Re: [PATCH] NFS: LOOKUP_DIRECTORY is also ok with symlinks

[Paul Menzel <pmenzel@xxxxxxxxxxxxx>]

Dear Trond,


Am 08.02.22 um 19:38 schrieb trondmy@xxxxxxxxxx:
> From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
>
> Commit ac795161c936 (NFSv4: Handle case where the lookup of a directory
> fails) [1], part of Linux since 5.17-rc2, introduced a regression, where
> a symbolic link on an NFS mount to a directory on another NFS does not
> resolve(?) the first time it is accessed:
>
> Reported-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
> Fixes: ac795161c936 ("NFSv4: Handle case where the lookup of a directory fails")
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

Thank you for fixing it so quickly. My colleague verified, that it fixes 
our issue.

Tested-by: Donald Buczek <buczek@xxxxxxxxxxxxx>


Kind regards,

Paul


> ---
>   fs/nfs/dir.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
> index e128503728f2..6dee4e12d381 100644
> --- a/fs/nfs/dir.c
> +++ b/fs/nfs/dir.c
> @@ -2051,14 +2051,14 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
>   	if (!res) {
>   		inode = d_inode(dentry);
>   		if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
> -		    !S_ISDIR(inode->i_mode))
> +		    !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
>   			res = ERR_PTR(-ENOTDIR);
>   		else if (inode && S_ISREG(inode->i_mode))
>   			res = ERR_PTR(-EOPENSTALE);
>   	} else if (!IS_ERR(res)) {
>   		inode = d_inode(res);
>   		if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
> -		    !S_ISDIR(inode->i_mode)) {
> +		    !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) {
>   			dput(res);
>   			res = ERR_PTR(-ENOTDIR);
>   		} else if (inode && S_ISREG(inode->i_mode)) {