On Dec 07, 2005 15:13 +0200, Pekka J Enberg wrote:
> On Wed, 7 Dec 2005, Andreas Dilger wrote:
> > The bug mentions some reasons why this patch is sub-optimal - namely that
> > the beginning of the UUID has common fields in it. It may make more sense
> > to e.g. XOR the first 2 * u32 with the last 2 * u32 to reduce the chance
> > of an FSID collision.
>
> This patch changes ext3_statfs() to return a FSID based on 64 bit XOR of the
> 128 bit filesystem UUID as suggested by Andreas Dilger. This patch is partial
> fix for Bugzilla Bug <http://bugzilla.kernel.org/show_bug.cgi?id=136>.
That seems at least slightly better, as it involves all the bits.
Question - what is rule for "Signed-off-by:"? I'm hesitant to add that if
I haven't actually compiled+tested a fix, as I've seen too many instances
of "obvious fix contains bug" to believe visual inspection is enough. If
"Signed-off-by:" simply indicates "Yes, this person approves of the change
in principle" then that's OK by me. Andrew, do you use the "CC" tag for
that?
> Signed-off-by: Pekka Enberg <[email protected]>
> ---
>
> 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
> @@ -2294,6 +2294,7 @@ static int ext3_statfs (struct super_blo
> struct ext3_super_block *es = EXT3_SB(sb)->s_es;
> unsigned long overhead;
> int i;
> + u64 fsid;
>
> if (test_opt (sb, MINIX_DF))
> overhead = 0;
> @@ -2340,6 +2341,10 @@ static int ext3_statfs (struct super_blo
> buf->f_files = le32_to_cpu(es->s_inodes_count);
> buf->f_ffree = ext3_count_free_inodes (sb);
> 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;
> }
>
Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
