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 all the existing codes,
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: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: adam900710

fs/btrfs/dev-replace.c

@@ -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

@@ -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

@@ -487,15 +487,15 @@ 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;
 		}
 	}
 	invalidate_bdev(bdev);
 	*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);