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 <h...@lst.de> Signed-off-by: Dan Williams <dan.j.willi...@intel.com> --- drivers/Makefile | 2 drivers/dax/Kconfig | 10 + drivers/dax/Makefile | 5 + drivers/dax/dax.h | 20 +-- drivers/dax/device-dax.h | 25 ++++ drivers/dax/device.c | 241 ++++++---------------------------- drivers/dax/pmem.c | 2 drivers/dax/super.c | 303 +++++++++++++++++++++++++++++++++++++++++++ include/linux/dax.h | 3 tools/testing/nvdimm/Kbuild | 10 + 10 files changed, 404 insertions(+), 217 deletions(-) create mode 100644 drivers/dax/device-dax.h rename drivers/dax/{dax.c => device.c} (77%) create mode 100644 drivers/dax/super.c diff --git a/drivers/Makefile b/drivers/Makefile index 2eced9afba53..0442e982cf35 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -71,7 +71,7 @@ obj-$(CONFIG_PARPORT) += parport/ obj-$(CONFIG_NVM) += lightnvm/ obj-y += base/ block/ misc/ mfd/ nfc/ obj-$(CONFIG_LIBNVDIMM) += nvdimm/ -obj-$(CONFIG_DEV_DAX) += dax/ +obj-$(CONFIG_DAX) += dax/ obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/ obj-$(CONFIG_NUBUS) += nubus/ obj-y += macintosh/ diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index 9e95bf94eb13..b7053eafd88e 100644 --- a/drivers/dax/Kconfig +++ b/drivers/dax/Kconfig @@ -1,8 +1,13 @@ -menuconfig DEV_DAX +menuconfig DAX tristate "DAX: direct access to differentiated memory" + select SRCU default m if NVDIMM_DAX + +if DAX + +config DEV_DAX + tristate "Device DAX: direct access mapping device" depends on TRANSPARENT_HUGEPAGE - select SRCU help Support raw access to differentiated (persistence, bandwidth, latency...) memory via an mmap(2) capable character @@ -11,7 +16,6 @@ menuconfig DEV_DAX baseline memory pool. Mappings of a /dev/daxX.Y device impose restrictions that make the mapping behavior deterministic. -if DEV_DAX config DEV_DAX_PMEM tristate "PMEM DAX: direct access to persistent memory" diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile index 27c54e38478a..dc7422530462 100644 --- a/drivers/dax/Makefile +++ b/drivers/dax/Makefile @@ -1,4 +1,7 @@ -obj-$(CONFIG_DEV_DAX) += dax.o +obj-$(CONFIG_DAX) += dax.o +obj-$(CONFIG_DEV_DAX) += device_dax.o obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o +dax-y := super.o dax_pmem-y := pmem.o +device_dax-y := device.o diff --git a/drivers/dax/dax.h b/drivers/dax/dax.h index ea176d875d60..2472d9da96db 100644 --- a/drivers/dax/dax.h +++ b/drivers/dax/dax.h @@ -1,5 +1,5 @@ /* - * Copyright(c) 2016 Intel Corporation. All rights reserved. + * Copyright(c) 2016 - 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 @@ -12,14 +12,12 @@ */ #ifndef __DAX_H__ #define __DAX_H__ -struct device; -struct dev_dax; -struct resource; -struct dax_region; -void dax_region_put(struct dax_region *dax_region); -struct dax_region *alloc_dax_region(struct device *parent, - int region_id, struct resource *res, unsigned int align, - void *addr, unsigned long flags); -struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, - struct resource *res, int count); +struct dax_device; +struct dax_device *alloc_dax(void *private); +void put_dax(struct dax_device *dax_dev); +bool dax_alive(struct dax_device *dax_dev); +void kill_dax(struct dax_device *dax_dev); +struct dax_device *inode_dax(struct inode *inode); +struct inode *dax_inode(struct dax_device *dax_dev); +void *dax_get_private(struct dax_device *dax_dev); #endif /* __DAX_H__ */ diff --git a/drivers/dax/device-dax.h b/drivers/dax/device-dax.h new file mode 100644 index 000000000000..fdcd9769ffde --- /dev/null +++ b/drivers/dax/device-dax.h @@ -0,0 +1,25 @@ +/* + * Copyright(c) 2016 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. + */ +#ifndef __DEVICE_DAX_H__ +#define __DEVICE_DAX_H__ +struct device; +struct dev_dax; +struct resource; +struct dax_region; +void dax_region_put(struct dax_region *dax_region); +struct dax_region *alloc_dax_region(struct device *parent, + int region_id, struct resource *res, unsigned int align, + void *addr, unsigned long flags); +struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, + struct resource *res, int count); +#endif /* __DEVICE_DAX_H__ */ diff --git a/drivers/dax/dax.c b/drivers/dax/device.c similarity index 77% rename from drivers/dax/dax.c rename to drivers/dax/device.c index 376fdd353aea..19a42edbfa03 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/device.c @@ -1,5 +1,5 @@ /* - * Copyright(c) 2016 Intel Corporation. All rights reserved. + * Copyright(c) 2016 - 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 @@ -13,10 +13,7 @@ #include <linux/pagemap.h> #include <linux/module.h> #include <linux/device.h> -#include <linux/magic.h> -#include <linux/mount.h> #include <linux/pfn_t.h> -#include <linux/hash.h> #include <linux/cdev.h> #include <linux/slab.h> #include <linux/dax.h> @@ -24,16 +21,7 @@ #include <linux/mm.h> #include "dax.h" -static dev_t dax_devt; -DEFINE_STATIC_SRCU(dax_srcu); static struct class *dax_class; -static DEFINE_IDA(dax_minor_ida); -static int nr_dax = CONFIG_NR_DEV_DAX; -module_param(nr_dax, int, S_IRUGO); -static struct vfsmount *dax_mnt; -static struct kmem_cache *dax_cache __read_mostly; -static struct super_block *dax_superblock __read_mostly; -MODULE_PARM_DESC(nr_dax, "max number of device-dax instances"); /** * struct dax_region - mapping infrastructure for dax devices @@ -59,19 +47,16 @@ struct dax_region { /** * struct dev_dax - instance data for a subdivision of a dax region * @region - parent region - * @dev - device backing the character device - * @cdev - core chardev data - * @alive - !alive + srcu grace period == no new mappings can be established + * @dax_dev - core dax functionality + * @dev - device core * @id - child id in the region * @num_resources - number of physical address extents in this device * @res - array of physical address ranges */ struct dev_dax { struct dax_region *region; - struct inode *inode; + struct dax_device *dax_dev; struct device dev; - struct cdev cdev; - bool alive; int id; int num_resources; struct resource res[0]; @@ -144,117 +129,6 @@ static const struct attribute_group *dax_region_attribute_groups[] = { NULL, }; -static struct inode *dax_alloc_inode(struct super_block *sb) -{ - return kmem_cache_alloc(dax_cache, GFP_KERNEL); -} - -static void dax_i_callback(struct rcu_head *head) -{ - struct inode *inode = container_of(head, struct inode, i_rcu); - - kmem_cache_free(dax_cache, inode); -} - -static void dax_destroy_inode(struct inode *inode) -{ - 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_type = { - .name = "dax", - .mount = dax_mount, - .kill_sb = kill_anon_super, -}; - -static int dax_test(struct inode *inode, void *data) -{ - return inode->i_cdev == data; -} - -static int dax_set(struct inode *inode, void *data) -{ - inode->i_cdev = data; - return 0; -} - -static struct inode *dax_inode_get(struct cdev *cdev, dev_t devt) -{ - struct inode *inode; - - inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), - dax_test, dax_set, cdev); - - if (!inode) - return NULL; - - if (inode->i_state & I_NEW) { - inode->i_mode = S_IFCHR; - inode->i_flags = S_DAX; - inode->i_rdev = devt; - mapping_set_gfp_mask(&inode->i_data, GFP_USER); - unlock_new_inode(inode); - } - return inode; -} - -static void init_once(void *inode) -{ - inode_init_once(inode); -} - -static int dax_inode_init(void) -{ - int rc; - - dax_cache = kmem_cache_create("dax_cache", sizeof(struct inode), 0, - (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| - SLAB_MEM_SPREAD|SLAB_ACCOUNT), - init_once); - if (!dax_cache) - return -ENOMEM; - - rc = register_filesystem(&dax_type); - if (rc) - goto err_register_fs; - - dax_mnt = kern_mount(&dax_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_type); - err_register_fs: - kmem_cache_destroy(dax_cache); - - return rc; -} - -static void dax_inode_exit(void) -{ - kern_unmount(dax_mnt); - unregister_filesystem(&dax_type); - kmem_cache_destroy(dax_cache); -} - static void dax_region_free(struct kref *kref) { struct dax_region *dax_region; @@ -363,7 +237,7 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma, struct device *dev = &dev_dax->dev; unsigned long mask; - if (!dev_dax->alive) + if (!dax_alive(dev_dax->dax_dev)) return -ENXIO; /* prevent private mappings from being established */ @@ -582,7 +456,7 @@ static int dev_dax_huge_fault(struct vm_fault *vmf, ? "write" : "read", vmf->vma->vm_start, vmf->vma->vm_end, pe_size); - id = srcu_read_lock(&dax_srcu); + id = dax_read_lock(); switch (pe_size) { case PE_SIZE_PTE: rc = __dev_dax_pte_fault(dev_dax, vmf); @@ -596,7 +470,7 @@ static int dev_dax_huge_fault(struct vm_fault *vmf, default: rc = VM_FAULT_SIGBUS; } - srcu_read_unlock(&dax_srcu, id); + dax_read_unlock(id); return rc; } @@ -614,11 +488,17 @@ static const struct vm_operations_struct dax_vm_ops = { static int dax_mmap(struct file *filp, struct vm_area_struct *vma) { struct dev_dax *dev_dax = filp->private_data; - int rc; + int rc, id; dev_dbg(&dev_dax->dev, "%s\n", __func__); + /* + * We lock to check dax_dev liveness and will re-check at + * fault time. + */ + id = dax_read_lock(); rc = check_vma(dev_dax, vma, __func__); + dax_read_unlock(id); if (rc) return rc; @@ -664,12 +544,13 @@ static unsigned long dax_get_unmapped_area(struct file *filp, static int dax_open(struct inode *inode, struct file *filp) { - struct dev_dax *dev_dax; + struct dax_device *dax_dev = inode_dax(inode); + struct inode *__dax_inode = dax_inode(dax_dev); + struct dev_dax *dev_dax = dax_get_private(dax_dev); - dev_dax = container_of(inode->i_cdev, struct dev_dax, cdev); dev_dbg(&dev_dax->dev, "%s\n", __func__); - inode->i_mapping = dev_dax->inode->i_mapping; - inode->i_mapping->host = dev_dax->inode; + inode->i_mapping = __dax_inode->i_mapping; + inode->i_mapping->host = __dax_inode; filp->f_mapping = inode->i_mapping; filp->private_data = dev_dax; inode->i_flags = S_DAX; @@ -698,36 +579,34 @@ static void dev_dax_release(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); struct dax_region *dax_region = dev_dax->region; + struct dax_device *dax_dev = dev_dax->dax_dev; ida_simple_remove(&dax_region->ida, dev_dax->id); - ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); dax_region_put(dax_region); - iput(dev_dax->inode); + put_dax(dax_dev); kfree(dev_dax); } static void kill_dev_dax(struct dev_dax *dev_dax) { - /* - * Note, rcu is not protecting the liveness of dev_dax, rcu is - * ensuring that any fault handlers that might have seen - * dev_dax->alive == true, have completed. Any fault handlers - * that start after synchronize_srcu() has started will abort - * upon seeing dev_dax->alive == false. - */ - dev_dax->alive = false; - synchronize_srcu(&dax_srcu); - unmap_mapping_range(dev_dax->inode->i_mapping, 0, 0, 1); + struct dax_device *dax_dev = dev_dax->dax_dev; + struct inode *inode = dax_inode(dax_dev); + + kill_dax(dax_dev); + unmap_mapping_range(inode->i_mapping, 0, 0, 1); } static void unregister_dev_dax(void *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_device *dax_dev = dev_dax->dax_dev; + struct inode *inode = dax_inode(dax_dev); + struct cdev *cdev = inode->i_cdev; dev_dbg(dev, "%s\n", __func__); kill_dev_dax(dev_dax); - cdev_device_del(&dev_dax->cdev, dev); + cdev_device_del(cdev, dev); put_device(dev); } @@ -735,11 +614,12 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, struct resource *res, int count) { struct device *parent = dax_region->dev; + struct dax_device *dax_dev; struct dev_dax *dev_dax; - int rc = 0, minor, i; + struct inode *inode; struct device *dev; struct cdev *cdev; - dev_t dev_t; + int rc = 0, i; dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, GFP_KERNEL); if (!dev_dax) @@ -765,33 +645,25 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, goto err_id; } - minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL); - if (minor < 0) { - rc = minor; - goto err_minor; - } + dax_dev = alloc_dax(dev_dax); + if (!dax_dev) + goto err_dax; - dev_t = MKDEV(MAJOR(dax_devt), minor); + /* 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"); diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index 2c736fc4508b..d4ca19bd74eb 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -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; diff --git a/drivers/dax/super.c b/drivers/dax/super.c new file mode 100644 index 000000000000..c9f85f1c086e --- /dev/null +++ b/drivers/dax/super.c @@ -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); diff --git a/include/linux/dax.h b/include/linux/dax.h index d8a3dc042e1c..5b62f5d19aea 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -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 diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild index 405212be044a..2033ad03b8cd 100644 --- a/tools/testing/nvdimm/Kbuild +++ b/tools/testing/nvdimm/Kbuild @@ -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
