xref: /freebsd/lib/libufs/sblock.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2002 Juli Mallett.  All rights reserved.
5  *
6  * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
7  * FreeBSD project.  Redistribution and use in source and binary forms, with
8  * or without modification, are permitted provided that the following
9  * conditions are met:
10  *
11  * 1. Redistribution of source code must retain the above copyright notice,
12  *    this list of conditions and the following disclaimer.
13  * 2. Redistribution in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/mount.h>
33 #include <sys/disklabel.h>
34 #include <sys/stat.h>
35 
36 #include <ufs/ufs/extattr.h>
37 #include <ufs/ufs/quota.h>
38 #include <ufs/ufs/ufsmount.h>
39 #include <ufs/ufs/dinode.h>
40 #include <ufs/ffs/fs.h>
41 
42 #include <errno.h>
43 #include <stdio.h>
44 #include <string.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 
48 #include <libufs.h>
49 
50 static int handle_disk_read(struct uufsd *, struct fs *, int);
51 
52 /*
53  * Read the standard superblock.
54  *
55  * The following option flags can be or'ed into disk->d_lookupflags:
56  *
57  * UFS_NOMSG indicates that superblock inconsistency error messages
58  *    should not be printed.
59  *
60  * UFS_NOCSUM causes only the superblock itself to be returned, but does
61  *    not read in any auxillary data structures like the cylinder group
62  *    summary information.
63  */
64 int
65 sbread(struct uufsd *disk)
66 {
67 	struct fs *fs;
68 	int error;
69 
70 	error = sbget(disk->d_fd, &fs, disk->d_sblockloc, disk->d_lookupflags);
71 	return (handle_disk_read(disk, fs, error));
72 }
73 
74 /*
75  * Make an extensive search to find a superblock. If the superblock
76  * in the standard place cannot be used, try looking for one of the
77  * backup superblocks.
78  *
79  * The flags parameter is made up of the following or'ed together options:
80  *
81  * UFS_NOMSG indicates that superblock inconsistency error messages
82  *    should not be printed.
83  *
84  * UFS_NOCSUM causes only the superblock itself to be returned, but does
85  *    not read in any auxillary data structures like the cylinder group
86  *    summary information.
87  */
88 int
89 sbfind(struct uufsd *disk, int flags)
90 {
91 	struct fs *fs;
92 	int error;
93 
94 	error = sbsearch(disk->d_fd, &fs, flags);
95 	return (handle_disk_read(disk, fs, error));
96 }
97 
98 static int
99 handle_disk_read(struct uufsd *disk, struct fs *fs, int error)
100 {
101 
102 	ERROR(disk, NULL);
103 	if (error != 0) {
104 		switch (error) {
105 		case EIO:
106 			ERROR(disk, "non-existent or truncated superblock");
107 			break;
108 		case ENOENT:
109 			ERROR(disk, "no usable known superblock found");
110 			break;
111 		case EINTEGRITY:
112 			ERROR(disk, "superblock check-hash failure");
113 			break;
114 		case ENOSPC:
115 			ERROR(disk, "failed to allocate space for superblock "
116 			    "information");
117 			break;
118 		case EINVAL:
119 			ERROR(disk, "The previous newfs operation on this "
120 			    "volume did not complete.\nYou must complete "
121 			    "newfs before using this volume.");
122 			break;
123 		default:
124 			ERROR(disk, "unknown superblock read error");
125 			errno = EIO;
126 			break;
127 		}
128 		disk->d_ufs = 0;
129 		return (-1);
130 	}
131 	memcpy(&disk->d_fs, fs, fs->fs_sbsize);
132 	free(fs);
133 	fs = &disk->d_fs;
134 	if (fs->fs_magic == FS_UFS1_MAGIC)
135 		disk->d_ufs = 1;
136 	if (fs->fs_magic == FS_UFS2_MAGIC)
137 		disk->d_ufs = 2;
138 	disk->d_bsize = fs->fs_fsize / fsbtodb(fs, 1);
139 	disk->d_sblock = fs->fs_sblockloc / disk->d_bsize;
140 	disk->d_si = fs->fs_si;
141 	return (0);
142 }
143 
144 int
145 sbwrite(struct uufsd *disk, int all)
146 {
147 	struct fs *fs;
148 	int rv;
149 
150 	ERROR(disk, NULL);
151 
152 	rv = ufs_disk_write(disk);
153 	if (rv == -1) {
154 		ERROR(disk, "failed to open disk for writing");
155 		return (-1);
156 	}
157 
158 	fs = &disk->d_fs;
159 	if ((errno = sbput(disk->d_fd, fs, all ? fs->fs_ncg : 0)) != 0) {
160 		switch (errno) {
161 		case EIO:
162 			ERROR(disk, "failed to write superblock");
163 			break;
164 		default:
165 			ERROR(disk, "unknown superblock write error");
166 			errno = EIO;
167 			break;
168 		}
169 		return (-1);
170 	}
171 	return (0);
172 }
173 
174 /*
175  * These are the low-level functions that actually read and write
176  * the superblock and its associated data. The actual work is done by
177  * the functions ffs_sbget and ffs_sbput in /sys/ufs/ffs/ffs_subr.c.
178  */
179 static int use_pread(void *devfd, off_t loc, void **bufp, int size);
180 static int use_pwrite(void *devfd, off_t loc, void *buf, int size);
181 
182 /*
183  * The following two functions read a superblock. Their flags
184  * parameter are made up of the following or'ed together options:
185  *
186  * UFS_NOMSG indicates that superblock inconsistency error messages
187  *    should not be printed.
188  *
189  * UFS_NOCSUM causes only the superblock itself to be returned, but does
190  *    not read in any auxillary data structures like the cylinder group
191  *    summary information.
192  *
193  * Read a superblock from the devfd device allocating memory returned
194  * in fsp.
195  */
196 int
197 sbget(int devfd, struct fs **fsp, off_t sblockloc, int flags)
198 {
199 	int error;
200 
201 	error = ffs_sbget(&devfd, fsp, sblockloc, flags, "user", use_pread);
202 	fflush(NULL); /* flush any messages */
203 	return (error);
204 }
205 
206 /*
207  * Make an extensive search of the devfd device to find a superblock.
208  * If the superblock in the standard place cannot be used, try looking
209  * for one of the backup superblocks. If found, memory is allocated and
210  * returned in fsp.
211  */
212 int
213 sbsearch(int devfd, struct fs **fsp, int flags)
214 {
215 	int error;
216 
217 	error = ffs_sbsearch(&devfd, fsp, flags, "user", use_pread);
218 	fflush(NULL); /* flush any messages */
219 	return (error);
220 }
221 
222 /*
223  * A read function for use by user-level programs using libufs.
224  */
225 static int
226 use_pread(void *devfd, off_t loc, void **bufp, int size)
227 {
228 	int fd;
229 
230 	fd = *(int *)devfd;
231 	if ((*bufp = malloc(size)) == NULL)
232 		return (ENOSPC);
233 	if (pread(fd, *bufp, size, loc) != size)
234 		return (EIO);
235 	return (0);
236 }
237 
238 /*
239  * Write a superblock to the devfd device from the memory pointed to by fs.
240  * Also write out the superblock summary information but do not free the
241  * summary information memory.
242  *
243  * Additionally write out numaltwrite of the alternate superblocks. Use
244  * fs->fs_ncg to write out all of the alternate superblocks.
245  */
246 int
247 sbput(int devfd, struct fs *fs, int numaltwrite)
248 {
249 	struct csum *savedcsp;
250 	off_t savedactualloc;
251 	int i, error;
252 
253 	error = ffs_sbput(&devfd, fs, fs->fs_sblockactualloc, use_pwrite);
254 	fflush(NULL); /* flush any messages */
255 	if (error != 0 || numaltwrite == 0)
256 		return (error);
257 	savedactualloc = fs->fs_sblockactualloc;
258 	if (fs->fs_si != NULL) {
259 		savedcsp = fs->fs_csp;
260 		fs->fs_csp = NULL;
261 	}
262 	for (i = 0; i < numaltwrite; i++) {
263 		fs->fs_sblockactualloc = dbtob(fsbtodb(fs, cgsblock(fs, i)));
264 		if ((error = ffs_sbput(&devfd, fs, fs->fs_sblockactualloc,
265 		     use_pwrite)) != 0) {
266 			fflush(NULL); /* flush any messages */
267 			fs->fs_sblockactualloc = savedactualloc;
268 			fs->fs_csp = savedcsp;
269 			return (error);
270 		}
271 	}
272 	fs->fs_sblockactualloc = savedactualloc;
273 	if (fs->fs_si != NULL)
274 		fs->fs_csp = savedcsp;
275 	fflush(NULL); /* flush any messages */
276 	return (0);
277 }
278 
279 /*
280  * A write function for use by user-level programs using sbput in libufs.
281  */
282 static int
283 use_pwrite(void *devfd, off_t loc, void *buf, int size)
284 {
285 	int fd;
286 
287 	fd = *(int *)devfd;
288 	if (pwrite(fd, buf, size, loc) != size)
289 		return (EIO);
290 	return (0);
291 }
292