Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
274dcf55 MM |
2 | /* |
3 | * (C) 2001 Clemson University and The University of Chicago | |
4 | * | |
5 | * See COPYING in top-level directory. | |
6 | */ | |
7 | #include "protocol.h" | |
575e9461 MM |
8 | #include "orangefs-kernel.h" |
9 | #include "orangefs-bufmap.h" | |
274dcf55 | 10 | |
ea2c9c9f AV |
11 | struct slot_map { |
12 | int c; | |
13 | wait_queue_head_t q; | |
14 | int count; | |
15 | unsigned long *map; | |
16 | }; | |
17 | ||
18 | static struct slot_map rw_map = { | |
19 | .c = -1, | |
20 | .q = __WAIT_QUEUE_HEAD_INITIALIZER(rw_map.q) | |
21 | }; | |
22 | static struct slot_map readdir_map = { | |
23 | .c = -1, | |
24 | .q = __WAIT_QUEUE_HEAD_INITIALIZER(readdir_map.q) | |
25 | }; | |
26 | ||
27 | ||
28 | static void install(struct slot_map *m, int count, unsigned long *map) | |
29 | { | |
30 | spin_lock(&m->q.lock); | |
31 | m->c = m->count = count; | |
32 | m->map = map; | |
33 | wake_up_all_locked(&m->q); | |
34 | spin_unlock(&m->q.lock); | |
35 | } | |
36 | ||
37 | static void mark_killed(struct slot_map *m) | |
38 | { | |
39 | spin_lock(&m->q.lock); | |
40 | m->c -= m->count + 1; | |
41 | spin_unlock(&m->q.lock); | |
42 | } | |
43 | ||
44 | static void run_down(struct slot_map *m) | |
45 | { | |
46 | DEFINE_WAIT(wait); | |
47 | spin_lock(&m->q.lock); | |
48 | if (m->c != -1) { | |
49 | for (;;) { | |
2055da97 | 50 | if (likely(list_empty(&wait.entry))) |
ac6424b9 | 51 | __add_wait_queue_entry_tail(&m->q, &wait); |
ea2c9c9f AV |
52 | set_current_state(TASK_UNINTERRUPTIBLE); |
53 | ||
54 | if (m->c == -1) | |
55 | break; | |
56 | ||
57 | spin_unlock(&m->q.lock); | |
58 | schedule(); | |
59 | spin_lock(&m->q.lock); | |
60 | } | |
61 | __remove_wait_queue(&m->q, &wait); | |
62 | __set_current_state(TASK_RUNNING); | |
63 | } | |
64 | m->map = NULL; | |
65 | spin_unlock(&m->q.lock); | |
66 | } | |
67 | ||
68 | static void put(struct slot_map *m, int slot) | |
69 | { | |
70 | int v; | |
71 | spin_lock(&m->q.lock); | |
72 | __clear_bit(slot, m->map); | |
73 | v = ++m->c; | |
c2676ef8 | 74 | if (v > 0) |
ea2c9c9f | 75 | wake_up_locked(&m->q); |
c2676ef8 | 76 | if (unlikely(v == -1)) /* finished dying */ |
ea2c9c9f AV |
77 | wake_up_all_locked(&m->q); |
78 | spin_unlock(&m->q.lock); | |
79 | } | |
80 | ||
81 | static int wait_for_free(struct slot_map *m) | |
82 | { | |
83 | long left = slot_timeout_secs * HZ; | |
84 | DEFINE_WAIT(wait); | |
85 | ||
86 | do { | |
87 | long n = left, t; | |
2055da97 | 88 | if (likely(list_empty(&wait.entry))) |
ac6424b9 | 89 | __add_wait_queue_entry_tail_exclusive(&m->q, &wait); |
ea2c9c9f AV |
90 | set_current_state(TASK_INTERRUPTIBLE); |
91 | ||
92 | if (m->c > 0) | |
93 | break; | |
94 | ||
95 | if (m->c < 0) { | |
96 | /* we are waiting for map to be installed */ | |
97 | /* it would better be there soon, or we go away */ | |
98 | if (n > ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ) | |
99 | n = ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ; | |
100 | } | |
101 | spin_unlock(&m->q.lock); | |
102 | t = schedule_timeout(n); | |
103 | spin_lock(&m->q.lock); | |
104 | if (unlikely(!t) && n != left && m->c < 0) | |
105 | left = t; | |
106 | else | |
107 | left = t + (left - n); | |
08d405c8 | 108 | if (signal_pending(current)) |
ea2c9c9f AV |
109 | left = -EINTR; |
110 | } while (left > 0); | |
111 | ||
2055da97 IM |
112 | if (!list_empty(&wait.entry)) |
113 | list_del(&wait.entry); | |
ea2c9c9f AV |
114 | else if (left <= 0 && waitqueue_active(&m->q)) |
115 | __wake_up_locked_key(&m->q, TASK_INTERRUPTIBLE, NULL); | |
116 | __set_current_state(TASK_RUNNING); | |
117 | ||
118 | if (likely(left > 0)) | |
119 | return 0; | |
120 | ||
121 | return left < 0 ? -EINTR : -ETIMEDOUT; | |
122 | } | |
123 | ||
124 | static int get(struct slot_map *m) | |
125 | { | |
126 | int res = 0; | |
127 | spin_lock(&m->q.lock); | |
128 | if (unlikely(m->c <= 0)) | |
129 | res = wait_for_free(m); | |
130 | if (likely(!res)) { | |
131 | m->c--; | |
132 | res = find_first_zero_bit(m->map, m->count); | |
133 | __set_bit(res, m->map); | |
134 | } | |
135 | spin_unlock(&m->q.lock); | |
136 | return res; | |
137 | } | |
274dcf55 | 138 | |
bf89f584 MB |
139 | /* used to describe mapped buffers */ |
140 | struct orangefs_bufmap_desc { | |
817e9b4d | 141 | void __user *uaddr; /* user space address pointer */ |
bf89f584 MB |
142 | struct page **page_array; /* array of mapped pages */ |
143 | int array_count; /* size of above arrays */ | |
144 | struct list_head list_link; | |
145 | }; | |
146 | ||
8bb8aefd | 147 | static struct orangefs_bufmap { |
274dcf55 MM |
148 | int desc_size; |
149 | int desc_shift; | |
150 | int desc_count; | |
151 | int total_size; | |
152 | int page_count; | |
153 | ||
154 | struct page **page_array; | |
8bb8aefd | 155 | struct orangefs_bufmap_desc *desc_array; |
274dcf55 MM |
156 | |
157 | /* array to track usage of buffer descriptors */ | |
ea2c9c9f | 158 | unsigned long *buffer_index_array; |
274dcf55 MM |
159 | |
160 | /* array to track usage of buffer descriptors for readdir */ | |
ea2c9c9f AV |
161 | #define N DIV_ROUND_UP(ORANGEFS_READDIR_DEFAULT_DESC_COUNT, BITS_PER_LONG) |
162 | unsigned long readdir_index_array[N]; | |
163 | #undef N | |
8bb8aefd | 164 | } *__orangefs_bufmap; |
274dcf55 | 165 | |
8bb8aefd | 166 | static DEFINE_SPINLOCK(orangefs_bufmap_lock); |
274dcf55 MM |
167 | |
168 | static void | |
8bb8aefd | 169 | orangefs_bufmap_unmap(struct orangefs_bufmap *bufmap) |
274dcf55 MM |
170 | { |
171 | int i; | |
172 | ||
173 | for (i = 0; i < bufmap->page_count; i++) | |
09cbfeaf | 174 | put_page(bufmap->page_array[i]); |
274dcf55 MM |
175 | } |
176 | ||
177 | static void | |
8bb8aefd | 178 | orangefs_bufmap_free(struct orangefs_bufmap *bufmap) |
274dcf55 MM |
179 | { |
180 | kfree(bufmap->page_array); | |
181 | kfree(bufmap->desc_array); | |
182 | kfree(bufmap->buffer_index_array); | |
183 | kfree(bufmap); | |
184 | } | |
185 | ||
b09d10df | 186 | /* |
95f5f88f | 187 | * XXX: Can the size and shift change while the caller gives up the |
b09d10df MB |
188 | * XXX: lock between calling this and doing something useful? |
189 | */ | |
190 | ||
765a75b3 | 191 | int orangefs_bufmap_size_query(void) |
274dcf55 | 192 | { |
b09d10df MB |
193 | struct orangefs_bufmap *bufmap; |
194 | int size = 0; | |
17804184 AV |
195 | spin_lock(&orangefs_bufmap_lock); |
196 | bufmap = __orangefs_bufmap; | |
197 | if (bufmap) | |
b09d10df | 198 | size = bufmap->desc_size; |
17804184 | 199 | spin_unlock(&orangefs_bufmap_lock); |
274dcf55 MM |
200 | return size; |
201 | } | |
202 | ||
765a75b3 | 203 | int orangefs_bufmap_shift_query(void) |
274dcf55 | 204 | { |
b09d10df MB |
205 | struct orangefs_bufmap *bufmap; |
206 | int shift = 0; | |
17804184 AV |
207 | spin_lock(&orangefs_bufmap_lock); |
208 | bufmap = __orangefs_bufmap; | |
209 | if (bufmap) | |
b09d10df | 210 | shift = bufmap->desc_shift; |
17804184 | 211 | spin_unlock(&orangefs_bufmap_lock); |
274dcf55 MM |
212 | return shift; |
213 | } | |
214 | ||
215 | static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq); | |
216 | static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq); | |
217 | ||
8bb8aefd YL |
218 | static struct orangefs_bufmap * |
219 | orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc) | |
274dcf55 | 220 | { |
8bb8aefd | 221 | struct orangefs_bufmap *bufmap; |
274dcf55 MM |
222 | |
223 | bufmap = kzalloc(sizeof(*bufmap), GFP_KERNEL); | |
224 | if (!bufmap) | |
225 | goto out; | |
226 | ||
274dcf55 MM |
227 | bufmap->total_size = user_desc->total_size; |
228 | bufmap->desc_count = user_desc->count; | |
229 | bufmap->desc_size = user_desc->size; | |
230 | bufmap->desc_shift = ilog2(bufmap->desc_size); | |
231 | ||
274dcf55 | 232 | bufmap->buffer_index_array = |
ea2c9c9f | 233 | kzalloc(DIV_ROUND_UP(bufmap->desc_count, BITS_PER_LONG), GFP_KERNEL); |
07a25853 | 234 | if (!bufmap->buffer_index_array) |
274dcf55 | 235 | goto out_free_bufmap; |
274dcf55 MM |
236 | |
237 | bufmap->desc_array = | |
8bb8aefd | 238 | kcalloc(bufmap->desc_count, sizeof(struct orangefs_bufmap_desc), |
274dcf55 | 239 | GFP_KERNEL); |
07a25853 | 240 | if (!bufmap->desc_array) |
274dcf55 | 241 | goto out_free_index_array; |
274dcf55 MM |
242 | |
243 | bufmap->page_count = bufmap->total_size / PAGE_SIZE; | |
244 | ||
245 | /* allocate storage to track our page mappings */ | |
246 | bufmap->page_array = | |
247 | kcalloc(bufmap->page_count, sizeof(struct page *), GFP_KERNEL); | |
248 | if (!bufmap->page_array) | |
249 | goto out_free_desc_array; | |
250 | ||
251 | return bufmap; | |
252 | ||
253 | out_free_desc_array: | |
254 | kfree(bufmap->desc_array); | |
255 | out_free_index_array: | |
256 | kfree(bufmap->buffer_index_array); | |
257 | out_free_bufmap: | |
258 | kfree(bufmap); | |
259 | out: | |
260 | return NULL; | |
261 | } | |
262 | ||
263 | static int | |
8bb8aefd YL |
264 | orangefs_bufmap_map(struct orangefs_bufmap *bufmap, |
265 | struct ORANGEFS_dev_map_desc *user_desc) | |
274dcf55 MM |
266 | { |
267 | int pages_per_desc = bufmap->desc_size / PAGE_SIZE; | |
268 | int offset = 0, ret, i; | |
269 | ||
270 | /* map the pages */ | |
16742f2d AV |
271 | ret = get_user_pages_fast((unsigned long)user_desc->ptr, |
272 | bufmap->page_count, 1, bufmap->page_array); | |
274dcf55 MM |
273 | |
274 | if (ret < 0) | |
275 | return ret; | |
276 | ||
277 | if (ret != bufmap->page_count) { | |
8bb8aefd | 278 | gossip_err("orangefs error: asked for %d pages, only got %d.\n", |
274dcf55 MM |
279 | bufmap->page_count, ret); |
280 | ||
281 | for (i = 0; i < ret; i++) { | |
282 | SetPageError(bufmap->page_array[i]); | |
09cbfeaf | 283 | put_page(bufmap->page_array[i]); |
274dcf55 MM |
284 | } |
285 | return -ENOMEM; | |
286 | } | |
287 | ||
288 | /* | |
289 | * ideally we want to get kernel space pointers for each page, but | |
290 | * we can't kmap that many pages at once if highmem is being used. | |
291 | * so instead, we just kmap/kunmap the page address each time the | |
292 | * kaddr is needed. | |
293 | */ | |
294 | for (i = 0; i < bufmap->page_count; i++) | |
295 | flush_dcache_page(bufmap->page_array[i]); | |
296 | ||
297 | /* build a list of available descriptors */ | |
298 | for (offset = 0, i = 0; i < bufmap->desc_count; i++) { | |
299 | bufmap->desc_array[i].page_array = &bufmap->page_array[offset]; | |
300 | bufmap->desc_array[i].array_count = pages_per_desc; | |
301 | bufmap->desc_array[i].uaddr = | |
302 | (user_desc->ptr + (i * pages_per_desc * PAGE_SIZE)); | |
303 | offset += pages_per_desc; | |
304 | } | |
305 | ||
306 | return 0; | |
307 | } | |
308 | ||
309 | /* | |
8bb8aefd | 310 | * orangefs_bufmap_initialize() |
274dcf55 MM |
311 | * |
312 | * initializes the mapped buffer interface | |
313 | * | |
314 | * returns 0 on success, -errno on failure | |
315 | */ | |
8bb8aefd | 316 | int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc) |
274dcf55 | 317 | { |
8bb8aefd | 318 | struct orangefs_bufmap *bufmap; |
274dcf55 MM |
319 | int ret = -EINVAL; |
320 | ||
321 | gossip_debug(GOSSIP_BUFMAP_DEBUG, | |
8bb8aefd | 322 | "orangefs_bufmap_initialize: called (ptr (" |
274dcf55 MM |
323 | "%p) sz (%d) cnt(%d).\n", |
324 | user_desc->ptr, | |
325 | user_desc->size, | |
326 | user_desc->count); | |
327 | ||
eb82fbcf DC |
328 | if (user_desc->total_size < 0 || |
329 | user_desc->size < 0 || | |
330 | user_desc->count < 0) | |
331 | goto out; | |
332 | ||
274dcf55 MM |
333 | /* |
334 | * sanity check alignment and size of buffer that caller wants to | |
335 | * work with | |
336 | */ | |
337 | if (PAGE_ALIGN((unsigned long)user_desc->ptr) != | |
338 | (unsigned long)user_desc->ptr) { | |
8bb8aefd | 339 | gossip_err("orangefs error: memory alignment (front). %p\n", |
274dcf55 MM |
340 | user_desc->ptr); |
341 | goto out; | |
342 | } | |
343 | ||
344 | if (PAGE_ALIGN(((unsigned long)user_desc->ptr + user_desc->total_size)) | |
345 | != (unsigned long)(user_desc->ptr + user_desc->total_size)) { | |
8bb8aefd | 346 | gossip_err("orangefs error: memory alignment (back).(%p + %d)\n", |
274dcf55 MM |
347 | user_desc->ptr, |
348 | user_desc->total_size); | |
349 | goto out; | |
350 | } | |
351 | ||
352 | if (user_desc->total_size != (user_desc->size * user_desc->count)) { | |
8bb8aefd | 353 | gossip_err("orangefs error: user provided an oddly sized buffer: (%d, %d, %d)\n", |
274dcf55 MM |
354 | user_desc->total_size, |
355 | user_desc->size, | |
356 | user_desc->count); | |
357 | goto out; | |
358 | } | |
359 | ||
360 | if ((user_desc->size % PAGE_SIZE) != 0) { | |
8bb8aefd | 361 | gossip_err("orangefs error: bufmap size not page size divisible (%d).\n", |
274dcf55 MM |
362 | user_desc->size); |
363 | goto out; | |
364 | } | |
365 | ||
366 | ret = -ENOMEM; | |
8bb8aefd | 367 | bufmap = orangefs_bufmap_alloc(user_desc); |
274dcf55 MM |
368 | if (!bufmap) |
369 | goto out; | |
370 | ||
8bb8aefd | 371 | ret = orangefs_bufmap_map(bufmap, user_desc); |
274dcf55 MM |
372 | if (ret) |
373 | goto out_free_bufmap; | |
374 | ||
375 | ||
8bb8aefd YL |
376 | spin_lock(&orangefs_bufmap_lock); |
377 | if (__orangefs_bufmap) { | |
378 | spin_unlock(&orangefs_bufmap_lock); | |
379 | gossip_err("orangefs: error: bufmap already initialized.\n"); | |
ea2c9c9f | 380 | ret = -EINVAL; |
274dcf55 MM |
381 | goto out_unmap_bufmap; |
382 | } | |
8bb8aefd | 383 | __orangefs_bufmap = bufmap; |
ea2c9c9f AV |
384 | install(&rw_map, |
385 | bufmap->desc_count, | |
386 | bufmap->buffer_index_array); | |
387 | install(&readdir_map, | |
388 | ORANGEFS_READDIR_DEFAULT_DESC_COUNT, | |
389 | bufmap->readdir_index_array); | |
8bb8aefd | 390 | spin_unlock(&orangefs_bufmap_lock); |
274dcf55 | 391 | |
274dcf55 | 392 | gossip_debug(GOSSIP_BUFMAP_DEBUG, |
8bb8aefd | 393 | "orangefs_bufmap_initialize: exiting normally\n"); |
274dcf55 MM |
394 | return 0; |
395 | ||
396 | out_unmap_bufmap: | |
8bb8aefd | 397 | orangefs_bufmap_unmap(bufmap); |
274dcf55 | 398 | out_free_bufmap: |
8bb8aefd | 399 | orangefs_bufmap_free(bufmap); |
274dcf55 MM |
400 | out: |
401 | return ret; | |
402 | } | |
403 | ||
404 | /* | |
8bb8aefd | 405 | * orangefs_bufmap_finalize() |
274dcf55 MM |
406 | * |
407 | * shuts down the mapped buffer interface and releases any resources | |
408 | * associated with it | |
409 | * | |
410 | * no return value | |
411 | */ | |
8bb8aefd | 412 | void orangefs_bufmap_finalize(void) |
274dcf55 | 413 | { |
ea2c9c9f AV |
414 | struct orangefs_bufmap *bufmap = __orangefs_bufmap; |
415 | if (!bufmap) | |
416 | return; | |
8bb8aefd | 417 | gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs_bufmap_finalize: called\n"); |
ea2c9c9f AV |
418 | mark_killed(&rw_map); |
419 | mark_killed(&readdir_map); | |
274dcf55 | 420 | gossip_debug(GOSSIP_BUFMAP_DEBUG, |
8bb8aefd | 421 | "orangefs_bufmap_finalize: exiting normally\n"); |
274dcf55 MM |
422 | } |
423 | ||
ea2c9c9f | 424 | void orangefs_bufmap_run_down(void) |
274dcf55 | 425 | { |
ea2c9c9f AV |
426 | struct orangefs_bufmap *bufmap = __orangefs_bufmap; |
427 | if (!bufmap) | |
274dcf55 | 428 | return; |
ea2c9c9f AV |
429 | run_down(&rw_map); |
430 | run_down(&readdir_map); | |
431 | spin_lock(&orangefs_bufmap_lock); | |
432 | __orangefs_bufmap = NULL; | |
433 | spin_unlock(&orangefs_bufmap_lock); | |
434 | orangefs_bufmap_unmap(bufmap); | |
435 | orangefs_bufmap_free(bufmap); | |
274dcf55 MM |
436 | } |
437 | ||
438 | /* | |
8bb8aefd | 439 | * orangefs_bufmap_get() |
274dcf55 MM |
440 | * |
441 | * gets a free mapped buffer descriptor, will sleep until one becomes | |
442 | * available if necessary | |
443 | * | |
b8a99a8f | 444 | * returns slot on success, -errno on failure |
274dcf55 | 445 | */ |
b8a99a8f | 446 | int orangefs_bufmap_get(void) |
274dcf55 | 447 | { |
b8a99a8f | 448 | return get(&rw_map); |
274dcf55 MM |
449 | } |
450 | ||
451 | /* | |
8bb8aefd | 452 | * orangefs_bufmap_put() |
274dcf55 MM |
453 | * |
454 | * returns a mapped buffer descriptor to the collection | |
455 | * | |
456 | * no return value | |
457 | */ | |
1357d06d | 458 | void orangefs_bufmap_put(int buffer_index) |
274dcf55 | 459 | { |
ea2c9c9f | 460 | put(&rw_map, buffer_index); |
274dcf55 MM |
461 | } |
462 | ||
463 | /* | |
7d221485 | 464 | * orangefs_readdir_index_get() |
274dcf55 MM |
465 | * |
466 | * gets a free descriptor, will sleep until one becomes | |
467 | * available if necessary. | |
468 | * Although the readdir buffers are not mapped into kernel space | |
469 | * we could do that at a later point of time. Regardless, these | |
470 | * indices are used by the client-core. | |
471 | * | |
b8a99a8f | 472 | * returns slot on success, -errno on failure |
274dcf55 | 473 | */ |
b8a99a8f | 474 | int orangefs_readdir_index_get(void) |
274dcf55 | 475 | { |
b8a99a8f | 476 | return get(&readdir_map); |
274dcf55 MM |
477 | } |
478 | ||
82d37f19 | 479 | void orangefs_readdir_index_put(int buffer_index) |
274dcf55 | 480 | { |
ea2c9c9f | 481 | put(&readdir_map, buffer_index); |
274dcf55 MM |
482 | } |
483 | ||
b5e376ea | 484 | /* |
95f5f88f | 485 | * we've been handed an iovec, we need to copy it to |
b5e376ea MM |
486 | * the shared memory descriptor at "buffer_index". |
487 | */ | |
bf6bf606 | 488 | int orangefs_bufmap_copy_from_iovec(struct iov_iter *iter, |
54804949 MM |
489 | int buffer_index, |
490 | size_t size) | |
274dcf55 | 491 | { |
bf6bf606 | 492 | struct orangefs_bufmap_desc *to; |
4d1c4404 | 493 | int i; |
274dcf55 MM |
494 | |
495 | gossip_debug(GOSSIP_BUFMAP_DEBUG, | |
34204fde | 496 | "%s: buffer_index:%d: size:%zu:\n", |
4d1c4404 | 497 | __func__, buffer_index, size); |
274dcf55 | 498 | |
bf6bf606 | 499 | to = &__orangefs_bufmap->desc_array[buffer_index]; |
4d1c4404 | 500 | for (i = 0; size; i++) { |
34204fde AV |
501 | struct page *page = to->page_array[i]; |
502 | size_t n = size; | |
503 | if (n > PAGE_SIZE) | |
504 | n = PAGE_SIZE; | |
890559e3 | 505 | if (copy_page_from_iter(page, 0, n, iter) != n) |
34204fde AV |
506 | return -EFAULT; |
507 | size -= n; | |
274dcf55 | 508 | } |
34204fde | 509 | return 0; |
274dcf55 MM |
510 | } |
511 | ||
512 | /* | |
b5e376ea MM |
513 | * we've been handed an iovec, we need to fill it from |
514 | * the shared memory descriptor at "buffer_index". | |
274dcf55 | 515 | */ |
bf6bf606 | 516 | int orangefs_bufmap_copy_to_iovec(struct iov_iter *iter, |
5c278228 AV |
517 | int buffer_index, |
518 | size_t size) | |
274dcf55 | 519 | { |
bf6bf606 | 520 | struct orangefs_bufmap_desc *from; |
4d1c4404 | 521 | int i; |
274dcf55 | 522 | |
bf6bf606 | 523 | from = &__orangefs_bufmap->desc_array[buffer_index]; |
274dcf55 | 524 | gossip_debug(GOSSIP_BUFMAP_DEBUG, |
5c278228 AV |
525 | "%s: buffer_index:%d: size:%zu:\n", |
526 | __func__, buffer_index, size); | |
274dcf55 | 527 | |
274dcf55 | 528 | |
5c278228 AV |
529 | for (i = 0; size; i++) { |
530 | struct page *page = from->page_array[i]; | |
531 | size_t n = size; | |
532 | if (n > PAGE_SIZE) | |
533 | n = PAGE_SIZE; | |
534 | n = copy_page_to_iter(page, 0, n, iter); | |
535 | if (!n) | |
536 | return -EFAULT; | |
537 | size -= n; | |
274dcf55 | 538 | } |
5c278228 | 539 | return 0; |
274dcf55 | 540 | } |