Blame view
kernel/relay.c
32.6 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 |
* * This file is released under the GPL. */ #include <linux/errno.h> #include <linux/stddef.h> #include <linux/slab.h> |
9984de1a5 kernel: Map most ... |
18 |
#include <linux/export.h> |
b86ff981a [PATCH] relay: mi... |
19 20 21 22 |
#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 |
/* * 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); } /* |
a1e096129 relay: nopage |
40 |
* fault() vm_op implementation for relay file mapping. |
b86ff981a [PATCH] relay: mi... |
41 |
*/ |
a1e096129 relay: nopage |
42 |
static int relay_buf_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
b86ff981a [PATCH] relay: mi... |
43 44 45 |
{ struct page *page; struct rchan_buf *buf = vma->vm_private_data; |
a1e096129 relay: nopage |
46 |
pgoff_t pgoff = vmf->pgoff; |
b86ff981a [PATCH] relay: mi... |
47 |
|
b86ff981a [PATCH] relay: mi... |
48 |
if (!buf) |
a1e096129 relay: nopage |
49 |
return VM_FAULT_OOM; |
b86ff981a [PATCH] relay: mi... |
50 |
|
a1e096129 relay: nopage |
51 |
page = vmalloc_to_page(buf->start + (pgoff << PAGE_SHIFT)); |
b86ff981a [PATCH] relay: mi... |
52 |
if (!page) |
a1e096129 relay: nopage |
53 |
return VM_FAULT_SIGBUS; |
b86ff981a [PATCH] relay: mi... |
54 |
get_page(page); |
a1e096129 relay: nopage |
55 |
vmf->page = page; |
b86ff981a [PATCH] relay: mi... |
56 |
|
a1e096129 relay: nopage |
57 |
return 0; |
b86ff981a [PATCH] relay: mi... |
58 59 60 61 62 |
} /* * vm_ops for relay file mappings. */ |
f0f37e2f7 const: mark struc... |
63 |
static const struct vm_operations_struct relay_file_mmap_ops = { |
a1e096129 relay: nopage |
64 |
.fault = relay_buf_fault, |
b86ff981a [PATCH] relay: mi... |
65 66 |
.close = relay_file_mmap_close, }; |
68ab3d883 relayfs: support ... |
67 68 69 70 71 |
/* * allocate an array of pointers of struct page */ static struct page **relay_alloc_page_array(unsigned int n_pages) { |
408af87a3 Clean up relay_al... |
72 73 74 75 |
const size_t pa_size = n_pages * sizeof(struct page *); if (pa_size > PAGE_SIZE) return vzalloc(pa_size); return kzalloc(pa_size, GFP_KERNEL); |
68ab3d883 relayfs: support ... |
76 77 78 79 80 81 82 83 84 85 86 87 |
} /* * free an array of pointers of struct page */ static void relay_free_page_array(struct page **array) { if (is_vmalloc_addr(array)) vfree(array); else kfree(array); } |
b86ff981a [PATCH] relay: mi... |
88 89 90 91 92 93 94 95 96 |
/** * 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... |
97 |
static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma) |
b86ff981a [PATCH] relay: mi... |
98 99 100 101 102 103 104 105 106 107 108 |
{ 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; |
2f98735c9 vm audit: add VM_... |
109 |
vma->vm_flags |= VM_DONTEXPAND; |
b86ff981a [PATCH] relay: mi... |
110 111 112 113 114 115 116 117 118 119 120 |
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... |
121 |
* Returns a pointer to the resulting buffer, %NULL if unsuccessful. The |
221415d76 [PATCH] relay: ad... |
122 |
* passed in size will get page aligned, if it isn't already. |
b86ff981a [PATCH] relay: mi... |
123 |
*/ |
221415d76 [PATCH] relay: ad... |
124 |
static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size) |
b86ff981a [PATCH] relay: mi... |
125 126 127 |
{ void *mem; unsigned int i, j, n_pages; |
221415d76 [PATCH] relay: ad... |
128 129 |
*size = PAGE_ALIGN(*size); n_pages = *size >> PAGE_SHIFT; |
b86ff981a [PATCH] relay: mi... |
130 |
|
68ab3d883 relayfs: support ... |
131 |
buf->page_array = relay_alloc_page_array(n_pages); |
b86ff981a [PATCH] relay: mi... |
132 133 134 135 136 137 138 |
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... |
139 |
set_page_private(buf->page_array[i], (unsigned long)buf); |
b86ff981a [PATCH] relay: mi... |
140 141 142 143 |
} mem = vmap(buf->page_array, n_pages, VM_MAP, PAGE_KERNEL); if (!mem) goto depopulate; |
221415d76 [PATCH] relay: ad... |
144 |
memset(mem, 0, *size); |
b86ff981a [PATCH] relay: mi... |
145 146 147 148 149 150 |
buf->page_count = n_pages; return mem; depopulate: for (j = 0; j < i; j++) __free_page(buf->page_array[j]); |
68ab3d883 relayfs: support ... |
151 |
relay_free_page_array(buf->page_array); |
b86ff981a [PATCH] relay: mi... |
152 153 154 155 156 |
return NULL; } /** * relay_create_buf - allocate and initialize a channel buffer |
4c78a6639 [PATCH] kernel-do... |
157 |
* @chan: the relay channel |
b86ff981a [PATCH] relay: mi... |
158 |
* |
4c78a6639 [PATCH] kernel-do... |
159 |
* Returns channel buffer if successful, %NULL otherwise. |
b86ff981a [PATCH] relay: mi... |
160 |
*/ |
01c55ed32 kernel/relay.c: m... |
161 |
static struct rchan_buf *relay_create_buf(struct rchan *chan) |
b86ff981a [PATCH] relay: mi... |
162 |
{ |
cd8612808 [PATCH] Fix numer... |
163 |
struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL); |
b86ff981a [PATCH] relay: mi... |
164 165 166 167 168 169 |
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... |
170 |
buf->start = relay_alloc_buf(buf, &chan->alloc_size); |
b86ff981a [PATCH] relay: mi... |
171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 |
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... |
186 |
* @kref: target kernel reference that contains the relay channel |
b86ff981a [PATCH] relay: mi... |
187 188 189 |
* * Should only be called from kref_put(). */ |
01c55ed32 kernel/relay.c: m... |
190 |
static void relay_destroy_channel(struct kref *kref) |
b86ff981a [PATCH] relay: mi... |
191 192 193 194 195 196 197 198 199 |
{ 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... |
200 |
static void relay_destroy_buf(struct rchan_buf *buf) |
b86ff981a [PATCH] relay: mi... |
201 202 203 204 205 206 207 208 |
{ 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]); |
68ab3d883 relayfs: support ... |
209 |
relay_free_page_array(buf->page_array); |
b86ff981a [PATCH] relay: mi... |
210 |
} |
23c887522 [PATCH] Relay: ad... |
211 |
chan->buf[buf->cpu] = NULL; |
b86ff981a [PATCH] relay: mi... |
212 213 214 215 216 217 218 |
kfree(buf->padding); kfree(buf); kref_put(&chan->kref, relay_destroy_channel); } /** * relay_remove_buf - remove a channel buffer |
4c78a6639 [PATCH] kernel-do... |
219 |
* @kref: target kernel reference that contains the relay buffer |
b86ff981a [PATCH] relay: mi... |
220 221 222 223 224 |
* * 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... |
225 |
static void relay_remove_buf(struct kref *kref) |
b86ff981a [PATCH] relay: mi... |
226 227 228 229 230 231 232 233 234 235 236 237 |
{ 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... |
238 |
static int relay_buf_empty(struct rchan_buf *buf) |
b86ff981a [PATCH] relay: mi... |
239 240 241 |
{ return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1; } |
b86ff981a [PATCH] relay: mi... |
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 |
/** * 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, |
f4ae40a6a switch debugfs to... |
300 |
umode_t mode, |
b86ff981a [PATCH] relay: mi... |
301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 |
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... |
326 |
* @data: contains the channel buffer |
b86ff981a [PATCH] relay: mi... |
327 |
* |
7c9cb3830 relay: use plain ... |
328 |
* This is the timer function used to defer reader waking. |
b86ff981a [PATCH] relay: mi... |
329 |
*/ |
7c9cb3830 relay: use plain ... |
330 |
static void wakeup_readers(unsigned long data) |
b86ff981a [PATCH] relay: mi... |
331 |
{ |
7c9cb3830 relay: use plain ... |
332 |
struct rchan_buf *buf = (struct rchan_buf *)data; |
b86ff981a [PATCH] relay: mi... |
333 334 335 336 337 338 339 340 |
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 ... |
341 |
* See relay_reset() for description of effect. |
b86ff981a [PATCH] relay: mi... |
342 |
*/ |
192636ad9 [PATCH] relay: re... |
343 |
static void __relay_reset(struct rchan_buf *buf, unsigned int init) |
b86ff981a [PATCH] relay: mi... |
344 345 346 347 348 349 |
{ size_t i; if (init) { init_waitqueue_head(&buf->read_wait); kref_init(&buf->kref); |
7c9cb3830 relay: use plain ... |
350 351 352 |
setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf); } else del_timer_sync(&buf->timer); |
b86ff981a [PATCH] relay: mi... |
353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 |
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 ... |
375 |
* NOTE. Care should be taken that the channel isn't actually |
b86ff981a [PATCH] relay: mi... |
376 377 378 379 380 |
* being used by anything when this call is made. */ void relay_reset(struct rchan *chan) { unsigned int i; |
b86ff981a [PATCH] relay: mi... |
381 382 383 |
if (!chan) return; |
1bfbc608b whitespace fixes:... |
384 |
if (chan->is_global && chan->buf[0]) { |
23c887522 [PATCH] Relay: ad... |
385 386 |
__relay_reset(chan->buf[0], 0); return; |
b86ff981a [PATCH] relay: mi... |
387 |
} |
23c887522 [PATCH] Relay: ad... |
388 389 |
mutex_lock(&relay_channels_mutex); |
98ba4031a relay: fix cpu of... |
390 |
for_each_possible_cpu(i) |
23c887522 [PATCH] Relay: ad... |
391 392 393 |
if (chan->buf[i]) __relay_reset(chan->buf[i], 0); mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
394 395 |
} EXPORT_SYMBOL_GPL(relay_reset); |
20d8b67c0 relay: add buffer... |
396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 |
static inline void relay_set_buf_dentry(struct rchan_buf *buf, struct dentry *dentry) { buf->dentry = dentry; buf->dentry->d_inode->i_size = buf->early_bytes; } static struct dentry *relay_create_buf_file(struct rchan *chan, struct rchan_buf *buf, unsigned int cpu) { struct dentry *dentry; char *tmpname; tmpname = kzalloc(NAME_MAX + 1, GFP_KERNEL); if (!tmpname) return NULL; snprintf(tmpname, NAME_MAX, "%s%d", chan->base_filename, cpu); /* Create file in fs */ dentry = chan->cb->create_buf_file(tmpname, chan->parent, S_IRUSR, buf, &chan->is_global); kfree(tmpname); return dentry; } |
4c78a6639 [PATCH] kernel-do... |
424 |
/* |
b86ff981a [PATCH] relay: mi... |
425 426 |
* relay_open_buf - create a new relay channel buffer * |
23c887522 [PATCH] Relay: ad... |
427 |
* used by relay_open() and CPU hotplug. |
b86ff981a [PATCH] relay: mi... |
428 |
*/ |
23c887522 [PATCH] Relay: ad... |
429 |
static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu) |
b86ff981a [PATCH] relay: mi... |
430 |
{ |
23c887522 [PATCH] Relay: ad... |
431 |
struct rchan_buf *buf = NULL; |
b86ff981a [PATCH] relay: mi... |
432 |
struct dentry *dentry; |
23c887522 [PATCH] Relay: ad... |
433 |
if (chan->is_global) |
b86ff981a [PATCH] relay: mi... |
434 435 436 437 |
return chan->buf[0]; buf = relay_create_buf(chan); if (!buf) |
20d8b67c0 relay: add buffer... |
438 439 440 441 442 443 444 445 |
return NULL; if (chan->has_base_filename) { dentry = relay_create_buf_file(chan, buf, cpu); if (!dentry) goto free_buf; relay_set_buf_dentry(buf, dentry); } |
23c887522 [PATCH] Relay: ad... |
446 447 448 |
buf->cpu = cpu; __relay_reset(buf, 1); |
b86ff981a [PATCH] relay: mi... |
449 |
|
23c887522 [PATCH] Relay: ad... |
450 451 452 453 |
if(chan->is_global) { chan->buf[0] = buf; buf->cpu = 0; } |
20d8b67c0 relay: add buffer... |
454 |
return buf; |
23c887522 [PATCH] Relay: ad... |
455 456 457 |
free_buf: relay_destroy_buf(buf); |
20d8b67c0 relay: add buffer... |
458 |
return NULL; |
b86ff981a [PATCH] relay: mi... |
459 460 461 462 463 464 465 466 467 468 |
} /** * 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... |
469 |
static void relay_close_buf(struct rchan_buf *buf) |
b86ff981a [PATCH] relay: mi... |
470 471 |
{ buf->finalized = 1; |
7c9cb3830 relay: use plain ... |
472 |
del_timer_sync(&buf->timer); |
b86ff981a [PATCH] relay: mi... |
473 474 |
kref_put(&buf->kref, relay_remove_buf); } |
192636ad9 [PATCH] relay: re... |
475 |
static void setup_callbacks(struct rchan *chan, |
b86ff981a [PATCH] relay: mi... |
476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 |
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... |
497 498 499 500 501 |
* relay_hotcpu_callback - CPU hotplug callback * @nb: notifier block * @action: hotplug action to take * @hcpu: CPU number * |
05fb6bf0b [PATCH] kernel-do... |
502 |
* Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD) |
23c887522 [PATCH] Relay: ad... |
503 504 505 506 507 508 509 510 511 512 |
*/ 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... |
513 |
case CPU_UP_PREPARE_FROZEN: |
23c887522 [PATCH] Relay: ad... |
514 515 516 517 518 519 520 521 522 523 524 |
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); |
80b5184cc kernel/: convert ... |
525 |
return notifier_from_errno(-ENOMEM); |
23c887522 [PATCH] Relay: ad... |
526 527 528 529 530 |
} } mutex_unlock(&relay_channels_mutex); break; case CPU_DEAD: |
8bb784428 Add suspend-relat... |
531 |
case CPU_DEAD_FROZEN: |
23c887522 [PATCH] Relay: ad... |
532 533 534 535 536 537 538 539 |
/* No need to flush the cpu : will be flushed upon * final relay_flush() call. */ break; } return NOTIFY_OK; } /** |
b86ff981a [PATCH] relay: mi... |
540 |
* relay_open - create a new relay channel |
20d8b67c0 relay: add buffer... |
541 542 |
* @base_filename: base name of files to create, %NULL for buffering only * @parent: dentry of parent directory, %NULL for root directory or buffer |
b86ff981a [PATCH] relay: mi... |
543 544 545 |
* @subbuf_size: size of sub-buffers * @n_subbufs: number of sub-buffers * @cb: client callback functions |
23c887522 [PATCH] Relay: ad... |
546 |
* @private_data: user-defined data |
b86ff981a [PATCH] relay: mi... |
547 |
* |
4c78a6639 [PATCH] kernel-do... |
548 |
* Returns channel pointer if successful, %NULL otherwise. |
b86ff981a [PATCH] relay: mi... |
549 550 551 552 |
* * 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 ... |
553 |
* permissions will be %S_IRUSR. |
b86ff981a [PATCH] relay: mi... |
554 555 556 557 558 |
*/ struct rchan *relay_open(const char *base_filename, struct dentry *parent, size_t subbuf_size, size_t n_subbufs, |
23c887522 [PATCH] Relay: ad... |
559 560 |
struct rchan_callbacks *cb, void *private_data) |
b86ff981a [PATCH] relay: mi... |
561 562 563 |
{ unsigned int i; struct rchan *chan; |
b86ff981a [PATCH] relay: mi... |
564 565 566 |
if (!(subbuf_size && n_subbufs)) return NULL; |
cd8612808 [PATCH] Fix numer... |
567 |
chan = kzalloc(sizeof(struct rchan), GFP_KERNEL); |
b86ff981a [PATCH] relay: mi... |
568 569 570 571 572 573 574 |
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... |
575 576 |
chan->parent = parent; chan->private_data = private_data; |
20d8b67c0 relay: add buffer... |
577 578 579 580 |
if (base_filename) { chan->has_base_filename = 1; strlcpy(chan->base_filename, base_filename, NAME_MAX); } |
b86ff981a [PATCH] relay: mi... |
581 582 |
setup_callbacks(chan, cb); kref_init(&chan->kref); |
23c887522 [PATCH] Relay: ad... |
583 |
mutex_lock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
584 |
for_each_online_cpu(i) { |
23c887522 [PATCH] Relay: ad... |
585 |
chan->buf[i] = relay_open_buf(chan, i); |
b86ff981a [PATCH] relay: mi... |
586 587 |
if (!chan->buf[i]) goto free_bufs; |
b86ff981a [PATCH] relay: mi... |
588 |
} |
23c887522 [PATCH] Relay: ad... |
589 590 |
list_add(&chan->list, &relay_channels); mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
591 |
|
b86ff981a [PATCH] relay: mi... |
592 593 594 |
return chan; free_bufs: |
98ba4031a relay: fix cpu of... |
595 596 597 |
for_each_possible_cpu(i) { if (chan->buf[i]) relay_close_buf(chan->buf[i]); |
b86ff981a [PATCH] relay: mi... |
598 |
} |
b86ff981a [PATCH] relay: mi... |
599 |
|
b86ff981a [PATCH] relay: mi... |
600 |
kref_put(&chan->kref, relay_destroy_channel); |
23c887522 [PATCH] Relay: ad... |
601 |
mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
602 603 604 |
return NULL; } EXPORT_SYMBOL_GPL(relay_open); |
20d8b67c0 relay: add buffer... |
605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 |
struct rchan_percpu_buf_dispatcher { struct rchan_buf *buf; struct dentry *dentry; }; /* Called in atomic context. */ static void __relay_set_buf_dentry(void *info) { struct rchan_percpu_buf_dispatcher *p = info; relay_set_buf_dentry(p->buf, p->dentry); } /** * relay_late_setup_files - triggers file creation * @chan: channel to operate on * @base_filename: base name of files to create * @parent: dentry of parent directory, %NULL for root directory * * Returns 0 if successful, non-zero otherwise. * * Use to setup files for a previously buffer-only channel. * Useful to do early tracing in kernel, before VFS is up, for example. */ int relay_late_setup_files(struct rchan *chan, const char *base_filename, struct dentry *parent) { int err = 0; unsigned int i, curr_cpu; unsigned long flags; struct dentry *dentry; struct rchan_percpu_buf_dispatcher disp; if (!chan || !base_filename) return -EINVAL; strlcpy(chan->base_filename, base_filename, NAME_MAX); mutex_lock(&relay_channels_mutex); /* Is chan already set up? */ |
b786c6a98 relay: fix lock i... |
646 647 |
if (unlikely(chan->has_base_filename)) { mutex_unlock(&relay_channels_mutex); |
20d8b67c0 relay: add buffer... |
648 |
return -EEXIST; |
b786c6a98 relay: fix lock i... |
649 |
} |
20d8b67c0 relay: add buffer... |
650 651 652 653 654 655 656 657 658 659 |
chan->has_base_filename = 1; chan->parent = parent; curr_cpu = get_cpu(); /* * The CPU hotplug notifier ran before us and created buffers with * no files associated. So it's safe to call relay_setup_buf_file() * on all currently online CPUs. */ for_each_online_cpu(i) { if (unlikely(!chan->buf[i])) { |
7a51cffbd relayfs: replace ... |
660 661 |
WARN_ONCE(1, KERN_ERR "CPU has no buffer! "); |
20d8b67c0 relay: add buffer... |
662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 |
err = -EINVAL; break; } dentry = relay_create_buf_file(chan, chan->buf[i], i); if (unlikely(!dentry)) { err = -EINVAL; break; } if (curr_cpu == i) { local_irq_save(flags); relay_set_buf_dentry(chan->buf[i], dentry); local_irq_restore(flags); } else { disp.buf = chan->buf[i]; disp.dentry = dentry; smp_mb(); /* relay_channels_mutex must be held, so wait. */ err = smp_call_function_single(i, __relay_set_buf_dentry, &disp, 1); } if (unlikely(err)) break; } put_cpu(); mutex_unlock(&relay_channels_mutex); return err; } |
b86ff981a [PATCH] relay: mi... |
693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 |
/** * 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++; |
20d8b67c0 relay: add buffer... |
716 717 718 719 720 721 722 |
if (buf->dentry) buf->dentry->d_inode->i_size += buf->chan->subbuf_size - buf->padding[old_subbuf]; else buf->early_bytes += buf->chan->subbuf_size - buf->padding[old_subbuf]; |
221415d76 [PATCH] relay: ad... |
723 |
smp_mb(); |
7c9cb3830 relay: use plain ... |
724 725 726 727 728 729 730 |
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. */ |
74019224a timers: add mod_t... |
731 |
mod_timer(&buf->timer, jiffies + 1); |
b86ff981a [PATCH] relay: mi... |
732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 |
} 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 ... |
766 |
* NOTE. Kernel clients don't need to call this function if the channel |
b86ff981a [PATCH] relay: mi... |
767 768 769 770 771 772 773 774 775 776 |
* mode is 'overwrite'. */ void relay_subbufs_consumed(struct rchan *chan, unsigned int cpu, size_t subbufs_consumed) { struct rchan_buf *buf; if (!chan) return; |
2c53d9109 relay: fix for po... |
777 778 |
if (cpu >= NR_CPUS || !chan->buf[cpu] || subbufs_consumed > chan->n_subbufs) |
b86ff981a [PATCH] relay: mi... |
779 780 781 |
return; buf = chan->buf[cpu]; |
2c53d9109 relay: fix for po... |
782 |
if (subbufs_consumed > buf->subbufs_produced - buf->subbufs_consumed) |
b86ff981a [PATCH] relay: mi... |
783 |
buf->subbufs_consumed = buf->subbufs_produced; |
2c53d9109 relay: fix for po... |
784 785 |
else buf->subbufs_consumed += subbufs_consumed; |
b86ff981a [PATCH] relay: mi... |
786 787 788 789 790 791 792 793 794 795 796 797 |
} 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... |
798 799 800 |
if (!chan) return; |
23c887522 [PATCH] Relay: ad... |
801 802 803 804 805 806 807 |
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... |
808 809 810 811 812 813 |
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... |
814 |
list_del(&chan->list); |
b86ff981a [PATCH] relay: mi... |
815 |
kref_put(&chan->kref, relay_destroy_channel); |
23c887522 [PATCH] Relay: ad... |
816 |
mutex_unlock(&relay_channels_mutex); |
b86ff981a [PATCH] relay: mi... |
817 818 819 820 821 822 823 |
} EXPORT_SYMBOL_GPL(relay_close); /** * relay_flush - close the channel * @chan: the channel * |
4c78a6639 [PATCH] kernel-do... |
824 |
* Flushes all channel buffers, i.e. forces buffer switch. |
b86ff981a [PATCH] relay: mi... |
825 826 827 828 |
*/ void relay_flush(struct rchan *chan) { unsigned int i; |
b86ff981a [PATCH] relay: mi... |
829 830 831 |
if (!chan) return; |
23c887522 [PATCH] Relay: ad... |
832 833 834 |
if (chan->is_global && chan->buf[0]) { relay_switch_subbuf(chan->buf[0], 0); return; |
b86ff981a [PATCH] relay: mi... |
835 |
} |
23c887522 [PATCH] Relay: ad... |
836 837 838 839 840 841 |
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... |
842 843 844 845 846 847 848 849 850 851 852 853 |
} 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... |
854 |
struct rchan_buf *buf = inode->i_private; |
b86ff981a [PATCH] relay: mi... |
855 856 |
kref_get(&buf->kref); filp->private_data = buf; |
37529fe9f set relay file ca... |
857 |
return nonseekable_open(inode, filp); |
b86ff981a [PATCH] relay: mi... |
858 859 860 861 862 863 864 |
} /** * relay_file_mmap - mmap file op for relay files * @filp: the file * @vma: the vma describing what to map * |
72fd4a35a [PATCH] Numerous ... |
865 |
* Calls upon relay_mmap_buf() to map the file into user space. |
b86ff981a [PATCH] relay: mi... |
866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 |
*/ 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... |
912 |
/* |
b86ff981a [PATCH] relay: mi... |
913 914 915 916 917 918 919 920 921 |
* 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; |
321944503 relay: fix "full ... |
922 923 924 |
if (buf->subbufs_produced == buf->subbufs_consumed && buf->offset == buf->bytes_consumed) return; |
b86ff981a [PATCH] relay: mi... |
925 926 927 928 929 930 |
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... |
931 932 933 934 |
if (!read_pos) read_subbuf = buf->subbufs_consumed % n_subbufs; else read_subbuf = read_pos / buf->chan->subbuf_size; |
b86ff981a [PATCH] relay: mi... |
935 936 937 938 939 940 941 942 |
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... |
943 |
/* |
b86ff981a [PATCH] relay: mi... |
944 945 946 947 |
* 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... |
948 949 |
size_t subbuf_size = buf->chan->subbuf_size; size_t n_subbufs = buf->chan->n_subbufs; |
221415d76 [PATCH] relay: ad... |
950 951 |
size_t produced = buf->subbufs_produced; size_t consumed = buf->subbufs_consumed; |
b86ff981a [PATCH] relay: mi... |
952 |
|
221415d76 [PATCH] relay: ad... |
953 |
relay_file_read_consume(buf, read_pos, 0); |
b86ff981a [PATCH] relay: mi... |
954 |
|
321944503 relay: fix "full ... |
955 |
consumed = buf->subbufs_consumed; |
221415d76 [PATCH] relay: ad... |
956 957 958 959 |
if (unlikely(buf->offset > subbuf_size)) { if (produced == consumed) return 0; return 1; |
b86ff981a [PATCH] relay: mi... |
960 |
} |
221415d76 [PATCH] relay: ad... |
961 |
if (unlikely(produced - consumed >= n_subbufs)) { |
a66e356c0 relayfs: fix over... |
962 |
consumed = produced - n_subbufs + 1; |
221415d76 [PATCH] relay: ad... |
963 |
buf->subbufs_consumed = consumed; |
a66e356c0 relayfs: fix over... |
964 |
buf->bytes_consumed = 0; |
221415d76 [PATCH] relay: ad... |
965 |
} |
1bfbc608b whitespace fixes:... |
966 |
|
221415d76 [PATCH] relay: ad... |
967 968 969 970 971 |
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:... |
972 |
|
321944503 relay: fix "full ... |
973 974 975 976 |
if (consumed == produced) { if (buf->offset == subbuf_size && buf->subbufs_produced > buf->subbufs_consumed) return 1; |
b86ff981a [PATCH] relay: mi... |
977 |
return 0; |
321944503 relay: fix "full ... |
978 |
} |
b86ff981a [PATCH] relay: mi... |
979 |
|
b86ff981a [PATCH] relay: mi... |
980 981 982 983 984 |
return 1; } /** * relay_file_read_subbuf_avail - return bytes available in sub-buffer |
4c78a6639 [PATCH] kernel-do... |
985 986 |
* @read_pos: file read position * @buf: relay channel buffer |
b86ff981a [PATCH] relay: mi... |
987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 |
*/ 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... |
1012 1013 |
* @read_pos: file read position * @buf: relay channel buffer |
b86ff981a [PATCH] relay: mi... |
1014 |
* |
72fd4a35a [PATCH] Numerous ... |
1015 |
* If the @read_pos is in the middle of padding, return the |
b86ff981a [PATCH] relay: mi... |
1016 1017 1018 1019 1020 1021 1022 1023 1024 |
* 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: ... |
1025 |
size_t consumed = buf->subbufs_consumed % n_subbufs; |
b86ff981a [PATCH] relay: mi... |
1026 |
|
8d62fdebd relay file read: ... |
1027 1028 |
if (!read_pos) read_pos = consumed * subbuf_size + buf->bytes_consumed; |
b86ff981a [PATCH] relay: mi... |
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 |
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... |
1043 1044 1045 |
* @read_pos: file read position * @buf: relay channel buffer * @count: number of bytes to be read |
b86ff981a [PATCH] relay: mi... |
1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 |
*/ 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... |
1066 |
/* |
6dac40a7c [PATCH] relay: co... |
1067 |
* subbuf_read_actor - read up to one subbuf's worth of data |
b86ff981a [PATCH] relay: mi... |
1068 |
*/ |
6dac40a7c [PATCH] relay: co... |
1069 1070 1071 1072 1073 |
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... |
1074 |
{ |
b86ff981a [PATCH] relay: mi... |
1075 |
void *from; |
6dac40a7c [PATCH] relay: co... |
1076 |
int ret = 0; |
b86ff981a [PATCH] relay: mi... |
1077 1078 |
from = buf->start + read_start; |
6dac40a7c [PATCH] relay: co... |
1079 |
ret = avail; |
ba2397efe [PATCH] make kern... |
1080 |
if (copy_to_user(desc->arg.buf, from, avail)) { |
6dac40a7c [PATCH] relay: co... |
1081 1082 |
desc->error = -EFAULT; ret = 0; |
b86ff981a [PATCH] relay: mi... |
1083 |
} |
6dac40a7c [PATCH] relay: co... |
1084 1085 1086 |
desc->arg.data += ret; desc->written += ret; desc->count -= ret; |
b86ff981a [PATCH] relay: mi... |
1087 1088 |
return ret; } |
6dac40a7c [PATCH] relay: co... |
1089 1090 1091 1092 1093 |
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... |
1094 |
/* |
6dac40a7c [PATCH] relay: co... |
1095 1096 |
* relay_file_read_subbufs - read count bytes, bridging subbuf boundaries */ |
192636ad9 [PATCH] relay: re... |
1097 1098 1099 1100 |
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... |
1101 |
{ |
6dac40a7c [PATCH] relay: co... |
1102 1103 |
struct rchan_buf *buf = filp->private_data; size_t read_start, avail; |
6dac40a7c [PATCH] relay: co... |
1104 |
int ret; |
221415d76 [PATCH] relay: ad... |
1105 |
|
ba2397efe [PATCH] make kern... |
1106 |
if (!desc->count) |
221415d76 [PATCH] relay: ad... |
1107 |
return 0; |
f3a43f3f6 [PATCH] kernel: c... |
1108 |
mutex_lock(&filp->f_path.dentry->d_inode->i_mutex); |
221415d76 [PATCH] relay: ad... |
1109 |
do { |
6dac40a7c [PATCH] relay: co... |
1110 1111 1112 1113 1114 1115 |
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... |
1116 |
break; |
221415d76 [PATCH] relay: ad... |
1117 |
|
ba2397efe [PATCH] make kern... |
1118 1119 1120 |
avail = min(desc->count, avail); ret = subbuf_actor(read_start, buf, avail, desc, actor); if (desc->error < 0) |
6dac40a7c [PATCH] relay: co... |
1121 1122 1123 1124 1125 1126 |
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... |
1127 |
} while (desc->count && ret); |
f3a43f3f6 [PATCH] kernel: c... |
1128 |
mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex); |
6dac40a7c [PATCH] relay: co... |
1129 |
|
ba2397efe [PATCH] make kern... |
1130 |
return desc->written; |
6dac40a7c [PATCH] relay: co... |
1131 1132 1133 1134 1135 1136 1137 |
} static ssize_t relay_file_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { |
ba2397efe [PATCH] make kern... |
1138 1139 1140 1141 1142 1143 1144 |
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... |
1145 |
} |
1db60cf20 relay: use splice... |
1146 1147 1148 1149 1150 1151 1152 1153 1154 |
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... |
1155 1156 |
static void relay_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buffer *buf) |
6dac40a7c [PATCH] relay: co... |
1157 |
{ |
ebf990934 splice: relay sup... |
1158 1159 1160 |
struct rchan_buf *rbuf; rbuf = (struct rchan_buf *)page_private(buf->page); |
1db60cf20 relay: use splice... |
1161 |
relay_consume_bytes(rbuf, buf->private); |
ebf990934 splice: relay sup... |
1162 |
} |
28dfef8fe const: constify r... |
1163 |
static const struct pipe_buf_operations relay_pipe_buf_ops = { |
ebf990934 splice: relay sup... |
1164 1165 1166 |
.can_merge = 0, .map = generic_pipe_buf_map, .unmap = generic_pipe_buf_unmap, |
cac36bb06 pipe: change the ... |
1167 |
.confirm = generic_pipe_buf_confirm, |
ebf990934 splice: relay sup... |
1168 1169 1170 1171 |
.release = relay_pipe_buf_release, .steal = generic_pipe_buf_steal, .get = generic_pipe_buf_get, }; |
5eb7f9fa8 relay: set an spd... |
1172 1173 1174 |
static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i) { } |
d3f35d98b relay: fixup kern... |
1175 |
/* |
ebf990934 splice: relay sup... |
1176 1177 |
* subbuf_splice_actor - splice up to one subbuf's worth of data */ |
5f1664f92 splice: comparing... |
1178 |
static ssize_t subbuf_splice_actor(struct file *in, |
ebf990934 splice: relay sup... |
1179 1180 1181 1182 1183 1184 |
loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags, int *nonpad_ret) { |
5f1664f92 splice: comparing... |
1185 |
unsigned int pidx, poff, total_len, subbuf_pages, nr_pages; |
ebf990934 splice: relay sup... |
1186 1187 |
struct rchan_buf *rbuf = in->private_data; unsigned int subbuf_size = rbuf->chan->subbuf_size; |
24da24de2 relay: fix bogus ... |
1188 1189 1190 |
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... |
1191 1192 1193 |
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; |
35f3d14db pipe: add support... |
1194 1195 |
struct page *pages[PIPE_DEF_BUFFERS]; struct partial_page partial[PIPE_DEF_BUFFERS]; |
1db60cf20 relay: use splice... |
1196 1197 1198 1199 1200 1201 |
struct splice_pipe_desc spd = { .pages = pages, .nr_pages = 0, .partial = partial, .flags = flags, .ops = &relay_pipe_buf_ops, |
5eb7f9fa8 relay: set an spd... |
1202 |
.spd_release = relay_page_release, |
1db60cf20 relay: use splice... |
1203 |
}; |
5f1664f92 splice: comparing... |
1204 |
ssize_t ret; |
ebf990934 splice: relay sup... |
1205 1206 1207 |
if (rbuf->subbufs_produced == rbuf->subbufs_consumed) return 0; |
35f3d14db pipe: add support... |
1208 1209 |
if (splice_grow_spd(pipe, &spd)) return -ENOMEM; |
ebf990934 splice: relay sup... |
1210 |
|
1db60cf20 relay: use splice... |
1211 1212 1213 1214 1215 |
/* * 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... |
1216 1217 1218 1219 |
subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT; pidx = (read_start / PAGE_SIZE) % subbuf_pages; poff = read_start & ~PAGE_MASK; |
35f3d14db pipe: add support... |
1220 |
nr_pages = min_t(unsigned int, subbuf_pages, pipe->buffers); |
ebf990934 splice: relay sup... |
1221 |
|
16d546694 relay: fix subbuf... |
1222 |
for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) { |
1db60cf20 relay: use splice... |
1223 1224 |
unsigned int this_len, this_end, private; unsigned int cur_pos = read_start + total_len; |
ebf990934 splice: relay sup... |
1225 |
|
1db60cf20 relay: use splice... |
1226 |
if (!len) |
ebf990934 splice: relay sup... |
1227 |
break; |
ebf990934 splice: relay sup... |
1228 |
|
1db60cf20 relay: use splice... |
1229 1230 |
this_len = min_t(unsigned long, len, PAGE_SIZE - poff); private = this_len; |
ebf990934 splice: relay sup... |
1231 |
|
1db60cf20 relay: use splice... |
1232 1233 |
spd.pages[spd.nr_pages] = rbuf->page_array[pidx]; spd.partial[spd.nr_pages].offset = poff; |
ebf990934 splice: relay sup... |
1234 |
|
1db60cf20 relay: use splice... |
1235 1236 1237 1238 |
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... |
1239 |
} |
1db60cf20 relay: use splice... |
1240 1241 |
spd.partial[spd.nr_pages].len = this_len; spd.partial[spd.nr_pages].private = private; |
ebf990934 splice: relay sup... |
1242 |
|
1db60cf20 relay: use splice... |
1243 1244 1245 1246 |
len -= this_len; total_len += this_len; poff = 0; pidx = (pidx + 1) % subbuf_pages; |
ebf990934 splice: relay sup... |
1247 |
|
1db60cf20 relay: use splice... |
1248 1249 |
if (this_end >= nonpad_end) { spd.nr_pages++; |
ebf990934 splice: relay sup... |
1250 1251 |
break; } |
ebf990934 splice: relay sup... |
1252 |
} |
35f3d14db pipe: add support... |
1253 |
ret = 0; |
1db60cf20 relay: use splice... |
1254 |
if (!spd.nr_pages) |
35f3d14db pipe: add support... |
1255 |
goto out; |
ebf990934 splice: relay sup... |
1256 |
|
1db60cf20 relay: use splice... |
1257 1258 |
ret = *nonpad_ret = splice_to_pipe(pipe, &spd); if (ret < 0 || ret < total_len) |
35f3d14db pipe: add support... |
1259 |
goto out; |
ebf990934 splice: relay sup... |
1260 |
|
1db60cf20 relay: use splice... |
1261 1262 |
if (read_start + ret == nonpad_end) ret += padding; |
35f3d14db pipe: add support... |
1263 1264 |
out: splice_shrink_spd(pipe, &spd); |
1db60cf20 relay: use splice... |
1265 |
return ret; |
ebf990934 splice: relay sup... |
1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 |
} 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; |
a82c53a0e splice: fix sendf... |
1280 |
while (len && !spliced) { |
ebf990934 splice: relay sup... |
1281 1282 1283 1284 |
ret = subbuf_splice_actor(in, ppos, pipe, len, flags, &nonpad_ret); if (ret < 0) break; else if (!ret) { |
fbb5b7ae4 relayfs: fix infi... |
1285 |
if (flags & SPLICE_F_NONBLOCK) |
ebf990934 splice: relay sup... |
1286 |
ret = -EAGAIN; |
fbb5b7ae4 relayfs: fix infi... |
1287 |
break; |
ebf990934 splice: relay sup... |
1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 |
} *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... |
1303 |
} |
15ad7cdcf [PATCH] struct se... |
1304 |
const struct file_operations relay_file_operations = { |
b86ff981a [PATCH] relay: mi... |
1305 1306 1307 1308 1309 1310 |
.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... |
1311 |
.splice_read = relay_file_splice_read, |
b86ff981a [PATCH] relay: mi... |
1312 1313 |
}; EXPORT_SYMBOL_GPL(relay_file_operations); |
23c887522 [PATCH] Relay: ad... |
1314 1315 1316 1317 1318 1319 1320 |
static __init int relay_init(void) { hotcpu_notifier(relay_hotcpu_callback, 0); return 0; } |
20d8b67c0 relay: add buffer... |
1321 |
early_initcall(relay_init); |