Commit | Line | Data |
---|---|---|
067da729 | 1 | /* ufs_lookup.c 6.23 85/05/22 */ |
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; |
87c05e6e KM |
139 | int docache; /* == 0 do not cache last component */ |
140 | int makeentry; /* != 0 if name to be added to cache */ | |
f93197fc KM |
141 | unsigned hash; /* value of name hash for entry */ |
142 | union nchash *nhp; /* cache chain head for entry */ | |
143 | int isdotdot; /* != 0 if current name is ".." */ | |
d870be74 | 144 | int flag; /* op ie, LOOKUP, CREATE, or DELETE */ |
9e7c949b | 145 | off_t enduseful; /* pointer past last used dir slot */ |
10873320 | 146 | |
d870be74 KM |
147 | lockparent = ndp->ni_nameiop & LOCKPARENT; |
148 | docache = (ndp->ni_nameiop & NOCACHE) ^ NOCACHE; | |
149 | flag = ndp->ni_nameiop &~ (LOCKPARENT|NOCACHE|FOLLOW); | |
87c05e6e | 150 | if (flag == DELETE || lockparent) |
f93197fc | 151 | docache = 0; |
f5039631 | 152 | /* |
6bd0bb92 BJ |
153 | * Get a buffer for the name to be translated, and copy the |
154 | * name into the buffer. | |
f5039631 | 155 | */ |
db9631a2 KM |
156 | nbp = freenamebuf; |
157 | if (nbp == NULL) | |
158 | nbp = geteblk(MAXPATHLEN); | |
159 | else | |
160 | freenamebuf = nbp->av_forw; | |
d870be74 | 161 | if (ndp->ni_segflg == UIO_SYSSPACE) |
76335100 KM |
162 | error = copystr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
163 | (u_int *)0); | |
d870be74 | 164 | else |
76335100 KM |
165 | error = copyinstr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
166 | (u_int *)0); | |
d870be74 KM |
167 | if (error) { |
168 | u.u_error = error; | |
6bd0bb92 | 169 | goto bad; |
d870be74 | 170 | } |
6bd0bb92 | 171 | |
10873320 | 172 | /* |
6bd0bb92 | 173 | * Get starting directory. |
10873320 | 174 | */ |
6bd0bb92 | 175 | cp = nbp->b_un.b_addr; |
f5039631 BJ |
176 | if (*cp == '/') { |
177 | while (*cp == '/') | |
178 | cp++; | |
10873320 BJ |
179 | if ((dp = u.u_rdir) == NULL) |
180 | dp = rootdir; | |
6bd0bb92 BJ |
181 | } else |
182 | dp = u.u_cdir; | |
183 | fs = dp->i_fs; | |
56700195 | 184 | ILOCK(dp); |
f5039631 | 185 | dp->i_count++; |
d870be74 | 186 | ndp->ni_pdir = (struct inode *)0xc0000000; /* illegal */ |
9e7c949b | 187 | ndp->ni_endoff = 0; |
6bd0bb92 | 188 | |
10873320 | 189 | /* |
6bd0bb92 BJ |
190 | * We come to dirloop to search a new directory. |
191 | * The directory must be locked so that it can be | |
192 | * iput, and fs must be already set to dp->i_fs. | |
10873320 | 193 | */ |
6bd0bb92 | 194 | dirloop: |
a0aead5a | 195 | /* |
6bd0bb92 | 196 | * Check accessiblity of directory. |
a0aead5a | 197 | */ |
6bd0bb92 | 198 | if ((dp->i_mode&IFMT) != IFDIR) { |
10873320 | 199 | u.u_error = ENOTDIR; |
6bd0bb92 BJ |
200 | goto bad; |
201 | } | |
202 | if (access(dp, IEXEC)) | |
203 | goto bad; | |
204 | ||
6f004ab5 | 205 | dirloop2: |
6bd0bb92 | 206 | /* |
d870be74 | 207 | * Copy next component of name to ndp->ni_dent. |
6bd0bb92 | 208 | */ |
f93197fc | 209 | hash = 0; |
6bd0bb92 | 210 | for (i = 0; *cp != 0 && *cp != '/'; cp++) { |
6459ebe0 | 211 | if (i >= MAXNAMLEN) { |
067da729 | 212 | u.u_error = ENAMETOOLONG; |
d870be74 KM |
213 | goto bad; |
214 | } | |
067da729 KM |
215 | if (*cp & 0200) |
216 | if ((*cp&0377) == ('/'|0200) || flag != DELETE) { | |
217 | u.u_error = EINVAL; | |
218 | goto bad; | |
219 | } | |
d870be74 | 220 | ndp->ni_dent.d_name[i++] = *cp; |
f93197fc | 221 | hash += (unsigned char)*cp * i; |
6459ebe0 | 222 | } |
d870be74 KM |
223 | ndp->ni_dent.d_namlen = i; |
224 | ndp->ni_dent.d_name[i] = '\0'; | |
4a287f19 | 225 | isdotdot = (i == 2 && |
d870be74 | 226 | ndp->ni_dent.d_name[0] == '.' && ndp->ni_dent.d_name[1] == '.'); |
87c05e6e KM |
227 | makeentry = 1; |
228 | if (*cp == '\0' && docache == 0) | |
229 | makeentry = 0; | |
6bd0bb92 BJ |
230 | |
231 | /* | |
232 | * Check for degenerate name (e.g. / or "") | |
233 | * which is a way of talking about a directory, | |
234 | * e.g. like "/." or ".". | |
235 | */ | |
d870be74 | 236 | if (ndp->ni_dent.d_name[0] == '\0') { |
f93197fc | 237 | if (flag != LOOKUP || lockparent) { |
78abd7aa | 238 | u.u_error = EISDIR; |
6bd0bb92 | 239 | goto bad; |
f5039631 | 240 | } |
db9631a2 KM |
241 | nbp->av_forw = freenamebuf; |
242 | freenamebuf = nbp; | |
6459ebe0 | 243 | return (dp); |
f5039631 | 244 | } |
6bd0bb92 | 245 | |
f93197fc KM |
246 | /* |
247 | * We now have a segment name to search for, and a directory to search. | |
248 | * | |
249 | * Before tediously performing a linear scan of the directory, | |
250 | * check the name cache to see if the directory/name pair | |
251 | * we are looking for is known already. We don't do this | |
252 | * if the segment name is long, simply so the cache can avoid | |
253 | * holding long names (which would either waste space, or | |
254 | * add greatly to the complexity). | |
255 | */ | |
d870be74 | 256 | if (ndp->ni_dent.d_namlen > NCHNAMLEN) { |
f93197fc | 257 | nchstats.ncs_long++; |
87c05e6e | 258 | makeentry = 0; |
f93197fc KM |
259 | } else { |
260 | nhp = &nchash[NHASH(hash, dp->i_number, dp->i_dev)]; | |
261 | for (ncp = nhp->nch_forw; ncp != (struct nch *)nhp; | |
262 | ncp = ncp->nc_forw) { | |
263 | if (ncp->nc_ino == dp->i_number && | |
264 | ncp->nc_dev == dp->i_dev && | |
d870be74 KM |
265 | ncp->nc_nlen == ndp->ni_dent.d_namlen && |
266 | !bcmp(ncp->nc_name, ndp->ni_dent.d_name, | |
267 | ncp->nc_nlen)) | |
f93197fc KM |
268 | break; |
269 | } | |
270 | ||
271 | if (ncp == (struct nch *)nhp) { | |
272 | nchstats.ncs_miss++; | |
273 | ncp = NULL; | |
274 | } else { | |
4a287f19 | 275 | if (ncp->nc_id != ncp->nc_ip->i_id) { |
8ac1234a | 276 | nchstats.ncs_falsehits++; |
87c05e6e | 277 | } else if (!makeentry) { |
4a287f19 KM |
278 | nchstats.ncs_badhits++; |
279 | } else { | |
f93197fc KM |
280 | |
281 | /* | |
282 | * move this slot to end of LRU | |
283 | * chain, if not already there | |
284 | */ | |
285 | if (ncp->nc_nxt) { | |
286 | /* remove from LRU chain */ | |
287 | *ncp->nc_prev = ncp->nc_nxt; | |
288 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
289 | ||
290 | /* and replace at end of it */ | |
291 | ncp->nc_nxt = NULL; | |
292 | ncp->nc_prev = nchtail; | |
293 | *nchtail = ncp; | |
294 | nchtail = &ncp->nc_nxt; | |
295 | } | |
296 | ||
4a287f19 KM |
297 | /* |
298 | * Get the next inode in the path. | |
56700195 | 299 | * See comment above other `IUNLOCK' code for |
4a287f19 KM |
300 | * an explaination of the locking protocol. |
301 | */ | |
f93197fc | 302 | pdp = dp; |
87c05e6e KM |
303 | if (!isdotdot || dp != u.u_rdir) |
304 | dp = ncp->nc_ip; | |
f93197fc KM |
305 | if (dp == NULL) |
306 | panic("nami: null cache ino"); | |
87c05e6e | 307 | if (pdp == dp) { |
f93197fc | 308 | dp->i_count++; |
87c05e6e KM |
309 | } else if (isdotdot) { |
310 | IUNLOCK(pdp); | |
311 | igrab(dp); | |
312 | } else { | |
313 | igrab(dp); | |
314 | IUNLOCK(pdp); | |
8ac1234a | 315 | } |
f93197fc | 316 | |
4a287f19 KM |
317 | /* |
318 | * Verify that the inode that we got | |
319 | * did not change while we were waiting | |
320 | * for it to be locked. | |
321 | */ | |
322 | if (ncp->nc_id != ncp->nc_ip->i_id) { | |
323 | iput(dp); | |
56700195 | 324 | ILOCK(pdp); |
4a287f19 KM |
325 | dp = pdp; |
326 | nchstats.ncs_falsehits++; | |
327 | } else { | |
d870be74 KM |
328 | ndp->ni_dent.d_ino = dp->i_number; |
329 | /* ni_dent.d_reclen is garbage ... */ | |
4a287f19 KM |
330 | nchstats.ncs_goodhits++; |
331 | goto haveino; | |
332 | } | |
333 | } | |
f93197fc KM |
334 | |
335 | /* | |
8ac1234a SL |
336 | * Last component and we are renaming or deleting, |
337 | * the cache entry is invalid, or otherwise don't | |
338 | * want cache entry to exist. | |
f93197fc KM |
339 | */ |
340 | ||
f93197fc KM |
341 | /* remove from LRU chain */ |
342 | *ncp->nc_prev = ncp->nc_nxt; | |
343 | if (ncp->nc_nxt) | |
344 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
345 | else | |
346 | nchtail = ncp->nc_prev; | |
347 | ||
348 | /* remove from hash chain */ | |
349 | remque(ncp); | |
350 | ||
f93197fc KM |
351 | /* insert at head of LRU list (first to grab) */ |
352 | ncp->nc_nxt = nchhead; | |
353 | ncp->nc_prev = &nchhead; | |
354 | nchhead->nc_prev = &ncp->nc_nxt; | |
355 | nchhead = ncp; | |
356 | ||
357 | /* and make a dummy hash chain */ | |
358 | ncp->nc_forw = ncp; | |
359 | ncp->nc_back = ncp; | |
360 | ||
361 | ncp = NULL; | |
362 | } | |
363 | } | |
364 | ||
6459ebe0 | 365 | /* |
6bd0bb92 BJ |
366 | * Suppress search for slots unless creating |
367 | * file and at end of pathname, in which case | |
368 | * we watch for a place to put the new file in | |
369 | * case it doesn't already exist. | |
6459ebe0 | 370 | */ |
6bd0bb92 | 371 | slotstatus = FOUND; |
4f083fd7 | 372 | if (flag == CREATE && *cp == 0) { |
6bd0bb92 BJ |
373 | slotstatus = NONE; |
374 | slotfreespace = 0; | |
d870be74 | 375 | slotneeded = DIRSIZ(&ndp->ni_dent); |
6bd0bb92 | 376 | } |
84ef30ec KM |
377 | /* |
378 | * If this is the same directory that this process | |
379 | * previously searched, pick up where we last left off. | |
f93197fc | 380 | * We cache only lookups as these are the most common |
84ef30ec KM |
381 | * and have the greatest payoff. Caching CREATE has little |
382 | * benefit as it usually must search the entire directory | |
383 | * to determine that the entry does not exist. Caching the | |
384 | * location of the last DELETE has not reduced profiling time | |
385 | * and hence has been removed in the interest of simplicity. | |
386 | */ | |
387 | if (flag != LOOKUP || dp->i_number != u.u_ncache.nc_inumber || | |
388 | dp->i_dev != u.u_ncache.nc_dev) { | |
d870be74 | 389 | ndp->ni_offset = 0; |
84ef30ec KM |
390 | numdirpasses = 1; |
391 | } else { | |
f93197fc | 392 | if ((dp->i_flag & ICHG) || dp->i_ctime >= u.u_ncache.nc_time) { |
c1658e77 KM |
393 | if (u.u_ncache.nc_prevoffset > dp->i_size) |
394 | u.u_ncache.nc_prevoffset = 0; | |
395 | else | |
396 | u.u_ncache.nc_prevoffset &= ~(DIRBLKSIZ - 1); | |
84ef30ec KM |
397 | u.u_ncache.nc_time = time.tv_sec; |
398 | } | |
d870be74 KM |
399 | ndp->ni_offset = u.u_ncache.nc_prevoffset; |
400 | entryoffsetinblock = blkoff(fs, ndp->ni_offset); | |
84ef30ec | 401 | if (entryoffsetinblock != 0) { |
d870be74 | 402 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
84ef30ec KM |
403 | if (bp == 0) |
404 | goto bad; | |
405 | } | |
406 | numdirpasses = 2; | |
f93197fc | 407 | nchstats.ncs_2passes++; |
84ef30ec KM |
408 | } |
409 | endsearch = roundup(dp->i_size, DIRBLKSIZ); | |
9e7c949b | 410 | enduseful = 0; |
6bd0bb92 | 411 | |
84ef30ec | 412 | searchloop: |
d870be74 | 413 | while (ndp->ni_offset < endsearch) { |
f5039631 BJ |
414 | /* |
415 | * If offset is on a block boundary, | |
416 | * read the next directory block. | |
417 | * Release previous if it exists. | |
418 | */ | |
d870be74 | 419 | if (blkoff(fs, ndp->ni_offset) == 0) { |
f5039631 BJ |
420 | if (bp != NULL) |
421 | brelse(bp); | |
d870be74 | 422 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
6bd0bb92 BJ |
423 | if (bp == 0) |
424 | goto bad; | |
425 | entryoffsetinblock = 0; | |
6459ebe0 | 426 | } |
6bd0bb92 | 427 | |
6459ebe0 | 428 | /* |
6bd0bb92 | 429 | * If still looking for a slot, and at a DIRBLKSIZE |
d82d5deb | 430 | * boundary, have to start looking for free space again. |
6459ebe0 | 431 | */ |
6bd0bb92 BJ |
432 | if (slotstatus == NONE && |
433 | (entryoffsetinblock&(DIRBLKSIZ-1)) == 0) { | |
434 | slotoffset = -1; | |
435 | slotfreespace = 0; | |
436 | } | |
437 | ||
438 | /* | |
d82d5deb KM |
439 | * Get pointer to next entry. |
440 | * Full validation checks are slow, so we only check | |
441 | * enough to insure forward progress through the | |
442 | * directory. Complete checks can be run by patching | |
443 | * "dirchk" to be true. | |
6bd0bb92 BJ |
444 | */ |
445 | ep = (struct direct *)(bp->b_un.b_addr + entryoffsetinblock); | |
d82d5deb KM |
446 | if (ep->d_reclen <= 0 || |
447 | dirchk && dirbadentry(ep, entryoffsetinblock)) { | |
d870be74 | 448 | dirbad(dp, ndp->ni_offset, "mangled entry"); |
d82d5deb | 449 | i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); |
d870be74 | 450 | ndp->ni_offset += i; |
6bd0bb92 | 451 | entryoffsetinblock += i; |
6459ebe0 KM |
452 | continue; |
453 | } | |
6bd0bb92 | 454 | |
6459ebe0 | 455 | /* |
6bd0bb92 | 456 | * If an appropriate sized slot has not yet been found, |
6459ebe0 KM |
457 | * check to see if one is available. Also accumulate space |
458 | * in the current block so that we can determine if | |
459 | * compaction is viable. | |
460 | */ | |
6bd0bb92 BJ |
461 | if (slotstatus != FOUND) { |
462 | int size = ep->d_reclen; | |
463 | ||
6459ebe0 KM |
464 | if (ep->d_ino != 0) |
465 | size -= DIRSIZ(ep); | |
466 | if (size > 0) { | |
6bd0bb92 BJ |
467 | if (size >= slotneeded) { |
468 | slotstatus = FOUND; | |
d870be74 | 469 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
470 | slotsize = ep->d_reclen; |
471 | } else if (slotstatus == NONE) { | |
472 | slotfreespace += size; | |
473 | if (slotoffset == -1) | |
d870be74 | 474 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
475 | if (slotfreespace >= slotneeded) { |
476 | slotstatus = COMPACT; | |
d870be74 KM |
477 | slotsize = ndp->ni_offset + |
478 | ep->d_reclen - slotoffset; | |
6bd0bb92 | 479 | } |
6459ebe0 | 480 | } |
f5039631 | 481 | } |
f5039631 | 482 | } |
6bd0bb92 | 483 | |
f5039631 | 484 | /* |
6bd0bb92 | 485 | * Check for a name match. |
f5039631 | 486 | */ |
6bd0bb92 | 487 | if (ep->d_ino) { |
d870be74 KM |
488 | if (ep->d_namlen == ndp->ni_dent.d_namlen && |
489 | !bcmp(ndp->ni_dent.d_name, ep->d_name, | |
490 | ep->d_namlen)) | |
6bd0bb92 BJ |
491 | goto found; |
492 | } | |
d870be74 KM |
493 | prevoff = ndp->ni_offset; |
494 | ndp->ni_offset += ep->d_reclen; | |
6bd0bb92 | 495 | entryoffsetinblock += ep->d_reclen; |
9e7c949b KM |
496 | if (ep->d_ino) |
497 | enduseful = ndp->ni_offset; | |
6bd0bb92 | 498 | } |
f93197fc | 499 | /* notfound: */ |
84ef30ec | 500 | /* |
f93197fc | 501 | * If we started in the middle of the directory and failed |
84ef30ec KM |
502 | * to find our target, we must check the beginning as well. |
503 | */ | |
504 | if (numdirpasses == 2) { | |
505 | numdirpasses--; | |
d870be74 | 506 | ndp->ni_offset = 0; |
84ef30ec KM |
507 | endsearch = u.u_ncache.nc_prevoffset; |
508 | goto searchloop; | |
509 | } | |
6bd0bb92 BJ |
510 | /* |
511 | * If creating, and at end of pathname and current | |
4f083fd7 SL |
512 | * directory has not been removed, then can consider |
513 | * allowing file to be created. | |
6bd0bb92 | 514 | */ |
4f083fd7 | 515 | if (flag == CREATE && *cp == 0 && dp->i_nlink != 0) { |
f5039631 | 516 | /* |
6bd0bb92 BJ |
517 | * Access for write is interpreted as allowing |
518 | * creation of files in the directory. | |
f5039631 | 519 | */ |
6bd0bb92 BJ |
520 | if (access(dp, IWRITE)) |
521 | goto bad; | |
f5039631 | 522 | /* |
6bd0bb92 BJ |
523 | * Return an indication of where the new directory |
524 | * entry should be put. If we didn't find a slot, | |
d870be74 KM |
525 | * then set ndp->ni_count to 0 indicating that the new |
526 | * slot belongs at the end of the directory. If we found | |
527 | * a slot, then the new entry can be put in the range | |
528 | * [ndp->ni_offset .. ndp->ni_offset + ndp->ni_count) | |
f5039631 | 529 | */ |
84ef30ec | 530 | if (slotstatus == NONE) { |
d870be74 KM |
531 | ndp->ni_offset = roundup(dp->i_size, DIRBLKSIZ); |
532 | ndp->ni_count = 0; | |
9e7c949b | 533 | enduseful = ndp->ni_offset; |
84ef30ec | 534 | } else { |
d870be74 KM |
535 | ndp->ni_offset = slotoffset; |
536 | ndp->ni_count = slotsize; | |
9e7c949b KM |
537 | if (enduseful < slotoffset + slotsize) |
538 | enduseful = slotoffset + slotsize; | |
5485e062 | 539 | } |
9e7c949b | 540 | ndp->ni_endoff = roundup(enduseful, DIRBLKSIZ); |
6bd0bb92 BJ |
541 | dp->i_flag |= IUPD|ICHG; |
542 | if (bp) | |
543 | brelse(bp); | |
db9631a2 KM |
544 | nbp->av_forw = freenamebuf; |
545 | freenamebuf = nbp; | |
f5039631 | 546 | /* |
6bd0bb92 BJ |
547 | * We return with the directory locked, so that |
548 | * the parameters we set up above will still be | |
549 | * valid if we actually decide to do a direnter(). | |
550 | * We return NULL to indicate that the entry doesn't | |
551 | * currently exist, leaving a pointer to the (locked) | |
d870be74 | 552 | * directory inode in ndp->ni_pdir. |
f5039631 | 553 | */ |
d870be74 | 554 | ndp->ni_pdir = dp; |
6bd0bb92 BJ |
555 | return (NULL); |
556 | } | |
557 | u.u_error = ENOENT; | |
558 | goto bad; | |
559 | found: | |
f93197fc KM |
560 | if (numdirpasses == 2) |
561 | nchstats.ncs_pass2++; | |
6bd0bb92 BJ |
562 | /* |
563 | * Check that directory length properly reflects presence | |
564 | * of this entry. | |
565 | */ | |
4a0415d6 | 566 | if (entryoffsetinblock + DIRSIZ(ep) > dp->i_size) { |
d870be74 | 567 | dirbad(dp, ndp->ni_offset, "i_size too small"); |
4a0415d6 | 568 | dp->i_size = entryoffsetinblock + DIRSIZ(ep); |
6bd0bb92 BJ |
569 | dp->i_flag |= IUPD|ICHG; |
570 | } | |
571 | ||
572 | /* | |
84ef30ec | 573 | * Found component in pathname. |
f93197fc | 574 | * If the final component of path name, save information |
84ef30ec KM |
575 | * in the cache as to where the entry was found. |
576 | */ | |
577 | if (*cp == '\0' && flag == LOOKUP) { | |
d870be74 | 578 | u.u_ncache.nc_prevoffset = ndp->ni_offset; |
84ef30ec KM |
579 | u.u_ncache.nc_inumber = dp->i_number; |
580 | u.u_ncache.nc_dev = dp->i_dev; | |
581 | u.u_ncache.nc_time = time.tv_sec; | |
582 | } | |
583 | /* | |
87c05e6e | 584 | * Save directory entry's inode number and reclen in ndp->ni_dent, |
84ef30ec | 585 | * and release directory buffer. |
6bd0bb92 | 586 | */ |
87c05e6e KM |
587 | ndp->ni_dent.d_ino = ep->d_ino; |
588 | ndp->ni_dent.d_reclen = ep->d_reclen; | |
6bd0bb92 BJ |
589 | brelse(bp); |
590 | bp = NULL; | |
591 | ||
592 | /* | |
593 | * If deleting, and at end of pathname, return | |
594 | * parameters which can be used to remove file. | |
4f083fd7 | 595 | * If the lockparent flag isn't set, we return only |
d870be74 | 596 | * the directory (in ndp->ni_pdir), otherwise we go |
4f083fd7 | 597 | * on and lock the inode, being careful with ".". |
6bd0bb92 | 598 | */ |
4f083fd7 | 599 | if (flag == DELETE && *cp == 0) { |
6bd0bb92 BJ |
600 | /* |
601 | * Write access to directory required to delete files. | |
602 | */ | |
603 | if (access(dp, IWRITE)) | |
604 | goto bad; | |
d870be74 | 605 | ndp->ni_pdir = dp; /* for dirremove() */ |
6bd0bb92 | 606 | /* |
d870be74 | 607 | * Return pointer to current entry in ndp->ni_offset, |
6bd0bb92 | 608 | * and distance past previous entry (if there |
d870be74 KM |
609 | * is a previous entry in this block) in ndp->ni_count. |
610 | * Save directory inode pointer in ndp->ni_pdir for dirremove(). | |
6bd0bb92 | 611 | */ |
d870be74 KM |
612 | if ((ndp->ni_offset&(DIRBLKSIZ-1)) == 0) |
613 | ndp->ni_count = 0; | |
6bd0bb92 | 614 | else |
d870be74 | 615 | ndp->ni_count = ndp->ni_offset - prevoff; |
4f083fd7 | 616 | if (lockparent) { |
d870be74 | 617 | if (dp->i_number == ndp->ni_dent.d_ino) |
4f083fd7 SL |
618 | dp->i_count++; |
619 | else { | |
d870be74 | 620 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 621 | if (dp == NULL) { |
d870be74 | 622 | iput(ndp->ni_pdir); |
4f083fd7 SL |
623 | goto bad; |
624 | } | |
f93197fc | 625 | /* |
9ba16c41 | 626 | * If directory is "sticky", then user must own |
f93197fc KM |
627 | * the directory, or the file in it, else he |
628 | * may not delete it (unless he's root). This | |
629 | * implements append-only directories. | |
630 | */ | |
d870be74 | 631 | if ((ndp->ni_pdir->i_mode & ISVTX) && |
f93197fc | 632 | u.u_uid != 0 && |
d870be74 | 633 | u.u_uid != ndp->ni_pdir->i_uid && |
f93197fc | 634 | dp->i_uid != u.u_uid) { |
d870be74 | 635 | iput(ndp->ni_pdir); |
f93197fc KM |
636 | u.u_error = EPERM; |
637 | goto bad; | |
638 | } | |
4f083fd7 SL |
639 | } |
640 | } | |
db9631a2 KM |
641 | nbp->av_forw = freenamebuf; |
642 | freenamebuf = nbp; | |
6bd0bb92 BJ |
643 | return (dp); |
644 | } | |
645 | ||
646 | /* | |
647 | * Special handling for ".." allowing chdir out of mounted | |
648 | * file system: indirect .. in root inode to reevaluate | |
649 | * in directory file system was mounted on. | |
650 | */ | |
4a287f19 | 651 | if (isdotdot) { |
87c05e6e | 652 | if (dp == u.u_rdir) { |
d870be74 | 653 | ndp->ni_dent.d_ino = dp->i_number; |
87c05e6e KM |
654 | makeentry = 0; |
655 | } else if (ndp->ni_dent.d_ino == ROOTINO && | |
6bd0bb92 BJ |
656 | dp->i_number == ROOTINO) { |
657 | for (i = 1; i < NMOUNT; i++) | |
658 | if (mount[i].m_bufp != NULL && | |
659 | mount[i].m_dev == dp->i_dev) { | |
6459ebe0 | 660 | iput(dp); |
6bd0bb92 | 661 | dp = mount[i].m_inodp; |
56700195 | 662 | ILOCK(dp); |
f5039631 | 663 | dp->i_count++; |
6bd0bb92 BJ |
664 | fs = dp->i_fs; |
665 | cp -= 2; /* back over .. */ | |
666 | goto dirloop2; | |
f5039631 | 667 | } |
10873320 | 668 | } |
6bd0bb92 BJ |
669 | } |
670 | ||
4f083fd7 SL |
671 | /* |
672 | * If rewriting (rename), return the inode and the | |
673 | * information required to rewrite the present directory | |
674 | * Must get inode of directory entry to verify it's a | |
675 | * regular file, or empty directory. | |
676 | */ | |
677 | if ((flag == CREATE && lockparent) && *cp == 0) { | |
678 | if (access(dp, IWRITE)) | |
679 | goto bad; | |
d870be74 | 680 | ndp->ni_pdir = dp; /* for dirrewrite() */ |
4f083fd7 SL |
681 | /* |
682 | * Careful about locking second inode. | |
683 | * This can only occur if the target is ".". | |
684 | */ | |
d870be74 | 685 | if (dp->i_number == ndp->ni_dent.d_ino) { |
4f083fd7 SL |
686 | u.u_error = EISDIR; /* XXX */ |
687 | goto bad; | |
688 | } | |
d870be74 | 689 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 690 | if (dp == NULL) { |
d870be74 | 691 | iput(ndp->ni_pdir); |
4f083fd7 SL |
692 | goto bad; |
693 | } | |
db9631a2 KM |
694 | nbp->av_forw = freenamebuf; |
695 | freenamebuf = nbp; | |
4f083fd7 SL |
696 | return (dp); |
697 | } | |
698 | ||
6bd0bb92 | 699 | /* |
bde63aa5 KM |
700 | * Check for symbolic link, which may require us to massage the |
701 | * name before we continue translation. We do not `iput' the | |
702 | * directory because we may need it again if the symbolic link | |
703 | * is relative to the current directory. Instead we save it | |
704 | * unlocked as "pdp". We must get the target inode before unlocking | |
705 | * the directory to insure that the inode will not be removed | |
706 | * before we get it. We prevent deadlock by always fetching | |
707 | * inodes from the root, moving down the directory tree. Thus | |
708 | * when following backward pointers ".." we must unlock the | |
709 | * parent directory before getting the requested directory. | |
710 | * There is a potential race condition here if both the current | |
711 | * and parent directories are removed before the `iget' for the | |
712 | * inode associated with ".." returns. We hope that this occurs | |
713 | * infrequently since we cannot avoid this race condition without | |
a4358a25 | 714 | * implementing a sophisticated deadlock detection algorithm. |
bde63aa5 KM |
715 | * Note also that this simple deadlock detection scheme will not |
716 | * work if the file system has any hard links other than ".." | |
717 | * that point backwards in the directory structure. | |
6bd0bb92 BJ |
718 | */ |
719 | pdp = dp; | |
f93197fc | 720 | if (isdotdot) { |
56700195 | 721 | IUNLOCK(pdp); /* race to get the inode */ |
d870be74 | 722 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
bde63aa5 KM |
723 | if (dp == NULL) |
724 | goto bad2; | |
d870be74 | 725 | } else if (dp->i_number == ndp->ni_dent.d_ino) { |
bde63aa5 KM |
726 | dp->i_count++; /* we want ourself, ie "." */ |
727 | } else { | |
d870be74 | 728 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
56700195 | 729 | IUNLOCK(pdp); |
bde63aa5 KM |
730 | if (dp == NULL) |
731 | goto bad2; | |
732 | } | |
f93197fc KM |
733 | |
734 | /* | |
067da729 | 735 | * insert name into cache if appropriate |
f93197fc | 736 | */ |
87c05e6e | 737 | if (makeentry) { |
f93197fc KM |
738 | if (ncp != NULL) |
739 | panic("nami: duplicating cache"); | |
740 | ||
741 | /* | |
742 | * free the cache slot at head of lru chain | |
743 | */ | |
744 | if (ncp = nchhead) { | |
745 | /* remove from lru chain */ | |
746 | *ncp->nc_prev = ncp->nc_nxt; | |
747 | if (ncp->nc_nxt) | |
748 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
749 | else | |
750 | nchtail = ncp->nc_prev; | |
751 | ||
752 | /* remove from old hash chain */ | |
753 | remque(ncp); | |
754 | ||
f93197fc KM |
755 | /* grab the inode we just found */ |
756 | ncp->nc_ip = dp; | |
f93197fc KM |
757 | |
758 | /* fill in cache info */ | |
759 | ncp->nc_ino = pdp->i_number; /* parents inum */ | |
760 | ncp->nc_dev = pdp->i_dev; /* & device */ | |
761 | ncp->nc_idev = dp->i_dev; /* our device */ | |
8ac1234a | 762 | ncp->nc_id = dp->i_id; /* identifier */ |
d870be74 KM |
763 | ncp->nc_nlen = ndp->ni_dent.d_namlen; |
764 | bcopy(ndp->ni_dent.d_name, ncp->nc_name, ncp->nc_nlen); | |
f93197fc KM |
765 | |
766 | /* link at end of lru chain */ | |
767 | ncp->nc_nxt = NULL; | |
768 | ncp->nc_prev = nchtail; | |
769 | *nchtail = ncp; | |
770 | nchtail = &ncp->nc_nxt; | |
771 | ||
772 | /* and insert on hash chain */ | |
773 | insque(ncp, nhp); | |
774 | } | |
775 | } | |
776 | ||
777 | haveino: | |
6bd0bb92 BJ |
778 | fs = dp->i_fs; |
779 | ||
780 | /* | |
781 | * Check for symbolic link | |
782 | */ | |
d870be74 KM |
783 | if ((dp->i_mode & IFMT) == IFLNK && |
784 | ((ndp->ni_nameiop & FOLLOW) || *cp == '/')) { | |
9f024ffc | 785 | u_int pathlen = strlen(cp) + 1; |
6bd0bb92 | 786 | |
067da729 KM |
787 | if (dp->i_size + pathlen >= MAXPATHLEN - 1) { |
788 | u.u_error = ENAMETOOLONG; | |
789 | goto bad2; | |
790 | } | |
791 | if (++nlink > MAXSYMLINKS) { | |
6bd0bb92 BJ |
792 | u.u_error = ELOOP; |
793 | goto bad2; | |
794 | } | |
d36096be | 795 | ovbcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen); |
a6b6f679 | 796 | u.u_error = |
4f083fd7 | 797 | rdwri(UIO_READ, dp, nbp->b_un.b_addr, (int)dp->i_size, |
9f024ffc | 798 | 0, 1, (int *)0); |
6bd0bb92 BJ |
799 | if (u.u_error) |
800 | goto bad2; | |
801 | cp = nbp->b_un.b_addr; | |
802 | iput(dp); | |
f5039631 | 803 | if (*cp == '/') { |
6bd0bb92 | 804 | irele(pdp); |
f5039631 BJ |
805 | while (*cp == '/') |
806 | cp++; | |
6bd0bb92 BJ |
807 | if ((dp = u.u_rdir) == NULL) |
808 | dp = rootdir; | |
56700195 | 809 | ILOCK(dp); |
6bd0bb92 BJ |
810 | dp->i_count++; |
811 | } else { | |
812 | dp = pdp; | |
56700195 | 813 | ILOCK(dp); |
f5039631 | 814 | } |
6bd0bb92 BJ |
815 | fs = dp->i_fs; |
816 | goto dirloop; | |
10873320 | 817 | } |
6bd0bb92 | 818 | |
10873320 | 819 | /* |
6bd0bb92 BJ |
820 | * Not a symbolic link. If more pathname, |
821 | * continue at next component, else return. | |
10873320 | 822 | */ |
6bd0bb92 BJ |
823 | if (*cp == '/') { |
824 | while (*cp == '/') | |
825 | cp++; | |
4f083fd7 | 826 | irele(pdp); |
6bd0bb92 | 827 | goto dirloop; |
10873320 | 828 | } |
db9631a2 KM |
829 | nbp->av_forw = freenamebuf; |
830 | freenamebuf = nbp; | |
4f083fd7 | 831 | if (lockparent) |
d870be74 | 832 | ndp->ni_pdir = pdp; |
4f083fd7 SL |
833 | else |
834 | irele(pdp); | |
6bd0bb92 BJ |
835 | return (dp); |
836 | bad2: | |
837 | irele(pdp); | |
838 | bad: | |
839 | if (bp) | |
840 | brelse(bp); | |
841 | if (dp) | |
842 | iput(dp); | |
db9631a2 KM |
843 | nbp->av_forw = freenamebuf; |
844 | freenamebuf = nbp; | |
6459ebe0 | 845 | return (NULL); |
10873320 BJ |
846 | } |
847 | ||
f93197fc | 848 | |
d870be74 | 849 | dirbad(ip, offset, how) |
6bd0bb92 | 850 | struct inode *ip; |
d870be74 | 851 | off_t offset; |
6bd0bb92 BJ |
852 | char *how; |
853 | { | |
854 | ||
855 | printf("%s: bad dir ino %d at offset %d: %s\n", | |
d870be74 | 856 | ip->i_fs->fs_fsmnt, ip->i_number, offset, how); |
6bd0bb92 BJ |
857 | } |
858 | ||
d82d5deb KM |
859 | /* |
860 | * Do consistency checking on a directory entry: | |
861 | * record length must be multiple of 4 | |
862 | * record length must not be non-negative | |
863 | * entry must fit in rest of its DIRBLKSIZ block | |
864 | * record must be large enough to contain entry | |
865 | * name is not longer than MAXNAMLEN | |
866 | * name must be as long as advertised, and null terminated | |
867 | */ | |
868 | dirbadentry(ep, entryoffsetinblock) | |
6bd0bb92 | 869 | register struct direct *ep; |
d82d5deb | 870 | int entryoffsetinblock; |
6bd0bb92 | 871 | { |
6bd0bb92 BJ |
872 | register int i; |
873 | ||
d82d5deb KM |
874 | if ((ep->d_reclen & 0x3) != 0 || ep->d_reclen <= 0 || |
875 | ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || | |
876 | ep->d_reclen < DIRSIZ(ep) || ep->d_namlen > MAXNAMLEN) | |
877 | return (1); | |
6bd0bb92 | 878 | for (i = 0; i < ep->d_namlen; i++) |
d870be74 | 879 | if (ep->d_name[i] == '\0') |
6bd0bb92 BJ |
880 | return (1); |
881 | return (ep->d_name[i]); | |
882 | } | |
883 | ||
6bd0bb92 BJ |
884 | /* |
885 | * Write a directory entry after a call to namei, using the parameters | |
886 | * which it left in the u. area. The argument ip is the inode which | |
d870be74 | 887 | * the new directory entry will refer to. The u. area field ndp->ni_pdir is |
6bd0bb92 | 888 | * a pointer to the directory to be written, which was left locked by |
d870be74 | 889 | * namei. Remaining parameters (ndp->ni_offset, ndp->ni_count) indicate |
6bd0bb92 BJ |
890 | * how the space for the new entry is to be gotten. |
891 | */ | |
d870be74 | 892 | direnter(ip, ndp) |
6bd0bb92 | 893 | struct inode *ip; |
d870be74 | 894 | register struct nameidata *ndp; |
f5039631 | 895 | { |
6bd0bb92 | 896 | register struct direct *ep, *nep; |
9e7c949b | 897 | register struct inode *dp = ndp->ni_pdir; |
6bd0bb92 | 898 | struct buf *bp; |
efa3a91c | 899 | int loc, spacefree, error = 0; |
b32450f4 BJ |
900 | u_int dsize; |
901 | int newentrysize; | |
6bd0bb92 | 902 | char *dirbuf; |
f5039631 | 903 | |
d870be74 KM |
904 | ndp->ni_dent.d_ino = ip->i_number; |
905 | newentrysize = DIRSIZ(&ndp->ni_dent); | |
906 | if (ndp->ni_count == 0) { | |
6bd0bb92 | 907 | /* |
d870be74 KM |
908 | * If ndp->ni_count is 0, then namei could find no space in the |
909 | * directory. In this case ndp->ni_offset will be on a directory | |
6bd0bb92 BJ |
910 | * block boundary and we will write the new entry into a fresh |
911 | * block. | |
912 | */ | |
d870be74 | 913 | if (ndp->ni_offset&(DIRBLKSIZ-1)) |
6bd0bb92 | 914 | panic("wdir: newblk"); |
d870be74 | 915 | ndp->ni_dent.d_reclen = DIRBLKSIZ; |
9e7c949b | 916 | error = rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, |
d870be74 | 917 | newentrysize, ndp->ni_offset, 1, (int *)0); |
23de9f20 KM |
918 | if (DIRBLKSIZ > dp->i_fs->fs_fsize) |
919 | panic("wdir: blksize"); /* XXX - should grow w/bmap() */ | |
920 | else | |
921 | dp->i_size = roundup(dp->i_size, DIRBLKSIZ); | |
9e7c949b | 922 | iput(dp); |
f2a5ad78 | 923 | return (error); |
6bd0bb92 BJ |
924 | } |
925 | ||
926 | /* | |
d870be74 KM |
927 | * If ndp->ni_count is non-zero, then namei found space for the new |
928 | * entry in the range ndp->ni_offset to ndp->ni_offset + ndp->ni_count. | |
6bd0bb92 BJ |
929 | * in the directory. To use this space, we may have to compact |
930 | * the entries located there, by copying them together towards | |
931 | * the beginning of the block, leaving the free space in | |
932 | * one usable chunk at the end. | |
933 | */ | |
934 | ||
935 | /* | |
936 | * Increase size of directory if entry eats into new space. | |
937 | * This should never push the size past a new multiple of | |
938 | * DIRBLKSIZE. | |
23de9f20 KM |
939 | * |
940 | * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. | |
6bd0bb92 | 941 | */ |
9e7c949b KM |
942 | if (ndp->ni_offset + ndp->ni_count > dp->i_size) |
943 | dp->i_size = ndp->ni_offset + ndp->ni_count; | |
6bd0bb92 BJ |
944 | |
945 | /* | |
946 | * Get the block containing the space for the new directory | |
f2a5ad78 | 947 | * entry. Should return error by result instead of u.u_error. |
6bd0bb92 | 948 | */ |
9e7c949b | 949 | bp = blkatoff(dp, ndp->ni_offset, (char **)&dirbuf); |
4f083fd7 | 950 | if (bp == 0) { |
9e7c949b | 951 | iput(dp); |
f2a5ad78 | 952 | return (u.u_error); |
4f083fd7 | 953 | } |
6bd0bb92 BJ |
954 | |
955 | /* | |
956 | * Find space for the new entry. In the simple case, the | |
957 | * entry at offset base will have the space. If it does | |
958 | * not, then namei arranged that compacting the region | |
d870be74 | 959 | * ndp->ni_offset to ndp->ni_offset+ndp->ni_count would yield the space. |
6bd0bb92 BJ |
960 | */ |
961 | ep = (struct direct *)dirbuf; | |
962 | dsize = DIRSIZ(ep); | |
efa3a91c | 963 | spacefree = ep->d_reclen - dsize; |
d870be74 | 964 | for (loc = ep->d_reclen; loc < ndp->ni_count; ) { |
6bd0bb92 BJ |
965 | nep = (struct direct *)(dirbuf + loc); |
966 | if (ep->d_ino) { | |
967 | /* trim the existing slot */ | |
968 | ep->d_reclen = dsize; | |
969 | ep = (struct direct *)((char *)ep + dsize); | |
970 | } else { | |
971 | /* overwrite; nothing there; header is ours */ | |
efa3a91c | 972 | spacefree += dsize; |
6bd0bb92 BJ |
973 | } |
974 | dsize = DIRSIZ(nep); | |
efa3a91c | 975 | spacefree += nep->d_reclen - dsize; |
6bd0bb92 | 976 | loc += nep->d_reclen; |
9f024ffc | 977 | bcopy((caddr_t)nep, (caddr_t)ep, dsize); |
6bd0bb92 BJ |
978 | } |
979 | /* | |
980 | * Update the pointer fields in the previous entry (if any), | |
981 | * copy in the new entry, and write out the block. | |
982 | */ | |
983 | if (ep->d_ino == 0) { | |
efa3a91c | 984 | if (spacefree + dsize < newentrysize) |
6bd0bb92 | 985 | panic("wdir: compact1"); |
d870be74 | 986 | ndp->ni_dent.d_reclen = spacefree + dsize; |
6bd0bb92 | 987 | } else { |
efa3a91c | 988 | if (spacefree < newentrysize) |
6bd0bb92 | 989 | panic("wdir: compact2"); |
d870be74 | 990 | ndp->ni_dent.d_reclen = spacefree; |
6bd0bb92 BJ |
991 | ep->d_reclen = dsize; |
992 | ep = (struct direct *)((char *)ep + dsize); | |
993 | } | |
d870be74 | 994 | bcopy((caddr_t)&ndp->ni_dent, (caddr_t)ep, (u_int)newentrysize); |
6bd0bb92 | 995 | bwrite(bp); |
9e7c949b KM |
996 | dp->i_flag |= IUPD|ICHG; |
997 | if (ndp->ni_endoff && ndp->ni_endoff < dp->i_size) | |
998 | itrunc(dp, ndp->ni_endoff); | |
999 | iput(dp); | |
f2a5ad78 | 1000 | return (error); |
6bd0bb92 BJ |
1001 | } |
1002 | ||
4f083fd7 SL |
1003 | /* |
1004 | * Remove a directory entry after a call to namei, using the | |
1005 | * parameters which it left in the u. area. The u. entry | |
d870be74 KM |
1006 | * ni_offset contains the offset into the directory of the |
1007 | * entry to be eliminated. The ni_count field contains the | |
4f083fd7 SL |
1008 | * size of the previous record in the directory. If this |
1009 | * is 0, the first entry is being deleted, so we need only | |
1010 | * zero the inode number to mark the entry as free. If the | |
1011 | * entry isn't the first in the directory, we must reclaim | |
1012 | * the space of the now empty record by adding the record size | |
1013 | * to the size of the previous entry. | |
1014 | */ | |
d870be74 KM |
1015 | dirremove(ndp) |
1016 | register struct nameidata *ndp; | |
6bd0bb92 | 1017 | { |
d870be74 | 1018 | register struct inode *dp = ndp->ni_pdir; |
6bd0bb92 BJ |
1019 | register struct buf *bp; |
1020 | struct direct *ep; | |
1021 | ||
d870be74 | 1022 | if (ndp->ni_count == 0) { |
6bd0bb92 BJ |
1023 | /* |
1024 | * First entry in block: set d_ino to zero. | |
1025 | */ | |
d870be74 KM |
1026 | ndp->ni_dent.d_ino = 0; |
1027 | (void) rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1028 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
36d4ed87 | 1029 | } else { |
6bd0bb92 BJ |
1030 | /* |
1031 | * Collapse new free space into previous entry. | |
1032 | */ | |
d870be74 KM |
1033 | bp = blkatoff(dp, (int)(ndp->ni_offset - ndp->ni_count), |
1034 | (char **)&ep); | |
6bd0bb92 BJ |
1035 | if (bp == 0) |
1036 | return (0); | |
d870be74 | 1037 | ep->d_reclen += ndp->ni_dent.d_reclen; |
6bd0bb92 BJ |
1038 | bwrite(bp); |
1039 | dp->i_flag |= IUPD|ICHG; | |
1040 | } | |
1041 | return (1); | |
10873320 | 1042 | } |
6459ebe0 | 1043 | |
4f083fd7 SL |
1044 | /* |
1045 | * Rewrite an existing directory entry to point at the inode | |
1046 | * supplied. The parameters describing the directory entry are | |
1047 | * set up by a call to namei. | |
1048 | */ | |
d870be74 | 1049 | dirrewrite(dp, ip, ndp) |
4f083fd7 | 1050 | struct inode *dp, *ip; |
d870be74 | 1051 | struct nameidata *ndp; |
4f083fd7 SL |
1052 | { |
1053 | ||
d870be74 KM |
1054 | ndp->ni_dent.d_ino = ip->i_number; |
1055 | u.u_error = rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1056 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
4f083fd7 SL |
1057 | iput(dp); |
1058 | } | |
1059 | ||
4a0415d6 SL |
1060 | /* |
1061 | * Return buffer with contents of block "offset" | |
1062 | * from the beginning of directory "ip". If "res" | |
1063 | * is non-zero, fill it in with a pointer to the | |
1064 | * remaining space in the directory. | |
1065 | */ | |
6bd0bb92 | 1066 | struct buf * |
4a0415d6 | 1067 | blkatoff(ip, offset, res) |
6bd0bb92 BJ |
1068 | struct inode *ip; |
1069 | off_t offset; | |
1070 | char **res; | |
6459ebe0 | 1071 | { |
6bd0bb92 | 1072 | register struct fs *fs = ip->i_fs; |
3fd23f5c | 1073 | daddr_t lbn = lblkno(fs, offset); |
6bd0bb92 | 1074 | int bsize = blksize(fs, ip, lbn); |
6bd0bb92 | 1075 | register struct buf *bp; |
7e4f159c | 1076 | daddr_t bn; |
6459ebe0 | 1077 | |
7e4f159c | 1078 | bn = bmap(ip, lbn, B_READ, bsize); |
6bd0bb92 BJ |
1079 | if (u.u_error) |
1080 | return (0); | |
7e4f159c KM |
1081 | if (bn == (daddr_t)-1) { |
1082 | dirbad(ip, offset, "hole in dir"); | |
1083 | return (0); | |
1084 | } | |
1085 | bp = bread(ip->i_dev, fsbtodb(fs, bn), bsize); | |
6bd0bb92 BJ |
1086 | if (bp->b_flags & B_ERROR) { |
1087 | brelse(bp); | |
1088 | return (0); | |
1089 | } | |
1090 | if (res) | |
7e4f159c | 1091 | *res = bp->b_un.b_addr + blkoff(fs, offset); |
6bd0bb92 | 1092 | return (bp); |
6459ebe0 | 1093 | } |
4f083fd7 SL |
1094 | |
1095 | /* | |
1096 | * Check if a directory is empty or not. | |
1097 | * Inode supplied must be locked. | |
17d11193 SL |
1098 | * |
1099 | * Using a struct dirtemplate here is not precisely | |
1100 | * what we want, but better than using a struct direct. | |
1101 | * | |
1102 | * NB: does not handle corrupted directories. | |
4f083fd7 | 1103 | */ |
68f21562 | 1104 | dirempty(ip, parentino) |
05d2bbce | 1105 | register struct inode *ip; |
68f21562 | 1106 | ino_t parentino; |
4f083fd7 SL |
1107 | { |
1108 | register off_t off; | |
17d11193 SL |
1109 | struct dirtemplate dbuf; |
1110 | register struct direct *dp = (struct direct *)&dbuf; | |
05d2bbce | 1111 | int error, count; |
17d11193 | 1112 | #define MINDIRSIZ (sizeof (struct dirtemplate) / 2) |
4f083fd7 SL |
1113 | |
1114 | for (off = 0; off < ip->i_size; off += dp->d_reclen) { | |
41413014 KM |
1115 | if (dp->d_reclen <= 0) |
1116 | return (0); | |
17d11193 SL |
1117 | error = rdwri(UIO_READ, ip, (caddr_t)dp, MINDIRSIZ, |
1118 | off, 1, &count); | |
1119 | /* | |
1120 | * Since we read MINDIRSIZ, residual must | |
1121 | * be 0 unless we're at end of file. | |
1122 | */ | |
1123 | if (error || count != 0) | |
4f083fd7 | 1124 | return (0); |
17d11193 | 1125 | /* skip empty entries */ |
4f083fd7 SL |
1126 | if (dp->d_ino == 0) |
1127 | continue; | |
17d11193 SL |
1128 | /* accept only "." and ".." */ |
1129 | if (dp->d_namlen > 2) | |
1130 | return (0); | |
4f083fd7 SL |
1131 | if (dp->d_name[0] != '.') |
1132 | return (0); | |
17d11193 SL |
1133 | /* |
1134 | * At this point d_namlen must be 1 or 2. | |
1135 | * 1 implies ".", 2 implies ".." if second | |
1136 | * char is also "." | |
1137 | */ | |
68f21562 KM |
1138 | if (dp->d_namlen == 1) |
1139 | continue; | |
1140 | if (dp->d_name[1] == '.' && dp->d_ino == parentino) | |
4f083fd7 SL |
1141 | continue; |
1142 | return (0); | |
1143 | } | |
1144 | return (1); | |
1145 | } | |
b1aa93b9 KM |
1146 | |
1147 | /* | |
1148 | * Check if source directory is in the path of the target directory. | |
1149 | * Target is supplied locked, source is unlocked. | |
1150 | * The target is always iput() before returning. | |
1151 | */ | |
1152 | checkpath(source, target) | |
1153 | struct inode *source, *target; | |
1154 | { | |
1155 | struct dirtemplate dirbuf; | |
1156 | register struct inode *ip; | |
1157 | int error = 0; | |
1158 | ||
1159 | ip = target; | |
1160 | if (ip->i_number == source->i_number) { | |
1161 | error = EEXIST; | |
1162 | goto out; | |
1163 | } | |
1164 | if (ip->i_number == ROOTINO) | |
1165 | goto out; | |
1166 | ||
1167 | for (;;) { | |
1168 | if ((ip->i_mode&IFMT) != IFDIR) { | |
1169 | error = ENOTDIR; | |
1170 | break; | |
1171 | } | |
1172 | error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, | |
1173 | sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); | |
1174 | if (error != 0) | |
1175 | break; | |
1176 | if (dirbuf.dotdot_namlen != 2 || | |
4a287f19 KM |
1177 | dirbuf.dotdot_name[0] != '.' || |
1178 | dirbuf.dotdot_name[1] != '.') { | |
b1aa93b9 KM |
1179 | error = ENOTDIR; |
1180 | break; | |
1181 | } | |
1182 | if (dirbuf.dotdot_ino == source->i_number) { | |
1183 | error = EINVAL; | |
1184 | break; | |
1185 | } | |
1186 | if (dirbuf.dotdot_ino == ROOTINO) | |
1187 | break; | |
1188 | iput(ip); | |
1189 | ip = iget(ip->i_dev, ip->i_fs, dirbuf.dotdot_ino); | |
1190 | if (ip == NULL) { | |
1191 | error = u.u_error; | |
1192 | break; | |
1193 | } | |
1194 | } | |
1195 | ||
1196 | out: | |
1197 | if (error == ENOTDIR) | |
1198 | printf("checkpath: .. not a directory\n"); | |
1199 | if (ip != NULL) | |
1200 | iput(ip); | |
1201 | return (error); | |
1202 | } | |
f93197fc KM |
1203 | |
1204 | /* | |
1205 | * Name cache initialization, from main() when we are booting | |
1206 | */ | |
1207 | nchinit() | |
1208 | { | |
1209 | register union nchash *nchp; | |
1210 | register struct nch *ncp; | |
1211 | ||
1212 | nchhead = 0; | |
1213 | nchtail = &nchhead; | |
1214 | ||
1215 | for (ncp = nch; ncp < &nch[nchsize]; ncp++) { | |
1216 | ncp->nc_forw = ncp; /* hash chain */ | |
1217 | ncp->nc_back = ncp; | |
1218 | ||
1219 | ncp->nc_nxt = NULL; /* lru chain */ | |
1220 | *nchtail = ncp; | |
1221 | ncp->nc_prev = nchtail; | |
1222 | nchtail = &ncp->nc_nxt; | |
1223 | ||
1224 | /* all else is zero already */ | |
1225 | } | |
1226 | ||
1227 | for (nchp = nchash; nchp < &nchash[NCHHASH]; nchp++) { | |
1228 | nchp->nch_head[0] = nchp; | |
1229 | nchp->nch_head[1] = nchp; | |
1230 | } | |
1231 | } | |
1232 | ||
1233 | /* | |
1234 | * Cache flush, called when filesys is umounted to | |
1235 | * remove entries that would now be invalid | |
1236 | * | |
1237 | * The line "nxtcp = nchhead" near the end is to avoid potential problems | |
1238 | * if the cache lru chain is modified while we are dumping the | |
1239 | * inode. This makes the algorithm O(n^2), but do you think I care? | |
1240 | */ | |
1241 | nchinval(dev) | |
1242 | register dev_t dev; | |
1243 | { | |
1244 | register struct nch *ncp, *nxtcp; | |
1245 | ||
1246 | for (ncp = nchhead; ncp; ncp = nxtcp) { | |
1247 | nxtcp = ncp->nc_nxt; | |
1248 | ||
1249 | if (ncp->nc_ip == NULL || | |
1250 | (ncp->nc_idev != dev && ncp->nc_dev != dev)) | |
1251 | continue; | |
1252 | ||
4a287f19 | 1253 | /* free the resources we had */ |
f93197fc KM |
1254 | ncp->nc_idev = NODEV; |
1255 | ncp->nc_dev = NODEV; | |
4a287f19 | 1256 | ncp->nc_id = NULL; |
f93197fc | 1257 | ncp->nc_ino = 0; |
4a287f19 KM |
1258 | ncp->nc_ip = NULL; |
1259 | ||
f93197fc KM |
1260 | |
1261 | /* remove the entry from its hash chain */ | |
1262 | remque(ncp); | |
1263 | /* and make a dummy one */ | |
1264 | ncp->nc_forw = ncp; | |
1265 | ncp->nc_back = ncp; | |
1266 | ||
1267 | /* delete this entry from LRU chain */ | |
1268 | *ncp->nc_prev = nxtcp; | |
1269 | if (nxtcp) | |
1270 | nxtcp->nc_prev = ncp->nc_prev; | |
1271 | else | |
1272 | nchtail = ncp->nc_prev; | |
1273 | ||
f93197fc KM |
1274 | /* cause rescan of list, it may have altered */ |
1275 | nxtcp = nchhead; | |
1276 | /* put the now-free entry at head of LRU */ | |
1277 | ncp->nc_nxt = nxtcp; | |
1278 | ncp->nc_prev = &nchhead; | |
1279 | nxtcp->nc_prev = &ncp->nc_nxt; | |
1280 | nchhead = ncp; | |
1281 | } | |
1282 | } | |
9ffa8d54 KM |
1283 | |
1284 | /* | |
1285 | * Name cache invalidation of all entries. | |
1286 | */ | |
1287 | cacheinvalall() | |
1288 | { | |
1289 | register struct nch *ncp; | |
1290 | ||
1291 | for (ncp = nch; ncp < &nch[nchsize]; ncp++) { | |
1292 | ncp->nc_id = 0; | |
1293 | } | |
1294 | } |