xref: /dragonfly/sys/dev/disk/md/md.c (revision 9ddb8543) 
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 1.20 2008/09/07 08:09:39 swildner 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,
140 		    (long long)bio->bio_offset,
141 		    bp->b_bcount, bp->b_data);
142 	}
143 	bio->bio_driver_info = dev;
144 	sc = dev->si_drv1;
145 	if (sc->type == MD_MALLOC) {
146 		mdstrategy_malloc(ap);
147 	} else {
148 		mdstrategy_preload(ap);
149 	}
150 	return(0);
151 }
152 
153 
154 static int
155 mdstrategy_malloc(struct dev_strategy_args *ap)
156 {
157 	cdev_t dev = ap->a_head.a_dev;
158 	struct bio *bio = ap->a_bio;
159 	struct buf *bp = bio->bio_buf;
160 	unsigned secno, nsec, secval, uc;
161 	u_char *secp, **secpp, *dst;
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,
168 		    (long long)bio->bio_offset,
169 		    bp->b_bcount, bp->b_data);
170 
171 	sc = dev->si_drv1;
172 
173 	crit_enter();
174 
175 	bioqdisksort(&sc->bio_queue, bio);
176 
177 	if (sc->busy) {
178 		crit_exit();
179 		return(0);
180 	}
181 
182 	sc->busy++;
183 
184 	while (1) {
185 		bio = bioq_first(&sc->bio_queue);
186 		if (bio == NULL) {
187 			crit_exit();
188 			break;
189 		}
190 		crit_exit();
191 		bioq_remove(&sc->bio_queue, bio);
192 		bp = bio->bio_buf;
193 
194 		devstat_start_transaction(&sc->stats);
195 
196 		switch (bp->b_cmd) {
197 		case BUF_CMD_FREEBLKS:
198 		case BUF_CMD_READ:
199 		case BUF_CMD_WRITE:
200 			break;
201 		default:
202 			panic("md: bad b_cmd %d", bp->b_cmd);
203 		}
204 
205 		nsec = bp->b_bcount >> DEV_BSHIFT;
206 		secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT);
207 		dst = bp->b_data;
208 		while (nsec--) {
209 			if (secno < sc->nsecp) {
210 				secpp = &sc->secp[secno];
211 				if ((u_int)(uintptr_t)*secpp > 255) {
212 					secp = *secpp;
213 					secval = 0;
214 				} else {
215 					secp = 0;
216 					secval = (u_int)(uintptr_t)*secpp;
217 				}
218 			} else {
219 				secpp = 0;
220 				secp = 0;
221 				secval = 0;
222 			}
223 			if (md_debug > 2)
224 				kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval);
225 
226 			switch (bp->b_cmd) {
227 			case BUF_CMD_FREEBLKS:
228 				if (secpp) {
229 					if (secp)
230 						FREE(secp, M_MDSECT);
231 					*secpp = 0;
232 				}
233 				break;
234 			case BUF_CMD_READ:
235 				if (secp) {
236 					bcopy(secp, dst, DEV_BSIZE);
237 				} else if (secval) {
238 					for (i = 0; i < DEV_BSIZE; i++)
239 						dst[i] = secval;
240 				} else {
241 					bzero(dst, DEV_BSIZE);
242 				}
243 				break;
244 			case BUF_CMD_WRITE:
245 				uc = dst[0];
246 				for (i = 1; i < DEV_BSIZE; i++)
247 					if (dst[i] != uc)
248 						break;
249 				if (i == DEV_BSIZE && !uc) {
250 					if (secp)
251 						FREE(secp, M_MDSECT);
252 					if (secpp)
253 						*secpp = (u_char *)(uintptr_t)uc;
254 				} else {
255 					if (!secpp) {
256 						MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK | M_ZERO);
257 						bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *));
258 						FREE(sc->secp, M_MD);
259 						sc->secp = secpp;
260 						sc->nsecp = secno + nsec + 1;
261 						secpp = &sc->secp[secno];
262 					}
263 					if (i == DEV_BSIZE) {
264 						if (secp)
265 							FREE(secp, M_MDSECT);
266 						*secpp = (u_char *)(uintptr_t)uc;
267 					} else {
268 						if (!secp)
269 							MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK);
270 						bcopy(dst, secp, DEV_BSIZE);
271 
272 						*secpp = secp;
273 					}
274 				}
275 				break;
276 			default:
277 				panic("md: bad b_cmd %d", bp->b_cmd);
278 
279 			}
280 			secno++;
281 			dst += DEV_BSIZE;
282 		}
283 		bp->b_resid = 0;
284 		devstat_end_transaction_buf(&sc->stats, bp);
285 		biodone(bio);
286 		crit_enter();
287 	}
288 	sc->busy = 0;
289 	return(0);
290 }
291 
292 
293 static int
294 mdstrategy_preload(struct dev_strategy_args *ap)
295 {
296 	cdev_t dev = ap->a_head.a_dev;
297 	struct bio *bio = ap->a_bio;
298 	struct buf *bp = bio->bio_buf;
299 	struct md_s *sc;
300 
301 	if (md_debug > 1)
302 		kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n",
303 		    bp, devtoname(dev), bp->b_flags,
304 		    (long long)bio->bio_offset,
305 		    bp->b_bcount, bp->b_data);
306 
307 	sc = dev->si_drv1;
308 
309 	crit_enter();
310 
311 	bioqdisksort(&sc->bio_queue, bio);
312 
313 	if (sc->busy) {
314 		crit_exit();
315 		return(0);
316 	}
317 
318 	sc->busy++;
319 
320 	while (1) {
321 		bio = bioq_first(&sc->bio_queue);
322 		if (bio)
323 			bioq_remove(&sc->bio_queue, bio);
324 		crit_exit();
325 		if (bio == NULL)
326 			break;
327 
328 		devstat_start_transaction(&sc->stats);
329 
330 		switch (bp->b_cmd) {
331 		case BUF_CMD_FREEBLKS:
332 			break;
333 		case BUF_CMD_READ:
334 			bcopy(sc->pl_ptr + bio->bio_offset,
335 			       bp->b_data, bp->b_bcount);
336 			break;
337 		case BUF_CMD_WRITE:
338 			bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset,
339 			      bp->b_bcount);
340 			break;
341 		default:
342 			panic("md: bad cmd %d\n", bp->b_cmd);
343 		}
344 		bp->b_resid = 0;
345 		devstat_end_transaction_buf(&sc->stats, bp);
346 		biodone(bio);
347 		crit_enter();
348 	}
349 	sc->busy = 0;
350 	return(0);
351 }
352 
353 static struct md_s *
354 mdcreate(void)
355 {
356 	struct md_s *sc;
357 	struct disk_info info;
358 
359 	MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK | M_ZERO);
360 	sc->unit = mdunits++;
361 	bioq_init(&sc->bio_queue);
362 	devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE,
363 		DEVSTAT_NO_ORDERED_TAGS,
364 		DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
365 		DEVSTAT_PRIORITY_OTHER);
366 	sc->dev = disk_create(sc->unit, &sc->disk, &md_ops);
367 	sc->dev->si_drv1 = sc;
368 	sc->dev->si_iosize_max = DFLTPHYS;
369 
370 	bzero(&info, sizeof(info));
371 	info.d_media_blksize = DEV_BSIZE;	/* mandatory */
372 	info.d_media_blocks = sc->nsect;
373 
374 	info.d_secpertrack = 1024;		/* optional */
375 	info.d_nheads = 1;
376 	info.d_secpercyl = info.d_secpertrack * info.d_nheads;
377 	info.d_ncylinders = (u_int)(info.d_media_blocks / info.d_secpercyl);
378 	disk_setdiskinfo(&sc->disk, &info);
379 
380 	return (sc);
381 }
382 
383 static void
384 mdcreate_preload(u_char *image, unsigned length)
385 {
386 	struct md_s *sc;
387 
388 	sc = mdcreate();
389 	sc->type = MD_PRELOAD;
390 	sc->nsect = length / DEV_BSIZE;
391 	sc->pl_ptr = image;
392 	sc->pl_len = length;
393 
394 	if (sc->unit == 0)
395 		mdrootready = 1;
396 }
397 
398 static void
399 mdcreate_malloc(void)
400 {
401 	struct md_s *sc;
402 
403 	sc = mdcreate();
404 	sc->type = MD_MALLOC;
405 
406 	sc->nsect = MD_NSECT;	/* for now */
407 	MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK | M_ZERO);
408 	sc->nsecp = 1;
409 	kprintf("md%d: Malloc disk\n", sc->unit);
410 }
411 
412 static void
413 md_drvinit(void *unused)
414 {
415 
416 	caddr_t mod;
417 	caddr_t c;
418 	u_char *ptr, *name, *type;
419 	unsigned len;
420 
421 #ifdef MD_ROOT_SIZE
422 	mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024);
423 #endif
424 	mod = NULL;
425 	while ((mod = preload_search_next_name(mod)) != NULL) {
426 		name = (char *)preload_search_info(mod, MODINFO_NAME);
427 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
428 		if (name == NULL)
429 			continue;
430 		if (type == NULL)
431 			continue;
432 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
433 			continue;
434 		c = preload_search_info(mod, MODINFO_ADDR);
435 		ptr = *(u_char **)c;
436 		c = preload_search_info(mod, MODINFO_SIZE);
437 		len = *(unsigned *)c;
438 		kprintf("md%d: Preloaded image <%s> %d bytes at %p\n",
439 		   mdunits, name, len, ptr);
440 		mdcreate_preload(ptr, len);
441 	}
442 	mdcreate_malloc();
443 }
444 
445 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL)
446 
447 #ifdef MD_ROOT
448 static void
449 md_takeroot(void *junk)
450 {
451 	if (mdrootready)
452 		rootdevnames[0] = "ufs:/dev/md0c";
453 }
454 
455 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL);
456 #endif
457