1 files changed, 38 insertions, 49 deletions

diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index fa96bbb26343..2d7f165d0f1d 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -86,46 +86,25 @@ struct ea_buffer {
 #define EA_MALLOC       0x0008
 
 
+static int is_known_namespace(const char *name)
+{
+        if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
+            strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
+            strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
+            strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
+                return false;
+
+        return true;
+}
+
 /*
  * These three routines are used to recognize on-disk extended attributes
  * that are in a recognized namespace.  If the attribute is not recognized,
  * "os2." is prepended to the name
  */
-static inline int is_os2_xattr(struct jfs_ea *ea)
+static int is_os2_xattr(struct jfs_ea *ea)
 {
-        /*
-         * Check for "system."
-         */
-        if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
-            !strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
-                return false;
-        /*
-         * Check for "user."
-         */
-        if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
-            !strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
-                return false;
-        /*
-         * Check for "security."
-         */
-        if ((ea->namelen >= XATTR_SECURITY_PREFIX_LEN) &&
-            !strncmp(ea->name, XATTR_SECURITY_PREFIX,
-                     XATTR_SECURITY_PREFIX_LEN))
-                return false;
-        /*
-         * Check for "trusted."
-         */
-        if ((ea->namelen >= XATTR_TRUSTED_PREFIX_LEN) &&
-            !strncmp(ea->name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
-                return false;
-        /*
-         * Add any other valid namespace prefixes here
-         */
-
-        /*
-         * We assume it's OS/2's flat namespace
-         */
-        return true;
+        return !is_known_namespace(ea->name);
 }
 
 static inline int name_size(struct jfs_ea *ea)
@@ -764,13 +743,23 @@ static int can_set_xattr(struct inode *inode, const char *name,
         if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
                 return can_set_system_xattr(inode, name, value, value_len);
 
+        if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
+                /*
+                 * This makes sure that we aren't trying to set an
+                 * attribute in a different namespace by prefixing it
+                 * with "os2."
+                 */
+                if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN))
+                                return -EOPNOTSUPP;
+                return 0;
+        }
+
         /*
          * Don't allow setting an attribute in an unknown namespace.
          */
         if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
             strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
-            strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
-            strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN))
+            strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
                 return -EOPNOTSUPP;
 
         return 0;
@@ -952,19 +941,8 @@ ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
         int xattr_size;
         ssize_t size;
         int namelen = strlen(name);
-        char *os2name = NULL;
         char *value;
 
-        if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
-                os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
-                                  GFP_KERNEL);
-                if (!os2name)
-                        return -ENOMEM;
-                strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
-                name = os2name;
-                namelen -= XATTR_OS2_PREFIX_LEN;
-        }
-
         down_read(&JFS_IP(inode)->xattr_sem);
 
         xattr_size = ea_get(inode, &ea_buf, 0);
@@ -1002,8 +980,6 @@ ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
       out:
         up_read(&JFS_IP(inode)->xattr_sem);
 
-        kfree(os2name);
-
         return size;
 }
 
@@ -1012,6 +988,19 @@ ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
 {
         int err;
 
+        if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
+                /*
+                 * skip past "os2." prefix
+                 */
+                name += XATTR_OS2_PREFIX_LEN;
+                /*
+                 * Don't allow retrieving properly prefixed attributes
+                 * by prepending them with "os2."
+                 */
+                if (is_known_namespace(name))
+                        return -EOPNOTSUPP;
+        }
+
         err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);
 
         return err;