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Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm 

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (48 commits)
  dm mpath: change to be request based
  dm: disable interrupt when taking map_lock
  dm: do not set QUEUE_ORDERED_DRAIN if request based
  dm: enable request based option
  dm: prepare for request based option
  dm raid1: add userspace log
  dm: calculate queue limits during resume not load
  dm log: fix create_log_context to use logical_block_size of log device
  dm target:s introduce iterate devices fn
  dm table: establish queue limits by copying table limits
  dm table: replace struct io_restrictions with struct queue_limits
  dm table: validate device logical_block_size
  dm table: ensure targets are aligned to logical_block_size
  dm ioctl: support cookies for udev
  dm: sysfs add suspended attribute
  dm table: improve warning message when devices not freed before destruction
  dm mpath: add service time load balancer
  dm mpath: add queue length load balancer
  dm mpath: add start_io and nr_bytes to path selectors
  dm snapshot: use barrier when writing exception store
  ...
This commit is contained in:
Linus Torvalds 2009-06-24 10:26:54 -07:00
parent ea94b5034b f40c67f0f7
commit c3cb5e1939
35 changed files with 3992 additions and 434 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
Documentation/device-mapper/dm-log.txt Normal file
View File

@ -0,0 +1,54 @@
Device-Mapper Logging
=====================
The device-mapper logging code is used by some of the device-mapper
RAID targets to track regions of the disk that are not consistent.
A region (or portion of the address space) of the disk may be
inconsistent because a RAID stripe is currently being operated on or
a machine died while the region was being altered. In the case of
mirrors, a region would be considered dirty/inconsistent while you
are writing to it because the writes need to be replicated for all
the legs of the mirror and may not reach the legs at the same time.
Once all writes are complete, the region is considered clean again.
There is a generic logging interface that the device-mapper RAID
implementations use to perform logging operations (see
dm_dirty_log_type in include/linux/dm-dirty-log.h). Various different
logging implementations are available and provide different
capabilities. The list includes:
Type Files
==== =====
disk drivers/md/dm-log.c
core drivers/md/dm-log.c
userspace drivers/md/dm-log-userspace* include/linux/dm-log-userspace.h
The "disk" log type
-------------------
This log implementation commits the log state to disk. This way, the
logging state survives reboots/crashes.
The "core" log type
-------------------
This log implementation keeps the log state in memory. The log state
will not survive a reboot or crash, but there may be a small boost in
performance. This method can also be used if no storage device is
available for storing log state.
The "userspace" log type
------------------------
This log type simply provides a way to export the log API to userspace,
so log implementations can be done there. This is done by forwarding most
logging requests to userspace, where a daemon receives and processes the
request.
The structure used for communication between kernel and userspace are
located in include/linux/dm-log-userspace.h. Due to the frequency,
diversity, and 2-way communication nature of the exchanges between
kernel and userspace, 'connector' is used as the interface for
communication.
There are currently two userspace log implementations that leverage this
framework - "clustered_disk" and "clustered_core". These implementations
provide a cluster-coherent log for shared-storage. Device-mapper mirroring
can be used in a shared-storage environment when the cluster log implementations
are employed.

39
Documentation/device-mapper/dm-queue-length.txt Normal file
View File

@ -0,0 +1,39 @@
dm-queue-length
===============
dm-queue-length is a path selector module for device-mapper targets,
which selects a path with the least number of in-flight I/Os.
The path selector name is 'queue-length'.
Table parameters for each path: [<repeat_count>]
<repeat_count>: The number of I/Os to dispatch using the selected
path before switching to the next path.
If not given, internal default is used. To check
the default value, see the activated table.
Status for each path: <status> <fail-count> <in-flight>
<status>: 'A' if the path is active, 'F' if the path is failed.
<fail-count>: The number of path failures.
<in-flight>: The number of in-flight I/Os on the path.
Algorithm
=========
dm-queue-length increments/decrements 'in-flight' when an I/O is
dispatched/completed respectively.
dm-queue-length selects a path with the minimum 'in-flight'.
Examples
========
In case that 2 paths (sda and sdb) are used with repeat_count == 128.
# echo "0 10 multipath 0 0 1 1 queue-length 0 2 1 8:0 128 8:16 128" \
dmsetup create test
#
# dmsetup table
test: 0 10 multipath 0 0 1 1 queue-length 0 2 1 8:0 128 8:16 128
#
# dmsetup status
test: 0 10 multipath 2 0 0 0 1 1 E 0 2 1 8:0 A 0 0 8:16 A 0 0

91
Documentation/device-mapper/dm-service-time.txt Normal file
View File

@ -0,0 +1,91 @@
dm-service-time
===============
dm-service-time is a path selector module for device-mapper targets,
which selects a path with the shortest estimated service time for
the incoming I/O.
The service time for each path is estimated by dividing the total size
of in-flight I/Os on a path with the performance value of the path.
The performance value is a relative throughput value among all paths
in a path-group, and it can be specified as a table argument.
The path selector name is 'service-time'.
Table parameters for each path: [<repeat_count> [<relative_throughput>]]
<repeat_count>: The number of I/Os to dispatch using the selected
path before switching to the next path.
If not given, internal default is used. To check
the default value, see the activated table.
<relative_throughput>: The relative throughput value of the path
among all paths in the path-group.
The valid range is 0-100.
If not given, minimum value '1' is used.
If '0' is given, the path isn't selected while
other paths having a positive value are available.
Status for each path: <status> <fail-count> <in-flight-size> \
<relative_throughput>
<status>: 'A' if the path is active, 'F' if the path is failed.
<fail-count>: The number of path failures.
<in-flight-size>: The size of in-flight I/Os on the path.
<relative_throughput>: The relative throughput value of the path
among all paths in the path-group.
Algorithm
=========
dm-service-time adds the I/O size to 'in-flight-size' when the I/O is
dispatched and substracts when completed.
Basically, dm-service-time selects a path having minimum service time
which is calculated by:
('in-flight-size' + 'size-of-incoming-io') / 'relative_throughput'
However, some optimizations below are used to reduce the calculation
as much as possible.
1. If the paths have the same 'relative_throughput', skip
the division and just compare the 'in-flight-size'.
2. If the paths have the same 'in-flight-size', skip the division
and just compare the 'relative_throughput'.
3. If some paths have non-zero 'relative_throughput' and others
have zero 'relative_throughput', ignore those paths with zero
'relative_throughput'.
If such optimizations can't be applied, calculate service time, and
compare service time.
If calculated service time is equal, the path having maximum
'relative_throughput' may be better. So compare 'relative_throughput'
then.
Examples
========
In case that 2 paths (sda and sdb) are used with repeat_count == 128
and sda has an average throughput 1GB/s and sdb has 4GB/s,
'relative_throughput' value may be '1' for sda and '4' for sdb.
# echo "0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 1 8:16 128 4" \
dmsetup create test
#
# dmsetup table
test: 0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 1 8:16 128 4
#
# dmsetup status
test: 0 10 multipath 2 0 0 0 1 1 E 0 2 2 8:0 A 0 0 1 8:16 A 0 0 4
Or '2' for sda and '8' for sdb would be also true.
# echo "0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 2 8:16 128 8" \
dmsetup create test
#
# dmsetup table
test: 0 10 multipath 0 0 1 1 service-time 0 2 2 8:0 128 2 8:16 128 8
#
# dmsetup status
test: 0 10 multipath 2 0 0 0 1 1 E 0 2 2 8:0 A 0 0 2 8:16 A 0 0 8

30
drivers/md/Kconfig
View File

@ -231,6 +231,17 @@ config DM_MIRROR
Allow volume managers to mirror logical volumes, also
needed for live data migration tools such as 'pvmove'.
config DM_LOG_USERSPACE
tristate "Mirror userspace logging (EXPERIMENTAL)"
depends on DM_MIRROR && EXPERIMENTAL && NET
select CONNECTOR
---help---
The userspace logging module provides a mechanism for
relaying the dm-dirty-log API to userspace. Log designs
which are more suited to userspace implementation (e.g.
shared storage logs) or experimental logs can be implemented
by leveraging this framework.
config DM_ZERO
tristate "Zero target"
depends on BLK_DEV_DM
@ -249,6 +260,25 @@ config DM_MULTIPATH
---help---
Allow volume managers to support multipath hardware.
config DM_MULTIPATH_QL
tristate "I/O Path Selector based on the number of in-flight I/Os"
depends on DM_MULTIPATH
---help---
This path selector is a dynamic load balancer which selects
the path with the least number of in-flight I/Os.
If unsure, say N.
config DM_MULTIPATH_ST
tristate "I/O Path Selector based on the service time"
depends on DM_MULTIPATH
---help---
This path selector is a dynamic load balancer which selects
the path expected to complete the incoming I/O in the shortest
time.
If unsure, say N.
config DM_DELAY
tristate "I/O delaying target (EXPERIMENTAL)"
depends on BLK_DEV_DM && EXPERIMENTAL

5
drivers/md/Makefile
View File

@ -8,6 +8,8 @@ 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
dm-mirror-y += dm-raid1.o
dm-log-userspace-y \
+= dm-log-userspace-base.o dm-log-userspace-transfer.o
md-mod-y += md.o bitmap.o
raid456-y += raid5.o
raid6_pq-y += raid6algos.o raid6recov.o raid6tables.o \
@ -36,8 +38,11 @@ obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o
obj-$(CONFIG_DM_CRYPT) += dm-crypt.o
obj-$(CONFIG_DM_DELAY) += dm-delay.o
obj-$(CONFIG_DM_MULTIPATH) += dm-multipath.o dm-round-robin.o
obj-$(CONFIG_DM_MULTIPATH_QL) += dm-queue-length.o
obj-$(CONFIG_DM_MULTIPATH_ST) += dm-service-time.o
obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o
obj-$(CONFIG_DM_MIRROR) += dm-mirror.o dm-log.o dm-region-hash.o
obj-$(CONFIG_DM_LOG_USERSPACE) += dm-log-userspace.o
obj-$(CONFIG_DM_ZERO) += dm-zero.o
quiet_cmd_unroll = UNROLL $@

19
drivers/md/dm-crypt.c
View File

@ -1132,6 +1132,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad_crypt_queue;
}
ti->num_flush_requests = 1;
ti->private = cc;
return 0;
@ -1189,6 +1190,13 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
union map_info *map_context)
{
struct dm_crypt_io *io;
struct crypt_config *cc;
if (unlikely(bio_empty_barrier(bio))) {
cc = ti->private;
bio->bi_bdev = cc->dev->bdev;
return DM_MAPIO_REMAPPED;
}
io = crypt_io_alloc(ti, bio, bio->bi_sector - ti->begin);
@ -1305,9 +1313,17 @@ static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
}
static int crypt_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct crypt_config *cc = ti->private;
return fn(ti, cc->dev, cc->start, data);
}
static struct target_type crypt_target = {
.name = "crypt",
.version= {1, 6, 0},
.version = {1, 7, 0},
.module = THIS_MODULE,
.ctr = crypt_ctr,
.dtr = crypt_dtr,
@ -1318,6 +1334,7 @@ static struct target_type crypt_target = {
.resume = crypt_resume,
.message = crypt_message,
.merge = crypt_merge,
.iterate_devices = crypt_iterate_devices,
};
static int __init dm_crypt_init(void)

26
drivers/md/dm-delay.c
View File

@ -197,6 +197,7 @@ out:
mutex_init(&dc->timer_lock);
atomic_set(&dc->may_delay, 1);
ti->num_flush_requests = 1;
ti->private = dc;
return 0;
@ -278,8 +279,9 @@ static int delay_map(struct dm_target *ti, struct bio *bio,
if ((bio_data_dir(bio) == WRITE) && (dc->dev_write)) {
bio->bi_bdev = dc->dev_write->bdev;
bio->bi_sector = dc->start_write +
(bio->bi_sector - ti->begin);
if (bio_sectors(bio))
bio->bi_sector = dc->start_write +
(bio->bi_sector - ti->begin);
return delay_bio(dc, dc->write_delay, bio);
}
@ -316,9 +318,26 @@ static int delay_status(struct dm_target *ti, status_type_t type,
return 0;
}
static int delay_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct delay_c *dc = ti->private;
int ret = 0;
ret = fn(ti, dc->dev_read, dc->start_read, data);
if (ret)
goto out;
if (dc->dev_write)
ret = fn(ti, dc->dev_write, dc->start_write, data);
out:
return ret;
}
static struct target_type delay_target = {
.name = "delay",
.version = {1, 0, 2},
.version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = delay_ctr,
.dtr = delay_dtr,
@ -326,6 +345,7 @@ static struct target_type delay_target = {
.presuspend = delay_presuspend,
.resume = delay_resume,
.status = delay_status,
.iterate_devices = delay_iterate_devices,
};
static int __init dm_delay_init(void)

2
drivers/md/dm-exception-store.c
View File

@ -216,7 +216,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
return -EINVAL;
}
type = get_type(argv[1]);
type = get_type(&persistent);
if (!type) {
ti->error = "Exception store type not recognised";
r = -EINVAL;

2
drivers/md/dm-exception-store.h
View File

@ -156,7 +156,7 @@ static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
*/
static inline sector_t get_dev_size(struct block_device *bdev)
{
return bdev->bd_inode->i_size >> SECTOR_SHIFT;
return i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
}
static inline chunk_t sector_to_chunk(struct dm_exception_store *store,

14
drivers/md/dm-io.c
View File

@ -22,6 +22,7 @@ struct dm_io_client {
/* FIXME: can we shrink this ? */
struct io {
unsigned long error_bits;
unsigned long eopnotsupp_bits;
atomic_t count;
struct task_struct *sleeper;
struct dm_io_client *client;
@ -107,8 +108,11 @@ static inline unsigned bio_get_region(struct bio *bio)
*---------------------------------------------------------------*/
static void dec_count(struct io *io, unsigned int region, int error)
{
if (error)
if (error) {
set_bit(region, &io->error_bits);
if (error == -EOPNOTSUPP)
set_bit(region, &io->eopnotsupp_bits);
}
if (atomic_dec_and_test(&io->count)) {
if (io->sleeper)
@ -360,7 +364,9 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
return -EIO;
}
retry:
io.error_bits = 0;
io.eopnotsupp_bits = 0;
atomic_set(&io.count, 1); /* see dispatch_io() */
io.sleeper = current;
io.client = client;
@ -377,6 +383,11 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions,
}
set_current_state(TASK_RUNNING);
if (io.eopnotsupp_bits && (rw & (1 << BIO_RW_BARRIER))) {
rw &= ~(1 << BIO_RW_BARRIER);
goto retry;
}
if (error_bits)
*error_bits = io.error_bits;
@ -397,6 +408,7 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions,
io = mempool_alloc(client->pool, GFP_NOIO);
io->error_bits = 0;
io->eopnotsupp_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = NULL;
io->client = client;

27
drivers/md/dm-ioctl.c
View File

@ -276,7 +276,7 @@ retry:
up_write(&_hash_lock);
}
static int dm_hash_rename(const char *old, const char *new)
static int dm_hash_rename(uint32_t cookie, const char *old, const char *new)
{
char *new_name, *old_name;
struct hash_cell *hc;
@ -333,7 +333,7 @@ static int dm_hash_rename(const char *old, const char *new)
dm_table_put(table);
}
dm_kobject_uevent(hc->md);
dm_kobject_uevent(hc->md, KOBJ_CHANGE, cookie);
dm_put(hc->md);
up_write(&_hash_lock);
@ -680,6 +680,9 @@ static int dev_remove(struct dm_ioctl *param, size_t param_size)
__hash_remove(hc);
up_write(&_hash_lock);
dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr);
dm_put(md);
param->data_size = 0;
return 0;
@ -715,7 +718,7 @@ static int dev_rename(struct dm_ioctl *param, size_t param_size)
return r;
param->data_size = 0;
return dm_hash_rename(param->name, new_name);
return dm_hash_rename(param->event_nr, param->name, new_name);
}
static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
@ -842,8 +845,11 @@ static int do_resume(struct dm_ioctl *param)
if (dm_suspended(md))
r = dm_resume(md);
if (!r)
if (!r) {
dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr);
r = __dev_status(md, param);
}
dm_put(md);
return r;
@ -1044,6 +1050,12 @@ static int populate_table(struct dm_table *table,
next = spec->next;
}
r = dm_table_set_type(table);
if (r) {
DMWARN("unable to set table type");
return r;
}
return dm_table_complete(table);
}
@ -1089,6 +1101,13 @@ static int table_load(struct dm_ioctl *param, size_t param_size)
goto out;
}
r = dm_table_alloc_md_mempools(t);
if (r) {
DMWARN("unable to allocate mempools for this table");
dm_table_destroy(t);
goto out;
}
down_write(&_hash_lock);
hc = dm_get_mdptr(md);
if (!hc || hc->md != md) {

15
drivers/md/dm-linear.c
View File

@ -53,6 +53,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad;
}
ti->num_flush_requests = 1;
ti->private = lc;
return 0;
@ -81,7 +82,8 @@ static void linear_map_bio(struct dm_target *ti, struct bio *bio)
struct linear_c *lc = ti->private;
bio->bi_bdev = lc->dev->bdev;
bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
if (bio_sectors(bio))
bio->bi_sector = linear_map_sector(ti, bio->bi_sector);
}
static int linear_map(struct dm_target *ti, struct bio *bio,
@ -132,9 +134,17 @@ static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
}
static int linear_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct linear_c *lc = ti->private;
return fn(ti, lc->dev, lc->start, data);
}
static struct target_type linear_target = {
.name = "linear",
.version= {1, 0, 3},
.version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = linear_ctr,
.dtr = linear_dtr,
@ -142,6 +152,7 @@ static struct target_type linear_target = {
.status = linear_status,
.ioctl = linear_ioctl,
.merge = linear_merge,
.iterate_devices = linear_iterate_devices,
};
int __init dm_linear_init(void)

696
drivers/md/dm-log-userspace-base.c Normal file
View File

@ -0,0 +1,696 @@
/*
* Copyright (C) 2006-2009 Red Hat, Inc.
*
* This file is released under the LGPL.
*/
#include <linux/bio.h>
#include <linux/dm-dirty-log.h>
#include <linux/device-mapper.h>
#include <linux/dm-log-userspace.h>
#include "dm-log-userspace-transfer.h"
struct flush_entry {
int type;
region_t region;
struct list_head list;
};
struct log_c {
struct dm_target *ti;
uint32_t region_size;
region_t region_count;
char uuid[DM_UUID_LEN];
char *usr_argv_str;
uint32_t usr_argc;
/*
* in_sync_hint gets set when doing is_remote_recovering. It
* represents the first region that needs recovery. IOW, the
* first zero bit of sync_bits. This can be useful for to limit
* traffic for calls like is_remote_recovering and get_resync_work,
* but be take care in its use for anything else.
*/
uint64_t in_sync_hint;
spinlock_t flush_lock;
struct list_head flush_list; /* only for clear and mark requests */
};
static mempool_t *flush_entry_pool;
static void *flush_entry_alloc(gfp_t gfp_mask, void *pool_data)
{
return kmalloc(sizeof(struct flush_entry), gfp_mask);
}
static void flush_entry_free(void *element, void *pool_data)
{
kfree(element);
}
static int userspace_do_request(struct log_c *lc, const char *uuid,
int request_type, char *data, size_t data_size,
char *rdata, size_t *rdata_size)
{
int r;
/*
* If the server isn't there, -ESRCH is returned,
* and we must keep trying until the server is
* restored.
*/
retry:
r = dm_consult_userspace(uuid, request_type, data,
data_size, rdata, rdata_size);
if (r != -ESRCH)
return r;
DMERR(" Userspace log server not found.");
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(2*HZ);
DMWARN("Attempting to contact userspace log server...");
r = dm_consult_userspace(uuid, DM_ULOG_CTR, lc->usr_argv_str,
strlen(lc->usr_argv_str) + 1,
NULL, NULL);
if (!r)
break;
}
DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete");
r = dm_consult_userspace(uuid, DM_ULOG_RESUME, NULL,
0, NULL, NULL);
if (!r)
goto retry;
DMERR("Error trying to resume userspace log: %d", r);
return -ESRCH;
}
static int build_constructor_string(struct dm_target *ti,
unsigned argc, char **argv,
char **ctr_str)
{
int i, str_size;
char *str = NULL;
*ctr_str = NULL;
for (i = 0, str_size = 0; i < argc; i++)
str_size += strlen(argv[i]) + 1; /* +1 for space between args */
str_size += 20; /* Max number of chars in a printed u64 number */
str = kzalloc(str_size, GFP_KERNEL);
if (!str) {
DMWARN("Unable to allocate memory for constructor string");
return -ENOMEM;
}
for (i = 0, str_size = 0; i < argc; i++)
str_size += sprintf(str + str_size, "%s ", argv[i]);
str_size += sprintf(str + str_size, "%llu",
(unsigned long long)ti->len);
*ctr_str = str;
return str_size;
}
/*
* userspace_ctr
*
* argv contains:
* <UUID> <other args>
* Where 'other args' is the userspace implementation specific log
* arguments. An example might be:
* <UUID> clustered_disk <arg count> <log dev> <region_size> [[no]sync]
*
* So, this module will strip off the <UUID> for identification purposes
* when communicating with userspace about a log; but will pass on everything
* else.
*/
static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
unsigned argc, char **argv)
{
int r = 0;
int str_size;
char *ctr_str = NULL;
struct log_c *lc = NULL;
uint64_t rdata;
size_t rdata_size = sizeof(rdata);
if (argc < 3) {
DMWARN("Too few arguments to userspace dirty log");
return -EINVAL;
}
lc = kmalloc(sizeof(*lc), GFP_KERNEL);
if (!lc) {
DMWARN("Unable to allocate userspace log context.");
return -ENOMEM;
}
lc->ti = ti;
if (strlen(argv[0]) > (DM_UUID_LEN - 1)) {
DMWARN("UUID argument too long.");
kfree(lc);
return -EINVAL;
}
strncpy(lc->uuid, argv[0], DM_UUID_LEN);
spin_lock_init(&lc->flush_lock);
INIT_LIST_HEAD(&lc->flush_list);
str_size = build_constructor_string(ti, argc - 1, argv + 1, &ctr_str);
if (str_size < 0) {
kfree(lc);
return str_size;
}
/* Send table string */
r = dm_consult_userspace(lc->uuid, DM_ULOG_CTR,
ctr_str, str_size, NULL, NULL);
if (r == -ESRCH) {
DMERR("Userspace log server not found");
goto out;
}
/* Since the region size does not change, get it now */
rdata_size = sizeof(rdata);
r = dm_consult_userspace(lc->uuid, DM_ULOG_GET_REGION_SIZE,
NULL, 0, (char *)&rdata, &rdata_size);
if (r) {
DMERR("Failed to get region size of dirty log");
goto out;
}
lc->region_size = (uint32_t)rdata;
lc->region_count = dm_sector_div_up(ti->len, lc->region_size);
out:
if (r) {
kfree(lc);
kfree(ctr_str);
} else {
lc->usr_argv_str = ctr_str;
lc->usr_argc = argc;
log->context = lc;
}
return r;
}
static void userspace_dtr(struct dm_dirty_log *log)
{
int r;
struct log_c *lc = log->context;
r = dm_consult_userspace(lc->uuid, DM_ULOG_DTR,
NULL, 0,
NULL, NULL);
kfree(lc->usr_argv_str);
kfree(lc);
return;
}
static int userspace_presuspend(struct dm_dirty_log *log)
{
int r;
struct log_c *lc = log->context;
r = dm_consult_userspace(lc->uuid, DM_ULOG_PRESUSPEND,
NULL, 0,
NULL, NULL);
return r;
}
static int userspace_postsuspend(struct dm_dirty_log *log)
{
int r;
struct log_c *lc = log->context;
r = dm_consult_userspace(lc->uuid, DM_ULOG_POSTSUSPEND,
NULL, 0,
NULL, NULL);
return r;
}
static int userspace_resume(struct dm_dirty_log *log)
{
int r;
struct log_c *lc = log->context;
lc->in_sync_hint = 0;
r = dm_consult_userspace(lc->uuid, DM_ULOG_RESUME,
NULL, 0,
NULL, NULL);
return r;
}
static uint32_t userspace_get_region_size(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
return lc->region_size;
}
/*
* userspace_is_clean
*
* Check whether a region is clean. If there is any sort of
* failure when consulting the server, we return not clean.
*
* Returns: 1 if clean, 0 otherwise
*/
static int userspace_is_clean(struct dm_dirty_log *log, region_t region)
{
int r;
uint64_t region64 = (uint64_t)region;
int64_t is_clean;
size_t rdata_size;
struct log_c *lc = log->context;
rdata_size = sizeof(is_clean);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_CLEAN,
(char *)&region64, sizeof(region64),
(char *)&is_clean, &rdata_size);
return (r) ? 0 : (int)is_clean;
}
/*
* userspace_in_sync
*
* Check if the region is in-sync. If there is any sort
* of failure when consulting the server, we assume that
* the region is not in sync.
*
* If 'can_block' is set, return immediately
*
* Returns: 1 if in-sync, 0 if not-in-sync, -EWOULDBLOCK
*/
static int userspace_in_sync(struct dm_dirty_log *log, region_t region,
int can_block)
{
int r;
uint64_t region64 = region;
int64_t in_sync;
size_t rdata_size;
struct log_c *lc = log->context;
/*
* We can never respond directly - even if in_sync_hint is
* set. This is because another machine could see a device
* failure and mark the region out-of-sync. If we don't go
* to userspace to ask, we might think the region is in-sync
* and allow a read to pick up data that is stale. (This is
* very unlikely if a device actually fails; but it is very
* likely if a connection to one device from one machine fails.)
*
* There still might be a problem if the mirror caches the region
* state as in-sync... but then this call would not be made. So,
* that is a mirror problem.
*/
if (!can_block)
return -EWOULDBLOCK;
rdata_size = sizeof(in_sync);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_IN_SYNC,
(char *)&region64, sizeof(region64),
(char *)&in_sync, &rdata_size);
return (r) ? 0 : (int)in_sync;
}
/*
* userspace_flush
*
* This function is ok to block.
* The flush happens in two stages. First, it sends all
* clear/mark requests that are on the list. Then it
* tells the server to commit them. This gives the
* server a chance to optimise the commit, instead of
* doing it for every request.
*
* Additionally, we could implement another thread that
* sends the requests up to the server - reducing the
* load on flush. Then the flush would have less in
* the list and be responsible for the finishing commit.
*
* Returns: 0 on success, < 0 on failure
*/
static int userspace_flush(struct dm_dirty_log *log)
{
int r = 0;
unsigned long flags;
struct log_c *lc = log->context;
LIST_HEAD(flush_list);
struct flush_entry *fe, *tmp_fe;
spin_lock_irqsave(&lc->flush_lock, flags);
list_splice_init(&lc->flush_list, &flush_list);
spin_unlock_irqrestore(&lc->flush_lock, flags);
if (list_empty(&flush_list))
return 0;
/*
* FIXME: Count up requests, group request types,
* allocate memory to stick all requests in and
* send to server in one go. Failing the allocation,
* do it one by one.
*/
list_for_each_entry(fe, &flush_list, list) {
r = userspace_do_request(lc, lc->uuid, fe->type,
(char *)&fe->region,
sizeof(fe->region),
NULL, NULL);
if (r)
goto fail;
}
r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH,
NULL, 0, NULL, NULL);
fail:
/*
* We can safely remove these entries, even if failure.
* Calling code will receive an error and will know that
* the log facility has failed.
*/
list_for_each_entry_safe(fe, tmp_fe, &flush_list, list) {
list_del(&fe->list);
mempool_free(fe, flush_entry_pool);
}
if (r)
dm_table_event(lc->ti->table);
return r;
}
/*
* userspace_mark_region
*
* This function should avoid blocking unless absolutely required.
* (Memory allocation is valid for blocking.)
*/
static void userspace_mark_region(struct dm_dirty_log *log, region_t region)
{
unsigned long flags;
struct log_c *lc = log->context;
struct flush_entry *fe;
/* Wait for an allocation, but _never_ fail */
fe = mempool_alloc(flush_entry_pool, GFP_NOIO);
BUG_ON(!fe);
spin_lock_irqsave(&lc->flush_lock, flags);
fe->type = DM_ULOG_MARK_REGION;
fe->region = region;
list_add(&fe->list, &lc->flush_list);
spin_unlock_irqrestore(&lc->flush_lock, flags);
return;
}
/*
* userspace_clear_region
*
* This function must not block.
* So, the alloc can't block. In the worst case, it is ok to
* fail. It would simply mean we can't clear the region.
* Does nothing to current sync context, but does mean
* the region will be re-sync'ed on a reload of the mirror
* even though it is in-sync.
*/
static void userspace_clear_region(struct dm_dirty_log *log, region_t region)
{
unsigned long flags;
struct log_c *lc = log->context;
struct flush_entry *fe;
/*
* If we fail to allocate, we skip the clearing of
* the region. This doesn't hurt us in any way, except
* to cause the region to be resync'ed when the
* device is activated next time.
*/
fe = mempool_alloc(flush_entry_pool, GFP_ATOMIC);
if (!fe) {
DMERR("Failed to allocate memory to clear region.");
return;
}
spin_lock_irqsave(&lc->flush_lock, flags);
fe->type = DM_ULOG_CLEAR_REGION;
fe->region = region;
list_add(&fe->list, &lc->flush_list);
spin_unlock_irqrestore(&lc->flush_lock, flags);
return;
}
/*
* userspace_get_resync_work
*
* Get a region that needs recovery. It is valid to return
* an error for this function.
*
* Returns: 1 if region filled, 0 if no work, <0 on error
*/
static int userspace_get_resync_work(struct dm_dirty_log *log, region_t *region)
{
int r;
size_t rdata_size;
struct log_c *lc = log->context;
struct {
int64_t i; /* 64-bit for mix arch compatibility */
region_t r;
} pkg;
if (lc->in_sync_hint >= lc->region_count)
return 0;
rdata_size = sizeof(pkg);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_RESYNC_WORK,
NULL, 0,
(char *)&pkg, &rdata_size);
*region = pkg.r;
return (r) ? r : (int)pkg.i;
}
/*
* userspace_set_region_sync
*
* Set the sync status of a given region. This function
* must not fail.
*/
static void userspace_set_region_sync(struct dm_dirty_log *log,
region_t region, int in_sync)
{
int r;
struct log_c *lc = log->context;
struct {
region_t r;
int64_t i;
} pkg;
pkg.r = region;
pkg.i = (int64_t)in_sync;
r = userspace_do_request(lc, lc->uuid, DM_ULOG_SET_REGION_SYNC,
(char *)&pkg, sizeof(pkg),
NULL, NULL);
/*
* It would be nice to be able to report failures.
* However, it is easy emough to detect and resolve.
*/
return;
}
/*
* userspace_get_sync_count
*
* If there is any sort of failure when consulting the server,
* we assume that the sync count is zero.
*
* Returns: sync count on success, 0 on failure
*/
static region_t userspace_get_sync_count(struct dm_dirty_log *log)
{
int r;
size_t rdata_size;
uint64_t sync_count;
struct log_c *lc = log->context;
rdata_size = sizeof(sync_count);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_SYNC_COUNT,
NULL, 0,
(char *)&sync_count, &rdata_size);
if (r)
return 0;
if (sync_count >= lc->region_count)
lc->in_sync_hint = lc->region_count;
return (region_t)sync_count;
}
/*
* userspace_status
*
* Returns: amount of space consumed
*/
static int userspace_status(struct dm_dirty_log *log, status_type_t status_type,
char *result, unsigned maxlen)
{
int r = 0;
size_t sz = (size_t)maxlen;
struct log_c *lc = log->context;
switch (status_type) {
case STATUSTYPE_INFO:
r = userspace_do_request(lc, lc->uuid, DM_ULOG_STATUS_INFO,
NULL, 0,
result, &sz);
if (r) {
sz = 0;
DMEMIT("%s 1 COM_FAILURE", log->type->name);
}
break;
case STATUSTYPE_TABLE:
sz = 0;
DMEMIT("%s %u %s %s", log->type->name, lc->usr_argc + 1,
lc->uuid, lc->usr_argv_str);
break;
}
return (r) ? 0 : (int)sz;
}
/*
* userspace_is_remote_recovering
*
* Returns: 1 if region recovering, 0 otherwise
*/
static int userspace_is_remote_recovering(struct dm_dirty_log *log,
region_t region)
{
int r;
uint64_t region64 = region;
struct log_c *lc = log->context;
static unsigned long long limit;
struct {
int64_t is_recovering;
uint64_t in_sync_hint;
} pkg;
size_t rdata_size = sizeof(pkg);
/*
* Once the mirror has been reported to be in-sync,
* it will never again ask for recovery work. So,
* we can safely say there is not a remote machine
* recovering if the device is in-sync. (in_sync_hint
* must be reset at resume time.)
*/
if (region < lc->in_sync_hint)
return 0;
else if (jiffies < limit)
return 1;
limit = jiffies + (HZ / 4);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_REMOTE_RECOVERING,
(char *)&region64, sizeof(region64),
(char *)&pkg, &rdata_size);
if (r)
return 1;
lc->in_sync_hint = pkg.in_sync_hint;
return (int)pkg.is_recovering;
}
static struct dm_dirty_log_type _userspace_type = {
.name = "userspace",
.module = THIS_MODULE,
.ctr = userspace_ctr,
.dtr = userspace_dtr,
.presuspend = userspace_presuspend,
.postsuspend = userspace_postsuspend,
.resume = userspace_resume,
.get_region_size = userspace_get_region_size,
.is_clean = userspace_is_clean,
.in_sync = userspace_in_sync,
.flush = userspace_flush,
.mark_region = userspace_mark_region,
.clear_region = userspace_clear_region,
.get_resync_work = userspace_get_resync_work,
.set_region_sync = userspace_set_region_sync,
.get_sync_count = userspace_get_sync_count,
.status = userspace_status,
.is_remote_recovering = userspace_is_remote_recovering,
};
static int __init userspace_dirty_log_init(void)
{
int r = 0;
flush_entry_pool = mempool_create(100, flush_entry_alloc,
flush_entry_free, NULL);
if (!flush_entry_pool) {
DMWARN("Unable to create flush_entry_pool: No memory.");
return -ENOMEM;
}
r = dm_ulog_tfr_init();
if (r) {
DMWARN("Unable to initialize userspace log communications");
mempool_destroy(flush_entry_pool);
return r;
}
r = dm_dirty_log_type_register(&_userspace_type);
if (r) {
DMWARN("Couldn't register userspace dirty log type");
dm_ulog_tfr_exit();
mempool_destroy(flush_entry_pool);
return r;
}
DMINFO("version 1.0.0 loaded");
return 0;
}
static void __exit userspace_dirty_log_exit(void)
{
dm_dirty_log_type_unregister(&_userspace_type);
dm_ulog_tfr_exit();
mempool_destroy(flush_entry_pool);
DMINFO("version 1.0.0 unloaded");
return;
}
module_init(userspace_dirty_log_init);
module_exit(userspace_dirty_log_exit);
MODULE_DESCRIPTION(DM_NAME " userspace dirty log link");
MODULE_AUTHOR("Jonathan Brassow <dm-devel@redhat.com>");
MODULE_LICENSE("GPL");

276
drivers/md/dm-log-userspace-transfer.c Normal file
View File

@ -0,0 +1,276 @@
/*
* Copyright (C) 2006-2009 Red Hat, Inc.
*
* This file is released under the LGPL.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <net/sock.h>
#include <linux/workqueue.h>
#include <linux/connector.h>
#include <linux/device-mapper.h>
#include <linux/dm-log-userspace.h>
#include "dm-log-userspace-transfer.h"
static uint32_t dm_ulog_seq;
/*
* Netlink/Connector is an unreliable protocol. How long should
* we wait for a response before assuming it was lost and retrying?
* (If we do receive a response after this time, it will be discarded
* and the response to the resent request will be waited for.
*/
#define DM_ULOG_RETRY_TIMEOUT (15 * HZ)
/*
* Pre-allocated space for speed
*/
#define DM_ULOG_PREALLOCED_SIZE 512
static struct cn_msg *prealloced_cn_msg;
static struct dm_ulog_request *prealloced_ulog_tfr;
static struct cb_id ulog_cn_id = {
.idx = CN_IDX_DM,
.val = CN_VAL_DM_USERSPACE_LOG
};
static DEFINE_MUTEX(dm_ulog_lock);
struct receiving_pkg {
struct list_head list;
struct completion complete;
uint32_t seq;
int error;
size_t *data_size;
char *data;
};
static DEFINE_SPINLOCK(receiving_list_lock);
static struct list_head receiving_list;
static int dm_ulog_sendto_server(struct dm_ulog_request *tfr)
{
int r;
struct cn_msg *msg = prealloced_cn_msg;
memset(msg, 0, sizeof(struct cn_msg));
msg->id.idx = ulog_cn_id.idx;
msg->id.val = ulog_cn_id.val;
msg->ack = 0;
msg->seq = tfr->seq;
msg->len = sizeof(struct dm_ulog_request) + tfr->data_size;
r = cn_netlink_send(msg, 0, gfp_any());
return r;
}
/*
* Parameters for this function can be either msg or tfr, but not
* both. This function fills in the reply for a waiting request.
* If just msg is given, then the reply is simply an ACK from userspace
* that the request was received.
*
* Returns: 0 on success, -ENOENT on failure
*/
static int fill_pkg(struct cn_msg *msg, struct dm_ulog_request *tfr)
{
uint32_t rtn_seq = (msg) ? msg->seq : (tfr) ? tfr->seq : 0;
struct receiving_pkg *pkg;
/*
* The 'receiving_pkg' entries in this list are statically
* allocated on the stack in 'dm_consult_userspace'.
* Each process that is waiting for a reply from the user
* space server will have an entry in this list.
*
* We are safe to do it this way because the stack space
* is unique to each process, but still addressable by
* other processes.
*/
list_for_each_entry(pkg, &receiving_list, list) {
if (rtn_seq != pkg->seq)
continue;
if (msg) {
pkg->error = -msg->ack;
/*
* If we are trying again, we will need to know our
* storage capacity. Otherwise, along with the
* error code, we make explicit that we have no data.
*/
if (pkg->error != -EAGAIN)
*(pkg->data_size) = 0;
} else if (tfr->data_size > *(pkg->data_size)) {
DMERR("Insufficient space to receive package [%u] "
"(%u vs %lu)", tfr->request_type,
tfr->data_size, *(pkg->data_size));
*(pkg->data_size) = 0;
pkg->error = -ENOSPC;
} else {
pkg->error = tfr->error;
memcpy(pkg->data, tfr->data, tfr->data_size);
*(pkg->data_size) = tfr->data_size;
}
complete(&pkg->complete);
return 0;
}
return -ENOENT;
}
/*
* This is the connector callback that delivers data
* that was sent from userspace.
*/
static void cn_ulog_callback(void *data)
{
struct cn_msg *msg = (struct cn_msg *)data;
struct dm_ulog_request *tfr = (struct dm_ulog_request *)(msg + 1);
spin_lock(&receiving_list_lock);
if (msg->len == 0)
fill_pkg(msg, NULL);
else if (msg->len < sizeof(*tfr))
DMERR("Incomplete message received (expected %u, got %u): [%u]",
(unsigned)sizeof(*tfr), msg->len, msg->seq);
else
fill_pkg(NULL, tfr);
spin_unlock(&receiving_list_lock);
}
/**
* dm_consult_userspace
* @uuid: log's uuid (must be DM_UUID_LEN in size)
* @request_type: found in include/linux/dm-log-userspace.h
* @data: data to tx to the server
* @data_size: size of data in bytes
* @rdata: place to put return data from server
* @rdata_size: value-result (amount of space given/amount of space used)
*
* rdata_size is undefined on failure.
*
* Memory used to communicate with userspace is zero'ed
* before populating to ensure that no unwanted bits leak
* from kernel space to user-space. All userspace log communications
* between kernel and user space go through this function.
*
* Returns: 0 on success, -EXXX on failure
**/
int dm_consult_userspace(const char *uuid, int request_type,
char *data, size_t data_size,
char *rdata, size_t *rdata_size)
{
int r = 0;
size_t dummy = 0;
int overhead_size =
sizeof(struct dm_ulog_request *) + sizeof(struct cn_msg);
struct dm_ulog_request *tfr = prealloced_ulog_tfr;
struct receiving_pkg pkg;
if (data_size > (DM_ULOG_PREALLOCED_SIZE - overhead_size)) {
DMINFO("Size of tfr exceeds preallocated size");
return -EINVAL;
}
if (!rdata_size)
rdata_size = &dummy;
resend:
/*
* We serialize the sending of requests so we can
* use the preallocated space.
*/
mutex_lock(&dm_ulog_lock);
memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - overhead_size);
memcpy(tfr->uuid, uuid, DM_UUID_LEN);
tfr->seq = dm_ulog_seq++;
/*
* Must be valid request type (all other bits set to
* zero). This reserves other bits for possible future
* use.
*/
tfr->request_type = request_type & DM_ULOG_REQUEST_MASK;
tfr->data_size = data_size;
if (data && data_size)
memcpy(tfr->data, data, data_size);
memset(&pkg, 0, sizeof(pkg));
init_completion(&pkg.complete);
pkg.seq = tfr->seq;
pkg.data_size = rdata_size;
pkg.data = rdata;
spin_lock(&receiving_list_lock);
list_add(&(pkg.list), &receiving_list);
spin_unlock(&receiving_list_lock);
r = dm_ulog_sendto_server(tfr);
mutex_unlock(&dm_ulog_lock);
if (r) {
DMERR("Unable to send log request [%u] to userspace: %d",
request_type, r);
spin_lock(&receiving_list_lock);
list_del_init(&(pkg.list));
spin_unlock(&receiving_list_lock);
goto out;
}
r = wait_for_completion_timeout(&(pkg.complete), DM_ULOG_RETRY_TIMEOUT);
spin_lock(&receiving_list_lock);
list_del_init(&(pkg.list));
spin_unlock(&receiving_list_lock);
if (!r) {
DMWARN("[%s] Request timed out: [%u/%u] - retrying",
(strlen(uuid) > 8) ?
(uuid + (strlen(uuid) - 8)) : (uuid),
request_type, pkg.seq);
goto resend;
}
r = pkg.error;
if (r == -EAGAIN)
goto resend;
out:
return r;
}
int dm_ulog_tfr_init(void)
{
int r;
void *prealloced;
INIT_LIST_HEAD(&receiving_list);
prealloced = kmalloc(DM_ULOG_PREALLOCED_SIZE, GFP_KERNEL);
if (!prealloced)
return -ENOMEM;
prealloced_cn_msg = prealloced;
prealloced_ulog_tfr = prealloced + sizeof(struct cn_msg);
r = cn_add_callback(&ulog_cn_id, "dmlogusr", cn_ulog_callback);
if (r) {
cn_del_callback(&ulog_cn_id);
return r;
}
return 0;
}
void dm_ulog_tfr_exit(void)
{
cn_del_callback(&ulog_cn_id);
kfree(prealloced_cn_msg);
}

18
drivers/md/dm-log-userspace-transfer.h Normal file
View File

@ -0,0 +1,18 @@
/*
* Copyright (C) 2006-2009 Red Hat, Inc.
*
* This file is released under the LGPL.
*/
#ifndef __DM_LOG_USERSPACE_TRANSFER_H__
#define __DM_LOG_USERSPACE_TRANSFER_H__
#define DM_MSG_PREFIX "dm-log-userspace"
int dm_ulog_tfr_init(void);
void dm_ulog_tfr_exit(void);
int dm_consult_userspace(const char *uuid, int request_type,
char *data, size_t data_size,
char *rdata, size_t *rdata_size);
#endif /* __DM_LOG_USERSPACE_TRANSFER_H__ */

9
drivers/md/dm-log.c
View File

@ -412,11 +412,12 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
/*
* Buffer holds both header and bitset.
*/
buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
bitset_size,
ti->limits.logical_block_size);
buf_size =
dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
bdev_logical_block_size(lc->header_location.
bdev));
if (buf_size > dev->bdev->bd_inode->i_size) {
if (buf_size > i_size_read(dev->bdev->bd_inode)) {
DMWARN("log device %s too small: need %llu bytes",
dev->name, (unsigned long long)buf_size);
kfree(lc);

334
drivers/md/dm-mpath.c
View File

@ -8,7 +8,6 @@
#include <linux/device-mapper.h>
#include "dm-path-selector.h"
#include "dm-bio-record.h"
#include "dm-uevent.h"
#include <linux/ctype.h>
@ -35,6 +34,7 @@ struct pgpath {
struct dm_path path;
struct work_struct deactivate_path;
struct work_struct activate_path;
};
#define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
@ -64,8 +64,6 @@ struct multipath {
spinlock_t lock;
const char *hw_handler_name;
struct work_struct activate_path;
struct pgpath *pgpath_to_activate;
unsigned nr_priority_groups;
struct list_head priority_groups;
unsigned pg_init_required; /* pg_init needs calling? */
@ -84,7 +82,7 @@ struct multipath {
unsigned pg_init_count; /* Number of times pg_init called */
struct work_struct process_queued_ios;
struct bio_list queued_ios;
struct list_head queued_ios;
unsigned queue_size;
struct work_struct trigger_event;
@ -101,7 +99,7 @@ struct multipath {
*/
struct dm_mpath_io {
struct pgpath *pgpath;
struct dm_bio_details details;
size_t nr_bytes;
};
typedef int (*action_fn) (struct pgpath *pgpath);
@ -128,6 +126,7 @@ static struct pgpath *alloc_pgpath(void)
if (pgpath) {
pgpath->is_active = 1;
INIT_WORK(&pgpath->deactivate_path, deactivate_path);
INIT_WORK(&pgpath->activate_path, activate_path);
}
return pgpath;
@ -160,7 +159,6 @@ static struct priority_group *alloc_priority_group(void)
static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
{
unsigned long flags;
struct pgpath *pgpath, *tmp;
struct multipath *m = ti->private;
@ -169,10 +167,6 @@ static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
if (m->hw_handler_name)
scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev));
dm_put_device(ti, pgpath->path.dev);
spin_lock_irqsave(&m->lock, flags);
if (m->pgpath_to_activate == pgpath)
m->pgpath_to_activate = NULL;
spin_unlock_irqrestore(&m->lock, flags);
free_pgpath(pgpath);
}
}
@ -198,11 +192,11 @@ 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;
INIT_WORK(&m->process_queued_ios, process_queued_ios);
INIT_WORK(&m->trigger_event, trigger_event);
INIT_WORK(&m->activate_path, activate_path);
m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);
if (!m->mpio_pool) {
kfree(m);
@ -250,11 +244,12 @@ static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
m->pg_init_count = 0;
}
static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg)
static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg,
size_t nr_bytes)
{
struct dm_path *path;
path = pg->ps.type->select_path(&pg->ps, &m->repeat_count);
path = pg->ps.type->select_path(&pg->ps, &m->repeat_count, nr_bytes);
if (!path)
return -ENXIO;
@ -266,7 +261,7 @@ static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg)
return 0;
}
static void __choose_pgpath(struct multipath *m)
static void __choose_pgpath(struct multipath *m, size_t nr_bytes)
{
struct priority_group *pg;
unsigned bypassed = 1;
@ -278,12 +273,12 @@ static void __choose_pgpath(struct multipath *m)
if (m->next_pg) {
pg = m->next_pg;
m->next_pg = NULL;
if (!__choose_path_in_pg(m, pg))
if (!__choose_path_in_pg(m, pg, nr_bytes))
return;
}
/* Don't change PG until it has no remaining paths */
if (m->current_pg && !__choose_path_in_pg(m, m->current_pg))
if (m->current_pg && !__choose_path_in_pg(m, m->current_pg, nr_bytes))
return;
/*
@ -295,7 +290,7 @@ static void __choose_pgpath(struct multipath *m)
list_for_each_entry(pg, &m->priority_groups, list) {
if (pg->bypassed == bypassed)
continue;
if (!__choose_path_in_pg(m, pg))
if (!__choose_path_in_pg(m, pg, nr_bytes))
return;
}
} while (bypassed--);
@ -322,19 +317,21 @@ static int __must_push_back(struct multipath *m)
dm_noflush_suspending(m->ti));
}
static int map_io(struct multipath *m, struct bio *bio,
static int map_io(struct multipath *m, struct request *clone,
struct dm_mpath_io *mpio, unsigned was_queued)
{
int r = DM_MAPIO_REMAPPED;
size_t nr_bytes = blk_rq_bytes(clone);
unsigned long flags;
struct pgpath *pgpath;
struct block_device *bdev;
spin_lock_irqsave(&m->lock, flags);
/* Do we need to select a new pgpath? */
if (!m->current_pgpath ||
(!m->queue_io && (m->repeat_count && --m->repeat_count == 0)))
__choose_pgpath(m);
__choose_pgpath(m, nr_bytes);
pgpath = m->current_pgpath;
@ -344,21 +341,28 @@ static int map_io(struct multipath *m, struct bio *bio,
if ((pgpath && m->queue_io) ||
(!pgpath && m->queue_if_no_path)) {
/* Queue for the daemon to resubmit */
bio_list_add(&m->queued_ios, bio);
list_add_tail(&clone->queuelist, &m->queued_ios);
m->queue_size++;
if ((m->pg_init_required && !m->pg_init_in_progress) ||
!m->queue_io)
queue_work(kmultipathd, &m->process_queued_ios);
pgpath = NULL;
r = DM_MAPIO_SUBMITTED;
} else if (pgpath)
bio->bi_bdev = pgpath->path.dev->bdev;
else if (__must_push_back(m))
} 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 */
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,
nr_bytes);
spin_unlock_irqrestore(&m->lock, flags);
@ -396,30 +400,31 @@ static void dispatch_queued_ios(struct multipath *m)
{
int r;
unsigned long flags;
struct bio *bio = NULL, *next;
struct dm_mpath_io *mpio;
union map_info *info;
struct request *clone, *n;
LIST_HEAD(cl);
spin_lock_irqsave(&m->lock, flags);
bio = bio_list_get(&m->queued_ios);
list_splice_init(&m->queued_ios, &cl);
spin_unlock_irqrestore(&m->lock, flags);
while (bio) {
next = bio->bi_next;
bio->bi_next = NULL;
list_for_each_entry_safe(clone, n, &cl, queuelist) {
list_del_init(&clone->queuelist);
info = dm_get_mapinfo(bio);
info = dm_get_rq_mapinfo(clone);
mpio = info->ptr;
r = map_io(m, bio, mpio, 1);
if (r < 0)
bio_endio(bio, r);
else if (r == DM_MAPIO_REMAPPED)
generic_make_request(bio);
else if (r == DM_MAPIO_REQUEUE)
bio_endio(bio, -EIO);
bio = next;
r = map_io(m, clone, mpio, 1);
if (r < 0) {
mempool_free(mpio, m->mpio_pool);
dm_kill_unmapped_request(clone, r);
} else if (r == DM_MAPIO_REMAPPED)
dm_dispatch_request(clone);
else if (r == DM_MAPIO_REQUEUE) {
mempool_free(mpio, m->mpio_pool);
dm_requeue_unmapped_request(clone);
}
}
}
@ -427,8 +432,8 @@ 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 init_required = 0, must_queue = 1;
struct pgpath *pgpath = NULL, *tmp;
unsigned must_queue = 1;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
@ -437,7 +442,7 @@ static void process_queued_ios(struct work_struct *work)
goto out;
if (!m->current_pgpath)
__choose_pgpath(m);
__choose_pgpath(m, 0);
pgpath = m->current_pgpath;
@ -446,19 +451,15 @@ static void process_queued_ios(struct work_struct *work)
must_queue = 0;
if (m->pg_init_required && !m->pg_init_in_progress && pgpath) {
m->pgpath_to_activate = pgpath;
m->pg_init_count++;
m->pg_init_required = 0;
m->pg_init_in_progress = 1;
init_required = 1;
list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) {
if (queue_work(kmpath_handlerd, &tmp->activate_path))
m->pg_init_in_progress++;
}
}
out:
spin_unlock_irqrestore(&m->lock, flags);
if (init_required)
queue_work(kmpath_handlerd, &m->activate_path);
if (!must_queue)
dispatch_queued_ios(m);
}
@ -553,6 +554,12 @@ static int parse_path_selector(struct arg_set *as, struct priority_group *pg,
return -EINVAL;
}
if (ps_argc > as->argc) {
dm_put_path_selector(pst);
ti->error = "not enough arguments for path selector";
return -EINVAL;
}
r = pst->create(&pg->ps, ps_argc, as->argv);
if (r) {
dm_put_path_selector(pst);
@ -591,9 +598,20 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
}
if (m->hw_handler_name) {
r = scsi_dh_attach(bdev_get_queue(p->path.dev->bdev),
m->hw_handler_name);
struct request_queue *q = bdev_get_queue(p->path.dev->bdev);
r = scsi_dh_attach(q, m->hw_handler_name);
if (r == -EBUSY) {
/*
* Already attached to different hw_handler,
* try to reattach with correct one.
*/
scsi_dh_detach(q);
r = scsi_dh_attach(q, m->hw_handler_name);
}
if (r < 0) {
ti->error = "error attaching hardware handler";
dm_put_device(ti, p->path.dev);
goto bad;
}
@ -699,6 +717,11 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m)
if (!hw_argc)
return 0;
if (hw_argc > as->argc) {
ti->error = "not enough arguments for hardware handler";
return -EINVAL;
}
m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL);
request_module("scsi_dh_%s", m->hw_handler_name);
if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
@ -823,6 +846,8 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
goto bad;
}
ti->num_flush_requests = 1;
return 0;
bad:
@ -836,25 +861,29 @@ static void multipath_dtr(struct dm_target *ti)
flush_workqueue(kmpath_handlerd);
flush_workqueue(kmultipathd);
flush_scheduled_work();
free_multipath(m);
}
/*
* Map bios, recording original fields for later in case we have to resubmit
* Map cloned requests
*/
static int multipath_map(struct dm_target *ti, struct bio *bio,
static int multipath_map(struct dm_target *ti, struct request *clone,
union map_info *map_context)
{
int r;
struct dm_mpath_io *mpio;
struct multipath *m = (struct multipath *) ti->private;
mpio = mempool_alloc(m->mpio_pool, GFP_NOIO);
dm_bio_record(&mpio->details, bio);
mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC);
if (!mpio)
/* ENOMEM, requeue */
return DM_MAPIO_REQUEUE;
memset(mpio, 0, sizeof(*mpio));
map_context->ptr = mpio;
bio->bi_rw |= (1 << BIO_RW_FAILFAST_TRANSPORT);
r = map_io(m, bio, mpio, 0);
clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
r = map_io(m, clone, mpio, 0);
if (r < 0 || r == DM_MAPIO_REQUEUE)
mempool_free(mpio, m->mpio_pool);
@ -924,9 +953,13 @@ static int reinstate_path(struct pgpath *pgpath)
pgpath->is_active = 1;
m->current_pgpath = NULL;
if (!m->nr_valid_paths++ && m->queue_size)
if (!m->nr_valid_paths++ && m->queue_size) {
m->current_pgpath = NULL;
queue_work(kmultipathd, &m->process_queued_ios);
} else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) {
if (queue_work(kmpath_handlerd, &pgpath->activate_path))
m->pg_init_in_progress++;
}
dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
pgpath->path.dev->name, m->nr_valid_paths);
@ -1102,87 +1135,70 @@ static void pg_init_done(struct dm_path *path, int errors)
spin_lock_irqsave(&m->lock, flags);
if (errors) {
DMERR("Could not failover device. Error %d.", errors);
m->current_pgpath = NULL;
m->current_pg = NULL;
if (pgpath == m->current_pgpath) {
DMERR("Could not failover device. Error %d.", errors);
m->current_pgpath = NULL;
m->current_pg = NULL;
}
} else if (!m->pg_init_required) {
m->queue_io = 0;
pg->bypassed = 0;
}
m->pg_init_in_progress = 0;
queue_work(kmultipathd, &m->process_queued_ios);
m->pg_init_in_progress--;
if (!m->pg_init_in_progress)
queue_work(kmultipathd, &m->process_queued_ios);
spin_unlock_irqrestore(&m->lock, flags);
}
static void activate_path(struct work_struct *work)
{
int ret;
struct multipath *m =
container_of(work, struct multipath, activate_path);
struct dm_path *path;
unsigned long flags;
struct pgpath *pgpath =
container_of(work, struct pgpath, activate_path);
spin_lock_irqsave(&m->lock, flags);
path = &m->pgpath_to_activate->path;
m->pgpath_to_activate = NULL;
spin_unlock_irqrestore(&m->lock, flags);
if (!path)
return;
ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev));
pg_init_done(path, ret);
ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
pg_init_done(&pgpath->path, ret);
}
/*
* end_io handling
*/
static int do_end_io(struct multipath *m, struct bio *bio,
static int do_end_io(struct multipath *m, struct request *clone,
int error, struct dm_mpath_io *mpio)
{
/*
* We don't queue any clone request inside the multipath target
* during end I/O handling, since those clone requests don't have
* bio clones. If we queue them inside the multipath target,
* we need to make bio clones, that requires memory allocation.
* (See drivers/md/dm.c:end_clone_bio() about why the clone requests
* don't have bio clones.)
* Instead of queueing the clone request here, we queue the original
* request into dm core, which will remake a clone request and
* clone bios for it and resubmit it later.
*/
int r = DM_ENDIO_REQUEUE;
unsigned long flags;
if (!error)
if (!error && !clone->errors)
return 0; /* I/O complete */
if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio))
return error;
if (error == -EOPNOTSUPP)
return error;
spin_lock_irqsave(&m->lock, flags);
if (!m->nr_valid_paths) {
if (__must_push_back(m)) {
spin_unlock_irqrestore(&m->lock, flags);
return DM_ENDIO_REQUEUE;
} else if (!m->queue_if_no_path) {
spin_unlock_irqrestore(&m->lock, flags);
return -EIO;
} else {
spin_unlock_irqrestore(&m->lock, flags);
goto requeue;
}
}
spin_unlock_irqrestore(&m->lock, flags);
if (mpio->pgpath)
fail_path(mpio->pgpath);
requeue:
dm_bio_restore(&mpio->details, bio);
/* queue for the daemon to resubmit or fail */
spin_lock_irqsave(&m->lock, flags);
bio_list_add(&m->queued_ios, bio);
m->queue_size++;
if (!m->queue_io)
queue_work(kmultipathd, &m->process_queued_ios);
if (!m->nr_valid_paths && !m->queue_if_no_path && !__must_push_back(m))
r = -EIO;
spin_unlock_irqrestore(&m->lock, flags);
return DM_ENDIO_INCOMPLETE; /* io not complete */
return r;
}
static int multipath_end_io(struct dm_target *ti, struct bio *bio,
static int multipath_end_io(struct dm_target *ti, struct request *clone,
int error, union map_info *map_context)
{
struct multipath *m = ti->private;
@ -1191,14 +1207,13 @@ static int multipath_end_io(struct dm_target *ti, struct bio *bio,
struct path_selector *ps;
int r;
r = do_end_io(m, bio, error, mpio);
r = do_end_io(m, clone, error, mpio);
if (pgpath) {
ps = &pgpath->pg->ps;
if (ps->type->end_io)
ps->type->end_io(ps, &pgpath->path);
ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
}
if (r != DM_ENDIO_INCOMPLETE)
mempool_free(mpio, m->mpio_pool);
mempool_free(mpio, m->mpio_pool);
return r;
}
@ -1411,7 +1426,7 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
spin_lock_irqsave(&m->lock, flags);
if (!m->current_pgpath)
__choose_pgpath(m);
__choose_pgpath(m, 0);
if (m->current_pgpath) {
bdev = m->current_pgpath->path.dev->bdev;
@ -1428,22 +1443,113 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
}
static int multipath_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct multipath *m = ti->private;
struct priority_group *pg;
struct pgpath *p;
int ret = 0;
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(p, &pg->pgpaths, list) {
ret = fn(ti, p->path.dev, ti->begin, data);
if (ret)
goto out;
}
}
out:
return ret;
}
static int __pgpath_busy(struct pgpath *pgpath)
{
struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
return dm_underlying_device_busy(q);
}
/*
* We return "busy", only when we can map I/Os but underlying devices
* are busy (so even if we map I/Os now, the I/Os will wait on
* the underlying queue).
* In other words, if we want to kill I/Os or queue them inside us
* due to map unavailability, we don't return "busy". Otherwise,
* dm core won't give us the I/Os and we can't do what we want.
*/
static int multipath_busy(struct dm_target *ti)
{
int busy = 0, has_active = 0;
struct multipath *m = ti->private;
struct priority_group *pg;
struct pgpath *pgpath;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
/* Guess which priority_group will be used at next mapping time */
if (unlikely(!m->current_pgpath && m->next_pg))
pg = m->next_pg;
else if (likely(m->current_pg))
pg = m->current_pg;
else
/*
* We don't know which pg will be used at next mapping time.
* We don't call __choose_pgpath() here to avoid to trigger
* pg_init just by busy checking.
* So we don't know whether underlying devices we will be using
* at next mapping time are busy or not. Just try mapping.
*/
goto out;
/*
* If there is one non-busy active path at least, the path selector
* will be able to select it. So we consider such a pg as not busy.
*/
busy = 1;
list_for_each_entry(pgpath, &pg->pgpaths, list)
if (pgpath->is_active) {
has_active = 1;
if (!__pgpath_busy(pgpath)) {
busy = 0;
break;
}
}
if (!has_active)
/*
* No active path in this pg, so this pg won't be used and
* the current_pg will be changed at next mapping time.
* We need to try mapping to determine it.
*/
busy = 0;
out:
spin_unlock_irqrestore(&m->lock, flags);
return busy;
}
/*-----------------------------------------------------------------
* Module setup
*---------------------------------------------------------------*/
static struct target_type multipath_target = {
.name = "multipath",
.version = {1, 0, 5},
.version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = multipath_ctr,
.dtr = multipath_dtr,
.map = multipath_map,
.end_io = multipath_end_io,
.map_rq = multipath_map,
.rq_end_io = multipath_end_io,
.presuspend = multipath_presuspend,
.resume = multipath_resume,
.status = multipath_status,
.message = multipath_message,
.ioctl = multipath_ioctl,
.iterate_devices = multipath_iterate_devices,
.busy = multipath_busy,
};
static int __init dm_multipath_init(void)

8
drivers/md/dm-path-selector.h
View File

@ -56,7 +56,8 @@ struct path_selector_type {
* the path fails.
*/
struct dm_path *(*select_path) (struct path_selector *ps,
unsigned *repeat_count);
unsigned *repeat_count,
size_t nr_bytes);
/*
* Notify the selector that a path has failed.
@ -75,7 +76,10 @@ struct path_selector_type {
int (*status) (struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned int maxlen);
int (*end_io) (struct path_selector *ps, struct dm_path *path);
int (*start_io) (struct path_selector *ps, struct dm_path *path,
size_t nr_bytes);
int (*end_io) (struct path_selector *ps, struct dm_path *path,
size_t nr_bytes);
};
/* Register a path selector */

263
drivers/md/dm-queue-length.c Normal file
View File

@ -0,0 +1,263 @@
/*
* Copyright (C) 2004-2005 IBM Corp. All Rights Reserved.
* Copyright (C) 2006-2009 NEC Corporation.
*
* dm-queue-length.c
*
* Module Author: Stefan Bader, IBM
* Modified by: Kiyoshi Ueda, NEC
*
* This file is released under the GPL.
*
* queue-length path selector - choose a path with the least number of
* in-flight I/Os.
*/
#include "dm.h"
#include "dm-path-selector.h"
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <asm/atomic.h>
#define DM_MSG_PREFIX "multipath queue-length"
#define QL_MIN_IO 128
#define QL_VERSION "0.1.0"
struct selector {
struct list_head valid_paths;
struct list_head failed_paths;
};
struct path_info {
struct list_head list;
struct dm_path *path;
unsigned repeat_count;
atomic_t qlen; /* the number of in-flight I/Os */
};
static struct selector *alloc_selector(void)
{
struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s) {
INIT_LIST_HEAD(&s->valid_paths);
INIT_LIST_HEAD(&s->failed_paths);
}
return s;
}
static int ql_create(struct path_selector *ps, unsigned argc, char **argv)
{
struct selector *s = alloc_selector();
if (!s)
return -ENOMEM;
ps->context = s;
return 0;
}
static void ql_free_paths(struct list_head *paths)
{
struct path_info *pi, *next;
list_for_each_entry_safe(pi, next, paths, list) {
list_del(&pi->list);
kfree(pi);
}
}
static void ql_destroy(struct path_selector *ps)
{
struct selector *s = ps->context;
ql_free_paths(&s->valid_paths);
ql_free_paths(&s->failed_paths);
kfree(s);
ps->context = NULL;
}
static int ql_status(struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned maxlen)
{
unsigned sz = 0;
struct path_info *pi;
/* When called with NULL path, return selector status/args. */
if (!path)
DMEMIT("0 ");
else {
pi = path->pscontext;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%d ", atomic_read(&pi->qlen));
break;
case STATUSTYPE_TABLE:
DMEMIT("%u ", pi->repeat_count);
break;
}
}
return sz;
}
static int ql_add_path(struct path_selector *ps, struct dm_path *path,
int argc, char **argv, char **error)
{
struct selector *s = ps->context;
struct path_info *pi;
unsigned repeat_count = QL_MIN_IO;
/*
* Arguments: [<repeat_count>]
* <repeat_count>: The number of I/Os before switching path.
* If not given, default (QL_MIN_IO) is used.
*/
if (argc > 1) {
*error = "queue-length ps: incorrect number of arguments";
return -EINVAL;
}
if ((argc == 1) && (sscanf(argv[0], "%u", &repeat_count) != 1)) {
*error = "queue-length ps: invalid repeat count";
return -EINVAL;
}
/* Allocate the path information structure */
pi = kmalloc(sizeof(*pi), GFP_KERNEL);
if (!pi) {
*error = "queue-length ps: Error allocating path information";
return -ENOMEM;
}
pi->path = path;
pi->repeat_count = repeat_count;
atomic_set(&pi->qlen, 0);
path->pscontext = pi;
list_add_tail(&pi->list, &s->valid_paths);
return 0;
}
static void ql_fail_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
list_move(&pi->list, &s->failed_paths);
}
static int ql_reinstate_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
list_move_tail(&pi->list, &s->valid_paths);
return 0;
}
/*
* Select a path having the minimum number of in-flight I/Os
*/
static struct dm_path *ql_select_path(struct path_selector *ps,
unsigned *repeat_count, size_t nr_bytes)
{
struct selector *s = ps->context;
struct path_info *pi = NULL, *best = NULL;
if (list_empty(&s->valid_paths))
return NULL;
/* Change preferred (first in list) path to evenly balance. */
list_move_tail(s->valid_paths.next, &s->valid_paths);
list_for_each_entry(pi, &s->valid_paths, list) {
if (!best ||
(atomic_read(&pi->qlen) < atomic_read(&best->qlen)))
best = pi;
if (!atomic_read(&best->qlen))
break;
}
if (!best)
return NULL;
*repeat_count = best->repeat_count;
return best->path;
}
static int ql_start_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes)
{
struct path_info *pi = path->pscontext;
atomic_inc(&pi->qlen);
return 0;
}
static int ql_end_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes)
{
struct path_info *pi = path->pscontext;
atomic_dec(&pi->qlen);
return 0;
}
static struct path_selector_type ql_ps = {
.name = "queue-length",
.module = THIS_MODULE,
.table_args = 1,
.info_args = 1,
.create = ql_create,
.destroy = ql_destroy,
.status = ql_status,
.add_path = ql_add_path,
.fail_path = ql_fail_path,
.reinstate_path = ql_reinstate_path,
.select_path = ql_select_path,
.start_io = ql_start_io,
.end_io = ql_end_io,
};
static int __init dm_ql_init(void)
{
int r = dm_register_path_selector(&ql_ps);
if (r < 0)
DMERR("register failed %d", r);
DMINFO("version " QL_VERSION " loaded");
return r;
}
static void __exit dm_ql_exit(void)
{
int r = dm_unregister_path_selector(&ql_ps);
if (r < 0)
DMERR("unregister failed %d", r);
}
module_init(dm_ql_init);
module_exit(dm_ql_exit);
MODULE_AUTHOR("Stefan Bader <Stefan.Bader at de.ibm.com>");
MODULE_DESCRIPTION(
"(C) Copyright IBM Corp. 2004,2005 All Rights Reserved.\n"
DM_NAME " path selector to balance the number of in-flight I/Os"
);
MODULE_LICENSE("GPL");

17
drivers/md/dm-raid1.c
View File

@ -1283,9 +1283,23 @@ static int mirror_status(struct dm_target *ti, status_type_t type,
return 0;
}
static int mirror_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct mirror_set *ms = ti->private;
int ret = 0;
unsigned i;
for (i = 0; !ret && i < ms->nr_mirrors; i++)
ret = fn(ti, ms->mirror[i].dev,
ms->mirror[i].offset, data);
return ret;
}
static struct target_type mirror_target = {
.name = "mirror",
.version = {1, 0, 20},
.version = {1, 12, 0},
.module = THIS_MODULE,
.ctr = mirror_ctr,
.dtr = mirror_dtr,
@ -1295,6 +1309,7 @@ static struct target_type mirror_target = {
.postsuspend = mirror_postsuspend,
.resume = mirror_resume,
.status = mirror_status,
.iterate_devices = mirror_iterate_devices,
};
static int __init dm_mirror_init(void)

2
drivers/md/dm-region-hash.c
View File

@ -283,7 +283,7 @@ static struct dm_region *__rh_alloc(struct dm_region_hash *rh, region_t region)
nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC);
if (unlikely(!nreg))
nreg = kmalloc(sizeof(*nreg), GFP_NOIO);
nreg = kmalloc(sizeof(*nreg), GFP_NOIO | __GFP_NOFAIL);
nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?
DM_RH_CLEAN : DM_RH_NOSYNC;

2
drivers/md/dm-round-robin.c
View File

@ -161,7 +161,7 @@ static int rr_reinstate_path(struct path_selector *ps, struct dm_path *p)
}
static struct dm_path *rr_select_path(struct path_selector *ps,
unsigned *repeat_count)
unsigned *repeat_count, size_t nr_bytes)
{
struct selector *s = (struct selector *) ps->context;
struct path_info *pi = NULL;

339
drivers/md/dm-service-time.c Normal file
View File

@ -0,0 +1,339 @@
/*
* Copyright (C) 2007-2009 NEC Corporation. All Rights Reserved.
*
* Module Author: Kiyoshi Ueda
*
* This file is released under the GPL.
*
* Throughput oriented path selector.
*/
#include "dm.h"
#include "dm-path-selector.h"
#define DM_MSG_PREFIX "multipath service-time"
#define ST_MIN_IO 1
#define ST_MAX_RELATIVE_THROUGHPUT 100
#define ST_MAX_RELATIVE_THROUGHPUT_SHIFT 7
#define ST_MAX_INFLIGHT_SIZE ((size_t)-1 >> ST_MAX_RELATIVE_THROUGHPUT_SHIFT)
#define ST_VERSION "0.2.0"
struct selector {
struct list_head valid_paths;
struct list_head failed_paths;
};
struct path_info {
struct list_head list;
struct dm_path *path;
unsigned repeat_count;
unsigned relative_throughput;
atomic_t in_flight_size; /* Total size of in-flight I/Os */
};
static struct selector *alloc_selector(void)
{
struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s) {
INIT_LIST_HEAD(&s->valid_paths);
INIT_LIST_HEAD(&s->failed_paths);
}
return s;
}
static int st_create(struct path_selector *ps, unsigned argc, char **argv)
{
struct selector *s = alloc_selector();
if (!s)
return -ENOMEM;
ps->context = s;
return 0;
}
static void free_paths(struct list_head *paths)
{
struct path_info *pi, *next;
list_for_each_entry_safe(pi, next, paths, list) {
list_del(&pi->list);
kfree(pi);
}
}
static void st_destroy(struct path_selector *ps)
{
struct selector *s = ps->context;
free_paths(&s->valid_paths);
free_paths(&s->failed_paths);
kfree(s);
ps->context = NULL;
}
static int st_status(struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned maxlen)
{
unsigned sz = 0;
struct path_info *pi;
if (!path)
DMEMIT("0 ");
else {
pi = path->pscontext;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%d %u ", atomic_read(&pi->in_flight_size),
pi->relative_throughput);
break;
case STATUSTYPE_TABLE:
DMEMIT("%u %u ", pi->repeat_count,
pi->relative_throughput);
break;
}
}
return sz;
}
static int st_add_path(struct path_selector *ps, struct dm_path *path,
int argc, char **argv, char **error)
{
struct selector *s = ps->context;
struct path_info *pi;
unsigned repeat_count = ST_MIN_IO;
unsigned relative_throughput = 1;
/*
* Arguments: [<repeat_count> [<relative_throughput>]]
* <repeat_count>: The number of I/Os before switching path.
* If not given, default (ST_MIN_IO) is used.
* <relative_throughput>: The relative throughput value of
* the path among all paths in the path-group.
* The valid range: 0-<ST_MAX_RELATIVE_THROUGHPUT>
* If not given, minimum value '1' is used.
* If '0' is given, the path isn't selected while
* other paths having a positive value are
* available.
*/
if (argc > 2) {
*error = "service-time ps: incorrect number of arguments";
return -EINVAL;
}
if (argc && (sscanf(argv[0], "%u", &repeat_count) != 1)) {
*error = "service-time ps: invalid repeat count";
return -EINVAL;
}
if ((argc == 2) &&
(sscanf(argv[1], "%u", &relative_throughput) != 1 ||
relative_throughput > ST_MAX_RELATIVE_THROUGHPUT)) {
*error = "service-time ps: invalid relative_throughput value";
return -EINVAL;
}
/* allocate the path */
pi = kmalloc(sizeof(*pi), GFP_KERNEL);
if (!pi) {
*error = "service-time ps: Error allocating path context";
return -ENOMEM;
}
pi->path = path;
pi->repeat_count = repeat_count;
pi->relative_throughput = relative_throughput;
atomic_set(&pi->in_flight_size, 0);
path->pscontext = pi;
list_add_tail(&pi->list, &s->valid_paths);
return 0;
}
static void st_fail_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
list_move(&pi->list, &s->failed_paths);
}
static int st_reinstate_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
list_move_tail(&pi->list, &s->valid_paths);
return 0;
}
/*
* Compare the estimated service time of 2 paths, pi1 and pi2,
* for the incoming I/O.
*
* Returns:
* < 0 : pi1 is better
* 0 : no difference between pi1 and pi2
* > 0 : pi2 is better
*
* Description:
* Basically, the service time is estimated by:
* ('pi->in-flight-size' + 'incoming') / 'pi->relative_throughput'
* To reduce the calculation, some optimizations are made.
* (See comments inline)
*/
static int st_compare_load(struct path_info *pi1, struct path_info *pi2,
size_t incoming)
{
size_t sz1, sz2, st1, st2;
sz1 = atomic_read(&pi1->in_flight_size);
sz2 = atomic_read(&pi2->in_flight_size);
/*
* Case 1: Both have same throughput value. Choose less loaded path.
*/
if (pi1->relative_throughput == pi2->relative_throughput)
return sz1 - sz2;
/*
* Case 2a: Both have same load. Choose higher throughput path.
* Case 2b: One path has no throughput value. Choose the other one.
*/
if (sz1 == sz2 ||
!pi1->relative_throughput || !pi2->relative_throughput)
return pi2->relative_throughput - pi1->relative_throughput;
/*
* Case 3: Calculate service time. Choose faster path.
* Service time using pi1:
* st1 = (sz1 + incoming) / pi1->relative_throughput
* Service time using pi2:
* st2 = (sz2 + incoming) / pi2->relative_throughput
*
* To avoid the division, transform the expression to use
* multiplication.
* Because ->relative_throughput > 0 here, if st1 < st2,
* the expressions below are the same meaning:
* (sz1 + incoming) / pi1->relative_throughput <
* (sz2 + incoming) / pi2->relative_throughput
* (sz1 + incoming) * pi2->relative_throughput <
* (sz2 + incoming) * pi1->relative_throughput
* So use the later one.
*/
sz1 += incoming;
sz2 += incoming;
if (unlikely(sz1 >= ST_MAX_INFLIGHT_SIZE ||
sz2 >= ST_MAX_INFLIGHT_SIZE)) {
/*
* Size may be too big for multiplying pi->relative_throughput
* and overflow.
* To avoid the overflow and mis-selection, shift down both.
*/
sz1 >>= ST_MAX_RELATIVE_THROUGHPUT_SHIFT;
sz2 >>= ST_MAX_RELATIVE_THROUGHPUT_SHIFT;
}
st1 = sz1 * pi2->relative_throughput;
st2 = sz2 * pi1->relative_throughput;
if (st1 != st2)
return st1 - st2;
/*
* Case 4: Service time is equal. Choose higher throughput path.
*/
return pi2->relative_throughput - pi1->relative_throughput;
}
static struct dm_path *st_select_path(struct path_selector *ps,
unsigned *repeat_count, size_t nr_bytes)
{
struct selector *s = ps->context;
struct path_info *pi = NULL, *best = NULL;
if (list_empty(&s->valid_paths))
return NULL;
/* Change preferred (first in list) path to evenly balance. */
list_move_tail(s->valid_paths.next, &s->valid_paths);
list_for_each_entry(pi, &s->valid_paths, list)
if (!best || (st_compare_load(pi, best, nr_bytes) < 0))
best = pi;
if (!best)
return NULL;
*repeat_count = best->repeat_count;
return best->path;
}
static int st_start_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes)
{
struct path_info *pi = path->pscontext;
atomic_add(nr_bytes, &pi->in_flight_size);
return 0;
}
static int st_end_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes)
{
struct path_info *pi = path->pscontext;
atomic_sub(nr_bytes, &pi->in_flight_size);
return 0;
}
static struct path_selector_type st_ps = {
.name = "service-time",
.module = THIS_MODULE,
.table_args = 2,
.info_args = 2,
.create = st_create,
.destroy = st_destroy,
.status = st_status,
.add_path = st_add_path,
.fail_path = st_fail_path,
.reinstate_path = st_reinstate_path,
.select_path = st_select_path,
.start_io = st_start_io,
.end_io = st_end_io,
};
static int __init dm_st_init(void)
{
int r = dm_register_path_selector(&st_ps);
if (r < 0)
DMERR("register failed %d", r);
DMINFO("version " ST_VERSION " loaded");
return r;
}
static void __exit dm_st_exit(void)
{
int r = dm_unregister_path_selector(&st_ps);
if (r < 0)
DMERR("unregister failed %d", r);
}
module_init(dm_st_init);
module_exit(dm_st_exit);
MODULE_DESCRIPTION(DM_NAME " throughput oriented path selector");
MODULE_AUTHOR("Kiyoshi Ueda <k-ueda@ct.jp.nec.com>");
MODULE_LICENSE("GPL");

2
drivers/md/dm-snap-persistent.c
View File

@ -636,7 +636,7 @@ static void persistent_commit_exception(struct dm_exception_store *store,
/*
* Commit exceptions to disk.
*/
if (ps->valid && area_io(ps, WRITE))
if (ps->valid && area_io(ps, WRITE_BARRIER))
ps->valid = 0;
/*

11
drivers/md/dm-snap.c
View File

@ -678,6 +678,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ti->private = s;
ti->split_io = s->store->chunk_size;
ti->num_flush_requests = 1;
return 0;
@ -1030,6 +1031,11 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
if (unlikely(bio_empty_barrier(bio))) {
bio->bi_bdev = s->store->cow->bdev;
return DM_MAPIO_REMAPPED;
}
chunk = sector_to_chunk(s->store, bio->bi_sector);
/* Full snapshots are not usable */
@ -1338,6 +1344,8 @@ static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
}
ti->private = dev;
ti->num_flush_requests = 1;
return 0;
}
@ -1353,6 +1361,9 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
struct dm_dev *dev = ti->private;
bio->bi_bdev = dev->bdev;
if (unlikely(bio_empty_barrier(bio)))
return DM_MAPIO_REMAPPED;
/* Only tell snapshots if this is a write */
return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED;
}

33
drivers/md/dm-stripe.c
View File

@ -167,6 +167,7 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
sc->stripes = stripes;
sc->stripe_width = width;
ti->split_io = chunk_size;
ti->num_flush_requests = stripes;
sc->chunk_mask = ((sector_t) chunk_size) - 1;
for (sc->chunk_shift = 0; chunk_size; sc->chunk_shift++)
@ -211,10 +212,18 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
union map_info *map_context)
{
struct stripe_c *sc = (struct stripe_c *) ti->private;
sector_t offset, chunk;
uint32_t stripe;
sector_t offset = bio->bi_sector - ti->begin;
sector_t chunk = offset >> sc->chunk_shift;
uint32_t stripe = sector_div(chunk, sc->stripes);
if (unlikely(bio_empty_barrier(bio))) {
BUG_ON(map_context->flush_request >= sc->stripes);
bio->bi_bdev = sc->stripe[map_context->flush_request].dev->bdev;
return DM_MAPIO_REMAPPED;
}
offset = bio->bi_sector - ti->begin;
chunk = offset >> sc->chunk_shift;
stripe = sector_div(chunk, sc->stripes);
bio->bi_bdev = sc->stripe[stripe].dev->bdev;
bio->bi_sector = sc->stripe[stripe].physical_start +
@ -304,15 +313,31 @@ static int stripe_end_io(struct dm_target *ti, struct bio *bio,
return error;
}
static int stripe_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct stripe_c *sc = ti->private;
int ret = 0;
unsigned i = 0;
do
ret = fn(ti, sc->stripe[i].dev,
sc->stripe[i].physical_start, data);
while (!ret && ++i < sc->stripes);
return ret;
}
static struct target_type stripe_target = {
.name = "striped",
.version = {1, 1, 0},
.version = {1, 2, 0},
.module = THIS_MODULE,
.ctr = stripe_ctr,
.dtr = stripe_dtr,
.map = stripe_map,
.end_io = stripe_end_io,
.status = stripe_status,
.iterate_devices = stripe_iterate_devices,
};
int __init dm_stripe_init(void)

9
drivers/md/dm-sysfs.c
View File

@ -57,12 +57,21 @@ static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf)
return strlen(buf);
}
static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
{
sprintf(buf, "%d\n", dm_suspended(md));
return strlen(buf);
}
static DM_ATTR_RO(name);
static DM_ATTR_RO(uuid);
static DM_ATTR_RO(suspended);
static struct attribute *dm_attrs[] = {
&dm_attr_name.attr,
&dm_attr_uuid.attr,
&dm_attr_suspended.attr,
NULL,
};

463
drivers/md/dm-table.c
View File

@ -41,6 +41,7 @@
struct dm_table {
struct mapped_device *md;
atomic_t holders;
unsigned type;
/* btree table */
unsigned int depth;
@ -62,15 +63,11 @@ struct dm_table {
/* a list of devices used by this table */
struct list_head devices;
/*
* These are optimistic limits taken from all the
* targets, some targets will need smaller limits.
*/
struct io_restrictions limits;
/* events get handed up using this callback */
void (*event_fn)(void *);
void *event_context;
struct dm_md_mempools *mempools;
};
/*
@ -88,43 +85,6 @@ static unsigned int int_log(unsigned int n, unsigned int base)
return result;
}
/*
* Returns the minimum that is _not_ zero, unless both are zero.
*/
#define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r))
/*
* Combine two io_restrictions, always taking the lower value.
*/
static void combine_restrictions_low(struct io_restrictions *lhs,
struct io_restrictions *rhs)
{
lhs->max_sectors =
min_not_zero(lhs->max_sectors, rhs->max_sectors);
lhs->max_phys_segments =
min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments);
lhs->max_hw_segments =
min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments);
lhs->logical_block_size = max(lhs->logical_block_size,
rhs->logical_block_size);
lhs->max_segment_size =
min_not_zero(lhs->max_segment_size, rhs->max_segment_size);
lhs->max_hw_sectors =
min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors);
lhs->seg_boundary_mask =
min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask);
lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn);
lhs->no_cluster |= rhs->no_cluster;
}
/*
* Calculate the index of the child node of the n'th node k'th key.
*/
@ -267,6 +227,8 @@ static void free_devices(struct list_head *devices)
list_for_each_safe(tmp, next, devices) {
struct dm_dev_internal *dd =
list_entry(tmp, struct dm_dev_internal, list);
DMWARN("dm_table_destroy: dm_put_device call missing for %s",
dd->dm_dev.name);
kfree(dd);
}
}
@ -296,12 +258,10 @@ void dm_table_destroy(struct dm_table *t)
vfree(t->highs);
/* free the device list */
if (t->devices.next != &t->devices) {
DMWARN("devices still present during destroy: "
"dm_table_remove_device calls missing");
if (t->devices.next != &t->devices)
free_devices(&t->devices);
}
dm_free_md_mempools(t->mempools);
kfree(t);
}
@ -385,15 +345,48 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
/*
* If possible, this checks an area of a destination device is valid.
*/
static int check_device_area(struct dm_dev_internal *dd, sector_t start,
sector_t len)
static int device_area_is_valid(struct dm_target *ti, struct dm_dev *dev,
sector_t start, void *data)
{
sector_t dev_size = dd->dm_dev.bdev->bd_inode->i_size >> SECTOR_SHIFT;
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
sector_t dev_size =
i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
unsigned short logical_block_size_sectors =
limits->logical_block_size >> SECTOR_SHIFT;
char b[BDEVNAME_SIZE];
if (!dev_size)
return 1;
return ((start < dev_size) && (len <= (dev_size - start)));
if ((start >= dev_size) || (start + ti->len > dev_size)) {
DMWARN("%s: %s too small for target",
dm_device_name(ti->table->md), bdevname(bdev, b));
return 0;
}
if (logical_block_size_sectors <= 1)
return 1;
if (start & (logical_block_size_sectors - 1)) {
DMWARN("%s: start=%llu not aligned to h/w "
"logical block size %hu of %s",
dm_device_name(ti->table->md),
(unsigned long long)start,
limits->logical_block_size, bdevname(bdev, b));
return 0;
}
if (ti->len & (logical_block_size_sectors - 1)) {
DMWARN("%s: len=%llu not aligned to h/w "
"logical block size %hu of %s",
dm_device_name(ti->table->md),
(unsigned long long)ti->len,
limits->logical_block_size, bdevname(bdev, b));
return 0;
}
return 1;
}
/*
@ -479,38 +472,32 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
}
atomic_inc(&dd->count);
if (!check_device_area(dd, start, len)) {
DMWARN("device %s too small for target", path);
dm_put_device(ti, &dd->dm_dev);
return -EINVAL;
}
*result = &dd->dm_dev;
return 0;
}
void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev)
/*
* Returns the minimum that is _not_ zero, unless both are zero.
*/
#define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r))
int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
sector_t start, void *data)
{
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
struct request_queue *q = bdev_get_queue(bdev);
struct io_restrictions *rs = &ti->limits;
char b[BDEVNAME_SIZE];
if (unlikely(!q)) {
DMWARN("%s: Cannot set limits for nonexistent device %s",
dm_device_name(ti->table->md), bdevname(bdev, b));
return;
return 0;
}
/*
* Combine the device limits low.
*
* FIXME: if we move an io_restriction struct
* into q this would just be a call to
* combine_restrictions_low()
*/
rs->max_sectors =
min_not_zero(rs->max_sectors, queue_max_sectors(q));
if (blk_stack_limits(limits, &q->limits, start) < 0)
DMWARN("%s: target device %s is misaligned",
dm_device_name(ti->table->md), bdevname(bdev, b));
/*
* Check if merge fn is supported.
@ -519,48 +506,21 @@ void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev)
*/
if (q->merge_bvec_fn && !ti->type->merge)
rs->max_sectors =
min_not_zero(rs->max_sectors,
limits->max_sectors =
min_not_zero(limits->max_sectors,
(unsigned int) (PAGE_SIZE >> 9));
rs->max_phys_segments =
min_not_zero(rs->max_phys_segments,
queue_max_phys_segments(q));
rs->max_hw_segments =
min_not_zero(rs->max_hw_segments, queue_max_hw_segments(q));
rs->logical_block_size = max(rs->logical_block_size,
queue_logical_block_size(q));
rs->max_segment_size =
min_not_zero(rs->max_segment_size, queue_max_segment_size(q));
rs->max_hw_sectors =
min_not_zero(rs->max_hw_sectors, queue_max_hw_sectors(q));
rs->seg_boundary_mask =
min_not_zero(rs->seg_boundary_mask,
queue_segment_boundary(q));
rs->bounce_pfn = min_not_zero(rs->bounce_pfn, queue_bounce_pfn(q));
rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
return 0;
}
EXPORT_SYMBOL_GPL(dm_set_device_limits);
int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
sector_t len, fmode_t mode, struct dm_dev **result)
{
int r = __table_get_device(ti->table, ti, path,
start, len, mode, result);
if (!r)
dm_set_device_limits(ti, (*result)->bdev);
return r;
return __table_get_device(ti->table, ti, path,
start, len, mode, result);
}
/*
* Decrement a devices use count and remove it if necessary.
*/
@ -675,24 +635,78 @@ int dm_split_args(int *argc, char ***argvp, char *input)
return 0;
}
static void check_for_valid_limits(struct io_restrictions *rs)
/*
* Impose necessary and sufficient conditions on a devices's table such
* that any incoming bio which respects its logical_block_size can be
* processed successfully. If it falls across the boundary between
* two or more targets, the size of each piece it gets split into must
* be compatible with the logical_block_size of the target processing it.
*/
static int validate_hardware_logical_block_alignment(struct dm_table *table,
struct queue_limits *limits)
{
if (!rs->max_sectors)
rs->max_sectors = SAFE_MAX_SECTORS;
if (!rs->max_hw_sectors)
rs->max_hw_sectors = SAFE_MAX_SECTORS;
if (!rs->max_phys_segments)
rs->max_phys_segments = MAX_PHYS_SEGMENTS;
if (!rs->max_hw_segments)
rs->max_hw_segments = MAX_HW_SEGMENTS;
if (!rs->logical_block_size)
rs->logical_block_size = 1 << SECTOR_SHIFT;
if (!rs->max_segment_size)
rs->max_segment_size = MAX_SEGMENT_SIZE;
if (!rs->seg_boundary_mask)
rs->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
if (!rs->bounce_pfn)
rs->bounce_pfn = -1;
/*
* This function uses arithmetic modulo the logical_block_size
* (in units of 512-byte sectors).
*/
unsigned short device_logical_block_size_sects =
limits->logical_block_size >> SECTOR_SHIFT;
/*
* Offset of the start of the next table entry, mod logical_block_size.
*/
unsigned short next_target_start = 0;
/*
* Given an aligned bio that extends beyond the end of a
* target, how many sectors must the next target handle?
*/
unsigned short remaining = 0;
struct dm_target *uninitialized_var(ti);
struct queue_limits ti_limits;
unsigned i = 0;
/*
* Check each entry in the table in turn.
*/
while (i < dm_table_get_num_targets(table)) {
ti = dm_table_get_target(table, i++);
blk_set_default_limits(&ti_limits);
/* combine all target devices' limits */
if (ti->type->iterate_devices)
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
/*
* If the remaining sectors fall entirely within this
* table entry are they compatible with its logical_block_size?
*/
if (remaining < ti->len &&
remaining & ((ti_limits.logical_block_size >>
SECTOR_SHIFT) - 1))
break; /* Error */
next_target_start =
(unsigned short) ((next_target_start + ti->len) &
(device_logical_block_size_sects - 1));
remaining = next_target_start ?
device_logical_block_size_sects - next_target_start : 0;
}
if (remaining) {
DMWARN("%s: table line %u (start sect %llu len %llu) "
"not aligned to h/w logical block size %hu",
dm_device_name(table->md), i,
(unsigned long long) ti->begin,
(unsigned long long) ti->len,
limits->logical_block_size);
return -EINVAL;
}
return 0;
}
int dm_table_add_target(struct dm_table *t, const char *type,
@ -747,9 +761,6 @@ int dm_table_add_target(struct dm_table *t, const char *type,
t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
/* FIXME: the plan is to combine high here and then have
* the merge fn apply the target level restrictions. */
combine_restrictions_low(&t->limits, &tgt->limits);
return 0;
bad:
@ -758,6 +769,104 @@ int dm_table_add_target(struct dm_table *t, const char *type,
return r;
}
int dm_table_set_type(struct dm_table *t)
{
unsigned i;
unsigned bio_based = 0, request_based = 0;
struct dm_target *tgt;
struct dm_dev_internal *dd;
struct list_head *devices;
for (i = 0; i < t->num_targets; i++) {
tgt = t->targets + i;
if (dm_target_request_based(tgt))
request_based = 1;
else
bio_based = 1;
if (bio_based && request_based) {
DMWARN("Inconsistent table: different target types"
" can't be mixed up");
return -EINVAL;
}
}
if (bio_based) {
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;
return 0;
}
BUG_ON(!request_based); /* No targets in this table */
/* Non-request-stackable devices can't be used for request-based dm */
devices = dm_table_get_devices(t);
list_for_each_entry(dd, devices, list) {
if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
DMWARN("table load rejected: including"
" non-request-stackable devices");
return -EINVAL;
}
}
/*
* Request-based dm supports only tables that have a single target now.
* To support multiple targets, request splitting support is needed,
* and that needs lots of changes in the block-layer.
* (e.g. request completion process for partial completion.)
*/
if (t->num_targets > 1) {
DMWARN("Request-based dm doesn't support multiple targets yet");
return -EINVAL;
}
t->type = DM_TYPE_REQUEST_BASED;
return 0;
}
unsigned dm_table_get_type(struct dm_table *t)
{
return t->type;
}
bool dm_table_bio_based(struct dm_table *t)
{
return dm_table_get_type(t) == DM_TYPE_BIO_BASED;
}
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)
{
unsigned type = dm_table_get_type(t);
if (unlikely(type == DM_TYPE_NONE)) {
DMWARN("no table type is set, can't allocate mempools");
return -EINVAL;
}
t->mempools = dm_alloc_md_mempools(type);
if (!t->mempools)
return -ENOMEM;
return 0;
}
void dm_table_free_md_mempools(struct dm_table *t)
{
dm_free_md_mempools(t->mempools);
t->mempools = NULL;
}
struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
{
return t->mempools;
}
static int setup_indexes(struct dm_table *t)
{
int i;
@ -792,8 +901,6 @@ int dm_table_complete(struct dm_table *t)
int r = 0;
unsigned int leaf_nodes;
check_for_valid_limits(&t->limits);
/* how many indexes will the btree have ? */
leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
@ -868,6 +975,57 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
return &t->targets[(KEYS_PER_NODE * n) + k];
}
/*
* Establish the new table's queue_limits and validate them.
*/
int dm_calculate_queue_limits(struct dm_table *table,
struct queue_limits *limits)
{
struct dm_target *uninitialized_var(ti);
struct queue_limits ti_limits;
unsigned i = 0;
blk_set_default_limits(limits);
while (i < dm_table_get_num_targets(table)) {
blk_set_default_limits(&ti_limits);
ti = dm_table_get_target(table, i++);
if (!ti->type->iterate_devices)
goto combine_limits;
/*
* Combine queue limits of all the devices this target uses.
*/
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
/*
* Check each device area is consistent with the target's
* overall queue limits.
*/
if (!ti->type->iterate_devices(ti, device_area_is_valid,
&ti_limits))
return -EINVAL;
combine_limits:
/*
* Merge this target's queue limits into the overall limits
* for the table.
*/
if (blk_stack_limits(limits, &ti_limits, 0) < 0)
DMWARN("%s: target device "
"(start sect %llu len %llu) "
"is misaligned",
dm_device_name(table->md),
(unsigned long long) ti->begin,
(unsigned long long) ti->len);
}
return validate_hardware_logical_block_alignment(table, limits);
}
/*
* Set the integrity profile for this device if all devices used have
* matching profiles.
@ -907,27 +1065,42 @@ no_integrity:
return;
}
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q)
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
/*
* Make sure we obey the optimistic sub devices
* restrictions.
* Each target device in the table has a data area that should normally
* be aligned such that the DM device's alignment_offset is 0.
* FIXME: Propagate alignment_offsets up the stack and warn of
* sub-optimal or inconsistent settings.
*/
blk_queue_max_sectors(q, t->limits.max_sectors);
blk_queue_max_phys_segments(q, t->limits.max_phys_segments);
blk_queue_max_hw_segments(q, t->limits.max_hw_segments);
blk_queue_logical_block_size(q, t->limits.logical_block_size);
blk_queue_max_segment_size(q, t->limits.max_segment_size);
blk_queue_max_hw_sectors(q, t->limits.max_hw_sectors);
blk_queue_segment_boundary(q, t->limits.seg_boundary_mask);
blk_queue_bounce_limit(q, t->limits.bounce_pfn);
limits->alignment_offset = 0;
limits->misaligned = 0;
if (t->limits.no_cluster)
/*
* Copy table's limits to the DM device's request_queue
*/
q->limits = *limits;
if (limits->no_cluster)
queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
else
queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q);
dm_table_set_integrity(t);
/*
* QUEUE_FLAG_STACKABLE must be set after all queue settings are
* visible to other CPUs because, once the flag is set, incoming bios
* are processed by request-based dm, which refers to the queue
* settings.
* Until the flag set, bios are passed to bio-based dm and queued to
* md->deferred where queue settings are not needed yet.
* Those bios are passed to request-based dm at the resume time.
*/
smp_mb();
if (dm_table_request_based(t))
queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
}
unsigned int dm_table_get_num_targets(struct dm_table *t)
@ -1023,6 +1196,20 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits)
return r;
}
int dm_table_any_busy_target(struct dm_table *t)
{
unsigned i;
struct dm_target *ti;
for (i = 0; i < t->num_targets; i++) {
ti = t->targets + i;
if (ti->type->busy && ti->type->busy(ti))
return 1;
}
return 0;
}
void dm_table_unplug_all(struct dm_table *t)
{
struct dm_dev_internal *dd;

1133
drivers/md/dm.c
View File

File diff suppressed because it is too large Load Diff

35
drivers/md/dm.h
View File

@ -22,6 +22,13 @@
#define DM_SUSPEND_LOCKFS_FLAG (1 << 0)
#define DM_SUSPEND_NOFLUSH_FLAG (1 << 1)
/*
* Type of table and mapped_device's mempool
*/
#define DM_TYPE_NONE 0
#define DM_TYPE_BIO_BASED 1
#define DM_TYPE_REQUEST_BASED 2
/*
* List of devices that a metadevice uses and should open/close.
*/
@ -32,6 +39,7 @@ struct dm_dev_internal {
};
struct dm_table;
struct dm_md_mempools;
/*-----------------------------------------------------------------
* Internal table functions.
@ -41,18 +49,34 @@ void dm_table_event_callback(struct dm_table *t,
void (*fn)(void *), void *context);
struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
int dm_calculate_queue_limits(struct dm_table *table,
struct queue_limits *limits);
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits);
struct list_head *dm_table_get_devices(struct dm_table *t);
void dm_table_presuspend_targets(struct dm_table *t);
void dm_table_postsuspend_targets(struct dm_table *t);
int dm_table_resume_targets(struct dm_table *t);
int dm_table_any_congested(struct dm_table *t, int bdi_bits);
int dm_table_any_busy_target(struct dm_table *t);
int dm_table_set_type(struct dm_table *t);
unsigned dm_table_get_type(struct dm_table *t);
bool dm_table_bio_based(struct dm_table *t);
bool dm_table_request_based(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);
/*
* To check the return value from dm_table_find_target().
*/
#define dm_target_is_valid(t) ((t)->table)
/*
* To check whether the target type is request-based or not (bio-based).
*/
#define dm_target_request_based(t) ((t)->type->map_rq != NULL)
/*-----------------------------------------------------------------
* A registry of target types.
*---------------------------------------------------------------*/
@ -92,9 +116,16 @@ void dm_stripe_exit(void);
int dm_open_count(struct mapped_device *md);
int dm_lock_for_deletion(struct mapped_device *md);
void dm_kobject_uevent(struct mapped_device *md);
void dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
unsigned cookie);
int dm_kcopyd_init(void);
void dm_kcopyd_exit(void);
/*
* Mempool operations
*/
struct dm_md_mempools *dm_alloc_md_mempools(unsigned type);
void dm_free_md_mempools(struct dm_md_mempools *pools);
#endif

1
include/linux/Kbuild
View File

@ -57,6 +57,7 @@ header-y += dlmconstants.h
header-y += dlm_device.h
header-y += dlm_netlink.h
header-y += dm-ioctl.h
header-y += dm-log-userspace.h
header-y += dn.h
header-y += dqblk_xfs.h
header-y += efs_fs_sb.h

4
include/linux/connector.h
View File

@ -41,8 +41,10 @@
#define CN_IDX_BB 0x5 /* BlackBoard, from the TSP GPL sampling framework */
#define CN_DST_IDX 0x6
#define CN_DST_VAL 0x1
#define CN_IDX_DM 0x7 /* Device Mapper */
#define CN_VAL_DM_USERSPACE_LOG 0x1
#define CN_NETLINK_USERS 7
#define CN_NETLINK_USERS 8
/*
* Maximum connector's message size.

47
include/linux/device-mapper.h
View File

@ -11,6 +11,7 @@
#include <linux/bio.h>
#include <linux/blkdev.h>
struct dm_dev;
struct dm_target;
struct dm_table;
struct mapped_device;
@ -21,6 +22,7 @@ typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
union map_info {
void *ptr;
unsigned long long ll;
unsigned flush_request;
};
/*
@ -80,6 +82,15 @@ typedef int (*dm_ioctl_fn) (struct dm_target *ti, unsigned int cmd,
typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
struct bio_vec *biovec, int max_size);
typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
struct dm_dev *dev,
sector_t physical_start,
void *data);
typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
iterate_devices_callout_fn fn,
void *data);
/*
* Returns:
* 0: The target can handle the next I/O immediately.
@ -92,7 +103,8 @@ void dm_error(const char *message);
/*
* Combine device limits.
*/
void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev);
int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
sector_t start, void *data);
struct dm_dev {
struct block_device *bdev;
@ -138,23 +150,12 @@ struct target_type {
dm_ioctl_fn ioctl;
dm_merge_fn merge;
dm_busy_fn busy;
dm_iterate_devices_fn iterate_devices;
/* For internal device-mapper use. */
struct list_head list;
};
struct io_restrictions {
unsigned long bounce_pfn;
unsigned long seg_boundary_mask;
unsigned max_hw_sectors;
unsigned max_sectors;
unsigned max_segment_size;
unsigned short logical_block_size;
unsigned short max_hw_segments;
unsigned short max_phys_segments;
unsigned char no_cluster; /* inverted so that 0 is default */
};
struct dm_target {
struct dm_table *table;
struct target_type *type;
@ -163,15 +164,18 @@ struct dm_target {
sector_t begin;
sector_t len;
/* FIXME: turn this into a mask, and merge with io_restrictions */
/* Always a power of 2 */
sector_t split_io;
/*
* These are automatically filled in by
* dm_table_get_device.
* A number of zero-length barrier requests that will be submitted
* to the target for the purpose of flushing cache.
*
* The request number will be placed in union map_info->flush_request.
* It is a responsibility of the target driver to remap these requests
* to the real underlying devices.
*/
struct io_restrictions limits;
unsigned num_flush_requests;
/* target specific data */
void *private;
@ -230,6 +234,7 @@ struct gendisk *dm_disk(struct mapped_device *md);
int dm_suspended(struct mapped_device *md);
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);
/*
* Geometry functions.
@ -392,4 +397,12 @@ static inline unsigned long to_bytes(sector_t n)
return (n << SECTOR_SHIFT);
}
/*-----------------------------------------------------------------
* Helper for block layer and dm core operations
*---------------------------------------------------------------*/
void dm_dispatch_request(struct request *rq);
void dm_requeue_unmapped_request(struct request *rq);
void dm_kill_unmapped_request(struct request *rq, int error);
int dm_underlying_device_busy(struct request_queue *q);
#endif /* _LINUX_DEVICE_MAPPER_H */

14
include/linux/dm-ioctl.h
View File

@ -123,6 +123,16 @@ struct dm_ioctl {
__u32 target_count; /* in/out */
__s32 open_count; /* out */
__u32 flags; /* in/out */
/*
* event_nr holds either the event number (input and output) or the
* udev cookie value (input only).
* The DM_DEV_WAIT ioctl takes an event number as input.
* The DM_SUSPEND, DM_DEV_REMOVE and DM_DEV_RENAME ioctls
* use the field as a cookie to return in the DM_COOKIE
* variable with the uevents they issue.
* For output, the ioctls return the event number, not the cookie.
*/
__u32 event_nr; /* in/out */
__u32 padding;
@ -256,9 +266,9 @@ enum {
#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)
#define DM_VERSION_MAJOR 4
#define DM_VERSION_MINOR 14
#define DM_VERSION_MINOR 15
#define DM_VERSION_PATCHLEVEL 0
#define DM_VERSION_EXTRA "-ioctl (2008-04-23)"
#define DM_VERSION_EXTRA "-ioctl (2009-04-01)"
/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */

386
include/linux/dm-log-userspace.h Normal file
View File

@ -0,0 +1,386 @@
/*
* Copyright (C) 2006-2009 Red Hat, Inc.
*
* This file is released under the LGPL.
*/
#ifndef __DM_LOG_USERSPACE_H__
#define __DM_LOG_USERSPACE_H__
#include <linux/dm-ioctl.h> /* For DM_UUID_LEN */
/*
* The device-mapper userspace log module consists of a kernel component and
* a user-space component. The kernel component implements the API defined
* in dm-dirty-log.h. Its purpose is simply to pass the parameters and
* return values of those API functions between kernel and user-space.
*
* Below are defined the 'request_types' - DM_ULOG_CTR, DM_ULOG_DTR, etc.
* These request types represent the different functions in the device-mapper
* dirty log API. Each of these is described in more detail below.
*
* The user-space program must listen for requests from the kernel (representing
* the various API functions) and process them.
*
* User-space begins by setting up the communication link (error checking
* removed for clarity):
* fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
* addr.nl_family = AF_NETLINK;
* addr.nl_groups = CN_IDX_DM;
* addr.nl_pid = 0;
* r = bind(fd, (struct sockaddr *) &addr, sizeof(addr));
* opt = addr.nl_groups;
* setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &opt, sizeof(opt));
*
* User-space will then wait to receive requests form the kernel, which it
* will process as described below. The requests are received in the form,
* ((struct dm_ulog_request) + (additional data)). Depending on the request
* type, there may or may not be 'additional data'. In the descriptions below,
* you will see 'Payload-to-userspace' and 'Payload-to-kernel'. The
* 'Payload-to-userspace' is what the kernel sends in 'additional data' as
* necessary parameters to complete the request. The 'Payload-to-kernel' is
* the 'additional data' returned to the kernel that contains the necessary
* results of the request. The 'data_size' field in the dm_ulog_request
* structure denotes the availability and amount of payload data.
*/
/*
* DM_ULOG_CTR corresponds to (found in dm-dirty-log.h):
* int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,
* unsigned argc, char **argv);
*
* Payload-to-userspace:
* A single string containing all the argv arguments separated by ' 's
* Payload-to-kernel:
* None. ('data_size' in the dm_ulog_request struct should be 0.)
*
* The UUID contained in the dm_ulog_request structure is the reference that
* will be used by all request types to a specific log. The constructor must
* record this assotiation with instance created.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_CTR 1
/*
* DM_ULOG_DTR corresponds to (found in dm-dirty-log.h):
* void (*dtr)(struct dm_dirty_log *log);
*
* Payload-to-userspace:
* A single string containing all the argv arguments separated by ' 's
* Payload-to-kernel:
* None. ('data_size' in the dm_ulog_request struct should be 0.)
*
* The UUID contained in the dm_ulog_request structure is all that is
* necessary to identify the log instance being destroyed. There is no
* payload data.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and clearing
* 'data_size' appropriately.
*/
#define DM_ULOG_DTR 2
/*
* DM_ULOG_PRESUSPEND corresponds to (found in dm-dirty-log.h):
* int (*presuspend)(struct dm_dirty_log *log);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* None.
*
* The UUID contained in the dm_ulog_request structure is all that is
* necessary to identify the log instance being presuspended. There is no
* payload data.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_PRESUSPEND 3
/*
* DM_ULOG_POSTSUSPEND corresponds to (found in dm-dirty-log.h):
* int (*postsuspend)(struct dm_dirty_log *log);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* None.
*
* The UUID contained in the dm_ulog_request structure is all that is
* necessary to identify the log instance being postsuspended. There is no
* payload data.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_POSTSUSPEND 4
/*
* DM_ULOG_RESUME corresponds to (found in dm-dirty-log.h):
* int (*resume)(struct dm_dirty_log *log);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* None.
*
* The UUID contained in the dm_ulog_request structure is all that is
* necessary to identify the log instance being resumed. There is no
* payload data.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_RESUME 5
/*
* DM_ULOG_GET_REGION_SIZE corresponds to (found in dm-dirty-log.h):
* uint32_t (*get_region_size)(struct dm_dirty_log *log);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* uint64_t - contains the region size
*
* The region size is something that was determined at constructor time.
* It is returned in the payload area and 'data_size' is set to
* reflect this.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field appropriately.
*/
#define DM_ULOG_GET_REGION_SIZE 6
/*
* DM_ULOG_IS_CLEAN corresponds to (found in dm-dirty-log.h):
* int (*is_clean)(struct dm_dirty_log *log, region_t region);
*
* Payload-to-userspace:
* uint64_t - the region to get clean status on
* Payload-to-kernel:
* int64_t - 1 if clean, 0 otherwise
*
* Payload is sizeof(uint64_t) and contains the region for which the clean
* status is being made.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - filling the payload with 0 (not clean) or
* 1 (clean), setting 'data_size' and 'error' appropriately.
*/
#define DM_ULOG_IS_CLEAN 7
/*
* DM_ULOG_IN_SYNC corresponds to (found in dm-dirty-log.h):
* int (*in_sync)(struct dm_dirty_log *log, region_t region,
* int can_block);
*
* Payload-to-userspace:
* uint64_t - the region to get sync status on
* Payload-to-kernel:
* int64_t - 1 if in-sync, 0 otherwise
*
* Exactly the same as 'is_clean' above, except this time asking "has the
* region been recovered?" vs. "is the region not being modified?"
*/
#define DM_ULOG_IN_SYNC 8
/*
* DM_ULOG_FLUSH corresponds to (found in dm-dirty-log.h):
* int (*flush)(struct dm_dirty_log *log);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* None.
*
* No incoming or outgoing payload. Simply flush log state to disk.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and clearing
* 'data_size' appropriately.
*/
#define DM_ULOG_FLUSH 9
/*
* DM_ULOG_MARK_REGION corresponds to (found in dm-dirty-log.h):
* void (*mark_region)(struct dm_dirty_log *log, region_t region);
*
* Payload-to-userspace:
* uint64_t [] - region(s) to mark
* Payload-to-kernel:
* None.
*
* Incoming payload contains the one or more regions to mark dirty.
* The number of regions contained in the payload can be determined from
* 'data_size/sizeof(uint64_t)'.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and clearing
* 'data_size' appropriately.
*/
#define DM_ULOG_MARK_REGION 10
/*
* DM_ULOG_CLEAR_REGION corresponds to (found in dm-dirty-log.h):
* void (*clear_region)(struct dm_dirty_log *log, region_t region);
*
* Payload-to-userspace:
* uint64_t [] - region(s) to clear
* Payload-to-kernel:
* None.
*
* Incoming payload contains the one or more regions to mark clean.
* The number of regions contained in the payload can be determined from
* 'data_size/sizeof(uint64_t)'.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and clearing
* 'data_size' appropriately.
*/
#define DM_ULOG_CLEAR_REGION 11
/*
* DM_ULOG_GET_RESYNC_WORK corresponds to (found in dm-dirty-log.h):
* int (*get_resync_work)(struct dm_dirty_log *log, region_t *region);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* {
* int64_t i; -- 1 if recovery necessary, 0 otherwise
* uint64_t r; -- The region to recover if i=1
* }
* 'data_size' should be set appropriately.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field appropriately.
*/
#define DM_ULOG_GET_RESYNC_WORK 12
/*
* DM_ULOG_SET_REGION_SYNC corresponds to (found in dm-dirty-log.h):
* void (*set_region_sync)(struct dm_dirty_log *log,
* region_t region, int in_sync);
*
* Payload-to-userspace:
* {
* uint64_t - region to set sync state on
* int64_t - 0 if not-in-sync, 1 if in-sync
* }
* Payload-to-kernel:
* None.
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and clearing
* 'data_size' appropriately.
*/
#define DM_ULOG_SET_REGION_SYNC 13
/*
* DM_ULOG_GET_SYNC_COUNT corresponds to (found in dm-dirty-log.h):
* region_t (*get_sync_count)(struct dm_dirty_log *log);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* uint64_t - the number of in-sync regions
*
* No incoming payload. Kernel-bound payload contains the number of
* regions that are in-sync (in a size_t).
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_GET_SYNC_COUNT 14
/*
* DM_ULOG_STATUS_INFO corresponds to (found in dm-dirty-log.h):
* int (*status)(struct dm_dirty_log *log, STATUSTYPE_INFO,
* char *result, unsigned maxlen);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* Character string containing STATUSTYPE_INFO
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_STATUS_INFO 15
/*
* DM_ULOG_STATUS_TABLE corresponds to (found in dm-dirty-log.h):
* int (*status)(struct dm_dirty_log *log, STATUSTYPE_TABLE,
* char *result, unsigned maxlen);
*
* Payload-to-userspace:
* None.
* Payload-to-kernel:
* Character string containing STATUSTYPE_TABLE
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_STATUS_TABLE 16
/*
* DM_ULOG_IS_REMOTE_RECOVERING corresponds to (found in dm-dirty-log.h):
* int (*is_remote_recovering)(struct dm_dirty_log *log, region_t region);
*
* Payload-to-userspace:
* uint64_t - region to determine recovery status on
* Payload-to-kernel:
* {
* int64_t is_recovering; -- 0 if no, 1 if yes
* uint64_t in_sync_hint; -- lowest region still needing resync
* }
*
* When the request has been processed, user-space must return the
* dm_ulog_request to the kernel - setting the 'error' field and
* 'data_size' appropriately.
*/
#define DM_ULOG_IS_REMOTE_RECOVERING 17
/*
* (DM_ULOG_REQUEST_MASK & request_type) to get the request type
*
* Payload-to-userspace:
* A single string containing all the argv arguments separated by ' 's
* Payload-to-kernel:
* None. ('data_size' in the dm_ulog_request struct should be 0.)
*
* We are reserving 8 bits of the 32-bit 'request_type' field for the
* various request types above. The remaining 24-bits are currently
* set to zero and are reserved for future use and compatibility concerns.
*
* User-space should always use DM_ULOG_REQUEST_TYPE to aquire the
* request type from the 'request_type' field to maintain forward compatibility.
*/
#define DM_ULOG_REQUEST_MASK 0xFF
#define DM_ULOG_REQUEST_TYPE(request_type) \
(DM_ULOG_REQUEST_MASK & (request_type))
struct dm_ulog_request {
char uuid[DM_UUID_LEN]; /* Ties a request to a specific mirror log */
char padding[7]; /* Padding because DM_UUID_LEN = 129 */
int32_t error; /* Used to report back processing errors */
uint32_t seq; /* Sequence number for request */
uint32_t request_type; /* DM_ULOG_* defined above */
uint32_t data_size; /* How much data (not including this struct) */
char data[0];
};
#endif /* __DM_LOG_USERSPACE_H__ */