From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 78693215782 for ; Mon, 17 Mar 2025 05:11:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742188268; cv=none; b=Ojgh0SwlftRs/rjDQMh4B5gyoR1mR7s6TB063W7pqTHCChMir51VCOQGIRN+kQul+PUY1EFNz3JQISQlZ+9jqcbmN+nnS23NZi5CYTr08txu2tw3F74hOjmHJPuF3OJpe5KkMYf19dq5fpGxw/zeI60xcOXJtJUEb+gMhkA+zSE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742188268; c=relaxed/simple; bh=+3KiU35OyI3zeCm4kQ+e2Gf3F5X4aX+v3yjFKtoHhA0=; h=Date:To:From:Subject:Message-Id; b=O5NHaRK4qmbSfXhvm/H4f+bI17umi0OJBAyJpYZVZv97WFV+zMBmXHorpW4JpOTNT/SanhM8B7jg1/+nqAa8AJUBYkFdupVRmpXr6cGrhSSH11jFwy3pQcskdYSd9C2ld8Ag4HHq06LuZYvd2auRIlp0UYPcUW6q3Lpd8HL8kY8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=n4sMr8VF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="n4sMr8VF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4ACD1C4CEEC; Mon, 17 Mar 2025 05:11:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1742188268; bh=+3KiU35OyI3zeCm4kQ+e2Gf3F5X4aX+v3yjFKtoHhA0=; h=Date:To:From:Subject:From; b=n4sMr8VF4va5k0Z5EFk7FKbWJ+JEs8duiPcZzxqY4Taip+pRq7ieKPL+aKRVETIPN XmfC3HW1hjygjBl9V9k5YpYbVT3Jp6USL1Bp4yEWjikqllmbe5CNF3vTt1T8aPRkMi kx/s0ZhIWxD5hLtoxFA9eNSNZzuyzrb+pD0EEjPI= Date: Sun, 16 Mar 2025 22:11:07 -0700 To: mm-commits@vger.kernel.org,willy@infradead.org,tzimmermann@suse.de,soci@c64.rulez.org,simona.vetter@ffwll.ch,mcanal@igalia.com,jayakumar.lkml@gmail.com,deller@gmx.de,david@redhat.com,lorenzo.stoakes@oracle.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] fb_defio-do-not-use-deprecated-page-mapping-index-fields.patch removed from -mm tree Message-Id: <20250317051108.4ACD1C4CEEC@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: fb_defio: do not use deprecated page->mapping, index fields has been removed from the -mm tree. Its filename was fb_defio-do-not-use-deprecated-page-mapping-index-fields.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Lorenzo Stoakes Subject: fb_defio: do not use deprecated page->mapping, index fields Date: Sat, 8 Feb 2025 15:52:56 +0000 With the introduction of mapping_wrprotect_range() there is no need to use folio_mkclean() in order to write-protect mappings of frame buffer pages, and therefore no need to inappropriately set kernel-allocated page->index, mapping fields to permit this operation. Instead, store the pointer to the page cache object for the mapped driver in the fb_deferred_io object, and use the already stored page offset from the pageref object to look up mappings in order to write-protect them. This is justified, as for the page objects to store a mapping pointer at the point of assignment of pages, they must all reference the same underlying address_space object. Since the life time of the pagerefs is also the lifetime of the fb_deferred_io object, storing the pointer here makes sense. This eliminates the need for all of the logic around setting and maintaining page->index,mapping which we remove. This eliminates the use of folio_mkclean() entirely but otherwise should have no functional change. [lorenzo.stoakes@oracle.com: fixup unused variable warnings] Link: https://lkml.kernel.org/r/d4018405-2762-4385-a816-e54cc23839ac@lucifer.local Link: https://lkml.kernel.org/r/81171ab16c14e3df28f6de9d14982cee528d8519.1739029358.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Tested-by: Kajtar Zsolt Acked-by: Thomas Zimmermann Cc: David Hildenbrand Cc: Helge Deller Cc: Jaya Kumar Cc: Maíra Canal Cc: Matthew Wilcox Cc: Simona Vetter Signed-off-by: Andrew Morton --- drivers/video/fbdev/core/fb_defio.c | 43 +++++++++----------------- include/linux/fb.h | 1 2 files changed, 16 insertions(+), 28 deletions(-) --- a/drivers/video/fbdev/core/fb_defio.c~fb_defio-do-not-use-deprecated-page-mapping-index-fields +++ a/drivers/video/fbdev/core/fb_defio.c @@ -69,14 +69,6 @@ out: return pageref; } -static void fb_deferred_io_pageref_clear(struct fb_deferred_io_pageref *pageref) -{ - struct page *page = pageref->page; - - if (page) - page->mapping = NULL; -} - static struct fb_deferred_io_pageref *fb_deferred_io_pageref_get(struct fb_info *info, unsigned long offset, struct page *page) @@ -140,13 +132,10 @@ static vm_fault_t fb_deferred_io_fault(s if (!page) return VM_FAULT_SIGBUS; - if (vmf->vma->vm_file) - page->mapping = vmf->vma->vm_file->f_mapping; - else - printk(KERN_ERR "no mapping available\n"); + if (!vmf->vma->vm_file) + fb_err(info, "no mapping available\n"); - BUG_ON(!page->mapping); - page->index = vmf->pgoff; /* for folio_mkclean() */ + BUG_ON(!info->fbdefio->mapping); vmf->page = page; return 0; @@ -194,9 +183,9 @@ static vm_fault_t fb_deferred_io_track_p /* * We want the page to remain locked from ->page_mkwrite until - * the PTE is marked dirty to avoid folio_mkclean() being called - * before the PTE is updated, which would leave the page ignored - * by defio. + * the PTE is marked dirty to avoid mapping_wrprotect_range() + * being called before the PTE is updated, which would leave + * the page ignored by defio. * Do this by locking the page here and informing the caller * about it with VM_FAULT_LOCKED. */ @@ -274,15 +263,17 @@ static void fb_deferred_io_work(struct w struct fb_deferred_io_pageref *pageref, *next; struct fb_deferred_io *fbdefio = info->fbdefio; - /* here we mkclean the pages, then do all deferred IO */ + /* here we wrprotect the page's mappings, then do all deferred IO. */ mutex_lock(&fbdefio->lock); +#ifdef CONFIG_MMU list_for_each_entry(pageref, &fbdefio->pagereflist, list) { - struct folio *folio = page_folio(pageref->page); + struct page *page = pageref->page; + pgoff_t pgoff = pageref->offset >> PAGE_SHIFT; - folio_lock(folio); - folio_mkclean(folio); - folio_unlock(folio); + mapping_wrprotect_range(fbdefio->mapping, pgoff, + page_to_pfn(page), 1); } +#endif /* driver's callback with pagereflist */ fbdefio->deferred_io(info, &fbdefio->pagereflist); @@ -337,6 +328,7 @@ void fb_deferred_io_open(struct fb_info { struct fb_deferred_io *fbdefio = info->fbdefio; + fbdefio->mapping = file->f_mapping; file->f_mapping->a_ops = &fb_deferred_io_aops; fbdefio->open_count++; } @@ -344,13 +336,7 @@ EXPORT_SYMBOL_GPL(fb_deferred_io_open); static void fb_deferred_io_lastclose(struct fb_info *info) { - unsigned long i; - flush_delayed_work(&info->deferred_work); - - /* clear out the mapping that we setup */ - for (i = 0; i < info->npagerefs; ++i) - fb_deferred_io_pageref_clear(&info->pagerefs[i]); } void fb_deferred_io_release(struct fb_info *info) @@ -370,5 +356,6 @@ void fb_deferred_io_cleanup(struct fb_in kvfree(info->pagerefs); mutex_destroy(&fbdefio->lock); + fbdefio->mapping = NULL; } EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup); --- a/include/linux/fb.h~fb_defio-do-not-use-deprecated-page-mapping-index-fields +++ a/include/linux/fb.h @@ -225,6 +225,7 @@ struct fb_deferred_io { int open_count; /* number of opened files; protected by fb_info lock */ struct mutex lock; /* mutex that protects the pageref list */ struct list_head pagereflist; /* list of pagerefs for touched pages */ + struct address_space *mapping; /* page cache object for fb device */ /* callback */ struct page *(*get_page)(struct fb_info *info, unsigned long offset); void (*deferred_io)(struct fb_info *info, struct list_head *pagelist); _ Patches currently in -mm which might be from lorenzo.stoakes@oracle.com are mm-mremap-correctly-handle-partial-mremap-of-vma-starting-at-0.patch mm-mremap-refactor-mremap-system-call-implementation.patch mm-mremap-introduce-and-use-vma_remap_struct-threaded-state.patch mm-mremap-initial-refactor-of-move_vma.patch mm-mremap-complete-refactor-of-move_vma.patch mm-mremap-refactor-move_page_tables-abstracting-state.patch mm-mremap-thread-state-through-move-page-table-operation.patch