Commit de339cbf authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: call bdev_fput() to reclaim the blk_holder immediately 



As part of the preparation for btrfs blk_holder_ops, we want to ensure
the holder of a block device has a proper lifespan.

However btrfs is always using fput() to close a block device, which has
one problem:

- fput() is deferred
  Meaning we can have a block device with invalid (aka, freed) holder.

To avoid the problem and align the behavior to other code, just call
bdev_fput() instead.

There is some extra requirement on the locking, but that's all resolved
by previous patches and we should be safe to call bdev_fput().

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 9f43d0ff

fs/btrfs/dev-replace.c

+1 −1
Original line number Diff line number Diff line
@@ -327,7 +327,7 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, 
	return 0;



error:

	fput(bdev_file);

	bdev_fput(bdev_file);

	return ret;

}

fs/btrfs/ioctl.c

+2 −2
Original line number Diff line number Diff line
@@ -2696,7 +2696,7 @@ static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg) 
err_drop:

	mnt_drop_write_file(file);

	if (bdev_file)

		fput(bdev_file);

		bdev_fput(bdev_file);

out:

	btrfs_put_dev_args_from_path(&args);

	kfree(vol_args);
@@ -2747,7 +2747,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) 


	mnt_drop_write_file(file);

	if (bdev_file)

		fput(bdev_file);

		bdev_fput(bdev_file);

out:

	btrfs_put_dev_args_from_path(&args);

out_free:

fs/btrfs/volumes.c

+9 −9
Original line number Diff line number Diff line
@@ -487,7 +487,7 @@ btrfs_get_bdev_and_sb(const char *device_path, blk_mode_t flags, void *holder, 
	if (holder) {

		ret = set_blocksize(*bdev_file, BTRFS_BDEV_BLOCKSIZE);

		if (ret) {

			fput(*bdev_file);

			bdev_fput(*bdev_file);

			goto error;

		}

	}
@@ -495,7 +495,7 @@ btrfs_get_bdev_and_sb(const char *device_path, blk_mode_t flags, void *holder, 
	*disk_super = btrfs_read_disk_super(bdev, 0, false);

	if (IS_ERR(*disk_super)) {

		ret = PTR_ERR(*disk_super);

		fput(*bdev_file);

		bdev_fput(*bdev_file);

		goto error;

	}
@@ -719,7 +719,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices, 


error_free_page:

	btrfs_release_disk_super(disk_super);

	fput(bdev_file);

	bdev_fput(bdev_file);



	return -EINVAL;

}
@@ -1069,7 +1069,7 @@ static void __btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, 
			continue;



		if (device->bdev_file) {

			fput(device->bdev_file);

			bdev_fput(device->bdev_file);

			device->bdev = NULL;

			device->bdev_file = NULL;

			fs_devices->open_devices--;
@@ -1116,7 +1116,7 @@ static void btrfs_close_bdev(struct btrfs_device *device) 
		invalidate_bdev(device->bdev);

	}



	fput(device->bdev_file);

	bdev_fput(device->bdev_file);

}



static void btrfs_close_one_device(struct btrfs_device *device)
@@ -1489,7 +1489,7 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, 
	btrfs_release_disk_super(disk_super);



error_bdev_put:

	fput(bdev_file);

	bdev_fput(bdev_file);



	return device;

}
@@ -2293,7 +2293,7 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, 
	 * free the device.

	 *

	 * We cannot call btrfs_close_bdev() here because we're holding the sb

	 * write lock, and fput() on the block device will pull in the

	 * write lock, and bdev_fput() on the block device will pull in the

	 * ->open_mutex on the block device and it's dependencies.  Instead

	 *  just flush the device and let the caller do the final bdev_release.

	 */
@@ -2472,7 +2472,7 @@ int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info, 
	else

		memcpy(args->fsid, disk_super->fsid, BTRFS_FSID_SIZE);

	btrfs_release_disk_super(disk_super);

	fput(bdev_file);

	bdev_fput(bdev_file);

	return 0;

}
@@ -2920,7 +2920,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path 
error_free_device:

	btrfs_free_device(device);

error:

	fput(bdev_file);

	bdev_fput(bdev_file);

	if (locked) {

		mutex_unlock(&uuid_mutex);

		up_write(&sb->s_umount);