[PATCH 6.18.y 2/4] f2fs: reject setattr size changes on large folio files

[Sasha Levin <sashal@kernel.org>]

From: Wenjie Qi <qwjhust@gmail.com>

[ Upstream commit 242d30bfc0a84b8b5de0a88821b53c9ad7fd31c4 ]

F2FS large folios are only enabled for immutable non-compressed files.
Writable open and writable mmap reject such mappings, but truncate(2)
through f2fs_setattr() misses the same guard.

If FS_IMMUTABLE_FL is cleared while the inode is still cached, the mapping
can keep large-folio support and ATTR_SIZE can change i_size. Reject size
changes in that state.

Cc: stable@kernel.org
Fixes: 05e65c14ea59 ("f2fs: support large folio for immutable non-compressed case")
Signed-off-by: Wenjie Qi <qiwenjie@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable-dep-of: 2b8704b6a8b2 ("f2fs: fix to reset all pinned status during fggc")
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 47b94e57cc7f2..c9550bbf6b795 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1136,6 +1136,8 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		return -EPERM;
 
 	if ((attr->ia_valid & ATTR_SIZE)) {
+		if (mapping_large_folio_support(inode->i_mapping))
+			return -EOPNOTSUPP;
 		if (!f2fs_is_compress_backend_ready(inode) ||
 				IS_DEVICE_ALIASING(inode))
 			return -EOPNOTSUPP;
-- 
2.53.0