From patchwork Thu Sep 3 20:04:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 11754643 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3D965618 for ; Thu, 3 Sep 2020 20:04:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2FC7120897 for ; Thu, 3 Sep 2020 20:04:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728525AbgICUE0 (ORCPT ); Thu, 3 Sep 2020 16:04:26 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:57742 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727065AbgICUEZ (ORCPT ); Thu, 3 Sep 2020 16:04:25 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id CD07B29B092 From: Gabriel Krisman Bertazi To: viro@zeniv.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, jack@suse.cz, khazhy@google.com, Gabriel Krisman Bertazi , kernel@collabora.com Subject: [PATCH v2 1/3] direct-io: clean up error paths of do_blockdev_direct_IO Date: Thu, 3 Sep 2020 16:04:12 -0400 Message-Id: <20200903200414.673105-2-krisman@collabora.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200903200414.673105-1-krisman@collabora.com> References: <20200903200414.673105-1-krisman@collabora.com> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org In preparation to resort DIO checks, reduce code duplication of error handling in do_blockdev_direct_IO. Signed-off-by: Gabriel Krisman Bertazi --- fs/direct-io.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index 183299892465..04aae41323d7 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1170,7 +1170,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, blkbits = blksize_bits(bdev_logical_block_size(bdev)); blocksize_mask = (1 << blkbits) - 1; if (align & blocksize_mask) - goto out; + return -EINVAL; } /* watch out for a 0 len io from a tricksy fs */ @@ -1178,9 +1178,8 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, return 0; dio = kmem_cache_alloc(dio_cache, GFP_KERNEL); - retval = -ENOMEM; if (!dio) - goto out; + return -ENOMEM; /* * Believe it or not, zeroing out the page array caused a .5% * performance regression in a database benchmark. So, we take @@ -1199,22 +1198,16 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, retval = filemap_write_and_wait_range(mapping, offset, end - 1); - if (retval) { - inode_unlock(inode); - kmem_cache_free(dio_cache, dio); - goto out; - } + if (retval) + goto fail_dio; } } /* Once we sampled i_size check for reads beyond EOF */ dio->i_size = i_size_read(inode); if (iov_iter_rw(iter) == READ && offset >= dio->i_size) { - if (dio->flags & DIO_LOCKING) - inode_unlock(inode); - kmem_cache_free(dio_cache, dio); retval = 0; - goto out; + goto fail_dio; } /* @@ -1263,8 +1256,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, * We grab i_mutex only for reads so we don't have * to release it here */ - kmem_cache_free(dio_cache, dio); - goto out; + goto fail_dio_unlocked; } } @@ -1368,7 +1360,15 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, } else BUG_ON(retval != -EIOCBQUEUED); -out: + return retval; + +fail_dio: + if (dio->flags & DIO_LOCKING) { + inode_unlock(inode); + } +fail_dio_unlocked: + kmem_cache_free(dio_cache, dio); + return retval; } From patchwork Thu Sep 3 20:04:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 11754645 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 73F36618 for ; Thu, 3 Sep 2020 20:04:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D60F208C7 for ; Thu, 3 Sep 2020 20:04:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728850AbgICUE2 (ORCPT ); Thu, 3 Sep 2020 16:04:28 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:57750 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727065AbgICUE2 (ORCPT ); Thu, 3 Sep 2020 16:04:28 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 50BA529B164 From: Gabriel Krisman Bertazi To: viro@zeniv.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, jack@suse.cz, khazhy@google.com, Gabriel Krisman Bertazi , kernel@collabora.com Subject: [PATCH v2 2/3] direct-io: don't force writeback for reads beyond EOF Date: Thu, 3 Sep 2020 16:04:13 -0400 Message-Id: <20200903200414.673105-3-krisman@collabora.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200903200414.673105-1-krisman@collabora.com> References: <20200903200414.673105-1-krisman@collabora.com> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org If a DIO read starts past EOF, the kernel won't attempt it, so we don't need to flush dirty pages before failing the syscall. Suggested-by: Jan Kara Signed-off-by: Gabriel Krisman Bertazi Reviewed-by: Jan Kara --- fs/direct-io.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index 04aae41323d7..43460c8e0f90 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1188,19 +1188,9 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, memset(dio, 0, offsetof(struct dio, pages)); dio->flags = flags; - if (dio->flags & DIO_LOCKING) { - if (iov_iter_rw(iter) == READ) { - struct address_space *mapping = - iocb->ki_filp->f_mapping; - - /* will be released by direct_io_worker */ - inode_lock(inode); - - retval = filemap_write_and_wait_range(mapping, offset, - end - 1); - if (retval) - goto fail_dio; - } + if (dio->flags & DIO_LOCKING && iov_iter_rw(iter) == READ) { + /* will be released by direct_io_worker */ + inode_lock(inode); } /* Once we sampled i_size check for reads beyond EOF */ @@ -1210,6 +1200,14 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, goto fail_dio; } + if (dio->flags & DIO_LOCKING && iov_iter_rw(iter) == READ) { + struct address_space *mapping = iocb->ki_filp->f_mapping; + + retval = filemap_write_and_wait_range(mapping, offset, end - 1); + if (retval) + goto fail_dio; + } + /* * For file extending writes updating i_size before data writeouts * complete can expose uninitialized blocks in dumb filesystems. From patchwork Thu Sep 3 20:04:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 11754647 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E9EB513B1 for ; Thu, 3 Sep 2020 20:04:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF75020897 for ; Thu, 3 Sep 2020 20:04:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729036AbgICUEe (ORCPT ); Thu, 3 Sep 2020 16:04:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728852AbgICUEe (ORCPT ); Thu, 3 Sep 2020 16:04:34 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70B4BC061244 for ; Thu, 3 Sep 2020 13:04:33 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 3403B29B165 From: Gabriel Krisman Bertazi To: viro@zeniv.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, jack@suse.cz, khazhy@google.com, Gabriel Krisman Bertazi , kernel@collabora.com, Jamie Liu Subject: [PATCH v2 3/3] direct-io: defer alignment check until after the EOF check Date: Thu, 3 Sep 2020 16:04:14 -0400 Message-Id: <20200903200414.673105-4-krisman@collabora.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200903200414.673105-1-krisman@collabora.com> References: <20200903200414.673105-1-krisman@collabora.com> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Prior to commit 9fe55eea7e4b ("Fix race when checking i_size on direct i/o read"), an unaligned direct read past end of file would trigger EOF, since generic_file_aio_read detected this read-at-EOF condition and skipped the direct IO read entirely, returning 0. After that change, the read now reaches dio_generic, which detects the misalignment and returns EINVAL. This consolidates the generic direct-io to follow the same behavior of filesystems. Apparently, this fix will only affect ocfs2 since other filesystems do this verification before calling do_blockdev_direct_IO, with the exception of f2fs, which has the same bug, but is fixed in the next patch. it can be verified by a read loop on a file that does a partial read before EOF (On file that doesn't end at an aligned address). The following code fails on an unaligned file on filesystems without prior validation without this patch, but not on btrfs, ext4, and xfs. while (done < total) { ssize_t delta = pread(fd, buf + done, total - done, off + done); if (!delta) break; ... } Fix this regression by moving the misalignment check to after the EOF check added by commit 74cedf9b6c60 ("direct-io: Fix negative return from dio read beyond eof"). Based on a patch by Jamie Liu. Reported-by: Jamie Liu Signed-off-by: Gabriel Krisman Bertazi --- fs/direct-io.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index 43460c8e0f90..01131a1674b8 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1165,14 +1165,6 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, * the early prefetch in the caller enough time. */ - if (align & blocksize_mask) { - if (bdev) - blkbits = blksize_bits(bdev_logical_block_size(bdev)); - blocksize_mask = (1 << blkbits) - 1; - if (align & blocksize_mask) - return -EINVAL; - } - /* watch out for a 0 len io from a tricksy fs */ if (iov_iter_rw(iter) == READ && !count) return 0; @@ -1200,6 +1192,14 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, goto fail_dio; } + if (align & blocksize_mask) { + if (bdev) + blkbits = blksize_bits(bdev_logical_block_size(bdev)); + blocksize_mask = (1 << blkbits) - 1; + if (align & blocksize_mask) + goto fail_dio; + } + if (dio->flags & DIO_LOCKING && iov_iter_rw(iter) == READ) { struct address_space *mapping = iocb->ki_filp->f_mapping;