[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>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 768fb8d9e67a..fe5ab2aa2899 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -1113,8 +1113,9 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
         return 0;
 }
 
-static int ufs_statfs (struct super_block *sb, struct kstatfs *buf)
+static int ufs_statfs (struct dentry *dentry, struct kstatfs *buf)
 {
+        struct super_block *sb = dentry->d_sb;
         struct ufs_sb_private_info * uspi;
         struct ufs_super_block_first * usb1;
         struct ufs_super_block * usb;