Commit | Line | Data |
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7b6be844 DW |
1 | /* |
2 | * Copyright(c) 2017 Intel Corporation. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of version 2 of the GNU General Public License as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | */ | |
13 | #include <linux/pagemap.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/mount.h> | |
16 | #include <linux/magic.h> | |
ef510424 | 17 | #include <linux/genhd.h> |
7b6be844 DW |
18 | #include <linux/cdev.h> |
19 | #include <linux/hash.h> | |
20 | #include <linux/slab.h> | |
7e026c8c | 21 | #include <linux/uio.h> |
6568b08b | 22 | #include <linux/dax.h> |
7b6be844 DW |
23 | #include <linux/fs.h> |
24 | ||
7b6be844 DW |
25 | static dev_t dax_devt; |
26 | DEFINE_STATIC_SRCU(dax_srcu); | |
27 | static struct vfsmount *dax_mnt; | |
28 | static DEFINE_IDA(dax_minor_ida); | |
29 | static struct kmem_cache *dax_cache __read_mostly; | |
30 | static struct super_block *dax_superblock __read_mostly; | |
31 | ||
72058005 DW |
32 | #define DAX_HASH_SIZE (PAGE_SIZE / sizeof(struct hlist_head)) |
33 | static struct hlist_head dax_host_list[DAX_HASH_SIZE]; | |
34 | static DEFINE_SPINLOCK(dax_host_lock); | |
35 | ||
7b6be844 DW |
36 | int dax_read_lock(void) |
37 | { | |
38 | return srcu_read_lock(&dax_srcu); | |
39 | } | |
40 | EXPORT_SYMBOL_GPL(dax_read_lock); | |
41 | ||
42 | void dax_read_unlock(int id) | |
43 | { | |
44 | srcu_read_unlock(&dax_srcu, id); | |
45 | } | |
46 | EXPORT_SYMBOL_GPL(dax_read_unlock); | |
47 | ||
9d109081 | 48 | #ifdef CONFIG_BLOCK |
ef510424 DW |
49 | int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, |
50 | pgoff_t *pgoff) | |
51 | { | |
52 | phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512; | |
53 | ||
54 | if (pgoff) | |
55 | *pgoff = PHYS_PFN(phys_off); | |
56 | if (phys_off % PAGE_SIZE || size % PAGE_SIZE) | |
57 | return -EINVAL; | |
58 | return 0; | |
59 | } | |
60 | EXPORT_SYMBOL(bdev_dax_pgoff); | |
61 | ||
62 | /** | |
63 | * __bdev_dax_supported() - Check if the device supports dax for filesystem | |
64 | * @sb: The superblock of the device | |
65 | * @blocksize: The block size of the device | |
66 | * | |
67 | * This is a library function for filesystems to check if the block device | |
68 | * can be mounted with dax option. | |
69 | * | |
70 | * Return: negative errno if unsupported, 0 if supported. | |
71 | */ | |
72 | int __bdev_dax_supported(struct super_block *sb, int blocksize) | |
73 | { | |
74 | struct block_device *bdev = sb->s_bdev; | |
75 | struct dax_device *dax_dev; | |
76 | pgoff_t pgoff; | |
77 | int err, id; | |
78 | void *kaddr; | |
79 | pfn_t pfn; | |
80 | long len; | |
81 | ||
82 | if (blocksize != PAGE_SIZE) { | |
83 | pr_err("VFS (%s): error: unsupported blocksize for dax\n", | |
84 | sb->s_id); | |
85 | return -EINVAL; | |
86 | } | |
87 | ||
88 | err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); | |
89 | if (err) { | |
90 | pr_err("VFS (%s): error: unaligned partition for dax\n", | |
91 | sb->s_id); | |
92 | return err; | |
93 | } | |
94 | ||
95 | dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); | |
96 | if (!dax_dev) { | |
97 | pr_err("VFS (%s): error: device does not support dax\n", | |
98 | sb->s_id); | |
99 | return -EOPNOTSUPP; | |
100 | } | |
101 | ||
102 | id = dax_read_lock(); | |
103 | len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); | |
104 | dax_read_unlock(id); | |
105 | ||
106 | put_dax(dax_dev); | |
107 | ||
108 | if (len < 1) { | |
109 | pr_err("VFS (%s): error: dax access failed (%ld)", | |
110 | sb->s_id, len); | |
111 | return len < 0 ? len : -EIO; | |
112 | } | |
113 | ||
114 | return 0; | |
115 | } | |
116 | EXPORT_SYMBOL_GPL(__bdev_dax_supported); | |
9d109081 | 117 | #endif |
ef510424 | 118 | |
9a60c3ef DW |
119 | enum dax_device_flags { |
120 | /* !alive + rcu grace period == no new operations / mappings */ | |
121 | DAXDEV_ALIVE, | |
6e0c90d6 DW |
122 | /* gate whether dax_flush() calls the low level flush routine */ |
123 | DAXDEV_WRITE_CACHE, | |
9a60c3ef DW |
124 | }; |
125 | ||
7b6be844 DW |
126 | /** |
127 | * struct dax_device - anchor object for dax services | |
128 | * @inode: core vfs | |
129 | * @cdev: optional character interface for "device dax" | |
72058005 | 130 | * @host: optional name for lookups where the device path is not available |
7b6be844 | 131 | * @private: dax driver private data |
9a60c3ef | 132 | * @flags: state and boolean properties |
7b6be844 DW |
133 | */ |
134 | struct dax_device { | |
72058005 | 135 | struct hlist_node list; |
7b6be844 DW |
136 | struct inode inode; |
137 | struct cdev cdev; | |
72058005 | 138 | const char *host; |
7b6be844 | 139 | void *private; |
9a60c3ef | 140 | unsigned long flags; |
6568b08b | 141 | const struct dax_operations *ops; |
7b6be844 DW |
142 | }; |
143 | ||
6e0c90d6 DW |
144 | static ssize_t write_cache_show(struct device *dev, |
145 | struct device_attribute *attr, char *buf) | |
146 | { | |
147 | struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); | |
148 | ssize_t rc; | |
149 | ||
150 | WARN_ON_ONCE(!dax_dev); | |
151 | if (!dax_dev) | |
152 | return -ENXIO; | |
153 | ||
154 | rc = sprintf(buf, "%d\n", !!test_bit(DAXDEV_WRITE_CACHE, | |
155 | &dax_dev->flags)); | |
156 | put_dax(dax_dev); | |
157 | return rc; | |
158 | } | |
159 | ||
160 | static ssize_t write_cache_store(struct device *dev, | |
161 | struct device_attribute *attr, const char *buf, size_t len) | |
162 | { | |
163 | bool write_cache; | |
164 | int rc = strtobool(buf, &write_cache); | |
165 | struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); | |
166 | ||
167 | WARN_ON_ONCE(!dax_dev); | |
168 | if (!dax_dev) | |
169 | return -ENXIO; | |
170 | ||
171 | if (rc) | |
172 | len = rc; | |
173 | else if (write_cache) | |
174 | set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); | |
175 | else | |
176 | clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); | |
177 | ||
178 | put_dax(dax_dev); | |
179 | return len; | |
180 | } | |
181 | static DEVICE_ATTR_RW(write_cache); | |
182 | ||
183 | static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) | |
184 | { | |
185 | struct device *dev = container_of(kobj, typeof(*dev), kobj); | |
186 | struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); | |
187 | ||
188 | WARN_ON_ONCE(!dax_dev); | |
189 | if (!dax_dev) | |
190 | return 0; | |
191 | ||
192 | if (a == &dev_attr_write_cache.attr && !dax_dev->ops->flush) | |
193 | return 0; | |
194 | return a->mode; | |
195 | } | |
196 | ||
197 | static struct attribute *dax_attributes[] = { | |
198 | &dev_attr_write_cache.attr, | |
199 | NULL, | |
200 | }; | |
201 | ||
202 | struct attribute_group dax_attribute_group = { | |
203 | .name = "dax", | |
204 | .attrs = dax_attributes, | |
205 | .is_visible = dax_visible, | |
206 | }; | |
207 | EXPORT_SYMBOL_GPL(dax_attribute_group); | |
208 | ||
b0686260 DW |
209 | /** |
210 | * dax_direct_access() - translate a device pgoff to an absolute pfn | |
211 | * @dax_dev: a dax_device instance representing the logical memory range | |
212 | * @pgoff: offset in pages from the start of the device to translate | |
213 | * @nr_pages: number of consecutive pages caller can handle relative to @pfn | |
214 | * @kaddr: output parameter that returns a virtual address mapping of pfn | |
215 | * @pfn: output parameter that returns an absolute pfn translation of @pgoff | |
216 | * | |
217 | * Return: negative errno if an error occurs, otherwise the number of | |
218 | * pages accessible at the device relative @pgoff. | |
219 | */ | |
220 | long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, | |
221 | void **kaddr, pfn_t *pfn) | |
222 | { | |
223 | long avail; | |
224 | ||
225 | /* | |
226 | * The device driver is allowed to sleep, in order to make the | |
227 | * memory directly accessible. | |
228 | */ | |
229 | might_sleep(); | |
230 | ||
231 | if (!dax_dev) | |
232 | return -EOPNOTSUPP; | |
233 | ||
234 | if (!dax_alive(dax_dev)) | |
235 | return -ENXIO; | |
236 | ||
237 | if (nr_pages < 0) | |
238 | return nr_pages; | |
239 | ||
240 | avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages, | |
241 | kaddr, pfn); | |
242 | if (!avail) | |
243 | return -ERANGE; | |
244 | return min(avail, nr_pages); | |
245 | } | |
246 | EXPORT_SYMBOL_GPL(dax_direct_access); | |
247 | ||
7e026c8c DW |
248 | size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, |
249 | size_t bytes, struct iov_iter *i) | |
250 | { | |
251 | if (!dax_alive(dax_dev)) | |
252 | return 0; | |
253 | ||
7e026c8c DW |
254 | return dax_dev->ops->copy_from_iter(dax_dev, pgoff, addr, bytes, i); |
255 | } | |
256 | EXPORT_SYMBOL_GPL(dax_copy_from_iter); | |
257 | ||
abebfbe2 DW |
258 | void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, |
259 | size_t size) | |
260 | { | |
261 | if (!dax_alive(dax_dev)) | |
262 | return; | |
263 | ||
6e0c90d6 DW |
264 | if (!test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags)) |
265 | return; | |
266 | ||
abebfbe2 DW |
267 | if (dax_dev->ops->flush) |
268 | dax_dev->ops->flush(dax_dev, pgoff, addr, size); | |
269 | } | |
270 | EXPORT_SYMBOL_GPL(dax_flush); | |
271 | ||
6e0c90d6 DW |
272 | void dax_write_cache(struct dax_device *dax_dev, bool wc) |
273 | { | |
274 | if (wc) | |
275 | set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); | |
276 | else | |
277 | clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); | |
278 | } | |
279 | EXPORT_SYMBOL_GPL(dax_write_cache); | |
280 | ||
273752c9 VG |
281 | bool dax_write_cache_enabled(struct dax_device *dax_dev) |
282 | { | |
283 | return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); | |
284 | } | |
285 | EXPORT_SYMBOL_GPL(dax_write_cache_enabled); | |
286 | ||
7b6be844 DW |
287 | bool dax_alive(struct dax_device *dax_dev) |
288 | { | |
289 | lockdep_assert_held(&dax_srcu); | |
9a60c3ef | 290 | return test_bit(DAXDEV_ALIVE, &dax_dev->flags); |
7b6be844 DW |
291 | } |
292 | EXPORT_SYMBOL_GPL(dax_alive); | |
293 | ||
72058005 DW |
294 | static int dax_host_hash(const char *host) |
295 | { | |
296 | return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE; | |
297 | } | |
298 | ||
7b6be844 DW |
299 | /* |
300 | * Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring | |
301 | * that any fault handlers or operations that might have seen | |
302 | * dax_alive(), have completed. Any operations that start after | |
303 | * synchronize_srcu() has run will abort upon seeing !dax_alive(). | |
304 | */ | |
305 | void kill_dax(struct dax_device *dax_dev) | |
306 | { | |
307 | if (!dax_dev) | |
308 | return; | |
309 | ||
9a60c3ef | 310 | clear_bit(DAXDEV_ALIVE, &dax_dev->flags); |
72058005 | 311 | |
7b6be844 | 312 | synchronize_srcu(&dax_srcu); |
72058005 DW |
313 | |
314 | spin_lock(&dax_host_lock); | |
315 | hlist_del_init(&dax_dev->list); | |
316 | spin_unlock(&dax_host_lock); | |
317 | ||
7b6be844 DW |
318 | dax_dev->private = NULL; |
319 | } | |
320 | EXPORT_SYMBOL_GPL(kill_dax); | |
321 | ||
322 | static struct inode *dax_alloc_inode(struct super_block *sb) | |
323 | { | |
324 | struct dax_device *dax_dev; | |
b9d39d17 | 325 | struct inode *inode; |
7b6be844 DW |
326 | |
327 | dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL); | |
b9d39d17 DW |
328 | inode = &dax_dev->inode; |
329 | inode->i_rdev = 0; | |
330 | return inode; | |
7b6be844 DW |
331 | } |
332 | ||
333 | static struct dax_device *to_dax_dev(struct inode *inode) | |
334 | { | |
335 | return container_of(inode, struct dax_device, inode); | |
336 | } | |
337 | ||
338 | static void dax_i_callback(struct rcu_head *head) | |
339 | { | |
340 | struct inode *inode = container_of(head, struct inode, i_rcu); | |
341 | struct dax_device *dax_dev = to_dax_dev(inode); | |
342 | ||
72058005 DW |
343 | kfree(dax_dev->host); |
344 | dax_dev->host = NULL; | |
b9d39d17 DW |
345 | if (inode->i_rdev) |
346 | ida_simple_remove(&dax_minor_ida, MINOR(inode->i_rdev)); | |
7b6be844 DW |
347 | kmem_cache_free(dax_cache, dax_dev); |
348 | } | |
349 | ||
350 | static void dax_destroy_inode(struct inode *inode) | |
351 | { | |
352 | struct dax_device *dax_dev = to_dax_dev(inode); | |
353 | ||
9a60c3ef | 354 | WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags), |
7b6be844 DW |
355 | "kill_dax() must be called before final iput()\n"); |
356 | call_rcu(&inode->i_rcu, dax_i_callback); | |
357 | } | |
358 | ||
359 | static const struct super_operations dax_sops = { | |
360 | .statfs = simple_statfs, | |
361 | .alloc_inode = dax_alloc_inode, | |
362 | .destroy_inode = dax_destroy_inode, | |
363 | .drop_inode = generic_delete_inode, | |
364 | }; | |
365 | ||
366 | static struct dentry *dax_mount(struct file_system_type *fs_type, | |
367 | int flags, const char *dev_name, void *data) | |
368 | { | |
369 | return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC); | |
370 | } | |
371 | ||
372 | static struct file_system_type dax_fs_type = { | |
373 | .name = "dax", | |
374 | .mount = dax_mount, | |
375 | .kill_sb = kill_anon_super, | |
376 | }; | |
377 | ||
378 | static int dax_test(struct inode *inode, void *data) | |
379 | { | |
380 | dev_t devt = *(dev_t *) data; | |
381 | ||
382 | return inode->i_rdev == devt; | |
383 | } | |
384 | ||
385 | static int dax_set(struct inode *inode, void *data) | |
386 | { | |
387 | dev_t devt = *(dev_t *) data; | |
388 | ||
389 | inode->i_rdev = devt; | |
390 | return 0; | |
391 | } | |
392 | ||
393 | static struct dax_device *dax_dev_get(dev_t devt) | |
394 | { | |
395 | struct dax_device *dax_dev; | |
396 | struct inode *inode; | |
397 | ||
398 | inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), | |
399 | dax_test, dax_set, &devt); | |
400 | ||
401 | if (!inode) | |
402 | return NULL; | |
403 | ||
404 | dax_dev = to_dax_dev(inode); | |
405 | if (inode->i_state & I_NEW) { | |
9a60c3ef | 406 | set_bit(DAXDEV_ALIVE, &dax_dev->flags); |
7b6be844 DW |
407 | inode->i_cdev = &dax_dev->cdev; |
408 | inode->i_mode = S_IFCHR; | |
409 | inode->i_flags = S_DAX; | |
410 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
411 | unlock_new_inode(inode); | |
412 | } | |
413 | ||
414 | return dax_dev; | |
415 | } | |
416 | ||
72058005 DW |
417 | static void dax_add_host(struct dax_device *dax_dev, const char *host) |
418 | { | |
419 | int hash; | |
420 | ||
421 | /* | |
422 | * Unconditionally init dax_dev since it's coming from a | |
423 | * non-zeroed slab cache | |
424 | */ | |
425 | INIT_HLIST_NODE(&dax_dev->list); | |
426 | dax_dev->host = host; | |
427 | if (!host) | |
428 | return; | |
429 | ||
430 | hash = dax_host_hash(host); | |
431 | spin_lock(&dax_host_lock); | |
432 | hlist_add_head(&dax_dev->list, &dax_host_list[hash]); | |
433 | spin_unlock(&dax_host_lock); | |
434 | } | |
435 | ||
6568b08b DW |
436 | struct dax_device *alloc_dax(void *private, const char *__host, |
437 | const struct dax_operations *ops) | |
7b6be844 DW |
438 | { |
439 | struct dax_device *dax_dev; | |
72058005 | 440 | const char *host; |
7b6be844 DW |
441 | dev_t devt; |
442 | int minor; | |
443 | ||
72058005 DW |
444 | host = kstrdup(__host, GFP_KERNEL); |
445 | if (__host && !host) | |
446 | return NULL; | |
447 | ||
cf1e2289 | 448 | minor = ida_simple_get(&dax_minor_ida, 0, MINORMASK+1, GFP_KERNEL); |
7b6be844 | 449 | if (minor < 0) |
72058005 | 450 | goto err_minor; |
7b6be844 DW |
451 | |
452 | devt = MKDEV(MAJOR(dax_devt), minor); | |
453 | dax_dev = dax_dev_get(devt); | |
454 | if (!dax_dev) | |
72058005 | 455 | goto err_dev; |
7b6be844 | 456 | |
72058005 | 457 | dax_add_host(dax_dev, host); |
6568b08b | 458 | dax_dev->ops = ops; |
7b6be844 DW |
459 | dax_dev->private = private; |
460 | return dax_dev; | |
461 | ||
72058005 | 462 | err_dev: |
7b6be844 | 463 | ida_simple_remove(&dax_minor_ida, minor); |
72058005 DW |
464 | err_minor: |
465 | kfree(host); | |
7b6be844 DW |
466 | return NULL; |
467 | } | |
468 | EXPORT_SYMBOL_GPL(alloc_dax); | |
469 | ||
470 | void put_dax(struct dax_device *dax_dev) | |
471 | { | |
472 | if (!dax_dev) | |
473 | return; | |
474 | iput(&dax_dev->inode); | |
475 | } | |
476 | EXPORT_SYMBOL_GPL(put_dax); | |
477 | ||
72058005 DW |
478 | /** |
479 | * dax_get_by_host() - temporary lookup mechanism for filesystem-dax | |
480 | * @host: alternate name for the device registered by a dax driver | |
481 | */ | |
482 | struct dax_device *dax_get_by_host(const char *host) | |
483 | { | |
484 | struct dax_device *dax_dev, *found = NULL; | |
485 | int hash, id; | |
486 | ||
487 | if (!host) | |
488 | return NULL; | |
489 | ||
490 | hash = dax_host_hash(host); | |
491 | ||
492 | id = dax_read_lock(); | |
493 | spin_lock(&dax_host_lock); | |
494 | hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) { | |
495 | if (!dax_alive(dax_dev) | |
496 | || strcmp(host, dax_dev->host) != 0) | |
497 | continue; | |
498 | ||
499 | if (igrab(&dax_dev->inode)) | |
500 | found = dax_dev; | |
501 | break; | |
502 | } | |
503 | spin_unlock(&dax_host_lock); | |
504 | dax_read_unlock(id); | |
505 | ||
506 | return found; | |
507 | } | |
508 | EXPORT_SYMBOL_GPL(dax_get_by_host); | |
509 | ||
7b6be844 DW |
510 | /** |
511 | * inode_dax: convert a public inode into its dax_dev | |
512 | * @inode: An inode with i_cdev pointing to a dax_dev | |
513 | * | |
514 | * Note this is not equivalent to to_dax_dev() which is for private | |
515 | * internal use where we know the inode filesystem type == dax_fs_type. | |
516 | */ | |
517 | struct dax_device *inode_dax(struct inode *inode) | |
518 | { | |
519 | struct cdev *cdev = inode->i_cdev; | |
520 | ||
521 | return container_of(cdev, struct dax_device, cdev); | |
522 | } | |
523 | EXPORT_SYMBOL_GPL(inode_dax); | |
524 | ||
525 | struct inode *dax_inode(struct dax_device *dax_dev) | |
526 | { | |
527 | return &dax_dev->inode; | |
528 | } | |
529 | EXPORT_SYMBOL_GPL(dax_inode); | |
530 | ||
531 | void *dax_get_private(struct dax_device *dax_dev) | |
532 | { | |
533 | return dax_dev->private; | |
534 | } | |
535 | EXPORT_SYMBOL_GPL(dax_get_private); | |
536 | ||
537 | static void init_once(void *_dax_dev) | |
538 | { | |
539 | struct dax_device *dax_dev = _dax_dev; | |
540 | struct inode *inode = &dax_dev->inode; | |
541 | ||
b9d39d17 | 542 | memset(dax_dev, 0, sizeof(*dax_dev)); |
7b6be844 DW |
543 | inode_init_once(inode); |
544 | } | |
545 | ||
546 | static int __dax_fs_init(void) | |
547 | { | |
548 | int rc; | |
549 | ||
550 | dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0, | |
551 | (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| | |
552 | SLAB_MEM_SPREAD|SLAB_ACCOUNT), | |
553 | init_once); | |
554 | if (!dax_cache) | |
555 | return -ENOMEM; | |
556 | ||
557 | rc = register_filesystem(&dax_fs_type); | |
558 | if (rc) | |
559 | goto err_register_fs; | |
560 | ||
561 | dax_mnt = kern_mount(&dax_fs_type); | |
562 | if (IS_ERR(dax_mnt)) { | |
563 | rc = PTR_ERR(dax_mnt); | |
564 | goto err_mount; | |
565 | } | |
566 | dax_superblock = dax_mnt->mnt_sb; | |
567 | ||
568 | return 0; | |
569 | ||
570 | err_mount: | |
571 | unregister_filesystem(&dax_fs_type); | |
572 | err_register_fs: | |
573 | kmem_cache_destroy(dax_cache); | |
574 | ||
575 | return rc; | |
576 | } | |
577 | ||
578 | static void __dax_fs_exit(void) | |
579 | { | |
580 | kern_unmount(dax_mnt); | |
581 | unregister_filesystem(&dax_fs_type); | |
582 | kmem_cache_destroy(dax_cache); | |
583 | } | |
584 | ||
585 | static int __init dax_fs_init(void) | |
586 | { | |
587 | int rc; | |
588 | ||
589 | rc = __dax_fs_init(); | |
590 | if (rc) | |
591 | return rc; | |
592 | ||
cf1e2289 | 593 | rc = alloc_chrdev_region(&dax_devt, 0, MINORMASK+1, "dax"); |
7b6be844 DW |
594 | if (rc) |
595 | __dax_fs_exit(); | |
596 | return rc; | |
597 | } | |
598 | ||
599 | static void __exit dax_fs_exit(void) | |
600 | { | |
cf1e2289 | 601 | unregister_chrdev_region(dax_devt, MINORMASK+1); |
7b6be844 DW |
602 | ida_destroy(&dax_minor_ida); |
603 | __dax_fs_exit(); | |
604 | } | |
605 | ||
606 | MODULE_AUTHOR("Intel Corporation"); | |
607 | MODULE_LICENSE("GPL v2"); | |
608 | subsys_initcall(dax_fs_init); | |
609 | module_exit(dax_fs_exit); |