1 /*
2 * UAE - The Un*x Amiga Emulator
3 *
4 * Library of functions to make emulated filesystem as independent as
5 * possible of the host filesystem's capabilities.
6 *
7 * Copyright 1999 Bernd Schmidt
8 */
9
10 #include "sysconfig.h"
11 #include "sysdeps.h"
12
13 #include "threaddep/thread.h"
14 #include "options.h"
15 #include "uae.h"
16 #include "memory.h"
17 #include "custom.h"
18 #include "newcpu.h"
19 #include "filesys.h"
20 #include "autoconf.h"
21 #include "fsusage.h"
22 #include "scsidev.h"
23 #include "fsdb.h"
24
25 /* The on-disk format is as follows:
26 * Offset 0, 1 byte, valid
27 * Offset 1, 4 bytes, mode
28 * Offset 5, 257 bytes, aname
29 * Offset 263, 257 bytes, nname
30 * Offset 518, 81 bytes, comment
31 */
32
nname_begin(char * nname)33 char *nname_begin (char *nname)
34 {
35 char *p = strrchr (nname, FSDB_DIR_SEPARATOR);
36 if (p)
37 return p + 1;
38 return nname;
39 }
40
41 /* Find the name REL in directory DIRNAME. If we find a file that
42 * has exactly the same name, return REL. If we find a file that
43 * has the same name when compared case-insensitively, return a
44 * malloced string that contains the name we found. If no file
45 * exists that compares equal to REL, return 0. */
fsdb_search_dir(const char * dirname,char * rel)46 char *fsdb_search_dir (const char *dirname, char *rel)
47 {
48 char *p = 0;
49 struct dirent *de;
50 DIR *dir = opendir (dirname);
51
52 /* This really shouldn't happen... */
53 if (! dir)
54 return 0;
55
56 while (p == 0 && (de = readdir (dir)) != 0) {
57 if (strcmp (de->d_name, rel) == 0)
58 p = rel;
59 else if (strcasecmp (de->d_name, rel) == 0)
60 p = my_strdup (de->d_name);
61 }
62 closedir (dir);
63 return p;
64 }
65
get_fsdb(a_inode * dir,const char * mode)66 static FILE *get_fsdb (a_inode *dir, const char *mode)
67 {
68 char *n = build_nname (dir->nname, FSDB_FILE);
69 FILE *f = fopen (n, mode);
70 free (n);
71 return f;
72 }
73
kill_fsdb(a_inode * dir)74 static void kill_fsdb (a_inode *dir)
75 {
76 char *n = build_nname (dir->nname, FSDB_FILE);
77 unlink (n);
78 free (n);
79 }
80
81 /* Prune the db file the first time this directory is opened in a session. */
fsdb_clean_dir(a_inode * dir)82 void fsdb_clean_dir (a_inode *dir)
83 {
84 char buf[1 + 4 + 257 + 257 + 81];
85 char *n = build_nname (dir->nname, FSDB_FILE);
86 FILE *f = fopen (n, "r+b");
87 off_t pos1 = 0, pos2 = 0;
88
89 if (f == 0)
90 return;
91 for (;; pos2 += sizeof buf) {
92 if (fread (buf, 1, sizeof buf, f) < sizeof buf)
93 break;
94 if (buf[0] == 0)
95 continue;
96 if (pos1 != pos2) {
97 fseek (f, pos1, SEEK_SET);
98 fwrite (buf, 1, sizeof buf, f);
99 fseek (f, pos2 + sizeof buf, SEEK_SET);
100 }
101 pos1 += sizeof buf;
102 }
103 fclose (f);
104 truncate (n, pos1);
105 free (n);
106 }
107
aino_from_buf(a_inode * base,char * buf,long off)108 static a_inode *aino_from_buf (a_inode *base, char *buf, long off)
109 {
110 uae_u32 mode;
111 a_inode *aino = (a_inode *) xmalloc (sizeof (a_inode));
112
113 mode = do_get_mem_long ((uae_u32 *)(buf + 1));
114 buf += 5;
115 aino->aname = my_strdup (buf);
116 buf += 257;
117 aino->nname = build_nname (base->nname, buf);
118 buf += 257;
119 aino->comment = *buf != '\0' ? my_strdup (buf) : 0;
120 fsdb_fill_file_attrs (aino);
121 aino->amigaos_mode = mode;
122 aino->has_dbentry = 1;
123 aino->dirty = 0;
124 aino->db_offset = off;
125 return aino;
126 }
127
fsdb_lookup_aino_aname(a_inode * base,const char * aname)128 a_inode *fsdb_lookup_aino_aname (a_inode *base, const char *aname)
129 {
130 FILE *f = get_fsdb (base, "rb");
131 long off = 0;
132
133 if (f == 0)
134 return 0;
135
136 for (;;) {
137 char buf[1 + 4 + 257 + 257 + 81];
138 if (fread (buf, 1, sizeof buf, f) < sizeof buf)
139 break;
140 if (buf[0] != 0 && same_aname (buf + 5, aname)) {
141 fclose (f);
142 return aino_from_buf (base, buf, off);
143 }
144 off += sizeof buf;
145 }
146 fclose (f);
147 return 0;
148 }
149
fsdb_lookup_aino_nname(a_inode * base,const char * nname)150 a_inode *fsdb_lookup_aino_nname (a_inode *base, const char *nname)
151 {
152 FILE *f = get_fsdb (base, "rb");
153 long off = 0;
154
155 if (f == 0)
156 return 0;
157
158 for (;;) {
159 char buf[1 + 4 + 257 + 257 + 81];
160 if (fread (buf, 1, sizeof buf, f) < sizeof buf)
161 break;
162 if (buf[0] != 0 && strcmp (buf + 5 + 257, nname) == 0) {
163 fclose (f);
164 return aino_from_buf (base, buf, off);
165 }
166 off += sizeof buf;
167 }
168 fclose (f);
169 return 0;
170 }
171
fsdb_used_as_nname(a_inode * base,const char * nname)172 int fsdb_used_as_nname (a_inode *base, const char *nname)
173 {
174 FILE *f = get_fsdb (base, "rb");
175 if (f == 0)
176 return 0;
177 for (;;) {
178 char buf[1 + 4 + 257 + 257 + 81];
179 if (fread (buf, 1, sizeof buf, f) < sizeof buf)
180 break;
181 if (buf[0] == 0)
182 continue;
183 if (strcmp (buf + 5 + 257, nname) == 0) {
184 fclose (f);
185 return 1;
186 }
187 }
188 fclose (f);
189 return 0;
190 }
191
needs_dbentry(a_inode * aino)192 static int needs_dbentry (a_inode *aino)
193 {
194 const char *an_begin, *nn_begin;
195
196 if (aino->deleted)
197 return 0;
198
199 if (! fsdb_mode_representable_p (aino) || aino->comment != 0)
200 return 1;
201
202 nn_begin = nname_begin (aino->nname);
203 return strcmp (nn_begin, aino->aname) != 0;
204 }
205
write_aino(FILE * f,a_inode * aino)206 static void write_aino (FILE *f, a_inode *aino)
207 {
208 char buf[1 + 4 + 257 + 257 + 81];
209 buf[0] = aino->needs_dbentry;
210 do_put_mem_long ((uae_u32 *)(buf + 1), aino->amigaos_mode);
211 strncpy (buf + 5, aino->aname, 256);
212 buf[5 + 256] = '\0';
213 strncpy (buf + 5 + 257, nname_begin (aino->nname), 256);
214 buf[5 + 257 + 256] = '\0';
215 strncpy (buf + 5 + 2*257, aino->comment ? aino->comment : "", 80);
216 buf[5 + 2 * 257 + 80] = '\0';
217 fwrite (buf, 1, sizeof buf, f);
218 aino->has_dbentry = aino->needs_dbentry;
219 }
220
221 /* Write back the db file for a directory. */
222
fsdb_dir_writeback(a_inode * dir)223 void fsdb_dir_writeback (a_inode *dir)
224 {
225 FILE *f;
226 int changes_needed = 0;
227 int entries_needed = 0;
228 a_inode *aino;
229
230 /* First pass: clear dirty bits where unnecessary, and see if any work
231 * needs to be done. */
232 for (aino = dir->child; aino; aino = aino->sibling) {
233 int old_needs_dbentry = aino->needs_dbentry;
234 aino->needs_dbentry = old_needs_dbentry;
235 if (! aino->dirty)
236 continue;
237 aino->needs_dbentry = needs_dbentry (aino);
238 entries_needed |= aino->needs_dbentry;
239 if (! aino->needs_dbentry && ! old_needs_dbentry)
240 aino->dirty = 0;
241 else
242 changes_needed = 1;
243 }
244 if (! entries_needed) {
245 kill_fsdb (dir);
246 return;
247 }
248
249 if (! changes_needed)
250 return;
251
252 f = get_fsdb (dir, "r+b");
253 if (f == 0) {
254 f = get_fsdb (dir, "w+b");
255 if (f == 0)
256 /* This shouldn't happen... */
257 return;
258 }
259
260 for (aino = dir->child; aino; aino = aino->sibling) {
261 off_t pos;
262
263 if (! aino->dirty)
264 continue;
265 aino->dirty = 0;
266
267 if (! aino->has_dbentry) {
268 aino->db_offset = fseek (f, 0, SEEK_END);
269 aino->has_dbentry = 1;
270 } else
271 fseek (f, aino->db_offset, SEEK_SET);
272
273 write_aino (f, aino);
274 }
275 fclose (f);
276 }
277