xref: /dragonfly/sys/dev/disk/md/md.c (revision b40e316c) 
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 1.7 2004/05/13 23:49:15 dillon Exp $
11  *
12  */
13 
14 #include "opt_mfs.h"		/* We have adopted some tasks from MFS */
15 #include "opt_md.h"		/* We have adopted some tasks from MFS */
16 
17 #include <sys/param.h>
18 #include <sys/systm.h>
19 #include <sys/buf.h>
20 #include <sys/conf.h>
21 #include <sys/devicestat.h>
22 #include <sys/disk.h>
23 #include <sys/kernel.h>
24 #include <sys/malloc.h>
25 #include <sys/sysctl.h>
26 #include <sys/linker.h>
27 #include <sys/proc.h>
28 #include <sys/buf2.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(MFS_ROOT) && !defined(MD_ROOT)
41 #define MD_ROOT MFS_ROOT
42 #warning "option MFS_ROOT has been superceeded by MD_ROOT"
43 #endif
44 
45 #if defined(MFS_ROOT_SIZE) && !defined(MD_ROOT_SIZE)
46 #define MD_ROOT_SIZE MFS_ROOT_SIZE
47 #warning "option MFS_ROOT_SIZE has been superceeded by MD_ROOT_SIZE"
48 #endif
49 
50 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE)
51 /* Image gets put here: */
52 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here";
53 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here";
54 #endif
55 
56 static int mdrootready;
57 
58 static void mdcreate_malloc(void);
59 
60 #define CDEV_MAJOR	95
61 
62 static d_strategy_t mdstrategy;
63 static d_strategy_t mdstrategy_preload;
64 static d_strategy_t mdstrategy_malloc;
65 static d_open_t mdopen;
66 static d_ioctl_t mdioctl;
67 
68 static struct cdevsw md_cdevsw = {
69         /* name */      "md",
70         /* maj */       CDEV_MAJOR,
71         /* flags */     D_DISK | D_CANFREE | D_MEMDISK,
72 	/* port */	NULL,
73 	/* clone */	NULL,
74 
75         /* open */      mdopen,
76         /* close */     nullclose,
77         /* read */      physread,
78         /* write */     physwrite,
79         /* ioctl */     mdioctl,
80         /* poll */      nopoll,
81         /* mmap */      nommap,
82         /* strategy */  mdstrategy,
83         /* dump */      nodump,
84         /* psize */     nopsize,
85 };
86 
87 struct md_s {
88 	int unit;
89 	struct devstat stats;
90 	struct buf_queue_head buf_queue;
91 	struct disk disk;
92 	dev_t dev;
93 	int busy;
94 	enum {MD_MALLOC, MD_PRELOAD} type;
95 	unsigned nsect;
96 
97 	/* MD_MALLOC related fields */
98 	unsigned nsecp;
99 	u_char **secp;
100 
101 	/* MD_PRELOAD related fields */
102 	u_char *pl_ptr;
103 	unsigned pl_len;
104 };
105 
106 static int mdunits;
107 
108 static int
109 mdopen(dev_t dev, int flag, int fmt, struct thread *td)
110 {
111 	struct md_s *sc;
112 	struct disklabel *dl;
113 
114 	if (md_debug)
115 		printf("mdopen(%s %x %x %p)\n",
116 			devtoname(dev), flag, fmt, td);
117 
118 	sc = dev->si_drv1;
119 	if (sc->unit + 1 == mdunits)
120 		mdcreate_malloc();
121 
122 	dl = &sc->disk.d_label;
123 	bzero(dl, sizeof(*dl));
124 	dl->d_secsize = DEV_BSIZE;
125 	dl->d_nsectors = 1024;
126 	dl->d_ntracks = 1;
127 	dl->d_secpercyl = dl->d_nsectors * dl->d_ntracks;
128 	dl->d_secperunit = sc->nsect;
129 	dl->d_ncylinders = dl->d_secperunit / dl->d_secpercyl;
130 	return (0);
131 }
132 
133 static int
134 mdioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct thread *td)
135 {
136 
137 	if (md_debug)
138 		printf("mdioctl(%s %lx %p %x %p)\n",
139 			devtoname(dev), cmd, addr, flags, td);
140 
141 	return (ENOIOCTL);
142 }
143 
144 static void
145 mdstrategy(struct buf *bp)
146 {
147 	struct md_s *sc;
148 
149 	if (md_debug > 1)
150 		printf("mdstrategy(%p) %s %lx, %d, %ld, %p)\n",
151 		    bp, devtoname(bp->b_dev), bp->b_flags, bp->b_blkno,
152 		    bp->b_bcount / DEV_BSIZE, bp->b_data);
153 
154 	sc = bp->b_dev->si_drv1;
155 	if (sc->type == MD_MALLOC) {
156 		mdstrategy_malloc(bp);
157 	} else {
158 		mdstrategy_preload(bp);
159 	}
160 	return;
161 }
162 
163 
164 static void
165 mdstrategy_malloc(struct buf *bp)
166 {
167 	int s, i;
168 	struct md_s *sc;
169 	devstat_trans_flags dop;
170 	u_char *secp, **secpp, *dst;
171 	unsigned secno, nsec, secval, uc;
172 
173 	if (md_debug > 1)
174 		printf("mdstrategy_malloc(%p) %s %lx, %d, %ld, %p)\n",
175 		    bp, devtoname(bp->b_dev), bp->b_flags, bp->b_blkno,
176 		    bp->b_bcount / DEV_BSIZE, bp->b_data);
177 
178 	sc = bp->b_dev->si_drv1;
179 
180 	s = splbio();
181 
182 	bufqdisksort(&sc->buf_queue, bp);
183 
184 	if (sc->busy) {
185 		splx(s);
186 		return;
187 	}
188 
189 	sc->busy++;
190 
191 	while (1) {
192 		bp = bufq_first(&sc->buf_queue);
193 		if (bp)
194 			bufq_remove(&sc->buf_queue, bp);
195 		splx(s);
196 		if (!bp)
197 			break;
198 
199 		devstat_start_transaction(&sc->stats);
200 
201 		if (bp->b_flags & B_FREEBUF)
202 			dop = DEVSTAT_NO_DATA;
203 		else if (bp->b_flags & B_READ)
204 			dop = DEVSTAT_READ;
205 		else
206 			dop = DEVSTAT_WRITE;
207 
208 		nsec = bp->b_bcount / DEV_BSIZE;
209 		secno = bp->b_pblkno;
210 		dst = bp->b_data;
211 		while (nsec--) {
212 
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 				printf("%lx %p %p %d\n", bp->b_flags, secpp, secp, secval);
229 
230 			if (bp->b_flags & B_FREEBUF) {
231 				if (secpp) {
232 					if (secp)
233 						FREE(secp, M_MDSECT);
234 					*secpp = 0;
235 				}
236 			} else if (bp->b_flags & B_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 			} else {
246 				uc = dst[0];
247 				for (i = 1; i < DEV_BSIZE; i++)
248 					if (dst[i] != uc)
249 						break;
250 				if (i == DEV_BSIZE && !uc) {
251 					if (secp)
252 						FREE(secp, M_MDSECT);
253 					if (secpp)
254 						*secpp = (u_char *)uc;
255 				} else {
256 					if (!secpp) {
257 						MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK);
258 						bzero(secpp, (secno + nsec + 1) * sizeof(u_char *));
259 						bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *));
260 						FREE(sc->secp, M_MD);
261 						sc->secp = secpp;
262 						sc->nsecp = secno + nsec + 1;
263 						secpp = &sc->secp[secno];
264 					}
265 					if (i == DEV_BSIZE) {
266 						if (secp)
267 							FREE(secp, M_MDSECT);
268 						*secpp = (u_char *)uc;
269 					} else {
270 						if (!secp)
271 							MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK);
272 						bcopy(dst, secp, DEV_BSIZE);
273 
274 						*secpp = secp;
275 					}
276 				}
277 			}
278 			secno++;
279 			dst += DEV_BSIZE;
280 		}
281 		bp->b_resid = 0;
282 		devstat_end_transaction_buf(&sc->stats, bp);
283 		biodone(bp);
284 		s = splbio();
285 	}
286 	sc->busy = 0;
287 	return;
288 }
289 
290 
291 static void
292 mdstrategy_preload(struct buf *bp)
293 {
294 	int s;
295 	struct md_s *sc;
296 	devstat_trans_flags dop;
297 
298 	if (md_debug > 1)
299 		printf("mdstrategy_preload(%p) %s %lx, %d, %ld, %p)\n",
300 		    bp, devtoname(bp->b_dev), bp->b_flags, bp->b_blkno,
301 		    bp->b_bcount / DEV_BSIZE, bp->b_data);
302 
303 	sc = bp->b_dev->si_drv1;
304 
305 	s = splbio();
306 
307 	bufqdisksort(&sc->buf_queue, bp);
308 
309 	if (sc->busy) {
310 		splx(s);
311 		return;
312 	}
313 
314 	sc->busy++;
315 
316 	while (1) {
317 		bp = bufq_first(&sc->buf_queue);
318 		if (bp)
319 			bufq_remove(&sc->buf_queue, bp);
320 		splx(s);
321 		if (!bp)
322 			break;
323 
324 		devstat_start_transaction(&sc->stats);
325 
326 		if (bp->b_flags & B_FREEBUF) {
327 			dop = DEVSTAT_NO_DATA;
328 		} else if (bp->b_flags & B_READ) {
329 			dop = DEVSTAT_READ;
330 			bcopy(sc->pl_ptr + (bp->b_pblkno << DEV_BSHIFT), bp->b_data, bp->b_bcount);
331 		} else {
332 			dop = DEVSTAT_WRITE;
333 			bcopy(bp->b_data, sc->pl_ptr + (bp->b_pblkno << DEV_BSHIFT), bp->b_bcount);
334 		}
335 		bp->b_resid = 0;
336 		devstat_end_transaction_buf(&sc->stats, bp);
337 		biodone(bp);
338 		s = splbio();
339 	}
340 	sc->busy = 0;
341 	return;
342 }
343 
344 static struct md_s *
345 mdcreate(void)
346 {
347 	struct md_s *sc;
348 
349 	MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK);
350 	bzero(sc, sizeof(*sc));
351 	sc->unit = mdunits++;
352 	bufq_init(&sc->buf_queue);
353 	devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE,
354 		DEVSTAT_NO_ORDERED_TAGS,
355 		DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER,
356 		DEVSTAT_PRIORITY_OTHER);
357 	sc->dev = disk_create(sc->unit, &sc->disk, 0, &md_cdevsw);
358 	sc->dev->si_drv1 = sc;
359 	return (sc);
360 }
361 
362 static void
363 mdcreate_preload(u_char *image, unsigned length)
364 {
365 	struct md_s *sc;
366 
367 	sc = mdcreate();
368 	sc->type = MD_PRELOAD;
369 	sc->nsect = length / DEV_BSIZE;
370 	sc->pl_ptr = image;
371 	sc->pl_len = length;
372 
373 	if (sc->unit == 0)
374 		mdrootready = 1;
375 }
376 
377 static void
378 mdcreate_malloc(void)
379 {
380 	struct md_s *sc;
381 
382 	sc = mdcreate();
383 	sc->type = MD_MALLOC;
384 
385 	sc->nsect = MD_NSECT;	/* for now */
386 	MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK);
387 	bzero(sc->secp, sizeof(u_char *));
388 	sc->nsecp = 1;
389 	printf("md%d: Malloc disk\n", sc->unit);
390 }
391 
392 static void
393 md_drvinit(void *unused)
394 {
395 
396 	caddr_t mod;
397 	caddr_t c;
398 	u_char *ptr, *name, *type;
399 	unsigned len;
400 
401 #ifdef MD_ROOT_SIZE
402 	mdcreate_preload(mfs_root, MD_ROOT_SIZE*1024);
403 #endif
404 	mod = NULL;
405 	while ((mod = preload_search_next_name(mod)) != NULL) {
406 		name = (char *)preload_search_info(mod, MODINFO_NAME);
407 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
408 		if (name == NULL)
409 			continue;
410 		if (type == NULL)
411 			continue;
412 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
413 			continue;
414 		c = preload_search_info(mod, MODINFO_ADDR);
415 		ptr = *(u_char **)c;
416 		c = preload_search_info(mod, MODINFO_SIZE);
417 		len = *(unsigned *)c;
418 		printf("md%d: Preloaded image <%s> %d bytes at %p\n",
419 		   mdunits, name, len, ptr);
420 		mdcreate_preload(ptr, len);
421 	}
422 	mdcreate_malloc();
423 }
424 
425 SYSINIT(mddev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL)
426 
427 #ifdef MD_ROOT
428 static void
429 md_takeroot(void *junk)
430 {
431 	if (mdrootready)
432 		rootdevnames[0] = "ufs:/dev/md0c";
433 }
434 
435 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL);
436 #endif
437