Re: [PATCH v6 1/8] btrfs: disable various operations on encrypted inodes

[Qu Wenruo <wqu@suse.com>]

在 2025/11/13 06:06, Daniel Vacek 写道:
> From: Omar Sandoval <osandov@osandov.com>
> 
> Initially, only normal data extents will be encrypted. This change
> forbids various other bits:
> - allows reflinking only if both inodes have the same encryption status
> - disable inline data on encrypted inodes

I'm wondering how will this affect other users of inlined data. 
Especially for symbol links.

Symbol links always store they link source inside an inline data file 
extent. Does such content also get encrypted?

Thanks,
Qu

> 
> Signed-off-by: Omar Sandoval <osandov@osandov.com>
> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Daniel Vacek <neelx@suse.com>
> ---
> v5 was 'Reviewed-by: Boris Burkov <boris@bur.io>' [1] but the rebase
> changed the code a bit so dropping.
> 
> [1] https://lore.kernel.org/linux-btrfs/20240124195303.GC1789919@zen.localdomain/
> ---
>   fs/btrfs/inode.c   | 4 ++++
>   fs/btrfs/reflink.c | 7 +++++++
>   2 files changed, 11 insertions(+)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 8737914e8552..b810e831fc23 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -592,6 +592,10 @@ static bool can_cow_file_range_inline(struct btrfs_inode *inode,
>   	if (size < i_size_read(&inode->vfs_inode))
>   		return false;
>   
> +	/* Encrypted file cannot be inlined. */
> +	if (IS_ENCRYPTED(&inode->vfs_inode))
> +		return false;
> +
>   	return true;
>   }
>   
> diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
> index 775a32a7953a..3c9c570d6493 100644
> --- a/fs/btrfs/reflink.c
> +++ b/fs/btrfs/reflink.c
> @@ -1,6 +1,7 @@
>   // SPDX-License-Identifier: GPL-2.0
>   
>   #include <linux/blkdev.h>
> +#include <linux/fscrypt.h>
>   #include <linux/iversion.h>
>   #include "ctree.h"
>   #include "fs.h"
> @@ -789,6 +790,12 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
>   		ASSERT(inode_in->vfs_inode.i_sb == inode_out->vfs_inode.i_sb);
>   	}
>   
> +	/*
> +	 * Can only reflink encrypted files if both files are encrypted.
> +	 */
> +	if (IS_ENCRYPTED(&inode_in->vfs_inode) != IS_ENCRYPTED(&inode_out->vfs_inode))
> +		return -EINVAL;
> +
>   	/* Don't make the dst file partly checksummed */
>   	if ((inode_in->flags & BTRFS_INODE_NODATASUM) !=
>   	    (inode_out->flags & BTRFS_INODE_NODATASUM)) {