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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
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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(). ...
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+.. SPDX-License-Identifier: GPL-2.0
+
+=======================
+Squashfs 4.0 Filesystem
+=======================
+
+Squashfs is a compressed read-only filesystem for Linux.
+
+It uses zlib, lz4, lzo, or xz compression to compress files, inodes and
+directories. Inodes in the system are very small and all blocks are packed to
+minimise data overhead. Block sizes greater than 4K are supported up to a
+maximum of 1Mbytes (default block size 128K).
+
+Squashfs is intended for general read-only filesystem use, for archival
+use (i.e. in cases where a .tar.gz file may be used), and in constrained
+block device/memory systems (e.g. embedded systems) where low overhead is
+needed.
+
+Mailing list: squashfs-devel@lists.sourceforge.net
+Web site: www.squashfs.org
+
+1. Filesystem Features
+----------------------
+
+Squashfs filesystem features versus Cramfs:
+
+============================== ========= ==========
+ Squashfs Cramfs
+============================== ========= ==========
+Max filesystem size 2^64 256 MiB
+Max file size ~ 2 TiB 16 MiB
+Max files unlimited unlimited
+Max directories unlimited unlimited
+Max entries per directory unlimited unlimited
+Max block size 1 MiB 4 KiB
+Metadata compression yes no
+Directory indexes yes no
+Sparse file support yes no
+Tail-end packing (fragments) yes no
+Exportable (NFS etc.) yes no
+Hard link support yes no
+"." and ".." in readdir yes no
+Real inode numbers yes no
+32-bit uids/gids yes no
+File creation time yes no
+Xattr support yes no
+ACL support no no
+============================== ========= ==========
+
+Squashfs compresses data, inodes and directories. In addition, inode and
+directory data are highly compacted, and packed on byte boundaries. Each
+compressed inode is on average 8 bytes in length (the exact length varies on
+file type, i.e. regular file, directory, symbolic link, and block/char device
+inodes have different sizes).
+
+2. Using Squashfs
+-----------------
+
+As squashfs is a read-only filesystem, the mksquashfs program must be used to
+create populated squashfs filesystems. This and other squashfs utilities
+can be obtained from http://www.squashfs.org. Usage instructions can be
+obtained from this site also.
+
+The squashfs-tools development tree is now located on kernel.org
+ git://git.kernel.org/pub/scm/fs/squashfs/squashfs-tools.git
+
+3. Squashfs Filesystem Design
+-----------------------------
+
+A squashfs filesystem consists of a maximum of nine parts, packed together on a
+byte alignment::
+
+ ---------------
+ | superblock |
+ |---------------|
+ | compression |
+ | options |
+ |---------------|
+ | datablocks |
+ | & fragments |
+ |---------------|
+ | inode table |
+ |---------------|
+ | directory |
+ | table |
+ |---------------|
+ | fragment |
+ | table |
+ |---------------|
+ | export |
+ | table |
+ |---------------|
+ | uid/gid |
+ | lookup table |
+ |---------------|
+ | xattr |
+ | table |
+ ---------------
+
+Compressed data blocks are written to the filesystem as files are read from
+the source directory, and checked for duplicates. Once all file data has been
+written the completed inode, directory, fragment, export, uid/gid lookup and
+xattr tables are written.
+
+3.1 Compression options
+-----------------------
+
+Compressors can optionally support compression specific options (e.g.
+dictionary size). If non-default compression options have been used, then
+these are stored here.
+
+3.2 Inodes
+----------
+
+Metadata (inodes and directories) are compressed in 8Kbyte blocks. Each
+compressed block is prefixed by a two byte length, the top bit is set if the
+block is uncompressed. A block will be uncompressed if the -noI option is set,
+or if the compressed block was larger than the uncompressed block.
+
+Inodes are packed into the metadata blocks, and are not aligned to block
+boundaries, therefore inodes overlap compressed blocks. Inodes are identified
+by a 48-bit number which encodes the location of the compressed metadata block
+containing the inode, and the byte offset into that block where the inode is
+placed (<block, offset>).
+
+To maximise compression there are different inodes for each file type
+(regular file, directory, device, etc.), the inode contents and length
+varying with the type.
+
+To further maximise compression, two types of regular file inode and
+directory inode are defined: inodes optimised for frequently occurring
+regular files and directories, and extended types where extra
+information has to be stored.
+
+3.3 Directories
+---------------
+
+Like inodes, directories are packed into compressed metadata blocks, stored
+in a directory table. Directories are accessed using the start address of
+the metablock containing the directory and the offset into the
+decompressed block (<block, offset>).
+
+Directories are organised in a slightly complex way, and are not simply
+a list of file names. The organisation takes advantage of the
+fact that (in most cases) the inodes of the files will be in the same
+compressed metadata block, and therefore, can share the start block.
+Directories are therefore organised in a two level list, a directory
+header containing the shared start block value, and a sequence of directory
+entries, each of which share the shared start block. A new directory header
+is written once/if the inode start block changes. The directory
+header/directory entry list is repeated as many times as necessary.
+
+Directories are sorted, and can contain a directory index to speed up
+file lookup. Directory indexes store one entry per metablock, each entry
+storing the index/filename mapping to the first directory header
+in each metadata block. Directories are sorted in alphabetical order,
+and at lookup the index is scanned linearly looking for the first filename
+alphabetically larger than the filename being looked up. At this point the
+location of the metadata block the filename is in has been found.
+The general idea of the index is to ensure only one metadata block needs to be
+decompressed to do a lookup irrespective of the length of the directory.
+This scheme has the advantage that it doesn't require extra memory overhead
+and doesn't require much extra storage on disk.
+
+3.4 File data
+-------------
+
+Regular files consist of a sequence of contiguous compressed blocks, and/or a
+compressed fragment block (tail-end packed block). The compressed size
+of each datablock is stored in a block list contained within the
+file inode.
+
+To speed up access to datablocks when reading 'large' files (256 Mbytes or
+larger), the code implements an index cache that caches the mapping from
+block index to datablock location on disk.
+
+The index cache allows Squashfs to handle large files (up to 1.75 TiB) while
+retaining a simple and space-efficient block list on disk. The cache
+is split into slots, caching up to eight 224 GiB files (128 KiB blocks).
+Larger files use multiple slots, with 1.75 TiB files using all 8 slots.
+The index cache is designed to be memory efficient, and by default uses
+16 KiB.
+
+3.5 Fragment lookup table
+-------------------------
+
+Regular files can contain a fragment index which is mapped to a fragment
+location on disk and compressed size using a fragment lookup table. This
+fragment lookup table is itself stored compressed into metadata blocks.
+A second index table is used to locate these. This second index table for
+speed of access (and because it is small) is read at mount time and cached
+in memory.
+
+3.6 Uid/gid lookup table
+------------------------
+
+For space efficiency regular files store uid and gid indexes, which are
+converted to 32-bit uids/gids using an id look up table. This table is
+stored compressed into metadata blocks. A second index table is used to
+locate these. This second index table for speed of access (and because it
+is small) is read at mount time and cached in memory.
+
+3.7 Export table
+----------------
+
+To enable Squashfs filesystems to be exportable (via NFS etc.) filesystems
+can optionally (disabled with the -no-exports Mksquashfs option) contain
+an inode number to inode disk location lookup table. This is required to
+enable Squashfs to map inode numbers passed in filehandles to the inode
+location on disk, which is necessary when the export code reinstantiates
+expired/flushed inodes.
+
+This table is stored compressed into metadata blocks. A second index table is
+used to locate these. This second index table for speed of access (and because
+it is small) is read at mount time and cached in memory.
+
+3.8 Xattr table
+---------------
+
+The xattr table contains extended attributes for each inode. The xattrs
+for each inode are stored in a list, each list entry containing a type,
+name and value field. The type field encodes the xattr prefix
+("user.", "trusted." etc) and it also encodes how the name/value fields
+should be interpreted. Currently the type indicates whether the value
+is stored inline (in which case the value field contains the xattr value),
+or if it is stored out of line (in which case the value field stores a
+reference to where the actual value is stored). This allows large values
+to be stored out of line improving scanning and lookup performance and it
+also allows values to be de-duplicated, the value being stored once, and
+all other occurrences holding an out of line reference to that value.
+
+The xattr lists are packed into compressed 8K metadata blocks.
+To reduce overhead in inodes, rather than storing the on-disk
+location of the xattr list inside each inode, a 32-bit xattr id
+is stored. This xattr id is mapped into the location of the xattr
+list using a second xattr id lookup table.
+
+4. TODOs and Outstanding Issues
+-------------------------------
+
+4.1 TODO list
+-------------
+
+Implement ACL support.
+
+4.2 Squashfs Internal Cache
+---------------------------
+
+Blocks in Squashfs are compressed. To avoid repeatedly decompressing
+recently accessed data Squashfs uses two small metadata and fragment caches.
+
+The cache is not used for file datablocks, these are decompressed and cached in
+the page-cache in the normal way. The cache is used to temporarily cache
+fragment and metadata blocks which have been read as a result of a metadata
+(i.e. inode or directory) or fragment access. Because metadata and fragments
+are packed together into blocks (to gain greater compression) the read of a
+particular piece of metadata or fragment will retrieve other metadata/fragments
+which have been packed with it, these because of locality-of-reference may be
+read in the near future. Temporarily caching them ensures they are available
+for near future access without requiring an additional read and decompress.
+
+In the future this internal cache may be replaced with an implementation which
+uses the kernel page cache. Because the page cache operates on page sized
+units this may introduce additional complexity in terms of locking and
+associated race conditions.