Blame view
fs/splice.c
38.9 KB
5274f052e [PATCH] Introduce... |
1 2 3 4 5 6 7 8 9 10 11 |
/* * "splice": joining two ropes together by interweaving their strands. * * This is the "extended pipe" functionality, where a pipe is used as * an arbitrary in-memory buffer. Think of a pipe as a small kernel * buffer that you can use to transfer data from one end to the other. * * The traditional unix read/write is extended with a "splice()" operation * that transfers data buffers to or from a pipe buffer. * * Named by Larry McVoy, original implementation from Linus, extended by |
c2058e061 [PATCH] splice: a... |
12 13 |
* Jens to support splicing to files, network, direct splicing, etc and * fixing lots of bugs. |
5274f052e [PATCH] Introduce... |
14 |
* |
0fe234795 [PATCH] Update ax... |
15 |
* Copyright (C) 2005-2006 Jens Axboe <axboe@kernel.dk> |
c2058e061 [PATCH] splice: a... |
16 17 |
* Copyright (C) 2005-2006 Linus Torvalds <torvalds@osdl.org> * Copyright (C) 2006 Ingo Molnar <mingo@elte.hu> |
5274f052e [PATCH] Introduce... |
18 19 20 21 22 |
* */ #include <linux/fs.h> #include <linux/file.h> #include <linux/pagemap.h> |
d6b29d7ce splice: divorce t... |
23 |
#include <linux/splice.h> |
5274f052e [PATCH] Introduce... |
24 |
#include <linux/mm_inline.h> |
5abc97aa2 [PATCH] splice: a... |
25 |
#include <linux/swap.h> |
4f6f0bd2f [PATCH] splice: i... |
26 27 |
#include <linux/writeback.h> #include <linux/buffer_head.h> |
a0f067802 [PATCH] splice ex... |
28 |
#include <linux/module.h> |
4f6f0bd2f [PATCH] splice: i... |
29 |
#include <linux/syscalls.h> |
912d35f86 [PATCH] Add suppo... |
30 |
#include <linux/uio.h> |
29ce20586 security: revalid... |
31 |
#include <linux/security.h> |
5274f052e [PATCH] Introduce... |
32 |
|
83f9135bd [PATCH] splice: a... |
33 34 35 36 37 38 |
/* * Attempt to steal a page from a pipe buffer. This should perhaps go into * a vm helper function, it's already simplified quite a bit by the * addition of remove_mapping(). If success is returned, the caller may * attempt to reuse this page for another destination. */ |
76ad4d111 [PATCH] splice: r... |
39 |
static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, |
5abc97aa2 [PATCH] splice: a... |
40 41 42 |
struct pipe_buffer *buf) { struct page *page = buf->page; |
9e94cd4fd [PATCH] splice: r... |
43 |
struct address_space *mapping; |
5abc97aa2 [PATCH] splice: a... |
44 |
|
9e0267c26 [PATCH] splice: f... |
45 |
lock_page(page); |
9e94cd4fd [PATCH] splice: r... |
46 47 48 |
mapping = page_mapping(page); if (mapping) { WARN_ON(!PageUptodate(page)); |
5abc97aa2 [PATCH] splice: a... |
49 |
|
9e94cd4fd [PATCH] splice: r... |
50 51 52 53 54 55 56 57 58 |
/* * At least for ext2 with nobh option, we need to wait on * writeback completing on this page, since we'll remove it * from the pagecache. Otherwise truncate wont wait on the * page, allowing the disk blocks to be reused by someone else * before we actually wrote our data to them. fs corruption * ensues. */ wait_on_page_writeback(page); |
ad8d6f0a7 [PATCH] splice: p... |
59 |
|
ca39d651d splice: handle tr... |
60 61 |
if (PagePrivate(page) && !try_to_release_page(page, GFP_KERNEL)) goto out_unlock; |
4f6f0bd2f [PATCH] splice: i... |
62 |
|
9e94cd4fd [PATCH] splice: r... |
63 64 65 66 67 68 69 70 |
/* * If we succeeded in removing the mapping, set LRU flag * and return good. */ if (remove_mapping(mapping, page)) { buf->flags |= PIPE_BUF_FLAG_LRU; return 0; } |
9e0267c26 [PATCH] splice: f... |
71 |
} |
5abc97aa2 [PATCH] splice: a... |
72 |
|
9e94cd4fd [PATCH] splice: r... |
73 74 75 76 |
/* * Raced with truncate or failed to remove page from current * address space, unlock and return failure. */ |
ca39d651d splice: handle tr... |
77 |
out_unlock: |
9e94cd4fd [PATCH] splice: r... |
78 79 |
unlock_page(page); return 1; |
5abc97aa2 [PATCH] splice: a... |
80 |
} |
76ad4d111 [PATCH] splice: r... |
81 |
static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe, |
5274f052e [PATCH] Introduce... |
82 83 84 |
struct pipe_buffer *buf) { page_cache_release(buf->page); |
1432873af [PATCH] splice: L... |
85 |
buf->flags &= ~PIPE_BUF_FLAG_LRU; |
5274f052e [PATCH] Introduce... |
86 |
} |
0845718da pipe: add documen... |
87 88 89 90 |
/* * Check whether the contents of buf is OK to access. Since the content * is a page cache page, IO may be in flight. */ |
cac36bb06 pipe: change the ... |
91 92 |
static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe, struct pipe_buffer *buf) |
5274f052e [PATCH] Introduce... |
93 94 |
{ struct page *page = buf->page; |
49d0b21be [PATCH] splice: o... |
95 |
int err; |
5274f052e [PATCH] Introduce... |
96 97 |
if (!PageUptodate(page)) { |
49d0b21be [PATCH] splice: o... |
98 99 100 101 |
lock_page(page); /* * Page got truncated/unhashed. This will cause a 0-byte |
73d62d83e [PATCH] splice: c... |
102 |
* splice, if this is the first page. |
49d0b21be [PATCH] splice: o... |
103 104 105 106 107 |
*/ if (!page->mapping) { err = -ENODATA; goto error; } |
5274f052e [PATCH] Introduce... |
108 |
|
49d0b21be [PATCH] splice: o... |
109 |
/* |
73d62d83e [PATCH] splice: c... |
110 |
* Uh oh, read-error from disk. |
49d0b21be [PATCH] splice: o... |
111 112 113 114 115 116 117 |
*/ if (!PageUptodate(page)) { err = -EIO; goto error; } /* |
f84d75199 [PATCH] pipe: int... |
118 |
* Page is ok afterall, we are done. |
49d0b21be [PATCH] splice: o... |
119 |
*/ |
5274f052e [PATCH] Introduce... |
120 |
unlock_page(page); |
5274f052e [PATCH] Introduce... |
121 |
} |
f84d75199 [PATCH] pipe: int... |
122 |
return 0; |
49d0b21be [PATCH] splice: o... |
123 124 |
error: unlock_page(page); |
f84d75199 [PATCH] pipe: int... |
125 |
return err; |
70524490e [PATCH] splice: a... |
126 |
} |
d4c3cca94 [PATCH] constify ... |
127 |
static const struct pipe_buf_operations page_cache_pipe_buf_ops = { |
5274f052e [PATCH] Introduce... |
128 |
.can_merge = 0, |
f84d75199 [PATCH] pipe: int... |
129 130 |
.map = generic_pipe_buf_map, .unmap = generic_pipe_buf_unmap, |
cac36bb06 pipe: change the ... |
131 |
.confirm = page_cache_pipe_buf_confirm, |
5274f052e [PATCH] Introduce... |
132 |
.release = page_cache_pipe_buf_release, |
5abc97aa2 [PATCH] splice: a... |
133 |
.steal = page_cache_pipe_buf_steal, |
f84d75199 [PATCH] pipe: int... |
134 |
.get = generic_pipe_buf_get, |
5274f052e [PATCH] Introduce... |
135 |
}; |
912d35f86 [PATCH] Add suppo... |
136 137 138 |
static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { |
7afa6fd03 [PATCH] vmsplice:... |
139 140 |
if (!(buf->flags & PIPE_BUF_FLAG_GIFT)) return 1; |
1432873af [PATCH] splice: L... |
141 |
buf->flags |= PIPE_BUF_FLAG_LRU; |
330ab7161 [PATCH] vmsplice:... |
142 |
return generic_pipe_buf_steal(pipe, buf); |
912d35f86 [PATCH] Add suppo... |
143 |
} |
d4c3cca94 [PATCH] constify ... |
144 |
static const struct pipe_buf_operations user_page_pipe_buf_ops = { |
912d35f86 [PATCH] Add suppo... |
145 |
.can_merge = 0, |
f84d75199 [PATCH] pipe: int... |
146 147 |
.map = generic_pipe_buf_map, .unmap = generic_pipe_buf_unmap, |
cac36bb06 pipe: change the ... |
148 |
.confirm = generic_pipe_buf_confirm, |
912d35f86 [PATCH] Add suppo... |
149 150 |
.release = page_cache_pipe_buf_release, .steal = user_page_pipe_buf_steal, |
f84d75199 [PATCH] pipe: int... |
151 |
.get = generic_pipe_buf_get, |
912d35f86 [PATCH] Add suppo... |
152 |
}; |
932cc6d4f splice: completel... |
153 154 155 156 157 158 |
/** * splice_to_pipe - fill passed data into a pipe * @pipe: pipe to fill * @spd: data to fill * * Description: |
79685b8de docbook: add pipe... |
159 |
* @spd contains a map of pages and len/offset tuples, along with |
932cc6d4f splice: completel... |
160 161 162 |
* the struct pipe_buf_operations associated with these pages. This * function will link that data to the pipe. * |
83f9135bd [PATCH] splice: a... |
163 |
*/ |
d6b29d7ce splice: divorce t... |
164 165 |
ssize_t splice_to_pipe(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) |
5274f052e [PATCH] Introduce... |
166 |
{ |
00de00bda splice: fix leak ... |
167 |
unsigned int spd_pages = spd->nr_pages; |
912d35f86 [PATCH] Add suppo... |
168 |
int ret, do_wakeup, page_nr; |
5274f052e [PATCH] Introduce... |
169 170 171 |
ret = 0; do_wakeup = 0; |
912d35f86 [PATCH] Add suppo... |
172 |
page_nr = 0; |
5274f052e [PATCH] Introduce... |
173 |
|
3a326a2ce [PATCH] introduce... |
174 175 |
if (pipe->inode) mutex_lock(&pipe->inode->i_mutex); |
5274f052e [PATCH] Introduce... |
176 |
|
5274f052e [PATCH] Introduce... |
177 |
for (;;) { |
3a326a2ce [PATCH] introduce... |
178 |
if (!pipe->readers) { |
5274f052e [PATCH] Introduce... |
179 180 181 182 183 |
send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; break; } |
6f767b042 [PATCH] splice: s... |
184 185 |
if (pipe->nrbufs < PIPE_BUFFERS) { int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1); |
3a326a2ce [PATCH] introduce... |
186 |
struct pipe_buffer *buf = pipe->bufs + newbuf; |
5274f052e [PATCH] Introduce... |
187 |
|
912d35f86 [PATCH] Add suppo... |
188 189 190 |
buf->page = spd->pages[page_nr]; buf->offset = spd->partial[page_nr].offset; buf->len = spd->partial[page_nr].len; |
497f9625c pipe: allow passi... |
191 |
buf->private = spd->partial[page_nr].private; |
912d35f86 [PATCH] Add suppo... |
192 |
buf->ops = spd->ops; |
7afa6fd03 [PATCH] vmsplice:... |
193 194 |
if (spd->flags & SPLICE_F_GIFT) buf->flags |= PIPE_BUF_FLAG_GIFT; |
6f767b042 [PATCH] splice: s... |
195 |
pipe->nrbufs++; |
912d35f86 [PATCH] Add suppo... |
196 197 |
page_nr++; ret += buf->len; |
6f767b042 [PATCH] splice: s... |
198 199 |
if (pipe->inode) do_wakeup = 1; |
5274f052e [PATCH] Introduce... |
200 |
|
912d35f86 [PATCH] Add suppo... |
201 |
if (!--spd->nr_pages) |
5274f052e [PATCH] Introduce... |
202 |
break; |
6f767b042 [PATCH] splice: s... |
203 |
if (pipe->nrbufs < PIPE_BUFFERS) |
5274f052e [PATCH] Introduce... |
204 205 206 207 |
continue; break; } |
912d35f86 [PATCH] Add suppo... |
208 |
if (spd->flags & SPLICE_F_NONBLOCK) { |
29e350944 splice: add SPLIC... |
209 210 211 212 |
if (!ret) ret = -EAGAIN; break; } |
5274f052e [PATCH] Introduce... |
213 214 215 216 217 218 219 |
if (signal_pending(current)) { if (!ret) ret = -ERESTARTSYS; break; } if (do_wakeup) { |
c0bd1f650 [PATCH] splice: o... |
220 |
smp_mb(); |
3a326a2ce [PATCH] introduce... |
221 222 223 |
if (waitqueue_active(&pipe->wait)) wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
5274f052e [PATCH] Introduce... |
224 225 |
do_wakeup = 0; } |
3a326a2ce [PATCH] introduce... |
226 227 228 |
pipe->waiting_writers++; pipe_wait(pipe); pipe->waiting_writers--; |
5274f052e [PATCH] Introduce... |
229 |
} |
02676e5ae splice: only chec... |
230 |
if (pipe->inode) { |
3a326a2ce [PATCH] introduce... |
231 |
mutex_unlock(&pipe->inode->i_mutex); |
5274f052e [PATCH] Introduce... |
232 |
|
02676e5ae splice: only chec... |
233 234 235 236 237 238 |
if (do_wakeup) { smp_mb(); if (waitqueue_active(&pipe->wait)) wake_up_interruptible(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); } |
5274f052e [PATCH] Introduce... |
239 |
} |
00de00bda splice: fix leak ... |
240 |
while (page_nr < spd_pages) |
bbdfc2f70 [SPLICE]: Don't a... |
241 |
spd->spd_release(spd, page_nr++); |
5274f052e [PATCH] Introduce... |
242 243 244 |
return ret; } |
bbdfc2f70 [SPLICE]: Don't a... |
245 246 247 248 |
static void spd_release_page(struct splice_pipe_desc *spd, unsigned int i) { page_cache_release(spd->pages[i]); } |
3a326a2ce [PATCH] introduce... |
249 |
static int |
cbb7e577e [PATCH] splice: p... |
250 251 252 |
__generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
253 254 |
{ struct address_space *mapping = in->f_mapping; |
d8983910a readahead: pass r... |
255 |
unsigned int loff, nr_pages, req_pages; |
16c523dda [PATCH] splice: c... |
256 |
struct page *pages[PIPE_BUFFERS]; |
912d35f86 [PATCH] Add suppo... |
257 |
struct partial_page partial[PIPE_BUFFERS]; |
5274f052e [PATCH] Introduce... |
258 |
struct page *page; |
91ad66ef4 [PATCH] splice: c... |
259 260 |
pgoff_t index, end_index; loff_t isize; |
eb20796bf [PATCH] splice: m... |
261 |
int error, page_nr; |
912d35f86 [PATCH] Add suppo... |
262 263 264 265 266 |
struct splice_pipe_desc spd = { .pages = pages, .partial = partial, .flags = flags, .ops = &page_cache_pipe_buf_ops, |
bbdfc2f70 [SPLICE]: Don't a... |
267 |
.spd_release = spd_release_page, |
912d35f86 [PATCH] Add suppo... |
268 |
}; |
5274f052e [PATCH] Introduce... |
269 |
|
cbb7e577e [PATCH] splice: p... |
270 |
index = *ppos >> PAGE_CACHE_SHIFT; |
912d35f86 [PATCH] Add suppo... |
271 |
loff = *ppos & ~PAGE_CACHE_MASK; |
d8983910a readahead: pass r... |
272 273 |
req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; nr_pages = min(req_pages, (unsigned)PIPE_BUFFERS); |
5274f052e [PATCH] Introduce... |
274 275 |
/* |
eb20796bf [PATCH] splice: m... |
276 277 278 |
* Lookup the (hopefully) full range of pages we need. */ spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, pages); |
431a4820b readahead: move s... |
279 |
index += spd.nr_pages; |
82aa5d618 [PATCH] splice: f... |
280 |
|
eb20796bf [PATCH] splice: m... |
281 282 |
/* * If find_get_pages_contig() returned fewer pages than we needed, |
431a4820b readahead: move s... |
283 |
* readahead/allocate the rest and fill in the holes. |
eb20796bf [PATCH] splice: m... |
284 |
*/ |
431a4820b readahead: move s... |
285 |
if (spd.nr_pages < nr_pages) |
cf914a7d6 readahead: split ... |
286 287 |
page_cache_sync_readahead(mapping, &in->f_ra, in, index, req_pages - spd.nr_pages); |
431a4820b readahead: move s... |
288 |
|
932cc6d4f splice: completel... |
289 |
error = 0; |
eb20796bf [PATCH] splice: m... |
290 |
while (spd.nr_pages < nr_pages) { |
82aa5d618 [PATCH] splice: f... |
291 |
/* |
eb20796bf [PATCH] splice: m... |
292 293 |
* Page could be there, find_get_pages_contig() breaks on * the first hole. |
5274f052e [PATCH] Introduce... |
294 |
*/ |
7480a9043 [PATCH] splice: s... |
295 296 |
page = find_get_page(mapping, index); if (!page) { |
e27dedd84 [PATCH] splice: c... |
297 |
/* |
eb20796bf [PATCH] splice: m... |
298 |
* page didn't exist, allocate one. |
7480a9043 [PATCH] splice: s... |
299 300 301 302 303 304 |
*/ page = page_cache_alloc_cold(mapping); if (!page) break; error = add_to_page_cache_lru(page, mapping, index, |
4cd135046 splice: use mappi... |
305 |
mapping_gfp_mask(mapping)); |
7480a9043 [PATCH] splice: s... |
306 307 |
if (unlikely(error)) { page_cache_release(page); |
a0548871e [PATCH] splice: r... |
308 309 |
if (error == -EEXIST) continue; |
7480a9043 [PATCH] splice: s... |
310 311 |
break; } |
eb20796bf [PATCH] splice: m... |
312 313 314 315 316 |
/* * add_to_page_cache() locks the page, unlock it * to avoid convoluting the logic below even more. */ unlock_page(page); |
7480a9043 [PATCH] splice: s... |
317 |
} |
eb20796bf [PATCH] splice: m... |
318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 |
pages[spd.nr_pages++] = page; index++; } /* * Now loop over the map and see if we need to start IO on any * pages, fill in the partial map, etc. */ index = *ppos >> PAGE_CACHE_SHIFT; nr_pages = spd.nr_pages; spd.nr_pages = 0; for (page_nr = 0; page_nr < nr_pages; page_nr++) { unsigned int this_len; if (!len) break; /* * this_len is the max we'll use from this page */ this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); page = pages[page_nr]; |
a08a166fe readahead: conver... |
340 |
if (PageReadahead(page)) |
cf914a7d6 readahead: split ... |
341 |
page_cache_async_readahead(mapping, &in->f_ra, in, |
d8983910a readahead: pass r... |
342 |
page, index, req_pages - page_nr); |
a08a166fe readahead: conver... |
343 |
|
7480a9043 [PATCH] splice: s... |
344 345 346 347 |
/* * If the page isn't uptodate, we may need to start io on it */ if (!PageUptodate(page)) { |
c4f895cbe [PATCH] splice: c... |
348 349 350 351 |
/* * If in nonblock mode then dont block on waiting * for an in-flight io page */ |
9ae9d68cb [PATCH] splice():... |
352 |
if (flags & SPLICE_F_NONBLOCK) { |
529ae9aaa mm: rename page t... |
353 |
if (!trylock_page(page)) { |
8191ecd1d splice: fix infin... |
354 |
error = -EAGAIN; |
9ae9d68cb [PATCH] splice():... |
355 |
break; |
8191ecd1d splice: fix infin... |
356 |
} |
9ae9d68cb [PATCH] splice():... |
357 358 |
} else lock_page(page); |
7480a9043 [PATCH] splice: s... |
359 360 |
/* |
32502b841 splice: fix gener... |
361 362 363 364 |
* Page was truncated, or invalidated by the * filesystem. Redo the find/create, but this time the * page is kept locked, so there's no chance of another * race with truncate/invalidate. |
7480a9043 [PATCH] splice: s... |
365 366 367 |
*/ if (!page->mapping) { unlock_page(page); |
32502b841 splice: fix gener... |
368 369 370 371 372 373 374 375 376 |
page = find_or_create_page(mapping, index, mapping_gfp_mask(mapping)); if (!page) { error = -ENOMEM; break; } page_cache_release(pages[page_nr]); pages[page_nr] = page; |
7480a9043 [PATCH] splice: s... |
377 378 379 380 381 382 383 384 |
} /* * page was already under io and is now done, great */ if (PageUptodate(page)) { unlock_page(page); goto fill_it; } |
5274f052e [PATCH] Introduce... |
385 |
|
7480a9043 [PATCH] splice: s... |
386 387 388 389 |
/* * need to read in the page */ error = mapping->a_ops->readpage(in, page); |
5274f052e [PATCH] Introduce... |
390 |
if (unlikely(error)) { |
eb20796bf [PATCH] splice: m... |
391 392 393 394 395 396 |
/* * We really should re-lookup the page here, * but it complicates things a lot. Instead * lets just do what we already stored, and * we'll get it the next time we are called. */ |
7480a9043 [PATCH] splice: s... |
397 |
if (error == AOP_TRUNCATED_PAGE) |
eb20796bf [PATCH] splice: m... |
398 |
error = 0; |
5274f052e [PATCH] Introduce... |
399 400 |
break; } |
620a324b7 splice: __generic... |
401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 |
} fill_it: /* * i_size must be checked after PageUptodate. */ isize = i_size_read(mapping->host); end_index = (isize - 1) >> PAGE_CACHE_SHIFT; if (unlikely(!isize || index > end_index)) break; /* * if this is the last page, see if we need to shrink * the length and stop */ if (end_index == index) { unsigned int plen; |
91ad66ef4 [PATCH] splice: c... |
417 418 |
/* |
620a324b7 splice: __generic... |
419 |
* max good bytes in this page |
91ad66ef4 [PATCH] splice: c... |
420 |
*/ |
620a324b7 splice: __generic... |
421 422 |
plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1; if (plen <= loff) |
91ad66ef4 [PATCH] splice: c... |
423 |
break; |
91ad66ef4 [PATCH] splice: c... |
424 425 |
/* |
620a324b7 splice: __generic... |
426 |
* force quit after adding this page |
91ad66ef4 [PATCH] splice: c... |
427 |
*/ |
620a324b7 splice: __generic... |
428 429 |
this_len = min(this_len, plen - loff); len = this_len; |
5274f052e [PATCH] Introduce... |
430 |
} |
620a324b7 splice: __generic... |
431 |
|
eb20796bf [PATCH] splice: m... |
432 433 |
partial[page_nr].offset = loff; partial[page_nr].len = this_len; |
82aa5d618 [PATCH] splice: f... |
434 |
len -= this_len; |
91ad66ef4 [PATCH] splice: c... |
435 |
loff = 0; |
eb20796bf [PATCH] splice: m... |
436 437 |
spd.nr_pages++; index++; |
5274f052e [PATCH] Introduce... |
438 |
} |
eb20796bf [PATCH] splice: m... |
439 |
/* |
475ecade6 splice: __generic... |
440 |
* Release any pages at the end, if we quit early. 'page_nr' is how far |
eb20796bf [PATCH] splice: m... |
441 442 443 444 |
* we got, 'nr_pages' is how many pages are in the map. */ while (page_nr < nr_pages) page_cache_release(pages[page_nr++]); |
f4e6b498d readahead: combin... |
445 |
in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; |
eb20796bf [PATCH] splice: m... |
446 |
|
912d35f86 [PATCH] Add suppo... |
447 |
if (spd.nr_pages) |
00522fb41 [PATCH] splice: r... |
448 |
return splice_to_pipe(pipe, &spd); |
5274f052e [PATCH] Introduce... |
449 |
|
7480a9043 [PATCH] splice: s... |
450 |
return error; |
5274f052e [PATCH] Introduce... |
451 |
} |
83f9135bd [PATCH] splice: a... |
452 453 454 |
/** * generic_file_splice_read - splice data from file to a pipe * @in: file to splice from |
932cc6d4f splice: completel... |
455 |
* @ppos: position in @in |
83f9135bd [PATCH] splice: a... |
456 457 458 459 |
* @pipe: pipe to splice to * @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
460 461 462 463 464 |
* Description: * Will read pages from given file and fill them into a pipe. Can be * used as long as the address_space operations for the source implements * a readpage() hook. * |
83f9135bd [PATCH] splice: a... |
465 |
*/ |
cbb7e577e [PATCH] splice: p... |
466 467 468 |
ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
469 |
{ |
d366d3988 splice: move inod... |
470 |
loff_t isize, left; |
8191ecd1d splice: fix infin... |
471 |
int ret; |
d366d3988 splice: move inod... |
472 473 474 475 476 477 478 479 |
isize = i_size_read(in->f_mapping->host); if (unlikely(*ppos >= isize)) return 0; left = isize - *ppos; if (unlikely(left < len)) len = left; |
5274f052e [PATCH] Introduce... |
480 |
|
8191ecd1d splice: fix infin... |
481 482 |
ret = __generic_file_splice_read(in, ppos, pipe, len, flags); if (ret > 0) |
cbb7e577e [PATCH] splice: p... |
483 |
*ppos += ret; |
5274f052e [PATCH] Introduce... |
484 485 486 |
return ret; } |
059a8f373 [PATCH] splice: e... |
487 |
EXPORT_SYMBOL(generic_file_splice_read); |
5274f052e [PATCH] Introduce... |
488 |
/* |
4f6f0bd2f [PATCH] splice: i... |
489 |
* Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' |
016b661e2 [PATCH] splice: f... |
490 |
* using sendpage(). Return the number of bytes sent. |
5274f052e [PATCH] Introduce... |
491 |
*/ |
76ad4d111 [PATCH] splice: r... |
492 |
static int pipe_to_sendpage(struct pipe_inode_info *pipe, |
5274f052e [PATCH] Introduce... |
493 494 |
struct pipe_buffer *buf, struct splice_desc *sd) { |
6a14b90bb vmsplice: add vms... |
495 |
struct file *file = sd->u.file; |
5274f052e [PATCH] Introduce... |
496 |
loff_t pos = sd->pos; |
f84d75199 [PATCH] pipe: int... |
497 |
int ret, more; |
5274f052e [PATCH] Introduce... |
498 |
|
cac36bb06 pipe: change the ... |
499 |
ret = buf->ops->confirm(pipe, buf); |
f84d75199 [PATCH] pipe: int... |
500 501 |
if (!ret) { more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len; |
5274f052e [PATCH] Introduce... |
502 |
|
f84d75199 [PATCH] pipe: int... |
503 504 505 |
ret = file->f_op->sendpage(file, buf->page, buf->offset, sd->len, &pos, more); } |
5274f052e [PATCH] Introduce... |
506 |
|
016b661e2 [PATCH] splice: f... |
507 |
return ret; |
5274f052e [PATCH] Introduce... |
508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 |
} /* * This is a little more tricky than the file -> pipe splicing. There are * basically three cases: * * - Destination page already exists in the address space and there * are users of it. For that case we have no other option that * copying the data. Tough luck. * - Destination page already exists in the address space, but there * are no users of it. Make sure it's uptodate, then drop it. Fall * through to last case. * - Destination page does not exist, we can add the pipe page to * the page cache and avoid the copy. * |
83f9135bd [PATCH] splice: a... |
523 524 525 526 527 528 |
* If asked to move pages to the output file (SPLICE_F_MOVE is set in * sd->flags), we attempt to migrate pages from the pipe to the output * file address space page cache. This is possible if no one else has * the pipe page referenced outside of the pipe and page cache. If * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create * a new page in the output file page cache and fill/dirty that. |
5274f052e [PATCH] Introduce... |
529 |
*/ |
76ad4d111 [PATCH] splice: r... |
530 |
static int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf, |
5274f052e [PATCH] Introduce... |
531 532 |
struct splice_desc *sd) { |
6a14b90bb vmsplice: add vms... |
533 |
struct file *file = sd->u.file; |
5274f052e [PATCH] Introduce... |
534 |
struct address_space *mapping = file->f_mapping; |
016b661e2 [PATCH] splice: f... |
535 |
unsigned int offset, this_len; |
5274f052e [PATCH] Introduce... |
536 |
struct page *page; |
afddba49d fs: introduce wri... |
537 |
void *fsdata; |
3e7ee3e7b [PATCH] splice: f... |
538 |
int ret; |
5274f052e [PATCH] Introduce... |
539 540 |
/* |
49d0b21be [PATCH] splice: o... |
541 |
* make sure the data in this buffer is uptodate |
5274f052e [PATCH] Introduce... |
542 |
*/ |
cac36bb06 pipe: change the ... |
543 |
ret = buf->ops->confirm(pipe, buf); |
f84d75199 [PATCH] pipe: int... |
544 545 |
if (unlikely(ret)) return ret; |
5274f052e [PATCH] Introduce... |
546 |
|
5274f052e [PATCH] Introduce... |
547 |
offset = sd->pos & ~PAGE_CACHE_MASK; |
016b661e2 [PATCH] splice: f... |
548 549 550 |
this_len = sd->len; if (this_len + offset > PAGE_CACHE_SIZE) this_len = PAGE_CACHE_SIZE - offset; |
afddba49d fs: introduce wri... |
551 552 553 554 |
ret = pagecache_write_begin(file, mapping, sd->pos, this_len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); if (unlikely(ret)) goto out; |
5274f052e [PATCH] Introduce... |
555 |
|
0568b409c [PATCH] splice: f... |
556 |
if (buf->page != page) { |
f84d75199 [PATCH] pipe: int... |
557 558 559 |
/* * Careful, ->map() uses KM_USER0! */ |
76ad4d111 [PATCH] splice: r... |
560 |
char *src = buf->ops->map(pipe, buf, 1); |
f84d75199 [PATCH] pipe: int... |
561 |
char *dst = kmap_atomic(page, KM_USER1); |
5abc97aa2 [PATCH] splice: a... |
562 |
|
016b661e2 [PATCH] splice: f... |
563 |
memcpy(dst + offset, src + buf->offset, this_len); |
5abc97aa2 [PATCH] splice: a... |
564 |
flush_dcache_page(page); |
f84d75199 [PATCH] pipe: int... |
565 |
kunmap_atomic(dst, KM_USER1); |
76ad4d111 [PATCH] splice: r... |
566 |
buf->ops->unmap(pipe, buf, src); |
5abc97aa2 [PATCH] splice: a... |
567 |
} |
afddba49d fs: introduce wri... |
568 569 |
ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len, page, fsdata); |
5274f052e [PATCH] Introduce... |
570 |
out: |
5274f052e [PATCH] Introduce... |
571 572 |
return ret; } |
932cc6d4f splice: completel... |
573 574 575 576 577 578 579 580 581 582 583 584 |
/** * __splice_from_pipe - splice data from a pipe to given actor * @pipe: pipe to splice from * @sd: information to @actor * @actor: handler that splices the data * * Description: * This function does little more than loop over the pipe and call * @actor to do the actual moving of a single struct pipe_buffer to * the desired destination. See pipe_to_file, pipe_to_sendpage, or * pipe_to_user. * |
83f9135bd [PATCH] splice: a... |
585 |
*/ |
c66ab6fa7 splice: abstract ... |
586 587 |
ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd, splice_actor *actor) |
5274f052e [PATCH] Introduce... |
588 |
{ |
5274f052e [PATCH] Introduce... |
589 |
int ret, do_wakeup, err; |
5274f052e [PATCH] Introduce... |
590 591 592 |
ret = 0; do_wakeup = 0; |
5274f052e [PATCH] Introduce... |
593 |
for (;;) { |
6f767b042 [PATCH] splice: s... |
594 595 |
if (pipe->nrbufs) { struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; |
d4c3cca94 [PATCH] constify ... |
596 |
const struct pipe_buf_operations *ops = buf->ops; |
5274f052e [PATCH] Introduce... |
597 |
|
c66ab6fa7 splice: abstract ... |
598 599 600 |
sd->len = buf->len; if (sd->len > sd->total_len) sd->len = sd->total_len; |
5274f052e [PATCH] Introduce... |
601 |
|
c66ab6fa7 splice: abstract ... |
602 |
err = actor(pipe, buf, sd); |
016b661e2 [PATCH] splice: f... |
603 |
if (err <= 0) { |
5274f052e [PATCH] Introduce... |
604 605 606 607 608 |
if (!ret && err != -ENODATA) ret = err; break; } |
016b661e2 [PATCH] splice: f... |
609 610 611 |
ret += err; buf->offset += err; buf->len -= err; |
c66ab6fa7 splice: abstract ... |
612 613 614 615 |
sd->len -= err; sd->pos += err; sd->total_len -= err; if (sd->len) |
016b661e2 [PATCH] splice: f... |
616 |
continue; |
73d62d83e [PATCH] splice: c... |
617 |
|
5274f052e [PATCH] Introduce... |
618 619 |
if (!buf->len) { buf->ops = NULL; |
3a326a2ce [PATCH] introduce... |
620 |
ops->release(pipe, buf); |
6f767b042 [PATCH] splice: s... |
621 622 623 624 |
pipe->curbuf = (pipe->curbuf + 1) & (PIPE_BUFFERS - 1); pipe->nrbufs--; if (pipe->inode) do_wakeup = 1; |
5274f052e [PATCH] Introduce... |
625 |
} |
c66ab6fa7 splice: abstract ... |
626 |
if (!sd->total_len) |
5274f052e [PATCH] Introduce... |
627 628 |
break; } |
6f767b042 [PATCH] splice: s... |
629 |
if (pipe->nrbufs) |
5274f052e [PATCH] Introduce... |
630 |
continue; |
3a326a2ce [PATCH] introduce... |
631 |
if (!pipe->writers) |
5274f052e [PATCH] Introduce... |
632 |
break; |
3a326a2ce [PATCH] introduce... |
633 |
if (!pipe->waiting_writers) { |
5274f052e [PATCH] Introduce... |
634 635 636 |
if (ret) break; } |
c66ab6fa7 splice: abstract ... |
637 |
if (sd->flags & SPLICE_F_NONBLOCK) { |
29e350944 splice: add SPLIC... |
638 639 640 641 |
if (!ret) ret = -EAGAIN; break; } |
5274f052e [PATCH] Introduce... |
642 643 644 645 646 647 648 |
if (signal_pending(current)) { if (!ret) ret = -ERESTARTSYS; break; } if (do_wakeup) { |
c0bd1f650 [PATCH] splice: o... |
649 |
smp_mb(); |
3a326a2ce [PATCH] introduce... |
650 651 652 |
if (waitqueue_active(&pipe->wait)) wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
5274f052e [PATCH] Introduce... |
653 654 |
do_wakeup = 0; } |
3a326a2ce [PATCH] introduce... |
655 |
pipe_wait(pipe); |
5274f052e [PATCH] Introduce... |
656 |
} |
5274f052e [PATCH] Introduce... |
657 |
if (do_wakeup) { |
c0bd1f650 [PATCH] splice: o... |
658 |
smp_mb(); |
3a326a2ce [PATCH] introduce... |
659 660 661 |
if (waitqueue_active(&pipe->wait)) wake_up_interruptible(&pipe->wait); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
5274f052e [PATCH] Introduce... |
662 |
} |
5274f052e [PATCH] Introduce... |
663 |
return ret; |
5274f052e [PATCH] Introduce... |
664 |
} |
40bee44ea Export __splice_f... |
665 |
EXPORT_SYMBOL(__splice_from_pipe); |
5274f052e [PATCH] Introduce... |
666 |
|
932cc6d4f splice: completel... |
667 668 669 670 671 672 673 674 675 676 677 678 679 680 |
/** * splice_from_pipe - splice data from a pipe to a file * @pipe: pipe to splice from * @out: file to splice to * @ppos: position in @out * @len: how many bytes to splice * @flags: splice modifier flags * @actor: handler that splices the data * * Description: * See __splice_from_pipe. This function locks the input and output inodes, * otherwise it's identical to __splice_from_pipe(). * */ |
6da618098 [PATCH] Introduce... |
681 682 683 684 685 686 |
ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags, splice_actor *actor) { ssize_t ret; struct inode *inode = out->f_mapping->host; |
c66ab6fa7 splice: abstract ... |
687 688 689 690 |
struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, |
6a14b90bb vmsplice: add vms... |
691 |
.u.file = out, |
c66ab6fa7 splice: abstract ... |
692 |
}; |
6da618098 [PATCH] Introduce... |
693 694 695 696 697 698 699 700 |
/* * The actor worker might be calling ->prepare_write and * ->commit_write. Most of the time, these expect i_mutex to * be held. Since this may result in an ABBA deadlock with * pipe->inode, we have to order lock acquiry here. */ inode_double_lock(inode, pipe->inode); |
c66ab6fa7 splice: abstract ... |
701 |
ret = __splice_from_pipe(pipe, &sd, actor); |
6da618098 [PATCH] Introduce... |
702 703 704 705 706 707 708 709 710 |
inode_double_unlock(inode, pipe->inode); return ret; } /** * generic_file_splice_write_nolock - generic_file_splice_write without mutexes * @pipe: pipe info * @out: file to write to |
932cc6d4f splice: completel... |
711 |
* @ppos: position in @out |
6da618098 [PATCH] Introduce... |
712 713 714 |
* @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
715 716 717 718 |
* Description: * Will either move or copy pages (determined by @flags options) from * the given pipe inode to the given file. The caller is responsible * for acquiring i_mutex on both inodes. |
6da618098 [PATCH] Introduce... |
719 720 721 722 723 724 725 726 |
* */ ssize_t generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags) { struct address_space *mapping = out->f_mapping; struct inode *inode = mapping->host; |
c66ab6fa7 splice: abstract ... |
727 728 729 730 |
struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, |
6a14b90bb vmsplice: add vms... |
731 |
.u.file = out, |
c66ab6fa7 splice: abstract ... |
732 |
}; |
6da618098 [PATCH] Introduce... |
733 734 |
ssize_t ret; int err; |
2f1936b87 [patch 3/5] vfs: ... |
735 |
err = file_remove_suid(out); |
8c34e2d63 [PATCH] Remove SU... |
736 737 |
if (unlikely(err)) return err; |
c66ab6fa7 splice: abstract ... |
738 |
ret = __splice_from_pipe(pipe, &sd, pipe_to_file); |
6da618098 [PATCH] Introduce... |
739 |
if (ret > 0) { |
17ee4f49a splice: adjust ba... |
740 |
unsigned long nr_pages; |
6da618098 [PATCH] Introduce... |
741 |
*ppos += ret; |
17ee4f49a splice: adjust ba... |
742 |
nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
6da618098 [PATCH] Introduce... |
743 744 745 746 747 748 749 750 751 752 753 754 |
/* * If file or inode is SYNC and we actually wrote some data, * sync it. */ if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) { err = generic_osync_inode(inode, mapping, OSYNC_METADATA|OSYNC_DATA); if (err) ret = err; } |
17ee4f49a splice: adjust ba... |
755 |
balance_dirty_pages_ratelimited_nr(mapping, nr_pages); |
6da618098 [PATCH] Introduce... |
756 757 758 759 760 761 |
} return ret; } EXPORT_SYMBOL(generic_file_splice_write_nolock); |
83f9135bd [PATCH] splice: a... |
762 763 |
/** * generic_file_splice_write - splice data from a pipe to a file |
3a326a2ce [PATCH] introduce... |
764 |
* @pipe: pipe info |
83f9135bd [PATCH] splice: a... |
765 |
* @out: file to write to |
932cc6d4f splice: completel... |
766 |
* @ppos: position in @out |
83f9135bd [PATCH] splice: a... |
767 768 769 |
* @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
770 771 772 |
* Description: * Will either move or copy pages (determined by @flags options) from * the given pipe inode to the given file. |
83f9135bd [PATCH] splice: a... |
773 774 |
* */ |
3a326a2ce [PATCH] introduce... |
775 776 |
ssize_t generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, |
cbb7e577e [PATCH] splice: p... |
777 |
loff_t *ppos, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
778 |
{ |
4f6f0bd2f [PATCH] splice: i... |
779 |
struct address_space *mapping = out->f_mapping; |
8c34e2d63 [PATCH] Remove SU... |
780 |
struct inode *inode = mapping->host; |
7f3d4ee10 vfs: splice remov... |
781 782 783 784 785 786 |
struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, .u.file = out, }; |
3a326a2ce [PATCH] introduce... |
787 |
ssize_t ret; |
7f3d4ee10 vfs: splice remov... |
788 |
inode_double_lock(inode, pipe->inode); |
2f1936b87 [patch 3/5] vfs: ... |
789 |
ret = file_remove_suid(out); |
7f3d4ee10 vfs: splice remov... |
790 791 792 |
if (likely(!ret)) ret = __splice_from_pipe(pipe, &sd, pipe_to_file); inode_double_unlock(inode, pipe->inode); |
a4514ebd8 [PATCH] splice: o... |
793 |
if (ret > 0) { |
17ee4f49a splice: adjust ba... |
794 |
unsigned long nr_pages; |
a4514ebd8 [PATCH] splice: o... |
795 |
*ppos += ret; |
17ee4f49a splice: adjust ba... |
796 |
nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
a4514ebd8 [PATCH] splice: o... |
797 798 799 800 801 802 |
/* * If file or inode is SYNC and we actually wrote some data, * sync it. */ if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) { |
7f3d4ee10 vfs: splice remov... |
803 |
int err; |
a4514ebd8 [PATCH] splice: o... |
804 805 806 807 |
mutex_lock(&inode->i_mutex); err = generic_osync_inode(inode, mapping, OSYNC_METADATA|OSYNC_DATA); mutex_unlock(&inode->i_mutex); |
4f6f0bd2f [PATCH] splice: i... |
808 |
|
a4514ebd8 [PATCH] splice: o... |
809 810 811 |
if (err) ret = err; } |
17ee4f49a splice: adjust ba... |
812 |
balance_dirty_pages_ratelimited_nr(mapping, nr_pages); |
4f6f0bd2f [PATCH] splice: i... |
813 814 815 |
} return ret; |
5274f052e [PATCH] Introduce... |
816 |
} |
059a8f373 [PATCH] splice: e... |
817 |
EXPORT_SYMBOL(generic_file_splice_write); |
83f9135bd [PATCH] splice: a... |
818 819 |
/** * generic_splice_sendpage - splice data from a pipe to a socket |
932cc6d4f splice: completel... |
820 |
* @pipe: pipe to splice from |
83f9135bd [PATCH] splice: a... |
821 |
* @out: socket to write to |
932cc6d4f splice: completel... |
822 |
* @ppos: position in @out |
83f9135bd [PATCH] splice: a... |
823 824 825 |
* @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
826 827 828 |
* Description: * Will send @len bytes from the pipe to a network socket. No data copying * is involved. |
83f9135bd [PATCH] splice: a... |
829 830 |
* */ |
3a326a2ce [PATCH] introduce... |
831 |
ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, |
cbb7e577e [PATCH] splice: p... |
832 |
loff_t *ppos, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
833 |
{ |
00522fb41 [PATCH] splice: r... |
834 |
return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); |
5274f052e [PATCH] Introduce... |
835 |
} |
059a8f373 [PATCH] splice: e... |
836 |
EXPORT_SYMBOL(generic_splice_sendpage); |
a0f067802 [PATCH] splice ex... |
837 |
|
83f9135bd [PATCH] splice: a... |
838 839 840 |
/* * Attempt to initiate a splice from pipe to file. */ |
3a326a2ce [PATCH] introduce... |
841 |
static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, |
cbb7e577e [PATCH] splice: p... |
842 |
loff_t *ppos, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
843 |
{ |
5274f052e [PATCH] Introduce... |
844 |
int ret; |
49570e9b2 [PATCH] splice: u... |
845 |
if (unlikely(!out->f_op || !out->f_op->splice_write)) |
5274f052e [PATCH] Introduce... |
846 |
return -EINVAL; |
49570e9b2 [PATCH] splice: u... |
847 |
if (unlikely(!(out->f_mode & FMODE_WRITE))) |
5274f052e [PATCH] Introduce... |
848 |
return -EBADF; |
efc968d45 Don't allow splic... |
849 850 |
if (unlikely(out->f_flags & O_APPEND)) return -EINVAL; |
cbb7e577e [PATCH] splice: p... |
851 |
ret = rw_verify_area(WRITE, out, ppos, len); |
5274f052e [PATCH] Introduce... |
852 853 |
if (unlikely(ret < 0)) return ret; |
cbb7e577e [PATCH] splice: p... |
854 |
return out->f_op->splice_write(pipe, out, ppos, len, flags); |
5274f052e [PATCH] Introduce... |
855 |
} |
83f9135bd [PATCH] splice: a... |
856 857 858 |
/* * Attempt to initiate a splice from a file to a pipe. */ |
cbb7e577e [PATCH] splice: p... |
859 860 861 |
static long do_splice_to(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
862 |
{ |
5274f052e [PATCH] Introduce... |
863 |
int ret; |
49570e9b2 [PATCH] splice: u... |
864 |
if (unlikely(!in->f_op || !in->f_op->splice_read)) |
5274f052e [PATCH] Introduce... |
865 |
return -EINVAL; |
49570e9b2 [PATCH] splice: u... |
866 |
if (unlikely(!(in->f_mode & FMODE_READ))) |
5274f052e [PATCH] Introduce... |
867 |
return -EBADF; |
cbb7e577e [PATCH] splice: p... |
868 |
ret = rw_verify_area(READ, in, ppos, len); |
5274f052e [PATCH] Introduce... |
869 870 |
if (unlikely(ret < 0)) return ret; |
cbb7e577e [PATCH] splice: p... |
871 |
return in->f_op->splice_read(in, ppos, pipe, len, flags); |
5274f052e [PATCH] Introduce... |
872 |
} |
932cc6d4f splice: completel... |
873 874 875 876 877 878 879 880 881 |
/** * splice_direct_to_actor - splices data directly between two non-pipes * @in: file to splice from * @sd: actor information on where to splice to * @actor: handles the data splicing * * Description: * This is a special case helper to splice directly between two * points, without requiring an explicit pipe. Internally an allocated |
79685b8de docbook: add pipe... |
882 |
* pipe is cached in the process, and reused during the lifetime of |
932cc6d4f splice: completel... |
883 884 |
* that process. * |
c66ab6fa7 splice: abstract ... |
885 886 887 |
*/ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, splice_direct_actor *actor) |
b92ce5589 [PATCH] splice: a... |
888 889 890 891 |
{ struct pipe_inode_info *pipe; long ret, bytes; umode_t i_mode; |
c66ab6fa7 splice: abstract ... |
892 893 |
size_t len; int i, flags; |
b92ce5589 [PATCH] splice: a... |
894 895 896 897 898 899 |
/* * We require the input being a regular file, as we don't want to * randomly drop data for eg socket -> socket splicing. Use the * piped splicing for that! */ |
0f7fc9e4d [PATCH] VFS: chan... |
900 |
i_mode = in->f_path.dentry->d_inode->i_mode; |
b92ce5589 [PATCH] splice: a... |
901 902 903 904 905 906 907 908 |
if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode))) return -EINVAL; /* * neither in nor out is a pipe, setup an internal pipe attached to * 'out' and transfer the wanted data from 'in' to 'out' through that */ pipe = current->splice_pipe; |
49570e9b2 [PATCH] splice: u... |
909 |
if (unlikely(!pipe)) { |
b92ce5589 [PATCH] splice: a... |
910 911 912 913 914 915 |
pipe = alloc_pipe_info(NULL); if (!pipe) return -ENOMEM; /* * We don't have an immediate reader, but we'll read the stuff |
00522fb41 [PATCH] splice: r... |
916 |
* out of the pipe right after the splice_to_pipe(). So set |
b92ce5589 [PATCH] splice: a... |
917 918 919 920 921 922 923 924 |
* PIPE_READERS appropriately. */ pipe->readers = 1; current->splice_pipe = pipe; } /* |
73d62d83e [PATCH] splice: c... |
925 |
* Do the splice. |
b92ce5589 [PATCH] splice: a... |
926 927 928 |
*/ ret = 0; bytes = 0; |
c66ab6fa7 splice: abstract ... |
929 930 931 932 933 934 935 |
len = sd->total_len; flags = sd->flags; /* * Don't block on output, we have to drain the direct pipe. */ sd->flags &= ~SPLICE_F_NONBLOCK; |
b92ce5589 [PATCH] splice: a... |
936 937 |
while (len) { |
51a92c0f6 splice: fix offse... |
938 |
size_t read_len; |
a82c53a0e splice: fix sendf... |
939 |
loff_t pos = sd->pos, prev_pos = pos; |
b92ce5589 [PATCH] splice: a... |
940 |
|
bcd4f3acb splice: direct sp... |
941 |
ret = do_splice_to(in, &pos, pipe, len, flags); |
51a92c0f6 splice: fix offse... |
942 |
if (unlikely(ret <= 0)) |
b92ce5589 [PATCH] splice: a... |
943 944 945 |
goto out_release; read_len = ret; |
c66ab6fa7 splice: abstract ... |
946 |
sd->total_len = read_len; |
b92ce5589 [PATCH] splice: a... |
947 948 949 950 951 952 |
/* * NOTE: nonblocking mode only applies to the input. We * must not do the output in nonblocking mode as then we * could get stuck data in the internal pipe: */ |
c66ab6fa7 splice: abstract ... |
953 |
ret = actor(pipe, sd); |
a82c53a0e splice: fix sendf... |
954 955 |
if (unlikely(ret <= 0)) { sd->pos = prev_pos; |
b92ce5589 [PATCH] splice: a... |
956 |
goto out_release; |
a82c53a0e splice: fix sendf... |
957 |
} |
b92ce5589 [PATCH] splice: a... |
958 959 960 |
bytes += ret; len -= ret; |
bcd4f3acb splice: direct sp... |
961 |
sd->pos = pos; |
b92ce5589 [PATCH] splice: a... |
962 |
|
a82c53a0e splice: fix sendf... |
963 964 |
if (ret < read_len) { sd->pos = prev_pos + ret; |
51a92c0f6 splice: fix offse... |
965 |
goto out_release; |
a82c53a0e splice: fix sendf... |
966 |
} |
b92ce5589 [PATCH] splice: a... |
967 |
} |
9e97198db splice: fix probl... |
968 |
done: |
b92ce5589 [PATCH] splice: a... |
969 |
pipe->nrbufs = pipe->curbuf = 0; |
808487085 splice: always up... |
970 |
file_accessed(in); |
b92ce5589 [PATCH] splice: a... |
971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 |
return bytes; out_release: /* * If we did an incomplete transfer we must release * the pipe buffers in question: */ for (i = 0; i < PIPE_BUFFERS; i++) { struct pipe_buffer *buf = pipe->bufs + i; if (buf->ops) { buf->ops->release(pipe, buf); buf->ops = NULL; } } |
b92ce5589 [PATCH] splice: a... |
986 |
|
9e97198db splice: fix probl... |
987 988 |
if (!bytes) bytes = ret; |
c66ab6fa7 splice: abstract ... |
989 |
|
9e97198db splice: fix probl... |
990 |
goto done; |
c66ab6fa7 splice: abstract ... |
991 992 993 994 995 996 |
} EXPORT_SYMBOL(splice_direct_to_actor); static int direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) { |
6a14b90bb vmsplice: add vms... |
997 |
struct file *file = sd->u.file; |
c66ab6fa7 splice: abstract ... |
998 999 1000 |
return do_splice_from(pipe, file, &sd->pos, sd->total_len, sd->flags); } |
932cc6d4f splice: completel... |
1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 |
/** * do_splice_direct - splices data directly between two files * @in: file to splice from * @ppos: input file offset * @out: file to splice to * @len: number of bytes to splice * @flags: splice modifier flags * * Description: * For use by do_sendfile(). splice can easily emulate sendfile, but * doing it in the application would incur an extra system call * (splice in + splice out, as compared to just sendfile()). So this helper * can splice directly through a process-private pipe. * */ |
c66ab6fa7 splice: abstract ... |
1016 1017 1018 1019 1020 1021 1022 1023 |
long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, size_t len, unsigned int flags) { struct splice_desc sd = { .len = len, .total_len = len, .flags = flags, .pos = *ppos, |
6a14b90bb vmsplice: add vms... |
1024 |
.u.file = out, |
c66ab6fa7 splice: abstract ... |
1025 |
}; |
51a92c0f6 splice: fix offse... |
1026 |
long ret; |
c66ab6fa7 splice: abstract ... |
1027 1028 |
ret = splice_direct_to_actor(in, &sd, direct_splice_actor); |
51a92c0f6 splice: fix offse... |
1029 |
if (ret > 0) |
a82c53a0e splice: fix sendf... |
1030 |
*ppos = sd.pos; |
51a92c0f6 splice: fix offse... |
1031 |
|
c66ab6fa7 splice: abstract ... |
1032 |
return ret; |
b92ce5589 [PATCH] splice: a... |
1033 |
} |
83f9135bd [PATCH] splice: a... |
1034 |
/* |
ddac0d39c [PATCH] splice: f... |
1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 |
* After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same * location, so checking ->i_pipe is not enough to verify that this is a * pipe. */ static inline struct pipe_inode_info *pipe_info(struct inode *inode) { if (S_ISFIFO(inode->i_mode)) return inode->i_pipe; return NULL; } /* |
83f9135bd [PATCH] splice: a... |
1048 1049 |
* Determine where to splice to/from. */ |
529565dcb [PATCH] splice: a... |
1050 1051 1052 |
static long do_splice(struct file *in, loff_t __user *off_in, struct file *out, loff_t __user *off_out, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
1053 |
{ |
3a326a2ce [PATCH] introduce... |
1054 |
struct pipe_inode_info *pipe; |
cbb7e577e [PATCH] splice: p... |
1055 |
loff_t offset, *off; |
a4514ebd8 [PATCH] splice: o... |
1056 |
long ret; |
5274f052e [PATCH] Introduce... |
1057 |
|
0f7fc9e4d [PATCH] VFS: chan... |
1058 |
pipe = pipe_info(in->f_path.dentry->d_inode); |
529565dcb [PATCH] splice: a... |
1059 1060 1061 |
if (pipe) { if (off_in) return -ESPIPE; |
b92ce5589 [PATCH] splice: a... |
1062 1063 1064 |
if (off_out) { if (out->f_op->llseek == no_llseek) return -EINVAL; |
cbb7e577e [PATCH] splice: p... |
1065 |
if (copy_from_user(&offset, off_out, sizeof(loff_t))) |
b92ce5589 [PATCH] splice: a... |
1066 |
return -EFAULT; |
cbb7e577e [PATCH] splice: p... |
1067 1068 1069 |
off = &offset; } else off = &out->f_pos; |
529565dcb [PATCH] splice: a... |
1070 |
|
a4514ebd8 [PATCH] splice: o... |
1071 1072 1073 1074 1075 1076 |
ret = do_splice_from(pipe, out, off, len, flags); if (off_out && copy_to_user(off_out, off, sizeof(loff_t))) ret = -EFAULT; return ret; |
529565dcb [PATCH] splice: a... |
1077 |
} |
5274f052e [PATCH] Introduce... |
1078 |
|
0f7fc9e4d [PATCH] VFS: chan... |
1079 |
pipe = pipe_info(out->f_path.dentry->d_inode); |
529565dcb [PATCH] splice: a... |
1080 1081 1082 |
if (pipe) { if (off_out) return -ESPIPE; |
b92ce5589 [PATCH] splice: a... |
1083 1084 1085 |
if (off_in) { if (in->f_op->llseek == no_llseek) return -EINVAL; |
cbb7e577e [PATCH] splice: p... |
1086 |
if (copy_from_user(&offset, off_in, sizeof(loff_t))) |
b92ce5589 [PATCH] splice: a... |
1087 |
return -EFAULT; |
cbb7e577e [PATCH] splice: p... |
1088 1089 1090 |
off = &offset; } else off = &in->f_pos; |
529565dcb [PATCH] splice: a... |
1091 |
|
a4514ebd8 [PATCH] splice: o... |
1092 1093 1094 1095 1096 1097 |
ret = do_splice_to(in, off, pipe, len, flags); if (off_in && copy_to_user(off_in, off, sizeof(loff_t))) ret = -EFAULT; return ret; |
529565dcb [PATCH] splice: a... |
1098 |
} |
5274f052e [PATCH] Introduce... |
1099 1100 1101 |
return -EINVAL; } |
912d35f86 [PATCH] Add suppo... |
1102 1103 1104 1105 1106 1107 1108 1109 1110 |
/* * Map an iov into an array of pages and offset/length tupples. With the * partial_page structure, we can map several non-contiguous ranges into * our ones pages[] map instead of splitting that operation into pieces. * Could easily be exported as a generic helper for other users, in which * case one would probably want to add a 'max_nr_pages' parameter as well. */ static int get_iovec_page_array(const struct iovec __user *iov, unsigned int nr_vecs, struct page **pages, |
7afa6fd03 [PATCH] vmsplice:... |
1111 |
struct partial_page *partial, int aligned) |
912d35f86 [PATCH] Add suppo... |
1112 1113 |
{ int buffers = 0, error = 0; |
912d35f86 [PATCH] Add suppo... |
1114 1115 |
while (nr_vecs) { unsigned long off, npages; |
757239576 Fix possible spli... |
1116 |
struct iovec entry; |
912d35f86 [PATCH] Add suppo... |
1117 1118 1119 |
void __user *base; size_t len; int i; |
757239576 Fix possible spli... |
1120 |
error = -EFAULT; |
bc40d73c9 splice: use get_u... |
1121 |
if (copy_from_user(&entry, iov, sizeof(entry))) |
912d35f86 [PATCH] Add suppo... |
1122 |
break; |
757239576 Fix possible spli... |
1123 1124 |
base = entry.iov_base; len = entry.iov_len; |
912d35f86 [PATCH] Add suppo... |
1125 1126 1127 |
/* * Sanity check this iovec. 0 read succeeds. */ |
757239576 Fix possible spli... |
1128 |
error = 0; |
912d35f86 [PATCH] Add suppo... |
1129 1130 1131 |
if (unlikely(!len)) break; error = -EFAULT; |
712a30e63 splice: fix user ... |
1132 |
if (!access_ok(VERIFY_READ, base, len)) |
912d35f86 [PATCH] Add suppo... |
1133 1134 1135 1136 1137 1138 1139 |
break; /* * Get this base offset and number of pages, then map * in the user pages. */ off = (unsigned long) base & ~PAGE_MASK; |
7afa6fd03 [PATCH] vmsplice:... |
1140 1141 1142 1143 1144 1145 1146 1147 |
/* * If asked for alignment, the offset must be zero and the * length a multiple of the PAGE_SIZE. */ error = -EINVAL; if (aligned && (off || len & ~PAGE_MASK)) break; |
912d35f86 [PATCH] Add suppo... |
1148 1149 1150 |
npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; if (npages > PIPE_BUFFERS - buffers) npages = PIPE_BUFFERS - buffers; |
bc40d73c9 splice: use get_u... |
1151 1152 |
error = get_user_pages_fast((unsigned long)base, npages, 0, &pages[buffers]); |
912d35f86 [PATCH] Add suppo... |
1153 1154 1155 1156 1157 1158 1159 1160 |
if (unlikely(error <= 0)) break; /* * Fill this contiguous range into the partial page map. */ for (i = 0; i < error; i++) { |
7591489a8 [PATCH] vmsplice:... |
1161 |
const int plen = min_t(size_t, len, PAGE_SIZE - off); |
912d35f86 [PATCH] Add suppo... |
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 |
partial[buffers].offset = off; partial[buffers].len = plen; off = 0; len -= plen; buffers++; } /* * We didn't complete this iov, stop here since it probably * means we have to move some of this into a pipe to * be able to continue. */ if (len) break; /* * Don't continue if we mapped fewer pages than we asked for, * or if we mapped the max number of pages that we have * room for. */ if (error < npages || buffers == PIPE_BUFFERS) break; nr_vecs--; iov++; } |
912d35f86 [PATCH] Add suppo... |
1190 1191 1192 1193 1194 |
if (buffers) return buffers; return error; } |
6a14b90bb vmsplice: add vms... |
1195 1196 1197 1198 1199 |
static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) { char *src; int ret; |
cac36bb06 pipe: change the ... |
1200 |
ret = buf->ops->confirm(pipe, buf); |
6a14b90bb vmsplice: add vms... |
1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 |
if (unlikely(ret)) return ret; /* * See if we can use the atomic maps, by prefaulting in the * pages and doing an atomic copy */ if (!fault_in_pages_writeable(sd->u.userptr, sd->len)) { src = buf->ops->map(pipe, buf, 1); ret = __copy_to_user_inatomic(sd->u.userptr, src + buf->offset, sd->len); buf->ops->unmap(pipe, buf, src); if (!ret) { ret = sd->len; goto out; } } /* * No dice, use slow non-atomic map and copy */ src = buf->ops->map(pipe, buf, 0); ret = sd->len; if (copy_to_user(sd->u.userptr, src + buf->offset, sd->len)) ret = -EFAULT; |
6866bef40 splice: fix doubl... |
1227 |
buf->ops->unmap(pipe, buf, src); |
6a14b90bb vmsplice: add vms... |
1228 1229 1230 |
out: if (ret > 0) sd->u.userptr += ret; |
6a14b90bb vmsplice: add vms... |
1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 |
return ret; } /* * For lack of a better implementation, implement vmsplice() to userspace * as a simple copy of the pipes pages to the user iov. */ static long vmsplice_to_user(struct file *file, const struct iovec __user *iov, unsigned long nr_segs, unsigned int flags) { struct pipe_inode_info *pipe; struct splice_desc sd; ssize_t size; int error; long ret; pipe = pipe_info(file->f_path.dentry->d_inode); if (!pipe) return -EBADF; if (pipe->inode) mutex_lock(&pipe->inode->i_mutex); error = ret = 0; while (nr_segs) { void __user *base; size_t len; /* * Get user address base and length for this iovec. */ error = get_user(base, &iov->iov_base); if (unlikely(error)) break; error = get_user(len, &iov->iov_len); if (unlikely(error)) break; /* * Sanity check this iovec. 0 read succeeds. */ if (unlikely(!len)) break; if (unlikely(!base)) { error = -EFAULT; break; } |
8811930dc splice: missing u... |
1278 1279 1280 1281 |
if (unlikely(!access_ok(VERIFY_WRITE, base, len))) { error = -EFAULT; break; } |
6a14b90bb vmsplice: add vms... |
1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 |
sd.len = 0; sd.total_len = len; sd.flags = flags; sd.u.userptr = base; sd.pos = 0; size = __splice_from_pipe(pipe, &sd, pipe_to_user); if (size < 0) { if (!ret) ret = size; break; } ret += size; if (size < len) break; nr_segs--; iov++; } if (pipe->inode) mutex_unlock(&pipe->inode->i_mutex); if (!ret) ret = error; return ret; } |
912d35f86 [PATCH] Add suppo... |
1313 1314 1315 1316 |
/* * vmsplice splices a user address range into a pipe. It can be thought of * as splice-from-memory, where the regular splice is splice-from-file (or * to file). In both cases the output is a pipe, naturally. |
912d35f86 [PATCH] Add suppo... |
1317 |
*/ |
6a14b90bb vmsplice: add vms... |
1318 1319 |
static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov, unsigned long nr_segs, unsigned int flags) |
912d35f86 [PATCH] Add suppo... |
1320 |
{ |
ddac0d39c [PATCH] splice: f... |
1321 |
struct pipe_inode_info *pipe; |
912d35f86 [PATCH] Add suppo... |
1322 1323 1324 1325 1326 1327 1328 |
struct page *pages[PIPE_BUFFERS]; struct partial_page partial[PIPE_BUFFERS]; struct splice_pipe_desc spd = { .pages = pages, .partial = partial, .flags = flags, .ops = &user_page_pipe_buf_ops, |
bbdfc2f70 [SPLICE]: Don't a... |
1329 |
.spd_release = spd_release_page, |
912d35f86 [PATCH] Add suppo... |
1330 |
}; |
0f7fc9e4d [PATCH] VFS: chan... |
1331 |
pipe = pipe_info(file->f_path.dentry->d_inode); |
ddac0d39c [PATCH] splice: f... |
1332 |
if (!pipe) |
912d35f86 [PATCH] Add suppo... |
1333 |
return -EBADF; |
912d35f86 [PATCH] Add suppo... |
1334 |
|
7afa6fd03 [PATCH] vmsplice:... |
1335 1336 |
spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial, flags & SPLICE_F_GIFT); |
912d35f86 [PATCH] Add suppo... |
1337 1338 |
if (spd.nr_pages <= 0) return spd.nr_pages; |
00522fb41 [PATCH] splice: r... |
1339 |
return splice_to_pipe(pipe, &spd); |
912d35f86 [PATCH] Add suppo... |
1340 |
} |
6a14b90bb vmsplice: add vms... |
1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 |
/* * Note that vmsplice only really supports true splicing _from_ user memory * to a pipe, not the other way around. Splicing from user memory is a simple * operation that can be supported without any funky alignment restrictions * or nasty vm tricks. We simply map in the user memory and fill them into * a pipe. The reverse isn't quite as easy, though. There are two possible * solutions for that: * * - memcpy() the data internally, at which point we might as well just * do a regular read() on the buffer anyway. * - Lots of nasty vm tricks, that are neither fast nor flexible (it * has restriction limitations on both ends of the pipe). * * Currently we punt and implement it as a normal copy, see pipe_to_user(). * */ |
912d35f86 [PATCH] Add suppo... |
1357 1358 1359 1360 1361 1362 |
asmlinkage long sys_vmsplice(int fd, const struct iovec __user *iov, unsigned long nr_segs, unsigned int flags) { struct file *file; long error; int fput; |
6a14b90bb vmsplice: add vms... |
1363 1364 1365 1366 |
if (unlikely(nr_segs > UIO_MAXIOV)) return -EINVAL; else if (unlikely(!nr_segs)) return 0; |
912d35f86 [PATCH] Add suppo... |
1367 1368 1369 1370 |
error = -EBADF; file = fget_light(fd, &fput); if (file) { if (file->f_mode & FMODE_WRITE) |
6a14b90bb vmsplice: add vms... |
1371 1372 1373 |
error = vmsplice_to_pipe(file, iov, nr_segs, flags); else if (file->f_mode & FMODE_READ) error = vmsplice_to_user(file, iov, nr_segs, flags); |
912d35f86 [PATCH] Add suppo... |
1374 1375 1376 1377 1378 1379 |
fput_light(file, fput); } return error; } |
529565dcb [PATCH] splice: a... |
1380 1381 1382 |
asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, int fd_out, loff_t __user *off_out, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
1383 1384 1385 1386 1387 1388 1389 1390 1391 |
{ long error; struct file *in, *out; int fput_in, fput_out; if (unlikely(!len)) return 0; error = -EBADF; |
529565dcb [PATCH] splice: a... |
1392 |
in = fget_light(fd_in, &fput_in); |
5274f052e [PATCH] Introduce... |
1393 1394 |
if (in) { if (in->f_mode & FMODE_READ) { |
529565dcb [PATCH] splice: a... |
1395 |
out = fget_light(fd_out, &fput_out); |
5274f052e [PATCH] Introduce... |
1396 1397 |
if (out) { if (out->f_mode & FMODE_WRITE) |
529565dcb [PATCH] splice: a... |
1398 1399 1400 |
error = do_splice(in, off_in, out, off_out, len, flags); |
5274f052e [PATCH] Introduce... |
1401 1402 1403 1404 1405 1406 1407 1408 1409 |
fput_light(out, fput_out); } } fput_light(in, fput_in); } return error; } |
70524490e [PATCH] splice: a... |
1410 1411 |
/* |
aadd06e5c [PATCH] splice: f... |
1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 |
* Make sure there's data to read. Wait for input if we can, otherwise * return an appropriate error. */ static int link_ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) { int ret; /* * Check ->nrbufs without the inode lock first. This function * is speculative anyways, so missing one is ok. */ if (pipe->nrbufs) return 0; ret = 0; mutex_lock(&pipe->inode->i_mutex); while (!pipe->nrbufs) { if (signal_pending(current)) { ret = -ERESTARTSYS; break; } if (!pipe->writers) break; if (!pipe->waiting_writers) { if (flags & SPLICE_F_NONBLOCK) { ret = -EAGAIN; break; } } pipe_wait(pipe); } mutex_unlock(&pipe->inode->i_mutex); return ret; } /* * Make sure there's writeable room. Wait for room if we can, otherwise * return an appropriate error. */ static int link_opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) { int ret; /* * Check ->nrbufs without the inode lock first. This function * is speculative anyways, so missing one is ok. */ if (pipe->nrbufs < PIPE_BUFFERS) return 0; ret = 0; mutex_lock(&pipe->inode->i_mutex); while (pipe->nrbufs >= PIPE_BUFFERS) { if (!pipe->readers) { send_sig(SIGPIPE, current, 0); ret = -EPIPE; break; } if (flags & SPLICE_F_NONBLOCK) { ret = -EAGAIN; break; } if (signal_pending(current)) { ret = -ERESTARTSYS; break; } pipe->waiting_writers++; pipe_wait(pipe); pipe->waiting_writers--; } mutex_unlock(&pipe->inode->i_mutex); return ret; } /* |
70524490e [PATCH] splice: a... |
1491 1492 1493 1494 1495 1496 1497 |
* Link contents of ipipe to opipe. */ static int link_pipe(struct pipe_inode_info *ipipe, struct pipe_inode_info *opipe, size_t len, unsigned int flags) { struct pipe_buffer *ibuf, *obuf; |
aadd06e5c [PATCH] splice: f... |
1498 |
int ret = 0, i = 0, nbuf; |
70524490e [PATCH] splice: a... |
1499 1500 1501 1502 1503 1504 |
/* * Potential ABBA deadlock, work around it by ordering lock * grabbing by inode address. Otherwise two different processes * could deadlock (one doing tee from A -> B, the other from B -> A). */ |
62752ee19 [PATCH] Take i_mu... |
1505 |
inode_double_lock(ipipe->inode, opipe->inode); |
70524490e [PATCH] splice: a... |
1506 |
|
aadd06e5c [PATCH] splice: f... |
1507 |
do { |
70524490e [PATCH] splice: a... |
1508 1509 1510 1511 1512 1513 |
if (!opipe->readers) { send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; break; } |
70524490e [PATCH] splice: a... |
1514 |
|
aadd06e5c [PATCH] splice: f... |
1515 1516 1517 1518 1519 1520 |
/* * If we have iterated all input buffers or ran out of * output room, break. */ if (i >= ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS) break; |
70524490e [PATCH] splice: a... |
1521 |
|
aadd06e5c [PATCH] splice: f... |
1522 1523 |
ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1)); nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1); |
70524490e [PATCH] splice: a... |
1524 1525 |
/* |
aadd06e5c [PATCH] splice: f... |
1526 1527 |
* Get a reference to this pipe buffer, * so we can copy the contents over. |
70524490e [PATCH] splice: a... |
1528 |
*/ |
aadd06e5c [PATCH] splice: f... |
1529 1530 1531 1532 |
ibuf->ops->get(ipipe, ibuf); obuf = opipe->bufs + nbuf; *obuf = *ibuf; |
2a27250e6 [PATCH] tee: link... |
1533 |
/* |
aadd06e5c [PATCH] splice: f... |
1534 1535 |
* Don't inherit the gift flag, we need to * prevent multiple steals of this page. |
2a27250e6 [PATCH] tee: link... |
1536 |
*/ |
aadd06e5c [PATCH] splice: f... |
1537 |
obuf->flags &= ~PIPE_BUF_FLAG_GIFT; |
70524490e [PATCH] splice: a... |
1538 |
|
aadd06e5c [PATCH] splice: f... |
1539 1540 |
if (obuf->len > len) obuf->len = len; |
70524490e [PATCH] splice: a... |
1541 |
|
aadd06e5c [PATCH] splice: f... |
1542 1543 1544 1545 1546 |
opipe->nrbufs++; ret += obuf->len; len -= obuf->len; i++; } while (len); |
70524490e [PATCH] splice: a... |
1547 |
|
02cf01aea splice: only retu... |
1548 1549 1550 1551 1552 1553 |
/* * return EAGAIN if we have the potential of some data in the * future, otherwise just return 0 */ if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK)) ret = -EAGAIN; |
62752ee19 [PATCH] Take i_mu... |
1554 |
inode_double_unlock(ipipe->inode, opipe->inode); |
70524490e [PATCH] splice: a... |
1555 |
|
aadd06e5c [PATCH] splice: f... |
1556 1557 1558 1559 |
/* * If we put data in the output pipe, wakeup any potential readers. */ if (ret > 0) { |
70524490e [PATCH] splice: a... |
1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 |
smp_mb(); if (waitqueue_active(&opipe->wait)) wake_up_interruptible(&opipe->wait); kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN); } return ret; } /* * This is a tee(1) implementation that works on pipes. It doesn't copy * any data, it simply references the 'in' pages on the 'out' pipe. * The 'flags' used are the SPLICE_F_* variants, currently the only * applicable one is SPLICE_F_NONBLOCK. */ static long do_tee(struct file *in, struct file *out, size_t len, unsigned int flags) { |
0f7fc9e4d [PATCH] VFS: chan... |
1578 1579 |
struct pipe_inode_info *ipipe = pipe_info(in->f_path.dentry->d_inode); struct pipe_inode_info *opipe = pipe_info(out->f_path.dentry->d_inode); |
aadd06e5c [PATCH] splice: f... |
1580 |
int ret = -EINVAL; |
70524490e [PATCH] splice: a... |
1581 1582 |
/* |
aadd06e5c [PATCH] splice: f... |
1583 1584 |
* Duplicate the contents of ipipe to opipe without actually * copying the data. |
70524490e [PATCH] splice: a... |
1585 |
*/ |
aadd06e5c [PATCH] splice: f... |
1586 1587 1588 1589 1590 1591 1592 1593 |
if (ipipe && opipe && ipipe != opipe) { /* * Keep going, unless we encounter an error. The ipipe/opipe * ordering doesn't really matter. */ ret = link_ipipe_prep(ipipe, flags); if (!ret) { ret = link_opipe_prep(opipe, flags); |
02cf01aea splice: only retu... |
1594 |
if (!ret) |
aadd06e5c [PATCH] splice: f... |
1595 |
ret = link_pipe(ipipe, opipe, len, flags); |
aadd06e5c [PATCH] splice: f... |
1596 1597 |
} } |
70524490e [PATCH] splice: a... |
1598 |
|
aadd06e5c [PATCH] splice: f... |
1599 |
return ret; |
70524490e [PATCH] splice: a... |
1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 |
} asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags) { struct file *in; int error, fput_in; if (unlikely(!len)) return 0; error = -EBADF; in = fget_light(fdin, &fput_in); if (in) { if (in->f_mode & FMODE_READ) { int fput_out; struct file *out = fget_light(fdout, &fput_out); if (out) { if (out->f_mode & FMODE_WRITE) error = do_tee(in, out, len, flags); fput_light(out, fput_out); } } fput_light(in, fput_in); } return error; } |