hi,
as a start i am using unionfs for about half a year and the current CVS
versions are the most stable ever. no oops for months in my nfs-root
related environment. well done!
so how about a new release (1.1.2) ;-)?
as i am working with nfs-mounted branches i have to compile unionfs.ko
with "-DNFS_SECURITY_HOLE" to get rid of some "-EACCES" return values of
my nfs server. it would be handy to set an equivalent mount option for
any union that is used. this would lead to the following advantages:
- it would be possible to have independent secure and insecure mounts
side by side
- upstream kernels/modules could be used in nfs related environments
without the need for recompiling or a global security hole
beneath is a patch providing a per union mount option "nfsperms". this
option can be "secure" (default) or "insecure". so if you mount your
union with "nfsperms=insecure" the nfs server return value "-EACCES"
leads to a standard Unix permissions check only in this union.
cheers,
martin
--- unionfs-20060112-2205/unionfs.h.org 2006-01-13 09:01:26.418630983 +0000
+++ unionfs-20060112-2205/unionfs.h 2006-01-13 09:29:52.058797978 +0000
@@ -750,7 +750,10 @@
/* 1 = f/s mounter permission, 0 = check for COPYUP_OWNER */
#define COPYUP_FS_MOUNTER 16
-#define VALID_MOUNT_FLAGS (DELETE_WHITEOUT | COPYUP_OWNER | COPYUP_FS_MOUNTER)
+/* 1 = only standard Unix permissions check on nfs if -EACCESS, 0 = no special
permission treatment */
+#define NFS_INSECURE 32
+
+#define VALID_MOUNT_FLAGS (DELETE_WHITEOUT | COPYUP_OWNER | COPYUP_FS_MOUNTER
| NFS_INSECURE)
/*
* MACROS:
--- unionfs-20060112-2205/main.c.org 2006-01-13 09:33:34.857822350 +0000
+++ unionfs-20060112-2205/main.c 2006-01-13 09:44:12.964777406 +0000
@@ -523,6 +523,20 @@
}
continue;
}
+ if (!strcmp("nfsperms", optname)) {
+ if (!strcmp("secure", optarg)) {
+ /* default */
+ } else if (!strcmp("insecure", optarg)) {
+ MOUNT_FLAG(sb) |= NFS_INSECURE;
+ } else {
+ printk(KERN_WARNING
+ "unionfs: invalid nfsperms option
'%s'\n",
+ optarg);
+ err = -EINVAL;
+ goto out_error;
+ }
+ continue;
+ }
/* All of these options require an integer argument. */
intval = simple_strtoul(optarg, &endptr, 0);
--- unionfs-20060112-2205/super.c.org 2006-01-13 09:45:01.187229205 +0000
+++ unionfs-20060112-2205/super.c 2006-01-13 09:47:25.073787777 +0000
@@ -472,6 +472,12 @@
seq_printf(m, ",copyup=mounter");
else
seq_printf(m, ",copyup=preserve");
+
+ if (IS_SET(sb, NFS_INSECURE))
+ seq_printf(m, ",nfsperms=insecure");
+ else
+ seq_printf(m, ",nfsperms=secure");
+
out:
if (tmp)
free_page(tmp);
--- unionfs-20060112-2205/inode.c.org 2006-01-13 09:47:38.471301544 +0000
+++ unionfs-20060112-2205/inode.c 2006-01-13 09:55:40.934757358 +0000
@@ -806,10 +806,11 @@
}
/* Basically copied from the kernel vfs permission(), but we've changed
- * the following: (1) the IS_RDONLY check is skipped, and (2) if you define
- * -DNFS_SECURITY_HOLE, we assume that -EACCES means that the export is
- * read-only and we should check standard Unix permissions. This means
- * that NFS ACL checks (or other advanced permission features) are bypassed.
+ * the following: (1) the IS_RDONLY check is skipped, and (2) if you set
+ * the mount option `nfsperms=insceure', we assume that -EACCES means that
+ * the export is read-only and we should check standard Unix permissions.
+ * This means that NFS ACL checks (or other advanced permission features)
+ * are bypassed.
*/
static int inode_permission(struct inode *inode, int mask, struct nameidata
*nd,
int bindex)
@@ -835,17 +836,15 @@
submask = mask & ~MAY_APPEND;
if (inode->i_op && inode->i_op->permission) {
retval = inode->i_op->permission(inode, submask, nd);
-#ifdef NFS_SECURITY_HOLE
-#define IS_NFS(inode) (!strcmp("nfs", (inode)->i_sb->s_type->name))
if ((retval == -EACCES) && (submask & MAY_WRITE) &&
- IS_NFS(inode)) {
+ (!strcmp("nfs", (inode)->i_sb->s_type->name)) &&
+ IS_SET(nd->mnt->mnt_sb, NFS_INSECURE)) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,10)
retval = vfs_permission(inode, submask);
#else
retval = generic_permission(inode, submask, NULL);
#endif
}
-#endif
} else {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,10)
retval = vfs_permission(inode, submask);
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