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2012 Linux Storage, Filesystem, and Memory Management Summit - Day 1

Posted Apr 5, 2012 14:14 UTC (Thu) by etienne (subscriber, #25256)
Parent article: 2012 Linux Storage, Filesystem, and Memory Management Summit - Day 1

> Stable pages

I am not a specialist, but isn't any journaled filesystem need stable pages to store the journal itself?

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Posted Apr 5, 2012 14:55 UTC (Thu) by cladisch (✭ supporter ✭, #50193) [Link]

> isn't any journaled filesystem need stable pages to store the journal itself?

Yes; but unstable pages are modified by applications after calling write() without notifying the kernel.
I'd hope that pages containing journal data are not exported to userspace, and that filesystem code knows what it's doing.

2012 Linux Storage, Filesystem, and Memory Management Summit - Day 1

Posted Apr 17, 2012 13:22 UTC (Tue) by intgr (subscriber, #39733) [Link]

Posting to an old comment, but: journalling filesystems generally only journal *metadata* operations, not file operations. ext3+ by default, too. But ext3+ is an exception here, you can configure it to journal data too with the data=journal flag. Not sure how it behaves wrt the application modifying a pending page underneath it though.