xref: /dflybsd-src/sys/dev/disk/md/md.c (revision 9b5a99654f820c32a9fb8fa9bae3c3b12fe27a0b) 
1 /*
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7  * ----------------------------------------------------------------------------
8  *
9  * $FreeBSD: src/sys/dev/md/md.c,v 1.8.2.2 2002/08/19 17:43:34 jdp Exp $
10  * $DragonFly: src/sys/dev/disk/md/md.c,v 1.16 2007/05/15 00:01:03 dillon Exp $
11  *
12  */
13 
14 #include "opt_md.h"		/* We have adopted some tasks from MFS */
15 
16 #include <sys/param.h>
17 #include <sys/systm.h>
18 #include <sys/buf.h>
19 #include <sys/conf.h>
20 #include <sys/devicestat.h>
21 #include <sys/disk.h>
22 #include <sys/kernel.h>
23 #include <sys/malloc.h>
24 #include <sys/sysctl.h>
25 #include <sys/linker.h>
26 #include <sys/proc.h>
27 #include <sys/buf2.h>
28 #include <sys/thread2.h>
29 
30 #ifndef MD_NSECT
31 #define MD_NSECT (10000 * 2)
32 #endif
33 
34 MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk");
35 MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors");
36 
37 static int md_debug;
38 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, "");
39 
40 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE)
41 /* Image gets put here: */
42 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here";
43 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here";
44 #endif
45 
46 static int mdrootready;
47 
48 static void mdcreate_malloc(void);
49 
50 #define CDEV_MAJOR	95
51 
52 static d_strategy_t mdstrategy;
53 static d_strategy_t mdstrategy_preload;
54 static d_strategy_t mdstrategy_malloc;
55 static d_open_t mdopen;
56 static d_ioctl_t mdioctl;
57 
58 static struct dev_ops md_ops = {
59 	{ "md", CDEV_MAJOR, D_DISK | D_CANFREE | D_MEMDISK },
60         .d_open =	mdopen,
61         .d_close =	nullclose,
62         .d_read =	physread,
63         .d_write =	physwrite,
64         .d_ioctl =	mdioctl,
65         .d_strategy =	mdstrategy,
66 };
67 
68 struct md_s {
69 	int unit;
70 	struct devstat stats;
71 	struct bio_queue_head bio_queue;
72 	struct disk disk;
73 	cdev_t dev;
74 	int busy;
75 	enum {MD_MALLOC, MD_PRELOAD} type;
76 	unsigned nsect;
77 
78 	/* MD_MALLOC related fields */
79 	unsigned nsecp;
80 	u_char **secp;
81 
82 	/* MD_PRELOAD related fields */
83 	u_char *pl_ptr;
84 	unsigned pl_len;
85 };
86 
87 static int mdunits;
88 
89 static int
90 mdopen(struct dev_open_args *ap)
91 {
92 	cdev_t dev = ap->a_head.a_dev;
93 	struct md_s *sc;
94 	struct disk_info info;
95 
96 	if (md_debug)
97 		kprintf("mdopen(%s %x %x)\n",
98 			devtoname(dev), ap->a_oflags, ap->a_devtype);
99 
100 	sc = dev->si_drv1;
101 	if (sc->unit + 1 == mdunits)
102 		mdcreate_malloc();
103 
104 	bzero(&info, sizeof(info));
105 	info.d_media_blksize = DEV_BSIZE;	/* mandatory */
106 	info.d_media_blocks = sc->nsect;
107 
108 	info.d_secpertrack = 1024;		/* optional */
109 	info.d_nheads = 1;
110 	info.d_secpercyl = info.d_secpertrack * info.d_nheads;
111 	info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl);
112 	disk_setdiskinfo(&sc->disk, &info);
113 
114 	return (0);
115 }
116 
117 static int
118 mdioctl(struct dev_ioctl_args *ap)
119 {
120 	cdev_t dev = ap->a_head.a_dev;
121 
122 	if (md_debug)
123 		kprintf("mdioctl(%s %lx %p %x)\n",
124 			devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag);
125 
126 	return (ENOIOCTL);
127 }
128 
129 static int
130 mdstrategy(struct dev_strategy_args *ap)
131 {
132 	cdev_t dev = ap->a_head.a_dev;
133 	struct bio *bio = ap->a_bio;
134 	struct buf *bp = bio->bio_buf;
135 	struct md_s *sc;
136 
137 	if (md_debug > 1) {
138 		kprintf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n",
139 		    bp, devtoname(dev), bp->b_flags, bio->bio_offset,
140 		    bp->b_bcount, bp->b_data);
141 	}
142 	bio->bio_driver_info = dev;
143 	sc = dev->si_drv1;
144 	if (sc->type == MD_MALLOC) {
145 		mdstrategy_malloc(ap);
146 	} else {
147 		mdstrategy_preload(ap);
148 	}
149 	return(0);
150 }
151 
152 
153 static int
154 mdstrategy_malloc(struct dev_strategy_args *ap)
155 {
156 	cdev_t dev = ap->a_head.a_dev;
157 	struct bio *bio = ap->a_bio;
158 	struct buf *bp = bio->bio_buf;
159 	unsigned secno, nsec, secval, uc;
160 	u_char *secp, **secpp, *dst;
161 	devstat_trans_flags dop;
162 	struct md_s *sc;
163 	int i;
164 
165 	if (md_debug > 1)
166 		kprintf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n",
167 		    bp, devtoname(dev), bp->b_flags, bio->bio_offset,
168 		    bp->b_bcount, bp->b_data);
169 
170 	sc = dev->si_drv1;
171 
172 	crit_enter();
173 
174 	bioqdisksort(&sc->bio_queue, bio);
175 
176 	if (sc->busy) {
177 		crit_exit();
178 		return(0);
179 	}
180 
181 	sc->busy++;
182 
183 	while (1) {
184 		bio = bioq_first(&sc->bio_queue);
185 		if (bp)
186 			bioq_remove(&sc->bio_queue, bio);
187 		crit_exit();
188 		if (bio == NULL)
189 			break;
190 
191 		devstat_start_transaction(&sc->stats);
192 
193 		switch(bp->b_cmd) {
194 		case BUF_CMD_FREEBLKS:
195 			dop = DEVSTAT_NO_DATA;
196 			break;
197 		case BUF_CMD_READ:
198 			dop = DEVSTAT_READ;
199 			break;
200 		case BUF_CMD_WRITE:
201 			dop = DEVSTAT_WRITE;
202 			break;
203 		default:
204 			panic("md: bad b_cmd %d", bp->b_cmd);
205 		}
206 
207 		nsec = bp->b_bcount >> DEV_BSHIFT;
208 		secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT);
209 		dst = bp->b_data;
210 		while (nsec--) {
211 			if (secno < sc->nsecp) {
212 				secpp = &sc->secp[secno];
213 				if ((u_int)*secpp > 255) {
214 					secp = *secpp;
215 					secval = 0;
216 				} else {
217 					secp = 0;
218 					secval = (u_int) *secpp;
219 				}
220 			} else {
221 				secpp = 0;
222 				secp = 0;
223 				secval = 0;
224 			}
225 			if (md_debug > 2)
226 				kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval);
227 
228 			switch(bp->b_cmd) {
229 			case BUF_CMD_FREEBLKS:
230 				if (secpp) {
231 					if (secp)
232 						FREE(secp, M_MDSECT);
233 					*secpp = 0;
234 				}
235 				break;
236 			case BUF_CMD_READ:
237 				if (secp) {
238 					bcopy(secp, dst, DEV_BSIZE);
239 				} else if (secval) {
240 					for (i = 0; i < DEV_BSIZE; i++)
241 						dst[i] = secval;
242 				} else {
243 					bzero(dst, DEV_BSIZE);
244 				}
245 				break;
246 			case BUF_CMD_WRITE:
247 				uc = dst[0];
248 				for (i = 1; i < DEV_BSIZE; i++)
249 					if (dst[i] != uc)
250 						break;
251 				if (i == DEV_BSIZE && !uc) {
252 					if (secp)
253 						FREE(secp, M_MDSECT);
254 					if (secpp)
255 						*secpp = (u_char *)uc;
256 				} else {
257 					if (!secpp) {
258 						MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK);
259 						bzero(secpp, (secno + nsec + 1) * sizeof(u_char *));
260 						bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *));
261 						FREE(sc->secp, M_MD);
262 						sc->secp = secpp;
263 						sc->nsecp = secno + nsec + 1;
264 						secpp = &sc->secp[secno];
265 					}
266 					if (i == DEV_BSIZE) {
267 						if (secp)
268 							FREE(secp, M_MDSECT);
269 						*secpp = (u_char *)uc;
270 					} else {
271 						if (!secp)
272 							MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK);
273 						bcopy(dst, secp, DEV_BSIZE);
274 
275 						*secpp = secp;
276 					}
277 				}
278 				break;
279 			default:
280 				panic("md: bad b_cmd %d", bp->b_cmd);
281 
282 			}
283 			secno++;
284 			dst += DEV_BSIZE;
285 		}
286 		bp->b_resid = 0;
287 		devstat_end_transaction_buf(&sc->stats, bp);
288 		biodone(bio);
289 		crit_enter();
290 	}
291 	sc->busy = 0;
292 	return(0);
293 }
294 
295 
296 static int
297 mdstrategy_preload(struct dev_strategy_args *ap)
298 {
299 	cdev_t dev = ap->a_head.a_dev;
300 	struct bio *bio = ap->a_bio;
301 	struct buf *bp = bio->bio_buf;
302 	devstat_trans_flags dop;
303 	struct md_s *sc;
304 
305 	if (md_debug > 1)
306 		kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n",
307 		    bp, devtoname(dev), bp->b_flags, bio->bio_offset,
308 		    bp->b_bcount, bp->b_data);
309 
310 	sc = dev->si_drv1;
311 
312 	crit_enter();
313 
314 	bioqdisksort(&sc->bio_queue, bio);
315 
316 	if (sc->busy) {
317 		crit_exit();
318 		return(0);
319 	}
320 
321 	sc->busy++;
322 
323 	while (1) {
324 		bio = bioq_first(&sc->bio_queue);
325 		if (bio)
326 			bioq_remove(&sc->bio_queue, bio);
327 		crit_exit();
328 		if (bio == NULL)
329 			break;
330 
331 		devstat_start_transaction(&sc->stats);
332 
333 		switch(bp->b_cmd) {
334 		case BUF_CMD_FREEBLKS:
335 			dop = DEVSTAT_NO_DATA;
336 			break;
337 		case BUF_CMD_READ:
338 			dop = DEVSTAT_READ;
339 			bcopy(sc->pl_ptr + bio->bio_offset,
340 			       bp->b_data, bp->b_bcount);
341 			break;
342 		case BUF_CMD_WRITE:
343 			dop = DEVSTAT_WRITE;
344 			bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset,
345 			      bp->b_bcount);
346 			break;
347 		default:
348 			panic("md: bad cmd %d\n", bp->b_cmd);
349 		}
350 		bp->b_resid = 0;
351 		devstat_end_transaction_buf(&sc->stats, bp);
352 		biodone(bio);
353 		crit_enter();
354 	}
355 	sc->busy = 0;
356 	return(0);
357 }
358 
359 static struct md_s *
360 mdcreate(void)
361 {
362 	struct md_s *sc;
363 
364 	MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK);
365 	bzero(sc, sizeof(*sc));
366 	sc->unit = mdunits++;
367 	bioq_init(&sc->bio_queue);
368 	devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE,
369 		DEVSTAT_NO_ORDERED_TAGS,
370 		DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
371 		DEVSTAT_PRIORITY_OTHER);
372 	sc->dev = disk_create(sc->unit, &sc->disk, &md_ops);
373 	sc->dev->si_drv1 = sc;
374 	return (sc);
375 }
376 
377 static void
378 mdcreate_preload(u_char *image, unsigned length)
379 {
380 	struct md_s *sc;
381 
382 	sc = mdcreate();
383 	sc->type = MD_PRELOAD;
384 	sc->nsect = length / DEV_BSIZE;
385 	sc->pl_ptr = image;
386 	sc->pl_len = length;
387 
388 	if (sc->unit == 0)
389 		mdrootready = 1;
390 }
391 
392 static void
393 mdcreate_malloc(void)
394 {
395 	struct md_s *sc;
396 
397 	sc = mdcreate();
398 	sc->type = MD_MALLOC;
399 
400 	sc->nsect = MD_NSECT;	/* for now */
401 	MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK);
402 	bzero(sc->secp, sizeof(u_char *));
403 	sc->nsecp = 1;
404 	kprintf("md%d: Malloc disk\n", sc->unit);
405 }
406 
407 static void
408 md_drvinit(void *unused)
409 {
410 
411 	caddr_t mod;
412 	caddr_t c;
413 	u_char *ptr, *name, *type;
414 	unsigned len;
415 
416 #ifdef MD_ROOT_SIZE
417 	mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024);
418 #endif
419 	mod = NULL;
420 	while ((mod = preload_search_next_name(mod)) != NULL) {
421 		name = (char *)preload_search_info(mod, MODINFO_NAME);
422 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
423 		if (name == NULL)
424 			continue;
425 		if (type == NULL)
426 			continue;
427 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
428 			continue;
429 		c = preload_search_info(mod, MODINFO_ADDR);
430 		ptr = *(u_char **)c;
431 		c = preload_search_info(mod, MODINFO_SIZE);
432 		len = *(unsigned *)c;
433 		kprintf("md%d: Preloaded image <%s> %d bytes at %p\n",
434 		   mdunits, name, len, ptr);
435 		mdcreate_preload(ptr, len);
436 	}
437 	mdcreate_malloc();
438 }
439 
440 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL)
441 
442 #ifdef MD_ROOT
443 static void
444 md_takeroot(void *junk)
445 {
446 	if (mdrootready)
447 		rootdevnames[0] = "ufs:/dev/md0c";
448 }
449 
450 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL);
451 #endif
452