[PATCH v4 1/1] nfs42: client needs to strip file mode's suid/sgid bit after ALLOCATE op

[PATCH v4 1/1] nfs42: client needs to strip file mode's suid/sgid bit after ALLOCATE op

[Dai Ngo]

The Linux NFS server strips the SUID and SGID from the file mode
on ALLOCATE op.

Modify _nfs42_proc_fallocate to add NFS_INO_REVAL_FORCED to
nfs_set_cache_invalid's argument to force update of the file
mode suid/sgid bit.

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
---
v3 -> v4: add Suggested-by and Reviewed-by tag.

 fs/nfs/nfs42proc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 63802d195556..9d2f07feeb29 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -81,7 +81,8 @@ static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
 	if (status == 0) {
 		if (nfs_should_remove_suid(inode)) {
 			spin_lock(&inode->i_lock);
-			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
+			nfs_set_cache_invalid(inode,
+				NFS_INO_REVAL_FORCED | NFS_INO_INVALID_MODE);
 			spin_unlock(&inode->i_lock);
 		}
 		status = nfs_post_op_update_inode_force_wcc(inode,
-- 
2.9.5

Re: [PATCH v4 1/1] nfs42: client needs to strip file mode's suid/sgid bit after ALLOCATE op

[Jeff Layton]

On Mon, 2023-09-18 at 23:30 -0700, Dai Ngo wrote:
> The Linux NFS server strips the SUID and SGID from the file mode
> on ALLOCATE op.
> 
> Modify _nfs42_proc_fallocate to add NFS_INO_REVAL_FORCED to
> nfs_set_cache_invalid's argument to force update of the file
> mode suid/sgid bit.
> 
> Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
> Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
> Reviewed-by: Jeff Layton <jlayton@kernel.org>
> ---
> v3 -> v4: add Suggested-by and Reviewed-by tag.
> 
>  fs/nfs/nfs42proc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
> index 63802d195556..9d2f07feeb29 100644
> --- a/fs/nfs/nfs42proc.c
> +++ b/fs/nfs/nfs42proc.c
> @@ -81,7 +81,8 @@ static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
>  	if (status == 0) {
>  		if (nfs_should_remove_suid(inode)) {
>  			spin_lock(&inode->i_lock);
> -			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE);
> +			nfs_set_cache_invalid(inode,
> +				NFS_INO_REVAL_FORCED | NFS_INO_INVALID_MODE);
>  			spin_unlock(&inode->i_lock);
>  		}
>  		status = nfs_post_op_update_inode_force_wcc(inode,

This fixes generic/683 and generic/684 for me, when nfsd has issued a
write delegation. This was posted some time ago. Is there some reason
this hasn't been merged yet?

Tested-by: Jeff Layton <jlayton@kernel.org>