Commit | Line | Data |
---|---|---|
7b8b5a01 | 1 | /* vfs_cluster.c 4.5 %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" | |
973ecc4f | 13 | #include "../h/trace.h" |
663dbc72 | 14 | |
5603d07d BJ |
15 | /* |
16 | * The following several routines allocate and free | |
17 | * buffers with various side effects. In general the | |
18 | * arguments to an allocate routine are a device and | |
19 | * a block number, and the value is a pointer to | |
20 | * to the buffer header; the buffer is marked "busy" | |
21 | * so that no one else can touch it. If the block was | |
22 | * already in core, no I/O need be done; if it is | |
23 | * already busy, the process waits until it becomes free. | |
24 | * The following routines allocate a buffer: | |
25 | * getblk | |
26 | * bread | |
27 | * breada | |
28 | * baddr (if it is incore) | |
29 | * Eventually the buffer must be released, possibly with the | |
30 | * side effect of writing it out, by using one of | |
31 | * bwrite | |
32 | * bdwrite | |
33 | * bawrite | |
34 | * brelse | |
35 | */ | |
36 | ||
37 | #define BUFHSZ 63 | |
38 | #define BUFHASH(blkno) (blkno % BUFHSZ) | |
39 | short bufhash[BUFHSZ]; | |
40 | ||
41 | /* | |
42 | * Initialize hash links for buffers. | |
43 | */ | |
44 | bhinit() | |
45 | { | |
46 | register int i; | |
47 | ||
48 | for (i = 0; i < BUFHSZ; i++) | |
49 | bufhash[i] = -1; | |
50 | } | |
51 | ||
663dbc72 BJ |
52 | /* #define DISKMON 1 */ |
53 | ||
54 | #ifdef DISKMON | |
55 | struct { | |
56 | int nbuf; | |
57 | long nread; | |
58 | long nreada; | |
59 | long ncache; | |
60 | long nwrite; | |
61 | long bufcount[NBUF]; | |
62 | } io_info; | |
63 | #endif | |
64 | ||
65 | /* | |
66 | * Swap IO headers - | |
67 | * They contain the necessary information for the swap I/O. | |
68 | * At any given time, a swap header can be in three | |
69 | * different lists. When free it is in the free list, | |
70 | * when allocated and the I/O queued, it is on the swap | |
71 | * device list, and finally, if the operation was a dirty | |
72 | * page push, when the I/O completes, it is inserted | |
73 | * in a list of cleaned pages to be processed by the pageout daemon. | |
74 | */ | |
75 | struct buf swbuf[NSWBUF]; | |
76 | short swsize[NSWBUF]; /* CAN WE JUST USE B_BCOUNT? */ | |
77 | int swpf[NSWBUF]; | |
78 | ||
663dbc72 BJ |
79 | |
80 | #ifdef FASTVAX | |
81 | #define notavail(bp) \ | |
82 | { \ | |
83 | int s = spl6(); \ | |
84 | (bp)->av_back->av_forw = (bp)->av_forw; \ | |
85 | (bp)->av_forw->av_back = (bp)->av_back; \ | |
86 | (bp)->b_flags |= B_BUSY; \ | |
87 | splx(s); \ | |
88 | } | |
89 | #endif | |
90 | ||
91 | /* | |
92 | * Read in (if necessary) the block and return a buffer pointer. | |
93 | */ | |
94 | struct buf * | |
95 | bread(dev, blkno) | |
96 | dev_t dev; | |
97 | daddr_t blkno; | |
98 | { | |
99 | register struct buf *bp; | |
100 | ||
101 | bp = getblk(dev, blkno); | |
102 | if (bp->b_flags&B_DONE) { | |
973ecc4f BJ |
103 | #ifdef EPAWNJ |
104 | trace(TR_BREAD|TR_HIT, dev, blkno); | |
105 | #endif | |
663dbc72 BJ |
106 | #ifdef DISKMON |
107 | io_info.ncache++; | |
108 | #endif | |
109 | return(bp); | |
110 | } | |
111 | bp->b_flags |= B_READ; | |
112 | bp->b_bcount = BSIZE; | |
113 | (*bdevsw[major(dev)].d_strategy)(bp); | |
973ecc4f BJ |
114 | #ifdef EPAWNJ |
115 | trace(TR_BREAD|TR_MISS, dev, blkno); | |
116 | #endif | |
663dbc72 BJ |
117 | #ifdef DISKMON |
118 | io_info.nread++; | |
119 | #endif | |
120 | u.u_vm.vm_inblk++; /* pay for read */ | |
121 | iowait(bp); | |
122 | return(bp); | |
123 | } | |
124 | ||
125 | /* | |
126 | * Read in the block, like bread, but also start I/O on the | |
127 | * read-ahead block (which is not allocated to the caller) | |
128 | */ | |
129 | struct buf * | |
130 | breada(dev, blkno, rablkno) | |
131 | dev_t dev; | |
132 | daddr_t blkno, rablkno; | |
133 | { | |
134 | register struct buf *bp, *rabp; | |
135 | ||
136 | bp = NULL; | |
137 | if (!incore(dev, blkno)) { | |
138 | bp = getblk(dev, blkno); | |
139 | if ((bp->b_flags&B_DONE) == 0) { | |
140 | bp->b_flags |= B_READ; | |
141 | bp->b_bcount = BSIZE; | |
142 | (*bdevsw[major(dev)].d_strategy)(bp); | |
973ecc4f BJ |
143 | #ifdef EPAWNJ |
144 | trace(TR_BREAD|TR_MISS, dev, blkno); | |
145 | #endif | |
663dbc72 BJ |
146 | #ifdef DISKMON |
147 | io_info.nread++; | |
148 | #endif | |
149 | u.u_vm.vm_inblk++; /* pay for read */ | |
150 | } | |
973ecc4f BJ |
151 | #ifdef EPAWNJ |
152 | else | |
153 | trace(TR_BREAD|TR_HIT, dev, blkno); | |
154 | #endif | |
663dbc72 BJ |
155 | } |
156 | if (rablkno && !incore(dev, rablkno)) { | |
157 | rabp = getblk(dev, rablkno); | |
973ecc4f | 158 | if (rabp->b_flags & B_DONE) { |
663dbc72 | 159 | brelse(rabp); |
973ecc4f BJ |
160 | #ifdef EPAWNJ |
161 | trace(TR_BREAD|TR_HIT|TR_RA, dev, blkno); | |
162 | #endif | |
163 | } else { | |
663dbc72 BJ |
164 | rabp->b_flags |= B_READ|B_ASYNC; |
165 | rabp->b_bcount = BSIZE; | |
166 | (*bdevsw[major(dev)].d_strategy)(rabp); | |
973ecc4f BJ |
167 | #ifdef EPAWNJ |
168 | trace(TR_BREAD|TR_MISS|TR_RA, dev, rablock); | |
169 | #endif | |
663dbc72 BJ |
170 | #ifdef DISKMON |
171 | io_info.nreada++; | |
172 | #endif | |
173 | u.u_vm.vm_inblk++; /* pay in advance */ | |
174 | } | |
175 | } | |
176 | if(bp == NULL) | |
177 | return(bread(dev, blkno)); | |
178 | iowait(bp); | |
179 | return(bp); | |
180 | } | |
181 | ||
182 | /* | |
183 | * Write the buffer, waiting for completion. | |
184 | * Then release the buffer. | |
185 | */ | |
186 | bwrite(bp) | |
187 | register struct buf *bp; | |
188 | { | |
189 | register flag; | |
190 | ||
191 | flag = bp->b_flags; | |
192 | bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI | B_AGE); | |
193 | bp->b_bcount = BSIZE; | |
194 | #ifdef DISKMON | |
195 | io_info.nwrite++; | |
196 | #endif | |
197 | if ((flag&B_DELWRI) == 0) | |
198 | u.u_vm.vm_oublk++; /* noone paid yet */ | |
973ecc4f BJ |
199 | #ifdef EPAWNJ |
200 | trace(TR_BWRITE, bp->b_dev, dbtofsb(bp->b_blkno)); | |
201 | #endif | |
663dbc72 BJ |
202 | (*bdevsw[major(bp->b_dev)].d_strategy)(bp); |
203 | if ((flag&B_ASYNC) == 0) { | |
204 | iowait(bp); | |
205 | brelse(bp); | |
206 | } else if (flag & B_DELWRI) | |
207 | bp->b_flags |= B_AGE; | |
208 | else | |
209 | geterror(bp); | |
210 | } | |
211 | ||
212 | /* | |
213 | * Release the buffer, marking it so that if it is grabbed | |
214 | * for another purpose it will be written out before being | |
215 | * given up (e.g. when writing a partial block where it is | |
216 | * assumed that another write for the same block will soon follow). | |
217 | * This can't be done for magtape, since writes must be done | |
218 | * in the same order as requested. | |
219 | */ | |
220 | bdwrite(bp) | |
221 | register struct buf *bp; | |
222 | { | |
223 | register struct buf *dp; | |
224 | ||
225 | if ((bp->b_flags&B_DELWRI) == 0) | |
226 | u.u_vm.vm_oublk++; /* noone paid yet */ | |
227 | dp = bdevsw[major(bp->b_dev)].d_tab; | |
228 | if(dp->b_flags & B_TAPE) | |
229 | bawrite(bp); | |
230 | else { | |
231 | bp->b_flags |= B_DELWRI | B_DONE; | |
232 | brelse(bp); | |
233 | } | |
234 | } | |
235 | ||
236 | /* | |
237 | * Release the buffer, start I/O on it, but don't wait for completion. | |
238 | */ | |
239 | bawrite(bp) | |
240 | register struct buf *bp; | |
241 | { | |
242 | ||
243 | bp->b_flags |= B_ASYNC; | |
244 | bwrite(bp); | |
245 | } | |
246 | ||
247 | /* | |
248 | * release the buffer, with no I/O implied. | |
249 | */ | |
250 | brelse(bp) | |
251 | register struct buf *bp; | |
252 | { | |
253 | register struct buf **backp; | |
254 | register s; | |
255 | ||
256 | if (bp->b_flags&B_WANTED) | |
257 | wakeup((caddr_t)bp); | |
258 | if (bfreelist.b_flags&B_WANTED) { | |
259 | bfreelist.b_flags &= ~B_WANTED; | |
260 | wakeup((caddr_t)&bfreelist); | |
261 | } | |
5603d07d BJ |
262 | if ((bp->b_flags&B_ERROR) && bp->b_dev != NODEV) { |
263 | bunhash(bp); | |
663dbc72 | 264 | bp->b_dev = NODEV; /* no assoc. on error */ |
5603d07d | 265 | } |
663dbc72 BJ |
266 | s = spl6(); |
267 | if(bp->b_flags & (B_AGE|B_ERROR)) { | |
268 | backp = &bfreelist.av_forw; | |
269 | (*backp)->av_back = bp; | |
270 | bp->av_forw = *backp; | |
271 | *backp = bp; | |
272 | bp->av_back = &bfreelist; | |
273 | } else { | |
274 | backp = &bfreelist.av_back; | |
275 | (*backp)->av_forw = bp; | |
276 | bp->av_back = *backp; | |
277 | *backp = bp; | |
278 | bp->av_forw = &bfreelist; | |
279 | } | |
280 | bp->b_flags &= ~(B_WANTED|B_BUSY|B_ASYNC|B_AGE); | |
281 | splx(s); | |
282 | } | |
283 | ||
284 | /* | |
285 | * See if the block is associated with some buffer | |
286 | * (mainly to avoid getting hung up on a wait in breada) | |
287 | */ | |
288 | incore(dev, blkno) | |
289 | dev_t dev; | |
290 | daddr_t blkno; | |
291 | { | |
292 | register struct buf *bp; | |
663dbc72 BJ |
293 | register int dblkno = fsbtodb(blkno); |
294 | ||
5603d07d BJ |
295 | for (bp = &buf[bufhash[BUFHASH(blkno)]]; bp != &buf[-1]; |
296 | bp = &buf[bp->b_hlink]) | |
7b8b5a01 RE |
297 | if (bp->b_blkno == dblkno && bp->b_dev == dev |
298 | && !(bp->b_flags & B_INVAL)) | |
5603d07d | 299 | return (1); |
5603d07d | 300 | return (0); |
663dbc72 BJ |
301 | } |
302 | ||
303 | struct buf * | |
304 | baddr(dev, blkno) | |
305 | dev_t dev; | |
306 | daddr_t blkno; | |
307 | { | |
308 | ||
309 | if (incore(dev, blkno)) | |
310 | return (bread(dev, blkno)); | |
311 | return (0); | |
312 | } | |
313 | ||
314 | /* | |
315 | * Assign a buffer for the given block. If the appropriate | |
316 | * block is already associated, return it; otherwise search | |
317 | * for the oldest non-busy buffer and reassign it. | |
318 | */ | |
319 | struct buf * | |
320 | getblk(dev, blkno) | |
321 | dev_t dev; | |
322 | daddr_t blkno; | |
323 | { | |
5603d07d | 324 | register struct buf *bp, *dp, *ep; |
01659974 | 325 | register int i, x, dblkno; |
663dbc72 | 326 | |
01659974 BJ |
327 | if ((unsigned)blkno >= 1 << (sizeof(int)*NBBY-PGSHIFT)) |
328 | blkno = 1 << ((sizeof(int)*NBBY-PGSHIFT) + 1); | |
329 | dblkno = fsbtodb(blkno); | |
663dbc72 | 330 | loop: |
81263dba | 331 | (void) spl0(); |
5603d07d BJ |
332 | for (bp = &buf[bufhash[BUFHASH(blkno)]]; bp != &buf[-1]; |
333 | bp = &buf[bp->b_hlink]) { | |
7b8b5a01 RE |
334 | if (bp->b_blkno != dblkno || bp->b_dev != dev |
335 | || bp->b_flags & B_INVAL) | |
663dbc72 | 336 | continue; |
81263dba | 337 | (void) spl6(); |
663dbc72 BJ |
338 | if (bp->b_flags&B_BUSY) { |
339 | bp->b_flags |= B_WANTED; | |
340 | sleep((caddr_t)bp, PRIBIO+1); | |
341 | goto loop; | |
342 | } | |
81263dba | 343 | (void) spl0(); |
663dbc72 BJ |
344 | #ifdef DISKMON |
345 | i = 0; | |
346 | dp = bp->av_forw; | |
347 | while (dp != &bfreelist) { | |
348 | i++; | |
349 | dp = dp->av_forw; | |
350 | } | |
351 | if (i<NBUF) | |
352 | io_info.bufcount[i]++; | |
353 | #endif | |
354 | notavail(bp); | |
355 | bp->b_flags |= B_CACHE; | |
356 | return(bp); | |
357 | } | |
5603d07d BJ |
358 | if (major(dev) >= nblkdev) |
359 | panic("blkdev"); | |
360 | dp = bdevsw[major(dev)].d_tab; | |
361 | if (dp == NULL) | |
362 | panic("devtab"); | |
81263dba | 363 | (void) spl6(); |
663dbc72 BJ |
364 | if (bfreelist.av_forw == &bfreelist) { |
365 | bfreelist.b_flags |= B_WANTED; | |
366 | sleep((caddr_t)&bfreelist, PRIBIO+1); | |
367 | goto loop; | |
368 | } | |
283cac0a | 369 | (void) spl0(); |
663dbc72 BJ |
370 | bp = bfreelist.av_forw; |
371 | notavail(bp); | |
372 | if (bp->b_flags & B_DELWRI) { | |
373 | bp->b_flags |= B_ASYNC; | |
374 | bwrite(bp); | |
375 | goto loop; | |
376 | } | |
5603d07d BJ |
377 | if (bp->b_dev == NODEV) |
378 | goto done; | |
379 | /* INLINE EXPANSION OF bunhash(bp) */ | |
973ecc4f BJ |
380 | #ifdef EPAWNJ |
381 | trace(TR_BRELSE, bp->b_dev, dbtofsb(bp->b_blkno)); | |
382 | #endif | |
99fae0e8 | 383 | (void) spl6(); |
5603d07d BJ |
384 | i = BUFHASH(dbtofsb(bp->b_blkno)); |
385 | x = bp - buf; | |
386 | if (bufhash[i] == x) { | |
387 | bufhash[i] = bp->b_hlink; | |
388 | } else { | |
389 | for (ep = &buf[bufhash[i]]; ep != &buf[-1]; | |
390 | ep = &buf[ep->b_hlink]) | |
391 | if (ep->b_hlink == x) { | |
392 | ep->b_hlink = bp->b_hlink; | |
393 | goto done; | |
394 | } | |
395 | panic("getblk"); | |
396 | } | |
397 | done: | |
99fae0e8 | 398 | (void) spl0(); |
5603d07d | 399 | /* END INLINE EXPANSION */ |
663dbc72 BJ |
400 | bp->b_flags = B_BUSY; |
401 | bp->b_back->b_forw = bp->b_forw; | |
402 | bp->b_forw->b_back = bp->b_back; | |
403 | bp->b_forw = dp->b_forw; | |
404 | bp->b_back = dp; | |
405 | dp->b_forw->b_back = bp; | |
406 | dp->b_forw = bp; | |
407 | bp->b_dev = dev; | |
408 | bp->b_blkno = dblkno; | |
5603d07d BJ |
409 | i = BUFHASH(blkno); |
410 | bp->b_hlink = bufhash[i]; | |
411 | bufhash[i] = bp - buf; | |
663dbc72 BJ |
412 | return(bp); |
413 | } | |
414 | ||
415 | /* | |
416 | * get an empty block, | |
417 | * not assigned to any particular device | |
418 | */ | |
419 | struct buf * | |
420 | geteblk() | |
421 | { | |
436518b9 | 422 | register struct buf *bp, *dp; |
663dbc72 BJ |
423 | |
424 | loop: | |
81263dba | 425 | (void) spl6(); |
663dbc72 BJ |
426 | while (bfreelist.av_forw == &bfreelist) { |
427 | bfreelist.b_flags |= B_WANTED; | |
428 | sleep((caddr_t)&bfreelist, PRIBIO+1); | |
429 | } | |
81263dba | 430 | (void) spl0(); |
663dbc72 BJ |
431 | dp = &bfreelist; |
432 | bp = bfreelist.av_forw; | |
433 | notavail(bp); | |
434 | if (bp->b_flags & B_DELWRI) { | |
435 | bp->b_flags |= B_ASYNC; | |
436 | bwrite(bp); | |
437 | goto loop; | |
438 | } | |
973ecc4f BJ |
439 | if (bp->b_dev != NODEV) { |
440 | #ifdef EPAWNJ | |
441 | trace(TR_BRELSE, bp->b_dev, dbtofsb(bp->b_blkno)); | |
442 | #endif | |
5603d07d | 443 | bunhash(bp); |
973ecc4f | 444 | } |
663dbc72 BJ |
445 | bp->b_flags = B_BUSY; |
446 | bp->b_back->b_forw = bp->b_forw; | |
447 | bp->b_forw->b_back = bp->b_back; | |
448 | bp->b_forw = dp->b_forw; | |
449 | bp->b_back = dp; | |
450 | dp->b_forw->b_back = bp; | |
451 | dp->b_forw = bp; | |
452 | bp->b_dev = (dev_t)NODEV; | |
5603d07d | 453 | bp->b_hlink = -1; |
663dbc72 BJ |
454 | return(bp); |
455 | } | |
456 | ||
5603d07d BJ |
457 | bunhash(bp) |
458 | register struct buf *bp; | |
459 | { | |
460 | register struct buf *ep; | |
99fae0e8 | 461 | register int i, x, s; |
5603d07d BJ |
462 | |
463 | if (bp->b_dev == NODEV) | |
464 | return; | |
99fae0e8 | 465 | s = spl6(); |
5603d07d BJ |
466 | i = BUFHASH(dbtofsb(bp->b_blkno)); |
467 | x = bp - buf; | |
468 | if (bufhash[i] == x) { | |
469 | bufhash[i] = bp->b_hlink; | |
99fae0e8 | 470 | goto ret; |
5603d07d BJ |
471 | } |
472 | for (ep = &buf[bufhash[i]]; ep != &buf[-1]; | |
473 | ep = &buf[ep->b_hlink]) | |
474 | if (ep->b_hlink == x) { | |
475 | ep->b_hlink = bp->b_hlink; | |
99fae0e8 | 476 | goto ret; |
5603d07d BJ |
477 | } |
478 | panic("bunhash"); | |
99fae0e8 BJ |
479 | ret: |
480 | splx(s); | |
5603d07d BJ |
481 | } |
482 | ||
663dbc72 BJ |
483 | /* |
484 | * Wait for I/O completion on the buffer; return errors | |
485 | * to the user. | |
486 | */ | |
487 | iowait(bp) | |
488 | register struct buf *bp; | |
489 | { | |
490 | ||
81263dba | 491 | (void) spl6(); |
663dbc72 BJ |
492 | while ((bp->b_flags&B_DONE)==0) |
493 | sleep((caddr_t)bp, PRIBIO); | |
81263dba | 494 | (void) spl0(); |
663dbc72 BJ |
495 | geterror(bp); |
496 | } | |
497 | ||
498 | #ifndef FASTVAX | |
499 | /* | |
500 | * Unlink a buffer from the available list and mark it busy. | |
501 | * (internal interface) | |
502 | */ | |
503 | notavail(bp) | |
504 | register struct buf *bp; | |
505 | { | |
506 | register s; | |
507 | ||
508 | s = spl6(); | |
509 | bp->av_back->av_forw = bp->av_forw; | |
510 | bp->av_forw->av_back = bp->av_back; | |
511 | bp->b_flags |= B_BUSY; | |
512 | splx(s); | |
513 | } | |
514 | #endif | |
515 | ||
516 | /* | |
517 | * Mark I/O complete on a buffer. If the header | |
518 | * indicates a dirty page push completion, the | |
519 | * header is inserted into the ``cleaned'' list | |
520 | * to be processed by the pageout daemon. Otherwise | |
521 | * release it if I/O is asynchronous, and wake | |
522 | * up anyone waiting for it. | |
523 | */ | |
524 | iodone(bp) | |
525 | register struct buf *bp; | |
526 | { | |
527 | register int s; | |
528 | ||
80e7c811 BJ |
529 | if (bp->b_flags & B_DONE) |
530 | panic("dup iodone"); | |
663dbc72 BJ |
531 | bp->b_flags |= B_DONE; |
532 | if (bp->b_flags & B_DIRTY) { | |
533 | if (bp->b_flags & B_ERROR) | |
534 | panic("IO err in push"); | |
535 | s = spl6(); | |
536 | cnt.v_pgout++; | |
537 | bp->av_forw = bclnlist; | |
538 | bp->b_bcount = swsize[bp - swbuf]; | |
539 | bp->b_pfcent = swpf[bp - swbuf]; | |
540 | bclnlist = bp; | |
541 | if (bswlist.b_flags & B_WANTED) | |
542 | wakeup((caddr_t)&proc[2]); | |
543 | splx(s); | |
a3ee1d55 | 544 | return; |
663dbc72 BJ |
545 | } |
546 | if (bp->b_flags&B_ASYNC) | |
547 | brelse(bp); | |
548 | else { | |
549 | bp->b_flags &= ~B_WANTED; | |
550 | wakeup((caddr_t)bp); | |
551 | } | |
552 | } | |
553 | ||
554 | /* | |
555 | * Zero the core associated with a buffer. | |
556 | */ | |
557 | clrbuf(bp) | |
558 | struct buf *bp; | |
559 | { | |
560 | register *p; | |
561 | register c; | |
562 | ||
563 | p = bp->b_un.b_words; | |
564 | c = BSIZE/sizeof(int); | |
565 | do | |
566 | *p++ = 0; | |
567 | while (--c); | |
568 | bp->b_resid = 0; | |
569 | } | |
570 | ||
571 | /* | |
572 | * swap I/O - | |
573 | * | |
574 | * If the flag indicates a dirty page push initiated | |
575 | * by the pageout daemon, we map the page into the i th | |
576 | * virtual page of process 2 (the daemon itself) where i is | |
577 | * the index of the swap header that has been allocated. | |
578 | * We simply initialize the header and queue the I/O but | |
579 | * do not wait for completion. When the I/O completes, | |
580 | * iodone() will link the header to a list of cleaned | |
581 | * pages to be processed by the pageout daemon. | |
582 | */ | |
583 | swap(p, dblkno, addr, nbytes, rdflg, flag, dev, pfcent) | |
584 | struct proc *p; | |
585 | swblk_t dblkno; | |
586 | caddr_t addr; | |
587 | int flag, nbytes; | |
588 | dev_t dev; | |
589 | unsigned pfcent; | |
590 | { | |
591 | register struct buf *bp; | |
592 | register int c; | |
593 | int p2dp; | |
594 | register struct pte *dpte, *vpte; | |
595 | ||
81263dba | 596 | (void) spl6(); |
663dbc72 BJ |
597 | while (bswlist.av_forw == NULL) { |
598 | bswlist.b_flags |= B_WANTED; | |
599 | sleep((caddr_t)&bswlist, PSWP+1); | |
600 | } | |
601 | bp = bswlist.av_forw; | |
602 | bswlist.av_forw = bp->av_forw; | |
81263dba | 603 | (void) spl0(); |
663dbc72 BJ |
604 | |
605 | bp->b_flags = B_BUSY | B_PHYS | rdflg | flag; | |
606 | if ((bp->b_flags & (B_DIRTY|B_PGIN)) == 0) | |
607 | if (rdflg == B_READ) | |
608 | sum.v_pswpin += btoc(nbytes); | |
609 | else | |
610 | sum.v_pswpout += btoc(nbytes); | |
611 | bp->b_proc = p; | |
612 | if (flag & B_DIRTY) { | |
613 | p2dp = ((bp - swbuf) * CLSIZE) * KLMAX; | |
614 | dpte = dptopte(&proc[2], p2dp); | |
615 | vpte = vtopte(p, btop(addr)); | |
616 | for (c = 0; c < nbytes; c += NBPG) { | |
617 | if (vpte->pg_pfnum == 0 || vpte->pg_fod) | |
618 | panic("swap bad pte"); | |
619 | *dpte++ = *vpte++; | |
620 | } | |
621 | bp->b_un.b_addr = (caddr_t)ctob(p2dp); | |
622 | } else | |
623 | bp->b_un.b_addr = addr; | |
624 | while (nbytes > 0) { | |
625 | c = imin(ctob(120), nbytes); | |
626 | bp->b_bcount = c; | |
627 | bp->b_blkno = dblkno; | |
628 | bp->b_dev = dev; | |
d2f87136 BJ |
629 | if (flag & B_DIRTY) { |
630 | swpf[bp - swbuf] = pfcent; | |
631 | swsize[bp - swbuf] = nbytes; | |
632 | } | |
663dbc72 BJ |
633 | (*bdevsw[major(dev)].d_strategy)(bp); |
634 | if (flag & B_DIRTY) { | |
635 | if (c < nbytes) | |
636 | panic("big push"); | |
663dbc72 BJ |
637 | return; |
638 | } | |
81263dba | 639 | (void) spl6(); |
663dbc72 BJ |
640 | while((bp->b_flags&B_DONE)==0) |
641 | sleep((caddr_t)bp, PSWP); | |
81263dba | 642 | (void) spl0(); |
663dbc72 BJ |
643 | bp->b_un.b_addr += c; |
644 | bp->b_flags &= ~B_DONE; | |
645 | if (bp->b_flags & B_ERROR) { | |
646 | if ((flag & (B_UAREA|B_PAGET)) || rdflg == B_WRITE) | |
647 | panic("hard IO err in swap"); | |
648 | swkill(p, (char *)0); | |
649 | } | |
650 | nbytes -= c; | |
651 | dblkno += btoc(c); | |
652 | } | |
81263dba | 653 | (void) spl6(); |
663dbc72 BJ |
654 | bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS|B_PAGET|B_UAREA|B_DIRTY); |
655 | bp->av_forw = bswlist.av_forw; | |
656 | bswlist.av_forw = bp; | |
657 | if (bswlist.b_flags & B_WANTED) { | |
658 | bswlist.b_flags &= ~B_WANTED; | |
659 | wakeup((caddr_t)&bswlist); | |
660 | wakeup((caddr_t)&proc[2]); | |
661 | } | |
81263dba | 662 | (void) spl0(); |
663dbc72 BJ |
663 | } |
664 | ||
665 | /* | |
666 | * If rout == 0 then killed on swap error, else | |
667 | * rout is the name of the routine where we ran out of | |
668 | * swap space. | |
669 | */ | |
670 | swkill(p, rout) | |
671 | struct proc *p; | |
672 | char *rout; | |
673 | { | |
674 | ||
675 | printf("%d: ", p->p_pid); | |
676 | if (rout) | |
677 | printf("out of swap space in %s\n", rout); | |
678 | else | |
679 | printf("killed on swap error\n"); | |
680 | /* | |
681 | * To be sure no looping (e.g. in vmsched trying to | |
682 | * swap out) mark process locked in core (as though | |
683 | * done by user) after killing it so noone will try | |
684 | * to swap it out. | |
685 | */ | |
a30d2e97 | 686 | psignal(p, SIGKILL); |
663dbc72 BJ |
687 | p->p_flag |= SULOCK; |
688 | } | |
689 | ||
690 | /* | |
691 | * make sure all write-behind blocks | |
692 | * on dev (or NODEV for all) | |
693 | * are flushed out. | |
694 | * (from umount and update) | |
695 | */ | |
696 | bflush(dev) | |
697 | dev_t dev; | |
698 | { | |
699 | register struct buf *bp; | |
700 | ||
701 | loop: | |
81263dba | 702 | (void) spl6(); |
663dbc72 BJ |
703 | for (bp = bfreelist.av_forw; bp != &bfreelist; bp = bp->av_forw) { |
704 | if (bp->b_flags&B_DELWRI && (dev == NODEV||dev==bp->b_dev)) { | |
705 | bp->b_flags |= B_ASYNC; | |
706 | notavail(bp); | |
707 | bwrite(bp); | |
708 | goto loop; | |
709 | } | |
710 | } | |
81263dba | 711 | (void) spl0(); |
663dbc72 BJ |
712 | } |
713 | ||
714 | /* | |
715 | * Raw I/O. The arguments are | |
716 | * The strategy routine for the device | |
717 | * A buffer, which will always be a special buffer | |
718 | * header owned exclusively by the device for this purpose | |
719 | * The device number | |
720 | * Read/write flag | |
721 | * Essentially all the work is computing physical addresses and | |
722 | * validating them. | |
723 | * If the user has the proper access privilidges, the process is | |
724 | * marked 'delayed unlock' and the pages involved in the I/O are | |
725 | * faulted and locked. After the completion of the I/O, the above pages | |
726 | * are unlocked. | |
727 | */ | |
728 | physio(strat, bp, dev, rw, mincnt) | |
729 | int (*strat)(); | |
730 | register struct buf *bp; | |
731 | unsigned (*mincnt)(); | |
732 | { | |
733 | register int c; | |
734 | char *a; | |
735 | ||
736 | if (useracc(u.u_base,u.u_count,rw==B_READ?B_WRITE:B_READ) == NULL) { | |
737 | u.u_error = EFAULT; | |
738 | return; | |
739 | } | |
81263dba | 740 | (void) spl6(); |
663dbc72 BJ |
741 | while (bp->b_flags&B_BUSY) { |
742 | bp->b_flags |= B_WANTED; | |
743 | sleep((caddr_t)bp, PRIBIO+1); | |
744 | } | |
745 | bp->b_error = 0; | |
746 | bp->b_proc = u.u_procp; | |
747 | bp->b_un.b_addr = u.u_base; | |
748 | while (u.u_count != 0 && bp->b_error==0) { | |
749 | bp->b_flags = B_BUSY | B_PHYS | rw; | |
750 | bp->b_dev = dev; | |
751 | bp->b_blkno = u.u_offset >> PGSHIFT; | |
752 | bp->b_bcount = u.u_count; | |
753 | (*mincnt)(bp); | |
754 | c = bp->b_bcount; | |
755 | u.u_procp->p_flag |= SPHYSIO; | |
756 | vslock(a = bp->b_un.b_addr, c); | |
757 | (*strat)(bp); | |
81263dba | 758 | (void) spl6(); |
663dbc72 BJ |
759 | while ((bp->b_flags&B_DONE) == 0) |
760 | sleep((caddr_t)bp, PRIBIO); | |
761 | vsunlock(a, c, rw); | |
762 | u.u_procp->p_flag &= ~SPHYSIO; | |
763 | if (bp->b_flags&B_WANTED) | |
764 | wakeup((caddr_t)bp); | |
81263dba | 765 | (void) spl0(); |
663dbc72 BJ |
766 | bp->b_un.b_addr += c; |
767 | u.u_count -= c; | |
768 | u.u_offset += c; | |
769 | } | |
770 | bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS); | |
771 | u.u_count = bp->b_resid; | |
772 | geterror(bp); | |
773 | } | |
774 | ||
775 | /*ARGSUSED*/ | |
776 | unsigned | |
777 | minphys(bp) | |
778 | struct buf *bp; | |
779 | { | |
780 | ||
781 | if (bp->b_bcount > 60 * 1024) | |
782 | bp->b_bcount = 60 * 1024; | |
783 | } | |
784 | ||
785 | /* | |
786 | * Pick up the device's error number and pass it to the user; | |
787 | * if there is an error but the number is 0 set a generalized | |
788 | * code. Actually the latter is always true because devices | |
789 | * don't yet return specific errors. | |
790 | */ | |
791 | geterror(bp) | |
792 | register struct buf *bp; | |
793 | { | |
794 | ||
795 | if (bp->b_flags&B_ERROR) | |
796 | if ((u.u_error = bp->b_error)==0) | |
797 | u.u_error = EIO; | |
798 | } | |
7b8b5a01 RE |
799 | |
800 | /* | |
801 | * Invalidate in core blocks belonging to closed or umounted filesystem | |
802 | * | |
803 | * This is not nicely done at all - the buffer ought to be removed from the | |
804 | * hash chains & have its dev/blkno fields clobbered, but unfortunately we | |
805 | * can't do that here, as it is quite possible that the block is still | |
806 | * being used for i/o. Eventually, all disc drivers should be forced to | |
807 | * have a close routine, which ought ensure that the queue is empty, then | |
808 | * properly flush the queues. Until that happy day, this suffices for | |
809 | * correctness. ... kre | |
810 | */ | |
811 | binval(dev) | |
812 | dev_t dev; | |
813 | { | |
814 | register struct buf *bp, *dp; | |
815 | ||
816 | dp = bdevsw[major(dev)].d_tab; | |
817 | ||
818 | for (bp = dp->b_forw; bp != dp; bp = bp->b_forw) | |
819 | if (bp->b_dev == dev) | |
820 | bp->b_flags |= B_INVAL; | |
821 | } |