From patchwork Thu Jul 4 11:23:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Pankaj Raghav (Samsung)" X-Patchwork-Id: 13723615 Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) (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 782481AD9CA; Thu, 4 Jul 2024 11:23:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720092238; cv=none; b=eVbIHm28FK1B1v9Tokvs+oZAoTJ4ZNlPGD3oZb8qiS9XxNhw+7Zu706GDY1oRvWg2fpggglztSM2xbCV8WE4lChWEGs+OFrwe+aGT+BvU0C3BuaVUeEEYvSKmRl8W7JLn8wwvY1Hug4aGhL2U9TRuWBRAzvIjEhv2Tfrbmorl9o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720092238; c=relaxed/simple; bh=Y6wnkr9YicCwKOn6q4dbs0j5MDwg7izxrtZViWy+w08=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FukPhH9/n4NNUFLOLgaK6XPKaqx/FDvfCeNXizdboqPAV418lZBtaYlYU7DTWuFvAVqOJgYKmTq4kG8nxF+JpklojuNOXAZSR5yVwsEvWVPULxJx3mAeGG4GXwKCflsqvShgdJbyrIAMgnFk7uK9LNi4DdZsQdg4tpCJnXV7ZW0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pankajraghav.com; spf=pass smtp.mailfrom=pankajraghav.com; dkim=pass (2048-bit key) header.d=pankajraghav.com header.i=@pankajraghav.com header.b=Y9I71uW1; arc=none smtp.client-ip=80.241.56.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pankajraghav.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pankajraghav.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pankajraghav.com header.i=@pankajraghav.com header.b="Y9I71uW1" Received: from smtp102.mailbox.org (smtp102.mailbox.org [IPv6:2001:67c:2050:b231:465::102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4WFDmg3MR7z9tVf; Thu, 4 Jul 2024 13:23:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1720092227; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xbld/pizLMEJfrPYBqwQ81gjcSKIsZj5n7TDu8kDUY0=; b=Y9I71uW1qPx88w5xzTVV6UMtblN7zGG5xvC8xb6Mz8YbcDkhM23RoZtzGBKmOssWQWqr5e N6p5+KEKnZsKkXHz3za1P9qz7JBW77U+ZFe7QzIJO+J0nJ+V0mnEaDOs3CFqZYzpgmtYcm E+MIyO1Go3GbYRC2VFtt+CyVFvNEE0u/TW7ll43usBLUFNcNXfQeiPY25ndN7uRo0g4jAD G1//e2FtVmsyQLz0x6pcNksViZ1gK9tFOppFcYZ7sFI5rjPhYBDhK9UkBn0jay5rTelnLO smWW/vns2NyOtHQs56Cts2K2VIKIPMjrJsOQ+gug2XmGzfm/7PoYv2Dv9l+DOA== From: "Pankaj Raghav (Samsung)" To: david@fromorbit.com, willy@infradead.org, chandan.babu@oracle.com, djwong@kernel.org, brauner@kernel.org, akpm@linux-foundation.org Cc: yang@os.amperecomputing.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, john.g.garry@oracle.com, linux-fsdevel@vger.kernel.org, hare@suse.de, p.raghav@samsung.com, mcgrof@kernel.org, gost.dev@samsung.com, cl@os.amperecomputing.com, linux-xfs@vger.kernel.org, kernel@pankajraghav.com, hch@lst.de, Zi Yan Subject: [PATCH v9 05/10] filemap: cap PTE range to be created to allowed zero fill in folio_map_range() Date: Thu, 4 Jul 2024 11:23:15 +0000 Message-ID: <20240704112320.82104-6-kernel@pankajraghav.com> In-Reply-To: <20240704112320.82104-1-kernel@pankajraghav.com> References: <20240704112320.82104-1-kernel@pankajraghav.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: 4WFDmg3MR7z9tVf From: Pankaj Raghav Usually the page cache does not extend beyond the size of the inode, therefore, no PTEs are created for folios that extend beyond the size. But with LBS support, we might extend page cache beyond the size of the inode as we need to guarantee folios of minimum order. While doing a read, do_fault_around() can create PTEs for pages that lie beyond the EOF leading to incorrect error return when accessing a page beyond the mapped file. Cap the PTE range to be created for the page cache up to the end of file(EOF) in filemap_map_pages() so that return error codes are consistent with POSIX[1] for LBS configurations. generic/749(currently in xfstest-dev patches-in-queue branch [0]) has been created to trigger this edge case. This also fixes generic/749 for tmpfs with huge=always on systems with 4k base page size. [0] https://lore.kernel.org/all/20240615002935.1033031-3-mcgrof@kernel.org/ [1](from mmap(2)) SIGBUS Attempted access to a page of the buffer that lies beyond the end of the mapped file. For an explanation of the treatment of the bytes in the page that corresponds to the end of a mapped file that is not a multiple of the page size, see NOTES. Signed-off-by: Luis Chamberlain Signed-off-by: Pankaj Raghav Reviewed-by: Hannes Reinecke Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Darrick J. Wong --- mm/filemap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/filemap.c b/mm/filemap.c index d27e9ac54309d..d322109274532 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3608,7 +3608,7 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, struct vm_area_struct *vma = vmf->vma; struct file *file = vma->vm_file; struct address_space *mapping = file->f_mapping; - pgoff_t last_pgoff = start_pgoff; + pgoff_t file_end, last_pgoff = start_pgoff; unsigned long addr; XA_STATE(xas, &mapping->i_pages, start_pgoff); struct folio *folio; @@ -3634,6 +3634,10 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, goto out; } + file_end = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE) - 1; + if (end_pgoff > file_end) + end_pgoff = file_end; + folio_type = mm_counter_file(folio); do { unsigned long end;