abebfbe2f7
Allow device-mapper to route flush operations to the per-target implementation. In order for the device stacking to work we need a dax_dev and a pgoff relative to that device. This gives each layer of the stack the information it needs to look up the operation pointer for the next level. This conceptually allows for an array of mixed device drivers with varying flush implementations. Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2927 lines
66 KiB
C
2927 lines
66 KiB
C
/*
|
|
* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
|
|
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
|
|
*
|
|
* This file is released under the GPL.
|
|
*/
|
|
|
|
#include "dm-core.h"
|
|
#include "dm-rq.h"
|
|
#include "dm-uevent.h"
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/sched/signal.h>
|
|
#include <linux/blkpg.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/mempool.h>
|
|
#include <linux/dax.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/uio.h>
|
|
#include <linux/hdreg.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/pr.h>
|
|
|
|
#define DM_MSG_PREFIX "core"
|
|
|
|
#ifdef CONFIG_PRINTK
|
|
/*
|
|
* ratelimit state to be used in DMXXX_LIMIT().
|
|
*/
|
|
DEFINE_RATELIMIT_STATE(dm_ratelimit_state,
|
|
DEFAULT_RATELIMIT_INTERVAL,
|
|
DEFAULT_RATELIMIT_BURST);
|
|
EXPORT_SYMBOL(dm_ratelimit_state);
|
|
#endif
|
|
|
|
/*
|
|
* Cookies are numeric values sent with CHANGE and REMOVE
|
|
* uevents while resuming, removing or renaming the device.
|
|
*/
|
|
#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
|
|
#define DM_COOKIE_LENGTH 24
|
|
|
|
static const char *_name = DM_NAME;
|
|
|
|
static unsigned int major = 0;
|
|
static unsigned int _major = 0;
|
|
|
|
static DEFINE_IDR(_minor_idr);
|
|
|
|
static DEFINE_SPINLOCK(_minor_lock);
|
|
|
|
static void do_deferred_remove(struct work_struct *w);
|
|
|
|
static DECLARE_WORK(deferred_remove_work, do_deferred_remove);
|
|
|
|
static struct workqueue_struct *deferred_remove_workqueue;
|
|
|
|
/*
|
|
* One of these is allocated per bio.
|
|
*/
|
|
struct dm_io {
|
|
struct mapped_device *md;
|
|
int error;
|
|
atomic_t io_count;
|
|
struct bio *bio;
|
|
unsigned long start_time;
|
|
spinlock_t endio_lock;
|
|
struct dm_stats_aux stats_aux;
|
|
};
|
|
|
|
#define MINOR_ALLOCED ((void *)-1)
|
|
|
|
/*
|
|
* Bits for the md->flags field.
|
|
*/
|
|
#define DMF_BLOCK_IO_FOR_SUSPEND 0
|
|
#define DMF_SUSPENDED 1
|
|
#define DMF_FROZEN 2
|
|
#define DMF_FREEING 3
|
|
#define DMF_DELETING 4
|
|
#define DMF_NOFLUSH_SUSPENDING 5
|
|
#define DMF_DEFERRED_REMOVE 6
|
|
#define DMF_SUSPENDED_INTERNALLY 7
|
|
|
|
#define DM_NUMA_NODE NUMA_NO_NODE
|
|
static int dm_numa_node = DM_NUMA_NODE;
|
|
|
|
/*
|
|
* For mempools pre-allocation at the table loading time.
|
|
*/
|
|
struct dm_md_mempools {
|
|
mempool_t *io_pool;
|
|
struct bio_set *bs;
|
|
};
|
|
|
|
struct table_device {
|
|
struct list_head list;
|
|
atomic_t count;
|
|
struct dm_dev dm_dev;
|
|
};
|
|
|
|
static struct kmem_cache *_io_cache;
|
|
static struct kmem_cache *_rq_tio_cache;
|
|
static struct kmem_cache *_rq_cache;
|
|
|
|
/*
|
|
* Bio-based DM's mempools' reserved IOs set by the user.
|
|
*/
|
|
#define RESERVED_BIO_BASED_IOS 16
|
|
static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
|
|
|
|
static int __dm_get_module_param_int(int *module_param, int min, int max)
|
|
{
|
|
int param = ACCESS_ONCE(*module_param);
|
|
int modified_param = 0;
|
|
bool modified = true;
|
|
|
|
if (param < min)
|
|
modified_param = min;
|
|
else if (param > max)
|
|
modified_param = max;
|
|
else
|
|
modified = false;
|
|
|
|
if (modified) {
|
|
(void)cmpxchg(module_param, param, modified_param);
|
|
param = modified_param;
|
|
}
|
|
|
|
return param;
|
|
}
|
|
|
|
unsigned __dm_get_module_param(unsigned *module_param,
|
|
unsigned def, unsigned max)
|
|
{
|
|
unsigned param = ACCESS_ONCE(*module_param);
|
|
unsigned modified_param = 0;
|
|
|
|
if (!param)
|
|
modified_param = def;
|
|
else if (param > max)
|
|
modified_param = max;
|
|
|
|
if (modified_param) {
|
|
(void)cmpxchg(module_param, param, modified_param);
|
|
param = modified_param;
|
|
}
|
|
|
|
return param;
|
|
}
|
|
|
|
unsigned dm_get_reserved_bio_based_ios(void)
|
|
{
|
|
return __dm_get_module_param(&reserved_bio_based_ios,
|
|
RESERVED_BIO_BASED_IOS, DM_RESERVED_MAX_IOS);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
|
|
|
|
static unsigned dm_get_numa_node(void)
|
|
{
|
|
return __dm_get_module_param_int(&dm_numa_node,
|
|
DM_NUMA_NODE, num_online_nodes() - 1);
|
|
}
|
|
|
|
static int __init local_init(void)
|
|
{
|
|
int r = -ENOMEM;
|
|
|
|
/* allocate a slab for the dm_ios */
|
|
_io_cache = KMEM_CACHE(dm_io, 0);
|
|
if (!_io_cache)
|
|
return r;
|
|
|
|
_rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
|
|
if (!_rq_tio_cache)
|
|
goto out_free_io_cache;
|
|
|
|
_rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request),
|
|
__alignof__(struct request), 0, NULL);
|
|
if (!_rq_cache)
|
|
goto out_free_rq_tio_cache;
|
|
|
|
r = dm_uevent_init();
|
|
if (r)
|
|
goto out_free_rq_cache;
|
|
|
|
deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);
|
|
if (!deferred_remove_workqueue) {
|
|
r = -ENOMEM;
|
|
goto out_uevent_exit;
|
|
}
|
|
|
|
_major = major;
|
|
r = register_blkdev(_major, _name);
|
|
if (r < 0)
|
|
goto out_free_workqueue;
|
|
|
|
if (!_major)
|
|
_major = r;
|
|
|
|
return 0;
|
|
|
|
out_free_workqueue:
|
|
destroy_workqueue(deferred_remove_workqueue);
|
|
out_uevent_exit:
|
|
dm_uevent_exit();
|
|
out_free_rq_cache:
|
|
kmem_cache_destroy(_rq_cache);
|
|
out_free_rq_tio_cache:
|
|
kmem_cache_destroy(_rq_tio_cache);
|
|
out_free_io_cache:
|
|
kmem_cache_destroy(_io_cache);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void local_exit(void)
|
|
{
|
|
flush_scheduled_work();
|
|
destroy_workqueue(deferred_remove_workqueue);
|
|
|
|
kmem_cache_destroy(_rq_cache);
|
|
kmem_cache_destroy(_rq_tio_cache);
|
|
kmem_cache_destroy(_io_cache);
|
|
unregister_blkdev(_major, _name);
|
|
dm_uevent_exit();
|
|
|
|
_major = 0;
|
|
|
|
DMINFO("cleaned up");
|
|
}
|
|
|
|
static int (*_inits[])(void) __initdata = {
|
|
local_init,
|
|
dm_target_init,
|
|
dm_linear_init,
|
|
dm_stripe_init,
|
|
dm_io_init,
|
|
dm_kcopyd_init,
|
|
dm_interface_init,
|
|
dm_statistics_init,
|
|
};
|
|
|
|
static void (*_exits[])(void) = {
|
|
local_exit,
|
|
dm_target_exit,
|
|
dm_linear_exit,
|
|
dm_stripe_exit,
|
|
dm_io_exit,
|
|
dm_kcopyd_exit,
|
|
dm_interface_exit,
|
|
dm_statistics_exit,
|
|
};
|
|
|
|
static int __init dm_init(void)
|
|
{
|
|
const int count = ARRAY_SIZE(_inits);
|
|
|
|
int r, i;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
r = _inits[i]();
|
|
if (r)
|
|
goto bad;
|
|
}
|
|
|
|
return 0;
|
|
|
|
bad:
|
|
while (i--)
|
|
_exits[i]();
|
|
|
|
return r;
|
|
}
|
|
|
|
static void __exit dm_exit(void)
|
|
{
|
|
int i = ARRAY_SIZE(_exits);
|
|
|
|
while (i--)
|
|
_exits[i]();
|
|
|
|
/*
|
|
* Should be empty by this point.
|
|
*/
|
|
idr_destroy(&_minor_idr);
|
|
}
|
|
|
|
/*
|
|
* Block device functions
|
|
*/
|
|
int dm_deleting_md(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_DELETING, &md->flags);
|
|
}
|
|
|
|
static int dm_blk_open(struct block_device *bdev, fmode_t mode)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
spin_lock(&_minor_lock);
|
|
|
|
md = bdev->bd_disk->private_data;
|
|
if (!md)
|
|
goto out;
|
|
|
|
if (test_bit(DMF_FREEING, &md->flags) ||
|
|
dm_deleting_md(md)) {
|
|
md = NULL;
|
|
goto out;
|
|
}
|
|
|
|
dm_get(md);
|
|
atomic_inc(&md->open_count);
|
|
out:
|
|
spin_unlock(&_minor_lock);
|
|
|
|
return md ? 0 : -ENXIO;
|
|
}
|
|
|
|
static void dm_blk_close(struct gendisk *disk, fmode_t mode)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
spin_lock(&_minor_lock);
|
|
|
|
md = disk->private_data;
|
|
if (WARN_ON(!md))
|
|
goto out;
|
|
|
|
if (atomic_dec_and_test(&md->open_count) &&
|
|
(test_bit(DMF_DEFERRED_REMOVE, &md->flags)))
|
|
queue_work(deferred_remove_workqueue, &deferred_remove_work);
|
|
|
|
dm_put(md);
|
|
out:
|
|
spin_unlock(&_minor_lock);
|
|
}
|
|
|
|
int dm_open_count(struct mapped_device *md)
|
|
{
|
|
return atomic_read(&md->open_count);
|
|
}
|
|
|
|
/*
|
|
* Guarantees nothing is using the device before it's deleted.
|
|
*/
|
|
int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred)
|
|
{
|
|
int r = 0;
|
|
|
|
spin_lock(&_minor_lock);
|
|
|
|
if (dm_open_count(md)) {
|
|
r = -EBUSY;
|
|
if (mark_deferred)
|
|
set_bit(DMF_DEFERRED_REMOVE, &md->flags);
|
|
} else if (only_deferred && !test_bit(DMF_DEFERRED_REMOVE, &md->flags))
|
|
r = -EEXIST;
|
|
else
|
|
set_bit(DMF_DELETING, &md->flags);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
int dm_cancel_deferred_remove(struct mapped_device *md)
|
|
{
|
|
int r = 0;
|
|
|
|
spin_lock(&_minor_lock);
|
|
|
|
if (test_bit(DMF_DELETING, &md->flags))
|
|
r = -EBUSY;
|
|
else
|
|
clear_bit(DMF_DEFERRED_REMOVE, &md->flags);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void do_deferred_remove(struct work_struct *w)
|
|
{
|
|
dm_deferred_remove();
|
|
}
|
|
|
|
sector_t dm_get_size(struct mapped_device *md)
|
|
{
|
|
return get_capacity(md->disk);
|
|
}
|
|
|
|
struct request_queue *dm_get_md_queue(struct mapped_device *md)
|
|
{
|
|
return md->queue;
|
|
}
|
|
|
|
struct dm_stats *dm_get_stats(struct mapped_device *md)
|
|
{
|
|
return &md->stats;
|
|
}
|
|
|
|
static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
|
|
return dm_get_geometry(md, geo);
|
|
}
|
|
|
|
static int dm_grab_bdev_for_ioctl(struct mapped_device *md,
|
|
struct block_device **bdev,
|
|
fmode_t *mode)
|
|
{
|
|
struct dm_target *tgt;
|
|
struct dm_table *map;
|
|
int srcu_idx, r;
|
|
|
|
retry:
|
|
r = -ENOTTY;
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
if (!map || !dm_table_get_size(map))
|
|
goto out;
|
|
|
|
/* We only support devices that have a single target */
|
|
if (dm_table_get_num_targets(map) != 1)
|
|
goto out;
|
|
|
|
tgt = dm_table_get_target(map, 0);
|
|
if (!tgt->type->prepare_ioctl)
|
|
goto out;
|
|
|
|
if (dm_suspended_md(md)) {
|
|
r = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
r = tgt->type->prepare_ioctl(tgt, bdev, mode);
|
|
if (r < 0)
|
|
goto out;
|
|
|
|
bdgrab(*bdev);
|
|
dm_put_live_table(md, srcu_idx);
|
|
return r;
|
|
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
if (r == -ENOTCONN && !fatal_signal_pending(current)) {
|
|
msleep(10);
|
|
goto retry;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (r > 0) {
|
|
/*
|
|
* Target determined this ioctl is being issued against a
|
|
* subset of the parent bdev; require extra privileges.
|
|
*/
|
|
if (!capable(CAP_SYS_RAWIO)) {
|
|
DMWARN_LIMIT(
|
|
"%s: sending ioctl %x to DM device without required privilege.",
|
|
current->comm, cmd);
|
|
r = -ENOIOCTLCMD;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
|
|
out:
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static struct dm_io *alloc_io(struct mapped_device *md)
|
|
{
|
|
return mempool_alloc(md->io_pool, GFP_NOIO);
|
|
}
|
|
|
|
static void free_io(struct mapped_device *md, struct dm_io *io)
|
|
{
|
|
mempool_free(io, md->io_pool);
|
|
}
|
|
|
|
static void free_tio(struct dm_target_io *tio)
|
|
{
|
|
bio_put(&tio->clone);
|
|
}
|
|
|
|
int md_in_flight(struct mapped_device *md)
|
|
{
|
|
return atomic_read(&md->pending[READ]) +
|
|
atomic_read(&md->pending[WRITE]);
|
|
}
|
|
|
|
static void start_io_acct(struct dm_io *io)
|
|
{
|
|
struct mapped_device *md = io->md;
|
|
struct bio *bio = io->bio;
|
|
int cpu;
|
|
int rw = bio_data_dir(bio);
|
|
|
|
io->start_time = jiffies;
|
|
|
|
cpu = part_stat_lock();
|
|
part_round_stats(cpu, &dm_disk(md)->part0);
|
|
part_stat_unlock();
|
|
atomic_set(&dm_disk(md)->part0.in_flight[rw],
|
|
atomic_inc_return(&md->pending[rw]));
|
|
|
|
if (unlikely(dm_stats_used(&md->stats)))
|
|
dm_stats_account_io(&md->stats, bio_data_dir(bio),
|
|
bio->bi_iter.bi_sector, bio_sectors(bio),
|
|
false, 0, &io->stats_aux);
|
|
}
|
|
|
|
static void end_io_acct(struct dm_io *io)
|
|
{
|
|
struct mapped_device *md = io->md;
|
|
struct bio *bio = io->bio;
|
|
unsigned long duration = jiffies - io->start_time;
|
|
int pending;
|
|
int rw = bio_data_dir(bio);
|
|
|
|
generic_end_io_acct(rw, &dm_disk(md)->part0, io->start_time);
|
|
|
|
if (unlikely(dm_stats_used(&md->stats)))
|
|
dm_stats_account_io(&md->stats, bio_data_dir(bio),
|
|
bio->bi_iter.bi_sector, bio_sectors(bio),
|
|
true, duration, &io->stats_aux);
|
|
|
|
/*
|
|
* After this is decremented the bio must not be touched if it is
|
|
* a flush.
|
|
*/
|
|
pending = atomic_dec_return(&md->pending[rw]);
|
|
atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
|
|
pending += atomic_read(&md->pending[rw^0x1]);
|
|
|
|
/* nudge anyone waiting on suspend queue */
|
|
if (!pending)
|
|
wake_up(&md->wait);
|
|
}
|
|
|
|
/*
|
|
* Add the bio to the list of deferred io.
|
|
*/
|
|
static void queue_io(struct mapped_device *md, struct bio *bio)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&md->deferred_lock, flags);
|
|
bio_list_add(&md->deferred, bio);
|
|
spin_unlock_irqrestore(&md->deferred_lock, flags);
|
|
queue_work(md->wq, &md->work);
|
|
}
|
|
|
|
/*
|
|
* Everyone (including functions in this file), should use this
|
|
* function to access the md->map field, and make sure they call
|
|
* dm_put_live_table() when finished.
|
|
*/
|
|
struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
|
|
{
|
|
*srcu_idx = srcu_read_lock(&md->io_barrier);
|
|
|
|
return srcu_dereference(md->map, &md->io_barrier);
|
|
}
|
|
|
|
void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
|
|
{
|
|
srcu_read_unlock(&md->io_barrier, srcu_idx);
|
|
}
|
|
|
|
void dm_sync_table(struct mapped_device *md)
|
|
{
|
|
synchronize_srcu(&md->io_barrier);
|
|
synchronize_rcu_expedited();
|
|
}
|
|
|
|
/*
|
|
* A fast alternative to dm_get_live_table/dm_put_live_table.
|
|
* The caller must not block between these two functions.
|
|
*/
|
|
static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
|
|
{
|
|
rcu_read_lock();
|
|
return rcu_dereference(md->map);
|
|
}
|
|
|
|
static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
|
|
{
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/*
|
|
* Open a table device so we can use it as a map destination.
|
|
*/
|
|
static int open_table_device(struct table_device *td, dev_t dev,
|
|
struct mapped_device *md)
|
|
{
|
|
static char *_claim_ptr = "I belong to device-mapper";
|
|
struct block_device *bdev;
|
|
|
|
int r;
|
|
|
|
BUG_ON(td->dm_dev.bdev);
|
|
|
|
bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _claim_ptr);
|
|
if (IS_ERR(bdev))
|
|
return PTR_ERR(bdev);
|
|
|
|
r = bd_link_disk_holder(bdev, dm_disk(md));
|
|
if (r) {
|
|
blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
|
|
return r;
|
|
}
|
|
|
|
td->dm_dev.bdev = bdev;
|
|
td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Close a table device that we've been using.
|
|
*/
|
|
static void close_table_device(struct table_device *td, struct mapped_device *md)
|
|
{
|
|
if (!td->dm_dev.bdev)
|
|
return;
|
|
|
|
bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
|
|
blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
|
|
put_dax(td->dm_dev.dax_dev);
|
|
td->dm_dev.bdev = NULL;
|
|
td->dm_dev.dax_dev = NULL;
|
|
}
|
|
|
|
static struct table_device *find_table_device(struct list_head *l, dev_t dev,
|
|
fmode_t mode) {
|
|
struct table_device *td;
|
|
|
|
list_for_each_entry(td, l, list)
|
|
if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
|
|
return td;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
|
|
struct dm_dev **result) {
|
|
int r;
|
|
struct table_device *td;
|
|
|
|
mutex_lock(&md->table_devices_lock);
|
|
td = find_table_device(&md->table_devices, dev, mode);
|
|
if (!td) {
|
|
td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
|
|
if (!td) {
|
|
mutex_unlock(&md->table_devices_lock);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
td->dm_dev.mode = mode;
|
|
td->dm_dev.bdev = NULL;
|
|
|
|
if ((r = open_table_device(td, dev, md))) {
|
|
mutex_unlock(&md->table_devices_lock);
|
|
kfree(td);
|
|
return r;
|
|
}
|
|
|
|
format_dev_t(td->dm_dev.name, dev);
|
|
|
|
atomic_set(&td->count, 0);
|
|
list_add(&td->list, &md->table_devices);
|
|
}
|
|
atomic_inc(&td->count);
|
|
mutex_unlock(&md->table_devices_lock);
|
|
|
|
*result = &td->dm_dev;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_table_device);
|
|
|
|
void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
|
|
{
|
|
struct table_device *td = container_of(d, struct table_device, dm_dev);
|
|
|
|
mutex_lock(&md->table_devices_lock);
|
|
if (atomic_dec_and_test(&td->count)) {
|
|
close_table_device(td, md);
|
|
list_del(&td->list);
|
|
kfree(td);
|
|
}
|
|
mutex_unlock(&md->table_devices_lock);
|
|
}
|
|
EXPORT_SYMBOL(dm_put_table_device);
|
|
|
|
static void free_table_devices(struct list_head *devices)
|
|
{
|
|
struct list_head *tmp, *next;
|
|
|
|
list_for_each_safe(tmp, next, devices) {
|
|
struct table_device *td = list_entry(tmp, struct table_device, list);
|
|
|
|
DMWARN("dm_destroy: %s still exists with %d references",
|
|
td->dm_dev.name, atomic_read(&td->count));
|
|
kfree(td);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get the geometry associated with a dm device
|
|
*/
|
|
int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
|
|
{
|
|
*geo = md->geometry;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set the geometry of a device.
|
|
*/
|
|
int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
|
|
{
|
|
sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
|
|
|
|
if (geo->start > sz) {
|
|
DMWARN("Start sector is beyond the geometry limits.");
|
|
return -EINVAL;
|
|
}
|
|
|
|
md->geometry = *geo;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*-----------------------------------------------------------------
|
|
* CRUD START:
|
|
* A more elegant soln is in the works that uses the queue
|
|
* merge fn, unfortunately there are a couple of changes to
|
|
* the block layer that I want to make for this. So in the
|
|
* interests of getting something for people to use I give
|
|
* you this clearly demarcated crap.
|
|
*---------------------------------------------------------------*/
|
|
|
|
static int __noflush_suspending(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
}
|
|
|
|
/*
|
|
* Decrements the number of outstanding ios that a bio has been
|
|
* cloned into, completing the original io if necc.
|
|
*/
|
|
static void dec_pending(struct dm_io *io, int error)
|
|
{
|
|
unsigned long flags;
|
|
int io_error;
|
|
struct bio *bio;
|
|
struct mapped_device *md = io->md;
|
|
|
|
/* Push-back supersedes any I/O errors */
|
|
if (unlikely(error)) {
|
|
spin_lock_irqsave(&io->endio_lock, flags);
|
|
if (!(io->error > 0 && __noflush_suspending(md)))
|
|
io->error = error;
|
|
spin_unlock_irqrestore(&io->endio_lock, flags);
|
|
}
|
|
|
|
if (atomic_dec_and_test(&io->io_count)) {
|
|
if (io->error == DM_ENDIO_REQUEUE) {
|
|
/*
|
|
* Target requested pushing back the I/O.
|
|
*/
|
|
spin_lock_irqsave(&md->deferred_lock, flags);
|
|
if (__noflush_suspending(md))
|
|
bio_list_add_head(&md->deferred, io->bio);
|
|
else
|
|
/* noflush suspend was interrupted. */
|
|
io->error = -EIO;
|
|
spin_unlock_irqrestore(&md->deferred_lock, flags);
|
|
}
|
|
|
|
io_error = io->error;
|
|
bio = io->bio;
|
|
end_io_acct(io);
|
|
free_io(md, io);
|
|
|
|
if (io_error == DM_ENDIO_REQUEUE)
|
|
return;
|
|
|
|
if ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size) {
|
|
/*
|
|
* Preflush done for flush with data, reissue
|
|
* without REQ_PREFLUSH.
|
|
*/
|
|
bio->bi_opf &= ~REQ_PREFLUSH;
|
|
queue_io(md, bio);
|
|
} else {
|
|
/* done with normal IO or empty flush */
|
|
bio->bi_error = io_error;
|
|
bio_endio(bio);
|
|
}
|
|
}
|
|
}
|
|
|
|
void disable_write_same(struct mapped_device *md)
|
|
{
|
|
struct queue_limits *limits = dm_get_queue_limits(md);
|
|
|
|
/* device doesn't really support WRITE SAME, disable it */
|
|
limits->max_write_same_sectors = 0;
|
|
}
|
|
|
|
void disable_write_zeroes(struct mapped_device *md)
|
|
{
|
|
struct queue_limits *limits = dm_get_queue_limits(md);
|
|
|
|
/* device doesn't really support WRITE ZEROES, disable it */
|
|
limits->max_write_zeroes_sectors = 0;
|
|
}
|
|
|
|
static void clone_endio(struct bio *bio)
|
|
{
|
|
int error = bio->bi_error;
|
|
int r = error;
|
|
struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
|
|
struct dm_io *io = tio->io;
|
|
struct mapped_device *md = tio->io->md;
|
|
dm_endio_fn endio = tio->ti->type->end_io;
|
|
|
|
if (endio) {
|
|
r = endio(tio->ti, bio, error);
|
|
if (r < 0 || r == DM_ENDIO_REQUEUE)
|
|
/*
|
|
* error and requeue request are handled
|
|
* in dec_pending().
|
|
*/
|
|
error = r;
|
|
else if (r == DM_ENDIO_INCOMPLETE)
|
|
/* The target will handle the io */
|
|
return;
|
|
else if (r) {
|
|
DMWARN("unimplemented target endio return value: %d", r);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
if (unlikely(r == -EREMOTEIO)) {
|
|
if (bio_op(bio) == REQ_OP_WRITE_SAME &&
|
|
!bdev_get_queue(bio->bi_bdev)->limits.max_write_same_sectors)
|
|
disable_write_same(md);
|
|
if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
|
|
!bdev_get_queue(bio->bi_bdev)->limits.max_write_zeroes_sectors)
|
|
disable_write_zeroes(md);
|
|
}
|
|
|
|
free_tio(tio);
|
|
dec_pending(io, error);
|
|
}
|
|
|
|
/*
|
|
* Return maximum size of I/O possible at the supplied sector up to the current
|
|
* target boundary.
|
|
*/
|
|
static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
|
|
{
|
|
sector_t target_offset = dm_target_offset(ti, sector);
|
|
|
|
return ti->len - target_offset;
|
|
}
|
|
|
|
static sector_t max_io_len(sector_t sector, struct dm_target *ti)
|
|
{
|
|
sector_t len = max_io_len_target_boundary(sector, ti);
|
|
sector_t offset, max_len;
|
|
|
|
/*
|
|
* Does the target need to split even further?
|
|
*/
|
|
if (ti->max_io_len) {
|
|
offset = dm_target_offset(ti, sector);
|
|
if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
|
|
max_len = sector_div(offset, ti->max_io_len);
|
|
else
|
|
max_len = offset & (ti->max_io_len - 1);
|
|
max_len = ti->max_io_len - max_len;
|
|
|
|
if (len > max_len)
|
|
len = max_len;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
|
|
{
|
|
if (len > UINT_MAX) {
|
|
DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
|
|
(unsigned long long)len, UINT_MAX);
|
|
ti->error = "Maximum size of target IO is too large";
|
|
return -EINVAL;
|
|
}
|
|
|
|
ti->max_io_len = (uint32_t) len;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
|
|
|
|
static struct dm_target *dm_dax_get_live_target(struct mapped_device *md,
|
|
sector_t sector, int *srcu_idx)
|
|
{
|
|
struct dm_table *map;
|
|
struct dm_target *ti;
|
|
|
|
map = dm_get_live_table(md, srcu_idx);
|
|
if (!map)
|
|
return NULL;
|
|
|
|
ti = dm_table_find_target(map, sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return NULL;
|
|
|
|
return ti;
|
|
}
|
|
|
|
static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
|
|
long nr_pages, void **kaddr, pfn_t *pfn)
|
|
{
|
|
struct mapped_device *md = dax_get_private(dax_dev);
|
|
sector_t sector = pgoff * PAGE_SECTORS;
|
|
struct dm_target *ti;
|
|
long len, ret = -EIO;
|
|
int srcu_idx;
|
|
|
|
ti = dm_dax_get_live_target(md, sector, &srcu_idx);
|
|
|
|
if (!ti)
|
|
goto out;
|
|
if (!ti->type->direct_access)
|
|
goto out;
|
|
len = max_io_len(sector, ti) / PAGE_SECTORS;
|
|
if (len < 1)
|
|
goto out;
|
|
nr_pages = min(len, nr_pages);
|
|
if (ti->type->direct_access)
|
|
ret = ti->type->direct_access(ti, pgoff, nr_pages, kaddr, pfn);
|
|
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
|
|
void *addr, size_t bytes, struct iov_iter *i)
|
|
{
|
|
struct mapped_device *md = dax_get_private(dax_dev);
|
|
sector_t sector = pgoff * PAGE_SECTORS;
|
|
struct dm_target *ti;
|
|
long ret = 0;
|
|
int srcu_idx;
|
|
|
|
ti = dm_dax_get_live_target(md, sector, &srcu_idx);
|
|
|
|
if (!ti)
|
|
goto out;
|
|
if (!ti->type->dax_copy_from_iter) {
|
|
ret = copy_from_iter(addr, bytes, i);
|
|
goto out;
|
|
}
|
|
ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void dm_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
|
|
size_t size)
|
|
{
|
|
struct mapped_device *md = dax_get_private(dax_dev);
|
|
sector_t sector = pgoff * PAGE_SECTORS;
|
|
struct dm_target *ti;
|
|
int srcu_idx;
|
|
|
|
ti = dm_dax_get_live_target(md, sector, &srcu_idx);
|
|
|
|
if (!ti)
|
|
goto out;
|
|
if (ti->type->dax_flush)
|
|
ti->type->dax_flush(ti, pgoff, addr, size);
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
}
|
|
|
|
/*
|
|
* A target may call dm_accept_partial_bio only from the map routine. It is
|
|
* allowed for all bio types except REQ_PREFLUSH.
|
|
*
|
|
* dm_accept_partial_bio informs the dm that the target only wants to process
|
|
* additional n_sectors sectors of the bio and the rest of the data should be
|
|
* sent in a next bio.
|
|
*
|
|
* A diagram that explains the arithmetics:
|
|
* +--------------------+---------------+-------+
|
|
* | 1 | 2 | 3 |
|
|
* +--------------------+---------------+-------+
|
|
*
|
|
* <-------------- *tio->len_ptr --------------->
|
|
* <------- bi_size ------->
|
|
* <-- n_sectors -->
|
|
*
|
|
* Region 1 was already iterated over with bio_advance or similar function.
|
|
* (it may be empty if the target doesn't use bio_advance)
|
|
* Region 2 is the remaining bio size that the target wants to process.
|
|
* (it may be empty if region 1 is non-empty, although there is no reason
|
|
* to make it empty)
|
|
* The target requires that region 3 is to be sent in the next bio.
|
|
*
|
|
* If the target wants to receive multiple copies of the bio (via num_*bios, etc),
|
|
* the partially processed part (the sum of regions 1+2) must be the same for all
|
|
* copies of the bio.
|
|
*/
|
|
void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
|
|
{
|
|
struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
|
|
unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
|
|
BUG_ON(bio->bi_opf & REQ_PREFLUSH);
|
|
BUG_ON(bi_size > *tio->len_ptr);
|
|
BUG_ON(n_sectors > bi_size);
|
|
*tio->len_ptr -= bi_size - n_sectors;
|
|
bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
|
|
|
|
/*
|
|
* Flush current->bio_list when the target map method blocks.
|
|
* This fixes deadlocks in snapshot and possibly in other targets.
|
|
*/
|
|
struct dm_offload {
|
|
struct blk_plug plug;
|
|
struct blk_plug_cb cb;
|
|
};
|
|
|
|
static void flush_current_bio_list(struct blk_plug_cb *cb, bool from_schedule)
|
|
{
|
|
struct dm_offload *o = container_of(cb, struct dm_offload, cb);
|
|
struct bio_list list;
|
|
struct bio *bio;
|
|
int i;
|
|
|
|
INIT_LIST_HEAD(&o->cb.list);
|
|
|
|
if (unlikely(!current->bio_list))
|
|
return;
|
|
|
|
for (i = 0; i < 2; i++) {
|
|
list = current->bio_list[i];
|
|
bio_list_init(¤t->bio_list[i]);
|
|
|
|
while ((bio = bio_list_pop(&list))) {
|
|
struct bio_set *bs = bio->bi_pool;
|
|
if (unlikely(!bs) || bs == fs_bio_set) {
|
|
bio_list_add(¤t->bio_list[i], bio);
|
|
continue;
|
|
}
|
|
|
|
spin_lock(&bs->rescue_lock);
|
|
bio_list_add(&bs->rescue_list, bio);
|
|
queue_work(bs->rescue_workqueue, &bs->rescue_work);
|
|
spin_unlock(&bs->rescue_lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void dm_offload_start(struct dm_offload *o)
|
|
{
|
|
blk_start_plug(&o->plug);
|
|
o->cb.callback = flush_current_bio_list;
|
|
list_add(&o->cb.list, ¤t->plug->cb_list);
|
|
}
|
|
|
|
static void dm_offload_end(struct dm_offload *o)
|
|
{
|
|
list_del(&o->cb.list);
|
|
blk_finish_plug(&o->plug);
|
|
}
|
|
|
|
static void __map_bio(struct dm_target_io *tio)
|
|
{
|
|
int r;
|
|
sector_t sector;
|
|
struct dm_offload o;
|
|
struct bio *clone = &tio->clone;
|
|
struct dm_target *ti = tio->ti;
|
|
|
|
clone->bi_end_io = clone_endio;
|
|
|
|
/*
|
|
* Map the clone. If r == 0 we don't need to do
|
|
* anything, the target has assumed ownership of
|
|
* this io.
|
|
*/
|
|
atomic_inc(&tio->io->io_count);
|
|
sector = clone->bi_iter.bi_sector;
|
|
|
|
dm_offload_start(&o);
|
|
r = ti->type->map(ti, clone);
|
|
dm_offload_end(&o);
|
|
|
|
if (r == DM_MAPIO_REMAPPED) {
|
|
/* the bio has been remapped so dispatch it */
|
|
|
|
trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone,
|
|
tio->io->bio->bi_bdev->bd_dev, sector);
|
|
|
|
generic_make_request(clone);
|
|
} else if (r < 0 || r == DM_MAPIO_REQUEUE) {
|
|
/* error the io and bail out, or requeue it if needed */
|
|
dec_pending(tio->io, r);
|
|
free_tio(tio);
|
|
} else if (r != DM_MAPIO_SUBMITTED) {
|
|
DMWARN("unimplemented target map return value: %d", r);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
struct clone_info {
|
|
struct mapped_device *md;
|
|
struct dm_table *map;
|
|
struct bio *bio;
|
|
struct dm_io *io;
|
|
sector_t sector;
|
|
unsigned sector_count;
|
|
};
|
|
|
|
static void bio_setup_sector(struct bio *bio, sector_t sector, unsigned len)
|
|
{
|
|
bio->bi_iter.bi_sector = sector;
|
|
bio->bi_iter.bi_size = to_bytes(len);
|
|
}
|
|
|
|
/*
|
|
* Creates a bio that consists of range of complete bvecs.
|
|
*/
|
|
static int clone_bio(struct dm_target_io *tio, struct bio *bio,
|
|
sector_t sector, unsigned len)
|
|
{
|
|
struct bio *clone = &tio->clone;
|
|
|
|
__bio_clone_fast(clone, bio);
|
|
|
|
if (unlikely(bio_integrity(bio) != NULL)) {
|
|
int r;
|
|
|
|
if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
|
|
!dm_target_passes_integrity(tio->ti->type))) {
|
|
DMWARN("%s: the target %s doesn't support integrity data.",
|
|
dm_device_name(tio->io->md),
|
|
tio->ti->type->name);
|
|
return -EIO;
|
|
}
|
|
|
|
r = bio_integrity_clone(clone, bio, GFP_NOIO);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
|
|
clone->bi_iter.bi_size = to_bytes(len);
|
|
|
|
if (unlikely(bio_integrity(bio) != NULL))
|
|
bio_integrity_trim(clone, 0, len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct dm_target_io *alloc_tio(struct clone_info *ci,
|
|
struct dm_target *ti,
|
|
unsigned target_bio_nr)
|
|
{
|
|
struct dm_target_io *tio;
|
|
struct bio *clone;
|
|
|
|
clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
|
|
tio = container_of(clone, struct dm_target_io, clone);
|
|
|
|
tio->io = ci->io;
|
|
tio->ti = ti;
|
|
tio->target_bio_nr = target_bio_nr;
|
|
|
|
return tio;
|
|
}
|
|
|
|
static void __clone_and_map_simple_bio(struct clone_info *ci,
|
|
struct dm_target *ti,
|
|
unsigned target_bio_nr, unsigned *len)
|
|
{
|
|
struct dm_target_io *tio = alloc_tio(ci, ti, target_bio_nr);
|
|
struct bio *clone = &tio->clone;
|
|
|
|
tio->len_ptr = len;
|
|
|
|
__bio_clone_fast(clone, ci->bio);
|
|
if (len)
|
|
bio_setup_sector(clone, ci->sector, *len);
|
|
|
|
__map_bio(tio);
|
|
}
|
|
|
|
static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
|
|
unsigned num_bios, unsigned *len)
|
|
{
|
|
unsigned target_bio_nr;
|
|
|
|
for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
|
|
__clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
|
|
}
|
|
|
|
static int __send_empty_flush(struct clone_info *ci)
|
|
{
|
|
unsigned target_nr = 0;
|
|
struct dm_target *ti;
|
|
|
|
BUG_ON(bio_has_data(ci->bio));
|
|
while ((ti = dm_table_get_target(ci->map, target_nr++)))
|
|
__send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
|
|
sector_t sector, unsigned *len)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
struct dm_target_io *tio;
|
|
unsigned target_bio_nr;
|
|
unsigned num_target_bios = 1;
|
|
int r = 0;
|
|
|
|
/*
|
|
* Does the target want to receive duplicate copies of the bio?
|
|
*/
|
|
if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
|
|
num_target_bios = ti->num_write_bios(ti, bio);
|
|
|
|
for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
|
|
tio = alloc_tio(ci, ti, target_bio_nr);
|
|
tio->len_ptr = len;
|
|
r = clone_bio(tio, bio, sector, *len);
|
|
if (r < 0) {
|
|
free_tio(tio);
|
|
break;
|
|
}
|
|
__map_bio(tio);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
|
|
|
|
static unsigned get_num_discard_bios(struct dm_target *ti)
|
|
{
|
|
return ti->num_discard_bios;
|
|
}
|
|
|
|
static unsigned get_num_write_same_bios(struct dm_target *ti)
|
|
{
|
|
return ti->num_write_same_bios;
|
|
}
|
|
|
|
static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
|
|
{
|
|
return ti->num_write_zeroes_bios;
|
|
}
|
|
|
|
typedef bool (*is_split_required_fn)(struct dm_target *ti);
|
|
|
|
static bool is_split_required_for_discard(struct dm_target *ti)
|
|
{
|
|
return ti->split_discard_bios;
|
|
}
|
|
|
|
static int __send_changing_extent_only(struct clone_info *ci,
|
|
get_num_bios_fn get_num_bios,
|
|
is_split_required_fn is_split_required)
|
|
{
|
|
struct dm_target *ti;
|
|
unsigned len;
|
|
unsigned num_bios;
|
|
|
|
do {
|
|
ti = dm_table_find_target(ci->map, ci->sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return -EIO;
|
|
|
|
/*
|
|
* Even though the device advertised support for this type of
|
|
* request, that does not mean every target supports it, and
|
|
* reconfiguration might also have changed that since the
|
|
* check was performed.
|
|
*/
|
|
num_bios = get_num_bios ? get_num_bios(ti) : 0;
|
|
if (!num_bios)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (is_split_required && !is_split_required(ti))
|
|
len = min((sector_t)ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
|
|
else
|
|
len = min((sector_t)ci->sector_count, max_io_len(ci->sector, ti));
|
|
|
|
__send_duplicate_bios(ci, ti, num_bios, &len);
|
|
|
|
ci->sector += len;
|
|
} while (ci->sector_count -= len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __send_discard(struct clone_info *ci)
|
|
{
|
|
return __send_changing_extent_only(ci, get_num_discard_bios,
|
|
is_split_required_for_discard);
|
|
}
|
|
|
|
static int __send_write_same(struct clone_info *ci)
|
|
{
|
|
return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
|
|
}
|
|
|
|
static int __send_write_zeroes(struct clone_info *ci)
|
|
{
|
|
return __send_changing_extent_only(ci, get_num_write_zeroes_bios, NULL);
|
|
}
|
|
|
|
/*
|
|
* Select the correct strategy for processing a non-flush bio.
|
|
*/
|
|
static int __split_and_process_non_flush(struct clone_info *ci)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
struct dm_target *ti;
|
|
unsigned len;
|
|
int r;
|
|
|
|
if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
|
|
return __send_discard(ci);
|
|
else if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
|
|
return __send_write_same(ci);
|
|
else if (unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES))
|
|
return __send_write_zeroes(ci);
|
|
|
|
ti = dm_table_find_target(ci->map, ci->sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return -EIO;
|
|
|
|
len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
|
|
|
|
r = __clone_and_map_data_bio(ci, ti, ci->sector, &len);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ci->sector += len;
|
|
ci->sector_count -= len;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Entry point to split a bio into clones and submit them to the targets.
|
|
*/
|
|
static void __split_and_process_bio(struct mapped_device *md,
|
|
struct dm_table *map, struct bio *bio)
|
|
{
|
|
struct clone_info ci;
|
|
int error = 0;
|
|
|
|
if (unlikely(!map)) {
|
|
bio_io_error(bio);
|
|
return;
|
|
}
|
|
|
|
ci.map = map;
|
|
ci.md = md;
|
|
ci.io = alloc_io(md);
|
|
ci.io->error = 0;
|
|
atomic_set(&ci.io->io_count, 1);
|
|
ci.io->bio = bio;
|
|
ci.io->md = md;
|
|
spin_lock_init(&ci.io->endio_lock);
|
|
ci.sector = bio->bi_iter.bi_sector;
|
|
|
|
start_io_acct(ci.io);
|
|
|
|
if (bio->bi_opf & REQ_PREFLUSH) {
|
|
ci.bio = &ci.md->flush_bio;
|
|
ci.sector_count = 0;
|
|
error = __send_empty_flush(&ci);
|
|
/* dec_pending submits any data associated with flush */
|
|
} else {
|
|
ci.bio = bio;
|
|
ci.sector_count = bio_sectors(bio);
|
|
while (ci.sector_count && !error)
|
|
error = __split_and_process_non_flush(&ci);
|
|
}
|
|
|
|
/* drop the extra reference count */
|
|
dec_pending(ci.io, error);
|
|
}
|
|
/*-----------------------------------------------------------------
|
|
* CRUD END
|
|
*---------------------------------------------------------------*/
|
|
|
|
/*
|
|
* The request function that just remaps the bio built up by
|
|
* dm_merge_bvec.
|
|
*/
|
|
static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
int rw = bio_data_dir(bio);
|
|
struct mapped_device *md = q->queuedata;
|
|
int srcu_idx;
|
|
struct dm_table *map;
|
|
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
|
|
generic_start_io_acct(rw, bio_sectors(bio), &dm_disk(md)->part0);
|
|
|
|
/* if we're suspended, we have to queue this io for later */
|
|
if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
|
|
dm_put_live_table(md, srcu_idx);
|
|
|
|
if (!(bio->bi_opf & REQ_RAHEAD))
|
|
queue_io(md, bio);
|
|
else
|
|
bio_io_error(bio);
|
|
return BLK_QC_T_NONE;
|
|
}
|
|
|
|
__split_and_process_bio(md, map, bio);
|
|
dm_put_live_table(md, srcu_idx);
|
|
return BLK_QC_T_NONE;
|
|
}
|
|
|
|
static int dm_any_congested(void *congested_data, int bdi_bits)
|
|
{
|
|
int r = bdi_bits;
|
|
struct mapped_device *md = congested_data;
|
|
struct dm_table *map;
|
|
|
|
if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
|
|
if (dm_request_based(md)) {
|
|
/*
|
|
* With request-based DM we only need to check the
|
|
* top-level queue for congestion.
|
|
*/
|
|
r = md->queue->backing_dev_info->wb.state & bdi_bits;
|
|
} else {
|
|
map = dm_get_live_table_fast(md);
|
|
if (map)
|
|
r = dm_table_any_congested(map, bdi_bits);
|
|
dm_put_live_table_fast(md);
|
|
}
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
/*-----------------------------------------------------------------
|
|
* An IDR is used to keep track of allocated minor numbers.
|
|
*---------------------------------------------------------------*/
|
|
static void free_minor(int minor)
|
|
{
|
|
spin_lock(&_minor_lock);
|
|
idr_remove(&_minor_idr, minor);
|
|
spin_unlock(&_minor_lock);
|
|
}
|
|
|
|
/*
|
|
* See if the device with a specific minor # is free.
|
|
*/
|
|
static int specific_minor(int minor)
|
|
{
|
|
int r;
|
|
|
|
if (minor >= (1 << MINORBITS))
|
|
return -EINVAL;
|
|
|
|
idr_preload(GFP_KERNEL);
|
|
spin_lock(&_minor_lock);
|
|
|
|
r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
idr_preload_end();
|
|
if (r < 0)
|
|
return r == -ENOSPC ? -EBUSY : r;
|
|
return 0;
|
|
}
|
|
|
|
static int next_free_minor(int *minor)
|
|
{
|
|
int r;
|
|
|
|
idr_preload(GFP_KERNEL);
|
|
spin_lock(&_minor_lock);
|
|
|
|
r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
idr_preload_end();
|
|
if (r < 0)
|
|
return r;
|
|
*minor = r;
|
|
return 0;
|
|
}
|
|
|
|
static const struct block_device_operations dm_blk_dops;
|
|
static const struct dax_operations dm_dax_ops;
|
|
|
|
static void dm_wq_work(struct work_struct *work);
|
|
|
|
void dm_init_md_queue(struct mapped_device *md)
|
|
{
|
|
/*
|
|
* Request-based dm devices cannot be stacked on top of bio-based dm
|
|
* devices. The type of this dm device may not have been decided yet.
|
|
* The type is decided at the first table loading time.
|
|
* To prevent problematic device stacking, clear the queue flag
|
|
* for request stacking support until then.
|
|
*
|
|
* This queue is new, so no concurrency on the queue_flags.
|
|
*/
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
|
|
|
|
/*
|
|
* Initialize data that will only be used by a non-blk-mq DM queue
|
|
* - must do so here (in alloc_dev callchain) before queue is used
|
|
*/
|
|
md->queue->queuedata = md;
|
|
md->queue->backing_dev_info->congested_data = md;
|
|
}
|
|
|
|
void dm_init_normal_md_queue(struct mapped_device *md)
|
|
{
|
|
md->use_blk_mq = false;
|
|
dm_init_md_queue(md);
|
|
|
|
/*
|
|
* Initialize aspects of queue that aren't relevant for blk-mq
|
|
*/
|
|
md->queue->backing_dev_info->congested_fn = dm_any_congested;
|
|
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
|
|
}
|
|
|
|
static void cleanup_mapped_device(struct mapped_device *md)
|
|
{
|
|
if (md->wq)
|
|
destroy_workqueue(md->wq);
|
|
if (md->kworker_task)
|
|
kthread_stop(md->kworker_task);
|
|
mempool_destroy(md->io_pool);
|
|
if (md->bs)
|
|
bioset_free(md->bs);
|
|
|
|
if (md->dax_dev) {
|
|
kill_dax(md->dax_dev);
|
|
put_dax(md->dax_dev);
|
|
md->dax_dev = NULL;
|
|
}
|
|
|
|
if (md->disk) {
|
|
spin_lock(&_minor_lock);
|
|
md->disk->private_data = NULL;
|
|
spin_unlock(&_minor_lock);
|
|
del_gendisk(md->disk);
|
|
put_disk(md->disk);
|
|
}
|
|
|
|
if (md->queue)
|
|
blk_cleanup_queue(md->queue);
|
|
|
|
cleanup_srcu_struct(&md->io_barrier);
|
|
|
|
if (md->bdev) {
|
|
bdput(md->bdev);
|
|
md->bdev = NULL;
|
|
}
|
|
|
|
dm_mq_cleanup_mapped_device(md);
|
|
}
|
|
|
|
/*
|
|
* Allocate and initialise a blank device with a given minor.
|
|
*/
|
|
static struct mapped_device *alloc_dev(int minor)
|
|
{
|
|
int r, numa_node_id = dm_get_numa_node();
|
|
struct dax_device *dax_dev;
|
|
struct mapped_device *md;
|
|
void *old_md;
|
|
|
|
md = kzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
|
|
if (!md) {
|
|
DMWARN("unable to allocate device, out of memory.");
|
|
return NULL;
|
|
}
|
|
|
|
if (!try_module_get(THIS_MODULE))
|
|
goto bad_module_get;
|
|
|
|
/* get a minor number for the dev */
|
|
if (minor == DM_ANY_MINOR)
|
|
r = next_free_minor(&minor);
|
|
else
|
|
r = specific_minor(minor);
|
|
if (r < 0)
|
|
goto bad_minor;
|
|
|
|
r = init_srcu_struct(&md->io_barrier);
|
|
if (r < 0)
|
|
goto bad_io_barrier;
|
|
|
|
md->numa_node_id = numa_node_id;
|
|
md->use_blk_mq = dm_use_blk_mq_default();
|
|
md->init_tio_pdu = false;
|
|
md->type = DM_TYPE_NONE;
|
|
mutex_init(&md->suspend_lock);
|
|
mutex_init(&md->type_lock);
|
|
mutex_init(&md->table_devices_lock);
|
|
spin_lock_init(&md->deferred_lock);
|
|
atomic_set(&md->holders, 1);
|
|
atomic_set(&md->open_count, 0);
|
|
atomic_set(&md->event_nr, 0);
|
|
atomic_set(&md->uevent_seq, 0);
|
|
INIT_LIST_HEAD(&md->uevent_list);
|
|
INIT_LIST_HEAD(&md->table_devices);
|
|
spin_lock_init(&md->uevent_lock);
|
|
|
|
md->queue = blk_alloc_queue_node(GFP_KERNEL, numa_node_id);
|
|
if (!md->queue)
|
|
goto bad;
|
|
|
|
dm_init_md_queue(md);
|
|
|
|
md->disk = alloc_disk_node(1, numa_node_id);
|
|
if (!md->disk)
|
|
goto bad;
|
|
|
|
atomic_set(&md->pending[0], 0);
|
|
atomic_set(&md->pending[1], 0);
|
|
init_waitqueue_head(&md->wait);
|
|
INIT_WORK(&md->work, dm_wq_work);
|
|
init_waitqueue_head(&md->eventq);
|
|
init_completion(&md->kobj_holder.completion);
|
|
md->kworker_task = NULL;
|
|
|
|
md->disk->major = _major;
|
|
md->disk->first_minor = minor;
|
|
md->disk->fops = &dm_blk_dops;
|
|
md->disk->queue = md->queue;
|
|
md->disk->private_data = md;
|
|
sprintf(md->disk->disk_name, "dm-%d", minor);
|
|
|
|
dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
|
|
if (!dax_dev)
|
|
goto bad;
|
|
md->dax_dev = dax_dev;
|
|
|
|
add_disk(md->disk);
|
|
format_dev_t(md->name, MKDEV(_major, minor));
|
|
|
|
md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
|
|
if (!md->wq)
|
|
goto bad;
|
|
|
|
md->bdev = bdget_disk(md->disk, 0);
|
|
if (!md->bdev)
|
|
goto bad;
|
|
|
|
bio_init(&md->flush_bio, NULL, 0);
|
|
md->flush_bio.bi_bdev = md->bdev;
|
|
md->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
|
|
|
|
dm_stats_init(&md->stats);
|
|
|
|
/* Populate the mapping, nobody knows we exist yet */
|
|
spin_lock(&_minor_lock);
|
|
old_md = idr_replace(&_minor_idr, md, minor);
|
|
spin_unlock(&_minor_lock);
|
|
|
|
BUG_ON(old_md != MINOR_ALLOCED);
|
|
|
|
return md;
|
|
|
|
bad:
|
|
cleanup_mapped_device(md);
|
|
bad_io_barrier:
|
|
free_minor(minor);
|
|
bad_minor:
|
|
module_put(THIS_MODULE);
|
|
bad_module_get:
|
|
kfree(md);
|
|
return NULL;
|
|
}
|
|
|
|
static void unlock_fs(struct mapped_device *md);
|
|
|
|
static void free_dev(struct mapped_device *md)
|
|
{
|
|
int minor = MINOR(disk_devt(md->disk));
|
|
|
|
unlock_fs(md);
|
|
|
|
cleanup_mapped_device(md);
|
|
|
|
free_table_devices(&md->table_devices);
|
|
dm_stats_cleanup(&md->stats);
|
|
free_minor(minor);
|
|
|
|
module_put(THIS_MODULE);
|
|
kfree(md);
|
|
}
|
|
|
|
static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
|
|
{
|
|
struct dm_md_mempools *p = dm_table_get_md_mempools(t);
|
|
|
|
if (md->bs) {
|
|
/* The md already has necessary mempools. */
|
|
if (dm_table_bio_based(t)) {
|
|
/*
|
|
* Reload bioset because front_pad may have changed
|
|
* because a different table was loaded.
|
|
*/
|
|
bioset_free(md->bs);
|
|
md->bs = p->bs;
|
|
p->bs = NULL;
|
|
}
|
|
/*
|
|
* There's no need to reload with request-based dm
|
|
* because the size of front_pad doesn't change.
|
|
* Note for future: If you are to reload bioset,
|
|
* prep-ed requests in the queue may refer
|
|
* to bio from the old bioset, so you must walk
|
|
* through the queue to unprep.
|
|
*/
|
|
goto out;
|
|
}
|
|
|
|
BUG_ON(!p || md->io_pool || md->bs);
|
|
|
|
md->io_pool = p->io_pool;
|
|
p->io_pool = NULL;
|
|
md->bs = p->bs;
|
|
p->bs = NULL;
|
|
|
|
out:
|
|
/* mempool bind completed, no longer need any mempools in the table */
|
|
dm_table_free_md_mempools(t);
|
|
}
|
|
|
|
/*
|
|
* Bind a table to the device.
|
|
*/
|
|
static void event_callback(void *context)
|
|
{
|
|
unsigned long flags;
|
|
LIST_HEAD(uevents);
|
|
struct mapped_device *md = (struct mapped_device *) context;
|
|
|
|
spin_lock_irqsave(&md->uevent_lock, flags);
|
|
list_splice_init(&md->uevent_list, &uevents);
|
|
spin_unlock_irqrestore(&md->uevent_lock, flags);
|
|
|
|
dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
|
|
|
|
atomic_inc(&md->event_nr);
|
|
wake_up(&md->eventq);
|
|
}
|
|
|
|
/*
|
|
* Protected by md->suspend_lock obtained by dm_swap_table().
|
|
*/
|
|
static void __set_size(struct mapped_device *md, sector_t size)
|
|
{
|
|
lockdep_assert_held(&md->suspend_lock);
|
|
|
|
set_capacity(md->disk, size);
|
|
|
|
i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
|
|
}
|
|
|
|
/*
|
|
* Returns old map, which caller must destroy.
|
|
*/
|
|
static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
|
|
struct queue_limits *limits)
|
|
{
|
|
struct dm_table *old_map;
|
|
struct request_queue *q = md->queue;
|
|
sector_t size;
|
|
|
|
lockdep_assert_held(&md->suspend_lock);
|
|
|
|
size = dm_table_get_size(t);
|
|
|
|
/*
|
|
* Wipe any geometry if the size of the table changed.
|
|
*/
|
|
if (size != dm_get_size(md))
|
|
memset(&md->geometry, 0, sizeof(md->geometry));
|
|
|
|
__set_size(md, size);
|
|
|
|
dm_table_event_callback(t, event_callback, md);
|
|
|
|
/*
|
|
* The queue hasn't been stopped yet, if the old table type wasn't
|
|
* for request-based during suspension. So stop it to prevent
|
|
* I/O mapping before resume.
|
|
* This must be done before setting the queue restrictions,
|
|
* because request-based dm may be run just after the setting.
|
|
*/
|
|
if (dm_table_request_based(t)) {
|
|
dm_stop_queue(q);
|
|
/*
|
|
* Leverage the fact that request-based DM targets are
|
|
* immutable singletons and establish md->immutable_target
|
|
* - used to optimize both dm_request_fn and dm_mq_queue_rq
|
|
*/
|
|
md->immutable_target = dm_table_get_immutable_target(t);
|
|
}
|
|
|
|
__bind_mempools(md, t);
|
|
|
|
old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
rcu_assign_pointer(md->map, (void *)t);
|
|
md->immutable_target_type = dm_table_get_immutable_target_type(t);
|
|
|
|
dm_table_set_restrictions(t, q, limits);
|
|
if (old_map)
|
|
dm_sync_table(md);
|
|
|
|
return old_map;
|
|
}
|
|
|
|
/*
|
|
* Returns unbound table for the caller to free.
|
|
*/
|
|
static struct dm_table *__unbind(struct mapped_device *md)
|
|
{
|
|
struct dm_table *map = rcu_dereference_protected(md->map, 1);
|
|
|
|
if (!map)
|
|
return NULL;
|
|
|
|
dm_table_event_callback(map, NULL, NULL);
|
|
RCU_INIT_POINTER(md->map, NULL);
|
|
dm_sync_table(md);
|
|
|
|
return map;
|
|
}
|
|
|
|
/*
|
|
* Constructor for a new device.
|
|
*/
|
|
int dm_create(int minor, struct mapped_device **result)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
md = alloc_dev(minor);
|
|
if (!md)
|
|
return -ENXIO;
|
|
|
|
dm_sysfs_init(md);
|
|
|
|
*result = md;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Functions to manage md->type.
|
|
* All are required to hold md->type_lock.
|
|
*/
|
|
void dm_lock_md_type(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->type_lock);
|
|
}
|
|
|
|
void dm_unlock_md_type(struct mapped_device *md)
|
|
{
|
|
mutex_unlock(&md->type_lock);
|
|
}
|
|
|
|
void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type)
|
|
{
|
|
BUG_ON(!mutex_is_locked(&md->type_lock));
|
|
md->type = type;
|
|
}
|
|
|
|
enum dm_queue_mode dm_get_md_type(struct mapped_device *md)
|
|
{
|
|
return md->type;
|
|
}
|
|
|
|
struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
|
|
{
|
|
return md->immutable_target_type;
|
|
}
|
|
|
|
/*
|
|
* The queue_limits are only valid as long as you have a reference
|
|
* count on 'md'.
|
|
*/
|
|
struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
|
|
{
|
|
BUG_ON(!atomic_read(&md->holders));
|
|
return &md->queue->limits;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_queue_limits);
|
|
|
|
/*
|
|
* Setup the DM device's queue based on md's type
|
|
*/
|
|
int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t)
|
|
{
|
|
int r;
|
|
enum dm_queue_mode type = dm_get_md_type(md);
|
|
|
|
switch (type) {
|
|
case DM_TYPE_REQUEST_BASED:
|
|
r = dm_old_init_request_queue(md, t);
|
|
if (r) {
|
|
DMERR("Cannot initialize queue for request-based mapped device");
|
|
return r;
|
|
}
|
|
break;
|
|
case DM_TYPE_MQ_REQUEST_BASED:
|
|
r = dm_mq_init_request_queue(md, t);
|
|
if (r) {
|
|
DMERR("Cannot initialize queue for request-based dm-mq mapped device");
|
|
return r;
|
|
}
|
|
break;
|
|
case DM_TYPE_BIO_BASED:
|
|
case DM_TYPE_DAX_BIO_BASED:
|
|
dm_init_normal_md_queue(md);
|
|
blk_queue_make_request(md->queue, dm_make_request);
|
|
/*
|
|
* DM handles splitting bios as needed. Free the bio_split bioset
|
|
* since it won't be used (saves 1 process per bio-based DM device).
|
|
*/
|
|
bioset_free(md->queue->bio_split);
|
|
md->queue->bio_split = NULL;
|
|
|
|
if (type == DM_TYPE_DAX_BIO_BASED)
|
|
queue_flag_set_unlocked(QUEUE_FLAG_DAX, md->queue);
|
|
break;
|
|
case DM_TYPE_NONE:
|
|
WARN_ON_ONCE(true);
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct mapped_device *dm_get_md(dev_t dev)
|
|
{
|
|
struct mapped_device *md;
|
|
unsigned minor = MINOR(dev);
|
|
|
|
if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
|
|
return NULL;
|
|
|
|
spin_lock(&_minor_lock);
|
|
|
|
md = idr_find(&_minor_idr, minor);
|
|
if (md) {
|
|
if ((md == MINOR_ALLOCED ||
|
|
(MINOR(disk_devt(dm_disk(md))) != minor) ||
|
|
dm_deleting_md(md) ||
|
|
test_bit(DMF_FREEING, &md->flags))) {
|
|
md = NULL;
|
|
goto out;
|
|
}
|
|
dm_get(md);
|
|
}
|
|
|
|
out:
|
|
spin_unlock(&_minor_lock);
|
|
|
|
return md;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_md);
|
|
|
|
void *dm_get_mdptr(struct mapped_device *md)
|
|
{
|
|
return md->interface_ptr;
|
|
}
|
|
|
|
void dm_set_mdptr(struct mapped_device *md, void *ptr)
|
|
{
|
|
md->interface_ptr = ptr;
|
|
}
|
|
|
|
void dm_get(struct mapped_device *md)
|
|
{
|
|
atomic_inc(&md->holders);
|
|
BUG_ON(test_bit(DMF_FREEING, &md->flags));
|
|
}
|
|
|
|
int dm_hold(struct mapped_device *md)
|
|
{
|
|
spin_lock(&_minor_lock);
|
|
if (test_bit(DMF_FREEING, &md->flags)) {
|
|
spin_unlock(&_minor_lock);
|
|
return -EBUSY;
|
|
}
|
|
dm_get(md);
|
|
spin_unlock(&_minor_lock);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_hold);
|
|
|
|
const char *dm_device_name(struct mapped_device *md)
|
|
{
|
|
return md->name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_device_name);
|
|
|
|
static void __dm_destroy(struct mapped_device *md, bool wait)
|
|
{
|
|
struct request_queue *q = dm_get_md_queue(md);
|
|
struct dm_table *map;
|
|
int srcu_idx;
|
|
|
|
might_sleep();
|
|
|
|
spin_lock(&_minor_lock);
|
|
idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
|
|
set_bit(DMF_FREEING, &md->flags);
|
|
spin_unlock(&_minor_lock);
|
|
|
|
blk_set_queue_dying(q);
|
|
|
|
if (dm_request_based(md) && md->kworker_task)
|
|
kthread_flush_worker(&md->kworker);
|
|
|
|
/*
|
|
* Take suspend_lock so that presuspend and postsuspend methods
|
|
* do not race with internal suspend.
|
|
*/
|
|
mutex_lock(&md->suspend_lock);
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
if (!dm_suspended_md(md)) {
|
|
dm_table_presuspend_targets(map);
|
|
dm_table_postsuspend_targets(map);
|
|
}
|
|
/* dm_put_live_table must be before msleep, otherwise deadlock is possible */
|
|
dm_put_live_table(md, srcu_idx);
|
|
mutex_unlock(&md->suspend_lock);
|
|
|
|
/*
|
|
* Rare, but there may be I/O requests still going to complete,
|
|
* for example. Wait for all references to disappear.
|
|
* No one should increment the reference count of the mapped_device,
|
|
* after the mapped_device state becomes DMF_FREEING.
|
|
*/
|
|
if (wait)
|
|
while (atomic_read(&md->holders))
|
|
msleep(1);
|
|
else if (atomic_read(&md->holders))
|
|
DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
|
|
dm_device_name(md), atomic_read(&md->holders));
|
|
|
|
dm_sysfs_exit(md);
|
|
dm_table_destroy(__unbind(md));
|
|
free_dev(md);
|
|
}
|
|
|
|
void dm_destroy(struct mapped_device *md)
|
|
{
|
|
__dm_destroy(md, true);
|
|
}
|
|
|
|
void dm_destroy_immediate(struct mapped_device *md)
|
|
{
|
|
__dm_destroy(md, false);
|
|
}
|
|
|
|
void dm_put(struct mapped_device *md)
|
|
{
|
|
atomic_dec(&md->holders);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_put);
|
|
|
|
static int dm_wait_for_completion(struct mapped_device *md, long task_state)
|
|
{
|
|
int r = 0;
|
|
DEFINE_WAIT(wait);
|
|
|
|
while (1) {
|
|
prepare_to_wait(&md->wait, &wait, task_state);
|
|
|
|
if (!md_in_flight(md))
|
|
break;
|
|
|
|
if (signal_pending_state(task_state, current)) {
|
|
r = -EINTR;
|
|
break;
|
|
}
|
|
|
|
io_schedule();
|
|
}
|
|
finish_wait(&md->wait, &wait);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Process the deferred bios
|
|
*/
|
|
static void dm_wq_work(struct work_struct *work)
|
|
{
|
|
struct mapped_device *md = container_of(work, struct mapped_device,
|
|
work);
|
|
struct bio *c;
|
|
int srcu_idx;
|
|
struct dm_table *map;
|
|
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
|
|
while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
|
|
spin_lock_irq(&md->deferred_lock);
|
|
c = bio_list_pop(&md->deferred);
|
|
spin_unlock_irq(&md->deferred_lock);
|
|
|
|
if (!c)
|
|
break;
|
|
|
|
if (dm_request_based(md))
|
|
generic_make_request(c);
|
|
else
|
|
__split_and_process_bio(md, map, c);
|
|
}
|
|
|
|
dm_put_live_table(md, srcu_idx);
|
|
}
|
|
|
|
static void dm_queue_flush(struct mapped_device *md)
|
|
{
|
|
clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
smp_mb__after_atomic();
|
|
queue_work(md->wq, &md->work);
|
|
}
|
|
|
|
/*
|
|
* Swap in a new table, returning the old one for the caller to destroy.
|
|
*/
|
|
struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
|
|
{
|
|
struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
|
|
struct queue_limits limits;
|
|
int r;
|
|
|
|
mutex_lock(&md->suspend_lock);
|
|
|
|
/* device must be suspended */
|
|
if (!dm_suspended_md(md))
|
|
goto out;
|
|
|
|
/*
|
|
* If the new table has no data devices, retain the existing limits.
|
|
* This helps multipath with queue_if_no_path if all paths disappear,
|
|
* then new I/O is queued based on these limits, and then some paths
|
|
* reappear.
|
|
*/
|
|
if (dm_table_has_no_data_devices(table)) {
|
|
live_map = dm_get_live_table_fast(md);
|
|
if (live_map)
|
|
limits = md->queue->limits;
|
|
dm_put_live_table_fast(md);
|
|
}
|
|
|
|
if (!live_map) {
|
|
r = dm_calculate_queue_limits(table, &limits);
|
|
if (r) {
|
|
map = ERR_PTR(r);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
map = __bind(md, table, &limits);
|
|
|
|
out:
|
|
mutex_unlock(&md->suspend_lock);
|
|
return map;
|
|
}
|
|
|
|
/*
|
|
* Functions to lock and unlock any filesystem running on the
|
|
* device.
|
|
*/
|
|
static int lock_fs(struct mapped_device *md)
|
|
{
|
|
int r;
|
|
|
|
WARN_ON(md->frozen_sb);
|
|
|
|
md->frozen_sb = freeze_bdev(md->bdev);
|
|
if (IS_ERR(md->frozen_sb)) {
|
|
r = PTR_ERR(md->frozen_sb);
|
|
md->frozen_sb = NULL;
|
|
return r;
|
|
}
|
|
|
|
set_bit(DMF_FROZEN, &md->flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void unlock_fs(struct mapped_device *md)
|
|
{
|
|
if (!test_bit(DMF_FROZEN, &md->flags))
|
|
return;
|
|
|
|
thaw_bdev(md->bdev, md->frozen_sb);
|
|
md->frozen_sb = NULL;
|
|
clear_bit(DMF_FROZEN, &md->flags);
|
|
}
|
|
|
|
/*
|
|
* @suspend_flags: DM_SUSPEND_LOCKFS_FLAG and/or DM_SUSPEND_NOFLUSH_FLAG
|
|
* @task_state: e.g. TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE
|
|
* @dmf_suspended_flag: DMF_SUSPENDED or DMF_SUSPENDED_INTERNALLY
|
|
*
|
|
* If __dm_suspend returns 0, the device is completely quiescent
|
|
* now. There is no request-processing activity. All new requests
|
|
* are being added to md->deferred list.
|
|
*/
|
|
static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
|
|
unsigned suspend_flags, long task_state,
|
|
int dmf_suspended_flag)
|
|
{
|
|
bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
|
|
bool noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG;
|
|
int r;
|
|
|
|
lockdep_assert_held(&md->suspend_lock);
|
|
|
|
/*
|
|
* DMF_NOFLUSH_SUSPENDING must be set before presuspend.
|
|
* This flag is cleared before dm_suspend returns.
|
|
*/
|
|
if (noflush)
|
|
set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
else
|
|
pr_debug("%s: suspending with flush\n", dm_device_name(md));
|
|
|
|
/*
|
|
* This gets reverted if there's an error later and the targets
|
|
* provide the .presuspend_undo hook.
|
|
*/
|
|
dm_table_presuspend_targets(map);
|
|
|
|
/*
|
|
* Flush I/O to the device.
|
|
* Any I/O submitted after lock_fs() may not be flushed.
|
|
* noflush takes precedence over do_lockfs.
|
|
* (lock_fs() flushes I/Os and waits for them to complete.)
|
|
*/
|
|
if (!noflush && do_lockfs) {
|
|
r = lock_fs(md);
|
|
if (r) {
|
|
dm_table_presuspend_undo_targets(map);
|
|
return r;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Here we must make sure that no processes are submitting requests
|
|
* to target drivers i.e. no one may be executing
|
|
* __split_and_process_bio. This is called from dm_request and
|
|
* dm_wq_work.
|
|
*
|
|
* To get all processes out of __split_and_process_bio in dm_request,
|
|
* we take the write lock. To prevent any process from reentering
|
|
* __split_and_process_bio from dm_request and quiesce the thread
|
|
* (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
|
|
* flush_workqueue(md->wq).
|
|
*/
|
|
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
if (map)
|
|
synchronize_srcu(&md->io_barrier);
|
|
|
|
/*
|
|
* Stop md->queue before flushing md->wq in case request-based
|
|
* dm defers requests to md->wq from md->queue.
|
|
*/
|
|
if (dm_request_based(md)) {
|
|
dm_stop_queue(md->queue);
|
|
if (md->kworker_task)
|
|
kthread_flush_worker(&md->kworker);
|
|
}
|
|
|
|
flush_workqueue(md->wq);
|
|
|
|
/*
|
|
* At this point no more requests are entering target request routines.
|
|
* We call dm_wait_for_completion to wait for all existing requests
|
|
* to finish.
|
|
*/
|
|
r = dm_wait_for_completion(md, task_state);
|
|
if (!r)
|
|
set_bit(dmf_suspended_flag, &md->flags);
|
|
|
|
if (noflush)
|
|
clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
if (map)
|
|
synchronize_srcu(&md->io_barrier);
|
|
|
|
/* were we interrupted ? */
|
|
if (r < 0) {
|
|
dm_queue_flush(md);
|
|
|
|
if (dm_request_based(md))
|
|
dm_start_queue(md->queue);
|
|
|
|
unlock_fs(md);
|
|
dm_table_presuspend_undo_targets(map);
|
|
/* pushback list is already flushed, so skip flush */
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* We need to be able to change a mapping table under a mounted
|
|
* filesystem. For example we might want to move some data in
|
|
* the background. Before the table can be swapped with
|
|
* dm_bind_table, dm_suspend must be called to flush any in
|
|
* flight bios and ensure that any further io gets deferred.
|
|
*/
|
|
/*
|
|
* Suspend mechanism in request-based dm.
|
|
*
|
|
* 1. Flush all I/Os by lock_fs() if needed.
|
|
* 2. Stop dispatching any I/O by stopping the request_queue.
|
|
* 3. Wait for all in-flight I/Os to be completed or requeued.
|
|
*
|
|
* To abort suspend, start the request_queue.
|
|
*/
|
|
int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
|
|
{
|
|
struct dm_table *map = NULL;
|
|
int r = 0;
|
|
|
|
retry:
|
|
mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
|
|
|
|
if (dm_suspended_md(md)) {
|
|
r = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (dm_suspended_internally_md(md)) {
|
|
/* already internally suspended, wait for internal resume */
|
|
mutex_unlock(&md->suspend_lock);
|
|
r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
|
|
if (r)
|
|
return r;
|
|
goto retry;
|
|
}
|
|
|
|
map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
|
|
r = __dm_suspend(md, map, suspend_flags, TASK_INTERRUPTIBLE, DMF_SUSPENDED);
|
|
if (r)
|
|
goto out_unlock;
|
|
|
|
dm_table_postsuspend_targets(map);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&md->suspend_lock);
|
|
return r;
|
|
}
|
|
|
|
static int __dm_resume(struct mapped_device *md, struct dm_table *map)
|
|
{
|
|
if (map) {
|
|
int r = dm_table_resume_targets(map);
|
|
if (r)
|
|
return r;
|
|
}
|
|
|
|
dm_queue_flush(md);
|
|
|
|
/*
|
|
* Flushing deferred I/Os must be done after targets are resumed
|
|
* so that mapping of targets can work correctly.
|
|
* Request-based dm is queueing the deferred I/Os in its request_queue.
|
|
*/
|
|
if (dm_request_based(md))
|
|
dm_start_queue(md->queue);
|
|
|
|
unlock_fs(md);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int dm_resume(struct mapped_device *md)
|
|
{
|
|
int r;
|
|
struct dm_table *map = NULL;
|
|
|
|
retry:
|
|
r = -EINVAL;
|
|
mutex_lock_nested(&md->suspend_lock, SINGLE_DEPTH_NESTING);
|
|
|
|
if (!dm_suspended_md(md))
|
|
goto out;
|
|
|
|
if (dm_suspended_internally_md(md)) {
|
|
/* already internally suspended, wait for internal resume */
|
|
mutex_unlock(&md->suspend_lock);
|
|
r = wait_on_bit(&md->flags, DMF_SUSPENDED_INTERNALLY, TASK_INTERRUPTIBLE);
|
|
if (r)
|
|
return r;
|
|
goto retry;
|
|
}
|
|
|
|
map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
if (!map || !dm_table_get_size(map))
|
|
goto out;
|
|
|
|
r = __dm_resume(md, map);
|
|
if (r)
|
|
goto out;
|
|
|
|
clear_bit(DMF_SUSPENDED, &md->flags);
|
|
out:
|
|
mutex_unlock(&md->suspend_lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Internal suspend/resume works like userspace-driven suspend. It waits
|
|
* until all bios finish and prevents issuing new bios to the target drivers.
|
|
* It may be used only from the kernel.
|
|
*/
|
|
|
|
static void __dm_internal_suspend(struct mapped_device *md, unsigned suspend_flags)
|
|
{
|
|
struct dm_table *map = NULL;
|
|
|
|
lockdep_assert_held(&md->suspend_lock);
|
|
|
|
if (md->internal_suspend_count++)
|
|
return; /* nested internal suspend */
|
|
|
|
if (dm_suspended_md(md)) {
|
|
set_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
|
|
return; /* nest suspend */
|
|
}
|
|
|
|
map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock));
|
|
|
|
/*
|
|
* Using TASK_UNINTERRUPTIBLE because only NOFLUSH internal suspend is
|
|
* supported. Properly supporting a TASK_INTERRUPTIBLE internal suspend
|
|
* would require changing .presuspend to return an error -- avoid this
|
|
* until there is a need for more elaborate variants of internal suspend.
|
|
*/
|
|
(void) __dm_suspend(md, map, suspend_flags, TASK_UNINTERRUPTIBLE,
|
|
DMF_SUSPENDED_INTERNALLY);
|
|
|
|
dm_table_postsuspend_targets(map);
|
|
}
|
|
|
|
static void __dm_internal_resume(struct mapped_device *md)
|
|
{
|
|
BUG_ON(!md->internal_suspend_count);
|
|
|
|
if (--md->internal_suspend_count)
|
|
return; /* resume from nested internal suspend */
|
|
|
|
if (dm_suspended_md(md))
|
|
goto done; /* resume from nested suspend */
|
|
|
|
/*
|
|
* NOTE: existing callers don't need to call dm_table_resume_targets
|
|
* (which may fail -- so best to avoid it for now by passing NULL map)
|
|
*/
|
|
(void) __dm_resume(md, NULL);
|
|
|
|
done:
|
|
clear_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
|
|
smp_mb__after_atomic();
|
|
wake_up_bit(&md->flags, DMF_SUSPENDED_INTERNALLY);
|
|
}
|
|
|
|
void dm_internal_suspend_noflush(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->suspend_lock);
|
|
__dm_internal_suspend(md, DM_SUSPEND_NOFLUSH_FLAG);
|
|
mutex_unlock(&md->suspend_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_suspend_noflush);
|
|
|
|
void dm_internal_resume(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->suspend_lock);
|
|
__dm_internal_resume(md);
|
|
mutex_unlock(&md->suspend_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_resume);
|
|
|
|
/*
|
|
* Fast variants of internal suspend/resume hold md->suspend_lock,
|
|
* which prevents interaction with userspace-driven suspend.
|
|
*/
|
|
|
|
void dm_internal_suspend_fast(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->suspend_lock);
|
|
if (dm_suspended_md(md) || dm_suspended_internally_md(md))
|
|
return;
|
|
|
|
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
synchronize_srcu(&md->io_barrier);
|
|
flush_workqueue(md->wq);
|
|
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_suspend_fast);
|
|
|
|
void dm_internal_resume_fast(struct mapped_device *md)
|
|
{
|
|
if (dm_suspended_md(md) || dm_suspended_internally_md(md))
|
|
goto done;
|
|
|
|
dm_queue_flush(md);
|
|
|
|
done:
|
|
mutex_unlock(&md->suspend_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_internal_resume_fast);
|
|
|
|
/*-----------------------------------------------------------------
|
|
* Event notification.
|
|
*---------------------------------------------------------------*/
|
|
int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
|
|
unsigned cookie)
|
|
{
|
|
char udev_cookie[DM_COOKIE_LENGTH];
|
|
char *envp[] = { udev_cookie, NULL };
|
|
|
|
if (!cookie)
|
|
return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
|
|
else {
|
|
snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
|
|
DM_COOKIE_ENV_VAR_NAME, cookie);
|
|
return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
|
|
action, envp);
|
|
}
|
|
}
|
|
|
|
uint32_t dm_next_uevent_seq(struct mapped_device *md)
|
|
{
|
|
return atomic_add_return(1, &md->uevent_seq);
|
|
}
|
|
|
|
uint32_t dm_get_event_nr(struct mapped_device *md)
|
|
{
|
|
return atomic_read(&md->event_nr);
|
|
}
|
|
|
|
int dm_wait_event(struct mapped_device *md, int event_nr)
|
|
{
|
|
return wait_event_interruptible(md->eventq,
|
|
(event_nr != atomic_read(&md->event_nr)));
|
|
}
|
|
|
|
void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&md->uevent_lock, flags);
|
|
list_add(elist, &md->uevent_list);
|
|
spin_unlock_irqrestore(&md->uevent_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* The gendisk is only valid as long as you have a reference
|
|
* count on 'md'.
|
|
*/
|
|
struct gendisk *dm_disk(struct mapped_device *md)
|
|
{
|
|
return md->disk;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_disk);
|
|
|
|
struct kobject *dm_kobject(struct mapped_device *md)
|
|
{
|
|
return &md->kobj_holder.kobj;
|
|
}
|
|
|
|
struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
|
|
|
|
if (test_bit(DMF_FREEING, &md->flags) ||
|
|
dm_deleting_md(md))
|
|
return NULL;
|
|
|
|
dm_get(md);
|
|
return md;
|
|
}
|
|
|
|
int dm_suspended_md(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_SUSPENDED, &md->flags);
|
|
}
|
|
|
|
int dm_suspended_internally_md(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_SUSPENDED_INTERNALLY, &md->flags);
|
|
}
|
|
|
|
int dm_test_deferred_remove_flag(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_DEFERRED_REMOVE, &md->flags);
|
|
}
|
|
|
|
int dm_suspended(struct dm_target *ti)
|
|
{
|
|
return dm_suspended_md(dm_table_get_md(ti->table));
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_suspended);
|
|
|
|
int dm_noflush_suspending(struct dm_target *ti)
|
|
{
|
|
return __noflush_suspending(dm_table_get_md(ti->table));
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_noflush_suspending);
|
|
|
|
struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
|
|
unsigned integrity, unsigned per_io_data_size)
|
|
{
|
|
struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
|
|
unsigned int pool_size = 0;
|
|
unsigned int front_pad;
|
|
|
|
if (!pools)
|
|
return NULL;
|
|
|
|
switch (type) {
|
|
case DM_TYPE_BIO_BASED:
|
|
case DM_TYPE_DAX_BIO_BASED:
|
|
pool_size = dm_get_reserved_bio_based_ios();
|
|
front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
|
|
|
|
pools->io_pool = mempool_create_slab_pool(pool_size, _io_cache);
|
|
if (!pools->io_pool)
|
|
goto out;
|
|
break;
|
|
case DM_TYPE_REQUEST_BASED:
|
|
case DM_TYPE_MQ_REQUEST_BASED:
|
|
pool_size = dm_get_reserved_rq_based_ios();
|
|
front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
|
|
/* per_io_data_size is used for blk-mq pdu at queue allocation */
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
pools->bs = bioset_create_nobvec(pool_size, front_pad);
|
|
if (!pools->bs)
|
|
goto out;
|
|
|
|
if (integrity && bioset_integrity_create(pools->bs, pool_size))
|
|
goto out;
|
|
|
|
return pools;
|
|
|
|
out:
|
|
dm_free_md_mempools(pools);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void dm_free_md_mempools(struct dm_md_mempools *pools)
|
|
{
|
|
if (!pools)
|
|
return;
|
|
|
|
mempool_destroy(pools->io_pool);
|
|
|
|
if (pools->bs)
|
|
bioset_free(pools->bs);
|
|
|
|
kfree(pools);
|
|
}
|
|
|
|
struct dm_pr {
|
|
u64 old_key;
|
|
u64 new_key;
|
|
u32 flags;
|
|
bool fail_early;
|
|
};
|
|
|
|
static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
|
|
void *data)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
struct dm_table *table;
|
|
struct dm_target *ti;
|
|
int ret = -ENOTTY, srcu_idx;
|
|
|
|
table = dm_get_live_table(md, &srcu_idx);
|
|
if (!table || !dm_table_get_size(table))
|
|
goto out;
|
|
|
|
/* We only support devices that have a single target */
|
|
if (dm_table_get_num_targets(table) != 1)
|
|
goto out;
|
|
ti = dm_table_get_target(table, 0);
|
|
|
|
ret = -EINVAL;
|
|
if (!ti->type->iterate_devices)
|
|
goto out;
|
|
|
|
ret = ti->type->iterate_devices(ti, fn, data);
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* For register / unregister we need to manually call out to every path.
|
|
*/
|
|
static int __dm_pr_register(struct dm_target *ti, struct dm_dev *dev,
|
|
sector_t start, sector_t len, void *data)
|
|
{
|
|
struct dm_pr *pr = data;
|
|
const struct pr_ops *ops = dev->bdev->bd_disk->fops->pr_ops;
|
|
|
|
if (!ops || !ops->pr_register)
|
|
return -EOPNOTSUPP;
|
|
return ops->pr_register(dev->bdev, pr->old_key, pr->new_key, pr->flags);
|
|
}
|
|
|
|
static int dm_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
|
|
u32 flags)
|
|
{
|
|
struct dm_pr pr = {
|
|
.old_key = old_key,
|
|
.new_key = new_key,
|
|
.flags = flags,
|
|
.fail_early = true,
|
|
};
|
|
int ret;
|
|
|
|
ret = dm_call_pr(bdev, __dm_pr_register, &pr);
|
|
if (ret && new_key) {
|
|
/* unregister all paths if we failed to register any path */
|
|
pr.old_key = new_key;
|
|
pr.new_key = 0;
|
|
pr.flags = 0;
|
|
pr.fail_early = false;
|
|
dm_call_pr(bdev, __dm_pr_register, &pr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int dm_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
|
|
u32 flags)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_reserve)
|
|
r = ops->pr_reserve(bdev, key, type, flags);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static int dm_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_release)
|
|
r = ops->pr_release(bdev, key, type);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static int dm_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
|
|
enum pr_type type, bool abort)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_preempt)
|
|
r = ops->pr_preempt(bdev, old_key, new_key, type, abort);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static int dm_pr_clear(struct block_device *bdev, u64 key)
|
|
{
|
|
struct mapped_device *md = bdev->bd_disk->private_data;
|
|
const struct pr_ops *ops;
|
|
fmode_t mode;
|
|
int r;
|
|
|
|
r = dm_grab_bdev_for_ioctl(md, &bdev, &mode);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
ops = bdev->bd_disk->fops->pr_ops;
|
|
if (ops && ops->pr_clear)
|
|
r = ops->pr_clear(bdev, key);
|
|
else
|
|
r = -EOPNOTSUPP;
|
|
|
|
bdput(bdev);
|
|
return r;
|
|
}
|
|
|
|
static const struct pr_ops dm_pr_ops = {
|
|
.pr_register = dm_pr_register,
|
|
.pr_reserve = dm_pr_reserve,
|
|
.pr_release = dm_pr_release,
|
|
.pr_preempt = dm_pr_preempt,
|
|
.pr_clear = dm_pr_clear,
|
|
};
|
|
|
|
static const struct block_device_operations dm_blk_dops = {
|
|
.open = dm_blk_open,
|
|
.release = dm_blk_close,
|
|
.ioctl = dm_blk_ioctl,
|
|
.getgeo = dm_blk_getgeo,
|
|
.pr_ops = &dm_pr_ops,
|
|
.owner = THIS_MODULE
|
|
};
|
|
|
|
static const struct dax_operations dm_dax_ops = {
|
|
.direct_access = dm_dax_direct_access,
|
|
.copy_from_iter = dm_dax_copy_from_iter,
|
|
.flush = dm_dax_flush,
|
|
};
|
|
|
|
/*
|
|
* module hooks
|
|
*/
|
|
module_init(dm_init);
|
|
module_exit(dm_exit);
|
|
|
|
module_param(major, uint, 0);
|
|
MODULE_PARM_DESC(major, "The major number of the device mapper");
|
|
|
|
module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
|
|
|
|
module_param(dm_numa_node, int, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(dm_numa_node, "NUMA node for DM device memory allocations");
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " driver");
|
|
MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|