lkml.org 
[lkml]   [2018]   [Aug]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.9 035/144] f2fs: fix race in between GC and atomic open
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit 27319ba4044c0c67d62ae39e53c0118c89f0a029 ]

Thread GC thread
- f2fs_ioc_start_atomic_write
- get_dirty_pages
- filemap_write_and_wait_range
- f2fs_gc
- do_garbage_collect
- gc_data_segment
- move_data_page
- f2fs_is_atomic_file
- set_page_dirty
- set_inode_flag(, FI_ATOMIC_FILE)

Dirty data page can still be generated by GC in race condition as
above call stack.

This patch adds fi->dio_rwsem[WRITE] in f2fs_ioc_start_atomic_write
to avoid such race.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/f2fs/file.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1512,6 +1512,8 @@ static int f2fs_ioc_start_atomic_write(s

inode_lock(inode);

+ down_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
+
if (f2fs_is_atomic_file(inode))
goto out;

@@ -1532,6 +1534,7 @@ static int f2fs_ioc_start_atomic_write(s
if (ret)
clear_inode_flag(inode, FI_ATOMIC_FILE);
out:
+ up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
inode_unlock(inode);
mnt_drop_write_file(filp);
return ret;

\
 
 \ /
  Last update: 2018-08-01 19:46    [W:0.689 / U:0.304 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site