Re: [PATCH v2 7/7] mm, dax: unmap dax mappings at bdev shutdown

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

 



On Wed, Nov 25, 2015 at 10:37 AM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> Currently dax mappings leak past / survive block_device shutdown.  While
> page cache pages are permitted to be read/written after the block_device
> is torn down this is not acceptable in the dax case as all media access
> must end when the device is disabled.  The pfn backing a dax mapping is
> permitted to be invalidated after bdev shutdown and this is indeed the
> case with brd.
>
> When a dax capable block_device driver calls del_gendisk_queue() in its
> shutdown path it needs to ensure that all DAX pfns are unmapped, and
> that no new mappings can be established.  This is different than the
> pagecache backed case where the disk is protected by the queue being
> torn down which ends I/O to the device.  Since dax bypasses the page
> cache we need to unconditionally unmap the inode.
>
> Cc: Jan Kara <jack@xxxxxxxx>
> Cc: Dave Chinner <david@xxxxxxxxxxxxx>
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
> [honza: drop changes to truncate_inode_pages_final]
> [honza: ensure mappings can't be re-established]
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---

Dave, can this patch move forward while we figure out ->shutdown() for
super_operations?
--
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



[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux