From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 744ABC4708F for ; Tue, 1 Jun 2021 14:30:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E937F61209 for ; Tue, 1 Jun 2021 14:30:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E937F61209 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6846C6B006C; Tue, 1 Jun 2021 10:30:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6347B6B006E; Tue, 1 Jun 2021 10:30:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4AF1C6B0070; Tue, 1 Jun 2021 10:30:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0158.hostedemail.com [216.40.44.158]) by kanga.kvack.org (Postfix) with ESMTP id 12C866B006C for ; Tue, 1 Jun 2021 10:30:43 -0400 (EDT) Received: from smtpin32.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id ABD01BEF1 for ; Tue, 1 Jun 2021 14:30:42 +0000 (UTC) X-FDA: 78205391124.32.7F7C705 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf20.hostedemail.com (Postfix) with ESMTP id C808B569 for ; Tue, 1 Jun 2021 14:30:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:To:From:Date:Sender:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description; bh=HJDgl1iY2Z3fUN3IPfhLi/UD9VZIA/neNyy393ulZWo=; b=Srqfo/9bnr/j7N2SYfCtTP9zGa enNfxpv7x7y9A2cEgwGiiCqgSJgUaZr//4MkdKoO9ffCC+NP8vVGdYU8UK1A+oF2AEOLyaOfY9DOe QQTYghj92V6d47Kaaf0o6KgS4rzaojSz+8Kq+Faf5yYLpqXnQZNn/u9I71jf6CdGi2o2Xra/dRc2L zOV6Jbnk0GeDKYnPhw9C7afLakax84WLSWsYOtQaGy9FzM9a5SW3Sriz16goK46YNQ8PHjiiy5Y4b vDfN9vHI0j/w9yokgGHxG5QA3aFHQ1Gsph4oFOm91dHj0hHiMakyylRClhsEyCPgGQ3FKW374vl8l q/+f51Fw==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lo5Pa-00A7Ao-Uf; Tue, 01 Jun 2021 14:30:31 +0000 Date: Tue, 1 Jun 2021 15:30:30 +0100 From: Matthew Wilcox To: Nathan Chancellor , linux-fbdev@vger.kernel.org, linux-mm@kvack.org, Jani Nikula , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, William Kucharski , Ian Campbell , linux-fsdevel@vger.kernel.org, Jaya Kumar , Christoph Hellwig Subject: Re: [PATCH v2] fb_defio: Remove custom address_space_operations Message-ID: References: <20210310185530.1053320-1-willy@infradead.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="OUZuLF3ujgGn3J2J" Content-Disposition: inline In-Reply-To: Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="Srqfo/9b"; dmarc=none; spf=none (imf20.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Stat-Signature: xx74ngnwpaymdctg593m1c1amnp8w6rp X-Rspamd-Queue-Id: C808B569 X-Rspamd-Server: rspam02 X-HE-Tag: 1622557823-878281 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --OUZuLF3ujgGn3J2J Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Jun 01, 2021 at 04:10:32PM +0200, Daniel Vetter wrote: > On Sun, May 30, 2021 at 10:14:22PM +0100, Matthew Wilcox wrote: > > On Sun, May 30, 2021 at 12:13:05PM -0700, Nathan Chancellor wrote: > > > Hi Matthew, > > > > > > On Wed, Mar 10, 2021 at 06:55:30PM +0000, Matthew Wilcox (Oracle) wrote: > > > > There's no need to give the page an address_space. Leaving the > > > > page->mapping as NULL will cause the VM to handle set_page_dirty() > > > > the same way that it's handled now, and that was the only reason to > > > > set the address_space in the first place. > > > > > > > > Signed-off-by: Matthew Wilcox (Oracle) > > > > Reviewed-by: Christoph Hellwig > > > > Reviewed-by: William Kucharski > > > > > > This patch in mainline as commit ccf953d8f3d6 ("fb_defio: Remove custom > > > address_space_operations") causes my Hyper-V based VM to no longer make > > > it to a graphical environment. > > > > Hi Nathan, > > > > Thanks for the report. I sent Daniel a revert patch with a full > > explanation last week, which I assume he'll queue up for a pull soon. > > You can just git revert ccf953d8f3d6 for yourself until that shows up. > > Sorry for the inconvenience. > > Uh that patch didn't get cc'ed to any list so I've ignored it. I've found > it now, but lack of lore link is awkward. Can you pls resubmit with > dri-devel on cc? fbdev list is dead, I don't look there. How about I just attach it here? --OUZuLF3ujgGn3J2J Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="0001-Revert-fb_defio-Remove-custom-address_space_operatio.patch" >From e88921d0775d87323a8688af37dfd7cdebdde5a9 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 25 May 2021 08:37:33 -0400 Subject: [PATCH] Revert "fb_defio: Remove custom address_space_operations" Commit ccf953d8f3d6 makes framebuffers which use deferred I/O stop displaying updates after the first one. This is because the pages handled by fb_defio no longer have a page_mapping(). That prevents page_mkclean() from marking the PTEs as clean, and so writes are only noticed the first time. Reported-by: Andy Shevchenko Signed-off-by: Matthew Wilcox (Oracle) --- drivers/video/fbdev/core/fb_defio.c | 35 +++++++++++++++++++++++++++++ drivers/video/fbdev/core/fbmem.c | 4 ++++ include/linux/fb.h | 3 +++ 3 files changed, 42 insertions(+) diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index b292887a2481..a591d291b231 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -52,6 +52,13 @@ static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf) return VM_FAULT_SIGBUS; get_page(page); + + if (vmf->vma->vm_file) + page->mapping = vmf->vma->vm_file->f_mapping; + else + printk(KERN_ERR "no mapping available\n"); + + BUG_ON(!page->mapping); page->index = vmf->pgoff; vmf->page = page; @@ -144,6 +151,17 @@ static const struct vm_operations_struct fb_deferred_io_vm_ops = { .page_mkwrite = fb_deferred_io_mkwrite, }; +static int fb_deferred_io_set_page_dirty(struct page *page) +{ + if (!PageDirty(page)) + SetPageDirty(page); + return 0; +} + +static const struct address_space_operations fb_deferred_io_aops = { + .set_page_dirty = fb_deferred_io_set_page_dirty, +}; + int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma) { vma->vm_ops = &fb_deferred_io_vm_ops; @@ -194,12 +212,29 @@ void fb_deferred_io_init(struct fb_info *info) } EXPORT_SYMBOL_GPL(fb_deferred_io_init); +void fb_deferred_io_open(struct fb_info *info, + struct inode *inode, + struct file *file) +{ + file->f_mapping->a_ops = &fb_deferred_io_aops; +} +EXPORT_SYMBOL_GPL(fb_deferred_io_open); + void fb_deferred_io_cleanup(struct fb_info *info) { struct fb_deferred_io *fbdefio = info->fbdefio; + struct page *page; + int i; BUG_ON(!fbdefio); cancel_delayed_work_sync(&info->deferred_work); + + /* clear out the mapping that we setup */ + for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) { + page = fb_deferred_io_page(info, i); + page->mapping = NULL; + } + mutex_destroy(&fbdefio->lock); } EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup); diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 072780b0e570..98f193078c05 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1415,6 +1415,10 @@ __releases(&info->lock) if (res) module_put(info->fbops->owner); } +#ifdef CONFIG_FB_DEFERRED_IO + if (info->fbdefio) + fb_deferred_io_open(info, inode, file); +#endif out: unlock_fb_info(info); if (res) diff --git a/include/linux/fb.h b/include/linux/fb.h index a8dccd23c249..ecfbcc0553a5 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -659,6 +659,9 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, /* drivers/video/fb_defio.c */ int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma); extern void fb_deferred_io_init(struct fb_info *info); +extern void fb_deferred_io_open(struct fb_info *info, + struct inode *inode, + struct file *file); extern void fb_deferred_io_cleanup(struct fb_info *info); extern int fb_deferred_io_fsync(struct file *file, loff_t start, loff_t end, int datasync); -- 2.30.2 --OUZuLF3ujgGn3J2J--