From 726c334223180e3c0197cc980a432681370d4baf Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 23 Jun 2006 02:02:58 -0700
Subject: [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>
---
 fs/fat/inode.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'fs/fat')

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index c1ce284f8a94..7c35d582ec10 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -539,18 +539,18 @@ static int fat_remount(struct super_block *sb, int *flags, char *data)
 	return 0;
 }
 
-static int fat_statfs(struct super_block *sb, struct kstatfs *buf)
+static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
-	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
 
 	/* If the count of free cluster is still unknown, counts it here. */
 	if (sbi->free_clusters == -1) {
-		int err = fat_count_free_clusters(sb);
+		int err = fat_count_free_clusters(dentry->d_sb);
 		if (err)
 			return err;
 	}
 
-	buf->f_type = sb->s_magic;
+	buf->f_type = dentry->d_sb->s_magic;
 	buf->f_bsize = sbi->cluster_size;
 	buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
 	buf->f_bfree = sbi->free_clusters;
-- 
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