Messages in this thread | | | Date | Fri, 16 May 2014 08:16:24 +1000 | From | Dave Chinner <> | Subject | Re: [PATCH V2 2/2] fs: print a message when freezing/unfreezing filesystems |
| |
On Thu, May 15, 2014 at 12:13:56PM +0200, Jan Kara wrote: > On Thu 15-05-14 08:37:45, Dave Chinner wrote: > > On Thu, May 15, 2014 at 08:00:52AM +1000, Dave Chinner wrote: > > > On Wed, May 14, 2014 at 01:39:45PM +0200, Jan Kara wrote: > > > > On Wed 14-05-14 13:26:21, Mateusz Guzik wrote: > > > > > On Wed, May 14, 2014 at 01:14:49PM +0200, Jan Kara wrote: > > > > > > On Wed 14-05-14 00:04:43, Mateusz Guzik wrote: > > > > > > > This helps hang troubleshooting efforts when only dmesg is available. > > > > > > > > > > > > > > While here remove code duplication with MS_RDONLY case and fix a > > > > > > > whitespace nit. > > > > > > I'm somewhat undecided here I have to say. On one hand I don't like > > > > > > printing to kernel log when everything is fine and kernel is operating > > > > > > normally. On the other hand I've seen quite a few cases where people have > > > > > > shot themselves in the foot with filesystem freezing so having some trace > > > > > > of this in the log doesn't seem like a completely bad thing either. What do > > > > > > other people think? > > > > > > > > > > > > > > > > I would like to note that the kernel already prints messages when e.g. > > > > > filesystems get mounted. > > > > Yeah, that's a fair point. > > > > > > But filesystems choose to output that info, not the VFS. When you do > > > a remount,ro there is no output in syslog, because filesystems don't > > > need to dump any output - the state change is reflected in > > > /proc/self/mounts. IMO frozen should state should be communicated > > > the same way so that it is silent when it just works, and the state > > > can easily be determined when something goes wrong. > > > > Say, like this: > > > > $ grep /mnt/test /proc/mounts > > /dev/vda /mnt/test xfs rw,relatime,attr2,inode64,noquota 0 0 > > $ sudo xfs_freeze -f /mnt/test > > $ grep /mnt/test /proc/mounts > > /dev/vda /mnt/test xfs rw,frozen,relatime,attr2,inode64,noquota 0 0 > > $ sudo xfs_freeze -u /mnt/test > > $ grep /mnt/test /proc/mounts > > /dev/vda /mnt/test xfs rw,relatime,attr2,inode64,noquota 0 0 > > $ > > > > Patch below does this. > Hum, same as Eric I'm not very enthusiastic about a fake mount option in > /proc/mounts. Maybe we could stuff some extra field in /proc/self/mountinfo?
sure - I'd forgotten about /proc/self/mountinfo, but the way i wrote the patch will also dump the information into it. It's just a case of moving the code to show_mountinfo() rather than show_sb_opts().
If that's acceptible for everyone, then I'll update the patch to do that....
Cheers,
Dave. -- Dave Chinner david@fromorbit.com
| |