Commit 04535d27 authored by Linus Torvalds's avatar Linus Torvalds

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
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
......@@ -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
......
......@@ -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
......
......@@ -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 */
......@@ -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 @@ out:
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;
......
......@@ -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?
......
......@@ -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)