knfsd: nfsd4: make readonly access depend on pseudoflavor

Allow readonly access to vary depending on the pseudoflavor, using the flag
passed with each pseudoflavor in the export downcall.  The rest of the flags
are ignored for now, though some day we might also allow id squashing to vary
based on the flavor.

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nfsd/vfs.c

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 8e109e5..e90f4a8 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -328,7 +328,7 @@
 	/* The size case is special. It changes the file as well as the attributes.  */
 	if (iap->ia_valid & ATTR_SIZE) {
 		if (iap->ia_size < inode->i_size) {
-			err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
+			err = nfsd_permission(rqstp, fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
 			if (err)
 				goto out;
 		}
@@ -616,7 +616,7 @@
 
 			sresult |= map->access;
 
-			err2 = nfsd_permission(export, dentry, map->how);
+			err2 = nfsd_permission(rqstp, export, dentry, map->how);
 			switch (err2) {
 			case nfs_ok:
 				result |= map->access;
@@ -1043,7 +1043,7 @@
 	__be32		err;
 
 	if (file) {
-		err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
+		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
 				MAY_READ|MAY_OWNER_OVERRIDE);
 		if (err)
 			goto out;
@@ -1072,7 +1072,7 @@
 	__be32			err = 0;
 
 	if (file) {
-		err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
+		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
 				MAY_WRITE|MAY_OWNER_OVERRIDE);
 		if (err)
 			goto out;
@@ -1801,7 +1801,8 @@
  * Check for a user's access permissions to this inode.
  */
 __be32
-nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc)
+nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
+					struct dentry *dentry, int acc)
 {
 	struct inode	*inode = dentry->d_inode;
 	int		err;
@@ -1832,7 +1833,7 @@
 	 */
 	if (!(acc & MAY_LOCAL_ACCESS))
 		if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
-			if (EX_RDONLY(exp) || IS_RDONLY(inode))
+			if (EX_RDONLY(exp, rqstp) || IS_RDONLY(inode))
 				return nfserr_rofs;
 			if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
 				return nfserr_perm;