17b6be844SDan Williams /* 27b6be844SDan Williams * Copyright(c) 2017 Intel Corporation. All rights reserved. 37b6be844SDan Williams * 47b6be844SDan Williams * This program is free software; you can redistribute it and/or modify 57b6be844SDan Williams * it under the terms of version 2 of the GNU General Public License as 67b6be844SDan Williams * published by the Free Software Foundation. 77b6be844SDan Williams * 87b6be844SDan Williams * This program is distributed in the hope that it will be useful, but 97b6be844SDan Williams * WITHOUT ANY WARRANTY; without even the implied warranty of 107b6be844SDan Williams * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 117b6be844SDan Williams * General Public License for more details. 127b6be844SDan Williams */ 137b6be844SDan Williams #include <linux/pagemap.h> 147b6be844SDan Williams #include <linux/module.h> 157b6be844SDan Williams #include <linux/mount.h> 167b6be844SDan Williams #include <linux/magic.h> 17ef510424SDan Williams #include <linux/genhd.h> 187b6be844SDan Williams #include <linux/cdev.h> 197b6be844SDan Williams #include <linux/hash.h> 207b6be844SDan Williams #include <linux/slab.h> 217e026c8cSDan Williams #include <linux/uio.h> 226568b08bSDan Williams #include <linux/dax.h> 237b6be844SDan Williams #include <linux/fs.h> 247b6be844SDan Williams 257b6be844SDan Williams static dev_t dax_devt; 267b6be844SDan Williams DEFINE_STATIC_SRCU(dax_srcu); 277b6be844SDan Williams static struct vfsmount *dax_mnt; 287b6be844SDan Williams static DEFINE_IDA(dax_minor_ida); 297b6be844SDan Williams static struct kmem_cache *dax_cache __read_mostly; 307b6be844SDan Williams static struct super_block *dax_superblock __read_mostly; 317b6be844SDan Williams 3272058005SDan Williams #define DAX_HASH_SIZE (PAGE_SIZE / sizeof(struct hlist_head)) 3372058005SDan Williams static struct hlist_head dax_host_list[DAX_HASH_SIZE]; 3472058005SDan Williams static DEFINE_SPINLOCK(dax_host_lock); 3572058005SDan Williams 367b6be844SDan Williams int dax_read_lock(void) 377b6be844SDan Williams { 387b6be844SDan Williams return srcu_read_lock(&dax_srcu); 397b6be844SDan Williams } 407b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_lock); 417b6be844SDan Williams 427b6be844SDan Williams void dax_read_unlock(int id) 437b6be844SDan Williams { 447b6be844SDan Williams srcu_read_unlock(&dax_srcu, id); 457b6be844SDan Williams } 467b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_unlock); 477b6be844SDan Williams 489d109081SDan Williams #ifdef CONFIG_BLOCK 49ef510424SDan Williams int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, 50ef510424SDan Williams pgoff_t *pgoff) 51ef510424SDan Williams { 52ef510424SDan Williams phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512; 53ef510424SDan Williams 54ef510424SDan Williams if (pgoff) 55ef510424SDan Williams *pgoff = PHYS_PFN(phys_off); 56ef510424SDan Williams if (phys_off % PAGE_SIZE || size % PAGE_SIZE) 57ef510424SDan Williams return -EINVAL; 58ef510424SDan Williams return 0; 59ef510424SDan Williams } 60ef510424SDan Williams EXPORT_SYMBOL(bdev_dax_pgoff); 61ef510424SDan Williams 62ef510424SDan Williams /** 63ef510424SDan Williams * __bdev_dax_supported() - Check if the device supports dax for filesystem 64ef510424SDan Williams * @sb: The superblock of the device 65ef510424SDan Williams * @blocksize: The block size of the device 66ef510424SDan Williams * 67ef510424SDan Williams * This is a library function for filesystems to check if the block device 68ef510424SDan Williams * can be mounted with dax option. 69ef510424SDan Williams * 70ef510424SDan Williams * Return: negative errno if unsupported, 0 if supported. 71ef510424SDan Williams */ 72ef510424SDan Williams int __bdev_dax_supported(struct super_block *sb, int blocksize) 73ef510424SDan Williams { 74ef510424SDan Williams struct block_device *bdev = sb->s_bdev; 75ef510424SDan Williams struct dax_device *dax_dev; 76ef510424SDan Williams pgoff_t pgoff; 77ef510424SDan Williams int err, id; 78ef510424SDan Williams void *kaddr; 79ef510424SDan Williams pfn_t pfn; 80ef510424SDan Williams long len; 81ef510424SDan Williams 82ef510424SDan Williams if (blocksize != PAGE_SIZE) { 83ef510424SDan Williams pr_err("VFS (%s): error: unsupported blocksize for dax\n", 84ef510424SDan Williams sb->s_id); 85ef510424SDan Williams return -EINVAL; 86ef510424SDan Williams } 87ef510424SDan Williams 88ef510424SDan Williams err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); 89ef510424SDan Williams if (err) { 90ef510424SDan Williams pr_err("VFS (%s): error: unaligned partition for dax\n", 91ef510424SDan Williams sb->s_id); 92ef510424SDan Williams return err; 93ef510424SDan Williams } 94ef510424SDan Williams 95ef510424SDan Williams dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); 96ef510424SDan Williams if (!dax_dev) { 97ef510424SDan Williams pr_err("VFS (%s): error: device does not support dax\n", 98ef510424SDan Williams sb->s_id); 99ef510424SDan Williams return -EOPNOTSUPP; 100ef510424SDan Williams } 101ef510424SDan Williams 102ef510424SDan Williams id = dax_read_lock(); 103ef510424SDan Williams len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); 104ef510424SDan Williams dax_read_unlock(id); 105ef510424SDan Williams 106ef510424SDan Williams put_dax(dax_dev); 107ef510424SDan Williams 108ef510424SDan Williams if (len < 1) { 109ef510424SDan Williams pr_err("VFS (%s): error: dax access failed (%ld)", 110ef510424SDan Williams sb->s_id, len); 111ef510424SDan Williams return len < 0 ? len : -EIO; 112ef510424SDan Williams } 113ef510424SDan Williams 114ef510424SDan Williams return 0; 115ef510424SDan Williams } 116ef510424SDan Williams EXPORT_SYMBOL_GPL(__bdev_dax_supported); 1179d109081SDan Williams #endif 118ef510424SDan Williams 1197b6be844SDan Williams /** 1207b6be844SDan Williams * struct dax_device - anchor object for dax services 1217b6be844SDan Williams * @inode: core vfs 1227b6be844SDan Williams * @cdev: optional character interface for "device dax" 12372058005SDan Williams * @host: optional name for lookups where the device path is not available 1247b6be844SDan Williams * @private: dax driver private data 1257b6be844SDan Williams * @alive: !alive + rcu grace period == no new operations / mappings 1267b6be844SDan Williams */ 1277b6be844SDan Williams struct dax_device { 12872058005SDan Williams struct hlist_node list; 1297b6be844SDan Williams struct inode inode; 1307b6be844SDan Williams struct cdev cdev; 13172058005SDan Williams const char *host; 1327b6be844SDan Williams void *private; 1337b6be844SDan Williams bool alive; 1346568b08bSDan Williams const struct dax_operations *ops; 1357b6be844SDan Williams }; 1367b6be844SDan Williams 137b0686260SDan Williams /** 138b0686260SDan Williams * dax_direct_access() - translate a device pgoff to an absolute pfn 139b0686260SDan Williams * @dax_dev: a dax_device instance representing the logical memory range 140b0686260SDan Williams * @pgoff: offset in pages from the start of the device to translate 141b0686260SDan Williams * @nr_pages: number of consecutive pages caller can handle relative to @pfn 142b0686260SDan Williams * @kaddr: output parameter that returns a virtual address mapping of pfn 143b0686260SDan Williams * @pfn: output parameter that returns an absolute pfn translation of @pgoff 144b0686260SDan Williams * 145b0686260SDan Williams * Return: negative errno if an error occurs, otherwise the number of 146b0686260SDan Williams * pages accessible at the device relative @pgoff. 147b0686260SDan Williams */ 148b0686260SDan Williams long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 149b0686260SDan Williams void **kaddr, pfn_t *pfn) 150b0686260SDan Williams { 151b0686260SDan Williams long avail; 152b0686260SDan Williams 153b0686260SDan Williams /* 154b0686260SDan Williams * The device driver is allowed to sleep, in order to make the 155b0686260SDan Williams * memory directly accessible. 156b0686260SDan Williams */ 157b0686260SDan Williams might_sleep(); 158b0686260SDan Williams 159b0686260SDan Williams if (!dax_dev) 160b0686260SDan Williams return -EOPNOTSUPP; 161b0686260SDan Williams 162b0686260SDan Williams if (!dax_alive(dax_dev)) 163b0686260SDan Williams return -ENXIO; 164b0686260SDan Williams 165b0686260SDan Williams if (nr_pages < 0) 166b0686260SDan Williams return nr_pages; 167b0686260SDan Williams 168b0686260SDan Williams avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages, 169b0686260SDan Williams kaddr, pfn); 170b0686260SDan Williams if (!avail) 171b0686260SDan Williams return -ERANGE; 172b0686260SDan Williams return min(avail, nr_pages); 173b0686260SDan Williams } 174b0686260SDan Williams EXPORT_SYMBOL_GPL(dax_direct_access); 175b0686260SDan Williams 1767e026c8cSDan Williams size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, 1777e026c8cSDan Williams size_t bytes, struct iov_iter *i) 1787e026c8cSDan Williams { 1797e026c8cSDan Williams if (!dax_alive(dax_dev)) 1807e026c8cSDan Williams return 0; 1817e026c8cSDan Williams 1827e026c8cSDan Williams if (!dax_dev->ops->copy_from_iter) 1837e026c8cSDan Williams return copy_from_iter(addr, bytes, i); 1847e026c8cSDan Williams return dax_dev->ops->copy_from_iter(dax_dev, pgoff, addr, bytes, i); 1857e026c8cSDan Williams } 1867e026c8cSDan Williams EXPORT_SYMBOL_GPL(dax_copy_from_iter); 1877e026c8cSDan Williams 1887b6be844SDan Williams bool dax_alive(struct dax_device *dax_dev) 1897b6be844SDan Williams { 1907b6be844SDan Williams lockdep_assert_held(&dax_srcu); 1917b6be844SDan Williams return dax_dev->alive; 1927b6be844SDan Williams } 1937b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_alive); 1947b6be844SDan Williams 19572058005SDan Williams static int dax_host_hash(const char *host) 19672058005SDan Williams { 19772058005SDan Williams return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE; 19872058005SDan Williams } 19972058005SDan Williams 2007b6be844SDan Williams /* 2017b6be844SDan Williams * Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring 2027b6be844SDan Williams * that any fault handlers or operations that might have seen 2037b6be844SDan Williams * dax_alive(), have completed. Any operations that start after 2047b6be844SDan Williams * synchronize_srcu() has run will abort upon seeing !dax_alive(). 2057b6be844SDan Williams */ 2067b6be844SDan Williams void kill_dax(struct dax_device *dax_dev) 2077b6be844SDan Williams { 2087b6be844SDan Williams if (!dax_dev) 2097b6be844SDan Williams return; 2107b6be844SDan Williams 2117b6be844SDan Williams dax_dev->alive = false; 21272058005SDan Williams 2137b6be844SDan Williams synchronize_srcu(&dax_srcu); 21472058005SDan Williams 21572058005SDan Williams spin_lock(&dax_host_lock); 21672058005SDan Williams hlist_del_init(&dax_dev->list); 21772058005SDan Williams spin_unlock(&dax_host_lock); 21872058005SDan Williams 2197b6be844SDan Williams dax_dev->private = NULL; 2207b6be844SDan Williams } 2217b6be844SDan Williams EXPORT_SYMBOL_GPL(kill_dax); 2227b6be844SDan Williams 2237b6be844SDan Williams static struct inode *dax_alloc_inode(struct super_block *sb) 2247b6be844SDan Williams { 2257b6be844SDan Williams struct dax_device *dax_dev; 2267b6be844SDan Williams 2277b6be844SDan Williams dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL); 2287b6be844SDan Williams return &dax_dev->inode; 2297b6be844SDan Williams } 2307b6be844SDan Williams 2317b6be844SDan Williams static struct dax_device *to_dax_dev(struct inode *inode) 2327b6be844SDan Williams { 2337b6be844SDan Williams return container_of(inode, struct dax_device, inode); 2347b6be844SDan Williams } 2357b6be844SDan Williams 2367b6be844SDan Williams static void dax_i_callback(struct rcu_head *head) 2377b6be844SDan Williams { 2387b6be844SDan Williams struct inode *inode = container_of(head, struct inode, i_rcu); 2397b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 2407b6be844SDan Williams 24172058005SDan Williams kfree(dax_dev->host); 24272058005SDan Williams dax_dev->host = NULL; 2437b6be844SDan Williams ida_simple_remove(&dax_minor_ida, MINOR(inode->i_rdev)); 2447b6be844SDan Williams kmem_cache_free(dax_cache, dax_dev); 2457b6be844SDan Williams } 2467b6be844SDan Williams 2477b6be844SDan Williams static void dax_destroy_inode(struct inode *inode) 2487b6be844SDan Williams { 2497b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 2507b6be844SDan Williams 2517b6be844SDan Williams WARN_ONCE(dax_dev->alive, 2527b6be844SDan Williams "kill_dax() must be called before final iput()\n"); 2537b6be844SDan Williams call_rcu(&inode->i_rcu, dax_i_callback); 2547b6be844SDan Williams } 2557b6be844SDan Williams 2567b6be844SDan Williams static const struct super_operations dax_sops = { 2577b6be844SDan Williams .statfs = simple_statfs, 2587b6be844SDan Williams .alloc_inode = dax_alloc_inode, 2597b6be844SDan Williams .destroy_inode = dax_destroy_inode, 2607b6be844SDan Williams .drop_inode = generic_delete_inode, 2617b6be844SDan Williams }; 2627b6be844SDan Williams 2637b6be844SDan Williams static struct dentry *dax_mount(struct file_system_type *fs_type, 2647b6be844SDan Williams int flags, const char *dev_name, void *data) 2657b6be844SDan Williams { 2667b6be844SDan Williams return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC); 2677b6be844SDan Williams } 2687b6be844SDan Williams 2697b6be844SDan Williams static struct file_system_type dax_fs_type = { 2707b6be844SDan Williams .name = "dax", 2717b6be844SDan Williams .mount = dax_mount, 2727b6be844SDan Williams .kill_sb = kill_anon_super, 2737b6be844SDan Williams }; 2747b6be844SDan Williams 2757b6be844SDan Williams static int dax_test(struct inode *inode, void *data) 2767b6be844SDan Williams { 2777b6be844SDan Williams dev_t devt = *(dev_t *) data; 2787b6be844SDan Williams 2797b6be844SDan Williams return inode->i_rdev == devt; 2807b6be844SDan Williams } 2817b6be844SDan Williams 2827b6be844SDan Williams static int dax_set(struct inode *inode, void *data) 2837b6be844SDan Williams { 2847b6be844SDan Williams dev_t devt = *(dev_t *) data; 2857b6be844SDan Williams 2867b6be844SDan Williams inode->i_rdev = devt; 2877b6be844SDan Williams return 0; 2887b6be844SDan Williams } 2897b6be844SDan Williams 2907b6be844SDan Williams static struct dax_device *dax_dev_get(dev_t devt) 2917b6be844SDan Williams { 2927b6be844SDan Williams struct dax_device *dax_dev; 2937b6be844SDan Williams struct inode *inode; 2947b6be844SDan Williams 2957b6be844SDan Williams inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), 2967b6be844SDan Williams dax_test, dax_set, &devt); 2977b6be844SDan Williams 2987b6be844SDan Williams if (!inode) 2997b6be844SDan Williams return NULL; 3007b6be844SDan Williams 3017b6be844SDan Williams dax_dev = to_dax_dev(inode); 3027b6be844SDan Williams if (inode->i_state & I_NEW) { 3037b6be844SDan Williams dax_dev->alive = true; 3047b6be844SDan Williams inode->i_cdev = &dax_dev->cdev; 3057b6be844SDan Williams inode->i_mode = S_IFCHR; 3067b6be844SDan Williams inode->i_flags = S_DAX; 3077b6be844SDan Williams mapping_set_gfp_mask(&inode->i_data, GFP_USER); 3087b6be844SDan Williams unlock_new_inode(inode); 3097b6be844SDan Williams } 3107b6be844SDan Williams 3117b6be844SDan Williams return dax_dev; 3127b6be844SDan Williams } 3137b6be844SDan Williams 31472058005SDan Williams static void dax_add_host(struct dax_device *dax_dev, const char *host) 31572058005SDan Williams { 31672058005SDan Williams int hash; 31772058005SDan Williams 31872058005SDan Williams /* 31972058005SDan Williams * Unconditionally init dax_dev since it's coming from a 32072058005SDan Williams * non-zeroed slab cache 32172058005SDan Williams */ 32272058005SDan Williams INIT_HLIST_NODE(&dax_dev->list); 32372058005SDan Williams dax_dev->host = host; 32472058005SDan Williams if (!host) 32572058005SDan Williams return; 32672058005SDan Williams 32772058005SDan Williams hash = dax_host_hash(host); 32872058005SDan Williams spin_lock(&dax_host_lock); 32972058005SDan Williams hlist_add_head(&dax_dev->list, &dax_host_list[hash]); 33072058005SDan Williams spin_unlock(&dax_host_lock); 33172058005SDan Williams } 33272058005SDan Williams 3336568b08bSDan Williams struct dax_device *alloc_dax(void *private, const char *__host, 3346568b08bSDan Williams const struct dax_operations *ops) 3357b6be844SDan Williams { 3367b6be844SDan Williams struct dax_device *dax_dev; 33772058005SDan Williams const char *host; 3387b6be844SDan Williams dev_t devt; 3397b6be844SDan Williams int minor; 3407b6be844SDan Williams 34172058005SDan Williams host = kstrdup(__host, GFP_KERNEL); 34272058005SDan Williams if (__host && !host) 34372058005SDan Williams return NULL; 34472058005SDan Williams 345cf1e2289SDan Williams minor = ida_simple_get(&dax_minor_ida, 0, MINORMASK+1, GFP_KERNEL); 3467b6be844SDan Williams if (minor < 0) 34772058005SDan Williams goto err_minor; 3487b6be844SDan Williams 3497b6be844SDan Williams devt = MKDEV(MAJOR(dax_devt), minor); 3507b6be844SDan Williams dax_dev = dax_dev_get(devt); 3517b6be844SDan Williams if (!dax_dev) 35272058005SDan Williams goto err_dev; 3537b6be844SDan Williams 35472058005SDan Williams dax_add_host(dax_dev, host); 3556568b08bSDan Williams dax_dev->ops = ops; 3567b6be844SDan Williams dax_dev->private = private; 3577b6be844SDan Williams return dax_dev; 3587b6be844SDan Williams 35972058005SDan Williams err_dev: 3607b6be844SDan Williams ida_simple_remove(&dax_minor_ida, minor); 36172058005SDan Williams err_minor: 36272058005SDan Williams kfree(host); 3637b6be844SDan Williams return NULL; 3647b6be844SDan Williams } 3657b6be844SDan Williams EXPORT_SYMBOL_GPL(alloc_dax); 3667b6be844SDan Williams 3677b6be844SDan Williams void put_dax(struct dax_device *dax_dev) 3687b6be844SDan Williams { 3697b6be844SDan Williams if (!dax_dev) 3707b6be844SDan Williams return; 3717b6be844SDan Williams iput(&dax_dev->inode); 3727b6be844SDan Williams } 3737b6be844SDan Williams EXPORT_SYMBOL_GPL(put_dax); 3747b6be844SDan Williams 3757b6be844SDan Williams /** 37672058005SDan Williams * dax_get_by_host() - temporary lookup mechanism for filesystem-dax 37772058005SDan Williams * @host: alternate name for the device registered by a dax driver 37872058005SDan Williams */ 37972058005SDan Williams struct dax_device *dax_get_by_host(const char *host) 38072058005SDan Williams { 38172058005SDan Williams struct dax_device *dax_dev, *found = NULL; 38272058005SDan Williams int hash, id; 38372058005SDan Williams 38472058005SDan Williams if (!host) 38572058005SDan Williams return NULL; 38672058005SDan Williams 38772058005SDan Williams hash = dax_host_hash(host); 38872058005SDan Williams 38972058005SDan Williams id = dax_read_lock(); 39072058005SDan Williams spin_lock(&dax_host_lock); 39172058005SDan Williams hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) { 39272058005SDan Williams if (!dax_alive(dax_dev) 39372058005SDan Williams || strcmp(host, dax_dev->host) != 0) 39472058005SDan Williams continue; 39572058005SDan Williams 39672058005SDan Williams if (igrab(&dax_dev->inode)) 39772058005SDan Williams found = dax_dev; 39872058005SDan Williams break; 39972058005SDan Williams } 40072058005SDan Williams spin_unlock(&dax_host_lock); 40172058005SDan Williams dax_read_unlock(id); 40272058005SDan Williams 40372058005SDan Williams return found; 40472058005SDan Williams } 40572058005SDan Williams EXPORT_SYMBOL_GPL(dax_get_by_host); 40672058005SDan Williams 40772058005SDan Williams /** 4087b6be844SDan Williams * inode_dax: convert a public inode into its dax_dev 4097b6be844SDan Williams * @inode: An inode with i_cdev pointing to a dax_dev 4107b6be844SDan Williams * 4117b6be844SDan Williams * Note this is not equivalent to to_dax_dev() which is for private 4127b6be844SDan Williams * internal use where we know the inode filesystem type == dax_fs_type. 4137b6be844SDan Williams */ 4147b6be844SDan Williams struct dax_device *inode_dax(struct inode *inode) 4157b6be844SDan Williams { 4167b6be844SDan Williams struct cdev *cdev = inode->i_cdev; 4177b6be844SDan Williams 4187b6be844SDan Williams return container_of(cdev, struct dax_device, cdev); 4197b6be844SDan Williams } 4207b6be844SDan Williams EXPORT_SYMBOL_GPL(inode_dax); 4217b6be844SDan Williams 4227b6be844SDan Williams struct inode *dax_inode(struct dax_device *dax_dev) 4237b6be844SDan Williams { 4247b6be844SDan Williams return &dax_dev->inode; 4257b6be844SDan Williams } 4267b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_inode); 4277b6be844SDan Williams 4287b6be844SDan Williams void *dax_get_private(struct dax_device *dax_dev) 4297b6be844SDan Williams { 4307b6be844SDan Williams return dax_dev->private; 4317b6be844SDan Williams } 4327b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_get_private); 4337b6be844SDan Williams 4347b6be844SDan Williams static void init_once(void *_dax_dev) 4357b6be844SDan Williams { 4367b6be844SDan Williams struct dax_device *dax_dev = _dax_dev; 4377b6be844SDan Williams struct inode *inode = &dax_dev->inode; 4387b6be844SDan Williams 4397b6be844SDan Williams inode_init_once(inode); 4407b6be844SDan Williams } 4417b6be844SDan Williams 4427b6be844SDan Williams static int __dax_fs_init(void) 4437b6be844SDan Williams { 4447b6be844SDan Williams int rc; 4457b6be844SDan Williams 4467b6be844SDan Williams dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0, 4477b6be844SDan Williams (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 4487b6be844SDan Williams SLAB_MEM_SPREAD|SLAB_ACCOUNT), 4497b6be844SDan Williams init_once); 4507b6be844SDan Williams if (!dax_cache) 4517b6be844SDan Williams return -ENOMEM; 4527b6be844SDan Williams 4537b6be844SDan Williams rc = register_filesystem(&dax_fs_type); 4547b6be844SDan Williams if (rc) 4557b6be844SDan Williams goto err_register_fs; 4567b6be844SDan Williams 4577b6be844SDan Williams dax_mnt = kern_mount(&dax_fs_type); 4587b6be844SDan Williams if (IS_ERR(dax_mnt)) { 4597b6be844SDan Williams rc = PTR_ERR(dax_mnt); 4607b6be844SDan Williams goto err_mount; 4617b6be844SDan Williams } 4627b6be844SDan Williams dax_superblock = dax_mnt->mnt_sb; 4637b6be844SDan Williams 4647b6be844SDan Williams return 0; 4657b6be844SDan Williams 4667b6be844SDan Williams err_mount: 4677b6be844SDan Williams unregister_filesystem(&dax_fs_type); 4687b6be844SDan Williams err_register_fs: 4697b6be844SDan Williams kmem_cache_destroy(dax_cache); 4707b6be844SDan Williams 4717b6be844SDan Williams return rc; 4727b6be844SDan Williams } 4737b6be844SDan Williams 4747b6be844SDan Williams static void __dax_fs_exit(void) 4757b6be844SDan Williams { 4767b6be844SDan Williams kern_unmount(dax_mnt); 4777b6be844SDan Williams unregister_filesystem(&dax_fs_type); 4787b6be844SDan Williams kmem_cache_destroy(dax_cache); 4797b6be844SDan Williams } 4807b6be844SDan Williams 4817b6be844SDan Williams static int __init dax_fs_init(void) 4827b6be844SDan Williams { 4837b6be844SDan Williams int rc; 4847b6be844SDan Williams 4857b6be844SDan Williams rc = __dax_fs_init(); 4867b6be844SDan Williams if (rc) 4877b6be844SDan Williams return rc; 4887b6be844SDan Williams 489cf1e2289SDan Williams rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax"); 4907b6be844SDan Williams if (rc) 4917b6be844SDan Williams __dax_fs_exit(); 4927b6be844SDan Williams return rc; 4937b6be844SDan Williams } 4947b6be844SDan Williams 4957b6be844SDan Williams static void __exit dax_fs_exit(void) 4967b6be844SDan Williams { 497cf1e2289SDan Williams unregister_chrdev_region(dax_devt, MINORMASK+1); 4987b6be844SDan Williams ida_destroy(&dax_minor_ida); 4997b6be844SDan Williams __dax_fs_exit(); 5007b6be844SDan Williams } 5017b6be844SDan Williams 5027b6be844SDan Williams MODULE_AUTHOR("Intel Corporation"); 5037b6be844SDan Williams MODULE_LICENSE("GPL v2"); 5047b6be844SDan Williams subsys_initcall(dax_fs_init); 5057b6be844SDan Williams module_exit(dax_fs_exit); 506