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, 980 insertions, 0 deletions

diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
new file mode 100644
index 000000000..4b92f9253
--- /dev/null
+++ b/fs/xfs/scrub/repair.c
@@ -0,0 +1,980 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_btree.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_alloc.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_refcount_btree.h"
+#include "xfs_extent_busy.h"
+#include "xfs_ag.h"
+#include "xfs_ag_resv.h"
+#include "xfs_quota.h"
+#include "xfs_qm.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+#include "scrub/bitmap.h"
+
+/*
+ * Attempt to repair some metadata, if the metadata is corrupt and userspace
+ * told us to fix it.  This function returns -EAGAIN to mean "re-run scrub",
+ * and will set *fixed to true if it thinks it repaired anything.
+ */
+int
+xrep_attempt(
+	struct xfs_scrub	*sc)
+{
+	int			error = 0;
+
+	trace_xrep_attempt(XFS_I(file_inode(sc->file)), sc->sm, error);
+
+	xchk_ag_btcur_free(&sc->sa);
+
+	/* Repair whatever's broken. */
+	ASSERT(sc->ops->repair);
+	error = sc->ops->repair(sc);
+	trace_xrep_done(XFS_I(file_inode(sc->file)), sc->sm, error);
+	switch (error) {
+	case 0:
+		/*
+		 * Repair succeeded.  Commit the fixes and perform a second
+		 * scrub so that we can tell userspace if we fixed the problem.
+		 */
+		sc->sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT;
+		sc->flags |= XREP_ALREADY_FIXED;
+		return -EAGAIN;
+	case -EDEADLOCK:
+		/* Tell the caller to try again having grabbed all the locks. */
+		if (!(sc->flags & XCHK_TRY_HARDER)) {
+			sc->flags |= XCHK_TRY_HARDER;
+			return -EAGAIN;
+		}
+		/*
+		 * We tried harder but still couldn't grab all the resources
+		 * we needed to fix it.  The corruption has not been fixed,
+		 * so exit to userspace with the scan's output flags unchanged.
+		 */
+		return 0;
+	default:
+		/*
+		 * EAGAIN tells the caller to re-scrub, so we cannot return
+		 * that here.
+		 */
+		ASSERT(error != -EAGAIN);
+		return error;
+	}
+}
+
+/*
+ * Complain about unfixable problems in the filesystem.  We don't log
+ * corruptions when IFLAG_REPAIR wasn't set on the assumption that the driver
+ * program is xfs_scrub, which will call back with IFLAG_REPAIR set if the
+ * administrator isn't running xfs_scrub in no-repairs mode.
+ *
+ * Use this helper function because _ratelimited silently declares a static
+ * structure to track rate limiting information.
+ */
+void
+xrep_failure(
+	struct xfs_mount	*mp)
+{
+	xfs_alert_ratelimited(mp,
+"Corruption not fixed during online repair.  Unmount and run xfs_repair.");
+}
+
+/*
+ * Repair probe -- userspace uses this to probe if we're willing to repair a
+ * given mountpoint.
+ */
+int
+xrep_probe(
+	struct xfs_scrub	*sc)
+{
+	int			error = 0;
+
+	if (xchk_should_terminate(sc, &error))
+		return error;
+
+	return 0;
+}
+
+/*
+ * Roll a transaction, keeping the AG headers locked and reinitializing
+ * the btree cursors.
+ */
+int
+xrep_roll_ag_trans(
+	struct xfs_scrub	*sc)
+{
+	int			error;
+
+	/*
+	 * Keep the AG header buffers locked while we roll the transaction.
+	 * Ensure that both AG buffers are dirty and held when we roll the
+	 * transaction so that they move forward in the log without losing the
+	 * bli (and hence the bli type) when the transaction commits.
+	 *
+	 * Normal code would never hold clean buffers across a roll, but repair
+	 * needs both buffers to maintain a total lock on the AG.
+	 */
+	if (sc->sa.agi_bp) {
+		xfs_ialloc_log_agi(sc->tp, sc->sa.agi_bp, XFS_AGI_MAGICNUM);
+		xfs_trans_bhold(sc->tp, sc->sa.agi_bp);
+	}
+
+	if (sc->sa.agf_bp) {
+		xfs_alloc_log_agf(sc->tp, sc->sa.agf_bp, XFS_AGF_MAGICNUM);
+		xfs_trans_bhold(sc->tp, sc->sa.agf_bp);
+	}
+
+	/*
+	 * Roll the transaction.  We still hold the AG header buffers locked
+	 * regardless of whether or not that succeeds.  On failure, the buffers
+	 * will be released during teardown on our way out of the kernel.  If
+	 * successful, join the buffers to the new transaction and move on.
+	 */
+	error = xfs_trans_roll(&sc->tp);
+	if (error)
+		return error;
+
+	/* Join the AG headers to the new transaction. */
+	if (sc->sa.agi_bp)
+		xfs_trans_bjoin(sc->tp, sc->sa.agi_bp);
+	if (sc->sa.agf_bp)
+		xfs_trans_bjoin(sc->tp, sc->sa.agf_bp);
+
+	return 0;
+}
+
+/*
+ * Does the given AG have enough space to rebuild a btree?  Neither AG
+ * reservation can be critical, and we must have enough space (factoring
+ * in AG reservations) to construct a whole btree.
+ */
+bool
+xrep_ag_has_space(
+	struct xfs_perag	*pag,
+	xfs_extlen_t		nr_blocks,
+	enum xfs_ag_resv_type	type)
+{
+	return  !xfs_ag_resv_critical(pag, XFS_AG_RESV_RMAPBT) &&
+		!xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA) &&
+		pag->pagf_freeblks > xfs_ag_resv_needed(pag, type) + nr_blocks;
+}
+
+/*
+ * Figure out how many blocks to reserve for an AG repair.  We calculate the
+ * worst case estimate for the number of blocks we'd need to rebuild one of
+ * any type of per-AG btree.
+ */
+xfs_extlen_t
+xrep_calc_ag_resblks(
+	struct xfs_scrub		*sc)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_scrub_metadata	*sm = sc->sm;
+	struct xfs_perag		*pag;
+	struct xfs_buf			*bp;
+	xfs_agino_t			icount = NULLAGINO;
+	xfs_extlen_t			aglen = NULLAGBLOCK;
+	xfs_extlen_t			usedlen;
+	xfs_extlen_t			freelen;
+	xfs_extlen_t			bnobt_sz;
+	xfs_extlen_t			inobt_sz;
+	xfs_extlen_t			rmapbt_sz;
+	xfs_extlen_t			refcbt_sz;
+	int				error;
+
+	if (!(sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
+		return 0;
+
+	pag = xfs_perag_get(mp, sm->sm_agno);
+	if (pag->pagi_init) {
+		/* Use in-core icount if possible. */
+		icount = pag->pagi_count;
+	} else {
+		/* Try to get the actual counters from disk. */
+		error = xfs_ialloc_read_agi(pag, NULL, &bp);
+		if (!error) {
+			icount = pag->pagi_count;
+			xfs_buf_relse(bp);
+		}
+	}
+
+	/* Now grab the block counters from the AGF. */
+	error = xfs_alloc_read_agf(pag, NULL, 0, &bp);
+	if (error) {
+		aglen = pag->block_count;
+		freelen = aglen;
+		usedlen = aglen;
+	} else {
+		struct xfs_agf	*agf = bp->b_addr;
+
+		aglen = be32_to_cpu(agf->agf_length);
+		freelen = be32_to_cpu(agf->agf_freeblks);
+		usedlen = aglen - freelen;
+		xfs_buf_relse(bp);
+	}
+
+	/* If the icount is impossible, make some worst-case assumptions. */
+	if (icount == NULLAGINO ||
+	    !xfs_verify_agino(pag, icount)) {
+		icount = pag->agino_max - pag->agino_min + 1;
+	}
+
+	/* If the block counts are impossible, make worst-case assumptions. */
+	if (aglen == NULLAGBLOCK ||
+	    aglen != pag->block_count ||
+	    freelen >= aglen) {
+		aglen = pag->block_count;
+		freelen = aglen;
+		usedlen = aglen;
+	}
+	xfs_perag_put(pag);
+
+	trace_xrep_calc_ag_resblks(mp, sm->sm_agno, icount, aglen,
+			freelen, usedlen);
+
+	/*
+	 * Figure out how many blocks we'd need worst case to rebuild
+	 * each type of btree.  Note that we can only rebuild the
+	 * bnobt/cntbt or inobt/finobt as pairs.
+	 */
+	bnobt_sz = 2 * xfs_allocbt_calc_size(mp, freelen);
+	if (xfs_has_sparseinodes(mp))
+		inobt_sz = xfs_iallocbt_calc_size(mp, icount /
+				XFS_INODES_PER_HOLEMASK_BIT);
+	else
+		inobt_sz = xfs_iallocbt_calc_size(mp, icount /
+				XFS_INODES_PER_CHUNK);
+	if (xfs_has_finobt(mp))
+		inobt_sz *= 2;
+	if (xfs_has_reflink(mp))
+		refcbt_sz = xfs_refcountbt_calc_size(mp, usedlen);
+	else
+		refcbt_sz = 0;
+	if (xfs_has_rmapbt(mp)) {
+		/*
+		 * Guess how many blocks we need to rebuild the rmapbt.
+		 * For non-reflink filesystems we can't have more records than
+		 * used blocks.  However, with reflink it's possible to have
+		 * more than one rmap record per AG block.  We don't know how
+		 * many rmaps there could be in the AG, so we start off with
+		 * what we hope is an generous over-estimation.
+		 */
+		if (xfs_has_reflink(mp))
+			rmapbt_sz = xfs_rmapbt_calc_size(mp,
+					(unsigned long long)aglen * 2);
+		else
+			rmapbt_sz = xfs_rmapbt_calc_size(mp, usedlen);
+	} else {
+		rmapbt_sz = 0;
+	}
+
+	trace_xrep_calc_ag_resblks_btsize(mp, sm->sm_agno, bnobt_sz,
+			inobt_sz, rmapbt_sz, refcbt_sz);
+
+	return max(max(bnobt_sz, inobt_sz), max(rmapbt_sz, refcbt_sz));
+}
+
+/* Allocate a block in an AG. */
+int
+xrep_alloc_ag_block(
+	struct xfs_scrub		*sc,
+	const struct xfs_owner_info	*oinfo,
+	xfs_fsblock_t			*fsbno,
+	enum xfs_ag_resv_type		resv)
+{
+	struct xfs_alloc_arg		args = {0};
+	xfs_agblock_t			bno;
+	int				error;
+
+	switch (resv) {
+	case XFS_AG_RESV_AGFL:
+	case XFS_AG_RESV_RMAPBT:
+		error = xfs_alloc_get_freelist(sc->sa.pag, sc->tp,
+				sc->sa.agf_bp, &bno, 1);
+		if (error)
+			return error;
+		if (bno == NULLAGBLOCK)
+			return -ENOSPC;
+		xfs_extent_busy_reuse(sc->mp, sc->sa.pag, bno, 1, false);
+		*fsbno = XFS_AGB_TO_FSB(sc->mp, sc->sa.pag->pag_agno, bno);
+		if (resv == XFS_AG_RESV_RMAPBT)
+			xfs_ag_resv_rmapbt_alloc(sc->mp, sc->sa.pag->pag_agno);
+		return 0;
+	default:
+		break;
+	}
+
+	args.tp = sc->tp;
+	args.mp = sc->mp;
+	args.oinfo = *oinfo;
+	args.fsbno = XFS_AGB_TO_FSB(args.mp, sc->sa.pag->pag_agno, 0);
+	args.minlen = 1;
+	args.maxlen = 1;
+	args.prod = 1;
+	args.type = XFS_ALLOCTYPE_THIS_AG;
+	args.resv = resv;
+
+	error = xfs_alloc_vextent(&args);
+	if (error)
+		return error;
+	if (args.fsbno == NULLFSBLOCK)
+		return -ENOSPC;
+	ASSERT(args.len == 1);
+	*fsbno = args.fsbno;
+
+	return 0;
+}
+
+/* Initialize a new AG btree root block with zero entries. */
+int
+xrep_init_btblock(
+	struct xfs_scrub		*sc,
+	xfs_fsblock_t			fsb,
+	struct xfs_buf			**bpp,
+	xfs_btnum_t			btnum,
+	const struct xfs_buf_ops	*ops)
+{
+	struct xfs_trans		*tp = sc->tp;
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_buf			*bp;
+	int				error;
+
+	trace_xrep_init_btblock(mp, XFS_FSB_TO_AGNO(mp, fsb),
+			XFS_FSB_TO_AGBNO(mp, fsb), btnum);
+
+	ASSERT(XFS_FSB_TO_AGNO(mp, fsb) == sc->sa.pag->pag_agno);
+	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
+			XFS_FSB_TO_DADDR(mp, fsb), XFS_FSB_TO_BB(mp, 1), 0,
+			&bp);
+	if (error)
+		return error;
+	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
+	xfs_btree_init_block(mp, bp, btnum, 0, 0, sc->sa.pag->pag_agno);
+	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_BTREE_BUF);
+	xfs_trans_log_buf(tp, bp, 0, BBTOB(bp->b_length) - 1);
+	bp->b_ops = ops;
+	*bpp = bp;
+
+	return 0;
+}
+
+/*
+ * Reconstructing per-AG Btrees
+ *
+ * When a space btree is corrupt, we don't bother trying to fix it.  Instead,
+ * we scan secondary space metadata to derive the records that should be in
+ * the damaged btree, initialize a fresh btree root, and insert the records.
+ * Note that for rebuilding the rmapbt we scan all the primary data to
+ * generate the new records.
+ *
+ * However, that leaves the matter of removing all the metadata describing the
+ * old broken structure.  For primary metadata we use the rmap data to collect
+ * every extent with a matching rmap owner (bitmap); we then iterate all other
+ * metadata structures with the same rmap owner to collect the extents that
+ * cannot be removed (sublist).  We then subtract sublist from bitmap to
+ * derive the blocks that were used by the old btree.  These blocks can be
+ * reaped.
+ *
+ * For rmapbt reconstructions we must use different tactics for extent
+ * collection.  First we iterate all primary metadata (this excludes the old
+ * rmapbt, obviously) to generate new rmap records.  The gaps in the rmap
+ * records are collected as bitmap.  The bnobt records are collected as
+ * sublist.  As with the other btrees we subtract sublist from bitmap, and the
+ * result (since the rmapbt lives in the free space) are the blocks from the
+ * old rmapbt.
+ *
+ * Disposal of Blocks from Old per-AG Btrees
+ *
+ * Now that we've constructed a new btree to replace the damaged one, we want
+ * to dispose of the blocks that (we think) the old btree was using.
+ * Previously, we used the rmapbt to collect the extents (bitmap) with the
+ * rmap owner corresponding to the tree we rebuilt, collected extents for any
+ * blocks with the same rmap owner that are owned by another data structure
+ * (sublist), and subtracted sublist from bitmap.  In theory the extents
+ * remaining in bitmap are the old btree's blocks.
+ *
+ * Unfortunately, it's possible that the btree was crosslinked with other
+ * blocks on disk.  The rmap data can tell us if there are multiple owners, so
+ * if the rmapbt says there is an owner of this block other than @oinfo, then
+ * the block is crosslinked.  Remove the reverse mapping and continue.
+ *
+ * If there is one rmap record, we can free the block, which removes the
+ * reverse mapping but doesn't add the block to the free space.  Our repair
+ * strategy is to hope the other metadata objects crosslinked on this block
+ * will be rebuilt (atop different blocks), thereby removing all the cross
+ * links.
+ *
+ * If there are no rmap records at all, we also free the block.  If the btree
+ * being rebuilt lives in the free space (bnobt/cntbt/rmapbt) then there isn't
+ * supposed to be a rmap record and everything is ok.  For other btrees there
+ * had to have been an rmap entry for the block to have ended up on @bitmap,
+ * so if it's gone now there's something wrong and the fs will shut down.
+ *
+ * Note: If there are multiple rmap records with only the same rmap owner as
+ * the btree we're trying to rebuild and the block is indeed owned by another
+ * data structure with the same rmap owner, then the block will be in sublist
+ * and therefore doesn't need disposal.  If there are multiple rmap records
+ * with only the same rmap owner but the block is not owned by something with
+ * the same rmap owner, the block will be freed.
+ *
+ * The caller is responsible for locking the AG headers for the entire rebuild
+ * operation so that nothing else can sneak in and change the AG state while
+ * we're not looking.  We also assume that the caller already invalidated any
+ * buffers associated with @bitmap.
+ */
+
+/*
+ * Invalidate buffers for per-AG btree blocks we're dumping.  This function
+ * is not intended for use with file data repairs; we have bunmapi for that.
+ */
+int
+xrep_invalidate_blocks(
+	struct xfs_scrub	*sc,
+	struct xbitmap		*bitmap)
+{
+	struct xbitmap_range	*bmr;
+	struct xbitmap_range	*n;
+	struct xfs_buf		*bp;
+	xfs_fsblock_t		fsbno;
+
+	/*
+	 * For each block in each extent, see if there's an incore buffer for
+	 * exactly that block; if so, invalidate it.  The buffer cache only
+	 * lets us look for one buffer at a time, so we have to look one block
+	 * at a time.  Avoid invalidating AG headers and post-EOFS blocks
+	 * because we never own those; and if we can't TRYLOCK the buffer we
+	 * assume it's owned by someone else.
+	 */
+	for_each_xbitmap_block(fsbno, bmr, n, bitmap) {
+		int		error;
+
+		/* Skip AG headers and post-EOFS blocks */
+		if (!xfs_verify_fsbno(sc->mp, fsbno))
+			continue;
+		error = xfs_buf_incore(sc->mp->m_ddev_targp,
+				XFS_FSB_TO_DADDR(sc->mp, fsbno),
+				XFS_FSB_TO_BB(sc->mp, 1), XBF_TRYLOCK, &bp);
+		if (error)
+			continue;
+
+		xfs_trans_bjoin(sc->tp, bp);
+		xfs_trans_binval(sc->tp, bp);
+	}
+
+	return 0;
+}
+
+/* Ensure the freelist is the correct size. */
+int
+xrep_fix_freelist(
+	struct xfs_scrub	*sc,
+	bool			can_shrink)
+{
+	struct xfs_alloc_arg	args = {0};
+
+	args.mp = sc->mp;
+	args.tp = sc->tp;
+	args.agno = sc->sa.pag->pag_agno;
+	args.alignment = 1;
+	args.pag = sc->sa.pag;
+
+	return xfs_alloc_fix_freelist(&args,
+			can_shrink ? 0 : XFS_ALLOC_FLAG_NOSHRINK);
+}
+
+/*
+ * Put a block back on the AGFL.
+ */
+STATIC int
+xrep_put_freelist(
+	struct xfs_scrub	*sc,
+	xfs_agblock_t		agbno)
+{
+	struct xfs_buf		*agfl_bp;
+	int			error;
+
+	/* Make sure there's space on the freelist. */
+	error = xrep_fix_freelist(sc, true);
+	if (error)
+		return error;
+
+	/*
+	 * Since we're "freeing" a lost block onto the AGFL, we have to
+	 * create an rmap for the block prior to merging it or else other
+	 * parts will break.
+	 */
+	error = xfs_rmap_alloc(sc->tp, sc->sa.agf_bp, sc->sa.pag, agbno, 1,
+			&XFS_RMAP_OINFO_AG);
+	if (error)
+		return error;
+
+	/* Put the block on the AGFL. */
+	error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);
+	if (error)
+		return error;
+
+	error = xfs_alloc_put_freelist(sc->sa.pag, sc->tp, sc->sa.agf_bp,
+			agfl_bp, agbno, 0);
+	if (error)
+		return error;
+	xfs_extent_busy_insert(sc->tp, sc->sa.pag, agbno, 1,
+			XFS_EXTENT_BUSY_SKIP_DISCARD);
+
+	return 0;
+}
+
+/* Dispose of a single block. */
+STATIC int
+xrep_reap_block(
+	struct xfs_scrub		*sc,
+	xfs_fsblock_t			fsbno,
+	const struct xfs_owner_info	*oinfo,
+	enum xfs_ag_resv_type		resv)
+{
+	struct xfs_btree_cur		*cur;
+	struct xfs_buf			*agf_bp = NULL;
+	xfs_agblock_t			agbno;
+	bool				has_other_rmap;
+	int				error;
+
+	agbno = XFS_FSB_TO_AGBNO(sc->mp, fsbno);
+	ASSERT(XFS_FSB_TO_AGNO(sc->mp, fsbno) == sc->sa.pag->pag_agno);
+
+	/*
+	 * If we are repairing per-inode metadata, we need to read in the AGF
+	 * buffer.  Otherwise, we're repairing a per-AG structure, so reuse
+	 * the AGF buffer that the setup functions already grabbed.
+	 */
+	if (sc->ip) {
+		error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
+		if (error)
+			return error;
+	} else {
+		agf_bp = sc->sa.agf_bp;
+	}
+	cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf_bp, sc->sa.pag);
+
+	/* Can we find any other rmappings? */
+	error = xfs_rmap_has_other_keys(cur, agbno, 1, oinfo, &has_other_rmap);
+	xfs_btree_del_cursor(cur, error);
+	if (error)
+		goto out_free;
+
+	/*
+	 * If there are other rmappings, this block is cross linked and must
+	 * not be freed.  Remove the reverse mapping and move on.  Otherwise,
+	 * we were the only owner of the block, so free the extent, which will
+	 * also remove the rmap.
+	 *
+	 * XXX: XFS doesn't support detecting the case where a single block
+	 * metadata structure is crosslinked with a multi-block structure
+	 * because the buffer cache doesn't detect aliasing problems, so we
+	 * can't fix 100% of crosslinking problems (yet).  The verifiers will
+	 * blow on writeout, the filesystem will shut down, and the admin gets
+	 * to run xfs_repair.
+	 */
+	if (has_other_rmap)
+		error = xfs_rmap_free(sc->tp, agf_bp, sc->sa.pag, agbno,
+					1, oinfo);
+	else if (resv == XFS_AG_RESV_AGFL)
+		error = xrep_put_freelist(sc, agbno);
+	else
+		error = xfs_free_extent(sc->tp, fsbno, 1, oinfo, resv);
+	if (agf_bp != sc->sa.agf_bp)
+		xfs_trans_brelse(sc->tp, agf_bp);
+	if (error)
+		return error;
+
+	if (sc->ip)
+		return xfs_trans_roll_inode(&sc->tp, sc->ip);
+	return xrep_roll_ag_trans(sc);
+
+out_free:
+	if (agf_bp != sc->sa.agf_bp)
+		xfs_trans_brelse(sc->tp, agf_bp);
+	return error;
+}
+
+/* Dispose of every block of every extent in the bitmap. */
+int
+xrep_reap_extents(
+	struct xfs_scrub		*sc,
+	struct xbitmap			*bitmap,
+	const struct xfs_owner_info	*oinfo,
+	enum xfs_ag_resv_type		type)
+{
+	struct xbitmap_range		*bmr;
+	struct xbitmap_range		*n;
+	xfs_fsblock_t			fsbno;
+	int				error = 0;
+
+	ASSERT(xfs_has_rmapbt(sc->mp));
+
+	for_each_xbitmap_block(fsbno, bmr, n, bitmap) {
+		ASSERT(sc->ip != NULL ||
+		       XFS_FSB_TO_AGNO(sc->mp, fsbno) == sc->sa.pag->pag_agno);
+		trace_xrep_dispose_btree_extent(sc->mp,
+				XFS_FSB_TO_AGNO(sc->mp, fsbno),
+				XFS_FSB_TO_AGBNO(sc->mp, fsbno), 1);
+
+		error = xrep_reap_block(sc, fsbno, oinfo, type);
+		if (error)
+			break;
+	}
+
+	return error;
+}
+
+/*
+ * Finding per-AG Btree Roots for AGF/AGI Reconstruction
+ *
+ * If the AGF or AGI become slightly corrupted, it may be necessary to rebuild
+ * the AG headers by using the rmap data to rummage through the AG looking for
+ * btree roots.  This is not guaranteed to work if the AG is heavily damaged
+ * or the rmap data are corrupt.
+ *
+ * Callers of xrep_find_ag_btree_roots must lock the AGF and AGFL
+ * buffers if the AGF is being rebuilt; or the AGF and AGI buffers if the
+ * AGI is being rebuilt.  It must maintain these locks until it's safe for
+ * other threads to change the btrees' shapes.  The caller provides
+ * information about the btrees to look for by passing in an array of
+ * xrep_find_ag_btree with the (rmap owner, buf_ops, magic) fields set.
+ * The (root, height) fields will be set on return if anything is found.  The
+ * last element of the array should have a NULL buf_ops to mark the end of the
+ * array.
+ *
+ * For every rmapbt record matching any of the rmap owners in btree_info,
+ * read each block referenced by the rmap record.  If the block is a btree
+ * block from this filesystem matching any of the magic numbers and has a
+ * level higher than what we've already seen, remember the block and the
+ * height of the tree required to have such a block.  When the call completes,
+ * we return the highest block we've found for each btree description; those
+ * should be the roots.
+ */
+
+struct xrep_findroot {
+	struct xfs_scrub		*sc;
+	struct xfs_buf			*agfl_bp;
+	struct xfs_agf			*agf;
+	struct xrep_find_ag_btree	*btree_info;
+};
+
+/* See if our block is in the AGFL. */
+STATIC int
+xrep_findroot_agfl_walk(
+	struct xfs_mount	*mp,
+	xfs_agblock_t		bno,
+	void			*priv)
+{
+	xfs_agblock_t		*agbno = priv;
+
+	return (*agbno == bno) ? -ECANCELED : 0;
+}
+
+/* Does this block match the btree information passed in? */
+STATIC int
+xrep_findroot_block(
+	struct xrep_findroot		*ri,
+	struct xrep_find_ag_btree	*fab,
+	uint64_t			owner,
+	xfs_agblock_t			agbno,
+	bool				*done_with_block)
+{
+	struct xfs_mount		*mp = ri->sc->mp;
+	struct xfs_buf			*bp;
+	struct xfs_btree_block		*btblock;
+	xfs_daddr_t			daddr;
+	int				block_level;
+	int				error = 0;
+
+	daddr = XFS_AGB_TO_DADDR(mp, ri->sc->sa.pag->pag_agno, agbno);
+
+	/*
+	 * Blocks in the AGFL have stale contents that might just happen to
+	 * have a matching magic and uuid.  We don't want to pull these blocks
+	 * in as part of a tree root, so we have to filter out the AGFL stuff
+	 * here.  If the AGFL looks insane we'll just refuse to repair.
+	 */
+	if (owner == XFS_RMAP_OWN_AG) {
+		error = xfs_agfl_walk(mp, ri->agf, ri->agfl_bp,
+				xrep_findroot_agfl_walk, &agbno);
+		if (error == -ECANCELED)
+			return 0;
+		if (error)
+			return error;
+	}
+
+	/*
+	 * Read the buffer into memory so that we can see if it's a match for
+	 * our btree type.  We have no clue if it is beforehand, and we want to
+	 * avoid xfs_trans_read_buf's behavior of dumping the DONE state (which
+	 * will cause needless disk reads in subsequent calls to this function)
+	 * and logging metadata verifier failures.
+	 *
+	 * Therefore, pass in NULL buffer ops.  If the buffer was already in
+	 * memory from some other caller it will already have b_ops assigned.
+	 * If it was in memory from a previous unsuccessful findroot_block
+	 * call, the buffer won't have b_ops but it should be clean and ready
+	 * for us to try to verify if the read call succeeds.  The same applies
+	 * if the buffer wasn't in memory at all.
+	 *
+	 * Note: If we never match a btree type with this buffer, it will be
+	 * left in memory with NULL b_ops.  This shouldn't be a problem unless
+	 * the buffer gets written.
+	 */
+	error = xfs_trans_read_buf(mp, ri->sc->tp, mp->m_ddev_targp, daddr,
+			mp->m_bsize, 0, &bp, NULL);
+	if (error)
+		return error;
+
+	/* Ensure the block magic matches the btree type we're looking for. */
+	btblock = XFS_BUF_TO_BLOCK(bp);
+	ASSERT(fab->buf_ops->magic[1] != 0);
+	if (btblock->bb_magic != fab->buf_ops->magic[1])
+		goto out;
+
+	/*
+	 * If the buffer already has ops applied and they're not the ones for
+	 * this btree type, we know this block doesn't match the btree and we
+	 * can bail out.
+	 *
+	 * If the buffer ops match ours, someone else has already validated
+	 * the block for us, so we can move on to checking if this is a root
+	 * block candidate.
+	 *
+	 * If the buffer does not have ops, nobody has successfully validated
+	 * the contents and the buffer cannot be dirty.  If the magic, uuid,
+	 * and structure match this btree type then we'll move on to checking
+	 * if it's a root block candidate.  If there is no match, bail out.
+	 */
+	if (bp->b_ops) {
+		if (bp->b_ops != fab->buf_ops)
+			goto out;
+	} else {
+		ASSERT(!xfs_trans_buf_is_dirty(bp));
+		if (!uuid_equal(&btblock->bb_u.s.bb_uuid,
+				&mp->m_sb.sb_meta_uuid))
+			goto out;
+		/*
+		 * Read verifiers can reference b_ops, so we set the pointer
+		 * here.  If the verifier fails we'll reset the buffer state
+		 * to what it was before we touched the buffer.
+		 */
+		bp->b_ops = fab->buf_ops;
+		fab->buf_ops->verify_read(bp);
+		if (bp->b_error) {
+			bp->b_ops = NULL;
+			bp->b_error = 0;
+			goto out;
+		}
+
+		/*
+		 * Some read verifiers will (re)set b_ops, so we must be
+		 * careful not to change b_ops after running the verifier.
+		 */
+	}
+
+	/*
+	 * This block passes the magic/uuid and verifier tests for this btree
+	 * type.  We don't need the caller to try the other tree types.
+	 */
+	*done_with_block = true;
+
+	/*
+	 * Compare this btree block's level to the height of the current
+	 * candidate root block.
+	 *
+	 * If the level matches the root we found previously, throw away both
+	 * blocks because there can't be two candidate roots.
+	 *
+	 * If level is lower in the tree than the root we found previously,
+	 * ignore this block.
+	 */
+	block_level = xfs_btree_get_level(btblock);
+	if (block_level + 1 == fab->height) {
+		fab->root = NULLAGBLOCK;
+		goto out;
+	} else if (block_level < fab->height) {
+		goto out;
+	}
+
+	/*
+	 * This is the highest block in the tree that we've found so far.
+	 * Update the btree height to reflect what we've learned from this
+	 * block.
+	 */
+	fab->height = block_level + 1;
+
+	/*
+	 * If this block doesn't have sibling pointers, then it's the new root
+	 * block candidate.  Otherwise, the root will be found farther up the
+	 * tree.
+	 */
+	if (btblock->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) &&
+	    btblock->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
+		fab->root = agbno;
+	else
+		fab->root = NULLAGBLOCK;
+
+	trace_xrep_findroot_block(mp, ri->sc->sa.pag->pag_agno, agbno,
+			be32_to_cpu(btblock->bb_magic), fab->height - 1);
+out:
+	xfs_trans_brelse(ri->sc->tp, bp);
+	return error;
+}
+
+/*
+ * Do any of the blocks in this rmap record match one of the btrees we're
+ * looking for?
+ */
+STATIC int
+xrep_findroot_rmap(
+	struct xfs_btree_cur		*cur,
+	const struct xfs_rmap_irec	*rec,
+	void				*priv)
+{
+	struct xrep_findroot		*ri = priv;
+	struct xrep_find_ag_btree	*fab;
+	xfs_agblock_t			b;
+	bool				done;
+	int				error = 0;
+
+	/* Ignore anything that isn't AG metadata. */
+	if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner))
+		return 0;
+
+	/* Otherwise scan each block + btree type. */
+	for (b = 0; b < rec->rm_blockcount; b++) {
+		done = false;
+		for (fab = ri->btree_info; fab->buf_ops; fab++) {
+			if (rec->rm_owner != fab->rmap_owner)
+				continue;
+			error = xrep_findroot_block(ri, fab,
+					rec->rm_owner, rec->rm_startblock + b,
+					&done);
+			if (error)
+				return error;
+			if (done)
+				break;
+		}
+	}
+
+	return 0;
+}
+
+/* Find the roots of the per-AG btrees described in btree_info. */
+int
+xrep_find_ag_btree_roots(
+	struct xfs_scrub		*sc,
+	struct xfs_buf			*agf_bp,
+	struct xrep_find_ag_btree	*btree_info,
+	struct xfs_buf			*agfl_bp)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xrep_findroot		ri;
+	struct xrep_find_ag_btree	*fab;
+	struct xfs_btree_cur		*cur;
+	int				error;
+
+	ASSERT(xfs_buf_islocked(agf_bp));
+	ASSERT(agfl_bp == NULL || xfs_buf_islocked(agfl_bp));
+
+	ri.sc = sc;
+	ri.btree_info = btree_info;
+	ri.agf = agf_bp->b_addr;
+	ri.agfl_bp = agfl_bp;
+	for (fab = btree_info; fab->buf_ops; fab++) {
+		ASSERT(agfl_bp || fab->rmap_owner != XFS_RMAP_OWN_AG);
+		ASSERT(XFS_RMAP_NON_INODE_OWNER(fab->rmap_owner));
+		fab->root = NULLAGBLOCK;
+		fab->height = 0;
+	}
+
+	cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
+	error = xfs_rmap_query_all(cur, xrep_findroot_rmap, &ri);
+	xfs_btree_del_cursor(cur, error);
+
+	return error;
+}
+
+/* Force a quotacheck the next time we mount. */
+void
+xrep_force_quotacheck(
+	struct xfs_scrub	*sc,
+	xfs_dqtype_t		type)
+{
+	uint			flag;
+
+	flag = xfs_quota_chkd_flag(type);
+	if (!(flag & sc->mp->m_qflags))
+		return;
+
+	mutex_lock(&sc->mp->m_quotainfo->qi_quotaofflock);
+	sc->mp->m_qflags &= ~flag;
+	spin_lock(&sc->mp->m_sb_lock);
+	sc->mp->m_sb.sb_qflags &= ~flag;
+	spin_unlock(&sc->mp->m_sb_lock);
+	xfs_log_sb(sc->tp);
+	mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock);
+}
+
+/*
+ * Attach dquots to this inode, or schedule quotacheck to fix them.
+ *
+ * This function ensures that the appropriate dquots are attached to an inode.
+ * We cannot allow the dquot code to allocate an on-disk dquot block here
+ * because we're already in transaction context with the inode locked.  The
+ * on-disk dquot should already exist anyway.  If the quota code signals
+ * corruption or missing quota information, schedule quotacheck, which will
+ * repair corruptions in the quota metadata.
+ */
+int
+xrep_ino_dqattach(
+	struct xfs_scrub	*sc)
+{
+	int			error;
+
+	error = xfs_qm_dqattach_locked(sc->ip, false);
+	switch (error) {
+	case -EFSBADCRC:
+	case -EFSCORRUPTED:
+	case -ENOENT:
+		xfs_err_ratelimited(sc->mp,
+"inode %llu repair encountered quota error %d, quotacheck forced.",
+				(unsigned long long)sc->ip->i_ino, error);
+		if (XFS_IS_UQUOTA_ON(sc->mp) && !sc->ip->i_udquot)
+			xrep_force_quotacheck(sc, XFS_DQTYPE_USER);
+		if (XFS_IS_GQUOTA_ON(sc->mp) && !sc->ip->i_gdquot)
+			xrep_force_quotacheck(sc, XFS_DQTYPE_GROUP);
+		if (XFS_IS_PQUOTA_ON(sc->mp) && !sc->ip->i_pdquot)
+			xrep_force_quotacheck(sc, XFS_DQTYPE_PROJ);
+		fallthrough;
+	case -ESRCH:
+		error = 0;
+		break;
+	default:
+		break;
+	}
+
+	return error;
+}