Messages in this thread | | | Date | Fri, 16 May 2014 08:51:41 +1000 | From | Dave Chinner <> | Subject | Re: [PATCH V2 2/2] fs: print a message when freezing/unfreezing filesystems |
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On Fri, May 16, 2014 at 12:34:40AM +0200, Mateusz Guzik wrote: > On Fri, May 16, 2014 at 08:21:35AM +1000, Dave Chinner wrote: > > > IOW, a new column in mountinfo. For frozen filesystems it would contain > > > 'frozen_by=[%s]:[%d]' (escaped comm, pid). > > > > I really don't see that the process that froze the filesystem is > > particularly useful - it many cases that process is long gone (e.g. > > fsfreeze is being used to allow a HW array to take a snapshot). Just > > the fact it is in the process of freezing (if stuck, stack trace in > > sysrq-w should be present) or frozen (freezing process may be long > > gone, and is mostly irrelevant because you're now tracking down why > > a thaw hasn't happened)... > > There are deamons which perform freezing and unfreezing on their own. > Thus storing the name along with pid helps to determine whether someone > went behind such daemon's back, or maybe it's the daemon which "forgot" to > unfreeze after all.
Such a daemon should be logging the fact that it's freezing and thawing the filesystem. The kernel is not the place to track what buggy userspace applications are doing wrong.
Cheers,
Dave. -- Dave Chinner david@fromorbit.com
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