4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Miklos Szeredi <mszeredi@xxxxxxxxxx>
[ Upstream commit a6795a585929d94ca3e931bc8518f8deb8bbe627 ]
The underlying real file used by overlayfs still contains the overlay path.
This results in mnt_want_write_file() calls by the filesystem getting
freeze protection on the wrong inode (the overlayfs one instead of the real
one).
Fix by using file_inode(file)->i_sb instead of file->f_path.mnt->mnt_sb.
Reported-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/namespace.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -446,10 +446,10 @@ int mnt_want_write_file_path(struct file
{
int ret;
- sb_start_write(file->f_path.mnt->mnt_sb);
+ sb_start_write(file_inode(file)->i_sb);
ret = __mnt_want_write_file(file);
if (ret)
- sb_end_write(file->f_path.mnt->mnt_sb);
+ sb_end_write(file_inode(file)->i_sb);
return ret;
}
@@ -540,7 +540,8 @@ void __mnt_drop_write_file(struct file *
void mnt_drop_write_file_path(struct file *file)
{
- mnt_drop_write(file->f_path.mnt);
+ __mnt_drop_write_file(file);
+ sb_end_write(file_inode(file)->i_sb);
}
void mnt_drop_write_file(struct file *file)
