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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 D13C8C4338F for ; Thu, 19 Aug 2021 19:41:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B79F7610A5 for ; Thu, 19 Aug 2021 19:41:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234928AbhHSTmJ (ORCPT ); Thu, 19 Aug 2021 15:42:09 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:39374 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234849AbhHSTmE (ORCPT ); Thu, 19 Aug 2021 15:42:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629402087; 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=gT4348yPCYfQqUSX/zFOChtx5I7LeegseB0c7lotXZM=; b=Cq0M2/5Wd99uQCfyfj2nCgiG8IMIdqGn+HARUtXFm69IygHYL6FykvvrXHS2uwfXgJqGjB 7yxCMvSQa0WCb/bpI8JNgQUmK8WfrfQ8QCKXD7nCn6dx3/7yPOWGNdmdph0b47iLrpK0rI n5Wof6bCDihdNlEZt+SHEh010F4UjP8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-593-4AAdm2USOayUcrSUEcP_PA-1; Thu, 19 Aug 2021 15:41:26 -0400 X-MC-Unique: 4AAdm2USOayUcrSUEcP_PA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9E8771026208; Thu, 19 Aug 2021 19:41:24 +0000 (UTC) Received: from max.com (unknown [10.40.194.206]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1E33960938; Thu, 19 Aug 2021 19:41:21 +0000 (UTC) From: Andreas Gruenbacher To: Linus Torvalds , Alexander Viro , Christoph Hellwig , "Darrick J. Wong" Cc: Jan Kara , Matthew Wilcox , cluster-devel@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com, Andreas Gruenbacher Subject: [PATCH v6 04/19] Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable Date: Thu, 19 Aug 2021 21:40:47 +0200 Message-Id: <20210819194102.1491495-5-agruenba@redhat.com> In-Reply-To: <20210819194102.1491495-1-agruenba@redhat.com> References: <20210819194102.1491495-1-agruenba@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Turn iov_iter_fault_in_readable into a function that returns the number of bytes not faulted in (similar to copy_to_user) instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in, but also new users that are happy if any pages can be faulted in. Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make sure that code that uses it can be fixed instead of breaking silently. Signed-off-by: Andreas Gruenbacher --- fs/btrfs/file.c | 2 +- fs/f2fs/file.c | 2 +- fs/fuse/file.c | 2 +- fs/iomap/buffered-io.c | 2 +- fs/ntfs/file.c | 2 +- include/linux/uio.h | 2 +- lib/iov_iter.c | 33 +++++++++++++++++++++------------ mm/filemap.c | 2 +- 8 files changed, 28 insertions(+), 19 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ee34497500e1..281c77cfe91a 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1698,7 +1698,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, * Fault pages before locking them in prepare_pages * to avoid recursive lock */ - if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, write_bytes))) { ret = -EFAULT; break; } diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 6afd4562335f..b04b6c909a8b 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -4259,7 +4259,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) size_t target_size = 0; int err; - if (iov_iter_fault_in_readable(from, iov_iter_count(from))) + if (fault_in_iov_iter_readable(from, iov_iter_count(from))) set_inode_flag(inode, FI_NO_PREALLOC); if ((iocb->ki_flags & IOCB_NOWAIT)) { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 97f860cfc195..da49ef71dab5 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1160,7 +1160,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia, again: err = -EFAULT; - if (iov_iter_fault_in_readable(ii, bytes)) + if (fault_in_iov_iter_readable(ii, bytes)) break; err = -ENOMEM; diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 87ccb3438bec..7dc42dd3a724 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -749,7 +749,7 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, * same page as we're writing to, without it being marked * up-to-date. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index ab4f3362466d..a43adeacd930 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -1829,7 +1829,7 @@ static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i, * pages being swapped out between us bringing them into memory * and doing the actual copying. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } diff --git a/include/linux/uio.h b/include/linux/uio.h index 82c3c3e819e0..12d30246c2e9 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -119,7 +119,7 @@ size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes, struct iov_iter *i); void iov_iter_advance(struct iov_iter *i, size_t bytes); void iov_iter_revert(struct iov_iter *i, size_t bytes); -int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes); +size_t fault_in_iov_iter_readable(const struct iov_iter *i, size_t bytes); size_t iov_iter_single_seg_count(const struct iov_iter *i); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 069cedd9d7b4..082ab155496d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -430,33 +430,42 @@ static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t by } /* + * fault_in_iov_iter_readable - fault in iov iterator for reading + * @i: iterator + * @size: maximum length + * * Fault in one or more iovecs of the given iov_iter, to a maximum length of - * bytes. For each iovec, fault in each page that constitutes the iovec. + * @size. For each iovec, fault in each page that constitutes the iovec. + * + * Returns the number of bytes not faulted in (like copy_to_user() and + * copy_from_user()). * - * Return 0 on success, or non-zero if the memory could not be accessed (i.e. - * because it is an invalid address). + * Always returns 0 for non-userspace iterators. */ -int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes) +size_t fault_in_iov_iter_readable(const struct iov_iter *i, size_t size) { if (iter_is_iovec(i)) { + size_t count = min(size, iov_iter_count(i)); const struct iovec *p; size_t skip; - if (bytes > i->count) - bytes = i->count; - for (p = i->iov, skip = i->iov_offset; bytes; p++, skip = 0) { - size_t len = min(bytes, p->iov_len - skip); + size -= count; + for (p = i->iov, skip = i->iov_offset; count; p++, skip = 0) { + size_t len = min(count, p->iov_len - skip); + size_t ret; if (unlikely(!len)) continue; - if (fault_in_readable(p->iov_base + skip, len)) - return -EFAULT; - bytes -= len; + ret = fault_in_readable(p->iov_base + skip, len); + count -= len - ret; + if (ret) + break; } + return count + size; } return 0; } -EXPORT_SYMBOL(iov_iter_fault_in_readable); +EXPORT_SYMBOL(fault_in_iov_iter_readable); void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov, unsigned long nr_segs, diff --git a/mm/filemap.c b/mm/filemap.c index 4dec3bc7752e..83af8a534339 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3643,7 +3643,7 @@ ssize_t generic_perform_write(struct file *file, * same page as we're writing to, without it being marked * up-to-date. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } -- 2.26.3 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=-13.8 required=3.0 tests=BAYES_00, 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 B9F99C43216 for ; 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Thu, 19 Aug 2021 19:41:21 +0000 (UTC) From: Andreas Gruenbacher To: Linus Torvalds , Alexander Viro , Christoph Hellwig , "Darrick J. Wong" Date: Thu, 19 Aug 2021 21:40:47 +0200 Message-Id: <20210819194102.1491495-5-agruenba@redhat.com> In-Reply-To: <20210819194102.1491495-1-agruenba@redhat.com> References: <20210819194102.1491495-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Proofpoint-SPF-Result: pass X-Proofpoint-SPF-Record: v=spf1 ip4:103.23.64.2 ip4:103.23.65.2 ip4:103.23.66.26 ip4:103.23.67.26 ip4:107.21.15.141 ip4:108.177.8.0/21 ip4:128.17.0.0/20 ip4:128.17.128.0/20 ip4:128.17.192.0/20 ip4:128.17.64.0/20 ip4:128.245.0.0/20 ip4:128.245.64.0/20 ip4:13.110.208.0/21 ip4:13.110.216.0/22 ip4:13.111.0.0/16 ip4:136.147.128.0/20 ip4:136.147.176.0/20 include:spf1.redhat.com -all X-Proofpoint-SPF-VenPass: Allowed X-Source-IP: 216.205.24.124 X-ServerName: us-smtp-delivery-124.mimecast.com X-Proofpoint-SPF-Result: pass X-Proofpoint-SPF-Record: v=spf1 ip4:103.23.64.2 ip4:103.23.65.2 ip4:103.23.66.26 ip4:103.23.67.26 ip4:107.21.15.141 ip4:108.177.8.0/21 ip4:128.17.0.0/20 ip4:128.17.128.0/20 ip4:128.17.192.0/20 ip4:128.17.64.0/20 ip4:128.245.0.0/20 ip4:128.245.64.0/20 ip4:13.110.208.0/21 ip4:13.110.216.0/22 ip4:13.111.0.0/16 ip4:136.147.128.0/20 ip4:136.147.176.0/20 include:spf1.redhat.com -all X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10081 signatures=668682 X-Proofpoint-Spam-Reason: safe X-Spam: OrgSafeList X-SpamRule: orgsafelist X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10081 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 adultscore=0 bulkscore=0 suspectscore=0 mlxlogscore=999 phishscore=0 mlxscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108190114 Cc: Jan Kara , Andreas Gruenbacher , linux-kernel@vger.kernel.org, cluster-devel@redhat.com, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com Subject: [Ocfs2-devel] [PATCH v6 04/19] Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10081 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 malwarescore=0 mlxscore=0 spamscore=0 suspectscore=0 mlxlogscore=999 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108190114 X-Proofpoint-ORIG-GUID: cmy0Sbyu0x1NENlrm5r5qkYiNgKIzbUc X-Proofpoint-GUID: cmy0Sbyu0x1NENlrm5r5qkYiNgKIzbUc Turn iov_iter_fault_in_readable into a function that returns the number of bytes not faulted in (similar to copy_to_user) instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in, but also new users that are happy if any pages can be faulted in. Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make sure that code that uses it can be fixed instead of breaking silently. Signed-off-by: Andreas Gruenbacher --- fs/btrfs/file.c | 2 +- fs/f2fs/file.c | 2 +- fs/fuse/file.c | 2 +- fs/iomap/buffered-io.c | 2 +- fs/ntfs/file.c | 2 +- include/linux/uio.h | 2 +- lib/iov_iter.c | 33 +++++++++++++++++++++------------ mm/filemap.c | 2 +- 8 files changed, 28 insertions(+), 19 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ee34497500e1..281c77cfe91a 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1698,7 +1698,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, * Fault pages before locking them in prepare_pages * to avoid recursive lock */ - if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, write_bytes))) { ret = -EFAULT; break; } diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 6afd4562335f..b04b6c909a8b 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -4259,7 +4259,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) size_t target_size = 0; int err; - if (iov_iter_fault_in_readable(from, iov_iter_count(from))) + if (fault_in_iov_iter_readable(from, iov_iter_count(from))) set_inode_flag(inode, FI_NO_PREALLOC); if ((iocb->ki_flags & IOCB_NOWAIT)) { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 97f860cfc195..da49ef71dab5 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1160,7 +1160,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia, again: err = -EFAULT; - if (iov_iter_fault_in_readable(ii, bytes)) + if (fault_in_iov_iter_readable(ii, bytes)) break; err = -ENOMEM; diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 87ccb3438bec..7dc42dd3a724 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -749,7 +749,7 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, * same page as we're writing to, without it being marked * up-to-date. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index ab4f3362466d..a43adeacd930 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -1829,7 +1829,7 @@ static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i, * pages being swapped out between us bringing them into memory * and doing the actual copying. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } diff --git a/include/linux/uio.h b/include/linux/uio.h index 82c3c3e819e0..12d30246c2e9 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -119,7 +119,7 @@ size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes, struct iov_iter *i); void iov_iter_advance(struct iov_iter *i, size_t bytes); void iov_iter_revert(struct iov_iter *i, size_t bytes); -int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes); +size_t fault_in_iov_iter_readable(const struct iov_iter *i, size_t bytes); size_t iov_iter_single_seg_count(const struct iov_iter *i); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 069cedd9d7b4..082ab155496d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -430,33 +430,42 @@ static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t by } /* + * fault_in_iov_iter_readable - fault in iov iterator for reading + * @i: iterator + * @size: maximum length + * * Fault in one or more iovecs of the given iov_iter, to a maximum length of - * bytes. For each iovec, fault in each page that constitutes the iovec. + * @size. For each iovec, fault in each page that constitutes the iovec. + * + * Returns the number of bytes not faulted in (like copy_to_user() and + * copy_from_user()). * - * Return 0 on success, or non-zero if the memory could not be accessed (i.e. - * because it is an invalid address). + * Always returns 0 for non-userspace iterators. */ -int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes) +size_t fault_in_iov_iter_readable(const struct iov_iter *i, size_t size) { if (iter_is_iovec(i)) { + size_t count = min(size, iov_iter_count(i)); const struct iovec *p; size_t skip; - if (bytes > i->count) - bytes = i->count; - for (p = i->iov, skip = i->iov_offset; bytes; p++, skip = 0) { - size_t len = min(bytes, p->iov_len - skip); + size -= count; + for (p = i->iov, skip = i->iov_offset; count; p++, skip = 0) { + size_t len = min(count, p->iov_len - skip); + size_t ret; if (unlikely(!len)) continue; - if (fault_in_readable(p->iov_base + skip, len)) - return -EFAULT; - bytes -= len; + ret = fault_in_readable(p->iov_base + skip, len); + count -= len - ret; + if (ret) + break; } + return count + size; } return 0; } -EXPORT_SYMBOL(iov_iter_fault_in_readable); +EXPORT_SYMBOL(fault_in_iov_iter_readable); void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov, unsigned long nr_segs, diff --git a/mm/filemap.c b/mm/filemap.c index 4dec3bc7752e..83af8a534339 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3643,7 +3643,7 @@ ssize_t generic_perform_write(struct file *file, * same page as we're writing to, without it being marked * up-to-date. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } -- 2.26.3 _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Gruenbacher Date: Thu, 19 Aug 2021 21:40:47 +0200 Subject: [Cluster-devel] [PATCH v6 04/19] Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable In-Reply-To: <20210819194102.1491495-1-agruenba@redhat.com> References: <20210819194102.1491495-1-agruenba@redhat.com> Message-ID: <20210819194102.1491495-5-agruenba@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Turn iov_iter_fault_in_readable into a function that returns the number of bytes not faulted in (similar to copy_to_user) instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in, but also new users that are happy if any pages can be faulted in. Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make sure that code that uses it can be fixed instead of breaking silently. Signed-off-by: Andreas Gruenbacher --- fs/btrfs/file.c | 2 +- fs/f2fs/file.c | 2 +- fs/fuse/file.c | 2 +- fs/iomap/buffered-io.c | 2 +- fs/ntfs/file.c | 2 +- include/linux/uio.h | 2 +- lib/iov_iter.c | 33 +++++++++++++++++++++------------ mm/filemap.c | 2 +- 8 files changed, 28 insertions(+), 19 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ee34497500e1..281c77cfe91a 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1698,7 +1698,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, * Fault pages before locking them in prepare_pages * to avoid recursive lock */ - if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, write_bytes))) { ret = -EFAULT; break; } diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 6afd4562335f..b04b6c909a8b 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -4259,7 +4259,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) size_t target_size = 0; int err; - if (iov_iter_fault_in_readable(from, iov_iter_count(from))) + if (fault_in_iov_iter_readable(from, iov_iter_count(from))) set_inode_flag(inode, FI_NO_PREALLOC); if ((iocb->ki_flags & IOCB_NOWAIT)) { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 97f860cfc195..da49ef71dab5 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1160,7 +1160,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia, again: err = -EFAULT; - if (iov_iter_fault_in_readable(ii, bytes)) + if (fault_in_iov_iter_readable(ii, bytes)) break; err = -ENOMEM; diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 87ccb3438bec..7dc42dd3a724 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -749,7 +749,7 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, * same page as we're writing to, without it being marked * up-to-date. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index ab4f3362466d..a43adeacd930 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -1829,7 +1829,7 @@ static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i, * pages being swapped out between us bringing them into memory * and doing the actual copying. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } diff --git a/include/linux/uio.h b/include/linux/uio.h index 82c3c3e819e0..12d30246c2e9 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -119,7 +119,7 @@ size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes, struct iov_iter *i); void iov_iter_advance(struct iov_iter *i, size_t bytes); void iov_iter_revert(struct iov_iter *i, size_t bytes); -int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes); +size_t fault_in_iov_iter_readable(const struct iov_iter *i, size_t bytes); size_t iov_iter_single_seg_count(const struct iov_iter *i); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 069cedd9d7b4..082ab155496d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -430,33 +430,42 @@ static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t by } /* + * fault_in_iov_iter_readable - fault in iov iterator for reading + * @i: iterator + * @size: maximum length + * * Fault in one or more iovecs of the given iov_iter, to a maximum length of - * bytes. For each iovec, fault in each page that constitutes the iovec. + * @size. For each iovec, fault in each page that constitutes the iovec. + * + * Returns the number of bytes not faulted in (like copy_to_user() and + * copy_from_user()). * - * Return 0 on success, or non-zero if the memory could not be accessed (i.e. - * because it is an invalid address). + * Always returns 0 for non-userspace iterators. */ -int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes) +size_t fault_in_iov_iter_readable(const struct iov_iter *i, size_t size) { if (iter_is_iovec(i)) { + size_t count = min(size, iov_iter_count(i)); const struct iovec *p; size_t skip; - if (bytes > i->count) - bytes = i->count; - for (p = i->iov, skip = i->iov_offset; bytes; p++, skip = 0) { - size_t len = min(bytes, p->iov_len - skip); + size -= count; + for (p = i->iov, skip = i->iov_offset; count; p++, skip = 0) { + size_t len = min(count, p->iov_len - skip); + size_t ret; if (unlikely(!len)) continue; - if (fault_in_readable(p->iov_base + skip, len)) - return -EFAULT; - bytes -= len; + ret = fault_in_readable(p->iov_base + skip, len); + count -= len - ret; + if (ret) + break; } + return count + size; } return 0; } -EXPORT_SYMBOL(iov_iter_fault_in_readable); +EXPORT_SYMBOL(fault_in_iov_iter_readable); void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov, unsigned long nr_segs, diff --git a/mm/filemap.c b/mm/filemap.c index 4dec3bc7752e..83af8a534339 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3643,7 +3643,7 @@ ssize_t generic_perform_write(struct file *file, * same page as we're writing to, without it being marked * up-to-date. */ - if (unlikely(iov_iter_fault_in_readable(i, bytes))) { + if (unlikely(fault_in_iov_iter_readable(i, bytes))) { status = -EFAULT; break; } -- 2.26.3