On Mon, Nov 30, 2015 at 2:03 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > 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? Disregard, I'm straightened out now. -- 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
