Re: [Lsf-pc] [LSF/MM TOPIC] Badblocks checking/representation in filesystems

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Jan 18, 2017 at 03:39:17PM -0500, Jeff Moyer wrote:
> Jan Kara <jack@xxxxxxx> writes:
> 
> > On Tue 17-01-17 15:14:21, Vishal Verma wrote:
> >> Your note on the online repair does raise another tangentially related
> >> topic. Currently, if there are badblocks, writes via the bio submission
> >> path will clear the error (if the hardware is able to remap the bad
> >> locations). However, if the filesystem is mounted eith DAX, even
> >> non-mmap operations - read() and write() will go through the dax paths
> >> (dax_do_io()). We haven't found a good/agreeable way to perform
> >> error-clearing in this case. So currently, if a dax mounted filesystem
> >> has badblocks, the only way to clear those badblocks is to mount it
> >> without DAX, and overwrite/zero the bad locations. This is a pretty
> >> terrible user experience, and I'm hoping this can be solved in a better
> >> way.
> >
> > Please remind me, what is the problem with DAX code doing necessary work to
> > clear the error when it gets EIO from memcpy on write?
> 
> You won't get an MCE for a store;  only loads generate them.
> 
> Won't fallocate FL_ZERO_RANGE clear bad blocks when mounted with -o dax?

Not necessarily; XFS usually implements this by punching out the range
and then reallocating it as unwritten blocks.

--D

> 
> Cheers,
> Jeff
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux RAID]     [Linux SCSI]     [Linux ATA RAID]     [IDE]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Device Mapper]

  Powered by Linux