Messages in this thread | | | From | "Takashi Sato" <> | Subject | Re: [RFC] ext3 freeze feature | Date | Mon, 28 Jan 2008 22:07:38 +0900 |
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Hi,
Thank you for your comments.
> That's inherently unsafe - you can have multiple unfreezes > running in parallel which seriously screws with the bdev semaphore > count that is used to lock the device due to doing multiple up()s > for every down. > > Your timeout thingy guarantee that at some point you will get > multiple up()s occuring due to the timer firing racing with > a thaw ioctl. > > If this interface is to be more widely exported, then it needs > a complete revamp of the bdev is locked while it is frozen so > that there is no chance of a double up() ever occuring on the > bd_mount_sem due to racing thaws.....
My patch has the race condition as you said. I will fix it.
Cheers, Takashi
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