From: Jan K. <ja...@su...> - 2012-03-01 12:23:33
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Bah, the subject should have been 0/9... Sorry. Honza On Thu 01-03-12 12:41:34, Jan Kara wrote: > Hello, > > to provide reliable support for filesystem freezing, filesystems need to have > complete control over when metadata is changed. In particular, > file_update_time() calls from page fault code make it impossible for > filesystems to prevent inodes from being dirtied while the filesystem is > frozen. > > To fix the issue, this patch set changes page fault code to call > file_update_time() only when ->page_mkwrite() callback is not provided. If the > callback is provided, it is the responsibility of the filesystem to perform > update of i_mtime / i_ctime if needed. We also push file_update_time() call > to all existing ->page_mkwrite() implementations if the time update does not > obviously happen by other means. If you know your filesystem does not need > update of modification times in ->page_mkwrite() handler, please speak up and > I'll drop the patch for your filesystem. > > As a side note, an alternative would be to remove call of file_update_time() > from page fault code altogether and require all filesystems needing it to do > that in their ->page_mkwrite() implementation. That is certainly possible > although maybe slightly inefficient and would require auditting 100+ > vm_operations_structs *shiver*. > > Changes since v1: > * Dropped patches for filesystems which don't need them > * Added some acks > * Improved sysfs patch by Alex Elder's suggestion > > Andrew, would you be willing to merge these patches via your tree? > > Honza > > CC: Jaya Kumar <ja...@in...> > CC: Sage Weil <sa...@ne...> > CC: cep...@vg... > CC: Steve French <sf...@sa...> > CC: lin...@vg... > CC: Eric Van Hensbergen <er...@gm...> > CC: Ron Minnich <rmi...@sa...> > CC: Latchesar Ionkov <lu...@io...> > CC: v9f...@li... > CC: Miklos Szeredi <mi...@sz...> > CC: fus...@li... > CC: Steven Whitehouse <swh...@re...> > CC: clu...@re... > CC: Greg Kroah-Hartman <gr...@li...> > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to maj...@vg... > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jan Kara <ja...@su...> SUSE Labs, CR |