Commit | Line | Data |
---|---|---|
76335100 | 1 | /* ufs_lookup.c 6.13 84/07/08 */ |
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" |
84ef30ec | 13 | #include "../h/kernel.h" |
10873320 | 14 | |
4a0415d6 | 15 | struct buf *blkatoff(); |
db9631a2 | 16 | struct buf *freenamebuf; |
4f083fd7 | 17 | int dirchk = 0; |
f93197fc KM |
18 | |
19 | /* | |
20 | * Structures associated with name cacheing. | |
21 | */ | |
22 | #define NCHHASH 32 /* size of hash table */ | |
23 | ||
24 | #if ((NCHHASH)&((NCHHASH)-1)) != 0 | |
25 | #define NHASH(h, i, d) ((unsigned)((h) + (i) + 13 * (int)(d)) % (NCHHASH)) | |
26 | #else | |
27 | #define NHASH(h, i, d) ((unsigned)((h) + (i) + 13 * (int)(d)) & ((NCHHASH)-1)) | |
28 | #endif | |
29 | ||
30 | union nchash { | |
31 | union nchash *nch_head[2]; | |
32 | struct nch *nch_chain[2]; | |
33 | } nchash[NCHHASH]; | |
34 | #define nch_forw nch_chain[0] | |
35 | #define nch_back nch_chain[1] | |
36 | ||
d17f522c KM |
37 | struct nch *nchhead, **nchtail; /* LRU chain pointers */ |
38 | struct nchstats nchstats; /* cache effectiveness statistics */ | |
f93197fc | 39 | |
10873320 | 40 | /* |
6bd0bb92 BJ |
41 | * Convert a pathname into a pointer to a locked inode, |
42 | * with side effects usable in creating and removing files. | |
43 | * This is a very central and rather complicated routine. | |
44 | * | |
d870be74 KM |
45 | * The segflg defines whether the name is to be copied from user |
46 | * space or kernel space. | |
4f083fd7 SL |
47 | * |
48 | * The flag argument is (LOOKUP, CREATE, DELETE) depending on whether | |
49 | * the name is to be (looked up, created, deleted). If flag has | |
50 | * LOCKPARENT or'ed into it and the target of the pathname exists, | |
51 | * namei returns both the target and its parent directory locked. | |
52 | * If the file system is not maintained in a strict tree hierarchy, | |
53 | * this can result in a deadlock situation. When creating and | |
54 | * LOCKPARENT is specified, the target may not be ".". When deleting | |
55 | * and LOCKPARENT is specified, the target may be ".", but the caller | |
56 | * must check to insure it does an irele and iput instead of two iputs. | |
57 | * | |
d870be74 | 58 | * The FOLLOW flag is set when symbolic links are to be followed |
4f083fd7 | 59 | * when they occur at the end of the name translation process. |
10873320 | 60 | * |
f93197fc KM |
61 | * Name caching works as follows: |
62 | * | |
63 | * names found by directory scans are retained in a cache | |
64 | * for future reference. It is managed LRU, so frequently | |
65 | * used names will hang around. Cache is indexed by hash value | |
66 | * obtained from (ino,dev,name) where ino & dev refer to the | |
67 | * directory containing name. | |
68 | * | |
69 | * For simplicity (and economy of storage), names longer than | |
70 | * some (small) maximum length are not cached, they occur | |
71 | * infrequently in any case, and are almost never of interest. | |
72 | * | |
73 | * Upon reaching the last segment of a path, if the reference | |
74 | * is for DELETE, or NOCACHE is set (rewrite), and the | |
75 | * name is located in the cache, it will be dropped. | |
76 | * | |
77 | * We must be sure never to enter the name ".." into the cache | |
78 | * because of the extremely kludgey way that rename() alters | |
79 | * ".." in a situation like | |
80 | * mv a/x b/x | |
81 | * where x is a directory, and x/.. is the ".." in question. | |
82 | * | |
83 | * Overall outline of namei: | |
6bd0bb92 BJ |
84 | * |
85 | * copy in name | |
86 | * get starting directory | |
87 | * dirloop: | |
88 | * check accessibility of directory | |
89 | * dirloop2: | |
d870be74 | 90 | * copy next component of name to ndp->ni_dent |
6bd0bb92 | 91 | * handle degenerate case where name is null string |
f93197fc KM |
92 | * look for name in cache, if found, then if at end of path |
93 | * and deleting or creating, drop it, else to haveino | |
6bd0bb92 BJ |
94 | * search for name in directory, to found or notfound |
95 | * notfound: | |
4f083fd7 | 96 | * if creating, return locked directory, leaving info on avail. slots |
6bd0bb92 BJ |
97 | * else return error |
98 | * found: | |
99 | * if at end of path and deleting, return information to allow delete | |
f93197fc | 100 | * if at end of path and rewriting (create and LOCKPARENT), lock target |
4f083fd7 | 101 | * inode and return info to allow rewrite |
6bd0bb92 | 102 | * if .. and on mounted filesys, look in mount table for parent |
f93197fc KM |
103 | * if not at end, if neither creating nor deleting, add name to cache |
104 | * haveino: | |
6bd0bb92 BJ |
105 | * if symbolic link, massage name in buffer and continue at dirloop |
106 | * if more components of name, do next level at dirloop | |
107 | * return the answer as locked inode | |
4f083fd7 SL |
108 | * |
109 | * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent inode, | |
110 | * but unlocked. | |
10873320 BJ |
111 | */ |
112 | struct inode * | |
d870be74 KM |
113 | namei(ndp) |
114 | register struct nameidata *ndp; | |
10873320 | 115 | { |
6bd0bb92 BJ |
116 | register char *cp; /* pointer into pathname argument */ |
117 | /* these variables refer to things which must be freed or unlocked */ | |
118 | register struct inode *dp = 0; /* the directory we are searching */ | |
f93197fc | 119 | register struct nch *ncp; /* cache slot for entry */ |
6bd0bb92 BJ |
120 | register struct fs *fs; /* file system that directory is in */ |
121 | register struct buf *bp = 0; /* a buffer of directory entries */ | |
122 | register struct direct *ep; /* the current directory entry */ | |
123 | int entryoffsetinblock; /* offset of ep in bp's buffer */ | |
124 | register struct buf *nbp; /* buffer storing path name argument */ | |
125 | /* these variables hold information about the search for a slot */ | |
126 | enum {NONE, COMPACT, FOUND} slotstatus; | |
127 | int slotoffset = -1; /* offset of area with free space */ | |
128 | int slotsize; /* size of area at slotoffset */ | |
129 | int slotfreespace; /* amount of space free in slot */ | |
130 | int slotneeded; /* size of the entry we're seeking */ | |
131 | /* */ | |
84ef30ec KM |
132 | int numdirpasses; /* strategy for directory search */ |
133 | int endsearch; /* offset to end directory search */ | |
d870be74 | 134 | int prevoff; /* ndp->ni_offset of previous entry */ |
6bd0bb92 BJ |
135 | int nlink = 0; /* number of symbolic links taken */ |
136 | struct inode *pdp; /* saved dp during symlink work */ | |
d870be74 | 137 | int error, i; |
4f083fd7 | 138 | int lockparent; |
f93197fc KM |
139 | int docache; |
140 | unsigned hash; /* value of name hash for entry */ | |
141 | union nchash *nhp; /* cache chain head for entry */ | |
142 | int isdotdot; /* != 0 if current name is ".." */ | |
d870be74 | 143 | int flag; /* op ie, LOOKUP, CREATE, or DELETE */ |
10873320 | 144 | |
d870be74 KM |
145 | lockparent = ndp->ni_nameiop & LOCKPARENT; |
146 | docache = (ndp->ni_nameiop & NOCACHE) ^ NOCACHE; | |
147 | flag = ndp->ni_nameiop &~ (LOCKPARENT|NOCACHE|FOLLOW); | |
f93197fc KM |
148 | if (flag == DELETE) |
149 | docache = 0; | |
f5039631 | 150 | /* |
6bd0bb92 BJ |
151 | * Get a buffer for the name to be translated, and copy the |
152 | * name into the buffer. | |
f5039631 | 153 | */ |
db9631a2 KM |
154 | nbp = freenamebuf; |
155 | if (nbp == NULL) | |
156 | nbp = geteblk(MAXPATHLEN); | |
157 | else | |
158 | freenamebuf = nbp->av_forw; | |
d870be74 | 159 | if (ndp->ni_segflg == UIO_SYSSPACE) |
76335100 KM |
160 | error = copystr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
161 | (u_int *)0); | |
d870be74 | 162 | else |
76335100 KM |
163 | error = copyinstr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
164 | (u_int *)0); | |
d870be74 KM |
165 | if (error) { |
166 | u.u_error = error; | |
6bd0bb92 | 167 | goto bad; |
d870be74 | 168 | } |
6bd0bb92 | 169 | |
10873320 | 170 | /* |
6bd0bb92 | 171 | * Get starting directory. |
10873320 | 172 | */ |
6bd0bb92 | 173 | cp = nbp->b_un.b_addr; |
f5039631 BJ |
174 | if (*cp == '/') { |
175 | while (*cp == '/') | |
176 | cp++; | |
10873320 BJ |
177 | if ((dp = u.u_rdir) == NULL) |
178 | dp = rootdir; | |
6bd0bb92 BJ |
179 | } else |
180 | dp = u.u_cdir; | |
181 | fs = dp->i_fs; | |
56700195 | 182 | ILOCK(dp); |
f5039631 | 183 | dp->i_count++; |
d870be74 | 184 | ndp->ni_pdir = (struct inode *)0xc0000000; /* illegal */ |
6bd0bb92 | 185 | |
10873320 | 186 | /* |
6bd0bb92 BJ |
187 | * We come to dirloop to search a new directory. |
188 | * The directory must be locked so that it can be | |
189 | * iput, and fs must be already set to dp->i_fs. | |
10873320 | 190 | */ |
6bd0bb92 | 191 | dirloop: |
a0aead5a | 192 | /* |
6bd0bb92 | 193 | * Check accessiblity of directory. |
a0aead5a | 194 | */ |
6bd0bb92 | 195 | if ((dp->i_mode&IFMT) != IFDIR) { |
10873320 | 196 | u.u_error = ENOTDIR; |
6bd0bb92 BJ |
197 | goto bad; |
198 | } | |
199 | if (access(dp, IEXEC)) | |
200 | goto bad; | |
201 | ||
6f004ab5 | 202 | dirloop2: |
6bd0bb92 | 203 | /* |
d870be74 | 204 | * Copy next component of name to ndp->ni_dent. |
6bd0bb92 | 205 | */ |
f93197fc | 206 | hash = 0; |
6bd0bb92 | 207 | for (i = 0; *cp != 0 && *cp != '/'; cp++) { |
6459ebe0 | 208 | if (i >= MAXNAMLEN) { |
f5039631 | 209 | u.u_error = ENOENT; |
6bd0bb92 | 210 | goto bad; |
6459ebe0 | 211 | } |
d870be74 KM |
212 | if ((*cp&0377) == ('/'|0200) || (*cp&0200) && flag != DELETE) { |
213 | u.u_error = EPERM; | |
214 | goto bad; | |
215 | } | |
216 | ndp->ni_dent.d_name[i++] = *cp; | |
f93197fc | 217 | hash += (unsigned char)*cp * i; |
6459ebe0 | 218 | } |
d870be74 KM |
219 | ndp->ni_dent.d_namlen = i; |
220 | ndp->ni_dent.d_name[i] = '\0'; | |
4a287f19 | 221 | isdotdot = (i == 2 && |
d870be74 | 222 | ndp->ni_dent.d_name[0] == '.' && ndp->ni_dent.d_name[1] == '.'); |
6bd0bb92 BJ |
223 | |
224 | /* | |
225 | * Check for degenerate name (e.g. / or "") | |
226 | * which is a way of talking about a directory, | |
227 | * e.g. like "/." or ".". | |
228 | */ | |
d870be74 | 229 | if (ndp->ni_dent.d_name[0] == '\0') { |
f93197fc | 230 | if (flag != LOOKUP || lockparent) { |
78abd7aa | 231 | u.u_error = EISDIR; |
6bd0bb92 | 232 | goto bad; |
f5039631 | 233 | } |
db9631a2 KM |
234 | nbp->av_forw = freenamebuf; |
235 | freenamebuf = nbp; | |
6459ebe0 | 236 | return (dp); |
f5039631 | 237 | } |
6bd0bb92 | 238 | |
f93197fc KM |
239 | /* |
240 | * We now have a segment name to search for, and a directory to search. | |
241 | * | |
242 | * Before tediously performing a linear scan of the directory, | |
243 | * check the name cache to see if the directory/name pair | |
244 | * we are looking for is known already. We don't do this | |
245 | * if the segment name is long, simply so the cache can avoid | |
246 | * holding long names (which would either waste space, or | |
247 | * add greatly to the complexity). | |
248 | */ | |
d870be74 | 249 | if (ndp->ni_dent.d_namlen > NCHNAMLEN) { |
f93197fc KM |
250 | nchstats.ncs_long++; |
251 | docache = 0; | |
252 | } else { | |
253 | nhp = &nchash[NHASH(hash, dp->i_number, dp->i_dev)]; | |
254 | for (ncp = nhp->nch_forw; ncp != (struct nch *)nhp; | |
255 | ncp = ncp->nc_forw) { | |
256 | if (ncp->nc_ino == dp->i_number && | |
257 | ncp->nc_dev == dp->i_dev && | |
d870be74 KM |
258 | ncp->nc_nlen == ndp->ni_dent.d_namlen && |
259 | !bcmp(ncp->nc_name, ndp->ni_dent.d_name, | |
260 | ncp->nc_nlen)) | |
f93197fc KM |
261 | break; |
262 | } | |
263 | ||
264 | if (ncp == (struct nch *)nhp) { | |
265 | nchstats.ncs_miss++; | |
266 | ncp = NULL; | |
267 | } else { | |
4a287f19 | 268 | if (ncp->nc_id != ncp->nc_ip->i_id) { |
8ac1234a | 269 | nchstats.ncs_falsehits++; |
4a287f19 KM |
270 | } else if (*cp == '\0' && !docache) { |
271 | nchstats.ncs_badhits++; | |
272 | } else { | |
f93197fc KM |
273 | |
274 | /* | |
275 | * move this slot to end of LRU | |
276 | * chain, if not already there | |
277 | */ | |
278 | if (ncp->nc_nxt) { | |
279 | /* remove from LRU chain */ | |
280 | *ncp->nc_prev = ncp->nc_nxt; | |
281 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
282 | ||
283 | /* and replace at end of it */ | |
284 | ncp->nc_nxt = NULL; | |
285 | ncp->nc_prev = nchtail; | |
286 | *nchtail = ncp; | |
287 | nchtail = &ncp->nc_nxt; | |
288 | } | |
289 | ||
4a287f19 KM |
290 | /* |
291 | * Get the next inode in the path. | |
56700195 | 292 | * See comment above other `IUNLOCK' code for |
4a287f19 KM |
293 | * an explaination of the locking protocol. |
294 | */ | |
f93197fc KM |
295 | pdp = dp; |
296 | dp = ncp->nc_ip; | |
297 | if (dp == NULL) | |
298 | panic("nami: null cache ino"); | |
8ac1234a | 299 | if (pdp == dp) |
f93197fc | 300 | dp->i_count++; |
56700195 | 301 | else { |
4a287f19 | 302 | if (isdotdot) { |
56700195 | 303 | IUNLOCK(pdp); |
4a287f19 KM |
304 | igrab(dp); |
305 | } else { | |
306 | igrab(dp); | |
56700195 | 307 | IUNLOCK(pdp); |
4a287f19 | 308 | } |
8ac1234a | 309 | } |
f93197fc | 310 | |
4a287f19 KM |
311 | /* |
312 | * Verify that the inode that we got | |
313 | * did not change while we were waiting | |
314 | * for it to be locked. | |
315 | */ | |
316 | if (ncp->nc_id != ncp->nc_ip->i_id) { | |
317 | iput(dp); | |
56700195 | 318 | ILOCK(pdp); |
4a287f19 KM |
319 | dp = pdp; |
320 | nchstats.ncs_falsehits++; | |
321 | } else { | |
d870be74 KM |
322 | ndp->ni_dent.d_ino = dp->i_number; |
323 | /* ni_dent.d_reclen is garbage ... */ | |
4a287f19 KM |
324 | nchstats.ncs_goodhits++; |
325 | goto haveino; | |
326 | } | |
327 | } | |
f93197fc KM |
328 | |
329 | /* | |
8ac1234a SL |
330 | * Last component and we are renaming or deleting, |
331 | * the cache entry is invalid, or otherwise don't | |
332 | * want cache entry to exist. | |
f93197fc KM |
333 | */ |
334 | ||
f93197fc KM |
335 | /* remove from LRU chain */ |
336 | *ncp->nc_prev = ncp->nc_nxt; | |
337 | if (ncp->nc_nxt) | |
338 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
339 | else | |
340 | nchtail = ncp->nc_prev; | |
341 | ||
342 | /* remove from hash chain */ | |
343 | remque(ncp); | |
344 | ||
f93197fc KM |
345 | /* insert at head of LRU list (first to grab) */ |
346 | ncp->nc_nxt = nchhead; | |
347 | ncp->nc_prev = &nchhead; | |
348 | nchhead->nc_prev = &ncp->nc_nxt; | |
349 | nchhead = ncp; | |
350 | ||
351 | /* and make a dummy hash chain */ | |
352 | ncp->nc_forw = ncp; | |
353 | ncp->nc_back = ncp; | |
354 | ||
355 | ncp = NULL; | |
356 | } | |
357 | } | |
358 | ||
6459ebe0 | 359 | /* |
6bd0bb92 BJ |
360 | * Suppress search for slots unless creating |
361 | * file and at end of pathname, in which case | |
362 | * we watch for a place to put the new file in | |
363 | * case it doesn't already exist. | |
6459ebe0 | 364 | */ |
6bd0bb92 | 365 | slotstatus = FOUND; |
4f083fd7 | 366 | if (flag == CREATE && *cp == 0) { |
6bd0bb92 BJ |
367 | slotstatus = NONE; |
368 | slotfreespace = 0; | |
d870be74 | 369 | slotneeded = DIRSIZ(&ndp->ni_dent); |
6bd0bb92 | 370 | } |
84ef30ec KM |
371 | /* |
372 | * If this is the same directory that this process | |
373 | * previously searched, pick up where we last left off. | |
f93197fc | 374 | * We cache only lookups as these are the most common |
84ef30ec KM |
375 | * and have the greatest payoff. Caching CREATE has little |
376 | * benefit as it usually must search the entire directory | |
377 | * to determine that the entry does not exist. Caching the | |
378 | * location of the last DELETE has not reduced profiling time | |
379 | * and hence has been removed in the interest of simplicity. | |
380 | */ | |
381 | if (flag != LOOKUP || dp->i_number != u.u_ncache.nc_inumber || | |
382 | dp->i_dev != u.u_ncache.nc_dev) { | |
d870be74 | 383 | ndp->ni_offset = 0; |
84ef30ec KM |
384 | numdirpasses = 1; |
385 | } else { | |
f93197fc | 386 | if ((dp->i_flag & ICHG) || dp->i_ctime >= u.u_ncache.nc_time) { |
84ef30ec KM |
387 | u.u_ncache.nc_prevoffset &= ~(DIRBLKSIZ - 1); |
388 | u.u_ncache.nc_time = time.tv_sec; | |
389 | } | |
d870be74 KM |
390 | ndp->ni_offset = u.u_ncache.nc_prevoffset; |
391 | entryoffsetinblock = blkoff(fs, ndp->ni_offset); | |
84ef30ec | 392 | if (entryoffsetinblock != 0) { |
d870be74 | 393 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
84ef30ec KM |
394 | if (bp == 0) |
395 | goto bad; | |
396 | } | |
397 | numdirpasses = 2; | |
f93197fc | 398 | nchstats.ncs_2passes++; |
84ef30ec KM |
399 | } |
400 | endsearch = roundup(dp->i_size, DIRBLKSIZ); | |
6bd0bb92 | 401 | |
84ef30ec | 402 | searchloop: |
d870be74 | 403 | while (ndp->ni_offset < endsearch) { |
f5039631 BJ |
404 | /* |
405 | * If offset is on a block boundary, | |
406 | * read the next directory block. | |
407 | * Release previous if it exists. | |
408 | */ | |
d870be74 | 409 | if (blkoff(fs, ndp->ni_offset) == 0) { |
f5039631 BJ |
410 | if (bp != NULL) |
411 | brelse(bp); | |
d870be74 | 412 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
6bd0bb92 BJ |
413 | if (bp == 0) |
414 | goto bad; | |
415 | entryoffsetinblock = 0; | |
6459ebe0 | 416 | } |
6bd0bb92 | 417 | |
6459ebe0 | 418 | /* |
6bd0bb92 | 419 | * If still looking for a slot, and at a DIRBLKSIZE |
d82d5deb | 420 | * boundary, have to start looking for free space again. |
6459ebe0 | 421 | */ |
6bd0bb92 BJ |
422 | if (slotstatus == NONE && |
423 | (entryoffsetinblock&(DIRBLKSIZ-1)) == 0) { | |
424 | slotoffset = -1; | |
425 | slotfreespace = 0; | |
426 | } | |
427 | ||
428 | /* | |
d82d5deb KM |
429 | * Get pointer to next entry. |
430 | * Full validation checks are slow, so we only check | |
431 | * enough to insure forward progress through the | |
432 | * directory. Complete checks can be run by patching | |
433 | * "dirchk" to be true. | |
6bd0bb92 BJ |
434 | */ |
435 | ep = (struct direct *)(bp->b_un.b_addr + entryoffsetinblock); | |
d82d5deb KM |
436 | if (ep->d_reclen <= 0 || |
437 | dirchk && dirbadentry(ep, entryoffsetinblock)) { | |
d870be74 | 438 | dirbad(dp, ndp->ni_offset, "mangled entry"); |
d82d5deb | 439 | i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); |
d870be74 | 440 | ndp->ni_offset += i; |
6bd0bb92 | 441 | entryoffsetinblock += i; |
6459ebe0 KM |
442 | continue; |
443 | } | |
6bd0bb92 | 444 | |
6459ebe0 | 445 | /* |
6bd0bb92 | 446 | * If an appropriate sized slot has not yet been found, |
6459ebe0 KM |
447 | * check to see if one is available. Also accumulate space |
448 | * in the current block so that we can determine if | |
449 | * compaction is viable. | |
450 | */ | |
6bd0bb92 BJ |
451 | if (slotstatus != FOUND) { |
452 | int size = ep->d_reclen; | |
453 | ||
6459ebe0 KM |
454 | if (ep->d_ino != 0) |
455 | size -= DIRSIZ(ep); | |
456 | if (size > 0) { | |
6bd0bb92 BJ |
457 | if (size >= slotneeded) { |
458 | slotstatus = FOUND; | |
d870be74 | 459 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
460 | slotsize = ep->d_reclen; |
461 | } else if (slotstatus == NONE) { | |
462 | slotfreespace += size; | |
463 | if (slotoffset == -1) | |
d870be74 | 464 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
465 | if (slotfreespace >= slotneeded) { |
466 | slotstatus = COMPACT; | |
d870be74 KM |
467 | slotsize = ndp->ni_offset + |
468 | ep->d_reclen - slotoffset; | |
6bd0bb92 | 469 | } |
6459ebe0 | 470 | } |
f5039631 | 471 | } |
f5039631 | 472 | } |
6bd0bb92 | 473 | |
f5039631 | 474 | /* |
6bd0bb92 | 475 | * Check for a name match. |
f5039631 | 476 | */ |
6bd0bb92 | 477 | if (ep->d_ino) { |
d870be74 KM |
478 | if (ep->d_namlen == ndp->ni_dent.d_namlen && |
479 | !bcmp(ndp->ni_dent.d_name, ep->d_name, | |
480 | ep->d_namlen)) | |
6bd0bb92 BJ |
481 | goto found; |
482 | } | |
d870be74 KM |
483 | prevoff = ndp->ni_offset; |
484 | ndp->ni_offset += ep->d_reclen; | |
6bd0bb92 BJ |
485 | entryoffsetinblock += ep->d_reclen; |
486 | } | |
f93197fc | 487 | /* notfound: */ |
84ef30ec | 488 | /* |
f93197fc | 489 | * If we started in the middle of the directory and failed |
84ef30ec KM |
490 | * to find our target, we must check the beginning as well. |
491 | */ | |
492 | if (numdirpasses == 2) { | |
493 | numdirpasses--; | |
d870be74 | 494 | ndp->ni_offset = 0; |
84ef30ec KM |
495 | endsearch = u.u_ncache.nc_prevoffset; |
496 | goto searchloop; | |
497 | } | |
6bd0bb92 BJ |
498 | /* |
499 | * If creating, and at end of pathname and current | |
4f083fd7 SL |
500 | * directory has not been removed, then can consider |
501 | * allowing file to be created. | |
6bd0bb92 | 502 | */ |
4f083fd7 | 503 | if (flag == CREATE && *cp == 0 && dp->i_nlink != 0) { |
f5039631 | 504 | /* |
6bd0bb92 BJ |
505 | * Access for write is interpreted as allowing |
506 | * creation of files in the directory. | |
f5039631 | 507 | */ |
6bd0bb92 BJ |
508 | if (access(dp, IWRITE)) |
509 | goto bad; | |
f5039631 | 510 | /* |
6bd0bb92 BJ |
511 | * Return an indication of where the new directory |
512 | * entry should be put. If we didn't find a slot, | |
d870be74 KM |
513 | * then set ndp->ni_count to 0 indicating that the new |
514 | * slot belongs at the end of the directory. If we found | |
515 | * a slot, then the new entry can be put in the range | |
516 | * [ndp->ni_offset .. ndp->ni_offset + ndp->ni_count) | |
f5039631 | 517 | */ |
84ef30ec | 518 | if (slotstatus == NONE) { |
d870be74 KM |
519 | ndp->ni_offset = roundup(dp->i_size, DIRBLKSIZ); |
520 | ndp->ni_count = 0; | |
84ef30ec | 521 | } else { |
d870be74 KM |
522 | ndp->ni_offset = slotoffset; |
523 | ndp->ni_count = slotsize; | |
5485e062 | 524 | } |
6bd0bb92 BJ |
525 | dp->i_flag |= IUPD|ICHG; |
526 | if (bp) | |
527 | brelse(bp); | |
db9631a2 KM |
528 | nbp->av_forw = freenamebuf; |
529 | freenamebuf = nbp; | |
f5039631 | 530 | /* |
6bd0bb92 BJ |
531 | * We return with the directory locked, so that |
532 | * the parameters we set up above will still be | |
533 | * valid if we actually decide to do a direnter(). | |
534 | * We return NULL to indicate that the entry doesn't | |
535 | * currently exist, leaving a pointer to the (locked) | |
d870be74 | 536 | * directory inode in ndp->ni_pdir. |
f5039631 | 537 | */ |
d870be74 | 538 | ndp->ni_pdir = dp; |
6bd0bb92 BJ |
539 | return (NULL); |
540 | } | |
541 | u.u_error = ENOENT; | |
542 | goto bad; | |
543 | found: | |
f93197fc KM |
544 | if (numdirpasses == 2) |
545 | nchstats.ncs_pass2++; | |
6bd0bb92 BJ |
546 | /* |
547 | * Check that directory length properly reflects presence | |
548 | * of this entry. | |
549 | */ | |
4a0415d6 | 550 | if (entryoffsetinblock + DIRSIZ(ep) > dp->i_size) { |
d870be74 | 551 | dirbad(dp, ndp->ni_offset, "i_size too small"); |
4a0415d6 | 552 | dp->i_size = entryoffsetinblock + DIRSIZ(ep); |
6bd0bb92 BJ |
553 | dp->i_flag |= IUPD|ICHG; |
554 | } | |
555 | ||
556 | /* | |
84ef30ec | 557 | * Found component in pathname. |
f93197fc | 558 | * If the final component of path name, save information |
84ef30ec KM |
559 | * in the cache as to where the entry was found. |
560 | */ | |
561 | if (*cp == '\0' && flag == LOOKUP) { | |
d870be74 | 562 | u.u_ncache.nc_prevoffset = ndp->ni_offset; |
84ef30ec KM |
563 | u.u_ncache.nc_inumber = dp->i_number; |
564 | u.u_ncache.nc_dev = dp->i_dev; | |
565 | u.u_ncache.nc_time = time.tv_sec; | |
566 | } | |
567 | /* | |
d870be74 | 568 | * Save directory entry in ndp->ni_dent, |
84ef30ec | 569 | * and release directory buffer. |
6bd0bb92 | 570 | */ |
d870be74 | 571 | bcopy((caddr_t)ep, (caddr_t)&ndp->ni_dent, (u_int)DIRSIZ(ep)); |
6bd0bb92 BJ |
572 | brelse(bp); |
573 | bp = NULL; | |
574 | ||
575 | /* | |
576 | * If deleting, and at end of pathname, return | |
577 | * parameters which can be used to remove file. | |
4f083fd7 | 578 | * If the lockparent flag isn't set, we return only |
d870be74 | 579 | * the directory (in ndp->ni_pdir), otherwise we go |
4f083fd7 | 580 | * on and lock the inode, being careful with ".". |
6bd0bb92 | 581 | */ |
4f083fd7 | 582 | if (flag == DELETE && *cp == 0) { |
6bd0bb92 BJ |
583 | /* |
584 | * Write access to directory required to delete files. | |
585 | */ | |
586 | if (access(dp, IWRITE)) | |
587 | goto bad; | |
d870be74 | 588 | ndp->ni_pdir = dp; /* for dirremove() */ |
6bd0bb92 | 589 | /* |
d870be74 | 590 | * Return pointer to current entry in ndp->ni_offset, |
6bd0bb92 | 591 | * and distance past previous entry (if there |
d870be74 KM |
592 | * is a previous entry in this block) in ndp->ni_count. |
593 | * Save directory inode pointer in ndp->ni_pdir for dirremove(). | |
6bd0bb92 | 594 | */ |
d870be74 KM |
595 | if ((ndp->ni_offset&(DIRBLKSIZ-1)) == 0) |
596 | ndp->ni_count = 0; | |
6bd0bb92 | 597 | else |
d870be74 | 598 | ndp->ni_count = ndp->ni_offset - prevoff; |
4f083fd7 | 599 | if (lockparent) { |
d870be74 | 600 | if (dp->i_number == ndp->ni_dent.d_ino) |
4f083fd7 SL |
601 | dp->i_count++; |
602 | else { | |
d870be74 | 603 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 604 | if (dp == NULL) { |
d870be74 | 605 | iput(ndp->ni_pdir); |
4f083fd7 SL |
606 | goto bad; |
607 | } | |
f93197fc | 608 | /* |
9ba16c41 | 609 | * If directory is "sticky", then user must own |
f93197fc KM |
610 | * the directory, or the file in it, else he |
611 | * may not delete it (unless he's root). This | |
612 | * implements append-only directories. | |
613 | */ | |
d870be74 | 614 | if ((ndp->ni_pdir->i_mode & ISVTX) && |
f93197fc | 615 | u.u_uid != 0 && |
d870be74 | 616 | u.u_uid != ndp->ni_pdir->i_uid && |
f93197fc | 617 | dp->i_uid != u.u_uid) { |
d870be74 | 618 | iput(ndp->ni_pdir); |
f93197fc KM |
619 | u.u_error = EPERM; |
620 | goto bad; | |
621 | } | |
4f083fd7 SL |
622 | } |
623 | } | |
db9631a2 KM |
624 | nbp->av_forw = freenamebuf; |
625 | freenamebuf = nbp; | |
6bd0bb92 BJ |
626 | return (dp); |
627 | } | |
628 | ||
629 | /* | |
630 | * Special handling for ".." allowing chdir out of mounted | |
631 | * file system: indirect .. in root inode to reevaluate | |
632 | * in directory file system was mounted on. | |
633 | */ | |
4a287f19 | 634 | if (isdotdot) { |
6bd0bb92 | 635 | if (dp == u.u_rdir) |
d870be74 KM |
636 | ndp->ni_dent.d_ino = dp->i_number; |
637 | else if (ndp->ni_dent.d_ino == ROOTINO && | |
6bd0bb92 BJ |
638 | dp->i_number == ROOTINO) { |
639 | for (i = 1; i < NMOUNT; i++) | |
640 | if (mount[i].m_bufp != NULL && | |
641 | mount[i].m_dev == dp->i_dev) { | |
6459ebe0 | 642 | iput(dp); |
6bd0bb92 | 643 | dp = mount[i].m_inodp; |
56700195 | 644 | ILOCK(dp); |
f5039631 | 645 | dp->i_count++; |
6bd0bb92 BJ |
646 | fs = dp->i_fs; |
647 | cp -= 2; /* back over .. */ | |
648 | goto dirloop2; | |
f5039631 | 649 | } |
10873320 | 650 | } |
6bd0bb92 BJ |
651 | } |
652 | ||
4f083fd7 SL |
653 | /* |
654 | * If rewriting (rename), return the inode and the | |
655 | * information required to rewrite the present directory | |
656 | * Must get inode of directory entry to verify it's a | |
657 | * regular file, or empty directory. | |
658 | */ | |
659 | if ((flag == CREATE && lockparent) && *cp == 0) { | |
660 | if (access(dp, IWRITE)) | |
661 | goto bad; | |
d870be74 | 662 | ndp->ni_pdir = dp; /* for dirrewrite() */ |
4f083fd7 SL |
663 | /* |
664 | * Careful about locking second inode. | |
665 | * This can only occur if the target is ".". | |
666 | */ | |
d870be74 | 667 | if (dp->i_number == ndp->ni_dent.d_ino) { |
4f083fd7 SL |
668 | u.u_error = EISDIR; /* XXX */ |
669 | goto bad; | |
670 | } | |
d870be74 | 671 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 672 | if (dp == NULL) { |
d870be74 | 673 | iput(ndp->ni_pdir); |
4f083fd7 SL |
674 | goto bad; |
675 | } | |
db9631a2 KM |
676 | nbp->av_forw = freenamebuf; |
677 | freenamebuf = nbp; | |
4f083fd7 SL |
678 | return (dp); |
679 | } | |
680 | ||
6bd0bb92 | 681 | /* |
bde63aa5 KM |
682 | * Check for symbolic link, which may require us to massage the |
683 | * name before we continue translation. We do not `iput' the | |
684 | * directory because we may need it again if the symbolic link | |
685 | * is relative to the current directory. Instead we save it | |
686 | * unlocked as "pdp". We must get the target inode before unlocking | |
687 | * the directory to insure that the inode will not be removed | |
688 | * before we get it. We prevent deadlock by always fetching | |
689 | * inodes from the root, moving down the directory tree. Thus | |
690 | * when following backward pointers ".." we must unlock the | |
691 | * parent directory before getting the requested directory. | |
692 | * There is a potential race condition here if both the current | |
693 | * and parent directories are removed before the `iget' for the | |
694 | * inode associated with ".." returns. We hope that this occurs | |
695 | * infrequently since we cannot avoid this race condition without | |
a4358a25 | 696 | * implementing a sophisticated deadlock detection algorithm. |
bde63aa5 KM |
697 | * Note also that this simple deadlock detection scheme will not |
698 | * work if the file system has any hard links other than ".." | |
699 | * that point backwards in the directory structure. | |
6bd0bb92 BJ |
700 | */ |
701 | pdp = dp; | |
f93197fc | 702 | if (isdotdot) { |
56700195 | 703 | IUNLOCK(pdp); /* race to get the inode */ |
d870be74 | 704 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
bde63aa5 KM |
705 | if (dp == NULL) |
706 | goto bad2; | |
d870be74 | 707 | } else if (dp->i_number == ndp->ni_dent.d_ino) { |
bde63aa5 KM |
708 | dp->i_count++; /* we want ourself, ie "." */ |
709 | } else { | |
d870be74 | 710 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
56700195 | 711 | IUNLOCK(pdp); |
bde63aa5 KM |
712 | if (dp == NULL) |
713 | goto bad2; | |
714 | } | |
f93197fc KM |
715 | |
716 | /* | |
717 | * insert name into cache (if we want it, and it isn't "." or "..") | |
718 | * | |
719 | * all other cases where making a cache entry would be wrong | |
720 | * have already departed from the code sequence somewhere above. | |
721 | */ | |
8ac1234a | 722 | if (docache) { |
f93197fc KM |
723 | if (ncp != NULL) |
724 | panic("nami: duplicating cache"); | |
725 | ||
726 | /* | |
727 | * free the cache slot at head of lru chain | |
728 | */ | |
729 | if (ncp = nchhead) { | |
730 | /* remove from lru chain */ | |
731 | *ncp->nc_prev = ncp->nc_nxt; | |
732 | if (ncp->nc_nxt) | |
733 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
734 | else | |
735 | nchtail = ncp->nc_prev; | |
736 | ||
737 | /* remove from old hash chain */ | |
738 | remque(ncp); | |
739 | ||
f93197fc KM |
740 | /* grab the inode we just found */ |
741 | ncp->nc_ip = dp; | |
f93197fc KM |
742 | |
743 | /* fill in cache info */ | |
744 | ncp->nc_ino = pdp->i_number; /* parents inum */ | |
745 | ncp->nc_dev = pdp->i_dev; /* & device */ | |
746 | ncp->nc_idev = dp->i_dev; /* our device */ | |
8ac1234a | 747 | ncp->nc_id = dp->i_id; /* identifier */ |
d870be74 KM |
748 | ncp->nc_nlen = ndp->ni_dent.d_namlen; |
749 | bcopy(ndp->ni_dent.d_name, ncp->nc_name, ncp->nc_nlen); | |
f93197fc KM |
750 | |
751 | /* link at end of lru chain */ | |
752 | ncp->nc_nxt = NULL; | |
753 | ncp->nc_prev = nchtail; | |
754 | *nchtail = ncp; | |
755 | nchtail = &ncp->nc_nxt; | |
756 | ||
757 | /* and insert on hash chain */ | |
758 | insque(ncp, nhp); | |
759 | } | |
760 | } | |
761 | ||
762 | haveino: | |
6bd0bb92 BJ |
763 | fs = dp->i_fs; |
764 | ||
765 | /* | |
766 | * Check for symbolic link | |
767 | */ | |
d870be74 KM |
768 | if ((dp->i_mode & IFMT) == IFLNK && |
769 | ((ndp->ni_nameiop & FOLLOW) || *cp == '/')) { | |
9f024ffc | 770 | u_int pathlen = strlen(cp) + 1; |
6bd0bb92 BJ |
771 | |
772 | if (dp->i_size + pathlen >= MAXPATHLEN - 1 || | |
773 | ++nlink > MAXSYMLINKS) { | |
774 | u.u_error = ELOOP; | |
775 | goto bad2; | |
776 | } | |
d36096be | 777 | ovbcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen); |
a6b6f679 | 778 | u.u_error = |
4f083fd7 | 779 | rdwri(UIO_READ, dp, nbp->b_un.b_addr, (int)dp->i_size, |
9f024ffc | 780 | 0, 1, (int *)0); |
6bd0bb92 BJ |
781 | if (u.u_error) |
782 | goto bad2; | |
783 | cp = nbp->b_un.b_addr; | |
784 | iput(dp); | |
f5039631 | 785 | if (*cp == '/') { |
6bd0bb92 | 786 | irele(pdp); |
f5039631 BJ |
787 | while (*cp == '/') |
788 | cp++; | |
6bd0bb92 BJ |
789 | if ((dp = u.u_rdir) == NULL) |
790 | dp = rootdir; | |
56700195 | 791 | ILOCK(dp); |
6bd0bb92 BJ |
792 | dp->i_count++; |
793 | } else { | |
794 | dp = pdp; | |
56700195 | 795 | ILOCK(dp); |
f5039631 | 796 | } |
6bd0bb92 BJ |
797 | fs = dp->i_fs; |
798 | goto dirloop; | |
10873320 | 799 | } |
6bd0bb92 | 800 | |
10873320 | 801 | /* |
6bd0bb92 BJ |
802 | * Not a symbolic link. If more pathname, |
803 | * continue at next component, else return. | |
10873320 | 804 | */ |
6bd0bb92 BJ |
805 | if (*cp == '/') { |
806 | while (*cp == '/') | |
807 | cp++; | |
4f083fd7 | 808 | irele(pdp); |
6bd0bb92 | 809 | goto dirloop; |
10873320 | 810 | } |
db9631a2 KM |
811 | nbp->av_forw = freenamebuf; |
812 | freenamebuf = nbp; | |
4f083fd7 | 813 | if (lockparent) |
d870be74 | 814 | ndp->ni_pdir = pdp; |
4f083fd7 SL |
815 | else |
816 | irele(pdp); | |
6bd0bb92 BJ |
817 | return (dp); |
818 | bad2: | |
819 | irele(pdp); | |
820 | bad: | |
821 | if (bp) | |
822 | brelse(bp); | |
823 | if (dp) | |
824 | iput(dp); | |
db9631a2 KM |
825 | nbp->av_forw = freenamebuf; |
826 | freenamebuf = nbp; | |
6459ebe0 | 827 | return (NULL); |
10873320 BJ |
828 | } |
829 | ||
f93197fc | 830 | |
d870be74 | 831 | dirbad(ip, offset, how) |
6bd0bb92 | 832 | struct inode *ip; |
d870be74 | 833 | off_t offset; |
6bd0bb92 BJ |
834 | char *how; |
835 | { | |
836 | ||
837 | printf("%s: bad dir ino %d at offset %d: %s\n", | |
d870be74 | 838 | ip->i_fs->fs_fsmnt, ip->i_number, offset, how); |
6bd0bb92 BJ |
839 | } |
840 | ||
d82d5deb KM |
841 | /* |
842 | * Do consistency checking on a directory entry: | |
843 | * record length must be multiple of 4 | |
844 | * record length must not be non-negative | |
845 | * entry must fit in rest of its DIRBLKSIZ block | |
846 | * record must be large enough to contain entry | |
847 | * name is not longer than MAXNAMLEN | |
848 | * name must be as long as advertised, and null terminated | |
849 | */ | |
850 | dirbadentry(ep, entryoffsetinblock) | |
6bd0bb92 | 851 | register struct direct *ep; |
d82d5deb | 852 | int entryoffsetinblock; |
6bd0bb92 | 853 | { |
6bd0bb92 BJ |
854 | register int i; |
855 | ||
d82d5deb KM |
856 | if ((ep->d_reclen & 0x3) != 0 || ep->d_reclen <= 0 || |
857 | ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || | |
858 | ep->d_reclen < DIRSIZ(ep) || ep->d_namlen > MAXNAMLEN) | |
859 | return (1); | |
6bd0bb92 | 860 | for (i = 0; i < ep->d_namlen; i++) |
d870be74 | 861 | if (ep->d_name[i] == '\0') |
6bd0bb92 BJ |
862 | return (1); |
863 | return (ep->d_name[i]); | |
864 | } | |
865 | ||
6bd0bb92 BJ |
866 | /* |
867 | * Write a directory entry after a call to namei, using the parameters | |
868 | * which it left in the u. area. The argument ip is the inode which | |
d870be74 | 869 | * the new directory entry will refer to. The u. area field ndp->ni_pdir is |
6bd0bb92 | 870 | * a pointer to the directory to be written, which was left locked by |
d870be74 | 871 | * namei. Remaining parameters (ndp->ni_offset, ndp->ni_count) indicate |
6bd0bb92 BJ |
872 | * how the space for the new entry is to be gotten. |
873 | */ | |
d870be74 | 874 | direnter(ip, ndp) |
6bd0bb92 | 875 | struct inode *ip; |
d870be74 | 876 | register struct nameidata *ndp; |
f5039631 | 877 | { |
6bd0bb92 | 878 | register struct direct *ep, *nep; |
6bd0bb92 | 879 | struct buf *bp; |
efa3a91c | 880 | int loc, spacefree, error = 0; |
b32450f4 BJ |
881 | u_int dsize; |
882 | int newentrysize; | |
6bd0bb92 | 883 | char *dirbuf; |
f5039631 | 884 | |
d870be74 KM |
885 | ndp->ni_dent.d_ino = ip->i_number; |
886 | newentrysize = DIRSIZ(&ndp->ni_dent); | |
887 | if (ndp->ni_count == 0) { | |
6bd0bb92 | 888 | /* |
d870be74 KM |
889 | * If ndp->ni_count is 0, then namei could find no space in the |
890 | * directory. In this case ndp->ni_offset will be on a directory | |
6bd0bb92 BJ |
891 | * block boundary and we will write the new entry into a fresh |
892 | * block. | |
893 | */ | |
d870be74 | 894 | if (ndp->ni_offset&(DIRBLKSIZ-1)) |
6bd0bb92 | 895 | panic("wdir: newblk"); |
d870be74 KM |
896 | ndp->ni_dent.d_reclen = DIRBLKSIZ; |
897 | error = rdwri(UIO_WRITE, ndp->ni_pdir, (caddr_t)&ndp->ni_dent, | |
898 | newentrysize, ndp->ni_offset, 1, (int *)0); | |
899 | iput(ndp->ni_pdir); | |
f2a5ad78 | 900 | return (error); |
6bd0bb92 BJ |
901 | } |
902 | ||
903 | /* | |
d870be74 KM |
904 | * If ndp->ni_count is non-zero, then namei found space for the new |
905 | * entry in the range ndp->ni_offset to ndp->ni_offset + ndp->ni_count. | |
6bd0bb92 BJ |
906 | * in the directory. To use this space, we may have to compact |
907 | * the entries located there, by copying them together towards | |
908 | * the beginning of the block, leaving the free space in | |
909 | * one usable chunk at the end. | |
910 | */ | |
911 | ||
912 | /* | |
913 | * Increase size of directory if entry eats into new space. | |
914 | * This should never push the size past a new multiple of | |
915 | * DIRBLKSIZE. | |
916 | */ | |
d870be74 KM |
917 | if (ndp->ni_offset + ndp->ni_count > ndp->ni_pdir->i_size) |
918 | ndp->ni_pdir->i_size = ndp->ni_offset + ndp->ni_count; | |
6bd0bb92 BJ |
919 | |
920 | /* | |
921 | * Get the block containing the space for the new directory | |
f2a5ad78 | 922 | * entry. Should return error by result instead of u.u_error. |
6bd0bb92 | 923 | */ |
d870be74 | 924 | bp = blkatoff(ndp->ni_pdir, ndp->ni_offset, (char **)&dirbuf); |
4f083fd7 | 925 | if (bp == 0) { |
d870be74 | 926 | iput(ndp->ni_pdir); |
f2a5ad78 | 927 | return (u.u_error); |
4f083fd7 | 928 | } |
6bd0bb92 BJ |
929 | |
930 | /* | |
931 | * Find space for the new entry. In the simple case, the | |
932 | * entry at offset base will have the space. If it does | |
933 | * not, then namei arranged that compacting the region | |
d870be74 | 934 | * ndp->ni_offset to ndp->ni_offset+ndp->ni_count would yield the space. |
6bd0bb92 BJ |
935 | */ |
936 | ep = (struct direct *)dirbuf; | |
937 | dsize = DIRSIZ(ep); | |
efa3a91c | 938 | spacefree = ep->d_reclen - dsize; |
d870be74 | 939 | for (loc = ep->d_reclen; loc < ndp->ni_count; ) { |
6bd0bb92 BJ |
940 | nep = (struct direct *)(dirbuf + loc); |
941 | if (ep->d_ino) { | |
942 | /* trim the existing slot */ | |
943 | ep->d_reclen = dsize; | |
944 | ep = (struct direct *)((char *)ep + dsize); | |
945 | } else { | |
946 | /* overwrite; nothing there; header is ours */ | |
efa3a91c | 947 | spacefree += dsize; |
6bd0bb92 BJ |
948 | } |
949 | dsize = DIRSIZ(nep); | |
efa3a91c | 950 | spacefree += nep->d_reclen - dsize; |
6bd0bb92 | 951 | loc += nep->d_reclen; |
9f024ffc | 952 | bcopy((caddr_t)nep, (caddr_t)ep, dsize); |
6bd0bb92 BJ |
953 | } |
954 | /* | |
955 | * Update the pointer fields in the previous entry (if any), | |
956 | * copy in the new entry, and write out the block. | |
957 | */ | |
958 | if (ep->d_ino == 0) { | |
efa3a91c | 959 | if (spacefree + dsize < newentrysize) |
6bd0bb92 | 960 | panic("wdir: compact1"); |
d870be74 | 961 | ndp->ni_dent.d_reclen = spacefree + dsize; |
6bd0bb92 | 962 | } else { |
efa3a91c | 963 | if (spacefree < newentrysize) |
6bd0bb92 | 964 | panic("wdir: compact2"); |
d870be74 | 965 | ndp->ni_dent.d_reclen = spacefree; |
6bd0bb92 BJ |
966 | ep->d_reclen = dsize; |
967 | ep = (struct direct *)((char *)ep + dsize); | |
968 | } | |
d870be74 | 969 | bcopy((caddr_t)&ndp->ni_dent, (caddr_t)ep, (u_int)newentrysize); |
6bd0bb92 | 970 | bwrite(bp); |
d870be74 KM |
971 | ndp->ni_pdir->i_flag |= IUPD|ICHG; |
972 | iput(ndp->ni_pdir); | |
f2a5ad78 | 973 | return (error); |
6bd0bb92 BJ |
974 | } |
975 | ||
4f083fd7 SL |
976 | /* |
977 | * Remove a directory entry after a call to namei, using the | |
978 | * parameters which it left in the u. area. The u. entry | |
d870be74 KM |
979 | * ni_offset contains the offset into the directory of the |
980 | * entry to be eliminated. The ni_count field contains the | |
4f083fd7 SL |
981 | * size of the previous record in the directory. If this |
982 | * is 0, the first entry is being deleted, so we need only | |
983 | * zero the inode number to mark the entry as free. If the | |
984 | * entry isn't the first in the directory, we must reclaim | |
985 | * the space of the now empty record by adding the record size | |
986 | * to the size of the previous entry. | |
987 | */ | |
d870be74 KM |
988 | dirremove(ndp) |
989 | register struct nameidata *ndp; | |
6bd0bb92 | 990 | { |
d870be74 | 991 | register struct inode *dp = ndp->ni_pdir; |
6bd0bb92 BJ |
992 | register struct buf *bp; |
993 | struct direct *ep; | |
994 | ||
d870be74 | 995 | if (ndp->ni_count == 0) { |
6bd0bb92 BJ |
996 | /* |
997 | * First entry in block: set d_ino to zero. | |
998 | */ | |
d870be74 KM |
999 | ndp->ni_dent.d_ino = 0; |
1000 | (void) rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1001 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
36d4ed87 | 1002 | } else { |
6bd0bb92 BJ |
1003 | /* |
1004 | * Collapse new free space into previous entry. | |
1005 | */ | |
d870be74 KM |
1006 | bp = blkatoff(dp, (int)(ndp->ni_offset - ndp->ni_count), |
1007 | (char **)&ep); | |
6bd0bb92 BJ |
1008 | if (bp == 0) |
1009 | return (0); | |
d870be74 | 1010 | ep->d_reclen += ndp->ni_dent.d_reclen; |
6bd0bb92 BJ |
1011 | bwrite(bp); |
1012 | dp->i_flag |= IUPD|ICHG; | |
1013 | } | |
1014 | return (1); | |
10873320 | 1015 | } |
6459ebe0 | 1016 | |
4f083fd7 SL |
1017 | /* |
1018 | * Rewrite an existing directory entry to point at the inode | |
1019 | * supplied. The parameters describing the directory entry are | |
1020 | * set up by a call to namei. | |
1021 | */ | |
d870be74 | 1022 | dirrewrite(dp, ip, ndp) |
4f083fd7 | 1023 | struct inode *dp, *ip; |
d870be74 | 1024 | struct nameidata *ndp; |
4f083fd7 SL |
1025 | { |
1026 | ||
d870be74 KM |
1027 | ndp->ni_dent.d_ino = ip->i_number; |
1028 | u.u_error = rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1029 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
4f083fd7 SL |
1030 | iput(dp); |
1031 | } | |
1032 | ||
4a0415d6 SL |
1033 | /* |
1034 | * Return buffer with contents of block "offset" | |
1035 | * from the beginning of directory "ip". If "res" | |
1036 | * is non-zero, fill it in with a pointer to the | |
1037 | * remaining space in the directory. | |
1038 | */ | |
6bd0bb92 | 1039 | struct buf * |
4a0415d6 | 1040 | blkatoff(ip, offset, res) |
6bd0bb92 BJ |
1041 | struct inode *ip; |
1042 | off_t offset; | |
1043 | char **res; | |
6459ebe0 | 1044 | { |
6bd0bb92 | 1045 | register struct fs *fs = ip->i_fs; |
3fd23f5c | 1046 | daddr_t lbn = lblkno(fs, offset); |
6bd0bb92 BJ |
1047 | int base = blkoff(fs, offset); |
1048 | int bsize = blksize(fs, ip, lbn); | |
3fd23f5c | 1049 | daddr_t bn = fsbtodb(fs, bmap(ip, lbn, B_WRITE, base, bsize)); |
6bd0bb92 | 1050 | register struct buf *bp; |
6459ebe0 | 1051 | |
6bd0bb92 BJ |
1052 | if (u.u_error) |
1053 | return (0); | |
1054 | bp = bread(ip->i_dev, bn, bsize); | |
1055 | if (bp->b_flags & B_ERROR) { | |
1056 | brelse(bp); | |
1057 | return (0); | |
1058 | } | |
1059 | if (res) | |
1060 | *res = bp->b_un.b_addr + base; | |
6bd0bb92 | 1061 | return (bp); |
6459ebe0 | 1062 | } |
4f083fd7 SL |
1063 | |
1064 | /* | |
1065 | * Check if a directory is empty or not. | |
1066 | * Inode supplied must be locked. | |
17d11193 SL |
1067 | * |
1068 | * Using a struct dirtemplate here is not precisely | |
1069 | * what we want, but better than using a struct direct. | |
1070 | * | |
1071 | * NB: does not handle corrupted directories. | |
4f083fd7 SL |
1072 | */ |
1073 | dirempty(ip) | |
05d2bbce | 1074 | register struct inode *ip; |
4f083fd7 SL |
1075 | { |
1076 | register off_t off; | |
17d11193 SL |
1077 | struct dirtemplate dbuf; |
1078 | register struct direct *dp = (struct direct *)&dbuf; | |
05d2bbce | 1079 | int error, count; |
17d11193 | 1080 | #define MINDIRSIZ (sizeof (struct dirtemplate) / 2) |
4f083fd7 SL |
1081 | |
1082 | for (off = 0; off < ip->i_size; off += dp->d_reclen) { | |
17d11193 SL |
1083 | error = rdwri(UIO_READ, ip, (caddr_t)dp, MINDIRSIZ, |
1084 | off, 1, &count); | |
1085 | /* | |
1086 | * Since we read MINDIRSIZ, residual must | |
1087 | * be 0 unless we're at end of file. | |
1088 | */ | |
1089 | if (error || count != 0) | |
4f083fd7 | 1090 | return (0); |
17d11193 | 1091 | /* skip empty entries */ |
4f083fd7 SL |
1092 | if (dp->d_ino == 0) |
1093 | continue; | |
17d11193 SL |
1094 | /* accept only "." and ".." */ |
1095 | if (dp->d_namlen > 2) | |
1096 | return (0); | |
4f083fd7 SL |
1097 | if (dp->d_name[0] != '.') |
1098 | return (0); | |
17d11193 SL |
1099 | /* |
1100 | * At this point d_namlen must be 1 or 2. | |
1101 | * 1 implies ".", 2 implies ".." if second | |
1102 | * char is also "." | |
1103 | */ | |
1104 | if (dp->d_namlen == 1 || dp->d_name[1] == '.') | |
4f083fd7 SL |
1105 | continue; |
1106 | return (0); | |
1107 | } | |
1108 | return (1); | |
1109 | } | |
b1aa93b9 KM |
1110 | |
1111 | /* | |
1112 | * Check if source directory is in the path of the target directory. | |
1113 | * Target is supplied locked, source is unlocked. | |
1114 | * The target is always iput() before returning. | |
1115 | */ | |
1116 | checkpath(source, target) | |
1117 | struct inode *source, *target; | |
1118 | { | |
1119 | struct dirtemplate dirbuf; | |
1120 | register struct inode *ip; | |
1121 | int error = 0; | |
1122 | ||
1123 | ip = target; | |
1124 | if (ip->i_number == source->i_number) { | |
1125 | error = EEXIST; | |
1126 | goto out; | |
1127 | } | |
1128 | if (ip->i_number == ROOTINO) | |
1129 | goto out; | |
1130 | ||
1131 | for (;;) { | |
1132 | if ((ip->i_mode&IFMT) != IFDIR) { | |
1133 | error = ENOTDIR; | |
1134 | break; | |
1135 | } | |
1136 | error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, | |
1137 | sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); | |
1138 | if (error != 0) | |
1139 | break; | |
1140 | if (dirbuf.dotdot_namlen != 2 || | |
4a287f19 KM |
1141 | dirbuf.dotdot_name[0] != '.' || |
1142 | dirbuf.dotdot_name[1] != '.') { | |
b1aa93b9 KM |
1143 | error = ENOTDIR; |
1144 | break; | |
1145 | } | |
1146 | if (dirbuf.dotdot_ino == source->i_number) { | |
1147 | error = EINVAL; | |
1148 | break; | |
1149 | } | |
1150 | if (dirbuf.dotdot_ino == ROOTINO) | |
1151 | break; | |
1152 | iput(ip); | |
1153 | ip = iget(ip->i_dev, ip->i_fs, dirbuf.dotdot_ino); | |
1154 | if (ip == NULL) { | |
1155 | error = u.u_error; | |
1156 | break; | |
1157 | } | |
1158 | } | |
1159 | ||
1160 | out: | |
1161 | if (error == ENOTDIR) | |
1162 | printf("checkpath: .. not a directory\n"); | |
1163 | if (ip != NULL) | |
1164 | iput(ip); | |
1165 | return (error); | |
1166 | } | |
f93197fc KM |
1167 | |
1168 | /* | |
1169 | * Name cache initialization, from main() when we are booting | |
1170 | */ | |
1171 | nchinit() | |
1172 | { | |
1173 | register union nchash *nchp; | |
1174 | register struct nch *ncp; | |
1175 | ||
1176 | nchhead = 0; | |
1177 | nchtail = &nchhead; | |
1178 | ||
1179 | for (ncp = nch; ncp < &nch[nchsize]; ncp++) { | |
1180 | ncp->nc_forw = ncp; /* hash chain */ | |
1181 | ncp->nc_back = ncp; | |
1182 | ||
1183 | ncp->nc_nxt = NULL; /* lru chain */ | |
1184 | *nchtail = ncp; | |
1185 | ncp->nc_prev = nchtail; | |
1186 | nchtail = &ncp->nc_nxt; | |
1187 | ||
1188 | /* all else is zero already */ | |
1189 | } | |
1190 | ||
1191 | for (nchp = nchash; nchp < &nchash[NCHHASH]; nchp++) { | |
1192 | nchp->nch_head[0] = nchp; | |
1193 | nchp->nch_head[1] = nchp; | |
1194 | } | |
1195 | } | |
1196 | ||
1197 | /* | |
1198 | * Cache flush, called when filesys is umounted to | |
1199 | * remove entries that would now be invalid | |
1200 | * | |
1201 | * The line "nxtcp = nchhead" near the end is to avoid potential problems | |
1202 | * if the cache lru chain is modified while we are dumping the | |
1203 | * inode. This makes the algorithm O(n^2), but do you think I care? | |
1204 | */ | |
1205 | nchinval(dev) | |
1206 | register dev_t dev; | |
1207 | { | |
1208 | register struct nch *ncp, *nxtcp; | |
1209 | ||
1210 | for (ncp = nchhead; ncp; ncp = nxtcp) { | |
1211 | nxtcp = ncp->nc_nxt; | |
1212 | ||
1213 | if (ncp->nc_ip == NULL || | |
1214 | (ncp->nc_idev != dev && ncp->nc_dev != dev)) | |
1215 | continue; | |
1216 | ||
4a287f19 | 1217 | /* free the resources we had */ |
f93197fc KM |
1218 | ncp->nc_idev = NODEV; |
1219 | ncp->nc_dev = NODEV; | |
4a287f19 | 1220 | ncp->nc_id = NULL; |
f93197fc | 1221 | ncp->nc_ino = 0; |
4a287f19 KM |
1222 | ncp->nc_ip = NULL; |
1223 | ||
f93197fc KM |
1224 | |
1225 | /* remove the entry from its hash chain */ | |
1226 | remque(ncp); | |
1227 | /* and make a dummy one */ | |
1228 | ncp->nc_forw = ncp; | |
1229 | ncp->nc_back = ncp; | |
1230 | ||
1231 | /* delete this entry from LRU chain */ | |
1232 | *ncp->nc_prev = nxtcp; | |
1233 | if (nxtcp) | |
1234 | nxtcp->nc_prev = ncp->nc_prev; | |
1235 | else | |
1236 | nchtail = ncp->nc_prev; | |
1237 | ||
f93197fc KM |
1238 | /* cause rescan of list, it may have altered */ |
1239 | nxtcp = nchhead; | |
1240 | /* put the now-free entry at head of LRU */ | |
1241 | ncp->nc_nxt = nxtcp; | |
1242 | ncp->nc_prev = &nchhead; | |
1243 | nxtcp->nc_prev = &ncp->nc_nxt; | |
1244 | nchhead = ncp; | |
1245 | } | |
1246 | } |