Commit | Line | Data |
---|---|---|
23de9f20 | 1 | /* ufs_lookup.c 6.20 85/02/22 */ |
10873320 | 2 | |
94368568 JB |
3 | #include "param.h" |
4 | #include "systm.h" | |
5 | #include "inode.h" | |
6 | #include "fs.h" | |
7 | #include "mount.h" | |
8 | #include "dir.h" | |
9 | #include "user.h" | |
10 | #include "buf.h" | |
11 | #include "conf.h" | |
12 | #include "uio.h" | |
13 | #include "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 */ |
9e7c949b | 144 | off_t enduseful; /* pointer past last used dir slot */ |
10873320 | 145 | |
d870be74 KM |
146 | lockparent = ndp->ni_nameiop & LOCKPARENT; |
147 | docache = (ndp->ni_nameiop & NOCACHE) ^ NOCACHE; | |
148 | flag = ndp->ni_nameiop &~ (LOCKPARENT|NOCACHE|FOLLOW); | |
f93197fc KM |
149 | if (flag == DELETE) |
150 | docache = 0; | |
f5039631 | 151 | /* |
6bd0bb92 BJ |
152 | * Get a buffer for the name to be translated, and copy the |
153 | * name into the buffer. | |
f5039631 | 154 | */ |
db9631a2 KM |
155 | nbp = freenamebuf; |
156 | if (nbp == NULL) | |
157 | nbp = geteblk(MAXPATHLEN); | |
158 | else | |
159 | freenamebuf = nbp->av_forw; | |
d870be74 | 160 | if (ndp->ni_segflg == UIO_SYSSPACE) |
76335100 KM |
161 | error = copystr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
162 | (u_int *)0); | |
d870be74 | 163 | else |
76335100 KM |
164 | error = copyinstr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
165 | (u_int *)0); | |
d870be74 KM |
166 | if (error) { |
167 | u.u_error = error; | |
6bd0bb92 | 168 | goto bad; |
d870be74 | 169 | } |
6bd0bb92 | 170 | |
10873320 | 171 | /* |
6bd0bb92 | 172 | * Get starting directory. |
10873320 | 173 | */ |
6bd0bb92 | 174 | cp = nbp->b_un.b_addr; |
f5039631 BJ |
175 | if (*cp == '/') { |
176 | while (*cp == '/') | |
177 | cp++; | |
10873320 BJ |
178 | if ((dp = u.u_rdir) == NULL) |
179 | dp = rootdir; | |
6bd0bb92 BJ |
180 | } else |
181 | dp = u.u_cdir; | |
182 | fs = dp->i_fs; | |
56700195 | 183 | ILOCK(dp); |
f5039631 | 184 | dp->i_count++; |
d870be74 | 185 | ndp->ni_pdir = (struct inode *)0xc0000000; /* illegal */ |
9e7c949b | 186 | ndp->ni_endoff = 0; |
6bd0bb92 | 187 | |
10873320 | 188 | /* |
6bd0bb92 BJ |
189 | * We come to dirloop to search a new directory. |
190 | * The directory must be locked so that it can be | |
191 | * iput, and fs must be already set to dp->i_fs. | |
10873320 | 192 | */ |
6bd0bb92 | 193 | dirloop: |
a0aead5a | 194 | /* |
6bd0bb92 | 195 | * Check accessiblity of directory. |
a0aead5a | 196 | */ |
6bd0bb92 | 197 | if ((dp->i_mode&IFMT) != IFDIR) { |
10873320 | 198 | u.u_error = ENOTDIR; |
6bd0bb92 BJ |
199 | goto bad; |
200 | } | |
201 | if (access(dp, IEXEC)) | |
202 | goto bad; | |
203 | ||
6f004ab5 | 204 | dirloop2: |
6bd0bb92 | 205 | /* |
d870be74 | 206 | * Copy next component of name to ndp->ni_dent. |
6bd0bb92 | 207 | */ |
f93197fc | 208 | hash = 0; |
6bd0bb92 | 209 | for (i = 0; *cp != 0 && *cp != '/'; cp++) { |
6459ebe0 | 210 | if (i >= MAXNAMLEN) { |
f5039631 | 211 | u.u_error = ENOENT; |
6bd0bb92 | 212 | goto bad; |
6459ebe0 | 213 | } |
d870be74 KM |
214 | if ((*cp&0377) == ('/'|0200) || (*cp&0200) && flag != DELETE) { |
215 | u.u_error = EPERM; | |
216 | goto bad; | |
217 | } | |
218 | ndp->ni_dent.d_name[i++] = *cp; | |
f93197fc | 219 | hash += (unsigned char)*cp * i; |
6459ebe0 | 220 | } |
d870be74 KM |
221 | ndp->ni_dent.d_namlen = i; |
222 | ndp->ni_dent.d_name[i] = '\0'; | |
4a287f19 | 223 | isdotdot = (i == 2 && |
d870be74 | 224 | ndp->ni_dent.d_name[0] == '.' && ndp->ni_dent.d_name[1] == '.'); |
6bd0bb92 BJ |
225 | |
226 | /* | |
227 | * Check for degenerate name (e.g. / or "") | |
228 | * which is a way of talking about a directory, | |
229 | * e.g. like "/." or ".". | |
230 | */ | |
d870be74 | 231 | if (ndp->ni_dent.d_name[0] == '\0') { |
f93197fc | 232 | if (flag != LOOKUP || lockparent) { |
78abd7aa | 233 | u.u_error = EISDIR; |
6bd0bb92 | 234 | goto bad; |
f5039631 | 235 | } |
db9631a2 KM |
236 | nbp->av_forw = freenamebuf; |
237 | freenamebuf = nbp; | |
6459ebe0 | 238 | return (dp); |
f5039631 | 239 | } |
6bd0bb92 | 240 | |
f93197fc KM |
241 | /* |
242 | * We now have a segment name to search for, and a directory to search. | |
243 | * | |
244 | * Before tediously performing a linear scan of the directory, | |
245 | * check the name cache to see if the directory/name pair | |
246 | * we are looking for is known already. We don't do this | |
247 | * if the segment name is long, simply so the cache can avoid | |
248 | * holding long names (which would either waste space, or | |
249 | * add greatly to the complexity). | |
250 | */ | |
d870be74 | 251 | if (ndp->ni_dent.d_namlen > NCHNAMLEN) { |
f93197fc KM |
252 | nchstats.ncs_long++; |
253 | docache = 0; | |
254 | } else { | |
255 | nhp = &nchash[NHASH(hash, dp->i_number, dp->i_dev)]; | |
256 | for (ncp = nhp->nch_forw; ncp != (struct nch *)nhp; | |
257 | ncp = ncp->nc_forw) { | |
258 | if (ncp->nc_ino == dp->i_number && | |
259 | ncp->nc_dev == dp->i_dev && | |
d870be74 KM |
260 | ncp->nc_nlen == ndp->ni_dent.d_namlen && |
261 | !bcmp(ncp->nc_name, ndp->ni_dent.d_name, | |
262 | ncp->nc_nlen)) | |
f93197fc KM |
263 | break; |
264 | } | |
265 | ||
266 | if (ncp == (struct nch *)nhp) { | |
267 | nchstats.ncs_miss++; | |
268 | ncp = NULL; | |
269 | } else { | |
4a287f19 | 270 | if (ncp->nc_id != ncp->nc_ip->i_id) { |
8ac1234a | 271 | nchstats.ncs_falsehits++; |
4a287f19 KM |
272 | } else if (*cp == '\0' && !docache) { |
273 | nchstats.ncs_badhits++; | |
274 | } else { | |
f93197fc KM |
275 | |
276 | /* | |
277 | * move this slot to end of LRU | |
278 | * chain, if not already there | |
279 | */ | |
280 | if (ncp->nc_nxt) { | |
281 | /* remove from LRU chain */ | |
282 | *ncp->nc_prev = ncp->nc_nxt; | |
283 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
284 | ||
285 | /* and replace at end of it */ | |
286 | ncp->nc_nxt = NULL; | |
287 | ncp->nc_prev = nchtail; | |
288 | *nchtail = ncp; | |
289 | nchtail = &ncp->nc_nxt; | |
290 | } | |
291 | ||
4a287f19 KM |
292 | /* |
293 | * Get the next inode in the path. | |
56700195 | 294 | * See comment above other `IUNLOCK' code for |
4a287f19 KM |
295 | * an explaination of the locking protocol. |
296 | */ | |
f93197fc KM |
297 | pdp = dp; |
298 | dp = ncp->nc_ip; | |
299 | if (dp == NULL) | |
300 | panic("nami: null cache ino"); | |
8ac1234a | 301 | if (pdp == dp) |
f93197fc | 302 | dp->i_count++; |
56700195 | 303 | else { |
4a287f19 | 304 | if (isdotdot) { |
56700195 | 305 | IUNLOCK(pdp); |
4a287f19 KM |
306 | igrab(dp); |
307 | } else { | |
308 | igrab(dp); | |
56700195 | 309 | IUNLOCK(pdp); |
4a287f19 | 310 | } |
8ac1234a | 311 | } |
f93197fc | 312 | |
4a287f19 KM |
313 | /* |
314 | * Verify that the inode that we got | |
315 | * did not change while we were waiting | |
316 | * for it to be locked. | |
317 | */ | |
318 | if (ncp->nc_id != ncp->nc_ip->i_id) { | |
319 | iput(dp); | |
56700195 | 320 | ILOCK(pdp); |
4a287f19 KM |
321 | dp = pdp; |
322 | nchstats.ncs_falsehits++; | |
323 | } else { | |
d870be74 KM |
324 | ndp->ni_dent.d_ino = dp->i_number; |
325 | /* ni_dent.d_reclen is garbage ... */ | |
4a287f19 KM |
326 | nchstats.ncs_goodhits++; |
327 | goto haveino; | |
328 | } | |
329 | } | |
f93197fc KM |
330 | |
331 | /* | |
8ac1234a SL |
332 | * Last component and we are renaming or deleting, |
333 | * the cache entry is invalid, or otherwise don't | |
334 | * want cache entry to exist. | |
f93197fc KM |
335 | */ |
336 | ||
f93197fc KM |
337 | /* remove from LRU chain */ |
338 | *ncp->nc_prev = ncp->nc_nxt; | |
339 | if (ncp->nc_nxt) | |
340 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
341 | else | |
342 | nchtail = ncp->nc_prev; | |
343 | ||
344 | /* remove from hash chain */ | |
345 | remque(ncp); | |
346 | ||
f93197fc KM |
347 | /* insert at head of LRU list (first to grab) */ |
348 | ncp->nc_nxt = nchhead; | |
349 | ncp->nc_prev = &nchhead; | |
350 | nchhead->nc_prev = &ncp->nc_nxt; | |
351 | nchhead = ncp; | |
352 | ||
353 | /* and make a dummy hash chain */ | |
354 | ncp->nc_forw = ncp; | |
355 | ncp->nc_back = ncp; | |
356 | ||
357 | ncp = NULL; | |
358 | } | |
359 | } | |
360 | ||
6459ebe0 | 361 | /* |
6bd0bb92 BJ |
362 | * Suppress search for slots unless creating |
363 | * file and at end of pathname, in which case | |
364 | * we watch for a place to put the new file in | |
365 | * case it doesn't already exist. | |
6459ebe0 | 366 | */ |
6bd0bb92 | 367 | slotstatus = FOUND; |
4f083fd7 | 368 | if (flag == CREATE && *cp == 0) { |
6bd0bb92 BJ |
369 | slotstatus = NONE; |
370 | slotfreespace = 0; | |
d870be74 | 371 | slotneeded = DIRSIZ(&ndp->ni_dent); |
6bd0bb92 | 372 | } |
84ef30ec KM |
373 | /* |
374 | * If this is the same directory that this process | |
375 | * previously searched, pick up where we last left off. | |
f93197fc | 376 | * We cache only lookups as these are the most common |
84ef30ec KM |
377 | * and have the greatest payoff. Caching CREATE has little |
378 | * benefit as it usually must search the entire directory | |
379 | * to determine that the entry does not exist. Caching the | |
380 | * location of the last DELETE has not reduced profiling time | |
381 | * and hence has been removed in the interest of simplicity. | |
382 | */ | |
383 | if (flag != LOOKUP || dp->i_number != u.u_ncache.nc_inumber || | |
384 | dp->i_dev != u.u_ncache.nc_dev) { | |
d870be74 | 385 | ndp->ni_offset = 0; |
84ef30ec KM |
386 | numdirpasses = 1; |
387 | } else { | |
f93197fc | 388 | if ((dp->i_flag & ICHG) || dp->i_ctime >= u.u_ncache.nc_time) { |
c1658e77 KM |
389 | if (u.u_ncache.nc_prevoffset > dp->i_size) |
390 | u.u_ncache.nc_prevoffset = 0; | |
391 | else | |
392 | u.u_ncache.nc_prevoffset &= ~(DIRBLKSIZ - 1); | |
84ef30ec KM |
393 | u.u_ncache.nc_time = time.tv_sec; |
394 | } | |
d870be74 KM |
395 | ndp->ni_offset = u.u_ncache.nc_prevoffset; |
396 | entryoffsetinblock = blkoff(fs, ndp->ni_offset); | |
84ef30ec | 397 | if (entryoffsetinblock != 0) { |
d870be74 | 398 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
84ef30ec KM |
399 | if (bp == 0) |
400 | goto bad; | |
401 | } | |
402 | numdirpasses = 2; | |
f93197fc | 403 | nchstats.ncs_2passes++; |
84ef30ec KM |
404 | } |
405 | endsearch = roundup(dp->i_size, DIRBLKSIZ); | |
9e7c949b | 406 | enduseful = 0; |
6bd0bb92 | 407 | |
84ef30ec | 408 | searchloop: |
d870be74 | 409 | while (ndp->ni_offset < endsearch) { |
f5039631 BJ |
410 | /* |
411 | * If offset is on a block boundary, | |
412 | * read the next directory block. | |
413 | * Release previous if it exists. | |
414 | */ | |
d870be74 | 415 | if (blkoff(fs, ndp->ni_offset) == 0) { |
f5039631 BJ |
416 | if (bp != NULL) |
417 | brelse(bp); | |
d870be74 | 418 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
6bd0bb92 BJ |
419 | if (bp == 0) |
420 | goto bad; | |
421 | entryoffsetinblock = 0; | |
6459ebe0 | 422 | } |
6bd0bb92 | 423 | |
6459ebe0 | 424 | /* |
6bd0bb92 | 425 | * If still looking for a slot, and at a DIRBLKSIZE |
d82d5deb | 426 | * boundary, have to start looking for free space again. |
6459ebe0 | 427 | */ |
6bd0bb92 BJ |
428 | if (slotstatus == NONE && |
429 | (entryoffsetinblock&(DIRBLKSIZ-1)) == 0) { | |
430 | slotoffset = -1; | |
431 | slotfreespace = 0; | |
432 | } | |
433 | ||
434 | /* | |
d82d5deb KM |
435 | * Get pointer to next entry. |
436 | * Full validation checks are slow, so we only check | |
437 | * enough to insure forward progress through the | |
438 | * directory. Complete checks can be run by patching | |
439 | * "dirchk" to be true. | |
6bd0bb92 BJ |
440 | */ |
441 | ep = (struct direct *)(bp->b_un.b_addr + entryoffsetinblock); | |
d82d5deb KM |
442 | if (ep->d_reclen <= 0 || |
443 | dirchk && dirbadentry(ep, entryoffsetinblock)) { | |
d870be74 | 444 | dirbad(dp, ndp->ni_offset, "mangled entry"); |
d82d5deb | 445 | i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); |
d870be74 | 446 | ndp->ni_offset += i; |
6bd0bb92 | 447 | entryoffsetinblock += i; |
6459ebe0 KM |
448 | continue; |
449 | } | |
6bd0bb92 | 450 | |
6459ebe0 | 451 | /* |
6bd0bb92 | 452 | * If an appropriate sized slot has not yet been found, |
6459ebe0 KM |
453 | * check to see if one is available. Also accumulate space |
454 | * in the current block so that we can determine if | |
455 | * compaction is viable. | |
456 | */ | |
6bd0bb92 BJ |
457 | if (slotstatus != FOUND) { |
458 | int size = ep->d_reclen; | |
459 | ||
6459ebe0 KM |
460 | if (ep->d_ino != 0) |
461 | size -= DIRSIZ(ep); | |
462 | if (size > 0) { | |
6bd0bb92 BJ |
463 | if (size >= slotneeded) { |
464 | slotstatus = FOUND; | |
d870be74 | 465 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
466 | slotsize = ep->d_reclen; |
467 | } else if (slotstatus == NONE) { | |
468 | slotfreespace += size; | |
469 | if (slotoffset == -1) | |
d870be74 | 470 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
471 | if (slotfreespace >= slotneeded) { |
472 | slotstatus = COMPACT; | |
d870be74 KM |
473 | slotsize = ndp->ni_offset + |
474 | ep->d_reclen - slotoffset; | |
6bd0bb92 | 475 | } |
6459ebe0 | 476 | } |
f5039631 | 477 | } |
f5039631 | 478 | } |
6bd0bb92 | 479 | |
f5039631 | 480 | /* |
6bd0bb92 | 481 | * Check for a name match. |
f5039631 | 482 | */ |
6bd0bb92 | 483 | if (ep->d_ino) { |
d870be74 KM |
484 | if (ep->d_namlen == ndp->ni_dent.d_namlen && |
485 | !bcmp(ndp->ni_dent.d_name, ep->d_name, | |
486 | ep->d_namlen)) | |
6bd0bb92 BJ |
487 | goto found; |
488 | } | |
d870be74 KM |
489 | prevoff = ndp->ni_offset; |
490 | ndp->ni_offset += ep->d_reclen; | |
6bd0bb92 | 491 | entryoffsetinblock += ep->d_reclen; |
9e7c949b KM |
492 | if (ep->d_ino) |
493 | enduseful = ndp->ni_offset; | |
6bd0bb92 | 494 | } |
f93197fc | 495 | /* notfound: */ |
84ef30ec | 496 | /* |
f93197fc | 497 | * If we started in the middle of the directory and failed |
84ef30ec KM |
498 | * to find our target, we must check the beginning as well. |
499 | */ | |
500 | if (numdirpasses == 2) { | |
501 | numdirpasses--; | |
d870be74 | 502 | ndp->ni_offset = 0; |
84ef30ec KM |
503 | endsearch = u.u_ncache.nc_prevoffset; |
504 | goto searchloop; | |
505 | } | |
6bd0bb92 BJ |
506 | /* |
507 | * If creating, and at end of pathname and current | |
4f083fd7 SL |
508 | * directory has not been removed, then can consider |
509 | * allowing file to be created. | |
6bd0bb92 | 510 | */ |
4f083fd7 | 511 | if (flag == CREATE && *cp == 0 && dp->i_nlink != 0) { |
f5039631 | 512 | /* |
6bd0bb92 BJ |
513 | * Access for write is interpreted as allowing |
514 | * creation of files in the directory. | |
f5039631 | 515 | */ |
6bd0bb92 BJ |
516 | if (access(dp, IWRITE)) |
517 | goto bad; | |
f5039631 | 518 | /* |
6bd0bb92 BJ |
519 | * Return an indication of where the new directory |
520 | * entry should be put. If we didn't find a slot, | |
d870be74 KM |
521 | * then set ndp->ni_count to 0 indicating that the new |
522 | * slot belongs at the end of the directory. If we found | |
523 | * a slot, then the new entry can be put in the range | |
524 | * [ndp->ni_offset .. ndp->ni_offset + ndp->ni_count) | |
f5039631 | 525 | */ |
84ef30ec | 526 | if (slotstatus == NONE) { |
d870be74 KM |
527 | ndp->ni_offset = roundup(dp->i_size, DIRBLKSIZ); |
528 | ndp->ni_count = 0; | |
9e7c949b | 529 | enduseful = ndp->ni_offset; |
84ef30ec | 530 | } else { |
d870be74 KM |
531 | ndp->ni_offset = slotoffset; |
532 | ndp->ni_count = slotsize; | |
9e7c949b KM |
533 | if (enduseful < slotoffset + slotsize) |
534 | enduseful = slotoffset + slotsize; | |
5485e062 | 535 | } |
9e7c949b | 536 | ndp->ni_endoff = roundup(enduseful, DIRBLKSIZ); |
6bd0bb92 BJ |
537 | dp->i_flag |= IUPD|ICHG; |
538 | if (bp) | |
539 | brelse(bp); | |
db9631a2 KM |
540 | nbp->av_forw = freenamebuf; |
541 | freenamebuf = nbp; | |
f5039631 | 542 | /* |
6bd0bb92 BJ |
543 | * We return with the directory locked, so that |
544 | * the parameters we set up above will still be | |
545 | * valid if we actually decide to do a direnter(). | |
546 | * We return NULL to indicate that the entry doesn't | |
547 | * currently exist, leaving a pointer to the (locked) | |
d870be74 | 548 | * directory inode in ndp->ni_pdir. |
f5039631 | 549 | */ |
d870be74 | 550 | ndp->ni_pdir = dp; |
6bd0bb92 BJ |
551 | return (NULL); |
552 | } | |
553 | u.u_error = ENOENT; | |
554 | goto bad; | |
555 | found: | |
f93197fc KM |
556 | if (numdirpasses == 2) |
557 | nchstats.ncs_pass2++; | |
6bd0bb92 BJ |
558 | /* |
559 | * Check that directory length properly reflects presence | |
560 | * of this entry. | |
561 | */ | |
4a0415d6 | 562 | if (entryoffsetinblock + DIRSIZ(ep) > dp->i_size) { |
d870be74 | 563 | dirbad(dp, ndp->ni_offset, "i_size too small"); |
4a0415d6 | 564 | dp->i_size = entryoffsetinblock + DIRSIZ(ep); |
6bd0bb92 BJ |
565 | dp->i_flag |= IUPD|ICHG; |
566 | } | |
567 | ||
568 | /* | |
84ef30ec | 569 | * Found component in pathname. |
f93197fc | 570 | * If the final component of path name, save information |
84ef30ec KM |
571 | * in the cache as to where the entry was found. |
572 | */ | |
573 | if (*cp == '\0' && flag == LOOKUP) { | |
d870be74 | 574 | u.u_ncache.nc_prevoffset = ndp->ni_offset; |
84ef30ec KM |
575 | u.u_ncache.nc_inumber = dp->i_number; |
576 | u.u_ncache.nc_dev = dp->i_dev; | |
577 | u.u_ncache.nc_time = time.tv_sec; | |
578 | } | |
579 | /* | |
d870be74 | 580 | * Save directory entry in ndp->ni_dent, |
84ef30ec | 581 | * and release directory buffer. |
6bd0bb92 | 582 | */ |
d870be74 | 583 | bcopy((caddr_t)ep, (caddr_t)&ndp->ni_dent, (u_int)DIRSIZ(ep)); |
6bd0bb92 BJ |
584 | brelse(bp); |
585 | bp = NULL; | |
586 | ||
587 | /* | |
588 | * If deleting, and at end of pathname, return | |
589 | * parameters which can be used to remove file. | |
4f083fd7 | 590 | * If the lockparent flag isn't set, we return only |
d870be74 | 591 | * the directory (in ndp->ni_pdir), otherwise we go |
4f083fd7 | 592 | * on and lock the inode, being careful with ".". |
6bd0bb92 | 593 | */ |
4f083fd7 | 594 | if (flag == DELETE && *cp == 0) { |
6bd0bb92 BJ |
595 | /* |
596 | * Write access to directory required to delete files. | |
597 | */ | |
598 | if (access(dp, IWRITE)) | |
599 | goto bad; | |
d870be74 | 600 | ndp->ni_pdir = dp; /* for dirremove() */ |
6bd0bb92 | 601 | /* |
d870be74 | 602 | * Return pointer to current entry in ndp->ni_offset, |
6bd0bb92 | 603 | * and distance past previous entry (if there |
d870be74 KM |
604 | * is a previous entry in this block) in ndp->ni_count. |
605 | * Save directory inode pointer in ndp->ni_pdir for dirremove(). | |
6bd0bb92 | 606 | */ |
d870be74 KM |
607 | if ((ndp->ni_offset&(DIRBLKSIZ-1)) == 0) |
608 | ndp->ni_count = 0; | |
6bd0bb92 | 609 | else |
d870be74 | 610 | ndp->ni_count = ndp->ni_offset - prevoff; |
4f083fd7 | 611 | if (lockparent) { |
d870be74 | 612 | if (dp->i_number == ndp->ni_dent.d_ino) |
4f083fd7 SL |
613 | dp->i_count++; |
614 | else { | |
d870be74 | 615 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 616 | if (dp == NULL) { |
d870be74 | 617 | iput(ndp->ni_pdir); |
4f083fd7 SL |
618 | goto bad; |
619 | } | |
f93197fc | 620 | /* |
9ba16c41 | 621 | * If directory is "sticky", then user must own |
f93197fc KM |
622 | * the directory, or the file in it, else he |
623 | * may not delete it (unless he's root). This | |
624 | * implements append-only directories. | |
625 | */ | |
d870be74 | 626 | if ((ndp->ni_pdir->i_mode & ISVTX) && |
f93197fc | 627 | u.u_uid != 0 && |
d870be74 | 628 | u.u_uid != ndp->ni_pdir->i_uid && |
f93197fc | 629 | dp->i_uid != u.u_uid) { |
d870be74 | 630 | iput(ndp->ni_pdir); |
f93197fc KM |
631 | u.u_error = EPERM; |
632 | goto bad; | |
633 | } | |
4f083fd7 SL |
634 | } |
635 | } | |
db9631a2 KM |
636 | nbp->av_forw = freenamebuf; |
637 | freenamebuf = nbp; | |
6bd0bb92 BJ |
638 | return (dp); |
639 | } | |
640 | ||
641 | /* | |
642 | * Special handling for ".." allowing chdir out of mounted | |
643 | * file system: indirect .. in root inode to reevaluate | |
644 | * in directory file system was mounted on. | |
645 | */ | |
4a287f19 | 646 | if (isdotdot) { |
6bd0bb92 | 647 | if (dp == u.u_rdir) |
d870be74 KM |
648 | ndp->ni_dent.d_ino = dp->i_number; |
649 | else if (ndp->ni_dent.d_ino == ROOTINO && | |
6bd0bb92 BJ |
650 | dp->i_number == ROOTINO) { |
651 | for (i = 1; i < NMOUNT; i++) | |
652 | if (mount[i].m_bufp != NULL && | |
653 | mount[i].m_dev == dp->i_dev) { | |
6459ebe0 | 654 | iput(dp); |
6bd0bb92 | 655 | dp = mount[i].m_inodp; |
56700195 | 656 | ILOCK(dp); |
f5039631 | 657 | dp->i_count++; |
6bd0bb92 BJ |
658 | fs = dp->i_fs; |
659 | cp -= 2; /* back over .. */ | |
660 | goto dirloop2; | |
f5039631 | 661 | } |
10873320 | 662 | } |
6bd0bb92 BJ |
663 | } |
664 | ||
4f083fd7 SL |
665 | /* |
666 | * If rewriting (rename), return the inode and the | |
667 | * information required to rewrite the present directory | |
668 | * Must get inode of directory entry to verify it's a | |
669 | * regular file, or empty directory. | |
670 | */ | |
671 | if ((flag == CREATE && lockparent) && *cp == 0) { | |
672 | if (access(dp, IWRITE)) | |
673 | goto bad; | |
d870be74 | 674 | ndp->ni_pdir = dp; /* for dirrewrite() */ |
4f083fd7 SL |
675 | /* |
676 | * Careful about locking second inode. | |
677 | * This can only occur if the target is ".". | |
678 | */ | |
d870be74 | 679 | if (dp->i_number == ndp->ni_dent.d_ino) { |
4f083fd7 SL |
680 | u.u_error = EISDIR; /* XXX */ |
681 | goto bad; | |
682 | } | |
d870be74 | 683 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 684 | if (dp == NULL) { |
d870be74 | 685 | iput(ndp->ni_pdir); |
4f083fd7 SL |
686 | goto bad; |
687 | } | |
db9631a2 KM |
688 | nbp->av_forw = freenamebuf; |
689 | freenamebuf = nbp; | |
4f083fd7 SL |
690 | return (dp); |
691 | } | |
692 | ||
6bd0bb92 | 693 | /* |
bde63aa5 KM |
694 | * Check for symbolic link, which may require us to massage the |
695 | * name before we continue translation. We do not `iput' the | |
696 | * directory because we may need it again if the symbolic link | |
697 | * is relative to the current directory. Instead we save it | |
698 | * unlocked as "pdp". We must get the target inode before unlocking | |
699 | * the directory to insure that the inode will not be removed | |
700 | * before we get it. We prevent deadlock by always fetching | |
701 | * inodes from the root, moving down the directory tree. Thus | |
702 | * when following backward pointers ".." we must unlock the | |
703 | * parent directory before getting the requested directory. | |
704 | * There is a potential race condition here if both the current | |
705 | * and parent directories are removed before the `iget' for the | |
706 | * inode associated with ".." returns. We hope that this occurs | |
707 | * infrequently since we cannot avoid this race condition without | |
a4358a25 | 708 | * implementing a sophisticated deadlock detection algorithm. |
bde63aa5 KM |
709 | * Note also that this simple deadlock detection scheme will not |
710 | * work if the file system has any hard links other than ".." | |
711 | * that point backwards in the directory structure. | |
6bd0bb92 BJ |
712 | */ |
713 | pdp = dp; | |
f93197fc | 714 | if (isdotdot) { |
56700195 | 715 | IUNLOCK(pdp); /* race to get the inode */ |
d870be74 | 716 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
bde63aa5 KM |
717 | if (dp == NULL) |
718 | goto bad2; | |
d870be74 | 719 | } else if (dp->i_number == ndp->ni_dent.d_ino) { |
bde63aa5 KM |
720 | dp->i_count++; /* we want ourself, ie "." */ |
721 | } else { | |
d870be74 | 722 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
56700195 | 723 | IUNLOCK(pdp); |
bde63aa5 KM |
724 | if (dp == NULL) |
725 | goto bad2; | |
726 | } | |
f93197fc KM |
727 | |
728 | /* | |
729 | * insert name into cache (if we want it, and it isn't "." or "..") | |
730 | * | |
731 | * all other cases where making a cache entry would be wrong | |
732 | * have already departed from the code sequence somewhere above. | |
733 | */ | |
8ac1234a | 734 | if (docache) { |
f93197fc KM |
735 | if (ncp != NULL) |
736 | panic("nami: duplicating cache"); | |
737 | ||
738 | /* | |
739 | * free the cache slot at head of lru chain | |
740 | */ | |
741 | if (ncp = nchhead) { | |
742 | /* remove from lru chain */ | |
743 | *ncp->nc_prev = ncp->nc_nxt; | |
744 | if (ncp->nc_nxt) | |
745 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
746 | else | |
747 | nchtail = ncp->nc_prev; | |
748 | ||
749 | /* remove from old hash chain */ | |
750 | remque(ncp); | |
751 | ||
f93197fc KM |
752 | /* grab the inode we just found */ |
753 | ncp->nc_ip = dp; | |
f93197fc KM |
754 | |
755 | /* fill in cache info */ | |
756 | ncp->nc_ino = pdp->i_number; /* parents inum */ | |
757 | ncp->nc_dev = pdp->i_dev; /* & device */ | |
758 | ncp->nc_idev = dp->i_dev; /* our device */ | |
8ac1234a | 759 | ncp->nc_id = dp->i_id; /* identifier */ |
d870be74 KM |
760 | ncp->nc_nlen = ndp->ni_dent.d_namlen; |
761 | bcopy(ndp->ni_dent.d_name, ncp->nc_name, ncp->nc_nlen); | |
f93197fc KM |
762 | |
763 | /* link at end of lru chain */ | |
764 | ncp->nc_nxt = NULL; | |
765 | ncp->nc_prev = nchtail; | |
766 | *nchtail = ncp; | |
767 | nchtail = &ncp->nc_nxt; | |
768 | ||
769 | /* and insert on hash chain */ | |
770 | insque(ncp, nhp); | |
771 | } | |
772 | } | |
773 | ||
774 | haveino: | |
6bd0bb92 BJ |
775 | fs = dp->i_fs; |
776 | ||
777 | /* | |
778 | * Check for symbolic link | |
779 | */ | |
d870be74 KM |
780 | if ((dp->i_mode & IFMT) == IFLNK && |
781 | ((ndp->ni_nameiop & FOLLOW) || *cp == '/')) { | |
9f024ffc | 782 | u_int pathlen = strlen(cp) + 1; |
6bd0bb92 BJ |
783 | |
784 | if (dp->i_size + pathlen >= MAXPATHLEN - 1 || | |
785 | ++nlink > MAXSYMLINKS) { | |
786 | u.u_error = ELOOP; | |
787 | goto bad2; | |
788 | } | |
d36096be | 789 | ovbcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen); |
a6b6f679 | 790 | u.u_error = |
4f083fd7 | 791 | rdwri(UIO_READ, dp, nbp->b_un.b_addr, (int)dp->i_size, |
9f024ffc | 792 | 0, 1, (int *)0); |
6bd0bb92 BJ |
793 | if (u.u_error) |
794 | goto bad2; | |
795 | cp = nbp->b_un.b_addr; | |
796 | iput(dp); | |
f5039631 | 797 | if (*cp == '/') { |
6bd0bb92 | 798 | irele(pdp); |
f5039631 BJ |
799 | while (*cp == '/') |
800 | cp++; | |
6bd0bb92 BJ |
801 | if ((dp = u.u_rdir) == NULL) |
802 | dp = rootdir; | |
56700195 | 803 | ILOCK(dp); |
6bd0bb92 BJ |
804 | dp->i_count++; |
805 | } else { | |
806 | dp = pdp; | |
56700195 | 807 | ILOCK(dp); |
f5039631 | 808 | } |
6bd0bb92 BJ |
809 | fs = dp->i_fs; |
810 | goto dirloop; | |
10873320 | 811 | } |
6bd0bb92 | 812 | |
10873320 | 813 | /* |
6bd0bb92 BJ |
814 | * Not a symbolic link. If more pathname, |
815 | * continue at next component, else return. | |
10873320 | 816 | */ |
6bd0bb92 BJ |
817 | if (*cp == '/') { |
818 | while (*cp == '/') | |
819 | cp++; | |
4f083fd7 | 820 | irele(pdp); |
6bd0bb92 | 821 | goto dirloop; |
10873320 | 822 | } |
db9631a2 KM |
823 | nbp->av_forw = freenamebuf; |
824 | freenamebuf = nbp; | |
4f083fd7 | 825 | if (lockparent) |
d870be74 | 826 | ndp->ni_pdir = pdp; |
4f083fd7 SL |
827 | else |
828 | irele(pdp); | |
6bd0bb92 BJ |
829 | return (dp); |
830 | bad2: | |
831 | irele(pdp); | |
832 | bad: | |
833 | if (bp) | |
834 | brelse(bp); | |
835 | if (dp) | |
836 | iput(dp); | |
db9631a2 KM |
837 | nbp->av_forw = freenamebuf; |
838 | freenamebuf = nbp; | |
6459ebe0 | 839 | return (NULL); |
10873320 BJ |
840 | } |
841 | ||
f93197fc | 842 | |
d870be74 | 843 | dirbad(ip, offset, how) |
6bd0bb92 | 844 | struct inode *ip; |
d870be74 | 845 | off_t offset; |
6bd0bb92 BJ |
846 | char *how; |
847 | { | |
848 | ||
849 | printf("%s: bad dir ino %d at offset %d: %s\n", | |
d870be74 | 850 | ip->i_fs->fs_fsmnt, ip->i_number, offset, how); |
6bd0bb92 BJ |
851 | } |
852 | ||
d82d5deb KM |
853 | /* |
854 | * Do consistency checking on a directory entry: | |
855 | * record length must be multiple of 4 | |
856 | * record length must not be non-negative | |
857 | * entry must fit in rest of its DIRBLKSIZ block | |
858 | * record must be large enough to contain entry | |
859 | * name is not longer than MAXNAMLEN | |
860 | * name must be as long as advertised, and null terminated | |
861 | */ | |
862 | dirbadentry(ep, entryoffsetinblock) | |
6bd0bb92 | 863 | register struct direct *ep; |
d82d5deb | 864 | int entryoffsetinblock; |
6bd0bb92 | 865 | { |
6bd0bb92 BJ |
866 | register int i; |
867 | ||
d82d5deb KM |
868 | if ((ep->d_reclen & 0x3) != 0 || ep->d_reclen <= 0 || |
869 | ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || | |
870 | ep->d_reclen < DIRSIZ(ep) || ep->d_namlen > MAXNAMLEN) | |
871 | return (1); | |
6bd0bb92 | 872 | for (i = 0; i < ep->d_namlen; i++) |
d870be74 | 873 | if (ep->d_name[i] == '\0') |
6bd0bb92 BJ |
874 | return (1); |
875 | return (ep->d_name[i]); | |
876 | } | |
877 | ||
6bd0bb92 BJ |
878 | /* |
879 | * Write a directory entry after a call to namei, using the parameters | |
880 | * which it left in the u. area. The argument ip is the inode which | |
d870be74 | 881 | * the new directory entry will refer to. The u. area field ndp->ni_pdir is |
6bd0bb92 | 882 | * a pointer to the directory to be written, which was left locked by |
d870be74 | 883 | * namei. Remaining parameters (ndp->ni_offset, ndp->ni_count) indicate |
6bd0bb92 BJ |
884 | * how the space for the new entry is to be gotten. |
885 | */ | |
d870be74 | 886 | direnter(ip, ndp) |
6bd0bb92 | 887 | struct inode *ip; |
d870be74 | 888 | register struct nameidata *ndp; |
f5039631 | 889 | { |
6bd0bb92 | 890 | register struct direct *ep, *nep; |
9e7c949b | 891 | register struct inode *dp = ndp->ni_pdir; |
6bd0bb92 | 892 | struct buf *bp; |
efa3a91c | 893 | int loc, spacefree, error = 0; |
b32450f4 BJ |
894 | u_int dsize; |
895 | int newentrysize; | |
6bd0bb92 | 896 | char *dirbuf; |
f5039631 | 897 | |
d870be74 KM |
898 | ndp->ni_dent.d_ino = ip->i_number; |
899 | newentrysize = DIRSIZ(&ndp->ni_dent); | |
900 | if (ndp->ni_count == 0) { | |
6bd0bb92 | 901 | /* |
d870be74 KM |
902 | * If ndp->ni_count is 0, then namei could find no space in the |
903 | * directory. In this case ndp->ni_offset will be on a directory | |
6bd0bb92 BJ |
904 | * block boundary and we will write the new entry into a fresh |
905 | * block. | |
906 | */ | |
d870be74 | 907 | if (ndp->ni_offset&(DIRBLKSIZ-1)) |
6bd0bb92 | 908 | panic("wdir: newblk"); |
d870be74 | 909 | ndp->ni_dent.d_reclen = DIRBLKSIZ; |
9e7c949b | 910 | error = rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, |
d870be74 | 911 | newentrysize, ndp->ni_offset, 1, (int *)0); |
23de9f20 KM |
912 | if (DIRBLKSIZ > dp->i_fs->fs_fsize) |
913 | panic("wdir: blksize"); /* XXX - should grow w/bmap() */ | |
914 | else | |
915 | dp->i_size = roundup(dp->i_size, DIRBLKSIZ); | |
9e7c949b | 916 | iput(dp); |
f2a5ad78 | 917 | return (error); |
6bd0bb92 BJ |
918 | } |
919 | ||
920 | /* | |
d870be74 KM |
921 | * If ndp->ni_count is non-zero, then namei found space for the new |
922 | * entry in the range ndp->ni_offset to ndp->ni_offset + ndp->ni_count. | |
6bd0bb92 BJ |
923 | * in the directory. To use this space, we may have to compact |
924 | * the entries located there, by copying them together towards | |
925 | * the beginning of the block, leaving the free space in | |
926 | * one usable chunk at the end. | |
927 | */ | |
928 | ||
929 | /* | |
930 | * Increase size of directory if entry eats into new space. | |
931 | * This should never push the size past a new multiple of | |
932 | * DIRBLKSIZE. | |
23de9f20 KM |
933 | * |
934 | * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. | |
6bd0bb92 | 935 | */ |
9e7c949b KM |
936 | if (ndp->ni_offset + ndp->ni_count > dp->i_size) |
937 | dp->i_size = ndp->ni_offset + ndp->ni_count; | |
6bd0bb92 BJ |
938 | |
939 | /* | |
940 | * Get the block containing the space for the new directory | |
f2a5ad78 | 941 | * entry. Should return error by result instead of u.u_error. |
6bd0bb92 | 942 | */ |
9e7c949b | 943 | bp = blkatoff(dp, ndp->ni_offset, (char **)&dirbuf); |
4f083fd7 | 944 | if (bp == 0) { |
9e7c949b | 945 | iput(dp); |
f2a5ad78 | 946 | return (u.u_error); |
4f083fd7 | 947 | } |
6bd0bb92 BJ |
948 | |
949 | /* | |
950 | * Find space for the new entry. In the simple case, the | |
951 | * entry at offset base will have the space. If it does | |
952 | * not, then namei arranged that compacting the region | |
d870be74 | 953 | * ndp->ni_offset to ndp->ni_offset+ndp->ni_count would yield the space. |
6bd0bb92 BJ |
954 | */ |
955 | ep = (struct direct *)dirbuf; | |
956 | dsize = DIRSIZ(ep); | |
efa3a91c | 957 | spacefree = ep->d_reclen - dsize; |
d870be74 | 958 | for (loc = ep->d_reclen; loc < ndp->ni_count; ) { |
6bd0bb92 BJ |
959 | nep = (struct direct *)(dirbuf + loc); |
960 | if (ep->d_ino) { | |
961 | /* trim the existing slot */ | |
962 | ep->d_reclen = dsize; | |
963 | ep = (struct direct *)((char *)ep + dsize); | |
964 | } else { | |
965 | /* overwrite; nothing there; header is ours */ | |
efa3a91c | 966 | spacefree += dsize; |
6bd0bb92 BJ |
967 | } |
968 | dsize = DIRSIZ(nep); | |
efa3a91c | 969 | spacefree += nep->d_reclen - dsize; |
6bd0bb92 | 970 | loc += nep->d_reclen; |
9f024ffc | 971 | bcopy((caddr_t)nep, (caddr_t)ep, dsize); |
6bd0bb92 BJ |
972 | } |
973 | /* | |
974 | * Update the pointer fields in the previous entry (if any), | |
975 | * copy in the new entry, and write out the block. | |
976 | */ | |
977 | if (ep->d_ino == 0) { | |
efa3a91c | 978 | if (spacefree + dsize < newentrysize) |
6bd0bb92 | 979 | panic("wdir: compact1"); |
d870be74 | 980 | ndp->ni_dent.d_reclen = spacefree + dsize; |
6bd0bb92 | 981 | } else { |
efa3a91c | 982 | if (spacefree < newentrysize) |
6bd0bb92 | 983 | panic("wdir: compact2"); |
d870be74 | 984 | ndp->ni_dent.d_reclen = spacefree; |
6bd0bb92 BJ |
985 | ep->d_reclen = dsize; |
986 | ep = (struct direct *)((char *)ep + dsize); | |
987 | } | |
d870be74 | 988 | bcopy((caddr_t)&ndp->ni_dent, (caddr_t)ep, (u_int)newentrysize); |
6bd0bb92 | 989 | bwrite(bp); |
9e7c949b KM |
990 | dp->i_flag |= IUPD|ICHG; |
991 | if (ndp->ni_endoff && ndp->ni_endoff < dp->i_size) | |
992 | itrunc(dp, ndp->ni_endoff); | |
993 | iput(dp); | |
f2a5ad78 | 994 | return (error); |
6bd0bb92 BJ |
995 | } |
996 | ||
4f083fd7 SL |
997 | /* |
998 | * Remove a directory entry after a call to namei, using the | |
999 | * parameters which it left in the u. area. The u. entry | |
d870be74 KM |
1000 | * ni_offset contains the offset into the directory of the |
1001 | * entry to be eliminated. The ni_count field contains the | |
4f083fd7 SL |
1002 | * size of the previous record in the directory. If this |
1003 | * is 0, the first entry is being deleted, so we need only | |
1004 | * zero the inode number to mark the entry as free. If the | |
1005 | * entry isn't the first in the directory, we must reclaim | |
1006 | * the space of the now empty record by adding the record size | |
1007 | * to the size of the previous entry. | |
1008 | */ | |
d870be74 KM |
1009 | dirremove(ndp) |
1010 | register struct nameidata *ndp; | |
6bd0bb92 | 1011 | { |
d870be74 | 1012 | register struct inode *dp = ndp->ni_pdir; |
6bd0bb92 BJ |
1013 | register struct buf *bp; |
1014 | struct direct *ep; | |
1015 | ||
d870be74 | 1016 | if (ndp->ni_count == 0) { |
6bd0bb92 BJ |
1017 | /* |
1018 | * First entry in block: set d_ino to zero. | |
1019 | */ | |
d870be74 KM |
1020 | ndp->ni_dent.d_ino = 0; |
1021 | (void) rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1022 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
36d4ed87 | 1023 | } else { |
6bd0bb92 BJ |
1024 | /* |
1025 | * Collapse new free space into previous entry. | |
1026 | */ | |
d870be74 KM |
1027 | bp = blkatoff(dp, (int)(ndp->ni_offset - ndp->ni_count), |
1028 | (char **)&ep); | |
6bd0bb92 BJ |
1029 | if (bp == 0) |
1030 | return (0); | |
d870be74 | 1031 | ep->d_reclen += ndp->ni_dent.d_reclen; |
6bd0bb92 BJ |
1032 | bwrite(bp); |
1033 | dp->i_flag |= IUPD|ICHG; | |
1034 | } | |
1035 | return (1); | |
10873320 | 1036 | } |
6459ebe0 | 1037 | |
4f083fd7 SL |
1038 | /* |
1039 | * Rewrite an existing directory entry to point at the inode | |
1040 | * supplied. The parameters describing the directory entry are | |
1041 | * set up by a call to namei. | |
1042 | */ | |
d870be74 | 1043 | dirrewrite(dp, ip, ndp) |
4f083fd7 | 1044 | struct inode *dp, *ip; |
d870be74 | 1045 | struct nameidata *ndp; |
4f083fd7 SL |
1046 | { |
1047 | ||
d870be74 KM |
1048 | ndp->ni_dent.d_ino = ip->i_number; |
1049 | u.u_error = rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1050 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
4f083fd7 SL |
1051 | iput(dp); |
1052 | } | |
1053 | ||
4a0415d6 SL |
1054 | /* |
1055 | * Return buffer with contents of block "offset" | |
1056 | * from the beginning of directory "ip". If "res" | |
1057 | * is non-zero, fill it in with a pointer to the | |
1058 | * remaining space in the directory. | |
1059 | */ | |
6bd0bb92 | 1060 | struct buf * |
4a0415d6 | 1061 | blkatoff(ip, offset, res) |
6bd0bb92 BJ |
1062 | struct inode *ip; |
1063 | off_t offset; | |
1064 | char **res; | |
6459ebe0 | 1065 | { |
6bd0bb92 | 1066 | register struct fs *fs = ip->i_fs; |
3fd23f5c | 1067 | daddr_t lbn = lblkno(fs, offset); |
6bd0bb92 BJ |
1068 | int base = blkoff(fs, offset); |
1069 | int bsize = blksize(fs, ip, lbn); | |
3fd23f5c | 1070 | daddr_t bn = fsbtodb(fs, bmap(ip, lbn, B_WRITE, base, bsize)); |
6bd0bb92 | 1071 | register struct buf *bp; |
6459ebe0 | 1072 | |
6bd0bb92 BJ |
1073 | if (u.u_error) |
1074 | return (0); | |
1075 | bp = bread(ip->i_dev, bn, bsize); | |
1076 | if (bp->b_flags & B_ERROR) { | |
1077 | brelse(bp); | |
1078 | return (0); | |
1079 | } | |
1080 | if (res) | |
1081 | *res = bp->b_un.b_addr + base; | |
6bd0bb92 | 1082 | return (bp); |
6459ebe0 | 1083 | } |
4f083fd7 SL |
1084 | |
1085 | /* | |
1086 | * Check if a directory is empty or not. | |
1087 | * Inode supplied must be locked. | |
17d11193 SL |
1088 | * |
1089 | * Using a struct dirtemplate here is not precisely | |
1090 | * what we want, but better than using a struct direct. | |
1091 | * | |
1092 | * NB: does not handle corrupted directories. | |
4f083fd7 | 1093 | */ |
68f21562 | 1094 | dirempty(ip, parentino) |
05d2bbce | 1095 | register struct inode *ip; |
68f21562 | 1096 | ino_t parentino; |
4f083fd7 SL |
1097 | { |
1098 | register off_t off; | |
17d11193 SL |
1099 | struct dirtemplate dbuf; |
1100 | register struct direct *dp = (struct direct *)&dbuf; | |
05d2bbce | 1101 | int error, count; |
17d11193 | 1102 | #define MINDIRSIZ (sizeof (struct dirtemplate) / 2) |
4f083fd7 SL |
1103 | |
1104 | for (off = 0; off < ip->i_size; off += dp->d_reclen) { | |
41413014 KM |
1105 | if (dp->d_reclen <= 0) |
1106 | return (0); | |
17d11193 SL |
1107 | error = rdwri(UIO_READ, ip, (caddr_t)dp, MINDIRSIZ, |
1108 | off, 1, &count); | |
1109 | /* | |
1110 | * Since we read MINDIRSIZ, residual must | |
1111 | * be 0 unless we're at end of file. | |
1112 | */ | |
1113 | if (error || count != 0) | |
4f083fd7 | 1114 | return (0); |
17d11193 | 1115 | /* skip empty entries */ |
4f083fd7 SL |
1116 | if (dp->d_ino == 0) |
1117 | continue; | |
17d11193 SL |
1118 | /* accept only "." and ".." */ |
1119 | if (dp->d_namlen > 2) | |
1120 | return (0); | |
4f083fd7 SL |
1121 | if (dp->d_name[0] != '.') |
1122 | return (0); | |
17d11193 SL |
1123 | /* |
1124 | * At this point d_namlen must be 1 or 2. | |
1125 | * 1 implies ".", 2 implies ".." if second | |
1126 | * char is also "." | |
1127 | */ | |
68f21562 KM |
1128 | if (dp->d_namlen == 1) |
1129 | continue; | |
1130 | if (dp->d_name[1] == '.' && dp->d_ino == parentino) | |
4f083fd7 SL |
1131 | continue; |
1132 | return (0); | |
1133 | } | |
1134 | return (1); | |
1135 | } | |
b1aa93b9 KM |
1136 | |
1137 | /* | |
1138 | * Check if source directory is in the path of the target directory. | |
1139 | * Target is supplied locked, source is unlocked. | |
1140 | * The target is always iput() before returning. | |
1141 | */ | |
1142 | checkpath(source, target) | |
1143 | struct inode *source, *target; | |
1144 | { | |
1145 | struct dirtemplate dirbuf; | |
1146 | register struct inode *ip; | |
1147 | int error = 0; | |
1148 | ||
1149 | ip = target; | |
1150 | if (ip->i_number == source->i_number) { | |
1151 | error = EEXIST; | |
1152 | goto out; | |
1153 | } | |
1154 | if (ip->i_number == ROOTINO) | |
1155 | goto out; | |
1156 | ||
1157 | for (;;) { | |
1158 | if ((ip->i_mode&IFMT) != IFDIR) { | |
1159 | error = ENOTDIR; | |
1160 | break; | |
1161 | } | |
1162 | error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, | |
1163 | sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); | |
1164 | if (error != 0) | |
1165 | break; | |
1166 | if (dirbuf.dotdot_namlen != 2 || | |
4a287f19 KM |
1167 | dirbuf.dotdot_name[0] != '.' || |
1168 | dirbuf.dotdot_name[1] != '.') { | |
b1aa93b9 KM |
1169 | error = ENOTDIR; |
1170 | break; | |
1171 | } | |
1172 | if (dirbuf.dotdot_ino == source->i_number) { | |
1173 | error = EINVAL; | |
1174 | break; | |
1175 | } | |
1176 | if (dirbuf.dotdot_ino == ROOTINO) | |
1177 | break; | |
1178 | iput(ip); | |
1179 | ip = iget(ip->i_dev, ip->i_fs, dirbuf.dotdot_ino); | |
1180 | if (ip == NULL) { | |
1181 | error = u.u_error; | |
1182 | break; | |
1183 | } | |
1184 | } | |
1185 | ||
1186 | out: | |
1187 | if (error == ENOTDIR) | |
1188 | printf("checkpath: .. not a directory\n"); | |
1189 | if (ip != NULL) | |
1190 | iput(ip); | |
1191 | return (error); | |
1192 | } | |
f93197fc KM |
1193 | |
1194 | /* | |
1195 | * Name cache initialization, from main() when we are booting | |
1196 | */ | |
1197 | nchinit() | |
1198 | { | |
1199 | register union nchash *nchp; | |
1200 | register struct nch *ncp; | |
1201 | ||
1202 | nchhead = 0; | |
1203 | nchtail = &nchhead; | |
1204 | ||
1205 | for (ncp = nch; ncp < &nch[nchsize]; ncp++) { | |
1206 | ncp->nc_forw = ncp; /* hash chain */ | |
1207 | ncp->nc_back = ncp; | |
1208 | ||
1209 | ncp->nc_nxt = NULL; /* lru chain */ | |
1210 | *nchtail = ncp; | |
1211 | ncp->nc_prev = nchtail; | |
1212 | nchtail = &ncp->nc_nxt; | |
1213 | ||
1214 | /* all else is zero already */ | |
1215 | } | |
1216 | ||
1217 | for (nchp = nchash; nchp < &nchash[NCHHASH]; nchp++) { | |
1218 | nchp->nch_head[0] = nchp; | |
1219 | nchp->nch_head[1] = nchp; | |
1220 | } | |
1221 | } | |
1222 | ||
1223 | /* | |
1224 | * Cache flush, called when filesys is umounted to | |
1225 | * remove entries that would now be invalid | |
1226 | * | |
1227 | * The line "nxtcp = nchhead" near the end is to avoid potential problems | |
1228 | * if the cache lru chain is modified while we are dumping the | |
1229 | * inode. This makes the algorithm O(n^2), but do you think I care? | |
1230 | */ | |
1231 | nchinval(dev) | |
1232 | register dev_t dev; | |
1233 | { | |
1234 | register struct nch *ncp, *nxtcp; | |
1235 | ||
1236 | for (ncp = nchhead; ncp; ncp = nxtcp) { | |
1237 | nxtcp = ncp->nc_nxt; | |
1238 | ||
1239 | if (ncp->nc_ip == NULL || | |
1240 | (ncp->nc_idev != dev && ncp->nc_dev != dev)) | |
1241 | continue; | |
1242 | ||
4a287f19 | 1243 | /* free the resources we had */ |
f93197fc KM |
1244 | ncp->nc_idev = NODEV; |
1245 | ncp->nc_dev = NODEV; | |
4a287f19 | 1246 | ncp->nc_id = NULL; |
f93197fc | 1247 | ncp->nc_ino = 0; |
4a287f19 KM |
1248 | ncp->nc_ip = NULL; |
1249 | ||
f93197fc KM |
1250 | |
1251 | /* remove the entry from its hash chain */ | |
1252 | remque(ncp); | |
1253 | /* and make a dummy one */ | |
1254 | ncp->nc_forw = ncp; | |
1255 | ncp->nc_back = ncp; | |
1256 | ||
1257 | /* delete this entry from LRU chain */ | |
1258 | *ncp->nc_prev = nxtcp; | |
1259 | if (nxtcp) | |
1260 | nxtcp->nc_prev = ncp->nc_prev; | |
1261 | else | |
1262 | nchtail = ncp->nc_prev; | |
1263 | ||
f93197fc KM |
1264 | /* cause rescan of list, it may have altered */ |
1265 | nxtcp = nchhead; | |
1266 | /* put the now-free entry at head of LRU */ | |
1267 | ncp->nc_nxt = nxtcp; | |
1268 | ncp->nc_prev = &nchhead; | |
1269 | nxtcp->nc_prev = &ncp->nc_nxt; | |
1270 | nchhead = ncp; | |
1271 | } | |
1272 | } | |
9ffa8d54 KM |
1273 | |
1274 | /* | |
1275 | * Name cache invalidation of all entries. | |
1276 | */ | |
1277 | cacheinvalall() | |
1278 | { | |
1279 | register struct nch *ncp; | |
1280 | ||
1281 | for (ncp = nch; ncp < &nch[nchsize]; ncp++) { | |
1282 | ncp->nc_id = 0; | |
1283 | } | |
1284 | } |