diff options
| -rw-r--r-- | drivers/md/dm-table.c | 1 | ||||
| -rw-r--r-- | drivers/md/md.c | 1 | ||||
| -rw-r--r-- | fs/block_dev.c | 93 | ||||
| -rw-r--r-- | include/linux/fs.h | 8 |
4 files changed, 84 insertions, 19 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index dffa0ac7c4f..38e4eb1bb96 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 cf8594c5ea2..b76cfc89e1b 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 fe3f59c14a0..333a7bb4cb9 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 3984f2358d1..fb2190349cd 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 |