1 #ifdef PLAN9PORT	/* SORRY! */
2 #	include <u.h>
3 #	include <sys/types.h>
4 #	ifdef __linux__	/* REALLY SORRY! */
5 #		define CANBLOCKSIZE 1
6 #		include <sys/vfs.h>
7 #	elif defined(__FreeBSD__)
8 #		define CANBLOCKSIZE 1
9 #		include <sys/param.h>
10 #		include <sys/stat.h>
11 #		include <sys/mount.h>
12 #	endif
13 #endif
14 #include "stdinc.h"
15 #include <ctype.h>
16 #include "dat.h"
17 #include "fns.h"
18 
19 u32int	maxblocksize;
20 int	readonly;
21 
22 static int
23 strtoullsuf(char *p, char **pp, int rad, u64int *u)
24 {
25 	u64int v;
26 
27 	if(!isdigit((uchar)*p))
28 		return -1;
29 	v = strtoull(p, &p, rad);
30 	switch(*p){
31 	case 'k':
32 	case 'K':
33 		v *= 1024;
34 		p++;
35 		break;
36 	case 'm':
37 	case 'M':
38 		v *= 1024*1024;
39 		p++;
40 		break;
41 	case 'g':
42 	case 'G':
43 		v *= 1024*1024*1024;
44 		p++;
45 		break;
46 	case 't':
47 	case 'T':
48 		v *= 1024*1024;
49 		v *= 1024*1024;
50 		p++;
51 		break;
52 	}
53 	*pp = p;
54 	*u = v;
55 	return 0;
56 }
57 	
58 static int
59 parsepart(char *name, char **file, u64int *lo, u64int *hi)
60 {
61 	char *p;
62 
63 	*file = estrdup(name);
64 	if((p = strrchr(*file, ':')) == nil){
65 		*lo = 0;
66 		*hi = 0;
67 		return 0;
68 	}
69 	*p++ = 0;
70 	if(*p == '-')
71 		*lo = 0;
72 	else{
73 		if(strtoullsuf(p, &p, 0, lo) < 0){
74 			free(*file);
75 			return -1;
76 		}
77 	}
78 	if(*p == '-')
79 		p++;
80 	if(*p == 0){
81 		*hi = 0;
82 		return 0;
83 	}
84 	if(strtoullsuf(p, &p, 0, hi) < 0 || *p != 0){
85 		free(*file);
86 		return -1;
87 	}
88 	return 0;
89 }
90 
91 Part*
92 initpart(char *name, int mode)
93 {
94 	Part *part;
95 	Dir *dir;
96 	char *file;
97 	u64int lo, hi;
98 
99 	if(parsepart(name, &file, &lo, &hi) < 0)
100 		return nil;
101 	trace(TraceDisk, "initpart %s file %s lo 0x%llx hi 0x%llx", name, file, lo, hi);
102 	part = MKZ(Part);
103 	part->name = estrdup(name);
104 	part->filename = estrdup(file);
105 	if(readonly){
106 		mode &= (OREAD|OWRITE|ORDWR);
107 		mode |= OREAD;
108 	}
109 	part->fd = open(file, mode);
110 	if(part->fd < 0){
111 		if((mode&(OREAD|OWRITE|ORDWR)) == ORDWR)
112 			part->fd = open(file, (mode&~ORDWR)|OREAD);
113 		if(part->fd < 0){
114 			freepart(part);
115 			fprint(2, "can't open partition='%s': %r\n", file);
116 			seterr(EOk, "can't open partition='%s': %r", file);
117 			fprint(2, "%r\n");
118 			free(file);
119 			return nil;
120 		}
121 		fprint(2, "warning: %s opened for reading only\n", name);
122 	}
123 	part->offset = lo;
124 	dir = dirfstat(part->fd);
125 	if(dir == nil){
126 		freepart(part);
127 		seterr(EOk, "can't stat partition='%s': %r", file);
128 		free(file);
129 		return nil;
130 	}
131 	if(dir->length == 0){
132 		free(dir);
133 		freepart(part);
134 		seterr(EOk, "can't determine size of partition %s", file);
135 		free(file);
136 		return nil;
137 	}
138 	if(dir->length < hi || dir->length < lo){
139 		freepart(part);
140 		seterr(EOk, "partition '%s': bounds out of range (max %lld)", name, dir->length);
141 		free(dir);
142 		free(file);
143 		return nil;
144 	}
145 	if(hi == 0)
146 		hi = dir->length;
147 	part->size = hi - part->offset;
148 #ifdef CANBLOCKSIZE
149 	{
150 		struct statfs sfs;
151 		if(fstatfs(part->fd, &sfs) >= 0)
152 			part->fsblocksize = sfs.f_bsize;
153 	}
154 #endif
155 	free(dir);
156 	return part;
157 }
158 
159 void
160 freepart(Part *part)
161 {
162 	if(part == nil)
163 		return;
164 	if(part->fd >= 0)
165 		close(part->fd);
166 	free(part->name);
167 	free(part);
168 }
169 
170 void
171 partblocksize(Part *part, u32int blocksize)
172 {
173 	if(part->blocksize)
174 		sysfatal("resetting partition=%s's block size", part->name);
175 	part->blocksize = blocksize;
176 	if(blocksize > maxblocksize)
177 		maxblocksize = blocksize;
178 }
179 
180 /*
181  * Read/write some amount of data between a block device or file and a memory buffer.
182  *
183  * Most Unix systems require that when accessing a block device directly,
184  * the buffer, offset, and count are all multiples of the device block size,
185  * making this a lot more complicated than it otherwise would be.
186  * 
187  * Most of our callers will make things easy on us, but for some callers it's best
188  * if we just do the work here, with only one place to get it right (hopefully).
189  * 
190  * If everything is aligned properly, prwb will try to do big transfers in the main 
191  * body of the loop: up to MaxIo bytes at a time.  If everything isn't aligned properly,
192  * we work one block at a time.
193  */
194 #undef min
195 #define min(a, b) ((a) < (b) ? (a) : (b))
196 int
197 prwb(char *name, int fd, int isread, u64int offset, void *vbuf, u32int count, u32int blocksize)
198 {
199 	char *op;
200 	u8int *buf, *tmp, *freetmp, *dst;
201 	u32int c, delta, icount, opsize;
202 	int r;
203 
204 	buf = vbuf;
205 	tmp = nil;
206 	freetmp = nil;
207 	icount = count;
208 	opsize = blocksize;
209 
210 	if(count == 0){
211 		logerr(EStrange, "pwrb %s called to %s 0 bytes", name, isread ? "read" : "write");
212 		return 0;
213 	}
214 
215 	assert(blocksize > 0);
216 
217 	/* allocate blocksize-aligned temp buffer if needed */
218 	if((ulong)offset%blocksize || (ulong)buf%blocksize || count%blocksize){
219 		if((freetmp = malloc(blocksize*2)) == nil)
220 			return -1;
221 		tmp = freetmp;
222 		tmp += blocksize - (ulong)tmp%blocksize;
223 	}
224 
225 	/* handle beginning fringe */
226 	if((delta = (ulong)offset%blocksize) != 0){
227 		assert(tmp != nil);
228 		if((r=pread(fd, tmp, blocksize, offset-delta)) != blocksize){
229 			dst = tmp;
230 			offset = offset-delta;
231 			op = "read";
232 			goto Error;
233 		}
234 		c = min(count, blocksize-delta);
235 		assert(c > 0 && c < blocksize);
236 		if(isread)
237 			memmove(buf, tmp+delta, c);
238 		else{
239 			memmove(tmp+delta, buf, c);
240 			if((r=pwrite(fd, tmp, blocksize, offset-delta)) != blocksize){
241 				dst = tmp;
242 				offset = offset-delta;
243 				op = "read";
244 				goto Error;
245 			}
246 		}
247 		assert(c > 0);
248 		offset += c;
249 		buf += c;
250 		count -= c;
251 	}
252 
253 	/* handle full blocks */
254 	while(count >= blocksize){
255 		assert((ulong)offset%blocksize == 0);
256 		if((ulong)buf%blocksize){
257 			assert(tmp != nil);
258 			dst = tmp;
259 			opsize = blocksize;
260 		}else{
261 			dst = buf;
262 			opsize = count - count%blocksize;
263 			if(opsize > MaxIo)
264 				opsize = MaxIo;
265 		}
266 		if(isread){
267 			if((r=pread(fd, dst, opsize, offset))<=0 || r%blocksize){
268 				op = "read";
269 				goto Error;
270 			}
271 			if(dst == tmp){
272 				assert(r == blocksize);
273 				memmove(buf, tmp, blocksize);
274 			}
275 		}else{
276 			if(dst == tmp){
277 				assert(opsize == blocksize);
278 				memmove(dst, buf, blocksize);
279 			}
280 			if((r=pwrite(fd, dst, opsize, offset))<=0 || r%blocksize){
281 				op = "write";
282 				goto Error;
283 			}
284 			if(dst == tmp)
285 				assert(r == blocksize);
286 		}
287 		assert(r > 0);
288 		offset += r;
289 		buf += r;
290 		count -= r;
291 	}
292 
293 	/* handle ending fringe */
294 	if(count > 0){
295 		assert((ulong)offset%blocksize == 0);
296 		assert(tmp != nil);
297 		/*
298 		 * Complicated condition: if we're reading it's okay to get less than
299 		 * a block as long as it's enough to satisfy the read - maybe this is
300 		 * a normal file.  (We never write to normal files, or else things would
301 		 * be even more complicated.)
302 		 */
303 		r = pread(fd, tmp, blocksize, offset);
304 		if((isread && r < count) || (!isread && r != blocksize)){
305 print("FAILED isread=%d r=%d count=%d blocksize=%d\n", isread, r, count, blocksize);
306 			dst = tmp;
307 			op = "read";
308 			goto Error;
309 		}
310 		if(isread)
311 			memmove(buf, tmp, count);
312 		else{
313 			memmove(tmp, buf, count);
314 			if(pwrite(fd, tmp, opsize, offset) != blocksize){
315 				dst = tmp;
316 				op = "write";
317 				goto Error;
318 			}
319 		}
320 	}
321 	if(freetmp)
322 		free(freetmp);
323 	return icount;
324 
325 Error:
326 	seterr(EAdmin, "%s %s offset 0x%llux count %ud buf %p returned %d: %r",
327 		op, name, offset, opsize, dst, r);
328 	if(freetmp)
329 		free(freetmp);
330 	return -1;
331 }
332 
333 int
334 rwpart(Part *part, int isread, u64int offset, u8int *buf, u32int count)
335 {
336 	u32int blocksize;
337 
338 	trace(TraceDisk, "%s %s %ud at 0x%llx", 
339 		isread ? "read" : "write", part->name, count, offset);
340 	if(offset >= part->size || offset+count > part->size){
341 		seterr(EStrange, "out of bounds %s offset 0x%llux count %ud to partition %s size 0x%llux",
342 			isread ? "read" : "write", offset, count, part->name, part->size);
343 		return -1;
344 	}
345 
346 	blocksize = part->fsblocksize;
347 	if(blocksize == 0)
348 		blocksize = part->blocksize;
349 	if(blocksize == 0)
350 		blocksize = 4096;
351 
352 	return prwb(part->filename, part->fd, isread, part->offset+offset, buf, count, blocksize);
353 }
354 
355 int
356 readpart(Part *part, u64int offset, u8int *buf, u32int count)
357 {
358 	return rwpart(part, 1, offset, buf, count);
359 }
360 
361 int
362 writepart(Part *part, u64int offset, u8int *buf, u32int count)
363 {
364 	return rwpart(part, 0, offset, buf, count);
365 }
366 
367 ZBlock*
368 readfile(char *name)
369 {
370 	Part *p;
371 	ZBlock *b;
372 
373 	p = initpart(name, OREAD);
374 	if(p == nil)
375 		return nil;
376 	b = alloczblock(p->size, 0, p->blocksize);
377 	if(b == nil){
378 		seterr(EOk, "can't alloc %s: %r", name);
379 		freepart(p);
380 		return nil;
381 	}
382 	if(readpart(p, 0, b->data, p->size) < 0){
383 		seterr(EOk, "can't read %s: %r", name);
384 		freepart(p);
385 		freezblock(b);
386 		return nil;
387 	}
388 	freepart(p);
389 	return b;
390 }
391