[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, 4 insertions, 4 deletions

diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 1b58a9b7f6aa..ba1c88af49fe 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -196,17 +196,17 @@ static int adfs_remount(struct super_block *sb, int *flags, char *data)
         return parse_options(sb, data);
 }
 
-static int adfs_statfs(struct super_block *sb, struct kstatfs *buf)
+static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
-        struct adfs_sb_info *asb = ADFS_SB(sb);
+        struct adfs_sb_info *asb = ADFS_SB(dentry->d_sb);
 
         buf->f_type    = ADFS_SUPER_MAGIC;
         buf->f_namelen = asb->s_namelen;
-        buf->f_bsize   = sb->s_blocksize;
+        buf->f_bsize   = dentry->d_sb->s_blocksize;
         buf->f_blocks  = asb->s_size;
         buf->f_files   = asb->s_ids_per_zone * asb->s_map_size;
         buf->f_bavail  =
-        buf->f_bfree   = adfs_map_free(sb);
+        buf->f_bfree   = adfs_map_free(dentry->d_sb);
         buf->f_ffree   = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
 
         return 0;