From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- fs/ubifs/shrinker.c | 319 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 319 insertions(+) create mode 100644 fs/ubifs/shrinker.c (limited to 'fs/ubifs/shrinker.c') diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c new file mode 100644 index 000000000..d00a6f20a --- /dev/null +++ b/fs/ubifs/shrinker.c @@ -0,0 +1,319 @@ +// 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 implements UBIFS shrinker which evicts clean znodes from the TNC + * tree when Linux VM needs more RAM. + * + * We do not implement any LRU lists to find oldest znodes to free because it + * would add additional overhead to the file system fast paths. So the shrinker + * just walks the TNC tree when searching for znodes to free. + * + * If the root of a TNC sub-tree is clean and old enough, then the children are + * also clean and old enough. So the shrinker walks the TNC in level order and + * dumps entire sub-trees. + * + * The age of znodes is just the time-stamp when they were last looked at. + * The current shrinker first tries to evict old znodes, then young ones. + * + * Since the shrinker is global, it has to protect against races with FS + * un-mounts, which is done by the 'ubifs_infos_lock' and 'c->umount_mutex'. + */ + +#include "ubifs.h" + +/* List of all UBIFS file-system instances */ +LIST_HEAD(ubifs_infos); + +/* + * We number each shrinker run and record the number on the ubifs_info structure + * so that we can easily work out which ubifs_info structures have already been + * done by the current run. + */ +static unsigned int shrinker_run_no; + +/* Protects 'ubifs_infos' list */ +DEFINE_SPINLOCK(ubifs_infos_lock); + +/* Global clean znode counter (for all mounted UBIFS instances) */ +atomic_long_t ubifs_clean_zn_cnt; + +/** + * shrink_tnc - shrink TNC tree. + * @c: UBIFS file-system description object + * @nr: number of znodes to free + * @age: the age of znodes to free + * @contention: if any contention, this is set to %1 + * + * This function traverses TNC tree and frees clean znodes. It does not free + * clean znodes which younger then @age. Returns number of freed znodes. + */ +static int shrink_tnc(struct ubifs_info *c, int nr, int age, int *contention) +{ + int total_freed = 0; + struct ubifs_znode *znode, *zprev; + time64_t time = ktime_get_seconds(); + + ubifs_assert(c, mutex_is_locked(&c->umount_mutex)); + ubifs_assert(c, mutex_is_locked(&c->tnc_mutex)); + + if (!c->zroot.znode || atomic_long_read(&c->clean_zn_cnt) == 0) + return 0; + + /* + * Traverse the TNC tree in levelorder manner, so that it is possible + * to destroy large sub-trees. Indeed, if a znode is old, then all its + * children are older or of the same age. + * + * Note, we are holding 'c->tnc_mutex', so we do not have to lock the + * 'c->space_lock' when _reading_ 'c->clean_zn_cnt', because it is + * changed only when the 'c->tnc_mutex' is held. + */ + zprev = NULL; + znode = ubifs_tnc_levelorder_next(c, c->zroot.znode, NULL); + while (znode && total_freed < nr && + atomic_long_read(&c->clean_zn_cnt) > 0) { + int freed; + + /* + * If the znode is clean, but it is in the 'c->cnext' list, this + * means that this znode has just been written to flash as a + * part of commit and was marked clean. They will be removed + * from the list at end commit. We cannot change the list, + * because it is not protected by any mutex (design decision to + * make commit really independent and parallel to main I/O). So + * we just skip these znodes. + * + * Note, the 'clean_zn_cnt' counters are not updated until + * after the commit, so the UBIFS shrinker does not report + * the znodes which are in the 'c->cnext' list as freeable. + * + * Also note, if the root of a sub-tree is not in 'c->cnext', + * then the whole sub-tree is not in 'c->cnext' as well, so it + * is safe to dump whole sub-tree. + */ + + if (znode->cnext) { + /* + * Very soon these znodes will be removed from the list + * and become freeable. + */ + *contention = 1; + } else if (!ubifs_zn_dirty(znode) && + abs(time - znode->time) >= age) { + if (znode->parent) + znode->parent->zbranch[znode->iip].znode = NULL; + else + c->zroot.znode = NULL; + + freed = ubifs_destroy_tnc_subtree(c, znode); + atomic_long_sub(freed, &ubifs_clean_zn_cnt); + atomic_long_sub(freed, &c->clean_zn_cnt); + total_freed += freed; + znode = zprev; + } + + if (unlikely(!c->zroot.znode)) + break; + + zprev = znode; + znode = ubifs_tnc_levelorder_next(c, c->zroot.znode, znode); + cond_resched(); + } + + return total_freed; +} + +/** + * shrink_tnc_trees - shrink UBIFS TNC trees. + * @nr: number of znodes to free + * @age: the age of znodes to free + * @contention: if any contention, this is set to %1 + * + * This function walks the list of mounted UBIFS file-systems and frees clean + * znodes which are older than @age, until at least @nr znodes are freed. + * Returns the number of freed znodes. + */ +static int shrink_tnc_trees(int nr, int age, int *contention) +{ + struct ubifs_info *c; + struct list_head *p; + unsigned int run_no; + int freed = 0; + + spin_lock(&ubifs_infos_lock); + do { + run_no = ++shrinker_run_no; + } while (run_no == 0); + /* Iterate over all mounted UBIFS file-systems and try to shrink them */ + p = ubifs_infos.next; + while (p != &ubifs_infos) { + c = list_entry(p, struct ubifs_info, infos_list); + /* + * We move the ones we do to the end of the list, so we stop + * when we see one we have already done. + */ + if (c->shrinker_run_no == run_no) + break; + if (!mutex_trylock(&c->umount_mutex)) { + /* Some un-mount is in progress, try next FS */ + *contention = 1; + p = p->next; + continue; + } + /* + * We're holding 'c->umount_mutex', so the file-system won't go + * away. + */ + if (!mutex_trylock(&c->tnc_mutex)) { + mutex_unlock(&c->umount_mutex); + *contention = 1; + p = p->next; + continue; + } + spin_unlock(&ubifs_infos_lock); + /* + * OK, now we have TNC locked, the file-system cannot go away - + * it is safe to reap the cache. + */ + c->shrinker_run_no = run_no; + freed += shrink_tnc(c, nr, age, contention); + mutex_unlock(&c->tnc_mutex); + spin_lock(&ubifs_infos_lock); + /* Get the next list element before we move this one */ + p = p->next; + /* + * Move this one to the end of the list to provide some + * fairness. + */ + list_move_tail(&c->infos_list, &ubifs_infos); + mutex_unlock(&c->umount_mutex); + if (freed >= nr) + break; + } + spin_unlock(&ubifs_infos_lock); + return freed; +} + +/** + * kick_a_thread - kick a background thread to start commit. + * + * This function kicks a background thread to start background commit. Returns + * %-1 if a thread was kicked or there is another reason to assume the memory + * will soon be freed or become freeable. If there are no dirty znodes, returns + * %0. + */ +static int kick_a_thread(void) +{ + int i; + struct ubifs_info *c; + + /* + * Iterate over all mounted UBIFS file-systems and find out if there is + * already an ongoing commit operation there. If no, then iterate for + * the second time and initiate background commit. + */ + spin_lock(&ubifs_infos_lock); + for (i = 0; i < 2; i++) { + list_for_each_entry(c, &ubifs_infos, infos_list) { + long dirty_zn_cnt; + + if (!mutex_trylock(&c->umount_mutex)) { + /* + * Some un-mount is in progress, it will + * certainly free memory, so just return. + */ + spin_unlock(&ubifs_infos_lock); + return -1; + } + + dirty_zn_cnt = atomic_long_read(&c->dirty_zn_cnt); + + if (!dirty_zn_cnt || c->cmt_state == COMMIT_BROKEN || + c->ro_mount || c->ro_error) { + mutex_unlock(&c->umount_mutex); + continue; + } + + if (c->cmt_state != COMMIT_RESTING) { + spin_unlock(&ubifs_infos_lock); + mutex_unlock(&c->umount_mutex); + return -1; + } + + if (i == 1) { + list_move_tail(&c->infos_list, &ubifs_infos); + spin_unlock(&ubifs_infos_lock); + + ubifs_request_bg_commit(c); + mutex_unlock(&c->umount_mutex); + return -1; + } + mutex_unlock(&c->umount_mutex); + } + } + spin_unlock(&ubifs_infos_lock); + + return 0; +} + +unsigned long ubifs_shrink_count(struct shrinker *shrink, + struct shrink_control *sc) +{ + long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt); + + /* + * Due to the way UBIFS updates the clean znode counter it may + * temporarily be negative. + */ + return clean_zn_cnt >= 0 ? clean_zn_cnt : 1; +} + +unsigned long ubifs_shrink_scan(struct shrinker *shrink, + struct shrink_control *sc) +{ + unsigned long nr = sc->nr_to_scan; + int contention = 0; + unsigned long freed; + long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt); + + if (!clean_zn_cnt) { + /* + * No clean znodes, nothing to reap. All we can do in this case + * is to kick background threads to start commit, which will + * probably make clean znodes which, in turn, will be freeable. + * And we return -1 which means will make VM call us again + * later. + */ + dbg_tnc("no clean znodes, kick a thread"); + return kick_a_thread(); + } + + freed = shrink_tnc_trees(nr, OLD_ZNODE_AGE, &contention); + if (freed >= nr) + goto out; + + dbg_tnc("not enough old znodes, try to free young ones"); + freed += shrink_tnc_trees(nr - freed, YOUNG_ZNODE_AGE, &contention); + if (freed >= nr) + goto out; + + dbg_tnc("not enough young znodes, free all"); + freed += shrink_tnc_trees(nr - freed, 0, &contention); + + if (!freed && contention) { + dbg_tnc("freed nothing, but contention"); + return SHRINK_STOP; + } + +out: + dbg_tnc("%lu znodes were freed, requested %lu", freed, nr); + return freed; +} -- cgit v1.2.3