xref: /freebsd/sys/fs/ext2fs/ext2_inode_cnv.c (revision 2774f206809b8fd3a4904fe945f029a414fbc642)
1 /*-
2  * SPDX-License-Identifier: MIT-CMU
3  *
4  * Copyright (c) 1995 The University of Utah and
5  * the Computer Systems Laboratory at the University of Utah (CSL).
6  * All rights reserved.
7  *
8  * Permission to use, copy, modify and distribute this software is hereby
9  * granted provided that (1) source code retains these copyright, permission,
10  * and disclaimer notices, and (2) redistributions including binaries
11  * reproduce the notices in supporting documentation, and (3) all advertising
12  * materials mentioning features or use of this software display the following
13  * acknowledgement: ``This product includes software developed by the
14  * Computer Systems Laboratory at the University of Utah.''
15  *
16  * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
17  * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
18  * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19  *
20  * CSL requests users of this software to return to csl-dist@cs.utah.edu any
21  * improvements that they make and grant CSL redistribution rights.
22  *
23  *      Utah $Hdr$
24  * $FreeBSD$
25  */
26 
27 /*
28  * routines to convert on disk ext2 inodes into inodes and back
29  */
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/endian.h>
33 #include <sys/lock.h>
34 #include <sys/sdt.h>
35 #include <sys/stat.h>
36 #include <sys/vnode.h>
37 
38 #include <fs/ext2fs/fs.h>
39 #include <fs/ext2fs/inode.h>
40 #include <fs/ext2fs/ext2fs.h>
41 #include <fs/ext2fs/ext2_dinode.h>
42 #include <fs/ext2fs/ext2_extern.h>
43 
44 SDT_PROVIDER_DECLARE(ext2fs);
45 /*
46  * ext2fs trace probe:
47  * arg0: verbosity. Higher numbers give more verbose messages
48  * arg1: Textual message
49  */
50 SDT_PROBE_DEFINE2(ext2fs, , trace, inode_cnv, "int", "char*");
51 
52 #ifdef EXT2FS_PRINT_EXTENTS
53 void
54 ext2_print_inode(struct inode *in)
55 {
56 	int i;
57 	struct ext4_extent_header *ehp;
58 	struct ext4_extent *ep;
59 
60 	printf("Inode: %5ju", (uintmax_t)in->i_number);
61 	printf(	/* "Inode: %5d" */
62 	    " Type: %10s Mode: 0x%o Flags: 0x%x  Version: %d acl: 0x%jx\n",
63 	    "n/a", in->i_mode, in->i_flags, in->i_gen, in->i_facl);
64 	printf("User: %5u Group: %5u  Size: %ju\n",
65 	    in->i_uid, in->i_gid, (uintmax_t)in->i_size);
66 	printf("Links: %3d Blockcount: %ju\n",
67 	    in->i_nlink, (uintmax_t)in->i_blocks);
68 	printf("ctime: 0x%llx ", (unsigned long long)in->i_ctime);
69 	printf("atime: 0x%llx ", (unsigned long long)in->i_atime);
70 	printf("mtime: 0x%llx ", (unsigned long long)in->i_mtime);
71 	if (E2DI_HAS_XTIME(in))
72 		printf("crtime %llx\n", (unsigned long long)in->i_birthtime);
73 	else
74 		printf("\n");
75 	if (in->i_flag & IN_E4EXTENTS) {
76 		printf("Extents:\n");
77 		ehp = (struct ext4_extent_header *)in->i_db;
78 		printf("Header (magic 0x%x entries %d max %d depth %d gen %d)\n",
79 		    le16toh(ehp->eh_magic), le16toh(ehp->eh_ecount),
80 		    le16toh(ehp->eh_max), le16toh(ehp->eh_depth),
81 		    le32toh(ehp->eh_gen));
82 		ep = (struct ext4_extent *)(char *)(ehp + 1);
83 		printf("Index (blk %d len %d start_lo %d start_hi %d)\n",
84 		    le32toh(ep->e_blk),
85 		    le16toh(ep->e_len), le32toh(ep->e_start_lo),
86 		    le16toh(ep->e_start_hi));
87 		printf("\n");
88 	} else {
89 		printf("Blocks:");
90 		for (i = 0; i < (in->i_blocks <= 24 ? (in->i_blocks + 1) / 2 : 12); i++)
91 			printf("  %d", in->i_db[i]);
92 		printf("\n");
93 	}
94 }
95 #endif	/* EXT2FS_PRINT_EXTENTS */
96 
97 static inline bool
98 ext2_old_valid_dev(dev_t dev)
99 {
100 	return (major(dev) < 256 && minor(dev) < 256);
101 }
102 
103 static inline uint16_t
104 ext2_old_encode_dev(dev_t dev)
105 {
106 	return ((major(dev) << 8) | minor(dev));
107 }
108 
109 static inline dev_t
110 ext2_old_decode_dev(uint16_t val)
111 {
112 	return (makedev((val >> 8) & 255, val & 255));
113 }
114 
115 static inline uint32_t
116 ext2_new_encode_dev(dev_t dev)
117 {
118 	unsigned maj = major(dev);
119 	unsigned min = minor(dev);
120 
121 	return ((min & 0xff) | (maj << 8) | ((min & ~0xff) << 12));
122 }
123 
124 static inline dev_t
125 ext2_new_decode_dev(uint32_t dev)
126 {
127 	unsigned maj = (dev & 0xfff00) >> 8;
128 	unsigned min = (dev & 0xff) | ((dev >> 12) & 0xfff00);
129 
130 	return (makedev(maj, min));
131 }
132 
133 static inline void
134 ext2_decode_extra_time(ext_time_t *sec, int32_t *nsec, uint32_t extra)
135 {
136 	if (extra & htole32(EXT3_EPOCH_MASK))
137 		*sec += (uint64_t)(le32toh(extra) & EXT3_EPOCH_MASK) << 32;
138 
139 	*nsec = (le32toh(extra) & EXT3_NSEC_MASK) >> EXT3_EPOCH_BITS;
140 }
141 
142 /*
143  *	raw ext2 inode LE to host inode conversion
144  */
145 int
146 ext2_ei2i(struct ext2fs_dinode *ei, struct inode *ip)
147 {
148 	struct m_ext2fs *fs = ip->i_e2fs;
149 	uint32_t ei_flags_host;
150 	uint16_t ei_extra_isize_le;
151 	int i;
152 
153 	if ((ip->i_number < EXT2_FIRST_INO(fs) && ip->i_number != EXT2_ROOTINO) ||
154 	    (ip->i_number < EXT2_ROOTINO) ||
155 	    (ip->i_number > le32toh(fs->e2fs->e2fs_icount))) {
156 		SDT_PROBE2(ext2fs, , trace, inode_cnv, 1, "bad inode number");
157 		return (EINVAL);
158 	}
159 
160 	/*
161 	 * Godmar thinks - if the link count is zero, then the inode is
162 	 * unused - according to ext2 standards. Ufs marks this fact by
163 	 * setting i_mode to zero - why ? I can see that this might lead to
164 	 * problems in an undelete.
165 	 */
166 	ip->i_nlink = le16toh(ei->e2di_nlink);
167 	ip->i_mode = ip->i_nlink ? le16toh(ei->e2di_mode) : 0;
168 	if (ip->i_number == EXT2_ROOTINO &&
169 	    (ip->i_nlink < 2 || !S_ISDIR(ip->i_mode))) {
170 		SDT_PROBE2(ext2fs, , trace, inode_cnv, 1, "root inode invalid");
171 		return (EINVAL);
172 	}
173 
174 	/* Check extra inode size */
175 	ei_extra_isize_le = le16toh(ei->e2di_extra_isize);
176 	if (EXT2_INODE_SIZE(fs) > E2FS_REV0_INODE_SIZE) {
177 		if (E2FS_REV0_INODE_SIZE + ei_extra_isize_le >
178 		    EXT2_INODE_SIZE(fs) || (ei_extra_isize_le & 3)) {
179 			SDT_PROBE2(ext2fs, , trace, inode_cnv, 1,
180 			    "bad extra inode size");
181 			return (EINVAL);
182 		}
183 	}
184 
185 	ip->i_size = le32toh(ei->e2di_size);
186 	if (S_ISREG(ip->i_mode))
187 		ip->i_size |= (uint64_t)le32toh(ei->e2di_size_high) << 32;
188 	ip->i_atime = (signed)le32toh(ei->e2di_atime);
189 	ip->i_mtime = (signed)le32toh(ei->e2di_mtime);
190 	ip->i_ctime = (signed)le32toh(ei->e2di_ctime);
191 	if (E2DI_HAS_XTIME(ip)) {
192 		ext2_decode_extra_time(&ip->i_atime, &ip->i_atimensec,
193 		    ei->e2di_atime_extra);
194 		ext2_decode_extra_time(&ip->i_mtime, &ip->i_mtimensec,
195 		    ei->e2di_mtime_extra);
196 		ext2_decode_extra_time(&ip->i_ctime, &ip->i_ctimensec,
197 		    ei->e2di_ctime_extra);
198 		ip->i_birthtime = (signed)le32toh(ei->e2di_crtime);
199 		ext2_decode_extra_time(&ip->i_birthtime, &ip->i_birthnsec,
200 		    ei->e2di_crtime_extra);
201 	}
202 	ip->i_flags = 0;
203 	ei_flags_host = le32toh(ei->e2di_flags);
204 	ip->i_flags |= (ei_flags_host & EXT2_APPEND) ? SF_APPEND : 0;
205 	ip->i_flags |= (ei_flags_host & EXT2_IMMUTABLE) ? SF_IMMUTABLE : 0;
206 	ip->i_flags |= (ei_flags_host & EXT2_NODUMP) ? UF_NODUMP : 0;
207 	ip->i_flag |= (ei_flags_host & EXT3_INDEX) ? IN_E3INDEX : 0;
208 	ip->i_flag |= (ei_flags_host & EXT4_EXTENTS) ? IN_E4EXTENTS : 0;
209 	ip->i_blocks = le32toh(ei->e2di_nblock);
210 	ip->i_facl = le32toh(ei->e2di_facl);
211 	if (E2DI_HAS_HUGE_FILE(ip)) {
212 		ip->i_blocks |= (uint64_t)le16toh(ei->e2di_nblock_high) << 32;
213 		ip->i_facl |= (uint64_t)le16toh(ei->e2di_facl_high) << 32;
214 		if (ei_flags_host & EXT4_HUGE_FILE)
215 			ip->i_blocks = fsbtodb(ip->i_e2fs, ip->i_blocks);
216 	}
217 	ip->i_gen = le32toh(ei->e2di_gen);
218 	ip->i_uid = le16toh(ei->e2di_uid);
219 	ip->i_gid = le16toh(ei->e2di_gid);
220 	ip->i_uid |= (uint32_t)le16toh(ei->e2di_uid_high) << 16;
221 	ip->i_gid |= (uint32_t)le16toh(ei->e2di_gid_high) << 16;
222 
223 	if (S_ISCHR(ip->i_mode) || S_ISBLK(ip->i_mode)) {
224 		if (ei->e2di_blocks[0])
225 			ip->i_rdev = ext2_old_decode_dev(le32toh(ei->e2di_blocks[0]));
226 		else
227 			ip->i_rdev = ext2_new_decode_dev(le32toh(ei->e2di_blocks[1]));
228 	} else if ((ip->i_flag & IN_E4EXTENTS)) {
229 		memcpy(ip->i_data, ei->e2di_blocks, sizeof(ei->e2di_blocks));
230 	} else {
231 		for (i = 0; i < EXT2_NDADDR; i++)
232 			ip->i_db[i] = le32toh(ei->e2di_blocks[i]);
233 		for (i = 0; i < EXT2_NIADDR; i++)
234 			ip->i_ib[i] = le32toh(ei->e2di_blocks[EXT2_NDIR_BLOCKS + i]);
235 	}
236 
237 	/* Verify inode csum. */
238 	return (ext2_ei_csum_verify(ip, ei));
239 }
240 
241 static inline uint32_t
242 ext2_encode_extra_time(int64_t sec, int32_t nsec)
243 {
244 	uint32_t extra;
245 
246 	extra = ((sec - (int32_t)sec) >> 32) & EXT3_EPOCH_MASK;
247 
248 	return (htole32(extra | (nsec << EXT3_EPOCH_BITS)));
249 }
250 
251 /*
252  *	inode to raw ext2 LE inode conversion
253  */
254 int
255 ext2_i2ei(struct inode *ip, struct ext2fs_dinode *ei)
256 {
257 	struct m_ext2fs *fs;
258 	int i;
259 
260 	fs = ip->i_e2fs;
261 	ei->e2di_mode = htole16(ip->i_mode);
262 	ei->e2di_nlink = htole16(ip->i_nlink);
263 	ei->e2di_size = htole32(ip->i_size);
264 	if (S_ISREG(ip->i_mode))
265 		ei->e2di_size_high = htole32(ip->i_size >> 32);
266 	ei->e2di_atime = htole32(ip->i_atime);
267 	ei->e2di_mtime = htole32(ip->i_mtime);
268 	ei->e2di_ctime = htole32(ip->i_ctime);
269 	/*
270 	 * Godmar thinks: if dtime is nonzero, ext2 says this inode has been
271 	 * deleted, this would correspond to a zero link count
272 	 */
273 	ei->e2di_dtime = htole32(le16toh(ei->e2di_nlink) ? 0 :
274 	    le32toh(ei->e2di_mtime));
275 	if (E2DI_HAS_XTIME(ip)) {
276 		ei->e2di_ctime_extra = ext2_encode_extra_time(ip->i_ctime,
277 		    ip->i_ctimensec);
278 		ei->e2di_mtime_extra = ext2_encode_extra_time(ip->i_mtime,
279 		    ip->i_mtimensec);
280 		ei->e2di_atime_extra = ext2_encode_extra_time(ip->i_atime,
281 		    ip->i_atimensec);
282 		ei->e2di_crtime = htole32(ip->i_birthtime);
283 		ei->e2di_crtime_extra = ext2_encode_extra_time(ip->i_birthtime,
284 		    ip->i_birthnsec);
285 	}
286 	/* Keep these in host endian for a while since they change a lot */
287 	ei->e2di_flags = 0;
288 	ei->e2di_flags |= htole32((ip->i_flags & SF_APPEND) ? EXT2_APPEND : 0);
289 	ei->e2di_flags |= htole32((ip->i_flags & SF_IMMUTABLE) ? EXT2_IMMUTABLE : 0);
290 	ei->e2di_flags |= htole32((ip->i_flags & UF_NODUMP) ? EXT2_NODUMP : 0);
291 	ei->e2di_flags |= htole32((ip->i_flag & IN_E3INDEX) ? EXT3_INDEX : 0);
292 	ei->e2di_flags |= htole32((ip->i_flag & IN_E4EXTENTS) ? EXT4_EXTENTS : 0);
293 	if (ip->i_blocks > ~0U &&
294 	    !EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_HUGE_FILE)) {
295 		SDT_PROBE2(ext2fs, , trace, inode_cnv, 1, "i_blocks value is out of range");
296 		return (EIO);
297 	}
298 	if (ip->i_blocks <= 0xffffffffffffULL) {
299 		ei->e2di_nblock = htole32(ip->i_blocks & 0xffffffff);
300 		ei->e2di_nblock_high = htole16(ip->i_blocks >> 32 & 0xffff);
301 	} else {
302 		ei->e2di_flags |= htole32(EXT4_HUGE_FILE);
303 		ei->e2di_nblock = htole32(dbtofsb(fs, ip->i_blocks));
304 		ei->e2di_nblock_high = htole16(dbtofsb(fs, ip->i_blocks) >> 32 & 0xffff);
305 	}
306 
307 	ei->e2di_facl = htole32(ip->i_facl & 0xffffffff);
308 	ei->e2di_facl_high = htole16(ip->i_facl >> 32 & 0xffff);
309 	ei->e2di_gen = htole32(ip->i_gen);
310 	ei->e2di_uid = htole16(ip->i_uid & 0xffff);
311 	ei->e2di_uid_high = htole16(ip->i_uid >> 16 & 0xffff);
312 	ei->e2di_gid = htole16(ip->i_gid & 0xffff);
313 	ei->e2di_gid_high = htole16(ip->i_gid >> 16 & 0xffff);
314 
315 	if (S_ISCHR(ip->i_mode) || S_ISBLK(ip->i_mode)) {
316 		if (ext2_old_valid_dev(ip->i_rdev)) {
317 			ei->e2di_blocks[0] = htole32(ext2_old_encode_dev(ip->i_rdev));
318 			ei->e2di_blocks[1] = 0;
319 		} else {
320 			ei->e2di_blocks[0] = 0;
321 			ei->e2di_blocks[1] = htole32(ext2_new_encode_dev(ip->i_rdev));
322 			ei->e2di_blocks[2] = 0;
323 		}
324 	} else if ((ip->i_flag & IN_E4EXTENTS)) {
325 		memcpy(ei->e2di_blocks, ip->i_data, sizeof(ei->e2di_blocks));
326 	} else {
327 		for (i = 0; i < EXT2_NDADDR; i++)
328 			ei->e2di_blocks[i] = htole32(ip->i_db[i]);
329 		for (i = 0; i < EXT2_NIADDR; i++)
330 			ei->e2di_blocks[EXT2_NDIR_BLOCKS + i] = htole32(ip->i_ib[i]);
331 	}
332 
333 	/* Set inode csum. */
334 	ext2_ei_csum_set(ip, ei);
335 
336 	return (0);
337 }
338