Messages in this thread | | | Date | Sat, 26 Jan 2008 16:39:28 +1100 | From | David Chinner <> | Subject | Re: [RFC] ext3 freeze feature |
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On Sat, Jan 26, 2008 at 04:35:26PM +1100, David Chinner wrote: > On Fri, Jan 25, 2008 at 07:59:38PM +0900, Takashi Sato wrote: > > The points of the implementation are followings. > > - Add calls of the freeze function (freeze_bdev) and > > the unfreeze function (thaw_bdev) in ext3_ioctl(). > > > > - ext3_freeze_timeout() which calls the unfreeze function (thaw_bdev) > > is registered to the delayed work queue to unfreeze the filesystem > > automatically after the lapse of the specified time. > > Seems like pointless complexity to me - what happens if a > timeout occurs while the filsystem is still freezing? > > It's not uncommon for a freeze to take minutes if memory > is full of dirty data that needs to be flushed out, esp. if > dm-snap is doing COWs for every write issued....
Sorry, ignore this bit - I just realised the timer is set up after the freeze has occurred....
Still, that makes it potentially dangerous to whatever is being done while the filesystem is frozen....
Cheers,
Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group
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