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Add the ability to collect I/O statistics on user-defined regions of a

Browse source 
device-mapper device.  This dm-stats code required the reintroduction of
 a div64_u64_rem() helper, but as a separate method that doesn't slow
 down div64_u64() -- especially on 32-bit systems.
 
 Allow the error target to replace request-based DM devices
 (e.g. multipath) in addition to bio-based DM devices.
 
 Various other small code fixes and improvements to thin-provisioning, DM
 cache and the DM ioctl interface.
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Merge tag 'dm-3.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper updates from Mike Snitzer:
 "Add the ability to collect I/O statistics on user-defined regions of a
  device-mapper device.  This dm-stats code required the reintroduction
  of a div64_u64_rem() helper, but as a separate method that doesn't
  slow down div64_u64() -- especially on 32-bit systems.

  Allow the error target to replace request-based DM devices (e.g.
  multipath) in addition to bio-based DM devices.

  Various other small code fixes and improvements to thin-provisioning,
  DM cache and the DM ioctl interface"

* tag 'dm-3.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm stripe: silence a couple sparse warnings
  dm: add statistics support
  dm thin: always return -ENOSPC if no_free_space is set
  dm ioctl: cleanup error handling in table_load
  dm ioctl: increase granularity of type_lock when loading table
  dm ioctl: prevent rename to empty name or uuid
  dm thin: set pool read-only if breaking_sharing fails block allocation
  dm thin: prefix pool error messages with pool device name
  dm: allow error target to replace bio-based and request-based targets
  math64: New separate div64_u64_rem helper
  dm space map: optimise sm_ll_dec and sm_ll_inc
  dm btree: prefetch child nodes when walking tree for a dm_btree_del
  dm btree: use pop_frame in dm_btree_del to cleanup code
  dm cache: eliminate holes in cache structure
  dm cache: fix stacking of geometry limits
  dm thin: fix stacking of geometry limits
  dm thin: add data block size limits to Documentation
  dm cache: add data block size limits to code and Documentation
  dm cache: document metadata device is exclussive to a cache
  dm: stop using WQ_NON_REENTRANT
This commit is contained in:
Linus Torvalds 2013-09-10 13:06:15 -07:00
commit 7426d62871
25 changed files with 1621 additions and 162 deletions
Download patch file Download diff file Expand all files Collapse all files

2
drivers/md/Makefile
View file

@ -3,7 +3,7 @@
#
dm-mod-y += dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \
dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o
dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o dm-stats.o
dm-multipath-y += dm-path-selector.o dm-mpath.o
dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \
dm-snap-persistent.o

59
drivers/md/dm-cache-target.c
View file

@ -67,9 +67,11 @@ static void free_bitset(unsigned long *bits)
#define MIGRATION_COUNT_WINDOW 10
/*
* The block size of the device holding cache data must be >= 32KB
* The block size of the device holding cache data must be
* between 32KB and 1GB.
*/
#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT)
#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
/*
* FIXME: the cache is read/write for the time being.
@ -101,6 +103,8 @@ struct cache {
struct dm_target *ti;
struct dm_target_callbacks callbacks;
struct dm_cache_metadata *cmd;
/*
* Metadata is written to this device.
*/
@ -116,11 +120,6 @@ struct cache {
*/
struct dm_dev *cache_dev;
/*
* Cache features such as write-through.
*/
struct cache_features features;
/*
* Size of the origin device in _complete_ blocks and native sectors.
*/
@ -138,8 +137,6 @@ struct cache {
uint32_t sectors_per_block;
int sectors_per_block_shift;
struct dm_cache_metadata *cmd;
spinlock_t lock;
struct bio_list deferred_bios;
struct bio_list deferred_flush_bios;
@ -148,8 +145,8 @@ struct cache {
struct list_head completed_migrations;
struct list_head need_commit_migrations;
sector_t migration_threshold;
atomic_t nr_migrations;
wait_queue_head_t migration_wait;
atomic_t nr_migrations;
/*
* cache_size entries, dirty if set
@ -160,9 +157,16 @@ struct cache {
/*
* origin_blocks entries, discarded if set.
*/
uint32_t discard_block_size; /* a power of 2 times sectors per block */
dm_dblock_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
* save it and regurgitate.
*/
unsigned nr_ctr_args;
const char **ctr_args;
struct dm_kcopyd_client *copier;
struct workqueue_struct *wq;
@ -187,14 +191,12 @@ struct cache {
bool loaded_mappings:1;
bool loaded_discards:1;
struct cache_stats stats;
/*
* Rather than reconstructing the table line for the status we just
* save it and regurgitate.
* Cache features such as write-through.
*/
unsigned nr_ctr_args;
const char **ctr_args;
struct cache_features features;
struct cache_stats stats;
};
struct per_bio_data {
@ -1687,24 +1689,25 @@ static int parse_origin_dev(struct cache_args *ca, struct dm_arg_set *as,
static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
unsigned long tmp;
unsigned long block_size;
if (!at_least_one_arg(as, error))
return -EINVAL;
if (kstrtoul(dm_shift_arg(as), 10, &tmp) || !tmp ||
tmp < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
tmp & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size ||
block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
*error = "Invalid data block size";
return -EINVAL;
}
if (tmp > ca->cache_sectors) {
if (block_size > ca->cache_sectors) {
*error = "Data block size is larger than the cache device";
return -EINVAL;
}
ca->block_size = tmp;
ca->block_size = block_size;
return 0;
}
@ -2609,9 +2612,17 @@ static void set_discard_limits(struct cache *cache, struct queue_limits *limits)
static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct cache *cache = ti->private;
uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
blk_limits_io_min(limits, 0);
blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT);
/*
* If the system-determined stacked limits are compatible with the
* cache's blocksize (io_opt is a factor) do not override them.
*/
if (io_opt_sectors < cache->sectors_per_block ||
do_div(io_opt_sectors, cache->sectors_per_block)) {
blk_limits_io_min(limits, 0);
blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT);
}
set_discard_limits(cache, limits);
}

10
drivers/md/dm-crypt.c
View file

@ -1645,20 +1645,14 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
}
ret = -ENOMEM;
cc->io_queue = alloc_workqueue("kcryptd_io",
WQ_NON_REENTRANT|
WQ_MEM_RECLAIM,
1);
cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
if (!cc->io_queue) {
ti->error = "Couldn't create kcryptd io queue";
goto bad;
}
cc->crypt_queue = alloc_workqueue("kcryptd",
WQ_NON_REENTRANT|
WQ_CPU_INTENSIVE|
WQ_MEM_RECLAIM,
1);
WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
if (!cc->crypt_queue) {
ti->error = "Couldn't create kcryptd queue";
goto bad;

60
drivers/md/dm-ioctl.c
View file

@ -877,7 +877,7 @@ static int dev_rename(struct dm_ioctl *param, size_t param_size)
unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
if (new_data < param->data ||
invalid_str(new_data, (void *) param + param_size) ||
invalid_str(new_data, (void *) param + param_size) || !*new_data ||
strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
DMWARN("Invalid new mapped device name or uuid string supplied.");
return -EINVAL;
@ -1262,44 +1262,37 @@ static int table_load(struct dm_ioctl *param, size_t param_size)
r = dm_table_create(&t, get_mode(param), param->target_count, md);
if (r)
goto out;
goto err;
/* Protect md->type and md->queue against concurrent table loads. */
dm_lock_md_type(md);
r = populate_table(t, param, param_size);
if (r) {
dm_table_destroy(t);
goto out;
}
if (r)
goto err_unlock_md_type;
immutable_target_type = dm_get_immutable_target_type(md);
if (immutable_target_type &&
(immutable_target_type != dm_table_get_immutable_target_type(t))) {
DMWARN("can't replace immutable target type %s",
immutable_target_type->name);
dm_table_destroy(t);
r = -EINVAL;
goto out;
goto err_unlock_md_type;
}
/* Protect md->type and md->queue against concurrent table loads. */
dm_lock_md_type(md);
if (dm_get_md_type(md) == DM_TYPE_NONE)
/* Initial table load: acquire type of table. */
dm_set_md_type(md, dm_table_get_type(t));
else if (dm_get_md_type(md) != dm_table_get_type(t)) {
DMWARN("can't change device type after initial table load.");
dm_table_destroy(t);
dm_unlock_md_type(md);
r = -EINVAL;
goto out;
goto err_unlock_md_type;
}
/* setup md->queue to reflect md's type (may block) */
r = dm_setup_md_queue(md);
if (r) {
DMWARN("unable to set up device queue for new table.");
dm_table_destroy(t);
dm_unlock_md_type(md);
goto out;
goto err_unlock_md_type;
}
dm_unlock_md_type(md);
@ -1309,9 +1302,8 @@ static int table_load(struct dm_ioctl *param, size_t param_size)
if (!hc || hc->md != md) {
DMWARN("device has been removed from the dev hash table.");
up_write(&_hash_lock);
dm_table_destroy(t);
r = -ENXIO;
goto out;
goto err_destroy_table;
}
if (hc->new_map)
@ -1322,7 +1314,6 @@ static int table_load(struct dm_ioctl *param, size_t param_size)
param->flags |= DM_INACTIVE_PRESENT_FLAG;
__dev_status(md, param);
out:
if (old_map) {
dm_sync_table(md);
dm_table_destroy(old_map);
@ -1330,6 +1321,15 @@ out:
dm_put(md);
return 0;
err_unlock_md_type:
dm_unlock_md_type(md);
err_destroy_table:
dm_table_destroy(t);
err:
dm_put(md);
return r;
}
@ -1455,20 +1455,26 @@ static int table_status(struct dm_ioctl *param, size_t param_size)
return 0;
}
static bool buffer_test_overflow(char *result, unsigned maxlen)
{
return !maxlen || strlen(result) + 1 >= maxlen;
}
/*
* Process device-mapper dependent messages.
* Process device-mapper dependent messages. Messages prefixed with '@'
* are processed by the DM core. All others are delivered to the target.
* Returns a number <= 1 if message was processed by device mapper.
* Returns 2 if message should be delivered to the target.
*/
static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
char *result, unsigned maxlen)
{
return 2;
int r;
if (**argv != '@')
return 2; /* no '@' prefix, deliver to target */
r = dm_stats_message(md, argc, argv, result, maxlen);
if (r < 2)
return r;
DMERR("Unsupported message sent to DM core: %s", argv[0]);
return -EINVAL;
}
/*
@ -1542,7 +1548,7 @@ static int target_message(struct dm_ioctl *param, size_t param_size)
if (r == 1) {
param->flags |= DM_DATA_OUT_FLAG;
if (buffer_test_overflow(result, maxlen))
if (dm_message_test_buffer_overflow(result, maxlen))
param->flags |= DM_BUFFER_FULL_FLAG;
else
param->data_size = param->data_start + strlen(result) + 1;

3
drivers/md/dm-kcopyd.c
View file

@ -833,8 +833,7 @@ struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *thro
goto bad_slab;
INIT_WORK(&kc->kcopyd_work, do_work);
kc->kcopyd_wq = alloc_workqueue("kcopyd",
WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0);
kc->kcopyd_wq = alloc_workqueue("kcopyd", WQ_MEM_RECLAIM, 0);
if (!kc->kcopyd_wq)
goto bad_workqueue;

3
drivers/md/dm-raid1.c
View file

@ -1080,8 +1080,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ti->per_bio_data_size = sizeof(struct dm_raid1_bio_record);
ti->discard_zeroes_data_unsupported = true;
ms->kmirrord_wq = alloc_workqueue("kmirrord",
WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0);
ms->kmirrord_wq = alloc_workqueue("kmirrord", WQ_MEM_RECLAIM, 0);
if (!ms->kmirrord_wq) {
DMERR("couldn't start kmirrord");
r = -ENOMEM;

969
drivers/md/dm-stats.c Normal file
View file

@ -0,0 +1,969 @@
#include <linux/errno.h>
#include <linux/numa.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/threads.h>
#include <linux/preempt.h>
#include <linux/irqflags.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/device-mapper.h>
#include "dm.h"
#include "dm-stats.h"
#define DM_MSG_PREFIX "stats"
static int dm_stat_need_rcu_barrier;
/*
* Using 64-bit values to avoid overflow (which is a
* problem that block/genhd.c's IO accounting has).
*/
struct dm_stat_percpu {
unsigned long long sectors[2];
unsigned long long ios[2];
unsigned long long merges[2];
unsigned long long ticks[2];
unsigned long long io_ticks[2];
unsigned long long io_ticks_total;
unsigned long long time_in_queue;
};
struct dm_stat_shared {
atomic_t in_flight[2];
unsigned long stamp;
struct dm_stat_percpu tmp;
};
struct dm_stat {
struct list_head list_entry;
int id;
size_t n_entries;
sector_t start;
sector_t end;
sector_t step;
const char *program_id;
const char *aux_data;
struct rcu_head rcu_head;
size_t shared_alloc_size;
size_t percpu_alloc_size;
struct dm_stat_percpu *stat_percpu[NR_CPUS];
struct dm_stat_shared stat_shared[0];
};
struct dm_stats_last_position {
sector_t last_sector;
unsigned last_rw;
};
/*
* A typo on the command line could possibly make the kernel run out of memory
* and crash. To prevent the crash we account all used memory. We fail if we
* exhaust 1/4 of all memory or 1/2 of vmalloc space.
*/
#define DM_STATS_MEMORY_FACTOR 4
#define DM_STATS_VMALLOC_FACTOR 2
static DEFINE_SPINLOCK(shared_memory_lock);
static unsigned long shared_memory_amount;
static bool __check_shared_memory(size_t alloc_size)
{
size_t a;
a = shared_memory_amount + alloc_size;
if (a < shared_memory_amount)
return false;
if (a >> PAGE_SHIFT > totalram_pages / DM_STATS_MEMORY_FACTOR)
return false;
#ifdef CONFIG_MMU
if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR)
return false;
#endif
return true;
}
static bool check_shared_memory(size_t alloc_size)
{
bool ret;
spin_lock_irq(&shared_memory_lock);
ret = __check_shared_memory(alloc_size);
spin_unlock_irq(&shared_memory_lock);
return ret;
}
static bool claim_shared_memory(size_t alloc_size)
{
spin_lock_irq(&shared_memory_lock);
if (!__check_shared_memory(alloc_size)) {
spin_unlock_irq(&shared_memory_lock);
return false;
}
shared_memory_amount += alloc_size;
spin_unlock_irq(&shared_memory_lock);
return true;
}
static void free_shared_memory(size_t alloc_size)
{
unsigned long flags;
spin_lock_irqsave(&shared_memory_lock, flags);
if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) {
spin_unlock_irqrestore(&shared_memory_lock, flags);
DMCRIT("Memory usage accounting bug.");
return;
}
shared_memory_amount -= alloc_size;
spin_unlock_irqrestore(&shared_memory_lock, flags);
}
static void *dm_kvzalloc(size_t alloc_size, int node)
{
void *p;
if (!claim_shared_memory(alloc_size))
return NULL;
if (alloc_size <= KMALLOC_MAX_SIZE) {
p = kzalloc_node(alloc_size, GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN, node);
if (p)
return p;
}
p = vzalloc_node(alloc_size, node);
if (p)
return p;
free_shared_memory(alloc_size);
return NULL;
}
static void dm_kvfree(void *ptr, size_t alloc_size)
{
if (!ptr)
return;
free_shared_memory(alloc_size);
if (is_vmalloc_addr(ptr))
vfree(ptr);
else
kfree(ptr);
}
static void dm_stat_free(struct rcu_head *head)
{
int cpu;
struct dm_stat *s = container_of(head, struct dm_stat, rcu_head);
kfree(s->program_id);
kfree(s->aux_data);
for_each_possible_cpu(cpu)
dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
dm_kvfree(s, s->shared_alloc_size);
}
static int dm_stat_in_flight(struct dm_stat_shared *shared)
{
return atomic_read(&shared->in_flight[READ]) +
atomic_read(&shared->in_flight[WRITE]);
}
void dm_stats_init(struct dm_stats *stats)
{
int cpu;
struct dm_stats_last_position *last;
mutex_init(&stats->mutex);
INIT_LIST_HEAD(&stats->list);
stats->last = alloc_percpu(struct dm_stats_last_position);
for_each_possible_cpu(cpu) {
last = per_cpu_ptr(stats->last, cpu);
last->last_sector = (sector_t)ULLONG_MAX;
last->last_rw = UINT_MAX;
}
}
void dm_stats_cleanup(struct dm_stats *stats)
{
size_t ni;
struct dm_stat *s;
struct dm_stat_shared *shared;
while (!list_empty(&stats->list)) {
s = container_of(stats->list.next, struct dm_stat, list_entry);
list_del(&s->list_entry);
for (ni = 0; ni < s->n_entries; ni++) {
shared = &s->stat_shared[ni];
if (WARN_ON(dm_stat_in_flight(shared))) {
DMCRIT("leaked in-flight counter at index %lu "
"(start %llu, end %llu, step %llu): reads %d, writes %d",
(unsigned long)ni,
(unsigned long long)s->start,
(unsigned long long)s->end,
(unsigned long long)s->step,
atomic_read(&shared->in_flight[READ]),
atomic_read(&shared->in_flight[WRITE]));
}
}
dm_stat_free(&s->rcu_head);
}
free_percpu(stats->last);
}
static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
sector_t step, const char *program_id, const char *aux_data,
void (*suspend_callback)(struct mapped_device *),
void (*resume_callback)(struct mapped_device *),
struct mapped_device *md)
{
struct list_head *l;
struct dm_stat *s, *tmp_s;
sector_t n_entries;
size_t ni;
size_t shared_alloc_size;
size_t percpu_alloc_size;
struct dm_stat_percpu *p;
int cpu;
int ret_id;
int r;
if (end < start || !step)
return -EINVAL;
n_entries = end - start;
if (dm_sector_div64(n_entries, step))
n_entries++;
if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1))
return -EOVERFLOW;
shared_alloc_size = sizeof(struct dm_stat) + (size_t)n_entries * sizeof(struct dm_stat_shared);
if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries)
return -EOVERFLOW;
percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu);
if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries)
return -EOVERFLOW;
if (!check_shared_memory(shared_alloc_size + num_possible_cpus() * percpu_alloc_size))
return -ENOMEM;
s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE);
if (!s)
return -ENOMEM;
s->n_entries = n_entries;
s->start = start;
s->end = end;
s->step = step;
s->shared_alloc_size = shared_alloc_size;
s->percpu_alloc_size = percpu_alloc_size;
s->program_id = kstrdup(program_id, GFP_KERNEL);
if (!s->program_id) {
r = -ENOMEM;
goto out;
}
s->aux_data = kstrdup(aux_data, GFP_KERNEL);
if (!s->aux_data) {
r = -ENOMEM;
goto out;
}
for (ni = 0; ni < n_entries; ni++) {
atomic_set(&s->stat_shared[ni].in_flight[READ], 0);
atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0);
}
for_each_possible_cpu(cpu) {
p = dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu));
if (!p) {
r = -ENOMEM;
goto out;
}
s->stat_percpu[cpu] = p;
}
/*
* Suspend/resume to make sure there is no i/o in flight,
* so that newly created statistics will be exact.
*
* (note: we couldn't suspend earlier because we must not
* allocate memory while suspended)
*/
suspend_callback(md);
mutex_lock(&stats->mutex);
s->id = 0;
list_for_each(l, &stats->list) {
tmp_s = container_of(l, struct dm_stat, list_entry);
if (WARN_ON(tmp_s->id < s->id)) {
r = -EINVAL;
goto out_unlock_resume;
}
if (tmp_s->id > s->id)
break;
if (unlikely(s->id == INT_MAX)) {
r = -ENFILE;
goto out_unlock_resume;
}
s->id++;
}
ret_id = s->id;
list_add_tail_rcu(&s->list_entry, l);
mutex_unlock(&stats->mutex);
resume_callback(md);
return ret_id;
out_unlock_resume:
mutex_unlock(&stats->mutex);
resume_callback(md);
out:
dm_stat_free(&s->rcu_head);
return r;
}
static struct dm_stat *__dm_stats_find(struct dm_stats *stats, int id)
{
struct dm_stat *s;
list_for_each_entry(s, &stats->list, list_entry) {
if (s->id > id)
break;
if (s->id == id)
return s;
}
return NULL;
}
static int dm_stats_delete(struct dm_stats *stats, int id)
{
struct dm_stat *s;
int cpu;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
list_del_rcu(&s->list_entry);
mutex_unlock(&stats->mutex);
/*
* vfree can't be called from RCU callback
*/
for_each_possible_cpu(cpu)
if (is_vmalloc_addr(s->stat_percpu))
goto do_sync_free;
if (is_vmalloc_addr(s)) {
do_sync_free:
synchronize_rcu_expedited();
dm_stat_free(&s->rcu_head);
} else {
ACCESS_ONCE(dm_stat_need_rcu_barrier) = 1;
call_rcu(&s->rcu_head, dm_stat_free);
}
return 0;
}
static int dm_stats_list(struct dm_stats *stats, const char *program,
char *result, unsigned maxlen)
{
struct dm_stat *s;
sector_t len;
unsigned sz = 0;
/*
* Output format:
* <region_id>: <start_sector>+<length> <step> <program_id> <aux_data>
*/
mutex_lock(&stats->mutex);
list_for_each_entry(s, &stats->list, list_entry) {
if (!program || !strcmp(program, s->program_id)) {
len = s->end - s->start;
DMEMIT("%d: %llu+%llu %llu %s %s\n", s->id,
(unsigned long long)s->start,
(unsigned long long)len,
(unsigned long long)s->step,
s->program_id,
s->aux_data);
}
}
mutex_unlock(&stats->mutex);
return 1;
}
static void dm_stat_round(struct dm_stat_shared *shared, struct dm_stat_percpu *p)
{
/*
* This is racy, but so is part_round_stats_single.
*/
unsigned long now = jiffies;
unsigned in_flight_read;
unsigned in_flight_write;
unsigned long difference = now - shared->stamp;
if (!difference)
return;
in_flight_read = (unsigned)atomic_read(&shared->in_flight[READ]);
in_flight_write = (unsigned)atomic_read(&shared->in_flight[WRITE]);
if (in_flight_read)
p->io_ticks[READ] += difference;
if (in_flight_write)
p->io_ticks[WRITE] += difference;
if (in_flight_read + in_flight_write) {
p->io_ticks_total += difference;
p->time_in_queue += (in_flight_read + in_flight_write) * difference;
}
shared->stamp = now;
}
static void dm_stat_for_entry(struct dm_stat *s, size_t entry,
unsigned long bi_rw, sector_t len, bool merged,
bool end, unsigned long duration)
{
unsigned long idx = bi_rw & REQ_WRITE;
struct dm_stat_shared *shared = &s->stat_shared[entry];
struct dm_stat_percpu *p;
/*
* For strict correctness we should use local_irq_disable/enable
* instead of preempt_disable/enable.
*
* This is racy if the driver finishes bios from non-interrupt
* context as well as from interrupt context or from more different
* interrupts.
*
* However, the race only results in not counting some events,
* so it is acceptable.
*
* part_stat_lock()/part_stat_unlock() have this race too.
*/
preempt_disable();
p = &s->stat_percpu[smp_processor_id()][entry];
if (!end) {
dm_stat_round(shared, p);
atomic_inc(&shared->in_flight[idx]);
} else {
dm_stat_round(shared, p);
atomic_dec(&shared->in_flight[idx]);
p->sectors[idx] += len;
p->ios[idx] += 1;
p->merges[idx] += merged;
p->ticks[idx] += duration;
}
preempt_enable();
}
static void __dm_stat_bio(struct dm_stat *s, unsigned long bi_rw,
sector_t bi_sector, sector_t end_sector,
bool end, unsigned long duration,
struct dm_stats_aux *stats_aux)
{
sector_t rel_sector, offset, todo, fragment_len;
size_t entry;
if (end_sector <= s->start || bi_sector >= s->end)
return;
if (unlikely(bi_sector < s->start)) {
rel_sector = 0;
todo = end_sector - s->start;
} else {
rel_sector = bi_sector - s->start;
todo = end_sector - bi_sector;
}
if (unlikely(end_sector > s->end))
todo -= (end_sector - s->end);
offset = dm_sector_div64(rel_sector, s->step);
entry = rel_sector;
do {
if (WARN_ON_ONCE(entry >= s->n_entries)) {
DMCRIT("Invalid area access in region id %d", s->id);
return;
}
fragment_len = todo;
if (fragment_len > s->step - offset)
fragment_len = s->step - offset;
dm_stat_for_entry(s, entry, bi_rw, fragment_len,
stats_aux->merged, end, duration);
todo -= fragment_len;
entry++;
offset = 0;
} while (unlikely(todo != 0));
}
void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
sector_t bi_sector, unsigned bi_sectors, bool end,
unsigned long duration, struct dm_stats_aux *stats_aux)
{
struct dm_stat *s;
sector_t end_sector;
struct dm_stats_last_position *last;
if (unlikely(!bi_sectors))
return;
end_sector = bi_sector + bi_sectors;
if (!end) {
/*
* A race condition can at worst result in the merged flag being
* misrepresented, so we don't have to disable preemption here.
*/
last = __this_cpu_ptr(stats->last);
stats_aux->merged =
(bi_sector == (ACCESS_ONCE(last->last_sector) &&
((bi_rw & (REQ_WRITE | REQ_DISCARD)) ==
(ACCESS_ONCE(last->last_rw) & (REQ_WRITE | REQ_DISCARD)))
));
ACCESS_ONCE(last->last_sector) = end_sector;
ACCESS_ONCE(last->last_rw) = bi_rw;
}
rcu_read_lock();
list_for_each_entry_rcu(s, &stats->list, list_entry)
__dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration, stats_aux);
rcu_read_unlock();
}
static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared,
struct dm_stat *s, size_t x)
{
int cpu;
struct dm_stat_percpu *p;
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
dm_stat_round(shared, p);
local_irq_enable();
memset(&shared->tmp, 0, sizeof(shared->tmp));
for_each_possible_cpu(cpu) {
p = &s->stat_percpu[cpu][x];
shared->tmp.sectors[READ] += ACCESS_ONCE(p->sectors[READ]);
shared->tmp.sectors[WRITE] += ACCESS_ONCE(p->sectors[WRITE]);
shared->tmp.ios[READ] += ACCESS_ONCE(p->ios[READ]);
shared->tmp.ios[WRITE] += ACCESS_ONCE(p->ios[WRITE]);
shared->tmp.merges[READ] += ACCESS_ONCE(p->merges[READ]);
shared->tmp.merges[WRITE] += ACCESS_ONCE(p->merges[WRITE]);
shared->tmp.ticks[READ] += ACCESS_ONCE(p->ticks[READ]);
shared->tmp.ticks[WRITE] += ACCESS_ONCE(p->ticks[WRITE]);
shared->tmp.io_ticks[READ] += ACCESS_ONCE(p->io_ticks[READ]);
shared->tmp.io_ticks[WRITE] += ACCESS_ONCE(p->io_ticks[WRITE]);
shared->tmp.io_ticks_total += ACCESS_ONCE(p->io_ticks_total);
shared->tmp.time_in_queue += ACCESS_ONCE(p->time_in_queue);
}
}
static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end,
bool init_tmp_percpu_totals)
{
size_t x;
struct dm_stat_shared *shared;
struct dm_stat_percpu *p;
for (x = idx_start; x < idx_end; x++) {
shared = &s->stat_shared[x];
if (init_tmp_percpu_totals)
__dm_stat_init_temporary_percpu_totals(shared, s, x);
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
p->sectors[READ] -= shared->tmp.sectors[READ];
p->sectors[WRITE] -= shared->tmp.sectors[WRITE];
p->ios[READ] -= shared->tmp.ios[READ];
p->ios[WRITE] -= shared->tmp.ios[WRITE];
p->merges[READ] -= shared->tmp.merges[READ];
p->merges[WRITE] -= shared->tmp.merges[WRITE];
p->ticks[READ] -= shared->tmp.ticks[READ];
p->ticks[WRITE] -= shared->tmp.ticks[WRITE];
p->io_ticks[READ] -= shared->tmp.io_ticks[READ];
p->io_ticks[WRITE] -= shared->tmp.io_ticks[WRITE];
p->io_ticks_total -= shared->tmp.io_ticks_total;
p->time_in_queue -= shared->tmp.time_in_queue;
local_irq_enable();
}
}
static int dm_stats_clear(struct dm_stats *stats, int id)
{
struct dm_stat *s;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
__dm_stat_clear(s, 0, s->n_entries, true);
mutex_unlock(&stats->mutex);
return 1;
}
/*
* This is like jiffies_to_msec, but works for 64-bit values.
*/
static unsigned long long dm_jiffies_to_msec64(unsigned long long j)
{
unsigned long long result = 0;
unsigned mult;
if (j)
result = jiffies_to_msecs(j & 0x3fffff);
if (j >= 1 << 22) {
mult = jiffies_to_msecs(1 << 22);
result += (unsigned long long)mult * (unsigned long long)jiffies_to_msecs((j >> 22) & 0x3fffff);
}
if (j >= 1ULL << 44)
result += (unsigned long long)mult * (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j >> 44);
return result;
}
static int dm_stats_print(struct dm_stats *stats, int id,
size_t idx_start, size_t idx_len,
bool clear, char *result, unsigned maxlen)
{
unsigned sz = 0;
struct dm_stat *s;
size_t x;
sector_t start, end, step;
size_t idx_end;
struct dm_stat_shared *shared;
/*
* Output format:
* <start_sector>+<length> counters
*/
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
idx_end = idx_start + idx_len;
if (idx_end < idx_start ||
idx_end > s->n_entries)
idx_end = s->n_entries;
if (idx_start > idx_end)
idx_start = idx_end;
step = s->step;
start = s->start + (step * idx_start);
for (x = idx_start; x < idx_end; x++, start = end) {
shared = &s->stat_shared[x];
end = start + step;
if (unlikely(end > s->end))
end = s->end;
__dm_stat_init_temporary_percpu_totals(shared, s, x);
DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu\n",
(unsigned long long)start,
(unsigned long long)step,
shared->tmp.ios[READ],
shared->tmp.merges[READ],
shared->tmp.sectors[READ],
dm_jiffies_to_msec64(shared->tmp.ticks[READ]),
shared->tmp.ios[WRITE],
shared->tmp.merges[WRITE],
shared->tmp.sectors[WRITE],
dm_jiffies_to_msec64(shared->tmp.ticks[WRITE]),
dm_stat_in_flight(shared),
dm_jiffies_to_msec64(shared->tmp.io_ticks_total),
dm_jiffies_to_msec64(shared->tmp.time_in_queue),
dm_jiffies_to_msec64(shared->tmp.io_ticks[READ]),
dm_jiffies_to_msec64(shared->tmp.io_ticks[WRITE]));
if (unlikely(sz + 1 >= maxlen))
goto buffer_overflow;
}
if (clear)
__dm_stat_clear(s, idx_start, idx_end, false);
buffer_overflow:
mutex_unlock(&stats->mutex);
return 1;
}
static int dm_stats_set_aux(struct dm_stats *stats, int id, const char *aux_data)
{
struct dm_stat *s;
const char *new_aux_data;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
new_aux_data = kstrdup(aux_data, GFP_KERNEL);
if (!new_aux_data) {
mutex_unlock(&stats->mutex);
return -ENOMEM;
}
kfree(s->aux_data);
s->aux_data = new_aux_data;
mutex_unlock(&stats->mutex);
return 0;
}
static int message_stats_create(struct mapped_device *md,
unsigned argc, char **argv,
char *result, unsigned maxlen)
{
int id;
char dummy;
unsigned long long start, end, len, step;
unsigned divisor;
const char *program_id, *aux_data;
/*
* Input format:
* <range> <step> [<program_id> [<aux_data>]]
*/
if (argc < 3 || argc > 5)
return -EINVAL;
if (!strcmp(argv[1], "-")) {
start = 0;
len = dm_get_size(md);
if (!len)
len = 1;
} else if (sscanf(argv[1], "%llu+%llu%c", &start, &len, &dummy) != 2 ||
start != (sector_t)start || len != (sector_t)len)
return -EINVAL;
end = start + len;
if (start >= end)
return -EINVAL;
if (sscanf(argv[2], "/%u%c", &divisor, &dummy) == 1) {
step = end - start;
if (do_div(step, divisor))
step++;
if (!step)
step = 1;
} else if (sscanf(argv[2], "%llu%c", &step, &dummy) != 1 ||
step != (sector_t)step || !step)
return -EINVAL;
program_id = "-";
aux_data = "-";
if (argc > 3)
program_id = argv[3];
if (argc > 4)
aux_data = argv[4];
/*
* If a buffer overflow happens after we created the region,
* it's too late (the userspace would retry with a larger
* buffer, but the region id that caused the overflow is already
* leaked). So we must detect buffer overflow in advance.
*/
snprintf(result, maxlen, "%d", INT_MAX);
if (dm_message_test_buffer_overflow(result, maxlen))
return 1;
id = dm_stats_create(dm_get_stats(md), start, end, step, program_id, aux_data,
dm_internal_suspend, dm_internal_resume, md);
if (id < 0)
return id;
snprintf(result, maxlen, "%d", id);
return 1;
}
static int message_stats_delete(struct mapped_device *md,
unsigned argc, char **argv)
{
int id;
char dummy;
if (argc != 2)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_delete(dm_get_stats(md), id);
}
static int message_stats_clear(struct mapped_device *md,
unsigned argc, char **argv)
{
int id;
char dummy;
if (argc != 2)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_clear(dm_get_stats(md), id);
}
static int message_stats_list(struct mapped_device *md,
unsigned argc, char **argv,
char *result, unsigned maxlen)
{
int r;
const char *program = NULL;
if (argc < 1 || argc > 2)
return -EINVAL;
if (argc > 1) {
program = kstrdup(argv[1], GFP_KERNEL);
if (!program)
return -ENOMEM;
}
r = dm_stats_list(dm_get_stats(md), program, result, maxlen);
kfree(program);
return r;
}
static int message_stats_print(struct mapped_device *md,
unsigned argc, char **argv, bool clear,
char *result, unsigned maxlen)
{
int id;
char dummy;
unsigned long idx_start = 0, idx_len = ULONG_MAX;
if (argc != 2 && argc != 4)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
if (argc > 3) {
if (strcmp(argv[2], "-") &&
sscanf(argv[2], "%lu%c", &idx_start, &dummy) != 1)
return -EINVAL;
if (strcmp(argv[3], "-") &&
sscanf(argv[3], "%lu%c", &idx_len, &dummy) != 1)
return -EINVAL;
}
return dm_stats_print(dm_get_stats(md), id, idx_start, idx_len, clear,
result, maxlen);
}
static int message_stats_set_aux(struct mapped_device *md,
unsigned argc, char **argv)
{
int id;
char dummy;
if (argc != 3)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_set_aux(dm_get_stats(md), id, argv[2]);
}
int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
char *result, unsigned maxlen)
{
int r;
if (dm_request_based(md)) {
DMWARN("Statistics are only supported for bio-based devices");
return -EOPNOTSUPP;
}
/* All messages here must start with '@' */
if (!strcasecmp(argv[0], "@stats_create"))
r = message_stats_create(md, argc, argv, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_delete"))
r = message_stats_delete(md, argc, argv);
else if (!strcasecmp(argv[0], "@stats_clear"))
r = message_stats_clear(md, argc, argv);
else if (!strcasecmp(argv[0], "@stats_list"))
r = message_stats_list(md, argc, argv, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_print"))
r = message_stats_print(md, argc, argv, false, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_print_clear"))
r = message_stats_print(md, argc, argv, true, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_set_aux"))
r = message_stats_set_aux(md, argc, argv);
else
return 2; /* this wasn't a stats message */
if (r == -EINVAL)
DMWARN("Invalid parameters for message %s", argv[0]);
return r;
}
int __init dm_statistics_init(void)
{
dm_stat_need_rcu_barrier = 0;
return 0;
}
void dm_statistics_exit(void)
{
if (dm_stat_need_rcu_barrier)
rcu_barrier();
if (WARN_ON(shared_memory_amount))
DMCRIT("shared_memory_amount leaked: %lu", shared_memory_amount);
}
module_param_named(stats_current_allocated_bytes, shared_memory_amount, ulong, S_IRUGO);
MODULE_PARM_DESC(stats_current_allocated_bytes, "Memory currently used by statistics");

40
drivers/md/dm-stats.h Normal file
View file

@ -0,0 +1,40 @@
#ifndef DM_STATS_H
#define DM_STATS_H
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/list.h>
int dm_statistics_init(void);
void dm_statistics_exit(void);
struct dm_stats {
struct mutex mutex;
struct list_head list; /* list of struct dm_stat */
struct dm_stats_last_position __percpu *last;
sector_t last_sector;
unsigned last_rw;
};
struct dm_stats_aux {
bool merged;
};
void dm_stats_init(struct dm_stats *st);
void dm_stats_cleanup(struct dm_stats *st);
struct mapped_device;
int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
char *result, unsigned maxlen);
void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
sector_t bi_sector, unsigned bi_sectors, bool end,
unsigned long duration, struct dm_stats_aux *aux);
static inline bool dm_stats_used(struct dm_stats *st)
{
return !list_empty(&st->list);
}
#endif

1
drivers/md/dm-stripe.c
View file

@ -4,6 +4,7 @@
* This file is released under the GPL.
*/
#include "dm.h"
#include <linux/device-mapper.h>
#include <linux/module.h>

20
drivers/md/dm-table.c
View file

@ -860,14 +860,17 @@ EXPORT_SYMBOL(dm_consume_args);
static int dm_table_set_type(struct dm_table *t)
{
unsigned i;
unsigned bio_based = 0, request_based = 0;
unsigned bio_based = 0, request_based = 0, hybrid = 0;
struct dm_target *tgt;
struct dm_dev_internal *dd;
struct list_head *devices;
unsigned live_md_type;
for (i = 0; i < t->num_targets; i++) {
tgt = t->targets + i;
if (dm_target_request_based(tgt))
if (dm_target_hybrid(tgt))
hybrid = 1;
else if (dm_target_request_based(tgt))
request_based = 1;
else
bio_based = 1;
@ -879,6 +882,19 @@ static int dm_table_set_type(struct dm_table *t)
}
}
if (hybrid && !bio_based && !request_based) {
/*
* The targets can work either way.
* Determine the type from the live device.
* Default to bio-based if device is new.
*/
live_md_type = dm_get_md_type(t->md);
if (live_md_type == DM_TYPE_REQUEST_BASED)
request_based = 1;
else
bio_based = 1;
}
if (bio_based) {
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;

9
drivers/md/dm-target.c
View file

@ -131,12 +131,19 @@ static int io_err_map(struct dm_target *tt, struct bio *bio)
return -EIO;
}
static int io_err_map_rq(struct dm_target *ti, struct request *clone,
union map_info *map_context)
{
return -EIO;
}
static struct target_type error_target = {
.name = "error",
.version = {1, 1, 0},
.version = {1, 2, 0},
.ctr = io_err_ctr,
.dtr = io_err_dtr,
.map = io_err_map,
.map_rq = io_err_map_rq,
};
int __init dm_target_init(void)

124
drivers/md/dm-thin.c
View file

@ -887,7 +887,8 @@ static int commit(struct pool *pool)
r = dm_pool_commit_metadata(pool->pmd);
if (r)
DMERR_LIMIT("commit failed: error = %d", r);
DMERR_LIMIT("%s: commit failed: error = %d",
dm_device_name(pool->pool_md), r);
return r;
}
@ -917,6 +918,13 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
unsigned long flags;
struct pool *pool = tc->pool;
/*
* Once no_free_space is set we must not allow allocation to succeed.
* Otherwise it is difficult to explain, debug, test and support.
*/
if (pool->no_free_space)
return -ENOSPC;
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
if (r)
return r;
@ -931,31 +939,30 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
}
if (!free_blocks) {
if (pool->no_free_space)
/*
* Try to commit to see if that will free up some
* more space.
*/
(void) commit_or_fallback(pool);
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
if (r)
return r;
/*
* If we still have no space we set a flag to avoid
* doing all this checking and return -ENOSPC. This
* flag serves as a latch that disallows allocations from
* this pool until the admin takes action (e.g. resize or
* table reload).
*/
if (!free_blocks) {
DMWARN("%s: no free space available.",
dm_device_name(pool->pool_md));
spin_lock_irqsave(&pool->lock, flags);
pool->no_free_space = 1;
spin_unlock_irqrestore(&pool->lock, flags);
return -ENOSPC;
else {
/*
* Try to commit to see if that will free up some
* more space.
*/
(void) commit_or_fallback(pool);
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
if (r)
return r;
/*
* If we still have no space we set a flag to avoid
* doing all this checking and return -ENOSPC.
*/
if (!free_blocks) {
DMWARN("%s: no free space available.",
dm_device_name(pool->pool_md));
spin_lock_irqsave(&pool->lock, flags);
pool->no_free_space = 1;
spin_unlock_irqrestore(&pool->lock, flags);
return -ENOSPC;
}
}
}
@ -1085,6 +1092,7 @@ static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
{
int r;
dm_block_t data_block;
struct pool *pool = tc->pool;
r = alloc_data_block(tc, &data_block);
switch (r) {
@ -1094,13 +1102,14 @@ static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
break;
case -ENOSPC:
no_space(tc->pool, cell);
no_space(pool, cell);
break;
default:
DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
__func__, r);
cell_error(tc->pool, cell);
set_pool_mode(pool, PM_READ_ONLY);
cell_error(pool, cell);
break;
}
}
@ -1386,7 +1395,8 @@ static void set_pool_mode(struct pool *pool, enum pool_mode mode)
switch (mode) {
case PM_FAIL:
DMERR("switching pool to failure mode");
DMERR("%s: switching pool to failure mode",
dm_device_name(pool->pool_md));
pool->process_bio = process_bio_fail;
pool->process_discard = process_bio_fail;
pool->process_prepared_mapping = process_prepared_mapping_fail;
@ -1394,10 +1404,12 @@ static void set_pool_mode(struct pool *pool, enum pool_mode mode)
break;
case PM_READ_ONLY:
DMERR("switching pool to read-only mode");
DMERR("%s: switching pool to read-only mode",
dm_device_name(pool->pool_md));
r = dm_pool_abort_metadata(pool->pmd);
if (r) {
DMERR("aborting transaction failed");
DMERR("%s: aborting transaction failed",
dm_device_name(pool->pool_md));
set_pool_mode(pool, PM_FAIL);
} else {
dm_pool_metadata_read_only(pool->pmd);
@ -2156,19 +2168,22 @@ static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
if (r) {
DMERR("failed to retrieve data device size");
DMERR("%s: failed to retrieve data device size",
dm_device_name(pool->pool_md));
return r;
}
if (data_size < sb_data_size) {
DMERR("pool target (%llu blocks) too small: expected %llu",
DMERR("%s: pool target (%llu blocks) too small: expected %llu",
dm_device_name(pool->pool_md),
(unsigned long long)data_size, sb_data_size);
return -EINVAL;
} else if (data_size > sb_data_size) {
r = dm_pool_resize_data_dev(pool->pmd, data_size);
if (r) {
DMERR("failed to resize data device");
DMERR("%s: failed to resize data device",
dm_device_name(pool->pool_md));
set_pool_mode(pool, PM_READ_ONLY);
return r;
}
@ -2192,19 +2207,22 @@ static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit)
r = dm_pool_get_metadata_dev_size(pool->pmd, &sb_metadata_dev_size);
if (r) {
DMERR("failed to retrieve data device size");
DMERR("%s: failed to retrieve metadata device size",
dm_device_name(pool->pool_md));
return r;
}
if (metadata_dev_size < sb_metadata_dev_size) {
DMERR("metadata device (%llu blocks) too small: expected %llu",
DMERR("%s: metadata device (%llu blocks) too small: expected %llu",
dm_device_name(pool->pool_md),
metadata_dev_size, sb_metadata_dev_size);
return -EINVAL;
} else if (metadata_dev_size > sb_metadata_dev_size) {
r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size);
if (r) {
DMERR("failed to resize metadata device");
DMERR("%s: failed to resize metadata device",
dm_device_name(pool->pool_md));
return r;
}
@ -2530,37 +2548,43 @@ static void pool_status(struct dm_target *ti, status_type_t type,
r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
if (r) {
DMERR("dm_pool_get_metadata_transaction_id returned %d", r);
DMERR("%s: dm_pool_get_metadata_transaction_id returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free_blocks_metadata);
if (r) {
DMERR("dm_pool_get_free_metadata_block_count returned %d", r);
DMERR("%s: dm_pool_get_free_metadata_block_count returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
if (r) {
DMERR("dm_pool_get_metadata_dev_size returned %d", r);
DMERR("%s: dm_pool_get_metadata_dev_size returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_free_block_count(pool->pmd, &nr_free_blocks_data);
if (r) {
DMERR("dm_pool_get_free_block_count returned %d", r);
DMERR("%s: dm_pool_get_free_block_count returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
if (r) {
DMERR("dm_pool_get_data_dev_size returned %d", r);
DMERR("%s: dm_pool_get_data_dev_size returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
if (r) {
DMERR("dm_pool_get_metadata_snap returned %d", r);
DMERR("%s: dm_pool_get_metadata_snap returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
@ -2648,9 +2672,17 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
blk_limits_io_min(limits, 0);
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
/*
* If the system-determined stacked limits are compatible with the
* pool's blocksize (io_opt is a factor) do not override them.
*/
if (io_opt_sectors < pool->sectors_per_block ||
do_div(io_opt_sectors, pool->sectors_per_block)) {
blk_limits_io_min(limits, 0);
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
}
/*
* pt->adjusted_pf is a staging area for the actual features to use.
@ -2669,7 +2701,7 @@ static struct target_type pool_target = {
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
.version = {1, 8, 0},
.version = {1, 9, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,
@ -2956,7 +2988,7 @@ static int thin_iterate_devices(struct dm_target *ti,
static struct target_type thin_target = {
.name = "thin",
.version = {1, 8, 0},
.version = {1, 9, 0},
.module = THIS_MODULE,
.ctr = thin_ctr,
.dtr = thin_dtr,

70
drivers/md/dm.c
View file

@ -60,6 +60,7 @@ struct dm_io {
struct bio *bio;
unsigned long start_time;
spinlock_t endio_lock;
struct dm_stats_aux stats_aux;
};
/*
@ -198,6 +199,8 @@ struct mapped_device {
/* zero-length flush that will be cloned and submitted to targets */
struct bio flush_bio;
struct dm_stats stats;
};
/*
@ -269,6 +272,7 @@ static int (*_inits[])(void) __initdata = {
dm_io_init,
dm_kcopyd_init,
dm_interface_init,
dm_statistics_init,
};
static void (*_exits[])(void) = {
@ -279,6 +283,7 @@ static void (*_exits[])(void) = {
dm_io_exit,
dm_kcopyd_exit,
dm_interface_exit,
dm_statistics_exit,
};
static int __init dm_init(void)
@ -384,6 +389,16 @@ int dm_lock_for_deletion(struct mapped_device *md)
return r;
}
sector_t dm_get_size(struct mapped_device *md)
{
return get_capacity(md->disk);
}
struct dm_stats *dm_get_stats(struct mapped_device *md)
{
return &md->stats;
}
static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct mapped_device *md = bdev->bd_disk->private_data;
@ -466,8 +481,9 @@ static int md_in_flight(struct mapped_device *md)
static void start_io_acct(struct dm_io *io)
{
struct mapped_device *md = io->md;
struct bio *bio = io->bio;
int cpu;
int rw = bio_data_dir(io->bio);
int rw = bio_data_dir(bio);
io->start_time = jiffies;
@ -476,6 +492,10 @@ static void start_io_acct(struct dm_io *io)
part_stat_unlock();
atomic_set(&dm_disk(md)->part0.in_flight[rw],
atomic_inc_return(&md->pending[rw]));
if (unlikely(dm_stats_used(&md->stats)))
dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector,
bio_sectors(bio), false, 0, &io->stats_aux);
}
static void end_io_acct(struct dm_io *io)
@ -491,6 +511,10 @@ static void end_io_acct(struct dm_io *io)
part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
part_stat_unlock();
if (unlikely(dm_stats_used(&md->stats)))
dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector,
bio_sectors(bio), true, duration, &io->stats_aux);
/*
* After this is decremented the bio must not be touched if it is
* a flush.
@ -1519,7 +1543,7 @@ static void _dm_request(struct request_queue *q, struct bio *bio)
return;
}
static int dm_request_based(struct mapped_device *md)
int dm_request_based(struct mapped_device *md)
{
return blk_queue_stackable(md->queue);
}
@ -1946,8 +1970,7 @@ static struct mapped_device *alloc_dev(int minor)
add_disk(md->disk);
format_dev_t(md->name, MKDEV(_major, minor));
md->wq = alloc_workqueue("kdmflush",
WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0);
md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
if (!md->wq)
goto bad_thread;
@ -1959,6 +1982,8 @@ static struct mapped_device *alloc_dev(int minor)
md->flush_bio.bi_bdev = md->bdev;
md->flush_bio.bi_rw = WRITE_FLUSH;
dm_stats_init(&md->stats);
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);
old_md = idr_replace(&_minor_idr, md, minor);
@ -2010,6 +2035,7 @@ static void free_dev(struct mapped_device *md)
put_disk(md->disk);
blk_cleanup_queue(md->queue);
dm_stats_cleanup(&md->stats);
module_put(THIS_MODULE);
kfree(md);
}
@ -2151,7 +2177,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
/*
* Wipe any geometry if the size of the table changed.
*/
if (size != get_capacity(md->disk))
if (size != dm_get_size(md))
memset(&md->geometry, 0, sizeof(md->geometry));
__set_size(md, size);
@ -2236,11 +2262,13 @@ void dm_unlock_md_type(struct mapped_device *md)
void dm_set_md_type(struct mapped_device *md, unsigned type)
{
BUG_ON(!mutex_is_locked(&md->type_lock));
md->type = type;
}
unsigned dm_get_md_type(struct mapped_device *md)
{
BUG_ON(!mutex_is_locked(&md->type_lock));
return md->type;
}
@ -2695,6 +2723,38 @@ out:
return r;
}
/*
* Internal suspend/resume works like userspace-driven suspend. It waits
* until all bios finish and prevents issuing new bios to the target drivers.
* It may be used only from the kernel.
*
* Internal suspend holds md->suspend_lock, which prevents interaction with
* userspace-driven suspend.
*/
void dm_internal_suspend(struct mapped_device *md)
{
mutex_lock(&md->suspend_lock);
if (dm_suspended_md(md))
return;
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
synchronize_srcu(&md->io_barrier);
flush_workqueue(md->wq);
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
}
void dm_internal_resume(struct mapped_device *md)
{
if (dm_suspended_md(md))
goto done;
dm_queue_flush(md);
done:
mutex_unlock(&md->suspend_lock);
}
/*-----------------------------------------------------------------
* Event notification.
*---------------------------------------------------------------*/

27
drivers/md/dm.h
View file

@ -16,6 +16,8 @@
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include "dm-stats.h"
/*
* Suspend feature flags
*/
@ -88,11 +90,22 @@ int dm_setup_md_queue(struct mapped_device *md);
*/
#define dm_target_is_valid(t) ((t)->table)
/*
* To check whether the target type is bio-based or not (request-based).
*/
#define dm_target_bio_based(t) ((t)->type->map != NULL)
/*
* To check whether the target type is request-based or not (bio-based).
*/
#define dm_target_request_based(t) ((t)->type->map_rq != NULL)
/*
* To check whether the target type is a hybrid (capable of being
* either request-based or bio-based).
*/
#define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
/*-----------------------------------------------------------------
* A registry of target types.
*---------------------------------------------------------------*/
@ -146,10 +159,16 @@ void dm_destroy(struct mapped_device *md);
void dm_destroy_immediate(struct mapped_device *md);
int dm_open_count(struct mapped_device *md);
int dm_lock_for_deletion(struct mapped_device *md);
int dm_request_based(struct mapped_device *md);
sector_t dm_get_size(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,
unsigned cookie);
void dm_internal_suspend(struct mapped_device *md);
void dm_internal_resume(struct mapped_device *md);
int dm_io_init(void);
void dm_io_exit(void);
@ -162,4 +181,12 @@ void dm_kcopyd_exit(void);
struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size);
void dm_free_md_mempools(struct dm_md_mempools *pools);
/*
* Helpers that are used by DM core
*/
static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
{
return !maxlen || strlen(result) + 1 >= maxlen;
}
#endif

5
drivers/md/persistent-data/dm-block-manager.c
View file

@ -615,6 +615,11 @@ int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
}
EXPORT_SYMBOL_GPL(dm_bm_flush_and_unlock);
void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b)
{
dm_bufio_prefetch(bm->bufio, b, 1);
}
void dm_bm_set_read_only(struct dm_block_manager *bm)
{
bm->read_only = true;

5
drivers/md/persistent-data/dm-block-manager.h
View file

@ -108,6 +108,11 @@ int dm_bm_unlock(struct dm_block *b);
int dm_bm_flush_and_unlock(struct dm_block_manager *bm,
struct dm_block *superblock);
/*
* Request data be prefetched into the cache.
*/
void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b);
/*
* Switches the bm to a read only mode. Once read-only mode
* has been entered the following functions will return -EPERM.

28
drivers/md/persistent-data/dm-btree.c
View file

@ -161,6 +161,7 @@ struct frame {
};
struct del_stack {
struct dm_btree_info *info;
struct dm_transaction_manager *tm;
int top;
struct frame spine[MAX_SPINE_DEPTH];
@ -183,6 +184,20 @@ static int unprocessed_frames(struct del_stack *s)
return s->top >= 0;
}
static void prefetch_children(struct del_stack *s, struct frame *f)
{
unsigned i;
struct dm_block_manager *bm = dm_tm_get_bm(s->tm);
for (i = 0; i < f->nr_children; i++)
dm_bm_prefetch(bm, value64(f->n, i));
}
static bool is_internal_level(struct dm_btree_info *info, struct frame *f)
{
return f->level < (info->levels - 1);
}
static int push_frame(struct del_stack *s, dm_block_t b, unsigned level)
{
int r;
@ -205,6 +220,7 @@ static int push_frame(struct del_stack *s, dm_block_t b, unsigned level)
dm_tm_dec(s->tm, b);
else {
uint32_t flags;
struct frame *f = s->spine + ++s->top;
r = dm_tm_read_lock(s->tm, b, &btree_node_validator, &f->b);
@ -217,6 +233,10 @@ static int push_frame(struct del_stack *s, dm_block_t b, unsigned level)
f->level = level;
f->nr_children = le32_to_cpu(f->n->header.nr_entries);
f->current_child = 0;
flags = le32_to_cpu(f->n->header.flags);
if (flags & INTERNAL_NODE || is_internal_level(s->info, f))
prefetch_children(s, f);
}
return 0;
@ -230,11 +250,6 @@ static void pop_frame(struct del_stack *s)
dm_tm_unlock(s->tm, f->b);
}
static bool is_internal_level(struct dm_btree_info *info, struct frame *f)
{
return f->level < (info->levels - 1);
}
int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
{
int r;
@ -243,6 +258,7 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
s = kmalloc(sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;
s->info = info;
s->tm = info->tm;
s->top = -1;
@ -287,7 +303,7 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
info->value_type.dec(info->value_type.context,
value_ptr(f->n, i));
}
f->current_child = f->nr_children;
pop_frame(s);
}
}

79
drivers/md/persistent-data/dm-space-map-common.c
View file

@ -292,16 +292,11 @@ int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
return dm_tm_unlock(ll->tm, blk);
}
int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
uint32_t *result)
{
__le32 le_rc;
int r = sm_ll_lookup_bitmap(ll, b, result);
if (r)
return r;
if (*result != 3)
return r;
int r;
r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
if (r < 0)
@ -312,6 +307,19 @@ int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
return r;
}
int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
{
int r = sm_ll_lookup_bitmap(ll, b, result);
if (r)
return r;
if (*result != 3)
return r;
return sm_ll_lookup_big_ref_count(ll, b, result);
}
int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
dm_block_t end, dm_block_t *result)
{
@ -372,11 +380,12 @@ int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
return -ENOSPC;
}
int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
uint32_t ref_count, enum allocation_event *ev)
static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
uint32_t (*mutator)(void *context, uint32_t old),
void *context, enum allocation_event *ev)
{
int r;
uint32_t bit, old;
uint32_t bit, old, ref_count;
struct dm_block *nb;
dm_block_t index = b;
struct disk_index_entry ie_disk;
@ -399,6 +408,14 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
bm_le = dm_bitmap_data(nb);
old = sm_lookup_bitmap(bm_le, bit);
if (old > 2) {
r = sm_ll_lookup_big_ref_count(ll, b, &old);
if (r < 0)
return r;
}
ref_count = mutator(context, old);
if (ref_count <= 2) {
sm_set_bitmap(bm_le, bit, ref_count);
@ -448,31 +465,35 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
return ll->save_ie(ll, index, &ie_disk);
}
static uint32_t set_ref_count(void *context, uint32_t old)
{
return *((uint32_t *) context);
}
int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
uint32_t ref_count, enum allocation_event *ev)
{
return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
}
static uint32_t inc_ref_count(void *context, uint32_t old)
{
return old + 1;
}
int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
{
int r;
uint32_t rc;
return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
}
r = sm_ll_lookup(ll, b, &rc);
if (r)
return r;
return sm_ll_insert(ll, b, rc + 1, ev);
static uint32_t dec_ref_count(void *context, uint32_t old)
{
return old - 1;
}
int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
{
int r;
uint32_t rc;
r = sm_ll_lookup(ll, b, &rc);
if (r)
return r;
if (!rc)
return -EINVAL;
return sm_ll_insert(ll, b, rc - 1, ev);
return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
}
int sm_ll_commit(struct ll_disk *ll)