xref: /dragonfly/sys/dev/disk/md/md.c (revision 8a7bdfea) 
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 1.19 2008/01/05 14:02:37 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, 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 (bio == NULL) {
186 			crit_exit();
187 			break;
188 		}
189 		crit_exit();
190 		bioq_remove(&sc->bio_queue, bio);
191 		bp = bio->bio_buf;
192 
193 		devstat_start_transaction(&sc->stats);
194 
195 		switch(bp->b_cmd) {
196 		case BUF_CMD_FREEBLKS:
197 			dop = DEVSTAT_NO_DATA;
198 			break;
199 		case BUF_CMD_READ:
200 			dop = DEVSTAT_READ;
201 			break;
202 		case BUF_CMD_WRITE:
203 			dop = DEVSTAT_WRITE;
204 			break;
205 		default:
206 			panic("md: bad b_cmd %d", bp->b_cmd);
207 		}
208 
209 		nsec = bp->b_bcount >> DEV_BSHIFT;
210 		secno = (unsigned)(bio->bio_offset >> DEV_BSHIFT);
211 		dst = bp->b_data;
212 		while (nsec--) {
213 			if (secno < sc->nsecp) {
214 				secpp = &sc->secp[secno];
215 				if ((u_int)*secpp > 255) {
216 					secp = *secpp;
217 					secval = 0;
218 				} else {
219 					secp = 0;
220 					secval = (u_int) *secpp;
221 				}
222 			} else {
223 				secpp = 0;
224 				secp = 0;
225 				secval = 0;
226 			}
227 			if (md_debug > 2)
228 				kprintf("%08x %p %p %d\n", bp->b_flags, secpp, secp, secval);
229 
230 			switch(bp->b_cmd) {
231 			case BUF_CMD_FREEBLKS:
232 				if (secpp) {
233 					if (secp)
234 						FREE(secp, M_MDSECT);
235 					*secpp = 0;
236 				}
237 				break;
238 			case BUF_CMD_READ:
239 				if (secp) {
240 					bcopy(secp, dst, DEV_BSIZE);
241 				} else if (secval) {
242 					for (i = 0; i < DEV_BSIZE; i++)
243 						dst[i] = secval;
244 				} else {
245 					bzero(dst, DEV_BSIZE);
246 				}
247 				break;
248 			case BUF_CMD_WRITE:
249 				uc = dst[0];
250 				for (i = 1; i < DEV_BSIZE; i++)
251 					if (dst[i] != uc)
252 						break;
253 				if (i == DEV_BSIZE && !uc) {
254 					if (secp)
255 						FREE(secp, M_MDSECT);
256 					if (secpp)
257 						*secpp = (u_char *)uc;
258 				} else {
259 					if (!secpp) {
260 						MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK | M_ZERO);
261 						bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *));
262 						FREE(sc->secp, M_MD);
263 						sc->secp = secpp;
264 						sc->nsecp = secno + nsec + 1;
265 						secpp = &sc->secp[secno];
266 					}
267 					if (i == DEV_BSIZE) {
268 						if (secp)
269 							FREE(secp, M_MDSECT);
270 						*secpp = (u_char *)uc;
271 					} else {
272 						if (!secp)
273 							MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK);
274 						bcopy(dst, secp, DEV_BSIZE);
275 
276 						*secpp = secp;
277 					}
278 				}
279 				break;
280 			default:
281 				panic("md: bad b_cmd %d", bp->b_cmd);
282 
283 			}
284 			secno++;
285 			dst += DEV_BSIZE;
286 		}
287 		bp->b_resid = 0;
288 		devstat_end_transaction_buf(&sc->stats, bp);
289 		biodone(bio);
290 		crit_enter();
291 	}
292 	sc->busy = 0;
293 	return(0);
294 }
295 
296 
297 static int
298 mdstrategy_preload(struct dev_strategy_args *ap)
299 {
300 	cdev_t dev = ap->a_head.a_dev;
301 	struct bio *bio = ap->a_bio;
302 	struct buf *bp = bio->bio_buf;
303 	devstat_trans_flags dop;
304 	struct md_s *sc;
305 
306 	if (md_debug > 1)
307 		kprintf("mdstrategy_preload(%p) %s %08x, %lld, %d, %p)\n",
308 		    bp, devtoname(dev), bp->b_flags, bio->bio_offset,
309 		    bp->b_bcount, bp->b_data);
310 
311 	sc = dev->si_drv1;
312 
313 	crit_enter();
314 
315 	bioqdisksort(&sc->bio_queue, bio);
316 
317 	if (sc->busy) {
318 		crit_exit();
319 		return(0);
320 	}
321 
322 	sc->busy++;
323 
324 	while (1) {
325 		bio = bioq_first(&sc->bio_queue);
326 		if (bio)
327 			bioq_remove(&sc->bio_queue, bio);
328 		crit_exit();
329 		if (bio == NULL)
330 			break;
331 
332 		devstat_start_transaction(&sc->stats);
333 
334 		switch(bp->b_cmd) {
335 		case BUF_CMD_FREEBLKS:
336 			dop = DEVSTAT_NO_DATA;
337 			break;
338 		case BUF_CMD_READ:
339 			dop = DEVSTAT_READ;
340 			bcopy(sc->pl_ptr + bio->bio_offset,
341 			       bp->b_data, bp->b_bcount);
342 			break;
343 		case BUF_CMD_WRITE:
344 			dop = DEVSTAT_WRITE;
345 			bcopy(bp->b_data, sc->pl_ptr + bio->bio_offset,
346 			      bp->b_bcount);
347 			break;
348 		default:
349 			panic("md: bad cmd %d\n", bp->b_cmd);
350 		}
351 		bp->b_resid = 0;
352 		devstat_end_transaction_buf(&sc->stats, bp);
353 		biodone(bio);
354 		crit_enter();
355 	}
356 	sc->busy = 0;
357 	return(0);
358 }
359 
360 static struct md_s *
361 mdcreate(void)
362 {
363 	struct md_s *sc;
364 
365 	MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK | M_ZERO);
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 	sc->dev->si_iosize_max = DFLTPHYS;
375 
376 	return (sc);
377 }
378 
379 static void
380 mdcreate_preload(u_char *image, unsigned length)
381 {
382 	struct md_s *sc;
383 
384 	sc = mdcreate();
385 	sc->type = MD_PRELOAD;
386 	sc->nsect = length / DEV_BSIZE;
387 	sc->pl_ptr = image;
388 	sc->pl_len = length;
389 
390 	if (sc->unit == 0)
391 		mdrootready = 1;
392 }
393 
394 static void
395 mdcreate_malloc(void)
396 {
397 	struct md_s *sc;
398 
399 	sc = mdcreate();
400 	sc->type = MD_MALLOC;
401 
402 	sc->nsect = MD_NSECT;	/* for now */
403 	MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK | M_ZERO);
404 	sc->nsecp = 1;
405 	kprintf("md%d: Malloc disk\n", sc->unit);
406 }
407 
408 static void
409 md_drvinit(void *unused)
410 {
411 
412 	caddr_t mod;
413 	caddr_t c;
414 	u_char *ptr, *name, *type;
415 	unsigned len;
416 
417 #ifdef MD_ROOT_SIZE
418 	mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024);
419 #endif
420 	mod = NULL;
421 	while ((mod = preload_search_next_name(mod)) != NULL) {
422 		name = (char *)preload_search_info(mod, MODINFO_NAME);
423 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
424 		if (name == NULL)
425 			continue;
426 		if (type == NULL)
427 			continue;
428 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
429 			continue;
430 		c = preload_search_info(mod, MODINFO_ADDR);
431 		ptr = *(u_char **)c;
432 		c = preload_search_info(mod, MODINFO_SIZE);
433 		len = *(unsigned *)c;
434 		kprintf("md%d: Preloaded image <%s> %d bytes at %p\n",
435 		   mdunits, name, len, ptr);
436 		mdcreate_preload(ptr, len);
437 	}
438 	mdcreate_malloc();
439 }
440 
441 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL)
442 
443 #ifdef MD_ROOT
444 static void
445 md_takeroot(void *junk)
446 {
447 	if (mdrootready)
448 		rootdevnames[0] = "ufs:/dev/md0c";
449 }
450 
451 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL);
452 #endif
453