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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [xiafs/] [namei.c] - Blame information for rev 1777

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Line No. Rev Author Line
1 1628 jcastillo 
/*
2 
 *  Linux/fs/xiafs/namei.c
3 
 *
4 
 *  Copyright (C) Q. Frank Xia, 1993.
5 
 *
6 
 *  Based on Linus' minix/namei.c
7 
 *  Copyright (C) Linus Torvalds, 1991, 1992.
8 
 *
9 
 *  This software may be redistributed per Linux Copyright.
10 
 */
11 
 
12 
#include <linux/sched.h>
13 
#include <linux/xia_fs.h>
14 
#include <linux/kernel.h>
15 
#include <linux/string.h>
16 
#include <linux/stat.h>
17 
#include <linux/fcntl.h>
18 
#include <linux/errno.h>
19 
 
20 
#include <asm/segment.h>
21 
 
22 
#include "xiafs_mac.h"
23 
 
24 
#define RNDUP4(x)       ((3+(u_long)(x)) & ~3)
25 
/*
26 
 * ok, we cannot use strncmp, as the name is not in our data space.
27 
 * Thus we'll have to use xiafs_match. No big problem. Match also makes
28 
 * some sanity tests.
29 
 *
30 
 * NOTE! unlike strncmp, xiafs_match returns 1 for success, 0 for failure.
31 
 */
32 
static int xiafs_match(int len, const char * name, struct xiafs_direct * dep)
33 
{
34 
    int i;
35 
 
36 
    if (!dep || !dep->d_ino || len > _XIAFS_NAME_LEN)
37 
        return 0;
38 
    /* "" means "." ---> so paths like "/usr/lib//libc.a" work */
39 
    if (!len && (dep->d_name[0]=='.') && (dep->d_name[1]=='\0'))
40 
        return 1;
41 
    if (len != dep->d_name_len)
42 
        return 0;
43 
    for (i=0; i < len; i++)
44 
        if (*name++ != dep->d_name[i])
45 
            return 0;
46 
    return 1;
47 
}
48 
 
49 
/*
50 
 *      xiafs_find_entry()
51 
 *
52 
 * finds an entry in the specified directory with the wanted name. It
53 
 * returns the cache buffer in which the entry was found, and the entry
54 
 * itself (as a parameter - res_dir). It does NOT read the inode of the
55 
 * entry - you'll have to do that yourself if you want to.
56 
 */
57 
static struct buffer_head *
58 
xiafs_find_entry(struct inode * inode, const char * name, int namelen,
59 
               struct xiafs_direct ** res_dir, struct xiafs_direct ** res_pre)
60 
{
61 
    int i, zones, pos;
62 
    struct buffer_head * bh;
63 
    struct xiafs_direct * dep, * dep_pre;
64 
 
65 
    *res_dir = NULL;
66 
    if (!inode)
67 
        return NULL;
68 
    if (namelen > _XIAFS_NAME_LEN)
69 
        return NULL;
70 
 
71 
    if (inode->i_size & (XIAFS_ZSIZE(inode->i_sb) - 1)) {
72 
        printk("XIA-FS: bad dir size (%s %d)\n", WHERE_ERR);
73 
        return NULL;
74 
    }
75 
    zones=inode->i_size >> XIAFS_ZSIZE_BITS(inode->i_sb);
76 
    for (i=0; i < zones; i++ ) {
77 
        bh = xiafs_bread(inode, i, 0);
78 
        if (!bh)
79 
            continue;
80 
        dep_pre=dep=(struct xiafs_direct *)bh->b_data;
81 
        if (!i && (dep->d_rec_len != 12 || !dep->d_ino ||
82 
                   dep->d_name_len != 1 || strcmp(dep->d_name, "."))) {
83 
            printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
84 
            brelse(bh);
85 
            return NULL;
86 
        }
87 
        pos = 0;
88 
        while ( pos < XIAFS_ZSIZE(inode->i_sb) ) {
89 
            if (dep->d_ino > inode->i_sb->u.xiafs_sb.s_ninodes ||
90 
                dep->d_rec_len < 12 ||
91 
                dep->d_rec_len+(char *)dep > bh->b_data+XIAFS_ZSIZE(inode->i_sb) ||
92 
                dep->d_name_len + 8 > dep->d_rec_len || dep->d_name_len <= 0 ||
93 
                dep->d_name[dep->d_name_len] ) {
94 
                brelse(bh);
95 
                return NULL;
96 
            }
97 
            if (xiafs_match(namelen, name, dep)) {
98 
                *res_dir=dep;
99 
                if (res_pre)
100 
                    *res_pre=dep_pre;
101 
                return bh;
102 
            }
103 
            pos += dep->d_rec_len;
104 
            dep_pre=dep;
105 
            dep=(struct xiafs_direct *)(bh->b_data + pos);
106 
        }
107 
        brelse(bh);
108 
        if (pos > XIAFS_ZSIZE(inode->i_sb)) {
109 
            printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
110 
            return NULL;
111 
        }
112 
    }
113 
    return NULL;
114 
}
115 
 
116 
int xiafs_lookup(struct inode * dir, const char * name, int len,
117 
               struct inode ** result)
118 
{
119 
    int ino;
120 
    struct xiafs_direct * dep;
121 
    struct buffer_head * bh;
122 
 
123 
    *result = NULL;
124 
    if (!dir)
125 
        return -ENOENT;
126 
    if (!S_ISDIR(dir->i_mode)) {
127 
        iput(dir);
128 
        return -ENOENT;
129 
    }
130 
    if (!(bh = xiafs_find_entry(dir, name, len, &dep, NULL))) {
131 
        iput(dir);
132 
        return -ENOENT;
133 
    }
134 
    ino = dep->d_ino;
135 
    brelse(bh);
136 
    if (!(*result = iget(dir->i_sb, ino))) {
137 
        iput(dir);
138 
        return -EACCES;
139 
    }
140 
    iput(dir);
141 
    return 0;
142 
}
143 
 
144 
/*
145 
 *      xiafs_add_entry()
146 
 *
147 
 * adds a file entry to the specified directory, using the same
148 
 * semantics as xiafs_find_entry(). It returns NULL if it failed.
149 
 *
150 
 * NOTE!! The inode part of 'de' is left at 0 - which means you
151 
 * may not sleep between calling this and putting something into
152 
 * the entry, as someone else might have used it while you slept.
153 
 */
154 
static struct buffer_head * xiafs_add_entry(struct inode * dir,
155 
        const char * name, int namelen, struct xiafs_direct ** res_dir,
156 
        struct xiafs_direct ** res_pre)
157 
{
158 
    int i, pos, offset;
159 
    struct buffer_head * bh;
160 
    struct xiafs_direct * de, * de_pre;
161 
 
162 
    *res_dir = NULL;
163 
    if (!dir || !namelen || namelen > _XIAFS_NAME_LEN)
164 
        return NULL;
165 
 
166 
    if (dir->i_size & (XIAFS_ZSIZE(dir->i_sb) - 1)) {
167 
        printk("XIA-FS: bad dir size (%s %d)\n", WHERE_ERR);
168 
        return NULL;
169 
    }
170 
    pos=0;
171 
    for ( ; ; ) {
172 
        bh =  xiafs_bread(dir, pos >> XIAFS_ZSIZE_BITS(dir->i_sb), pos ? 1:0);
173 
        if (!bh)
174 
            return NULL;
175 
        de_pre=de=(struct xiafs_direct *)bh->b_data;
176 
        if (!pos) {
177 
            if (de->d_rec_len != 12 || !de->d_ino || de->d_name_len != 1 ||
178 
                strcmp(de->d_name, ".")) {
179 
                printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
180 
                brelse(bh);
181 
                return NULL;
182 
            }
183 
            offset = 12;
184 
            de_pre=de=(struct xiafs_direct *)(bh->b_data+12);
185 
        } else
186 
            offset = 0;
187 
        while (offset < XIAFS_ZSIZE(dir->i_sb)) {
188 
            if (pos >= dir->i_size) {
189 
                de->d_ino=0;
190 
                de->d_name_len=0;
191 
                de->d_name[0]=0;
192 
                de->d_rec_len=XIAFS_ZSIZE(dir->i_sb);
193 
                dir->i_size += XIAFS_ZSIZE(dir->i_sb);
194 
                dir->i_dirt = 1;
195 
            } else {
196 
                if (de->d_ino > dir->i_sb->u.xiafs_sb.s_ninodes ||
197 
                    de->d_rec_len < 12 ||
198 
                    (char *)de+de->d_rec_len > bh->b_data+XIAFS_ZSIZE(dir->i_sb) ||
199 
                    de->d_name_len + 8 > de->d_rec_len ||
200 
                    de->d_name[de->d_name_len]) {
201 
                    printk("XIA-FS: bad directory entry (%s %d)\n", WHERE_ERR);
202 
                    brelse(bh);
203 
                    return NULL;
204 
                }
205 
                if (de->d_ino &&
206 
                    RNDUP4(de->d_name_len)+RNDUP4(namelen)+16<=de->d_rec_len) {
207 
                    i=RNDUP4(de->d_name_len)+8;
208 
                    de_pre=de;
209 
                    de=(struct xiafs_direct *)(i+(u_char *)de_pre);
210 
                    de->d_ino=0;
211 
                    de->d_rec_len=de_pre->d_rec_len-i;
212 
                    de_pre->d_rec_len=i;
213 
                }
214 
            }
215 
            if (!de->d_ino && RNDUP4(namelen)+8 <= de->d_rec_len) {
216 
                /*
217 
                 * XXX all times should be set by caller upon successful
218 
                 * completion.
219 
                 */
220 
                dir->i_ctime = dir->i_mtime = CURRENT_TIME;
221 
                dir->i_dirt = 1;
222 
                memcpy(de->d_name, name, namelen);
223 
                de->d_name[namelen]=0;
224 
                de->d_name_len=namelen;
225 
                mark_buffer_dirty(bh, 1);
226 
                *res_dir = de;
227 
                if (res_pre)
228 
                    *res_pre = de_pre;
229 
                return bh;
230 
            }
231 
            offset+=de->d_rec_len;
232 
            de_pre=de;
233 
            de=(struct xiafs_direct *)(bh->b_data+offset);
234 
        }
235 
        brelse(bh);
236 
        if (offset > XIAFS_ZSIZE(dir->i_sb)) {
237 
            printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
238 
            return NULL;
239 
        }
240 
        pos+=XIAFS_ZSIZE(dir->i_sb);
241 
    }
242 
    return NULL;
243 
}
244 
 
245 
int xiafs_create(struct inode * dir, const char * name, int len, int mode,
246 
        struct inode ** result)
247 
{
248 
    struct inode * inode;
249 
    struct buffer_head * bh;
250 
    struct xiafs_direct * de;
251 
 
252 
    *result = NULL;
253 
    if (!dir)
254 
        return -ENOENT;
255 
    inode = xiafs_new_inode(dir);
256 
    if (!inode) {
257 
        iput(dir);
258 
        return -ENOSPC;
259 
    }
260 
    inode->i_op = &xiafs_file_inode_operations;
261 
    inode->i_mode = mode;
262 
    inode->i_dirt = 1;
263 
    bh = xiafs_add_entry(dir, name, len, &de, NULL);
264 
    if (!bh) {
265 
        inode->i_nlink--;
266 
        inode->i_dirt = 1;
267 
        iput(inode);
268 
        iput(dir);
269 
        return -ENOSPC;
270 
    }
271 
    de->d_ino = inode->i_ino;
272 
    mark_buffer_dirty(bh, 1);
273 
    brelse(bh);
274 
    iput(dir);
275 
    *result = inode;
276 
    return 0;
277 
}
278 
 
279 
int xiafs_mknod(struct inode *dir, const char *name, int len, int mode, int rdev)
280 
{
281 
    struct inode * inode;
282 
    struct buffer_head * bh;
283 
    struct xiafs_direct * de;
284 
 
285 
    if (!dir)
286 
        return -ENOENT;
287 
    bh = xiafs_find_entry(dir,name,len,&de, NULL);
288 
    if (bh) {
289 
        brelse(bh);
290 
        iput(dir);
291 
        return -EEXIST;
292 
    }
293 
    inode = xiafs_new_inode(dir);
294 
    if (!inode) {
295 
        iput(dir);
296 
        return -ENOSPC;
297 
    }
298 
    inode->i_uid = current->fsuid;
299 
    inode->i_mode = mode;
300 
    inode->i_op = NULL;
301 
    if (S_ISREG(inode->i_mode))
302 
        inode->i_op = &xiafs_file_inode_operations;
303 
    else if (S_ISDIR(inode->i_mode)) {
304 
        inode->i_op = &xiafs_dir_inode_operations;
305 
        if (dir->i_mode & S_ISGID)
306 
            inode->i_mode |= S_ISGID;
307 
    }
308 
    else if (S_ISLNK(inode->i_mode))
309 
        inode->i_op = &xiafs_symlink_inode_operations;
310 
    else if (S_ISCHR(inode->i_mode))
311 
        inode->i_op = &chrdev_inode_operations;
312 
    else if (S_ISBLK(inode->i_mode))
313 
        inode->i_op = &blkdev_inode_operations;
314 
    else if (S_ISFIFO(inode->i_mode))
315 
        init_fifo(inode);
316 
    if (S_ISBLK(mode) || S_ISCHR(mode))
317 
        inode->i_rdev = to_kdev_t(rdev);
318 
    inode->i_atime = inode->i_ctime = inode->i_atime = CURRENT_TIME;
319 
    inode->i_dirt = 1;
320 
    bh = xiafs_add_entry(dir, name, len, &de, NULL);
321 
    if (!bh) {
322 
        inode->i_nlink--;
323 
        inode->i_dirt = 1;
324 
        iput(inode);
325 
        iput(dir);
326 
        return -ENOSPC;
327 
    }
328 
    de->d_ino = inode->i_ino;
329 
    mark_buffer_dirty(bh, 1);
330 
    brelse(bh);
331 
    iput(dir);
332 
    iput(inode);
333 
    return 0;
334 
}
335 
 
336 
int xiafs_mkdir(struct inode * dir, const char * name, int len, int mode)
337 
{
338 
    struct inode * inode;
339 
    struct buffer_head * bh, *dir_block;
340 
    struct xiafs_direct * de;
341 
 
342 
    bh = xiafs_find_entry(dir,name,len,&de, NULL);
343 
    if (bh) {
344 
        brelse(bh);
345 
        iput(dir);
346 
        return -EEXIST;
347 
    }
348 
    if (dir->i_nlink > 64000) {
349 
        iput(dir);
350 
        return -EMLINK;
351 
    }
352 
    inode = xiafs_new_inode(dir);
353 
    if (!inode) {
354 
        iput(dir);
355 
        return -ENOSPC;
356 
    }
357 
    inode->i_op = &xiafs_dir_inode_operations;
358 
    inode->i_size = XIAFS_ZSIZE(dir->i_sb);
359 
    inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME;
360 
    inode->i_dirt = 1;
361 
    dir_block = xiafs_bread(inode,0,1);
362 
    if (!dir_block) {
363 
        iput(dir);
364 
        inode->i_nlink--;
365 
        inode->i_dirt = 1;
366 
        iput(inode);
367 
        return -ENOSPC;
368 
    }
369 
    de = (struct xiafs_direct *) dir_block->b_data;
370 
    de->d_ino=inode->i_ino;
371 
    strcpy(de->d_name,".");
372 
    de->d_name_len=1;
373 
    de->d_rec_len=12;
374 
    de =(struct xiafs_direct *)(12 + dir_block->b_data);
375 
    de->d_ino = dir->i_ino;
376 
    strcpy(de->d_name,"..");
377 
    de->d_name_len=2;
378 
    de->d_rec_len=XIAFS_ZSIZE(dir->i_sb)-12;
379 
    inode->i_nlink = 2;
380 
    mark_buffer_dirty(dir_block, 1);
381 
    brelse(dir_block);
382 
    inode->i_mode = S_IFDIR | (mode & S_IRWXUGO & ~current->fs->umask);
383 
    if (dir->i_mode & S_ISGID)
384 
        inode->i_mode |= S_ISGID;
385 
    inode->i_dirt = 1;
386 
    bh = xiafs_add_entry(dir, name, len, &de, NULL);
387 
    if (!bh) {
388 
        iput(dir);
389 
        inode->i_nlink=0;
390 
        iput(inode);
391 
        return -ENOSPC;
392 
    }
393 
    de->d_ino = inode->i_ino;
394 
    mark_buffer_dirty(bh, 1);
395 
    dir->i_nlink++;
396 
    dir->i_dirt = 1;
397 
    iput(dir);
398 
    iput(inode);
399 
    brelse(bh);
400 
    return 0;
401 
}
402 
 
403 
/*
404 
 * routine to check that the specified directory is empty (for rmdir)
405 
 */
406 
static int empty_dir(struct inode * inode)
407 
{
408 
    int i, zones, offset;
409 
    struct buffer_head * bh;
410 
    struct xiafs_direct * de;
411 
 
412 
    if (inode->i_size & (XIAFS_ZSIZE(inode->i_sb)-1) ) {
413 
        printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
414 
        return 1;
415 
    }
416 
 
417 
    zones=inode->i_size >> XIAFS_ZSIZE_BITS(inode->i_sb);
418 
    for (i=0; i < zones; i++) {
419 
        bh =  xiafs_bread(inode, i, 0);
420 
        if (!i) {
421 
            if (!bh) {
422 
                printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
423 
                return 1;
424 
            }
425 
            de=(struct xiafs_direct *)bh->b_data;
426 
            if (de->d_ino != inode->i_ino || strcmp(".", de->d_name) ||
427 
                    de->d_rec_len != 12 ) {
428 
                printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
429 
                brelse(bh);
430 
                return 1;
431 
            }
432 
            de=(struct xiafs_direct *)(12 + bh->b_data);
433 
            if (!de->d_ino || strcmp("..", de->d_name)) {
434 
                printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
435 
                brelse(bh);
436 
                return 1;
437 
            }
438 
            offset=de->d_rec_len+12;
439 
        }
440 
        else
441 
            offset = 0;
442 
        if (!bh)
443 
            continue;
444 
        while (offset < XIAFS_ZSIZE(inode->i_sb)) {
445 
            de=(struct xiafs_direct *)(bh->b_data+offset);
446 
            if (de->d_ino > inode->i_sb->u.xiafs_sb.s_ninodes ||
447 
                de->d_rec_len < 12 ||
448 
                (char *)de+de->d_rec_len > bh->b_data+XIAFS_ZSIZE(inode->i_sb) ||
449 
                de->d_name_len + 8 > de->d_rec_len ||
450 
                de->d_name[de->d_name_len]) {
451 
                printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR);
452 
                brelse(bh);
453 
                return 1;
454 
            }
455 
            if (de->d_ino) {
456 
                brelse(bh);
457 
                return 0;
458 
            }
459 
            offset+=de->d_rec_len;
460 
        }
461 
        brelse(bh);
462 
    }
463 
    return 1;
464 
}
465 
 
466 
static void xiafs_rm_entry(struct xiafs_direct *de, struct xiafs_direct * de_pre)
467 
{
468 
    if (de==de_pre) {
469 
        de->d_ino=0;
470 
        return;
471 
    }
472 
    while (de_pre->d_rec_len+(u_char *)de_pre < (u_char *)de) {
473 
        if (de_pre->d_rec_len < 12) {
474 
            printk("XIA-FS: bad directory entry (%s %d)\n", WHERE_ERR);
475 
            return;
476 
        }
477 
        de_pre=(struct xiafs_direct *)(de_pre->d_rec_len+(u_char *)de_pre);
478 
    }
479 
    if (de_pre->d_rec_len+(u_char *)de_pre > (u_char *)de) {
480 
        printk("XIA-FS: bad directory entry (%s %d)\n", WHERE_ERR);
481 
        return;
482 
    }
483 
    de_pre->d_rec_len+=de->d_rec_len;
484 
}
485 
 
486 
int xiafs_rmdir(struct inode * dir, const char * name, int len)
487 
{
488 
    int retval;
489 
    struct inode * inode;
490 
    struct buffer_head * bh;
491 
    struct xiafs_direct * de, * de_pre;
492 
 
493 
    inode = NULL;
494 
    bh = xiafs_find_entry(dir, name, len, &de, &de_pre);
495 
    retval = -ENOENT;
496 
    if (!bh)
497 
        goto end_rmdir;
498 
    retval = -EPERM;
499 
    if (!(inode = iget(dir->i_sb, de->d_ino)))
500 
        goto end_rmdir;
501 
    if ((dir->i_mode & S_ISVTX) && !fsuser() &&
502 
            current->fsuid != inode->i_uid &&
503 
            current->fsuid != dir->i_uid)
504 
        goto end_rmdir;
505 
    if (inode->i_dev != dir->i_dev)
506 
        goto end_rmdir;
507 
    if (inode == dir)   /* we may not delete ".", but "../dir" is ok */
508 
        goto end_rmdir;
509 
    if (!S_ISDIR(inode->i_mode)) {
510 
        retval = -ENOTDIR;
511 
        goto end_rmdir;
512 
    }
513 
    if (!empty_dir(inode)) {
514 
        retval = -ENOTEMPTY;
515 
        goto end_rmdir;
516 
    }
517 
    if (inode->i_count > 1) {
518 
        retval = -EBUSY;
519 
        goto end_rmdir;
520 
    }
521 
    if (inode->i_nlink != 2)
522 
        printk("XIA-FS: empty directory has nlink!=2 (%s %d)\n", WHERE_ERR);
523 
    xiafs_rm_entry(de, de_pre);
524 
    mark_buffer_dirty(bh, 1);
525 
    inode->i_nlink=0;
526 
    inode->i_dirt=1;
527 
    dir->i_nlink--;
528 
    inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
529 
    dir->i_dirt=1;
530 
    retval = 0;
531 
end_rmdir:
532 
    iput(dir);
533 
    iput(inode);
534 
    brelse(bh);
535 
    return retval;
536 
}
537 
 
538 
int xiafs_unlink(struct inode * dir, const char * name, int len)
539 
{
540 
    int retval;
541 
    struct inode * inode;
542 
    struct buffer_head * bh;
543 
    struct xiafs_direct * de, * de_pre;
544 
 
545 
repeat:
546 
    retval = -ENOENT;
547 
    inode = NULL;
548 
    bh = xiafs_find_entry(dir, name, len, &de, &de_pre);
549 
    if (!bh)
550 
        goto end_unlink;
551 
    if (!(inode = iget(dir->i_sb, de->d_ino)))
552 
        goto end_unlink;
553 
    retval = -EPERM;
554 
    if (S_ISDIR(inode->i_mode))
555 
        goto end_unlink;
556 
    if (de->d_ino != inode->i_ino) {
557 
        iput(inode);
558 
        brelse(bh);
559 
        current->counter = 0;
560 
        schedule();
561 
        goto repeat;
562 
    }
563 
    if ((dir->i_mode & S_ISVTX) && !fsuser() &&
564 
            current->fsuid != inode->i_uid &&
565 
            current->fsuid != dir->i_uid)
566 
        goto end_unlink;
567 
    if (!inode->i_nlink) {
568 
        printk("XIA-FS: Deleting nonexistent file (%s %d)\n", WHERE_ERR);
569 
        inode->i_nlink=1;
570 
    }
571 
    xiafs_rm_entry(de, de_pre);
572 
    mark_buffer_dirty(bh, 1);
573 
    inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
574 
    dir->i_dirt = 1;
575 
    inode->i_nlink--;
576 
    inode->i_dirt = 1;
577 
    retval = 0;
578 
end_unlink:
579 
    brelse(bh);
580 
    iput(inode);
581 
    iput(dir);
582 
    return retval;
583 
}
584 
 
585 
int xiafs_symlink(struct inode * dir, const char * name,
586 
                int len, const char * symname)
587 
{
588 
    struct xiafs_direct * de;
589 
    struct inode * inode = NULL;
590 
    struct buffer_head * bh = NULL, * name_block = NULL;
591 
    int i;
592 
    char c;
593 
 
594 
    bh = xiafs_find_entry(dir,name,len, &de, NULL);
595 
    if (bh) {
596 
        brelse(bh);
597 
        iput(dir);
598 
        return -EEXIST;
599 
    }
600 
    if (!(inode = xiafs_new_inode(dir))) {
601 
        iput(dir);
602 
        return -ENOSPC;
603 
    }
604 
    inode->i_mode = S_IFLNK | S_IRWXUGO;
605 
    inode->i_op = &xiafs_symlink_inode_operations;
606 
    name_block = xiafs_bread(inode,0,1);
607 
    if (!name_block) {
608 
        iput(dir);
609 
        inode->i_nlink--;
610 
        inode->i_dirt = 1;
611 
        iput(inode);
612 
        return -ENOSPC;
613 
    }
614 
    for (i = 0; i < BLOCK_SIZE-1 && (c=*symname++); i++)
615 
        name_block->b_data[i] = c;
616 
    name_block->b_data[i] = 0;
617 
    mark_buffer_dirty(name_block, 1);
618 
    brelse(name_block);
619 
    inode->i_size = i;
620 
    inode->i_dirt = 1;
621 
    bh = xiafs_add_entry(dir, name, len, &de, NULL);
622 
    if (!bh) {
623 
        inode->i_nlink--;
624 
        inode->i_dirt = 1;
625 
        iput(inode);
626 
        iput(dir);
627 
        return -ENOSPC;
628 
    }
629 
    de->d_ino = inode->i_ino;
630 
    mark_buffer_dirty(bh, 1);
631 
    brelse(bh);
632 
    iput(dir);
633 
    iput(inode);
634 
    return 0;
635 
}
636 
 
637 
int xiafs_link(struct inode * oldinode, struct inode * dir,
638 
             const char * name, int len)
639 
{
640 
    struct xiafs_direct * de;
641 
    struct buffer_head * bh;
642 
 
643 
    if (S_ISDIR(oldinode->i_mode)) {
644 
        iput(oldinode);
645 
        iput(dir);
646 
        return -EPERM;
647 
    }
648 
    if (oldinode->i_nlink > 64000) {
649 
        iput(oldinode);
650 
        iput(dir);
651 
        return -EMLINK;
652 
    }
653 
    bh = xiafs_find_entry(dir, name, len, &de, NULL);
654 
    if (bh) {
655 
        brelse(bh);
656 
        iput(dir);
657 
        iput(oldinode);
658 
        return -EEXIST;
659 
    }
660 
    bh = xiafs_add_entry(dir, name, len, &de, NULL);
661 
    if (!bh) {
662 
        iput(dir);
663 
        iput(oldinode);
664 
        return -ENOSPC;
665 
    }
666 
    de->d_ino = oldinode->i_ino;
667 
    mark_buffer_dirty(bh, 1);
668 
    brelse(bh);
669 
    iput(dir);
670 
    oldinode->i_nlink++;
671 
    oldinode->i_ctime = CURRENT_TIME;
672 
    oldinode->i_dirt = 1;
673 
    iput(oldinode);
674 
    return 0;
675 
}
676 
 
677 
static int subdir(struct inode * new_inode, struct inode * old_inode)
678 
{
679 
    int ino;
680 
    int result;
681 
 
682 
    new_inode->i_count++;
683 
    result = 0;
684 
    for (;;) {
685 
        if (new_inode == old_inode) {
686 
            result = 1;
687 
            break;
688 
        }
689 
        if (new_inode->i_dev != old_inode->i_dev)
690 
            break;
691 
        ino = new_inode->i_ino;
692 
        if (xiafs_lookup(new_inode,"..",2,&new_inode))
693 
            break;
694 
        if (new_inode->i_ino == ino)
695 
            break;
696 
    }
697 
    iput(new_inode);
698 
    return result;
699 
}
700 
 
701 
#define PARENT_INO(buffer) \
702 
    (((struct xiafs_direct *) ((u_char *)(buffer) + 12))->d_ino)
703 
 
704 
/*
705 
 * rename uses retry to avoid race-conditions: at least they should be minimal.
706 
 * it tries to allocate all the blocks, then sanity-checks, and if the sanity-
707 
 * checks fail, it tries to restart itself again. Very practical - no changes
708 
 * are done until we know everything works ok.. and then all the changes can be
709 
 * done in one fell swoop when we have claimed all the buffers needed.
710 
 *
711 
 * Anybody can rename anything with this: the permission checks are left to the
712 
 * higher-level routines.
713 
 */
714 
static int do_xiafs_rename(struct inode * old_dir, const char * old_name,
715 
                         int old_len, struct inode * new_dir,
716 
                         const char * new_name, int new_len,
717 
                         int must_be_dir)
718 
{
719 
    struct inode * old_inode, * new_inode;
720 
    struct buffer_head * old_bh, * new_bh, * dir_bh;
721 
    struct xiafs_direct * old_de, * old_de_pre, * new_de, * new_de_pre;
722 
    int retval;
723 
 
724 
try_again:
725 
    old_inode = new_inode = NULL;
726 
    old_bh = new_bh = dir_bh = NULL;
727 
    old_bh = xiafs_find_entry(old_dir, old_name, old_len, &old_de, &old_de_pre);
728 
    retval = -ENOENT;
729 
    if (!old_bh)
730 
        goto end_rename;
731 
    old_inode = __iget(old_dir->i_sb, old_de->d_ino, 0); /* don't cross mnt-points */
732 
    if (!old_inode)
733 
        goto end_rename;
734 
    if (must_be_dir && !S_ISDIR(old_inode->i_mode))
735 
        goto end_rename;
736 
    retval = -EPERM;
737 
    if ((old_dir->i_mode & S_ISVTX) &&
738 
            current->fsuid != old_inode->i_uid &&
739 
            current->fsuid != old_dir->i_uid && !fsuser())
740 
        goto end_rename;
741 
    new_bh = xiafs_find_entry(new_dir, new_name, new_len, &new_de, NULL);
742 
    if (new_bh) {
743 
        new_inode = __iget(new_dir->i_sb, new_de->d_ino, 0);
744 
        if (!new_inode) {
745 
            brelse(new_bh);
746 
            new_bh = NULL;
747 
        }
748 
    }
749 
    if (new_inode == old_inode) {
750 
        retval = 0;
751 
        goto end_rename;
752 
    }
753 
    if (new_inode && S_ISDIR(new_inode->i_mode)) {
754 
        retval = -EEXIST;
755 
        goto end_rename;
756 
    }
757 
    retval = -EPERM;
758 
    if (new_inode && (new_dir->i_mode & S_ISVTX) &&
759 
            current->fsuid != new_inode->i_uid &&
760 
            current->fsuid != new_dir->i_uid && !fsuser())
761 
        goto end_rename;
762 
    if (S_ISDIR(old_inode->i_mode)) {
763 
        retval = -EEXIST;
764 
        if (new_bh)
765 
            goto end_rename;
766 
        if ((retval = permission(old_inode, MAY_WRITE)) != 0)
767 
            goto end_rename;
768 
        retval = -EINVAL;
769 
        if (subdir(new_dir, old_inode))
770 
            goto end_rename;
771 
        retval = -EIO;
772 
        dir_bh = xiafs_bread(old_inode,0,0);
773 
        if (!dir_bh)
774 
            goto end_rename;
775 
        if (PARENT_INO(dir_bh->b_data) != old_dir->i_ino)
776 
            goto end_rename;
777 
        retval = -EMLINK;
778 
        if (new_dir->i_nlink > 64000)
779 
            goto end_rename;
780 
    }
781 
    if (!new_bh)
782 
        new_bh = xiafs_add_entry(new_dir, new_name, new_len, &new_de, &new_de_pre);
783 
    retval = -ENOSPC;
784 
    if (!new_bh)
785 
        goto end_rename;
786 
    /* sanity checking */
787 
    if ( (new_inode && (new_de->d_ino != new_inode->i_ino))
788 
            || (new_de->d_ino && !new_inode)
789 
            || (old_de->d_ino != old_inode->i_ino)) {
790 
        xiafs_rm_entry(new_de, new_de_pre);
791 
        brelse(old_bh);
792 
        brelse(new_bh);
793 
        brelse(dir_bh);
794 
        iput(old_inode);
795 
        iput(new_inode);
796 
        current->counter=0;
797 
        schedule();
798 
        goto try_again;
799 
    }
800 
    xiafs_rm_entry(old_de, old_de_pre);
801 
    new_de->d_ino = old_inode->i_ino;
802 
    if (new_inode) {
803 
        new_inode->i_nlink--;
804 
        new_inode->i_dirt = 1;
805 
    }
806 
    mark_buffer_dirty(old_bh, 1);
807 
    mark_buffer_dirty(new_bh, 1);
808 
    if (dir_bh) {
809 
        PARENT_INO(dir_bh->b_data) = new_dir->i_ino;
810 
        mark_buffer_dirty(dir_bh, 1);
811 
        old_dir->i_nlink--;
812 
        new_dir->i_nlink++;
813 
        old_dir->i_dirt = 1;
814 
        new_dir->i_dirt = 1;
815 
    }
816 
    retval = 0;
817 
end_rename:
818 
    brelse(dir_bh);
819 
    brelse(old_bh);
820 
    brelse(new_bh);
821 
    iput(old_inode);
822 
    iput(new_inode);
823 
    iput(old_dir);
824 
    iput(new_dir);
825 
    return retval;
826 
}
827 
 
828 
/*
829 
 * Ok, rename also locks out other renames, as they can change the parent of
830 
 * a directory, and we don't want any races. Other races are checked for by
831 
 * "do_rename()", which restarts if there are inconsistencies.
832 
 *
833 
 * Note that there is no race between different filesystems: it's only within
834 
 * the same device that races occur: many renames can happen at once, as long
835 
 * as they are on different partitions.
836 
 */
837 
int xiafs_rename(struct inode * old_dir, const char * old_name, int old_len,
838 
        struct inode * new_dir, const char * new_name, int new_len,
839 
        int must_be_dir)
840 
{
841 
    static struct wait_queue * wait = NULL;
842 
    static int lock = 0;
843 
    int result;
844 
 
845 
    while (lock)
846 
        sleep_on(&wait);
847 
    lock = 1;
848 
    result = do_xiafs_rename(old_dir, old_name, old_len,
849 
                           new_dir, new_name, new_len,
850 
                           must_be_dir);
851 
    lock = 0;
852 
    wake_up(&wait);
853 
    return result;
854 
}

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