From patchwork Fri Sep 24 13:09:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12515331 Received: from heian.cn.fujitsu.com (mail.cn.fujitsu.com [183.91.158.132]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 257C472 for ; Fri, 24 Sep 2021 13:11:22 +0000 (UTC) IronPort-Data: A9a23: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 IronPort-HdrOrdr: A9a23:nz33yK8SZT2iN8yk2ZVuk+C9I+orL9Y04lQ7vn2ZKCY0TiX2ra2TdZggvyMc6wxxZJhDo7+90cC7KBu2yXcc2/hzAV7IZmXbUQWTQr1f0Q== X-IronPort-AV: E=Sophos;i="5.85,319,1624291200"; d="scan'208";a="114917442" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 24 Sep 2021 21:10:18 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id B477D4D0DC7C; Fri, 24 Sep 2021 21:10:15 +0800 (CST) Received: from G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.85) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Fri, 24 Sep 2021 21:10:14 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.23 via Frontend Transport; Fri, 24 Sep 2021 21:10:14 +0800 From: Shiyang Ruan To: , , , , CC: , , , , Subject: [PATCH v7 3/8] mm: factor helpers for memory_failure_dev_pagemap Date: Fri, 24 Sep 2021 21:09:54 +0800 Message-ID: <20210924130959.2695749-4-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210924130959.2695749-1-ruansy.fnst@fujitsu.com> References: <20210924130959.2695749-1-ruansy.fnst@fujitsu.com> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-yoursite-MailScanner-ID: B477D4D0DC7C.A425A X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com X-Spam-Status: No memory_failure_dev_pagemap code is a bit complex before introduce RMAP feature for fsdax. So it is needed to factor some helper functions to simplify these code. Signed-off-by: Shiyang Ruan Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- mm/memory-failure.c | 140 ++++++++++++++++++++++++-------------------- 1 file changed, 76 insertions(+), 64 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 54879c339024..8ff9b52823c0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1430,6 +1430,79 @@ static int try_to_split_thp_page(struct page *page, const char *msg) return 0; } +static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn, + struct address_space *mapping, pgoff_t index, int flags) +{ + struct to_kill *tk; + unsigned long size = 0; + + list_for_each_entry(tk, to_kill, nd) + if (tk->size_shift) + size = max(size, 1UL << tk->size_shift); + if (size) { + /* + * Unmap the largest mapping to avoid breaking up device-dax + * mappings which are constant size. The actual size of the + * mapping being torn down is communicated in siginfo, see + * kill_proc() + */ + loff_t start = (index << PAGE_SHIFT) & ~(size - 1); + + unmap_mapping_range(mapping, start, size, 0); + } + + kill_procs(to_kill, flags & MF_MUST_KILL, false, pfn, flags); +} + +static int mf_generic_kill_procs(unsigned long long pfn, int flags, + struct dev_pagemap *pgmap) +{ + struct page *page = pfn_to_page(pfn); + LIST_HEAD(to_kill); + dax_entry_t cookie; + + /* + * Prevent the inode from being freed while we are interrogating + * the address_space, typically this would be handled by + * lock_page(), but dax pages do not use the page lock. This + * also prevents changes to the mapping of this pfn until + * poison signaling is complete. + */ + cookie = dax_lock_page(page); + if (!cookie) + return -EBUSY; + + if (hwpoison_filter(page)) + return 0; + + if (pgmap->type == MEMORY_DEVICE_PRIVATE) { + /* + * TODO: Handle HMM pages which may need coordination + * with device-side memory. + */ + return -EBUSY; + } + + /* + * Use this flag as an indication that the dax page has been + * remapped UC to prevent speculative consumption of poison. + */ + SetPageHWPoison(page); + + /* + * Unlike System-RAM there is no possibility to swap in a + * different physical page at a given virtual address, so all + * userspace consumption of ZONE_DEVICE memory necessitates + * SIGBUS (i.e. MF_MUST_KILL) + */ + flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; + collect_procs(page, &to_kill, true); + + unmap_and_kill(&to_kill, pfn, page->mapping, page->index, flags); + dax_unlock_page(page, cookie); + return 0; +} + static int memory_failure_hugetlb(unsigned long pfn, int flags) { struct page *p = pfn_to_page(pfn); @@ -1519,12 +1592,8 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, struct dev_pagemap *pgmap) { struct page *page = pfn_to_page(pfn); - unsigned long size = 0; - struct to_kill *tk; LIST_HEAD(tokill); - int rc = -EBUSY; - loff_t start; - dax_entry_t cookie; + int rc = -ENXIO; if (flags & MF_COUNT_INCREASED) /* @@ -1533,67 +1602,10 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, put_page(page); /* device metadata space is not recoverable */ - if (!pgmap_pfn_valid(pgmap, pfn)) { - rc = -ENXIO; - goto out; - } - - /* - * Prevent the inode from being freed while we are interrogating - * the address_space, typically this would be handled by - * lock_page(), but dax pages do not use the page lock. This - * also prevents changes to the mapping of this pfn until - * poison signaling is complete. - */ - cookie = dax_lock_page(page); - if (!cookie) + if (!pgmap_pfn_valid(pgmap, pfn)) goto out; - if (hwpoison_filter(page)) { - rc = 0; - goto unlock; - } - - if (pgmap->type == MEMORY_DEVICE_PRIVATE) { - /* - * TODO: Handle HMM pages which may need coordination - * with device-side memory. - */ - goto unlock; - } - - /* - * Use this flag as an indication that the dax page has been - * remapped UC to prevent speculative consumption of poison. - */ - SetPageHWPoison(page); - - /* - * Unlike System-RAM there is no possibility to swap in a - * different physical page at a given virtual address, so all - * userspace consumption of ZONE_DEVICE memory necessitates - * SIGBUS (i.e. MF_MUST_KILL) - */ - flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; - collect_procs(page, &tokill, flags & MF_ACTION_REQUIRED); - - list_for_each_entry(tk, &tokill, nd) - if (tk->size_shift) - size = max(size, 1UL << tk->size_shift); - if (size) { - /* - * Unmap the largest mapping to avoid breaking up - * device-dax mappings which are constant size. The - * actual size of the mapping being torn down is - * communicated in siginfo, see kill_proc() - */ - start = (page->index << PAGE_SHIFT) & ~(size - 1); - unmap_mapping_range(page->mapping, start, size, 0); - } - kill_procs(&tokill, flags & MF_MUST_KILL, false, pfn, flags); - rc = 0; -unlock: - dax_unlock_page(page, cookie); + rc = mf_generic_kill_procs(pfn, flags, pgmap); out: /* drop pgmap ref acquired in caller */ put_dev_pagemap(pgmap);