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Commit 04535d27 authored by Linus Torvalds's avatar Linus Torvalds
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Merge tag 'dm-3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm 

Pull device mapper changes from Mike Snitzer:

 - Fix dm-cache corruption caused by discard_block_size > cache_block_size

 - Fix a lock-inversion detected by LOCKDEP in dm-cache

 - Fix a dangling bio bug in the dm-thinp target's process_deferred_bios
   error path

 - Fix corruption due to non-atomic transaction commit which allowed a
   metadata superblock to be written before all other metadata was
   successfully written -- this is common to all targets that use the
   persistent-data library's transaction manager (dm-thinp, dm-cache and
   dm-era).

 - Various small cleanups in the DM core

 - Add the dm-era target which is useful for keeping track of which
   blocks were written within a user defined period of time called an
   'era'.  Use cases include tracking changed blocks for backup
   software, and partially invalidating the contents of a cache to
   restore cache coherency after rolling back a vendor snapshot.

 - Improve the on-disk layout of multithreaded writes to the
   dm-thin-pool by splitting the pool's deferred bio list to be a
   per-thin device list and then sorting that list using an rb_tree.
   The subsequent read throughput of the data written via multiple
   threads improved by ~70%.

 - Simplify the multipath target's handling of queuing IO by pushing
   requests back to the request queue rather than queueing the IO
   internally.

* tag 'dm-3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (24 commits)
  dm cache: fix a lock-inversion
  dm thin: sort the per thin deferred bios using an rb_tree
  dm thin: use per thin device deferred bio lists
  dm thin: simplify pool_is_congested
  dm thin: fix dangling bio in process_deferred_bios error path
  dm mpath: print more useful warnings in multipath_message()
  dm-mpath: do not activate failed paths
  dm mpath: remove extra nesting in map function
  dm mpath: remove map_io()
  dm mpath: reduce memory pressure when requeuing
  dm mpath: remove process_queued_ios()
  dm mpath: push back requests instead of queueing
  dm table: add dm_table_run_md_queue_async
  dm mpath: do not call pg_init when it is already running
  dm: use RCU_INIT_POINTER instead of rcu_assign_pointer in __unbind
  dm: stop using bi_private
  dm: remove dm_get_mapinfo
  dm: make dm_table_alloc_md_mempools static
  dm: take care to copy the space map roots before locking the superblock
  dm transaction manager: fix corruption due to non-atomic transaction commit
  ...
parents 3f583bc2 0596661f
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Documentation/device-mapper/era.txt 0 → 100644
View file @ 04535d27
Introduction
============
dm-era is a target that behaves similar to the linear target. In
addition it keeps track of which blocks were written within a user
defined period of time called an 'era'. Each era target instance
maintains the current era as a monotonically increasing 32-bit
counter.
Use cases include tracking changed blocks for backup software, and
partially invalidating the contents of a cache to restore cache
coherency after rolling back a vendor snapshot.
Constructor
===========
era <metadata dev> <origin dev> <block size>
metadata dev : fast device holding the persistent metadata
origin dev : device holding data blocks that may change
block size : block size of origin data device, granularity that is
tracked by the target
Messages
========
None of the dm messages take any arguments.
checkpoint
----------
Possibly move to a new era. You shouldn't assume the era has
incremented. After sending this message, you should check the
current era via the status line.
take_metadata_snap
------------------
Create a clone of the metadata, to allow a userland process to read it.
drop_metadata_snap
------------------
Drop the metadata snapshot.
Status
======
<metadata block size> <#used metadata blocks>/<#total metadata blocks>
<current era> <held metadata root | '-'>
metadata block size : Fixed block size for each metadata block in
sectors
#used metadata blocks : Number of metadata blocks used
#total metadata blocks : Total number of metadata blocks
current era : The current era
held metadata root : The location, in blocks, of the metadata root
that has been 'held' for userspace read
access. '-' indicates there is no held root
Detailed use case
=================
The scenario of invalidating a cache when rolling back a vendor
snapshot was the primary use case when developing this target:
Taking a vendor snapshot
------------------------
- Send a checkpoint message to the era target
- Make a note of the current era in its status line
- Take vendor snapshot (the era and snapshot should be forever
associated now).
Rolling back to an vendor snapshot
----------------------------------
- Cache enters passthrough mode (see: dm-cache's docs in cache.txt)
- Rollback vendor storage
- Take metadata snapshot
- Ascertain which blocks have been written since the snapshot was taken
by checking each block's era
- Invalidate those blocks in the caching software
- Cache returns to writeback/writethrough mode
Memory usage
============
The target uses a bitset to record writes in the current era. It also
has a spare bitset ready for switching over to a new era. Other than
that it uses a few 4k blocks for updating metadata.
(4 * nr_blocks) bytes + buffers
Resilience
==========
Metadata is updated on disk before a write to a previously unwritten
block is performed. As such dm-era should not be effected by a hard
crash such as power failure.
Userland tools
==============
Userland tools are found in the increasingly poorly named
thin-provisioning-tools project:
https://github.com/jthornber/thin-provisioning-tools
drivers/md/Kconfig
View file @ 04535d27
......@@ -285,6 +285,17 @@ config DM_CACHE_CLEANER
A simple cache policy that writes back all data to the
origin. Used when decommissioning a dm-cache.
config DM_ERA
tristate "Era target (EXPERIMENTAL)"
depends on BLK_DEV_DM
default n
select DM_PERSISTENT_DATA
select DM_BIO_PRISON
---help---
dm-era tracks which parts of a block device are written to
over time. Useful for maintaining cache coherency when using
vendor snapshots.
config DM_MIRROR
tristate "Mirror target"
depends on BLK_DEV_DM
......
drivers/md/Makefile
View file @ 04535d27
......@@ -14,6 +14,7 @@ dm-thin-pool-y += dm-thin.o dm-thin-metadata.o
dm-cache-y += dm-cache-target.o dm-cache-metadata.o dm-cache-policy.o
dm-cache-mq-y += dm-cache-policy-mq.o
dm-cache-cleaner-y += dm-cache-policy-cleaner.o
dm-era-y += dm-era-target.o
md-mod-y += md.o bitmap.o
raid456-y += raid5.o
......@@ -53,6 +54,7 @@ obj-$(CONFIG_DM_VERITY) += dm-verity.o
obj-$(CONFIG_DM_CACHE) += dm-cache.o
obj-$(CONFIG_DM_CACHE_MQ) += dm-cache-mq.o
obj-$(CONFIG_DM_CACHE_CLEANER) += dm-cache-cleaner.o
obj-$(CONFIG_DM_ERA) += dm-era.o
ifeq ($(CONFIG_DM_UEVENT),y)
dm-mod-objs += dm-uevent.o
......
drivers/md/dm-cache-block-types.h
View file @ 04535d27
......@@ -19,7 +19,6 @@
typedef dm_block_t __bitwise__ dm_oblock_t;
typedef uint32_t __bitwise__ dm_cblock_t;
typedef dm_block_t __bitwise__ dm_dblock_t;
static inline dm_oblock_t to_oblock(dm_block_t b)
{
......@@ -41,14 +40,4 @@ static inline uint32_t from_cblock(dm_cblock_t b)
return (__force uint32_t) b;
}
static inline dm_dblock_t to_dblock(dm_block_t b)
{
return (__force dm_dblock_t) b;
}
static inline dm_block_t from_dblock(dm_dblock_t b)
{
return (__force dm_block_t) b;
}
#endif /* DM_CACHE_BLOCK_TYPES_H */
drivers/md/dm-cache-metadata.c
View file @ 04535d27
......@@ -109,7 +109,7 @@ struct dm_cache_metadata {
dm_block_t discard_root;
sector_t discard_block_size;
dm_dblock_t discard_nr_blocks;
dm_oblock_t discard_nr_blocks;
sector_t data_block_size;
dm_cblock_t cache_blocks;
......@@ -120,6 +120,12 @@ struct dm_cache_metadata {
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];
};
/*-------------------------------------------------------------------
......@@ -260,11 +266,31 @@ static void __setup_mapping_info(struct dm_cache_metadata *cmd)
}
}
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;
......@@ -272,12 +298,16 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd)
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);
......@@ -293,16 +323,13 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd)
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->discard_nr_blocks = cpu_to_le64(from_oblock(cmd->discard_nr_blocks));
disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
disk_super->data_block_size = cpu_to_le32(cmd->data_block_size);
disk_super->cache_blocks = cpu_to_le32(0);
......@@ -313,10 +340,6 @@ static int __write_initial_superblock(struct dm_cache_metadata *cmd)
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)
......@@ -496,7 +519,7 @@ static void read_superblock_fields(struct dm_cache_metadata *cmd,
cmd->hint_root = le64_to_cpu(disk_super->hint_root);
cmd->discard_root = le64_to_cpu(disk_super->discard_root);
cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size);
cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks));
cmd->discard_nr_blocks = to_oblock(le64_to_cpu(disk_super->discard_nr_blocks));
cmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks));
strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name));
......@@ -530,8 +553,9 @@ static int __begin_transaction_flags(struct dm_cache_metadata *cmd,
disk_super = dm_block_data(sblock);
update_flags(disk_super, mutator);
read_superblock_fields(cmd, disk_super);
dm_bm_unlock(sblock);
return dm_bm_flush_and_unlock(cmd->bm, sblock);
return dm_bm_flush(cmd->bm);
}
static int __begin_transaction(struct dm_cache_metadata *cmd)
......@@ -559,7 +583,6 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
flags_mutator mutator)
{
int r;
size_t metadata_len;
struct cache_disk_superblock *disk_super;
struct dm_block *sblock;
......@@ -577,8 +600,8 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
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);
......@@ -594,7 +617,7 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
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->discard_nr_blocks = cpu_to_le64(from_oblock(cmd->discard_nr_blocks));
disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks));
strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name));
disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]);
......@@ -605,13 +628,7 @@ static int __commit_transaction(struct dm_cache_metadata *cmd,
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);
}
......@@ -771,15 +788,15 @@ int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
sector_t discard_block_size,
dm_dblock_t new_nr_entries)
dm_oblock_t new_nr_entries)
{
int r;
down_write(&cmd->root_lock);
r = dm_bitset_resize(&cmd->discard_info,
cmd->discard_root,
from_dblock(cmd->discard_nr_blocks),
from_dblock(new_nr_entries),
from_oblock(cmd->discard_nr_blocks),
from_oblock(new_nr_entries),
false, &cmd->discard_root);
if (!r) {
cmd->discard_block_size = discard_block_size;
......@@ -792,28 +809,28 @@ int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
return r;
}
static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
static int __set_discard(struct dm_cache_metadata *cmd, dm_oblock_t b)
{
return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root,
from_dblock(b), &cmd->discard_root);
from_oblock(b), &cmd->discard_root);
}
static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
static int __clear_discard(struct dm_cache_metadata *cmd, dm_oblock_t b)
{
return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root,
from_dblock(b), &cmd->discard_root);
from_oblock(b), &cmd->discard_root);
}
static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b,
static int __is_discarded(struct dm_cache_metadata *cmd, dm_oblock_t b,
bool *is_discarded)
{
return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root,
from_dblock(b), &cmd->discard_root,
from_oblock(b), &cmd->discard_root,
is_discarded);
}
static int __discard(struct dm_cache_metadata *cmd,
dm_dblock_t dblock, bool discard)
dm_oblock_t dblock, bool discard)
{
int r;
......@@ -826,7 +843,7 @@ static int __discard(struct dm_cache_metadata *cmd,
}
int dm_cache_set_discard(struct dm_cache_metadata *cmd,
dm_dblock_t dblock, bool discard)
dm_oblock_t dblock, bool discard)
{
int r;
......@@ -844,8 +861,8 @@ static int __load_discards(struct dm_cache_metadata *cmd,
dm_block_t b;
bool discard;
for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
dm_dblock_t dblock = to_dblock(b);
for (b = 0; b < from_oblock(cmd->discard_nr_blocks); b++) {
dm_oblock_t dblock = to_oblock(b);
if (cmd->clean_when_opened) {
r = __is_discarded(cmd, dblock, &discard);
......@@ -1228,22 +1245,12 @@ static int begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *po
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;
down_write(&cmd->root_lock);
r = begin_hints(cmd, policy);
up_write(&cmd->root_lock);
return r;
}
static int save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
uint32_t hint)
{
int r;
__le32 value = cpu_to_le32(hint);
__dm_bless_for_disk(&value);
r = dm_array_set_value(&cmd->hint_info, cmd->hint_root,
......@@ -1253,16 +1260,25 @@ static int save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
return r;
}
int dm_cache_save_hint(struct dm_cache_metadata *cmd, dm_cblock_t cblock,
uint32_t hint)
static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy)
{
int r;
if (!hints_array_initialized(cmd))
return 0;
r = begin_hints(cmd, policy);
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;
down_write(&cmd->root_lock);
r = save_hint(cmd, cblock, hint);
r = write_hints(cmd, policy);
up_write(&cmd->root_lock);
return r;
......
drivers/md/dm-cache-metadata.h
View file @ 04535d27
......@@ -72,14 +72,14 @@ dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd);
int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
sector_t discard_block_size,
dm_dblock_t new_nr_entries);
dm_oblock_t new_nr_entries);
typedef int (*load_discard_fn)(void *context, sector_t discard_block_size,
dm_dblock_t dblock, bool discarded);
dm_oblock_t dblock, bool discarded);
int dm_cache_load_discards(struct dm_cache_metadata *cmd,
load_discard_fn fn, void *context);
int dm_cache_set_discard(struct dm_cache_metadata *cmd, dm_dblock_t dblock, bool discard);
int dm_cache_set_discard(struct dm_cache_metadata *cmd, dm_oblock_t dblock, bool discard);
int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock);
int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock, dm_oblock_t oblock);
......@@ -128,14 +128,7 @@ void dm_cache_dump(struct dm_cache_metadata *cmd);
* rather than querying the policy for each cblock, we let it walk its data
* structures and fill in the hints in whatever order it wishes.
*/
int dm_cache_begin_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *p);
/*
* requests hints for every cblock and stores in the metadata device.
*/
int dm_cache_save_hint(struct dm_cache_metadata *cmd,
dm_cblock_t cblock, uint32_t hint);
int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *p);
/*
* Query method. Are all the blocks in the cache clean?
......
drivers/md/dm-cache-target.c
View file @ 04535d27
......@@ -237,9 +237,8 @@ struct cache {
/*
* origin_blocks entries, discarded if set.
*/
dm_dblock_t discard_nr_blocks;
dm_oblock_t discard_nr_blocks;
unsigned long *discard_bitset;
uint32_t discard_block_size; /* a power of 2 times sectors per block */
/*
* Rather than reconstructing the table line for the status we just
......@@ -526,48 +525,33 @@ static dm_block_t block_div(dm_block_t b, uint32_t n)
return b;
}
static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock)
{
uint32_t discard_blocks = cache->discard_block_size;
dm_block_t b = from_oblock(oblock);
if (!block_size_is_power_of_two(cache))
discard_blocks = discard_blocks / cache->sectors_per_block;
else
discard_blocks >>= cache->sectors_per_block_shift;
b = block_div(b, discard_blocks);
return to_dblock(b);
}
static void set_discard(struct cache *cache, dm_dblock_t b)
static void set_discard(struct cache *cache, dm_oblock_t b)
{
unsigned long flags;
atomic_inc(&cache->stats.discard_count);
spin_lock_irqsave(&cache->lock, flags);
set_bit(from_dblock(b), cache->discard_bitset);
set_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
}
static void clear_discard(struct cache *cache, dm_dblock_t b)
static void clear_discard(struct cache *cache, dm_oblock_t b)
{
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
clear_bit(from_dblock(b), cache->discard_bitset);
clear_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
}
static bool is_discarded(struct cache *cache, dm_dblock_t b)
static bool is_discarded(struct cache *cache, dm_oblock_t b)
{
int r;
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
r = test_bit(from_dblock(b), cache->discard_bitset);
r = test_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
return r;
......@@ -579,8 +563,7 @@ static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b)
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
r = test_bit(from_dblock(oblock_to_dblock(cache, b)),
cache->discard_bitset);
r = test_bit(from_oblock(b), cache->discard_bitset);
spin_unlock_irqrestore(&cache->lock, flags);
return r;
......@@ -705,7 +688,7 @@ static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio,
check_if_tick_bio_needed(cache, bio);
remap_to_origin(cache, bio);
if (bio_data_dir(bio) == WRITE)
clear_discard(cache, oblock_to_dblock(cache, oblock));
clear_discard(cache, oblock);
}
static void remap_to_cache_dirty(struct cache *cache, struct bio *bio,
......@@ -715,7 +698,7 @@ static void remap_to_cache_dirty(struct cache *cache, struct bio *bio,
remap_to_cache(cache, bio, cblock);
if (bio_data_dir(bio) == WRITE) {
set_dirty(cache, oblock, cblock);
clear_discard(cache, oblock_to_dblock(cache, oblock));
clear_discard(cache, oblock);
}
}
......@@ -1288,14 +1271,14 @@ static void process_flush_bio(struct cache *cache, struct bio *bio)
static void process_discard_bio(struct cache *cache, struct bio *bio)
{
dm_block_t start_block = dm_sector_div_up(bio->bi_iter.bi_sector,
cache->discard_block_size);
cache->sectors_per_block);
dm_block_t end_block = bio_end_sector(bio);
dm_block_t b;
end_block = block_div(end_block, cache->discard_block_size);
end_block = block_div(end_block, cache->sectors_per_block);
for (b = start_block; b < end_block; b++)
set_discard(cache, to_dblock(b));
set_discard(cache, to_oblock(b));
bio_endio(bio, 0);
}
......@@ -2171,35 +2154,6 @@ static int create_cache_policy(struct cache *cache, struct cache_args *ca,
return 0;
}
/*
* We want the discard block size to be a power of two, at least the size
* of the cache block size, and have no more than 2^14 discard blocks
* across the origin.
*/
#define MAX_DISCARD_BLOCKS (1 << 14)
static bool too_many_discard_blocks(sector_t discard_block_size,
sector_t origin_size)
{
(void) sector_div(origin_size, discard_block_size);
return origin_size > MAX_DISCARD_BLOCKS;
}
static sector_t calculate_discard_block_size(sector_t cache_block_size,
sector_t origin_size)
{
sector_t discard_block_size;
discard_block_size = roundup_pow_of_two(cache_block_size);
if (origin_size)
while (too_many_discard_blocks(discard_block_size, origin_size))
discard_block_size *= 2;
return discard_block_size;
}
#define DEFAULT_MIGRATION_THRESHOLD 2048
static int cache_create(struct cache_args *ca, struct cache **result)
......@@ -2321,16 +2275,13 @@ static int cache_create(struct cache_args *ca, struct cache **result)
}
clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size));
cache->discard_block_size =
calculate_discard_block_size(cache->sectors_per_block,
cache->origin_sectors);
cache->discard_nr_blocks = oblock_to_dblock(cache, cache->origin_blocks);
cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks));
cache->discard_nr_blocks = cache->origin_blocks;
cache->discard_bitset = alloc_bitset(from_oblock(cache->discard_nr_blocks));
if (!cache->discard_bitset) {
*error = "could not allocate discard bitset";
goto bad;
}
clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks));
clear_bitset(cache->discard_bitset, from_oblock(cache->discard_nr_blocks));
cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(cache->copier)) {
......@@ -2614,16 +2565,16 @@ static int write_discard_bitset(struct cache *cache)
{
unsigned i, r;
r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size,
cache->discard_nr_blocks);
r = dm_cache_discard_bitset_resize(cache->cmd, cache->sectors_per_block,
cache->origin_blocks);
if (r) {
DMERR("could not resize on-disk discard bitset");
return r;
}
for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) {
r = dm_cache_set_discard(cache->cmd, to_dblock(i),
is_discarded(cache, to_dblock(i)));
for (i = 0; i < from_oblock(cache->discard_nr_blocks); i++) {
r = dm_cache_set_discard(cache->cmd, to_oblock(i),
is_discarded(cache, to_oblock(i)));
if (r)
return r;
}
......@@ -2631,30 +2582,6 @@ static int write_discard_bitset(struct cache *cache)
return 0;
}
static int save_hint(void *context, dm_cblock_t cblock, dm_oblock_t oblock,
uint32_t hint)
{
struct cache *cache = context;
return dm_cache_save_hint(cache->cmd, cblock, hint);
}
static int write_hints(struct cache *cache)
{
int r;
r = dm_cache_begin_hints(cache->cmd, cache->policy);
if (r) {
DMERR("dm_cache_begin_hints failed");
return r;
}
r = policy_walk_mappings(cache->policy, save_hint, cache);
if (r)
DMERR("policy_walk_mappings failed");
return r;
}
/*
* returns true on success
*/
......@@ -2672,7 +2599,7 @@ static bool sync_metadata(struct cache *cache)
save_stats(cache);
r3 = write_hints(cache);
r3 = dm_cache_write_hints(cache->cmd, cache->policy);
if (r3)
DMERR("could not write hints");
......@@ -2720,16 +2647,14 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
}
static int load_discard(void *context, sector_t discard_block_size,
dm_dblock_t dblock, bool discard)
dm_oblock_t oblock, bool discard)
{
struct cache *cache = context;
/* FIXME: handle mis-matched block size */
if (discard)
set_discard(cache, dblock);
set_discard(cache, oblock);
else
clear_discard(cache, dblock);
clear_discard(cache, oblock);
return 0;
}
......@@ -3120,8 +3045,8 @@ static void set_discard_limits(struct cache *cache, struct queue_limits *limits)
/*
* FIXME: these limits may be incompatible with the cache device
*/
limits->max_discard_sectors = cache->discard_block_size * 1024;
limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT;
limits->max_discard_sectors = cache->sectors_per_block;
limits->discard_granularity = cache->sectors_per_block << SECTOR_SHIFT;
}
static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
......@@ -3145,7 +3070,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
static struct target_type cache_target = {
.name = "cache",
.version = {1, 3, 0},
.version = {1, 4, 0},
.module = THIS_MODULE,
.ctr = cache_ctr,
.dtr = cache_dtr,
......
drivers/md/dm-era-target.c 0 → 100644
View file @ 04535d27
#include "dm.h"
#include "persistent-data/dm-transaction-manager.h"
#include "persistent-data/dm-bitset.h"
#include "persistent-data/dm-space-map.h"
#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
#include <linux/init.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#define DM_MSG_PREFIX "era"
#define SUPERBLOCK_LOCATION 0
#define SUPERBLOCK_MAGIC 2126579579
#define SUPERBLOCK_CSUM_XOR 146538381
#define MIN_ERA_VERSION 1
#define MAX_ERA_VERSION 1
#define INVALID_WRITESET_ROOT SUPERBLOCK_LOCATION
#define MIN_BLOCK_SIZE 8
/*----------------------------------------------------------------
* Writeset
*--------------------------------------------------------------*/
struct writeset_metadata {
uint32_t nr_bits;
dm_block_t root;
};
struct writeset {
struct writeset_metadata md;
/*
* An in core copy of the bits to save constantly doing look ups on
* disk.
*/
unsigned long *bits;
};
/*
* This does not free off the on disk bitset as this will normally be done
* after digesting into the era array.
*/
static void writeset_free(struct writeset *ws)
{
vfree(ws->bits);
}
static int setup_on_disk_bitset(struct dm_disk_bitset *info,
unsigned nr_bits, dm_block_t *root)
{
int r;
r = dm_bitset_empty(info, root);
if (r)
return r;
return dm_bitset_resize(info, *root, 0, nr_bits, false, root);
}
static size_t bitset_size(unsigned nr_bits)
{
return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG);
}
/*
* Allocates memory for the in core bitset.
*/
static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks)
{
ws->md.nr_bits = nr_blocks;
ws->md.root = INVALID_WRITESET_ROOT;
ws->bits = vzalloc(bitset_size(nr_blocks));
if (!ws->bits) {
DMERR("%s: couldn't allocate in memory bitset", __func__);
return -ENOMEM;
}
return 0;
}
/*
* Wipes the in-core bitset, and creates a new on disk bitset.
*/
static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws)
{
int r;
memset(ws->bits, 0, bitset_size(ws->md.nr_bits));
r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root);
if (r) {
DMERR("%s: setup_on_disk_bitset failed", __func__);
return r;
}
return 0;
}
static bool writeset_marked(struct writeset *ws, dm_block_t block)
{
return test_bit(block, ws->bits);
}
static int writeset_marked_on_disk(struct dm_disk_bitset *info,
struct writeset_metadata *m, dm_block_t block,
bool *result)
{
dm_block_t old = m->root;
/*
* The bitset was flushed when it was archived, so we know there'll
* be no change to the root.
*/
int r = dm_bitset_test_bit(info, m->root, block, &m->root, result);
if (r) {
DMERR("%s: dm_bitset_test_bit failed", __func__);
return r;
}
BUG_ON(m->root != old);
return r;
}
/*
* Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was.
*/
static int writeset_test_and_set(struct dm_disk_bitset *info,
struct writeset *ws, uint32_t block)
{
int r;
if (!test_and_set_bit(block, ws->bits)) {
r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root);
if (r) {
/* FIXME: fail mode */
return r;
}
return 0;
}
return 1;
}
/*----------------------------------------------------------------
* On disk metadata layout
*--------------------------------------------------------------*/
#define SPACE_MAP_ROOT_SIZE 128
#define UUID_LEN 16
struct writeset_disk {
__le32 nr_bits;
__le64 root;
} __packed;
struct superblock_disk {
__le32 csum;
__le32 flags;
__le64 blocknr;
__u8 uuid[UUID_LEN];
__le64 magic;
__le32 version;
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
__le32 data_block_size;
__le32 metadata_block_size;
__le32 nr_blocks;
__le32 current_era;
struct writeset_disk current_writeset;
/*
* Only these two fields are valid within the metadata snapshot.
*/
__le64 writeset_tree_root;
__le64 era_array_root;
__le64 metadata_snap;
} __packed;
/*----------------------------------------------------------------
* Superblock validation
*--------------------------------------------------------------*/
static void sb_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
struct superblock_disk *disk = dm_block_data(b);
disk->blocknr = cpu_to_le64(dm_block_location(b));
disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags,
sb_block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
}
static int check_metadata_version(struct superblock_disk *disk)
{
uint32_t metadata_version = le32_to_cpu(disk->version);
if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) {
DMERR("Era metadata version %u found, but only versions between %u and %u supported.",
metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION);
return -EINVAL;
}
return 0;
}
static int sb_check(struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
struct superblock_disk *disk = dm_block_data(b);
__le32 csum_le;
if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) {
DMERR("sb_check failed: blocknr %llu: wanted %llu",
le64_to_cpu(disk->blocknr),
(unsigned long long)dm_block_location(b));
return -ENOTBLK;
}
if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) {
DMERR("sb_check failed: magic %llu: wanted %llu",
le64_to_cpu(disk->magic),
(unsigned long long) SUPERBLOCK_MAGIC);
return -EILSEQ;
}
csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags,
sb_block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
if (csum_le != disk->csum) {
DMERR("sb_check failed: csum %u: wanted %u",
le32_to_cpu(csum_le), le32_to_cpu(disk->csum));
return -EILSEQ;
}
return check_metadata_version(disk);
}
static struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check
};
/*----------------------------------------------------------------
* Low level metadata handling
*--------------------------------------------------------------*/
#define DM_ERA_METADATA_BLOCK_SIZE 4096
#define DM_ERA_METADATA_CACHE_SIZE 64
#define ERA_MAX_CONCURRENT_LOCKS 5
struct era_metadata {
struct block_device *bdev;
struct dm_block_manager *bm;
struct dm_space_map *sm;
struct dm_transaction_manager *tm;
dm_block_t block_size;
uint32_t nr_blocks;
uint32_t current_era;
/*
* We preallocate 2 writesets. When an era rolls over we
* switch between them. This means the allocation is done at
* preresume time, rather than on the io path.
*/
struct writeset writesets[2];
struct writeset *current_writeset;
dm_block_t writeset_tree_root;
dm_block_t era_array_root;
struct dm_disk_bitset bitset_info;
struct dm_btree_info writeset_tree_info;
struct dm_array_info era_array_info;
dm_block_t metadata_snap;
/*
* A flag that is set whenever a writeset has been archived.
*/
bool archived_writesets;
/*
* 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];
};
static int superblock_read_lock(struct era_metadata *md,
struct dm_block **sblock)
{
return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int superblock_lock_zero(struct era_metadata *md,
struct dm_block **sblock)
{
return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int superblock_lock(struct era_metadata *md,
struct dm_block **sblock)
{
return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
/* FIXME: duplication with cache and thin */
static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
{
int r;
unsigned i;
struct dm_block *b;
__le64 *data_le, zero = cpu_to_le64(0);
unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
/*
* We can't use a validator here - it may be all zeroes.
*/
r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &b);
if (r)
return r;
data_le = dm_block_data(b);
*result = true;
for (i = 0; i < sb_block_size; i++) {
if (data_le[i] != zero) {
*result = false;
break;
}
}
return dm_bm_unlock(b);
}
/*----------------------------------------------------------------*/
static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk)
{
disk->nr_bits = cpu_to_le32(core->nr_bits);
disk->root = cpu_to_le64(core->root);
}
static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core)
{
core->nr_bits = le32_to_cpu(disk->nr_bits);
core->root = le64_to_cpu(disk->root);
}
static void ws_inc(void *context, const void *value)
{
struct era_metadata *md = context;
struct writeset_disk ws_d;
dm_block_t b;
memcpy(&ws_d, value, sizeof(ws_d));
b = le64_to_cpu(ws_d.root);
dm_tm_inc(md->tm, b);
}
static void ws_dec(void *context, const void *value)
{
struct era_metadata *md = context;
struct writeset_disk ws_d;
dm_block_t b;
memcpy(&ws_d, value, sizeof(ws_d));
b = le64_to_cpu(ws_d.root);
dm_bitset_del(&md->bitset_info, b);
}
static int ws_eq(void *context, const void *value1, const void *value2)
{
return !memcmp(value1, value2, sizeof(struct writeset_metadata));
}
/*----------------------------------------------------------------*/
static void setup_writeset_tree_info(struct era_metadata *md)
{
struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type;
md->writeset_tree_info.tm = md->tm;
md->writeset_tree_info.levels = 1;
vt->context = md;
vt->size = sizeof(struct writeset_disk);
vt->inc = ws_inc;
vt->dec = ws_dec;
vt->equal = ws_eq;
}
static void setup_era_array_info(struct era_metadata *md)
{
struct dm_btree_value_type vt;
vt.context = NULL;
vt.size = sizeof(__le32);
vt.inc = NULL;
vt.dec = NULL;
vt.equal = NULL;
dm_array_info_init(&md->era_array_info, md->tm, &vt);
}
static void setup_infos(struct era_metadata *md)
{
dm_disk_bitset_init(md->tm, &md->bitset_info);
setup_writeset_tree_info(md);
setup_era_array_info(md);
}
/*----------------------------------------------------------------*/
static int create_fresh_metadata(struct era_metadata *md)
{
int r;
r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION,
&md->tm, &md->sm);
if (r < 0) {
DMERR("dm_tm_create_with_sm failed");
return r;
}
setup_infos(md);
r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root);
if (r) {
DMERR("couldn't create new writeset tree");
goto bad;
}
r = dm_array_empty(&md->era_array_info, &md->era_array_root);
if (r) {
DMERR("couldn't create era array");
goto bad;
}
return 0;
bad:
dm_sm_destroy(md->sm);
dm_tm_destroy(md->tm);
return r;
}
static int save_sm_root(struct era_metadata *md)
{
int r;
size_t metadata_len;
r = dm_sm_root_size(md->sm, &metadata_len);
if (r < 0)
return r;
return dm_sm_copy_root(md->sm, &md->metadata_space_map_root,
metadata_len);
}
static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk)
{
memcpy(&disk->metadata_space_map_root,
&md->metadata_space_map_root,
sizeof(md->metadata_space_map_root));
}
/*
* Writes a superblock, including the static fields that don't get updated
* with every commit (possible optimisation here). 'md' should be fully
* constructed when this is called.
*/
static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk)
{
disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC);
disk->flags = cpu_to_le32(0ul);
/* FIXME: can't keep blanking the uuid (uuid is currently unused though) */
memset(disk->uuid, 0, sizeof(disk->uuid));
disk->version = cpu_to_le32(MAX_ERA_VERSION);
copy_sm_root(md, disk);
disk->data_block_size = cpu_to_le32(md->block_size);
disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
disk->nr_blocks = cpu_to_le32(md->nr_blocks);
disk->current_era = cpu_to_le32(md->current_era);
ws_pack(&md->current_writeset->md, &disk->current_writeset);
disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root);
disk->era_array_root = cpu_to_le64(md->era_array_root);
disk->metadata_snap = cpu_to_le64(md->metadata_snap);
}
static int write_superblock(struct era_metadata *md)
{
int r;
struct dm_block *sblock;
struct superblock_disk *disk;
r = save_sm_root(md);
if (r) {
DMERR("%s: save_sm_root failed", __func__);
return r;
}
r = superblock_lock_zero(md, &sblock);
if (r)
return r;
disk = dm_block_data(sblock);
prepare_superblock(md, disk);
return dm_tm_commit(md->tm, sblock);
}
/*
* Assumes block_size and the infos are set.
*/
static int format_metadata(struct era_metadata *md)
{
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;
return dm_bm_unlock(sblock);
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,
DM_ERA_METADATA_CACHE_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 = save_sm_root(md);
if (r) {
DMERR("%s: save_sm_root failed", __func__);
return r;
}
r = dm_tm_pre_commit(md->tm);
if (r) {
DMERR("%s: pre commit 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);
r = dm_tm_unlock(md->tm, clone);
if (r) {
DMERR("%s: couldn't unlock clone", __func__);
md->metadata_snap = SUPERBLOCK_LOCATION;
return r;
}
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->bi_bdev = 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)
{
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;
ti->discards_supported = true;
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_FLUSH bios carry no data, so we're not interested in them.
*/
if (!(bio->bi_rw & REQ_FLUSH) &&
(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)
{
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 int era_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
struct bio_vec *biovec, int max_size)
{
struct era *era = ti->private;
struct request_queue *q = bdev_get_queue(era->origin_dev->bdev);
if (!q->merge_bvec_fn)
return max_size;
bvm->bi_bdev = era->origin_dev->bdev;
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
}
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,
.merge = era_merge,
.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");
drivers/md/dm-mpath.c
View file @ 04535d27
......@@ -93,10 +93,6 @@ struct multipath {
unsigned pg_init_count; /* Number of times pg_init called */
unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */
unsigned queue_size;
struct work_struct process_queued_ios;
struct list_head queued_ios;
struct work_struct trigger_event;
/*
......@@ -121,9 +117,9 @@ typedef int (*action_fn) (struct pgpath *pgpath);
static struct kmem_cache *_mpio_cache;
static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
static void process_queued_ios(struct work_struct *work);
static void trigger_event(struct work_struct *work);
static void activate_path(struct work_struct *work);
static int __pgpath_busy(struct pgpath *pgpath);
/*-----------------------------------------------
......@@ -195,11 +191,9 @@ static struct multipath *alloc_multipath(struct dm_target *ti)
m = kzalloc(sizeof(*m), GFP_KERNEL);
if (m) {
INIT_LIST_HEAD(&m->priority_groups);
INIT_LIST_HEAD(&m->queued_ios);
spin_lock_init(&m->lock);
m->queue_io = 1;
m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT;
INIT_WORK(&m->process_queued_ios, process_queued_ios);
INIT_WORK(&m->trigger_event, trigger_event);
init_waitqueue_head(&m->pg_init_wait);
mutex_init(&m->work_mutex);
......@@ -256,13 +250,21 @@ static void clear_mapinfo(struct multipath *m, union map_info *info)
* Path selection
*-----------------------------------------------*/
static void __pg_init_all_paths(struct multipath *m)
static int __pg_init_all_paths(struct multipath *m)
{
struct pgpath *pgpath;
unsigned long pg_init_delay = 0;
if (m->pg_init_in_progress || m->pg_init_disabled)
return 0;
m->pg_init_count++;
m->pg_init_required = 0;
/* Check here to reset pg_init_required */
if (!m->current_pg)
return 0;
if (m->pg_init_delay_retry)
pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ?
m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS);
......@@ -274,6 +276,7 @@ static void __pg_init_all_paths(struct multipath *m)
pg_init_delay))
m->pg_init_in_progress++;
}
return m->pg_init_in_progress;
}
static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
......@@ -365,19 +368,26 @@ static void __choose_pgpath(struct multipath *m, size_t nr_bytes)
*/
static int __must_push_back(struct multipath *m)
{
return (m->queue_if_no_path != m->saved_queue_if_no_path &&
dm_noflush_suspending(m->ti));
return (m->queue_if_no_path ||
(m->queue_if_no_path != m->saved_queue_if_no_path &&
dm_noflush_suspending(m->ti)));
}
static int map_io(struct multipath *m, struct request *clone,
union map_info *map_context, unsigned was_queued)
#define pg_ready(m) (!(m)->queue_io && !(m)->pg_init_required)
/*
* Map cloned requests
*/
static int multipath_map(struct dm_target *ti, struct request *clone,
union map_info *map_context)
{
int r = DM_MAPIO_REMAPPED;
struct multipath *m = (struct multipath *) ti->private;
int r = DM_MAPIO_REQUEUE;
size_t nr_bytes = blk_rq_bytes(clone);
unsigned long flags;
struct pgpath *pgpath;
struct block_device *bdev;
struct dm_mpath_io *mpio = map_context->ptr;
struct dm_mpath_io *mpio;
spin_lock_irqsave(&m->lock, flags);
......@@ -388,38 +398,33 @@ static int map_io(struct multipath *m, struct request *clone,
pgpath = m->current_pgpath;
if (was_queued)
m->queue_size--;
if (!pgpath) {
if (!__must_push_back(m))
r = -EIO; /* Failed */
goto out_unlock;
}
if (!pg_ready(m)) {
__pg_init_all_paths(m);
goto out_unlock;
}
if (set_mapinfo(m, map_context) < 0)
/* ENOMEM, requeue */
goto out_unlock;
if (m->pg_init_required) {
if (!m->pg_init_in_progress)
queue_work(kmultipathd, &m->process_queued_ios);
r = DM_MAPIO_REQUEUE;
} else if ((pgpath && m->queue_io) ||
(!pgpath && m->queue_if_no_path)) {
/* Queue for the daemon to resubmit */
list_add_tail(&clone->queuelist, &m->queued_ios);
m->queue_size++;
if (!m->queue_io)
queue_work(kmultipathd, &m->process_queued_ios);
pgpath = NULL;
r = DM_MAPIO_SUBMITTED;
} else if (pgpath) {
bdev = pgpath->path.dev->bdev;
clone->q = bdev_get_queue(bdev);
clone->rq_disk = bdev->bd_disk;
} else if (__must_push_back(m))
r = DM_MAPIO_REQUEUE;
else
r = -EIO; /* Failed */
clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
mpio = map_context->ptr;
mpio->pgpath = pgpath;
mpio->nr_bytes = nr_bytes;
if (r == DM_MAPIO_REMAPPED && pgpath->pg->ps.type->start_io)
pgpath->pg->ps.type->start_io(&pgpath->pg->ps, &pgpath->path,
if (pgpath->pg->ps.type->start_io)
pgpath->pg->ps.type->start_io(&pgpath->pg->ps,
&pgpath->path,
nr_bytes);
r = DM_MAPIO_REMAPPED;
out_unlock:
spin_unlock_irqrestore(&m->lock, flags);
return r;
......@@ -440,76 +445,14 @@ static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path,
else
m->saved_queue_if_no_path = queue_if_no_path;
m->queue_if_no_path = queue_if_no_path;
if (!m->queue_if_no_path && m->queue_size)
queue_work(kmultipathd, &m->process_queued_ios);
if (!m->queue_if_no_path)
dm_table_run_md_queue_async(m->ti->table);
spin_unlock_irqrestore(&m->lock, flags);
return 0;
}
/*-----------------------------------------------------------------
* The multipath daemon is responsible for resubmitting queued ios.
*---------------------------------------------------------------*/
static void dispatch_queued_ios(struct multipath *m)
{
int r;
unsigned long flags;
union map_info *info;
struct request *clone, *n;
LIST_HEAD(cl);
spin_lock_irqsave(&m->lock, flags);
list_splice_init(&m->queued_ios, &cl);
spin_unlock_irqrestore(&m->lock, flags);
list_for_each_entry_safe(clone, n, &cl, queuelist) {
list_del_init(&clone->queuelist);
info = dm_get_rq_mapinfo(clone);
r = map_io(m, clone, info, 1);
if (r < 0) {
clear_mapinfo(m, info);
dm_kill_unmapped_request(clone, r);
} else if (r == DM_MAPIO_REMAPPED)
dm_dispatch_request(clone);
else if (r == DM_MAPIO_REQUEUE) {
clear_mapinfo(m, info);
dm_requeue_unmapped_request(clone);
}
}
}
static void process_queued_ios(struct work_struct *work)
{
struct multipath *m =
container_of(work, struct multipath, process_queued_ios);
struct pgpath *pgpath = NULL;
unsigned must_queue = 1;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
if (!m->current_pgpath)
__choose_pgpath(m, 0);
pgpath = m->current_pgpath;
if ((pgpath && !m->queue_io) ||
(!pgpath && !m->queue_if_no_path))
must_queue = 0;
if (m->pg_init_required && !m->pg_init_in_progress && pgpath &&
!m->pg_init_disabled)
__pg_init_all_paths(m);
spin_unlock_irqrestore(&m->lock, flags);
if (!must_queue)
dispatch_queued_ios(m);
}
/*
* An event is triggered whenever a path is taken out of use.
* Includes path failure and PG bypass.
......@@ -971,27 +914,6 @@ static void multipath_dtr(struct dm_target *ti)
free_multipath(m);
}
/*
* Map cloned requests
*/
static int multipath_map(struct dm_target *ti, struct request *clone,
union map_info *map_context)
{
int r;
struct multipath *m = (struct multipath *) ti->private;
if (set_mapinfo(m, map_context) < 0)
/* ENOMEM, requeue */
return DM_MAPIO_REQUEUE;
clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
r = map_io(m, clone, map_context, 0);
if (r < 0 || r == DM_MAPIO_REQUEUE)
clear_mapinfo(m, map_context);
return r;
}
/*
* Take a path out of use.
*/
......@@ -1054,9 +976,9 @@ static int reinstate_path(struct pgpath *pgpath)
pgpath->is_active = 1;
if (!m->nr_valid_paths++ && m->queue_size) {
if (!m->nr_valid_paths++) {
m->current_pgpath = NULL;
queue_work(kmultipathd, &m->process_queued_ios);
dm_table_run_md_queue_async(m->ti->table);
} else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) {
if (queue_work(kmpath_handlerd, &pgpath->activate_path.work))
m->pg_init_in_progress++;
......@@ -1252,11 +1174,12 @@ static void pg_init_done(void *data, int errors)
/* Activations of other paths are still on going */
goto out;
if (!m->pg_init_required)
m->queue_io = 0;
if (m->pg_init_required) {
m->pg_init_delay_retry = delay_retry;
queue_work(kmultipathd, &m->process_queued_ios);
if (__pg_init_all_paths(m))
goto out;
}
m->queue_io = 0;
/*
* Wake up any thread waiting to suspend.
......@@ -1272,8 +1195,11 @@ static void activate_path(struct work_struct *work)
struct pgpath *pgpath =
container_of(work, struct pgpath, activate_path.work);
if (pgpath->is_active)
scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
pg_init_done, pgpath);
else
pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED);
}
static int noretry_error(int error)
......@@ -1433,7 +1359,7 @@ static void multipath_status(struct dm_target *ti, status_type_t type,
/* Features */
if (type == STATUSTYPE_INFO)
DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count);
DMEMIT("2 %u %u ", m->queue_io, m->pg_init_count);
else {
DMEMIT("%u ", m->queue_if_no_path +
(m->pg_init_retries > 0) * 2 +
......@@ -1552,7 +1478,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
}
if (argc != 2) {
DMWARN("Unrecognised multipath message received.");
DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc);
goto out;
}
......@@ -1570,7 +1496,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
else if (!strcasecmp(argv[0], "fail_path"))
action = fail_path;
else {
DMWARN("Unrecognised multipath message received.");
DMWARN("Unrecognised multipath message received: %s", argv[0]);
goto out;
}
......@@ -1632,8 +1558,17 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
r = err;
}
if (r == -ENOTCONN && !fatal_signal_pending(current))
queue_work(kmultipathd, &m->process_queued_ios);
if (r == -ENOTCONN && !fatal_signal_pending(current)) {
spin_lock_irqsave(&m->lock, flags);
if (!m->current_pg) {
/* Path status changed, redo selection */
__choose_pgpath(m, 0);
}
if (m->pg_init_required)
__pg_init_all_paths(m);
spin_unlock_irqrestore(&m->lock, flags);
dm_table_run_md_queue_async(m->ti->table);
}
return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
}
......@@ -1684,7 +1619,7 @@ static int multipath_busy(struct dm_target *ti)
spin_lock_irqsave(&m->lock, flags);
/* pg_init in progress, requeue until done */
if (m->pg_init_in_progress) {
if (!pg_ready(m)) {
busy = 1;
goto out;
}
......@@ -1737,7 +1672,7 @@ static int multipath_busy(struct dm_target *ti)
*---------------------------------------------------------------*/
static struct target_type multipath_target = {
.name = "multipath",
.version = {1, 6, 0},
.version = {1, 7, 0},
.module = THIS_MODULE,
.ctr = multipath_ctr,
.dtr = multipath_dtr,
......
drivers/md/dm-table.c
View file @ 04535d27
......@@ -945,7 +945,7 @@ bool dm_table_request_based(struct dm_table *t)
return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
}
int dm_table_alloc_md_mempools(struct dm_table *t)
static int dm_table_alloc_md_mempools(struct dm_table *t)
{
unsigned type = dm_table_get_type(t);
unsigned per_bio_data_size = 0;
......@@ -1618,6 +1618,25 @@ struct mapped_device *dm_table_get_md(struct dm_table *t)
}
EXPORT_SYMBOL(dm_table_get_md);
void dm_table_run_md_queue_async(struct dm_table *t)
{
struct mapped_device *md;
struct request_queue *queue;
unsigned long flags;
if (!dm_table_request_based(t))
return;
md = dm_table_get_md(t);
queue = dm_get_md_queue(md);
if (queue) {
spin_lock_irqsave(queue->queue_lock, flags);
blk_run_queue_async(queue);
spin_unlock_irqrestore(queue->queue_lock, flags);
}
}
EXPORT_SYMBOL(dm_table_run_md_queue_async);
static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
......
drivers/md/dm-thin-metadata.c
View file @ 04535d27
......@@ -192,6 +192,13 @@ struct dm_pool_metadata {
* operation possible in this state is the closing of the device.
*/
bool fail_io:1;
/*
* Reading the space map roots can fail, so we read it into these
* buffers before the superblock is locked and updated.
*/
__u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
};
struct dm_thin_device {
......@@ -431,26 +438,53 @@ static void __setup_btree_details(struct dm_pool_metadata *pmd)
pmd->details_info.value_type.equal = NULL;
}
static int save_sm_roots(struct dm_pool_metadata *pmd)
{
int r;
size_t len;
r = dm_sm_root_size(pmd->metadata_sm, &len);
if (r < 0)
return r;
r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
if (r < 0)
return r;
r = dm_sm_root_size(pmd->data_sm, &len);
if (r < 0)
return r;
return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
}
static void copy_sm_roots(struct dm_pool_metadata *pmd,
struct thin_disk_superblock *disk)
{
memcpy(&disk->metadata_space_map_root,
&pmd->metadata_space_map_root,
sizeof(pmd->metadata_space_map_root));
memcpy(&disk->data_space_map_root,
&pmd->data_space_map_root,
sizeof(pmd->data_space_map_root));
}
static int __write_initial_superblock(struct dm_pool_metadata *pmd)
{
int r;
struct dm_block *sblock;
size_t metadata_len, data_len;
struct thin_disk_superblock *disk_super;
sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT;
if (bdev_size > THIN_METADATA_MAX_SECTORS)
bdev_size = THIN_METADATA_MAX_SECTORS;
r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
if (r < 0)
return r;
r = dm_sm_root_size(pmd->data_sm, &data_len);
r = dm_sm_commit(pmd->data_sm);
if (r < 0)
return r;
r = dm_sm_commit(pmd->data_sm);
r = save_sm_roots(pmd);
if (r < 0)
return r;
......@@ -471,15 +505,7 @@ static int __write_initial_superblock(struct dm_pool_metadata *pmd)
disk_super->trans_id = 0;
disk_super->held_root = 0;
r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
metadata_len);
if (r < 0)
goto bad_locked;
r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
data_len);
if (r < 0)
goto bad_locked;
copy_sm_roots(pmd, disk_super);
disk_super->data_mapping_root = cpu_to_le64(pmd->root);
disk_super->device_details_root = cpu_to_le64(pmd->details_root);
......@@ -488,10 +514,6 @@ static int __write_initial_superblock(struct dm_pool_metadata *pmd)
disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
return dm_tm_commit(pmd->tm, sblock);
bad_locked:
dm_bm_unlock(sblock);
return r;
}
static int __format_metadata(struct dm_pool_metadata *pmd)
......@@ -769,6 +791,10 @@ static int __commit_transaction(struct dm_pool_metadata *pmd)
if (r < 0)
return r;
r = save_sm_roots(pmd);
if (r < 0)
return r;
r = superblock_lock(pmd, &sblock);
if (r)
return r;
......@@ -780,21 +806,9 @@ static int __commit_transaction(struct dm_pool_metadata *pmd)
disk_super->trans_id = cpu_to_le64(pmd->trans_id);
disk_super->flags = cpu_to_le32(pmd->flags);
r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
metadata_len);
if (r < 0)
goto out_locked;
r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
data_len);
if (r < 0)
goto out_locked;
copy_sm_roots(pmd, disk_super);
return dm_tm_commit(pmd->tm, sblock);
out_locked:
dm_bm_unlock(sblock);
return r;
}
struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
......
drivers/md/dm-thin.c
View file @ 04535d27
......@@ -12,9 +12,11 @@
#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
#include <linux/list.h>
#include <linux/rculist.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/rbtree.h>
#define DM_MSG_PREFIX "thin"
......@@ -178,12 +180,10 @@ struct pool {
unsigned ref_count;
spinlock_t lock;
struct bio_list deferred_bios;
struct bio_list deferred_flush_bios;
struct list_head prepared_mappings;
struct list_head prepared_discards;
struct bio_list retry_on_resume_list;
struct list_head active_thins;
struct dm_deferred_set *shared_read_ds;
struct dm_deferred_set *all_io_ds;
......@@ -220,6 +220,7 @@ struct pool_c {
* Target context for a thin.
*/
struct thin_c {
struct list_head list;
struct dm_dev *pool_dev;
struct dm_dev *origin_dev;
dm_thin_id dev_id;
......@@ -227,6 +228,10 @@ struct thin_c {
struct pool *pool;
struct dm_thin_device *td;
bool requeue_mode:1;
spinlock_t lock;
struct bio_list deferred_bio_list;
struct bio_list retry_on_resume_list;
struct rb_root sort_bio_list; /* sorted list of deferred bios */
};
/*----------------------------------------------------------------*/
......@@ -287,9 +292,9 @@ static void cell_defer_no_holder_no_free(struct thin_c *tc,
struct pool *pool = tc->pool;
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags);
dm_cell_release_no_holder(pool->prison, cell, &pool->deferred_bios);
spin_unlock_irqrestore(&pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
dm_cell_release_no_holder(pool->prison, cell, &tc->deferred_bio_list);
spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
......@@ -368,6 +373,7 @@ struct dm_thin_endio_hook {
struct dm_deferred_entry *shared_read_entry;
struct dm_deferred_entry *all_io_entry;
struct dm_thin_new_mapping *overwrite_mapping;
struct rb_node rb_node;
};
static void requeue_bio_list(struct thin_c *tc, struct bio_list *master)
......@@ -378,30 +384,22 @@ static void requeue_bio_list(struct thin_c *tc, struct bio_list *master)
bio_list_init(&bios);
spin_lock_irqsave(&tc->pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
bio_list_merge(&bios, master);
bio_list_init(master);
spin_unlock_irqrestore(&tc->pool->lock, flags);
spin_unlock_irqrestore(&tc->lock, flags);
while ((bio = bio_list_pop(&bios))) {
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
if (h->tc == tc)
while ((bio = bio_list_pop(&bios)))
bio_endio(bio, DM_ENDIO_REQUEUE);
else
bio_list_add(master, bio);
}
}
static void requeue_io(struct thin_c *tc)
{
struct pool *pool = tc->pool;
requeue_bio_list(tc, &pool->deferred_bios);
requeue_bio_list(tc, &pool->retry_on_resume_list);
requeue_bio_list(tc, &tc->deferred_bio_list);
requeue_bio_list(tc, &tc->retry_on_resume_list);
}
static void error_retry_list(struct pool *pool)
static void error_thin_retry_list(struct thin_c *tc)
{
struct bio *bio;
unsigned long flags;
......@@ -409,15 +407,25 @@ static void error_retry_list(struct pool *pool)
bio_list_init(&bios);
spin_lock_irqsave(&pool->lock, flags);
bio_list_merge(&bios, &pool->retry_on_resume_list);
bio_list_init(&pool->retry_on_resume_list);
spin_unlock_irqrestore(&pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
bio_list_merge(&bios, &tc->retry_on_resume_list);
bio_list_init(&tc->retry_on_resume_list);
spin_unlock_irqrestore(&tc->lock, flags);
while ((bio = bio_list_pop(&bios)))
bio_io_error(bio);
}
static void error_retry_list(struct pool *pool)
{
struct thin_c *tc;
rcu_read_lock();
list_for_each_entry_rcu(tc, &pool->active_thins, list)
error_thin_retry_list(tc);
rcu_read_unlock();
}
/*
* This section of code contains the logic for processing a thin device's IO.
* Much of the code depends on pool object resources (lists, workqueues, etc)
......@@ -608,9 +616,9 @@ static void cell_defer(struct thin_c *tc, struct dm_bio_prison_cell *cell)
struct pool *pool = tc->pool;
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags);
cell_release(pool, cell, &pool->deferred_bios);
spin_unlock_irqrestore(&tc->pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
cell_release(pool, cell, &tc->deferred_bio_list);
spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
......@@ -623,9 +631,9 @@ static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *c
struct pool *pool = tc->pool;
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags);
cell_release_no_holder(pool, cell, &pool->deferred_bios);
spin_unlock_irqrestore(&pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
cell_release_no_holder(pool, cell, &tc->deferred_bio_list);
spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
......@@ -1001,12 +1009,11 @@ static void retry_on_resume(struct bio *bio)
{
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
struct thin_c *tc = h->tc;
struct pool *pool = tc->pool;
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags);
bio_list_add(&pool->retry_on_resume_list, bio);
spin_unlock_irqrestore(&pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
bio_list_add(&tc->retry_on_resume_list, bio);
spin_unlock_irqrestore(&tc->lock, flags);
}
static bool should_error_unserviceable_bio(struct pool *pool)
......@@ -1363,38 +1370,111 @@ static int need_commit_due_to_time(struct pool *pool)
jiffies > pool->last_commit_jiffies + COMMIT_PERIOD;
}
static void process_deferred_bios(struct pool *pool)
#define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
#define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
static void __thin_bio_rb_add(struct thin_c *tc, struct bio *bio)
{
struct rb_node **rbp, *parent;
struct dm_thin_endio_hook *pbd;
sector_t bi_sector = bio->bi_iter.bi_sector;
rbp = &tc->sort_bio_list.rb_node;
parent = NULL;
while (*rbp) {
parent = *rbp;
pbd = thin_pbd(parent);
if (bi_sector < thin_bio(pbd)->bi_iter.bi_sector)
rbp = &(*rbp)->rb_left;
else
rbp = &(*rbp)->rb_right;
}
pbd = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
rb_link_node(&pbd->rb_node, parent, rbp);
rb_insert_color(&pbd->rb_node, &tc->sort_bio_list);
}
static void __extract_sorted_bios(struct thin_c *tc)
{
struct rb_node *node;
struct dm_thin_endio_hook *pbd;
struct bio *bio;
for (node = rb_first(&tc->sort_bio_list); node; node = rb_next(node)) {
pbd = thin_pbd(node);
bio = thin_bio(pbd);
bio_list_add(&tc->deferred_bio_list, bio);
rb_erase(&pbd->rb_node, &tc->sort_bio_list);
}
WARN_ON(!RB_EMPTY_ROOT(&tc->sort_bio_list));
}
static void __sort_thin_deferred_bios(struct thin_c *tc)
{
unsigned long flags;
struct bio *bio;
struct bio_list bios;
bio_list_init(&bios);
bio_list_merge(&bios, &tc->deferred_bio_list);
bio_list_init(&tc->deferred_bio_list);
spin_lock_irqsave(&pool->lock, flags);
bio_list_merge(&bios, &pool->deferred_bios);
bio_list_init(&pool->deferred_bios);
spin_unlock_irqrestore(&pool->lock, flags);
/* Sort deferred_bio_list using rb-tree */
while ((bio = bio_list_pop(&bios)))
__thin_bio_rb_add(tc, bio);
while ((bio = bio_list_pop(&bios))) {
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
struct thin_c *tc = h->tc;
/*
* Transfer the sorted bios in sort_bio_list back to
* deferred_bio_list to allow lockless submission of
* all bios.
*/
__extract_sorted_bios(tc);
}
static void process_thin_deferred_bios(struct thin_c *tc)
{
struct pool *pool = tc->pool;
unsigned long flags;
struct bio *bio;
struct bio_list bios;
struct blk_plug plug;
if (tc->requeue_mode) {
bio_endio(bio, DM_ENDIO_REQUEUE);
continue;
requeue_bio_list(tc, &tc->deferred_bio_list);
return;
}
bio_list_init(&bios);
spin_lock_irqsave(&tc->lock, flags);
if (bio_list_empty(&tc->deferred_bio_list)) {
spin_unlock_irqrestore(&tc->lock, flags);
return;
}
__sort_thin_deferred_bios(tc);
bio_list_merge(&bios, &tc->deferred_bio_list);
bio_list_init(&tc->deferred_bio_list);
spin_unlock_irqrestore(&tc->lock, flags);
blk_start_plug(&plug);
while ((bio = bio_list_pop(&bios))) {
/*
* If we've got no free new_mapping structs, and processing
* this bio might require one, we pause until there are some
* prepared mappings to process.
*/
if (ensure_next_mapping(pool)) {
spin_lock_irqsave(&pool->lock, flags);
bio_list_merge(&pool->deferred_bios, &bios);
spin_unlock_irqrestore(&pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
bio_list_add(&tc->deferred_bio_list, bio);
bio_list_merge(&tc->deferred_bio_list, &bios);
spin_unlock_irqrestore(&tc->lock, flags);
break;
}
......@@ -1403,6 +1483,20 @@ static void process_deferred_bios(struct pool *pool)
else
pool->process_bio(tc, bio);
}
blk_finish_plug(&plug);
}
static void process_deferred_bios(struct pool *pool)
{
unsigned long flags;
struct bio *bio;
struct bio_list bios;
struct thin_c *tc;
rcu_read_lock();
list_for_each_entry_rcu(tc, &pool->active_thins, list)
process_thin_deferred_bios(tc);
rcu_read_unlock();
/*
* If there are any deferred flush bios, we must commit
......@@ -1634,9 +1728,9 @@ static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
unsigned long flags;
struct pool *pool = tc->pool;
spin_lock_irqsave(&pool->lock, flags);
bio_list_add(&pool->deferred_bios, bio);
spin_unlock_irqrestore(&pool->lock, flags);
spin_lock_irqsave(&tc->lock, flags);
bio_list_add(&tc->deferred_bio_list, bio);
spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
......@@ -1757,26 +1851,29 @@ static int thin_bio_map(struct dm_target *ti, struct bio *bio)
static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
{
int r;
unsigned long flags;
struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
struct request_queue *q;
spin_lock_irqsave(&pt->pool->lock, flags);
r = !bio_list_empty(&pt->pool->retry_on_resume_list);
spin_unlock_irqrestore(&pt->pool->lock, flags);
if (get_pool_mode(pt->pool) == PM_OUT_OF_DATA_SPACE)
return 1;
if (!r) {
struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
r = bdi_congested(&q->backing_dev_info, bdi_bits);
}
return r;
q = bdev_get_queue(pt->data_dev->bdev);
return bdi_congested(&q->backing_dev_info, bdi_bits);
}
static void __requeue_bios(struct pool *pool)
static void requeue_bios(struct pool *pool)
{
bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
bio_list_init(&pool->retry_on_resume_list);
unsigned long flags;
struct thin_c *tc;
rcu_read_lock();
list_for_each_entry_rcu(tc, &pool->active_thins, list) {
spin_lock_irqsave(&tc->lock, flags);
bio_list_merge(&tc->deferred_bio_list, &tc->retry_on_resume_list);
bio_list_init(&tc->retry_on_resume_list);
spin_unlock_irqrestore(&tc->lock, flags);
}
rcu_read_unlock();
}
/*----------------------------------------------------------------
......@@ -1957,12 +2054,11 @@ static struct pool *pool_create(struct mapped_device *pool_md,
INIT_WORK(&pool->worker, do_worker);
INIT_DELAYED_WORK(&pool->waker, do_waker);
spin_lock_init(&pool->lock);
bio_list_init(&pool->deferred_bios);
bio_list_init(&pool->deferred_flush_bios);
INIT_LIST_HEAD(&pool->prepared_mappings);
INIT_LIST_HEAD(&pool->prepared_discards);
INIT_LIST_HEAD(&pool->active_thins);
pool->low_water_triggered = false;
bio_list_init(&pool->retry_on_resume_list);
pool->shared_read_ds = dm_deferred_set_create();
if (!pool->shared_read_ds) {
......@@ -2507,8 +2603,8 @@ static void pool_resume(struct dm_target *ti)
spin_lock_irqsave(&pool->lock, flags);
pool->low_water_triggered = false;
__requeue_bios(pool);
spin_unlock_irqrestore(&pool->lock, flags);
requeue_bios(pool);
do_waker(&pool->waker.work);
}
......@@ -2947,7 +3043,7 @@ static struct target_type pool_target = {
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
.version = {1, 11, 0},
.version = {1, 12, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,
......@@ -2968,6 +3064,12 @@ static struct target_type pool_target = {
static void thin_dtr(struct dm_target *ti)
{
struct thin_c *tc = ti->private;
unsigned long flags;
spin_lock_irqsave(&tc->pool->lock, flags);
list_del_rcu(&tc->list);
spin_unlock_irqrestore(&tc->pool->lock, flags);
synchronize_rcu();
mutex_lock(&dm_thin_pool_table.mutex);
......@@ -3014,6 +3116,10 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
r = -ENOMEM;
goto out_unlock;
}
spin_lock_init(&tc->lock);
bio_list_init(&tc->deferred_bio_list);
bio_list_init(&tc->retry_on_resume_list);
tc->sort_bio_list = RB_ROOT;
if (argc == 3) {
r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev);
......@@ -3085,6 +3191,17 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
mutex_unlock(&dm_thin_pool_table.mutex);
spin_lock(&tc->pool->lock);
list_add_tail_rcu(&tc->list, &tc->pool->active_thins);
spin_unlock(&tc->pool->lock);
/*
* This synchronize_rcu() call is needed here otherwise we risk a
* wake_worker() call finding no bios to process (because the newly
* added tc isn't yet visible). So this reduces latency since we
* aren't then dependent on the periodic commit to wake_worker().
*/
synchronize_rcu();
return 0;
bad_target_max_io_len:
......@@ -3250,7 +3367,7 @@ static int thin_iterate_devices(struct dm_target *ti,
static struct target_type thin_target = {
.name = "thin",
.version = {1, 11, 0},
.version = {1, 12, 0},
.module = THIS_MODULE,
.ctr = thin_ctr,
.dtr = thin_dtr,
......
drivers/md/dm.c
View file @ 04535d27
......@@ -94,13 +94,6 @@ struct dm_rq_clone_bio_info {
struct bio clone;
};
union map_info *dm_get_mapinfo(struct bio *bio)
{
if (bio && bio->bi_private)
return &((struct dm_target_io *)bio->bi_private)->info;
return NULL;
}
union map_info *dm_get_rq_mapinfo(struct request *rq)
{
if (rq && rq->end_io_data)
......@@ -475,6 +468,11 @@ sector_t dm_get_size(struct mapped_device *md)
return get_capacity(md->disk);
}
struct request_queue *dm_get_md_queue(struct mapped_device *md)
{
return md->queue;
}
struct dm_stats *dm_get_stats(struct mapped_device *md)
{
return &md->stats;
......@@ -760,7 +758,7 @@ static void dec_pending(struct dm_io *io, int error)
static void clone_endio(struct bio *bio, int error)
{
int r = 0;
struct dm_target_io *tio = bio->bi_private;
struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
struct dm_io *io = tio->io;
struct mapped_device *md = tio->io->md;
dm_endio_fn endio = tio->ti->type->end_io;
......@@ -794,7 +792,8 @@ static void clone_endio(struct bio *bio, int error)
*/
static void end_clone_bio(struct bio *clone, int error)
{
struct dm_rq_clone_bio_info *info = clone->bi_private;
struct dm_rq_clone_bio_info *info =
container_of(clone, struct dm_rq_clone_bio_info, clone);
struct dm_rq_target_io *tio = info->tio;
struct bio *bio = info->orig;
unsigned int nr_bytes = info->orig->bi_iter.bi_size;
......@@ -1120,7 +1119,6 @@ static void __map_bio(struct dm_target_io *tio)
struct dm_target *ti = tio->ti;
clone->bi_end_io = clone_endio;
clone->bi_private = tio;
/*
* Map the clone. If r == 0 we don't need to do
......@@ -1195,7 +1193,6 @@ static struct dm_target_io *alloc_tio(struct clone_info *ci,
tio->io = ci->io;
tio->ti = ti;
memset(&tio->info, 0, sizeof(tio->info));
tio->target_bio_nr = target_bio_nr;
return tio;
......@@ -1530,7 +1527,6 @@ static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
info->orig = bio_orig;
info->tio = tio;
bio->bi_end_io = end_clone_bio;
bio->bi_private = info;
return 0;
}
......@@ -2172,7 +2168,7 @@ static struct dm_table *__unbind(struct mapped_device *md)
return NULL;
dm_table_event_callback(map, NULL, NULL);
rcu_assign_pointer(md->map, NULL);
RCU_INIT_POINTER(md->map, NULL);
dm_sync_table(md);
return map;
......@@ -2873,8 +2869,6 @@ static const struct block_device_operations dm_blk_dops = {
.owner = THIS_MODULE
};
EXPORT_SYMBOL(dm_get_mapinfo);
/*
* module hooks
*/
......
drivers/md/dm.h
View file @ 04535d27
......@@ -73,7 +73,6 @@ unsigned dm_table_get_type(struct dm_table *t);
struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
bool dm_table_request_based(struct dm_table *t);
bool dm_table_supports_discards(struct dm_table *t);
int dm_table_alloc_md_mempools(struct dm_table *t);
void dm_table_free_md_mempools(struct dm_table *t);
struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
......@@ -189,6 +188,7 @@ int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only
int dm_cancel_deferred_remove(struct mapped_device *md);
int dm_request_based(struct mapped_device *md);
sector_t dm_get_size(struct mapped_device *md);
struct request_queue *dm_get_md_queue(struct mapped_device *md);
struct dm_stats *dm_get_stats(struct mapped_device *md);
int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
......
drivers/md/persistent-data/dm-bitset.c
View file @ 04535d27
......@@ -65,7 +65,7 @@ int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
int r;
__le64 value;
if (!info->current_index_set)
if (!info->current_index_set || !info->dirty)
return 0;
value = cpu_to_le64(info->current_bits);
......@@ -77,6 +77,8 @@ int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
return r;
info->current_index_set = false;
info->dirty = false;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_flush);
......@@ -94,6 +96,8 @@ static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
info->current_bits = le64_to_cpu(value);
info->current_index_set = true;
info->current_index = array_index;
info->dirty = false;
return 0;
}
......@@ -126,6 +130,8 @@ int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
return r;
set_bit(b, (unsigned long *) &info->current_bits);
info->dirty = true;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
......@@ -141,6 +147,8 @@ int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
return r;
clear_bit(b, (unsigned long *) &info->current_bits);
info->dirty = true;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
......
drivers/md/persistent-data/dm-bitset.h
View file @ 04535d27
......@@ -71,6 +71,7 @@ struct dm_disk_bitset {
uint64_t current_bits;
bool current_index_set:1;
bool dirty:1;
};
/*
......
drivers/md/persistent-data/dm-block-manager.c
View file @ 04535d27
......@@ -595,25 +595,14 @@ int dm_bm_unlock(struct dm_block *b)
}
EXPORT_SYMBOL_GPL(dm_bm_unlock);
int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
struct dm_block *superblock)
int dm_bm_flush(struct dm_block_manager *bm)
{
int r;
if (bm->read_only)
return -EPERM;
r = dm_bufio_write_dirty_buffers(bm->bufio);
if (unlikely(r)) {
dm_bm_unlock(superblock);
return r;
}
dm_bm_unlock(superblock);
return dm_bufio_write_dirty_buffers(bm->bufio);
}
EXPORT_SYMBOL_GPL(dm_bm_flush_and_unlock);
EXPORT_SYMBOL_GPL(dm_bm_flush);
void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b)
{
......
drivers/md/persistent-data/dm-block-manager.h
View file @ 04535d27
......@@ -105,8 +105,7 @@ int dm_bm_unlock(struct dm_block *b);
*
* This method always blocks.
*/
int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
struct dm_block *superblock);
int dm_bm_flush(struct dm_block_manager *bm);
/*
* Request data is prefetched into the cache.
......
drivers/md/persistent-data/dm-transaction-manager.c
View file @ 04535d27
......@@ -154,7 +154,7 @@ int dm_tm_pre_commit(struct dm_transaction_manager *tm)
if (r < 0)
return r;
return 0;
return dm_bm_flush(tm->bm);
}
EXPORT_SYMBOL_GPL(dm_tm_pre_commit);
......@@ -164,8 +164,9 @@ int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *root)
return -EWOULDBLOCK;
wipe_shadow_table(tm);
dm_bm_unlock(root);
return dm_bm_flush_and_unlock(tm->bm, root);
return dm_bm_flush(tm->bm);
}
EXPORT_SYMBOL_GPL(dm_tm_commit);
......
drivers/md/persistent-data/dm-transaction-manager.h
View file @ 04535d27
......@@ -38,18 +38,17 @@ struct dm_transaction_manager *dm_tm_create_non_blocking_clone(struct dm_transac
/*
* We use a 2-phase commit here.
*
* i) In the first phase the block manager is told to start flushing, and
* the changes to the space map are written to disk. You should interrogate
* your particular space map to get detail of its root node etc. to be
* included in your superblock.
* i) Make all changes for the transaction *except* for the superblock.
* Then call dm_tm_pre_commit() to flush them to disk.
*
* ii) @root will be committed last. You shouldn't use more than the
* first 512 bytes of @root if you wish the transaction to survive a power
* failure. You *must* have a write lock held on @root for both stage (i)
* and (ii). The commit will drop the write lock.
* ii) Lock your superblock. Update. Then call dm_tm_commit() which will
* unlock the superblock and flush it. No other blocks should be updated
* during this period. Care should be taken to never unlock a partially
* updated superblock; perform any operations that could fail *before* you
* take the superblock lock.
*/
int dm_tm_pre_commit(struct dm_transaction_manager *tm);
int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *root);
int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *superblock);
/*
* These methods are the only way to get hold of a writeable block.
......
include/linux/device-mapper.h
View file @ 04535d27
......@@ -23,7 +23,6 @@ typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
union map_info {
void *ptr;
unsigned long long ll;
};
/*
......@@ -291,7 +290,6 @@ struct dm_target_callbacks {
struct dm_target_io {
struct dm_io *io;
struct dm_target *ti;
union map_info info;
unsigned target_bio_nr;
struct bio clone;
};
......@@ -403,7 +401,6 @@ int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);
struct gendisk *dm_disk(struct mapped_device *md);
int dm_suspended(struct dm_target *ti);
int dm_noflush_suspending(struct dm_target *ti);
union map_info *dm_get_mapinfo(struct bio *bio);
union map_info *dm_get_rq_mapinfo(struct request *rq);
struct queue_limits *dm_get_queue_limits(struct mapped_device *md);
......@@ -465,6 +462,11 @@ struct mapped_device *dm_table_get_md(struct dm_table *t);
*/
void dm_table_event(struct dm_table *t);
/*
* Run the queue for request-based targets.
*/
void dm_table_run_md_queue_async(struct dm_table *t);
/*
* The device must be suspended before calling this method.
* Returns the previous table, which the caller must destroy.
......
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