Blame view
kernel/relay.c
29 KB
b86ff981a [PATCH] relay: mi... |
1 2 3 |
/* * Public API and common code for kernel->userspace relay file support. * |
c9b3febc5 Fix a use after f... |
4 |
* See Documentation/filesystems/relay.txt for an overview. |
b86ff981a [PATCH] relay: mi... |
5 6 7 8 9 |
* * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com) * * Moved to kernel/relay.c by Paul Mundt, 2006. |
23c887522 [PATCH] Relay: ad... |
10 11 |
* November 2006 - CPU hotplug support by Mathieu Desnoyers * (mathieu.desnoyers@polymtl.ca) |
b86ff981a [PATCH] relay: mi... |
12 13 14 15 16 17 18 19 20 21 22 |
* * This file is released under the GPL. */ #include <linux/errno.h> #include <linux/stddef.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/string.h> #include <linux/relay.h> #include <linux/vmalloc.h> #include <linux/mm.h> |
23c887522 [PATCH] Relay: ad... |
23 |
#include <linux/cpu.h> |
d6b29d7ce splice: divorce t... |
24 |
#include <linux/splice.h> |
23c887522 [PATCH] Relay: ad... |
25 26 27 28 |
/* list of open channels, for cpu hotplug */ static DEFINE_MUTEX(relay_channels_mutex); static LIST_HEAD(relay_channels); |
b86ff981a [PATCH] relay: mi... |
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 |
/* * close() vm_op implementation for relay file mapping. */ static void relay_file_mmap_close(struct vm_area_struct *vma) { struct rchan_buf *buf = vma->vm_private_data; buf->chan->cb->buf_unmapped(buf, vma->vm_file); } /* * nopage() vm_op implementation for relay file mapping. */ static struct page *relay_buf_nopage(struct vm_area_struct *vma, unsigned long address, int *type) { struct page *page; struct rchan_buf *buf = vma->vm_private_data; unsigned long offset = address - vma->vm_start; if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */ if (!buf) return NOPAGE_OOM; page = vmalloc_to_page(buf->start + offset); if (!page) return NOPAGE_OOM; get_page(page); if (type) *type = VM_FAULT_MINOR; return page; } /* * vm_ops for relay file mappings. */ static struct vm_operations_struct relay_file_mmap_ops = { .nopage = relay_buf_nopage, .close = relay_file_mmap_close, }; /** * relay_mmap_buf: - mmap channel buffer to process address space * @buf: relay channel buffer * @vma: vm_area_struct describing memory to be mapped * * Returns 0 if ok, negative on error * * Caller should already have grabbed mmap_sem. */ |
01c55ed32 kernel/relay.c: m... |
83 |
static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma) |
b86ff981a [PATCH] relay: mi... |
84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 |
{ unsigned long length = vma->vm_end - vma->vm_start; struct file *filp = vma->vm_file; if (!buf) return -EBADF; if (length != (unsigned long)buf->chan->alloc_size) return -EINVAL; vma->vm_ops = &relay_file_mmap_ops; vma->vm_private_data = buf; buf->chan->cb->buf_mapped(buf, filp); return 0; } /** * relay_alloc_buf - allocate a channel buffer * @buf: the buffer struct * @size: total size of the buffer * |
4c78a6639 [PATCH] kernel-do... |
106 |
* Returns a pointer to the resulting buffer, %NULL if unsuccessful. The |
221415d76 [PATCH] relay: ad... |
107 |
* passed in size will get page aligned, if it isn't already. |
b86ff981a [PATCH] relay: mi... |
108 |
*/ |
221415d76 [PATCH] relay: ad... |
109 |
static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size) |
b86ff981a [PATCH] relay: mi... |
110 111 112 |
{ void *mem; unsigned int i, j, n_pages; |
221415d76 [PATCH] relay: ad... |
113 114 |
*size = PAGE_ALIGN(*size); n_pages = *size >> PAGE_SHIFT; |
b86ff981a [PATCH] relay: mi... |
115 116 117 118 119 120 121 122 123 |
buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL); if (!buf->page_array) return NULL; for (i = 0; i < n_pages; i++) { buf->page_array[i] = alloc_page(GFP_KERNEL); if (unlikely(!buf->page_array[i])) goto depopulate; |
ebf990934 splice: relay sup... |
124 |
set_page_private(buf->page_array[i], (unsigned long)buf); |
b86ff981a [PATCH] relay: mi... |
125 126 127 128 |
} mem = vmap(buf->page_array, n_pages, VM_MAP, PAGE_KERNEL); if (!mem) goto depopulate; |
221415d76 [PATCH] relay: ad... |
129 |
memset(mem, 0, *size); |
b86ff981a [PATCH] relay: mi... |
130 131 132 133 134 135 136 137 138 139 140 141 |
buf->page_count = n_pages; return mem; depopulate: for (j = 0; j < i; j++) __free_page(buf->page_array[j]); kfree(buf->page_array); return NULL; } /** * relay_create_buf - allocate and initialize a channel buffer |
4c78a6639 [PATCH] kernel-do... |
142 |
* @chan: the relay channel |
b86ff981a [PATCH] relay: mi... |
143 |
* |
4c78a6639 [PATCH] kernel-do... |
144 |
* Returns channel buffer if successful, %NULL otherwise. |
b86ff981a [PATCH] relay: mi... |
145 |
*/ |
01c55ed32 kernel/relay.c: m... |
146 |
static struct rchan_buf *relay_create_buf(struct rchan *chan) |
b86ff981a [PATCH] relay: mi... |
147 |
{ |
cd8612808 [PATCH] Fix numer... |
148 |
struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL); |
b86ff981a [PATCH] relay: mi... |
149 150 151 152 153 154 |
if (!buf) return NULL; buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL); if (!buf->padding) goto free_buf; |
221415d76 [PATCH] relay: ad... |
155 |
buf->start = relay_alloc_buf(buf, &chan->alloc_size); |
b86ff981a [PATCH] relay: mi... |
156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 |
if (!buf->start) goto free_buf; buf->chan = chan; kref_get(&buf->chan->kref); return buf; free_buf: kfree(buf->padding); kfree(buf); return NULL; } /** * relay_destroy_channel - free the channel struct |
4c78a6639 [PATCH] kernel-do... |
171 |
* @kref: target kernel reference that contains the relay channel |
b86ff981a [PATCH] relay: mi... |
172 173 174 |
* * Should only be called from kref_put(). */ |
01c55ed32 kernel/relay.c: m... |
175 |
static void relay_destroy_channel(struct kref *kref) |
b86ff981a [PATCH] relay: mi... |
176 177 178 179 180 181 182 183 184 |
{ struct rchan *chan = container_of(kref, struct rchan, kref); kfree(chan); } /** * relay_destroy_buf - destroy an rchan_buf struct and associated buffer * @buf: the buffer struct */ |
01c55ed32 kernel/relay.c: m... |
185 |
static void relay_destroy_buf(struct rchan_buf *buf) |
b86ff981a [PATCH] relay: mi... |
186 187 188 189 190 191 192 193 194 195 |
{ struct rchan *chan = buf->chan; unsigned int i; if (likely(buf->start)) { vunmap(buf->start); for (i = 0; i < buf->page_count; i++) __free_page(buf->page_array[i]); kfree(buf->page_array); } |
23c887522 [PATCH] Relay: ad... |
196 |
chan->buf[buf->cpu] = NULL; |
b86ff981a [PATCH] relay: mi... |
197 198 199 200 201 202 203 |
kfree(buf->padding); kfree(buf); kref_put(&chan->kref, relay_destroy_channel); } /** * relay_remove_buf - remove a channel buffer |
4c78a6639 [PATCH] kernel-do... |
204 |
* @kref: target kernel reference that contains the relay buffer |
b86ff981a [PATCH] relay: mi... |
205 206 207 208 209 |
* * Removes the file from the fileystem, which also frees the * rchan_buf_struct and the channel buffer. Should only be called from * kref_put(). */ |
01c55ed32 kernel/relay.c: m... |
210 |
static void relay_remove_buf(struct kref *kref) |
b86ff981a [PATCH] relay: mi... |
211 212 213 214 215 216 217 218 219 220 221 222 |
{ struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref); buf->chan->cb->remove_buf_file(buf->dentry); relay_destroy_buf(buf); } /** * relay_buf_empty - boolean, is the channel buffer empty? * @buf: channel buffer * * Returns 1 if the buffer is empty, 0 otherwise. */ |
01c55ed32 kernel/relay.c: m... |
223 |
static int relay_buf_empty(struct rchan_buf *buf) |
b86ff981a [PATCH] relay: mi... |
224 225 226 |
{ return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1; } |
b86ff981a [PATCH] relay: mi... |
227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 |
/** * relay_buf_full - boolean, is the channel buffer full? * @buf: channel buffer * * Returns 1 if the buffer is full, 0 otherwise. */ int relay_buf_full(struct rchan_buf *buf) { size_t ready = buf->subbufs_produced - buf->subbufs_consumed; return (ready >= buf->chan->n_subbufs) ? 1 : 0; } EXPORT_SYMBOL_GPL(relay_buf_full); /* * High-level relay kernel API and associated functions. */ /* * rchan_callback implementations defining default channel behavior. Used * in place of corresponding NULL values in client callback struct. */ /* * subbuf_start() default callback. Does nothing. */ static int subbuf_start_default_callback (struct rchan_buf *buf, void *subbuf, void *prev_subbuf, size_t prev_padding) { if (relay_buf_full(buf)) return 0; return 1; } /* * buf_mapped() default callback. Does nothing. */ static void buf_mapped_default_callback(struct rchan_buf *buf, struct file *filp) { } /* * buf_unmapped() default callback. Does nothing. */ static void buf_unmapped_default_callback(struct rchan_buf *buf, struct file *filp) { } /* * create_buf_file_create() default callback. Does nothing. */ static struct dentry *create_buf_file_default_callback(const char *filename, struct dentry *parent, int mode, struct rchan_buf *buf, int *is_global) { return NULL; } /* * remove_buf_file() default callback. Does nothing. */ static int remove_buf_file_default_callback(struct dentry *dentry) { return -EINVAL; } /* relay channel default callbacks */ static struct rchan_callbacks default_channel_callbacks = { .subbuf_start = subbuf_start_default_callback, .buf_mapped = buf_mapped_default_callback, .buf_unmapped = buf_unmapped_default_callback, .create_buf_file = create_buf_file_default_callback, .remove_buf_file = remove_buf_file_default_callback, }; /** * wakeup_readers - wake up readers waiting on a channel |
9a9136e27 Merge git://git.k... |
311 |
* @data: contains the channel buffer |
b86ff981a [PATCH] relay: mi... |
312 |
* |
7c9cb3830 relay: use plain ... |
313 |
* This is the timer function used to defer reader waking. |
b86ff981a [PATCH] relay: mi... |
314 |
*/ |
7c9cb3830 relay: use plain ... |
315 |
static void wakeup_readers(unsigned long data) |
b86ff981a [PATCH] relay: mi... |
316 |
{ |
7c9cb3830 relay: use plain ... |
317 |
struct rchan_buf *buf = (struct rchan_buf *)data; |
b86ff981a [PATCH] relay: mi... |
318 319 320 321 322 323 324 325 |
wake_up_interruptible(&buf->read_wait); } /** * __relay_reset - reset a channel buffer * @buf: the channel buffer * @init: 1 if this is a first-time initialization * |
72fd4a35a [PATCH] Numerous ... |
326 |
* See relay_reset() for description of effect. |
b86ff981a [PATCH] relay: mi... |
327 |
*/ |
192636ad9 [PATCH] relay: re... |
328 |
static void __relay_reset(struct rchan_buf *buf, unsigned int init) |
b86ff981a [PATCH] relay: mi... |
329 330 331 332 333 334 |
{ size_t i; if (init) { init_waitqueue_head(&buf->read_wait); kref_init(&buf->kref); |
7c9cb3830 relay: use plain ... |
335 336 337 |
setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf); } else del_timer_sync(&buf->timer); |
b86ff981a [PATCH] relay: mi... |
338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 |
buf->subbufs_produced = 0; buf->subbufs_consumed = 0; buf->bytes_consumed = 0; buf->finalized = 0; buf->data = buf->start; buf->offset = 0; for (i = 0; i < buf->chan->n_subbufs; i++) buf->padding[i] = 0; buf->chan->cb->subbuf_start(buf, buf->data, NULL, 0); } /** * relay_reset - reset the channel * @chan: the channel * * This has the effect of erasing all data from all channel buffers * and restarting the channel in its initial state. The buffers * are not freed, so any mappings are still in effect. * |
72fd4a35a [PATCH] Numerous ... |
360 |
* NOTE. Care should be taken that the channel isn't actually |
b86ff981a [PATCH] relay: mi... |
361 362 363 364 365 |
* being used by anything when this call is made. */ void relay_reset(struct rchan *chan) { unsigned int i; |
b86ff981a [PATCH] relay: mi... |
366 367 368 |
if (!chan) return; |
1bfbc608b whitespace fixes:... |
369 |
if (chan->is_global && chan->buf[0]) { |
23c887522 [PATCH] Relay: ad... |
370 371 |
__relay_reset(chan->buf[0], 0); return; |
b86ff981a [PATCH] relay: mi... |
372 |
} |
23c887522 [PATCH] Relay: ad... |
373 374 375 376 377 378 |
mutex_lock(&relay_channels_mutex); for_each_online_cpu(i) if (chan->buf[i]) __relay_reset(chan->buf[i], 0); mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
379 380 |
} EXPORT_SYMBOL_GPL(relay_reset); |
4c78a6639 [PATCH] kernel-do... |
381 |
/* |
b86ff981a [PATCH] relay: mi... |
382 383 |
* relay_open_buf - create a new relay channel buffer * |
23c887522 [PATCH] Relay: ad... |
384 |
* used by relay_open() and CPU hotplug. |
b86ff981a [PATCH] relay: mi... |
385 |
*/ |
23c887522 [PATCH] Relay: ad... |
386 |
static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu) |
b86ff981a [PATCH] relay: mi... |
387 |
{ |
23c887522 [PATCH] Relay: ad... |
388 |
struct rchan_buf *buf = NULL; |
b86ff981a [PATCH] relay: mi... |
389 |
struct dentry *dentry; |
23c887522 [PATCH] Relay: ad... |
390 |
char *tmpname; |
b86ff981a [PATCH] relay: mi... |
391 |
|
23c887522 [PATCH] Relay: ad... |
392 |
if (chan->is_global) |
b86ff981a [PATCH] relay: mi... |
393 |
return chan->buf[0]; |
23c887522 [PATCH] Relay: ad... |
394 395 396 397 |
tmpname = kzalloc(NAME_MAX + 1, GFP_KERNEL); if (!tmpname) goto end; snprintf(tmpname, NAME_MAX, "%s%d", chan->base_filename, cpu); |
b86ff981a [PATCH] relay: mi... |
398 399 |
buf = relay_create_buf(chan); if (!buf) |
23c887522 [PATCH] Relay: ad... |
400 401 402 403 |
goto free_name; buf->cpu = cpu; __relay_reset(buf, 1); |
b86ff981a [PATCH] relay: mi... |
404 405 |
/* Create file in fs */ |
23c887522 [PATCH] Relay: ad... |
406 407 408 409 |
dentry = chan->cb->create_buf_file(tmpname, chan->parent, S_IRUSR, buf, &chan->is_global); if (!dentry) goto free_buf; |
b86ff981a [PATCH] relay: mi... |
410 411 |
buf->dentry = dentry; |
b86ff981a [PATCH] relay: mi... |
412 |
|
23c887522 [PATCH] Relay: ad... |
413 414 415 416 417 418 419 420 421 |
if(chan->is_global) { chan->buf[0] = buf; buf->cpu = 0; } goto free_name; free_buf: relay_destroy_buf(buf); |
c9b3febc5 Fix a use after f... |
422 |
buf = NULL; |
23c887522 [PATCH] Relay: ad... |
423 424 425 |
free_name: kfree(tmpname); end: |
b86ff981a [PATCH] relay: mi... |
426 427 428 429 430 431 432 433 434 435 436 |
return buf; } /** * relay_close_buf - close a channel buffer * @buf: channel buffer * * Marks the buffer finalized and restores the default callbacks. * The channel buffer and channel buffer data structure are then freed * automatically when the last reference is given up. */ |
192636ad9 [PATCH] relay: re... |
437 |
static void relay_close_buf(struct rchan_buf *buf) |
b86ff981a [PATCH] relay: mi... |
438 439 |
{ buf->finalized = 1; |
7c9cb3830 relay: use plain ... |
440 |
del_timer_sync(&buf->timer); |
b86ff981a [PATCH] relay: mi... |
441 442 |
kref_put(&buf->kref, relay_remove_buf); } |
192636ad9 [PATCH] relay: re... |
443 |
static void setup_callbacks(struct rchan *chan, |
b86ff981a [PATCH] relay: mi... |
444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 |
struct rchan_callbacks *cb) { if (!cb) { chan->cb = &default_channel_callbacks; return; } if (!cb->subbuf_start) cb->subbuf_start = subbuf_start_default_callback; if (!cb->buf_mapped) cb->buf_mapped = buf_mapped_default_callback; if (!cb->buf_unmapped) cb->buf_unmapped = buf_unmapped_default_callback; if (!cb->create_buf_file) cb->create_buf_file = create_buf_file_default_callback; if (!cb->remove_buf_file) cb->remove_buf_file = remove_buf_file_default_callback; chan->cb = cb; } /** |
23c887522 [PATCH] Relay: ad... |
465 466 467 468 469 |
* relay_hotcpu_callback - CPU hotplug callback * @nb: notifier block * @action: hotplug action to take * @hcpu: CPU number * |
05fb6bf0b [PATCH] kernel-do... |
470 |
* Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD) |
23c887522 [PATCH] Relay: ad... |
471 472 473 474 475 476 477 478 479 480 |
*/ static int __cpuinit relay_hotcpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu) { unsigned int hotcpu = (unsigned long)hcpu; struct rchan *chan; switch(action) { case CPU_UP_PREPARE: |
8bb784428 Add suspend-relat... |
481 |
case CPU_UP_PREPARE_FROZEN: |
23c887522 [PATCH] Relay: ad... |
482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 |
mutex_lock(&relay_channels_mutex); list_for_each_entry(chan, &relay_channels, list) { if (chan->buf[hotcpu]) continue; chan->buf[hotcpu] = relay_open_buf(chan, hotcpu); if(!chan->buf[hotcpu]) { printk(KERN_ERR "relay_hotcpu_callback: cpu %d buffer " "creation failed ", hotcpu); mutex_unlock(&relay_channels_mutex); return NOTIFY_BAD; } } mutex_unlock(&relay_channels_mutex); break; case CPU_DEAD: |
8bb784428 Add suspend-relat... |
499 |
case CPU_DEAD_FROZEN: |
23c887522 [PATCH] Relay: ad... |
500 501 502 503 504 505 506 507 |
/* No need to flush the cpu : will be flushed upon * final relay_flush() call. */ break; } return NOTIFY_OK; } /** |
b86ff981a [PATCH] relay: mi... |
508 509 |
* relay_open - create a new relay channel * @base_filename: base name of files to create |
4c78a6639 [PATCH] kernel-do... |
510 |
* @parent: dentry of parent directory, %NULL for root directory |
b86ff981a [PATCH] relay: mi... |
511 512 513 |
* @subbuf_size: size of sub-buffers * @n_subbufs: number of sub-buffers * @cb: client callback functions |
23c887522 [PATCH] Relay: ad... |
514 |
* @private_data: user-defined data |
b86ff981a [PATCH] relay: mi... |
515 |
* |
4c78a6639 [PATCH] kernel-do... |
516 |
* Returns channel pointer if successful, %NULL otherwise. |
b86ff981a [PATCH] relay: mi... |
517 518 519 520 |
* * Creates a channel buffer for each cpu using the sizes and * attributes specified. The created channel buffer files * will be named base_filename0...base_filenameN-1. File |
72fd4a35a [PATCH] Numerous ... |
521 |
* permissions will be %S_IRUSR. |
b86ff981a [PATCH] relay: mi... |
522 523 524 525 526 |
*/ struct rchan *relay_open(const char *base_filename, struct dentry *parent, size_t subbuf_size, size_t n_subbufs, |
23c887522 [PATCH] Relay: ad... |
527 528 |
struct rchan_callbacks *cb, void *private_data) |
b86ff981a [PATCH] relay: mi... |
529 530 531 |
{ unsigned int i; struct rchan *chan; |
b86ff981a [PATCH] relay: mi... |
532 533 534 535 536 |
if (!base_filename) return NULL; if (!(subbuf_size && n_subbufs)) return NULL; |
cd8612808 [PATCH] Fix numer... |
537 |
chan = kzalloc(sizeof(struct rchan), GFP_KERNEL); |
b86ff981a [PATCH] relay: mi... |
538 539 540 541 542 543 544 |
if (!chan) return NULL; chan->version = RELAYFS_CHANNEL_VERSION; chan->n_subbufs = n_subbufs; chan->subbuf_size = subbuf_size; chan->alloc_size = FIX_SIZE(subbuf_size * n_subbufs); |
23c887522 [PATCH] Relay: ad... |
545 546 547 |
chan->parent = parent; chan->private_data = private_data; strlcpy(chan->base_filename, base_filename, NAME_MAX); |
b86ff981a [PATCH] relay: mi... |
548 549 |
setup_callbacks(chan, cb); kref_init(&chan->kref); |
23c887522 [PATCH] Relay: ad... |
550 |
mutex_lock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
551 |
for_each_online_cpu(i) { |
23c887522 [PATCH] Relay: ad... |
552 |
chan->buf[i] = relay_open_buf(chan, i); |
b86ff981a [PATCH] relay: mi... |
553 554 |
if (!chan->buf[i]) goto free_bufs; |
b86ff981a [PATCH] relay: mi... |
555 |
} |
23c887522 [PATCH] Relay: ad... |
556 557 |
list_add(&chan->list, &relay_channels); mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
558 |
|
b86ff981a [PATCH] relay: mi... |
559 560 561 |
return chan; free_bufs: |
23c887522 [PATCH] Relay: ad... |
562 |
for_each_online_cpu(i) { |
b86ff981a [PATCH] relay: mi... |
563 564 565 |
if (!chan->buf[i]) break; relay_close_buf(chan->buf[i]); |
b86ff981a [PATCH] relay: mi... |
566 |
} |
b86ff981a [PATCH] relay: mi... |
567 |
|
b86ff981a [PATCH] relay: mi... |
568 |
kref_put(&chan->kref, relay_destroy_channel); |
23c887522 [PATCH] Relay: ad... |
569 |
mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 |
return NULL; } EXPORT_SYMBOL_GPL(relay_open); /** * relay_switch_subbuf - switch to a new sub-buffer * @buf: channel buffer * @length: size of current event * * Returns either the length passed in or 0 if full. * * Performs sub-buffer-switch tasks such as invoking callbacks, * updating padding counts, waking up readers, etc. */ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length) { void *old, *new; size_t old_subbuf, new_subbuf; if (unlikely(length > buf->chan->subbuf_size)) goto toobig; if (buf->offset != buf->chan->subbuf_size + 1) { buf->prev_padding = buf->chan->subbuf_size - buf->offset; old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs; buf->padding[old_subbuf] = buf->prev_padding; buf->subbufs_produced++; |
221415d76 [PATCH] relay: ad... |
597 598 599 |
buf->dentry->d_inode->i_size += buf->chan->subbuf_size - buf->padding[old_subbuf]; smp_mb(); |
7c9cb3830 relay: use plain ... |
600 601 602 603 604 605 606 607 |
if (waitqueue_active(&buf->read_wait)) /* * Calling wake_up_interruptible() from here * will deadlock if we happen to be logging * from the scheduler (trying to re-grab * rq->lock), so defer it. */ __mod_timer(&buf->timer, jiffies + 1); |
b86ff981a [PATCH] relay: mi... |
608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 |
} old = buf->data; new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs; new = buf->start + new_subbuf * buf->chan->subbuf_size; buf->offset = 0; if (!buf->chan->cb->subbuf_start(buf, new, old, buf->prev_padding)) { buf->offset = buf->chan->subbuf_size + 1; return 0; } buf->data = new; buf->padding[new_subbuf] = 0; if (unlikely(length + buf->offset > buf->chan->subbuf_size)) goto toobig; return length; toobig: buf->chan->last_toobig = length; return 0; } EXPORT_SYMBOL_GPL(relay_switch_subbuf); /** * relay_subbufs_consumed - update the buffer's sub-buffers-consumed count * @chan: the channel * @cpu: the cpu associated with the channel buffer to update * @subbufs_consumed: number of sub-buffers to add to current buf's count * * Adds to the channel buffer's consumed sub-buffer count. * subbufs_consumed should be the number of sub-buffers newly consumed, * not the total consumed. * |
72fd4a35a [PATCH] Numerous ... |
642 |
* NOTE. Kernel clients don't need to call this function if the channel |
b86ff981a [PATCH] relay: mi... |
643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 |
* mode is 'overwrite'. */ void relay_subbufs_consumed(struct rchan *chan, unsigned int cpu, size_t subbufs_consumed) { struct rchan_buf *buf; if (!chan) return; if (cpu >= NR_CPUS || !chan->buf[cpu]) return; buf = chan->buf[cpu]; buf->subbufs_consumed += subbufs_consumed; if (buf->subbufs_consumed > buf->subbufs_produced) buf->subbufs_consumed = buf->subbufs_produced; } EXPORT_SYMBOL_GPL(relay_subbufs_consumed); /** * relay_close - close the channel * @chan: the channel * * Closes all channel buffers and frees the channel. */ void relay_close(struct rchan *chan) { unsigned int i; |
b86ff981a [PATCH] relay: mi... |
673 674 675 |
if (!chan) return; |
23c887522 [PATCH] Relay: ad... |
676 677 678 679 680 681 682 |
mutex_lock(&relay_channels_mutex); if (chan->is_global && chan->buf[0]) relay_close_buf(chan->buf[0]); else for_each_possible_cpu(i) if (chan->buf[i]) relay_close_buf(chan->buf[i]); |
b86ff981a [PATCH] relay: mi... |
683 684 685 686 687 688 |
if (chan->last_toobig) printk(KERN_WARNING "relay: one or more items not logged " "[item size (%Zd) > sub-buffer size (%Zd)] ", chan->last_toobig, chan->subbuf_size); |
23c887522 [PATCH] Relay: ad... |
689 |
list_del(&chan->list); |
b86ff981a [PATCH] relay: mi... |
690 |
kref_put(&chan->kref, relay_destroy_channel); |
23c887522 [PATCH] Relay: ad... |
691 |
mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
692 693 694 695 696 697 698 |
} EXPORT_SYMBOL_GPL(relay_close); /** * relay_flush - close the channel * @chan: the channel * |
4c78a6639 [PATCH] kernel-do... |
699 |
* Flushes all channel buffers, i.e. forces buffer switch. |
b86ff981a [PATCH] relay: mi... |
700 701 702 703 |
*/ void relay_flush(struct rchan *chan) { unsigned int i; |
b86ff981a [PATCH] relay: mi... |
704 705 706 |
if (!chan) return; |
23c887522 [PATCH] Relay: ad... |
707 708 709 |
if (chan->is_global && chan->buf[0]) { relay_switch_subbuf(chan->buf[0], 0); return; |
b86ff981a [PATCH] relay: mi... |
710 |
} |
23c887522 [PATCH] Relay: ad... |
711 712 713 714 715 716 |
mutex_lock(&relay_channels_mutex); for_each_possible_cpu(i) if (chan->buf[i]) relay_switch_subbuf(chan->buf[i], 0); mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
717 718 719 720 721 722 723 724 725 726 727 728 |
} EXPORT_SYMBOL_GPL(relay_flush); /** * relay_file_open - open file op for relay files * @inode: the inode * @filp: the file * * Increments the channel buffer refcount. */ static int relay_file_open(struct inode *inode, struct file *filp) { |
8e18e2941 [PATCH] inode_die... |
729 |
struct rchan_buf *buf = inode->i_private; |
b86ff981a [PATCH] relay: mi... |
730 731 732 733 734 735 736 737 738 739 740 |
kref_get(&buf->kref); filp->private_data = buf; return 0; } /** * relay_file_mmap - mmap file op for relay files * @filp: the file * @vma: the vma describing what to map * |
72fd4a35a [PATCH] Numerous ... |
741 |
* Calls upon relay_mmap_buf() to map the file into user space. |
b86ff981a [PATCH] relay: mi... |
742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 |
*/ static int relay_file_mmap(struct file *filp, struct vm_area_struct *vma) { struct rchan_buf *buf = filp->private_data; return relay_mmap_buf(buf, vma); } /** * relay_file_poll - poll file op for relay files * @filp: the file * @wait: poll table * * Poll implemention. */ static unsigned int relay_file_poll(struct file *filp, poll_table *wait) { unsigned int mask = 0; struct rchan_buf *buf = filp->private_data; if (buf->finalized) return POLLERR; if (filp->f_mode & FMODE_READ) { poll_wait(filp, &buf->read_wait, wait); if (!relay_buf_empty(buf)) mask |= POLLIN | POLLRDNORM; } return mask; } /** * relay_file_release - release file op for relay files * @inode: the inode * @filp: the file * * Decrements the channel refcount, as the filesystem is * no longer using it. */ static int relay_file_release(struct inode *inode, struct file *filp) { struct rchan_buf *buf = filp->private_data; kref_put(&buf->kref, relay_remove_buf); return 0; } |
4c78a6639 [PATCH] kernel-do... |
788 |
/* |
b86ff981a [PATCH] relay: mi... |
789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 |
* relay_file_read_consume - update the consumed count for the buffer */ static void relay_file_read_consume(struct rchan_buf *buf, size_t read_pos, size_t bytes_consumed) { size_t subbuf_size = buf->chan->subbuf_size; size_t n_subbufs = buf->chan->n_subbufs; size_t read_subbuf; if (buf->bytes_consumed + bytes_consumed > subbuf_size) { relay_subbufs_consumed(buf->chan, buf->cpu, 1); buf->bytes_consumed = 0; } buf->bytes_consumed += bytes_consumed; |
a66e356c0 relayfs: fix over... |
805 806 807 808 |
if (!read_pos) read_subbuf = buf->subbufs_consumed % n_subbufs; else read_subbuf = read_pos / buf->chan->subbuf_size; |
b86ff981a [PATCH] relay: mi... |
809 810 811 812 813 814 815 816 |
if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) { if ((read_subbuf == buf->subbufs_produced % n_subbufs) && (buf->offset == subbuf_size)) return; relay_subbufs_consumed(buf->chan, buf->cpu, 1); buf->bytes_consumed = 0; } } |
4c78a6639 [PATCH] kernel-do... |
817 |
/* |
b86ff981a [PATCH] relay: mi... |
818 819 820 821 |
* relay_file_read_avail - boolean, are there unconsumed bytes available? */ static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos) { |
b86ff981a [PATCH] relay: mi... |
822 823 |
size_t subbuf_size = buf->chan->subbuf_size; size_t n_subbufs = buf->chan->n_subbufs; |
221415d76 [PATCH] relay: ad... |
824 825 |
size_t produced = buf->subbufs_produced; size_t consumed = buf->subbufs_consumed; |
b86ff981a [PATCH] relay: mi... |
826 |
|
221415d76 [PATCH] relay: ad... |
827 |
relay_file_read_consume(buf, read_pos, 0); |
b86ff981a [PATCH] relay: mi... |
828 |
|
221415d76 [PATCH] relay: ad... |
829 830 831 832 |
if (unlikely(buf->offset > subbuf_size)) { if (produced == consumed) return 0; return 1; |
b86ff981a [PATCH] relay: mi... |
833 |
} |
221415d76 [PATCH] relay: ad... |
834 |
if (unlikely(produced - consumed >= n_subbufs)) { |
a66e356c0 relayfs: fix over... |
835 |
consumed = produced - n_subbufs + 1; |
221415d76 [PATCH] relay: ad... |
836 |
buf->subbufs_consumed = consumed; |
a66e356c0 relayfs: fix over... |
837 |
buf->bytes_consumed = 0; |
221415d76 [PATCH] relay: ad... |
838 |
} |
1bfbc608b whitespace fixes:... |
839 |
|
221415d76 [PATCH] relay: ad... |
840 841 842 843 844 |
produced = (produced % n_subbufs) * subbuf_size + buf->offset; consumed = (consumed % n_subbufs) * subbuf_size + buf->bytes_consumed; if (consumed > produced) produced += n_subbufs * subbuf_size; |
1bfbc608b whitespace fixes:... |
845 |
|
221415d76 [PATCH] relay: ad... |
846 |
if (consumed == produced) |
b86ff981a [PATCH] relay: mi... |
847 |
return 0; |
b86ff981a [PATCH] relay: mi... |
848 849 850 851 852 |
return 1; } /** * relay_file_read_subbuf_avail - return bytes available in sub-buffer |
4c78a6639 [PATCH] kernel-do... |
853 854 |
* @read_pos: file read position * @buf: relay channel buffer |
b86ff981a [PATCH] relay: mi... |
855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 |
*/ static size_t relay_file_read_subbuf_avail(size_t read_pos, struct rchan_buf *buf) { size_t padding, avail = 0; size_t read_subbuf, read_offset, write_subbuf, write_offset; size_t subbuf_size = buf->chan->subbuf_size; write_subbuf = (buf->data - buf->start) / subbuf_size; write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset; read_subbuf = read_pos / subbuf_size; read_offset = read_pos % subbuf_size; padding = buf->padding[read_subbuf]; if (read_subbuf == write_subbuf) { if (read_offset + padding < write_offset) avail = write_offset - (read_offset + padding); } else avail = (subbuf_size - padding) - read_offset; return avail; } /** * relay_file_read_start_pos - find the first available byte to read |
4c78a6639 [PATCH] kernel-do... |
880 881 |
* @read_pos: file read position * @buf: relay channel buffer |
b86ff981a [PATCH] relay: mi... |
882 |
* |
72fd4a35a [PATCH] Numerous ... |
883 |
* If the @read_pos is in the middle of padding, return the |
b86ff981a [PATCH] relay: mi... |
884 885 886 887 888 889 890 891 892 |
* position of the first actually available byte, otherwise * return the original value. */ static size_t relay_file_read_start_pos(size_t read_pos, struct rchan_buf *buf) { size_t read_subbuf, padding, padding_start, padding_end; size_t subbuf_size = buf->chan->subbuf_size; size_t n_subbufs = buf->chan->n_subbufs; |
8d62fdebd relay file read: ... |
893 |
size_t consumed = buf->subbufs_consumed % n_subbufs; |
b86ff981a [PATCH] relay: mi... |
894 |
|
8d62fdebd relay file read: ... |
895 896 |
if (!read_pos) read_pos = consumed * subbuf_size + buf->bytes_consumed; |
b86ff981a [PATCH] relay: mi... |
897 898 899 900 901 902 903 904 905 906 907 908 909 910 |
read_subbuf = read_pos / subbuf_size; padding = buf->padding[read_subbuf]; padding_start = (read_subbuf + 1) * subbuf_size - padding; padding_end = (read_subbuf + 1) * subbuf_size; if (read_pos >= padding_start && read_pos < padding_end) { read_subbuf = (read_subbuf + 1) % n_subbufs; read_pos = read_subbuf * subbuf_size; } return read_pos; } /** * relay_file_read_end_pos - return the new read position |
4c78a6639 [PATCH] kernel-do... |
911 912 913 |
* @read_pos: file read position * @buf: relay channel buffer * @count: number of bytes to be read |
b86ff981a [PATCH] relay: mi... |
914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 |
*/ static size_t relay_file_read_end_pos(struct rchan_buf *buf, size_t read_pos, size_t count) { size_t read_subbuf, padding, end_pos; size_t subbuf_size = buf->chan->subbuf_size; size_t n_subbufs = buf->chan->n_subbufs; read_subbuf = read_pos / subbuf_size; padding = buf->padding[read_subbuf]; if (read_pos % subbuf_size + count + padding == subbuf_size) end_pos = (read_subbuf + 1) * subbuf_size; else end_pos = read_pos + count; if (end_pos >= subbuf_size * n_subbufs) end_pos = 0; return end_pos; } |
4c78a6639 [PATCH] kernel-do... |
934 |
/* |
6dac40a7c [PATCH] relay: co... |
935 |
* subbuf_read_actor - read up to one subbuf's worth of data |
b86ff981a [PATCH] relay: mi... |
936 |
*/ |
6dac40a7c [PATCH] relay: co... |
937 938 939 940 941 |
static int subbuf_read_actor(size_t read_start, struct rchan_buf *buf, size_t avail, read_descriptor_t *desc, read_actor_t actor) |
b86ff981a [PATCH] relay: mi... |
942 |
{ |
b86ff981a [PATCH] relay: mi... |
943 |
void *from; |
6dac40a7c [PATCH] relay: co... |
944 |
int ret = 0; |
b86ff981a [PATCH] relay: mi... |
945 946 |
from = buf->start + read_start; |
6dac40a7c [PATCH] relay: co... |
947 |
ret = avail; |
ba2397efe [PATCH] make kern... |
948 |
if (copy_to_user(desc->arg.buf, from, avail)) { |
6dac40a7c [PATCH] relay: co... |
949 950 |
desc->error = -EFAULT; ret = 0; |
b86ff981a [PATCH] relay: mi... |
951 |
} |
6dac40a7c [PATCH] relay: co... |
952 953 954 |
desc->arg.data += ret; desc->written += ret; desc->count -= ret; |
b86ff981a [PATCH] relay: mi... |
955 956 |
return ret; } |
6dac40a7c [PATCH] relay: co... |
957 958 959 960 961 |
typedef int (*subbuf_actor_t) (size_t read_start, struct rchan_buf *buf, size_t avail, read_descriptor_t *desc, read_actor_t actor); |
4c78a6639 [PATCH] kernel-do... |
962 |
/* |
6dac40a7c [PATCH] relay: co... |
963 964 |
* relay_file_read_subbufs - read count bytes, bridging subbuf boundaries */ |
192636ad9 [PATCH] relay: re... |
965 966 967 968 |
static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos, subbuf_actor_t subbuf_actor, read_actor_t actor, read_descriptor_t *desc) |
221415d76 [PATCH] relay: ad... |
969 |
{ |
6dac40a7c [PATCH] relay: co... |
970 971 |
struct rchan_buf *buf = filp->private_data; size_t read_start, avail; |
6dac40a7c [PATCH] relay: co... |
972 |
int ret; |
221415d76 [PATCH] relay: ad... |
973 |
|
ba2397efe [PATCH] make kern... |
974 |
if (!desc->count) |
221415d76 [PATCH] relay: ad... |
975 |
return 0; |
f3a43f3f6 [PATCH] kernel: c... |
976 |
mutex_lock(&filp->f_path.dentry->d_inode->i_mutex); |
221415d76 [PATCH] relay: ad... |
977 |
do { |
6dac40a7c [PATCH] relay: co... |
978 979 980 981 982 983 |
if (!relay_file_read_avail(buf, *ppos)) break; read_start = relay_file_read_start_pos(*ppos, buf); avail = relay_file_read_subbuf_avail(read_start, buf); if (!avail) |
221415d76 [PATCH] relay: ad... |
984 |
break; |
221415d76 [PATCH] relay: ad... |
985 |
|
ba2397efe [PATCH] make kern... |
986 987 988 |
avail = min(desc->count, avail); ret = subbuf_actor(read_start, buf, avail, desc, actor); if (desc->error < 0) |
6dac40a7c [PATCH] relay: co... |
989 990 991 992 993 994 |
break; if (ret) { relay_file_read_consume(buf, read_start, ret); *ppos = relay_file_read_end_pos(buf, read_start, ret); } |
ba2397efe [PATCH] make kern... |
995 |
} while (desc->count && ret); |
f3a43f3f6 [PATCH] kernel: c... |
996 |
mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex); |
6dac40a7c [PATCH] relay: co... |
997 |
|
ba2397efe [PATCH] make kern... |
998 |
return desc->written; |
6dac40a7c [PATCH] relay: co... |
999 1000 1001 1002 1003 1004 1005 |
} static ssize_t relay_file_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { |
ba2397efe [PATCH] make kern... |
1006 1007 1008 1009 1010 1011 1012 |
read_descriptor_t desc; desc.written = 0; desc.count = count; desc.arg.buf = buffer; desc.error = 0; return relay_file_read_subbufs(filp, ppos, subbuf_read_actor, NULL, &desc); |
6dac40a7c [PATCH] relay: co... |
1013 |
} |
1db60cf20 relay: use splice... |
1014 1015 1016 1017 1018 1019 1020 1021 1022 |
static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed) { rbuf->bytes_consumed += bytes_consumed; if (rbuf->bytes_consumed >= rbuf->chan->subbuf_size) { relay_subbufs_consumed(rbuf->chan, rbuf->cpu, 1); rbuf->bytes_consumed %= rbuf->chan->subbuf_size; } } |
ebf990934 splice: relay sup... |
1023 1024 |
static void relay_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buffer *buf) |
6dac40a7c [PATCH] relay: co... |
1025 |
{ |
ebf990934 splice: relay sup... |
1026 1027 1028 |
struct rchan_buf *rbuf; rbuf = (struct rchan_buf *)page_private(buf->page); |
1db60cf20 relay: use splice... |
1029 |
relay_consume_bytes(rbuf, buf->private); |
ebf990934 splice: relay sup... |
1030 1031 1032 1033 1034 1035 |
} static struct pipe_buf_operations relay_pipe_buf_ops = { .can_merge = 0, .map = generic_pipe_buf_map, .unmap = generic_pipe_buf_unmap, |
cac36bb06 pipe: change the ... |
1036 |
.confirm = generic_pipe_buf_confirm, |
ebf990934 splice: relay sup... |
1037 1038 1039 1040 |
.release = relay_pipe_buf_release, .steal = generic_pipe_buf_steal, .get = generic_pipe_buf_get, }; |
d3f35d98b relay: fixup kern... |
1041 |
/* |
ebf990934 splice: relay sup... |
1042 1043 1044 1045 1046 1047 1048 1049 1050 |
* subbuf_splice_actor - splice up to one subbuf's worth of data */ static int subbuf_splice_actor(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags, int *nonpad_ret) { |
1db60cf20 relay: use splice... |
1051 |
unsigned int pidx, poff, total_len, subbuf_pages, ret; |
ebf990934 splice: relay sup... |
1052 1053 |
struct rchan_buf *rbuf = in->private_data; unsigned int subbuf_size = rbuf->chan->subbuf_size; |
24da24de2 relay: fix bogus ... |
1054 1055 1056 |
uint64_t pos = (uint64_t) *ppos; uint32_t alloc_size = (uint32_t) rbuf->chan->alloc_size; size_t read_start = (size_t) do_div(pos, alloc_size); |
ebf990934 splice: relay sup... |
1057 1058 1059 |
size_t read_subbuf = read_start / subbuf_size; size_t padding = rbuf->padding[read_subbuf]; size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding; |
1db60cf20 relay: use splice... |
1060 1061 1062 1063 1064 1065 1066 1067 1068 |
struct page *pages[PIPE_BUFFERS]; struct partial_page partial[PIPE_BUFFERS]; struct splice_pipe_desc spd = { .pages = pages, .nr_pages = 0, .partial = partial, .flags = flags, .ops = &relay_pipe_buf_ops, }; |
ebf990934 splice: relay sup... |
1069 1070 1071 |
if (rbuf->subbufs_produced == rbuf->subbufs_consumed) return 0; |
1db60cf20 relay: use splice... |
1072 1073 1074 1075 1076 |
/* * Adjust read len, if longer than what is available */ if (len > (subbuf_size - read_start % subbuf_size)) len = subbuf_size - read_start % subbuf_size; |
ebf990934 splice: relay sup... |
1077 1078 1079 1080 |
subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT; pidx = (read_start / PAGE_SIZE) % subbuf_pages; poff = read_start & ~PAGE_MASK; |
1db60cf20 relay: use splice... |
1081 1082 1083 |
for (total_len = 0; spd.nr_pages < subbuf_pages; spd.nr_pages++) { unsigned int this_len, this_end, private; unsigned int cur_pos = read_start + total_len; |
ebf990934 splice: relay sup... |
1084 |
|
1db60cf20 relay: use splice... |
1085 |
if (!len) |
ebf990934 splice: relay sup... |
1086 |
break; |
ebf990934 splice: relay sup... |
1087 |
|
1db60cf20 relay: use splice... |
1088 1089 |
this_len = min_t(unsigned long, len, PAGE_SIZE - poff); private = this_len; |
ebf990934 splice: relay sup... |
1090 |
|
1db60cf20 relay: use splice... |
1091 1092 |
spd.pages[spd.nr_pages] = rbuf->page_array[pidx]; spd.partial[spd.nr_pages].offset = poff; |
ebf990934 splice: relay sup... |
1093 |
|
1db60cf20 relay: use splice... |
1094 1095 1096 1097 |
this_end = cur_pos + this_len; if (this_end >= nonpad_end) { this_len = nonpad_end - cur_pos; private = this_len + padding; |
ebf990934 splice: relay sup... |
1098 |
} |
1db60cf20 relay: use splice... |
1099 1100 |
spd.partial[spd.nr_pages].len = this_len; spd.partial[spd.nr_pages].private = private; |
ebf990934 splice: relay sup... |
1101 |
|
1db60cf20 relay: use splice... |
1102 1103 1104 1105 |
len -= this_len; total_len += this_len; poff = 0; pidx = (pidx + 1) % subbuf_pages; |
ebf990934 splice: relay sup... |
1106 |
|
1db60cf20 relay: use splice... |
1107 1108 |
if (this_end >= nonpad_end) { spd.nr_pages++; |
ebf990934 splice: relay sup... |
1109 1110 |
break; } |
ebf990934 splice: relay sup... |
1111 |
} |
1db60cf20 relay: use splice... |
1112 1113 |
if (!spd.nr_pages) return 0; |
ebf990934 splice: relay sup... |
1114 |
|
1db60cf20 relay: use splice... |
1115 1116 1117 |
ret = *nonpad_ret = splice_to_pipe(pipe, &spd); if (ret < 0 || ret < total_len) return ret; |
ebf990934 splice: relay sup... |
1118 |
|
1db60cf20 relay: use splice... |
1119 1120 1121 1122 |
if (read_start + ret == nonpad_end) ret += padding; return ret; |
ebf990934 splice: relay sup... |
1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 |
} static ssize_t relay_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { ssize_t spliced; int ret; int nonpad_ret = 0; ret = 0; spliced = 0; while (len) { ret = subbuf_splice_actor(in, ppos, pipe, len, flags, &nonpad_ret); if (ret < 0) break; else if (!ret) { |
ebf990934 splice: relay sup... |
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 |
if (spliced) break; if (flags & SPLICE_F_NONBLOCK) { ret = -EAGAIN; break; } } *ppos += ret; if (ret > len) len = 0; else len -= ret; spliced += nonpad_ret; nonpad_ret = 0; } if (spliced) return spliced; return ret; |
221415d76 [PATCH] relay: ad... |
1164 |
} |
15ad7cdcf [PATCH] struct se... |
1165 |
const struct file_operations relay_file_operations = { |
b86ff981a [PATCH] relay: mi... |
1166 1167 1168 1169 1170 1171 |
.open = relay_file_open, .poll = relay_file_poll, .mmap = relay_file_mmap, .read = relay_file_read, .llseek = no_llseek, .release = relay_file_release, |
ebf990934 splice: relay sup... |
1172 |
.splice_read = relay_file_splice_read, |
b86ff981a [PATCH] relay: mi... |
1173 1174 |
}; EXPORT_SYMBOL_GPL(relay_file_operations); |
23c887522 [PATCH] Relay: ad... |
1175 1176 1177 1178 1179 1180 1181 1182 1183 |
static __init int relay_init(void) { hotcpu_notifier(relay_hotcpu_callback, 0); return 0; } module_init(relay_init); |