xref: /dragonfly/sys/dev/disk/md/md.c (revision 23265324) 
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 1.15 2006/12/22 23:26:16 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 disklabel *dl;
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 	dl = &sc->disk.d_label;
105 	bzero(dl, sizeof(*dl));
106 	dl->d_secsize = DEV_BSIZE;
107 	dl->d_nsectors = 1024;
108 	dl->d_ntracks = 1;
109 	dl->d_secpercyl = dl->d_nsectors * dl->d_ntracks;
110 	dl->d_secperunit = sc->nsect;
111 	dl->d_ncylinders = dl->d_secperunit / dl->d_secpercyl;
112 	return (0);
113 }
114 
115 static int
116 mdioctl(struct dev_ioctl_args *ap)
117 {
118 	cdev_t dev = ap->a_head.a_dev;
119 
120 	if (md_debug)
121 		kprintf("mdioctl(%s %lx %p %x)\n",
122 			devtoname(dev), ap->a_cmd, ap->a_data, ap->a_fflag);
123 
124 	return (ENOIOCTL);
125 }
126 
127 static int
128 mdstrategy(struct dev_strategy_args *ap)
129 {
130 	cdev_t dev = ap->a_head.a_dev;
131 	struct bio *bio = ap->a_bio;
132 	struct buf *bp = bio->bio_buf;
133 	struct md_s *sc;
134 
135 	if (md_debug > 1) {
136 		kprintf("mdstrategy(%p) %s %08x, %lld, %d, %p)\n",
137 		    bp, devtoname(dev), bp->b_flags, bio->bio_offset,
138 		    bp->b_bcount, bp->b_data);
139 	}
140 	bio->bio_driver_info = dev;
141 	sc = dev->si_drv1;
142 	if (sc->type == MD_MALLOC) {
143 		mdstrategy_malloc(ap);
144 	} else {
145 		mdstrategy_preload(ap);
146 	}
147 	return(0);
148 }
149 
150 
151 static int
152 mdstrategy_malloc(struct dev_strategy_args *ap)
153 {
154 	cdev_t dev = ap->a_head.a_dev;
155 	struct bio *bio = ap->a_bio;
156 	struct buf *bp = bio->bio_buf;
157 	unsigned secno, nsec, secval, uc;
158 	u_char *secp, **secpp, *dst;
159 	devstat_trans_flags dop;
160 	struct md_s *sc;
161 	int i;
162 
163 	if (md_debug > 1)
164 		kprintf("mdstrategy_malloc(%p) %s %08xx, %lld, %d, %p)\n",
165 		    bp, devtoname(dev), bp->b_flags, bio->bio_offset,
166 		    bp->b_bcount, bp->b_data);
167 
168 	sc = dev->si_drv1;
169 
170 	crit_enter();
171 
172 	bioqdisksort(&sc->bio_queue, bio);
173 
174 	if (sc->busy) {
175 		crit_exit();
176 		return(0);
177 	}
178 
179 	sc->busy++;
180 
181 	while (1) {
182 		bio = bioq_first(&sc->bio_queue);
183 		if (bp)
184 			bioq_remove(&sc->bio_queue, bio);
185 		crit_exit();
186 		if (bio == NULL)
187 			break;
188 
189 		devstat_start_transaction(&sc->stats);
190 
191 		switch(bp->b_cmd) {
192 		case BUF_CMD_FREEBLKS:
193 			dop = DEVSTAT_NO_DATA;
194 			break;
195 		case BUF_CMD_READ:
196 			dop = DEVSTAT_READ;
197 			break;
198 		case BUF_CMD_WRITE:
199 			dop = DEVSTAT_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)*secpp > 255) {
212 					secp = *secpp;
213 					secval = 0;
214 				} else {
215 					secp = 0;
216 					secval = (u_int) *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 *)uc;
254 				} else {
255 					if (!secpp) {
256 						MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK);
257 						bzero(secpp, (secno + nsec + 1) * sizeof(u_char *));
258 						bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *));
259 						FREE(sc->secp, M_MD);
260 						sc->secp = secpp;
261 						sc->nsecp = secno + nsec + 1;
262 						secpp = &sc->secp[secno];
263 					}
264 					if (i == DEV_BSIZE) {
265 						if (secp)
266 							FREE(secp, M_MDSECT);
267 						*secpp = (u_char *)uc;
268 					} else {
269 						if (!secp)
270 							MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK);
271 						bcopy(dst, secp, DEV_BSIZE);
272 
273 						*secpp = secp;
274 					}
275 				}
276 				break;
277 			default:
278 				panic("md: bad b_cmd %d", bp->b_cmd);
279 
280 			}
281 			secno++;
282 			dst += DEV_BSIZE;
283 		}
284 		bp->b_resid = 0;
285 		devstat_end_transaction_buf(&sc->stats, bp);
286 		biodone(bio);
287 		crit_enter();
288 	}
289 	sc->busy = 0;
290 	return(0);
291 }
292 
293 
294 static int
295 mdstrategy_preload(struct dev_strategy_args *ap)
296 {
297 	cdev_t dev = ap->a_head.a_dev;
298 	struct bio *bio = ap->a_bio;
299 	struct buf *bp = bio->bio_buf;
300 	devstat_trans_flags dop;
301 	struct md_s *sc;
302 
303 	if (md_debug > 1)
304 		kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n",
305 		    bp, devtoname(dev), bp->b_flags, bio->bio_offset,
306 		    bp->b_bcount, bp->b_data);
307 
308 	sc = dev->si_drv1;
309 
310 	crit_enter();
311 
312 	bioqdisksort(&sc->bio_queue, bio);
313 
314 	if (sc->busy) {
315 		crit_exit();
316 		return(0);
317 	}
318 
319 	sc->busy++;
320 
321 	while (1) {
322 		bio = bioq_first(&sc->bio_queue);
323 		if (bio)
324 			bioq_remove(&sc->bio_queue, bio);
325 		crit_exit();
326 		if (bio == NULL)
327 			break;
328 
329 		devstat_start_transaction(&sc->stats);
330 
331 		switch(bp->b_cmd) {
332 		case BUF_CMD_FREEBLKS:
333 			dop = DEVSTAT_NO_DATA;
334 			break;
335 		case BUF_CMD_READ:
336 			dop = DEVSTAT_READ;
337 			bcopy(sc->pl_ptr + bio->bio_offset,
338 			       bp->b_data, bp->b_bcount);
339 			break;
340 		case BUF_CMD_WRITE:
341 			dop = DEVSTAT_WRITE;
342 			bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset,
343 			      bp->b_bcount);
344 			break;
345 		default:
346 			panic("md: bad cmd %d\n", bp->b_cmd);
347 		}
348 		bp->b_resid = 0;
349 		devstat_end_transaction_buf(&sc->stats, bp);
350 		biodone(bio);
351 		crit_enter();
352 	}
353 	sc->busy = 0;
354 	return(0);
355 }
356 
357 static struct md_s *
358 mdcreate(void)
359 {
360 	struct md_s *sc;
361 
362 	MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK);
363 	bzero(sc, sizeof(*sc));
364 	sc->unit = mdunits++;
365 	bioq_init(&sc->bio_queue);
366 	devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE,
367 		DEVSTAT_NO_ORDERED_TAGS,
368 		DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
369 		DEVSTAT_PRIORITY_OTHER);
370 	sc->dev = disk_create(sc->unit, &sc->disk, 0, &md_ops);
371 	sc->dev->si_drv1 = sc;
372 	return (sc);
373 }
374 
375 static void
376 mdcreate_preload(u_char *image, unsigned length)
377 {
378 	struct md_s *sc;
379 
380 	sc = mdcreate();
381 	sc->type = MD_PRELOAD;
382 	sc->nsect = length / DEV_BSIZE;
383 	sc->pl_ptr = image;
384 	sc->pl_len = length;
385 
386 	if (sc->unit == 0)
387 		mdrootready = 1;
388 }
389 
390 static void
391 mdcreate_malloc(void)
392 {
393 	struct md_s *sc;
394 
395 	sc = mdcreate();
396 	sc->type = MD_MALLOC;
397 
398 	sc->nsect = MD_NSECT;	/* for now */
399 	MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK);
400 	bzero(sc->secp, sizeof(u_char *));
401 	sc->nsecp = 1;
402 	kprintf("md%d: Malloc disk\n", sc->unit);
403 }
404 
405 static void
406 md_drvinit(void *unused)
407 {
408 
409 	caddr_t mod;
410 	caddr_t c;
411 	u_char *ptr, *name, *type;
412 	unsigned len;
413 
414 #ifdef MD_ROOT_SIZE
415 	mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024);
416 #endif
417 	mod = NULL;
418 	while ((mod = preload_search_next_name(mod)) != NULL) {
419 		name = (char *)preload_search_info(mod, MODINFO_NAME);
420 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
421 		if (name == NULL)
422 			continue;
423 		if (type == NULL)
424 			continue;
425 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
426 			continue;
427 		c = preload_search_info(mod, MODINFO_ADDR);
428 		ptr = *(u_char **)c;
429 		c = preload_search_info(mod, MODINFO_SIZE);
430 		len = *(unsigned *)c;
431 		kprintf("md%d: Preloaded image <%s> %d bytes at %p\n",
432 		   mdunits, name, len, ptr);
433 		mdcreate_preload(ptr, len);
434 	}
435 	mdcreate_malloc();
436 }
437 
438 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL)
439 
440 #ifdef MD_ROOT
441 static void
442 md_takeroot(void *junk)
443 {
444 	if (mdrootready)
445 		rootdevnames[0] = "ufs:/dev/md0c";
446 }
447 
448 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL);
449 #endif
450