Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 666 insertions, 0 deletions

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
new file mode 100644
index 000000000..f3d97eb14
--- /dev/null
+++ b/fs/overlayfs/file.c
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017 Red Hat, Inc.
+ */
+
+#include <linux/cred.h>
+#include <linux/file.h>
+#include <linux/filelock.h>
+#include <linux/mount.h>
+#include <linux/xattr.h>
+#include <linux/uio.h>
+#include <linux/uaccess.h>
+#include <linux/security.h>
+#include <linux/fs.h>
+#include <linux/backing-file.h>
+#include "overlayfs.h"
+
+static char ovl_whatisit(struct inode *inode, struct inode *realinode)
+{
+	if (realinode != ovl_inode_upper(inode))
+		return 'l';
+	if (ovl_has_upperdata(inode))
+		return 'u';
+	else
+		return 'm';
+}
+
+static struct file *ovl_open_realfile(const struct file *file,
+				      const struct path *realpath)
+{
+	struct inode *realinode = d_inode(realpath->dentry);
+	struct inode *inode = file_inode(file);
+	struct mnt_idmap *real_idmap;
+	struct file *realfile;
+	int flags = file->f_flags | OVL_OPEN_FLAGS;
+	int acc_mode = ACC_MODE(flags);
+	int err;
+
+	if (flags & O_APPEND)
+		acc_mode |= MAY_APPEND;
+
+	with_ovl_creds(inode->i_sb) {
+		real_idmap = mnt_idmap(realpath->mnt);
+		err = inode_permission(real_idmap, realinode, MAY_OPEN | acc_mode);
+		if (err) {
+			realfile = ERR_PTR(err);
+		} else {
+			if (!inode_owner_or_capable(real_idmap, realinode))
+				flags &= ~O_NOATIME;
+
+			realfile = backing_file_open(file,
+						     flags, realpath, current_cred());
+		}
+	}
+
+	pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n",
+		 file, file, ovl_whatisit(inode, realinode), file->f_flags,
+		 realfile, IS_ERR(realfile) ? 0 : realfile->f_flags);
+
+	return realfile;
+}
+
+#define OVL_SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT)
+
+static int ovl_change_flags(struct file *file, unsigned int flags)
+{
+	struct inode *inode = file_inode(file);
+	int err;
+
+	flags &= OVL_SETFL_MASK;
+
+	if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode))
+		return -EPERM;
+
+	if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT))
+		return -EINVAL;
+
+	if (file->f_op->check_flags) {
+		err = file->f_op->check_flags(flags);
+		if (err)
+			return err;
+	}
+
+	spin_lock(&file->f_lock);
+	file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags;
+	file->f_iocb_flags = iocb_flags(file);
+	spin_unlock(&file->f_lock);
+
+	return 0;
+}
+
+struct ovl_file {
+	struct file *realfile;
+	struct file *upperfile;
+};
+
+struct ovl_file *ovl_file_alloc(struct file *realfile)
+{
+	struct ovl_file *of = kzalloc_obj(struct ovl_file);
+
+	if (unlikely(!of))
+		return NULL;
+
+	of->realfile = realfile;
+	return of;
+}
+
+void ovl_file_free(struct ovl_file *of)
+{
+	fput(of->realfile);
+	if (of->upperfile)
+		fput(of->upperfile);
+	kfree(of);
+}
+
+static bool ovl_is_real_file(const struct file *realfile,
+			     const struct path *realpath)
+{
+	return file_inode(realfile) == d_inode(realpath->dentry);
+}
+
+static struct file *ovl_real_file_path(const struct file *file,
+				       const struct path *realpath)
+{
+	struct ovl_file *of = file->private_data;
+	struct file *realfile = of->realfile;
+
+	if (WARN_ON_ONCE(!realpath->dentry))
+		return ERR_PTR(-EIO);
+
+	/*
+	 * If the realfile that we want is not where the data used to be at
+	 * open time, either we'd been copied up, or it's an fsync of a
+	 * metacopied file.  We need the upperfile either way, so see if it
+	 * is already opened and if it is not then open and store it.
+	 */
+	if (unlikely(!ovl_is_real_file(realfile, realpath))) {
+		struct file *upperfile = READ_ONCE(of->upperfile);
+		struct file *old;
+
+		if (!upperfile) { /* Nobody opened upperfile yet */
+			upperfile = ovl_open_realfile(file, realpath);
+			if (IS_ERR(upperfile))
+				return upperfile;
+
+			/* Store the upperfile for later */
+			old = cmpxchg_release(&of->upperfile, NULL, upperfile);
+			if (old) { /* Someone opened upperfile before us */
+				fput(upperfile);
+				upperfile = old;
+			}
+		}
+		/*
+		 * Stored file must be from the right inode, unless someone's
+		 * been corrupting the upper layer.
+		 */
+		if (WARN_ON_ONCE(!ovl_is_real_file(upperfile, realpath)))
+			return ERR_PTR(-EIO);
+
+		realfile = upperfile;
+	}
+
+	/* Did the flags change since open? */
+	if (unlikely((file->f_flags ^ realfile->f_flags) & ~OVL_OPEN_FLAGS)) {
+		int err = ovl_change_flags(realfile, file->f_flags);
+
+		if (err)
+			return ERR_PTR(err);
+	}
+
+	return realfile;
+}
+
+static struct file *ovl_real_file(const struct file *file)
+{
+	struct dentry *dentry = file_dentry(file);
+	struct path realpath;
+	int err;
+
+	if (d_is_dir(dentry)) {
+		struct file *f = ovl_dir_real_file(file, false);
+
+		if (WARN_ON_ONCE(!f))
+			return ERR_PTR(-EIO);
+		return f;
+	}
+
+	/* lazy lookup and verify of lowerdata */
+	err = ovl_verify_lowerdata(dentry);
+	if (err)
+		return ERR_PTR(err);
+
+	ovl_path_realdata(dentry, &realpath);
+
+	return ovl_real_file_path(file, &realpath);
+}
+
+static int ovl_open(struct inode *inode, struct file *file)
+{
+	struct dentry *dentry = file_dentry(file);
+	struct file *realfile;
+	struct path realpath;
+	struct ovl_file *of;
+	int err;
+
+	/* lazy lookup and verify lowerdata */
+	err = ovl_verify_lowerdata(dentry);
+	if (err)
+		return err;
+
+	err = ovl_maybe_copy_up(dentry, file->f_flags);
+	if (err)
+		return err;
+
+	/* No longer need these flags, so don't pass them on to underlying fs */
+	file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
+
+	ovl_path_realdata(dentry, &realpath);
+	if (!realpath.dentry)
+		return -EIO;
+
+	realfile = ovl_open_realfile(file, &realpath);
+	if (IS_ERR(realfile))
+		return PTR_ERR(realfile);
+
+	of = ovl_file_alloc(realfile);
+	if (!of) {
+		fput(realfile);
+		return -ENOMEM;
+	}
+
+	file->private_data = of;
+
+	return 0;
+}
+
+static int ovl_release(struct inode *inode, struct file *file)
+{
+	ovl_file_free(file->private_data);
+	return 0;
+}
+
+static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct inode *inode = file_inode(file);
+	struct file *realfile;
+	loff_t ret;
+
+	/*
+	 * The two special cases below do not need to involve real fs,
+	 * so we can optimizing concurrent callers.
+	 */
+	if (offset == 0) {
+		if (whence == SEEK_CUR)
+			return file->f_pos;
+
+		if (whence == SEEK_SET)
+			return vfs_setpos(file, 0, 0);
+	}
+
+	realfile = ovl_real_file(file);
+	if (IS_ERR(realfile))
+		return PTR_ERR(realfile);
+
+	/*
+	 * Overlay file f_pos is the master copy that is preserved
+	 * through copy up and modified on read/write, but only real
+	 * fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose
+	 * limitations that are more strict than ->s_maxbytes for specific
+	 * files, so we use the real file to perform seeks.
+	 */
+	ovl_inode_lock(inode);
+	realfile->f_pos = file->f_pos;
+
+	with_ovl_creds(inode->i_sb)
+		ret = vfs_llseek(realfile, offset, whence);
+
+	file->f_pos = realfile->f_pos;
+	ovl_inode_unlock(inode);
+
+	return ret;
+}
+
+static void ovl_file_modified(struct file *file)
+{
+	/* Update size/mtime */
+	ovl_copyattr(file_inode(file));
+}
+
+static void ovl_file_end_write(struct kiocb *iocb, ssize_t ret)
+{
+	ovl_file_modified(iocb->ki_filp);
+}
+
+static void ovl_file_accessed(struct file *file)
+{
+	struct inode *inode, *upperinode;
+	struct timespec64 ctime, uctime;
+	struct timespec64 mtime, umtime;
+
+	if (file->f_flags & O_NOATIME)
+		return;
+
+	inode = file_inode(file);
+	upperinode = ovl_inode_upper(inode);
+
+	if (!upperinode)
+		return;
+
+	ctime = inode_get_ctime(inode);
+	uctime = inode_get_ctime(upperinode);
+	mtime = inode_get_mtime(inode);
+	umtime = inode_get_mtime(upperinode);
+	if ((!timespec64_equal(&mtime, &umtime)) ||
+	     !timespec64_equal(&ctime, &uctime)) {
+		inode_set_mtime_to_ts(inode, inode_get_mtime(upperinode));
+		inode_set_ctime_to_ts(inode, uctime);
+	}
+
+	touch_atime(&file->f_path);
+}
+
+static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct file *file = iocb->ki_filp;
+	struct file *realfile;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(file_inode(file)->i_sb),
+		.accessed = ovl_file_accessed,
+	};
+
+	if (!iov_iter_count(iter))
+		return 0;
+
+	realfile = ovl_real_file(file);
+	if (IS_ERR(realfile))
+		return PTR_ERR(realfile);
+
+	return backing_file_read_iter(realfile, iter, iocb, iocb->ki_flags,
+				      &ctx);
+}
+
+static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	struct file *realfile;
+	ssize_t ret;
+	int ifl = iocb->ki_flags;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(inode->i_sb),
+		.end_write = ovl_file_end_write,
+	};
+
+	if (!iov_iter_count(iter))
+		return 0;
+
+	inode_lock(inode);
+	/* Update mode */
+	ovl_copyattr(inode);
+
+	realfile = ovl_real_file(file);
+	ret = PTR_ERR(realfile);
+	if (IS_ERR(realfile))
+		goto out_unlock;
+
+	if (!ovl_should_sync(OVL_FS(inode->i_sb)))
+		ifl &= ~(IOCB_DSYNC | IOCB_SYNC);
+
+	ret = backing_file_write_iter(realfile, iter, iocb, ifl, &ctx);
+
+out_unlock:
+	inode_unlock(inode);
+
+	return ret;
+}
+
+static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,
+			       struct pipe_inode_info *pipe, size_t len,
+			       unsigned int flags)
+{
+	struct file *realfile;
+	ssize_t ret;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(file_inode(in)->i_sb),
+		.accessed = ovl_file_accessed,
+	};
+	struct kiocb iocb;
+
+	realfile = ovl_real_file(in);
+	if (IS_ERR(realfile))
+		return PTR_ERR(realfile);
+
+	init_sync_kiocb(&iocb, in);
+	iocb.ki_pos = *ppos;
+	ret = backing_file_splice_read(realfile, &iocb, pipe, len, flags, &ctx);
+	*ppos = iocb.ki_pos;
+
+	return ret;
+}
+
+/*
+ * Calling iter_file_splice_write() directly from overlay's f_op may deadlock
+ * due to lock order inversion between pipe->mutex in iter_file_splice_write()
+ * and file_start_write(realfile) in ovl_write_iter().
+ *
+ * So do everything ovl_write_iter() does and call iter_file_splice_write() on
+ * the real file.
+ */
+static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
+				loff_t *ppos, size_t len, unsigned int flags)
+{
+	struct file *realfile;
+	struct inode *inode = file_inode(out);
+	ssize_t ret;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(inode->i_sb),
+		.end_write = ovl_file_end_write,
+	};
+	struct kiocb iocb;
+
+	inode_lock(inode);
+	/* Update mode */
+	ovl_copyattr(inode);
+
+	realfile = ovl_real_file(out);
+	ret = PTR_ERR(realfile);
+	if (IS_ERR(realfile))
+		goto out_unlock;
+
+	init_sync_kiocb(&iocb, out);
+	iocb.ki_pos = *ppos;
+	ret = backing_file_splice_write(pipe, realfile, &iocb, len, flags, &ctx);
+	*ppos = iocb.ki_pos;
+
+out_unlock:
+	inode_unlock(inode);
+
+	return ret;
+}
+
+static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	struct dentry *dentry = file_dentry(file);
+	enum ovl_path_type type;
+	struct path upperpath;
+	struct file *upperfile;
+	int ret;
+
+	ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));
+	if (ret <= 0)
+		return ret;
+
+	/* Don't sync lower file for fear of receiving EROFS error */
+	type = ovl_path_type(dentry);
+	if (!OVL_TYPE_UPPER(type) || (datasync && OVL_TYPE_MERGE(type)))
+		return 0;
+
+	ovl_path_upper(dentry, &upperpath);
+	upperfile = ovl_real_file_path(file, &upperpath);
+	if (IS_ERR(upperfile))
+		return PTR_ERR(upperfile);
+
+	with_ovl_creds(file_inode(file)->i_sb)
+		return vfs_fsync_range(upperfile, start, end, datasync);
+}
+
+static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct ovl_file *of = file->private_data;
+	struct backing_file_ctx ctx = {
+		.cred = ovl_creds(file_inode(file)->i_sb),
+		.accessed = ovl_file_accessed,
+	};
+
+	return backing_file_mmap(of->realfile, vma, &ctx);
+}
+
+static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(file);
+	struct file *realfile;
+	int ret;
+
+	inode_lock(inode);
+	/* Update mode */
+	ovl_copyattr(inode);
+	ret = file_remove_privs(file);
+	if (ret)
+		goto out_unlock;
+
+	realfile = ovl_real_file(file);
+	ret = PTR_ERR(realfile);
+	if (IS_ERR(realfile))
+		goto out_unlock;
+
+	with_ovl_creds(inode->i_sb)
+		ret = vfs_fallocate(realfile, mode, offset, len);
+
+	/* Update size */
+	ovl_file_modified(file);
+
+out_unlock:
+	inode_unlock(inode);
+
+	return ret;
+}
+
+static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
+{
+	struct file *realfile;
+
+	realfile = ovl_real_file(file);
+	if (IS_ERR(realfile))
+		return PTR_ERR(realfile);
+
+	with_ovl_creds(file_inode(file)->i_sb)
+		return vfs_fadvise(realfile, offset, len, advice);
+}
+
+enum ovl_copyop {
+	OVL_COPY,
+	OVL_CLONE,
+	OVL_DEDUPE,
+};
+
+static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
+			    struct file *file_out, loff_t pos_out,
+			    loff_t len, unsigned int flags, enum ovl_copyop op)
+{
+	struct inode *inode_in = file_inode(file_in);
+	struct inode *inode_out = file_inode(file_out);
+	struct file *realfile_in, *realfile_out;
+	loff_t ret;
+
+	inode_lock(inode_out);
+	if (op != OVL_DEDUPE) {
+		/* Update mode */
+		ovl_copyattr(inode_out);
+		ret = file_remove_privs(file_out);
+		if (ret)
+			goto out_unlock;
+	}
+
+	realfile_out = ovl_real_file(file_out);
+	ret = PTR_ERR(realfile_out);
+	if (IS_ERR(realfile_out))
+		goto out_unlock;
+
+	realfile_in = ovl_real_file(file_in);
+	ret = PTR_ERR(realfile_in);
+	if (IS_ERR(realfile_in))
+		goto out_unlock;
+
+	/*
+	 * For cross-sb copy, vfs_copy_file_range() will verify read access with
+	 * the mounter creds of the dest fs mounter, so we need to explicitly
+	 * verify read access with the source mounter creds.
+	 */
+	if (unlikely(inode_in->i_sb != inode_out->i_sb)) {
+		with_ovl_creds(inode_in->i_sb) {
+			ret = rw_verify_area(READ, realfile_in, &pos_in, len);
+			if (unlikely(ret))
+				goto out_unlock;
+		}
+	}
+
+	with_ovl_creds(inode_out->i_sb) {
+		switch (op) {
+		case OVL_COPY:
+			ret = vfs_copy_file_range(realfile_in, pos_in,
+						  realfile_out, pos_out, len, flags);
+			break;
+
+		case OVL_CLONE:
+			ret = vfs_clone_file_range(realfile_in, pos_in,
+						   realfile_out, pos_out, len, flags);
+			break;
+
+		case OVL_DEDUPE:
+			ret = vfs_dedupe_file_range_one(realfile_in, pos_in,
+							realfile_out, pos_out, len,
+							flags);
+			break;
+		}
+	}
+
+	/* Update size */
+	ovl_file_modified(file_out);
+
+out_unlock:
+	inode_unlock(inode_out);
+
+	return ret;
+}
+
+static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
+				   struct file *file_out, loff_t pos_out,
+				   size_t len, unsigned int flags)
+{
+	return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
+			    OVL_COPY);
+}
+
+static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in,
+				   struct file *file_out, loff_t pos_out,
+				   loff_t len, unsigned int remap_flags)
+{
+	enum ovl_copyop op;
+
+	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
+		return -EINVAL;
+
+	if (remap_flags & REMAP_FILE_DEDUP)
+		op = OVL_DEDUPE;
+	else
+		op = OVL_CLONE;
+
+	/*
+	 * Don't copy up because of a dedupe request, this wouldn't make sense
+	 * most of the time (data would be duplicated instead of deduplicated).
+	 */
+	if (op == OVL_DEDUPE &&
+	    (!ovl_inode_upper(file_inode(file_in)) ||
+	     !ovl_inode_upper(file_inode(file_out))))
+		return -EPERM;
+
+	return ovl_copyfile(file_in, pos_in, file_out, pos_out, len,
+			    remap_flags, op);
+}
+
+static int ovl_flush(struct file *file, fl_owner_t id)
+{
+	struct file *realfile;
+	int err = 0;
+
+	realfile = ovl_real_file(file);
+	if (IS_ERR(realfile))
+		return PTR_ERR(realfile);
+
+	if (realfile->f_op->flush) {
+		with_ovl_creds(file_inode(file)->i_sb)
+			err = realfile->f_op->flush(realfile, id);
+	}
+
+	return err;
+}
+
+const struct file_operations ovl_file_operations = {
+	.open		= ovl_open,
+	.release	= ovl_release,
+	.llseek		= ovl_llseek,
+	.read_iter	= ovl_read_iter,
+	.write_iter	= ovl_write_iter,
+	.fsync		= ovl_fsync,
+	.mmap		= ovl_mmap,
+	.fallocate	= ovl_fallocate,
+	.fadvise	= ovl_fadvise,
+	.flush		= ovl_flush,
+	.splice_read    = ovl_splice_read,
+	.splice_write   = ovl_splice_write,
+
+	.copy_file_range	= ovl_copy_file_range,
+	.remap_file_range	= ovl_remap_file_range,
+	.setlease		= generic_setlease,
+};