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/configfs/symlink.c | 270 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 270 insertions(+) create mode 100644 fs/configfs/symlink.c (limited to 'fs/configfs/symlink.c') diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c new file mode 100644 index 000000000..69133ec1f --- /dev/null +++ b/fs/configfs/symlink.c @@ -0,0 +1,270 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * symlink.c - operations for configfs symlinks. + * + * Based on sysfs: + * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel + * + * configfs Copyright (C) 2005 Oracle. All rights reserved. + */ + +#include +#include +#include +#include + +#include +#include "configfs_internal.h" + +/* Protects attachments of new symlinks */ +DEFINE_MUTEX(configfs_symlink_mutex); + +static int item_depth(struct config_item * item) +{ + struct config_item * p = item; + int depth = 0; + do { depth++; } while ((p = p->ci_parent) && !configfs_is_root(p)); + return depth; +} + +static int item_path_length(struct config_item * item) +{ + struct config_item * p = item; + int length = 1; + do { + length += strlen(config_item_name(p)) + 1; + p = p->ci_parent; + } while (p && !configfs_is_root(p)); + return length; +} + +static void fill_item_path(struct config_item * item, char * buffer, int length) +{ + struct config_item * p; + + --length; + for (p = item; p && !configfs_is_root(p); p = p->ci_parent) { + int cur = strlen(config_item_name(p)); + + /* back up enough to print this bus id with '/' */ + length -= cur; + memcpy(buffer + length, config_item_name(p), cur); + *(buffer + --length) = '/'; + } +} + +static int configfs_get_target_path(struct config_item *item, + struct config_item *target, char *path) +{ + int depth, size; + char *s; + + depth = item_depth(item); + size = item_path_length(target) + depth * 3 - 1; + if (size > PATH_MAX) + return -ENAMETOOLONG; + + pr_debug("%s: depth = %d, size = %d\n", __func__, depth, size); + + for (s = path; depth--; s += 3) + strcpy(s,"../"); + + fill_item_path(target, path, size); + pr_debug("%s: path = '%s'\n", __func__, path); + return 0; +} + +static int create_link(struct config_item *parent_item, + struct config_item *item, + struct dentry *dentry) +{ + struct configfs_dirent *target_sd = item->ci_dentry->d_fsdata; + char *body; + int ret; + + if (!configfs_dirent_is_ready(target_sd)) + return -ENOENT; + + body = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!body) + return -ENOMEM; + + configfs_get(target_sd); + spin_lock(&configfs_dirent_lock); + if (target_sd->s_type & CONFIGFS_USET_DROPPING) { + spin_unlock(&configfs_dirent_lock); + configfs_put(target_sd); + kfree(body); + return -ENOENT; + } + target_sd->s_links++; + spin_unlock(&configfs_dirent_lock); + ret = configfs_get_target_path(parent_item, item, body); + if (!ret) + ret = configfs_create_link(target_sd, parent_item->ci_dentry, + dentry, body); + if (ret) { + spin_lock(&configfs_dirent_lock); + target_sd->s_links--; + spin_unlock(&configfs_dirent_lock); + configfs_put(target_sd); + kfree(body); + } + return ret; +} + + +static int get_target(const char *symname, struct path *path, + struct config_item **target, struct super_block *sb) +{ + int ret; + + ret = kern_path(symname, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, path); + if (!ret) { + if (path->dentry->d_sb == sb) { + *target = configfs_get_config_item(path->dentry); + if (!*target) { + ret = -ENOENT; + path_put(path); + } + } else { + ret = -EPERM; + path_put(path); + } + } + + return ret; +} + + +int configfs_symlink(struct mnt_idmap *idmap, struct inode *dir, + struct dentry *dentry, const char *symname) +{ + int ret; + struct path path; + struct configfs_dirent *sd; + struct config_item *parent_item; + struct config_item *target_item = NULL; + const struct config_item_type *type; + + sd = dentry->d_parent->d_fsdata; + /* + * Fake invisibility if dir belongs to a group/default groups hierarchy + * being attached + */ + if (!configfs_dirent_is_ready(sd)) + return -ENOENT; + + parent_item = configfs_get_config_item(dentry->d_parent); + type = parent_item->ci_type; + + ret = -EPERM; + if (!type || !type->ct_item_ops || + !type->ct_item_ops->allow_link) + goto out_put; + + /* + * This is really sick. What they wanted was a hybrid of + * link(2) and symlink(2) - they wanted the target resolved + * at syscall time (as link(2) would've done), be a directory + * (which link(2) would've refused to do) *AND* be a deep + * fucking magic, making the target busy from rmdir POV. + * symlink(2) is nothing of that sort, and the locking it + * gets matches the normal symlink(2) semantics. Without + * attempts to resolve the target (which might very well + * not even exist yet) done prior to locking the parent + * directory. This perversion, OTOH, needs to resolve + * the target, which would lead to obvious deadlocks if + * attempted with any directories locked. + * + * Unfortunately, that garbage is userland ABI and we should've + * said "no" back in 2005. Too late now, so we get to + * play very ugly games with locking. + * + * Try *ANYTHING* of that sort in new code, and you will + * really regret it. Just ask yourself - what could a BOFH + * do to me and do I want to find it out first-hand? + * + * AV, a thoroughly annoyed bastard. + */ + inode_unlock(dir); + ret = get_target(symname, &path, &target_item, dentry->d_sb); + inode_lock(dir); + if (ret) + goto out_put; + + if (dentry->d_inode || d_unhashed(dentry)) + ret = -EEXIST; + else + ret = inode_permission(&nop_mnt_idmap, dir, + MAY_WRITE | MAY_EXEC); + if (!ret) + ret = type->ct_item_ops->allow_link(parent_item, target_item); + if (!ret) { + mutex_lock(&configfs_symlink_mutex); + ret = create_link(parent_item, target_item, dentry); + mutex_unlock(&configfs_symlink_mutex); + if (ret && type->ct_item_ops->drop_link) + type->ct_item_ops->drop_link(parent_item, + target_item); + } + + config_item_put(target_item); + path_put(&path); + +out_put: + config_item_put(parent_item); + return ret; +} + +int configfs_unlink(struct inode *dir, struct dentry *dentry) +{ + struct configfs_dirent *sd = dentry->d_fsdata, *target_sd; + struct config_item *parent_item; + const struct config_item_type *type; + int ret; + + ret = -EPERM; /* What lack-of-symlink returns */ + if (!(sd->s_type & CONFIGFS_ITEM_LINK)) + goto out; + + target_sd = sd->s_element; + + parent_item = configfs_get_config_item(dentry->d_parent); + type = parent_item->ci_type; + + spin_lock(&configfs_dirent_lock); + list_del_init(&sd->s_sibling); + spin_unlock(&configfs_dirent_lock); + configfs_drop_dentry(sd, dentry->d_parent); + dput(dentry); + configfs_put(sd); + + /* + * drop_link() must be called before + * decrementing target's ->s_links, so that the order of + * drop_link(this, target) and drop_item(target) is preserved. + */ + if (type && type->ct_item_ops && + type->ct_item_ops->drop_link) + type->ct_item_ops->drop_link(parent_item, + target_sd->s_element); + + spin_lock(&configfs_dirent_lock); + target_sd->s_links--; + spin_unlock(&configfs_dirent_lock); + configfs_put(target_sd); + + config_item_put(parent_item); + + ret = 0; + +out: + return ret; +} + +const struct inode_operations configfs_symlink_inode_operations = { + .get_link = simple_get_link, + .setattr = configfs_setattr, +}; + -- cgit v1.2.3