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15637ed4 RG |
1 | /* |
2 | * Copyright (c) 1989, 1990, 1991, 1992 William F. Jolitz, TeleMuse | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This software is a component of "386BSD" developed by | |
16 | William F. Jolitz, TeleMuse. | |
17 | * 4. Neither the name of the developer nor the name "386BSD" | |
18 | * may be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ | |
22 | * AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS | |
23 | * SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT. | |
24 | * THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT | |
25 | * NOT MAKE USE THIS WORK. | |
26 | * | |
27 | * FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED | |
28 | * BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN | |
29 | * REFERENCES SUCH AS THE "PORTING UNIX TO THE 386" SERIES | |
30 | * (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING | |
31 | * JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND | |
32 | * LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE | |
33 | * ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS | |
34 | * OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992. | |
35 | * | |
36 | * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND | |
37 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
38 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
39 | * ARE DISCLAIMED. IN NO EVENT SHALL THE DEVELOPER BE LIABLE | |
40 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
41 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
42 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
43 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
44 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
45 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
46 | * SUCH DAMAGE. | |
47 | * | |
73419b27 | 48 | * $Id: vfs__bio.c,v 1.8 1993/11/07 17:46:24 wollman Exp $ |
15637ed4 | 49 | */ |
15637ed4 RG |
50 | |
51 | #include "param.h" | |
dd18dc33 | 52 | #include "systm.h" |
15637ed4 RG |
53 | #include "proc.h" |
54 | #include "vnode.h" | |
55 | #include "buf.h" | |
56 | #include "specdev.h" | |
57 | #include "mount.h" | |
58 | #include "malloc.h" | |
59 | #include "vm/vm.h" | |
60 | #include "resourcevar.h" | |
61 | ||
bbc3f849 GW |
62 | /* From sys/buf.h */ |
63 | struct buf *buf; /* the buffer pool itself */ | |
64 | char *buffers; | |
65 | int nbuf; /* number of buffer headers */ | |
66 | int bufpages; /* number of memory pages in the buffer pool */ | |
67 | struct buf *swbuf; /* swap I/O headers */ | |
68 | int nswbuf; | |
69 | struct bufhd bufhash[BUFHSZ]; /* heads of hash lists */ | |
70 | struct buf bfreelist[BQUEUES]; /* heads of available lists */ | |
71 | struct buf bswlist; /* head of free swap header list */ | |
72 | struct buf *bclnlist; /* head of cleaned page list */ | |
73 | ||
dbd7c74f | 74 | static struct buf *getnewbuf(int); |
15637ed4 RG |
75 | extern vm_map_t buffer_map; |
76 | ||
77 | /* | |
78 | * Initialize buffer headers and related structures. | |
79 | */ | |
80 | void bufinit() | |
81 | { | |
82 | struct bufhd *bh; | |
83 | struct buf *bp; | |
84 | ||
85 | /* first, make a null hash table */ | |
86 | for(bh = bufhash; bh < bufhash + BUFHSZ; bh++) { | |
87 | bh->b_flags = 0; | |
88 | bh->b_forw = (struct buf *)bh; | |
89 | bh->b_back = (struct buf *)bh; | |
90 | } | |
91 | ||
92 | /* next, make a null set of free lists */ | |
93 | for(bp = bfreelist; bp < bfreelist + BQUEUES; bp++) { | |
94 | bp->b_flags = 0; | |
95 | bp->av_forw = bp; | |
96 | bp->av_back = bp; | |
97 | bp->b_forw = bp; | |
98 | bp->b_back = bp; | |
99 | } | |
100 | ||
101 | /* finally, initialize each buffer header and stick on empty q */ | |
102 | for(bp = buf; bp < buf + nbuf ; bp++) { | |
103 | bp->b_flags = B_HEAD | B_INVAL; /* we're just an empty header */ | |
104 | bp->b_dev = NODEV; | |
105 | bp->b_vp = 0; | |
106 | binstailfree(bp, bfreelist + BQ_EMPTY); | |
107 | binshash(bp, bfreelist + BQ_EMPTY); | |
108 | } | |
109 | } | |
110 | ||
111 | /* | |
112 | * Find the block in the buffer pool. | |
113 | * If the buffer is not present, allocate a new buffer and load | |
114 | * its contents according to the filesystem fill routine. | |
115 | */ | |
116 | int | |
117 | bread(struct vnode *vp, daddr_t blkno, int size, struct ucred *cred, | |
118 | struct buf **bpp) | |
119 | { | |
120 | struct buf *bp; | |
121 | int rv = 0; | |
122 | ||
123 | bp = getblk (vp, blkno, size); | |
124 | ||
125 | /* if not found in cache, do some I/O */ | |
126 | if ((bp->b_flags & B_CACHE) == 0 || (bp->b_flags & B_INVAL) != 0) { | |
8a8a439a NW |
127 | if (curproc && curproc->p_stats) /* count block I/O */ |
128 | curproc->p_stats->p_ru.ru_inblock++; | |
15637ed4 RG |
129 | bp->b_flags |= B_READ; |
130 | bp->b_flags &= ~(B_DONE|B_ERROR|B_INVAL); | |
131 | if (cred != NOCRED) crhold(cred); /* 25 Apr 92*/ | |
132 | bp->b_rcred = cred; | |
133 | VOP_STRATEGY(bp); | |
134 | rv = biowait (bp); | |
135 | } | |
136 | *bpp = bp; | |
137 | ||
138 | return (rv); | |
139 | } | |
140 | ||
141 | /* | |
142 | * Operates like bread, but also starts I/O on the specified | |
143 | * read-ahead block. [See page 55 of Bach's Book] | |
144 | */ | |
145 | int | |
146 | breada(struct vnode *vp, daddr_t blkno, int size, daddr_t rablkno, int rabsize, | |
147 | struct ucred *cred, struct buf **bpp) | |
148 | { | |
149 | struct buf *bp, *rabp; | |
150 | int rv = 0, needwait = 0; | |
151 | ||
152 | bp = getblk (vp, blkno, size); | |
153 | ||
154 | /* if not found in cache, do some I/O */ | |
155 | if ((bp->b_flags & B_CACHE) == 0 || (bp->b_flags & B_INVAL) != 0) { | |
8a8a439a NW |
156 | if (curproc && curproc->p_stats) /* count block I/O */ |
157 | curproc->p_stats->p_ru.ru_inblock++; | |
15637ed4 RG |
158 | bp->b_flags |= B_READ; |
159 | bp->b_flags &= ~(B_DONE|B_ERROR|B_INVAL); | |
160 | if (cred != NOCRED) crhold(cred); /* 25 Apr 92*/ | |
161 | bp->b_rcred = cred; | |
162 | VOP_STRATEGY(bp); | |
163 | needwait++; | |
164 | } | |
165 | ||
166 | rabp = getblk (vp, rablkno, rabsize); | |
167 | ||
168 | /* if not found in cache, do some I/O (overlapped with first) */ | |
169 | if ((rabp->b_flags & B_CACHE) == 0 || (rabp->b_flags & B_INVAL) != 0) { | |
8a8a439a NW |
170 | if (curproc && curproc->p_stats) /* count block I/O */ |
171 | curproc->p_stats->p_ru.ru_inblock++; | |
15637ed4 RG |
172 | rabp->b_flags |= B_READ | B_ASYNC; |
173 | rabp->b_flags &= ~(B_DONE|B_ERROR|B_INVAL); | |
174 | if (cred != NOCRED) crhold(cred); /* 25 Apr 92*/ | |
175 | rabp->b_rcred = cred; | |
176 | VOP_STRATEGY(rabp); | |
177 | } else | |
178 | brelse(rabp); | |
179 | ||
180 | /* wait for original I/O */ | |
181 | if (needwait) | |
182 | rv = biowait (bp); | |
183 | ||
184 | *bpp = bp; | |
185 | return (rv); | |
186 | } | |
187 | ||
188 | /* | |
189 | * Synchronous write. | |
190 | * Release buffer on completion. | |
191 | */ | |
192 | int | |
193 | bwrite(register struct buf *bp) | |
194 | { | |
195 | int rv; | |
196 | ||
197 | if(bp->b_flags & B_INVAL) { | |
198 | brelse(bp); | |
199 | return (0); | |
200 | } else { | |
201 | int wasdelayed; | |
202 | ||
203 | if(!(bp->b_flags & B_BUSY)) | |
204 | panic("bwrite: not busy"); | |
205 | ||
206 | wasdelayed = bp->b_flags & B_DELWRI; | |
207 | bp->b_flags &= ~(B_READ|B_DONE|B_ERROR|B_ASYNC|B_DELWRI); | |
208 | if(wasdelayed) | |
209 | reassignbuf(bp, bp->b_vp); | |
210 | ||
8a8a439a NW |
211 | if (curproc && curproc->p_stats) /* count block I/O */ |
212 | curproc->p_stats->p_ru.ru_oublock++; | |
15637ed4 RG |
213 | bp->b_flags |= B_DIRTY; |
214 | bp->b_vp->v_numoutput++; | |
215 | VOP_STRATEGY(bp); | |
216 | rv = biowait(bp); | |
217 | brelse(bp); | |
218 | return (rv); | |
219 | } | |
220 | } | |
221 | ||
222 | /* | |
223 | * Delayed write. | |
224 | * | |
225 | * The buffer is marked dirty, but is not queued for I/O. | |
226 | * This routine should be used when the buffer is expected | |
227 | * to be modified again soon, typically a small write that | |
228 | * partially fills a buffer. | |
229 | * | |
230 | * NB: magnetic tapes cannot be delayed; they must be | |
231 | * written in the order that the writes are requested. | |
232 | */ | |
233 | void | |
234 | bdwrite(register struct buf *bp) | |
235 | { | |
236 | ||
237 | if(!(bp->b_flags & B_BUSY)) | |
238 | panic("bdwrite: not busy"); | |
239 | ||
240 | if(bp->b_flags & B_INVAL) { | |
241 | brelse(bp); | |
2877196e | 242 | return; |
15637ed4 RG |
243 | } |
244 | if(bp->b_flags & B_TAPE) { | |
245 | bwrite(bp); | |
246 | return; | |
247 | } | |
248 | bp->b_flags &= ~(B_READ|B_DONE); | |
249 | bp->b_flags |= B_DIRTY|B_DELWRI; | |
250 | reassignbuf(bp, bp->b_vp); | |
251 | brelse(bp); | |
252 | return; | |
253 | } | |
254 | ||
255 | /* | |
256 | * Asynchronous write. | |
257 | * Start I/O on a buffer, but do not wait for it to complete. | |
258 | * The buffer is released when the I/O completes. | |
259 | */ | |
260 | void | |
261 | bawrite(register struct buf *bp) | |
262 | { | |
263 | ||
264 | if(!(bp->b_flags & B_BUSY)) | |
265 | panic("bawrite: not busy"); | |
266 | ||
267 | if(bp->b_flags & B_INVAL) | |
268 | brelse(bp); | |
269 | else { | |
270 | int wasdelayed; | |
271 | ||
272 | wasdelayed = bp->b_flags & B_DELWRI; | |
273 | bp->b_flags &= ~(B_READ|B_DONE|B_ERROR|B_DELWRI); | |
274 | if(wasdelayed) | |
275 | reassignbuf(bp, bp->b_vp); | |
276 | ||
8a8a439a NW |
277 | if (curproc && curproc->p_stats) /* count block I/O */ |
278 | curproc->p_stats->p_ru.ru_oublock++; | |
15637ed4 RG |
279 | bp->b_flags |= B_DIRTY | B_ASYNC; |
280 | bp->b_vp->v_numoutput++; | |
281 | VOP_STRATEGY(bp); | |
282 | } | |
283 | } | |
284 | ||
285 | /* | |
286 | * Release a buffer. | |
287 | * Even if the buffer is dirty, no I/O is started. | |
288 | */ | |
289 | void | |
290 | brelse(register struct buf *bp) | |
291 | { | |
292 | int x; | |
293 | ||
294 | /* anyone need a "free" block? */ | |
295 | x=splbio(); | |
296 | if ((bfreelist + BQ_AGE)->b_flags & B_WANTED) { | |
297 | (bfreelist + BQ_AGE) ->b_flags &= ~B_WANTED; | |
298 | wakeup(bfreelist); | |
299 | } | |
300 | /* anyone need this very block? */ | |
301 | if (bp->b_flags & B_WANTED) { | |
302 | bp->b_flags &= ~B_WANTED; | |
303 | wakeup(bp); | |
304 | } | |
305 | ||
306 | if (bp->b_flags & (B_INVAL|B_ERROR)) { | |
307 | bp->b_flags |= B_INVAL; | |
308 | bp->b_flags &= ~(B_DELWRI|B_CACHE); | |
309 | if(bp->b_vp) | |
310 | brelvp(bp); | |
311 | } | |
312 | ||
313 | /* enqueue */ | |
314 | /* just an empty buffer head ... */ | |
315 | /*if(bp->b_flags & B_HEAD) | |
316 | binsheadfree(bp, bfreelist + BQ_EMPTY)*/ | |
317 | /* buffers with junk contents */ | |
318 | /*else*/ if(bp->b_flags & (B_ERROR|B_INVAL|B_NOCACHE)) | |
319 | binsheadfree(bp, bfreelist + BQ_AGE) | |
320 | /* buffers with stale but valid contents */ | |
321 | else if(bp->b_flags & B_AGE) | |
322 | binstailfree(bp, bfreelist + BQ_AGE) | |
323 | /* buffers with valid and quite potentially reuseable contents */ | |
324 | else | |
325 | binstailfree(bp, bfreelist + BQ_LRU) | |
326 | ||
327 | /* unlock */ | |
328 | bp->b_flags &= ~B_BUSY; | |
329 | splx(x); | |
330 | ||
331 | } | |
332 | ||
333 | int freebufspace; | |
334 | int allocbufspace; | |
335 | ||
336 | /* | |
337 | * Find a buffer which is available for use. | |
338 | * If free memory for buffer space and an empty header from the empty list, | |
339 | * use that. Otherwise, select something from a free list. | |
340 | * Preference is to AGE list, then LRU list. | |
341 | */ | |
342 | static struct buf * | |
343 | getnewbuf(int sz) | |
344 | { | |
345 | struct buf *bp; | |
346 | int x; | |
347 | ||
348 | x = splbio(); | |
349 | start: | |
350 | /* can we constitute a new buffer? */ | |
351 | if (freebufspace > sz | |
352 | && bfreelist[BQ_EMPTY].av_forw != (struct buf *)bfreelist+BQ_EMPTY) { | |
353 | caddr_t addr; | |
354 | ||
355 | /*#define notyet*/ | |
356 | #ifndef notyet | |
357 | if ((addr = malloc (sz, M_TEMP, M_WAITOK)) == 0) goto tryfree; | |
358 | #else /* notyet */ | |
359 | /* get new memory buffer */ | |
360 | if (round_page(sz) == sz) | |
361 | addr = (caddr_t) kmem_alloc_wired_wait(buffer_map, sz); | |
362 | else | |
363 | addr = (caddr_t) malloc (sz, M_TEMP, M_WAITOK); | |
364 | /*if ((addr = malloc (sz, M_TEMP, M_NOWAIT)) == 0) goto tryfree;*/ | |
365 | bzero(addr, sz); | |
366 | #endif /* notyet */ | |
367 | freebufspace -= sz; | |
368 | allocbufspace += sz; | |
369 | ||
370 | bp = bfreelist[BQ_EMPTY].av_forw; | |
371 | bp->b_flags = B_BUSY | B_INVAL; | |
372 | bremfree(bp); | |
373 | bp->b_un.b_addr = addr; | |
374 | bp->b_bufsize = sz; /* 20 Aug 92*/ | |
375 | goto fillin; | |
376 | } | |
377 | ||
378 | tryfree: | |
379 | if (bfreelist[BQ_AGE].av_forw != (struct buf *)bfreelist+BQ_AGE) { | |
380 | bp = bfreelist[BQ_AGE].av_forw; | |
381 | bremfree(bp); | |
382 | } else if (bfreelist[BQ_LRU].av_forw != (struct buf *)bfreelist+BQ_LRU) { | |
383 | bp = bfreelist[BQ_LRU].av_forw; | |
384 | bremfree(bp); | |
385 | } else { | |
386 | /* wait for a free buffer of any kind */ | |
387 | (bfreelist + BQ_AGE)->b_flags |= B_WANTED; | |
73419b27 | 388 | tsleep(bfreelist, PRIBIO, "newbuf", 0); |
15637ed4 RG |
389 | splx(x); |
390 | return (0); | |
391 | } | |
392 | ||
393 | /* if we are a delayed write, convert to an async write! */ | |
394 | if (bp->b_flags & B_DELWRI) { | |
395 | bp->b_flags |= B_BUSY; | |
396 | bawrite (bp); | |
397 | goto start; | |
398 | } | |
399 | ||
400 | ||
401 | if(bp->b_vp) | |
402 | brelvp(bp); | |
403 | ||
404 | /* we are not free, nor do we contain interesting data */ | |
405 | if (bp->b_rcred != NOCRED) crfree(bp->b_rcred); /* 25 Apr 92*/ | |
406 | if (bp->b_wcred != NOCRED) crfree(bp->b_wcred); | |
407 | bp->b_flags = B_BUSY; | |
408 | fillin: | |
409 | bremhash(bp); | |
410 | splx(x); | |
411 | bp->b_dev = NODEV; | |
412 | bp->b_vp = NULL; | |
413 | bp->b_blkno = bp->b_lblkno = 0; | |
414 | bp->b_iodone = 0; | |
415 | bp->b_error = 0; | |
8b376180 | 416 | bp->b_resid = 0; |
15637ed4 RG |
417 | bp->b_wcred = bp->b_rcred = NOCRED; |
418 | if (bp->b_bufsize != sz) | |
419 | allocbuf(bp, sz); | |
420 | bp->b_bcount = bp->b_bufsize = sz; | |
421 | bp->b_dirtyoff = bp->b_dirtyend = 0; | |
422 | return (bp); | |
423 | } | |
424 | ||
425 | /* | |
426 | * Check to see if a block is currently memory resident. | |
427 | */ | |
428 | struct buf * | |
429 | incore(struct vnode *vp, daddr_t blkno) | |
430 | { | |
431 | struct buf *bh; | |
432 | struct buf *bp; | |
433 | ||
434 | bh = BUFHASH(vp, blkno); | |
435 | ||
436 | /* Search hash chain */ | |
437 | bp = bh->b_forw; | |
438 | while (bp != (struct buf *) bh) { | |
439 | /* hit */ | |
440 | if (bp->b_lblkno == blkno && bp->b_vp == vp | |
441 | && (bp->b_flags & B_INVAL) == 0) | |
442 | return (bp); | |
443 | bp = bp->b_forw; | |
444 | } | |
445 | ||
446 | return(0); | |
447 | } | |
448 | ||
449 | /* | |
450 | * Get a block of requested size that is associated with | |
451 | * a given vnode and block offset. If it is found in the | |
452 | * block cache, mark it as having been found, make it busy | |
453 | * and return it. Otherwise, return an empty block of the | |
454 | * correct size. It is up to the caller to insure that the | |
455 | * cached blocks be of the correct size. | |
456 | */ | |
457 | struct buf * | |
458 | getblk(register struct vnode *vp, daddr_t blkno, int size) | |
459 | { | |
460 | struct buf *bp, *bh; | |
461 | int x; | |
462 | ||
463 | for (;;) { | |
464 | if (bp = incore(vp, blkno)) { | |
465 | x = splbio(); | |
466 | if (bp->b_flags & B_BUSY) { | |
467 | bp->b_flags |= B_WANTED; | |
73419b27 | 468 | tsleep (bp, PRIBIO, "getblk", 0); |
15637ed4 RG |
469 | splx(x); |
470 | continue; | |
471 | } | |
472 | bp->b_flags |= B_BUSY | B_CACHE; | |
473 | bremfree(bp); | |
474 | if (size > bp->b_bufsize) | |
475 | panic("now what do we do?"); | |
476 | /* if (bp->b_bufsize != size) allocbuf(bp, size); */ | |
477 | } else { | |
478 | ||
479 | if((bp = getnewbuf(size)) == 0) continue; | |
480 | bp->b_blkno = bp->b_lblkno = blkno; | |
481 | bgetvp(vp, bp); | |
482 | x = splbio(); | |
483 | bh = BUFHASH(vp, blkno); | |
484 | binshash(bp, bh); | |
485 | bp->b_flags = B_BUSY; | |
486 | } | |
487 | splx(x); | |
488 | return (bp); | |
489 | } | |
490 | } | |
491 | ||
492 | /* | |
493 | * Get an empty, disassociated buffer of given size. | |
494 | */ | |
495 | struct buf * | |
496 | geteblk(int size) | |
497 | { | |
498 | struct buf *bp; | |
499 | int x; | |
500 | ||
501 | while ((bp = getnewbuf(size)) == 0) | |
502 | ; | |
503 | x = splbio(); | |
504 | binshash(bp, bfreelist + BQ_AGE); | |
505 | splx(x); | |
506 | ||
507 | return (bp); | |
508 | } | |
509 | ||
510 | /* | |
511 | * Exchange a buffer's underlying buffer storage for one of different | |
512 | * size, taking care to maintain contents appropriately. When buffer | |
513 | * increases in size, caller is responsible for filling out additional | |
514 | * contents. When buffer shrinks in size, data is lost, so caller must | |
515 | * first return it to backing store before shrinking the buffer, as | |
516 | * no implied I/O will be done. | |
517 | * | |
518 | * Expanded buffer is returned as value. | |
519 | */ | |
520 | void | |
521 | allocbuf(register struct buf *bp, int size) | |
522 | { | |
523 | caddr_t newcontents; | |
524 | ||
525 | /* get new memory buffer */ | |
526 | #ifndef notyet | |
527 | newcontents = (caddr_t) malloc (size, M_TEMP, M_WAITOK); | |
528 | #else /* notyet */ | |
529 | if (round_page(size) == size) | |
530 | newcontents = (caddr_t) kmem_alloc_wired_wait(buffer_map, size); | |
531 | else | |
532 | newcontents = (caddr_t) malloc (size, M_TEMP, M_WAITOK); | |
533 | #endif /* notyet */ | |
534 | ||
535 | /* copy the old into the new, up to the maximum that will fit */ | |
536 | bcopy (bp->b_un.b_addr, newcontents, min(bp->b_bufsize, size)); | |
537 | ||
538 | /* return old contents to free heap */ | |
539 | #ifndef notyet | |
540 | free (bp->b_un.b_addr, M_TEMP); | |
541 | #else /* notyet */ | |
542 | if (round_page(bp->b_bufsize) == bp->b_bufsize) | |
543 | kmem_free_wakeup(buffer_map, bp->b_un.b_addr, bp->b_bufsize); | |
544 | else | |
545 | free (bp->b_un.b_addr, M_TEMP); | |
546 | #endif /* notyet */ | |
547 | ||
548 | /* adjust buffer cache's idea of memory allocated to buffer contents */ | |
549 | freebufspace -= size - bp->b_bufsize; | |
550 | allocbufspace += size - bp->b_bufsize; | |
551 | ||
552 | /* update buffer header */ | |
553 | bp->b_un.b_addr = newcontents; | |
554 | bp->b_bcount = bp->b_bufsize = size; | |
555 | } | |
556 | ||
557 | /* | |
558 | * Patiently await operations to complete on this buffer. | |
559 | * When they do, extract error value and return it. | |
560 | * Extract and return any errors associated with the I/O. | |
561 | * If an invalid block, force it off the lookup hash chains. | |
562 | */ | |
563 | int | |
564 | biowait(register struct buf *bp) | |
565 | { | |
566 | int x; | |
567 | ||
568 | x = splbio(); | |
569 | while ((bp->b_flags & B_DONE) == 0) | |
73419b27 | 570 | tsleep((caddr_t)bp, PRIBIO, "biowait", 0); |
15637ed4 RG |
571 | if((bp->b_flags & B_ERROR) || bp->b_error) { |
572 | if ((bp->b_flags & B_INVAL) == 0) { | |
573 | bp->b_flags |= B_INVAL; | |
574 | bremhash(bp); | |
575 | binshash(bp, bfreelist + BQ_AGE); | |
576 | } | |
577 | if (!bp->b_error) | |
578 | bp->b_error = EIO; | |
579 | else | |
580 | bp->b_flags |= B_ERROR; | |
581 | splx(x); | |
582 | return (bp->b_error); | |
583 | } else { | |
584 | splx(x); | |
585 | return (0); | |
586 | } | |
587 | } | |
588 | ||
589 | /* | |
590 | * Finish up operations on a buffer, calling an optional | |
591 | * function (if requested), and releasing the buffer if | |
592 | * marked asynchronous. Then mark this buffer done so that | |
593 | * others biowait()'ing for it will notice when they are | |
594 | * woken up from sleep(). | |
595 | */ | |
596 | int | |
597 | biodone(register struct buf *bp) | |
598 | { | |
599 | int x; | |
600 | ||
601 | x = splbio(); | |
602 | if (bp->b_flags & B_CALL) (*bp->b_iodone)(bp); | |
603 | bp->b_flags &= ~B_CALL; | |
604 | if ((bp->b_flags & (B_READ|B_DIRTY)) == B_DIRTY) { | |
605 | bp->b_flags &= ~B_DIRTY; | |
606 | vwakeup(bp); | |
607 | } | |
608 | if (bp->b_flags & B_ASYNC) | |
609 | brelse(bp); | |
610 | bp->b_flags &= ~B_ASYNC; | |
611 | bp->b_flags |= B_DONE; | |
612 | wakeup(bp); | |
613 | splx(x); | |
614 | } |