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1.1 root 1: /*
2: * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
3: * All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. All advertising materials mentioning features or use of this software
14: * must display the following acknowledgement:
15: * This product includes software developed by the University of
16: * California, Berkeley and its contributors.
17: * 4. Neither the name of the University nor the names of its contributors
18: * may be used to endorse or promote products derived from this software
19: * without specific prior written permission.
20: *
21: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31: * SUCH DAMAGE.
32: *
33: * @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91
34: */
35:
36: #include "param.h"
37: #include "systm.h"
38: #include "buf.h"
39: #include "disklabel.h"
40: #include "syslog.h"
41:
42: /*
43: * Seek sort for disks. We depend on the driver
44: * which calls us using b_resid as the current cylinder number.
45: *
46: * The argument dp structure holds a b_actf activity chain pointer
47: * on which we keep two queues, sorted in ascending cylinder order.
48: * The first queue holds those requests which are positioned after
49: * the current cylinder (in the first request); the second holds
50: * requests which came in after their cylinder number was passed.
51: * Thus we implement a one way scan, retracting after reaching the
52: * end of the drive to the first request on the second queue,
53: * at which time it becomes the first queue.
54: *
55: * A one-way scan is natural because of the way UNIX read-ahead
56: * blocks are allocated.
57: */
58:
59: #define b_cylin b_resid
60:
61: disksort(dp, bp)
62: register struct buf *dp, *bp;
63: {
64: register struct buf *ap;
65:
66: /*
67: * If nothing on the activity queue, then
68: * we become the only thing.
69: */
70: ap = dp->b_actf;
71: if(ap == NULL) {
72: dp->b_actf = bp;
73: dp->b_actl = bp;
74: bp->av_forw = NULL;
75: return;
76: }
77: /*
78: * If we lie after the first (currently active)
79: * request, then we must locate the second request list
80: * and add ourselves to it.
81: */
82: if (bp->b_cylin < ap->b_cylin) {
83: while (ap->av_forw) {
84: /*
85: * Check for an ``inversion'' in the
86: * normally ascending cylinder numbers,
87: * indicating the start of the second request list.
88: */
89: if (ap->av_forw->b_cylin < ap->b_cylin) {
90: /*
91: * Search the second request list
92: * for the first request at a larger
93: * cylinder number. We go before that;
94: * if there is no such request, we go at end.
95: */
96: do {
97: if (bp->b_cylin < ap->av_forw->b_cylin)
98: goto insert;
99: if (bp->b_cylin == ap->av_forw->b_cylin &&
100: bp->b_blkno < ap->av_forw->b_blkno)
101: goto insert;
102: ap = ap->av_forw;
103: } while (ap->av_forw);
104: goto insert; /* after last */
105: }
106: ap = ap->av_forw;
107: }
108: /*
109: * No inversions... we will go after the last, and
110: * be the first request in the second request list.
111: */
112: goto insert;
113: }
114: /*
115: * Request is at/after the current request...
116: * sort in the first request list.
117: */
118: while (ap->av_forw) {
119: /*
120: * We want to go after the current request
121: * if there is an inversion after it (i.e. it is
122: * the end of the first request list), or if
123: * the next request is a larger cylinder than our request.
124: */
125: if (ap->av_forw->b_cylin < ap->b_cylin ||
126: bp->b_cylin < ap->av_forw->b_cylin ||
127: (bp->b_cylin == ap->av_forw->b_cylin &&
128: bp->b_blkno < ap->av_forw->b_blkno))
129: goto insert;
130: ap = ap->av_forw;
131: }
132: /*
133: * Neither a second list nor a larger
134: * request... we go at the end of the first list,
135: * which is the same as the end of the whole schebang.
136: */
137: insert:
138: bp->av_forw = ap->av_forw;
139: ap->av_forw = bp;
140: if (ap == dp->b_actl)
141: dp->b_actl = bp;
142: }
143:
144: /*
145: * Attempt to read a disk label from a device
146: * using the indicated stategy routine.
147: * The label must be partly set up before this:
148: * secpercyl and anything required in the strategy routine
149: * (e.g., sector size) must be filled in before calling us.
150: * Returns null on success and an error string on failure.
151: */
152: char *
153: readdisklabel(dev, strat, lp)
154: dev_t dev;
155: int (*strat)();
156: register struct disklabel *lp;
157: {
158: register struct buf *bp;
159: struct disklabel *dlp;
160: char *msg = NULL;
161:
162: if (lp->d_secperunit == 0)
163: lp->d_secperunit = 0x1fffffff;
164: lp->d_npartitions = 1;
165: if (lp->d_partitions[0].p_size == 0)
166: lp->d_partitions[0].p_size = 0x1fffffff;
167: lp->d_partitions[0].p_offset = 0;
168:
169: bp = geteblk((int)lp->d_secsize);
170: bp->b_dev = dev;
171: bp->b_blkno = LABELSECTOR;
172: bp->b_bcount = lp->d_secsize;
173: bp->b_flags = B_BUSY | B_READ;
174: bp->b_cylin = LABELSECTOR / lp->d_secpercyl;
175: (*strat)(bp);
176: if (biowait(bp)) {
177: msg = "I/O error";
178: } else for (dlp = (struct disklabel *)bp->b_un.b_addr;
179: dlp <= (struct disklabel *)(bp->b_un.b_addr+DEV_BSIZE-sizeof(*dlp));
180: dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
181: if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
182: if (msg == NULL)
183: msg = "no disk label";
184: } else if (dlp->d_npartitions > MAXPARTITIONS ||
185: dkcksum(dlp) != 0)
186: msg = "disk label corrupted";
187: else {
188: *lp = *dlp;
189: msg = NULL;
190: break;
191: }
192: }
193: bp->b_flags = B_INVAL | B_AGE;
194: brelse(bp);
195: return (msg);
196: }
197:
198: /*
199: * Check new disk label for sensibility
200: * before setting it.
201: */
202: setdisklabel(olp, nlp, openmask)
203: register struct disklabel *olp, *nlp;
204: u_long openmask;
205: {
206: register i;
207: register struct partition *opp, *npp;
208:
209: if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
210: dkcksum(nlp) != 0)
211: return (EINVAL);
212: while ((i = ffs((long)openmask)) != 0) {
213: i--;
214: openmask &= ~(1 << i);
215: if (nlp->d_npartitions <= i)
216: return (EBUSY);
217: opp = &olp->d_partitions[i];
218: npp = &nlp->d_partitions[i];
219: if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size)
220: return (EBUSY);
221: /*
222: * Copy internally-set partition information
223: * if new label doesn't include it. XXX
224: */
225: if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
226: npp->p_fstype = opp->p_fstype;
227: npp->p_fsize = opp->p_fsize;
228: npp->p_frag = opp->p_frag;
229: npp->p_cpg = opp->p_cpg;
230: }
231: }
232: nlp->d_checksum = 0;
233: nlp->d_checksum = dkcksum(nlp);
234: *olp = *nlp;
235: return (0);
236: }
237:
238: /* encoding of disk minor numbers, should be elsewhere... */
239: #define dkunit(dev) (minor(dev) >> 3)
240: #define dkpart(dev) (minor(dev) & 07)
241: #define dkminor(unit, part) (((unit) << 3) | (part))
242:
243: /*
244: * Write disk label back to device after modification.
245: */
246: writedisklabel(dev, strat, lp)
247: dev_t dev;
248: int (*strat)();
249: register struct disklabel *lp;
250: {
251: struct buf *bp;
252: struct disklabel *dlp;
253: int labelpart;
254: int error = 0;
255:
256: labelpart = dkpart(dev);
257: if (lp->d_partitions[labelpart].p_offset != 0) {
258: if (lp->d_partitions[0].p_offset != 0)
259: return (EXDEV); /* not quite right */
260: labelpart = 0;
261: }
262: bp = geteblk((int)lp->d_secsize);
263: bp->b_dev = makedev(major(dev), dkminor(dkunit(dev), labelpart));
264: bp->b_blkno = LABELSECTOR;
265: bp->b_bcount = lp->d_secsize;
266: bp->b_flags = B_READ;
267: (*strat)(bp);
268: if (error = biowait(bp))
269: goto done;
270: for (dlp = (struct disklabel *)bp->b_un.b_addr;
271: dlp <= (struct disklabel *)
272: (bp->b_un.b_addr + lp->d_secsize - sizeof(*dlp));
273: dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
274: if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
275: dkcksum(dlp) == 0) {
276: *dlp = *lp;
277: bp->b_flags = B_WRITE;
278: (*strat)(bp);
279: error = biowait(bp);
280: goto done;
281: }
282: }
283: error = ESRCH;
284: done:
285: brelse(bp);
286: return (error);
287: }
288:
289: /*
290: * Compute checksum for disk label.
291: */
292: dkcksum(lp)
293: register struct disklabel *lp;
294: {
295: register u_short *start, *end;
296: register u_short sum = 0;
297:
298: start = (u_short *)lp;
299: end = (u_short *)&lp->d_partitions[lp->d_npartitions];
300: while (start < end)
301: sum ^= *start++;
302: return (sum);
303: }
304:
305: /*
306: * Disk error is the preface to plaintive error messages
307: * about failing disk transfers. It prints messages of the form
308:
309: hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)
310:
311: * if the offset of the error in the transfer and a disk label
312: * are both available. blkdone should be -1 if the position of the error
313: * is unknown; the disklabel pointer may be null from drivers that have not
314: * been converted to use them. The message is printed with printf
315: * if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
316: * The message should be completed (with at least a newline) with printf
317: * or addlog, respectively. There is no trailing space.
318: */
319: diskerr(bp, dname, what, pri, blkdone, lp)
320: register struct buf *bp;
321: char *dname, *what;
322: int pri, blkdone;
323: register struct disklabel *lp;
324: {
325: int unit = dkunit(bp->b_dev), part = dkpart(bp->b_dev);
326: register void (*pr) __P((const char *, ...));
327: char partname = 'a' + part;
328: int sn;
329:
330: if (pri != LOG_PRINTF) {
331: log(pri, "");
332: pr = addlog;
333: } else
334: pr = printf;
335: (*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
336: bp->b_flags & B_READ ? "read" : "writ");
337: sn = bp->b_blkno;
338: if (bp->b_bcount <= DEV_BSIZE)
339: (*pr)("%d", sn);
340: else {
341: if (blkdone >= 0) {
342: sn += blkdone;
343: (*pr)("%d of ", sn);
344: }
345: (*pr)("%d-%d", bp->b_blkno,
346: bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
347: }
348: if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
349: #ifdef tahoe
350: sn *= DEV_BSIZE / lp->d_secsize; /* XXX */
351: #endif
352: sn += lp->d_partitions[part].p_offset;
353: (*pr)(" (%s%d bn %d; cn %d", dname, unit, sn,
354: sn / lp->d_secpercyl);
355: sn %= lp->d_secpercyl;
356: (*pr)(" tn %d sn %d)", sn / lp->d_nsectors, sn % lp->d_nsectors);
357: }
358: }
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