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-rw-r--r--drivers/md/dm-table.c1
-rw-r--r--drivers/md/md.c1
-rw-r--r--fs/block_dev.c93
-rw-r--r--include/linux/fs.h8
4 files changed, 84 insertions, 19 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index dffa0ac7c4f0..38e4eb1bb965 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -350,6 +350,7 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
if (!d->dm_dev.bdev)
return;
+ bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
d->dm_dev.bdev = NULL;
}
diff --git a/drivers/md/md.c b/drivers/md/md.c
index cf8594c5ea21..b76cfc89e1b5 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1912,6 +1912,7 @@ static void unbind_rdev_from_array(mdk_rdev_t * rdev)
MD_BUG();
return;
}
+ bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
list_del_rcu(&rdev->same_set);
printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
rdev->mddev = NULL;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index fe3f59c14a02..333a7bb4cb9c 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -432,6 +432,9 @@ static void init_once(void *foo)
mutex_init(&bdev->bd_mutex);
INIT_LIST_HEAD(&bdev->bd_inodes);
INIT_LIST_HEAD(&bdev->bd_list);
+#ifdef CONFIG_SYSFS
+ INIT_LIST_HEAD(&bdev->bd_holder_disks);
+#endif
inode_init_once(&ei->vfs_inode);
/* Initialize mutex for freeze. */
mutex_init(&bdev->bd_fsfreeze_mutex);
@@ -779,6 +782,23 @@ static struct block_device *bd_start_claiming(struct block_device *bdev,
}
#ifdef CONFIG_SYSFS
+struct bd_holder_disk {
+ struct list_head list;
+ struct gendisk *disk;
+ int refcnt;
+};
+
+static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
+ struct gendisk *disk)
+{
+ struct bd_holder_disk *holder;
+
+ list_for_each_entry(holder, &bdev->bd_holder_disks, list)
+ if (holder->disk == disk)
+ return holder;
+ return NULL;
+}
+
static int add_symlink(struct kobject *from, struct kobject *to)
{
return sysfs_create_link(from, to, kobject_name(to));
@@ -794,6 +814,8 @@ static void del_symlink(struct kobject *from, struct kobject *to)
* @bdev: the claimed slave bdev
* @disk: the holding disk
*
+ * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
+ *
* This functions creates the following sysfs symlinks.
*
* - from "slaves" directory of the holder @disk to the claimed @bdev
@@ -817,47 +839,83 @@ static void del_symlink(struct kobject *from, struct kobject *to)
*/
int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
+ struct bd_holder_disk *holder;
int ret = 0;
mutex_lock(&bdev->bd_mutex);
- WARN_ON_ONCE(!bdev->bd_holder || bdev->bd_holder_disk);
+ WARN_ON_ONCE(!bdev->bd_holder);
/* FIXME: remove the following once add_disk() handles errors */
if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
goto out_unlock;
- ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- if (ret)
+ holder = bd_find_holder_disk(bdev, disk);
+ if (holder) {
+ holder->refcnt++;
goto out_unlock;
+ }
- ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
- if (ret) {
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ holder = kzalloc(sizeof(*holder), GFP_KERNEL);
+ if (!holder) {
+ ret = -ENOMEM;
goto out_unlock;
}
- bdev->bd_holder_disk = disk;
+ INIT_LIST_HEAD(&holder->list);
+ holder->disk = disk;
+ holder->refcnt = 1;
+
+ ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ if (ret)
+ goto out_free;
+
+ ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
+ if (ret)
+ goto out_del;
+
+ list_add(&holder->list, &bdev->bd_holder_disks);
+ goto out_unlock;
+
+out_del:
+ del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+out_free:
+ kfree(holder);
out_unlock:
mutex_unlock(&bdev->bd_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(bd_link_disk_holder);
-static void bd_unlink_disk_holder(struct block_device *bdev)
+/**
+ * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
+ * @bdev: the calimed slave bdev
+ * @disk: the holding disk
+ *
+ * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
- struct gendisk *disk = bdev->bd_holder_disk;
+ struct bd_holder_disk *holder;
- bdev->bd_holder_disk = NULL;
- if (!disk)
- return;
+ mutex_lock(&bdev->bd_mutex);
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- del_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
+ holder = bd_find_holder_disk(bdev, disk);
+
+ if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
+ del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ del_symlink(bdev->bd_part->holder_dir,
+ &disk_to_dev(disk)->kobj);
+ list_del_init(&holder->list);
+ kfree(holder);
+ }
+
+ mutex_unlock(&bdev->bd_mutex);
}
-#else
-static inline void bd_unlink_disk_holder(struct block_device *bdev)
-{ }
+EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
#endif
/**
@@ -1380,7 +1438,6 @@ int blkdev_put(struct block_device *bdev, fmode_t mode)
* unblock evpoll if it was a write holder.
*/
if (bdev_free) {
- bd_unlink_disk_holder(bdev);
if (bdev->bd_write_holder) {
disk_unblock_events(bdev->bd_disk);
bdev->bd_write_holder = false;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3984f2358d1f..fb2190349cdf 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -666,7 +666,7 @@ struct block_device {
int bd_holders;
bool bd_write_holder;
#ifdef CONFIG_SYSFS
- struct gendisk * bd_holder_disk; /* for sysfs slave linkng */
+ struct list_head bd_holder_disks;
#endif
struct block_device * bd_contains;
unsigned bd_block_size;
@@ -2058,12 +2058,18 @@ extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
extern int blkdev_put(struct block_device *bdev, fmode_t mode);
#ifdef CONFIG_SYSFS
extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
+extern void bd_unlink_disk_holder(struct block_device *bdev,
+ struct gendisk *disk);
#else
static inline int bd_link_disk_holder(struct block_device *bdev,
struct gendisk *disk)
{
return 0;
}
+static inline void bd_unlink_disk_holder(struct block_device *bdev,
+ struct gendisk *disk)
+{
+}
#endif
#endif
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-10 10:42:00 +0000