From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 10 Nov 2017 10:04:53 +0100 From: Christoph Hellwig To: Dan Williams Cc: linux-nvdimm@lists.01.org, Michal Hocko , linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, =?iso-8859-1?B?Suly9G1l?= Glisse , linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, hch@lst.de Subject: Re: [PATCH 12/15] mm, dax: enable filesystems to trigger page-idle callbacks Message-ID: <20171110090453.GC4895@lst.de> References: <150949209290.24061.6283157778959640151.stgit@dwillia2-desk3.amr.corp.intel.com> <150949216078.24061.1875240167277688258.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <150949216078.24061.1875240167277688258.stgit@dwillia2-desk3.amr.corp.intel.com> Sender: owner-linux-mm@kvack.org List-ID: > +DEFINE_MUTEX(devmap_lock); static? > +#if IS_ENABLED(CONFIG_FS_DAX) > +static void generic_dax_pagefree(struct page *page, void *data) > +{ > +} > + > +struct dax_device *fs_dax_claim_bdev(struct block_device *bdev, void *owner) > +{ > + struct dax_device *dax_dev; > + struct dev_pagemap *pgmap; > + > + if (!blk_queue_dax(bdev->bd_queue)) > + return NULL; > + dax_dev = fs_dax_get_by_host(bdev->bd_disk->disk_name); > + if (!dax_dev->pgmap) > + return dax_dev; > + pgmap = dax_dev->pgmap; > + mutex_lock(&devmap_lock); > + if ((pgmap->data && pgmap->data != owner) || pgmap->page_free > + || pgmap->page_fault > + || pgmap->type != MEMORY_DEVICE_HOST) { > + put_dax(dax_dev); > + mutex_unlock(&devmap_lock); > + return NULL; > + } > + > + pgmap->type = MEMORY_DEVICE_FS_DAX; > + pgmap->page_free = generic_dax_pagefree; > + pgmap->data = owner; > + mutex_unlock(&devmap_lock); All this deep magic will need some explanation. So far I don't understand it at all, but maybe the later patches will help.. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org