4.18-stable review patch. If anyone has any objections, please let me know.
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From: Miklos Szeredi mszeredi@redhat.com
[ 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@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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)