Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

[pandora-kernel.git] / fs / attr.c

diff --git a/fs/attr.c b/fs/attr.c
index ed44d8a..7ca4181 100644 (file)
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -14,35 +14,53 @@
 #include <linux/fcntl.h>
 #include <linux/security.h>
 
-/* Taken over from the old code... */
-
-/* POSIX UID/GID verification for setting inode attributes. */
+/**
+ * inode_change_ok - check if attribute changes to an inode are allowed
+ * @inode:     inode to check
+ * @attr:      attributes to change
+ *
+ * Check if we are allowed to change the attributes contained in @attr
+ * in the given inode.  This includes the normal unix access permission
+ * checks, as well as checks for rlimits and others.
+ *
+ * Should be called as the first thing in ->setattr implementations,
+ * possibly after taking additional locks.
+ */
 int inode_change_ok(const struct inode *inode, struct iattr *attr)
 {
-       int retval = -EPERM;
        unsigned int ia_valid = attr->ia_valid;
 
+       /*
+        * First check size constraints.  These can't be overriden using
+        * ATTR_FORCE.
+        */
+       if (ia_valid & ATTR_SIZE) {
+               int error = inode_newsize_ok(inode, attr->ia_size);
+               if (error)
+                       return error;
+       }
+
        /* If force is set do it anyway. */
        if (ia_valid & ATTR_FORCE)
-               goto fine;
+               return 0;
 
        /* Make sure a caller can chown. */
        if ((ia_valid & ATTR_UID) &&
            (current_fsuid() != inode->i_uid ||
             attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
-               goto error;
+               return -EPERM;
 
        /* Make sure caller can chgrp. */
        if ((ia_valid & ATTR_GID) &&
            (current_fsuid() != inode->i_uid ||
            (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
            !capable(CAP_CHOWN))
-               goto error;
+               return -EPERM;
 
        /* Make sure a caller can chmod. */
        if (ia_valid & ATTR_MODE) {
                if (!is_owner_or_cap(inode))
-                       goto error;
+                       return -EPERM;
                /* Also check the setgid bit! */
                if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
                                inode->i_gid) && !capable(CAP_FSETID))
@@ -52,12 +70,10 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr)
        /* Check for setting the inode time. */
        if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
                if (!is_owner_or_cap(inode))
-                       goto error;
+                       return -EPERM;
        }
-fine:
-       retval = 0;
-error:
-       return retval;
+
+       return 0;
 }
 EXPORT_SYMBOL(inode_change_ok);
 
@@ -113,7 +129,7 @@ EXPORT_SYMBOL(inode_newsize_ok);
  *
  * setattr_copy updates the inode's metadata with that specified
  * in attr. Noticably missing is inode size update, which is more complex
- * as it requires pagecache updates. See simple_setsize.
+ * as it requires pagecache updates.
  *
  * The inode is not marked as dirty after this operation. The rationale is
  * that for "simple" filesystems, the struct inode is the inode storage.