mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 02:30:34 +02:00 
			
		
		
		
	btrfs: do not background blkdev_put()
At the end of unmount/dev-delete, if the device exclusive open is not
actually closed, then there might be a race with another program in
the userland who is trying to open the device in exclusive mode and
it may fail for eg:
      unmount /btrfs; fsck /dev/x
      btrfs dev del /dev/x /btrfs; fsck /dev/x
so here background blkdev_put() is not a choice
Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
			
			
This commit is contained in:
		
							parent
							
								
									28b737f6ed
								
							
						
					
					
						commit
						1423881941
					
				
					 1 changed files with 19 additions and 8 deletions
				
			
		| 
						 | 
				
			
			@ -834,10 +834,6 @@ static void __free_device(struct work_struct *work)
 | 
			
		|||
	struct btrfs_device *device;
 | 
			
		||||
 | 
			
		||||
	device = container_of(work, struct btrfs_device, rcu_work);
 | 
			
		||||
 | 
			
		||||
	if (device->bdev)
 | 
			
		||||
		blkdev_put(device->bdev, device->mode);
 | 
			
		||||
 | 
			
		||||
	rcu_string_free(device->name);
 | 
			
		||||
	kfree(device);
 | 
			
		||||
}
 | 
			
		||||
| 
						 | 
				
			
			@ -852,6 +848,17 @@ static void free_device(struct rcu_head *head)
 | 
			
		|||
	schedule_work(&device->rcu_work);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static void btrfs_close_bdev(struct btrfs_device *device)
 | 
			
		||||
{
 | 
			
		||||
	if (device->bdev && device->writeable) {
 | 
			
		||||
		sync_blockdev(device->bdev);
 | 
			
		||||
		invalidate_bdev(device->bdev);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (device->bdev)
 | 
			
		||||
		blkdev_put(device->bdev, device->mode);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static void btrfs_close_one_device(struct btrfs_device *device)
 | 
			
		||||
{
 | 
			
		||||
	struct btrfs_fs_devices *fs_devices = device->fs_devices;
 | 
			
		||||
| 
						 | 
				
			
			@ -870,10 +877,7 @@ static void btrfs_close_one_device(struct btrfs_device *device)
 | 
			
		|||
	if (device->missing)
 | 
			
		||||
		fs_devices->missing_devices--;
 | 
			
		||||
 | 
			
		||||
	if (device->bdev && device->writeable) {
 | 
			
		||||
		sync_blockdev(device->bdev);
 | 
			
		||||
		invalidate_bdev(device->bdev);
 | 
			
		||||
	}
 | 
			
		||||
	btrfs_close_bdev(device);
 | 
			
		||||
 | 
			
		||||
	new_device = btrfs_alloc_device(NULL, &device->devid,
 | 
			
		||||
					device->uuid);
 | 
			
		||||
| 
						 | 
				
			
			@ -1932,6 +1936,8 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
 | 
			
		|||
		btrfs_sysfs_rm_device_link(root->fs_info->fs_devices, device);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	btrfs_close_bdev(device);
 | 
			
		||||
 | 
			
		||||
	call_rcu(&device->rcu, free_device);
 | 
			
		||||
 | 
			
		||||
	num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
 | 
			
		||||
| 
						 | 
				
			
			@ -2025,6 +2031,9 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
 | 
			
		|||
		/* zero out the old super if it is writable */
 | 
			
		||||
		btrfs_scratch_superblocks(srcdev->bdev, srcdev->name->str);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	btrfs_close_bdev(srcdev);
 | 
			
		||||
 | 
			
		||||
	call_rcu(&srcdev->rcu, free_device);
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
| 
						 | 
				
			
			@ -2080,6 +2089,8 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 | 
			
		|||
	 * the device_list_mutex lock.
 | 
			
		||||
	 */
 | 
			
		||||
	btrfs_scratch_superblocks(tgtdev->bdev, tgtdev->name->str);
 | 
			
		||||
 | 
			
		||||
	btrfs_close_bdev(tgtdev);
 | 
			
		||||
	call_rcu(&tgtdev->rcu, free_device);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
		Loading…
	
		Reference in a new issue