &cmd->discard_info);
sb_flags = le32_to_cpu(disk_super->flags);
cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags);
- return dm_bm_unlock(sblock);
+ dm_bm_unlock(sblock);
+
+ return 0;
bad:
dm_bm_unlock(sblock);
@@ -423,7 +479,8 @@
static int __open_or_format_metadata(struct dm_cache_metadata *cmd,
bool format_device)
{
- int r, unformatted;
+ int r;
+ bool unformatted = false;
r = __superblock_all_zeroes(cmd->bm, &unformatted);
if (r)
@@ -439,7 +496,7 @@
bool may_format_device)
{
int r;
- cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE,
+ cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
CACHE_METADATA_CACHE_SIZE,
CACHE_MAX_CONCURRENT_LOCKS);
if (IS_ERR(cmd->bm)) {
@@ -485,6 +542,7 @@
static void read_superblock_fields(struct dm_cache_metadata *cmd,
struct cache_disk_superblock *disk_super)
{
+ cmd->flags = le32_to_cpu(disk_super->flags);
cmd->root = le64_to_cpu(disk_super->mapping_root);
cmd->hint_root = le64_to_cpu(disk_super->hint_root);
cmd->discard_root = le64_to_cpu(disk_super->discard_root);
@@ -553,7 +611,6 @@
flags_mutator mutator)
{
int r;
- size_t metadata_len;
struct cache_disk_superblock *disk_super;
struct dm_block *sblock;
@@ -571,8 +628,8 @@
if (r < 0)
return r;
- r = dm_sm_root_size(cmd->metadata_sm, &metadata_len);
- if (r < 0)
+ r = __save_sm_root(cmd);
+ if (r)
return r;
r = superblock_lock(cmd, &sblock);
@@ -581,6 +638,7 @@
disk_super = dm_block_data(sblock);
+ disk_super->flags = cpu_to_le32(cmd->flags);
if (mutator)
update_flags(disk_super, mutator);
@@ -599,13 +657,7 @@
disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses);
disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits);
disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses);
-
- r = dm_sm_copy_root(cmd->metadata_sm, &disk_super->metadata_space_map_root,
- metadata_len);
- if (r < 0) {
- dm_bm_unlock(sblock);
- return r;
- }
+ __copy_sm_root(cmd, disk_super);
return dm_tm_commit(cmd->tm, sblock);
}
@@ -658,6 +710,7 @@
cmd->cache_blocks = 0;
cmd->policy_hint_size = policy_hint_size;
cmd->changed = true;
+ cmd->fail_io = false;
r = __create_persistent_data_objects(cmd, may_format_device);
if (r) {
@@ -761,25 +814,142 @@
list_del(&cmd->list);
mutex_unlock(&table_lock);
- __destroy_persistent_data_objects(cmd);
+ if (!cmd->fail_io)
+ __destroy_persistent_data_objects(cmd);
kfree(cmd);
}
}
+/*
+ * Checks that the given cache block is either unmapped or clean.
+ */
+static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b,
+ bool *result)
+{
+ int r;
+ __le64 value;
+ dm_oblock_t ob;
+ unsigned flags;
+
+ r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value);
+ if (r) {
+ DMERR("block_unmapped_or_clean failed");
+ return r;
+ }
+
+ unpack_value(value, &ob, &flags);
+ *result = !((flags & M_VALID) && (flags & M_DIRTY));
+
+ return 0;
+}
+
+static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
+ dm_cblock_t begin, dm_cblock_t end,
+ bool *result)
+{
+ int r;
+ *result = true;
+
+ while (begin != end) {
+ r = block_unmapped_or_clean(cmd, begin, result);
+ if (r)
+ return r;
+
+ if (!*result) {
+ DMERR("cache block %llu is dirty",
+ (unsigned long long) from_cblock(begin));
+ return 0;
+ }
+
+ begin = to_cblock(from_cblock(begin) + 1);
+ }
+
+ return 0;
+}
+
+static bool cmd_write_lock(struct dm_cache_metadata *cmd)
+{
+ down_write(&cmd->root_lock);
+ if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
+ up_write(&cmd->root_lock);
+ return false;
+ }
+ return true;
+}
+
+#define WRITE_LOCK(cmd) \
+ do { \
+ if (!cmd_write_lock((cmd))) \
+ return -EINVAL; \
+ } while(0)
+
+#define WRITE_LOCK_VOID(cmd) \
+ do { \
+ if (!cmd_write_lock((cmd))) \
+ return; \
+ } while(0)
+
+#define WRITE_UNLOCK(cmd) \
+ up_write(&(cmd)->root_lock)
+
+static bool cmd_read_lock(struct dm_cache_metadata *cmd)
+{
+ down_read(&cmd->root_lock);
+ if (cmd->fail_io) {
+ up_read(&cmd->root_lock);
+ return false;
+ }
+ return true;
+}
+
+#define READ_LOCK(cmd) \
+ do { \
+ if (!cmd_read_lock((cmd))) \
+ return -EINVAL; \
+ } while(0)
+
+#define READ_LOCK_VOID(cmd) \
+ do { \
+ if (!cmd_read_lock((cmd))) \
+ return; \
+ } while(0)
+
+#define READ_UNLOCK(cmd) \
+ up_read(&(cmd)->root_lock)
+
int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
{
int r;
+ bool clean;
__le64 null_mapping = pack_value(0, 0);
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
__dm_bless_for_disk(&null_mapping);
+
+ if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) {
+ r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean);
+ if (r) {
+ __dm_unbless_for_disk(&null_mapping);
+ goto out;
+ }
+
+ if (!clean) {
+ DMERR("unable to shrink cache due to dirty blocks");
+ r = -EINVAL;
+ __dm_unbless_for_disk(&null_mapping);
+ goto out;
+ }
+ }
+
r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks),
from_cblock(new_cache_size),
&null_mapping, &cmd->root);
if (!r)
cmd->cache_blocks = new_cache_size;
cmd->changed = true;
- up_write(&cmd->root_lock);
+
+out:
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -790,7 +960,7 @@
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = dm_bitset_resize(&cmd->discard_info,
cmd->discard_root,
from_dblock(cmd->discard_nr_blocks),
@@ -802,7 +972,7 @@
}
cmd->changed = true;
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -845,9 +1015,9 @@
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __discard(cmd, dblock, discard);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -882,22 +1052,20 @@
{
int r;
- down_read(&cmd->root_lock);
+ READ_LOCK(cmd);
r = __load_discards(cmd, fn, context);
- up_read(&cmd->root_lock);
+ READ_UNLOCK(cmd);
return r;
}
-dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd)
+int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result)
{
- dm_cblock_t r;
+ READ_LOCK(cmd);
+ *result = cmd->cache_blocks;
+ READ_UNLOCK(cmd);
- down_read(&cmd->root_lock);
- r = cmd->cache_blocks;
- up_read(&cmd->root_lock);
-
- return r;
+ return 0;
}
static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock)
@@ -919,9 +1087,9 @@
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __remove(cmd, cblock);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -947,9 +1115,9 @@
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __insert(cmd, cblock, oblock);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1055,9 +1223,9 @@
{
int r;
- down_read(&cmd->root_lock);
+ READ_LOCK(cmd);
r = __load_mappings(cmd, policy, fn, context);
- up_read(&cmd->root_lock);
+ READ_UNLOCK(cmd);
return r;
}
@@ -1082,18 +1250,18 @@
void dm_cache_dump(struct dm_cache_metadata *cmd)
{
- down_read(&cmd->root_lock);
+ READ_LOCK_VOID(cmd);
__dump_mappings(cmd);
- up_read(&cmd->root_lock);
+ READ_UNLOCK(cmd);
}
int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd)
{
int r;
- down_read(&cmd->root_lock);
+ READ_LOCK(cmd);
r = cmd->changed;
- up_read(&cmd->root_lock);
+ READ_UNLOCK(cmd);
return r;
}
@@ -1133,9 +1301,9 @@
{
int r;
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __dirty(cmd, cblock, dirty);
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1143,17 +1311,17 @@
void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
struct dm_cache_statistics *stats)
{
- down_read(&cmd->root_lock);
+ READ_LOCK_VOID(cmd);
*stats = cmd->stats;
- up_read(&cmd->root_lock);
+ READ_UNLOCK(cmd);
}
void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
struct dm_cache_statistics *stats)
{
- down_write(&cmd->root_lock);
+ WRITE_LOCK_VOID(cmd);
cmd->stats = *stats;
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
}
int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
@@ -1162,7 +1330,7 @@
flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
clear_clean_shutdown);
- down_write(&cmd->root_lock);
+ WRITE_LOCK(cmd);
r = __commit_transaction(cmd, mutator);
if (r)
goto out;
@@ -1170,7 +1338,7 @@
r = __begin_transaction(cmd);
out:
- up_write(&cmd->root_lock);
+ WRITE_UNLOCK(cmd);
return r;
}
@@ -1179,9 +1347,9 @@
{
int r = -EINVAL;
- down_read(&cmd->root_lock);
+ READ_LOCK(cmd);
r = dm_sm_get_nr_free(cmd->metadata_sm, result);
- up_read(&cmd->root_lock);
+ READ_UNLOCK(cmd);
return r;
}
@@ -1191,9 +1359,9 @@
{
int r = -EINVAL;
- down_read(&cmd->root_lock);
+ READ_LOCK(cmd);
r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
- up_read(&cmd->root_lock);
+ READ_UNLOCK(cmd);
return r;
}
@@ -1243,42 +1411,114 @@
return 0;
}
-int dm_cache_begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
+static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock, uint32_t hint)
+{
+ struct dm_cache_metadata *cmd = context;
+ __le32 value = cpu_to_le32(hint);
+ int r;
+
+ __dm_bless_for_disk(&value);
+
+ r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
+ from_cblock(cblock), &value, &cmd->hint_root);
+ cmd->changed = true;
+
+ return r;
+}
+
+static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
{
int r;
- down_write(&cmd->root_lock);
r = begin_hints(cmd, policy);
- up_write(&cmd->root_lock);
+ if (r) {
+ DMERR("begin_hints failed");
+ return r;
+ }
+
+ return policy_walk_mappings(policy, save_hint, cmd);
+}
+
+int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
+{
+ int r;
+
+ WRITE_LOCK(cmd);
+ r = write_hints(cmd, policy);
+ WRITE_UNLOCK(cmd);
return r;
}
-static int save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
- uint32_t hint)
+int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result)
{
int r;
- __le32 value = cpu_to_le32(hint);
- __dm_bless_for_disk(&value);
- r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
- from_cblock(cblock), &value, &cmd->hint_root);
- cmd->changed = true;
+ READ_LOCK(cmd);
+ r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result);
+ READ_UNLOCK(cmd);
return r;
}
-int dm_cache_save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
- uint32_t hint)
+void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd)
+{
+ WRITE_LOCK_VOID(cmd);
+ dm_bm_set_read_only(cmd->bm);
+ WRITE_UNLOCK(cmd);
+}
+
+void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd)
+{
+ WRITE_LOCK_VOID(cmd);
+ dm_bm_set_read_write(cmd->bm);
+ WRITE_UNLOCK(cmd);
+}
+
+int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd)
{
int r;
+ struct dm_block *sblock;
+ struct cache_disk_superblock *disk_super;
- if (!hints_array_initialized(cmd))
- return 0;
+ WRITE_LOCK(cmd);
+ set_bit(NEEDS_CHECK, &cmd->flags);
- down_write(&cmd->root_lock);
- r = save_hint(cmd, cblock, hint);
- up_write(&cmd->root_lock);
+ r = superblock_lock(cmd, &sblock);
+ if (r) {
+ DMERR("couldn't read superblock");
+ goto out;
+ }
+
+ disk_super = dm_block_data(sblock);
+ disk_super->flags = cpu_to_le32(cmd->flags);
+
+ dm_bm_unlock(sblock);
+
+out:
+ WRITE_UNLOCK(cmd);
+ return r;
+}
+
+int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result)
+{
+ READ_LOCK(cmd);
+ *result = !!test_bit(NEEDS_CHECK, &cmd->flags);
+ READ_UNLOCK(cmd);
+
+ return 0;
+}
+
+int dm_cache_metadata_abort(struct dm_cache_metadata *cmd)
+{
+ int r;
+
+ WRITE_LOCK(cmd);
+ __destroy_persistent_data_objects(cmd);
+ r = __create_persistent_data_objects(cmd, false);
+ if (r)
+ cmd->fail_io = true;
+ WRITE_UNLOCK(cmd);
return r;
}