Any updates with this, please? On Monday 04 August 2008 17:19, Nick Piggin wrote: > On Tuesday 29 July 2008 09:00, Christoph Hellwig wrote: > > On Mon, Jul 28, 2008 at 03:46:36PM -0700, akpm@xxxxxxxxxxxxxxxxxxxx wrote: > > > From: Hisashi Hifumi <hifumi.hisashi@xxxxxxxxxxxxx> > > > > > > When we read some part of a file through pagecache, if there is a > > > pagecache of corresponding index but this page is not uptodate, read IO > > > is issued and this page will be uptodate. > > > > I was under the impression we wanted to do this in a nicer way than > > the hacky method? > > This patch unfortunately appears like it may introduce an > uninitialized memory leak due to a data race between one > thread initializing a buffer then marking it uptodate, and > the other testing buffer uptodate then reading from the > buffer (buffer, read as: page memory covered by buffer head). > > For reference, this is basically the same class of data race > that I fixed 0ed361dec36945f3116ee1338638ada9a8920905 > > I should have picked up on this before it was merged, but I > was kind of rushed to review other things before they got > merged. > > I don't think this patch got quite enough justification to > warrant just blindly putting barriers in the buffer bitops. > The best-case numbers for it were reasonable enough when the > downside was only an extra branch or two in a relatively slow > path. I don't really know how best to go from here (maybe > someone can argue it is not a problem or come up with a better > fix?). > > Thanks, > Nick -- 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
