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> 216568b08bSDan Williams #include <linux/dax.h> 227b6be844SDan Williams #include <linux/fs.h> 237b6be844SDan Williams 247b6be844SDan Williams static int nr_dax = CONFIG_NR_DEV_DAX; 257b6be844SDan Williams module_param(nr_dax, int, S_IRUGO); 267b6be844SDan Williams MODULE_PARM_DESC(nr_dax, "max number of dax device instances"); 277b6be844SDan Williams 287b6be844SDan Williams static dev_t dax_devt; 297b6be844SDan Williams DEFINE_STATIC_SRCU(dax_srcu); 307b6be844SDan Williams static struct vfsmount *dax_mnt; 317b6be844SDan Williams static DEFINE_IDA(dax_minor_ida); 327b6be844SDan Williams static struct kmem_cache *dax_cache __read_mostly; 337b6be844SDan Williams static struct super_block *dax_superblock __read_mostly; 347b6be844SDan Williams 3572058005SDan Williams #define DAX_HASH_SIZE (PAGE_SIZE / sizeof(struct hlist_head)) 3672058005SDan Williams static struct hlist_head dax_host_list[DAX_HASH_SIZE]; 3772058005SDan Williams static DEFINE_SPINLOCK(dax_host_lock); 3872058005SDan Williams 397b6be844SDan Williams int dax_read_lock(void) 407b6be844SDan Williams { 417b6be844SDan Williams return srcu_read_lock(&dax_srcu); 427b6be844SDan Williams } 437b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_lock); 447b6be844SDan Williams 457b6be844SDan Williams void dax_read_unlock(int id) 467b6be844SDan Williams { 477b6be844SDan Williams srcu_read_unlock(&dax_srcu, id); 487b6be844SDan Williams } 497b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_unlock); 507b6be844SDan Williams 51ef510424SDan Williams int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, 52ef510424SDan Williams pgoff_t *pgoff) 53ef510424SDan Williams { 54ef510424SDan Williams phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512; 55ef510424SDan Williams 56ef510424SDan Williams if (pgoff) 57ef510424SDan Williams *pgoff = PHYS_PFN(phys_off); 58ef510424SDan Williams if (phys_off % PAGE_SIZE || size % PAGE_SIZE) 59ef510424SDan Williams return -EINVAL; 60ef510424SDan Williams return 0; 61ef510424SDan Williams } 62ef510424SDan Williams EXPORT_SYMBOL(bdev_dax_pgoff); 63ef510424SDan Williams 64ef510424SDan Williams /** 65ef510424SDan Williams * __bdev_dax_supported() - Check if the device supports dax for filesystem 66ef510424SDan Williams * @sb: The superblock of the device 67ef510424SDan Williams * @blocksize: The block size of the device 68ef510424SDan Williams * 69ef510424SDan Williams * This is a library function for filesystems to check if the block device 70ef510424SDan Williams * can be mounted with dax option. 71ef510424SDan Williams * 72ef510424SDan Williams * Return: negative errno if unsupported, 0 if supported. 73ef510424SDan Williams */ 74ef510424SDan Williams int __bdev_dax_supported(struct super_block *sb, int blocksize) 75ef510424SDan Williams { 76ef510424SDan Williams struct block_device *bdev = sb->s_bdev; 77ef510424SDan Williams struct dax_device *dax_dev; 78ef510424SDan Williams pgoff_t pgoff; 79ef510424SDan Williams int err, id; 80ef510424SDan Williams void *kaddr; 81ef510424SDan Williams pfn_t pfn; 82ef510424SDan Williams long len; 83ef510424SDan Williams 84ef510424SDan Williams if (blocksize != PAGE_SIZE) { 85ef510424SDan Williams pr_err("VFS (%s): error: unsupported blocksize for dax\n", 86ef510424SDan Williams sb->s_id); 87ef510424SDan Williams return -EINVAL; 88ef510424SDan Williams } 89ef510424SDan Williams 90ef510424SDan Williams err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); 91ef510424SDan Williams if (err) { 92ef510424SDan Williams pr_err("VFS (%s): error: unaligned partition for dax\n", 93ef510424SDan Williams sb->s_id); 94ef510424SDan Williams return err; 95ef510424SDan Williams } 96ef510424SDan Williams 97ef510424SDan Williams dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); 98ef510424SDan Williams if (!dax_dev) { 99ef510424SDan Williams pr_err("VFS (%s): error: device does not support dax\n", 100ef510424SDan Williams sb->s_id); 101ef510424SDan Williams return -EOPNOTSUPP; 102ef510424SDan Williams } 103ef510424SDan Williams 104ef510424SDan Williams id = dax_read_lock(); 105ef510424SDan Williams len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); 106ef510424SDan Williams dax_read_unlock(id); 107ef510424SDan Williams 108ef510424SDan Williams put_dax(dax_dev); 109ef510424SDan Williams 110ef510424SDan Williams if (len < 1) { 111ef510424SDan Williams pr_err("VFS (%s): error: dax access failed (%ld)", 112ef510424SDan Williams sb->s_id, len); 113ef510424SDan Williams return len < 0 ? len : -EIO; 114ef510424SDan Williams } 115ef510424SDan Williams 116ef510424SDan Williams return 0; 117ef510424SDan Williams } 118ef510424SDan Williams EXPORT_SYMBOL_GPL(__bdev_dax_supported); 119ef510424SDan Williams 1207b6be844SDan Williams /** 1217b6be844SDan Williams * struct dax_device - anchor object for dax services 1227b6be844SDan Williams * @inode: core vfs 1237b6be844SDan Williams * @cdev: optional character interface for "device dax" 12472058005SDan Williams * @host: optional name for lookups where the device path is not available 1257b6be844SDan Williams * @private: dax driver private data 1267b6be844SDan Williams * @alive: !alive + rcu grace period == no new operations / mappings 1277b6be844SDan Williams */ 1287b6be844SDan Williams struct dax_device { 12972058005SDan Williams struct hlist_node list; 1307b6be844SDan Williams struct inode inode; 1317b6be844SDan Williams struct cdev cdev; 13272058005SDan Williams const char *host; 1337b6be844SDan Williams void *private; 1347b6be844SDan Williams bool alive; 1356568b08bSDan Williams const struct dax_operations *ops; 1367b6be844SDan Williams }; 1377b6be844SDan Williams 138b0686260SDan Williams /** 139b0686260SDan Williams * dax_direct_access() - translate a device pgoff to an absolute pfn 140b0686260SDan Williams * @dax_dev: a dax_device instance representing the logical memory range 141b0686260SDan Williams * @pgoff: offset in pages from the start of the device to translate 142b0686260SDan Williams * @nr_pages: number of consecutive pages caller can handle relative to @pfn 143b0686260SDan Williams * @kaddr: output parameter that returns a virtual address mapping of pfn 144b0686260SDan Williams * @pfn: output parameter that returns an absolute pfn translation of @pgoff 145b0686260SDan Williams * 146b0686260SDan Williams * Return: negative errno if an error occurs, otherwise the number of 147b0686260SDan Williams * pages accessible at the device relative @pgoff. 148b0686260SDan Williams */ 149b0686260SDan Williams long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 150b0686260SDan Williams void **kaddr, pfn_t *pfn) 151b0686260SDan Williams { 152b0686260SDan Williams long avail; 153b0686260SDan Williams 154b0686260SDan Williams /* 155b0686260SDan Williams * The device driver is allowed to sleep, in order to make the 156b0686260SDan Williams * memory directly accessible. 157b0686260SDan Williams */ 158b0686260SDan Williams might_sleep(); 159b0686260SDan Williams 160b0686260SDan Williams if (!dax_dev) 161b0686260SDan Williams return -EOPNOTSUPP; 162b0686260SDan Williams 163b0686260SDan Williams if (!dax_alive(dax_dev)) 164b0686260SDan Williams return -ENXIO; 165b0686260SDan Williams 166b0686260SDan Williams if (nr_pages < 0) 167b0686260SDan Williams return nr_pages; 168b0686260SDan Williams 169b0686260SDan Williams avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages, 170b0686260SDan Williams kaddr, pfn); 171b0686260SDan Williams if (!avail) 172b0686260SDan Williams return -ERANGE; 173b0686260SDan Williams return min(avail, nr_pages); 174b0686260SDan Williams } 175b0686260SDan Williams EXPORT_SYMBOL_GPL(dax_direct_access); 176b0686260SDan Williams 1777b6be844SDan Williams bool dax_alive(struct dax_device *dax_dev) 1787b6be844SDan Williams { 1797b6be844SDan Williams lockdep_assert_held(&dax_srcu); 1807b6be844SDan Williams return dax_dev->alive; 1817b6be844SDan Williams } 1827b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_alive); 1837b6be844SDan Williams 18472058005SDan Williams static int dax_host_hash(const char *host) 18572058005SDan Williams { 18672058005SDan Williams return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE; 18772058005SDan Williams } 18872058005SDan Williams 1897b6be844SDan Williams /* 1907b6be844SDan Williams * Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring 1917b6be844SDan Williams * that any fault handlers or operations that might have seen 1927b6be844SDan Williams * dax_alive(), have completed. Any operations that start after 1937b6be844SDan Williams * synchronize_srcu() has run will abort upon seeing !dax_alive(). 1947b6be844SDan Williams */ 1957b6be844SDan Williams void kill_dax(struct dax_device *dax_dev) 1967b6be844SDan Williams { 1977b6be844SDan Williams if (!dax_dev) 1987b6be844SDan Williams return; 1997b6be844SDan Williams 2007b6be844SDan Williams dax_dev->alive = false; 20172058005SDan Williams 2027b6be844SDan Williams synchronize_srcu(&dax_srcu); 20372058005SDan Williams 20472058005SDan Williams spin_lock(&dax_host_lock); 20572058005SDan Williams hlist_del_init(&dax_dev->list); 20672058005SDan Williams spin_unlock(&dax_host_lock); 20772058005SDan Williams 2087b6be844SDan Williams dax_dev->private = NULL; 2097b6be844SDan Williams } 2107b6be844SDan Williams EXPORT_SYMBOL_GPL(kill_dax); 2117b6be844SDan Williams 2127b6be844SDan Williams static struct inode *dax_alloc_inode(struct super_block *sb) 2137b6be844SDan Williams { 2147b6be844SDan Williams struct dax_device *dax_dev; 2157b6be844SDan Williams 2167b6be844SDan Williams dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL); 2177b6be844SDan Williams return &dax_dev->inode; 2187b6be844SDan Williams } 2197b6be844SDan Williams 2207b6be844SDan Williams static struct dax_device *to_dax_dev(struct inode *inode) 2217b6be844SDan Williams { 2227b6be844SDan Williams return container_of(inode, struct dax_device, inode); 2237b6be844SDan Williams } 2247b6be844SDan Williams 2257b6be844SDan Williams static void dax_i_callback(struct rcu_head *head) 2267b6be844SDan Williams { 2277b6be844SDan Williams struct inode *inode = container_of(head, struct inode, i_rcu); 2287b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 2297b6be844SDan Williams 23072058005SDan Williams kfree(dax_dev->host); 23172058005SDan Williams dax_dev->host = NULL; 2327b6be844SDan Williams ida_simple_remove(&dax_minor_ida, MINOR(inode->i_rdev)); 2337b6be844SDan Williams kmem_cache_free(dax_cache, dax_dev); 2347b6be844SDan Williams } 2357b6be844SDan Williams 2367b6be844SDan Williams static void dax_destroy_inode(struct inode *inode) 2377b6be844SDan Williams { 2387b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 2397b6be844SDan Williams 2407b6be844SDan Williams WARN_ONCE(dax_dev->alive, 2417b6be844SDan Williams "kill_dax() must be called before final iput()\n"); 2427b6be844SDan Williams call_rcu(&inode->i_rcu, dax_i_callback); 2437b6be844SDan Williams } 2447b6be844SDan Williams 2457b6be844SDan Williams static const struct super_operations dax_sops = { 2467b6be844SDan Williams .statfs = simple_statfs, 2477b6be844SDan Williams .alloc_inode = dax_alloc_inode, 2487b6be844SDan Williams .destroy_inode = dax_destroy_inode, 2497b6be844SDan Williams .drop_inode = generic_delete_inode, 2507b6be844SDan Williams }; 2517b6be844SDan Williams 2527b6be844SDan Williams static struct dentry *dax_mount(struct file_system_type *fs_type, 2537b6be844SDan Williams int flags, const char *dev_name, void *data) 2547b6be844SDan Williams { 2557b6be844SDan Williams return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC); 2567b6be844SDan Williams } 2577b6be844SDan Williams 2587b6be844SDan Williams static struct file_system_type dax_fs_type = { 2597b6be844SDan Williams .name = "dax", 2607b6be844SDan Williams .mount = dax_mount, 2617b6be844SDan Williams .kill_sb = kill_anon_super, 2627b6be844SDan Williams }; 2637b6be844SDan Williams 2647b6be844SDan Williams static int dax_test(struct inode *inode, void *data) 2657b6be844SDan Williams { 2667b6be844SDan Williams dev_t devt = *(dev_t *) data; 2677b6be844SDan Williams 2687b6be844SDan Williams return inode->i_rdev == devt; 2697b6be844SDan Williams } 2707b6be844SDan Williams 2717b6be844SDan Williams static int dax_set(struct inode *inode, void *data) 2727b6be844SDan Williams { 2737b6be844SDan Williams dev_t devt = *(dev_t *) data; 2747b6be844SDan Williams 2757b6be844SDan Williams inode->i_rdev = devt; 2767b6be844SDan Williams return 0; 2777b6be844SDan Williams } 2787b6be844SDan Williams 2797b6be844SDan Williams static struct dax_device *dax_dev_get(dev_t devt) 2807b6be844SDan Williams { 2817b6be844SDan Williams struct dax_device *dax_dev; 2827b6be844SDan Williams struct inode *inode; 2837b6be844SDan Williams 2847b6be844SDan Williams inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), 2857b6be844SDan Williams dax_test, dax_set, &devt); 2867b6be844SDan Williams 2877b6be844SDan Williams if (!inode) 2887b6be844SDan Williams return NULL; 2897b6be844SDan Williams 2907b6be844SDan Williams dax_dev = to_dax_dev(inode); 2917b6be844SDan Williams if (inode->i_state & I_NEW) { 2927b6be844SDan Williams dax_dev->alive = true; 2937b6be844SDan Williams inode->i_cdev = &dax_dev->cdev; 2947b6be844SDan Williams inode->i_mode = S_IFCHR; 2957b6be844SDan Williams inode->i_flags = S_DAX; 2967b6be844SDan Williams mapping_set_gfp_mask(&inode->i_data, GFP_USER); 2977b6be844SDan Williams unlock_new_inode(inode); 2987b6be844SDan Williams } 2997b6be844SDan Williams 3007b6be844SDan Williams return dax_dev; 3017b6be844SDan Williams } 3027b6be844SDan Williams 30372058005SDan Williams static void dax_add_host(struct dax_device *dax_dev, const char *host) 30472058005SDan Williams { 30572058005SDan Williams int hash; 30672058005SDan Williams 30772058005SDan Williams /* 30872058005SDan Williams * Unconditionally init dax_dev since it's coming from a 30972058005SDan Williams * non-zeroed slab cache 31072058005SDan Williams */ 31172058005SDan Williams INIT_HLIST_NODE(&dax_dev->list); 31272058005SDan Williams dax_dev->host = host; 31372058005SDan Williams if (!host) 31472058005SDan Williams return; 31572058005SDan Williams 31672058005SDan Williams hash = dax_host_hash(host); 31772058005SDan Williams spin_lock(&dax_host_lock); 31872058005SDan Williams hlist_add_head(&dax_dev->list, &dax_host_list[hash]); 31972058005SDan Williams spin_unlock(&dax_host_lock); 32072058005SDan Williams } 32172058005SDan Williams 3226568b08bSDan Williams struct dax_device *alloc_dax(void *private, const char *__host, 3236568b08bSDan Williams const struct dax_operations *ops) 3247b6be844SDan Williams { 3257b6be844SDan Williams struct dax_device *dax_dev; 32672058005SDan Williams const char *host; 3277b6be844SDan Williams dev_t devt; 3287b6be844SDan Williams int minor; 3297b6be844SDan Williams 33072058005SDan Williams host = kstrdup(__host, GFP_KERNEL); 33172058005SDan Williams if (__host && !host) 33272058005SDan Williams return NULL; 33372058005SDan Williams 3347b6be844SDan Williams minor = ida_simple_get(&dax_minor_ida, 0, nr_dax, GFP_KERNEL); 3357b6be844SDan Williams if (minor < 0) 33672058005SDan Williams goto err_minor; 3377b6be844SDan Williams 3387b6be844SDan Williams devt = MKDEV(MAJOR(dax_devt), minor); 3397b6be844SDan Williams dax_dev = dax_dev_get(devt); 3407b6be844SDan Williams if (!dax_dev) 34172058005SDan Williams goto err_dev; 3427b6be844SDan Williams 34372058005SDan Williams dax_add_host(dax_dev, host); 3446568b08bSDan Williams dax_dev->ops = ops; 3457b6be844SDan Williams dax_dev->private = private; 3467b6be844SDan Williams return dax_dev; 3477b6be844SDan Williams 34872058005SDan Williams err_dev: 3497b6be844SDan Williams ida_simple_remove(&dax_minor_ida, minor); 35072058005SDan Williams err_minor: 35172058005SDan Williams kfree(host); 3527b6be844SDan Williams return NULL; 3537b6be844SDan Williams } 3547b6be844SDan Williams EXPORT_SYMBOL_GPL(alloc_dax); 3557b6be844SDan Williams 3567b6be844SDan Williams void put_dax(struct dax_device *dax_dev) 3577b6be844SDan Williams { 3587b6be844SDan Williams if (!dax_dev) 3597b6be844SDan Williams return; 3607b6be844SDan Williams iput(&dax_dev->inode); 3617b6be844SDan Williams } 3627b6be844SDan Williams EXPORT_SYMBOL_GPL(put_dax); 3637b6be844SDan Williams 3647b6be844SDan Williams /** 36572058005SDan Williams * dax_get_by_host() - temporary lookup mechanism for filesystem-dax 36672058005SDan Williams * @host: alternate name for the device registered by a dax driver 36772058005SDan Williams */ 36872058005SDan Williams struct dax_device *dax_get_by_host(const char *host) 36972058005SDan Williams { 37072058005SDan Williams struct dax_device *dax_dev, *found = NULL; 37172058005SDan Williams int hash, id; 37272058005SDan Williams 37372058005SDan Williams if (!host) 37472058005SDan Williams return NULL; 37572058005SDan Williams 37672058005SDan Williams hash = dax_host_hash(host); 37772058005SDan Williams 37872058005SDan Williams id = dax_read_lock(); 37972058005SDan Williams spin_lock(&dax_host_lock); 38072058005SDan Williams hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) { 38172058005SDan Williams if (!dax_alive(dax_dev) 38272058005SDan Williams || strcmp(host, dax_dev->host) != 0) 38372058005SDan Williams continue; 38472058005SDan Williams 38572058005SDan Williams if (igrab(&dax_dev->inode)) 38672058005SDan Williams found = dax_dev; 38772058005SDan Williams break; 38872058005SDan Williams } 38972058005SDan Williams spin_unlock(&dax_host_lock); 39072058005SDan Williams dax_read_unlock(id); 39172058005SDan Williams 39272058005SDan Williams return found; 39372058005SDan Williams } 39472058005SDan Williams EXPORT_SYMBOL_GPL(dax_get_by_host); 39572058005SDan Williams 39672058005SDan Williams /** 3977b6be844SDan Williams * inode_dax: convert a public inode into its dax_dev 3987b6be844SDan Williams * @inode: An inode with i_cdev pointing to a dax_dev 3997b6be844SDan Williams * 4007b6be844SDan Williams * Note this is not equivalent to to_dax_dev() which is for private 4017b6be844SDan Williams * internal use where we know the inode filesystem type == dax_fs_type. 4027b6be844SDan Williams */ 4037b6be844SDan Williams struct dax_device *inode_dax(struct inode *inode) 4047b6be844SDan Williams { 4057b6be844SDan Williams struct cdev *cdev = inode->i_cdev; 4067b6be844SDan Williams 4077b6be844SDan Williams return container_of(cdev, struct dax_device, cdev); 4087b6be844SDan Williams } 4097b6be844SDan Williams EXPORT_SYMBOL_GPL(inode_dax); 4107b6be844SDan Williams 4117b6be844SDan Williams struct inode *dax_inode(struct dax_device *dax_dev) 4127b6be844SDan Williams { 4137b6be844SDan Williams return &dax_dev->inode; 4147b6be844SDan Williams } 4157b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_inode); 4167b6be844SDan Williams 4177b6be844SDan Williams void *dax_get_private(struct dax_device *dax_dev) 4187b6be844SDan Williams { 4197b6be844SDan Williams return dax_dev->private; 4207b6be844SDan Williams } 4217b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_get_private); 4227b6be844SDan Williams 4237b6be844SDan Williams static void init_once(void *_dax_dev) 4247b6be844SDan Williams { 4257b6be844SDan Williams struct dax_device *dax_dev = _dax_dev; 4267b6be844SDan Williams struct inode *inode = &dax_dev->inode; 4277b6be844SDan Williams 4287b6be844SDan Williams inode_init_once(inode); 4297b6be844SDan Williams } 4307b6be844SDan Williams 4317b6be844SDan Williams static int __dax_fs_init(void) 4327b6be844SDan Williams { 4337b6be844SDan Williams int rc; 4347b6be844SDan Williams 4357b6be844SDan Williams dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0, 4367b6be844SDan Williams (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 4377b6be844SDan Williams SLAB_MEM_SPREAD|SLAB_ACCOUNT), 4387b6be844SDan Williams init_once); 4397b6be844SDan Williams if (!dax_cache) 4407b6be844SDan Williams return -ENOMEM; 4417b6be844SDan Williams 4427b6be844SDan Williams rc = register_filesystem(&dax_fs_type); 4437b6be844SDan Williams if (rc) 4447b6be844SDan Williams goto err_register_fs; 4457b6be844SDan Williams 4467b6be844SDan Williams dax_mnt = kern_mount(&dax_fs_type); 4477b6be844SDan Williams if (IS_ERR(dax_mnt)) { 4487b6be844SDan Williams rc = PTR_ERR(dax_mnt); 4497b6be844SDan Williams goto err_mount; 4507b6be844SDan Williams } 4517b6be844SDan Williams dax_superblock = dax_mnt->mnt_sb; 4527b6be844SDan Williams 4537b6be844SDan Williams return 0; 4547b6be844SDan Williams 4557b6be844SDan Williams err_mount: 4567b6be844SDan Williams unregister_filesystem(&dax_fs_type); 4577b6be844SDan Williams err_register_fs: 4587b6be844SDan Williams kmem_cache_destroy(dax_cache); 4597b6be844SDan Williams 4607b6be844SDan Williams return rc; 4617b6be844SDan Williams } 4627b6be844SDan Williams 4637b6be844SDan Williams static void __dax_fs_exit(void) 4647b6be844SDan Williams { 4657b6be844SDan Williams kern_unmount(dax_mnt); 4667b6be844SDan Williams unregister_filesystem(&dax_fs_type); 4677b6be844SDan Williams kmem_cache_destroy(dax_cache); 4687b6be844SDan Williams } 4697b6be844SDan Williams 4707b6be844SDan Williams static int __init dax_fs_init(void) 4717b6be844SDan Williams { 4727b6be844SDan Williams int rc; 4737b6be844SDan Williams 4747b6be844SDan Williams rc = __dax_fs_init(); 4757b6be844SDan Williams if (rc) 4767b6be844SDan Williams return rc; 4777b6be844SDan Williams 4787b6be844SDan Williams nr_dax = max(nr_dax, 256); 4797b6be844SDan Williams rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax"); 4807b6be844SDan Williams if (rc) 4817b6be844SDan Williams __dax_fs_exit(); 4827b6be844SDan Williams return rc; 4837b6be844SDan Williams } 4847b6be844SDan Williams 4857b6be844SDan Williams static void __exit dax_fs_exit(void) 4867b6be844SDan Williams { 4877b6be844SDan Williams unregister_chrdev_region(dax_devt, nr_dax); 4887b6be844SDan Williams ida_destroy(&dax_minor_ida); 4897b6be844SDan Williams __dax_fs_exit(); 4907b6be844SDan Williams } 4917b6be844SDan Williams 4927b6be844SDan Williams MODULE_AUTHOR("Intel Corporation"); 4937b6be844SDan Williams MODULE_LICENSE("GPL v2"); 4947b6be844SDan Williams subsys_initcall(dax_fs_init); 4957b6be844SDan Williams module_exit(dax_fs_exit); 496