Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 741 insertions, 0 deletions

diff --git a/fs/autofs/dev-ioctl.c b/fs/autofs/dev-ioctl.c
new file mode 100644
index 000000000..5bf781ea6
--- /dev/null
+++ b/fs/autofs/dev-ioctl.c
@@ -0,0 +1,741 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2008 Red Hat, Inc. All rights reserved.
+ * Copyright 2008 Ian Kent <raven@themaw.net>
+ */
+
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/compat.h>
+#include <linux/fdtable.h>
+#include <linux/magic.h>
+#include <linux/nospec.h>
+
+#include "autofs_i.h"
+
+/*
+ * This module implements an interface for routing autofs ioctl control
+ * commands via a miscellaneous device file.
+ *
+ * The alternate interface is needed because we need to be able open
+ * an ioctl file descriptor on an autofs mount that may be covered by
+ * another mount. This situation arises when starting automount(8)
+ * or other user space daemon which uses direct mounts or offset
+ * mounts (used for autofs lazy mount/umount of nested mount trees),
+ * which have been left busy at service shutdown.
+ */
+
+typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *,
+			struct autofs_dev_ioctl *);
+
+static int check_name(const char *name)
+{
+	if (!strchr(name, '/'))
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * Check a string doesn't overrun the chunk of
+ * memory we copied from user land.
+ */
+static int invalid_str(char *str, size_t size)
+{
+	if (memchr(str, 0, size))
+		return 0;
+	return -EINVAL;
+}
+
+/*
+ * Check that the user compiled against correct version of autofs
+ * misc device code.
+ *
+ * As well as checking the version compatibility this always copies
+ * the kernel interface version out.
+ */
+static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
+{
+	int err = 0;
+
+	if ((param->ver_major != AUTOFS_DEV_IOCTL_VERSION_MAJOR) ||
+	    (param->ver_minor > AUTOFS_DEV_IOCTL_VERSION_MINOR)) {
+		pr_warn("ioctl control interface version mismatch: "
+			"kernel(%u.%u), user(%u.%u), cmd(0x%08x)\n",
+			AUTOFS_DEV_IOCTL_VERSION_MAJOR,
+			AUTOFS_DEV_IOCTL_VERSION_MINOR,
+			param->ver_major, param->ver_minor, cmd);
+		err = -EINVAL;
+	}
+
+	/* Fill in the kernel version. */
+	param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
+	param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
+
+	return err;
+}
+
+/*
+ * Copy parameter control struct, including a possible path allocated
+ * at the end of the struct.
+ */
+static struct autofs_dev_ioctl *
+copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
+{
+	struct autofs_dev_ioctl tmp, *res;
+
+	if (copy_from_user(&tmp, in, AUTOFS_DEV_IOCTL_SIZE))
+		return ERR_PTR(-EFAULT);
+
+	if (tmp.size < AUTOFS_DEV_IOCTL_SIZE)
+		return ERR_PTR(-EINVAL);
+
+	if (tmp.size > AUTOFS_DEV_IOCTL_SIZE + PATH_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	res = memdup_user(in, tmp.size);
+	if (!IS_ERR(res))
+		res->size = tmp.size;
+
+	return res;
+}
+
+static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)
+{
+	kfree(param);
+}
+
+/*
+ * Check sanity of parameter control fields and if a path is present
+ * check that it is terminated and contains at least one "/".
+ */
+static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
+{
+	int err;
+
+	err = check_dev_ioctl_version(cmd, param);
+	if (err) {
+		pr_warn("invalid device control module version "
+			"supplied for cmd(0x%08x)\n", cmd);
+		goto out;
+	}
+
+	if (param->size > AUTOFS_DEV_IOCTL_SIZE) {
+		err = invalid_str(param->path, param->size - AUTOFS_DEV_IOCTL_SIZE);
+		if (err) {
+			pr_warn(
+			  "path string terminator missing for cmd(0x%08x)\n",
+			  cmd);
+			goto out;
+		}
+
+		err = check_name(param->path);
+		if (err) {
+			pr_warn("invalid path supplied for cmd(0x%08x)\n",
+				cmd);
+			goto out;
+		}
+	} else {
+		unsigned int inr = _IOC_NR(cmd);
+
+		if (inr == AUTOFS_DEV_IOCTL_OPENMOUNT_CMD ||
+		    inr == AUTOFS_DEV_IOCTL_REQUESTER_CMD ||
+		    inr == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) {
+			err = -EINVAL;
+			goto out;
+		}
+	}
+
+	err = 0;
+out:
+	return err;
+}
+
+/* Return autofs dev ioctl version */
+static int autofs_dev_ioctl_version(struct file *fp,
+				    struct autofs_sb_info *sbi,
+				    struct autofs_dev_ioctl *param)
+{
+	/* This should have already been set. */
+	param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
+	param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
+	return 0;
+}
+
+/* Return autofs module protocol version */
+static int autofs_dev_ioctl_protover(struct file *fp,
+				     struct autofs_sb_info *sbi,
+				     struct autofs_dev_ioctl *param)
+{
+	param->protover.version = sbi->version;
+	return 0;
+}
+
+/* Return autofs module protocol sub version */
+static int autofs_dev_ioctl_protosubver(struct file *fp,
+					struct autofs_sb_info *sbi,
+					struct autofs_dev_ioctl *param)
+{
+	param->protosubver.sub_version = sbi->sub_version;
+	return 0;
+}
+
+/* Find the topmost mount satisfying test() */
+static int find_autofs_mount(const char *pathname,
+			     struct path *res,
+			     int test(const struct path *path, void *data),
+			     void *data)
+{
+	struct path path;
+	int err;
+
+	err = kern_path(pathname, LOOKUP_MOUNTPOINT, &path);
+	if (err)
+		return err;
+	err = -ENOENT;
+	while (path.dentry == path.mnt->mnt_root) {
+		if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) {
+			if (test(&path, data)) {
+				path_get(&path);
+				*res = path;
+				err = 0;
+				break;
+			}
+		}
+		if (!follow_up(&path))
+			break;
+	}
+	path_put(&path);
+	return err;
+}
+
+static int test_by_dev(const struct path *path, void *p)
+{
+	return path->dentry->d_sb->s_dev == *(dev_t *)p;
+}
+
+static int test_by_type(const struct path *path, void *p)
+{
+	struct autofs_info *ino = autofs_dentry_ino(path->dentry);
+
+	return ino && ino->sbi->type & *(unsigned *)p;
+}
+
+/*
+ * Open a file descriptor on the autofs mount point corresponding
+ * to the given path and device number (aka. new_encode_dev(sb->s_dev)).
+ */
+static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid)
+{
+	int err, fd;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (likely(fd >= 0)) {
+		struct file *filp;
+		struct path path;
+
+		err = find_autofs_mount(name, &path, test_by_dev, &devid);
+		if (err)
+			goto out;
+
+		filp = dentry_open(&path, O_RDONLY, current_cred());
+		path_put(&path);
+		if (IS_ERR(filp)) {
+			err = PTR_ERR(filp);
+			goto out;
+		}
+
+		fd_install(fd, filp);
+	}
+
+	return fd;
+
+out:
+	put_unused_fd(fd);
+	return err;
+}
+
+/* Open a file descriptor on an autofs mount point */
+static int autofs_dev_ioctl_openmount(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	const char *path;
+	dev_t devid;
+	int err, fd;
+
+	/* param->path has been checked in validate_dev_ioctl() */
+
+	if (!param->openmount.devid)
+		return -EINVAL;
+
+	param->ioctlfd = -1;
+
+	path = param->path;
+	devid = new_decode_dev(param->openmount.devid);
+
+	err = 0;
+	fd = autofs_dev_ioctl_open_mountpoint(path, devid);
+	if (unlikely(fd < 0)) {
+		err = fd;
+		goto out;
+	}
+
+	param->ioctlfd = fd;
+out:
+	return err;
+}
+
+/* Close file descriptor allocated above (user can also use close(2)). */
+static int autofs_dev_ioctl_closemount(struct file *fp,
+				       struct autofs_sb_info *sbi,
+				       struct autofs_dev_ioctl *param)
+{
+	return close_fd(param->ioctlfd);
+}
+
+/*
+ * Send "ready" status for an existing wait (either a mount or an expire
+ * request).
+ */
+static int autofs_dev_ioctl_ready(struct file *fp,
+				  struct autofs_sb_info *sbi,
+				  struct autofs_dev_ioctl *param)
+{
+	autofs_wqt_t token;
+
+	token = (autofs_wqt_t) param->ready.token;
+	return autofs_wait_release(sbi, token, 0);
+}
+
+/*
+ * Send "fail" status for an existing wait (either a mount or an expire
+ * request).
+ */
+static int autofs_dev_ioctl_fail(struct file *fp,
+				 struct autofs_sb_info *sbi,
+				 struct autofs_dev_ioctl *param)
+{
+	autofs_wqt_t token;
+	int status;
+
+	token = (autofs_wqt_t) param->fail.token;
+	status = param->fail.status < 0 ? param->fail.status : -ENOENT;
+	return autofs_wait_release(sbi, token, status);
+}
+
+/*
+ * Set the pipe fd for kernel communication to the daemon.
+ *
+ * Normally this is set at mount using an option but if we
+ * are reconnecting to a busy mount then we need to use this
+ * to tell the autofs mount about the new kernel pipe fd. In
+ * order to protect mounts against incorrectly setting the
+ * pipefd we also require that the autofs mount be catatonic.
+ *
+ * This also sets the process group id used to identify the
+ * controlling process (eg. the owning automount(8) daemon).
+ */
+static int autofs_dev_ioctl_setpipefd(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	int pipefd;
+	int err = 0;
+	struct pid *new_pid = NULL;
+
+	if (param->setpipefd.pipefd == -1)
+		return -EINVAL;
+
+	pipefd = param->setpipefd.pipefd;
+
+	mutex_lock(&sbi->wq_mutex);
+	if (!(sbi->flags & AUTOFS_SBI_CATATONIC)) {
+		mutex_unlock(&sbi->wq_mutex);
+		return -EBUSY;
+	} else {
+		struct file *pipe;
+
+		new_pid = get_task_pid(current, PIDTYPE_PGID);
+
+		if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) {
+			pr_warn("not allowed to change PID namespace\n");
+			err = -EINVAL;
+			goto out;
+		}
+
+		pipe = fget(pipefd);
+		if (!pipe) {
+			err = -EBADF;
+			goto out;
+		}
+		if (autofs_prepare_pipe(pipe) < 0) {
+			err = -EPIPE;
+			fput(pipe);
+			goto out;
+		}
+		swap(sbi->oz_pgrp, new_pid);
+		sbi->pipefd = pipefd;
+		sbi->pipe = pipe;
+		sbi->flags &= ~AUTOFS_SBI_CATATONIC;
+	}
+out:
+	put_pid(new_pid);
+	mutex_unlock(&sbi->wq_mutex);
+	return err;
+}
+
+/*
+ * Make the autofs mount point catatonic, no longer responsive to
+ * mount requests. Also closes the kernel pipe file descriptor.
+ */
+static int autofs_dev_ioctl_catatonic(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	autofs_catatonic_mode(sbi);
+	return 0;
+}
+
+/* Set the autofs mount timeout */
+static int autofs_dev_ioctl_timeout(struct file *fp,
+				    struct autofs_sb_info *sbi,
+				    struct autofs_dev_ioctl *param)
+{
+	unsigned long timeout;
+
+	timeout = param->timeout.timeout;
+	param->timeout.timeout = sbi->exp_timeout / HZ;
+	sbi->exp_timeout = timeout * HZ;
+	return 0;
+}
+
+/*
+ * Return the uid and gid of the last request for the mount
+ *
+ * When reconstructing an autofs mount tree with active mounts
+ * we need to re-connect to mounts that may have used the original
+ * process uid and gid (or string variations of them) for mount
+ * lookups within the map entry.
+ */
+static int autofs_dev_ioctl_requester(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	struct autofs_info *ino;
+	struct path path;
+	dev_t devid;
+	int err = -ENOENT;
+
+	/* param->path has been checked in validate_dev_ioctl() */
+
+	devid = sbi->sb->s_dev;
+
+	param->requester.uid = param->requester.gid = -1;
+
+	err = find_autofs_mount(param->path, &path, test_by_dev, &devid);
+	if (err)
+		goto out;
+
+	ino = autofs_dentry_ino(path.dentry);
+	if (ino) {
+		err = 0;
+		autofs_expire_wait(&path, 0);
+		spin_lock(&sbi->fs_lock);
+		param->requester.uid =
+			from_kuid_munged(current_user_ns(), ino->uid);
+		param->requester.gid =
+			from_kgid_munged(current_user_ns(), ino->gid);
+		spin_unlock(&sbi->fs_lock);
+	}
+	path_put(&path);
+out:
+	return err;
+}
+
+/*
+ * Call repeatedly until it returns -EAGAIN, meaning there's nothing
+ * more that can be done.
+ */
+static int autofs_dev_ioctl_expire(struct file *fp,
+				   struct autofs_sb_info *sbi,
+				   struct autofs_dev_ioctl *param)
+{
+	struct vfsmount *mnt;
+	int how;
+
+	how = param->expire.how;
+	mnt = fp->f_path.mnt;
+
+	return autofs_do_expire_multi(sbi->sb, mnt, sbi, how);
+}
+
+/* Check if autofs mount point is in use */
+static int autofs_dev_ioctl_askumount(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	param->askumount.may_umount = 0;
+	if (may_umount(fp->f_path.mnt))
+		param->askumount.may_umount = 1;
+	return 0;
+}
+
+/*
+ * Check if the given path is a mountpoint.
+ *
+ * If we are supplied with the file descriptor of an autofs
+ * mount we're looking for a specific mount. In this case
+ * the path is considered a mountpoint if it is itself a
+ * mountpoint or contains a mount, such as a multi-mount
+ * without a root mount. In this case we return 1 if the
+ * path is a mount point and the super magic of the covering
+ * mount if there is one or 0 if it isn't a mountpoint.
+ *
+ * If we aren't supplied with a file descriptor then we
+ * lookup the path and check if it is the root of a mount.
+ * If a type is given we are looking for a particular autofs
+ * mount and if we don't find a match we return fail. If the
+ * located path is the root of a mount we return 1 along with
+ * the super magic of the mount or 0 otherwise.
+ *
+ * In both cases the device number (as returned by
+ * new_encode_dev()) is also returned.
+ */
+static int autofs_dev_ioctl_ismountpoint(struct file *fp,
+					 struct autofs_sb_info *sbi,
+					 struct autofs_dev_ioctl *param)
+{
+	struct path path;
+	const char *name;
+	unsigned int type;
+	unsigned int devid, magic;
+	int err = -ENOENT;
+
+	/* param->path has been checked in validate_dev_ioctl() */
+
+	name = param->path;
+	type = param->ismountpoint.in.type;
+
+	param->ismountpoint.out.devid = devid = 0;
+	param->ismountpoint.out.magic = magic = 0;
+
+	if (!fp || param->ioctlfd == -1) {
+		if (autofs_type_any(type))
+			err = kern_path(name, LOOKUP_FOLLOW | LOOKUP_MOUNTPOINT,
+					&path);
+		else
+			err = find_autofs_mount(name, &path,
+						test_by_type, &type);
+		if (err)
+			goto out;
+		devid = new_encode_dev(path.dentry->d_sb->s_dev);
+		err = 0;
+		if (path.mnt->mnt_root == path.dentry) {
+			err = 1;
+			magic = path.dentry->d_sb->s_magic;
+		}
+	} else {
+		dev_t dev = sbi->sb->s_dev;
+
+		err = find_autofs_mount(name, &path, test_by_dev, &dev);
+		if (err)
+			goto out;
+
+		devid = new_encode_dev(dev);
+
+		err = path_has_submounts(&path);
+
+		if (follow_down_one(&path))
+			magic = path.dentry->d_sb->s_magic;
+	}
+
+	param->ismountpoint.out.devid = devid;
+	param->ismountpoint.out.magic = magic;
+	path_put(&path);
+out:
+	return err;
+}
+
+/*
+ * Our range of ioctl numbers isn't 0 based so we need to shift
+ * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table
+ * lookup.
+ */
+#define cmd_idx(cmd)	(cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST))
+
+static ioctl_fn lookup_dev_ioctl(unsigned int cmd)
+{
+	static const ioctl_fn _ioctls[] = {
+		autofs_dev_ioctl_version,
+		autofs_dev_ioctl_protover,
+		autofs_dev_ioctl_protosubver,
+		autofs_dev_ioctl_openmount,
+		autofs_dev_ioctl_closemount,
+		autofs_dev_ioctl_ready,
+		autofs_dev_ioctl_fail,
+		autofs_dev_ioctl_setpipefd,
+		autofs_dev_ioctl_catatonic,
+		autofs_dev_ioctl_timeout,
+		autofs_dev_ioctl_requester,
+		autofs_dev_ioctl_expire,
+		autofs_dev_ioctl_askumount,
+		autofs_dev_ioctl_ismountpoint,
+	};
+	unsigned int idx = cmd_idx(cmd);
+
+	if (idx >= ARRAY_SIZE(_ioctls))
+		return NULL;
+	idx = array_index_nospec(idx, ARRAY_SIZE(_ioctls));
+	return _ioctls[idx];
+}
+
+/* ioctl dispatcher */
+static int _autofs_dev_ioctl(unsigned int command,
+			     struct autofs_dev_ioctl __user *user)
+{
+	struct autofs_dev_ioctl *param;
+	struct file *fp;
+	struct autofs_sb_info *sbi;
+	unsigned int cmd_first, cmd;
+	ioctl_fn fn = NULL;
+	int err = 0;
+
+	cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
+	cmd = _IOC_NR(command);
+
+	if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
+	    cmd - cmd_first > AUTOFS_DEV_IOCTL_IOC_COUNT) {
+		return -ENOTTY;
+	}
+
+	/* Only root can use ioctls other than AUTOFS_DEV_IOCTL_VERSION_CMD
+	 * and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
+	 */
+	if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+	    cmd != AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD &&
+	    !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/* Copy the parameters into kernel space. */
+	param = copy_dev_ioctl(user);
+	if (IS_ERR(param))
+		return PTR_ERR(param);
+
+	err = validate_dev_ioctl(command, param);
+	if (err)
+		goto out;
+
+	fn = lookup_dev_ioctl(cmd);
+	if (!fn) {
+		pr_warn("unknown command 0x%08x\n", command);
+		err = -ENOTTY;
+		goto out;
+	}
+
+	fp = NULL;
+	sbi = NULL;
+
+	/*
+	 * For obvious reasons the openmount can't have a file
+	 * descriptor yet. We don't take a reference to the
+	 * file during close to allow for immediate release,
+	 * and the same for retrieving ioctl version.
+	 */
+	if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+	    cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
+	    cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
+		struct super_block *sb;
+
+		fp = fget(param->ioctlfd);
+		if (!fp) {
+			if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
+				goto cont;
+			err = -EBADF;
+			goto out;
+		}
+
+		sb = file_inode(fp)->i_sb;
+		if (sb->s_type != &autofs_fs_type) {
+			err = -EINVAL;
+			fput(fp);
+			goto out;
+		}
+		sbi = autofs_sbi(sb);
+
+		/*
+		 * Admin needs to be able to set the mount catatonic in
+		 * order to be able to perform the re-open.
+		 */
+		if (!autofs_oz_mode(sbi) &&
+		    cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
+			err = -EACCES;
+			fput(fp);
+			goto out;
+		}
+	}
+cont:
+	err = fn(fp, sbi, param);
+
+	if (fp)
+		fput(fp);
+	if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
+		err = -EFAULT;
+out:
+	free_dev_ioctl(param);
+	return err;
+}
+
+static long autofs_dev_ioctl(struct file *file, unsigned int command,
+			     unsigned long u)
+{
+	int err;
+
+	err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u);
+	return (long) err;
+}
+
+#ifdef CONFIG_COMPAT
+static long autofs_dev_ioctl_compat(struct file *file, unsigned int command,
+				    unsigned long u)
+{
+	return autofs_dev_ioctl(file, command, (unsigned long) compat_ptr(u));
+}
+#else
+#define autofs_dev_ioctl_compat NULL
+#endif
+
+static const struct file_operations _dev_ioctl_fops = {
+	.unlocked_ioctl	 = autofs_dev_ioctl,
+	.compat_ioctl = autofs_dev_ioctl_compat,
+	.owner	 = THIS_MODULE,
+	.llseek = noop_llseek,
+};
+
+static struct miscdevice _autofs_dev_ioctl_misc = {
+	.minor		= AUTOFS_MINOR,
+	.name		= AUTOFS_DEVICE_NAME,
+	.fops		= &_dev_ioctl_fops,
+	.mode           = 0644,
+};
+
+MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);
+MODULE_ALIAS("devname:autofs");
+
+/* Register/deregister misc character device */
+int __init autofs_dev_ioctl_init(void)
+{
+	int r;
+
+	r = misc_register(&_autofs_dev_ioctl_misc);
+	if (r) {
+		pr_err("misc_register failed for control device\n");
+		return r;
+	}
+
+	return 0;
+}
+
+void autofs_dev_ioctl_exit(void)
+{
+	misc_deregister(&_autofs_dev_ioctl_misc);
+}