From:   Qinghua Jin <qhjin.dev@gmail.com>
To:     christian.brauner@ubuntu.com
Cc:     qhjin_dev@163.com, Qinghua Jin <qhjin.dev@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jan Kara <jack@suse.cz>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH] minix: fix bug when opening a file with O_DIRECT will
Date:   Thu,  6 Jan 2022 11:30:41 +0800
Message-Id: <20220106033042.347301-1-qhjin.dev@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Testcase:
1. create a minix file system and mount it
2. open a file on the file system with O_RDWR|O_CREAT|O_TRUNC|O_DIRECT
3. open fails with -EINVAL but leaves an empty file behind. All other
open() failures don't leave the failed open files behind.

It is hard to check the direct_IO op before creating the inode. Just as
ext4 and btrfs do, this patch will resolve the issue by allowing to 
create the file with O_DIRECT but returning error when writing the file.

Signed-off-by: Qinghua Jin <qhjin.dev@gmail.com>
---
 fs/minix/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index a71f1cf894b9..d4bd94234ef7 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -447,7 +447,8 @@ static const struct address_space_operations minix_aops = {
 	.writepage = minix_writepage,
 	.write_begin = minix_write_begin,
 	.write_end = generic_write_end,
-	.bmap = minix_bmap
+	.bmap = minix_bmap,
+	.direct_IO = noop_direct_IO
 };
 
 static const struct inode_operations minix_symlink_inode_operations = {
-- 
2.30.2