2019-06-04 08:11:33 +00:00
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// SPDX-License-Identifier: GPL-2.0-only
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2018-07-18 13:44:41 +00:00
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/*
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* Copyright (C) 2017 Red Hat, Inc.
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*/
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#include <linux/cred.h>
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#include <linux/file.h>
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2018-07-18 13:44:42 +00:00
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#include <linux/mount.h>
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2018-07-18 13:44:41 +00:00
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#include <linux/xattr.h>
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2018-07-18 13:44:41 +00:00
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#include <linux/uio.h>
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2019-05-06 07:41:02 +00:00
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#include <linux/uaccess.h>
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2020-01-17 12:49:29 +00:00
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#include <linux/splice.h>
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2020-06-02 20:20:26 +00:00
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#include <linux/security.h>
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2020-01-17 12:49:29 +00:00
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#include <linux/mm.h>
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#include <linux/fs.h>
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2018-07-18 13:44:41 +00:00
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#include "overlayfs.h"
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2019-11-20 09:45:26 +00:00
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struct ovl_aio_req {
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struct kiocb iocb;
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2021-09-30 03:22:28 +00:00
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refcount_t ref;
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2019-11-20 09:45:26 +00:00
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struct kiocb *orig_iocb;
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struct fd fd;
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};
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static struct kmem_cache *ovl_aio_request_cachep;
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2018-05-11 15:49:31 +00:00
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static char ovl_whatisit(struct inode *inode, struct inode *realinode)
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{
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if (realinode != ovl_inode_upper(inode))
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return 'l';
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if (ovl_has_upperdata(inode))
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return 'u';
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else
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return 'm';
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}
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2020-06-18 15:43:53 +00:00
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/* No atime modificaton nor notify on underlying */
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#define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY)
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2018-05-11 15:49:31 +00:00
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static struct file *ovl_open_realfile(const struct file *file,
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struct inode *realinode)
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2018-07-18 13:44:41 +00:00
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{
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struct inode *inode = file_inode(file);
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struct file *realfile;
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const struct cred *old_cred;
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2020-06-18 15:43:53 +00:00
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int flags = file->f_flags | OVL_OPEN_FLAGS;
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2020-06-02 20:20:26 +00:00
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int acc_mode = ACC_MODE(flags);
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int err;
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if (flags & O_APPEND)
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acc_mode |= MAY_APPEND;
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2018-07-18 13:44:41 +00:00
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old_cred = ovl_override_creds(inode->i_sb);
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2020-06-02 20:20:26 +00:00
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err = inode_permission(realinode, MAY_OPEN | acc_mode);
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if (err) {
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realfile = ERR_PTR(err);
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} else if (!inode_owner_or_capable(realinode)) {
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realfile = ERR_PTR(-EPERM);
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} else {
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realfile = open_with_fake_path(&file->f_path, flags, realinode,
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current_cred());
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}
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2018-07-18 13:44:41 +00:00
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revert_creds(old_cred);
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pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n",
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2018-05-11 15:49:31 +00:00
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file, file, ovl_whatisit(inode, realinode), file->f_flags,
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2018-07-18 13:44:41 +00:00
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realfile, IS_ERR(realfile) ? 0 : realfile->f_flags);
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return realfile;
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}
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2018-07-18 13:44:41 +00:00
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#define OVL_SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT)
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static int ovl_change_flags(struct file *file, unsigned int flags)
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{
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struct inode *inode = file_inode(file);
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int err;
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2020-06-18 15:43:53 +00:00
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flags |= OVL_OPEN_FLAGS;
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2018-07-18 13:44:41 +00:00
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/* If some flag changed that cannot be changed then something's amiss */
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if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK))
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return -EIO;
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flags &= OVL_SETFL_MASK;
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if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode))
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return -EPERM;
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if (flags & O_DIRECT) {
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if (!file->f_mapping->a_ops ||
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!file->f_mapping->a_ops->direct_IO)
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return -EINVAL;
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}
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if (file->f_op->check_flags) {
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err = file->f_op->check_flags(flags);
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if (err)
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return err;
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}
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spin_lock(&file->f_lock);
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file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags;
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spin_unlock(&file->f_lock);
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return 0;
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}
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2018-05-11 15:49:31 +00:00
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static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
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bool allow_meta)
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2018-07-18 13:44:41 +00:00
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{
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struct inode *inode = file_inode(file);
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2018-05-11 15:49:31 +00:00
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struct inode *realinode;
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2018-07-18 13:44:41 +00:00
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real->flags = 0;
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real->file = file->private_data;
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2018-05-11 15:49:31 +00:00
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if (allow_meta)
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realinode = ovl_inode_real(inode);
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else
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realinode = ovl_inode_realdata(inode);
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2018-07-18 13:44:41 +00:00
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/* Has it been copied up since we'd opened it? */
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2018-05-11 15:49:31 +00:00
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if (unlikely(file_inode(real->file) != realinode)) {
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2018-07-18 13:44:41 +00:00
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real->flags = FDPUT_FPUT;
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2018-05-11 15:49:31 +00:00
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real->file = ovl_open_realfile(file, realinode);
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2018-07-18 13:44:41 +00:00
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return PTR_ERR_OR_ZERO(real->file);
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}
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/* Did the flags change since open? */
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2020-06-18 15:43:53 +00:00
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if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS))
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2018-07-18 13:44:41 +00:00
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return ovl_change_flags(real->file, file->f_flags);
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return 0;
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}
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2018-05-11 15:49:31 +00:00
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static int ovl_real_fdget(const struct file *file, struct fd *real)
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{
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2020-09-29 07:28:47 +00:00
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if (d_is_dir(file_dentry(file))) {
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real->flags = 0;
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real->file = ovl_dir_real_file(file, false);
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return PTR_ERR_OR_ZERO(real->file);
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}
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2018-05-11 15:49:31 +00:00
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return ovl_real_fdget_meta(file, real, false);
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}
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2018-07-18 13:44:41 +00:00
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static int ovl_open(struct inode *inode, struct file *file)
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{
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struct file *realfile;
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int err;
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2019-01-22 05:01:39 +00:00
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err = ovl_maybe_copy_up(file_dentry(file), file->f_flags);
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2018-07-18 13:44:41 +00:00
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if (err)
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return err;
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/* No longer need these flags, so don't pass them on to underlying fs */
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file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
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2018-05-11 15:49:31 +00:00
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realfile = ovl_open_realfile(file, ovl_inode_realdata(inode));
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2018-07-18 13:44:41 +00:00
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if (IS_ERR(realfile))
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return PTR_ERR(realfile);
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file->private_data = realfile;
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return 0;
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}
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static int ovl_release(struct inode *inode, struct file *file)
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{
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fput(file->private_data);
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return 0;
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}
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static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
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{
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2019-02-27 11:32:11 +00:00
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struct inode *inode = file_inode(file);
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struct fd real;
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const struct cred *old_cred;
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2020-02-03 10:41:53 +00:00
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loff_t ret;
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2019-02-27 11:32:11 +00:00
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/*
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* The two special cases below do not need to involve real fs,
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* so we can optimizing concurrent callers.
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*/
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if (offset == 0) {
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if (whence == SEEK_CUR)
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return file->f_pos;
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if (whence == SEEK_SET)
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return vfs_setpos(file, 0, 0);
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}
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ret = ovl_real_fdget(file, &real);
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if (ret)
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return ret;
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/*
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* Overlay file f_pos is the master copy that is preserved
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* through copy up and modified on read/write, but only real
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* fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose
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* limitations that are more strict than ->s_maxbytes for specific
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* files, so we use the real file to perform seeks.
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*/
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2019-12-21 09:42:29 +00:00
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ovl_inode_lock(inode);
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2019-02-27 11:32:11 +00:00
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real.file->f_pos = file->f_pos;
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old_cred = ovl_override_creds(inode->i_sb);
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ret = vfs_llseek(real.file, offset, whence);
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revert_creds(old_cred);
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file->f_pos = real.file->f_pos;
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2019-12-21 09:42:29 +00:00
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ovl_inode_unlock(inode);
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2019-02-27 11:32:11 +00:00
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fdput(real);
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2018-07-18 13:44:41 +00:00
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2019-02-27 11:32:11 +00:00
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return ret;
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2018-07-18 13:44:41 +00:00
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}
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2018-07-18 13:44:41 +00:00
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static void ovl_file_accessed(struct file *file)
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{
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struct inode *inode, *upperinode;
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if (file->f_flags & O_NOATIME)
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return;
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inode = file_inode(file);
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upperinode = ovl_inode_upper(inode);
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if (!upperinode)
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return;
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if ((!timespec64_equal(&inode->i_mtime, &upperinode->i_mtime) ||
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!timespec64_equal(&inode->i_ctime, &upperinode->i_ctime))) {
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inode->i_mtime = upperinode->i_mtime;
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inode->i_ctime = upperinode->i_ctime;
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}
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touch_atime(&file->f_path);
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}
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2020-06-04 08:48:19 +00:00
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static rwf_t ovl_iocb_to_rwf(int ifl)
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2018-07-18 13:44:41 +00:00
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{
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rwf_t flags = 0;
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if (ifl & IOCB_NOWAIT)
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flags |= RWF_NOWAIT;
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if (ifl & IOCB_HIPRI)
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flags |= RWF_HIPRI;
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if (ifl & IOCB_DSYNC)
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flags |= RWF_DSYNC;
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if (ifl & IOCB_SYNC)
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flags |= RWF_SYNC;
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return flags;
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}
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2021-09-30 03:22:28 +00:00
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static inline void ovl_aio_put(struct ovl_aio_req *aio_req)
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{
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if (refcount_dec_and_test(&aio_req->ref)) {
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fdput(aio_req->fd);
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kmem_cache_free(ovl_aio_request_cachep, aio_req);
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}
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}
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2019-11-20 09:45:26 +00:00
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static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
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{
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struct kiocb *iocb = &aio_req->iocb;
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struct kiocb *orig_iocb = aio_req->orig_iocb;
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if (iocb->ki_flags & IOCB_WRITE) {
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struct inode *inode = file_inode(orig_iocb->ki_filp);
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2020-03-13 14:42:20 +00:00
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/* Actually acquired in ovl_write_iter() */
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__sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb,
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SB_FREEZE_WRITE);
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2019-11-20 09:45:26 +00:00
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file_end_write(iocb->ki_filp);
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ovl_copyattr(ovl_inode_real(inode), inode);
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}
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orig_iocb->ki_pos = iocb->ki_pos;
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2021-09-30 03:22:28 +00:00
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ovl_aio_put(aio_req);
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2019-11-20 09:45:26 +00:00
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}
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static void ovl_aio_rw_complete(struct kiocb *iocb, long res, long res2)
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{
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struct ovl_aio_req *aio_req = container_of(iocb,
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struct ovl_aio_req, iocb);
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struct kiocb *orig_iocb = aio_req->orig_iocb;
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ovl_aio_cleanup_handler(aio_req);
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orig_iocb->ki_complete(orig_iocb, res, res2);
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}
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2018-07-18 13:44:41 +00:00
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static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
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{
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struct file *file = iocb->ki_filp;
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struct fd real;
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const struct cred *old_cred;
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ssize_t ret;
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if (!iov_iter_count(iter))
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return 0;
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ret = ovl_real_fdget(file, &real);
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if (ret)
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return ret;
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2021-09-27 09:23:57 +00:00
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ret = -EINVAL;
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if (iocb->ki_flags & IOCB_DIRECT &&
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(!real.file->f_mapping->a_ops ||
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!real.file->f_mapping->a_ops->direct_IO))
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goto out_fdput;
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2018-07-18 13:44:41 +00:00
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old_cred = ovl_override_creds(file_inode(file)->i_sb);
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2019-11-20 09:45:26 +00:00
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if (is_sync_kiocb(iocb)) {
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ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
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2020-06-04 08:48:19 +00:00
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ovl_iocb_to_rwf(iocb->ki_flags));
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2019-11-20 09:45:26 +00:00
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} else {
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|
|
struct ovl_aio_req *aio_req;
|
|
|
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
|
|
|
|
if (!aio_req)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
aio_req->fd = real;
|
|
|
|
real.flags = 0;
|
|
|
|
aio_req->orig_iocb = iocb;
|
|
|
|
kiocb_clone(&aio_req->iocb, iocb, real.file);
|
|
|
|
aio_req->iocb.ki_complete = ovl_aio_rw_complete;
|
2021-09-30 03:22:28 +00:00
|
|
|
refcount_set(&aio_req->ref, 2);
|
2019-11-20 09:45:26 +00:00
|
|
|
ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter);
|
2021-09-30 03:22:28 +00:00
|
|
|
ovl_aio_put(aio_req);
|
2019-11-20 09:45:26 +00:00
|
|
|
if (ret != -EIOCBQUEUED)
|
|
|
|
ovl_aio_cleanup_handler(aio_req);
|
|
|
|
}
|
|
|
|
out:
|
2018-07-18 13:44:41 +00:00
|
|
|
revert_creds(old_cred);
|
|
|
|
ovl_file_accessed(file);
|
2021-09-27 09:23:57 +00:00
|
|
|
out_fdput:
|
2018-07-18 13:44:41 +00:00
|
|
|
fdput(real);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2018-07-18 13:44:41 +00:00
|
|
|
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 fd real;
|
|
|
|
const struct cred *old_cred;
|
|
|
|
ssize_t ret;
|
2020-08-31 18:15:29 +00:00
|
|
|
int ifl = iocb->ki_flags;
|
2018-07-18 13:44:41 +00:00
|
|
|
|
|
|
|
if (!iov_iter_count(iter))
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
inode_lock(inode);
|
|
|
|
/* Update mode */
|
|
|
|
ovl_copyattr(ovl_inode_real(inode), inode);
|
|
|
|
ret = file_remove_privs(file);
|
|
|
|
if (ret)
|
|
|
|
goto out_unlock;
|
|
|
|
|
|
|
|
ret = ovl_real_fdget(file, &real);
|
|
|
|
if (ret)
|
|
|
|
goto out_unlock;
|
|
|
|
|
2021-09-27 09:23:57 +00:00
|
|
|
ret = -EINVAL;
|
|
|
|
if (iocb->ki_flags & IOCB_DIRECT &&
|
|
|
|
(!real.file->f_mapping->a_ops ||
|
|
|
|
!real.file->f_mapping->a_ops->direct_IO))
|
|
|
|
goto out_fdput;
|
|
|
|
|
2020-08-31 18:15:29 +00:00
|
|
|
if (!ovl_should_sync(OVL_FS(inode->i_sb)))
|
|
|
|
ifl &= ~(IOCB_DSYNC | IOCB_SYNC);
|
|
|
|
|
2018-07-18 13:44:41 +00:00
|
|
|
old_cred = ovl_override_creds(file_inode(file)->i_sb);
|
2019-11-20 09:45:26 +00:00
|
|
|
if (is_sync_kiocb(iocb)) {
|
|
|
|
file_start_write(real.file);
|
|
|
|
ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
|
2020-08-31 18:15:29 +00:00
|
|
|
ovl_iocb_to_rwf(ifl));
|
2019-11-20 09:45:26 +00:00
|
|
|
file_end_write(real.file);
|
|
|
|
/* Update size */
|
|
|
|
ovl_copyattr(ovl_inode_real(inode), inode);
|
|
|
|
} else {
|
|
|
|
struct ovl_aio_req *aio_req;
|
|
|
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
|
|
|
|
if (!aio_req)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
file_start_write(real.file);
|
2020-03-13 14:42:20 +00:00
|
|
|
/* Pacify lockdep, same trick as done in aio_write() */
|
|
|
|
__sb_writers_release(file_inode(real.file)->i_sb,
|
|
|
|
SB_FREEZE_WRITE);
|
2019-11-20 09:45:26 +00:00
|
|
|
aio_req->fd = real;
|
|
|
|
real.flags = 0;
|
|
|
|
aio_req->orig_iocb = iocb;
|
|
|
|
kiocb_clone(&aio_req->iocb, iocb, real.file);
|
2020-08-31 18:15:29 +00:00
|
|
|
aio_req->iocb.ki_flags = ifl;
|
2019-11-20 09:45:26 +00:00
|
|
|
aio_req->iocb.ki_complete = ovl_aio_rw_complete;
|
2021-09-30 03:22:28 +00:00
|
|
|
refcount_set(&aio_req->ref, 2);
|
2019-11-20 09:45:26 +00:00
|
|
|
ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter);
|
2021-09-30 03:22:28 +00:00
|
|
|
ovl_aio_put(aio_req);
|
2019-11-20 09:45:26 +00:00
|
|
|
if (ret != -EIOCBQUEUED)
|
|
|
|
ovl_aio_cleanup_handler(aio_req);
|
|
|
|
}
|
|
|
|
out:
|
2018-07-18 13:44:41 +00:00
|
|
|
revert_creds(old_cred);
|
2021-09-27 09:23:57 +00:00
|
|
|
out_fdput:
|
2018-07-18 13:44:41 +00:00
|
|
|
fdput(real);
|
|
|
|
|
|
|
|
out_unlock:
|
|
|
|
inode_unlock(inode);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2021-07-28 08:38:43 +00:00
|
|
|
/*
|
|
|
|
* 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(real.file) 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 fd real;
|
|
|
|
const struct cred *old_cred;
|
|
|
|
struct inode *inode = file_inode(out);
|
|
|
|
struct inode *realinode = ovl_inode_real(inode);
|
|
|
|
ssize_t ret;
|
|
|
|
|
|
|
|
inode_lock(inode);
|
|
|
|
/* Update mode */
|
|
|
|
ovl_copyattr(realinode, inode);
|
|
|
|
ret = file_remove_privs(out);
|
|
|
|
if (ret)
|
|
|
|
goto out_unlock;
|
|
|
|
|
|
|
|
ret = ovl_real_fdget(out, &real);
|
|
|
|
if (ret)
|
|
|
|
goto out_unlock;
|
|
|
|
|
|
|
|
old_cred = ovl_override_creds(inode->i_sb);
|
|
|
|
file_start_write(real.file);
|
|
|
|
|
|
|
|
ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);
|
|
|
|
|
|
|
|
file_end_write(real.file);
|
|
|
|
/* Update size */
|
|
|
|
ovl_copyattr(realinode, inode);
|
|
|
|
revert_creds(old_cred);
|
|
|
|
fdput(real);
|
|
|
|
|
|
|
|
out_unlock:
|
|
|
|
inode_unlock(inode);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
|
|
|
|
{
|
|
|
|
struct fd real;
|
|
|
|
const struct cred *old_cred;
|
|
|
|
int ret;
|
|
|
|
|
ovl: implement volatile-specific fsync error behaviour
commit 335d3fc57941e5c6164c69d439aec1cb7a800876 upstream.
Overlayfs's volatile option allows the user to bypass all forced sync calls
to the upperdir filesystem. This comes at the cost of safety. We can never
ensure that the user's data is intact, but we can make a best effort to
expose whether or not the data is likely to be in a bad state.
The best way to handle this in the time being is that if an overlayfs's
upperdir experiences an error after a volatile mount occurs, that error
will be returned on fsync, fdatasync, sync, and syncfs. This is
contradictory to the traditional behaviour of VFS which fails the call
once, and only raises an error if a subsequent fsync error has occurred,
and been raised by the filesystem.
One awkward aspect of the patch is that we have to manually set the
superblock's errseq_t after the sync_fs callback as opposed to just
returning an error from syncfs. This is because the call chain looks
something like this:
sys_syncfs ->
sync_filesystem ->
__sync_filesystem ->
/* The return value is ignored here
sb->s_op->sync_fs(sb)
_sync_blockdev
/* Where the VFS fetches the error to raise to userspace */
errseq_check_and_advance
Because of this we call errseq_set every time the sync_fs callback occurs.
Due to the nature of this seen / unseen dichotomy, if the upperdir is an
inconsistent state at the initial mount time, overlayfs will refuse to
mount, as overlayfs cannot get a snapshot of the upperdir's errseq that
will increment on error until the user calls syncfs.
Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Fixes: c86243b090bc ("ovl: provide a mount option "volatile"")
Cc: stable@vger.kernel.org
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-08 00:10:43 +00:00
|
|
|
ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));
|
|
|
|
if (ret <= 0)
|
|
|
|
return ret;
|
2020-08-31 18:15:29 +00:00
|
|
|
|
2018-05-11 15:49:31 +00:00
|
|
|
ret = ovl_real_fdget_meta(file, &real, !datasync);
|
2018-07-18 13:44:42 +00:00
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
/* Don't sync lower file for fear of receiving EROFS error */
|
|
|
|
if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) {
|
|
|
|
old_cred = ovl_override_creds(file_inode(file)->i_sb);
|
|
|
|
ret = vfs_fsync_range(real.file, start, end, datasync);
|
|
|
|
revert_creds(old_cred);
|
|
|
|
}
|
|
|
|
|
|
|
|
fdput(real);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
|
|
|
|
{
|
|
|
|
struct file *realfile = file->private_data;
|
|
|
|
const struct cred *old_cred;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (!realfile->f_op->mmap)
|
|
|
|
return -ENODEV;
|
|
|
|
|
|
|
|
if (WARN_ON(file != vma->vm_file))
|
|
|
|
return -EIO;
|
|
|
|
|
|
|
|
vma->vm_file = get_file(realfile);
|
|
|
|
|
|
|
|
old_cred = ovl_override_creds(file_inode(file)->i_sb);
|
|
|
|
ret = call_mmap(vma->vm_file, vma);
|
|
|
|
revert_creds(old_cred);
|
|
|
|
|
|
|
|
if (ret) {
|
|
|
|
/* Drop reference count from new vm_file value */
|
|
|
|
fput(realfile);
|
|
|
|
} else {
|
|
|
|
/* Drop reference count from previous vm_file value */
|
|
|
|
fput(file);
|
|
|
|
}
|
|
|
|
|
|
|
|
ovl_file_accessed(file);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
|
|
|
|
{
|
|
|
|
struct inode *inode = file_inode(file);
|
|
|
|
struct fd real;
|
|
|
|
const struct cred *old_cred;
|
|
|
|
int ret;
|
|
|
|
|
2022-10-17 15:06:39 +00:00
|
|
|
inode_lock(inode);
|
|
|
|
/* Update mode */
|
|
|
|
ovl_copyattr(ovl_inode_real(inode), inode);
|
|
|
|
ret = file_remove_privs(file);
|
|
|
|
if (ret)
|
|
|
|
goto out_unlock;
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
ret = ovl_real_fdget(file, &real);
|
|
|
|
if (ret)
|
2022-10-17 15:06:39 +00:00
|
|
|
goto out_unlock;
|
2018-07-18 13:44:42 +00:00
|
|
|
|
|
|
|
old_cred = ovl_override_creds(file_inode(file)->i_sb);
|
|
|
|
ret = vfs_fallocate(real.file, mode, offset, len);
|
|
|
|
revert_creds(old_cred);
|
|
|
|
|
|
|
|
/* Update size */
|
|
|
|
ovl_copyattr(ovl_inode_real(inode), inode);
|
|
|
|
|
|
|
|
fdput(real);
|
|
|
|
|
2022-10-17 15:06:39 +00:00
|
|
|
out_unlock:
|
|
|
|
inode_unlock(inode);
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2018-08-28 07:58:41 +00:00
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
static long ovl_real_ioctl(struct file *file, unsigned int cmd,
|
|
|
|
unsigned long arg)
|
|
|
|
{
|
|
|
|
struct fd real;
|
|
|
|
long ret;
|
|
|
|
|
|
|
|
ret = ovl_real_fdget(file, &real);
|
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
2020-06-02 20:20:26 +00:00
|
|
|
ret = security_file_ioctl(real.file, cmd, arg);
|
2020-12-14 14:26:14 +00:00
|
|
|
if (!ret) {
|
|
|
|
/*
|
|
|
|
* Don't override creds, since we currently can't safely check
|
|
|
|
* permissions before doing so.
|
|
|
|
*/
|
2020-06-02 20:20:26 +00:00
|
|
|
ret = vfs_ioctl(real.file, cmd, arg);
|
2020-12-14 14:26:14 +00:00
|
|
|
}
|
2018-07-18 13:44:42 +00:00
|
|
|
|
|
|
|
fdput(real);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2019-05-26 06:28:25 +00:00
|
|
|
static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
|
2020-12-14 14:26:14 +00:00
|
|
|
unsigned long arg)
|
2018-07-18 13:44:42 +00:00
|
|
|
{
|
|
|
|
long ret;
|
|
|
|
struct inode *inode = file_inode(file);
|
2019-05-06 07:41:02 +00:00
|
|
|
|
|
|
|
if (!inode_owner_or_capable(inode))
|
|
|
|
return -EACCES;
|
|
|
|
|
|
|
|
ret = mnt_want_write_file(file);
|
|
|
|
if (ret)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
inode_lock(inode);
|
|
|
|
|
2020-12-14 14:26:14 +00:00
|
|
|
/*
|
|
|
|
* Prevent copy up if immutable and has no CAP_LINUX_IMMUTABLE
|
|
|
|
* capability.
|
|
|
|
*/
|
|
|
|
ret = -EPERM;
|
|
|
|
if (!ovl_has_upperdata(inode) && IS_IMMUTABLE(inode) &&
|
|
|
|
!capable(CAP_LINUX_IMMUTABLE))
|
2019-05-06 07:41:02 +00:00
|
|
|
goto unlock;
|
|
|
|
|
|
|
|
ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY);
|
|
|
|
if (ret)
|
|
|
|
goto unlock;
|
|
|
|
|
2019-05-26 06:28:25 +00:00
|
|
|
ret = ovl_real_ioctl(file, cmd, arg);
|
2019-05-06 07:41:02 +00:00
|
|
|
|
|
|
|
ovl_copyflags(ovl_inode_real(inode), inode);
|
|
|
|
unlock:
|
|
|
|
inode_unlock(inode);
|
|
|
|
|
|
|
|
mnt_drop_write_file(file);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
2020-09-29 07:28:47 +00:00
|
|
|
long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
2019-05-06 07:41:02 +00:00
|
|
|
{
|
|
|
|
long ret;
|
2018-07-18 13:44:42 +00:00
|
|
|
|
|
|
|
switch (cmd) {
|
|
|
|
case FS_IOC_GETFLAGS:
|
2019-05-26 06:28:25 +00:00
|
|
|
case FS_IOC_FSGETXATTR:
|
2018-07-18 13:44:42 +00:00
|
|
|
ret = ovl_real_ioctl(file, cmd, arg);
|
|
|
|
break;
|
|
|
|
|
2019-05-26 06:28:25 +00:00
|
|
|
case FS_IOC_FSSETXATTR:
|
2020-12-14 14:26:14 +00:00
|
|
|
case FS_IOC_SETFLAGS:
|
|
|
|
ret = ovl_ioctl_set_flags(file, cmd, arg);
|
2018-07-18 13:44:42 +00:00
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
ret = -ENOTTY;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2020-09-29 07:28:47 +00:00
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
2018-07-18 13:44:42 +00:00
|
|
|
{
|
|
|
|
switch (cmd) {
|
|
|
|
case FS_IOC32_GETFLAGS:
|
|
|
|
cmd = FS_IOC_GETFLAGS;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case FS_IOC32_SETFLAGS:
|
|
|
|
cmd = FS_IOC_SETFLAGS;
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
return -ENOIOCTLCMD;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ovl_ioctl(file, cmd, arg);
|
|
|
|
}
|
2020-09-29 07:28:47 +00:00
|
|
|
#endif
|
2018-07-18 13:44:42 +00:00
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
enum ovl_copyop {
|
|
|
|
OVL_COPY,
|
|
|
|
OVL_CLONE,
|
|
|
|
OVL_DEDUPE,
|
|
|
|
};
|
|
|
|
|
2018-10-29 23:41:49 +00:00
|
|
|
static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
|
2018-07-18 13:44:42 +00:00
|
|
|
struct file *file_out, loff_t pos_out,
|
2018-10-29 23:41:49 +00:00
|
|
|
loff_t len, unsigned int flags, enum ovl_copyop op)
|
2018-07-18 13:44:42 +00:00
|
|
|
{
|
|
|
|
struct inode *inode_out = file_inode(file_out);
|
|
|
|
struct fd real_in, real_out;
|
|
|
|
const struct cred *old_cred;
|
2018-10-29 23:41:49 +00:00
|
|
|
loff_t ret;
|
2018-07-18 13:44:42 +00:00
|
|
|
|
2022-10-17 15:06:38 +00:00
|
|
|
inode_lock(inode_out);
|
|
|
|
if (op != OVL_DEDUPE) {
|
|
|
|
/* Update mode */
|
|
|
|
ovl_copyattr(ovl_inode_real(inode_out), inode_out);
|
|
|
|
ret = file_remove_privs(file_out);
|
|
|
|
if (ret)
|
|
|
|
goto out_unlock;
|
|
|
|
}
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
ret = ovl_real_fdget(file_out, &real_out);
|
|
|
|
if (ret)
|
2022-10-17 15:06:38 +00:00
|
|
|
goto out_unlock;
|
2018-07-18 13:44:42 +00:00
|
|
|
|
|
|
|
ret = ovl_real_fdget(file_in, &real_in);
|
|
|
|
if (ret) {
|
|
|
|
fdput(real_out);
|
2022-10-17 15:06:38 +00:00
|
|
|
goto out_unlock;
|
2018-07-18 13:44:42 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
old_cred = ovl_override_creds(file_inode(file_out)->i_sb);
|
|
|
|
switch (op) {
|
|
|
|
case OVL_COPY:
|
|
|
|
ret = vfs_copy_file_range(real_in.file, pos_in,
|
|
|
|
real_out.file, pos_out, len, flags);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case OVL_CLONE:
|
2018-09-18 13:34:34 +00:00
|
|
|
ret = vfs_clone_file_range(real_in.file, pos_in,
|
2018-10-29 23:41:56 +00:00
|
|
|
real_out.file, pos_out, len, flags);
|
2018-07-18 13:44:42 +00:00
|
|
|
break;
|
|
|
|
|
|
|
|
case OVL_DEDUPE:
|
|
|
|
ret = vfs_dedupe_file_range_one(real_in.file, pos_in,
|
2018-10-29 23:42:03 +00:00
|
|
|
real_out.file, pos_out, len,
|
|
|
|
flags);
|
2018-07-18 13:44:42 +00:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
revert_creds(old_cred);
|
|
|
|
|
|
|
|
/* Update size */
|
|
|
|
ovl_copyattr(ovl_inode_real(inode_out), inode_out);
|
|
|
|
|
|
|
|
fdput(real_in);
|
|
|
|
fdput(real_out);
|
|
|
|
|
2022-10-17 15:06:38 +00:00
|
|
|
out_unlock:
|
|
|
|
inode_unlock(inode_out);
|
|
|
|
|
2018-07-18 13:44:42 +00:00
|
|
|
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);
|
|
|
|
}
|
|
|
|
|
2018-10-29 23:41:49 +00:00
|
|
|
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)
|
2018-07-18 13:44:42 +00:00
|
|
|
{
|
2018-10-29 23:41:21 +00:00
|
|
|
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;
|
2018-07-18 13:44:42 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* 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).
|
|
|
|
*/
|
2018-10-29 23:41:21 +00:00
|
|
|
if (op == OVL_DEDUPE &&
|
|
|
|
(!ovl_inode_upper(file_inode(file_in)) ||
|
|
|
|
!ovl_inode_upper(file_inode(file_out))))
|
2018-07-18 13:44:42 +00:00
|
|
|
return -EPERM;
|
|
|
|
|
2018-10-29 23:41:56 +00:00
|
|
|
return ovl_copyfile(file_in, pos_in, file_out, pos_out, len,
|
|
|
|
remap_flags, op);
|
2018-07-18 13:44:42 +00:00
|
|
|
}
|
|
|
|
|
2018-07-18 13:44:41 +00:00
|
|
|
const struct file_operations ovl_file_operations = {
|
|
|
|
.open = ovl_open,
|
|
|
|
.release = ovl_release,
|
|
|
|
.llseek = ovl_llseek,
|
2018-07-18 13:44:41 +00:00
|
|
|
.read_iter = ovl_read_iter,
|
2018-07-18 13:44:41 +00:00
|
|
|
.write_iter = ovl_write_iter,
|
2018-07-18 13:44:42 +00:00
|
|
|
.fsync = ovl_fsync,
|
2018-07-18 13:44:42 +00:00
|
|
|
.mmap = ovl_mmap,
|
2018-07-18 13:44:42 +00:00
|
|
|
.fallocate = ovl_fallocate,
|
2018-08-28 07:58:41 +00:00
|
|
|
.fadvise = ovl_fadvise,
|
2018-07-18 13:44:42 +00:00
|
|
|
.unlocked_ioctl = ovl_ioctl,
|
2020-09-29 07:28:47 +00:00
|
|
|
#ifdef CONFIG_COMPAT
|
2018-07-18 13:44:42 +00:00
|
|
|
.compat_ioctl = ovl_compat_ioctl,
|
2020-09-29 07:28:47 +00:00
|
|
|
#endif
|
2020-12-14 14:26:14 +00:00
|
|
|
.splice_read = generic_file_splice_read,
|
2021-07-28 08:38:43 +00:00
|
|
|
.splice_write = ovl_splice_write,
|
2018-07-18 13:44:42 +00:00
|
|
|
|
|
|
|
.copy_file_range = ovl_copy_file_range,
|
2018-10-29 23:41:21 +00:00
|
|
|
.remap_file_range = ovl_remap_file_range,
|
2018-07-18 13:44:41 +00:00
|
|
|
};
|
2019-11-20 09:45:26 +00:00
|
|
|
|
|
|
|
int __init ovl_aio_request_cache_init(void)
|
|
|
|
{
|
|
|
|
ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req",
|
|
|
|
sizeof(struct ovl_aio_req),
|
|
|
|
0, SLAB_HWCACHE_ALIGN, NULL);
|
|
|
|
if (!ovl_aio_request_cachep)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
void ovl_aio_request_cache_destroy(void)
|
|
|
|
{
|
|
|
|
kmem_cache_destroy(ovl_aio_request_cachep);
|
|
|
|
}
|