/*
* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
+ * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/moduleparam.h>
#include <linux/blkpg.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/mempool.h>
#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/hdreg.h>
+#include <linux/blktrace_api.h>
+#include <linux/smp_lock.h>
+#include <linux/vs_base.h>
+
+#define DM_MSG_PREFIX "core"
static const char *_name = DM_NAME;
-#define MAX_DEVICES 1024
static unsigned int major = 0;
static unsigned int _major = 0;
+static DEFINE_SPINLOCK(_minor_lock);
/*
* One of these is allocated per bio.
*/
int error;
struct bio *bio;
atomic_t io_count;
+ unsigned long start_time;
};
/*
union map_info info;
};
+union map_info *dm_get_mapinfo(struct bio *bio)
+{
+ if (bio && bio->bi_private)
+ return &((struct target_io *)bio->bi_private)->info;
+ return NULL;
+}
+
+#define MINOR_ALLOCED ((void *)-1)
+
/*
* Bits for the md->flags field.
*/
#define DMF_BLOCK_IO 0
#define DMF_SUSPENDED 1
-#define DMF_FS_LOCKED 2
+#define DMF_FROZEN 2
+#define DMF_FREEING 3
+#define DMF_DELETING 4
+#define DMF_NOFLUSH_SUSPENDING 5
struct mapped_device {
- struct rw_semaphore lock;
+ struct rw_semaphore io_lock;
+ struct semaphore suspend_lock;
+ spinlock_t pushback_lock;
rwlock_t map_lock;
atomic_t holders;
+ atomic_t open_count;
+ xid_t xid;
unsigned long flags;
request_queue_t *queue;
struct gendisk *disk;
+ char name[16];
+
+ void *interface_ptr;
/*
* A list of ios that arrived while we were suspended.
*/
atomic_t pending;
wait_queue_head_t wait;
- struct bio_list deferred;
+ struct bio_list deferred;
+ struct bio_list pushback;
/*
* The current mapping.
mempool_t *io_pool;
mempool_t *tio_pool;
+ struct bio_set *bs;
+
/*
* Event handling.
*/
* freeze/thaw support require holding onto a super block
*/
struct super_block *frozen_sb;
+ struct block_device *suspended_bdev;
+
+ /* forced geometry settings */
+ struct hd_geometry geometry;
};
#define MIN_IOS 256
-static kmem_cache_t *_io_cache;
-static kmem_cache_t *_tio_cache;
+static struct kmem_cache *_io_cache;
+static struct kmem_cache *_tio_cache;
static int __init local_init(void)
{
kmem_cache_destroy(_io_cache);
if (unregister_blkdev(_major, _name) < 0)
- DMERR("devfs_unregister_blkdev failed");
+ DMERR("unregister_blkdev failed");
_major = 0;
DMINFO("cleaned up");
}
-/*
- * We have a lot of init/exit functions, so it seems easier to
- * store them in an array. The disposable macro 'xx'
- * expands a prefix into a pair of function names.
- */
-static struct {
- int (*init) (void);
- void (*exit) (void);
-
-} _inits[] = {
-#define xx(n) {n ## _init, n ## _exit},
- xx(local)
- xx(dm_target)
- xx(dm_linear)
- xx(dm_stripe)
- xx(dm_interface)
-#undef xx
+int (*_inits[])(void) __initdata = {
+ local_init,
+ dm_target_init,
+ dm_linear_init,
+ dm_stripe_init,
+ dm_interface_init,
+};
+
+void (*_exits[])(void) = {
+ local_exit,
+ dm_target_exit,
+ dm_linear_exit,
+ dm_stripe_exit,
+ dm_interface_exit,
};
static int __init dm_init(void)
int r, i;
for (i = 0; i < count; i++) {
- r = _inits[i].init();
+ r = _inits[i]();
if (r)
goto bad;
}
bad:
while (i--)
- _inits[i].exit();
+ _exits[i]();
return r;
}
static void __exit dm_exit(void)
{
- int i = ARRAY_SIZE(_inits);
+ int i = ARRAY_SIZE(_exits);
while (i--)
- _inits[i].exit();
+ _exits[i]();
}
/*
static int dm_blk_open(struct inode *inode, struct file *file)
{
struct mapped_device *md;
+ int ret = -ENXIO;
+
+ spin_lock(&_minor_lock);
md = inode->i_bdev->bd_disk->private_data;
+ if (!md)
+ goto out;
+
+ if (test_bit(DMF_FREEING, &md->flags) ||
+ test_bit(DMF_DELETING, &md->flags))
+ goto out;
+
+ ret = -EACCES;
+ if (!vx_check(md->xid, VS_IDENT|VS_HOSTID))
+ goto out;
+
dm_get(md);
- return 0;
+ atomic_inc(&md->open_count);
+ ret = 0;
+out:
+ spin_unlock(&_minor_lock);
+ return ret;
}
static int dm_blk_close(struct inode *inode, struct file *file)
struct mapped_device *md;
md = inode->i_bdev->bd_disk->private_data;
+ atomic_dec(&md->open_count);
dm_put(md);
return 0;
}
+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)
+{
+ int r = 0;
+
+ spin_lock(&_minor_lock);
+
+ if (dm_open_count(md))
+ r = -EBUSY;
+ else
+ set_bit(DMF_DELETING, &md->flags);
+
+ spin_unlock(&_minor_lock);
+
+ return r;
+}
+
+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_blk_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct mapped_device *md;
+ struct dm_table *map;
+ struct dm_target *tgt;
+ int r = -ENOTTY;
+
+ /* We don't really need this lock, but we do need 'inode'. */
+ unlock_kernel();
+
+ md = inode->i_bdev->bd_disk->private_data;
+
+ map = dm_get_table(md);
+
+ 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 (dm_suspended(md)) {
+ r = -EAGAIN;
+ goto out;
+ }
+
+ if (tgt->type->ioctl)
+ r = tgt->type->ioctl(tgt, inode, file, cmd, arg);
+
+out:
+ dm_table_put(map);
+
+ lock_kernel();
+ return r;
+}
+
static inline struct dm_io *alloc_io(struct mapped_device *md)
{
return mempool_alloc(md->io_pool, GFP_NOIO);
mempool_free(tio, md->tio_pool);
}
+static void start_io_acct(struct dm_io *io)
+{
+ struct mapped_device *md = io->md;
+
+ io->start_time = jiffies;
+
+ preempt_disable();
+ disk_round_stats(dm_disk(md));
+ preempt_enable();
+ dm_disk(md)->in_flight = atomic_inc_return(&md->pending);
+}
+
+static int 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);
+
+ preempt_disable();
+ disk_round_stats(dm_disk(md));
+ preempt_enable();
+ dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending);
+
+ disk_stat_add(dm_disk(md), ticks[rw], duration);
+
+ return !pending;
+}
+
/*
* Add the bio to the list of deferred io.
*/
static int queue_io(struct mapped_device *md, struct bio *bio)
{
- down_write(&md->lock);
+ down_write(&md->io_lock);
if (!test_bit(DMF_BLOCK_IO, &md->flags)) {
- up_write(&md->lock);
+ up_write(&md->io_lock);
return 1;
}
bio_list_add(&md->deferred, bio);
- up_write(&md->lock);
+ up_write(&md->io_lock);
return 0; /* deferred successfully */
}
return t;
}
+/*
+ * 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;
+}
+
+/*
+ * Get the xid associated with a dm device
+ */
+xid_t dm_get_xid(struct mapped_device *md)
+{
+ return md->xid;
+}
+
/*-----------------------------------------------------------------
* CRUD START:
* A more elegant soln is in the works that uses the queue
* 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 inline void dec_pending(struct dm_io *io, int error)
+static void dec_pending(struct dm_io *io, int error)
{
- if (error)
+ unsigned long flags;
+
+ /* Push-back supersedes any I/O errors */
+ if (error && !(io->error > 0 && __noflush_suspending(io->md)))
io->error = error;
if (atomic_dec_and_test(&io->io_count)) {
- if (atomic_dec_and_test(&io->md->pending))
+ if (io->error == DM_ENDIO_REQUEUE) {
+ /*
+ * Target requested pushing back the I/O.
+ * This must be handled before the sleeper on
+ * suspend queue merges the pushback list.
+ */
+ spin_lock_irqsave(&io->md->pushback_lock, flags);
+ if (__noflush_suspending(io->md))
+ bio_list_add(&io->md->pushback, io->bio);
+ else
+ /* noflush suspend was interrupted. */
+ io->error = -EIO;
+ spin_unlock_irqrestore(&io->md->pushback_lock, flags);
+ }
+
+ if (end_io_acct(io))
/* nudge anyone waiting on suspend queue */
wake_up(&io->md->wait);
- bio_endio(io->bio, io->bio->bi_size, io->error);
+ if (io->error != DM_ENDIO_REQUEUE) {
+ blk_add_trace_bio(io->md->queue, io->bio,
+ BLK_TA_COMPLETE);
+
+ bio_endio(io->bio, io->bio->bi_size, io->error);
+ }
+
free_io(io->md, io);
}
}
{
int r = 0;
struct target_io *tio = bio->bi_private;
- struct dm_io *io = tio->io;
+ struct mapped_device *md = tio->io->md;
dm_endio_fn endio = tio->ti->type->end_io;
if (bio->bi_size)
if (endio) {
r = endio(tio->ti, bio, error, &tio->info);
- if (r < 0)
+ if (r < 0 || r == DM_ENDIO_REQUEUE)
+ /*
+ * error and requeue request are handled
+ * in dec_pending().
+ */
error = r;
-
- else if (r > 0)
- /* the target wants another shot at the io */
+ else if (r == DM_ENDIO_INCOMPLETE)
+ /* The target will handle the io */
return 1;
+ else if (r) {
+ DMWARN("unimplemented target endio return value: %d", r);
+ BUG();
+ }
}
- free_tio(io->md, tio);
- dec_pending(io, error);
+ dec_pending(tio->io, error);
+
+ /*
+ * Store md for cleanup instead of tio which is about to get freed.
+ */
+ bio->bi_private = md->bs;
+
bio_put(bio);
+ free_tio(md, tio);
return r;
}
*/
if (ti->split_io) {
sector_t boundary;
- boundary = dm_round_up(offset + 1, ti->split_io) - offset;
-
+ boundary = ((offset + ti->split_io) & ~(ti->split_io - 1))
+ - offset;
if (len > boundary)
len = boundary;
}
struct target_io *tio)
{
int r;
+ sector_t sector;
+ struct mapped_device *md;
/*
* Sanity checks.
* this io.
*/
atomic_inc(&tio->io->io_count);
+ sector = clone->bi_sector;
r = ti->type->map(ti, clone, &tio->info);
- if (r > 0)
+ if (r == DM_MAPIO_REMAPPED) {
/* the bio has been remapped so dispatch it */
- generic_make_request(clone);
- else if (r < 0) {
- /* error the io and bail out */
- struct dm_io *io = tio->io;
- free_tio(tio->io->md, tio);
- dec_pending(io, -EIO);
+ blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone,
+ tio->io->bio->bi_bdev->bd_dev, sector,
+ clone->bi_sector);
+
+ generic_make_request(clone);
+ } else if (r < 0 || r == DM_MAPIO_REQUEUE) {
+ /* error the io and bail out, or requeue it if needed */
+ md = tio->io->md;
+ dec_pending(tio->io, r);
+ /*
+ * Store bio_set for cleanup.
+ */
+ clone->bi_private = md->bs;
bio_put(clone);
+ free_tio(md, tio);
+ } else if (r) {
+ DMWARN("unimplemented target map return value: %d", r);
+ BUG();
}
}
unsigned short idx;
};
+static void dm_bio_destructor(struct bio *bio)
+{
+ struct bio_set *bs = bio->bi_private;
+
+ bio_free(bio, bs);
+}
+
/*
* Creates a little bio that is just does part of a bvec.
*/
static struct bio *split_bvec(struct bio *bio, sector_t sector,
unsigned short idx, unsigned int offset,
- unsigned int len)
+ unsigned int len, struct bio_set *bs)
{
struct bio *clone;
struct bio_vec *bv = bio->bi_io_vec + idx;
- clone = bio_alloc(GFP_NOIO, 1);
- memcpy(clone->bi_io_vec, bv, sizeof(*bv));
+ clone = bio_alloc_bioset(GFP_NOIO, 1, bs);
+ clone->bi_destructor = dm_bio_destructor;
+ *clone->bi_io_vec = *bv;
clone->bi_sector = sector;
clone->bi_bdev = bio->bi_bdev;
*/
static struct bio *clone_bio(struct bio *bio, sector_t sector,
unsigned short idx, unsigned short bv_count,
- unsigned int len)
+ unsigned int len, struct bio_set *bs)
{
struct bio *clone;
- clone = bio_clone(bio, GFP_NOIO);
+ clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
+ __bio_clone(clone, bio);
+ clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
clone->bi_vcnt = idx + bv_count;
* the remaining io with a single clone.
*/
clone = clone_bio(bio, ci->sector, ci->idx,
- bio->bi_vcnt - ci->idx, ci->sector_count);
+ bio->bi_vcnt - ci->idx, ci->sector_count,
+ ci->md->bs);
__map_bio(ti, clone, tio);
ci->sector_count = 0;
len += bv_len;
}
- clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len);
+ clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len,
+ ci->md->bs);
__map_bio(ti, clone, tio);
ci->sector += len;
} else {
/*
- * Create two copy bios to deal with io that has
- * been split across a target.
+ * Handle a bvec that must be split between two or more targets.
*/
struct bio_vec *bv = bio->bi_io_vec + ci->idx;
+ sector_t remaining = to_sector(bv->bv_len);
+ unsigned int offset = 0;
- clone = split_bvec(bio, ci->sector, ci->idx,
- bv->bv_offset, max);
- __map_bio(ti, clone, tio);
+ do {
+ if (offset) {
+ ti = dm_table_find_target(ci->map, ci->sector);
+ max = max_io_len(ci->md, ci->sector, ti);
- ci->sector += max;
- ci->sector_count -= max;
- ti = dm_table_find_target(ci->map, ci->sector);
-
- len = to_sector(bv->bv_len) - max;
- clone = split_bvec(bio, ci->sector, ci->idx,
- bv->bv_offset + to_bytes(max), len);
- tio = alloc_tio(ci->md);
- tio->io = ci->io;
- tio->ti = ti;
- memset(&tio->info, 0, sizeof(tio->info));
- __map_bio(ti, clone, tio);
+ tio = alloc_tio(ci->md);
+ tio->io = ci->io;
+ tio->ti = ti;
+ memset(&tio->info, 0, sizeof(tio->info));
+ }
+
+ len = min(remaining, max);
+
+ clone = split_bvec(bio, ci->sector, ci->idx,
+ bv->bv_offset + offset, len,
+ ci->md->bs);
+
+ __map_bio(ti, clone, tio);
+
+ ci->sector += len;
+ ci->sector_count -= len;
+ offset += to_bytes(len);
+ } while (remaining -= len);
- ci->sector += len;
- ci->sector_count -= len;
ci->idx++;
}
}
ci.sector_count = bio_sectors(bio);
ci.idx = bio->bi_idx;
- atomic_inc(&md->pending);
+ start_io_acct(ci.io);
while (ci.sector_count)
__clone_and_map(&ci);
static int dm_request(request_queue_t *q, struct bio *bio)
{
int r;
+ int rw = bio_data_dir(bio);
struct mapped_device *md = q->queuedata;
- down_read(&md->lock);
+ down_read(&md->io_lock);
+
+ disk_stat_inc(dm_disk(md), ios[rw]);
+ disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio));
/*
* If we're suspended we have to queue
* this io for later.
*/
while (test_bit(DMF_BLOCK_IO, &md->flags)) {
- up_read(&md->lock);
+ up_read(&md->io_lock);
if (bio_rw(bio) == READA) {
bio_io_error(bio, bio->bi_size);
* We're in a while loop, because someone could suspend
* before we get to the following read lock.
*/
- down_read(&md->lock);
+ down_read(&md->io_lock);
}
__split_bio(md, bio);
- up_read(&md->lock);
+ up_read(&md->io_lock);
return 0;
}
+static int dm_flush_all(request_queue_t *q, struct gendisk *disk,
+ sector_t *error_sector)
+{
+ struct mapped_device *md = q->queuedata;
+ struct dm_table *map = dm_get_table(md);
+ int ret = -ENXIO;
+
+ if (map) {
+ ret = dm_table_flush_all(map);
+ dm_table_put(map);
+ }
+
+ return ret;
+}
+
static void dm_unplug_all(request_queue_t *q)
{
struct mapped_device *md = q->queuedata;
}
/*-----------------------------------------------------------------
- * A bitset is used to keep track of allocated minor numbers.
+ * An IDR is used to keep track of allocated minor numbers.
*---------------------------------------------------------------*/
-static spinlock_t _minor_lock = SPIN_LOCK_UNLOCKED;
-static unsigned long _minor_bits[MAX_DEVICES / BITS_PER_LONG];
+static DEFINE_IDR(_minor_idr);
-static void free_minor(unsigned int minor)
+static void free_minor(int minor)
{
spin_lock(&_minor_lock);
- clear_bit(minor, _minor_bits);
+ idr_remove(&_minor_idr, minor);
spin_unlock(&_minor_lock);
}
/*
* See if the device with a specific minor # is free.
*/
-static int specific_minor(unsigned int minor)
+static int specific_minor(struct mapped_device *md, int minor)
{
- int r = -EBUSY;
+ int r, m;
- if (minor >= MAX_DEVICES) {
- DMWARN("request for a mapped_device beyond MAX_DEVICES (%d)",
- MAX_DEVICES);
+ if (minor >= (1 << MINORBITS))
return -EINVAL;
- }
+
+ r = idr_pre_get(&_minor_idr, GFP_KERNEL);
+ if (!r)
+ return -ENOMEM;
spin_lock(&_minor_lock);
- if (!test_and_set_bit(minor, _minor_bits))
- r = 0;
- spin_unlock(&_minor_lock);
+ if (idr_find(&_minor_idr, minor)) {
+ r = -EBUSY;
+ goto out;
+ }
+
+ r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m);
+ if (r)
+ goto out;
+
+ if (m != minor) {
+ idr_remove(&_minor_idr, m);
+ r = -EBUSY;
+ goto out;
+ }
+
+out:
+ spin_unlock(&_minor_lock);
return r;
}
-static int next_free_minor(unsigned int *minor)
+static int next_free_minor(struct mapped_device *md, int *minor)
{
- int r = -EBUSY;
- unsigned int m;
+ int r, m;
+
+ r = idr_pre_get(&_minor_idr, GFP_KERNEL);
+ if (!r)
+ return -ENOMEM;
spin_lock(&_minor_lock);
- m = find_first_zero_bit(_minor_bits, MAX_DEVICES);
- if (m != MAX_DEVICES) {
- set_bit(m, _minor_bits);
- *minor = m;
- r = 0;
+
+ r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m);
+ if (r) {
+ goto out;
}
- spin_unlock(&_minor_lock);
+ if (m >= (1 << MINORBITS)) {
+ idr_remove(&_minor_idr, m);
+ r = -ENOSPC;
+ goto out;
+ }
+
+ *minor = m;
+
+out:
+ spin_unlock(&_minor_lock);
return r;
}
/*
* Allocate and initialise a blank device with a given minor.
*/
-static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
+static struct mapped_device *alloc_dev(int minor)
{
int r;
struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL);
+ void *old_md;
if (!md) {
DMWARN("unable to allocate device, out of memory.");
return NULL;
}
+ if (!try_module_get(THIS_MODULE))
+ goto bad0;
+
/* get a minor number for the dev */
- r = persistent ? specific_minor(minor) : next_free_minor(&minor);
+ if (minor == DM_ANY_MINOR)
+ r = next_free_minor(md, &minor);
+ else
+ r = specific_minor(md, minor);
if (r < 0)
goto bad1;
memset(md, 0, sizeof(*md));
- init_rwsem(&md->lock);
+ init_rwsem(&md->io_lock);
+ init_MUTEX(&md->suspend_lock);
+ spin_lock_init(&md->pushback_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
+ atomic_set(&md->open_count, 0);
atomic_set(&md->event_nr, 0);
+ md->xid = vx_current_xid();
md->queue = blk_alloc_queue(GFP_KERNEL);
if (!md->queue)
- goto bad1;
+ goto bad1_free_minor;
md->queue->queuedata = md;
md->queue->backing_dev_info.congested_fn = dm_any_congested;
md->queue->backing_dev_info.congested_data = md;
blk_queue_make_request(md->queue, dm_request);
+ blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
md->queue->unplug_fn = dm_unplug_all;
+ md->queue->issue_flush_fn = dm_flush_all;
- md->io_pool = mempool_create(MIN_IOS, mempool_alloc_slab,
- mempool_free_slab, _io_cache);
- if (!md->io_pool)
- goto bad2;
+ md->io_pool = mempool_create_slab_pool(MIN_IOS, _io_cache);
+ if (!md->io_pool)
+ goto bad2;
- md->tio_pool = mempool_create(MIN_IOS, mempool_alloc_slab,
- mempool_free_slab, _tio_cache);
+ md->tio_pool = mempool_create_slab_pool(MIN_IOS, _tio_cache);
if (!md->tio_pool)
goto bad3;
+ md->bs = bioset_create(16, 16, 4);
+ if (!md->bs)
+ goto bad_no_bioset;
+
md->disk = alloc_disk(1);
if (!md->disk)
goto bad4;
+ atomic_set(&md->pending, 0);
+ init_waitqueue_head(&md->wait);
+ init_waitqueue_head(&md->eventq);
+
md->disk->major = _major;
md->disk->first_minor = minor;
md->disk->fops = &dm_blk_dops;
md->disk->private_data = md;
sprintf(md->disk->disk_name, "dm-%d", minor);
add_disk(md->disk);
+ format_dev_t(md->name, MKDEV(_major, minor));
- atomic_set(&md->pending, 0);
- init_waitqueue_head(&md->wait);
- init_waitqueue_head(&md->eventq);
+ /* 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;
bad4:
+ bioset_free(md->bs);
+ bad_no_bioset:
mempool_destroy(md->tio_pool);
bad3:
mempool_destroy(md->io_pool);
bad2:
- blk_put_queue(md->queue);
+ blk_cleanup_queue(md->queue);
+ bad1_free_minor:
free_minor(minor);
bad1:
+ module_put(THIS_MODULE);
+ bad0:
kfree(md);
return NULL;
}
static void free_dev(struct mapped_device *md)
{
- free_minor(md->disk->first_minor);
+ int minor = md->disk->first_minor;
+
+ if (md->suspended_bdev) {
+ thaw_bdev(md->suspended_bdev, NULL);
+ bdput(md->suspended_bdev);
+ }
mempool_destroy(md->tio_pool);
mempool_destroy(md->io_pool);
+ bioset_free(md->bs);
del_gendisk(md->disk);
+ free_minor(minor);
+
+ spin_lock(&_minor_lock);
+ md->disk->private_data = NULL;
+ spin_unlock(&_minor_lock);
+
put_disk(md->disk);
- blk_put_queue(md->queue);
+ blk_cleanup_queue(md->queue);
+ module_put(THIS_MODULE);
kfree(md);
}
{
struct mapped_device *md = (struct mapped_device *) context;
- atomic_inc(&md->event_nr);;
+ atomic_inc(&md->event_nr);
wake_up(&md->eventq);
}
-static void __set_size(struct gendisk *disk, sector_t size)
+static void __set_size(struct mapped_device *md, sector_t size)
{
- struct block_device *bdev;
+ set_capacity(md->disk, size);
- set_capacity(disk, size);
- bdev = bdget_disk(disk, 0);
- if (bdev) {
- down(&bdev->bd_inode->i_sem);
- i_size_write(bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
- up(&bdev->bd_inode->i_sem);
- bdput(bdev);
- }
+ mutex_lock(&md->suspended_bdev->bd_inode->i_mutex);
+ i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+ mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex);
}
static int __bind(struct mapped_device *md, struct dm_table *t)
sector_t size;
size = dm_table_get_size(t);
- __set_size(md->disk, size);
+
+ /*
+ * Wipe any geometry if the size of the table changed.
+ */
+ if (size != get_capacity(md->disk))
+ memset(&md->geometry, 0, sizeof(md->geometry));
+
+ if (md->suspended_bdev)
+ __set_size(md, size);
if (size == 0)
return 0;
+ dm_table_get(t);
+ dm_table_event_callback(t, event_callback, md);
+
write_lock(&md->map_lock);
md->map = t;
+ dm_table_set_restrictions(t, q);
write_unlock(&md->map_lock);
- dm_table_get(t);
- dm_table_event_callback(md->map, event_callback, md);
- dm_table_set_restrictions(t, q);
return 0;
}
/*
* Constructor for a new device.
*/
-static int create_aux(unsigned int minor, int persistent,
- struct mapped_device **result)
+int dm_create(int minor, struct mapped_device **result)
{
struct mapped_device *md;
- md = alloc_dev(minor, persistent);
+ md = alloc_dev(minor);
if (!md)
return -ENXIO;
return 0;
}
-int dm_create(struct mapped_device **result)
+static struct mapped_device *dm_find_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 && (md == MINOR_ALLOCED ||
+ (dm_disk(md)->first_minor != minor) ||
+ test_bit(DMF_FREEING, &md->flags))) {
+ md = NULL;
+ goto out;
+ }
+
+out:
+ spin_unlock(&_minor_lock);
+
+ return md;
+}
+
+struct mapped_device *dm_get_md(dev_t dev)
+{
+ struct mapped_device *md = dm_find_md(dev);
+
+ if (md)
+ dm_get(md);
+
+ return md;
+}
+
+void *dm_get_mdptr(struct mapped_device *md)
{
- return create_aux(0, 0, result);
+ return md->interface_ptr;
}
-int dm_create_with_minor(unsigned int minor, struct mapped_device **result)
+void dm_set_mdptr(struct mapped_device *md, void *ptr)
{
- return create_aux(minor, 1, result);
+ md->interface_ptr = ptr;
}
void dm_get(struct mapped_device *md)
atomic_inc(&md->holders);
}
+const char *dm_device_name(struct mapped_device *md)
+{
+ return md->name;
+}
+EXPORT_SYMBOL_GPL(dm_device_name);
+
void dm_put(struct mapped_device *md)
{
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map;
- if (atomic_dec_and_test(&md->holders)) {
- if (!test_bit(DMF_SUSPENDED, &md->flags) && map)
- dm_table_suspend_targets(map);
+ BUG_ON(test_bit(DMF_FREEING, &md->flags));
+
+ if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
+ map = dm_get_table(md);
+ idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor);
+ set_bit(DMF_FREEING, &md->flags);
+ spin_unlock(&_minor_lock);
+ if (!dm_suspended(md)) {
+ dm_table_presuspend_targets(map);
+ dm_table_postsuspend_targets(map);
+ }
__unbind(md);
+ dm_table_put(map);
free_dev(md);
}
-
- dm_table_put(map);
}
/*
*/
int dm_swap_table(struct mapped_device *md, struct dm_table *table)
{
- int r;
+ int r = -EINVAL;
- down_write(&md->lock);
+ down(&md->suspend_lock);
/* device must be suspended */
- if (!test_bit(DMF_SUSPENDED, &md->flags)) {
- up_write(&md->lock);
- return -EPERM;
- }
+ if (!dm_suspended(md))
+ goto out;
+
+ /* without bdev, the device size cannot be changed */
+ if (!md->suspended_bdev)
+ if (get_capacity(md->disk) != dm_table_get_size(table))
+ goto out;
__unbind(md);
r = __bind(md, table);
- if (r)
- return r;
- up_write(&md->lock);
- return 0;
+out:
+ up(&md->suspend_lock);
+ return r;
}
/*
* Functions to lock and unlock any filesystem running on the
* device.
*/
-static int __lock_fs(struct mapped_device *md)
+static int lock_fs(struct mapped_device *md)
{
- struct block_device *bdev;
+ int r;
- if (test_and_set_bit(DMF_FS_LOCKED, &md->flags))
- return 0;
+ WARN_ON(md->frozen_sb);
- bdev = bdget_disk(md->disk, 0);
- if (!bdev) {
- DMWARN("bdget failed in __lock_fs");
- return -ENOMEM;
+ md->frozen_sb = freeze_bdev(md->suspended_bdev);
+ if (IS_ERR(md->frozen_sb)) {
+ r = PTR_ERR(md->frozen_sb);
+ md->frozen_sb = NULL;
+ return r;
}
- WARN_ON(md->frozen_sb);
- md->frozen_sb = freeze_bdev(bdev);
+ set_bit(DMF_FROZEN, &md->flags);
+
/* don't bdput right now, we don't want the bdev
- * to go away while it is locked. We'll bdput
- * in __unlock_fs
+ * to go away while it is locked.
*/
return 0;
}
-static int __unlock_fs(struct mapped_device *md)
+static void unlock_fs(struct mapped_device *md)
{
- struct block_device *bdev;
-
- if (!test_and_clear_bit(DMF_FS_LOCKED, &md->flags))
- return 0;
-
- bdev = bdget_disk(md->disk, 0);
- if (!bdev) {
- DMWARN("bdget failed in __unlock_fs");
- return -ENOMEM;
- }
+ if (!test_bit(DMF_FROZEN, &md->flags))
+ return;
- thaw_bdev(bdev, md->frozen_sb);
+ thaw_bdev(md->suspended_bdev, md->frozen_sb);
md->frozen_sb = NULL;
- bdput(bdev);
- bdput(bdev);
- return 0;
+ clear_bit(DMF_FROZEN, &md->flags);
}
/*
* dm_bind_table, dm_suspend must be called to flush any in
* flight bios and ensure that any further io gets deferred.
*/
-int dm_suspend(struct mapped_device *md)
+int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
{
- struct dm_table *map;
+ struct dm_table *map = NULL;
+ unsigned long flags;
DECLARE_WAITQUEUE(wait, current);
+ struct bio *def;
+ int r = -EINVAL;
+ int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
+ int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;
- /* Flush I/O to the device. */
- down_read(&md->lock);
- if (test_bit(DMF_BLOCK_IO, &md->flags)) {
- up_read(&md->lock);
- return -EINVAL;
- }
+ down(&md->suspend_lock);
- __lock_fs(md);
- up_read(&md->lock);
+ if (dm_suspended(md))
+ goto out_unlock;
+
+ map = dm_get_table(md);
/*
- * First we set the BLOCK_IO flag so no more ios will be
- * mapped.
+ * DMF_NOFLUSH_SUSPENDING must be set before presuspend.
+ * This flag is cleared before dm_suspend returns.
*/
- down_write(&md->lock);
- if (test_bit(DMF_BLOCK_IO, &md->flags)) {
- /*
- * If we get here we know another thread is
- * trying to suspend as well, so we leave the fs
- * locked for this thread.
- */
- up_write(&md->lock);
- return -EINVAL;
+ if (noflush)
+ set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+
+ /* This does not get reverted if there's an error later. */
+ dm_table_presuspend_targets(map);
+
+ /* bdget() can stall if the pending I/Os are not flushed */
+ if (!noflush) {
+ md->suspended_bdev = bdget_disk(md->disk, 0);
+ if (!md->suspended_bdev) {
+ DMWARN("bdget failed in dm_suspend");
+ r = -ENOMEM;
+ goto flush_and_out;
+ }
+ }
+
+ /*
+ * Flush I/O to the device.
+ * noflush supersedes do_lockfs, because lock_fs() needs to flush I/Os.
+ */
+ if (do_lockfs && !noflush) {
+ r = lock_fs(md);
+ if (r)
+ goto out;
}
+ /*
+ * First we set the BLOCK_IO flag so no more ios will be mapped.
+ */
+ down_write(&md->io_lock);
set_bit(DMF_BLOCK_IO, &md->flags);
+
add_wait_queue(&md->wait, &wait);
- up_write(&md->lock);
+ up_write(&md->io_lock);
/* unplug */
- map = dm_get_table(md);
- if (map) {
+ if (map)
dm_table_unplug_all(map);
- dm_table_put(map);
- }
/*
* Then we wait for the already mapped ios to
}
set_current_state(TASK_RUNNING);
- down_write(&md->lock);
+ down_write(&md->io_lock);
remove_wait_queue(&md->wait, &wait);
+ if (noflush) {
+ spin_lock_irqsave(&md->pushback_lock, flags);
+ clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+ bio_list_merge_head(&md->deferred, &md->pushback);
+ bio_list_init(&md->pushback);
+ spin_unlock_irqrestore(&md->pushback_lock, flags);
+ }
+
/* were we interrupted ? */
+ r = -EINTR;
if (atomic_read(&md->pending)) {
- __unlock_fs(md);
clear_bit(DMF_BLOCK_IO, &md->flags);
- up_write(&md->lock);
- return -EINTR;
+ def = bio_list_get(&md->deferred);
+ __flush_deferred_io(md, def);
+ up_write(&md->io_lock);
+ unlock_fs(md);
+ goto out; /* pushback list is already flushed, so skip flush */
}
+ up_write(&md->io_lock);
+
+ dm_table_postsuspend_targets(map);
set_bit(DMF_SUSPENDED, &md->flags);
- map = dm_get_table(md);
- if (map)
- dm_table_suspend_targets(map);
+ r = 0;
+
+flush_and_out:
+ if (r && noflush) {
+ /*
+ * Because there may be already I/Os in the pushback list,
+ * flush them before return.
+ */
+ down_write(&md->io_lock);
+
+ spin_lock_irqsave(&md->pushback_lock, flags);
+ clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+ bio_list_merge_head(&md->deferred, &md->pushback);
+ bio_list_init(&md->pushback);
+ spin_unlock_irqrestore(&md->pushback_lock, flags);
+
+ def = bio_list_get(&md->deferred);
+ __flush_deferred_io(md, def);
+ up_write(&md->io_lock);
+ }
+
+out:
+ if (r && md->suspended_bdev) {
+ bdput(md->suspended_bdev);
+ md->suspended_bdev = NULL;
+ }
+
dm_table_put(map);
- up_write(&md->lock);
- return 0;
+out_unlock:
+ up(&md->suspend_lock);
+ return r;
}
int dm_resume(struct mapped_device *md)
{
+ int r = -EINVAL;
struct bio *def;
- struct dm_table *map = dm_get_table(md);
+ struct dm_table *map = NULL;
- down_write(&md->lock);
- if (!map ||
- !test_bit(DMF_SUSPENDED, &md->flags) ||
- !dm_table_get_size(map)) {
- up_write(&md->lock);
- dm_table_put(map);
- return -EINVAL;
- }
+ down(&md->suspend_lock);
+ if (!dm_suspended(md))
+ goto out;
- dm_table_resume_targets(map);
- clear_bit(DMF_SUSPENDED, &md->flags);
+ map = dm_get_table(md);
+ if (!map || !dm_table_get_size(map))
+ goto out;
+
+ r = dm_table_resume_targets(map);
+ if (r)
+ goto out;
+
+ down_write(&md->io_lock);
clear_bit(DMF_BLOCK_IO, &md->flags);
def = bio_list_get(&md->deferred);
__flush_deferred_io(md, def);
- up_write(&md->lock);
- __unlock_fs(md);
+ up_write(&md->io_lock);
+
+ unlock_fs(md);
+
+ if (md->suspended_bdev) {
+ bdput(md->suspended_bdev);
+ md->suspended_bdev = NULL;
+ }
+
+ clear_bit(DMF_SUSPENDED, &md->flags);
+
dm_table_unplug_all(map);
+
+ kobject_uevent(&md->disk->kobj, KOBJ_CHANGE);
+
+ r = 0;
+
+out:
dm_table_put(map);
+ up(&md->suspend_lock);
- return 0;
+ return r;
}
/*-----------------------------------------------------------------
return test_bit(DMF_SUSPENDED, &md->flags);
}
+int dm_noflush_suspending(struct dm_target *ti)
+{
+ struct mapped_device *md = dm_table_get_md(ti->table);
+ int r = __noflush_suspending(md);
+
+ dm_put(md);
+
+ return r;
+}
+EXPORT_SYMBOL_GPL(dm_noflush_suspending);
+
static struct block_device_operations dm_blk_dops = {
.open = dm_blk_open,
.release = dm_blk_close,
+ .ioctl = dm_blk_ioctl,
+ .getgeo = dm_blk_getgeo,
.owner = THIS_MODULE
};
+EXPORT_SYMBOL(dm_get_mapinfo);
+
/*
* module hooks
*/
module_param(major, uint, 0);
MODULE_PARM_DESC(major, "The major number of the device mapper");
MODULE_DESCRIPTION(DM_NAME " driver");
-MODULE_AUTHOR("Joe Thornber <thornber@sistina.com>");
+MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
MODULE_LICENSE("GPL");
git://git.onelab.eu / linux-2.6.git / blobdiff