Currently only mmap does not behave as stacked file operation,
although in practice there is less change to open a file in
RDONLY mode and take long time to do mmap but the fix looks
reasonable.
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
---
Hi Miklos,
I'm sorry that I did a mistake about signed-off-by tag in previous
email, so I resend this patch.
fs/overlayfs/file.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 3582c3ae819c..f98b1c0c975b 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -461,6 +461,7 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
{
struct file *realfile = file->private_data;
const struct cred *old_cred;
+ struct fd real;
int ret;
if (!realfile->f_op->mmap)
@@ -469,7 +470,11 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
if (WARN_ON(file != vma->vm_file))
return -EIO;
- vma->vm_file = get_file(realfile);
+ ret = ovl_real_fdget(file, &real);
+ if (ret)
+ return ret;
+
+ vma->vm_file = get_file(real.file);
old_cred = ovl_override_creds(file_inode(file)->i_sb);
ret = call_mmap(vma->vm_file, vma);
@@ -477,13 +482,14 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
if (ret) {
/* Drop reference count from new vm_file value */
- fput(realfile);
+ fput(real.file);
} else {
/* Drop reference count from previous vm_file value */
fput(file);
}
ovl_file_accessed(file);
+ fdput(real);
return ret;
}
--
2.26.2
