On Thu 20-02-14 19:21:07, Ted Tso wrote: > On Fri, Sep 27, 2013 at 06:05:17PM +0200, Jan Kara wrote: > > On Fri 27-09-13 19:54:03, Maxim Patlasov wrote: > > > While handling punch-hole fallocate, it's useless to truncate page cache > > > before removing the range from extent tree (or block map in indirect case) > > > because page cache can be re-populated (by read-ahead or read(2) or mmap-ed > > > read) immediately after truncating page cache, but before updating extent > > > tree (or block map). In that case the user will see stale data even after > > > fallocate is completed. > > > > > > Changed in v2 (Thanks to Jan Kara): > > > - Until the problem of data corruption resulting from pages backed by > > > already freed blocks is fully resolved, the simple thing we can do now > > > is to add another truncation of pagecache after punch hole is done. > > The patch looks good. You can add: > > Reviewed-by: Jan Kara <jack@xxxxxxx> > > I was going through old patches, and it looks like this one got > dropped. My apologies. > > As far as I can tell, the underlying problem in the VFS/MM layer > hasn't been solved yet (Jan, can you confirm?), so I've queued this > patch for the next merge window. Yes, we didn't solve it yet. Thanks for queueing the patch! Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
