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(). ... --- drivers/dax/super.c | 594 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 594 insertions(+) create mode 100644 drivers/dax/super.c (limited to 'drivers/dax/super.c') diff --git a/drivers/dax/super.c b/drivers/dax/super.c new file mode 100644 index 000000000..c4c4728a3 --- /dev/null +++ b/drivers/dax/super.c @@ -0,0 +1,594 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright(c) 2017 Intel Corporation. All rights reserved. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "dax-private.h" + +/** + * struct dax_device - anchor object for dax services + * @inode: core vfs + * @cdev: optional character interface for "device dax" + * @private: dax driver private data + * @flags: state and boolean properties + * @ops: operations for this device + * @holder_data: holder of a dax_device: could be filesystem or mapped device + * @holder_ops: operations for the inner holder + */ +struct dax_device { + struct inode inode; + struct cdev cdev; + void *private; + unsigned long flags; + const struct dax_operations *ops; + void *holder_data; + const struct dax_holder_operations *holder_ops; +}; + +static dev_t dax_devt; +DEFINE_STATIC_SRCU(dax_srcu); +static struct vfsmount *dax_mnt; +static DEFINE_IDA(dax_minor_ida); +static struct kmem_cache *dax_cache __read_mostly; +static struct super_block *dax_superblock __read_mostly; + +int dax_read_lock(void) +{ + return srcu_read_lock(&dax_srcu); +} +EXPORT_SYMBOL_GPL(dax_read_lock); + +void dax_read_unlock(int id) +{ + srcu_read_unlock(&dax_srcu, id); +} +EXPORT_SYMBOL_GPL(dax_read_unlock); + +#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX) +#include + +static DEFINE_XARRAY(dax_hosts); + +int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk) +{ + return xa_insert(&dax_hosts, (unsigned long)disk, dax_dev, GFP_KERNEL); +} +EXPORT_SYMBOL_GPL(dax_add_host); + +void dax_remove_host(struct gendisk *disk) +{ + xa_erase(&dax_hosts, (unsigned long)disk); +} +EXPORT_SYMBOL_GPL(dax_remove_host); + +/** + * fs_dax_get_by_bdev() - temporary lookup mechanism for filesystem-dax + * @bdev: block device to find a dax_device for + * @start_off: returns the byte offset into the dax_device that @bdev starts + * @holder: filesystem or mapped device inside the dax_device + * @ops: operations for the inner holder + */ +struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, u64 *start_off, + void *holder, const struct dax_holder_operations *ops) +{ + struct dax_device *dax_dev; + u64 part_size; + int id; + + if (!blk_queue_dax(bdev->bd_disk->queue)) + return NULL; + + *start_off = get_start_sect(bdev) * SECTOR_SIZE; + part_size = bdev_nr_sectors(bdev) * SECTOR_SIZE; + if (*start_off % PAGE_SIZE || part_size % PAGE_SIZE) { + pr_info("%pg: error: unaligned partition for dax\n", bdev); + return NULL; + } + + id = dax_read_lock(); + dax_dev = xa_load(&dax_hosts, (unsigned long)bdev->bd_disk); + if (!dax_dev || !dax_alive(dax_dev) || !igrab(&dax_dev->inode)) + dax_dev = NULL; + else if (holder) { + if (!cmpxchg(&dax_dev->holder_data, NULL, holder)) + dax_dev->holder_ops = ops; + else + dax_dev = NULL; + } + dax_read_unlock(id); + + return dax_dev; +} +EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev); + +void fs_put_dax(struct dax_device *dax_dev, void *holder) +{ + if (dax_dev && holder && + cmpxchg(&dax_dev->holder_data, holder, NULL) == holder) + dax_dev->holder_ops = NULL; + put_dax(dax_dev); +} +EXPORT_SYMBOL_GPL(fs_put_dax); +#endif /* CONFIG_BLOCK && CONFIG_FS_DAX */ + +enum dax_device_flags { + /* !alive + rcu grace period == no new operations / mappings */ + DAXDEV_ALIVE, + /* gate whether dax_flush() calls the low level flush routine */ + DAXDEV_WRITE_CACHE, + /* flag to check if device supports synchronous flush */ + DAXDEV_SYNC, + /* do not leave the caches dirty after writes */ + DAXDEV_NOCACHE, + /* handle CPU fetch exceptions during reads */ + DAXDEV_NOMC, +}; + +/** + * dax_direct_access() - translate a device pgoff to an absolute pfn + * @dax_dev: a dax_device instance representing the logical memory range + * @pgoff: offset in pages from the start of the device to translate + * @nr_pages: number of consecutive pages caller can handle relative to @pfn + * @mode: indicator on normal access or recovery write + * @kaddr: output parameter that returns a virtual address mapping of pfn + * @pfn: output parameter that returns an absolute pfn translation of @pgoff + * + * Return: negative errno if an error occurs, otherwise the number of + * pages accessible at the device relative @pgoff. + */ +long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, + enum dax_access_mode mode, void **kaddr, pfn_t *pfn) +{ + long avail; + + if (!dax_dev) + return -EOPNOTSUPP; + + if (!dax_alive(dax_dev)) + return -ENXIO; + + if (nr_pages < 0) + return -EINVAL; + + avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages, + mode, kaddr, pfn); + if (!avail) + return -ERANGE; + return min(avail, nr_pages); +} +EXPORT_SYMBOL_GPL(dax_direct_access); + +size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, + size_t bytes, struct iov_iter *i) +{ + if (!dax_alive(dax_dev)) + return 0; + + /* + * The userspace address for the memory copy has already been validated + * via access_ok() in vfs_write, so use the 'no check' version to bypass + * the HARDENED_USERCOPY overhead. + */ + if (test_bit(DAXDEV_NOCACHE, &dax_dev->flags)) + return _copy_from_iter_flushcache(addr, bytes, i); + return _copy_from_iter(addr, bytes, i); +} + +size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, + size_t bytes, struct iov_iter *i) +{ + if (!dax_alive(dax_dev)) + return 0; + + /* + * The userspace address for the memory copy has already been validated + * via access_ok() in vfs_red, so use the 'no check' version to bypass + * the HARDENED_USERCOPY overhead. + */ + if (test_bit(DAXDEV_NOMC, &dax_dev->flags)) + return _copy_mc_to_iter(addr, bytes, i); + return _copy_to_iter(addr, bytes, i); +} + +int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + size_t nr_pages) +{ + if (!dax_alive(dax_dev)) + return -ENXIO; + /* + * There are no callers that want to zero more than one page as of now. + * Once users are there, this check can be removed after the + * device mapper code has been updated to split ranges across targets. + */ + if (nr_pages != 1) + return -EIO; + + return dax_dev->ops->zero_page_range(dax_dev, pgoff, nr_pages); +} +EXPORT_SYMBOL_GPL(dax_zero_page_range); + +size_t dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff, + void *addr, size_t bytes, struct iov_iter *iter) +{ + if (!dax_dev->ops->recovery_write) + return 0; + return dax_dev->ops->recovery_write(dax_dev, pgoff, addr, bytes, iter); +} +EXPORT_SYMBOL_GPL(dax_recovery_write); + +int dax_holder_notify_failure(struct dax_device *dax_dev, u64 off, + u64 len, int mf_flags) +{ + int rc, id; + + id = dax_read_lock(); + if (!dax_alive(dax_dev)) { + rc = -ENXIO; + goto out; + } + + if (!dax_dev->holder_ops) { + rc = -EOPNOTSUPP; + goto out; + } + + rc = dax_dev->holder_ops->notify_failure(dax_dev, off, len, mf_flags); +out: + dax_read_unlock(id); + return rc; +} +EXPORT_SYMBOL_GPL(dax_holder_notify_failure); + +#ifdef CONFIG_ARCH_HAS_PMEM_API +void arch_wb_cache_pmem(void *addr, size_t size); +void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) +{ + if (unlikely(!dax_write_cache_enabled(dax_dev))) + return; + + arch_wb_cache_pmem(addr, size); +} +#else +void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) +{ +} +#endif +EXPORT_SYMBOL_GPL(dax_flush); + +void dax_write_cache(struct dax_device *dax_dev, bool wc) +{ + if (wc) + set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); + else + clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_write_cache); + +bool dax_write_cache_enabled(struct dax_device *dax_dev) +{ + return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_write_cache_enabled); + +bool dax_synchronous(struct dax_device *dax_dev) +{ + return test_bit(DAXDEV_SYNC, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_synchronous); + +void set_dax_synchronous(struct dax_device *dax_dev) +{ + set_bit(DAXDEV_SYNC, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(set_dax_synchronous); + +void set_dax_nocache(struct dax_device *dax_dev) +{ + set_bit(DAXDEV_NOCACHE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(set_dax_nocache); + +void set_dax_nomc(struct dax_device *dax_dev) +{ + set_bit(DAXDEV_NOMC, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(set_dax_nomc); + +bool dax_alive(struct dax_device *dax_dev) +{ + lockdep_assert_held(&dax_srcu); + return test_bit(DAXDEV_ALIVE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_alive); + +/* + * Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring + * that any fault handlers or operations that might have seen + * dax_alive(), have completed. Any operations that start after + * synchronize_srcu() has run will abort upon seeing !dax_alive(). + */ +void kill_dax(struct dax_device *dax_dev) +{ + if (!dax_dev) + return; + + if (dax_dev->holder_data != NULL) + dax_holder_notify_failure(dax_dev, 0, U64_MAX, 0); + + clear_bit(DAXDEV_ALIVE, &dax_dev->flags); + synchronize_srcu(&dax_srcu); + + /* clear holder data */ + dax_dev->holder_ops = NULL; + dax_dev->holder_data = NULL; +} +EXPORT_SYMBOL_GPL(kill_dax); + +void run_dax(struct dax_device *dax_dev) +{ + set_bit(DAXDEV_ALIVE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(run_dax); + +static struct inode *dax_alloc_inode(struct super_block *sb) +{ + struct dax_device *dax_dev; + struct inode *inode; + + dax_dev = alloc_inode_sb(sb, dax_cache, GFP_KERNEL); + if (!dax_dev) + return NULL; + + inode = &dax_dev->inode; + inode->i_rdev = 0; + return inode; +} + +static struct dax_device *to_dax_dev(struct inode *inode) +{ + return container_of(inode, struct dax_device, inode); +} + +static void dax_free_inode(struct inode *inode) +{ + struct dax_device *dax_dev = to_dax_dev(inode); + if (inode->i_rdev) + ida_free(&dax_minor_ida, iminor(inode)); + kmem_cache_free(dax_cache, dax_dev); +} + +static void dax_destroy_inode(struct inode *inode) +{ + struct dax_device *dax_dev = to_dax_dev(inode); + WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags), + "kill_dax() must be called before final iput()\n"); +} + +static const struct super_operations dax_sops = { + .statfs = simple_statfs, + .alloc_inode = dax_alloc_inode, + .destroy_inode = dax_destroy_inode, + .free_inode = dax_free_inode, + .drop_inode = generic_delete_inode, +}; + +static int dax_init_fs_context(struct fs_context *fc) +{ + struct pseudo_fs_context *ctx = init_pseudo(fc, DAXFS_MAGIC); + if (!ctx) + return -ENOMEM; + ctx->ops = &dax_sops; + return 0; +} + +static struct file_system_type dax_fs_type = { + .name = "dax", + .init_fs_context = dax_init_fs_context, + .kill_sb = kill_anon_super, +}; + +static int dax_test(struct inode *inode, void *data) +{ + dev_t devt = *(dev_t *) data; + + return inode->i_rdev == devt; +} + +static int dax_set(struct inode *inode, void *data) +{ + dev_t devt = *(dev_t *) data; + + inode->i_rdev = devt; + return 0; +} + +static struct dax_device *dax_dev_get(dev_t devt) +{ + struct dax_device *dax_dev; + struct inode *inode; + + inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), + dax_test, dax_set, &devt); + + if (!inode) + return NULL; + + dax_dev = to_dax_dev(inode); + if (inode->i_state & I_NEW) { + set_bit(DAXDEV_ALIVE, &dax_dev->flags); + inode->i_cdev = &dax_dev->cdev; + inode->i_mode = S_IFCHR; + inode->i_flags = S_DAX; + mapping_set_gfp_mask(&inode->i_data, GFP_USER); + unlock_new_inode(inode); + } + + return dax_dev; +} + +struct dax_device *alloc_dax(void *private, const struct dax_operations *ops) +{ + struct dax_device *dax_dev; + dev_t devt; + int minor; + + if (WARN_ON_ONCE(ops && !ops->zero_page_range)) + return ERR_PTR(-EINVAL); + + minor = ida_alloc_max(&dax_minor_ida, MINORMASK, GFP_KERNEL); + if (minor < 0) + return ERR_PTR(-ENOMEM); + + devt = MKDEV(MAJOR(dax_devt), minor); + dax_dev = dax_dev_get(devt); + if (!dax_dev) + goto err_dev; + + dax_dev->ops = ops; + dax_dev->private = private; + return dax_dev; + + err_dev: + ida_free(&dax_minor_ida, minor); + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(alloc_dax); + +void put_dax(struct dax_device *dax_dev) +{ + if (!dax_dev) + return; + iput(&dax_dev->inode); +} +EXPORT_SYMBOL_GPL(put_dax); + +/** + * dax_holder() - obtain the holder of a dax device + * @dax_dev: a dax_device instance + * + * Return: the holder's data which represents the holder if registered, + * otherwize NULL. + */ +void *dax_holder(struct dax_device *dax_dev) +{ + return dax_dev->holder_data; +} +EXPORT_SYMBOL_GPL(dax_holder); + +/** + * inode_dax: convert a public inode into its dax_dev + * @inode: An inode with i_cdev pointing to a dax_dev + * + * Note this is not equivalent to to_dax_dev() which is for private + * internal use where we know the inode filesystem type == dax_fs_type. + */ +struct dax_device *inode_dax(struct inode *inode) +{ + struct cdev *cdev = inode->i_cdev; + + return container_of(cdev, struct dax_device, cdev); +} +EXPORT_SYMBOL_GPL(inode_dax); + +struct inode *dax_inode(struct dax_device *dax_dev) +{ + return &dax_dev->inode; +} +EXPORT_SYMBOL_GPL(dax_inode); + +void *dax_get_private(struct dax_device *dax_dev) +{ + if (!test_bit(DAXDEV_ALIVE, &dax_dev->flags)) + return NULL; + return dax_dev->private; +} +EXPORT_SYMBOL_GPL(dax_get_private); + +static void init_once(void *_dax_dev) +{ + struct dax_device *dax_dev = _dax_dev; + struct inode *inode = &dax_dev->inode; + + memset(dax_dev, 0, sizeof(*dax_dev)); + inode_init_once(inode); +} + +static int dax_fs_init(void) +{ + int rc; + + dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0, + (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| + SLAB_MEM_SPREAD|SLAB_ACCOUNT), + init_once); + if (!dax_cache) + return -ENOMEM; + + dax_mnt = kern_mount(&dax_fs_type); + if (IS_ERR(dax_mnt)) { + rc = PTR_ERR(dax_mnt); + goto err_mount; + } + dax_superblock = dax_mnt->mnt_sb; + + return 0; + + err_mount: + kmem_cache_destroy(dax_cache); + + return rc; +} + +static void dax_fs_exit(void) +{ + kern_unmount(dax_mnt); + rcu_barrier(); + kmem_cache_destroy(dax_cache); +} + +static int __init dax_core_init(void) +{ + int rc; + + rc = dax_fs_init(); + if (rc) + return rc; + + rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax"); + if (rc) + goto err_chrdev; + + rc = dax_bus_init(); + if (rc) + goto err_bus; + return 0; + +err_bus: + unregister_chrdev_region(dax_devt, MINORMASK+1); +err_chrdev: + dax_fs_exit(); + return 0; +} + +static void __exit dax_core_exit(void) +{ + dax_bus_exit(); + unregister_chrdev_region(dax_devt, MINORMASK+1); + ida_destroy(&dax_minor_ida); + dax_fs_exit(); +} + +MODULE_AUTHOR("Intel Corporation"); +MODULE_LICENSE("GPL v2"); +subsys_initcall(dax_core_init); +module_exit(dax_core_exit); -- cgit v1.2.3