[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry
Give the statfs superblock operation a dentry pointer rather than a superblock
pointer.
This complements the get_sb() patch. That reduced the significance of
sb->s_root, allowing NFS to place a fake root there. However, NFS does
require a dentry to use as a target for the statfs operation. This permits
the root in the vfsmount to be used instead.
linux/mount.h has been added where necessary to make allyesconfig build
successfully.
Interest has also been expressed for use with the FUSE and XFS filesystems.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/security.h b/include/linux/security.h
index 47722d3..383c320 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -171,9 +171,9 @@
* Deallocate and clear the sb->s_security field.
* @sb contains the super_block structure to be modified.
* @sb_statfs:
- * Check permission before obtaining filesystem statistics for the @sb
- * filesystem.
- * @sb contains the super_block structure for the filesystem.
+ * Check permission before obtaining filesystem statistics for the @mnt
+ * mountpoint.
+ * @dentry is a handle on the superblock for the filesystem.
* Return 0 if permission is granted.
* @sb_mount:
* Check permission before an object specified by @dev_name is mounted on
@@ -1127,7 +1127,7 @@
int (*sb_copy_data)(struct file_system_type *type,
void *orig, void *copy);
int (*sb_kern_mount) (struct super_block *sb, void *data);
- int (*sb_statfs) (struct super_block * sb);
+ int (*sb_statfs) (struct dentry *dentry);
int (*sb_mount) (char *dev_name, struct nameidata * nd,
char *type, unsigned long flags, void *data);
int (*sb_check_sb) (struct vfsmount * mnt, struct nameidata * nd);
@@ -1450,9 +1450,9 @@
return security_ops->sb_kern_mount (sb, data);
}
-static inline int security_sb_statfs (struct super_block *sb)
+static inline int security_sb_statfs (struct dentry *dentry)
{
- return security_ops->sb_statfs (sb);
+ return security_ops->sb_statfs (dentry);
}
static inline int security_sb_mount (char *dev_name, struct nameidata *nd,
@@ -2162,7 +2162,7 @@
return 0;
}
-static inline int security_sb_statfs (struct super_block *sb)
+static inline int security_sb_statfs (struct dentry *dentry)
{
return 0;
}