[Ocfs2-devel] [PATCH] ocfs2: return f_fsid info in ocfs2_statfs(), v4

[Coly Li]

Currently f_fsid of struct kstatfs returned from ocfs2_statfs() is undefined (vfs layer fills 0 as
default). Since in some conditions, f_fsid value might be used as (f_fsid, ino) pair to
uniquely identify a file, ocfs2 should return a unique defined f_fsid value from ocfs2_statfs().

Because uuid_str is identified no mater on big or litlle endian machine, it's also endian consistent
to use osb->uuid_str to generate f_fsid value.

Signed-off-by: Coly Li <coly.li at suse.de>
Cc: Sunil Mushran <sunil.mushran at oracle.com>
Cc: Mark Fasheh <mfasheh at suse.com>
---
 fs/ocfs2/super.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 43ed113..c953933 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1425,6 +1425,10 @@ static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_bavail = buf->f_bfree;
 	buf->f_files = numbits;
 	buf->f_ffree = freebits;
+	buf->f_fsid.val[0] = crc32_le(0, osb->uuid_str, OCFS2_VOL_UUID_LEN)
+				& 0xFFFFFFFFUL;
+	buf->f_fsid.val[1] = crc32_le(0, osb->uuid_str + OCFS2_VOL_UUID_LEN,
+				OCFS2_VOL_UUID_LEN) & 0xFFFFFFFFUL;

 	brelse(bh);

-- 
Coly Li
SuSE Labs