Commit | Line | Data |
---|---|---|
99fae0e8 | 1 | /* vfs_cluster.c 3.12 %G% */ |
663dbc72 BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
5 | #include "../h/dir.h" | |
6 | #include "../h/user.h" | |
7 | #include "../h/buf.h" | |
8 | #include "../h/conf.h" | |
9 | #include "../h/proc.h" | |
10 | #include "../h/seg.h" | |
11 | #include "../h/pte.h" | |
12 | #include "../h/vm.h" | |
13 | ||
5603d07d BJ |
14 | /* |
15 | * The following several routines allocate and free | |
16 | * buffers with various side effects. In general the | |
17 | * arguments to an allocate routine are a device and | |
18 | * a block number, and the value is a pointer to | |
19 | * to the buffer header; the buffer is marked "busy" | |
20 | * so that no one else can touch it. If the block was | |
21 | * already in core, no I/O need be done; if it is | |
22 | * already busy, the process waits until it becomes free. | |
23 | * The following routines allocate a buffer: | |
24 | * getblk | |
25 | * bread | |
26 | * breada | |
27 | * baddr (if it is incore) | |
28 | * Eventually the buffer must be released, possibly with the | |
29 | * side effect of writing it out, by using one of | |
30 | * bwrite | |
31 | * bdwrite | |
32 | * bawrite | |
33 | * brelse | |
34 | */ | |
35 | ||
36 | #define BUFHSZ 63 | |
37 | #define BUFHASH(blkno) (blkno % BUFHSZ) | |
38 | short bufhash[BUFHSZ]; | |
39 | ||
40 | /* | |
41 | * Initialize hash links for buffers. | |
42 | */ | |
43 | bhinit() | |
44 | { | |
45 | register int i; | |
46 | ||
47 | for (i = 0; i < BUFHSZ; i++) | |
48 | bufhash[i] = -1; | |
49 | } | |
50 | ||
663dbc72 BJ |
51 | /* #define DISKMON 1 */ |
52 | ||
53 | #ifdef DISKMON | |
54 | struct { | |
55 | int nbuf; | |
56 | long nread; | |
57 | long nreada; | |
58 | long ncache; | |
59 | long nwrite; | |
60 | long bufcount[NBUF]; | |
61 | } io_info; | |
62 | #endif | |
63 | ||
64 | /* | |
65 | * Swap IO headers - | |
66 | * They contain the necessary information for the swap I/O. | |
67 | * At any given time, a swap header can be in three | |
68 | * different lists. When free it is in the free list, | |
69 | * when allocated and the I/O queued, it is on the swap | |
70 | * device list, and finally, if the operation was a dirty | |
71 | * page push, when the I/O completes, it is inserted | |
72 | * in a list of cleaned pages to be processed by the pageout daemon. | |
73 | */ | |
74 | struct buf swbuf[NSWBUF]; | |
75 | short swsize[NSWBUF]; /* CAN WE JUST USE B_BCOUNT? */ | |
76 | int swpf[NSWBUF]; | |
77 | ||
663dbc72 BJ |
78 | |
79 | #ifdef FASTVAX | |
80 | #define notavail(bp) \ | |
81 | { \ | |
82 | int s = spl6(); \ | |
83 | (bp)->av_back->av_forw = (bp)->av_forw; \ | |
84 | (bp)->av_forw->av_back = (bp)->av_back; \ | |
85 | (bp)->b_flags |= B_BUSY; \ | |
86 | splx(s); \ | |
87 | } | |
88 | #endif | |
89 | ||
90 | /* | |
91 | * Read in (if necessary) the block and return a buffer pointer. | |
92 | */ | |
93 | struct buf * | |
94 | bread(dev, blkno) | |
95 | dev_t dev; | |
96 | daddr_t blkno; | |
97 | { | |
98 | register struct buf *bp; | |
99 | ||
100 | bp = getblk(dev, blkno); | |
101 | if (bp->b_flags&B_DONE) { | |
102 | #ifdef DISKMON | |
103 | io_info.ncache++; | |
104 | #endif | |
105 | return(bp); | |
106 | } | |
107 | bp->b_flags |= B_READ; | |
108 | bp->b_bcount = BSIZE; | |
109 | (*bdevsw[major(dev)].d_strategy)(bp); | |
110 | #ifdef DISKMON | |
111 | io_info.nread++; | |
112 | #endif | |
113 | u.u_vm.vm_inblk++; /* pay for read */ | |
114 | iowait(bp); | |
115 | return(bp); | |
116 | } | |
117 | ||
118 | /* | |
119 | * Read in the block, like bread, but also start I/O on the | |
120 | * read-ahead block (which is not allocated to the caller) | |
121 | */ | |
122 | struct buf * | |
123 | breada(dev, blkno, rablkno) | |
124 | dev_t dev; | |
125 | daddr_t blkno, rablkno; | |
126 | { | |
127 | register struct buf *bp, *rabp; | |
128 | ||
129 | bp = NULL; | |
130 | if (!incore(dev, blkno)) { | |
131 | bp = getblk(dev, blkno); | |
132 | if ((bp->b_flags&B_DONE) == 0) { | |
133 | bp->b_flags |= B_READ; | |
134 | bp->b_bcount = BSIZE; | |
135 | (*bdevsw[major(dev)].d_strategy)(bp); | |
136 | #ifdef DISKMON | |
137 | io_info.nread++; | |
138 | #endif | |
139 | u.u_vm.vm_inblk++; /* pay for read */ | |
140 | } | |
141 | } | |
142 | if (rablkno && !incore(dev, rablkno)) { | |
143 | rabp = getblk(dev, rablkno); | |
144 | if (rabp->b_flags & B_DONE) | |
145 | brelse(rabp); | |
146 | else { | |
147 | rabp->b_flags |= B_READ|B_ASYNC; | |
148 | rabp->b_bcount = BSIZE; | |
149 | (*bdevsw[major(dev)].d_strategy)(rabp); | |
150 | #ifdef DISKMON | |
151 | io_info.nreada++; | |
152 | #endif | |
153 | u.u_vm.vm_inblk++; /* pay in advance */ | |
154 | } | |
155 | } | |
156 | if(bp == NULL) | |
157 | return(bread(dev, blkno)); | |
158 | iowait(bp); | |
159 | return(bp); | |
160 | } | |
161 | ||
162 | /* | |
163 | * Write the buffer, waiting for completion. | |
164 | * Then release the buffer. | |
165 | */ | |
166 | bwrite(bp) | |
167 | register struct buf *bp; | |
168 | { | |
169 | register flag; | |
170 | ||
171 | flag = bp->b_flags; | |
172 | bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI | B_AGE); | |
173 | bp->b_bcount = BSIZE; | |
174 | #ifdef DISKMON | |
175 | io_info.nwrite++; | |
176 | #endif | |
177 | if ((flag&B_DELWRI) == 0) | |
178 | u.u_vm.vm_oublk++; /* noone paid yet */ | |
179 | (*bdevsw[major(bp->b_dev)].d_strategy)(bp); | |
180 | if ((flag&B_ASYNC) == 0) { | |
181 | iowait(bp); | |
182 | brelse(bp); | |
183 | } else if (flag & B_DELWRI) | |
184 | bp->b_flags |= B_AGE; | |
185 | else | |
186 | geterror(bp); | |
187 | } | |
188 | ||
189 | /* | |
190 | * Release the buffer, marking it so that if it is grabbed | |
191 | * for another purpose it will be written out before being | |
192 | * given up (e.g. when writing a partial block where it is | |
193 | * assumed that another write for the same block will soon follow). | |
194 | * This can't be done for magtape, since writes must be done | |
195 | * in the same order as requested. | |
196 | */ | |
197 | bdwrite(bp) | |
198 | register struct buf *bp; | |
199 | { | |
200 | register struct buf *dp; | |
201 | ||
202 | if ((bp->b_flags&B_DELWRI) == 0) | |
203 | u.u_vm.vm_oublk++; /* noone paid yet */ | |
204 | dp = bdevsw[major(bp->b_dev)].d_tab; | |
205 | if(dp->b_flags & B_TAPE) | |
206 | bawrite(bp); | |
207 | else { | |
208 | bp->b_flags |= B_DELWRI | B_DONE; | |
209 | brelse(bp); | |
210 | } | |
211 | } | |
212 | ||
213 | /* | |
214 | * Release the buffer, start I/O on it, but don't wait for completion. | |
215 | */ | |
216 | bawrite(bp) | |
217 | register struct buf *bp; | |
218 | { | |
219 | ||
220 | bp->b_flags |= B_ASYNC; | |
221 | bwrite(bp); | |
222 | } | |
223 | ||
224 | /* | |
225 | * release the buffer, with no I/O implied. | |
226 | */ | |
227 | brelse(bp) | |
228 | register struct buf *bp; | |
229 | { | |
230 | register struct buf **backp; | |
231 | register s; | |
232 | ||
233 | if (bp->b_flags&B_WANTED) | |
234 | wakeup((caddr_t)bp); | |
235 | if (bfreelist.b_flags&B_WANTED) { | |
236 | bfreelist.b_flags &= ~B_WANTED; | |
237 | wakeup((caddr_t)&bfreelist); | |
238 | } | |
5603d07d BJ |
239 | if ((bp->b_flags&B_ERROR) && bp->b_dev != NODEV) { |
240 | bunhash(bp); | |
663dbc72 | 241 | bp->b_dev = NODEV; /* no assoc. on error */ |
5603d07d | 242 | } |
663dbc72 BJ |
243 | s = spl6(); |
244 | if(bp->b_flags & (B_AGE|B_ERROR)) { | |
245 | backp = &bfreelist.av_forw; | |
246 | (*backp)->av_back = bp; | |
247 | bp->av_forw = *backp; | |
248 | *backp = bp; | |
249 | bp->av_back = &bfreelist; | |
250 | } else { | |
251 | backp = &bfreelist.av_back; | |
252 | (*backp)->av_forw = bp; | |
253 | bp->av_back = *backp; | |
254 | *backp = bp; | |
255 | bp->av_forw = &bfreelist; | |
256 | } | |
257 | bp->b_flags &= ~(B_WANTED|B_BUSY|B_ASYNC|B_AGE); | |
258 | splx(s); | |
259 | } | |
260 | ||
261 | /* | |
262 | * See if the block is associated with some buffer | |
263 | * (mainly to avoid getting hung up on a wait in breada) | |
264 | */ | |
265 | incore(dev, blkno) | |
266 | dev_t dev; | |
267 | daddr_t blkno; | |
268 | { | |
269 | register struct buf *bp; | |
663dbc72 BJ |
270 | register int dblkno = fsbtodb(blkno); |
271 | ||
5603d07d BJ |
272 | for (bp = &buf[bufhash[BUFHASH(blkno)]]; bp != &buf[-1]; |
273 | bp = &buf[bp->b_hlink]) | |
fe8987fb | 274 | if (bp->b_blkno == dblkno && bp->b_dev == dev) |
5603d07d | 275 | return (1); |
5603d07d | 276 | return (0); |
663dbc72 BJ |
277 | } |
278 | ||
279 | struct buf * | |
280 | baddr(dev, blkno) | |
281 | dev_t dev; | |
282 | daddr_t blkno; | |
283 | { | |
284 | ||
285 | if (incore(dev, blkno)) | |
286 | return (bread(dev, blkno)); | |
287 | return (0); | |
288 | } | |
289 | ||
290 | /* | |
291 | * Assign a buffer for the given block. If the appropriate | |
292 | * block is already associated, return it; otherwise search | |
293 | * for the oldest non-busy buffer and reassign it. | |
294 | */ | |
295 | struct buf * | |
296 | getblk(dev, blkno) | |
297 | dev_t dev; | |
298 | daddr_t blkno; | |
299 | { | |
5603d07d BJ |
300 | register struct buf *bp, *dp, *ep; |
301 | register int i, x; | |
663dbc72 BJ |
302 | register int dblkno = fsbtodb(blkno); |
303 | ||
663dbc72 | 304 | loop: |
81263dba | 305 | (void) spl0(); |
5603d07d BJ |
306 | for (bp = &buf[bufhash[BUFHASH(blkno)]]; bp != &buf[-1]; |
307 | bp = &buf[bp->b_hlink]) { | |
308 | if (bp->b_blkno != dblkno || bp->b_dev != dev) | |
663dbc72 | 309 | continue; |
81263dba | 310 | (void) spl6(); |
663dbc72 BJ |
311 | if (bp->b_flags&B_BUSY) { |
312 | bp->b_flags |= B_WANTED; | |
313 | sleep((caddr_t)bp, PRIBIO+1); | |
314 | goto loop; | |
315 | } | |
81263dba | 316 | (void) spl0(); |
663dbc72 BJ |
317 | #ifdef DISKMON |
318 | i = 0; | |
319 | dp = bp->av_forw; | |
320 | while (dp != &bfreelist) { | |
321 | i++; | |
322 | dp = dp->av_forw; | |
323 | } | |
324 | if (i<NBUF) | |
325 | io_info.bufcount[i]++; | |
326 | #endif | |
327 | notavail(bp); | |
328 | bp->b_flags |= B_CACHE; | |
329 | return(bp); | |
330 | } | |
5603d07d BJ |
331 | if (major(dev) >= nblkdev) |
332 | panic("blkdev"); | |
333 | dp = bdevsw[major(dev)].d_tab; | |
334 | if (dp == NULL) | |
335 | panic("devtab"); | |
81263dba | 336 | (void) spl6(); |
663dbc72 BJ |
337 | if (bfreelist.av_forw == &bfreelist) { |
338 | bfreelist.b_flags |= B_WANTED; | |
339 | sleep((caddr_t)&bfreelist, PRIBIO+1); | |
340 | goto loop; | |
341 | } | |
342 | spl0(); | |
343 | bp = bfreelist.av_forw; | |
344 | notavail(bp); | |
345 | if (bp->b_flags & B_DELWRI) { | |
346 | bp->b_flags |= B_ASYNC; | |
347 | bwrite(bp); | |
348 | goto loop; | |
349 | } | |
5603d07d BJ |
350 | if (bp->b_dev == NODEV) |
351 | goto done; | |
352 | /* INLINE EXPANSION OF bunhash(bp) */ | |
99fae0e8 | 353 | (void) spl6(); |
5603d07d BJ |
354 | i = BUFHASH(dbtofsb(bp->b_blkno)); |
355 | x = bp - buf; | |
356 | if (bufhash[i] == x) { | |
357 | bufhash[i] = bp->b_hlink; | |
358 | } else { | |
359 | for (ep = &buf[bufhash[i]]; ep != &buf[-1]; | |
360 | ep = &buf[ep->b_hlink]) | |
361 | if (ep->b_hlink == x) { | |
362 | ep->b_hlink = bp->b_hlink; | |
363 | goto done; | |
364 | } | |
365 | panic("getblk"); | |
366 | } | |
367 | done: | |
99fae0e8 | 368 | (void) spl0(); |
5603d07d | 369 | /* END INLINE EXPANSION */ |
663dbc72 BJ |
370 | bp->b_flags = B_BUSY; |
371 | bp->b_back->b_forw = bp->b_forw; | |
372 | bp->b_forw->b_back = bp->b_back; | |
373 | bp->b_forw = dp->b_forw; | |
374 | bp->b_back = dp; | |
375 | dp->b_forw->b_back = bp; | |
376 | dp->b_forw = bp; | |
377 | bp->b_dev = dev; | |
378 | bp->b_blkno = dblkno; | |
5603d07d BJ |
379 | i = BUFHASH(blkno); |
380 | bp->b_hlink = bufhash[i]; | |
381 | bufhash[i] = bp - buf; | |
663dbc72 BJ |
382 | return(bp); |
383 | } | |
384 | ||
385 | /* | |
386 | * get an empty block, | |
387 | * not assigned to any particular device | |
388 | */ | |
389 | struct buf * | |
390 | geteblk() | |
391 | { | |
436518b9 | 392 | register struct buf *bp, *dp; |
663dbc72 BJ |
393 | |
394 | loop: | |
81263dba | 395 | (void) spl6(); |
663dbc72 BJ |
396 | while (bfreelist.av_forw == &bfreelist) { |
397 | bfreelist.b_flags |= B_WANTED; | |
398 | sleep((caddr_t)&bfreelist, PRIBIO+1); | |
399 | } | |
81263dba | 400 | (void) spl0(); |
663dbc72 BJ |
401 | dp = &bfreelist; |
402 | bp = bfreelist.av_forw; | |
403 | notavail(bp); | |
404 | if (bp->b_flags & B_DELWRI) { | |
405 | bp->b_flags |= B_ASYNC; | |
406 | bwrite(bp); | |
407 | goto loop; | |
408 | } | |
5603d07d BJ |
409 | if (bp->b_dev != NODEV) |
410 | bunhash(bp); | |
663dbc72 BJ |
411 | bp->b_flags = B_BUSY; |
412 | bp->b_back->b_forw = bp->b_forw; | |
413 | bp->b_forw->b_back = bp->b_back; | |
414 | bp->b_forw = dp->b_forw; | |
415 | bp->b_back = dp; | |
416 | dp->b_forw->b_back = bp; | |
417 | dp->b_forw = bp; | |
418 | bp->b_dev = (dev_t)NODEV; | |
5603d07d | 419 | bp->b_hlink = -1; |
663dbc72 BJ |
420 | return(bp); |
421 | } | |
422 | ||
5603d07d BJ |
423 | bunhash(bp) |
424 | register struct buf *bp; | |
425 | { | |
426 | register struct buf *ep; | |
99fae0e8 | 427 | register int i, x, s; |
5603d07d BJ |
428 | |
429 | if (bp->b_dev == NODEV) | |
430 | return; | |
99fae0e8 | 431 | s = spl6(); |
5603d07d BJ |
432 | i = BUFHASH(dbtofsb(bp->b_blkno)); |
433 | x = bp - buf; | |
434 | if (bufhash[i] == x) { | |
435 | bufhash[i] = bp->b_hlink; | |
99fae0e8 | 436 | goto ret; |
5603d07d BJ |
437 | } |
438 | for (ep = &buf[bufhash[i]]; ep != &buf[-1]; | |
439 | ep = &buf[ep->b_hlink]) | |
440 | if (ep->b_hlink == x) { | |
441 | ep->b_hlink = bp->b_hlink; | |
99fae0e8 | 442 | goto ret; |
5603d07d BJ |
443 | } |
444 | panic("bunhash"); | |
99fae0e8 BJ |
445 | ret: |
446 | splx(s); | |
5603d07d BJ |
447 | } |
448 | ||
663dbc72 BJ |
449 | /* |
450 | * Wait for I/O completion on the buffer; return errors | |
451 | * to the user. | |
452 | */ | |
453 | iowait(bp) | |
454 | register struct buf *bp; | |
455 | { | |
456 | ||
81263dba | 457 | (void) spl6(); |
663dbc72 BJ |
458 | while ((bp->b_flags&B_DONE)==0) |
459 | sleep((caddr_t)bp, PRIBIO); | |
81263dba | 460 | (void) spl0(); |
663dbc72 BJ |
461 | geterror(bp); |
462 | } | |
463 | ||
464 | #ifndef FASTVAX | |
465 | /* | |
466 | * Unlink a buffer from the available list and mark it busy. | |
467 | * (internal interface) | |
468 | */ | |
469 | notavail(bp) | |
470 | register struct buf *bp; | |
471 | { | |
472 | register s; | |
473 | ||
474 | s = spl6(); | |
475 | bp->av_back->av_forw = bp->av_forw; | |
476 | bp->av_forw->av_back = bp->av_back; | |
477 | bp->b_flags |= B_BUSY; | |
478 | splx(s); | |
479 | } | |
480 | #endif | |
481 | ||
482 | /* | |
483 | * Mark I/O complete on a buffer. If the header | |
484 | * indicates a dirty page push completion, the | |
485 | * header is inserted into the ``cleaned'' list | |
486 | * to be processed by the pageout daemon. Otherwise | |
487 | * release it if I/O is asynchronous, and wake | |
488 | * up anyone waiting for it. | |
489 | */ | |
490 | iodone(bp) | |
491 | register struct buf *bp; | |
492 | { | |
493 | register int s; | |
494 | ||
80e7c811 BJ |
495 | if (bp->b_flags & B_DONE) |
496 | panic("dup iodone"); | |
663dbc72 BJ |
497 | bp->b_flags |= B_DONE; |
498 | if (bp->b_flags & B_DIRTY) { | |
499 | if (bp->b_flags & B_ERROR) | |
500 | panic("IO err in push"); | |
501 | s = spl6(); | |
502 | cnt.v_pgout++; | |
503 | bp->av_forw = bclnlist; | |
504 | bp->b_bcount = swsize[bp - swbuf]; | |
505 | bp->b_pfcent = swpf[bp - swbuf]; | |
506 | bclnlist = bp; | |
507 | if (bswlist.b_flags & B_WANTED) | |
508 | wakeup((caddr_t)&proc[2]); | |
509 | splx(s); | |
a3ee1d55 | 510 | return; |
663dbc72 BJ |
511 | } |
512 | if (bp->b_flags&B_ASYNC) | |
513 | brelse(bp); | |
514 | else { | |
515 | bp->b_flags &= ~B_WANTED; | |
516 | wakeup((caddr_t)bp); | |
517 | } | |
518 | } | |
519 | ||
520 | /* | |
521 | * Zero the core associated with a buffer. | |
522 | */ | |
523 | clrbuf(bp) | |
524 | struct buf *bp; | |
525 | { | |
526 | register *p; | |
527 | register c; | |
528 | ||
529 | p = bp->b_un.b_words; | |
530 | c = BSIZE/sizeof(int); | |
531 | do | |
532 | *p++ = 0; | |
533 | while (--c); | |
534 | bp->b_resid = 0; | |
535 | } | |
536 | ||
537 | /* | |
538 | * swap I/O - | |
539 | * | |
540 | * If the flag indicates a dirty page push initiated | |
541 | * by the pageout daemon, we map the page into the i th | |
542 | * virtual page of process 2 (the daemon itself) where i is | |
543 | * the index of the swap header that has been allocated. | |
544 | * We simply initialize the header and queue the I/O but | |
545 | * do not wait for completion. When the I/O completes, | |
546 | * iodone() will link the header to a list of cleaned | |
547 | * pages to be processed by the pageout daemon. | |
548 | */ | |
549 | swap(p, dblkno, addr, nbytes, rdflg, flag, dev, pfcent) | |
550 | struct proc *p; | |
551 | swblk_t dblkno; | |
552 | caddr_t addr; | |
553 | int flag, nbytes; | |
554 | dev_t dev; | |
555 | unsigned pfcent; | |
556 | { | |
557 | register struct buf *bp; | |
558 | register int c; | |
559 | int p2dp; | |
560 | register struct pte *dpte, *vpte; | |
561 | ||
81263dba | 562 | (void) spl6(); |
663dbc72 BJ |
563 | while (bswlist.av_forw == NULL) { |
564 | bswlist.b_flags |= B_WANTED; | |
565 | sleep((caddr_t)&bswlist, PSWP+1); | |
566 | } | |
567 | bp = bswlist.av_forw; | |
568 | bswlist.av_forw = bp->av_forw; | |
81263dba | 569 | (void) spl0(); |
663dbc72 BJ |
570 | |
571 | bp->b_flags = B_BUSY | B_PHYS | rdflg | flag; | |
572 | if ((bp->b_flags & (B_DIRTY|B_PGIN)) == 0) | |
573 | if (rdflg == B_READ) | |
574 | sum.v_pswpin += btoc(nbytes); | |
575 | else | |
576 | sum.v_pswpout += btoc(nbytes); | |
577 | bp->b_proc = p; | |
578 | if (flag & B_DIRTY) { | |
579 | p2dp = ((bp - swbuf) * CLSIZE) * KLMAX; | |
580 | dpte = dptopte(&proc[2], p2dp); | |
581 | vpte = vtopte(p, btop(addr)); | |
582 | for (c = 0; c < nbytes; c += NBPG) { | |
583 | if (vpte->pg_pfnum == 0 || vpte->pg_fod) | |
584 | panic("swap bad pte"); | |
585 | *dpte++ = *vpte++; | |
586 | } | |
587 | bp->b_un.b_addr = (caddr_t)ctob(p2dp); | |
588 | } else | |
589 | bp->b_un.b_addr = addr; | |
590 | while (nbytes > 0) { | |
591 | c = imin(ctob(120), nbytes); | |
592 | bp->b_bcount = c; | |
593 | bp->b_blkno = dblkno; | |
594 | bp->b_dev = dev; | |
d2f87136 BJ |
595 | if (flag & B_DIRTY) { |
596 | swpf[bp - swbuf] = pfcent; | |
597 | swsize[bp - swbuf] = nbytes; | |
598 | } | |
663dbc72 BJ |
599 | (*bdevsw[major(dev)].d_strategy)(bp); |
600 | if (flag & B_DIRTY) { | |
601 | if (c < nbytes) | |
602 | panic("big push"); | |
663dbc72 BJ |
603 | return; |
604 | } | |
81263dba | 605 | (void) spl6(); |
663dbc72 BJ |
606 | while((bp->b_flags&B_DONE)==0) |
607 | sleep((caddr_t)bp, PSWP); | |
81263dba | 608 | (void) spl0(); |
663dbc72 BJ |
609 | bp->b_un.b_addr += c; |
610 | bp->b_flags &= ~B_DONE; | |
611 | if (bp->b_flags & B_ERROR) { | |
612 | if ((flag & (B_UAREA|B_PAGET)) || rdflg == B_WRITE) | |
613 | panic("hard IO err in swap"); | |
614 | swkill(p, (char *)0); | |
615 | } | |
616 | nbytes -= c; | |
617 | dblkno += btoc(c); | |
618 | } | |
81263dba | 619 | (void) spl6(); |
663dbc72 BJ |
620 | bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS|B_PAGET|B_UAREA|B_DIRTY); |
621 | bp->av_forw = bswlist.av_forw; | |
622 | bswlist.av_forw = bp; | |
623 | if (bswlist.b_flags & B_WANTED) { | |
624 | bswlist.b_flags &= ~B_WANTED; | |
625 | wakeup((caddr_t)&bswlist); | |
626 | wakeup((caddr_t)&proc[2]); | |
627 | } | |
81263dba | 628 | (void) spl0(); |
663dbc72 BJ |
629 | } |
630 | ||
631 | /* | |
632 | * If rout == 0 then killed on swap error, else | |
633 | * rout is the name of the routine where we ran out of | |
634 | * swap space. | |
635 | */ | |
636 | swkill(p, rout) | |
637 | struct proc *p; | |
638 | char *rout; | |
639 | { | |
640 | ||
641 | printf("%d: ", p->p_pid); | |
642 | if (rout) | |
643 | printf("out of swap space in %s\n", rout); | |
644 | else | |
645 | printf("killed on swap error\n"); | |
646 | /* | |
647 | * To be sure no looping (e.g. in vmsched trying to | |
648 | * swap out) mark process locked in core (as though | |
649 | * done by user) after killing it so noone will try | |
650 | * to swap it out. | |
651 | */ | |
a30d2e97 | 652 | psignal(p, SIGKILL); |
663dbc72 BJ |
653 | p->p_flag |= SULOCK; |
654 | } | |
655 | ||
656 | /* | |
657 | * make sure all write-behind blocks | |
658 | * on dev (or NODEV for all) | |
659 | * are flushed out. | |
660 | * (from umount and update) | |
661 | */ | |
662 | bflush(dev) | |
663 | dev_t dev; | |
664 | { | |
665 | register struct buf *bp; | |
666 | ||
667 | loop: | |
81263dba | 668 | (void) spl6(); |
663dbc72 BJ |
669 | for (bp = bfreelist.av_forw; bp != &bfreelist; bp = bp->av_forw) { |
670 | if (bp->b_flags&B_DELWRI && (dev == NODEV||dev==bp->b_dev)) { | |
671 | bp->b_flags |= B_ASYNC; | |
672 | notavail(bp); | |
673 | bwrite(bp); | |
674 | goto loop; | |
675 | } | |
676 | } | |
81263dba | 677 | (void) spl0(); |
663dbc72 BJ |
678 | } |
679 | ||
680 | /* | |
681 | * Raw I/O. The arguments are | |
682 | * The strategy routine for the device | |
683 | * A buffer, which will always be a special buffer | |
684 | * header owned exclusively by the device for this purpose | |
685 | * The device number | |
686 | * Read/write flag | |
687 | * Essentially all the work is computing physical addresses and | |
688 | * validating them. | |
689 | * If the user has the proper access privilidges, the process is | |
690 | * marked 'delayed unlock' and the pages involved in the I/O are | |
691 | * faulted and locked. After the completion of the I/O, the above pages | |
692 | * are unlocked. | |
693 | */ | |
694 | physio(strat, bp, dev, rw, mincnt) | |
695 | int (*strat)(); | |
696 | register struct buf *bp; | |
697 | unsigned (*mincnt)(); | |
698 | { | |
699 | register int c; | |
700 | char *a; | |
701 | ||
702 | if (useracc(u.u_base,u.u_count,rw==B_READ?B_WRITE:B_READ) == NULL) { | |
703 | u.u_error = EFAULT; | |
704 | return; | |
705 | } | |
81263dba | 706 | (void) spl6(); |
663dbc72 BJ |
707 | while (bp->b_flags&B_BUSY) { |
708 | bp->b_flags |= B_WANTED; | |
709 | sleep((caddr_t)bp, PRIBIO+1); | |
710 | } | |
711 | bp->b_error = 0; | |
712 | bp->b_proc = u.u_procp; | |
713 | bp->b_un.b_addr = u.u_base; | |
714 | while (u.u_count != 0 && bp->b_error==0) { | |
715 | bp->b_flags = B_BUSY | B_PHYS | rw; | |
716 | bp->b_dev = dev; | |
717 | bp->b_blkno = u.u_offset >> PGSHIFT; | |
718 | bp->b_bcount = u.u_count; | |
719 | (*mincnt)(bp); | |
720 | c = bp->b_bcount; | |
721 | u.u_procp->p_flag |= SPHYSIO; | |
722 | vslock(a = bp->b_un.b_addr, c); | |
723 | (*strat)(bp); | |
81263dba | 724 | (void) spl6(); |
663dbc72 BJ |
725 | while ((bp->b_flags&B_DONE) == 0) |
726 | sleep((caddr_t)bp, PRIBIO); | |
727 | vsunlock(a, c, rw); | |
728 | u.u_procp->p_flag &= ~SPHYSIO; | |
729 | if (bp->b_flags&B_WANTED) | |
730 | wakeup((caddr_t)bp); | |
81263dba | 731 | (void) spl0(); |
663dbc72 BJ |
732 | bp->b_un.b_addr += c; |
733 | u.u_count -= c; | |
734 | u.u_offset += c; | |
735 | } | |
736 | bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS); | |
737 | u.u_count = bp->b_resid; | |
738 | geterror(bp); | |
739 | } | |
740 | ||
741 | /*ARGSUSED*/ | |
742 | unsigned | |
743 | minphys(bp) | |
744 | struct buf *bp; | |
745 | { | |
746 | ||
747 | if (bp->b_bcount > 60 * 1024) | |
748 | bp->b_bcount = 60 * 1024; | |
749 | } | |
750 | ||
751 | /* | |
752 | * Pick up the device's error number and pass it to the user; | |
753 | * if there is an error but the number is 0 set a generalized | |
754 | * code. Actually the latter is always true because devices | |
755 | * don't yet return specific errors. | |
756 | */ | |
757 | geterror(bp) | |
758 | register struct buf *bp; | |
759 | { | |
760 | ||
761 | if (bp->b_flags&B_ERROR) | |
762 | if ((u.u_error = bp->b_error)==0) | |
763 | u.u_error = EIO; | |
764 | } |