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 *shake*. If I get acks on these patches, Andrew, would you be willing to take these patches? Honza CC: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> CC: Ingo Molnar <mingo@xxxxxxx> CC: Paul Mackerras <paulus@xxxxxxxxx> CC: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx> CC: Jaya Kumar <jayalk@xxxxxxxxxxxx> CC: Sage Weil <sage@xxxxxxxxxxxx> CC: ceph-devel@xxxxxxxxxxxxxxx CC: Steve French <sfrench@xxxxxxxxx> CC: linux-cifs@xxxxxxxxxxxxxxx CC: Eric Van Hensbergen <ericvh@xxxxxxxxx> CC: Ron Minnich <rminnich@xxxxxxxxxx> CC: Latchesar Ionkov <lucho@xxxxxxxxxx> CC: v9fs-developer@xxxxxxxxxxxxxxxxxxxxx CC: Miklos Szeredi <miklos@xxxxxxxxxx> CC: fuse-devel@xxxxxxxxxxxxxxxxxxxxx CC: Steven Whitehouse <swhiteho@xxxxxxxxxx> CC: cluster-devel@xxxxxxxxxx CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> CC: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> CC: linux-nfs@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
