ovl: add ovl_fadvise() (b833a366) · Commits · 戴 / test

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

Miklos Szeredi <mszeredi@redhat.com> Fixes: ("ovl: stack file ops") Signed-off-by:

fs/overlayfs/file.c

+20 −0

Original line number	Diff line number	Diff line
		@@ -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,