dax: refactor dax-fs into a generic provider of 'struct dax_device' instances
We want dax capable drivers to be able to publish a set of dax operations [1]. However, we do not want to further abuse block_devices to advertise these operations. Instead we will attach these operations to a dax device and add a lookup mechanism to go from block device path to a dax device. A dax capable driver like pmem or brd is responsible for registering a dax device, alongside a block device, and then a dax capable filesystem is responsible for retrieving the dax device by path name if it wants to call dax_operations. For now, we refactor the dax pseudo-fs to be a generic facility, rather than an implementation detail, of the device-dax use case. Where a "dax device" is just an inode + dax infrastructure, and "Device DAX" is a mapping service layered on top of that base 'struct dax_device'. "Filesystem DAX" is then a mapping service that layers a filesystem on top of that same base device. Filesystem DAX is associated with a block_device for now, but perhaps directly to a dax device in the future, or for new pmem-only filesystems. [1]: https://lkml.org/lkml/2017/1/19/880 Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams
parent
5f0694b300
commit
7b6be8444e
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@ -71,7 +71,7 @@ obj-$(CONFIG_PARPORT) += parport/
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obj-$(CONFIG_NVM) += lightnvm/
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obj-y += base/ block/ misc/ mfd/ nfc/
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obj-$(CONFIG_LIBNVDIMM) += nvdimm/
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obj-$(CONFIG_DEV_DAX) += dax/
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obj-$(CONFIG_DAX) += dax/
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obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/
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obj-$(CONFIG_NUBUS) += nubus/
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obj-y += macintosh/
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@ -1,8 +1,13 @@
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menuconfig DEV_DAX
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menuconfig DAX
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tristate "DAX: direct access to differentiated memory"
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default m if NVDIMM_DAX
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depends on TRANSPARENT_HUGEPAGE
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select SRCU
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default m if NVDIMM_DAX
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if DAX
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config DEV_DAX
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tristate "Device DAX: direct access mapping device"
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depends on TRANSPARENT_HUGEPAGE
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help
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Support raw access to differentiated (persistence, bandwidth,
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latency...) memory via an mmap(2) capable character
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@ -11,7 +16,6 @@ menuconfig DEV_DAX
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baseline memory pool. Mappings of a /dev/daxX.Y device impose
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restrictions that make the mapping behavior deterministic.
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if DEV_DAX
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config DEV_DAX_PMEM
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tristate "PMEM DAX: direct access to persistent memory"
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@ -1,4 +1,7 @@
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obj-$(CONFIG_DEV_DAX) += dax.o
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obj-$(CONFIG_DAX) += dax.o
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obj-$(CONFIG_DEV_DAX) += device_dax.o
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obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o
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dax-y := super.o
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dax_pmem-y := pmem.o
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device_dax-y := device.o
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@ -1,5 +1,5 @@
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/*
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* Copyright(c) 2016 Intel Corporation. All rights reserved.
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* Copyright(c) 2016 - 2017 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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@ -12,14 +12,12 @@
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*/
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#ifndef __DAX_H__
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#define __DAX_H__
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struct device;
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struct dev_dax;
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struct resource;
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struct dax_region;
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void dax_region_put(struct dax_region *dax_region);
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struct dax_region *alloc_dax_region(struct device *parent,
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int region_id, struct resource *res, unsigned int align,
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void *addr, unsigned long flags);
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struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
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struct resource *res, int count);
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struct dax_device;
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struct dax_device *alloc_dax(void *private);
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void put_dax(struct dax_device *dax_dev);
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bool dax_alive(struct dax_device *dax_dev);
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void kill_dax(struct dax_device *dax_dev);
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struct dax_device *inode_dax(struct inode *inode);
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struct inode *dax_inode(struct dax_device *dax_dev);
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void *dax_get_private(struct dax_device *dax_dev);
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#endif /* __DAX_H__ */
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@ -0,0 +1,25 @@
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/*
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* Copyright(c) 2016 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#ifndef __DEVICE_DAX_H__
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#define __DEVICE_DAX_H__
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struct device;
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struct dev_dax;
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struct resource;
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struct dax_region;
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void dax_region_put(struct dax_region *dax_region);
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struct dax_region *alloc_dax_region(struct device *parent,
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int region_id, struct resource *res, unsigned int align,
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void *addr, unsigned long flags);
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struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
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struct resource *res, int count);
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#endif /* __DEVICE_DAX_H__ */
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@ -1,5 +1,5 @@
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/*
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* Copyright(c) 2016 Intel Corporation. All rights reserved.
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* Copyright(c) 2016 - 2017 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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@ -13,10 +13,7 @@
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#include <linux/pagemap.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/magic.h>
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#include <linux/mount.h>
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#include <linux/pfn_t.h>
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#include <linux/hash.h>
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#include <linux/cdev.h>
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#include <linux/slab.h>
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#include <linux/dax.h>
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@ -24,16 +21,7 @@
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#include <linux/mm.h>
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#include "dax.h"
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static dev_t dax_devt;
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DEFINE_STATIC_SRCU(dax_srcu);
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static struct class *dax_class;
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static DEFINE_IDA(dax_minor_ida);
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static int nr_dax = CONFIG_NR_DEV_DAX;
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module_param(nr_dax, int, S_IRUGO);
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static struct vfsmount *dax_mnt;
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static struct kmem_cache *dax_cache __read_mostly;
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static struct super_block *dax_superblock __read_mostly;
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MODULE_PARM_DESC(nr_dax, "max number of device-dax instances");
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/**
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* struct dax_region - mapping infrastructure for dax devices
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@ -59,19 +47,16 @@ struct dax_region {
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/**
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* struct dev_dax - instance data for a subdivision of a dax region
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* @region - parent region
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* @dev - device backing the character device
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* @cdev - core chardev data
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* @alive - !alive + srcu grace period == no new mappings can be established
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* @dax_dev - core dax functionality
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* @dev - device core
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* @id - child id in the region
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* @num_resources - number of physical address extents in this device
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* @res - array of physical address ranges
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*/
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struct dev_dax {
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struct dax_region *region;
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struct inode *inode;
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struct dax_device *dax_dev;
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struct device dev;
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struct cdev cdev;
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bool alive;
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int id;
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int num_resources;
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struct resource res[0];
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@ -144,117 +129,6 @@ static const struct attribute_group *dax_region_attribute_groups[] = {
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NULL,
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};
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static struct inode *dax_alloc_inode(struct super_block *sb)
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{
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return kmem_cache_alloc(dax_cache, GFP_KERNEL);
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}
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static void dax_i_callback(struct rcu_head *head)
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{
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struct inode *inode = container_of(head, struct inode, i_rcu);
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kmem_cache_free(dax_cache, inode);
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}
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static void dax_destroy_inode(struct inode *inode)
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{
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call_rcu(&inode->i_rcu, dax_i_callback);
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}
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static const struct super_operations dax_sops = {
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.statfs = simple_statfs,
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.alloc_inode = dax_alloc_inode,
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.destroy_inode = dax_destroy_inode,
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.drop_inode = generic_delete_inode,
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};
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static struct dentry *dax_mount(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data)
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{
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return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC);
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}
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static struct file_system_type dax_type = {
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.name = "dax",
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.mount = dax_mount,
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.kill_sb = kill_anon_super,
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};
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static int dax_test(struct inode *inode, void *data)
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{
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return inode->i_cdev == data;
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}
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static int dax_set(struct inode *inode, void *data)
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{
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inode->i_cdev = data;
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return 0;
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}
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static struct inode *dax_inode_get(struct cdev *cdev, dev_t devt)
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{
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struct inode *inode;
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inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31),
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dax_test, dax_set, cdev);
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if (!inode)
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return NULL;
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if (inode->i_state & I_NEW) {
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inode->i_mode = S_IFCHR;
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inode->i_flags = S_DAX;
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inode->i_rdev = devt;
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mapping_set_gfp_mask(&inode->i_data, GFP_USER);
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unlock_new_inode(inode);
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}
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return inode;
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}
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static void init_once(void *inode)
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{
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inode_init_once(inode);
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}
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static int dax_inode_init(void)
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{
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int rc;
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dax_cache = kmem_cache_create("dax_cache", sizeof(struct inode), 0,
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(SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
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SLAB_MEM_SPREAD|SLAB_ACCOUNT),
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init_once);
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if (!dax_cache)
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return -ENOMEM;
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rc = register_filesystem(&dax_type);
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if (rc)
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goto err_register_fs;
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dax_mnt = kern_mount(&dax_type);
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if (IS_ERR(dax_mnt)) {
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rc = PTR_ERR(dax_mnt);
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goto err_mount;
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}
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dax_superblock = dax_mnt->mnt_sb;
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return 0;
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err_mount:
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unregister_filesystem(&dax_type);
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err_register_fs:
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kmem_cache_destroy(dax_cache);
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return rc;
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}
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static void dax_inode_exit(void)
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{
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kern_unmount(dax_mnt);
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unregister_filesystem(&dax_type);
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kmem_cache_destroy(dax_cache);
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}
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static void dax_region_free(struct kref *kref)
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{
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struct dax_region *dax_region;
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@ -363,7 +237,7 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
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struct device *dev = &dev_dax->dev;
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unsigned long mask;
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if (!dev_dax->alive)
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if (!dax_alive(dev_dax->dax_dev))
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return -ENXIO;
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/* prevent private mappings from being established */
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@ -582,7 +456,7 @@ static int dev_dax_huge_fault(struct vm_fault *vmf,
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? "write" : "read",
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vmf->vma->vm_start, vmf->vma->vm_end, pe_size);
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id = srcu_read_lock(&dax_srcu);
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id = dax_read_lock();
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switch (pe_size) {
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case PE_SIZE_PTE:
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rc = __dev_dax_pte_fault(dev_dax, vmf);
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@ -596,7 +470,7 @@ static int dev_dax_huge_fault(struct vm_fault *vmf,
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default:
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rc = VM_FAULT_SIGBUS;
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}
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srcu_read_unlock(&dax_srcu, id);
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dax_read_unlock(id);
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return rc;
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}
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@ -614,11 +488,17 @@ static const struct vm_operations_struct dax_vm_ops = {
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static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
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{
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struct dev_dax *dev_dax = filp->private_data;
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int rc;
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int rc, id;
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dev_dbg(&dev_dax->dev, "%s\n", __func__);
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/*
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* We lock to check dax_dev liveness and will re-check at
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* fault time.
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*/
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id = dax_read_lock();
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rc = check_vma(dev_dax, vma, __func__);
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dax_read_unlock(id);
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if (rc)
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return rc;
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@ -664,12 +544,13 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
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static int dax_open(struct inode *inode, struct file *filp)
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{
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struct dev_dax *dev_dax;
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struct dax_device *dax_dev = inode_dax(inode);
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struct inode *__dax_inode = dax_inode(dax_dev);
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struct dev_dax *dev_dax = dax_get_private(dax_dev);
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dev_dax = container_of(inode->i_cdev, struct dev_dax, cdev);
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dev_dbg(&dev_dax->dev, "%s\n", __func__);
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inode->i_mapping = dev_dax->inode->i_mapping;
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inode->i_mapping->host = dev_dax->inode;
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inode->i_mapping = __dax_inode->i_mapping;
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inode->i_mapping->host = __dax_inode;
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filp->f_mapping = inode->i_mapping;
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filp->private_data = dev_dax;
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inode->i_flags = S_DAX;
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@ -698,36 +579,34 @@ static void dev_dax_release(struct device *dev)
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{
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struct dev_dax *dev_dax = to_dev_dax(dev);
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struct dax_region *dax_region = dev_dax->region;
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struct dax_device *dax_dev = dev_dax->dax_dev;
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ida_simple_remove(&dax_region->ida, dev_dax->id);
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ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
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dax_region_put(dax_region);
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iput(dev_dax->inode);
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put_dax(dax_dev);
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kfree(dev_dax);
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}
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static void kill_dev_dax(struct dev_dax *dev_dax)
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{
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/*
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* Note, rcu is not protecting the liveness of dev_dax, rcu is
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* ensuring that any fault handlers that might have seen
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* dev_dax->alive == true, have completed. Any fault handlers
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* that start after synchronize_srcu() has started will abort
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* upon seeing dev_dax->alive == false.
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*/
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dev_dax->alive = false;
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synchronize_srcu(&dax_srcu);
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unmap_mapping_range(dev_dax->inode->i_mapping, 0, 0, 1);
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struct dax_device *dax_dev = dev_dax->dax_dev;
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struct inode *inode = dax_inode(dax_dev);
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kill_dax(dax_dev);
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unmap_mapping_range(inode->i_mapping, 0, 0, 1);
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}
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static void unregister_dev_dax(void *dev)
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{
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struct dev_dax *dev_dax = to_dev_dax(dev);
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struct dax_device *dax_dev = dev_dax->dax_dev;
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struct inode *inode = dax_inode(dax_dev);
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struct cdev *cdev = inode->i_cdev;
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dev_dbg(dev, "%s\n", __func__);
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kill_dev_dax(dev_dax);
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cdev_device_del(&dev_dax->cdev, dev);
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cdev_device_del(cdev, dev);
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put_device(dev);
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}
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@ -735,11 +614,12 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
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struct resource *res, int count)
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{
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struct device *parent = dax_region->dev;
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struct dax_device *dax_dev;
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struct dev_dax *dev_dax;
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int rc = 0, minor, i;
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struct inode *inode;
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struct device *dev;
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struct cdev *cdev;
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dev_t dev_t;
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int rc = 0, i;
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dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, GFP_KERNEL);
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if (!dev_dax)
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@ -765,33 +645,25 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
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goto err_id;
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}
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minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL);
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if (minor < 0) {
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rc = minor;
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goto err_minor;
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}
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dax_dev = alloc_dax(dev_dax);
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if (!dax_dev)
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goto err_dax;
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dev_t = MKDEV(MAJOR(dax_devt), minor);
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/* from here on we're committed to teardown via dax_dev_release() */
|
||||
dev = &dev_dax->dev;
|
||||
dev_dax->inode = dax_inode_get(&dev_dax->cdev, dev_t);
|
||||
if (!dev_dax->inode) {
|
||||
rc = -ENOMEM;
|
||||
goto err_inode;
|
||||
}
|
||||
|
||||
/* from here on we're committed to teardown via dev_dax_release() */
|
||||
device_initialize(dev);
|
||||
|
||||
cdev = &dev_dax->cdev;
|
||||
inode = dax_inode(dax_dev);
|
||||
cdev = inode->i_cdev;
|
||||
cdev_init(cdev, &dax_fops);
|
||||
cdev->owner = parent->driver->owner;
|
||||
|
||||
dev_dax->num_resources = count;
|
||||
dev_dax->alive = true;
|
||||
dev_dax->dax_dev = dax_dev;
|
||||
dev_dax->region = dax_region;
|
||||
kref_get(&dax_region->kref);
|
||||
|
||||
dev->devt = dev_t;
|
||||
dev->devt = inode->i_rdev;
|
||||
dev->class = dax_class;
|
||||
dev->parent = parent;
|
||||
dev->groups = dax_attribute_groups;
|
||||
|
|
@ -811,9 +683,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
|
|||
|
||||
return dev_dax;
|
||||
|
||||
err_inode:
|
||||
ida_simple_remove(&dax_minor_ida, minor);
|
||||
err_minor:
|
||||
err_dax:
|
||||
ida_simple_remove(&dax_region->ida, dev_dax->id);
|
||||
err_id:
|
||||
kfree(dev_dax);
|
||||
|
|
@ -824,38 +694,13 @@ EXPORT_SYMBOL_GPL(devm_create_dev_dax);
|
|||
|
||||
static int __init dax_init(void)
|
||||
{
|
||||
int rc;
|
||||
|
||||
rc = dax_inode_init();
|
||||
if (rc)
|
||||
return rc;
|
||||
|
||||
nr_dax = max(nr_dax, 256);
|
||||
rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax");
|
||||
if (rc)
|
||||
goto err_chrdev;
|
||||
|
||||
dax_class = class_create(THIS_MODULE, "dax");
|
||||
if (IS_ERR(dax_class)) {
|
||||
rc = PTR_ERR(dax_class);
|
||||
goto err_class;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
err_class:
|
||||
unregister_chrdev_region(dax_devt, nr_dax);
|
||||
err_chrdev:
|
||||
dax_inode_exit();
|
||||
return rc;
|
||||
return PTR_ERR_OR_ZERO(dax_class);
|
||||
}
|
||||
|
||||
static void __exit dax_exit(void)
|
||||
{
|
||||
class_destroy(dax_class);
|
||||
unregister_chrdev_region(dax_devt, nr_dax);
|
||||
ida_destroy(&dax_minor_ida);
|
||||
dax_inode_exit();
|
||||
}
|
||||
|
||||
MODULE_AUTHOR("Intel Corporation");
|
||||
|
|
@ -16,7 +16,7 @@
|
|||
#include <linux/pfn_t.h>
|
||||
#include "../nvdimm/pfn.h"
|
||||
#include "../nvdimm/nd.h"
|
||||
#include "dax.h"
|
||||
#include "device-dax.h"
|
||||
|
||||
struct dax_pmem {
|
||||
struct device *dev;
|
||||
|
|
|
|||
|
|
@ -0,0 +1,303 @@
|
|||
/*
|
||||
* Copyright(c) 2017 Intel Corporation. All rights reserved.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of version 2 of the GNU General Public License as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful, but
|
||||
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*/
|
||||
#include <linux/pagemap.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/mount.h>
|
||||
#include <linux/magic.h>
|
||||
#include <linux/cdev.h>
|
||||
#include <linux/hash.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/fs.h>
|
||||
|
||||
static int nr_dax = CONFIG_NR_DEV_DAX;
|
||||
module_param(nr_dax, int, S_IRUGO);
|
||||
MODULE_PARM_DESC(nr_dax, "max number of dax device instances");
|
||||
|
||||
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);
|
||||
|
||||
/**
|
||||
* struct dax_device - anchor object for dax services
|
||||
* @inode: core vfs
|
||||
* @cdev: optional character interface for "device dax"
|
||||
* @private: dax driver private data
|
||||
* @alive: !alive + rcu grace period == no new operations / mappings
|
||||
*/
|
||||
struct dax_device {
|
||||
struct inode inode;
|
||||
struct cdev cdev;
|
||||
void *private;
|
||||
bool alive;
|
||||
};
|
||||
|
||||
bool dax_alive(struct dax_device *dax_dev)
|
||||
{
|
||||
lockdep_assert_held(&dax_srcu);
|
||||
return dax_dev->alive;
|
||||
}
|
||||
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;
|
||||
|
||||
dax_dev->alive = false;
|
||||
synchronize_srcu(&dax_srcu);
|
||||
dax_dev->private = NULL;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(kill_dax);
|
||||
|
||||
static struct inode *dax_alloc_inode(struct super_block *sb)
|
||||
{
|
||||
struct dax_device *dax_dev;
|
||||
|
||||
dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL);
|
||||
return &dax_dev->inode;
|
||||
}
|
||||
|
||||
static struct dax_device *to_dax_dev(struct inode *inode)
|
||||
{
|
||||
return container_of(inode, struct dax_device, inode);
|
||||
}
|
||||
|
||||
static void dax_i_callback(struct rcu_head *head)
|
||||
{
|
||||
struct inode *inode = container_of(head, struct inode, i_rcu);
|
||||
struct dax_device *dax_dev = to_dax_dev(inode);
|
||||
|
||||
ida_simple_remove(&dax_minor_ida, MINOR(inode->i_rdev));
|
||||
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(dax_dev->alive,
|
||||
"kill_dax() must be called before final iput()\n");
|
||||
call_rcu(&inode->i_rcu, dax_i_callback);
|
||||
}
|
||||
|
||||
static const struct super_operations dax_sops = {
|
||||
.statfs = simple_statfs,
|
||||
.alloc_inode = dax_alloc_inode,
|
||||
.destroy_inode = dax_destroy_inode,
|
||||
.drop_inode = generic_delete_inode,
|
||||
};
|
||||
|
||||
static struct dentry *dax_mount(struct file_system_type *fs_type,
|
||||
int flags, const char *dev_name, void *data)
|
||||
{
|
||||
return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC);
|
||||
}
|
||||
|
||||
static struct file_system_type dax_fs_type = {
|
||||
.name = "dax",
|
||||
.mount = dax_mount,
|
||||
.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) {
|
||||
dax_dev->alive = true;
|
||||
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)
|
||||
{
|
||||
struct dax_device *dax_dev;
|
||||
dev_t devt;
|
||||
int minor;
|
||||
|
||||
minor = ida_simple_get(&dax_minor_ida, 0, nr_dax, GFP_KERNEL);
|
||||
if (minor < 0)
|
||||
return NULL;
|
||||
|
||||
devt = MKDEV(MAJOR(dax_devt), minor);
|
||||
dax_dev = dax_dev_get(devt);
|
||||
if (!dax_dev)
|
||||
goto err_inode;
|
||||
|
||||
dax_dev->private = private;
|
||||
return dax_dev;
|
||||
|
||||
err_inode:
|
||||
ida_simple_remove(&dax_minor_ida, minor);
|
||||
return NULL;
|
||||
}
|
||||
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);
|
||||
|
||||
/**
|
||||
* 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)
|
||||
{
|
||||
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;
|
||||
|
||||
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;
|
||||
|
||||
rc = register_filesystem(&dax_fs_type);
|
||||
if (rc)
|
||||
goto err_register_fs;
|
||||
|
||||
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:
|
||||
unregister_filesystem(&dax_fs_type);
|
||||
err_register_fs:
|
||||
kmem_cache_destroy(dax_cache);
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
static void __dax_fs_exit(void)
|
||||
{
|
||||
kern_unmount(dax_mnt);
|
||||
unregister_filesystem(&dax_fs_type);
|
||||
kmem_cache_destroy(dax_cache);
|
||||
}
|
||||
|
||||
static int __init dax_fs_init(void)
|
||||
{
|
||||
int rc;
|
||||
|
||||
rc = __dax_fs_init();
|
||||
if (rc)
|
||||
return rc;
|
||||
|
||||
nr_dax = max(nr_dax, 256);
|
||||
rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax");
|
||||
if (rc)
|
||||
__dax_fs_exit();
|
||||
return rc;
|
||||
}
|
||||
|
||||
static void __exit dax_fs_exit(void)
|
||||
{
|
||||
unregister_chrdev_region(dax_devt, nr_dax);
|
||||
ida_destroy(&dax_minor_ida);
|
||||
__dax_fs_exit();
|
||||
}
|
||||
|
||||
MODULE_AUTHOR("Intel Corporation");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
subsys_initcall(dax_fs_init);
|
||||
module_exit(dax_fs_exit);
|
||||
|
|
@ -8,6 +8,9 @@
|
|||
|
||||
struct iomap_ops;
|
||||
|
||||
int dax_read_lock(void);
|
||||
void dax_read_unlock(int id);
|
||||
|
||||
/*
|
||||
* We use lowest available bit in exceptional entry for locking, one bit for
|
||||
* the entry size (PMD) and two more to tell us if the entry is a huge zero
|
||||
|
|
|
|||
|
|
@ -28,7 +28,10 @@ obj-$(CONFIG_ND_BTT) += nd_btt.o
|
|||
obj-$(CONFIG_ND_BLK) += nd_blk.o
|
||||
obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
|
||||
obj-$(CONFIG_ACPI_NFIT) += nfit.o
|
||||
obj-$(CONFIG_DEV_DAX) += dax.o
|
||||
ifeq ($(CONFIG_DAX),m)
|
||||
obj-$(CONFIG_DAX) += dax.o
|
||||
endif
|
||||
obj-$(CONFIG_DEV_DAX) += device_dax.o
|
||||
obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o
|
||||
|
||||
nfit-y := $(ACPI_SRC)/core.o
|
||||
|
|
@ -48,9 +51,12 @@ nd_blk-y += config_check.o
|
|||
nd_e820-y := $(NVDIMM_SRC)/e820.o
|
||||
nd_e820-y += config_check.o
|
||||
|
||||
dax-y := $(DAX_SRC)/dax.o
|
||||
dax-y := $(DAX_SRC)/super.o
|
||||
dax-y += config_check.o
|
||||
|
||||
device_dax-y := $(DAX_SRC)/device.o
|
||||
device_dax-y += config_check.o
|
||||
|
||||
dax_pmem-y := $(DAX_SRC)/pmem.o
|
||||
dax_pmem-y += config_check.o
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue