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 dev_t dax_devt; 257b6be844SDan Williams DEFINE_STATIC_SRCU(dax_srcu); 267b6be844SDan Williams static struct vfsmount *dax_mnt; 277b6be844SDan Williams static DEFINE_IDA(dax_minor_ida); 287b6be844SDan Williams static struct kmem_cache *dax_cache __read_mostly; 297b6be844SDan Williams static struct super_block *dax_superblock __read_mostly; 307b6be844SDan Williams 3172058005SDan Williams #define DAX_HASH_SIZE (PAGE_SIZE / sizeof(struct hlist_head)) 3272058005SDan Williams static struct hlist_head dax_host_list[DAX_HASH_SIZE]; 3372058005SDan Williams static DEFINE_SPINLOCK(dax_host_lock); 3472058005SDan Williams 357b6be844SDan Williams int dax_read_lock(void) 367b6be844SDan Williams { 377b6be844SDan Williams return srcu_read_lock(&dax_srcu); 387b6be844SDan Williams } 397b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_lock); 407b6be844SDan Williams 417b6be844SDan Williams void dax_read_unlock(int id) 427b6be844SDan Williams { 437b6be844SDan Williams srcu_read_unlock(&dax_srcu, id); 447b6be844SDan Williams } 457b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_read_unlock); 467b6be844SDan Williams 47ef510424SDan Williams int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, 48ef510424SDan Williams pgoff_t *pgoff) 49ef510424SDan Williams { 50ef510424SDan Williams phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512; 51ef510424SDan Williams 52ef510424SDan Williams if (pgoff) 53ef510424SDan Williams *pgoff = PHYS_PFN(phys_off); 54ef510424SDan Williams if (phys_off % PAGE_SIZE || size % PAGE_SIZE) 55ef510424SDan Williams return -EINVAL; 56ef510424SDan Williams return 0; 57ef510424SDan Williams } 58ef510424SDan Williams EXPORT_SYMBOL(bdev_dax_pgoff); 59ef510424SDan Williams 60ef510424SDan Williams /** 61ef510424SDan Williams * __bdev_dax_supported() - Check if the device supports dax for filesystem 62ef510424SDan Williams * @sb: The superblock of the device 63ef510424SDan Williams * @blocksize: The block size of the device 64ef510424SDan Williams * 65ef510424SDan Williams * This is a library function for filesystems to check if the block device 66ef510424SDan Williams * can be mounted with dax option. 67ef510424SDan Williams * 68ef510424SDan Williams * Return: negative errno if unsupported, 0 if supported. 69ef510424SDan Williams */ 70ef510424SDan Williams int __bdev_dax_supported(struct super_block *sb, int blocksize) 71ef510424SDan Williams { 72ef510424SDan Williams struct block_device *bdev = sb->s_bdev; 73ef510424SDan Williams struct dax_device *dax_dev; 74ef510424SDan Williams pgoff_t pgoff; 75ef510424SDan Williams int err, id; 76ef510424SDan Williams void *kaddr; 77ef510424SDan Williams pfn_t pfn; 78ef510424SDan Williams long len; 79ef510424SDan Williams 80ef510424SDan Williams if (blocksize != PAGE_SIZE) { 81ef510424SDan Williams pr_err("VFS (%s): error: unsupported blocksize for dax\n", 82ef510424SDan Williams sb->s_id); 83ef510424SDan Williams return -EINVAL; 84ef510424SDan Williams } 85ef510424SDan Williams 86ef510424SDan Williams err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); 87ef510424SDan Williams if (err) { 88ef510424SDan Williams pr_err("VFS (%s): error: unaligned partition for dax\n", 89ef510424SDan Williams sb->s_id); 90ef510424SDan Williams return err; 91ef510424SDan Williams } 92ef510424SDan Williams 93ef510424SDan Williams dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); 94ef510424SDan Williams if (!dax_dev) { 95ef510424SDan Williams pr_err("VFS (%s): error: device does not support dax\n", 96ef510424SDan Williams sb->s_id); 97ef510424SDan Williams return -EOPNOTSUPP; 98ef510424SDan Williams } 99ef510424SDan Williams 100ef510424SDan Williams id = dax_read_lock(); 101ef510424SDan Williams len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); 102ef510424SDan Williams dax_read_unlock(id); 103ef510424SDan Williams 104ef510424SDan Williams put_dax(dax_dev); 105ef510424SDan Williams 106ef510424SDan Williams if (len < 1) { 107ef510424SDan Williams pr_err("VFS (%s): error: dax access failed (%ld)", 108ef510424SDan Williams sb->s_id, len); 109ef510424SDan Williams return len < 0 ? len : -EIO; 110ef510424SDan Williams } 111ef510424SDan Williams 112ef510424SDan Williams return 0; 113ef510424SDan Williams } 114ef510424SDan Williams EXPORT_SYMBOL_GPL(__bdev_dax_supported); 115ef510424SDan Williams 1167b6be844SDan Williams /** 1177b6be844SDan Williams * struct dax_device - anchor object for dax services 1187b6be844SDan Williams * @inode: core vfs 1197b6be844SDan Williams * @cdev: optional character interface for "device dax" 12072058005SDan Williams * @host: optional name for lookups where the device path is not available 1217b6be844SDan Williams * @private: dax driver private data 1227b6be844SDan Williams * @alive: !alive + rcu grace period == no new operations / mappings 1237b6be844SDan Williams */ 1247b6be844SDan Williams struct dax_device { 12572058005SDan Williams struct hlist_node list; 1267b6be844SDan Williams struct inode inode; 1277b6be844SDan Williams struct cdev cdev; 12872058005SDan Williams const char *host; 1297b6be844SDan Williams void *private; 1307b6be844SDan Williams bool alive; 1316568b08bSDan Williams const struct dax_operations *ops; 1327b6be844SDan Williams }; 1337b6be844SDan Williams 134b0686260SDan Williams /** 135b0686260SDan Williams * dax_direct_access() - translate a device pgoff to an absolute pfn 136b0686260SDan Williams * @dax_dev: a dax_device instance representing the logical memory range 137b0686260SDan Williams * @pgoff: offset in pages from the start of the device to translate 138b0686260SDan Williams * @nr_pages: number of consecutive pages caller can handle relative to @pfn 139b0686260SDan Williams * @kaddr: output parameter that returns a virtual address mapping of pfn 140b0686260SDan Williams * @pfn: output parameter that returns an absolute pfn translation of @pgoff 141b0686260SDan Williams * 142b0686260SDan Williams * Return: negative errno if an error occurs, otherwise the number of 143b0686260SDan Williams * pages accessible at the device relative @pgoff. 144b0686260SDan Williams */ 145b0686260SDan Williams long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, 146b0686260SDan Williams void **kaddr, pfn_t *pfn) 147b0686260SDan Williams { 148b0686260SDan Williams long avail; 149b0686260SDan Williams 150b0686260SDan Williams /* 151b0686260SDan Williams * The device driver is allowed to sleep, in order to make the 152b0686260SDan Williams * memory directly accessible. 153b0686260SDan Williams */ 154b0686260SDan Williams might_sleep(); 155b0686260SDan Williams 156b0686260SDan Williams if (!dax_dev) 157b0686260SDan Williams return -EOPNOTSUPP; 158b0686260SDan Williams 159b0686260SDan Williams if (!dax_alive(dax_dev)) 160b0686260SDan Williams return -ENXIO; 161b0686260SDan Williams 162b0686260SDan Williams if (nr_pages < 0) 163b0686260SDan Williams return nr_pages; 164b0686260SDan Williams 165b0686260SDan Williams avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages, 166b0686260SDan Williams kaddr, pfn); 167b0686260SDan Williams if (!avail) 168b0686260SDan Williams return -ERANGE; 169b0686260SDan Williams return min(avail, nr_pages); 170b0686260SDan Williams } 171b0686260SDan Williams EXPORT_SYMBOL_GPL(dax_direct_access); 172b0686260SDan Williams 1737b6be844SDan Williams bool dax_alive(struct dax_device *dax_dev) 1747b6be844SDan Williams { 1757b6be844SDan Williams lockdep_assert_held(&dax_srcu); 1767b6be844SDan Williams return dax_dev->alive; 1777b6be844SDan Williams } 1787b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_alive); 1797b6be844SDan Williams 18072058005SDan Williams static int dax_host_hash(const char *host) 18172058005SDan Williams { 18272058005SDan Williams return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE; 18372058005SDan Williams } 18472058005SDan Williams 1857b6be844SDan Williams /* 1867b6be844SDan Williams * Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring 1877b6be844SDan Williams * that any fault handlers or operations that might have seen 1887b6be844SDan Williams * dax_alive(), have completed. Any operations that start after 1897b6be844SDan Williams * synchronize_srcu() has run will abort upon seeing !dax_alive(). 1907b6be844SDan Williams */ 1917b6be844SDan Williams void kill_dax(struct dax_device *dax_dev) 1927b6be844SDan Williams { 1937b6be844SDan Williams if (!dax_dev) 1947b6be844SDan Williams return; 1957b6be844SDan Williams 1967b6be844SDan Williams dax_dev->alive = false; 19772058005SDan Williams 1987b6be844SDan Williams synchronize_srcu(&dax_srcu); 19972058005SDan Williams 20072058005SDan Williams spin_lock(&dax_host_lock); 20172058005SDan Williams hlist_del_init(&dax_dev->list); 20272058005SDan Williams spin_unlock(&dax_host_lock); 20372058005SDan Williams 2047b6be844SDan Williams dax_dev->private = NULL; 2057b6be844SDan Williams } 2067b6be844SDan Williams EXPORT_SYMBOL_GPL(kill_dax); 2077b6be844SDan Williams 2087b6be844SDan Williams static struct inode *dax_alloc_inode(struct super_block *sb) 2097b6be844SDan Williams { 2107b6be844SDan Williams struct dax_device *dax_dev; 2117b6be844SDan Williams 2127b6be844SDan Williams dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL); 2137b6be844SDan Williams return &dax_dev->inode; 2147b6be844SDan Williams } 2157b6be844SDan Williams 2167b6be844SDan Williams static struct dax_device *to_dax_dev(struct inode *inode) 2177b6be844SDan Williams { 2187b6be844SDan Williams return container_of(inode, struct dax_device, inode); 2197b6be844SDan Williams } 2207b6be844SDan Williams 2217b6be844SDan Williams static void dax_i_callback(struct rcu_head *head) 2227b6be844SDan Williams { 2237b6be844SDan Williams struct inode *inode = container_of(head, struct inode, i_rcu); 2247b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 2257b6be844SDan Williams 22672058005SDan Williams kfree(dax_dev->host); 22772058005SDan Williams dax_dev->host = NULL; 2287b6be844SDan Williams ida_simple_remove(&dax_minor_ida, MINOR(inode->i_rdev)); 2297b6be844SDan Williams kmem_cache_free(dax_cache, dax_dev); 2307b6be844SDan Williams } 2317b6be844SDan Williams 2327b6be844SDan Williams static void dax_destroy_inode(struct inode *inode) 2337b6be844SDan Williams { 2347b6be844SDan Williams struct dax_device *dax_dev = to_dax_dev(inode); 2357b6be844SDan Williams 2367b6be844SDan Williams WARN_ONCE(dax_dev->alive, 2377b6be844SDan Williams "kill_dax() must be called before final iput()\n"); 2387b6be844SDan Williams call_rcu(&inode->i_rcu, dax_i_callback); 2397b6be844SDan Williams } 2407b6be844SDan Williams 2417b6be844SDan Williams static const struct super_operations dax_sops = { 2427b6be844SDan Williams .statfs = simple_statfs, 2437b6be844SDan Williams .alloc_inode = dax_alloc_inode, 2447b6be844SDan Williams .destroy_inode = dax_destroy_inode, 2457b6be844SDan Williams .drop_inode = generic_delete_inode, 2467b6be844SDan Williams }; 2477b6be844SDan Williams 2487b6be844SDan Williams static struct dentry *dax_mount(struct file_system_type *fs_type, 2497b6be844SDan Williams int flags, const char *dev_name, void *data) 2507b6be844SDan Williams { 2517b6be844SDan Williams return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC); 2527b6be844SDan Williams } 2537b6be844SDan Williams 2547b6be844SDan Williams static struct file_system_type dax_fs_type = { 2557b6be844SDan Williams .name = "dax", 2567b6be844SDan Williams .mount = dax_mount, 2577b6be844SDan Williams .kill_sb = kill_anon_super, 2587b6be844SDan Williams }; 2597b6be844SDan Williams 2607b6be844SDan Williams static int dax_test(struct inode *inode, void *data) 2617b6be844SDan Williams { 2627b6be844SDan Williams dev_t devt = *(dev_t *) data; 2637b6be844SDan Williams 2647b6be844SDan Williams return inode->i_rdev == devt; 2657b6be844SDan Williams } 2667b6be844SDan Williams 2677b6be844SDan Williams static int dax_set(struct inode *inode, void *data) 2687b6be844SDan Williams { 2697b6be844SDan Williams dev_t devt = *(dev_t *) data; 2707b6be844SDan Williams 2717b6be844SDan Williams inode->i_rdev = devt; 2727b6be844SDan Williams return 0; 2737b6be844SDan Williams } 2747b6be844SDan Williams 2757b6be844SDan Williams static struct dax_device *dax_dev_get(dev_t devt) 2767b6be844SDan Williams { 2777b6be844SDan Williams struct dax_device *dax_dev; 2787b6be844SDan Williams struct inode *inode; 2797b6be844SDan Williams 2807b6be844SDan Williams inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), 2817b6be844SDan Williams dax_test, dax_set, &devt); 2827b6be844SDan Williams 2837b6be844SDan Williams if (!inode) 2847b6be844SDan Williams return NULL; 2857b6be844SDan Williams 2867b6be844SDan Williams dax_dev = to_dax_dev(inode); 2877b6be844SDan Williams if (inode->i_state & I_NEW) { 2887b6be844SDan Williams dax_dev->alive = true; 2897b6be844SDan Williams inode->i_cdev = &dax_dev->cdev; 2907b6be844SDan Williams inode->i_mode = S_IFCHR; 2917b6be844SDan Williams inode->i_flags = S_DAX; 2927b6be844SDan Williams mapping_set_gfp_mask(&inode->i_data, GFP_USER); 2937b6be844SDan Williams unlock_new_inode(inode); 2947b6be844SDan Williams } 2957b6be844SDan Williams 2967b6be844SDan Williams return dax_dev; 2977b6be844SDan Williams } 2987b6be844SDan Williams 29972058005SDan Williams static void dax_add_host(struct dax_device *dax_dev, const char *host) 30072058005SDan Williams { 30172058005SDan Williams int hash; 30272058005SDan Williams 30372058005SDan Williams /* 30472058005SDan Williams * Unconditionally init dax_dev since it's coming from a 30572058005SDan Williams * non-zeroed slab cache 30672058005SDan Williams */ 30772058005SDan Williams INIT_HLIST_NODE(&dax_dev->list); 30872058005SDan Williams dax_dev->host = host; 30972058005SDan Williams if (!host) 31072058005SDan Williams return; 31172058005SDan Williams 31272058005SDan Williams hash = dax_host_hash(host); 31372058005SDan Williams spin_lock(&dax_host_lock); 31472058005SDan Williams hlist_add_head(&dax_dev->list, &dax_host_list[hash]); 31572058005SDan Williams spin_unlock(&dax_host_lock); 31672058005SDan Williams } 31772058005SDan Williams 3186568b08bSDan Williams struct dax_device *alloc_dax(void *private, const char *__host, 3196568b08bSDan Williams const struct dax_operations *ops) 3207b6be844SDan Williams { 3217b6be844SDan Williams struct dax_device *dax_dev; 32272058005SDan Williams const char *host; 3237b6be844SDan Williams dev_t devt; 3247b6be844SDan Williams int minor; 3257b6be844SDan Williams 32672058005SDan Williams host = kstrdup(__host, GFP_KERNEL); 32772058005SDan Williams if (__host && !host) 32872058005SDan Williams return NULL; 32972058005SDan Williams 330cf1e2289SDan Williams minor = ida_simple_get(&dax_minor_ida, 0, MINORMASK+1, GFP_KERNEL); 3317b6be844SDan Williams if (minor < 0) 33272058005SDan Williams goto err_minor; 3337b6be844SDan Williams 3347b6be844SDan Williams devt = MKDEV(MAJOR(dax_devt), minor); 3357b6be844SDan Williams dax_dev = dax_dev_get(devt); 3367b6be844SDan Williams if (!dax_dev) 33772058005SDan Williams goto err_dev; 3387b6be844SDan Williams 33972058005SDan Williams dax_add_host(dax_dev, host); 3406568b08bSDan Williams dax_dev->ops = ops; 3417b6be844SDan Williams dax_dev->private = private; 3427b6be844SDan Williams return dax_dev; 3437b6be844SDan Williams 34472058005SDan Williams err_dev: 3457b6be844SDan Williams ida_simple_remove(&dax_minor_ida, minor); 34672058005SDan Williams err_minor: 34772058005SDan Williams kfree(host); 3487b6be844SDan Williams return NULL; 3497b6be844SDan Williams } 3507b6be844SDan Williams EXPORT_SYMBOL_GPL(alloc_dax); 3517b6be844SDan Williams 3527b6be844SDan Williams void put_dax(struct dax_device *dax_dev) 3537b6be844SDan Williams { 3547b6be844SDan Williams if (!dax_dev) 3557b6be844SDan Williams return; 3567b6be844SDan Williams iput(&dax_dev->inode); 3577b6be844SDan Williams } 3587b6be844SDan Williams EXPORT_SYMBOL_GPL(put_dax); 3597b6be844SDan Williams 3607b6be844SDan Williams /** 36172058005SDan Williams * dax_get_by_host() - temporary lookup mechanism for filesystem-dax 36272058005SDan Williams * @host: alternate name for the device registered by a dax driver 36372058005SDan Williams */ 36472058005SDan Williams struct dax_device *dax_get_by_host(const char *host) 36572058005SDan Williams { 36672058005SDan Williams struct dax_device *dax_dev, *found = NULL; 36772058005SDan Williams int hash, id; 36872058005SDan Williams 36972058005SDan Williams if (!host) 37072058005SDan Williams return NULL; 37172058005SDan Williams 37272058005SDan Williams hash = dax_host_hash(host); 37372058005SDan Williams 37472058005SDan Williams id = dax_read_lock(); 37572058005SDan Williams spin_lock(&dax_host_lock); 37672058005SDan Williams hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) { 37772058005SDan Williams if (!dax_alive(dax_dev) 37872058005SDan Williams || strcmp(host, dax_dev->host) != 0) 37972058005SDan Williams continue; 38072058005SDan Williams 38172058005SDan Williams if (igrab(&dax_dev->inode)) 38272058005SDan Williams found = dax_dev; 38372058005SDan Williams break; 38472058005SDan Williams } 38572058005SDan Williams spin_unlock(&dax_host_lock); 38672058005SDan Williams dax_read_unlock(id); 38772058005SDan Williams 38872058005SDan Williams return found; 38972058005SDan Williams } 39072058005SDan Williams EXPORT_SYMBOL_GPL(dax_get_by_host); 39172058005SDan Williams 39272058005SDan Williams /** 3937b6be844SDan Williams * inode_dax: convert a public inode into its dax_dev 3947b6be844SDan Williams * @inode: An inode with i_cdev pointing to a dax_dev 3957b6be844SDan Williams * 3967b6be844SDan Williams * Note this is not equivalent to to_dax_dev() which is for private 3977b6be844SDan Williams * internal use where we know the inode filesystem type == dax_fs_type. 3987b6be844SDan Williams */ 3997b6be844SDan Williams struct dax_device *inode_dax(struct inode *inode) 4007b6be844SDan Williams { 4017b6be844SDan Williams struct cdev *cdev = inode->i_cdev; 4027b6be844SDan Williams 4037b6be844SDan Williams return container_of(cdev, struct dax_device, cdev); 4047b6be844SDan Williams } 4057b6be844SDan Williams EXPORT_SYMBOL_GPL(inode_dax); 4067b6be844SDan Williams 4077b6be844SDan Williams struct inode *dax_inode(struct dax_device *dax_dev) 4087b6be844SDan Williams { 4097b6be844SDan Williams return &dax_dev->inode; 4107b6be844SDan Williams } 4117b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_inode); 4127b6be844SDan Williams 4137b6be844SDan Williams void *dax_get_private(struct dax_device *dax_dev) 4147b6be844SDan Williams { 4157b6be844SDan Williams return dax_dev->private; 4167b6be844SDan Williams } 4177b6be844SDan Williams EXPORT_SYMBOL_GPL(dax_get_private); 4187b6be844SDan Williams 4197b6be844SDan Williams static void init_once(void *_dax_dev) 4207b6be844SDan Williams { 4217b6be844SDan Williams struct dax_device *dax_dev = _dax_dev; 4227b6be844SDan Williams struct inode *inode = &dax_dev->inode; 4237b6be844SDan Williams 4247b6be844SDan Williams inode_init_once(inode); 4257b6be844SDan Williams } 4267b6be844SDan Williams 4277b6be844SDan Williams static int __dax_fs_init(void) 4287b6be844SDan Williams { 4297b6be844SDan Williams int rc; 4307b6be844SDan Williams 4317b6be844SDan Williams dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0, 4327b6be844SDan Williams (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 4337b6be844SDan Williams SLAB_MEM_SPREAD|SLAB_ACCOUNT), 4347b6be844SDan Williams init_once); 4357b6be844SDan Williams if (!dax_cache) 4367b6be844SDan Williams return -ENOMEM; 4377b6be844SDan Williams 4387b6be844SDan Williams rc = register_filesystem(&dax_fs_type); 4397b6be844SDan Williams if (rc) 4407b6be844SDan Williams goto err_register_fs; 4417b6be844SDan Williams 4427b6be844SDan Williams dax_mnt = kern_mount(&dax_fs_type); 4437b6be844SDan Williams if (IS_ERR(dax_mnt)) { 4447b6be844SDan Williams rc = PTR_ERR(dax_mnt); 4457b6be844SDan Williams goto err_mount; 4467b6be844SDan Williams } 4477b6be844SDan Williams dax_superblock = dax_mnt->mnt_sb; 4487b6be844SDan Williams 4497b6be844SDan Williams return 0; 4507b6be844SDan Williams 4517b6be844SDan Williams err_mount: 4527b6be844SDan Williams unregister_filesystem(&dax_fs_type); 4537b6be844SDan Williams err_register_fs: 4547b6be844SDan Williams kmem_cache_destroy(dax_cache); 4557b6be844SDan Williams 4567b6be844SDan Williams return rc; 4577b6be844SDan Williams } 4587b6be844SDan Williams 4597b6be844SDan Williams static void __dax_fs_exit(void) 4607b6be844SDan Williams { 4617b6be844SDan Williams kern_unmount(dax_mnt); 4627b6be844SDan Williams unregister_filesystem(&dax_fs_type); 4637b6be844SDan Williams kmem_cache_destroy(dax_cache); 4647b6be844SDan Williams } 4657b6be844SDan Williams 4667b6be844SDan Williams static int __init dax_fs_init(void) 4677b6be844SDan Williams { 4687b6be844SDan Williams int rc; 4697b6be844SDan Williams 4707b6be844SDan Williams rc = __dax_fs_init(); 4717b6be844SDan Williams if (rc) 4727b6be844SDan Williams return rc; 4737b6be844SDan Williams 474cf1e2289SDan Williams rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax"); 4757b6be844SDan Williams if (rc) 4767b6be844SDan Williams __dax_fs_exit(); 4777b6be844SDan Williams return rc; 4787b6be844SDan Williams } 4797b6be844SDan Williams 4807b6be844SDan Williams static void __exit dax_fs_exit(void) 4817b6be844SDan Williams { 482cf1e2289SDan Williams unregister_chrdev_region(dax_devt, MINORMASK+1); 4837b6be844SDan Williams ida_destroy(&dax_minor_ida); 4847b6be844SDan Williams __dax_fs_exit(); 4857b6be844SDan Williams } 4867b6be844SDan Williams 4877b6be844SDan Williams MODULE_AUTHOR("Intel Corporation"); 4887b6be844SDan Williams MODULE_LICENSE("GPL v2"); 4897b6be844SDan Williams subsys_initcall(dax_fs_init); 4907b6be844SDan Williams module_exit(dax_fs_exit); 491