Blame view
fs/splice.c
39.9 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> |
08e552c69 memcg: synchroniz... |
24 |
#include <linux/memcontrol.h> |
5274f052e [PATCH] Introduce... |
25 |
#include <linux/mm_inline.h> |
5abc97aa2 [PATCH] splice: a... |
26 |
#include <linux/swap.h> |
4f6f0bd2f [PATCH] splice: i... |
27 |
#include <linux/writeback.h> |
630d9c472 fs: reduce the us... |
28 |
#include <linux/export.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> |
5a0e3ad6a include cleanup: ... |
32 |
#include <linux/gfp.h> |
35f9c09fe tcp: tcp_sendpage... |
33 |
#include <linux/socket.h> |
76b021d05 convert vmsplice ... |
34 |
#include <linux/compat.h> |
06ae43f34 Don't bother with... |
35 |
#include "internal.h" |
5274f052e [PATCH] Introduce... |
36 |
|
83f9135bd [PATCH] splice: a... |
37 38 39 40 41 42 |
/* * 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... |
43 |
static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, |
5abc97aa2 [PATCH] splice: a... |
44 45 46 |
struct pipe_buffer *buf) { struct page *page = buf->page; |
9e94cd4fd [PATCH] splice: r... |
47 |
struct address_space *mapping; |
5abc97aa2 [PATCH] splice: a... |
48 |
|
9e0267c26 [PATCH] splice: f... |
49 |
lock_page(page); |
9e94cd4fd [PATCH] splice: r... |
50 51 52 |
mapping = page_mapping(page); if (mapping) { WARN_ON(!PageUptodate(page)); |
5abc97aa2 [PATCH] splice: a... |
53 |
|
9e94cd4fd [PATCH] splice: r... |
54 55 56 57 58 59 60 61 62 |
/* * 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... |
63 |
|
266cf658e FS-Cache: Recruit... |
64 65 |
if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) |
ca39d651d splice: handle tr... |
66 |
goto out_unlock; |
4f6f0bd2f [PATCH] splice: i... |
67 |
|
9e94cd4fd [PATCH] splice: r... |
68 69 70 71 72 73 74 75 |
/* * 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... |
76 |
} |
5abc97aa2 [PATCH] splice: a... |
77 |
|
9e94cd4fd [PATCH] splice: r... |
78 79 80 81 |
/* * Raced with truncate or failed to remove page from current * address space, unlock and return failure. */ |
ca39d651d splice: handle tr... |
82 |
out_unlock: |
9e94cd4fd [PATCH] splice: r... |
83 84 |
unlock_page(page); return 1; |
5abc97aa2 [PATCH] splice: a... |
85 |
} |
76ad4d111 [PATCH] splice: r... |
86 |
static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe, |
5274f052e [PATCH] Introduce... |
87 88 |
struct pipe_buffer *buf) { |
09cbfeaf1 mm, fs: get rid o... |
89 |
put_page(buf->page); |
1432873af [PATCH] splice: L... |
90 |
buf->flags &= ~PIPE_BUF_FLAG_LRU; |
5274f052e [PATCH] Introduce... |
91 |
} |
0845718da pipe: add documen... |
92 93 94 95 |
/* * 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 ... |
96 97 |
static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe, struct pipe_buffer *buf) |
5274f052e [PATCH] Introduce... |
98 99 |
{ struct page *page = buf->page; |
49d0b21be [PATCH] splice: o... |
100 |
int err; |
5274f052e [PATCH] Introduce... |
101 102 |
if (!PageUptodate(page)) { |
49d0b21be [PATCH] splice: o... |
103 104 105 106 |
lock_page(page); /* * Page got truncated/unhashed. This will cause a 0-byte |
73d62d83e [PATCH] splice: c... |
107 |
* splice, if this is the first page. |
49d0b21be [PATCH] splice: o... |
108 109 110 111 112 |
*/ if (!page->mapping) { err = -ENODATA; goto error; } |
5274f052e [PATCH] Introduce... |
113 |
|
49d0b21be [PATCH] splice: o... |
114 |
/* |
73d62d83e [PATCH] splice: c... |
115 |
* Uh oh, read-error from disk. |
49d0b21be [PATCH] splice: o... |
116 117 118 119 120 121 122 |
*/ if (!PageUptodate(page)) { err = -EIO; goto error; } /* |
f84d75199 [PATCH] pipe: int... |
123 |
* Page is ok afterall, we are done. |
49d0b21be [PATCH] splice: o... |
124 |
*/ |
5274f052e [PATCH] Introduce... |
125 |
unlock_page(page); |
5274f052e [PATCH] Introduce... |
126 |
} |
f84d75199 [PATCH] pipe: int... |
127 |
return 0; |
49d0b21be [PATCH] splice: o... |
128 129 |
error: unlock_page(page); |
f84d75199 [PATCH] pipe: int... |
130 |
return err; |
70524490e [PATCH] splice: a... |
131 |
} |
708e3508c tmpfs: clone shme... |
132 |
const struct pipe_buf_operations page_cache_pipe_buf_ops = { |
5274f052e [PATCH] Introduce... |
133 |
.can_merge = 0, |
cac36bb06 pipe: change the ... |
134 |
.confirm = page_cache_pipe_buf_confirm, |
5274f052e [PATCH] Introduce... |
135 |
.release = page_cache_pipe_buf_release, |
5abc97aa2 [PATCH] splice: a... |
136 |
.steal = page_cache_pipe_buf_steal, |
f84d75199 [PATCH] pipe: int... |
137 |
.get = generic_pipe_buf_get, |
5274f052e [PATCH] Introduce... |
138 |
}; |
912d35f86 [PATCH] Add suppo... |
139 140 141 |
static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { |
7afa6fd03 [PATCH] vmsplice:... |
142 143 |
if (!(buf->flags & PIPE_BUF_FLAG_GIFT)) return 1; |
1432873af [PATCH] splice: L... |
144 |
buf->flags |= PIPE_BUF_FLAG_LRU; |
330ab7161 [PATCH] vmsplice:... |
145 |
return generic_pipe_buf_steal(pipe, buf); |
912d35f86 [PATCH] Add suppo... |
146 |
} |
d4c3cca94 [PATCH] constify ... |
147 |
static const struct pipe_buf_operations user_page_pipe_buf_ops = { |
912d35f86 [PATCH] Add suppo... |
148 |
.can_merge = 0, |
cac36bb06 pipe: change the ... |
149 |
.confirm = generic_pipe_buf_confirm, |
912d35f86 [PATCH] Add suppo... |
150 151 |
.release = page_cache_pipe_buf_release, .steal = user_page_pipe_buf_steal, |
f84d75199 [PATCH] pipe: int... |
152 |
.get = generic_pipe_buf_get, |
912d35f86 [PATCH] Add suppo... |
153 |
}; |
825cdcb1a splice: add wakeu... |
154 155 156 157 158 159 160 |
static void wakeup_pipe_readers(struct pipe_inode_info *pipe) { smp_mb(); if (waitqueue_active(&pipe->wait)) wake_up_interruptible(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); } |
932cc6d4f splice: completel... |
161 162 163 164 165 166 |
/** * splice_to_pipe - fill passed data into a pipe * @pipe: pipe to fill * @spd: data to fill * * Description: |
79685b8de docbook: add pipe... |
167 |
* @spd contains a map of pages and len/offset tuples, along with |
932cc6d4f splice: completel... |
168 169 170 |
* the struct pipe_buf_operations associated with these pages. This * function will link that data to the pipe. * |
83f9135bd [PATCH] splice: a... |
171 |
*/ |
d6b29d7ce splice: divorce t... |
172 173 |
ssize_t splice_to_pipe(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) |
5274f052e [PATCH] Introduce... |
174 |
{ |
00de00bda splice: fix leak ... |
175 |
unsigned int spd_pages = spd->nr_pages; |
8924feff6 splice: lift pipe... |
176 |
int ret = 0, page_nr = 0; |
5274f052e [PATCH] Introduce... |
177 |
|
d6785d915 splice: handle ze... |
178 179 |
if (!spd_pages) return 0; |
8924feff6 splice: lift pipe... |
180 181 182 183 184 |
if (unlikely(!pipe->readers)) { send_sig(SIGPIPE, current, 0); ret = -EPIPE; goto out; } |
5274f052e [PATCH] Introduce... |
185 |
|
8924feff6 splice: lift pipe... |
186 187 188 |
while (pipe->nrbufs < pipe->buffers) { int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); struct pipe_buffer *buf = pipe->bufs + newbuf; |
5274f052e [PATCH] Introduce... |
189 |
|
8924feff6 splice: lift pipe... |
190 191 192 193 194 |
buf->page = spd->pages[page_nr]; buf->offset = spd->partial[page_nr].offset; buf->len = spd->partial[page_nr].len; buf->private = spd->partial[page_nr].private; buf->ops = spd->ops; |
5274f052e [PATCH] Introduce... |
195 |
|
8924feff6 splice: lift pipe... |
196 197 198 |
pipe->nrbufs++; page_nr++; ret += buf->len; |
29e350944 splice: add SPLIC... |
199 |
|
8924feff6 splice: lift pipe... |
200 |
if (!--spd->nr_pages) |
5274f052e [PATCH] Introduce... |
201 |
break; |
5274f052e [PATCH] Introduce... |
202 |
} |
8924feff6 splice: lift pipe... |
203 204 |
if (!ret) ret = -EAGAIN; |
5274f052e [PATCH] Introduce... |
205 |
|
8924feff6 splice: lift pipe... |
206 |
out: |
00de00bda splice: fix leak ... |
207 |
while (page_nr < spd_pages) |
bbdfc2f70 [SPLICE]: Don't a... |
208 |
spd->spd_release(spd, page_nr++); |
5274f052e [PATCH] Introduce... |
209 210 211 |
return ret; } |
2b514574f net: af_unix: imp... |
212 |
EXPORT_SYMBOL_GPL(splice_to_pipe); |
5274f052e [PATCH] Introduce... |
213 |
|
79fddc4ef new helper: add_t... |
214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 |
ssize_t add_to_pipe(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { int ret; if (unlikely(!pipe->readers)) { send_sig(SIGPIPE, current, 0); ret = -EPIPE; } else if (pipe->nrbufs == pipe->buffers) { ret = -EAGAIN; } else { int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); pipe->bufs[newbuf] = *buf; pipe->nrbufs++; return buf->len; } |
a779638cf pipe: add pipe_bu... |
229 |
pipe_buf_release(pipe, buf); |
79fddc4ef new helper: add_t... |
230 231 232 |
return ret; } EXPORT_SYMBOL(add_to_pipe); |
708e3508c tmpfs: clone shme... |
233 |
void spd_release_page(struct splice_pipe_desc *spd, unsigned int i) |
bbdfc2f70 [SPLICE]: Don't a... |
234 |
{ |
09cbfeaf1 mm, fs: get rid o... |
235 |
put_page(spd->pages[i]); |
bbdfc2f70 [SPLICE]: Don't a... |
236 |
} |
35f3d14db pipe: add support... |
237 238 239 240 |
/* * Check if we need to grow the arrays holding pages and partial page * descriptions. */ |
047fe3605 splice: fix racy ... |
241 |
int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) |
35f3d14db pipe: add support... |
242 |
{ |
047fe3605 splice: fix racy ... |
243 244 245 246 |
unsigned int buffers = ACCESS_ONCE(pipe->buffers); spd->nr_pages_max = buffers; if (buffers <= PIPE_DEF_BUFFERS) |
35f3d14db pipe: add support... |
247 |
return 0; |
047fe3605 splice: fix racy ... |
248 249 |
spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL); spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL); |
35f3d14db pipe: add support... |
250 251 252 253 254 255 256 257 |
if (spd->pages && spd->partial) return 0; kfree(spd->pages); kfree(spd->partial); return -ENOMEM; } |
047fe3605 splice: fix racy ... |
258 |
void splice_shrink_spd(struct splice_pipe_desc *spd) |
35f3d14db pipe: add support... |
259 |
{ |
047fe3605 splice: fix racy ... |
260 |
if (spd->nr_pages_max <= PIPE_DEF_BUFFERS) |
35f3d14db pipe: add support... |
261 262 263 264 265 |
return; kfree(spd->pages); kfree(spd->partial); } |
83f9135bd [PATCH] splice: a... |
266 267 268 |
/** * generic_file_splice_read - splice data from file to a pipe * @in: file to splice from |
932cc6d4f splice: completel... |
269 |
* @ppos: position in @in |
83f9135bd [PATCH] splice: a... |
270 271 272 273 |
* @pipe: pipe to splice to * @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
274 275 |
* Description: * Will read pages from given file and fill them into a pipe. Can be |
82c156f85 switch generic_fi... |
276 |
* used as long as it has more or less sane ->read_iter(). |
932cc6d4f splice: completel... |
277 |
* |
83f9135bd [PATCH] splice: a... |
278 |
*/ |
cbb7e577e [PATCH] splice: p... |
279 280 281 |
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... |
282 |
{ |
82c156f85 switch generic_fi... |
283 284 |
struct iov_iter to; struct kiocb kiocb; |
82c156f85 switch generic_fi... |
285 |
int idx, ret; |
be64f884b dax: unify ext2/4... |
286 |
|
82c156f85 switch generic_fi... |
287 288 289 290 291 |
iov_iter_pipe(&to, ITER_PIPE | READ, pipe, len); idx = to.idx; init_sync_kiocb(&kiocb, in); kiocb.ki_pos = *ppos; ret = in->f_op->read_iter(&kiocb, &to); |
723590ed5 splice: update mt... |
292 |
if (ret > 0) { |
82c156f85 switch generic_fi... |
293 |
*ppos = kiocb.ki_pos; |
723590ed5 splice: update mt... |
294 |
file_accessed(in); |
82c156f85 switch generic_fi... |
295 |
} else if (ret < 0) { |
c3a690240 fix ITER_PIPE int... |
296 297 298 |
to.idx = idx; to.iov_offset = 0; iov_iter_advance(&to, 0); /* to free what was emitted */ |
82c156f85 switch generic_fi... |
299 300 301 302 303 304 |
/* * callers of ->splice_read() expect -EAGAIN on * "can't put anything in there", rather than -EFAULT. */ if (ret == -EFAULT) ret = -EAGAIN; |
723590ed5 splice: update mt... |
305 |
} |
5274f052e [PATCH] Introduce... |
306 307 308 |
return ret; } |
059a8f373 [PATCH] splice: e... |
309 |
EXPORT_SYMBOL(generic_file_splice_read); |
241699cd7 new iov_iter flav... |
310 |
const struct pipe_buf_operations default_pipe_buf_ops = { |
6818173bd splice: implement... |
311 |
.can_merge = 0, |
6818173bd splice: implement... |
312 313 314 315 316 |
.confirm = generic_pipe_buf_confirm, .release = generic_pipe_buf_release, .steal = generic_pipe_buf_steal, .get = generic_pipe_buf_get, }; |
28a625cbc fuse: fix pipe_bu... |
317 318 319 320 321 322 323 324 325 |
static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { return 1; } /* Pipe buffer operations for a socket and similar. */ const struct pipe_buf_operations nosteal_pipe_buf_ops = { .can_merge = 0, |
28a625cbc fuse: fix pipe_bu... |
326 327 328 329 330 331 |
.confirm = generic_pipe_buf_confirm, .release = generic_pipe_buf_release, .steal = generic_pipe_buf_nosteal, .get = generic_pipe_buf_get, }; EXPORT_SYMBOL(nosteal_pipe_buf_ops); |
523ac9afc switch default_fi... |
332 |
static ssize_t kernel_readv(struct file *file, const struct kvec *vec, |
6818173bd splice: implement... |
333 334 335 336 337 338 339 340 341 |
unsigned long vlen, loff_t offset) { mm_segment_t old_fs; loff_t pos = offset; ssize_t res; old_fs = get_fs(); set_fs(get_ds()); /* The cast to a user pointer is valid due to the set_fs() */ |
793b80ef1 vfs: pass a flags... |
342 |
res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos, 0); |
6818173bd splice: implement... |
343 344 345 346 |
set_fs(old_fs); return res; } |
7bb307e89 export kernel_wri... |
347 |
ssize_t kernel_write(struct file *file, const char *buf, size_t count, |
b2858d7d1 splice: fix kmaps... |
348 |
loff_t pos) |
0b0a47f5c splice: implement... |
349 350 351 352 353 354 355 |
{ mm_segment_t old_fs; ssize_t res; old_fs = get_fs(); set_fs(get_ds()); /* The cast to a user pointer is valid due to the set_fs() */ |
7bb307e89 export kernel_wri... |
356 |
res = vfs_write(file, (__force const char __user *)buf, count, &pos); |
0b0a47f5c splice: implement... |
357 358 359 360 |
set_fs(old_fs); return res; } |
7bb307e89 export kernel_wri... |
361 |
EXPORT_SYMBOL(kernel_write); |
0b0a47f5c splice: implement... |
362 |
|
82c156f85 switch generic_fi... |
363 |
static ssize_t default_file_splice_read(struct file *in, loff_t *ppos, |
6818173bd splice: implement... |
364 365 366 |
struct pipe_inode_info *pipe, size_t len, unsigned int flags) { |
523ac9afc switch default_fi... |
367 368 369 |
struct kvec *vec, __vec[PIPE_DEF_BUFFERS]; struct iov_iter to; struct page **pages; |
6818173bd splice: implement... |
370 |
unsigned int nr_pages; |
523ac9afc switch default_fi... |
371 |
size_t offset, dummy, copied = 0; |
6818173bd splice: implement... |
372 |
ssize_t res; |
6818173bd splice: implement... |
373 |
int i; |
35f3d14db pipe: add support... |
374 |
|
523ac9afc switch default_fi... |
375 376 |
if (pipe->nrbufs == pipe->buffers) return -EAGAIN; |
35f3d14db pipe: add support... |
377 |
|
523ac9afc switch default_fi... |
378 379 380 381 |
/* * Try to keep page boundaries matching to source pagecache ones - * it probably won't be much help, but... */ |
09cbfeaf1 mm, fs: get rid o... |
382 |
offset = *ppos & ~PAGE_MASK; |
6818173bd splice: implement... |
383 |
|
523ac9afc switch default_fi... |
384 |
iov_iter_pipe(&to, ITER_PIPE | READ, pipe, len + offset); |
6818173bd splice: implement... |
385 |
|
523ac9afc switch default_fi... |
386 387 388 |
res = iov_iter_get_pages_alloc(&to, &pages, len + offset, &dummy); if (res <= 0) return -ENOMEM; |
6818173bd splice: implement... |
389 |
|
8e54cadab fix default_file_... |
390 391 |
BUG_ON(dummy); nr_pages = DIV_ROUND_UP(res, PAGE_SIZE); |
6818173bd splice: implement... |
392 |
|
523ac9afc switch default_fi... |
393 394 395 396 397 398 399 |
vec = __vec; if (nr_pages > PIPE_DEF_BUFFERS) { vec = kmalloc(nr_pages * sizeof(struct kvec), GFP_KERNEL); if (unlikely(!vec)) { res = -ENOMEM; goto out; } |
77f6bf57b splice: fix error... |
400 |
} |
6818173bd splice: implement... |
401 |
|
523ac9afc switch default_fi... |
402 403 404 405 406 407 408 409 410 |
pipe->bufs[to.idx].offset = offset; pipe->bufs[to.idx].len -= offset; for (i = 0; i < nr_pages; i++) { size_t this_len = min_t(size_t, len, PAGE_SIZE - offset); vec[i].iov_base = page_address(pages[i]) + offset; vec[i].iov_len = this_len; len -= this_len; offset = 0; |
6818173bd splice: implement... |
411 |
} |
6818173bd splice: implement... |
412 |
|
523ac9afc switch default_fi... |
413 414 415 |
res = kernel_readv(in, vec, nr_pages, *ppos); if (res > 0) { copied = res; |
6818173bd splice: implement... |
416 |
*ppos += res; |
523ac9afc switch default_fi... |
417 |
} |
6818173bd splice: implement... |
418 |
|
35f3d14db pipe: add support... |
419 420 |
if (vec != __vec) kfree(vec); |
523ac9afc switch default_fi... |
421 422 423 424 425 |
out: for (i = 0; i < nr_pages; i++) put_page(pages[i]); kvfree(pages); iov_iter_advance(&to, copied); /* truncates and discards */ |
6818173bd splice: implement... |
426 |
return res; |
6818173bd splice: implement... |
427 |
} |
6818173bd splice: implement... |
428 |
|
5274f052e [PATCH] Introduce... |
429 |
/* |
4f6f0bd2f [PATCH] splice: i... |
430 |
* Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' |
016b661e2 [PATCH] splice: f... |
431 |
* using sendpage(). Return the number of bytes sent. |
5274f052e [PATCH] Introduce... |
432 |
*/ |
76ad4d111 [PATCH] splice: r... |
433 |
static int pipe_to_sendpage(struct pipe_inode_info *pipe, |
5274f052e [PATCH] Introduce... |
434 435 |
struct pipe_buffer *buf, struct splice_desc *sd) { |
6a14b90bb vmsplice: add vms... |
436 |
struct file *file = sd->u.file; |
5274f052e [PATCH] Introduce... |
437 |
loff_t pos = sd->pos; |
a8adbe378 fs/splice: Pull b... |
438 |
int more; |
5274f052e [PATCH] Introduce... |
439 |
|
72c2d5319 file->f_op is nev... |
440 |
if (!likely(file->f_op->sendpage)) |
a8adbe378 fs/splice: Pull b... |
441 |
return -EINVAL; |
35f9c09fe tcp: tcp_sendpage... |
442 |
more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0; |
ae62ca7b0 tcp: fix MSG_SEND... |
443 444 |
if (sd->len < sd->total_len && pipe->nrbufs > 1) |
35f9c09fe tcp: tcp_sendpage... |
445 |
more |= MSG_SENDPAGE_NOTLAST; |
ae62ca7b0 tcp: fix MSG_SEND... |
446 |
|
a8adbe378 fs/splice: Pull b... |
447 448 |
return file->f_op->sendpage(file, buf->page, buf->offset, sd->len, &pos, more); |
5274f052e [PATCH] Introduce... |
449 |
} |
b3c2d2ddd splice: split up ... |
450 451 452 453 454 455 456 |
static void wakeup_pipe_writers(struct pipe_inode_info *pipe) { smp_mb(); if (waitqueue_active(&pipe->wait)) wake_up_interruptible(&pipe->wait); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } |
932cc6d4f splice: completel... |
457 |
/** |
b3c2d2ddd splice: split up ... |
458 |
* splice_from_pipe_feed - feed available data from a pipe to a file |
932cc6d4f splice: completel... |
459 460 461 462 463 |
* @pipe: pipe to splice from * @sd: information to @actor * @actor: handler that splices the data * * Description: |
b3c2d2ddd splice: split up ... |
464 465 466 467 468 469 470 |
* This function loops over the pipe and calls @actor to do the * actual moving of a single struct pipe_buffer to the desired * destination. It returns when there's no more buffers left in * the pipe or if the requested number of bytes (@sd->total_len) * have been copied. It returns a positive number (one) if the * pipe needs to be filled with more data, zero if the required * number of bytes have been copied and -errno on error. |
932cc6d4f splice: completel... |
471 |
* |
b3c2d2ddd splice: split up ... |
472 473 474 475 |
* This, together with splice_from_pipe_{begin,end,next}, may be * used to implement the functionality of __splice_from_pipe() when * locking is required around copying the pipe buffers to the * destination. |
83f9135bd [PATCH] splice: a... |
476 |
*/ |
96f9bc8fb fs/splice.c: remo... |
477 |
static int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd, |
b3c2d2ddd splice: split up ... |
478 |
splice_actor *actor) |
5274f052e [PATCH] Introduce... |
479 |
{ |
b3c2d2ddd splice: split up ... |
480 |
int ret; |
5274f052e [PATCH] Introduce... |
481 |
|
b3c2d2ddd splice: split up ... |
482 483 |
while (pipe->nrbufs) { struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; |
5274f052e [PATCH] Introduce... |
484 |
|
b3c2d2ddd splice: split up ... |
485 486 487 |
sd->len = buf->len; if (sd->len > sd->total_len) sd->len = sd->total_len; |
5274f052e [PATCH] Introduce... |
488 |
|
fba597db4 pipe: add pipe_bu... |
489 |
ret = pipe_buf_confirm(pipe, buf); |
a8adbe378 fs/splice: Pull b... |
490 |
if (unlikely(ret)) { |
b3c2d2ddd splice: split up ... |
491 492 493 494 |
if (ret == -ENODATA) ret = 0; return ret; } |
a8adbe378 fs/splice: Pull b... |
495 496 497 498 |
ret = actor(pipe, buf, sd); if (ret <= 0) return ret; |
b3c2d2ddd splice: split up ... |
499 500 501 502 503 504 505 506 507 |
buf->offset += ret; buf->len -= ret; sd->num_spliced += ret; sd->len -= ret; sd->pos += ret; sd->total_len -= ret; if (!buf->len) { |
a779638cf pipe: add pipe_bu... |
508 |
pipe_buf_release(pipe, buf); |
35f3d14db pipe: add support... |
509 |
pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); |
b3c2d2ddd splice: split up ... |
510 |
pipe->nrbufs--; |
6447a3cf1 get rid of pipe->... |
511 |
if (pipe->files) |
b3c2d2ddd splice: split up ... |
512 513 |
sd->need_wakeup = true; } |
5274f052e [PATCH] Introduce... |
514 |
|
b3c2d2ddd splice: split up ... |
515 516 517 |
if (!sd->total_len) return 0; } |
5274f052e [PATCH] Introduce... |
518 |
|
b3c2d2ddd splice: split up ... |
519 520 |
return 1; } |
5274f052e [PATCH] Introduce... |
521 |
|
b3c2d2ddd splice: split up ... |
522 523 524 525 526 527 528 529 530 531 |
/** * splice_from_pipe_next - wait for some data to splice from * @pipe: pipe to splice from * @sd: information about the splice operation * * Description: * This function will wait for some data and return a positive * value (one) if pipe buffers are available. It will return zero * or -errno if no more data needs to be spliced. */ |
96f9bc8fb fs/splice.c: remo... |
532 |
static int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd) |
b3c2d2ddd splice: split up ... |
533 |
{ |
c725bfce7 vfs: Make sendfil... |
534 535 536 537 538 539 |
/* * Check for signal early to make process killable when there are * always buffers available */ if (signal_pending(current)) return -ERESTARTSYS; |
b3c2d2ddd splice: split up ... |
540 541 542 |
while (!pipe->nrbufs) { if (!pipe->writers) return 0; |
016b661e2 [PATCH] splice: f... |
543 |
|
b3c2d2ddd splice: split up ... |
544 545 |
if (!pipe->waiting_writers && sd->num_spliced) return 0; |
73d62d83e [PATCH] splice: c... |
546 |
|
b3c2d2ddd splice: split up ... |
547 548 |
if (sd->flags & SPLICE_F_NONBLOCK) return -EAGAIN; |
5274f052e [PATCH] Introduce... |
549 |
|
b3c2d2ddd splice: split up ... |
550 551 |
if (signal_pending(current)) return -ERESTARTSYS; |
5274f052e [PATCH] Introduce... |
552 |
|
b3c2d2ddd splice: split up ... |
553 554 555 |
if (sd->need_wakeup) { wakeup_pipe_writers(pipe); sd->need_wakeup = false; |
5274f052e [PATCH] Introduce... |
556 |
} |
b3c2d2ddd splice: split up ... |
557 558 |
pipe_wait(pipe); } |
29e350944 splice: add SPLIC... |
559 |
|
b3c2d2ddd splice: split up ... |
560 561 |
return 1; } |
5274f052e [PATCH] Introduce... |
562 |
|
b3c2d2ddd splice: split up ... |
563 564 |
/** * splice_from_pipe_begin - start splicing from pipe |
b80901bbf splice: fix new k... |
565 |
* @sd: information about the splice operation |
b3c2d2ddd splice: split up ... |
566 567 568 569 570 571 |
* * Description: * This function should be called before a loop containing * splice_from_pipe_next() and splice_from_pipe_feed() to * initialize the necessary fields of @sd. */ |
96f9bc8fb fs/splice.c: remo... |
572 |
static void splice_from_pipe_begin(struct splice_desc *sd) |
b3c2d2ddd splice: split up ... |
573 574 575 576 |
{ sd->num_spliced = 0; sd->need_wakeup = false; } |
5274f052e [PATCH] Introduce... |
577 |
|
b3c2d2ddd splice: split up ... |
578 579 580 581 582 583 584 585 586 587 |
/** * splice_from_pipe_end - finish splicing from pipe * @pipe: pipe to splice from * @sd: information about the splice operation * * Description: * This function will wake up pipe writers if necessary. It should * be called after a loop containing splice_from_pipe_next() and * splice_from_pipe_feed(). */ |
96f9bc8fb fs/splice.c: remo... |
588 |
static void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd) |
b3c2d2ddd splice: split up ... |
589 590 591 592 |
{ if (sd->need_wakeup) wakeup_pipe_writers(pipe); } |
5274f052e [PATCH] Introduce... |
593 |
|
b3c2d2ddd splice: split up ... |
594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 |
/** * __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. * */ ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd, splice_actor *actor) { int ret; |
5274f052e [PATCH] Introduce... |
611 |
|
b3c2d2ddd splice: split up ... |
612 613 |
splice_from_pipe_begin(sd); do { |
c2489e07c vfs: Avoid softlo... |
614 |
cond_resched(); |
b3c2d2ddd splice: split up ... |
615 616 617 618 619 620 621 |
ret = splice_from_pipe_next(pipe, sd); if (ret > 0) ret = splice_from_pipe_feed(pipe, sd, actor); } while (ret > 0); splice_from_pipe_end(pipe, sd); return sd->num_spliced ? sd->num_spliced : ret; |
5274f052e [PATCH] Introduce... |
622 |
} |
40bee44ea Export __splice_f... |
623 |
EXPORT_SYMBOL(__splice_from_pipe); |
5274f052e [PATCH] Introduce... |
624 |
|
932cc6d4f splice: completel... |
625 626 627 628 629 630 631 632 633 634 |
/** * 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: |
2933970b9 splice: remove i_... |
635 |
* See __splice_from_pipe. This function locks the pipe inode, |
932cc6d4f splice: completel... |
636 637 638 |
* otherwise it's identical to __splice_from_pipe(). * */ |
6da618098 [PATCH] Introduce... |
639 640 641 642 643 |
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; |
c66ab6fa7 splice: abstract ... |
644 645 646 647 |
struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, |
6a14b90bb vmsplice: add vms... |
648 |
.u.file = out, |
c66ab6fa7 splice: abstract ... |
649 |
}; |
6da618098 [PATCH] Introduce... |
650 |
|
61e0d47c3 splice: add helpe... |
651 |
pipe_lock(pipe); |
c66ab6fa7 splice: abstract ... |
652 |
ret = __splice_from_pipe(pipe, &sd, actor); |
61e0d47c3 splice: add helpe... |
653 |
pipe_unlock(pipe); |
6da618098 [PATCH] Introduce... |
654 655 656 657 658 |
return ret; } /** |
8d0207652 ->splice_write() ... |
659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 |
* iter_file_splice_write - splice data from a pipe to a file * @pipe: pipe info * @out: file to write to * @ppos: position in @out * @len: number of bytes to splice * @flags: splice modifier flags * * Description: * Will either move or copy pages (determined by @flags options) from * the given pipe inode to the given file. * This one is ->write_iter-based. * */ ssize_t iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags) { struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, .u.file = out, }; int nbufs = pipe->buffers; struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec), GFP_KERNEL); ssize_t ret; if (unlikely(!array)) return -ENOMEM; pipe_lock(pipe); splice_from_pipe_begin(&sd); while (sd.total_len) { struct iov_iter from; |
8d0207652 ->splice_write() ... |
695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 |
size_t left; int n, idx; ret = splice_from_pipe_next(pipe, &sd); if (ret <= 0) break; if (unlikely(nbufs < pipe->buffers)) { kfree(array); nbufs = pipe->buffers; array = kcalloc(nbufs, sizeof(struct bio_vec), GFP_KERNEL); if (!array) { ret = -ENOMEM; break; } } /* build the vector */ left = sd.total_len; for (n = 0, idx = pipe->curbuf; left && n < pipe->nrbufs; n++, idx++) { struct pipe_buffer *buf = pipe->bufs + idx; size_t this_len = buf->len; if (this_len > left) this_len = left; if (idx == pipe->buffers - 1) idx = -1; |
fba597db4 pipe: add pipe_bu... |
724 |
ret = pipe_buf_confirm(pipe, buf); |
8d0207652 ->splice_write() ... |
725 726 727 728 729 730 731 732 733 734 735 |
if (unlikely(ret)) { if (ret == -ENODATA) ret = 0; goto done; } array[n].bv_page = buf->page; array[n].bv_len = this_len; array[n].bv_offset = buf->offset; left -= this_len; } |
05afcb77e new helper: iov_i... |
736 737 |
iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n, sd.total_len - left); |
dbe4e192a fs: add vfs_iter_... |
738 |
ret = vfs_iter_write(out, &from, &sd.pos); |
8d0207652 ->splice_write() ... |
739 740 741 742 743 |
if (ret <= 0) break; sd.num_spliced += ret; sd.total_len -= ret; |
dbe4e192a fs: add vfs_iter_... |
744 |
*ppos = sd.pos; |
8d0207652 ->splice_write() ... |
745 746 747 748 749 |
/* dismiss the fully eaten buffers, adjust the partial one */ while (ret) { struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; if (ret >= buf->len) { |
8d0207652 ->splice_write() ... |
750 751 |
ret -= buf->len; buf->len = 0; |
a779638cf pipe: add pipe_bu... |
752 |
pipe_buf_release(pipe, buf); |
8d0207652 ->splice_write() ... |
753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 |
pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); pipe->nrbufs--; if (pipe->files) sd.need_wakeup = true; } else { buf->offset += ret; buf->len -= ret; ret = 0; } } } done: kfree(array); splice_from_pipe_end(pipe, &sd); pipe_unlock(pipe); if (sd.num_spliced) ret = sd.num_spliced; return ret; } EXPORT_SYMBOL(iter_file_splice_write); |
b2858d7d1 splice: fix kmaps... |
777 778 |
static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) |
0b0a47f5c splice: implement... |
779 |
{ |
b2858d7d1 splice: fix kmaps... |
780 781 |
int ret; void *data; |
06ae43f34 Don't bother with... |
782 |
loff_t tmp = sd->pos; |
b2858d7d1 splice: fix kmaps... |
783 |
|
fbb32750a pipe: kill ->map(... |
784 |
data = kmap(buf->page); |
06ae43f34 Don't bother with... |
785 |
ret = __kernel_write(sd->u.file, data + buf->offset, sd->len, &tmp); |
fbb32750a pipe: kill ->map(... |
786 |
kunmap(buf->page); |
b2858d7d1 splice: fix kmaps... |
787 788 |
return ret; |
0b0a47f5c splice: implement... |
789 790 791 792 793 794 |
} static ssize_t default_file_splice_write(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags) { |
b2858d7d1 splice: fix kmaps... |
795 |
ssize_t ret; |
0b0a47f5c splice: implement... |
796 |
|
b2858d7d1 splice: fix kmaps... |
797 798 799 |
ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf); if (ret > 0) *ppos += ret; |
0b0a47f5c splice: implement... |
800 |
|
b2858d7d1 splice: fix kmaps... |
801 |
return ret; |
0b0a47f5c splice: implement... |
802 |
} |
83f9135bd [PATCH] splice: a... |
803 804 |
/** * generic_splice_sendpage - splice data from a pipe to a socket |
932cc6d4f splice: completel... |
805 |
* @pipe: pipe to splice from |
83f9135bd [PATCH] splice: a... |
806 |
* @out: socket to write to |
932cc6d4f splice: completel... |
807 |
* @ppos: position in @out |
83f9135bd [PATCH] splice: a... |
808 809 810 |
* @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
811 812 813 |
* Description: * Will send @len bytes from the pipe to a network socket. No data copying * is involved. |
83f9135bd [PATCH] splice: a... |
814 815 |
* */ |
3a326a2ce [PATCH] introduce... |
816 |
ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, |
cbb7e577e [PATCH] splice: p... |
817 |
loff_t *ppos, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
818 |
{ |
00522fb41 [PATCH] splice: r... |
819 |
return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); |
5274f052e [PATCH] Introduce... |
820 |
} |
059a8f373 [PATCH] splice: e... |
821 |
EXPORT_SYMBOL(generic_splice_sendpage); |
a0f067802 [PATCH] splice ex... |
822 |
|
83f9135bd [PATCH] splice: a... |
823 824 825 |
/* * Attempt to initiate a splice from pipe to file. */ |
3a326a2ce [PATCH] introduce... |
826 |
static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, |
cbb7e577e [PATCH] splice: p... |
827 |
loff_t *ppos, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
828 |
{ |
0b0a47f5c splice: implement... |
829 830 |
ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); |
5274f052e [PATCH] Introduce... |
831 |
|
72c2d5319 file->f_op is nev... |
832 |
if (out->f_op->splice_write) |
cc56f7de7 sendfile(): check... |
833 834 |
splice_write = out->f_op->splice_write; else |
0b0a47f5c splice: implement... |
835 |
splice_write = default_file_splice_write; |
500368f7f lift file_*_write... |
836 |
return splice_write(pipe, out, ppos, len, flags); |
5274f052e [PATCH] Introduce... |
837 |
} |
83f9135bd [PATCH] splice: a... |
838 839 840 |
/* * Attempt to initiate a splice from a file to a pipe. */ |
cbb7e577e [PATCH] splice: p... |
841 842 843 |
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... |
844 |
{ |
6818173bd splice: implement... |
845 846 |
ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); |
5274f052e [PATCH] Introduce... |
847 |
int ret; |
49570e9b2 [PATCH] splice: u... |
848 |
if (unlikely(!(in->f_mode & FMODE_READ))) |
5274f052e [PATCH] Introduce... |
849 |
return -EBADF; |
cbb7e577e [PATCH] splice: p... |
850 |
ret = rw_verify_area(READ, in, ppos, len); |
5274f052e [PATCH] Introduce... |
851 852 |
if (unlikely(ret < 0)) return ret; |
03cc0789a do_splice_to(): c... |
853 854 |
if (unlikely(len > MAX_RW_COUNT)) len = MAX_RW_COUNT; |
72c2d5319 file->f_op is nev... |
855 |
if (in->f_op->splice_read) |
cc56f7de7 sendfile(): check... |
856 857 |
splice_read = in->f_op->splice_read; else |
6818173bd splice: implement... |
858 859 860 |
splice_read = default_file_splice_read; return splice_read(in, ppos, pipe, len, flags); |
5274f052e [PATCH] Introduce... |
861 |
} |
932cc6d4f splice: completel... |
862 863 864 865 866 867 868 869 870 |
/** * 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... |
871 |
* pipe is cached in the process, and reused during the lifetime of |
932cc6d4f splice: completel... |
872 873 |
* that process. * |
c66ab6fa7 splice: abstract ... |
874 875 876 |
*/ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, splice_direct_actor *actor) |
b92ce5589 [PATCH] splice: a... |
877 878 879 880 |
{ struct pipe_inode_info *pipe; long ret, bytes; umode_t i_mode; |
c66ab6fa7 splice: abstract ... |
881 |
size_t len; |
0ff28d9f4 splice: sendfile(... |
882 |
int i, flags, more; |
b92ce5589 [PATCH] splice: a... |
883 884 885 886 887 888 |
/* * 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! */ |
496ad9aa8 new helper: file_... |
889 |
i_mode = file_inode(in)->i_mode; |
b92ce5589 [PATCH] splice: a... |
890 891 892 893 894 895 896 897 |
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... |
898 |
if (unlikely(!pipe)) { |
7bee130e2 get rid of alloc_... |
899 |
pipe = alloc_pipe_info(); |
b92ce5589 [PATCH] splice: a... |
900 901 902 903 904 |
if (!pipe) return -ENOMEM; /* * We don't have an immediate reader, but we'll read the stuff |
00522fb41 [PATCH] splice: r... |
905 |
* out of the pipe right after the splice_to_pipe(). So set |
b92ce5589 [PATCH] splice: a... |
906 907 908 909 910 911 912 913 |
* PIPE_READERS appropriately. */ pipe->readers = 1; current->splice_pipe = pipe; } /* |
73d62d83e [PATCH] splice: c... |
914 |
* Do the splice. |
b92ce5589 [PATCH] splice: a... |
915 916 917 |
*/ ret = 0; bytes = 0; |
c66ab6fa7 splice: abstract ... |
918 919 920 921 922 923 924 |
len = sd->total_len; flags = sd->flags; /* * Don't block on output, we have to drain the direct pipe. */ sd->flags &= ~SPLICE_F_NONBLOCK; |
0ff28d9f4 splice: sendfile(... |
925 |
more = sd->flags & SPLICE_F_MORE; |
b92ce5589 [PATCH] splice: a... |
926 927 |
while (len) { |
51a92c0f6 splice: fix offse... |
928 |
size_t read_len; |
a82c53a0e splice: fix sendf... |
929 |
loff_t pos = sd->pos, prev_pos = pos; |
b92ce5589 [PATCH] splice: a... |
930 |
|
bcd4f3acb splice: direct sp... |
931 |
ret = do_splice_to(in, &pos, pipe, len, flags); |
51a92c0f6 splice: fix offse... |
932 |
if (unlikely(ret <= 0)) |
b92ce5589 [PATCH] splice: a... |
933 934 935 |
goto out_release; read_len = ret; |
c66ab6fa7 splice: abstract ... |
936 |
sd->total_len = read_len; |
b92ce5589 [PATCH] splice: a... |
937 938 |
/* |
0ff28d9f4 splice: sendfile(... |
939 940 941 942 943 944 945 946 947 |
* If more data is pending, set SPLICE_F_MORE * If this is the last data and SPLICE_F_MORE was not set * initially, clears it. */ if (read_len < len) sd->flags |= SPLICE_F_MORE; else if (!more) sd->flags &= ~SPLICE_F_MORE; /* |
b92ce5589 [PATCH] splice: a... |
948 949 950 951 |
* 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 ... |
952 |
ret = actor(pipe, sd); |
a82c53a0e splice: fix sendf... |
953 954 |
if (unlikely(ret <= 0)) { sd->pos = prev_pos; |
b92ce5589 [PATCH] splice: a... |
955 |
goto out_release; |
a82c53a0e splice: fix sendf... |
956 |
} |
b92ce5589 [PATCH] splice: a... |
957 958 959 |
bytes += ret; len -= ret; |
bcd4f3acb splice: direct sp... |
960 |
sd->pos = pos; |
b92ce5589 [PATCH] splice: a... |
961 |
|
a82c53a0e splice: fix sendf... |
962 963 |
if (ret < read_len) { sd->pos = prev_pos + ret; |
51a92c0f6 splice: fix offse... |
964 |
goto out_release; |
a82c53a0e splice: fix sendf... |
965 |
} |
b92ce5589 [PATCH] splice: a... |
966 |
} |
9e97198db splice: fix probl... |
967 |
done: |
b92ce5589 [PATCH] splice: a... |
968 |
pipe->nrbufs = pipe->curbuf = 0; |
808487085 splice: always up... |
969 |
file_accessed(in); |
b92ce5589 [PATCH] splice: a... |
970 971 972 973 974 975 976 |
return bytes; out_release: /* * If we did an incomplete transfer we must release * the pipe buffers in question: */ |
35f3d14db pipe: add support... |
977 |
for (i = 0; i < pipe->buffers; i++) { |
b92ce5589 [PATCH] splice: a... |
978 |
struct pipe_buffer *buf = pipe->bufs + i; |
a779638cf pipe: add pipe_bu... |
979 980 |
if (buf->ops) pipe_buf_release(pipe, buf); |
b92ce5589 [PATCH] splice: a... |
981 |
} |
b92ce5589 [PATCH] splice: a... |
982 |
|
9e97198db splice: fix probl... |
983 984 |
if (!bytes) bytes = ret; |
c66ab6fa7 splice: abstract ... |
985 |
|
9e97198db splice: fix probl... |
986 |
goto done; |
c66ab6fa7 splice: abstract ... |
987 988 989 990 991 992 |
} EXPORT_SYMBOL(splice_direct_to_actor); static int direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) { |
6a14b90bb vmsplice: add vms... |
993 |
struct file *file = sd->u.file; |
c66ab6fa7 splice: abstract ... |
994 |
|
7995bd287 splice: don't pas... |
995 |
return do_splice_from(pipe, file, sd->opos, sd->total_len, |
2cb4b05e7 splice: direct_sp... |
996 |
sd->flags); |
c66ab6fa7 splice: abstract ... |
997 |
} |
932cc6d4f splice: completel... |
998 999 1000 1001 1002 |
/** * do_splice_direct - splices data directly between two files * @in: file to splice from * @ppos: input file offset * @out: file to splice to |
acdb37c36 fs: fix new splic... |
1003 |
* @opos: output file offset |
932cc6d4f splice: completel... |
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 |
* @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 ... |
1014 |
long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, |
7995bd287 splice: don't pas... |
1015 |
loff_t *opos, size_t len, unsigned int flags) |
c66ab6fa7 splice: abstract ... |
1016 1017 1018 1019 1020 1021 |
{ struct splice_desc sd = { .len = len, .total_len = len, .flags = flags, .pos = *ppos, |
6a14b90bb vmsplice: add vms... |
1022 |
.u.file = out, |
7995bd287 splice: don't pas... |
1023 |
.opos = opos, |
c66ab6fa7 splice: abstract ... |
1024 |
}; |
51a92c0f6 splice: fix offse... |
1025 |
long ret; |
c66ab6fa7 splice: abstract ... |
1026 |
|
18c67cb9f splice: lift chec... |
1027 1028 1029 1030 1031 1032 1033 1034 1035 |
if (unlikely(!(out->f_mode & FMODE_WRITE))) return -EBADF; if (unlikely(out->f_flags & O_APPEND)) return -EINVAL; ret = rw_verify_area(WRITE, out, opos, len); if (unlikely(ret < 0)) return ret; |
c66ab6fa7 splice: abstract ... |
1036 |
ret = splice_direct_to_actor(in, &sd, direct_splice_actor); |
51a92c0f6 splice: fix offse... |
1037 |
if (ret > 0) |
a82c53a0e splice: fix sendf... |
1038 |
*ppos = sd.pos; |
51a92c0f6 splice: fix offse... |
1039 |
|
c66ab6fa7 splice: abstract ... |
1040 |
return ret; |
b92ce5589 [PATCH] splice: a... |
1041 |
} |
1c118596a vfs: export do_sp... |
1042 |
EXPORT_SYMBOL(do_splice_direct); |
b92ce5589 [PATCH] splice: a... |
1043 |
|
8924feff6 splice: lift pipe... |
1044 1045 |
static int wait_for_space(struct pipe_inode_info *pipe, unsigned flags) { |
b6cce9b8e splice: reinstate... |
1046 1047 1048 1049 1050 1051 1052 |
for (;;) { if (unlikely(!pipe->readers)) { send_sig(SIGPIPE, current, 0); return -EPIPE; } if (pipe->nrbufs != pipe->buffers) return 0; |
8924feff6 splice: lift pipe... |
1053 1054 1055 1056 1057 1058 1059 1060 |
if (flags & SPLICE_F_NONBLOCK) return -EAGAIN; if (signal_pending(current)) return -ERESTARTSYS; pipe->waiting_writers++; pipe_wait(pipe); pipe->waiting_writers--; } |
8924feff6 splice: lift pipe... |
1061 |
} |
7c77f0b3f splice: implement... |
1062 1063 1064 |
static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, struct pipe_inode_info *opipe, size_t len, unsigned int flags); |
ddac0d39c [PATCH] splice: f... |
1065 1066 |
/* |
83f9135bd [PATCH] splice: a... |
1067 1068 |
* Determine where to splice to/from. */ |
529565dcb [PATCH] splice: a... |
1069 1070 1071 |
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... |
1072 |
{ |
7c77f0b3f splice: implement... |
1073 1074 |
struct pipe_inode_info *ipipe; struct pipe_inode_info *opipe; |
7995bd287 splice: don't pas... |
1075 |
loff_t offset; |
a4514ebd8 [PATCH] splice: o... |
1076 |
long ret; |
5274f052e [PATCH] Introduce... |
1077 |
|
71993e62a Rename 'pipe_info... |
1078 1079 |
ipipe = get_pipe_info(in); opipe = get_pipe_info(out); |
7c77f0b3f splice: implement... |
1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 |
if (ipipe && opipe) { if (off_in || off_out) return -ESPIPE; if (!(in->f_mode & FMODE_READ)) return -EBADF; if (!(out->f_mode & FMODE_WRITE)) return -EBADF; /* Splicing to self would be fun, but... */ if (ipipe == opipe) return -EINVAL; return splice_pipe_to_pipe(ipipe, opipe, len, flags); } if (ipipe) { |
529565dcb [PATCH] splice: a... |
1099 1100 |
if (off_in) return -ESPIPE; |
b92ce5589 [PATCH] splice: a... |
1101 |
if (off_out) { |
19c9a49b4 splice: check f_m... |
1102 |
if (!(out->f_mode & FMODE_PWRITE)) |
b92ce5589 [PATCH] splice: a... |
1103 |
return -EINVAL; |
cbb7e577e [PATCH] splice: p... |
1104 |
if (copy_from_user(&offset, off_out, sizeof(loff_t))) |
b92ce5589 [PATCH] splice: a... |
1105 |
return -EFAULT; |
7995bd287 splice: don't pas... |
1106 1107 1108 |
} else { offset = out->f_pos; } |
529565dcb [PATCH] splice: a... |
1109 |
|
18c67cb9f splice: lift chec... |
1110 1111 1112 1113 1114 1115 1116 1117 1118 |
if (unlikely(!(out->f_mode & FMODE_WRITE))) return -EBADF; if (unlikely(out->f_flags & O_APPEND)) return -EINVAL; ret = rw_verify_area(WRITE, out, &offset, len); if (unlikely(ret < 0)) return ret; |
500368f7f lift file_*_write... |
1119 |
file_start_write(out); |
7995bd287 splice: don't pas... |
1120 |
ret = do_splice_from(ipipe, out, &offset, len, flags); |
500368f7f lift file_*_write... |
1121 |
file_end_write(out); |
a4514ebd8 [PATCH] splice: o... |
1122 |
|
7995bd287 splice: don't pas... |
1123 1124 1125 |
if (!off_out) out->f_pos = offset; else if (copy_to_user(off_out, &offset, sizeof(loff_t))) |
a4514ebd8 [PATCH] splice: o... |
1126 1127 1128 |
ret = -EFAULT; return ret; |
529565dcb [PATCH] splice: a... |
1129 |
} |
5274f052e [PATCH] Introduce... |
1130 |
|
7c77f0b3f splice: implement... |
1131 |
if (opipe) { |
529565dcb [PATCH] splice: a... |
1132 1133 |
if (off_out) return -ESPIPE; |
b92ce5589 [PATCH] splice: a... |
1134 |
if (off_in) { |
19c9a49b4 splice: check f_m... |
1135 |
if (!(in->f_mode & FMODE_PREAD)) |
b92ce5589 [PATCH] splice: a... |
1136 |
return -EINVAL; |
cbb7e577e [PATCH] splice: p... |
1137 |
if (copy_from_user(&offset, off_in, sizeof(loff_t))) |
b92ce5589 [PATCH] splice: a... |
1138 |
return -EFAULT; |
7995bd287 splice: don't pas... |
1139 1140 1141 |
} else { offset = in->f_pos; } |
529565dcb [PATCH] splice: a... |
1142 |
|
8924feff6 splice: lift pipe... |
1143 1144 1145 1146 1147 1148 1149 |
pipe_lock(opipe); ret = wait_for_space(opipe, flags); if (!ret) ret = do_splice_to(in, &offset, opipe, len, flags); pipe_unlock(opipe); if (ret > 0) wakeup_pipe_readers(opipe); |
7995bd287 splice: don't pas... |
1150 1151 1152 |
if (!off_in) in->f_pos = offset; else if (copy_to_user(off_in, &offset, sizeof(loff_t))) |
a4514ebd8 [PATCH] splice: o... |
1153 1154 1155 |
ret = -EFAULT; return ret; |
529565dcb [PATCH] splice: a... |
1156 |
} |
5274f052e [PATCH] Introduce... |
1157 1158 1159 |
return -EINVAL; } |
79fddc4ef new helper: add_t... |
1160 1161 1162 |
static int iter_to_pipe(struct iov_iter *from, struct pipe_inode_info *pipe, unsigned flags) |
912d35f86 [PATCH] Add suppo... |
1163 |
{ |
79fddc4ef new helper: add_t... |
1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 |
struct pipe_buffer buf = { .ops = &user_page_pipe_buf_ops, .flags = flags }; size_t total = 0; int ret = 0; bool failed = false; while (iov_iter_count(from) && !failed) { struct page *pages[16]; |
db85a9eb2 splice: switch ge... |
1174 1175 |
ssize_t copied; size_t start; |
79fddc4ef new helper: add_t... |
1176 |
int n; |
db85a9eb2 splice: switch ge... |
1177 |
|
79fddc4ef new helper: add_t... |
1178 1179 1180 1181 1182 |
copied = iov_iter_get_pages(from, pages, ~0UL, 16, &start); if (copied <= 0) { ret = copied; break; } |
db85a9eb2 splice: switch ge... |
1183 |
|
79fddc4ef new helper: add_t... |
1184 |
for (n = 0; copied; n++, start = 0) { |
db85a9eb2 splice: switch ge... |
1185 |
int size = min_t(int, copied, PAGE_SIZE - start); |
79fddc4ef new helper: add_t... |
1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 |
if (!failed) { buf.page = pages[n]; buf.offset = start; buf.len = size; ret = add_to_pipe(pipe, &buf); if (unlikely(ret < 0)) { failed = true; } else { iov_iter_advance(from, ret); total += ret; } } else { put_page(pages[n]); } |
db85a9eb2 splice: switch ge... |
1200 |
copied -= size; |
912d35f86 [PATCH] Add suppo... |
1201 |
} |
912d35f86 [PATCH] Add suppo... |
1202 |
} |
79fddc4ef new helper: add_t... |
1203 |
return total ? total : ret; |
912d35f86 [PATCH] Add suppo... |
1204 |
} |
6a14b90bb vmsplice: add vms... |
1205 1206 1207 |
static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) { |
6130f5315 switch vmsplice_t... |
1208 1209 |
int n = copy_page_to_iter(buf->page, buf->offset, sd->len, sd->u.data); return n == sd->len ? n : -EFAULT; |
6a14b90bb vmsplice: add vms... |
1210 1211 1212 1213 1214 1215 |
} /* * For lack of a better implementation, implement vmsplice() to userspace * as a simple copy of the pipes pages to the user iov. */ |
6130f5315 switch vmsplice_t... |
1216 |
static long vmsplice_to_user(struct file *file, const struct iovec __user *uiov, |
6a14b90bb vmsplice: add vms... |
1217 1218 1219 1220 |
unsigned long nr_segs, unsigned int flags) { struct pipe_inode_info *pipe; struct splice_desc sd; |
6a14b90bb vmsplice: add vms... |
1221 |
long ret; |
6130f5315 switch vmsplice_t... |
1222 1223 1224 |
struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; struct iov_iter iter; |
6a14b90bb vmsplice: add vms... |
1225 |
|
71993e62a Rename 'pipe_info... |
1226 |
pipe = get_pipe_info(file); |
6a14b90bb vmsplice: add vms... |
1227 1228 |
if (!pipe) return -EBADF; |
345995fa4 vmsplice_to_user(... |
1229 1230 1231 1232 |
ret = import_iovec(READ, uiov, nr_segs, ARRAY_SIZE(iovstack), &iov, &iter); if (ret < 0) return ret; |
6a14b90bb vmsplice: add vms... |
1233 |
|
345995fa4 vmsplice_to_user(... |
1234 |
sd.total_len = iov_iter_count(&iter); |
6130f5315 switch vmsplice_t... |
1235 |
sd.len = 0; |
6130f5315 switch vmsplice_t... |
1236 1237 1238 |
sd.flags = flags; sd.u.data = &iter; sd.pos = 0; |
6a14b90bb vmsplice: add vms... |
1239 |
|
345995fa4 vmsplice_to_user(... |
1240 1241 1242 1243 1244 |
if (sd.total_len) { pipe_lock(pipe); ret = __splice_from_pipe(pipe, &sd, pipe_to_user); pipe_unlock(pipe); } |
6a14b90bb vmsplice: add vms... |
1245 |
|
345995fa4 vmsplice_to_user(... |
1246 |
kfree(iov); |
6a14b90bb vmsplice: add vms... |
1247 1248 |
return ret; } |
912d35f86 [PATCH] Add suppo... |
1249 1250 1251 1252 |
/* * 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... |
1253 |
*/ |
db85a9eb2 splice: switch ge... |
1254 |
static long vmsplice_to_pipe(struct file *file, const struct iovec __user *uiov, |
6a14b90bb vmsplice: add vms... |
1255 |
unsigned long nr_segs, unsigned int flags) |
912d35f86 [PATCH] Add suppo... |
1256 |
{ |
ddac0d39c [PATCH] splice: f... |
1257 |
struct pipe_inode_info *pipe; |
db85a9eb2 splice: switch ge... |
1258 1259 1260 |
struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; struct iov_iter from; |
35f3d14db pipe: add support... |
1261 |
long ret; |
79fddc4ef new helper: add_t... |
1262 1263 1264 1265 |
unsigned buf_flag = 0; if (flags & SPLICE_F_GIFT) buf_flag = PIPE_BUF_FLAG_GIFT; |
912d35f86 [PATCH] Add suppo... |
1266 |
|
71993e62a Rename 'pipe_info... |
1267 |
pipe = get_pipe_info(file); |
ddac0d39c [PATCH] splice: f... |
1268 |
if (!pipe) |
912d35f86 [PATCH] Add suppo... |
1269 |
return -EBADF; |
912d35f86 [PATCH] Add suppo... |
1270 |
|
db85a9eb2 splice: switch ge... |
1271 1272 1273 1274 |
ret = import_iovec(WRITE, uiov, nr_segs, ARRAY_SIZE(iovstack), &iov, &from); if (ret < 0) return ret; |
8924feff6 splice: lift pipe... |
1275 1276 |
pipe_lock(pipe); ret = wait_for_space(pipe, flags); |
79fddc4ef new helper: add_t... |
1277 1278 |
if (!ret) ret = iter_to_pipe(&from, pipe, buf_flag); |
8924feff6 splice: lift pipe... |
1279 1280 1281 |
pipe_unlock(pipe); if (ret > 0) wakeup_pipe_readers(pipe); |
db85a9eb2 splice: switch ge... |
1282 |
kfree(iov); |
35f3d14db pipe: add support... |
1283 |
return ret; |
912d35f86 [PATCH] Add suppo... |
1284 |
} |
6a14b90bb vmsplice: add vms... |
1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 |
/* * 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(). * */ |
836f92adf [CVE-2009-0029] S... |
1301 1302 |
SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov, unsigned long, nr_segs, unsigned int, flags) |
912d35f86 [PATCH] Add suppo... |
1303 |
{ |
2903ff019 switch simple cas... |
1304 |
struct fd f; |
912d35f86 [PATCH] Add suppo... |
1305 |
long error; |
912d35f86 [PATCH] Add suppo... |
1306 |
|
6a14b90bb vmsplice: add vms... |
1307 1308 1309 1310 |
if (unlikely(nr_segs > UIO_MAXIOV)) return -EINVAL; else if (unlikely(!nr_segs)) return 0; |
912d35f86 [PATCH] Add suppo... |
1311 |
error = -EBADF; |
2903ff019 switch simple cas... |
1312 1313 1314 1315 1316 1317 1318 1319 |
f = fdget(fd); if (f.file) { if (f.file->f_mode & FMODE_WRITE) error = vmsplice_to_pipe(f.file, iov, nr_segs, flags); else if (f.file->f_mode & FMODE_READ) error = vmsplice_to_user(f.file, iov, nr_segs, flags); fdput(f); |
912d35f86 [PATCH] Add suppo... |
1320 1321 1322 1323 |
} return error; } |
76b021d05 convert vmsplice ... |
1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 |
#ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, iov32, unsigned int, nr_segs, unsigned int, flags) { unsigned i; struct iovec __user *iov; if (nr_segs > UIO_MAXIOV) return -EINVAL; iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec)); for (i = 0; i < nr_segs; i++) { struct compat_iovec v; if (get_user(v.iov_base, &iov32[i].iov_base) || get_user(v.iov_len, &iov32[i].iov_len) || put_user(compat_ptr(v.iov_base), &iov[i].iov_base) || put_user(v.iov_len, &iov[i].iov_len)) return -EFAULT; } return sys_vmsplice(fd, iov, nr_segs, flags); } #endif |
836f92adf [CVE-2009-0029] S... |
1344 1345 1346 |
SYSCALL_DEFINE6(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... |
1347 |
{ |
2903ff019 switch simple cas... |
1348 |
struct fd in, out; |
5274f052e [PATCH] Introduce... |
1349 |
long error; |
5274f052e [PATCH] Introduce... |
1350 1351 1352 1353 1354 |
if (unlikely(!len)) return 0; error = -EBADF; |
2903ff019 switch simple cas... |
1355 1356 1357 1358 1359 1360 1361 1362 |
in = fdget(fd_in); if (in.file) { if (in.file->f_mode & FMODE_READ) { out = fdget(fd_out); if (out.file) { if (out.file->f_mode & FMODE_WRITE) error = do_splice(in.file, off_in, out.file, off_out, |
529565dcb [PATCH] splice: a... |
1363 |
len, flags); |
2903ff019 switch simple cas... |
1364 |
fdput(out); |
5274f052e [PATCH] Introduce... |
1365 1366 |
} } |
2903ff019 switch simple cas... |
1367 |
fdput(in); |
5274f052e [PATCH] Introduce... |
1368 |
} |
5274f052e [PATCH] Introduce... |
1369 1370 |
return error; } |
70524490e [PATCH] splice: a... |
1371 1372 |
/* |
aadd06e5c [PATCH] splice: f... |
1373 1374 1375 |
* Make sure there's data to read. Wait for input if we can, otherwise * return an appropriate error. */ |
7c77f0b3f splice: implement... |
1376 |
static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) |
aadd06e5c [PATCH] splice: f... |
1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 |
{ 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; |
61e0d47c3 splice: add helpe... |
1388 |
pipe_lock(pipe); |
aadd06e5c [PATCH] splice: f... |
1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 |
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); } |
61e0d47c3 splice: add helpe... |
1405 |
pipe_unlock(pipe); |
aadd06e5c [PATCH] splice: f... |
1406 1407 1408 1409 1410 1411 1412 |
return ret; } /* * Make sure there's writeable room. Wait for room if we can, otherwise * return an appropriate error. */ |
7c77f0b3f splice: implement... |
1413 |
static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) |
aadd06e5c [PATCH] splice: f... |
1414 1415 1416 1417 1418 1419 1420 |
{ int ret; /* * Check ->nrbufs without the inode lock first. This function * is speculative anyways, so missing one is ok. */ |
35f3d14db pipe: add support... |
1421 |
if (pipe->nrbufs < pipe->buffers) |
aadd06e5c [PATCH] splice: f... |
1422 1423 1424 |
return 0; ret = 0; |
61e0d47c3 splice: add helpe... |
1425 |
pipe_lock(pipe); |
aadd06e5c [PATCH] splice: f... |
1426 |
|
35f3d14db pipe: add support... |
1427 |
while (pipe->nrbufs >= pipe->buffers) { |
aadd06e5c [PATCH] splice: f... |
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 |
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--; } |
61e0d47c3 splice: add helpe... |
1445 |
pipe_unlock(pipe); |
aadd06e5c [PATCH] splice: f... |
1446 1447 1448 1449 |
return ret; } /* |
7c77f0b3f splice: implement... |
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 1491 |
* Splice contents of ipipe to opipe. */ static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, struct pipe_inode_info *opipe, size_t len, unsigned int flags) { struct pipe_buffer *ibuf, *obuf; int ret = 0, nbuf; bool input_wakeup = false; retry: ret = ipipe_prep(ipipe, flags); if (ret) return ret; ret = opipe_prep(opipe, flags); if (ret) return ret; /* * Potential ABBA deadlock, work around it by ordering lock * grabbing by pipe info address. Otherwise two different processes * could deadlock (one doing tee from A -> B, the other from B -> A). */ pipe_double_lock(ipipe, opipe); do { if (!opipe->readers) { send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; break; } if (!ipipe->nrbufs && !ipipe->writers) break; /* * Cannot make any progress, because either the input * pipe is empty or the output pipe is full. */ |
35f3d14db pipe: add support... |
1492 |
if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) { |
7c77f0b3f splice: implement... |
1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 |
/* Already processed some buffers, break */ if (ret) break; if (flags & SPLICE_F_NONBLOCK) { ret = -EAGAIN; break; } /* * We raced with another reader/writer and haven't * managed to process any buffers. A zero return * value means EOF, so retry instead. */ pipe_unlock(ipipe); pipe_unlock(opipe); goto retry; } ibuf = ipipe->bufs + ipipe->curbuf; |
35f3d14db pipe: add support... |
1513 |
nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); |
7c77f0b3f splice: implement... |
1514 1515 1516 1517 1518 1519 1520 1521 1522 |
obuf = opipe->bufs + nbuf; if (len >= ibuf->len) { /* * Simply move the whole buffer from ipipe to opipe */ *obuf = *ibuf; ibuf->ops = NULL; opipe->nrbufs++; |
35f3d14db pipe: add support... |
1523 |
ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1); |
7c77f0b3f splice: implement... |
1524 1525 1526 1527 1528 1529 1530 |
ipipe->nrbufs--; input_wakeup = true; } else { /* * Get a reference to this pipe buffer, * so we can copy the contents over. */ |
7bf2d1df8 pipe: add pipe_bu... |
1531 |
pipe_buf_get(ipipe, ibuf); |
7c77f0b3f splice: implement... |
1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 |
*obuf = *ibuf; /* * Don't inherit the gift flag, we need to * prevent multiple steals of this page. */ obuf->flags &= ~PIPE_BUF_FLAG_GIFT; obuf->len = len; opipe->nrbufs++; ibuf->offset += obuf->len; ibuf->len -= obuf->len; } ret += obuf->len; len -= obuf->len; } while (len); pipe_unlock(ipipe); pipe_unlock(opipe); /* * If we put data in the output pipe, wakeup any potential readers. */ |
825cdcb1a splice: add wakeu... |
1555 1556 |
if (ret > 0) wakeup_pipe_readers(opipe); |
7c77f0b3f splice: implement... |
1557 1558 1559 1560 1561 1562 1563 |
if (input_wakeup) wakeup_pipe_writers(ipipe); return ret; } /* |
70524490e [PATCH] splice: a... |
1564 1565 1566 1567 1568 1569 1570 |
* 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... |
1571 |
int ret = 0, i = 0, nbuf; |
70524490e [PATCH] splice: a... |
1572 1573 1574 |
/* * Potential ABBA deadlock, work around it by ordering lock |
61e0d47c3 splice: add helpe... |
1575 |
* grabbing by pipe info address. Otherwise two different processes |
70524490e [PATCH] splice: a... |
1576 1577 |
* could deadlock (one doing tee from A -> B, the other from B -> A). */ |
61e0d47c3 splice: add helpe... |
1578 |
pipe_double_lock(ipipe, opipe); |
70524490e [PATCH] splice: a... |
1579 |
|
aadd06e5c [PATCH] splice: f... |
1580 |
do { |
70524490e [PATCH] splice: a... |
1581 1582 1583 1584 1585 1586 |
if (!opipe->readers) { send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; break; } |
70524490e [PATCH] splice: a... |
1587 |
|
aadd06e5c [PATCH] splice: f... |
1588 1589 1590 1591 |
/* * If we have iterated all input buffers or ran out of * output room, break. */ |
35f3d14db pipe: add support... |
1592 |
if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) |
aadd06e5c [PATCH] splice: f... |
1593 |
break; |
70524490e [PATCH] splice: a... |
1594 |
|
35f3d14db pipe: add support... |
1595 1596 |
ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1)); nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); |
70524490e [PATCH] splice: a... |
1597 1598 |
/* |
aadd06e5c [PATCH] splice: f... |
1599 1600 |
* Get a reference to this pipe buffer, * so we can copy the contents over. |
70524490e [PATCH] splice: a... |
1601 |
*/ |
7bf2d1df8 pipe: add pipe_bu... |
1602 |
pipe_buf_get(ipipe, ibuf); |
aadd06e5c [PATCH] splice: f... |
1603 1604 1605 |
obuf = opipe->bufs + nbuf; *obuf = *ibuf; |
2a27250e6 [PATCH] tee: link... |
1606 |
/* |
aadd06e5c [PATCH] splice: f... |
1607 1608 |
* Don't inherit the gift flag, we need to * prevent multiple steals of this page. |
2a27250e6 [PATCH] tee: link... |
1609 |
*/ |
aadd06e5c [PATCH] splice: f... |
1610 |
obuf->flags &= ~PIPE_BUF_FLAG_GIFT; |
70524490e [PATCH] splice: a... |
1611 |
|
aadd06e5c [PATCH] splice: f... |
1612 1613 |
if (obuf->len > len) obuf->len = len; |
70524490e [PATCH] splice: a... |
1614 |
|
aadd06e5c [PATCH] splice: f... |
1615 1616 1617 1618 1619 |
opipe->nrbufs++; ret += obuf->len; len -= obuf->len; i++; } while (len); |
70524490e [PATCH] splice: a... |
1620 |
|
02cf01aea splice: only retu... |
1621 1622 1623 1624 1625 1626 |
/* * 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; |
61e0d47c3 splice: add helpe... |
1627 1628 |
pipe_unlock(ipipe); pipe_unlock(opipe); |
70524490e [PATCH] splice: a... |
1629 |
|
aadd06e5c [PATCH] splice: f... |
1630 1631 1632 |
/* * If we put data in the output pipe, wakeup any potential readers. */ |
825cdcb1a splice: add wakeu... |
1633 1634 |
if (ret > 0) wakeup_pipe_readers(opipe); |
70524490e [PATCH] splice: a... |
1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 |
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) { |
71993e62a Rename 'pipe_info... |
1648 1649 |
struct pipe_inode_info *ipipe = get_pipe_info(in); struct pipe_inode_info *opipe = get_pipe_info(out); |
aadd06e5c [PATCH] splice: f... |
1650 |
int ret = -EINVAL; |
70524490e [PATCH] splice: a... |
1651 1652 |
/* |
aadd06e5c [PATCH] splice: f... |
1653 1654 |
* Duplicate the contents of ipipe to opipe without actually * copying the data. |
70524490e [PATCH] splice: a... |
1655 |
*/ |
aadd06e5c [PATCH] splice: f... |
1656 1657 1658 1659 1660 |
if (ipipe && opipe && ipipe != opipe) { /* * Keep going, unless we encounter an error. The ipipe/opipe * ordering doesn't really matter. */ |
7c77f0b3f splice: implement... |
1661 |
ret = ipipe_prep(ipipe, flags); |
aadd06e5c [PATCH] splice: f... |
1662 |
if (!ret) { |
7c77f0b3f splice: implement... |
1663 |
ret = opipe_prep(opipe, flags); |
02cf01aea splice: only retu... |
1664 |
if (!ret) |
aadd06e5c [PATCH] splice: f... |
1665 |
ret = link_pipe(ipipe, opipe, len, flags); |
aadd06e5c [PATCH] splice: f... |
1666 1667 |
} } |
70524490e [PATCH] splice: a... |
1668 |
|
aadd06e5c [PATCH] splice: f... |
1669 |
return ret; |
70524490e [PATCH] splice: a... |
1670 |
} |
836f92adf [CVE-2009-0029] S... |
1671 |
SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags) |
70524490e [PATCH] splice: a... |
1672 |
{ |
2903ff019 switch simple cas... |
1673 1674 |
struct fd in; int error; |
70524490e [PATCH] splice: a... |
1675 1676 1677 1678 1679 |
if (unlikely(!len)) return 0; error = -EBADF; |
2903ff019 switch simple cas... |
1680 1681 1682 1683 1684 1685 1686 1687 1688 |
in = fdget(fdin); if (in.file) { if (in.file->f_mode & FMODE_READ) { struct fd out = fdget(fdout); if (out.file) { if (out.file->f_mode & FMODE_WRITE) error = do_tee(in.file, out.file, len, flags); fdput(out); |
70524490e [PATCH] splice: a... |
1689 1690 |
} } |
2903ff019 switch simple cas... |
1691 |
fdput(in); |
70524490e [PATCH] splice: a... |
1692 1693 1694 1695 |
} return error; } |