This is a note to let you know that I've just added the patch titled NFSv4: Turn off open-by-filehandle and NFS re-export for NFSv4.0 to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfsv4-turn-off-open-by-filehandle-and-nfs-re-export-.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 40fa1927954434c7d8903e58d83c12a72b8ad5e9 Author: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Date: Thu Aug 25 14:49:05 2022 -0400 NFSv4: Turn off open-by-filehandle and NFS re-export for NFSv4.0 [ Upstream commit 2a9d683b48c8a87e61a4215792d44c90bcbbb536 ] The NFSv4.0 protocol only supports open() by name. It cannot therefore be used with open_by_handle() and friends, nor can it be re-exported by knfsd. Reported-by: Chuck Lever III <chuck.lever@xxxxxxxxxx> Fixes: 20fa19027286 ("nfs: add export operations") Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 4034102010f0..b3fcc27b9564 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1029,22 +1029,31 @@ static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx) if (ctx && ctx->bsize) sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits); - if (server->nfs_client->rpc_ops->version != 2) { - /* The VFS shouldn't apply the umask to mode bits. We will do - * so ourselves when necessary. + switch (server->nfs_client->rpc_ops->version) { + case 2: + sb->s_time_gran = 1000; + sb->s_time_min = 0; + sb->s_time_max = U32_MAX; + break; + case 3: + /* + * The VFS shouldn't apply the umask to mode bits. + * We will do so ourselves when necessary. */ sb->s_flags |= SB_POSIXACL; sb->s_time_gran = 1; - sb->s_export_op = &nfs_export_ops; - } else - sb->s_time_gran = 1000; - - if (server->nfs_client->rpc_ops->version != 4) { sb->s_time_min = 0; sb->s_time_max = U32_MAX; - } else { + sb->s_export_op = &nfs_export_ops; + break; + case 4: + sb->s_flags |= SB_POSIXACL; + sb->s_time_gran = 1; sb->s_time_min = S64_MIN; sb->s_time_max = S64_MAX; + if (server->caps & NFS_CAP_ATOMIC_OPEN_V1) + sb->s_export_op = &nfs_export_ops; + break; } sb->s_magic = NFS_SUPER_MAGIC;