This source file includes following definitions.
- isofs_match
- isofs_find_entry
- isofs_lookup
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9 #include <linux/sched.h>
10 #include <linux/iso_fs.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/stat.h>
14 #include <linux/fcntl.h>
15 #include <asm/segment.h>
16 #include <linux/malloc.h>
17
18 #include <linux/errno.h>
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26
27 static int isofs_match(int len,const char * name, char * compare, int dlen)
28 {
29 register int same __asm__("ax");
30
31 if (!compare) return 0;
32
33 if (!len && (compare[0]==0) && (dlen==1))
34 return 1;
35
36 if (compare[0]==0 && dlen==1 && len == 1)
37 compare = ".";
38 if (compare[0]==1 && dlen==1 && len == 2) {
39 compare = "..";
40 dlen = 2;
41 };
42 #if 0
43 if (len <= 2) printk("Match: %d %d %s %d %d \n",len,dlen,compare,de->name[0], dlen);
44 #endif
45
46 if (dlen != len)
47 return 0;
48 __asm__("cld\n\t"
49 "repe ; cmpsb\n\t"
50 "setz %%al"
51 :"=a" (same)
52 :"0" (0),"S" ((long) name),"D" ((long) compare),"c" (len)
53 :"cx","di","si");
54 return same;
55 }
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64
65 static struct buffer_head * isofs_find_entry(struct inode * dir,
66 const char * name, int namelen, int * ino, int * ino_back)
67 {
68 unsigned long bufsize = ISOFS_BUFFER_SIZE(dir);
69 unsigned char bufbits = ISOFS_BUFFER_BITS(dir);
70 unsigned int block, i, f_pos, offset, inode_number;
71 struct buffer_head * bh;
72 void * cpnt = NULL;
73 unsigned int old_offset;
74 unsigned int backlink;
75 int dlen, rrflag, match;
76 char * dpnt;
77 struct iso_directory_record * de;
78 char c;
79
80 *ino = 0;
81 if (!dir) return NULL;
82
83 if (!(block = dir->u.isofs_i.i_first_extent)) return NULL;
84
85 f_pos = 0;
86
87 offset = f_pos & (bufsize - 1);
88 block = isofs_bmap(dir,f_pos >> bufbits);
89
90 if (!block || !(bh = bread(dir->i_dev,block,bufsize))) return NULL;
91
92 while (f_pos < dir->i_size) {
93 de = (struct iso_directory_record *) (bh->b_data + offset);
94 backlink = dir->i_ino;
95 inode_number = (block << bufbits) + (offset & (bufsize - 1));
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97
98
99
100 if (*((unsigned char *) de) == 0) {
101 brelse(bh);
102 offset = 0;
103 f_pos = ((f_pos & ~(ISOFS_BLOCK_SIZE - 1))
104 + ISOFS_BLOCK_SIZE);
105 block = isofs_bmap(dir,f_pos>>bufbits);
106 if (!block || !(bh = bread(dir->i_dev,block,bufsize)))
107 return 0;
108 continue;
109 }
110
111 old_offset = offset;
112 offset += *((unsigned char *) de);
113 f_pos += *((unsigned char *) de);
114
115
116
117 if (offset >= bufsize) {
118 cpnt = kmalloc(1 << ISOFS_BLOCK_BITS, GFP_KERNEL);
119 memcpy(cpnt, bh->b_data, bufsize);
120 de = (struct iso_directory_record *)
121 ((char *)cpnt + old_offset);
122 brelse(bh);
123 offset = f_pos & (bufsize - 1);
124 block = isofs_bmap(dir,f_pos>>bufbits);
125 if (!block || !(bh = bread(dir->i_dev,block,bufsize)))
126 return 0;
127 memcpy((char *)cpnt+bufsize,bh->b_data,bufsize);
128 }
129
130
131
132 if (de->name[0]==0 && de->name_len[0]==1) {
133 inode_number = dir->i_ino;
134 backlink = 0;
135 }
136
137
138
139 if (de->name[0]==1 && de->name_len[0]==1) {
140 #if 0
141 printk("Doing .. (%d %d)",
142 dir->i_sb->s_firstdatazone << bufbits,
143 dir->i_ino);
144 #endif
145 if((dir->i_sb->u.isofs_sb.s_firstdatazone
146 << bufbits) != dir->i_ino)
147 inode_number = dir->u.isofs_i.i_backlink;
148 else
149 inode_number = dir->i_ino;
150 backlink = 0;
151 }
152
153 dlen = de->name_len[0];
154 dpnt = de->name;
155
156 rrflag = get_rock_ridge_filename(de, &dpnt, &dlen, dir);
157 if (rrflag) {
158 if (rrflag == -1) goto out;
159 } else {
160 if(dir->i_sb->u.isofs_sb.s_mapping == 'n') {
161 for (i = 0; i < dlen; i++) {
162 c = dpnt[i];
163 if (c >= 'A' && c <= 'Z') c |= 0x20;
164 if (c == ';' && i == dlen-2 && dpnt[i+1] == '1') {
165 dlen -= 2;
166 break;
167 }
168 if (c == ';') c = '.';
169 de->name[i] = c;
170 }
171
172
173 if(dpnt[dlen-1] == '.' && namelen == dlen-1)
174 dlen--;
175 }
176 }
177 match = isofs_match(namelen,name,dpnt,dlen);
178 if (cpnt) {
179 kfree_s(cpnt, 1 << ISOFS_BLOCK_BITS);
180 cpnt = NULL;
181 }
182
183 if(rrflag) kfree(dpnt);
184 if (match) {
185 if(inode_number == -1) {
186
187 inode_number =
188 isofs_lookup_grandparent(dir,
189 find_rock_ridge_relocation(de,dir));
190 if(inode_number == -1){
191
192 printk("Backlink not properly set.\n");
193 goto out;
194 }
195 }
196 *ino = inode_number;
197 *ino_back = backlink;
198 return bh;
199 }
200 }
201 out:
202 if (cpnt)
203 kfree_s(cpnt, 1 << ISOFS_BLOCK_BITS);
204 brelse(bh);
205 return NULL;
206 }
207
208 int isofs_lookup(struct inode * dir,const char * name, int len,
209 struct inode ** result)
210 {
211 int ino, ino_back;
212 struct buffer_head * bh;
213
214 #ifdef DEBUG
215 printk("lookup: %x %d\n",dir->i_ino, len);
216 #endif
217 *result = NULL;
218 if (!dir)
219 return -ENOENT;
220
221 if (!S_ISDIR(dir->i_mode)) {
222 iput(dir);
223 return -ENOENT;
224 }
225
226 ino = 0;
227 if (dir->i_dev == cache.dev &&
228 dir->i_ino == cache.dir &&
229 len == cache.dlen &&
230 isofs_match(len, name, cache.filename, cache.dlen))
231 {
232 ino = cache.ino;
233 ino_back = dir->i_ino;
234
235
236 if (cache.dlen == 1 && cache.filename[0] == '.') ino = 0;
237 if (cache.dlen == 2 && cache.filename[0] == '.' &&
238 cache.filename[1] == '.') ino = 0;
239 };
240
241 if (!ino) {
242 if (!(bh = isofs_find_entry(dir,name,len, &ino, &ino_back))) {
243 iput(dir);
244 return -ENOENT;
245 }
246 brelse(bh);
247 };
248
249 if (!(*result = iget(dir->i_sb,ino))) {
250 iput(dir);
251 return -EACCES;
252 }
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260 if (ino_back && !(*result)->i_pipe && (*result)->i_sb == dir->i_sb) {
261 (*result)->u.isofs_i.i_backlink = ino_back;
262 }
263
264 iput(dir);
265 return 0;
266 }