[PATCH] nfsd3: Check write permission after checking existence

From: Ross Lagerwall <rosslagerwall@gmail.com>
To: linux-nfs@vger.kernel.org
Cc: "J. Bruce Fields" <bfields@fieldses.org>,
	Ross Lagerwall <rosslagerwall@gmail.com>
Subject: [PATCH] nfsd3: Check write permission after checking existence
Date: Sat,  9 Aug 2014 14:44:00 +0100	[thread overview]
Message-ID: <1407591840-19080-1-git-send-email-rosslagerwall@gmail.com> (raw)

When creating a file that already exists in a read-only directory with
O_EXCL, the NFSv3 server returns EACCES rather than EEXIST (which local
files and the NFSv4 server return).  Fix this by checking the MAY_CREATE
permission only if the file does not exist.  Since this already happens
in do_nfsd_create, the check in nfsd3_proc_create can simply be removed.

Signed-off-by: Ross Lagerwall <rosslagerwall@gmail.com>
---
 fs/nfsd/nfs3proc.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 4012899..8ebd4ac 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -227,11 +227,6 @@ nfsd3_proc_create(struct svc_rqst *rqstp, struct nfsd3_createargs *argp,
 	newfhp = fh_init(&resp->fh, NFS3_FHSIZE);
 	attr   = &argp->attrs;
 
-	/* Get the directory inode */
-	nfserr = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_CREATE);
-	if (nfserr)
-		RETURN_STATUS(nfserr);
-
 	/* Unfudge the mode bits */
 	attr->ia_mode &= ~S_IFMT;
 	if (!(attr->ia_valid & ATTR_MODE)) { 
-- 
2.0.3

