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-rw-r--r--drivers/md/dm-ioctl.c65
-rw-r--r--drivers/md/dm.c32
-rw-r--r--drivers/md/dm.h2
-rw-r--r--include/linux/dm-ioctl.h6
4 files changed, 81 insertions, 24 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index c826b3e..c6ce13b 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 952c49c..6982f86d 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 71ddd1e..9ebb24b 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 c67c678..9623bb6 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 */
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