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, 722 insertions, 0 deletions

diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
new file mode 100644
index 000000000..c4fc1047f
--- /dev/null
+++ b/fs/ubifs/commit.c
@@ -0,0 +1,722 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * Authors: Adrian Hunter
+ *          Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * This file implements functions that manage the running of the commit process.
+ * Each affected module has its own functions to accomplish their part in the
+ * commit and those functions are called here.
+ *
+ * The commit is the process whereby all updates to the index and LEB properties
+ * are written out together and the journal becomes empty. This keeps the
+ * file system consistent - at all times the state can be recreated by reading
+ * the index and LEB properties and then replaying the journal.
+ *
+ * The commit is split into two parts named "commit start" and "commit end".
+ * During commit start, the commit process has exclusive access to the journal
+ * by holding the commit semaphore down for writing. As few I/O operations as
+ * possible are performed during commit start, instead the nodes that are to be
+ * written are merely identified. During commit end, the commit semaphore is no
+ * longer held and the journal is again in operation, allowing users to continue
+ * to use the file system while the bulk of the commit I/O is performed. The
+ * purpose of this two-step approach is to prevent the commit from causing any
+ * latency blips. Note that in any case, the commit does not prevent lookups
+ * (as permitted by the TNC mutex), or access to VFS data structures e.g. page
+ * cache.
+ */
+
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include "ubifs.h"
+
+/*
+ * nothing_to_commit - check if there is nothing to commit.
+ * @c: UBIFS file-system description object
+ *
+ * This is a helper function which checks if there is anything to commit. It is
+ * used as an optimization to avoid starting the commit if it is not really
+ * necessary. Indeed, the commit operation always assumes flash I/O (e.g.,
+ * writing the commit start node to the log), and it is better to avoid doing
+ * this unnecessarily. E.g., 'ubifs_sync_fs()' runs the commit, but if there is
+ * nothing to commit, it is more optimal to avoid any flash I/O.
+ *
+ * This function has to be called with @c->commit_sem locked for writing -
+ * this function does not take LPT/TNC locks because the @c->commit_sem
+ * guarantees that we have exclusive access to the TNC and LPT data structures.
+ *
+ * This function returns %1 if there is nothing to commit and %0 otherwise.
+ */
+static int nothing_to_commit(struct ubifs_info *c)
+{
+	/*
+	 * During mounting or remounting from R/O mode to R/W mode we may
+	 * commit for various recovery-related reasons.
+	 */
+	if (c->mounting || c->remounting_rw)
+		return 0;
+
+	/*
+	 * If the root TNC node is dirty, we definitely have something to
+	 * commit.
+	 */
+	if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode))
+		return 0;
+
+	/*
+	 * Even though the TNC is clean, the LPT tree may have dirty nodes. For
+	 * example, this may happen if the budgeting subsystem invoked GC to
+	 * make some free space, and the GC found an LEB with only dirty and
+	 * free space. In this case GC would just change the lprops of this
+	 * LEB (by turning all space into free space) and unmap it.
+	 */
+	if (c->nroot && test_bit(DIRTY_CNODE, &c->nroot->flags))
+		return 0;
+
+	ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0);
+	ubifs_assert(c, c->dirty_pn_cnt == 0);
+	ubifs_assert(c, c->dirty_nn_cnt == 0);
+
+	return 1;
+}
+
+/**
+ * do_commit - commit the journal.
+ * @c: UBIFS file-system description object
+ *
+ * This function implements UBIFS commit. It has to be called with commit lock
+ * locked. Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int do_commit(struct ubifs_info *c)
+{
+	int err, new_ltail_lnum, old_ltail_lnum, i;
+	struct ubifs_zbranch zroot;
+	struct ubifs_lp_stats lst;
+
+	dbg_cmt("start");
+	ubifs_assert(c, !c->ro_media && !c->ro_mount);
+
+	if (c->ro_error) {
+		err = -EROFS;
+		goto out_up;
+	}
+
+	if (nothing_to_commit(c)) {
+		up_write(&c->commit_sem);
+		err = 0;
+		goto out_cancel;
+	}
+
+	/* Sync all write buffers (necessary for recovery) */
+	for (i = 0; i < c->jhead_cnt; i++) {
+		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
+		if (err)
+			goto out_up;
+	}
+
+	c->cmt_no += 1;
+	err = ubifs_gc_start_commit(c);
+	if (err)
+		goto out_up;
+	err = dbg_check_lprops(c);
+	if (err)
+		goto out_up;
+	err = ubifs_log_start_commit(c, &new_ltail_lnum);
+	if (err)
+		goto out_up;
+	err = ubifs_tnc_start_commit(c, &zroot);
+	if (err)
+		goto out_up;
+	err = ubifs_lpt_start_commit(c);
+	if (err)
+		goto out_up;
+	err = ubifs_orphan_start_commit(c);
+	if (err)
+		goto out_up;
+
+	ubifs_get_lp_stats(c, &lst);
+
+	up_write(&c->commit_sem);
+
+	err = ubifs_tnc_end_commit(c);
+	if (err)
+		goto out;
+	err = ubifs_lpt_end_commit(c);
+	if (err)
+		goto out;
+	err = ubifs_orphan_end_commit(c);
+	if (err)
+		goto out;
+	err = dbg_check_old_index(c, &zroot);
+	if (err)
+		goto out;
+
+	c->mst_node->cmt_no      = cpu_to_le64(c->cmt_no);
+	c->mst_node->log_lnum    = cpu_to_le32(new_ltail_lnum);
+	c->mst_node->root_lnum   = cpu_to_le32(zroot.lnum);
+	c->mst_node->root_offs   = cpu_to_le32(zroot.offs);
+	c->mst_node->root_len    = cpu_to_le32(zroot.len);
+	c->mst_node->ihead_lnum  = cpu_to_le32(c->ihead_lnum);
+	c->mst_node->ihead_offs  = cpu_to_le32(c->ihead_offs);
+	c->mst_node->index_size  = cpu_to_le64(c->bi.old_idx_sz);
+	c->mst_node->lpt_lnum    = cpu_to_le32(c->lpt_lnum);
+	c->mst_node->lpt_offs    = cpu_to_le32(c->lpt_offs);
+	c->mst_node->nhead_lnum  = cpu_to_le32(c->nhead_lnum);
+	c->mst_node->nhead_offs  = cpu_to_le32(c->nhead_offs);
+	c->mst_node->ltab_lnum   = cpu_to_le32(c->ltab_lnum);
+	c->mst_node->ltab_offs   = cpu_to_le32(c->ltab_offs);
+	c->mst_node->lsave_lnum  = cpu_to_le32(c->lsave_lnum);
+	c->mst_node->lsave_offs  = cpu_to_le32(c->lsave_offs);
+	c->mst_node->lscan_lnum  = cpu_to_le32(c->lscan_lnum);
+	c->mst_node->empty_lebs  = cpu_to_le32(lst.empty_lebs);
+	c->mst_node->idx_lebs    = cpu_to_le32(lst.idx_lebs);
+	c->mst_node->total_free  = cpu_to_le64(lst.total_free);
+	c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty);
+	c->mst_node->total_used  = cpu_to_le64(lst.total_used);
+	c->mst_node->total_dead  = cpu_to_le64(lst.total_dead);
+	c->mst_node->total_dark  = cpu_to_le64(lst.total_dark);
+	if (c->no_orphs)
+		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
+	else
+		c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS);
+
+	old_ltail_lnum = c->ltail_lnum;
+	err = ubifs_log_end_commit(c, new_ltail_lnum);
+	if (err)
+		goto out;
+
+	err = ubifs_log_post_commit(c, old_ltail_lnum);
+	if (err)
+		goto out;
+	err = ubifs_gc_end_commit(c);
+	if (err)
+		goto out;
+	err = ubifs_lpt_post_commit(c);
+	if (err)
+		goto out;
+
+out_cancel:
+	spin_lock(&c->cs_lock);
+	c->cmt_state = COMMIT_RESTING;
+	wake_up(&c->cmt_wq);
+	dbg_cmt("commit end");
+	spin_unlock(&c->cs_lock);
+	return 0;
+
+out_up:
+	up_write(&c->commit_sem);
+out:
+	ubifs_err(c, "commit failed, error %d", err);
+	spin_lock(&c->cs_lock);
+	c->cmt_state = COMMIT_BROKEN;
+	wake_up(&c->cmt_wq);
+	spin_unlock(&c->cs_lock);
+	ubifs_ro_mode(c, err);
+	return err;
+}
+
+/**
+ * run_bg_commit - run background commit if it is needed.
+ * @c: UBIFS file-system description object
+ *
+ * This function runs background commit if it is needed. Returns zero in case
+ * of success and a negative error code in case of failure.
+ */
+static int run_bg_commit(struct ubifs_info *c)
+{
+	spin_lock(&c->cs_lock);
+	/*
+	 * Run background commit only if background commit was requested or if
+	 * commit is required.
+	 */
+	if (c->cmt_state != COMMIT_BACKGROUND &&
+	    c->cmt_state != COMMIT_REQUIRED)
+		goto out;
+	spin_unlock(&c->cs_lock);
+
+	down_write(&c->commit_sem);
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_REQUIRED)
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+	else if (c->cmt_state == COMMIT_BACKGROUND)
+		c->cmt_state = COMMIT_RUNNING_BACKGROUND;
+	else
+		goto out_cmt_unlock;
+	spin_unlock(&c->cs_lock);
+
+	return do_commit(c);
+
+out_cmt_unlock:
+	up_write(&c->commit_sem);
+out:
+	spin_unlock(&c->cs_lock);
+	return 0;
+}
+
+/**
+ * ubifs_bg_thread - UBIFS background thread function.
+ * @info: points to the file-system description object
+ *
+ * This function implements various file-system background activities:
+ * o when a write-buffer timer expires it synchronizes the appropriate
+ *   write-buffer;
+ * o when the journal is about to be full, it starts in-advance commit.
+ *
+ * Note, other stuff like background garbage collection may be added here in
+ * future.
+ */
+int ubifs_bg_thread(void *info)
+{
+	int err;
+	struct ubifs_info *c = info;
+
+	ubifs_msg(c, "background thread \"%s\" started, PID %d",
+		  c->bgt_name, current->pid);
+	set_freezable();
+
+	while (1) {
+		if (kthread_should_stop())
+			break;
+
+		if (try_to_freeze())
+			continue;
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		/* Check if there is something to do */
+		if (!c->need_bgt) {
+			/*
+			 * Nothing prevents us from going sleep now and
+			 * be never woken up and block the task which
+			 * could wait in 'kthread_stop()' forever.
+			 */
+			if (kthread_should_stop())
+				break;
+			schedule();
+			continue;
+		} else
+			__set_current_state(TASK_RUNNING);
+
+		c->need_bgt = 0;
+		err = ubifs_bg_wbufs_sync(c);
+		if (err)
+			ubifs_ro_mode(c, err);
+
+		run_bg_commit(c);
+		cond_resched();
+	}
+
+	ubifs_msg(c, "background thread \"%s\" stops", c->bgt_name);
+	return 0;
+}
+
+/**
+ * ubifs_commit_required - set commit state to "required".
+ * @c: UBIFS file-system description object
+ *
+ * This function is called if a commit is required but cannot be done from the
+ * calling function, so it is just flagged instead.
+ */
+void ubifs_commit_required(struct ubifs_info *c)
+{
+	spin_lock(&c->cs_lock);
+	switch (c->cmt_state) {
+	case COMMIT_RESTING:
+	case COMMIT_BACKGROUND:
+		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
+			dbg_cstate(COMMIT_REQUIRED));
+		c->cmt_state = COMMIT_REQUIRED;
+		break;
+	case COMMIT_RUNNING_BACKGROUND:
+		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
+			dbg_cstate(COMMIT_RUNNING_REQUIRED));
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+		break;
+	case COMMIT_REQUIRED:
+	case COMMIT_RUNNING_REQUIRED:
+	case COMMIT_BROKEN:
+		break;
+	}
+	spin_unlock(&c->cs_lock);
+}
+
+/**
+ * ubifs_request_bg_commit - notify the background thread to do a commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function is called if the journal is full enough to make a commit
+ * worthwhile, so background thread is kicked to start it.
+ */
+void ubifs_request_bg_commit(struct ubifs_info *c)
+{
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_RESTING) {
+		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
+			dbg_cstate(COMMIT_BACKGROUND));
+		c->cmt_state = COMMIT_BACKGROUND;
+		spin_unlock(&c->cs_lock);
+		ubifs_wake_up_bgt(c);
+	} else
+		spin_unlock(&c->cs_lock);
+}
+
+/**
+ * wait_for_commit - wait for commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function sleeps until the commit operation is no longer running.
+ */
+static int wait_for_commit(struct ubifs_info *c)
+{
+	dbg_cmt("pid %d goes sleep", current->pid);
+
+	/*
+	 * The following sleeps if the condition is false, and will be woken
+	 * when the commit ends. It is possible, although very unlikely, that we
+	 * will wake up and see the subsequent commit running, rather than the
+	 * one we were waiting for, and go back to sleep.  However, we will be
+	 * woken again, so there is no danger of sleeping forever.
+	 */
+	wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND &&
+			      c->cmt_state != COMMIT_RUNNING_REQUIRED);
+	dbg_cmt("commit finished, pid %d woke up", current->pid);
+	return 0;
+}
+
+/**
+ * ubifs_run_commit - run or wait for commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function runs commit and returns zero in case of success and a negative
+ * error code in case of failure.
+ */
+int ubifs_run_commit(struct ubifs_info *c)
+{
+	int err = 0;
+
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_BROKEN) {
+		err = -EROFS;
+		goto out;
+	}
+
+	if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
+		/*
+		 * We set the commit state to 'running required' to indicate
+		 * that we want it to complete as quickly as possible.
+		 */
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+
+	if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
+		spin_unlock(&c->cs_lock);
+		return wait_for_commit(c);
+	}
+	spin_unlock(&c->cs_lock);
+
+	/* Ok, the commit is indeed needed */
+
+	down_write(&c->commit_sem);
+	spin_lock(&c->cs_lock);
+	/*
+	 * Since we unlocked 'c->cs_lock', the state may have changed, so
+	 * re-check it.
+	 */
+	if (c->cmt_state == COMMIT_BROKEN) {
+		err = -EROFS;
+		goto out_cmt_unlock;
+	}
+
+	if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
+		c->cmt_state = COMMIT_RUNNING_REQUIRED;
+
+	if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
+		up_write(&c->commit_sem);
+		spin_unlock(&c->cs_lock);
+		return wait_for_commit(c);
+	}
+	c->cmt_state = COMMIT_RUNNING_REQUIRED;
+	spin_unlock(&c->cs_lock);
+
+	err = do_commit(c);
+	return err;
+
+out_cmt_unlock:
+	up_write(&c->commit_sem);
+out:
+	spin_unlock(&c->cs_lock);
+	return err;
+}
+
+/**
+ * ubifs_gc_should_commit - determine if it is time for GC to run commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function is called by garbage collection to determine if commit should
+ * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal
+ * is full enough to start commit, this function returns true. It is not
+ * absolutely necessary to commit yet, but it feels like this should be better
+ * then to keep doing GC. This function returns %1 if GC has to initiate commit
+ * and %0 if not.
+ */
+int ubifs_gc_should_commit(struct ubifs_info *c)
+{
+	int ret = 0;
+
+	spin_lock(&c->cs_lock);
+	if (c->cmt_state == COMMIT_BACKGROUND) {
+		dbg_cmt("commit required now");
+		c->cmt_state = COMMIT_REQUIRED;
+	} else
+		dbg_cmt("commit not requested");
+	if (c->cmt_state == COMMIT_REQUIRED)
+		ret = 1;
+	spin_unlock(&c->cs_lock);
+	return ret;
+}
+
+/*
+ * Everything below is related to debugging.
+ */
+
+/**
+ * struct idx_node - hold index nodes during index tree traversal.
+ * @list: list
+ * @iip: index in parent (slot number of this indexing node in the parent
+ *       indexing node)
+ * @upper_key: all keys in this indexing node have to be less or equivalent to
+ *             this key
+ * @idx: index node (8-byte aligned because all node structures must be 8-byte
+ *       aligned)
+ */
+struct idx_node {
+	struct list_head list;
+	int iip;
+	union ubifs_key upper_key;
+	struct ubifs_idx_node idx __aligned(8);
+};
+
+/**
+ * dbg_old_index_check_init - get information for the next old index check.
+ * @c: UBIFS file-system description object
+ * @zroot: root of the index
+ *
+ * This function records information about the index that will be needed for the
+ * next old index check i.e. 'dbg_check_old_index()'.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot)
+{
+	struct ubifs_idx_node *idx;
+	int lnum, offs, len, err = 0;
+	struct ubifs_debug_info *d = c->dbg;
+
+	d->old_zroot = *zroot;
+	lnum = d->old_zroot.lnum;
+	offs = d->old_zroot.offs;
+	len = d->old_zroot.len;
+
+	idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
+	if (!idx)
+		return -ENOMEM;
+
+	err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
+	if (err)
+		goto out;
+
+	d->old_zroot_level = le16_to_cpu(idx->level);
+	d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum);
+out:
+	kfree(idx);
+	return err;
+}
+
+/**
+ * dbg_check_old_index - check the old copy of the index.
+ * @c: UBIFS file-system description object
+ * @zroot: root of the new index
+ *
+ * In order to be able to recover from an unclean unmount, a complete copy of
+ * the index must exist on flash. This is the "old" index. The commit process
+ * must write the "new" index to flash without overwriting or destroying any
+ * part of the old index. This function is run at commit end in order to check
+ * that the old index does indeed exist completely intact.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
+{
+	int lnum, offs, len, err = 0, last_level, child_cnt;
+	int first = 1, iip;
+	struct ubifs_debug_info *d = c->dbg;
+	union ubifs_key lower_key, upper_key, l_key, u_key;
+	unsigned long long last_sqnum;
+	struct ubifs_idx_node *idx;
+	struct list_head list;
+	struct idx_node *i;
+	size_t sz;
+
+	if (!dbg_is_chk_index(c))
+		return 0;
+
+	INIT_LIST_HEAD(&list);
+
+	sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) -
+	     UBIFS_IDX_NODE_SZ;
+
+	/* Start at the old zroot */
+	lnum = d->old_zroot.lnum;
+	offs = d->old_zroot.offs;
+	len = d->old_zroot.len;
+	iip = 0;
+
+	/*
+	 * Traverse the index tree preorder depth-first i.e. do a node and then
+	 * its subtrees from left to right.
+	 */
+	while (1) {
+		struct ubifs_branch *br;
+
+		/* Get the next index node */
+		i = kmalloc(sz, GFP_NOFS);
+		if (!i) {
+			err = -ENOMEM;
+			goto out_free;
+		}
+		i->iip = iip;
+		/* Keep the index nodes on our path in a linked list */
+		list_add_tail(&i->list, &list);
+		/* Read the index node */
+		idx = &i->idx;
+		err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
+		if (err)
+			goto out_free;
+		/* Validate index node */
+		child_cnt = le16_to_cpu(idx->child_cnt);
+		if (child_cnt < 1 || child_cnt > c->fanout) {
+			err = 1;
+			goto out_dump;
+		}
+		if (first) {
+			first = 0;
+			/* Check root level and sqnum */
+			if (le16_to_cpu(idx->level) != d->old_zroot_level) {
+				err = 2;
+				goto out_dump;
+			}
+			if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) {
+				err = 3;
+				goto out_dump;
+			}
+			/* Set last values as though root had a parent */
+			last_level = le16_to_cpu(idx->level) + 1;
+			last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1;
+			key_read(c, ubifs_idx_key(c, idx), &lower_key);
+			highest_ino_key(c, &upper_key, INUM_WATERMARK);
+		}
+		key_copy(c, &upper_key, &i->upper_key);
+		if (le16_to_cpu(idx->level) != last_level - 1) {
+			err = 3;
+			goto out_dump;
+		}
+		/*
+		 * The index is always written bottom up hence a child's sqnum
+		 * is always less than the parents.
+		 */
+		if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) {
+			err = 4;
+			goto out_dump;
+		}
+		/* Check key range */
+		key_read(c, ubifs_idx_key(c, idx), &l_key);
+		br = ubifs_idx_branch(c, idx, child_cnt - 1);
+		key_read(c, &br->key, &u_key);
+		if (keys_cmp(c, &lower_key, &l_key) > 0) {
+			err = 5;
+			goto out_dump;
+		}
+		if (keys_cmp(c, &upper_key, &u_key) < 0) {
+			err = 6;
+			goto out_dump;
+		}
+		if (keys_cmp(c, &upper_key, &u_key) == 0)
+			if (!is_hash_key(c, &u_key)) {
+				err = 7;
+				goto out_dump;
+			}
+		/* Go to next index node */
+		if (le16_to_cpu(idx->level) == 0) {
+			/* At the bottom, so go up until can go right */
+			while (1) {
+				/* Drop the bottom of the list */
+				list_del(&i->list);
+				kfree(i);
+				/* No more list means we are done */
+				if (list_empty(&list))
+					goto out;
+				/* Look at the new bottom */
+				i = list_entry(list.prev, struct idx_node,
+					       list);
+				idx = &i->idx;
+				/* Can we go right */
+				if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
+					iip = iip + 1;
+					break;
+				} else
+					/* Nope, so go up again */
+					iip = i->iip;
+			}
+		} else
+			/* Go down left */
+			iip = 0;
+		/*
+		 * We have the parent in 'idx' and now we set up for reading the
+		 * child pointed to by slot 'iip'.
+		 */
+		last_level = le16_to_cpu(idx->level);
+		last_sqnum = le64_to_cpu(idx->ch.sqnum);
+		br = ubifs_idx_branch(c, idx, iip);
+		lnum = le32_to_cpu(br->lnum);
+		offs = le32_to_cpu(br->offs);
+		len = le32_to_cpu(br->len);
+		key_read(c, &br->key, &lower_key);
+		if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
+			br = ubifs_idx_branch(c, idx, iip + 1);
+			key_read(c, &br->key, &upper_key);
+		} else
+			key_copy(c, &i->upper_key, &upper_key);
+	}
+out:
+	err = dbg_old_index_check_init(c, zroot);
+	if (err)
+		goto out_free;
+
+	return 0;
+
+out_dump:
+	ubifs_err(c, "dumping index node (iip=%d)", i->iip);
+	ubifs_dump_node(c, idx, ubifs_idx_node_sz(c, c->fanout));
+	list_del(&i->list);
+	kfree(i);
+	if (!list_empty(&list)) {
+		i = list_entry(list.prev, struct idx_node, list);
+		ubifs_err(c, "dumping parent index node");
+		ubifs_dump_node(c, &i->idx, ubifs_idx_node_sz(c, c->fanout));
+	}
+out_free:
+	while (!list_empty(&list)) {
+		i = list_entry(list.next, struct idx_node, list);
+		list_del(&i->list);
+		kfree(i);
+	}
+	ubifs_err(c, "failed, error %d", err);
+	if (err > 0)
+		err = -EINVAL;
+	return err;
+}