Commit | Line | Data |
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a62a8ef9 SH |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * virtio-fs: Virtio Filesystem | |
4 | * Copyright (C) 2018 Red Hat, Inc. | |
5 | */ | |
6 | ||
7 | #include <linux/fs.h> | |
22f3787e SH |
8 | #include <linux/dax.h> |
9 | #include <linux/pci.h> | |
10 | #include <linux/pfn_t.h> | |
dc90f084 | 11 | #include <linux/memremap.h> |
a62a8ef9 SH |
12 | #include <linux/module.h> |
13 | #include <linux/virtio.h> | |
14 | #include <linux/virtio_fs.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/fs_context.h> | |
1dd53957 | 17 | #include <linux/fs_parser.h> |
a62a8ef9 | 18 | #include <linux/highmem.h> |
22f3787e | 19 | #include <linux/uio.h> |
a62a8ef9 SH |
20 | #include "fuse_i.h" |
21 | ||
a7f0d7aa CK |
22 | /* Used to help calculate the FUSE connection's max_pages limit for a request's |
23 | * size. Parts of the struct fuse_req are sliced into scattergather lists in | |
24 | * addition to the pages used, so this can help account for that overhead. | |
25 | */ | |
26 | #define FUSE_HEADER_OVERHEAD 4 | |
27 | ||
a62a8ef9 SH |
28 | /* List of virtio-fs device instances and a lock for the list. Also provides |
29 | * mutual exclusion in device removal and mounting path | |
30 | */ | |
31 | static DEFINE_MUTEX(virtio_fs_mutex); | |
32 | static LIST_HEAD(virtio_fs_instances); | |
33 | ||
34 | enum { | |
35 | VQ_HIPRIO, | |
36 | VQ_REQUEST | |
37 | }; | |
38 | ||
b43b7e81 VG |
39 | #define VQ_NAME_LEN 24 |
40 | ||
a62a8ef9 SH |
41 | /* Per-virtqueue state */ |
42 | struct virtio_fs_vq { | |
43 | spinlock_t lock; | |
44 | struct virtqueue *vq; /* protected by ->lock */ | |
45 | struct work_struct done_work; | |
46 | struct list_head queued_reqs; | |
51fecdd2 | 47 | struct list_head end_reqs; /* End these requests */ |
a62a8ef9 SH |
48 | struct delayed_work dispatch_work; |
49 | struct fuse_dev *fud; | |
50 | bool connected; | |
51 | long in_flight; | |
724c15a4 | 52 | struct completion in_flight_zero; /* No inflight requests */ |
b43b7e81 | 53 | char name[VQ_NAME_LEN]; |
a62a8ef9 SH |
54 | } ____cacheline_aligned_in_smp; |
55 | ||
56 | /* A virtio-fs device instance */ | |
57 | struct virtio_fs { | |
58 | struct kref refcount; | |
59 | struct list_head list; /* on virtio_fs_instances */ | |
60 | char *tag; | |
61 | struct virtio_fs_vq *vqs; | |
62 | unsigned int nvqs; /* number of virtqueues */ | |
63 | unsigned int num_request_queues; /* number of request queues */ | |
22f3787e SH |
64 | struct dax_device *dax_dev; |
65 | ||
66 | /* DAX memory window where file contents are mapped */ | |
67 | void *window_kaddr; | |
68 | phys_addr_t window_phys_addr; | |
69 | size_t window_len; | |
a62a8ef9 SH |
70 | }; |
71 | ||
1efcf39e | 72 | struct virtio_fs_forget_req { |
a62a8ef9 SH |
73 | struct fuse_in_header ih; |
74 | struct fuse_forget_in arg; | |
1efcf39e VG |
75 | }; |
76 | ||
77 | struct virtio_fs_forget { | |
a62a8ef9 SH |
78 | /* This request can be temporarily queued on virt queue */ |
79 | struct list_head list; | |
1efcf39e | 80 | struct virtio_fs_forget_req req; |
a62a8ef9 SH |
81 | }; |
82 | ||
bb737bbe VG |
83 | struct virtio_fs_req_work { |
84 | struct fuse_req *req; | |
85 | struct virtio_fs_vq *fsvq; | |
86 | struct work_struct done_work; | |
87 | }; | |
88 | ||
a9bfd9dd VG |
89 | static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, |
90 | struct fuse_req *req, bool in_flight); | |
91 | ||
780b1b95 JX |
92 | static const struct constant_table dax_param_enums[] = { |
93 | {"always", FUSE_DAX_ALWAYS }, | |
94 | {"never", FUSE_DAX_NEVER }, | |
95 | {"inode", FUSE_DAX_INODE_USER }, | |
96 | {} | |
97 | }; | |
98 | ||
1dd53957 VG |
99 | enum { |
100 | OPT_DAX, | |
780b1b95 | 101 | OPT_DAX_ENUM, |
1dd53957 VG |
102 | }; |
103 | ||
104 | static const struct fs_parameter_spec virtio_fs_parameters[] = { | |
105 | fsparam_flag("dax", OPT_DAX), | |
780b1b95 | 106 | fsparam_enum("dax", OPT_DAX_ENUM, dax_param_enums), |
1dd53957 VG |
107 | {} |
108 | }; | |
109 | ||
84c21507 | 110 | static int virtio_fs_parse_param(struct fs_context *fsc, |
1dd53957 VG |
111 | struct fs_parameter *param) |
112 | { | |
113 | struct fs_parse_result result; | |
84c21507 | 114 | struct fuse_fs_context *ctx = fsc->fs_private; |
1dd53957 VG |
115 | int opt; |
116 | ||
84c21507 | 117 | opt = fs_parse(fsc, virtio_fs_parameters, param, &result); |
1dd53957 VG |
118 | if (opt < 0) |
119 | return opt; | |
120 | ||
121 | switch (opt) { | |
122 | case OPT_DAX: | |
780b1b95 JX |
123 | ctx->dax_mode = FUSE_DAX_ALWAYS; |
124 | break; | |
125 | case OPT_DAX_ENUM: | |
126 | ctx->dax_mode = result.uint_32; | |
1dd53957 VG |
127 | break; |
128 | default: | |
129 | return -EINVAL; | |
130 | } | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
84c21507 | 135 | static void virtio_fs_free_fsc(struct fs_context *fsc) |
1dd53957 | 136 | { |
84c21507 | 137 | struct fuse_fs_context *ctx = fsc->fs_private; |
1dd53957 VG |
138 | |
139 | kfree(ctx); | |
140 | } | |
141 | ||
a62a8ef9 SH |
142 | static inline struct virtio_fs_vq *vq_to_fsvq(struct virtqueue *vq) |
143 | { | |
144 | struct virtio_fs *fs = vq->vdev->priv; | |
145 | ||
146 | return &fs->vqs[vq->index]; | |
147 | } | |
148 | ||
c17ea009 VG |
149 | /* Should be called with fsvq->lock held. */ |
150 | static inline void inc_in_flight_req(struct virtio_fs_vq *fsvq) | |
151 | { | |
152 | fsvq->in_flight++; | |
153 | } | |
154 | ||
155 | /* Should be called with fsvq->lock held. */ | |
156 | static inline void dec_in_flight_req(struct virtio_fs_vq *fsvq) | |
157 | { | |
158 | WARN_ON(fsvq->in_flight <= 0); | |
159 | fsvq->in_flight--; | |
724c15a4 VG |
160 | if (!fsvq->in_flight) |
161 | complete(&fsvq->in_flight_zero); | |
c17ea009 VG |
162 | } |
163 | ||
a62a8ef9 SH |
164 | static void release_virtio_fs_obj(struct kref *ref) |
165 | { | |
166 | struct virtio_fs *vfs = container_of(ref, struct virtio_fs, refcount); | |
167 | ||
168 | kfree(vfs->vqs); | |
169 | kfree(vfs); | |
170 | } | |
171 | ||
172 | /* Make sure virtiofs_mutex is held */ | |
173 | static void virtio_fs_put(struct virtio_fs *fs) | |
174 | { | |
175 | kref_put(&fs->refcount, release_virtio_fs_obj); | |
176 | } | |
177 | ||
178 | static void virtio_fs_fiq_release(struct fuse_iqueue *fiq) | |
179 | { | |
180 | struct virtio_fs *vfs = fiq->priv; | |
181 | ||
182 | mutex_lock(&virtio_fs_mutex); | |
183 | virtio_fs_put(vfs); | |
184 | mutex_unlock(&virtio_fs_mutex); | |
185 | } | |
186 | ||
187 | static void virtio_fs_drain_queue(struct virtio_fs_vq *fsvq) | |
188 | { | |
189 | WARN_ON(fsvq->in_flight < 0); | |
190 | ||
191 | /* Wait for in flight requests to finish.*/ | |
724c15a4 VG |
192 | spin_lock(&fsvq->lock); |
193 | if (fsvq->in_flight) { | |
194 | /* We are holding virtio_fs_mutex. There should not be any | |
195 | * waiters waiting for completion. | |
196 | */ | |
197 | reinit_completion(&fsvq->in_flight_zero); | |
198 | spin_unlock(&fsvq->lock); | |
199 | wait_for_completion(&fsvq->in_flight_zero); | |
200 | } else { | |
a62a8ef9 | 201 | spin_unlock(&fsvq->lock); |
a62a8ef9 SH |
202 | } |
203 | ||
204 | flush_work(&fsvq->done_work); | |
205 | flush_delayed_work(&fsvq->dispatch_work); | |
206 | } | |
207 | ||
724c15a4 | 208 | static void virtio_fs_drain_all_queues_locked(struct virtio_fs *fs) |
a62a8ef9 SH |
209 | { |
210 | struct virtio_fs_vq *fsvq; | |
211 | int i; | |
212 | ||
213 | for (i = 0; i < fs->nvqs; i++) { | |
214 | fsvq = &fs->vqs[i]; | |
a62a8ef9 SH |
215 | virtio_fs_drain_queue(fsvq); |
216 | } | |
217 | } | |
218 | ||
724c15a4 VG |
219 | static void virtio_fs_drain_all_queues(struct virtio_fs *fs) |
220 | { | |
221 | /* Provides mutual exclusion between ->remove and ->kill_sb | |
222 | * paths. We don't want both of these draining queue at the | |
223 | * same time. Current completion logic reinits completion | |
224 | * and that means there should not be any other thread | |
225 | * doing reinit or waiting for completion already. | |
226 | */ | |
227 | mutex_lock(&virtio_fs_mutex); | |
228 | virtio_fs_drain_all_queues_locked(fs); | |
229 | mutex_unlock(&virtio_fs_mutex); | |
230 | } | |
231 | ||
a62a8ef9 SH |
232 | static void virtio_fs_start_all_queues(struct virtio_fs *fs) |
233 | { | |
234 | struct virtio_fs_vq *fsvq; | |
235 | int i; | |
236 | ||
237 | for (i = 0; i < fs->nvqs; i++) { | |
238 | fsvq = &fs->vqs[i]; | |
239 | spin_lock(&fsvq->lock); | |
240 | fsvq->connected = true; | |
241 | spin_unlock(&fsvq->lock); | |
242 | } | |
243 | } | |
244 | ||
245 | /* Add a new instance to the list or return -EEXIST if tag name exists*/ | |
246 | static int virtio_fs_add_instance(struct virtio_fs *fs) | |
247 | { | |
248 | struct virtio_fs *fs2; | |
249 | bool duplicate = false; | |
250 | ||
251 | mutex_lock(&virtio_fs_mutex); | |
252 | ||
253 | list_for_each_entry(fs2, &virtio_fs_instances, list) { | |
254 | if (strcmp(fs->tag, fs2->tag) == 0) | |
255 | duplicate = true; | |
256 | } | |
257 | ||
258 | if (!duplicate) | |
259 | list_add_tail(&fs->list, &virtio_fs_instances); | |
260 | ||
261 | mutex_unlock(&virtio_fs_mutex); | |
262 | ||
263 | if (duplicate) | |
264 | return -EEXIST; | |
265 | return 0; | |
266 | } | |
267 | ||
268 | /* Return the virtio_fs with a given tag, or NULL */ | |
269 | static struct virtio_fs *virtio_fs_find_instance(const char *tag) | |
270 | { | |
271 | struct virtio_fs *fs; | |
272 | ||
273 | mutex_lock(&virtio_fs_mutex); | |
274 | ||
275 | list_for_each_entry(fs, &virtio_fs_instances, list) { | |
276 | if (strcmp(fs->tag, tag) == 0) { | |
277 | kref_get(&fs->refcount); | |
278 | goto found; | |
279 | } | |
280 | } | |
281 | ||
282 | fs = NULL; /* not found */ | |
283 | ||
284 | found: | |
285 | mutex_unlock(&virtio_fs_mutex); | |
286 | ||
287 | return fs; | |
288 | } | |
289 | ||
290 | static void virtio_fs_free_devs(struct virtio_fs *fs) | |
291 | { | |
292 | unsigned int i; | |
293 | ||
294 | for (i = 0; i < fs->nvqs; i++) { | |
295 | struct virtio_fs_vq *fsvq = &fs->vqs[i]; | |
296 | ||
297 | if (!fsvq->fud) | |
298 | continue; | |
299 | ||
300 | fuse_dev_free(fsvq->fud); | |
301 | fsvq->fud = NULL; | |
302 | } | |
303 | } | |
304 | ||
305 | /* Read filesystem name from virtio config into fs->tag (must kfree()). */ | |
306 | static int virtio_fs_read_tag(struct virtio_device *vdev, struct virtio_fs *fs) | |
307 | { | |
308 | char tag_buf[sizeof_field(struct virtio_fs_config, tag)]; | |
309 | char *end; | |
310 | size_t len; | |
311 | ||
312 | virtio_cread_bytes(vdev, offsetof(struct virtio_fs_config, tag), | |
313 | &tag_buf, sizeof(tag_buf)); | |
314 | end = memchr(tag_buf, '\0', sizeof(tag_buf)); | |
315 | if (end == tag_buf) | |
316 | return -EINVAL; /* empty tag */ | |
317 | if (!end) | |
318 | end = &tag_buf[sizeof(tag_buf)]; | |
319 | ||
320 | len = end - tag_buf; | |
321 | fs->tag = devm_kmalloc(&vdev->dev, len + 1, GFP_KERNEL); | |
322 | if (!fs->tag) | |
323 | return -ENOMEM; | |
324 | memcpy(fs->tag, tag_buf, len); | |
325 | fs->tag[len] = '\0'; | |
326 | return 0; | |
327 | } | |
328 | ||
329 | /* Work function for hiprio completion */ | |
330 | static void virtio_fs_hiprio_done_work(struct work_struct *work) | |
331 | { | |
332 | struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq, | |
333 | done_work); | |
334 | struct virtqueue *vq = fsvq->vq; | |
335 | ||
336 | /* Free completed FUSE_FORGET requests */ | |
337 | spin_lock(&fsvq->lock); | |
338 | do { | |
339 | unsigned int len; | |
340 | void *req; | |
341 | ||
342 | virtqueue_disable_cb(vq); | |
343 | ||
344 | while ((req = virtqueue_get_buf(vq, &len)) != NULL) { | |
345 | kfree(req); | |
c17ea009 | 346 | dec_in_flight_req(fsvq); |
a62a8ef9 SH |
347 | } |
348 | } while (!virtqueue_enable_cb(vq) && likely(!virtqueue_is_broken(vq))); | |
349 | spin_unlock(&fsvq->lock); | |
350 | } | |
351 | ||
51fecdd2 | 352 | static void virtio_fs_request_dispatch_work(struct work_struct *work) |
a62a8ef9 | 353 | { |
51fecdd2 VG |
354 | struct fuse_req *req; |
355 | struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq, | |
356 | dispatch_work.work); | |
a9bfd9dd | 357 | int ret; |
51fecdd2 VG |
358 | |
359 | pr_debug("virtio-fs: worker %s called.\n", __func__); | |
360 | while (1) { | |
361 | spin_lock(&fsvq->lock); | |
362 | req = list_first_entry_or_null(&fsvq->end_reqs, struct fuse_req, | |
363 | list); | |
364 | if (!req) { | |
365 | spin_unlock(&fsvq->lock); | |
a9bfd9dd | 366 | break; |
51fecdd2 VG |
367 | } |
368 | ||
369 | list_del_init(&req->list); | |
370 | spin_unlock(&fsvq->lock); | |
8f622e94 | 371 | fuse_request_end(req); |
51fecdd2 | 372 | } |
a9bfd9dd VG |
373 | |
374 | /* Dispatch pending requests */ | |
375 | while (1) { | |
376 | spin_lock(&fsvq->lock); | |
377 | req = list_first_entry_or_null(&fsvq->queued_reqs, | |
378 | struct fuse_req, list); | |
379 | if (!req) { | |
380 | spin_unlock(&fsvq->lock); | |
381 | return; | |
382 | } | |
383 | list_del_init(&req->list); | |
384 | spin_unlock(&fsvq->lock); | |
385 | ||
386 | ret = virtio_fs_enqueue_req(fsvq, req, true); | |
387 | if (ret < 0) { | |
388 | if (ret == -ENOMEM || ret == -ENOSPC) { | |
389 | spin_lock(&fsvq->lock); | |
390 | list_add_tail(&req->list, &fsvq->queued_reqs); | |
391 | schedule_delayed_work(&fsvq->dispatch_work, | |
392 | msecs_to_jiffies(1)); | |
393 | spin_unlock(&fsvq->lock); | |
394 | return; | |
395 | } | |
396 | req->out.h.error = ret; | |
397 | spin_lock(&fsvq->lock); | |
398 | dec_in_flight_req(fsvq); | |
399 | spin_unlock(&fsvq->lock); | |
400 | pr_err("virtio-fs: virtio_fs_enqueue_req() failed %d\n", | |
401 | ret); | |
8f622e94 | 402 | fuse_request_end(req); |
a9bfd9dd VG |
403 | } |
404 | } | |
a62a8ef9 SH |
405 | } |
406 | ||
58ada94f VG |
407 | /* |
408 | * Returns 1 if queue is full and sender should wait a bit before sending | |
409 | * next request, 0 otherwise. | |
410 | */ | |
411 | static int send_forget_request(struct virtio_fs_vq *fsvq, | |
412 | struct virtio_fs_forget *forget, | |
413 | bool in_flight) | |
414 | { | |
415 | struct scatterlist sg; | |
416 | struct virtqueue *vq; | |
417 | int ret = 0; | |
418 | bool notify; | |
1efcf39e | 419 | struct virtio_fs_forget_req *req = &forget->req; |
58ada94f VG |
420 | |
421 | spin_lock(&fsvq->lock); | |
422 | if (!fsvq->connected) { | |
423 | if (in_flight) | |
424 | dec_in_flight_req(fsvq); | |
425 | kfree(forget); | |
426 | goto out; | |
427 | } | |
428 | ||
1efcf39e | 429 | sg_init_one(&sg, req, sizeof(*req)); |
58ada94f VG |
430 | vq = fsvq->vq; |
431 | dev_dbg(&vq->vdev->dev, "%s\n", __func__); | |
432 | ||
433 | ret = virtqueue_add_outbuf(vq, &sg, 1, forget, GFP_ATOMIC); | |
434 | if (ret < 0) { | |
435 | if (ret == -ENOMEM || ret == -ENOSPC) { | |
436 | pr_debug("virtio-fs: Could not queue FORGET: err=%d. Will try later\n", | |
437 | ret); | |
438 | list_add_tail(&forget->list, &fsvq->queued_reqs); | |
439 | schedule_delayed_work(&fsvq->dispatch_work, | |
440 | msecs_to_jiffies(1)); | |
441 | if (!in_flight) | |
442 | inc_in_flight_req(fsvq); | |
443 | /* Queue is full */ | |
444 | ret = 1; | |
445 | } else { | |
446 | pr_debug("virtio-fs: Could not queue FORGET: err=%d. Dropping it.\n", | |
447 | ret); | |
448 | kfree(forget); | |
449 | if (in_flight) | |
450 | dec_in_flight_req(fsvq); | |
451 | } | |
452 | goto out; | |
453 | } | |
454 | ||
455 | if (!in_flight) | |
456 | inc_in_flight_req(fsvq); | |
457 | notify = virtqueue_kick_prepare(vq); | |
458 | spin_unlock(&fsvq->lock); | |
459 | ||
460 | if (notify) | |
461 | virtqueue_notify(vq); | |
462 | return ret; | |
463 | out: | |
464 | spin_unlock(&fsvq->lock); | |
465 | return ret; | |
466 | } | |
467 | ||
a62a8ef9 SH |
468 | static void virtio_fs_hiprio_dispatch_work(struct work_struct *work) |
469 | { | |
470 | struct virtio_fs_forget *forget; | |
471 | struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq, | |
472 | dispatch_work.work); | |
a62a8ef9 SH |
473 | pr_debug("virtio-fs: worker %s called.\n", __func__); |
474 | while (1) { | |
475 | spin_lock(&fsvq->lock); | |
476 | forget = list_first_entry_or_null(&fsvq->queued_reqs, | |
477 | struct virtio_fs_forget, list); | |
478 | if (!forget) { | |
479 | spin_unlock(&fsvq->lock); | |
480 | return; | |
481 | } | |
482 | ||
483 | list_del(&forget->list); | |
a62a8ef9 | 484 | spin_unlock(&fsvq->lock); |
58ada94f VG |
485 | if (send_forget_request(fsvq, forget, true)) |
486 | return; | |
a62a8ef9 SH |
487 | } |
488 | } | |
489 | ||
490 | /* Allocate and copy args into req->argbuf */ | |
491 | static int copy_args_to_argbuf(struct fuse_req *req) | |
492 | { | |
493 | struct fuse_args *args = req->args; | |
494 | unsigned int offset = 0; | |
495 | unsigned int num_in; | |
496 | unsigned int num_out; | |
497 | unsigned int len; | |
498 | unsigned int i; | |
499 | ||
500 | num_in = args->in_numargs - args->in_pages; | |
501 | num_out = args->out_numargs - args->out_pages; | |
502 | len = fuse_len_args(num_in, (struct fuse_arg *) args->in_args) + | |
503 | fuse_len_args(num_out, args->out_args); | |
504 | ||
505 | req->argbuf = kmalloc(len, GFP_ATOMIC); | |
506 | if (!req->argbuf) | |
507 | return -ENOMEM; | |
508 | ||
509 | for (i = 0; i < num_in; i++) { | |
510 | memcpy(req->argbuf + offset, | |
511 | args->in_args[i].value, | |
512 | args->in_args[i].size); | |
513 | offset += args->in_args[i].size; | |
514 | } | |
515 | ||
516 | return 0; | |
517 | } | |
518 | ||
519 | /* Copy args out of and free req->argbuf */ | |
520 | static void copy_args_from_argbuf(struct fuse_args *args, struct fuse_req *req) | |
521 | { | |
522 | unsigned int remaining; | |
523 | unsigned int offset; | |
524 | unsigned int num_in; | |
525 | unsigned int num_out; | |
526 | unsigned int i; | |
527 | ||
528 | remaining = req->out.h.len - sizeof(req->out.h); | |
529 | num_in = args->in_numargs - args->in_pages; | |
530 | num_out = args->out_numargs - args->out_pages; | |
531 | offset = fuse_len_args(num_in, (struct fuse_arg *)args->in_args); | |
532 | ||
533 | for (i = 0; i < num_out; i++) { | |
534 | unsigned int argsize = args->out_args[i].size; | |
535 | ||
536 | if (args->out_argvar && | |
537 | i == args->out_numargs - 1 && | |
538 | argsize > remaining) { | |
539 | argsize = remaining; | |
540 | } | |
541 | ||
542 | memcpy(args->out_args[i].value, req->argbuf + offset, argsize); | |
543 | offset += argsize; | |
544 | ||
545 | if (i != args->out_numargs - 1) | |
546 | remaining -= argsize; | |
547 | } | |
548 | ||
549 | /* Store the actual size of the variable-length arg */ | |
550 | if (args->out_argvar) | |
551 | args->out_args[args->out_numargs - 1].size = remaining; | |
552 | ||
553 | kfree(req->argbuf); | |
554 | req->argbuf = NULL; | |
555 | } | |
556 | ||
557 | /* Work function for request completion */ | |
bb737bbe VG |
558 | static void virtio_fs_request_complete(struct fuse_req *req, |
559 | struct virtio_fs_vq *fsvq) | |
560 | { | |
561 | struct fuse_pqueue *fpq = &fsvq->fud->pq; | |
bb737bbe VG |
562 | struct fuse_args *args; |
563 | struct fuse_args_pages *ap; | |
564 | unsigned int len, i, thislen; | |
565 | struct page *page; | |
566 | ||
567 | /* | |
568 | * TODO verify that server properly follows FUSE protocol | |
569 | * (oh.uniq, oh.len) | |
570 | */ | |
571 | args = req->args; | |
572 | copy_args_from_argbuf(args, req); | |
573 | ||
574 | if (args->out_pages && args->page_zeroing) { | |
575 | len = args->out_args[args->out_numargs - 1].size; | |
576 | ap = container_of(args, typeof(*ap), args); | |
577 | for (i = 0; i < ap->num_pages; i++) { | |
578 | thislen = ap->descs[i].length; | |
579 | if (len < thislen) { | |
580 | WARN_ON(ap->descs[i].offset); | |
581 | page = ap->pages[i]; | |
582 | zero_user_segment(page, len, thislen); | |
583 | len = 0; | |
584 | } else { | |
585 | len -= thislen; | |
586 | } | |
587 | } | |
588 | } | |
589 | ||
590 | spin_lock(&fpq->lock); | |
591 | clear_bit(FR_SENT, &req->flags); | |
592 | spin_unlock(&fpq->lock); | |
593 | ||
8f622e94 | 594 | fuse_request_end(req); |
bb737bbe VG |
595 | spin_lock(&fsvq->lock); |
596 | dec_in_flight_req(fsvq); | |
597 | spin_unlock(&fsvq->lock); | |
598 | } | |
599 | ||
600 | static void virtio_fs_complete_req_work(struct work_struct *work) | |
601 | { | |
602 | struct virtio_fs_req_work *w = | |
603 | container_of(work, typeof(*w), done_work); | |
604 | ||
605 | virtio_fs_request_complete(w->req, w->fsvq); | |
606 | kfree(w); | |
607 | } | |
608 | ||
a62a8ef9 SH |
609 | static void virtio_fs_requests_done_work(struct work_struct *work) |
610 | { | |
611 | struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq, | |
612 | done_work); | |
613 | struct fuse_pqueue *fpq = &fsvq->fud->pq; | |
a62a8ef9 SH |
614 | struct virtqueue *vq = fsvq->vq; |
615 | struct fuse_req *req; | |
a62a8ef9 | 616 | struct fuse_req *next; |
bb737bbe | 617 | unsigned int len; |
a62a8ef9 SH |
618 | LIST_HEAD(reqs); |
619 | ||
620 | /* Collect completed requests off the virtqueue */ | |
621 | spin_lock(&fsvq->lock); | |
622 | do { | |
623 | virtqueue_disable_cb(vq); | |
624 | ||
625 | while ((req = virtqueue_get_buf(vq, &len)) != NULL) { | |
626 | spin_lock(&fpq->lock); | |
627 | list_move_tail(&req->list, &reqs); | |
628 | spin_unlock(&fpq->lock); | |
629 | } | |
630 | } while (!virtqueue_enable_cb(vq) && likely(!virtqueue_is_broken(vq))); | |
631 | spin_unlock(&fsvq->lock); | |
632 | ||
633 | /* End requests */ | |
634 | list_for_each_entry_safe(req, next, &reqs, list) { | |
a62a8ef9 | 635 | list_del_init(&req->list); |
a62a8ef9 | 636 | |
bb737bbe VG |
637 | /* blocking async request completes in a worker context */ |
638 | if (req->args->may_block) { | |
639 | struct virtio_fs_req_work *w; | |
640 | ||
641 | w = kzalloc(sizeof(*w), GFP_NOFS | __GFP_NOFAIL); | |
642 | INIT_WORK(&w->done_work, virtio_fs_complete_req_work); | |
643 | w->fsvq = fsvq; | |
644 | w->req = req; | |
645 | schedule_work(&w->done_work); | |
646 | } else { | |
647 | virtio_fs_request_complete(req, fsvq); | |
648 | } | |
a62a8ef9 SH |
649 | } |
650 | } | |
651 | ||
652 | /* Virtqueue interrupt handler */ | |
653 | static void virtio_fs_vq_done(struct virtqueue *vq) | |
654 | { | |
655 | struct virtio_fs_vq *fsvq = vq_to_fsvq(vq); | |
656 | ||
657 | dev_dbg(&vq->vdev->dev, "%s %s\n", __func__, fsvq->name); | |
658 | ||
659 | schedule_work(&fsvq->done_work); | |
660 | } | |
661 | ||
b43b7e81 VG |
662 | static void virtio_fs_init_vq(struct virtio_fs_vq *fsvq, char *name, |
663 | int vq_type) | |
664 | { | |
7c594bbd | 665 | strscpy(fsvq->name, name, VQ_NAME_LEN); |
b43b7e81 VG |
666 | spin_lock_init(&fsvq->lock); |
667 | INIT_LIST_HEAD(&fsvq->queued_reqs); | |
668 | INIT_LIST_HEAD(&fsvq->end_reqs); | |
669 | init_completion(&fsvq->in_flight_zero); | |
670 | ||
671 | if (vq_type == VQ_REQUEST) { | |
672 | INIT_WORK(&fsvq->done_work, virtio_fs_requests_done_work); | |
673 | INIT_DELAYED_WORK(&fsvq->dispatch_work, | |
674 | virtio_fs_request_dispatch_work); | |
675 | } else { | |
676 | INIT_WORK(&fsvq->done_work, virtio_fs_hiprio_done_work); | |
677 | INIT_DELAYED_WORK(&fsvq->dispatch_work, | |
678 | virtio_fs_hiprio_dispatch_work); | |
679 | } | |
680 | } | |
681 | ||
a62a8ef9 SH |
682 | /* Initialize virtqueues */ |
683 | static int virtio_fs_setup_vqs(struct virtio_device *vdev, | |
684 | struct virtio_fs *fs) | |
685 | { | |
686 | struct virtqueue **vqs; | |
687 | vq_callback_t **callbacks; | |
688 | const char **names; | |
689 | unsigned int i; | |
690 | int ret = 0; | |
691 | ||
2c0349ec MT |
692 | virtio_cread_le(vdev, struct virtio_fs_config, num_request_queues, |
693 | &fs->num_request_queues); | |
a62a8ef9 SH |
694 | if (fs->num_request_queues == 0) |
695 | return -EINVAL; | |
696 | ||
b43b7e81 | 697 | fs->nvqs = VQ_REQUEST + fs->num_request_queues; |
a62a8ef9 SH |
698 | fs->vqs = kcalloc(fs->nvqs, sizeof(fs->vqs[VQ_HIPRIO]), GFP_KERNEL); |
699 | if (!fs->vqs) | |
700 | return -ENOMEM; | |
701 | ||
702 | vqs = kmalloc_array(fs->nvqs, sizeof(vqs[VQ_HIPRIO]), GFP_KERNEL); | |
703 | callbacks = kmalloc_array(fs->nvqs, sizeof(callbacks[VQ_HIPRIO]), | |
704 | GFP_KERNEL); | |
705 | names = kmalloc_array(fs->nvqs, sizeof(names[VQ_HIPRIO]), GFP_KERNEL); | |
706 | if (!vqs || !callbacks || !names) { | |
707 | ret = -ENOMEM; | |
708 | goto out; | |
709 | } | |
710 | ||
b43b7e81 | 711 | /* Initialize the hiprio/forget request virtqueue */ |
a62a8ef9 | 712 | callbacks[VQ_HIPRIO] = virtio_fs_vq_done; |
b43b7e81 | 713 | virtio_fs_init_vq(&fs->vqs[VQ_HIPRIO], "hiprio", VQ_HIPRIO); |
a62a8ef9 | 714 | names[VQ_HIPRIO] = fs->vqs[VQ_HIPRIO].name; |
a62a8ef9 SH |
715 | |
716 | /* Initialize the requests virtqueues */ | |
717 | for (i = VQ_REQUEST; i < fs->nvqs; i++) { | |
b43b7e81 VG |
718 | char vq_name[VQ_NAME_LEN]; |
719 | ||
720 | snprintf(vq_name, VQ_NAME_LEN, "requests.%u", i - VQ_REQUEST); | |
721 | virtio_fs_init_vq(&fs->vqs[i], vq_name, VQ_REQUEST); | |
a62a8ef9 SH |
722 | callbacks[i] = virtio_fs_vq_done; |
723 | names[i] = fs->vqs[i].name; | |
724 | } | |
725 | ||
726 | ret = virtio_find_vqs(vdev, fs->nvqs, vqs, callbacks, names, NULL); | |
727 | if (ret < 0) | |
728 | goto out; | |
729 | ||
730 | for (i = 0; i < fs->nvqs; i++) | |
731 | fs->vqs[i].vq = vqs[i]; | |
732 | ||
733 | virtio_fs_start_all_queues(fs); | |
734 | out: | |
735 | kfree(names); | |
736 | kfree(callbacks); | |
737 | kfree(vqs); | |
738 | if (ret) | |
739 | kfree(fs->vqs); | |
740 | return ret; | |
741 | } | |
742 | ||
743 | /* Free virtqueues (device must already be reset) */ | |
1e5b9e04 | 744 | static void virtio_fs_cleanup_vqs(struct virtio_device *vdev) |
a62a8ef9 SH |
745 | { |
746 | vdev->config->del_vqs(vdev); | |
747 | } | |
748 | ||
22f3787e SH |
749 | /* Map a window offset to a page frame number. The window offset will have |
750 | * been produced by .iomap_begin(), which maps a file offset to a window | |
751 | * offset. | |
752 | */ | |
753 | static long virtio_fs_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, | |
e511c4a3 JC |
754 | long nr_pages, enum dax_access_mode mode, |
755 | void **kaddr, pfn_t *pfn) | |
22f3787e SH |
756 | { |
757 | struct virtio_fs *fs = dax_get_private(dax_dev); | |
758 | phys_addr_t offset = PFN_PHYS(pgoff); | |
73fb2c8b | 759 | size_t max_nr_pages = fs->window_len / PAGE_SIZE - pgoff; |
22f3787e SH |
760 | |
761 | if (kaddr) | |
762 | *kaddr = fs->window_kaddr + offset; | |
763 | if (pfn) | |
764 | *pfn = phys_to_pfn_t(fs->window_phys_addr + offset, | |
765 | PFN_DEV | PFN_MAP); | |
766 | return nr_pages > max_nr_pages ? max_nr_pages : nr_pages; | |
767 | } | |
768 | ||
22f3787e SH |
769 | static int virtio_fs_zero_page_range(struct dax_device *dax_dev, |
770 | pgoff_t pgoff, size_t nr_pages) | |
771 | { | |
772 | long rc; | |
773 | void *kaddr; | |
774 | ||
e511c4a3 JC |
775 | rc = dax_direct_access(dax_dev, pgoff, nr_pages, DAX_ACCESS, &kaddr, |
776 | NULL); | |
22f3787e SH |
777 | if (rc < 0) |
778 | return rc; | |
779 | memset(kaddr, 0, nr_pages << PAGE_SHIFT); | |
780 | dax_flush(dax_dev, kaddr, nr_pages << PAGE_SHIFT); | |
781 | return 0; | |
782 | } | |
783 | ||
784 | static const struct dax_operations virtio_fs_dax_ops = { | |
785 | .direct_access = virtio_fs_direct_access, | |
22f3787e SH |
786 | .zero_page_range = virtio_fs_zero_page_range, |
787 | }; | |
788 | ||
789 | static void virtio_fs_cleanup_dax(void *data) | |
790 | { | |
791 | struct dax_device *dax_dev = data; | |
792 | ||
793 | kill_dax(dax_dev); | |
794 | put_dax(dax_dev); | |
795 | } | |
796 | ||
797 | static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs) | |
798 | { | |
799 | struct virtio_shm_region cache_reg; | |
800 | struct dev_pagemap *pgmap; | |
801 | bool have_cache; | |
802 | ||
803 | if (!IS_ENABLED(CONFIG_FUSE_DAX)) | |
804 | return 0; | |
805 | ||
806 | /* Get cache region */ | |
807 | have_cache = virtio_get_shm_region(vdev, &cache_reg, | |
808 | (u8)VIRTIO_FS_SHMCAP_ID_CACHE); | |
809 | if (!have_cache) { | |
810 | dev_notice(&vdev->dev, "%s: No cache capability\n", __func__); | |
811 | return 0; | |
812 | } | |
813 | ||
814 | if (!devm_request_mem_region(&vdev->dev, cache_reg.addr, cache_reg.len, | |
815 | dev_name(&vdev->dev))) { | |
816 | dev_warn(&vdev->dev, "could not reserve region addr=0x%llx len=0x%llx\n", | |
817 | cache_reg.addr, cache_reg.len); | |
818 | return -EBUSY; | |
819 | } | |
820 | ||
821 | dev_notice(&vdev->dev, "Cache len: 0x%llx @ 0x%llx\n", cache_reg.len, | |
822 | cache_reg.addr); | |
823 | ||
824 | pgmap = devm_kzalloc(&vdev->dev, sizeof(*pgmap), GFP_KERNEL); | |
825 | if (!pgmap) | |
826 | return -ENOMEM; | |
827 | ||
828 | pgmap->type = MEMORY_DEVICE_FS_DAX; | |
829 | ||
830 | /* Ideally we would directly use the PCI BAR resource but | |
831 | * devm_memremap_pages() wants its own copy in pgmap. So | |
832 | * initialize a struct resource from scratch (only the start | |
833 | * and end fields will be used). | |
834 | */ | |
69456535 | 835 | pgmap->range = (struct range) { |
22f3787e SH |
836 | .start = (phys_addr_t) cache_reg.addr, |
837 | .end = (phys_addr_t) cache_reg.addr + cache_reg.len - 1, | |
838 | }; | |
69456535 | 839 | pgmap->nr_range = 1; |
22f3787e SH |
840 | |
841 | fs->window_kaddr = devm_memremap_pages(&vdev->dev, pgmap); | |
842 | if (IS_ERR(fs->window_kaddr)) | |
843 | return PTR_ERR(fs->window_kaddr); | |
844 | ||
845 | fs->window_phys_addr = (phys_addr_t) cache_reg.addr; | |
846 | fs->window_len = (phys_addr_t) cache_reg.len; | |
847 | ||
848 | dev_dbg(&vdev->dev, "%s: window kaddr 0x%px phys_addr 0x%llx len 0x%llx\n", | |
849 | __func__, fs->window_kaddr, cache_reg.addr, cache_reg.len); | |
850 | ||
30c6828a | 851 | fs->dax_dev = alloc_dax(fs, &virtio_fs_dax_ops); |
22f3787e SH |
852 | if (IS_ERR(fs->dax_dev)) |
853 | return PTR_ERR(fs->dax_dev); | |
854 | ||
855 | return devm_add_action_or_reset(&vdev->dev, virtio_fs_cleanup_dax, | |
856 | fs->dax_dev); | |
857 | } | |
858 | ||
a62a8ef9 SH |
859 | static int virtio_fs_probe(struct virtio_device *vdev) |
860 | { | |
861 | struct virtio_fs *fs; | |
862 | int ret; | |
863 | ||
864 | fs = kzalloc(sizeof(*fs), GFP_KERNEL); | |
865 | if (!fs) | |
866 | return -ENOMEM; | |
867 | kref_init(&fs->refcount); | |
868 | vdev->priv = fs; | |
869 | ||
870 | ret = virtio_fs_read_tag(vdev, fs); | |
871 | if (ret < 0) | |
872 | goto out; | |
873 | ||
874 | ret = virtio_fs_setup_vqs(vdev, fs); | |
875 | if (ret < 0) | |
876 | goto out; | |
877 | ||
878 | /* TODO vq affinity */ | |
879 | ||
22f3787e SH |
880 | ret = virtio_fs_setup_dax(vdev, fs); |
881 | if (ret < 0) | |
882 | goto out_vqs; | |
883 | ||
a62a8ef9 SH |
884 | /* Bring the device online in case the filesystem is mounted and |
885 | * requests need to be sent before we return. | |
886 | */ | |
887 | virtio_device_ready(vdev); | |
888 | ||
889 | ret = virtio_fs_add_instance(fs); | |
890 | if (ret < 0) | |
891 | goto out_vqs; | |
892 | ||
893 | return 0; | |
894 | ||
895 | out_vqs: | |
d9679d00 | 896 | virtio_reset_device(vdev); |
1e5b9e04 | 897 | virtio_fs_cleanup_vqs(vdev); |
c79c5e01 | 898 | kfree(fs->vqs); |
a62a8ef9 SH |
899 | |
900 | out: | |
901 | vdev->priv = NULL; | |
902 | kfree(fs); | |
903 | return ret; | |
904 | } | |
905 | ||
906 | static void virtio_fs_stop_all_queues(struct virtio_fs *fs) | |
907 | { | |
908 | struct virtio_fs_vq *fsvq; | |
909 | int i; | |
910 | ||
911 | for (i = 0; i < fs->nvqs; i++) { | |
912 | fsvq = &fs->vqs[i]; | |
913 | spin_lock(&fsvq->lock); | |
914 | fsvq->connected = false; | |
915 | spin_unlock(&fsvq->lock); | |
916 | } | |
917 | } | |
918 | ||
919 | static void virtio_fs_remove(struct virtio_device *vdev) | |
920 | { | |
921 | struct virtio_fs *fs = vdev->priv; | |
922 | ||
923 | mutex_lock(&virtio_fs_mutex); | |
924 | /* This device is going away. No one should get new reference */ | |
925 | list_del_init(&fs->list); | |
926 | virtio_fs_stop_all_queues(fs); | |
724c15a4 | 927 | virtio_fs_drain_all_queues_locked(fs); |
d9679d00 | 928 | virtio_reset_device(vdev); |
1e5b9e04 | 929 | virtio_fs_cleanup_vqs(vdev); |
a62a8ef9 SH |
930 | |
931 | vdev->priv = NULL; | |
932 | /* Put device reference on virtio_fs object */ | |
933 | virtio_fs_put(fs); | |
934 | mutex_unlock(&virtio_fs_mutex); | |
935 | } | |
936 | ||
937 | #ifdef CONFIG_PM_SLEEP | |
938 | static int virtio_fs_freeze(struct virtio_device *vdev) | |
939 | { | |
940 | /* TODO need to save state here */ | |
941 | pr_warn("virtio-fs: suspend/resume not yet supported\n"); | |
942 | return -EOPNOTSUPP; | |
943 | } | |
944 | ||
945 | static int virtio_fs_restore(struct virtio_device *vdev) | |
946 | { | |
947 | /* TODO need to restore state here */ | |
948 | return 0; | |
949 | } | |
950 | #endif /* CONFIG_PM_SLEEP */ | |
951 | ||
00929447 | 952 | static const struct virtio_device_id id_table[] = { |
a62a8ef9 SH |
953 | { VIRTIO_ID_FS, VIRTIO_DEV_ANY_ID }, |
954 | {}, | |
955 | }; | |
956 | ||
00929447 | 957 | static const unsigned int feature_table[] = {}; |
a62a8ef9 SH |
958 | |
959 | static struct virtio_driver virtio_fs_driver = { | |
960 | .driver.name = KBUILD_MODNAME, | |
961 | .driver.owner = THIS_MODULE, | |
962 | .id_table = id_table, | |
963 | .feature_table = feature_table, | |
964 | .feature_table_size = ARRAY_SIZE(feature_table), | |
965 | .probe = virtio_fs_probe, | |
966 | .remove = virtio_fs_remove, | |
967 | #ifdef CONFIG_PM_SLEEP | |
968 | .freeze = virtio_fs_freeze, | |
969 | .restore = virtio_fs_restore, | |
970 | #endif | |
971 | }; | |
972 | ||
973 | static void virtio_fs_wake_forget_and_unlock(struct fuse_iqueue *fiq) | |
974 | __releases(fiq->lock) | |
975 | { | |
976 | struct fuse_forget_link *link; | |
977 | struct virtio_fs_forget *forget; | |
1efcf39e | 978 | struct virtio_fs_forget_req *req; |
a62a8ef9 | 979 | struct virtio_fs *fs; |
a62a8ef9 | 980 | struct virtio_fs_vq *fsvq; |
a62a8ef9 | 981 | u64 unique; |
a62a8ef9 SH |
982 | |
983 | link = fuse_dequeue_forget(fiq, 1, NULL); | |
984 | unique = fuse_get_unique(fiq); | |
985 | ||
986 | fs = fiq->priv; | |
987 | fsvq = &fs->vqs[VQ_HIPRIO]; | |
988 | spin_unlock(&fiq->lock); | |
989 | ||
990 | /* Allocate a buffer for the request */ | |
991 | forget = kmalloc(sizeof(*forget), GFP_NOFS | __GFP_NOFAIL); | |
1efcf39e | 992 | req = &forget->req; |
a62a8ef9 | 993 | |
1efcf39e | 994 | req->ih = (struct fuse_in_header){ |
a62a8ef9 SH |
995 | .opcode = FUSE_FORGET, |
996 | .nodeid = link->forget_one.nodeid, | |
997 | .unique = unique, | |
1efcf39e | 998 | .len = sizeof(*req), |
a62a8ef9 | 999 | }; |
1efcf39e | 1000 | req->arg = (struct fuse_forget_in){ |
a62a8ef9 SH |
1001 | .nlookup = link->forget_one.nlookup, |
1002 | }; | |
1003 | ||
58ada94f | 1004 | send_forget_request(fsvq, forget, false); |
a62a8ef9 SH |
1005 | kfree(link); |
1006 | } | |
1007 | ||
1008 | static void virtio_fs_wake_interrupt_and_unlock(struct fuse_iqueue *fiq) | |
1009 | __releases(fiq->lock) | |
1010 | { | |
1011 | /* | |
1012 | * TODO interrupts. | |
1013 | * | |
1014 | * Normal fs operations on a local filesystems aren't interruptible. | |
1015 | * Exceptions are blocking lock operations; for example fcntl(F_SETLKW) | |
1016 | * with shared lock between host and guest. | |
1017 | */ | |
1018 | spin_unlock(&fiq->lock); | |
1019 | } | |
1020 | ||
42d3e2d0 VG |
1021 | /* Count number of scatter-gather elements required */ |
1022 | static unsigned int sg_count_fuse_pages(struct fuse_page_desc *page_descs, | |
1023 | unsigned int num_pages, | |
1024 | unsigned int total_len) | |
1025 | { | |
1026 | unsigned int i; | |
1027 | unsigned int this_len; | |
1028 | ||
1029 | for (i = 0; i < num_pages && total_len; i++) { | |
1030 | this_len = min(page_descs[i].length, total_len); | |
1031 | total_len -= this_len; | |
1032 | } | |
1033 | ||
1034 | return i; | |
1035 | } | |
1036 | ||
a62a8ef9 SH |
1037 | /* Return the number of scatter-gather list elements required */ |
1038 | static unsigned int sg_count_fuse_req(struct fuse_req *req) | |
1039 | { | |
1040 | struct fuse_args *args = req->args; | |
1041 | struct fuse_args_pages *ap = container_of(args, typeof(*ap), args); | |
42d3e2d0 | 1042 | unsigned int size, total_sgs = 1 /* fuse_in_header */; |
a62a8ef9 SH |
1043 | |
1044 | if (args->in_numargs - args->in_pages) | |
1045 | total_sgs += 1; | |
1046 | ||
42d3e2d0 VG |
1047 | if (args->in_pages) { |
1048 | size = args->in_args[args->in_numargs - 1].size; | |
1049 | total_sgs += sg_count_fuse_pages(ap->descs, ap->num_pages, | |
1050 | size); | |
1051 | } | |
a62a8ef9 SH |
1052 | |
1053 | if (!test_bit(FR_ISREPLY, &req->flags)) | |
1054 | return total_sgs; | |
1055 | ||
1056 | total_sgs += 1 /* fuse_out_header */; | |
1057 | ||
1058 | if (args->out_numargs - args->out_pages) | |
1059 | total_sgs += 1; | |
1060 | ||
42d3e2d0 VG |
1061 | if (args->out_pages) { |
1062 | size = args->out_args[args->out_numargs - 1].size; | |
1063 | total_sgs += sg_count_fuse_pages(ap->descs, ap->num_pages, | |
1064 | size); | |
1065 | } | |
a62a8ef9 SH |
1066 | |
1067 | return total_sgs; | |
1068 | } | |
1069 | ||
1070 | /* Add pages to scatter-gather list and return number of elements used */ | |
1071 | static unsigned int sg_init_fuse_pages(struct scatterlist *sg, | |
1072 | struct page **pages, | |
1073 | struct fuse_page_desc *page_descs, | |
1074 | unsigned int num_pages, | |
1075 | unsigned int total_len) | |
1076 | { | |
1077 | unsigned int i; | |
1078 | unsigned int this_len; | |
1079 | ||
1080 | for (i = 0; i < num_pages && total_len; i++) { | |
1081 | sg_init_table(&sg[i], 1); | |
1082 | this_len = min(page_descs[i].length, total_len); | |
1083 | sg_set_page(&sg[i], pages[i], this_len, page_descs[i].offset); | |
1084 | total_len -= this_len; | |
1085 | } | |
1086 | ||
1087 | return i; | |
1088 | } | |
1089 | ||
1090 | /* Add args to scatter-gather list and return number of elements used */ | |
1091 | static unsigned int sg_init_fuse_args(struct scatterlist *sg, | |
1092 | struct fuse_req *req, | |
1093 | struct fuse_arg *args, | |
1094 | unsigned int numargs, | |
1095 | bool argpages, | |
1096 | void *argbuf, | |
1097 | unsigned int *len_used) | |
1098 | { | |
1099 | struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args); | |
1100 | unsigned int total_sgs = 0; | |
1101 | unsigned int len; | |
1102 | ||
1103 | len = fuse_len_args(numargs - argpages, args); | |
1104 | if (len) | |
1105 | sg_init_one(&sg[total_sgs++], argbuf, len); | |
1106 | ||
1107 | if (argpages) | |
1108 | total_sgs += sg_init_fuse_pages(&sg[total_sgs], | |
1109 | ap->pages, ap->descs, | |
1110 | ap->num_pages, | |
1111 | args[numargs - 1].size); | |
1112 | ||
1113 | if (len_used) | |
1114 | *len_used = len; | |
1115 | ||
1116 | return total_sgs; | |
1117 | } | |
1118 | ||
1119 | /* Add a request to a virtqueue and kick the device */ | |
1120 | static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, | |
a9bfd9dd | 1121 | struct fuse_req *req, bool in_flight) |
a62a8ef9 SH |
1122 | { |
1123 | /* requests need at least 4 elements */ | |
1124 | struct scatterlist *stack_sgs[6]; | |
1125 | struct scatterlist stack_sg[ARRAY_SIZE(stack_sgs)]; | |
1126 | struct scatterlist **sgs = stack_sgs; | |
1127 | struct scatterlist *sg = stack_sg; | |
1128 | struct virtqueue *vq; | |
1129 | struct fuse_args *args = req->args; | |
1130 | unsigned int argbuf_used = 0; | |
1131 | unsigned int out_sgs = 0; | |
1132 | unsigned int in_sgs = 0; | |
1133 | unsigned int total_sgs; | |
1134 | unsigned int i; | |
1135 | int ret; | |
1136 | bool notify; | |
5dbe190f | 1137 | struct fuse_pqueue *fpq; |
a62a8ef9 SH |
1138 | |
1139 | /* Does the sglist fit on the stack? */ | |
1140 | total_sgs = sg_count_fuse_req(req); | |
1141 | if (total_sgs > ARRAY_SIZE(stack_sgs)) { | |
1142 | sgs = kmalloc_array(total_sgs, sizeof(sgs[0]), GFP_ATOMIC); | |
1143 | sg = kmalloc_array(total_sgs, sizeof(sg[0]), GFP_ATOMIC); | |
1144 | if (!sgs || !sg) { | |
1145 | ret = -ENOMEM; | |
1146 | goto out; | |
1147 | } | |
1148 | } | |
1149 | ||
1150 | /* Use a bounce buffer since stack args cannot be mapped */ | |
1151 | ret = copy_args_to_argbuf(req); | |
1152 | if (ret < 0) | |
1153 | goto out; | |
1154 | ||
1155 | /* Request elements */ | |
1156 | sg_init_one(&sg[out_sgs++], &req->in.h, sizeof(req->in.h)); | |
1157 | out_sgs += sg_init_fuse_args(&sg[out_sgs], req, | |
1158 | (struct fuse_arg *)args->in_args, | |
1159 | args->in_numargs, args->in_pages, | |
1160 | req->argbuf, &argbuf_used); | |
1161 | ||
1162 | /* Reply elements */ | |
1163 | if (test_bit(FR_ISREPLY, &req->flags)) { | |
1164 | sg_init_one(&sg[out_sgs + in_sgs++], | |
1165 | &req->out.h, sizeof(req->out.h)); | |
1166 | in_sgs += sg_init_fuse_args(&sg[out_sgs + in_sgs], req, | |
1167 | args->out_args, args->out_numargs, | |
1168 | args->out_pages, | |
1169 | req->argbuf + argbuf_used, NULL); | |
1170 | } | |
1171 | ||
1172 | WARN_ON(out_sgs + in_sgs != total_sgs); | |
1173 | ||
1174 | for (i = 0; i < total_sgs; i++) | |
1175 | sgs[i] = &sg[i]; | |
1176 | ||
1177 | spin_lock(&fsvq->lock); | |
1178 | ||
1179 | if (!fsvq->connected) { | |
1180 | spin_unlock(&fsvq->lock); | |
1181 | ret = -ENOTCONN; | |
1182 | goto out; | |
1183 | } | |
1184 | ||
1185 | vq = fsvq->vq; | |
1186 | ret = virtqueue_add_sgs(vq, sgs, out_sgs, in_sgs, req, GFP_ATOMIC); | |
1187 | if (ret < 0) { | |
1188 | spin_unlock(&fsvq->lock); | |
1189 | goto out; | |
1190 | } | |
1191 | ||
5dbe190f VG |
1192 | /* Request successfully sent. */ |
1193 | fpq = &fsvq->fud->pq; | |
1194 | spin_lock(&fpq->lock); | |
1195 | list_add_tail(&req->list, fpq->processing); | |
1196 | spin_unlock(&fpq->lock); | |
1197 | set_bit(FR_SENT, &req->flags); | |
1198 | /* matches barrier in request_wait_answer() */ | |
1199 | smp_mb__after_atomic(); | |
1200 | ||
a9bfd9dd VG |
1201 | if (!in_flight) |
1202 | inc_in_flight_req(fsvq); | |
a62a8ef9 SH |
1203 | notify = virtqueue_kick_prepare(vq); |
1204 | ||
1205 | spin_unlock(&fsvq->lock); | |
1206 | ||
1207 | if (notify) | |
1208 | virtqueue_notify(vq); | |
1209 | ||
1210 | out: | |
1211 | if (ret < 0 && req->argbuf) { | |
1212 | kfree(req->argbuf); | |
1213 | req->argbuf = NULL; | |
1214 | } | |
1215 | if (sgs != stack_sgs) { | |
1216 | kfree(sgs); | |
1217 | kfree(sg); | |
1218 | } | |
1219 | ||
1220 | return ret; | |
1221 | } | |
1222 | ||
1223 | static void virtio_fs_wake_pending_and_unlock(struct fuse_iqueue *fiq) | |
1224 | __releases(fiq->lock) | |
1225 | { | |
1226 | unsigned int queue_id = VQ_REQUEST; /* TODO multiqueue */ | |
1227 | struct virtio_fs *fs; | |
a62a8ef9 | 1228 | struct fuse_req *req; |
51fecdd2 | 1229 | struct virtio_fs_vq *fsvq; |
a62a8ef9 SH |
1230 | int ret; |
1231 | ||
1232 | WARN_ON(list_empty(&fiq->pending)); | |
1233 | req = list_last_entry(&fiq->pending, struct fuse_req, list); | |
1234 | clear_bit(FR_PENDING, &req->flags); | |
1235 | list_del_init(&req->list); | |
1236 | WARN_ON(!list_empty(&fiq->pending)); | |
1237 | spin_unlock(&fiq->lock); | |
1238 | ||
1239 | fs = fiq->priv; | |
a62a8ef9 SH |
1240 | |
1241 | pr_debug("%s: opcode %u unique %#llx nodeid %#llx in.len %u out.len %u\n", | |
1242 | __func__, req->in.h.opcode, req->in.h.unique, | |
1243 | req->in.h.nodeid, req->in.h.len, | |
1244 | fuse_len_args(req->args->out_numargs, req->args->out_args)); | |
1245 | ||
51fecdd2 | 1246 | fsvq = &fs->vqs[queue_id]; |
a9bfd9dd | 1247 | ret = virtio_fs_enqueue_req(fsvq, req, false); |
a62a8ef9 SH |
1248 | if (ret < 0) { |
1249 | if (ret == -ENOMEM || ret == -ENOSPC) { | |
a9bfd9dd VG |
1250 | /* |
1251 | * Virtqueue full. Retry submission from worker | |
1252 | * context as we might be holding fc->bg_lock. | |
1253 | */ | |
1254 | spin_lock(&fsvq->lock); | |
1255 | list_add_tail(&req->list, &fsvq->queued_reqs); | |
1256 | inc_in_flight_req(fsvq); | |
1257 | schedule_delayed_work(&fsvq->dispatch_work, | |
1258 | msecs_to_jiffies(1)); | |
1259 | spin_unlock(&fsvq->lock); | |
1260 | return; | |
a62a8ef9 SH |
1261 | } |
1262 | req->out.h.error = ret; | |
1263 | pr_err("virtio-fs: virtio_fs_enqueue_req() failed %d\n", ret); | |
51fecdd2 VG |
1264 | |
1265 | /* Can't end request in submission context. Use a worker */ | |
1266 | spin_lock(&fsvq->lock); | |
1267 | list_add_tail(&req->list, &fsvq->end_reqs); | |
1268 | schedule_delayed_work(&fsvq->dispatch_work, 0); | |
1269 | spin_unlock(&fsvq->lock); | |
a62a8ef9 SH |
1270 | return; |
1271 | } | |
1272 | } | |
1273 | ||
00929447 | 1274 | static const struct fuse_iqueue_ops virtio_fs_fiq_ops = { |
a62a8ef9 SH |
1275 | .wake_forget_and_unlock = virtio_fs_wake_forget_and_unlock, |
1276 | .wake_interrupt_and_unlock = virtio_fs_wake_interrupt_and_unlock, | |
1277 | .wake_pending_and_unlock = virtio_fs_wake_pending_and_unlock, | |
1278 | .release = virtio_fs_fiq_release, | |
1279 | }; | |
1280 | ||
1dd53957 | 1281 | static inline void virtio_fs_ctx_set_defaults(struct fuse_fs_context *ctx) |
a62a8ef9 | 1282 | { |
1dd53957 VG |
1283 | ctx->rootmode = S_IFDIR; |
1284 | ctx->default_permissions = 1; | |
1285 | ctx->allow_other = 1; | |
1286 | ctx->max_read = UINT_MAX; | |
1287 | ctx->blksize = 512; | |
1288 | ctx->destroy = true; | |
1289 | ctx->no_control = true; | |
1290 | ctx->no_force_umount = true; | |
1291 | } | |
1292 | ||
1293 | static int virtio_fs_fill_super(struct super_block *sb, struct fs_context *fsc) | |
a62a8ef9 | 1294 | { |
fcee216b MR |
1295 | struct fuse_mount *fm = get_fuse_mount_super(sb); |
1296 | struct fuse_conn *fc = fm->fc; | |
a62a8ef9 | 1297 | struct virtio_fs *fs = fc->iq.priv; |
1dd53957 | 1298 | struct fuse_fs_context *ctx = fsc->fs_private; |
a62a8ef9 SH |
1299 | unsigned int i; |
1300 | int err; | |
a62a8ef9 | 1301 | |
1dd53957 | 1302 | virtio_fs_ctx_set_defaults(ctx); |
a62a8ef9 SH |
1303 | mutex_lock(&virtio_fs_mutex); |
1304 | ||
1305 | /* After holding mutex, make sure virtiofs device is still there. | |
1306 | * Though we are holding a reference to it, drive ->remove might | |
1307 | * still have cleaned up virtual queues. In that case bail out. | |
1308 | */ | |
1309 | err = -EINVAL; | |
1310 | if (list_empty(&fs->list)) { | |
1311 | pr_info("virtio-fs: tag <%s> not found\n", fs->tag); | |
1312 | goto err; | |
1313 | } | |
1314 | ||
1315 | err = -ENOMEM; | |
1316 | /* Allocate fuse_dev for hiprio and notification queues */ | |
7fd3abfa | 1317 | for (i = 0; i < fs->nvqs; i++) { |
a62a8ef9 SH |
1318 | struct virtio_fs_vq *fsvq = &fs->vqs[i]; |
1319 | ||
1320 | fsvq->fud = fuse_dev_alloc(); | |
1321 | if (!fsvq->fud) | |
1322 | goto err_free_fuse_devs; | |
1323 | } | |
1324 | ||
7fd3abfa | 1325 | /* virtiofs allocates and installs its own fuse devices */ |
1dd53957 | 1326 | ctx->fudptr = NULL; |
780b1b95 JX |
1327 | if (ctx->dax_mode != FUSE_DAX_NEVER) { |
1328 | if (ctx->dax_mode == FUSE_DAX_ALWAYS && !fs->dax_dev) { | |
3f9b9efd VG |
1329 | err = -EINVAL; |
1330 | pr_err("virtio-fs: dax can't be enabled as filesystem" | |
1331 | " device does not support it.\n"); | |
1332 | goto err_free_fuse_devs; | |
1333 | } | |
1dd53957 | 1334 | ctx->dax_dev = fs->dax_dev; |
3f9b9efd | 1335 | } |
1dd53957 | 1336 | err = fuse_fill_super_common(sb, ctx); |
a62a8ef9 SH |
1337 | if (err < 0) |
1338 | goto err_free_fuse_devs; | |
1339 | ||
a62a8ef9 SH |
1340 | for (i = 0; i < fs->nvqs; i++) { |
1341 | struct virtio_fs_vq *fsvq = &fs->vqs[i]; | |
1342 | ||
a62a8ef9 SH |
1343 | fuse_dev_install(fsvq->fud, fc); |
1344 | } | |
1345 | ||
1346 | /* Previous unmount will stop all queues. Start these again */ | |
1347 | virtio_fs_start_all_queues(fs); | |
fcee216b | 1348 | fuse_send_init(fm); |
a62a8ef9 SH |
1349 | mutex_unlock(&virtio_fs_mutex); |
1350 | return 0; | |
1351 | ||
1352 | err_free_fuse_devs: | |
1353 | virtio_fs_free_devs(fs); | |
1354 | err: | |
1355 | mutex_unlock(&virtio_fs_mutex); | |
1356 | return err; | |
1357 | } | |
1358 | ||
fcee216b | 1359 | static void virtio_fs_conn_destroy(struct fuse_mount *fm) |
a62a8ef9 | 1360 | { |
fcee216b MR |
1361 | struct fuse_conn *fc = fm->fc; |
1362 | struct virtio_fs *vfs = fc->iq.priv; | |
1363 | struct virtio_fs_vq *fsvq = &vfs->vqs[VQ_HIPRIO]; | |
a62a8ef9 | 1364 | |
fcee216b MR |
1365 | /* Stop dax worker. Soon evict_inodes() will be called which |
1366 | * will free all memory ranges belonging to all inodes. | |
9a752d18 VG |
1367 | */ |
1368 | if (IS_ENABLED(CONFIG_FUSE_DAX)) | |
1369 | fuse_dax_cancel_work(fc); | |
a62a8ef9 SH |
1370 | |
1371 | /* Stop forget queue. Soon destroy will be sent */ | |
1372 | spin_lock(&fsvq->lock); | |
1373 | fsvq->connected = false; | |
1374 | spin_unlock(&fsvq->lock); | |
1375 | virtio_fs_drain_all_queues(vfs); | |
1376 | ||
fcee216b | 1377 | fuse_conn_destroy(fm); |
a62a8ef9 | 1378 | |
fcee216b | 1379 | /* fuse_conn_destroy() must have sent destroy. Stop all queues |
a62a8ef9 SH |
1380 | * and drain one more time and free fuse devices. Freeing fuse |
1381 | * devices will drop their reference on fuse_conn and that in | |
1382 | * turn will drop its reference on virtio_fs object. | |
1383 | */ | |
1384 | virtio_fs_stop_all_queues(vfs); | |
1385 | virtio_fs_drain_all_queues(vfs); | |
1386 | virtio_fs_free_devs(vfs); | |
1387 | } | |
1388 | ||
fcee216b MR |
1389 | static void virtio_kill_sb(struct super_block *sb) |
1390 | { | |
1391 | struct fuse_mount *fm = get_fuse_mount_super(sb); | |
1392 | bool last; | |
1393 | ||
1394 | /* If mount failed, we can still be called without any fc */ | |
d534d31d | 1395 | if (sb->s_root) { |
fcee216b MR |
1396 | last = fuse_mount_remove(fm); |
1397 | if (last) | |
1398 | virtio_fs_conn_destroy(fm); | |
1399 | } | |
1400 | kill_anon_super(sb); | |
a27c061a | 1401 | fuse_mount_destroy(fm); |
fcee216b MR |
1402 | } |
1403 | ||
a62a8ef9 SH |
1404 | static int virtio_fs_test_super(struct super_block *sb, |
1405 | struct fs_context *fsc) | |
1406 | { | |
fcee216b MR |
1407 | struct fuse_mount *fsc_fm = fsc->s_fs_info; |
1408 | struct fuse_mount *sb_fm = get_fuse_mount_super(sb); | |
a62a8ef9 | 1409 | |
fcee216b | 1410 | return fsc_fm->fc->iq.priv == sb_fm->fc->iq.priv; |
a62a8ef9 SH |
1411 | } |
1412 | ||
a62a8ef9 SH |
1413 | static int virtio_fs_get_tree(struct fs_context *fsc) |
1414 | { | |
1415 | struct virtio_fs *fs; | |
1416 | struct super_block *sb; | |
a7f0d7aa | 1417 | struct fuse_conn *fc = NULL; |
fcee216b | 1418 | struct fuse_mount *fm; |
a7f0d7aa CK |
1419 | unsigned int virtqueue_size; |
1420 | int err = -EIO; | |
a62a8ef9 SH |
1421 | |
1422 | /* This gets a reference on virtio_fs object. This ptr gets installed | |
1423 | * in fc->iq->priv. Once fuse_conn is going away, it calls ->put() | |
1424 | * to drop the reference to this object. | |
1425 | */ | |
1426 | fs = virtio_fs_find_instance(fsc->source); | |
1427 | if (!fs) { | |
1428 | pr_info("virtio-fs: tag <%s> not found\n", fsc->source); | |
1429 | return -EINVAL; | |
1430 | } | |
1431 | ||
a7f0d7aa CK |
1432 | virtqueue_size = virtqueue_get_vring_size(fs->vqs[VQ_REQUEST].vq); |
1433 | if (WARN_ON(virtqueue_size <= FUSE_HEADER_OVERHEAD)) | |
1434 | goto out_err; | |
1435 | ||
833c5a42 | 1436 | err = -ENOMEM; |
a62a8ef9 | 1437 | fc = kzalloc(sizeof(struct fuse_conn), GFP_KERNEL); |
833c5a42 MS |
1438 | if (!fc) |
1439 | goto out_err; | |
a62a8ef9 | 1440 | |
fcee216b | 1441 | fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL); |
833c5a42 MS |
1442 | if (!fm) |
1443 | goto out_err; | |
fcee216b | 1444 | |
0a7419c6 | 1445 | fuse_conn_init(fc, fm, fsc->user_ns, &virtio_fs_fiq_ops, fs); |
a62a8ef9 SH |
1446 | fc->release = fuse_free_conn; |
1447 | fc->delete_stale = true; | |
bf109c64 | 1448 | fc->auto_submounts = true; |
2d82ab25 | 1449 | fc->sync_fs = true; |
a62a8ef9 | 1450 | |
a7f0d7aa CK |
1451 | /* Tell FUSE to split requests that exceed the virtqueue's size */ |
1452 | fc->max_pages_limit = min_t(unsigned int, fc->max_pages_limit, | |
1453 | virtqueue_size - FUSE_HEADER_OVERHEAD); | |
1454 | ||
fcee216b | 1455 | fsc->s_fs_info = fm; |
b19d3d00 | 1456 | sb = sget_fc(fsc, virtio_fs_test_super, set_anon_super_fc); |
c191cd07 MS |
1457 | if (fsc->s_fs_info) |
1458 | fuse_mount_destroy(fm); | |
a62a8ef9 SH |
1459 | if (IS_ERR(sb)) |
1460 | return PTR_ERR(sb); | |
1461 | ||
1462 | if (!sb->s_root) { | |
1dd53957 | 1463 | err = virtio_fs_fill_super(sb, fsc); |
a62a8ef9 SH |
1464 | if (err) { |
1465 | deactivate_locked_super(sb); | |
1466 | return err; | |
1467 | } | |
1468 | ||
1469 | sb->s_flags |= SB_ACTIVE; | |
1470 | } | |
1471 | ||
1472 | WARN_ON(fsc->root); | |
1473 | fsc->root = dget(sb->s_root); | |
1474 | return 0; | |
833c5a42 MS |
1475 | |
1476 | out_err: | |
1477 | kfree(fc); | |
1478 | mutex_lock(&virtio_fs_mutex); | |
1479 | virtio_fs_put(fs); | |
1480 | mutex_unlock(&virtio_fs_mutex); | |
1481 | return err; | |
a62a8ef9 SH |
1482 | } |
1483 | ||
1484 | static const struct fs_context_operations virtio_fs_context_ops = { | |
84c21507 | 1485 | .free = virtio_fs_free_fsc, |
1dd53957 | 1486 | .parse_param = virtio_fs_parse_param, |
a62a8ef9 SH |
1487 | .get_tree = virtio_fs_get_tree, |
1488 | }; | |
1489 | ||
1490 | static int virtio_fs_init_fs_context(struct fs_context *fsc) | |
1491 | { | |
1dd53957 VG |
1492 | struct fuse_fs_context *ctx; |
1493 | ||
fe0a7bd8 GK |
1494 | if (fsc->purpose == FS_CONTEXT_FOR_SUBMOUNT) |
1495 | return fuse_init_fs_context_submount(fsc); | |
1496 | ||
1dd53957 VG |
1497 | ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); |
1498 | if (!ctx) | |
1499 | return -ENOMEM; | |
1500 | fsc->fs_private = ctx; | |
a62a8ef9 SH |
1501 | fsc->ops = &virtio_fs_context_ops; |
1502 | return 0; | |
1503 | } | |
1504 | ||
1505 | static struct file_system_type virtio_fs_type = { | |
1506 | .owner = THIS_MODULE, | |
1507 | .name = "virtiofs", | |
1508 | .init_fs_context = virtio_fs_init_fs_context, | |
1509 | .kill_sb = virtio_kill_sb, | |
1510 | }; | |
1511 | ||
1512 | static int __init virtio_fs_init(void) | |
1513 | { | |
1514 | int ret; | |
1515 | ||
1516 | ret = register_virtio_driver(&virtio_fs_driver); | |
1517 | if (ret < 0) | |
1518 | return ret; | |
1519 | ||
1520 | ret = register_filesystem(&virtio_fs_type); | |
1521 | if (ret < 0) { | |
1522 | unregister_virtio_driver(&virtio_fs_driver); | |
1523 | return ret; | |
1524 | } | |
1525 | ||
1526 | return 0; | |
1527 | } | |
1528 | module_init(virtio_fs_init); | |
1529 | ||
1530 | static void __exit virtio_fs_exit(void) | |
1531 | { | |
1532 | unregister_filesystem(&virtio_fs_type); | |
1533 | unregister_virtio_driver(&virtio_fs_driver); | |
1534 | } | |
1535 | module_exit(virtio_fs_exit); | |
1536 | ||
1537 | MODULE_AUTHOR("Stefan Hajnoczi <stefanha@redhat.com>"); | |
1538 | MODULE_DESCRIPTION("Virtio Filesystem"); | |
1539 | MODULE_LICENSE("GPL"); | |
1540 | MODULE_ALIAS_FS(KBUILD_MODNAME); | |
1541 | MODULE_DEVICE_TABLE(virtio, id_table); |