ovl: add ovl_fadvise()

Implement stacked fadvise to fix syscalls readahead(2) and fadvise64(2)
on an overlayfs file.

Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: d1d04ef857 ("ovl: stack file ops")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Amir Goldstein 2018-08-28 10:58:41 +03:00 committed by Miklos Szeredi
parent 3d8f761531
commit b833a36603

View file

@ -331,6 +331,25 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
return ret;
}
static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
{
struct fd real;
const struct cred *old_cred;
int ret;
ret = ovl_real_fdget(file, &real);
if (ret)
return ret;
old_cred = ovl_override_creds(file_inode(file)->i_sb);
ret = vfs_fadvise(real.file, offset, len, advice);
revert_creds(old_cred);
fdput(real);
return ret;
}
static long ovl_real_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
@ -499,6 +518,7 @@ const struct file_operations ovl_file_operations = {
.fsync = ovl_fsync,
.mmap = ovl_mmap,
.fallocate = ovl_fallocate,
.fadvise = ovl_fadvise,
.unlocked_ioctl = ovl_ioctl,
.compat_ioctl = ovl_compat_ioctl,