reiserfs: Fix reiserfs lock <-> i_mutex dependency inversion on xattr

[safe/jmp/linux-2.6] / fs / reiserfs / xattr_security.c

diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
index 1958b36..a92c879 100644 (file)
--- a/fs/reiserfs/xattr_security.c
+++ b/fs/reiserfs/xattr_security.c
@@ -4,6 +4,7 @@
 #include <linux/pagemap.h>
 #include <linux/xattr.h>
 #include <linux/reiserfs_xattr.h>
+#include <linux/security.h>
 #include <asm/uaccess.h>
 
 static int
@@ -31,35 +32,86 @@ security_set(struct inode *inode, const char *name, const void *buffer,
        return reiserfs_xattr_set(inode, name, buffer, size, flags);
 }
 
-static int security_del(struct inode *inode, const char *name)
+static size_t security_list(struct inode *inode, char *list, size_t list_len,
+                           const char *name, size_t namelen)
 {
-       if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
-               return -EINVAL;
+       const size_t len = namelen + 1;
 
        if (IS_PRIVATE(inode))
-               return -EPERM;
+               return 0;
+
+       if (list && len <= list_len) {
+               memcpy(list, name, namelen);
+               list[namelen] = '\0';
+       }
 
-       return 0;
+       return len;
 }
 
-static int
-security_list(struct inode *inode, const char *name, int namelen, char *out)
+/* Initializes the security context for a new inode and returns the number
+ * of blocks needed for the transaction. If successful, reiserfs_security
+ * must be released using reiserfs_security_free when the caller is done. */
+int reiserfs_security_init(struct inode *dir, struct inode *inode,
+                          struct reiserfs_security_handle *sec)
 {
-       int len = namelen;
+       int blocks = 0;
+       int error;
 
-       if (IS_PRIVATE(inode))
+       sec->name = NULL;
+
+       /* Don't add selinux attributes on xattrs - they'll never get used */
+       if (IS_PRIVATE(dir))
                return 0;
 
-       if (out)
-               memcpy(out, name, len);
+       error = security_inode_init_security(inode, dir, &sec->name,
+                                            &sec->value, &sec->length);
+       if (error) {
+               if (error == -EOPNOTSUPP)
+                       error = 0;
 
-       return len;
+               sec->name = NULL;
+               sec->value = NULL;
+               sec->length = 0;
+               return error;
+       }
+
+       if (sec->length) {
+               blocks = reiserfs_xattr_jcreate_nblocks(inode) +
+                        reiserfs_xattr_nblocks(inode, sec->length);
+               /* We don't want to count the directories twice if we have
+                * a default ACL. */
+               REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
+       }
+       return blocks;
+}
+
+int reiserfs_security_write(struct reiserfs_transaction_handle *th,
+                           struct inode *inode,
+                           struct reiserfs_security_handle *sec)
+{
+       int error;
+       if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
+               return -EINVAL;
+
+       error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
+                                         sec->length, XATTR_CREATE);
+       if (error == -ENODATA || error == -EOPNOTSUPP)
+               error = 0;
+
+       return error;
+}
+
+void reiserfs_security_free(struct reiserfs_security_handle *sec)
+{
+       kfree(sec->name);
+       kfree(sec->value);
+       sec->name = NULL;
+       sec->value = NULL;
 }
 
-struct reiserfs_xattr_handler security_handler = {
+struct xattr_handler reiserfs_xattr_security_handler = {
        .prefix = XATTR_SECURITY_PREFIX,
        .get = security_get,
        .set = security_set,
-       .del = security_del,
        .list = security_list,
 };