[PATCH 6.6 153/396] f2fs: truncate page cache before clearing flags when aborting atomic write

Greg Kroah-Hartman
2024-04-01T16:44:43Z

From: Sunmin Jeong <s_min.jeong@samsung.com>

[ Upstream commit 74b0ebcbdde4c7fe23c979e4cfc2fdbf349c39a3 ]

In f2fs_do_write_data_page, FI_ATOMIC_FILE flag selects the target inode
between the original inode and COW inode. When aborting atomic write and
writeback occur simultaneously, invalid data can be written to original
inode if the FI_ATOMIC_FILE flag is cleared meanwhile.

To prevent the problem, let's truncate all pages before clearing the flag

Atomic write thread Writeback thread
f2fs_abort_atomic_write
clear_inode_flag(inode, FI_ATOMIC_FILE)
__writeback_single_inode
do_writepages
f2fs_do_write_data_page
- use dn of original inode
truncate_inode_pages_final

Fixes: 3db1de0e582c ("f2fs: change the current atomic write way")
Cc: stable@vger.kernel.org #v5.19+
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Yeongjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/segment.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 0edd9feff6185..4549964819731 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -192,6 +192,9 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean)
if (!f2fs_is_atomic_file(inode))
return;

+ if (clean)
+ truncate_inode_pages_final(inode->i_mapping);
+
release_atomic_write_cnt(inode);
clear_inode_flag(inode, FI_ATOMIC_COMMITTED);
clear_inode_flag(inode, FI_ATOMIC_REPLACE);
@@ -201,7 +204,6 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean)
F2FS_I(inode)->atomic_write_task = NULL;

if (clean) {
- truncate_inode_pages_final(inode->i_mapping);
f2fs_i_size_write(inode, fi->original_i_size);
fi->original_i_size = 0;
}
--
2.43.0