Commit | Line | Data |
---|---|---|
a4358a25 | 1 | /* ufs_lookup.c 4.38 83/05/18 */ |
10873320 BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
5 | #include "../h/inode.h" | |
6459ebe0 | 6 | #include "../h/fs.h" |
10873320 BJ |
7 | #include "../h/mount.h" |
8 | #include "../h/dir.h" | |
9 | #include "../h/user.h" | |
10 | #include "../h/buf.h" | |
3cbbbe12 | 11 | #include "../h/conf.h" |
9f024ffc | 12 | #include "../h/uio.h" |
4f083fd7 | 13 | #include "../h/nami.h" |
10873320 | 14 | |
4a0415d6 | 15 | struct buf *blkatoff(); |
4f083fd7 | 16 | int dirchk = 0; |
10873320 | 17 | /* |
6bd0bb92 BJ |
18 | * Convert a pathname into a pointer to a locked inode, |
19 | * with side effects usable in creating and removing files. | |
20 | * This is a very central and rather complicated routine. | |
21 | * | |
22 | * The func argument gives the routine which returns successive | |
4f083fd7 SL |
23 | * characters of the name to be translated. |
24 | * | |
25 | * The flag argument is (LOOKUP, CREATE, DELETE) depending on whether | |
26 | * the name is to be (looked up, created, deleted). If flag has | |
27 | * LOCKPARENT or'ed into it and the target of the pathname exists, | |
28 | * namei returns both the target and its parent directory locked. | |
29 | * If the file system is not maintained in a strict tree hierarchy, | |
30 | * this can result in a deadlock situation. When creating and | |
31 | * LOCKPARENT is specified, the target may not be ".". When deleting | |
32 | * and LOCKPARENT is specified, the target may be ".", but the caller | |
33 | * must check to insure it does an irele and iput instead of two iputs. | |
34 | * | |
35 | * The follow argument is 1 when symbolic links are to be followed | |
36 | * when they occur at the end of the name translation process. | |
10873320 | 37 | * |
6bd0bb92 BJ |
38 | * Overall outline: |
39 | * | |
40 | * copy in name | |
41 | * get starting directory | |
42 | * dirloop: | |
43 | * check accessibility of directory | |
44 | * dirloop2: | |
45 | * copy next component of name to u.u_dent | |
46 | * handle degenerate case where name is null string | |
47 | * search for name in directory, to found or notfound | |
48 | * notfound: | |
4f083fd7 | 49 | * if creating, return locked directory, leaving info on avail. slots |
6bd0bb92 BJ |
50 | * else return error |
51 | * found: | |
52 | * if at end of path and deleting, return information to allow delete | |
4f083fd7 SL |
53 | * if at end of path and rewriting (create and LOCKPARENT), lock targe |
54 | * inode and return info to allow rewrite | |
6bd0bb92 BJ |
55 | * if .. and on mounted filesys, look in mount table for parent |
56 | * if symbolic link, massage name in buffer and continue at dirloop | |
57 | * if more components of name, do next level at dirloop | |
58 | * return the answer as locked inode | |
4f083fd7 SL |
59 | * |
60 | * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent inode, | |
61 | * but unlocked. | |
10873320 BJ |
62 | */ |
63 | struct inode * | |
f5039631 BJ |
64 | namei(func, flag, follow) |
65 | int (*func)(), flag, follow; | |
10873320 | 66 | { |
6bd0bb92 BJ |
67 | register char *cp; /* pointer into pathname argument */ |
68 | /* these variables refer to things which must be freed or unlocked */ | |
69 | register struct inode *dp = 0; /* the directory we are searching */ | |
70 | register struct fs *fs; /* file system that directory is in */ | |
71 | register struct buf *bp = 0; /* a buffer of directory entries */ | |
72 | register struct direct *ep; /* the current directory entry */ | |
73 | int entryoffsetinblock; /* offset of ep in bp's buffer */ | |
74 | register struct buf *nbp; /* buffer storing path name argument */ | |
75 | /* these variables hold information about the search for a slot */ | |
76 | enum {NONE, COMPACT, FOUND} slotstatus; | |
77 | int slotoffset = -1; /* offset of area with free space */ | |
78 | int slotsize; /* size of area at slotoffset */ | |
79 | int slotfreespace; /* amount of space free in slot */ | |
80 | int slotneeded; /* size of the entry we're seeking */ | |
81 | /* */ | |
82 | int dirsize; | |
83 | int prevoff; /* u.u_offset of previous entry */ | |
84 | int nlink = 0; /* number of symbolic links taken */ | |
85 | struct inode *pdp; /* saved dp during symlink work */ | |
86 | int i; | |
4f083fd7 | 87 | int lockparent; |
10873320 | 88 | |
4f083fd7 SL |
89 | lockparent = flag & LOCKPARENT; |
90 | flag &= ~LOCKPARENT; | |
f5039631 | 91 | /* |
6bd0bb92 BJ |
92 | * Get a buffer for the name to be translated, and copy the |
93 | * name into the buffer. | |
f5039631 | 94 | */ |
6459ebe0 | 95 | nbp = geteblk(MAXPATHLEN); |
6bd0bb92 BJ |
96 | for (cp = nbp->b_un.b_addr; *cp = (*func)(); ) { |
97 | if ((*cp&0377) == ('/'|0200) || (*cp&0200) && flag != 2) { | |
a21ae242 | 98 | u.u_error = EPERM; |
6bd0bb92 | 99 | goto bad; |
a21ae242 | 100 | } |
a21ae242 | 101 | cp++; |
6459ebe0 | 102 | if (cp >= nbp->b_un.b_addr + MAXPATHLEN) { |
f5039631 | 103 | u.u_error = ENOENT; |
6bd0bb92 | 104 | goto bad; |
f5039631 BJ |
105 | } |
106 | } | |
6bd0bb92 BJ |
107 | if (u.u_error) |
108 | goto bad; | |
109 | ||
10873320 | 110 | /* |
6bd0bb92 | 111 | * Get starting directory. |
10873320 | 112 | */ |
6bd0bb92 | 113 | cp = nbp->b_un.b_addr; |
f5039631 BJ |
114 | if (*cp == '/') { |
115 | while (*cp == '/') | |
116 | cp++; | |
10873320 BJ |
117 | if ((dp = u.u_rdir) == NULL) |
118 | dp = rootdir; | |
6bd0bb92 BJ |
119 | } else |
120 | dp = u.u_cdir; | |
121 | fs = dp->i_fs; | |
f5039631 BJ |
122 | ilock(dp); |
123 | dp->i_count++; | |
6bd0bb92 BJ |
124 | u.u_pdir = (struct inode *)0xc0000000; /* illegal */ |
125 | ||
10873320 | 126 | /* |
6bd0bb92 BJ |
127 | * We come to dirloop to search a new directory. |
128 | * The directory must be locked so that it can be | |
129 | * iput, and fs must be already set to dp->i_fs. | |
10873320 | 130 | */ |
6bd0bb92 | 131 | dirloop: |
a0aead5a | 132 | /* |
6bd0bb92 | 133 | * Check accessiblity of directory. |
a0aead5a | 134 | */ |
6bd0bb92 | 135 | if ((dp->i_mode&IFMT) != IFDIR) { |
10873320 | 136 | u.u_error = ENOTDIR; |
6bd0bb92 BJ |
137 | goto bad; |
138 | } | |
139 | if (access(dp, IEXEC)) | |
140 | goto bad; | |
141 | ||
6f004ab5 | 142 | dirloop2: |
6bd0bb92 BJ |
143 | /* |
144 | * Copy next component of name to u.u_dent. | |
145 | */ | |
146 | for (i = 0; *cp != 0 && *cp != '/'; cp++) { | |
6459ebe0 | 147 | if (i >= MAXNAMLEN) { |
f5039631 | 148 | u.u_error = ENOENT; |
6bd0bb92 | 149 | goto bad; |
6459ebe0 | 150 | } |
6bd0bb92 | 151 | u.u_dent.d_name[i++] = *cp; |
6459ebe0 KM |
152 | } |
153 | u.u_dent.d_namlen = i; | |
6bd0bb92 BJ |
154 | u.u_dent.d_name[i] = 0; |
155 | ||
156 | /* | |
157 | * Check for degenerate name (e.g. / or "") | |
158 | * which is a way of talking about a directory, | |
159 | * e.g. like "/." or ".". | |
160 | */ | |
161 | if (u.u_dent.d_name[0] == 0) { | |
c41d8c5c | 162 | if (flag || lockparent) { |
f5039631 | 163 | u.u_error = ENOENT; |
6bd0bb92 | 164 | goto bad; |
f5039631 | 165 | } |
6459ebe0 KM |
166 | brelse(nbp); |
167 | return (dp); | |
f5039631 | 168 | } |
6bd0bb92 | 169 | |
6459ebe0 | 170 | /* |
6bd0bb92 BJ |
171 | * Suppress search for slots unless creating |
172 | * file and at end of pathname, in which case | |
173 | * we watch for a place to put the new file in | |
174 | * case it doesn't already exist. | |
6459ebe0 | 175 | */ |
6bd0bb92 | 176 | slotstatus = FOUND; |
4f083fd7 | 177 | if (flag == CREATE && *cp == 0) { |
6bd0bb92 BJ |
178 | slotstatus = NONE; |
179 | slotfreespace = 0; | |
180 | slotneeded = DIRSIZ(&u.u_dent); | |
181 | } | |
182 | ||
183 | dirsize = roundup(dp->i_size, DIRBLKSIZ); | |
6459ebe0 | 184 | u.u_offset = 0; |
6bd0bb92 | 185 | while (u.u_offset < dirsize) { |
f5039631 BJ |
186 | /* |
187 | * If offset is on a block boundary, | |
188 | * read the next directory block. | |
189 | * Release previous if it exists. | |
190 | */ | |
6459ebe0 | 191 | if (blkoff(fs, u.u_offset) == 0) { |
f5039631 BJ |
192 | if (bp != NULL) |
193 | brelse(bp); | |
4a0415d6 | 194 | bp = blkatoff(dp, u.u_offset, (char **)0); |
6bd0bb92 BJ |
195 | if (bp == 0) |
196 | goto bad; | |
197 | entryoffsetinblock = 0; | |
6459ebe0 | 198 | } |
6bd0bb92 | 199 | |
6459ebe0 | 200 | /* |
6bd0bb92 BJ |
201 | * If still looking for a slot, and at a DIRBLKSIZE |
202 | * boundary, have to start looking for free space | |
203 | * again. | |
6459ebe0 | 204 | */ |
6bd0bb92 BJ |
205 | if (slotstatus == NONE && |
206 | (entryoffsetinblock&(DIRBLKSIZ-1)) == 0) { | |
207 | slotoffset = -1; | |
208 | slotfreespace = 0; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Get pointer to next entry, and do consistency checking: | |
213 | * record length must be multiple of 4 | |
4a0415d6 | 214 | * record length must not be zero |
6bd0bb92 BJ |
215 | * entry must fit in rest of this DIRBLKSIZ block |
216 | * record must be large enough to contain name | |
4a0415d6 SL |
217 | * When dirchk is set we also check: |
218 | * name is not longer than MAXNAMLEN | |
6bd0bb92 | 219 | * name must be as long as advertised, and null terminated |
4a0415d6 SL |
220 | * Checking last two conditions is done only when dirchk is |
221 | * set, to save time. | |
6bd0bb92 BJ |
222 | */ |
223 | ep = (struct direct *)(bp->b_un.b_addr + entryoffsetinblock); | |
224 | i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); | |
4a0415d6 SL |
225 | if ((ep->d_reclen & 0x3) || ep->d_reclen == 0 || |
226 | ep->d_reclen > i || DIRSIZ(ep) > ep->d_reclen || | |
227 | dirchk && (ep->d_namlen > MAXNAMLEN || dirbadname(ep))) { | |
6bd0bb92 | 228 | dirbad(dp, "mangled entry"); |
6459ebe0 | 229 | u.u_offset += i; |
6bd0bb92 | 230 | entryoffsetinblock += i; |
6459ebe0 KM |
231 | continue; |
232 | } | |
6bd0bb92 | 233 | |
6459ebe0 | 234 | /* |
6bd0bb92 | 235 | * If an appropriate sized slot has not yet been found, |
6459ebe0 KM |
236 | * check to see if one is available. Also accumulate space |
237 | * in the current block so that we can determine if | |
238 | * compaction is viable. | |
239 | */ | |
6bd0bb92 BJ |
240 | if (slotstatus != FOUND) { |
241 | int size = ep->d_reclen; | |
242 | ||
6459ebe0 KM |
243 | if (ep->d_ino != 0) |
244 | size -= DIRSIZ(ep); | |
245 | if (size > 0) { | |
6bd0bb92 BJ |
246 | if (size >= slotneeded) { |
247 | slotstatus = FOUND; | |
248 | slotoffset = u.u_offset; | |
249 | slotsize = ep->d_reclen; | |
250 | } else if (slotstatus == NONE) { | |
251 | slotfreespace += size; | |
252 | if (slotoffset == -1) | |
253 | slotoffset = u.u_offset; | |
254 | if (slotfreespace >= slotneeded) { | |
255 | slotstatus = COMPACT; | |
256 | slotsize = | |
257 | u.u_offset+ep->d_reclen - | |
258 | slotoffset; | |
259 | } | |
6459ebe0 | 260 | } |
f5039631 | 261 | } |
f5039631 | 262 | } |
6bd0bb92 | 263 | |
f5039631 | 264 | /* |
6bd0bb92 | 265 | * Check for a name match. |
f5039631 | 266 | */ |
6bd0bb92 BJ |
267 | if (ep->d_ino) { |
268 | if (ep->d_namlen == u.u_dent.d_namlen && | |
269 | !bcmp(u.u_dent.d_name, ep->d_name, ep->d_namlen)) | |
270 | goto found; | |
271 | } | |
272 | prevoff = u.u_offset; | |
6459ebe0 | 273 | u.u_offset += ep->d_reclen; |
6bd0bb92 BJ |
274 | entryoffsetinblock += ep->d_reclen; |
275 | } | |
276 | /* notfound: */ | |
277 | /* | |
278 | * If creating, and at end of pathname and current | |
4f083fd7 SL |
279 | * directory has not been removed, then can consider |
280 | * allowing file to be created. | |
6bd0bb92 | 281 | */ |
4f083fd7 | 282 | if (flag == CREATE && *cp == 0 && dp->i_nlink != 0) { |
f5039631 | 283 | /* |
6bd0bb92 BJ |
284 | * Access for write is interpreted as allowing |
285 | * creation of files in the directory. | |
f5039631 | 286 | */ |
6bd0bb92 BJ |
287 | if (access(dp, IWRITE)) |
288 | goto bad; | |
f5039631 | 289 | /* |
6bd0bb92 BJ |
290 | * Return an indication of where the new directory |
291 | * entry should be put. If we didn't find a slot, | |
292 | * then set u.u_count to 0 indicating that the | |
293 | * new slot belongs at the end of the directory. | |
294 | * If we found a slot, then the new entry can be | |
295 | * put in the range [u.u_offset..u.u_offset+u.u_count) | |
f5039631 | 296 | */ |
6bd0bb92 BJ |
297 | if (slotstatus == NONE) |
298 | u.u_count = 0; | |
299 | else { | |
300 | u.u_offset = slotoffset; | |
301 | u.u_count = slotsize; | |
5485e062 | 302 | } |
6bd0bb92 BJ |
303 | dp->i_flag |= IUPD|ICHG; |
304 | if (bp) | |
305 | brelse(bp); | |
306 | brelse(nbp); | |
f5039631 | 307 | /* |
6bd0bb92 BJ |
308 | * We return with the directory locked, so that |
309 | * the parameters we set up above will still be | |
310 | * valid if we actually decide to do a direnter(). | |
311 | * We return NULL to indicate that the entry doesn't | |
312 | * currently exist, leaving a pointer to the (locked) | |
313 | * directory inode in u.u_pdir. | |
f5039631 | 314 | */ |
6bd0bb92 BJ |
315 | u.u_pdir = dp; |
316 | return (NULL); | |
317 | } | |
318 | u.u_error = ENOENT; | |
319 | goto bad; | |
320 | found: | |
321 | /* | |
322 | * Check that directory length properly reflects presence | |
323 | * of this entry. | |
324 | */ | |
4a0415d6 | 325 | if (entryoffsetinblock + DIRSIZ(ep) > dp->i_size) { |
6bd0bb92 | 326 | dirbad(dp, "i_size too small"); |
4a0415d6 | 327 | dp->i_size = entryoffsetinblock + DIRSIZ(ep); |
6bd0bb92 BJ |
328 | dp->i_flag |= IUPD|ICHG; |
329 | } | |
330 | ||
331 | /* | |
332 | * Found component in pathname; save directory | |
333 | * entry in u.u_dent, and release directory buffer. | |
334 | */ | |
9f024ffc | 335 | bcopy((caddr_t)ep, (caddr_t)&u.u_dent, (u_int)DIRSIZ(ep)); |
6bd0bb92 BJ |
336 | brelse(bp); |
337 | bp = NULL; | |
338 | ||
339 | /* | |
340 | * If deleting, and at end of pathname, return | |
341 | * parameters which can be used to remove file. | |
4f083fd7 SL |
342 | * If the lockparent flag isn't set, we return only |
343 | * the directory (in u.u_pdir), otherwise we go | |
344 | * on and lock the inode, being careful with ".". | |
6bd0bb92 | 345 | */ |
4f083fd7 | 346 | if (flag == DELETE && *cp == 0) { |
6bd0bb92 BJ |
347 | /* |
348 | * Write access to directory required to delete files. | |
349 | */ | |
350 | if (access(dp, IWRITE)) | |
351 | goto bad; | |
4f083fd7 | 352 | u.u_pdir = dp; /* for dirremove() */ |
6bd0bb92 BJ |
353 | /* |
354 | * Return pointer to current entry in u.u_offset, | |
355 | * and distance past previous entry (if there | |
356 | * is a previous entry in this block) in u.u_count. | |
357 | * Save directory inode pointer in u.u_pdir for dirremove(). | |
358 | */ | |
359 | if ((u.u_offset&(DIRBLKSIZ-1)) == 0) | |
360 | u.u_count = 0; | |
361 | else | |
362 | u.u_count = u.u_offset - prevoff; | |
4f083fd7 SL |
363 | if (lockparent) { |
364 | if (dp->i_number == u.u_dent.d_ino) | |
365 | dp->i_count++; | |
366 | else { | |
367 | dp = iget(dp->i_dev, fs, u.u_dent.d_ino); | |
368 | if (dp == NULL) { | |
369 | iput(u.u_pdir); | |
370 | goto bad; | |
371 | } | |
372 | } | |
373 | } | |
6bd0bb92 | 374 | brelse(nbp); |
6bd0bb92 BJ |
375 | return (dp); |
376 | } | |
377 | ||
378 | /* | |
379 | * Special handling for ".." allowing chdir out of mounted | |
380 | * file system: indirect .. in root inode to reevaluate | |
381 | * in directory file system was mounted on. | |
382 | */ | |
383 | if (u.u_dent.d_name[0] == '.' && u.u_dent.d_name[1] == '.' && | |
384 | u.u_dent.d_name[2] == '\0') { | |
385 | if (dp == u.u_rdir) | |
386 | u.u_dent.d_ino = dp->i_number; | |
387 | else if (u.u_dent.d_ino == ROOTINO && | |
388 | dp->i_number == ROOTINO) { | |
389 | for (i = 1; i < NMOUNT; i++) | |
390 | if (mount[i].m_bufp != NULL && | |
391 | mount[i].m_dev == dp->i_dev) { | |
6459ebe0 | 392 | iput(dp); |
6bd0bb92 | 393 | dp = mount[i].m_inodp; |
f5039631 BJ |
394 | ilock(dp); |
395 | dp->i_count++; | |
6bd0bb92 BJ |
396 | fs = dp->i_fs; |
397 | cp -= 2; /* back over .. */ | |
398 | goto dirloop2; | |
f5039631 | 399 | } |
10873320 | 400 | } |
6bd0bb92 BJ |
401 | } |
402 | ||
4f083fd7 SL |
403 | /* |
404 | * If rewriting (rename), return the inode and the | |
405 | * information required to rewrite the present directory | |
406 | * Must get inode of directory entry to verify it's a | |
407 | * regular file, or empty directory. | |
408 | */ | |
409 | if ((flag == CREATE && lockparent) && *cp == 0) { | |
410 | if (access(dp, IWRITE)) | |
411 | goto bad; | |
412 | u.u_pdir = dp; /* for dirrewrite() */ | |
413 | /* | |
414 | * Careful about locking second inode. | |
415 | * This can only occur if the target is ".". | |
416 | */ | |
417 | if (dp->i_number == u.u_dent.d_ino) { | |
418 | u.u_error = EISDIR; /* XXX */ | |
419 | goto bad; | |
420 | } | |
421 | dp = iget(dp->i_dev, fs, u.u_dent.d_ino); | |
422 | if (dp == NULL) { | |
423 | iput(u.u_pdir); | |
424 | goto bad; | |
425 | } | |
426 | brelse(nbp); | |
427 | return (dp); | |
428 | } | |
429 | ||
6bd0bb92 | 430 | /* |
bde63aa5 KM |
431 | * Check for symbolic link, which may require us to massage the |
432 | * name before we continue translation. We do not `iput' the | |
433 | * directory because we may need it again if the symbolic link | |
434 | * is relative to the current directory. Instead we save it | |
435 | * unlocked as "pdp". We must get the target inode before unlocking | |
436 | * the directory to insure that the inode will not be removed | |
437 | * before we get it. We prevent deadlock by always fetching | |
438 | * inodes from the root, moving down the directory tree. Thus | |
439 | * when following backward pointers ".." we must unlock the | |
440 | * parent directory before getting the requested directory. | |
441 | * There is a potential race condition here if both the current | |
442 | * and parent directories are removed before the `iget' for the | |
443 | * inode associated with ".." returns. We hope that this occurs | |
444 | * infrequently since we cannot avoid this race condition without | |
a4358a25 | 445 | * implementing a sophisticated deadlock detection algorithm. |
bde63aa5 KM |
446 | * Note also that this simple deadlock detection scheme will not |
447 | * work if the file system has any hard links other than ".." | |
448 | * that point backwards in the directory structure. | |
6bd0bb92 BJ |
449 | */ |
450 | pdp = dp; | |
bde63aa5 KM |
451 | if (bcmp(u.u_dent.d_name, "..", 3) == 0) { |
452 | iunlock(pdp); /* race to get the inode */ | |
453 | dp = iget(dp->i_dev, fs, u.u_dent.d_ino); | |
454 | if (dp == NULL) | |
455 | goto bad2; | |
456 | } else if (dp->i_number == u.u_dent.d_ino) { | |
457 | dp->i_count++; /* we want ourself, ie "." */ | |
458 | } else { | |
459 | dp = iget(dp->i_dev, fs, u.u_dent.d_ino); | |
460 | iunlock(pdp); | |
461 | if (dp == NULL) | |
462 | goto bad2; | |
463 | } | |
6bd0bb92 BJ |
464 | fs = dp->i_fs; |
465 | ||
466 | /* | |
467 | * Check for symbolic link | |
468 | */ | |
469 | if ((dp->i_mode & IFMT) == IFLNK && (follow || *cp == '/')) { | |
9f024ffc | 470 | u_int pathlen = strlen(cp) + 1; |
6bd0bb92 BJ |
471 | |
472 | if (dp->i_size + pathlen >= MAXPATHLEN - 1 || | |
473 | ++nlink > MAXSYMLINKS) { | |
474 | u.u_error = ELOOP; | |
475 | goto bad2; | |
476 | } | |
d36096be | 477 | ovbcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen); |
a6b6f679 | 478 | u.u_error = |
4f083fd7 | 479 | rdwri(UIO_READ, dp, nbp->b_un.b_addr, (int)dp->i_size, |
9f024ffc | 480 | 0, 1, (int *)0); |
6bd0bb92 BJ |
481 | if (u.u_error) |
482 | goto bad2; | |
483 | cp = nbp->b_un.b_addr; | |
484 | iput(dp); | |
f5039631 | 485 | if (*cp == '/') { |
6bd0bb92 | 486 | irele(pdp); |
f5039631 BJ |
487 | while (*cp == '/') |
488 | cp++; | |
6bd0bb92 BJ |
489 | if ((dp = u.u_rdir) == NULL) |
490 | dp = rootdir; | |
491 | ilock(dp); | |
492 | dp->i_count++; | |
493 | } else { | |
494 | dp = pdp; | |
495 | ilock(dp); | |
f5039631 | 496 | } |
6bd0bb92 BJ |
497 | fs = dp->i_fs; |
498 | goto dirloop; | |
10873320 | 499 | } |
6bd0bb92 | 500 | |
10873320 | 501 | /* |
6bd0bb92 BJ |
502 | * Not a symbolic link. If more pathname, |
503 | * continue at next component, else return. | |
10873320 | 504 | */ |
6bd0bb92 BJ |
505 | if (*cp == '/') { |
506 | while (*cp == '/') | |
507 | cp++; | |
4f083fd7 | 508 | irele(pdp); |
6bd0bb92 | 509 | goto dirloop; |
10873320 | 510 | } |
6bd0bb92 | 511 | brelse(nbp); |
4f083fd7 SL |
512 | if (lockparent) |
513 | u.u_pdir = pdp; | |
514 | else | |
515 | irele(pdp); | |
6bd0bb92 BJ |
516 | return (dp); |
517 | bad2: | |
518 | irele(pdp); | |
519 | bad: | |
520 | if (bp) | |
521 | brelse(bp); | |
522 | if (dp) | |
523 | iput(dp); | |
f5039631 | 524 | brelse(nbp); |
6459ebe0 | 525 | return (NULL); |
10873320 BJ |
526 | } |
527 | ||
6bd0bb92 BJ |
528 | dirbad(ip, how) |
529 | struct inode *ip; | |
530 | char *how; | |
531 | { | |
532 | ||
533 | printf("%s: bad dir ino %d at offset %d: %s\n", | |
534 | ip->i_fs->fs_fsmnt, ip->i_number, u.u_offset, how); | |
535 | } | |
536 | ||
537 | dirbadname(ep) | |
538 | register struct direct *ep; | |
539 | { | |
6bd0bb92 BJ |
540 | register int i; |
541 | ||
542 | for (i = 0; i < ep->d_namlen; i++) | |
543 | if (ep->d_name[i] == 0) | |
544 | return (1); | |
545 | return (ep->d_name[i]); | |
546 | } | |
547 | ||
6bd0bb92 BJ |
548 | /* |
549 | * Write a directory entry after a call to namei, using the parameters | |
550 | * which it left in the u. area. The argument ip is the inode which | |
551 | * the new directory entry will refer to. The u. area field u.u_pdir is | |
552 | * a pointer to the directory to be written, which was left locked by | |
553 | * namei. Remaining parameters (u.u_offset, u.u_count) indicate | |
554 | * how the space for the new entry is to be gotten. | |
555 | */ | |
556 | direnter(ip) | |
557 | struct inode *ip; | |
f5039631 | 558 | { |
6bd0bb92 | 559 | register struct direct *ep, *nep; |
6bd0bb92 | 560 | struct buf *bp; |
efa3a91c | 561 | int loc, spacefree, error = 0; |
b32450f4 BJ |
562 | u_int dsize; |
563 | int newentrysize; | |
6bd0bb92 | 564 | char *dirbuf; |
f5039631 | 565 | |
6bd0bb92 BJ |
566 | u.u_dent.d_ino = ip->i_number; |
567 | u.u_segflg = 1; | |
568 | newentrysize = DIRSIZ(&u.u_dent); | |
569 | if (u.u_count == 0) { | |
570 | /* | |
571 | * If u.u_count is 0, then namei could find no space in the | |
572 | * directory. In this case u.u_offset will be on a directory | |
573 | * block boundary and we will write the new entry into a fresh | |
574 | * block. | |
575 | */ | |
576 | if (u.u_offset&(DIRBLKSIZ-1)) | |
577 | panic("wdir: newblk"); | |
578 | u.u_dent.d_reclen = DIRBLKSIZ; | |
f2a5ad78 | 579 | error = rdwri(UIO_WRITE, u.u_pdir, (caddr_t)&u.u_dent, |
b32450f4 | 580 | newentrysize, u.u_offset, 1, (int *)0); |
6bd0bb92 | 581 | iput(u.u_pdir); |
f2a5ad78 | 582 | return (error); |
6bd0bb92 BJ |
583 | } |
584 | ||
585 | /* | |
586 | * If u.u_count is non-zero, then namei found space for the | |
587 | * new entry in the range u.u_offset to u.u_offset+u.u_count. | |
588 | * in the directory. To use this space, we may have to compact | |
589 | * the entries located there, by copying them together towards | |
590 | * the beginning of the block, leaving the free space in | |
591 | * one usable chunk at the end. | |
592 | */ | |
593 | ||
594 | /* | |
595 | * Increase size of directory if entry eats into new space. | |
596 | * This should never push the size past a new multiple of | |
597 | * DIRBLKSIZE. | |
598 | */ | |
4f083fd7 | 599 | if (u.u_offset + u.u_count > u.u_pdir->i_size) |
6bd0bb92 | 600 | u.u_pdir->i_size = u.u_offset + u.u_count; |
6bd0bb92 BJ |
601 | |
602 | /* | |
603 | * Get the block containing the space for the new directory | |
f2a5ad78 | 604 | * entry. Should return error by result instead of u.u_error. |
6bd0bb92 | 605 | */ |
4a0415d6 | 606 | bp = blkatoff(u.u_pdir, u.u_offset, (char **)&dirbuf); |
4f083fd7 SL |
607 | if (bp == 0) { |
608 | iput(u.u_pdir); | |
f2a5ad78 | 609 | return (u.u_error); |
4f083fd7 | 610 | } |
6bd0bb92 BJ |
611 | |
612 | /* | |
613 | * Find space for the new entry. In the simple case, the | |
614 | * entry at offset base will have the space. If it does | |
615 | * not, then namei arranged that compacting the region | |
616 | * u.u_offset to u.u_offset+u.u_count would yield the space. | |
617 | */ | |
618 | ep = (struct direct *)dirbuf; | |
619 | dsize = DIRSIZ(ep); | |
efa3a91c | 620 | spacefree = ep->d_reclen - dsize; |
6bd0bb92 BJ |
621 | for (loc = ep->d_reclen; loc < u.u_count; ) { |
622 | nep = (struct direct *)(dirbuf + loc); | |
623 | if (ep->d_ino) { | |
624 | /* trim the existing slot */ | |
625 | ep->d_reclen = dsize; | |
626 | ep = (struct direct *)((char *)ep + dsize); | |
627 | } else { | |
628 | /* overwrite; nothing there; header is ours */ | |
efa3a91c | 629 | spacefree += dsize; |
6bd0bb92 BJ |
630 | } |
631 | dsize = DIRSIZ(nep); | |
efa3a91c | 632 | spacefree += nep->d_reclen - dsize; |
6bd0bb92 | 633 | loc += nep->d_reclen; |
9f024ffc | 634 | bcopy((caddr_t)nep, (caddr_t)ep, dsize); |
6bd0bb92 BJ |
635 | } |
636 | /* | |
637 | * Update the pointer fields in the previous entry (if any), | |
638 | * copy in the new entry, and write out the block. | |
639 | */ | |
640 | if (ep->d_ino == 0) { | |
efa3a91c | 641 | if (spacefree + dsize < newentrysize) |
6bd0bb92 | 642 | panic("wdir: compact1"); |
efa3a91c | 643 | u.u_dent.d_reclen = spacefree + dsize; |
6bd0bb92 | 644 | } else { |
efa3a91c | 645 | if (spacefree < newentrysize) |
6bd0bb92 | 646 | panic("wdir: compact2"); |
efa3a91c | 647 | u.u_dent.d_reclen = spacefree; |
6bd0bb92 BJ |
648 | ep->d_reclen = dsize; |
649 | ep = (struct direct *)((char *)ep + dsize); | |
650 | } | |
3fd23f5c | 651 | bcopy((caddr_t)&u.u_dent, (caddr_t)ep, (u_int)newentrysize); |
6bd0bb92 BJ |
652 | bwrite(bp); |
653 | u.u_pdir->i_flag |= IUPD|ICHG; | |
654 | iput(u.u_pdir); | |
f2a5ad78 | 655 | return (error); |
6bd0bb92 BJ |
656 | } |
657 | ||
4f083fd7 SL |
658 | /* |
659 | * Remove a directory entry after a call to namei, using the | |
660 | * parameters which it left in the u. area. The u. entry | |
661 | * u_offset contains the offset into the directory of the | |
662 | * entry to be eliminated. The u_count field contains the | |
663 | * size of the previous record in the directory. If this | |
664 | * is 0, the first entry is being deleted, so we need only | |
665 | * zero the inode number to mark the entry as free. If the | |
666 | * entry isn't the first in the directory, we must reclaim | |
667 | * the space of the now empty record by adding the record size | |
668 | * to the size of the previous entry. | |
669 | */ | |
6bd0bb92 BJ |
670 | dirremove() |
671 | { | |
672 | register struct inode *dp = u.u_pdir; | |
6bd0bb92 BJ |
673 | register struct buf *bp; |
674 | struct direct *ep; | |
675 | ||
36d4ed87 | 676 | if (u.u_count == 0) { |
6bd0bb92 BJ |
677 | /* |
678 | * First entry in block: set d_ino to zero. | |
679 | */ | |
36d4ed87 | 680 | u.u_dent.d_ino = 0; |
954ce9b1 | 681 | (void) rdwri(UIO_WRITE, dp, (caddr_t)&u.u_dent, |
b32450f4 | 682 | (int)DIRSIZ(&u.u_dent), u.u_offset, 1, (int *)0); |
36d4ed87 | 683 | } else { |
6bd0bb92 BJ |
684 | /* |
685 | * Collapse new free space into previous entry. | |
686 | */ | |
9f024ffc | 687 | bp = blkatoff(dp, (int)(u.u_offset - u.u_count), (char **)&ep); |
6bd0bb92 BJ |
688 | if (bp == 0) |
689 | return (0); | |
690 | ep->d_reclen += u.u_dent.d_reclen; | |
6bd0bb92 BJ |
691 | bwrite(bp); |
692 | dp->i_flag |= IUPD|ICHG; | |
693 | } | |
694 | return (1); | |
10873320 | 695 | } |
6459ebe0 | 696 | |
4f083fd7 SL |
697 | /* |
698 | * Rewrite an existing directory entry to point at the inode | |
699 | * supplied. The parameters describing the directory entry are | |
700 | * set up by a call to namei. | |
701 | */ | |
702 | dirrewrite(dp, ip) | |
703 | struct inode *dp, *ip; | |
704 | { | |
705 | ||
706 | u.u_dent.d_ino = ip->i_number; | |
707 | u.u_error = rdwri(UIO_WRITE, dp, (caddr_t)&u.u_dent, | |
708 | (int)DIRSIZ(&u.u_dent), u.u_offset, 1, (int *)0); | |
709 | iput(dp); | |
710 | } | |
711 | ||
4a0415d6 SL |
712 | /* |
713 | * Return buffer with contents of block "offset" | |
714 | * from the beginning of directory "ip". If "res" | |
715 | * is non-zero, fill it in with a pointer to the | |
716 | * remaining space in the directory. | |
717 | */ | |
6bd0bb92 | 718 | struct buf * |
4a0415d6 | 719 | blkatoff(ip, offset, res) |
6bd0bb92 BJ |
720 | struct inode *ip; |
721 | off_t offset; | |
722 | char **res; | |
6459ebe0 | 723 | { |
6bd0bb92 | 724 | register struct fs *fs = ip->i_fs; |
3fd23f5c | 725 | daddr_t lbn = lblkno(fs, offset); |
6bd0bb92 BJ |
726 | int base = blkoff(fs, offset); |
727 | int bsize = blksize(fs, ip, lbn); | |
3fd23f5c | 728 | daddr_t bn = fsbtodb(fs, bmap(ip, lbn, B_WRITE, base, bsize)); |
6bd0bb92 | 729 | register struct buf *bp; |
6459ebe0 | 730 | |
6bd0bb92 BJ |
731 | if (u.u_error) |
732 | return (0); | |
733 | bp = bread(ip->i_dev, bn, bsize); | |
734 | if (bp->b_flags & B_ERROR) { | |
735 | brelse(bp); | |
736 | return (0); | |
737 | } | |
738 | if (res) | |
739 | *res = bp->b_un.b_addr + base; | |
6bd0bb92 | 740 | return (bp); |
6459ebe0 | 741 | } |
4f083fd7 SL |
742 | |
743 | /* | |
744 | * Check if a directory is empty or not. | |
745 | * Inode supplied must be locked. | |
746 | */ | |
747 | dirempty(ip) | |
05d2bbce | 748 | register struct inode *ip; |
4f083fd7 SL |
749 | { |
750 | register off_t off; | |
751 | struct direct dbuf; | |
752 | register struct direct *dp = &dbuf; | |
05d2bbce | 753 | int error, count; |
4f083fd7 SL |
754 | |
755 | for (off = 0; off < ip->i_size; off += dp->d_reclen) { | |
756 | error = rdwri(UIO_READ, ip, (caddr_t)dp, | |
05d2bbce SL |
757 | sizeof (struct direct), off, 1, &count); |
758 | count = sizeof (struct direct) - count; | |
759 | #define MINDIRSIZ (sizeof (struct direct) - (MAXNAMLEN + 1)) | |
760 | if (error || count < MINDIRSIZ || count < DIRSIZ(dp)) | |
4f083fd7 SL |
761 | return (0); |
762 | if (dp->d_ino == 0) | |
763 | continue; | |
764 | if (dp->d_name[0] != '.') | |
765 | return (0); | |
766 | if (dp->d_namlen == 1 || | |
767 | (dp->d_namlen == 2 && dp->d_name[1] == '.')) | |
768 | continue; | |
769 | return (0); | |
770 | } | |
771 | return (1); | |
772 | } |