RE: [f2fs-dev] [PATCH 3/4] f2fs crypto: check encryption for tmpfile

From: Chao Yu
Date: Thu May 28 2015 - 06:21:10 EST


Hi Jaegeuk,

> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx]
> Sent: Wednesday, May 20, 2015 8:43 AM
> To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx;
> linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Jaegeuk Kim
> Subject: [f2fs-dev] [PATCH 3/4] f2fs crypto: check encryption for tmpfile
>
> This patch adds to check encryption for tmpfile in early stage.
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> fs/f2fs/namei.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
> index dded2b0..47066b0 100644
> --- a/fs/f2fs/namei.c
> +++ b/fs/f2fs/namei.c
> @@ -531,6 +531,11 @@ static int __f2fs_tmpfile(struct inode *dir, struct dentry *dentry,
> }
>
> f2fs_lock_op(sbi);
> +
> + err = f2fs_get_encryption_info(dir);
> + if (err)
> + goto out;
> +
> err = acquire_orphan_inode(sbi);
> if (err)
> goto out;
> --
> 2.1.1

I can't find the original thread, so I reply here.
Merged patch in dev branch shows that our code is modified as below:

static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
+ int err = f2fs_get_encryption_info(dir);
+ if (err)
+ return err;
+
return __f2fs_tmpfile(dir, dentry, mode, NULL);
}

It seems that, if we try to make a temp file in an unencrypted dir, we will
always fail with -ENODATA in f2fs_get_encryption_info because encryption
context is not exist in xattr.

So we should check dir with f2fs_encrypted_inode() before
f2fs_get_encryption_info() to avoid that.

Thanks,

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