[PATCH 6.9 009/374] f2fs: fix to wait on page writeback in __clone_blkaddrs()

Greg Kroah-Hartman
2024-06-06T14:08:29Z

From: Chao Yu <chao@kernel.org>

[ Upstream commit d3876e34e7e789e2cbdd782360fef2a777391082 ]

In below race condition, dst page may become writeback status
in __clone_blkaddrs(), it needs to wait writeback before update,
fix it.

Thread A GC Thread
- f2fs_move_file_range
- filemap_write_and_wait_range(dst)
- gc_data_segment
- f2fs_down_write(dst)
- move_data_page
- set_page_writeback(dst_page)
- f2fs_submit_page_write
- f2fs_up_write(dst)
- f2fs_down_write(dst)
- __exchange_data_block
- __clone_blkaddrs
- f2fs_get_new_data_page
- memcpy_page

Fixes: 0a2aa8fbb969 ("f2fs: refactor __exchange_data_block for speed up")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/file.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 1761ad125f97a..06e3a69b45dc7 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1325,6 +1325,9 @@ static int __clone_blkaddrs(struct inode *src_inode, struct inode *dst_inode,
f2fs_put_page(psrc, 1);
return PTR_ERR(pdst);
}
+
+ f2fs_wait_on_page_writeback(pdst, DATA, true, true);
+
memcpy_page(pdst, 0, psrc, 0, PAGE_SIZE);
set_page_dirty(pdst);
set_page_private_gcing(pdst);
--
2.43.0