From: Damien Le Moal <damien.lemoal@wdc.com>
To: linux-f2fs-devel@lists.sourceforge.net,
linux-kernel@vger.kernel.org, Jaegeuk Kim <jaegeuk@kernel.org>,
Chao Yu <yuchao0@huawei.com>
Cc: linux-fsdevel@vger.kernel.org,
Javier Gonzalez <javier@javigon.com>,
Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Subject: [PATCH] f2fs: Fix direct IO handling
Date: Tue, 26 Nov 2019 16:57:19 +0900 [thread overview]
Message-ID: <20191126075719.1046485-1-damien.lemoal@wdc.com> (raw)
f2fs_preallocate_blocks() identifies direct IOs using the IOCB_DIRECT
flag for a kiocb structure. However, the file system direct IO handler
function f2fs_direct_IO() may have decided that a direct IO has to be
exececuted as a buffered IO using the function f2fs_force_buffered_io().
This is the case for instance for volumes including zoned block device
and for unaligned write IOs with LFS mode enabled.
These 2 different methods of identifying direct IOs can result in
inconsistencies generating stale data access for direct reads after a
direct IO write that is treated as a buffered write. Fix this
inconsistency by combining the IOCB_DIRECT flag test with the result
of f2fs_force_buffered_io().
Reported-by: Javier Gonzalez <javier@javigon.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
fs/f2fs/data.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 5755e897a5f0..8ac2d3b70022 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1073,6 +1073,8 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
int flag;
int err = 0;
bool direct_io = iocb->ki_flags & IOCB_DIRECT;
+ bool do_direct_io = direct_io &&
+ !f2fs_force_buffered_io(inode, iocb, from);
/* convert inline data for Direct I/O*/
if (direct_io) {
@@ -1081,7 +1083,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
return err;
}
- if (direct_io && allow_outplace_dio(inode, iocb, from))
+ if (do_direct_io && allow_outplace_dio(inode, iocb, from))
return 0;
if (is_inode_flag_set(inode, FI_NO_PREALLOC))
--
2.23.0
next reply other threads:[~2019-11-26 7:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-26 7:57 Damien Le Moal [this message]
2019-11-26 8:34 ` [PATCH] f2fs: Fix direct IO handling Ritesh Harjani
2019-11-28 2:10 ` Damien Le Moal
2019-11-28 10:20 ` Ritesh Harjani
2019-11-30 7:27 ` Chao Yu
2019-11-30 7:19 ` Chao Yu
2019-11-26 16:33 ` Christoph Hellwig
2019-11-26 23:44 ` Jaegeuk Kim
2019-11-28 2:34 ` Shinichiro Kawasaki
2019-11-29 3:35 ` Javier Gonzalez
2019-11-30 6:43 ` Chao Yu
2019-12-03 17:33 ` [PATCH v2] " Jaegeuk Kim
2019-12-04 1:27 ` Chao Yu
2019-12-04 4:01 ` Shinichiro Kawasaki
2019-12-04 8:16 ` Javier Gonzalez
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