1 files changed, 79 insertions, 28 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 46f59d5365a0..a3a291f771f4 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -264,7 +264,6 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 	struct inode	*inode;
 	int		accmode = MAY_SATTR;
 	int		ftype = 0;
-	int		imode;
 	__be32		err;
 	int		host_err;
 	int		size_change = 0;
@@ -360,25 +359,25 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 		DQUOT_INIT(inode);
 	}
 
-	imode = inode->i_mode;
+	/* sanitize the mode change */
 	if (iap->ia_valid & ATTR_MODE) {
 		iap->ia_mode &= S_IALLUGO;
-		imode = iap->ia_mode |= (imode & ~S_IALLUGO);
-		/* if changing uid/gid revoke setuid/setgid in mode */
-		if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) {
-			iap->ia_valid |= ATTR_KILL_PRIV;
+		iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
+	}
+
+	/* Revoke setuid/setgid on chown */
+	if (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) ||
+	    ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)) {
+		iap->ia_valid |= ATTR_KILL_PRIV;
+		if (iap->ia_valid & ATTR_MODE) {
+			/* we're setting mode too, just clear the s*id bits */
 			iap->ia_mode &= ~S_ISUID;
+			if (iap->ia_mode & S_IXGRP)
+				iap->ia_mode &= ~S_ISGID;
+		} else {
+			/* set ATTR_KILL_* bits and let VFS handle it */
+			iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
 		}
-		if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
-			iap->ia_mode &= ~S_ISGID;
-	} else {
-		/*
-		 * Revoke setuid/setgid bit on chown/chgrp
-		 */
-		if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
-			iap->ia_valid |= ATTR_KILL_SUID | ATTR_KILL_PRIV;
-		if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
-			iap->ia_valid |= ATTR_KILL_SGID;
 	}
 
 	/* Change the attributes. */
@@ -988,7 +987,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
 	 * flushing the data to disk is handled separately below.
 	 */
 
-	if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */
+	if (!file->f_op->fsync) {/* COMMIT3 cannot work */
 	       stable = 2;
 	       *stablep = 2; /* FILE_SYNC */
 	}
@@ -1152,7 +1151,7 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
 }
 #endif /* CONFIG_NFSD_V3 */
 
-__be32
+static __be32
 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
 			struct iattr *iap)
 {
@@ -1255,23 +1254,35 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = 0;
 	switch (type) {
 	case S_IFREG:
+		host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
+		if (host_err)
+			goto out_nfserr;
 		host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
 		break;
 	case S_IFDIR:
+		host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
+		if (host_err)
+			goto out_nfserr;
 		host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
 		break;
 	case S_IFCHR:
 	case S_IFBLK:
 	case S_IFIFO:
 	case S_IFSOCK:
+		host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
+		if (host_err)
+			goto out_nfserr;
 		host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
 		break;
 	default:
 	        printk("nfsd: bad file type %o in nfsd_create\n", type);
 		host_err = -EINVAL;
+		goto out_nfserr;
 	}
-	if (host_err < 0)
+	if (host_err < 0) {
+		mnt_drop_write(fhp->fh_export->ex_path.mnt);
 		goto out_nfserr;
+	}
 
 	if (EX_ISSYNC(fhp->fh_export)) {
 		err = nfserrno(nfsd_sync_dir(dentry));
@@ -1282,6 +1293,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err2 = nfsd_create_setattr(rqstp, resfhp, iap);
 	if (err2)
 		err = err2;
+	mnt_drop_write(fhp->fh_export->ex_path.mnt);
 	/*
 	 * Update the file handle to get the new inode info.
 	 */
@@ -1359,6 +1371,9 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		v_atime = verifier[1]&0x7fffffff;
 	}
 	
+	host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
+	if (host_err)
+		goto out_nfserr;
 	if (dchild->d_inode) {
 		err = 0;
 
@@ -1390,12 +1405,15 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		case NFS3_CREATE_GUARDED:
 			err = nfserr_exist;
 		}
+		mnt_drop_write(fhp->fh_export->ex_path.mnt);
 		goto out;
 	}
 
 	host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
-	if (host_err < 0)
+	if (host_err < 0) {
+		mnt_drop_write(fhp->fh_export->ex_path.mnt);
 		goto out_nfserr;
+	}
 	if (created)
 		*created = 1;
 
@@ -1420,6 +1438,7 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (err2)
 		err = err2;
 
+	mnt_drop_write(fhp->fh_export->ex_path.mnt);
 	/*
 	 * Update the filehandle to get the new inode info.
 	 */
@@ -1522,6 +1541,10 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (iap && (iap->ia_valid & ATTR_MODE))
 		mode = iap->ia_mode & S_IALLUGO;
 
+	host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
+	if (host_err)
+		goto out_nfserr;
+
 	if (unlikely(path[plen] != 0)) {
 		char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
 		if (path_alloced == NULL)
@@ -1542,6 +1565,8 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = nfserrno(host_err);
 	fh_unlock(fhp);
 
+	mnt_drop_write(fhp->fh_export->ex_path.mnt);
+
 	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
 	dput(dnew);
 	if (err==0) err = cerr;
@@ -1592,6 +1617,11 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 	dold = tfhp->fh_dentry;
 	dest = dold->d_inode;
 
+	host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt);
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out_dput;
+	}
 	host_err = vfs_link(dold, dirp, dnew);
 	if (!host_err) {
 		if (EX_ISSYNC(ffhp->fh_export)) {
@@ -1605,7 +1635,8 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 		else
 			err = nfserrno(host_err);
 	}
-
+	mnt_drop_write(tfhp->fh_export->ex_path.mnt);
+out_dput:
 	dput(dnew);
 out_unlock:
 	fh_unlock(ffhp);
@@ -1678,13 +1709,20 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 	if (ndentry == trap)
 		goto out_dput_new;
 
-#ifdef MSNFS
-	if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
+	if (svc_msnfs(ffhp) &&
 		((atomic_read(&odentry->d_count) > 1)
 		 || (atomic_read(&ndentry->d_count) > 1))) {
 			host_err = -EPERM;
-	} else
-#endif
+			goto out_dput_new;
+	}
+
+	host_err = -EXDEV;
+	if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
+		goto out_dput_new;
+	host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt);
+	if (host_err)
+		goto out_dput_new;
+
 	host_err = vfs_rename(fdir, odentry, tdir, ndentry);
 	if (!host_err && EX_ISSYNC(tfhp->fh_export)) {
 		host_err = nfsd_sync_dir(tdentry);
@@ -1692,6 +1730,8 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 			host_err = nfsd_sync_dir(fdentry);
 	}
 
+	mnt_drop_write(ffhp->fh_export->ex_path.mnt);
+
  out_dput_new:
 	dput(ndentry);
  out_dput_old:
@@ -1750,6 +1790,10 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 	if (!type)
 		type = rdentry->d_inode->i_mode & S_IFMT;
 
+	host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
+	if (host_err)
+		goto out_nfserr;
+
 	if (type != S_IFDIR) { /* It's UNLINK */
 #ifdef MSNFS
 		if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
@@ -1765,10 +1809,12 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 	dput(rdentry);
 
 	if (host_err)
-		goto out_nfserr;
+		goto out_drop;
 	if (EX_ISSYNC(fhp->fh_export))
 		host_err = nfsd_sync_dir(dentry);
 
+out_drop:
+	mnt_drop_write(fhp->fh_export->ex_path.mnt);
 out_nfserr:
 	err = nfserrno(host_err);
 out:
@@ -1865,7 +1911,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 		inode->i_mode,
 		IS_IMMUTABLE(inode)?	" immut" : "",
 		IS_APPEND(inode)?	" append" : "",
-		IS_RDONLY(inode)?	" ro" : "");
+		__mnt_is_readonly(exp->ex_path.mnt)?	" ro" : "");
 	dprintk("      owner %d/%d user %d/%d\n",
 		inode->i_uid, inode->i_gid, current->fsuid, current->fsgid);
 #endif
@@ -1876,7 +1922,8 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 	 */
 	if (!(acc & MAY_LOCAL_ACCESS))
 		if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
-			if (exp_rdonly(rqstp, exp) || IS_RDONLY(inode))
+			if (exp_rdonly(rqstp, exp) ||
+			    __mnt_is_readonly(exp->ex_path.mnt))
 				return nfserr_rofs;
 			if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
 				return nfserr_perm;
@@ -2039,6 +2086,9 @@ nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
 	} else
 		size = 0;
 
+	error = mnt_want_write(fhp->fh_export->ex_path.mnt);
+	if (error)
+		goto getout;
 	if (size)
 		error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
 	else {
@@ -2050,6 +2100,7 @@ nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
 				error = 0;
 		}
 	}
+	mnt_drop_write(fhp->fh_export->ex_path.mnt);
 
 getout:
 	kfree(value);