From patchwork Tue Apr 19 04:50:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12817335 Received: from heian.cn.fujitsu.com (mail.cn.fujitsu.com [183.91.158.132]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1E550EA6 for ; Tue, 19 Apr 2022 04:52:06 +0000 (UTC) IronPort-Data: A9a23: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 IronPort-HdrOrdr: A9a23:lq6Z5qCgSbD7B1TlHemQ55DYdb4zR+YMi2TDtnoBLSC9F/b0qynAppomPGDP4gr5NEtApTniAtjkfZq/z+8X3WB5B97LMzUO01HYTr2Kg7GD/xTQXwX69sN4kZxrarVCDrTLZmRSvILX5xaZHr8brOW6zA== X-IronPort-AV: E=Sophos;i="5.88,333,1635177600"; d="scan'208";a="123671756" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 19 Apr 2022 12:50:54 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id 0B4AC4D169EC; Tue, 19 Apr 2022 12:50:49 +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; Tue, 19 Apr 2022 12:50:47 +0800 Received: from irides.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; Tue, 19 Apr 2022 12:50:46 +0800 From: Shiyang Ruan To: , , , , CC: , , , , , Christoph Hellwig Subject: [PATCH v13 2/7] mm: factor helpers for memory_failure_dev_pagemap Date: Tue, 19 Apr 2022 12:50:40 +0800 Message-ID: <20220419045045.1664996-3-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220419045045.1664996-1-ruansy.fnst@fujitsu.com> References: <20220419045045.1664996-1-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: 0B4AC4D169EC.A6135 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 Reviewed-by: Dan Williams Reviewed-by: Miaohe Lin --- mm/memory-failure.c | 157 ++++++++++++++++++++++++-------------------- 1 file changed, 87 insertions(+), 70 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index e3fbff5bd467..7c8c047bfdc8 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1498,6 +1498,90 @@ 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; + int rc = 0; + + /* + * Pages instantiated by device-dax (not filesystem-dax) + * may be compound pages. + */ + page = compound_head(page); + + /* + * 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)) { + rc = -EOPNOTSUPP; + goto unlock; + } + + 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); +unlock: + dax_unlock_page(page, cookie); + return rc; +} + /* * Called from hugetlb code with hugetlb_lock held. * @@ -1644,12 +1728,8 @@ 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) /* @@ -1658,73 +1738,10 @@ 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; - } - - /* - * Pages instantiated by device-dax (not filesystem-dax) - * may be compound pages. - */ - page = compound_head(page); - - /* - * 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 = -EOPNOTSUPP; - 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, true); - - 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, true, 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);