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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /fs/ubifs/shrinker.c | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
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().
...
Diffstat (limited to 'fs/ubifs/shrinker.c')
-rw-r--r-- | fs/ubifs/shrinker.c | 319 |
1 files changed, 319 insertions, 0 deletions
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; +} |