From ee3ae84ef40154c734dc2cbca5cf4b2f54c6c7c7 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 29 Apr 2013 10:35:36 -0400 Subject: NFSv4: Servers should only check SETATTR stateid open mode on size change The NFSv4 and NFSv4.1 specs are both clear that the server should only check stateid open mode if a SETATTR specifies the size attribute. If the open mode is not one that allows writing, then it returns NFS4ERR_OPENMODE. In the case where the SETATTR is not changing the size, the client will still pass it the delegation stateid to ensure that the server does not recall that delegation. In that case, the server should _ignore_ the delegation open mode, and simply apply standard permission checks. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 3bc847ce4838..982b4527551d 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2142,20 +2142,25 @@ static int _nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred, .rpc_cred = cred, }; unsigned long timestamp = jiffies; + fmode_t fmode; + bool truncate; int status; nfs_fattr_init(fattr); - if (state != NULL && nfs4_valid_open_stateid(state)) { + /* Servers should only apply open mode checks for file size changes */ + truncate = (sattr->ia_valid & ATTR_SIZE) ? true : false; + fmode = truncate ? FMODE_WRITE : FMODE_READ; + + if (nfs4_copy_delegation_stateid(&arg.stateid, inode, fmode)) { + /* Use that stateid */ + } else if (truncate && state != NULL && nfs4_valid_open_stateid(state)) { struct nfs_lockowner lockowner = { .l_owner = current->files, .l_pid = current->tgid, }; nfs4_select_rw_stateid(&arg.stateid, state, FMODE_WRITE, &lockowner); - } else if (nfs4_copy_delegation_stateid(&arg.stateid, inode, - FMODE_WRITE)) { - /* Use that stateid */ } else nfs4_stateid_copy(&arg.stateid, &zero_stateid); -- cgit v1.2.3-59-g8ed1b