Fill f_fsid field in btrfs_statfs()

Date: Mon, 18 Aug 2008 12:01:52 +0100
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index e830e0ed409a..6446ab73f35a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -489,6 +489,7 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
         struct btrfs_root *root = btrfs_sb(dentry->d_sb);
         struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
         int bits = dentry->d_sb->s_blocksize_bits;
+        __be32 *fsid = (__be32 *)root->fs_info->fsid;
 
         buf->f_namelen = BTRFS_NAME_LEN;
         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
@@ -497,6 +498,11 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
         buf->f_bavail = buf->f_bfree;
         buf->f_bsize = dentry->d_sb->s_blocksize;
         buf->f_type = BTRFS_SUPER_MAGIC;
+        /* We treat it as constant endianness (it doesn't matter _which_)
+           because we want the fsid to come out the same whether mounted 
+           on a big-endian or little-endian host */
+        buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
+        buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
         return 0;
 }