[PATCH AUTOSEL 5.9 014/147] f2fs: compress: fix to disallow enabling compress on non-empty file

Sasha Levin
2020-10-26T23:49:59Z

From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit 519a5a2f37b850f4eb86674a10d143088670a390 ]

Compressed inode and normal inode has different layout, so we should
disallow enabling compress on non-empty file to avoid race condition
during inode .i_addr array parsing and updating.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: Fix missing condition]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/file.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 8a422400e824d..4ec10256dc67f 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1836,6 +1836,8 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
if (iflags & F2FS_COMPR_FL) {
if (!f2fs_may_compress(inode))
return -EINVAL;
+ if (S_ISREG(inode->i_mode) && inode->i_size)
+ return -EINVAL;

set_compress_context(inode);
}
--
2.25.1