Greg KH / Factory,
I mostly lurk on the Ext4 kernel mailing list.
Just this morning I participated in a brief thread about ext4's newly merged online defrag ioctl which was pushed to Linus in the 2.6.31 merge window and is part of 2.6.31-rc7 at a minimum. As of rc7 there is not a Kconfig option to disable it.
Per http://marc.info/?l=linux-ext4&m=124992522305319&w=2, it currently can cause oop'es when defragging a sparse file, and the recently submitted patch to resolve that introduces file corruption of those same files.
I don't know if 11.2 had plans of including ex4defrag or not, but if so I believe this issue should be closely watched and may need to be dropped altogether until 11.3 comes along.
Even if userspace was not going to have the ex4defrag tool, having the ioctl in the final 11.2 shipping kernel also seems like a bad idea. I hope it gets somehow marked experimental before 2.6.31 goes final. If not Greg KH and his team may need to patch it out of the kernel for our release.
Greg
On Thu, Sep 03, 2009 at 10:51:00AM -0400, Greg Freemyer wrote:
Greg KH / Factory,
I mostly lurk on the Ext4 kernel mailing list.
Just this morning I participated in a brief thread about ext4's newly merged online defrag ioctl which was pushed to Linus in the 2.6.31 merge window and is part of 2.6.31-rc7 at a minimum. As of rc7 there is not a Kconfig option to disable it.
Per http://marc.info/?l=linux-ext4&m=124992522305319&w=2, it currently can cause oop'es when defragging a sparse file, and the recently submitted patch to resolve that introduces file corruption of those same files.
Then don't do that :)
I don't know if 11.2 had plans of including ex4defrag or not, but if so I believe this issue should be closely watched and may need to be dropped altogether until 11.3 comes along.
Even if userspace was not going to have the ex4defrag tool, having the ioctl in the final 11.2 shipping kernel also seems like a bad idea. I hope it gets somehow marked experimental before 2.6.31 goes final. If not Greg KH and his team may need to patch it out of the kernel for our release.
Nah, it will just stay as an experimental feature for people to play with if they want to. Perhaps we will end up with a fix that we can later add to the tree making it useful.
thanks,
greg k-h
Am Donnerstag 03 September 2009 schrieb Greg Freemyer:
Greg KH / Factory,
I mostly lurk on the Ext4 kernel mailing list.
Just this morning I participated in a brief thread about ext4's newly merged online defrag ioctl which was pushed to Linus in the 2.6.31 merge window and is part of 2.6.31-rc7 at a minimum. As of rc7 there is not a Kconfig option to disable it.
Per http://marc.info/?l=linux-ext4&m=124992522305319&w=2, it currently can cause oop'es when defragging a sparse file, and the recently submitted patch to resolve that introduces file corruption of those same files.
I don't know if 11.2 had plans of including ex4defrag or not, but if so I believe this issue should be closely watched and may need to be dropped altogether until 11.3 comes along.
e4defrag is not in the release branch of e2fsprogs and as such we did not include it. I played with it and also provided feedback to the ext4 list, but the results were not good enough to promote it - not yet. But my feedback got quite some discussions and patches started, so I'm very confident with our decision to go with ext4.
Greetings, Stephan
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Greg Freemyer -
Greg KH -
Stephan Kulow