[PATCH] ext3: fsid for statvfs

From: Pekka Enberg <[email protected]>

Update ext3_statfs to return an FSID that is a 64 bit XOR of the 128 bit
filesystem UUID as suggested by Andreas Dilger. See the following Bugzilla
entry for details:

  http://bugzilla.kernel.org/show_bug.cgi?id=136

Cc: Andreas Dilger <[email protected]>
Cc: Stephen Tweedie <[email protected]>
Signed-off-by: Pekka Enberg <[email protected]>
---

 fs/ext3/super.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: 2.6/fs/ext3/super.c
===================================================================
--- 2.6.orig/fs/ext3/super.c
+++ 2.6/fs/ext3/super.c
@@ -2385,6 +2385,7 @@ static int ext3_statfs (struct dentry * 
 	struct ext3_super_block *es = sbi->s_es;
 	ext3_fsblk_t overhead;
 	int i;
+	u64 fsid;
 
 	if (test_opt (sb, MINIX_DF))
 		overhead = 0;
@@ -2431,6 +2432,10 @@ static int ext3_statfs (struct dentry * 
 	buf->f_files = le32_to_cpu(es->s_inodes_count);
 	buf->f_ffree = percpu_counter_sum(&sbi->s_freeinodes_counter);
 	buf->f_namelen = EXT3_NAME_LEN;
+	fsid = le64_to_cpup((void *)es->s_uuid) ^
+	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
+	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
+	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
 	return 0;
 }