Commit 9dc4e6c4 authored Apr 09, 2012 by J. Bruce Fields

nfsd: don't fail unchecked creates of non-special files



Allow a v3 unchecked open of a non-regular file succeed as if it were a
lookup; typically a client in such a case will want to fall back on a
local open, so succeeding and giving it the filehandle is more useful
than failing with nfserr_exist, which makes it appear that nothing at
all exists by that name.

Similarly for v4, on an open-create, return the same errors we would on
an attempt to open a non-regular file, instead of returning
nfserr_exist.

This fixes a problem found doing a v4 open of a symlink with
O_RDONLY|O_CREAT, which resulted in the current client returning EEXIST.

Thanks also to Trond for analysis.

Cc: stable@kernel.org
Reported-by: Orion Poplawski <orion@cora.nwra.com>
Tested-by: Orion Poplawski <orion@cora.nwra.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

parent 00341028

fs/nfsd/nfs4proc.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -240,10 +240,10 @@ do_open_lookup(struct svc_rqst rqstp, struct svc_fh current_fh, struct nfsd4_o
		status = nfsd_lookup(rqstp, current_fh,
		open->op_fname.data, open->op_fname.len, resfh);
		fh_unlock(current_fh);
		}
		if (status)
		goto out;
		status = nfsd_check_obj_isreg(resfh);
		}
		if (status)
		goto out;

fs/nfsd/vfs.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1458,7 +1458,7 @@ do_nfsd_create(struct svc_rqst rqstp, struct svc_fh fhp,
		switch (createmode) {
		case NFS3_CREATE_UNCHECKED:
		if (! S_ISREG(dchild->d_inode->i_mode))
		err = nfserr_exist;
		goto out;
		else if (truncp) {
		/* in nfsv4, we need to treat this case a little
		* differently. we don't want to truncate the