diff options
| -rw-r--r-- | drivers/md/dm-ioctl.c | 65 | ||||
| -rw-r--r-- | drivers/md/dm.c | 32 | ||||
| -rw-r--r-- | drivers/md/dm.h | 2 | ||||
| -rw-r--r-- | include/linux/dm-ioctl.h | 6 |
4 files changed, 81 insertions, 24 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index c826b3e1799a..c6ce13b18747 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -48,7 +48,7 @@ struct vers_iter { static struct list_head _name_buckets[NUM_BUCKETS]; static struct list_head _uuid_buckets[NUM_BUCKETS]; -static void dm_hash_remove_all(void); +static void dm_hash_remove_all(int keep_open_devices); /* * Guards access to both hash tables. @@ -73,7 +73,7 @@ static int dm_hash_init(void) static void dm_hash_exit(void) { - dm_hash_remove_all(); + dm_hash_remove_all(0); devfs_remove(DM_DIR); } @@ -260,19 +260,41 @@ static void __hash_remove(struct hash_cell *hc) free_cell(hc); } -static void dm_hash_remove_all(void) +static void dm_hash_remove_all(int keep_open_devices) { - int i; + int i, dev_skipped, dev_removed; struct hash_cell *hc; struct list_head *tmp, *n; down_write(&_hash_lock); + +retry: + dev_skipped = dev_removed = 0; for (i = 0; i < NUM_BUCKETS; i++) { list_for_each_safe (tmp, n, _name_buckets + i) { hc = list_entry(tmp, struct hash_cell, name_list); + + if (keep_open_devices && + dm_lock_for_deletion(hc->md)) { + dev_skipped++; + continue; + } __hash_remove(hc); + dev_removed = 1; } } + + /* + * Some mapped devices may be using other mapped devices, so if any + * still exist, repeat until we make no further progress. + */ + if (dev_skipped) { + if (dev_removed) + goto retry; + + DMWARN("remove_all left %d open device(s)", dev_skipped); + } + up_write(&_hash_lock); } @@ -355,7 +377,7 @@ typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size); static int remove_all(struct dm_ioctl *param, size_t param_size) { - dm_hash_remove_all(); + dm_hash_remove_all(1); param->data_size = 0; return 0; } @@ -535,7 +557,6 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param) { struct gendisk *disk = dm_disk(md); struct dm_table *table; - struct block_device *bdev; param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | DM_ACTIVE_PRESENT_FLAG); @@ -545,20 +566,12 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param) param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor)); - if (!(param->flags & DM_SKIP_BDGET_FLAG)) { - bdev = bdget_disk(disk, 0); - if (!bdev) - return -ENXIO; - - /* - * Yes, this will be out of date by the time it gets back - * to userland, but it is still very useful for - * debugging. - */ - param->open_count = bdev->bd_openers; - bdput(bdev); - } else - param->open_count = -1; + /* + * Yes, this will be out of date by the time it gets back + * to userland, but it is still very useful for + * debugging. + */ + param->open_count = dm_open_count(md); if (disk->policy) param->flags |= DM_READONLY_FLAG; @@ -661,6 +674,7 @@ static int dev_remove(struct dm_ioctl *param, size_t param_size) { struct hash_cell *hc; struct mapped_device *md; + int r; down_write(&_hash_lock); hc = __find_device_hash_cell(param); @@ -673,6 +687,17 @@ static int dev_remove(struct dm_ioctl *param, size_t param_size) md = hc->md; + /* + * Ensure the device is not open and nothing further can open it. + */ + r = dm_lock_for_deletion(md); + if (r) { + DMWARN("unable to remove open device %s", hc->name); + up_write(&_hash_lock); + dm_put(md); + return r; + } + __hash_remove(hc); up_write(&_hash_lock); dm_put(md); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 952c49c3b9aa..6982f86db6dc 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -64,12 +64,14 @@ union map_info *dm_get_mapinfo(struct bio *bio) #define DMF_SUSPENDED 1 #define DMF_FROZEN 2 #define DMF_FREEING 3 +#define DMF_DELETING 4 struct mapped_device { struct rw_semaphore io_lock; struct semaphore suspend_lock; rwlock_t map_lock; atomic_t holders; + atomic_t open_count; unsigned long flags; @@ -228,12 +230,14 @@ static int dm_blk_open(struct inode *inode, struct file *file) if (!md) goto out; - if (test_bit(DMF_FREEING, &md->flags)) { + if (test_bit(DMF_FREEING, &md->flags) || + test_bit(DMF_DELETING, &md->flags)) { md = NULL; goto out; } dm_get(md); + atomic_inc(&md->open_count); out: spin_unlock(&_minor_lock); @@ -246,10 +250,35 @@ 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; @@ -867,6 +896,7 @@ static struct mapped_device *alloc_dev(int minor) init_MUTEX(&md->suspend_lock); rwlock_init(&md->map_lock); atomic_set(&md->holders, 1); + atomic_set(&md->open_count, 0); atomic_set(&md->event_nr, 0); md->queue = blk_alloc_queue(GFP_KERNEL); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 71ddd1e23007..9ebb24b037bc 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -123,5 +123,7 @@ void dm_stripe_exit(void); void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); union map_info *dm_get_mapinfo(struct bio *bio); +int dm_open_count(struct mapped_device *md); +int dm_lock_for_deletion(struct mapped_device *md); #endif diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h index c67c6786612a..9623bb625090 100644 --- a/include/linux/dm-ioctl.h +++ b/include/linux/dm-ioctl.h @@ -285,9 +285,9 @@ typedef char ioctl_struct[308]; #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 6 +#define DM_VERSION_MINOR 7 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2006-02-17)" +#define DM_VERSION_EXTRA "-ioctl (2006-06-24)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ @@ -314,7 +314,7 @@ typedef char ioctl_struct[308]; #define DM_BUFFER_FULL_FLAG (1 << 8) /* Out */ /* - * Set this to improve performance when you aren't going to use open_count. + * This flag is now ignored. */ #define DM_SKIP_BDGET_FLAG (1 << 9) /* In */ |