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, 963 insertions, 0 deletions

diff --git a/fs/ubifs/find.c b/fs/ubifs/find.c
new file mode 100644
index 000000000..873e6e1c9
--- /dev/null
+++ b/fs/ubifs/find.c
@@ -0,0 +1,963 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+/*
+ * This file contains functions for finding LEBs for various purposes e.g.
+ * garbage collection. In general, lprops category heaps and lists are used
+ * for fast access, falling back on scanning the LPT as a last resort.
+ */
+
+#include <linux/sort.h>
+#include "ubifs.h"
+
+/**
+ * struct scan_data - data provided to scan callback functions
+ * @min_space: minimum number of bytes for which to scan
+ * @pick_free: whether it is OK to scan for empty LEBs
+ * @lnum: LEB number found is returned here
+ * @exclude_index: whether to exclude index LEBs
+ */
+struct scan_data {
+	int min_space;
+	int pick_free;
+	int lnum;
+	int exclude_index;
+};
+
+/**
+ * valuable - determine whether LEB properties are valuable.
+ * @c: the UBIFS file-system description object
+ * @lprops: LEB properties
+ *
+ * This function return %1 if the LEB properties should be added to the LEB
+ * properties tree in memory. Otherwise %0 is returned.
+ */
+static int valuable(struct ubifs_info *c, const struct ubifs_lprops *lprops)
+{
+	int n, cat = lprops->flags & LPROPS_CAT_MASK;
+	struct ubifs_lpt_heap *heap;
+
+	switch (cat) {
+	case LPROPS_DIRTY:
+	case LPROPS_DIRTY_IDX:
+	case LPROPS_FREE:
+		heap = &c->lpt_heap[cat - 1];
+		if (heap->cnt < heap->max_cnt)
+			return 1;
+		if (lprops->free + lprops->dirty >= c->dark_wm)
+			return 1;
+		return 0;
+	case LPROPS_EMPTY:
+		n = c->lst.empty_lebs + c->freeable_cnt -
+		    c->lst.taken_empty_lebs;
+		if (n < c->lsave_cnt)
+			return 1;
+		return 0;
+	case LPROPS_FREEABLE:
+		return 1;
+	case LPROPS_FRDI_IDX:
+		return 1;
+	}
+	return 0;
+}
+
+/**
+ * scan_for_dirty_cb - dirty space scan callback.
+ * @c: the UBIFS file-system description object
+ * @lprops: LEB properties to scan
+ * @in_tree: whether the LEB properties are in main memory
+ * @data: information passed to and from the caller of the scan
+ *
+ * This function returns a code that indicates whether the scan should continue
+ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
+ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
+ * (%LPT_SCAN_STOP).
+ */
+static int scan_for_dirty_cb(struct ubifs_info *c,
+			     const struct ubifs_lprops *lprops, int in_tree,
+			     struct scan_data *data)
+{
+	int ret = LPT_SCAN_CONTINUE;
+
+	/* Exclude LEBs that are currently in use */
+	if (lprops->flags & LPROPS_TAKEN)
+		return LPT_SCAN_CONTINUE;
+	/* Determine whether to add these LEB properties to the tree */
+	if (!in_tree && valuable(c, lprops))
+		ret |= LPT_SCAN_ADD;
+	/* Exclude LEBs with too little space */
+	if (lprops->free + lprops->dirty < data->min_space)
+		return ret;
+	/* If specified, exclude index LEBs */
+	if (data->exclude_index && lprops->flags & LPROPS_INDEX)
+		return ret;
+	/* If specified, exclude empty or freeable LEBs */
+	if (lprops->free + lprops->dirty == c->leb_size) {
+		if (!data->pick_free)
+			return ret;
+	/* Exclude LEBs with too little dirty space (unless it is empty) */
+	} else if (lprops->dirty < c->dead_wm)
+		return ret;
+	/* Finally we found space */
+	data->lnum = lprops->lnum;
+	return LPT_SCAN_ADD | LPT_SCAN_STOP;
+}
+
+/**
+ * scan_for_dirty - find a data LEB with free space.
+ * @c: the UBIFS file-system description object
+ * @min_space: minimum amount free plus dirty space the returned LEB has to
+ *             have
+ * @pick_free: if it is OK to return a free or freeable LEB
+ * @exclude_index: whether to exclude index LEBs
+ *
+ * This function returns a pointer to the LEB properties found or a negative
+ * error code.
+ */
+static const struct ubifs_lprops *scan_for_dirty(struct ubifs_info *c,
+						 int min_space, int pick_free,
+						 int exclude_index)
+{
+	const struct ubifs_lprops *lprops;
+	struct ubifs_lpt_heap *heap;
+	struct scan_data data;
+	int err, i;
+
+	/* There may be an LEB with enough dirty space on the free heap */
+	heap = &c->lpt_heap[LPROPS_FREE - 1];
+	for (i = 0; i < heap->cnt; i++) {
+		lprops = heap->arr[i];
+		if (lprops->free + lprops->dirty < min_space)
+			continue;
+		if (lprops->dirty < c->dead_wm)
+			continue;
+		return lprops;
+	}
+	/*
+	 * A LEB may have fallen off of the bottom of the dirty heap, and ended
+	 * up as uncategorized even though it has enough dirty space for us now,
+	 * so check the uncategorized list. N.B. neither empty nor freeable LEBs
+	 * can end up as uncategorized because they are kept on lists not
+	 * finite-sized heaps.
+	 */
+	list_for_each_entry(lprops, &c->uncat_list, list) {
+		if (lprops->flags & LPROPS_TAKEN)
+			continue;
+		if (lprops->free + lprops->dirty < min_space)
+			continue;
+		if (exclude_index && (lprops->flags & LPROPS_INDEX))
+			continue;
+		if (lprops->dirty < c->dead_wm)
+			continue;
+		return lprops;
+	}
+	/* We have looked everywhere in main memory, now scan the flash */
+	if (c->pnodes_have >= c->pnode_cnt)
+		/* All pnodes are in memory, so skip scan */
+		return ERR_PTR(-ENOSPC);
+	data.min_space = min_space;
+	data.pick_free = pick_free;
+	data.lnum = -1;
+	data.exclude_index = exclude_index;
+	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
+				    (ubifs_lpt_scan_callback)scan_for_dirty_cb,
+				    &data);
+	if (err)
+		return ERR_PTR(err);
+	ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt);
+	c->lscan_lnum = data.lnum;
+	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
+	if (IS_ERR(lprops))
+		return lprops;
+	ubifs_assert(c, lprops->lnum == data.lnum);
+	ubifs_assert(c, lprops->free + lprops->dirty >= min_space);
+	ubifs_assert(c, lprops->dirty >= c->dead_wm ||
+		     (pick_free &&
+		      lprops->free + lprops->dirty == c->leb_size));
+	ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, !exclude_index || !(lprops->flags & LPROPS_INDEX));
+	return lprops;
+}
+
+/**
+ * ubifs_find_dirty_leb - find a dirty LEB for the Garbage Collector.
+ * @c: the UBIFS file-system description object
+ * @ret_lp: LEB properties are returned here on exit
+ * @min_space: minimum amount free plus dirty space the returned LEB has to
+ *             have
+ * @pick_free: controls whether it is OK to pick empty or index LEBs
+ *
+ * This function tries to find a dirty logical eraseblock which has at least
+ * @min_space free and dirty space. It prefers to take an LEB from the dirty or
+ * dirty index heap, and it falls-back to LPT scanning if the heaps are empty
+ * or do not have an LEB which satisfies the @min_space criteria.
+ *
+ * Note, LEBs which have less than dead watermark of free + dirty space are
+ * never picked by this function.
+ *
+ * The additional @pick_free argument controls if this function has to return a
+ * free or freeable LEB if one is present. For example, GC must to set it to %1,
+ * when called from the journal space reservation function, because the
+ * appearance of free space may coincide with the loss of enough dirty space
+ * for GC to succeed anyway.
+ *
+ * In contrast, if the Garbage Collector is called from budgeting, it should
+ * just make free space, not return LEBs which are already free or freeable.
+ *
+ * In addition @pick_free is set to %2 by the recovery process in order to
+ * recover gc_lnum in which case an index LEB must not be returned.
+ *
+ * This function returns zero and the LEB properties of found dirty LEB in case
+ * of success, %-ENOSPC if no dirty LEB was found and a negative error code in
+ * case of other failures. The returned LEB is marked as "taken".
+ */
+int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
+			 int min_space, int pick_free)
+{
+	int err = 0, sum, exclude_index = pick_free == 2 ? 1 : 0;
+	const struct ubifs_lprops *lp = NULL, *idx_lp = NULL;
+	struct ubifs_lpt_heap *heap, *idx_heap;
+
+	ubifs_get_lprops(c);
+
+	if (pick_free) {
+		int lebs, rsvd_idx_lebs = 0;
+
+		spin_lock(&c->space_lock);
+		lebs = c->lst.empty_lebs + c->idx_gc_cnt;
+		lebs += c->freeable_cnt - c->lst.taken_empty_lebs;
+
+		/*
+		 * Note, the index may consume more LEBs than have been reserved
+		 * for it. It is OK because it might be consolidated by GC.
+		 * But if the index takes fewer LEBs than it is reserved for it,
+		 * this function must avoid picking those reserved LEBs.
+		 */
+		if (c->bi.min_idx_lebs >= c->lst.idx_lebs) {
+			rsvd_idx_lebs = c->bi.min_idx_lebs -  c->lst.idx_lebs;
+			exclude_index = 1;
+		}
+		spin_unlock(&c->space_lock);
+
+		/* Check if there are enough free LEBs for the index */
+		if (rsvd_idx_lebs < lebs) {
+			/* OK, try to find an empty LEB */
+			lp = ubifs_fast_find_empty(c);
+			if (lp)
+				goto found;
+
+			/* Or a freeable LEB */
+			lp = ubifs_fast_find_freeable(c);
+			if (lp)
+				goto found;
+		} else
+			/*
+			 * We cannot pick free/freeable LEBs in the below code.
+			 */
+			pick_free = 0;
+	} else {
+		spin_lock(&c->space_lock);
+		exclude_index = (c->bi.min_idx_lebs >= c->lst.idx_lebs);
+		spin_unlock(&c->space_lock);
+	}
+
+	/* Look on the dirty and dirty index heaps */
+	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
+	idx_heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
+
+	if (idx_heap->cnt && !exclude_index) {
+		idx_lp = idx_heap->arr[0];
+		sum = idx_lp->free + idx_lp->dirty;
+		/*
+		 * Since we reserve thrice as much space for the index than it
+		 * actually takes, it does not make sense to pick indexing LEBs
+		 * with less than, say, half LEB of dirty space. May be half is
+		 * not the optimal boundary - this should be tested and
+		 * checked. This boundary should determine how much we use
+		 * in-the-gaps to consolidate the index comparing to how much
+		 * we use garbage collector to consolidate it. The "half"
+		 * criteria just feels to be fine.
+		 */
+		if (sum < min_space || sum < c->half_leb_size)
+			idx_lp = NULL;
+	}
+
+	if (heap->cnt) {
+		lp = heap->arr[0];
+		if (lp->dirty + lp->free < min_space)
+			lp = NULL;
+	}
+
+	/* Pick the LEB with most space */
+	if (idx_lp && lp) {
+		if (idx_lp->free + idx_lp->dirty >= lp->free + lp->dirty)
+			lp = idx_lp;
+	} else if (idx_lp && !lp)
+		lp = idx_lp;
+
+	if (lp) {
+		ubifs_assert(c, lp->free + lp->dirty >= c->dead_wm);
+		goto found;
+	}
+
+	/* Did not find a dirty LEB on the dirty heaps, have to scan */
+	dbg_find("scanning LPT for a dirty LEB");
+	lp = scan_for_dirty(c, min_space, pick_free, exclude_index);
+	if (IS_ERR(lp)) {
+		err = PTR_ERR(lp);
+		goto out;
+	}
+	ubifs_assert(c, lp->dirty >= c->dead_wm ||
+		     (pick_free && lp->free + lp->dirty == c->leb_size));
+
+found:
+	dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
+		 lp->lnum, lp->free, lp->dirty, lp->flags);
+
+	lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
+			     lp->flags | LPROPS_TAKEN, 0);
+	if (IS_ERR(lp)) {
+		err = PTR_ERR(lp);
+		goto out;
+	}
+
+	memcpy(ret_lp, lp, sizeof(struct ubifs_lprops));
+
+out:
+	ubifs_release_lprops(c);
+	return err;
+}
+
+/**
+ * scan_for_free_cb - free space scan callback.
+ * @c: the UBIFS file-system description object
+ * @lprops: LEB properties to scan
+ * @in_tree: whether the LEB properties are in main memory
+ * @data: information passed to and from the caller of the scan
+ *
+ * This function returns a code that indicates whether the scan should continue
+ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
+ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
+ * (%LPT_SCAN_STOP).
+ */
+static int scan_for_free_cb(struct ubifs_info *c,
+			    const struct ubifs_lprops *lprops, int in_tree,
+			    struct scan_data *data)
+{
+	int ret = LPT_SCAN_CONTINUE;
+
+	/* Exclude LEBs that are currently in use */
+	if (lprops->flags & LPROPS_TAKEN)
+		return LPT_SCAN_CONTINUE;
+	/* Determine whether to add these LEB properties to the tree */
+	if (!in_tree && valuable(c, lprops))
+		ret |= LPT_SCAN_ADD;
+	/* Exclude index LEBs */
+	if (lprops->flags & LPROPS_INDEX)
+		return ret;
+	/* Exclude LEBs with too little space */
+	if (lprops->free < data->min_space)
+		return ret;
+	/* If specified, exclude empty LEBs */
+	if (!data->pick_free && lprops->free == c->leb_size)
+		return ret;
+	/*
+	 * LEBs that have only free and dirty space must not be allocated
+	 * because they may have been unmapped already or they may have data
+	 * that is obsolete only because of nodes that are still sitting in a
+	 * wbuf.
+	 */
+	if (lprops->free + lprops->dirty == c->leb_size && lprops->dirty > 0)
+		return ret;
+	/* Finally we found space */
+	data->lnum = lprops->lnum;
+	return LPT_SCAN_ADD | LPT_SCAN_STOP;
+}
+
+/**
+ * do_find_free_space - find a data LEB with free space.
+ * @c: the UBIFS file-system description object
+ * @min_space: minimum amount of free space required
+ * @pick_free: whether it is OK to scan for empty LEBs
+ * @squeeze: whether to try to find space in a non-empty LEB first
+ *
+ * This function returns a pointer to the LEB properties found or a negative
+ * error code.
+ */
+static
+const struct ubifs_lprops *do_find_free_space(struct ubifs_info *c,
+					      int min_space, int pick_free,
+					      int squeeze)
+{
+	const struct ubifs_lprops *lprops;
+	struct ubifs_lpt_heap *heap;
+	struct scan_data data;
+	int err, i;
+
+	if (squeeze) {
+		lprops = ubifs_fast_find_free(c);
+		if (lprops && lprops->free >= min_space)
+			return lprops;
+	}
+	if (pick_free) {
+		lprops = ubifs_fast_find_empty(c);
+		if (lprops)
+			return lprops;
+	}
+	if (!squeeze) {
+		lprops = ubifs_fast_find_free(c);
+		if (lprops && lprops->free >= min_space)
+			return lprops;
+	}
+	/* There may be an LEB with enough free space on the dirty heap */
+	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
+	for (i = 0; i < heap->cnt; i++) {
+		lprops = heap->arr[i];
+		if (lprops->free >= min_space)
+			return lprops;
+	}
+	/*
+	 * A LEB may have fallen off of the bottom of the free heap, and ended
+	 * up as uncategorized even though it has enough free space for us now,
+	 * so check the uncategorized list. N.B. neither empty nor freeable LEBs
+	 * can end up as uncategorized because they are kept on lists not
+	 * finite-sized heaps.
+	 */
+	list_for_each_entry(lprops, &c->uncat_list, list) {
+		if (lprops->flags & LPROPS_TAKEN)
+			continue;
+		if (lprops->flags & LPROPS_INDEX)
+			continue;
+		if (lprops->free >= min_space)
+			return lprops;
+	}
+	/* We have looked everywhere in main memory, now scan the flash */
+	if (c->pnodes_have >= c->pnode_cnt)
+		/* All pnodes are in memory, so skip scan */
+		return ERR_PTR(-ENOSPC);
+	data.min_space = min_space;
+	data.pick_free = pick_free;
+	data.lnum = -1;
+	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
+				    (ubifs_lpt_scan_callback)scan_for_free_cb,
+				    &data);
+	if (err)
+		return ERR_PTR(err);
+	ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt);
+	c->lscan_lnum = data.lnum;
+	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
+	if (IS_ERR(lprops))
+		return lprops;
+	ubifs_assert(c, lprops->lnum == data.lnum);
+	ubifs_assert(c, lprops->free >= min_space);
+	ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, !(lprops->flags & LPROPS_INDEX));
+	return lprops;
+}
+
+/**
+ * ubifs_find_free_space - find a data LEB with free space.
+ * @c: the UBIFS file-system description object
+ * @min_space: minimum amount of required free space
+ * @offs: contains offset of where free space starts on exit
+ * @squeeze: whether to try to find space in a non-empty LEB first
+ *
+ * This function looks for an LEB with at least @min_space bytes of free space.
+ * It tries to find an empty LEB if possible. If no empty LEBs are available,
+ * this function searches for a non-empty data LEB. The returned LEB is marked
+ * as "taken".
+ *
+ * This function returns found LEB number in case of success, %-ENOSPC if it
+ * failed to find a LEB with @min_space bytes of free space and other a negative
+ * error codes in case of failure.
+ */
+int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *offs,
+			  int squeeze)
+{
+	const struct ubifs_lprops *lprops;
+	int lebs, rsvd_idx_lebs, pick_free = 0, err, lnum, flags;
+
+	dbg_find("min_space %d", min_space);
+	ubifs_get_lprops(c);
+
+	/* Check if there are enough empty LEBs for commit */
+	spin_lock(&c->space_lock);
+	if (c->bi.min_idx_lebs > c->lst.idx_lebs)
+		rsvd_idx_lebs = c->bi.min_idx_lebs -  c->lst.idx_lebs;
+	else
+		rsvd_idx_lebs = 0;
+	lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
+	       c->lst.taken_empty_lebs;
+	if (rsvd_idx_lebs < lebs)
+		/*
+		 * OK to allocate an empty LEB, but we still don't want to go
+		 * looking for one if there aren't any.
+		 */
+		if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
+			pick_free = 1;
+			/*
+			 * Because we release the space lock, we must account
+			 * for this allocation here. After the LEB properties
+			 * flags have been updated, we subtract one. Note, the
+			 * result of this is that lprops also decreases
+			 * @taken_empty_lebs in 'ubifs_change_lp()', so it is
+			 * off by one for a short period of time which may
+			 * introduce a small disturbance to budgeting
+			 * calculations, but this is harmless because at the
+			 * worst case this would make the budgeting subsystem
+			 * be more pessimistic than needed.
+			 *
+			 * Fundamentally, this is about serialization of the
+			 * budgeting and lprops subsystems. We could make the
+			 * @space_lock a mutex and avoid dropping it before
+			 * calling 'ubifs_change_lp()', but mutex is more
+			 * heavy-weight, and we want budgeting to be as fast as
+			 * possible.
+			 */
+			c->lst.taken_empty_lebs += 1;
+		}
+	spin_unlock(&c->space_lock);
+
+	lprops = do_find_free_space(c, min_space, pick_free, squeeze);
+	if (IS_ERR(lprops)) {
+		err = PTR_ERR(lprops);
+		goto out;
+	}
+
+	lnum = lprops->lnum;
+	flags = lprops->flags | LPROPS_TAKEN;
+
+	lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC, flags, 0);
+	if (IS_ERR(lprops)) {
+		err = PTR_ERR(lprops);
+		goto out;
+	}
+
+	if (pick_free) {
+		spin_lock(&c->space_lock);
+		c->lst.taken_empty_lebs -= 1;
+		spin_unlock(&c->space_lock);
+	}
+
+	*offs = c->leb_size - lprops->free;
+	ubifs_release_lprops(c);
+
+	if (*offs == 0) {
+		/*
+		 * Ensure that empty LEBs have been unmapped. They may not have
+		 * been, for example, because of an unclean unmount.  Also
+		 * LEBs that were freeable LEBs (free + dirty == leb_size) will
+		 * not have been unmapped.
+		 */
+		err = ubifs_leb_unmap(c, lnum);
+		if (err)
+			return err;
+	}
+
+	dbg_find("found LEB %d, free %d", lnum, c->leb_size - *offs);
+	ubifs_assert(c, *offs <= c->leb_size - min_space);
+	return lnum;
+
+out:
+	if (pick_free) {
+		spin_lock(&c->space_lock);
+		c->lst.taken_empty_lebs -= 1;
+		spin_unlock(&c->space_lock);
+	}
+	ubifs_release_lprops(c);
+	return err;
+}
+
+/**
+ * scan_for_idx_cb - callback used by the scan for a free LEB for the index.
+ * @c: the UBIFS file-system description object
+ * @lprops: LEB properties to scan
+ * @in_tree: whether the LEB properties are in main memory
+ * @data: information passed to and from the caller of the scan
+ *
+ * This function returns a code that indicates whether the scan should continue
+ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
+ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
+ * (%LPT_SCAN_STOP).
+ */
+static int scan_for_idx_cb(struct ubifs_info *c,
+			   const struct ubifs_lprops *lprops, int in_tree,
+			   struct scan_data *data)
+{
+	int ret = LPT_SCAN_CONTINUE;
+
+	/* Exclude LEBs that are currently in use */
+	if (lprops->flags & LPROPS_TAKEN)
+		return LPT_SCAN_CONTINUE;
+	/* Determine whether to add these LEB properties to the tree */
+	if (!in_tree && valuable(c, lprops))
+		ret |= LPT_SCAN_ADD;
+	/* Exclude index LEBS */
+	if (lprops->flags & LPROPS_INDEX)
+		return ret;
+	/* Exclude LEBs that cannot be made empty */
+	if (lprops->free + lprops->dirty != c->leb_size)
+		return ret;
+	/*
+	 * We are allocating for the index so it is safe to allocate LEBs with
+	 * only free and dirty space, because write buffers are sync'd at commit
+	 * start.
+	 */
+	data->lnum = lprops->lnum;
+	return LPT_SCAN_ADD | LPT_SCAN_STOP;
+}
+
+/**
+ * scan_for_leb_for_idx - scan for a free LEB for the index.
+ * @c: the UBIFS file-system description object
+ */
+static const struct ubifs_lprops *scan_for_leb_for_idx(struct ubifs_info *c)
+{
+	const struct ubifs_lprops *lprops;
+	struct scan_data data;
+	int err;
+
+	data.lnum = -1;
+	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
+				    (ubifs_lpt_scan_callback)scan_for_idx_cb,
+				    &data);
+	if (err)
+		return ERR_PTR(err);
+	ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt);
+	c->lscan_lnum = data.lnum;
+	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
+	if (IS_ERR(lprops))
+		return lprops;
+	ubifs_assert(c, lprops->lnum == data.lnum);
+	ubifs_assert(c, lprops->free + lprops->dirty == c->leb_size);
+	ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, !(lprops->flags & LPROPS_INDEX));
+	return lprops;
+}
+
+/**
+ * ubifs_find_free_leb_for_idx - find a free LEB for the index.
+ * @c: the UBIFS file-system description object
+ *
+ * This function looks for a free LEB and returns that LEB number. The returned
+ * LEB is marked as "taken", "index".
+ *
+ * Only empty LEBs are allocated. This is for two reasons. First, the commit
+ * calculates the number of LEBs to allocate based on the assumption that they
+ * will be empty. Secondly, free space at the end of an index LEB is not
+ * guaranteed to be empty because it may have been used by the in-the-gaps
+ * method prior to an unclean unmount.
+ *
+ * If no LEB is found %-ENOSPC is returned. For other failures another negative
+ * error code is returned.
+ */
+int ubifs_find_free_leb_for_idx(struct ubifs_info *c)
+{
+	const struct ubifs_lprops *lprops;
+	int lnum = -1, err, flags;
+
+	ubifs_get_lprops(c);
+
+	lprops = ubifs_fast_find_empty(c);
+	if (!lprops) {
+		lprops = ubifs_fast_find_freeable(c);
+		if (!lprops) {
+			/*
+			 * The first condition means the following: go scan the
+			 * LPT if there are uncategorized lprops, which means
+			 * there may be freeable LEBs there (UBIFS does not
+			 * store the information about freeable LEBs in the
+			 * master node).
+			 */
+			if (c->in_a_category_cnt != c->main_lebs ||
+			    c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
+				ubifs_assert(c, c->freeable_cnt == 0);
+				lprops = scan_for_leb_for_idx(c);
+				if (IS_ERR(lprops)) {
+					err = PTR_ERR(lprops);
+					goto out;
+				}
+			}
+		}
+	}
+
+	if (!lprops) {
+		err = -ENOSPC;
+		goto out;
+	}
+
+	lnum = lprops->lnum;
+
+	dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
+		 lnum, lprops->free, lprops->dirty, lprops->flags);
+
+	flags = lprops->flags | LPROPS_TAKEN | LPROPS_INDEX;
+	lprops = ubifs_change_lp(c, lprops, c->leb_size, 0, flags, 0);
+	if (IS_ERR(lprops)) {
+		err = PTR_ERR(lprops);
+		goto out;
+	}
+
+	ubifs_release_lprops(c);
+
+	/*
+	 * Ensure that empty LEBs have been unmapped. They may not have been,
+	 * for example, because of an unclean unmount. Also LEBs that were
+	 * freeable LEBs (free + dirty == leb_size) will not have been unmapped.
+	 */
+	err = ubifs_leb_unmap(c, lnum);
+	if (err) {
+		ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
+				    LPROPS_TAKEN | LPROPS_INDEX, 0);
+		return err;
+	}
+
+	return lnum;
+
+out:
+	ubifs_release_lprops(c);
+	return err;
+}
+
+static int cmp_dirty_idx(const struct ubifs_lprops **a,
+			 const struct ubifs_lprops **b)
+{
+	const struct ubifs_lprops *lpa = *a;
+	const struct ubifs_lprops *lpb = *b;
+
+	return lpa->dirty + lpa->free - lpb->dirty - lpb->free;
+}
+
+/**
+ * ubifs_save_dirty_idx_lnums - save an array of the most dirty index LEB nos.
+ * @c: the UBIFS file-system description object
+ *
+ * This function is called each commit to create an array of LEB numbers of
+ * dirty index LEBs sorted in order of dirty and free space.  This is used by
+ * the in-the-gaps method of TNC commit.
+ */
+int ubifs_save_dirty_idx_lnums(struct ubifs_info *c)
+{
+	int i;
+
+	ubifs_get_lprops(c);
+	/* Copy the LPROPS_DIRTY_IDX heap */
+	c->dirty_idx.cnt = c->lpt_heap[LPROPS_DIRTY_IDX - 1].cnt;
+	memcpy(c->dirty_idx.arr, c->lpt_heap[LPROPS_DIRTY_IDX - 1].arr,
+	       sizeof(void *) * c->dirty_idx.cnt);
+	/* Sort it so that the dirtiest is now at the end */
+	sort(c->dirty_idx.arr, c->dirty_idx.cnt, sizeof(void *),
+	     (int (*)(const void *, const void *))cmp_dirty_idx, NULL);
+	dbg_find("found %d dirty index LEBs", c->dirty_idx.cnt);
+	if (c->dirty_idx.cnt)
+		dbg_find("dirtiest index LEB is %d with dirty %d and free %d",
+			 c->dirty_idx.arr[c->dirty_idx.cnt - 1]->lnum,
+			 c->dirty_idx.arr[c->dirty_idx.cnt - 1]->dirty,
+			 c->dirty_idx.arr[c->dirty_idx.cnt - 1]->free);
+	/* Replace the lprops pointers with LEB numbers */
+	for (i = 0; i < c->dirty_idx.cnt; i++)
+		c->dirty_idx.arr[i] = (void *)(size_t)c->dirty_idx.arr[i]->lnum;
+	ubifs_release_lprops(c);
+	return 0;
+}
+
+/**
+ * scan_dirty_idx_cb - callback used by the scan for a dirty index LEB.
+ * @c: the UBIFS file-system description object
+ * @lprops: LEB properties to scan
+ * @in_tree: whether the LEB properties are in main memory
+ * @data: information passed to and from the caller of the scan
+ *
+ * This function returns a code that indicates whether the scan should continue
+ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
+ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
+ * (%LPT_SCAN_STOP).
+ */
+static int scan_dirty_idx_cb(struct ubifs_info *c,
+			   const struct ubifs_lprops *lprops, int in_tree,
+			   struct scan_data *data)
+{
+	int ret = LPT_SCAN_CONTINUE;
+
+	/* Exclude LEBs that are currently in use */
+	if (lprops->flags & LPROPS_TAKEN)
+		return LPT_SCAN_CONTINUE;
+	/* Determine whether to add these LEB properties to the tree */
+	if (!in_tree && valuable(c, lprops))
+		ret |= LPT_SCAN_ADD;
+	/* Exclude non-index LEBs */
+	if (!(lprops->flags & LPROPS_INDEX))
+		return ret;
+	/* Exclude LEBs with too little space */
+	if (lprops->free + lprops->dirty < c->min_idx_node_sz)
+		return ret;
+	/* Finally we found space */
+	data->lnum = lprops->lnum;
+	return LPT_SCAN_ADD | LPT_SCAN_STOP;
+}
+
+/**
+ * find_dirty_idx_leb - find a dirty index LEB.
+ * @c: the UBIFS file-system description object
+ *
+ * This function returns LEB number upon success and a negative error code upon
+ * failure.  In particular, -ENOSPC is returned if a dirty index LEB is not
+ * found.
+ *
+ * Note that this function scans the entire LPT but it is called very rarely.
+ */
+static int find_dirty_idx_leb(struct ubifs_info *c)
+{
+	const struct ubifs_lprops *lprops;
+	struct ubifs_lpt_heap *heap;
+	struct scan_data data;
+	int err, i, ret;
+
+	/* Check all structures in memory first */
+	data.lnum = -1;
+	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
+	for (i = 0; i < heap->cnt; i++) {
+		lprops = heap->arr[i];
+		ret = scan_dirty_idx_cb(c, lprops, 1, &data);
+		if (ret & LPT_SCAN_STOP)
+			goto found;
+	}
+	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
+		ret = scan_dirty_idx_cb(c, lprops, 1, &data);
+		if (ret & LPT_SCAN_STOP)
+			goto found;
+	}
+	list_for_each_entry(lprops, &c->uncat_list, list) {
+		ret = scan_dirty_idx_cb(c, lprops, 1, &data);
+		if (ret & LPT_SCAN_STOP)
+			goto found;
+	}
+	if (c->pnodes_have >= c->pnode_cnt)
+		/* All pnodes are in memory, so skip scan */
+		return -ENOSPC;
+	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
+				    (ubifs_lpt_scan_callback)scan_dirty_idx_cb,
+				    &data);
+	if (err)
+		return err;
+found:
+	ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt);
+	c->lscan_lnum = data.lnum;
+	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
+	if (IS_ERR(lprops))
+		return PTR_ERR(lprops);
+	ubifs_assert(c, lprops->lnum == data.lnum);
+	ubifs_assert(c, lprops->free + lprops->dirty >= c->min_idx_node_sz);
+	ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, (lprops->flags & LPROPS_INDEX));
+
+	dbg_find("found dirty LEB %d, free %d, dirty %d, flags %#x",
+		 lprops->lnum, lprops->free, lprops->dirty, lprops->flags);
+
+	lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC,
+				 lprops->flags | LPROPS_TAKEN, 0);
+	if (IS_ERR(lprops))
+		return PTR_ERR(lprops);
+
+	return lprops->lnum;
+}
+
+/**
+ * get_idx_gc_leb - try to get a LEB number from trivial GC.
+ * @c: the UBIFS file-system description object
+ */
+static int get_idx_gc_leb(struct ubifs_info *c)
+{
+	const struct ubifs_lprops *lp;
+	int err, lnum;
+
+	err = ubifs_get_idx_gc_leb(c);
+	if (err < 0)
+		return err;
+	lnum = err;
+	/*
+	 * The LEB was due to be unmapped after the commit but
+	 * it is needed now for this commit.
+	 */
+	lp = ubifs_lpt_lookup_dirty(c, lnum);
+	if (IS_ERR(lp))
+		return PTR_ERR(lp);
+	lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
+			     lp->flags | LPROPS_INDEX, -1);
+	if (IS_ERR(lp))
+		return PTR_ERR(lp);
+	dbg_find("LEB %d, dirty %d and free %d flags %#x",
+		 lp->lnum, lp->dirty, lp->free, lp->flags);
+	return lnum;
+}
+
+/**
+ * find_dirtiest_idx_leb - find dirtiest index LEB from dirtiest array.
+ * @c: the UBIFS file-system description object
+ */
+static int find_dirtiest_idx_leb(struct ubifs_info *c)
+{
+	const struct ubifs_lprops *lp;
+	int lnum;
+
+	while (1) {
+		if (!c->dirty_idx.cnt)
+			return -ENOSPC;
+		/* The lprops pointers were replaced by LEB numbers */
+		lnum = (size_t)c->dirty_idx.arr[--c->dirty_idx.cnt];
+		lp = ubifs_lpt_lookup(c, lnum);
+		if (IS_ERR(lp))
+			return PTR_ERR(lp);
+		if ((lp->flags & LPROPS_TAKEN) || !(lp->flags & LPROPS_INDEX))
+			continue;
+		lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
+				     lp->flags | LPROPS_TAKEN, 0);
+		if (IS_ERR(lp))
+			return PTR_ERR(lp);
+		break;
+	}
+	dbg_find("LEB %d, dirty %d and free %d flags %#x", lp->lnum, lp->dirty,
+		 lp->free, lp->flags);
+	ubifs_assert(c, lp->flags & LPROPS_TAKEN);
+	ubifs_assert(c, lp->flags & LPROPS_INDEX);
+	return lnum;
+}
+
+/**
+ * ubifs_find_dirty_idx_leb - try to find dirtiest index LEB as at last commit.
+ * @c: the UBIFS file-system description object
+ *
+ * This function attempts to find an untaken index LEB with the most free and
+ * dirty space that can be used without overwriting index nodes that were in the
+ * last index committed.
+ */
+int ubifs_find_dirty_idx_leb(struct ubifs_info *c)
+{
+	int err;
+
+	ubifs_get_lprops(c);
+
+	/*
+	 * We made an array of the dirtiest index LEB numbers as at the start of
+	 * last commit.  Try that array first.
+	 */
+	err = find_dirtiest_idx_leb(c);
+
+	/* Next try scanning the entire LPT */
+	if (err == -ENOSPC)
+		err = find_dirty_idx_leb(c);
+
+	/* Finally take any index LEBs awaiting trivial GC */
+	if (err == -ENOSPC)
+		err = get_idx_gc_leb(c);
+
+	ubifs_release_lprops(c);
+	return err;
+}