Re: ext3fs: umount+sync not enough to guarantee metadata-on-disk

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Andrew Morton wrote:
On Thu, 07 Jun 2007 12:11:58 -0400
Chuck Ebbert <[email protected]> wrote:

On 06/07/2007 11:41 AM, Andrew Morton wrote:
   mount /var/lib/mythtv -oremount,ro
   sync
   umount /var/lib/mythtv
Did this succeed?  If the application is still truncating that file, the
umount should have failed.
Shouldn't sync should wait for truncate to finish?

I can't think of anything in there at present which would cause that to
happen, and it's not immediately obvious how we _could_ make it happen - we
have an inode which potentially has no dirty pages and which is itself
clean.  The truncate can span multiple journal commits, so forcing a
journal commit in sync() won't necessarily block behind the truncate.

I guess we could ask sync to speculatively take and release every inode's
i_mutex or something.  But even that would involve quite some hoop-jumping
due to those infuriating spinlock-protected list_heads on the superblock.

hmm.

Yeah, I really don't know what to do with this either.
We have to have a bounds on how long we wait at shutdown,
but there doesn't seem to be an easy way to get notified
once a filesystem becomes idle (?).

I suppose I could have the script loop on /proc/interrupts until
it sees the disk activity has tapered off..

Cheers
-
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]
  Powered by Linux