Commit | Line | Data |
---|---|---|
da7c5cc6 | 1 | /* |
0880b18e | 2 | * Copyright (c) 1982, 1986 Regents of the University of California. |
da7c5cc6 KM |
3 | * All rights reserved. The Berkeley software License Agreement |
4 | * specifies the terms and conditions for redistribution. | |
5 | * | |
609e7cfa | 6 | * @(#)vfs_lookup.c 7.2 (Berkeley) %G% |
da7c5cc6 | 7 | */ |
10873320 | 8 | |
94368568 JB |
9 | #include "param.h" |
10 | #include "systm.h" | |
11 | #include "inode.h" | |
12 | #include "fs.h" | |
13 | #include "mount.h" | |
14 | #include "dir.h" | |
15 | #include "user.h" | |
16 | #include "buf.h" | |
17 | #include "conf.h" | |
18 | #include "uio.h" | |
19 | #include "kernel.h" | |
10873320 | 20 | |
4a0415d6 | 21 | struct buf *blkatoff(); |
db9631a2 | 22 | struct buf *freenamebuf; |
4f083fd7 | 23 | int dirchk = 0; |
f93197fc KM |
24 | |
25 | /* | |
26 | * Structures associated with name cacheing. | |
27 | */ | |
28 | #define NCHHASH 32 /* size of hash table */ | |
29 | ||
30 | #if ((NCHHASH)&((NCHHASH)-1)) != 0 | |
31 | #define NHASH(h, i, d) ((unsigned)((h) + (i) + 13 * (int)(d)) % (NCHHASH)) | |
32 | #else | |
33 | #define NHASH(h, i, d) ((unsigned)((h) + (i) + 13 * (int)(d)) & ((NCHHASH)-1)) | |
34 | #endif | |
35 | ||
a5e62f37 MK |
36 | union nchash { |
37 | union nchash *nch_head[2]; | |
7dba1c03 | 38 | struct namecache *nch_chain[2]; |
f93197fc KM |
39 | } nchash[NCHHASH]; |
40 | #define nch_forw nch_chain[0] | |
41 | #define nch_back nch_chain[1] | |
42 | ||
7dba1c03 | 43 | struct namecache *nchhead, **nchtail; /* LRU chain pointers */ |
d17f522c | 44 | struct nchstats nchstats; /* cache effectiveness statistics */ |
f93197fc | 45 | |
10873320 | 46 | /* |
7f69b0e6 | 47 | * Convert a pathname into a pointer to a locked inode. |
6bd0bb92 | 48 | * This is a very central and rather complicated routine. |
4f083fd7 | 49 | * If the file system is not maintained in a strict tree hierarchy, |
7f69b0e6 KM |
50 | * this can result in a deadlock situation (see comments in code below). |
51 | * | |
52 | * The flag argument is LOOKUP, CREATE, or DELETE depending on whether | |
53 | * the name is to be looked up, created, or deleted. When CREATE or | |
54 | * DELETE is specified, information usable in creating or deleteing a | |
55 | * directory entry is also calculated. If flag has LOCKPARENT or'ed | |
56 | * into it and the target of the pathname exists, namei returns both | |
57 | * the target and its parent directory locked. When creating and | |
4f083fd7 SL |
58 | * LOCKPARENT is specified, the target may not be ".". When deleting |
59 | * and LOCKPARENT is specified, the target may be ".", but the caller | |
60 | * must check to insure it does an irele and iput instead of two iputs. | |
61 | * | |
d870be74 | 62 | * The FOLLOW flag is set when symbolic links are to be followed |
4f083fd7 | 63 | * when they occur at the end of the name translation process. |
7f69b0e6 KM |
64 | * Symbolic links are always followed for all other pathname |
65 | * components other than the last. | |
66 | * | |
67 | * The segflg defines whether the name is to be copied from user | |
68 | * space or kernel space. | |
10873320 | 69 | * |
f93197fc KM |
70 | * Name caching works as follows: |
71 | * | |
a5e62f37 MK |
72 | * Names found by directory scans are retained in a cache |
73 | * for future reference. It is managed LRU, so frequently | |
74 | * used names will hang around. Cache is indexed by hash value | |
75 | * obtained from (ino,dev,name) where ino & dev refer to the | |
76 | * directory containing name. | |
f93197fc | 77 | * |
a5e62f37 | 78 | * For simplicity (and economy of storage), names longer than |
7f69b0e6 | 79 | * a maximum length of NCHNAMLEN are not cached; they occur |
a5e62f37 | 80 | * infrequently in any case, and are almost never of interest. |
f93197fc | 81 | * |
a5e62f37 MK |
82 | * Upon reaching the last segment of a path, if the reference |
83 | * is for DELETE, or NOCACHE is set (rewrite), and the | |
84 | * name is located in the cache, it will be dropped. | |
f93197fc | 85 | * |
f93197fc | 86 | * Overall outline of namei: |
6bd0bb92 BJ |
87 | * |
88 | * copy in name | |
89 | * get starting directory | |
90 | * dirloop: | |
91 | * check accessibility of directory | |
92 | * dirloop2: | |
d870be74 | 93 | * copy next component of name to ndp->ni_dent |
6bd0bb92 | 94 | * handle degenerate case where name is null string |
f93197fc KM |
95 | * look for name in cache, if found, then if at end of path |
96 | * and deleting or creating, drop it, else to haveino | |
6bd0bb92 BJ |
97 | * search for name in directory, to found or notfound |
98 | * notfound: | |
4f083fd7 | 99 | * if creating, return locked directory, leaving info on avail. slots |
6bd0bb92 BJ |
100 | * else return error |
101 | * found: | |
102 | * if at end of path and deleting, return information to allow delete | |
7f69b0e6 | 103 | * if at end of path and rewriting (CREATE and LOCKPARENT), lock target |
4f083fd7 | 104 | * inode and return info to allow rewrite |
6bd0bb92 | 105 | * if .. and on mounted filesys, look in mount table for parent |
7f69b0e6 KM |
106 | * if not at end, add name to cache; if at end and neither creating |
107 | * nor deleting, add name to cache | |
f93197fc | 108 | * haveino: |
6bd0bb92 BJ |
109 | * if symbolic link, massage name in buffer and continue at dirloop |
110 | * if more components of name, do next level at dirloop | |
111 | * return the answer as locked inode | |
4f083fd7 SL |
112 | * |
113 | * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent inode, | |
114 | * but unlocked. | |
10873320 BJ |
115 | */ |
116 | struct inode * | |
d870be74 KM |
117 | namei(ndp) |
118 | register struct nameidata *ndp; | |
10873320 | 119 | { |
6bd0bb92 BJ |
120 | register char *cp; /* pointer into pathname argument */ |
121 | /* these variables refer to things which must be freed or unlocked */ | |
122 | register struct inode *dp = 0; /* the directory we are searching */ | |
7dba1c03 | 123 | register struct namecache *ncp; /* cache slot for entry */ |
6bd0bb92 BJ |
124 | register struct fs *fs; /* file system that directory is in */ |
125 | register struct buf *bp = 0; /* a buffer of directory entries */ | |
126 | register struct direct *ep; /* the current directory entry */ | |
127 | int entryoffsetinblock; /* offset of ep in bp's buffer */ | |
128 | register struct buf *nbp; /* buffer storing path name argument */ | |
129 | /* these variables hold information about the search for a slot */ | |
130 | enum {NONE, COMPACT, FOUND} slotstatus; | |
131 | int slotoffset = -1; /* offset of area with free space */ | |
132 | int slotsize; /* size of area at slotoffset */ | |
133 | int slotfreespace; /* amount of space free in slot */ | |
134 | int slotneeded; /* size of the entry we're seeking */ | |
135 | /* */ | |
84ef30ec KM |
136 | int numdirpasses; /* strategy for directory search */ |
137 | int endsearch; /* offset to end directory search */ | |
d870be74 | 138 | int prevoff; /* ndp->ni_offset of previous entry */ |
6bd0bb92 BJ |
139 | int nlink = 0; /* number of symbolic links taken */ |
140 | struct inode *pdp; /* saved dp during symlink work */ | |
d870be74 | 141 | int error, i; |
4f083fd7 | 142 | int lockparent; |
87c05e6e KM |
143 | int docache; /* == 0 do not cache last component */ |
144 | int makeentry; /* != 0 if name to be added to cache */ | |
f93197fc KM |
145 | unsigned hash; /* value of name hash for entry */ |
146 | union nchash *nhp; /* cache chain head for entry */ | |
147 | int isdotdot; /* != 0 if current name is ".." */ | |
d870be74 | 148 | int flag; /* op ie, LOOKUP, CREATE, or DELETE */ |
9e7c949b | 149 | off_t enduseful; /* pointer past last used dir slot */ |
10873320 | 150 | |
d870be74 KM |
151 | lockparent = ndp->ni_nameiop & LOCKPARENT; |
152 | docache = (ndp->ni_nameiop & NOCACHE) ^ NOCACHE; | |
153 | flag = ndp->ni_nameiop &~ (LOCKPARENT|NOCACHE|FOLLOW); | |
87c05e6e | 154 | if (flag == DELETE || lockparent) |
f93197fc | 155 | docache = 0; |
f5039631 | 156 | /* |
6bd0bb92 BJ |
157 | * Get a buffer for the name to be translated, and copy the |
158 | * name into the buffer. | |
f5039631 | 159 | */ |
db9631a2 KM |
160 | nbp = freenamebuf; |
161 | if (nbp == NULL) | |
162 | nbp = geteblk(MAXPATHLEN); | |
163 | else | |
164 | freenamebuf = nbp->av_forw; | |
d870be74 | 165 | if (ndp->ni_segflg == UIO_SYSSPACE) |
76335100 KM |
166 | error = copystr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
167 | (u_int *)0); | |
d870be74 | 168 | else |
76335100 KM |
169 | error = copyinstr(ndp->ni_dirp, nbp->b_un.b_addr, MAXPATHLEN, |
170 | (u_int *)0); | |
d870be74 KM |
171 | if (error) { |
172 | u.u_error = error; | |
6bd0bb92 | 173 | goto bad; |
d870be74 | 174 | } |
6bd0bb92 | 175 | |
10873320 | 176 | /* |
6bd0bb92 | 177 | * Get starting directory. |
10873320 | 178 | */ |
6bd0bb92 | 179 | cp = nbp->b_un.b_addr; |
f5039631 BJ |
180 | if (*cp == '/') { |
181 | while (*cp == '/') | |
182 | cp++; | |
10873320 BJ |
183 | if ((dp = u.u_rdir) == NULL) |
184 | dp = rootdir; | |
6bd0bb92 BJ |
185 | } else |
186 | dp = u.u_cdir; | |
187 | fs = dp->i_fs; | |
56700195 | 188 | ILOCK(dp); |
f5039631 | 189 | dp->i_count++; |
d870be74 | 190 | ndp->ni_pdir = (struct inode *)0xc0000000; /* illegal */ |
9e7c949b | 191 | ndp->ni_endoff = 0; |
6bd0bb92 | 192 | |
10873320 | 193 | /* |
6bd0bb92 BJ |
194 | * We come to dirloop to search a new directory. |
195 | * The directory must be locked so that it can be | |
196 | * iput, and fs must be already set to dp->i_fs. | |
10873320 | 197 | */ |
6bd0bb92 | 198 | dirloop: |
a0aead5a | 199 | /* |
6bd0bb92 | 200 | * Check accessiblity of directory. |
a0aead5a | 201 | */ |
6bd0bb92 | 202 | if ((dp->i_mode&IFMT) != IFDIR) { |
10873320 | 203 | u.u_error = ENOTDIR; |
6bd0bb92 BJ |
204 | goto bad; |
205 | } | |
206 | if (access(dp, IEXEC)) | |
207 | goto bad; | |
208 | ||
6f004ab5 | 209 | dirloop2: |
6bd0bb92 | 210 | /* |
d870be74 | 211 | * Copy next component of name to ndp->ni_dent. |
6bd0bb92 | 212 | */ |
f93197fc | 213 | hash = 0; |
6bd0bb92 | 214 | for (i = 0; *cp != 0 && *cp != '/'; cp++) { |
6459ebe0 | 215 | if (i >= MAXNAMLEN) { |
067da729 | 216 | u.u_error = ENAMETOOLONG; |
d870be74 KM |
217 | goto bad; |
218 | } | |
067da729 KM |
219 | if (*cp & 0200) |
220 | if ((*cp&0377) == ('/'|0200) || flag != DELETE) { | |
221 | u.u_error = EINVAL; | |
222 | goto bad; | |
223 | } | |
d870be74 | 224 | ndp->ni_dent.d_name[i++] = *cp; |
f93197fc | 225 | hash += (unsigned char)*cp * i; |
6459ebe0 | 226 | } |
d870be74 KM |
227 | ndp->ni_dent.d_namlen = i; |
228 | ndp->ni_dent.d_name[i] = '\0'; | |
4a287f19 | 229 | isdotdot = (i == 2 && |
d870be74 | 230 | ndp->ni_dent.d_name[0] == '.' && ndp->ni_dent.d_name[1] == '.'); |
87c05e6e KM |
231 | makeentry = 1; |
232 | if (*cp == '\0' && docache == 0) | |
233 | makeentry = 0; | |
6bd0bb92 BJ |
234 | |
235 | /* | |
236 | * Check for degenerate name (e.g. / or "") | |
237 | * which is a way of talking about a directory, | |
238 | * e.g. like "/." or ".". | |
239 | */ | |
d870be74 | 240 | if (ndp->ni_dent.d_name[0] == '\0') { |
f93197fc | 241 | if (flag != LOOKUP || lockparent) { |
78abd7aa | 242 | u.u_error = EISDIR; |
6bd0bb92 | 243 | goto bad; |
f5039631 | 244 | } |
db9631a2 KM |
245 | nbp->av_forw = freenamebuf; |
246 | freenamebuf = nbp; | |
6459ebe0 | 247 | return (dp); |
f5039631 | 248 | } |
6bd0bb92 | 249 | |
f93197fc KM |
250 | /* |
251 | * We now have a segment name to search for, and a directory to search. | |
252 | * | |
253 | * Before tediously performing a linear scan of the directory, | |
254 | * check the name cache to see if the directory/name pair | |
255 | * we are looking for is known already. We don't do this | |
256 | * if the segment name is long, simply so the cache can avoid | |
257 | * holding long names (which would either waste space, or | |
258 | * add greatly to the complexity). | |
259 | */ | |
d870be74 | 260 | if (ndp->ni_dent.d_namlen > NCHNAMLEN) { |
f93197fc | 261 | nchstats.ncs_long++; |
87c05e6e | 262 | makeentry = 0; |
f93197fc KM |
263 | } else { |
264 | nhp = &nchash[NHASH(hash, dp->i_number, dp->i_dev)]; | |
7dba1c03 | 265 | for (ncp = nhp->nch_forw; ncp != (struct namecache *)nhp; |
f93197fc KM |
266 | ncp = ncp->nc_forw) { |
267 | if (ncp->nc_ino == dp->i_number && | |
268 | ncp->nc_dev == dp->i_dev && | |
d870be74 KM |
269 | ncp->nc_nlen == ndp->ni_dent.d_namlen && |
270 | !bcmp(ncp->nc_name, ndp->ni_dent.d_name, | |
a5e62f37 | 271 | (unsigned)ncp->nc_nlen)) |
f93197fc KM |
272 | break; |
273 | } | |
7dba1c03 | 274 | if (ncp == (struct namecache *)nhp) { |
f93197fc KM |
275 | nchstats.ncs_miss++; |
276 | ncp = NULL; | |
277 | } else { | |
7dba1c03 | 278 | if (ncp->nc_id != ncp->nc_ip->i_id) |
8ac1234a | 279 | nchstats.ncs_falsehits++; |
7dba1c03 | 280 | else if (!makeentry) |
4a287f19 | 281 | nchstats.ncs_badhits++; |
7dba1c03 | 282 | else { |
a5e62f37 MK |
283 | /* |
284 | * move this slot to end of LRU | |
285 | * chain, if not already there | |
286 | */ | |
f93197fc | 287 | if (ncp->nc_nxt) { |
a5e62f37 | 288 | /* remove from LRU chain */ |
f93197fc KM |
289 | *ncp->nc_prev = ncp->nc_nxt; |
290 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
291 | ||
a5e62f37 | 292 | /* and replace at end of it */ |
f93197fc KM |
293 | ncp->nc_nxt = NULL; |
294 | ncp->nc_prev = nchtail; | |
295 | *nchtail = ncp; | |
296 | nchtail = &ncp->nc_nxt; | |
297 | } | |
298 | ||
4a287f19 KM |
299 | /* |
300 | * Get the next inode in the path. | |
56700195 | 301 | * See comment above other `IUNLOCK' code for |
4a287f19 KM |
302 | * an explaination of the locking protocol. |
303 | */ | |
f93197fc | 304 | pdp = dp; |
87c05e6e KM |
305 | if (!isdotdot || dp != u.u_rdir) |
306 | dp = ncp->nc_ip; | |
f93197fc | 307 | if (dp == NULL) |
00e496b2 | 308 | panic("namei: null cache ino"); |
7dba1c03 | 309 | if (pdp == dp) |
f93197fc | 310 | dp->i_count++; |
7dba1c03 | 311 | else if (isdotdot) { |
87c05e6e KM |
312 | IUNLOCK(pdp); |
313 | igrab(dp); | |
314 | } else { | |
315 | igrab(dp); | |
316 | IUNLOCK(pdp); | |
8ac1234a | 317 | } |
f93197fc | 318 | |
4a287f19 KM |
319 | /* |
320 | * Verify that the inode that we got | |
321 | * did not change while we were waiting | |
322 | * for it to be locked. | |
323 | */ | |
324 | if (ncp->nc_id != ncp->nc_ip->i_id) { | |
325 | iput(dp); | |
56700195 | 326 | ILOCK(pdp); |
4a287f19 KM |
327 | dp = pdp; |
328 | nchstats.ncs_falsehits++; | |
329 | } else { | |
d870be74 KM |
330 | ndp->ni_dent.d_ino = dp->i_number; |
331 | /* ni_dent.d_reclen is garbage ... */ | |
4a287f19 KM |
332 | nchstats.ncs_goodhits++; |
333 | goto haveino; | |
334 | } | |
335 | } | |
f93197fc KM |
336 | |
337 | /* | |
8ac1234a SL |
338 | * Last component and we are renaming or deleting, |
339 | * the cache entry is invalid, or otherwise don't | |
340 | * want cache entry to exist. | |
f93197fc | 341 | */ |
a5e62f37 | 342 | /* remove from LRU chain */ |
f93197fc KM |
343 | *ncp->nc_prev = ncp->nc_nxt; |
344 | if (ncp->nc_nxt) | |
345 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
346 | else | |
347 | nchtail = ncp->nc_prev; | |
a5e62f37 MK |
348 | remque(ncp); /* remove from hash chain */ |
349 | /* insert at head of LRU list (first to grab) */ | |
f93197fc KM |
350 | ncp->nc_nxt = nchhead; |
351 | ncp->nc_prev = &nchhead; | |
352 | nchhead->nc_prev = &ncp->nc_nxt; | |
353 | nchhead = ncp; | |
a5e62f37 | 354 | /* and make a dummy hash chain */ |
f93197fc KM |
355 | ncp->nc_forw = ncp; |
356 | ncp->nc_back = ncp; | |
f93197fc KM |
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 { | |
00e496b2 KM |
388 | if (u.u_ncache.nc_prevoffset > dp->i_size) |
389 | u.u_ncache.nc_prevoffset = 0; | |
d870be74 KM |
390 | ndp->ni_offset = u.u_ncache.nc_prevoffset; |
391 | entryoffsetinblock = blkoff(fs, ndp->ni_offset); | |
84ef30ec | 392 | if (entryoffsetinblock != 0) { |
d870be74 | 393 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
84ef30ec KM |
394 | if (bp == 0) |
395 | goto bad; | |
396 | } | |
397 | numdirpasses = 2; | |
f93197fc | 398 | nchstats.ncs_2passes++; |
84ef30ec KM |
399 | } |
400 | endsearch = roundup(dp->i_size, DIRBLKSIZ); | |
9e7c949b | 401 | enduseful = 0; |
6bd0bb92 | 402 | |
84ef30ec | 403 | searchloop: |
d870be74 | 404 | while (ndp->ni_offset < endsearch) { |
f5039631 BJ |
405 | /* |
406 | * If offset is on a block boundary, | |
407 | * read the next directory block. | |
408 | * Release previous if it exists. | |
409 | */ | |
d870be74 | 410 | if (blkoff(fs, ndp->ni_offset) == 0) { |
f5039631 BJ |
411 | if (bp != NULL) |
412 | brelse(bp); | |
d870be74 | 413 | bp = blkatoff(dp, ndp->ni_offset, (char **)0); |
6bd0bb92 BJ |
414 | if (bp == 0) |
415 | goto bad; | |
416 | entryoffsetinblock = 0; | |
6459ebe0 KM |
417 | } |
418 | /* | |
6bd0bb92 | 419 | * If still looking for a slot, and at a DIRBLKSIZE |
d82d5deb | 420 | * boundary, have to start looking for free space again. |
6459ebe0 | 421 | */ |
6bd0bb92 BJ |
422 | if (slotstatus == NONE && |
423 | (entryoffsetinblock&(DIRBLKSIZ-1)) == 0) { | |
424 | slotoffset = -1; | |
425 | slotfreespace = 0; | |
426 | } | |
6bd0bb92 | 427 | /* |
d82d5deb KM |
428 | * Get pointer to next entry. |
429 | * Full validation checks are slow, so we only check | |
430 | * enough to insure forward progress through the | |
431 | * directory. Complete checks can be run by patching | |
432 | * "dirchk" to be true. | |
6bd0bb92 BJ |
433 | */ |
434 | ep = (struct direct *)(bp->b_un.b_addr + entryoffsetinblock); | |
a5e62f37 | 435 | if (ep->d_reclen == 0 || |
d82d5deb | 436 | dirchk && dirbadentry(ep, entryoffsetinblock)) { |
d870be74 | 437 | dirbad(dp, ndp->ni_offset, "mangled entry"); |
d82d5deb | 438 | i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); |
d870be74 | 439 | ndp->ni_offset += i; |
6bd0bb92 | 440 | entryoffsetinblock += i; |
6459ebe0 KM |
441 | continue; |
442 | } | |
6bd0bb92 | 443 | |
6459ebe0 | 444 | /* |
6bd0bb92 | 445 | * If an appropriate sized slot has not yet been found, |
6459ebe0 KM |
446 | * check to see if one is available. Also accumulate space |
447 | * in the current block so that we can determine if | |
448 | * compaction is viable. | |
449 | */ | |
6bd0bb92 BJ |
450 | if (slotstatus != FOUND) { |
451 | int size = ep->d_reclen; | |
452 | ||
6459ebe0 KM |
453 | if (ep->d_ino != 0) |
454 | size -= DIRSIZ(ep); | |
455 | if (size > 0) { | |
6bd0bb92 BJ |
456 | if (size >= slotneeded) { |
457 | slotstatus = FOUND; | |
d870be74 | 458 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
459 | slotsize = ep->d_reclen; |
460 | } else if (slotstatus == NONE) { | |
461 | slotfreespace += size; | |
462 | if (slotoffset == -1) | |
d870be74 | 463 | slotoffset = ndp->ni_offset; |
6bd0bb92 BJ |
464 | if (slotfreespace >= slotneeded) { |
465 | slotstatus = COMPACT; | |
d870be74 KM |
466 | slotsize = ndp->ni_offset + |
467 | ep->d_reclen - slotoffset; | |
6bd0bb92 | 468 | } |
6459ebe0 | 469 | } |
f5039631 | 470 | } |
f5039631 | 471 | } |
6bd0bb92 | 472 | |
f5039631 | 473 | /* |
6bd0bb92 | 474 | * Check for a name match. |
f5039631 | 475 | */ |
6bd0bb92 | 476 | if (ep->d_ino) { |
d870be74 KM |
477 | if (ep->d_namlen == ndp->ni_dent.d_namlen && |
478 | !bcmp(ndp->ni_dent.d_name, ep->d_name, | |
a5e62f37 | 479 | (unsigned)ep->d_namlen)) |
6bd0bb92 BJ |
480 | goto found; |
481 | } | |
d870be74 KM |
482 | prevoff = ndp->ni_offset; |
483 | ndp->ni_offset += ep->d_reclen; | |
6bd0bb92 | 484 | entryoffsetinblock += ep->d_reclen; |
9e7c949b KM |
485 | if (ep->d_ino) |
486 | enduseful = ndp->ni_offset; | |
6bd0bb92 | 487 | } |
f93197fc | 488 | /* notfound: */ |
84ef30ec | 489 | /* |
f93197fc | 490 | * If we started in the middle of the directory and failed |
84ef30ec KM |
491 | * to find our target, we must check the beginning as well. |
492 | */ | |
493 | if (numdirpasses == 2) { | |
494 | numdirpasses--; | |
d870be74 | 495 | ndp->ni_offset = 0; |
84ef30ec KM |
496 | endsearch = u.u_ncache.nc_prevoffset; |
497 | goto searchloop; | |
498 | } | |
6bd0bb92 BJ |
499 | /* |
500 | * If creating, and at end of pathname and current | |
4f083fd7 SL |
501 | * directory has not been removed, then can consider |
502 | * allowing file to be created. | |
6bd0bb92 | 503 | */ |
4f083fd7 | 504 | if (flag == CREATE && *cp == 0 && dp->i_nlink != 0) { |
f5039631 | 505 | /* |
6bd0bb92 BJ |
506 | * Access for write is interpreted as allowing |
507 | * creation of files in the directory. | |
f5039631 | 508 | */ |
6bd0bb92 BJ |
509 | if (access(dp, IWRITE)) |
510 | goto bad; | |
f5039631 | 511 | /* |
6bd0bb92 BJ |
512 | * Return an indication of where the new directory |
513 | * entry should be put. If we didn't find a slot, | |
d870be74 KM |
514 | * then set ndp->ni_count to 0 indicating that the new |
515 | * slot belongs at the end of the directory. If we found | |
516 | * a slot, then the new entry can be put in the range | |
517 | * [ndp->ni_offset .. ndp->ni_offset + ndp->ni_count) | |
f5039631 | 518 | */ |
84ef30ec | 519 | if (slotstatus == NONE) { |
d870be74 KM |
520 | ndp->ni_offset = roundup(dp->i_size, DIRBLKSIZ); |
521 | ndp->ni_count = 0; | |
9e7c949b | 522 | enduseful = ndp->ni_offset; |
84ef30ec | 523 | } else { |
d870be74 KM |
524 | ndp->ni_offset = slotoffset; |
525 | ndp->ni_count = slotsize; | |
9e7c949b KM |
526 | if (enduseful < slotoffset + slotsize) |
527 | enduseful = slotoffset + slotsize; | |
5485e062 | 528 | } |
9e7c949b | 529 | ndp->ni_endoff = roundup(enduseful, DIRBLKSIZ); |
6bd0bb92 BJ |
530 | dp->i_flag |= IUPD|ICHG; |
531 | if (bp) | |
532 | brelse(bp); | |
db9631a2 KM |
533 | nbp->av_forw = freenamebuf; |
534 | freenamebuf = nbp; | |
f5039631 | 535 | /* |
6bd0bb92 BJ |
536 | * We return with the directory locked, so that |
537 | * the parameters we set up above will still be | |
538 | * valid if we actually decide to do a direnter(). | |
539 | * We return NULL to indicate that the entry doesn't | |
540 | * currently exist, leaving a pointer to the (locked) | |
d870be74 | 541 | * directory inode in ndp->ni_pdir. |
f5039631 | 542 | */ |
d870be74 | 543 | ndp->ni_pdir = dp; |
6bd0bb92 BJ |
544 | return (NULL); |
545 | } | |
546 | u.u_error = ENOENT; | |
547 | goto bad; | |
548 | found: | |
f93197fc KM |
549 | if (numdirpasses == 2) |
550 | nchstats.ncs_pass2++; | |
6bd0bb92 BJ |
551 | /* |
552 | * Check that directory length properly reflects presence | |
553 | * of this entry. | |
554 | */ | |
4a0415d6 | 555 | if (entryoffsetinblock + DIRSIZ(ep) > dp->i_size) { |
d870be74 | 556 | dirbad(dp, ndp->ni_offset, "i_size too small"); |
4a0415d6 | 557 | dp->i_size = entryoffsetinblock + DIRSIZ(ep); |
6bd0bb92 BJ |
558 | dp->i_flag |= IUPD|ICHG; |
559 | } | |
560 | ||
561 | /* | |
84ef30ec | 562 | * Found component in pathname. |
f93197fc | 563 | * If the final component of path name, save information |
84ef30ec KM |
564 | * in the cache as to where the entry was found. |
565 | */ | |
566 | if (*cp == '\0' && flag == LOOKUP) { | |
00e496b2 | 567 | u.u_ncache.nc_prevoffset = ndp->ni_offset &~ (DIRBLKSIZ - 1); |
84ef30ec KM |
568 | u.u_ncache.nc_inumber = dp->i_number; |
569 | u.u_ncache.nc_dev = dp->i_dev; | |
84ef30ec KM |
570 | } |
571 | /* | |
87c05e6e | 572 | * Save directory entry's inode number and reclen in ndp->ni_dent, |
84ef30ec | 573 | * and release directory buffer. |
6bd0bb92 | 574 | */ |
87c05e6e KM |
575 | ndp->ni_dent.d_ino = ep->d_ino; |
576 | ndp->ni_dent.d_reclen = ep->d_reclen; | |
6bd0bb92 BJ |
577 | brelse(bp); |
578 | bp = NULL; | |
579 | ||
580 | /* | |
581 | * If deleting, and at end of pathname, return | |
582 | * parameters which can be used to remove file. | |
4f083fd7 | 583 | * If the lockparent flag isn't set, we return only |
d870be74 | 584 | * the directory (in ndp->ni_pdir), otherwise we go |
4f083fd7 | 585 | * on and lock the inode, being careful with ".". |
6bd0bb92 | 586 | */ |
4f083fd7 | 587 | if (flag == DELETE && *cp == 0) { |
6bd0bb92 BJ |
588 | /* |
589 | * Write access to directory required to delete files. | |
590 | */ | |
591 | if (access(dp, IWRITE)) | |
592 | goto bad; | |
d870be74 | 593 | ndp->ni_pdir = dp; /* for dirremove() */ |
6bd0bb92 | 594 | /* |
d870be74 | 595 | * Return pointer to current entry in ndp->ni_offset, |
6bd0bb92 | 596 | * and distance past previous entry (if there |
d870be74 KM |
597 | * is a previous entry in this block) in ndp->ni_count. |
598 | * Save directory inode pointer in ndp->ni_pdir for dirremove(). | |
6bd0bb92 | 599 | */ |
d870be74 KM |
600 | if ((ndp->ni_offset&(DIRBLKSIZ-1)) == 0) |
601 | ndp->ni_count = 0; | |
6bd0bb92 | 602 | else |
d870be74 | 603 | ndp->ni_count = ndp->ni_offset - prevoff; |
4f083fd7 | 604 | if (lockparent) { |
d870be74 | 605 | if (dp->i_number == ndp->ni_dent.d_ino) |
4f083fd7 SL |
606 | dp->i_count++; |
607 | else { | |
d870be74 | 608 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 609 | if (dp == NULL) { |
d870be74 | 610 | iput(ndp->ni_pdir); |
4f083fd7 SL |
611 | goto bad; |
612 | } | |
f93197fc | 613 | /* |
9ba16c41 | 614 | * If directory is "sticky", then user must own |
f93197fc KM |
615 | * the directory, or the file in it, else he |
616 | * may not delete it (unless he's root). This | |
617 | * implements append-only directories. | |
618 | */ | |
d870be74 | 619 | if ((ndp->ni_pdir->i_mode & ISVTX) && |
f93197fc | 620 | u.u_uid != 0 && |
d870be74 | 621 | u.u_uid != ndp->ni_pdir->i_uid && |
f93197fc | 622 | dp->i_uid != u.u_uid) { |
d870be74 | 623 | iput(ndp->ni_pdir); |
f93197fc KM |
624 | u.u_error = EPERM; |
625 | goto bad; | |
626 | } | |
4f083fd7 SL |
627 | } |
628 | } | |
db9631a2 KM |
629 | nbp->av_forw = freenamebuf; |
630 | freenamebuf = nbp; | |
6bd0bb92 BJ |
631 | return (dp); |
632 | } | |
633 | ||
634 | /* | |
635 | * Special handling for ".." allowing chdir out of mounted | |
636 | * file system: indirect .. in root inode to reevaluate | |
637 | * in directory file system was mounted on. | |
638 | */ | |
4a287f19 | 639 | if (isdotdot) { |
87c05e6e | 640 | if (dp == u.u_rdir) { |
d870be74 | 641 | ndp->ni_dent.d_ino = dp->i_number; |
87c05e6e KM |
642 | makeentry = 0; |
643 | } else if (ndp->ni_dent.d_ino == ROOTINO && | |
6bd0bb92 BJ |
644 | dp->i_number == ROOTINO) { |
645 | for (i = 1; i < NMOUNT; i++) | |
646 | if (mount[i].m_bufp != NULL && | |
647 | mount[i].m_dev == dp->i_dev) { | |
6459ebe0 | 648 | iput(dp); |
6bd0bb92 | 649 | dp = mount[i].m_inodp; |
56700195 | 650 | ILOCK(dp); |
f5039631 | 651 | dp->i_count++; |
6bd0bb92 BJ |
652 | fs = dp->i_fs; |
653 | cp -= 2; /* back over .. */ | |
654 | goto dirloop2; | |
f5039631 | 655 | } |
10873320 | 656 | } |
6bd0bb92 BJ |
657 | } |
658 | ||
4f083fd7 SL |
659 | /* |
660 | * If rewriting (rename), return the inode and the | |
661 | * information required to rewrite the present directory | |
662 | * Must get inode of directory entry to verify it's a | |
663 | * regular file, or empty directory. | |
664 | */ | |
665 | if ((flag == CREATE && lockparent) && *cp == 0) { | |
666 | if (access(dp, IWRITE)) | |
667 | goto bad; | |
d870be74 | 668 | ndp->ni_pdir = dp; /* for dirrewrite() */ |
4f083fd7 SL |
669 | /* |
670 | * Careful about locking second inode. | |
671 | * This can only occur if the target is ".". | |
672 | */ | |
d870be74 | 673 | if (dp->i_number == ndp->ni_dent.d_ino) { |
4f083fd7 SL |
674 | u.u_error = EISDIR; /* XXX */ |
675 | goto bad; | |
676 | } | |
d870be74 | 677 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
4f083fd7 | 678 | if (dp == NULL) { |
d870be74 | 679 | iput(ndp->ni_pdir); |
4f083fd7 SL |
680 | goto bad; |
681 | } | |
db9631a2 KM |
682 | nbp->av_forw = freenamebuf; |
683 | freenamebuf = nbp; | |
4f083fd7 SL |
684 | return (dp); |
685 | } | |
686 | ||
6bd0bb92 | 687 | /* |
bde63aa5 KM |
688 | * Check for symbolic link, which may require us to massage the |
689 | * name before we continue translation. We do not `iput' the | |
690 | * directory because we may need it again if the symbolic link | |
691 | * is relative to the current directory. Instead we save it | |
692 | * unlocked as "pdp". We must get the target inode before unlocking | |
693 | * the directory to insure that the inode will not be removed | |
694 | * before we get it. We prevent deadlock by always fetching | |
695 | * inodes from the root, moving down the directory tree. Thus | |
696 | * when following backward pointers ".." we must unlock the | |
697 | * parent directory before getting the requested directory. | |
698 | * There is a potential race condition here if both the current | |
699 | * and parent directories are removed before the `iget' for the | |
700 | * inode associated with ".." returns. We hope that this occurs | |
701 | * infrequently since we cannot avoid this race condition without | |
a4358a25 | 702 | * implementing a sophisticated deadlock detection algorithm. |
bde63aa5 KM |
703 | * Note also that this simple deadlock detection scheme will not |
704 | * work if the file system has any hard links other than ".." | |
705 | * that point backwards in the directory structure. | |
6bd0bb92 BJ |
706 | */ |
707 | pdp = dp; | |
f93197fc | 708 | if (isdotdot) { |
56700195 | 709 | IUNLOCK(pdp); /* race to get the inode */ |
d870be74 | 710 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
bde63aa5 KM |
711 | if (dp == NULL) |
712 | goto bad2; | |
d870be74 | 713 | } else if (dp->i_number == ndp->ni_dent.d_ino) { |
bde63aa5 KM |
714 | dp->i_count++; /* we want ourself, ie "." */ |
715 | } else { | |
d870be74 | 716 | dp = iget(dp->i_dev, fs, ndp->ni_dent.d_ino); |
56700195 | 717 | IUNLOCK(pdp); |
bde63aa5 KM |
718 | if (dp == NULL) |
719 | goto bad2; | |
720 | } | |
f93197fc KM |
721 | |
722 | /* | |
a5e62f37 | 723 | * Insert name into cache if appropriate. |
f93197fc | 724 | */ |
87c05e6e | 725 | if (makeentry) { |
f93197fc | 726 | if (ncp != NULL) |
00e496b2 | 727 | panic("namei: duplicating cache"); |
a5e62f37 MK |
728 | /* |
729 | * Free the cache slot at head of lru chain. | |
730 | */ | |
f93197fc | 731 | if (ncp = nchhead) { |
a5e62f37 | 732 | /* remove from lru chain */ |
f93197fc KM |
733 | *ncp->nc_prev = ncp->nc_nxt; |
734 | if (ncp->nc_nxt) | |
735 | ncp->nc_nxt->nc_prev = ncp->nc_prev; | |
736 | else | |
737 | nchtail = ncp->nc_prev; | |
a5e62f37 MK |
738 | remque(ncp); /* remove from old hash chain */ |
739 | /* grab the inode we just found */ | |
f93197fc | 740 | ncp->nc_ip = dp; |
a5e62f37 | 741 | /* fill in cache info */ |
f93197fc KM |
742 | ncp->nc_ino = pdp->i_number; /* parents inum */ |
743 | ncp->nc_dev = pdp->i_dev; /* & device */ | |
744 | ncp->nc_idev = dp->i_dev; /* our device */ | |
8ac1234a | 745 | ncp->nc_id = dp->i_id; /* identifier */ |
d870be74 | 746 | ncp->nc_nlen = ndp->ni_dent.d_namlen; |
a5e62f37 MK |
747 | bcopy(ndp->ni_dent.d_name, ncp->nc_name, |
748 | (unsigned)ncp->nc_nlen); | |
749 | /* link at end of lru chain */ | |
f93197fc KM |
750 | ncp->nc_nxt = NULL; |
751 | ncp->nc_prev = nchtail; | |
752 | *nchtail = ncp; | |
753 | nchtail = &ncp->nc_nxt; | |
a5e62f37 | 754 | /* and insert on hash chain */ |
f93197fc KM |
755 | insque(ncp, nhp); |
756 | } | |
757 | } | |
758 | ||
759 | haveino: | |
6bd0bb92 BJ |
760 | fs = dp->i_fs; |
761 | ||
762 | /* | |
763 | * Check for symbolic link | |
764 | */ | |
d870be74 KM |
765 | if ((dp->i_mode & IFMT) == IFLNK && |
766 | ((ndp->ni_nameiop & FOLLOW) || *cp == '/')) { | |
9f024ffc | 767 | u_int pathlen = strlen(cp) + 1; |
6bd0bb92 | 768 | |
067da729 KM |
769 | if (dp->i_size + pathlen >= MAXPATHLEN - 1) { |
770 | u.u_error = ENAMETOOLONG; | |
771 | goto bad2; | |
772 | } | |
773 | if (++nlink > MAXSYMLINKS) { | |
6bd0bb92 BJ |
774 | u.u_error = ELOOP; |
775 | goto bad2; | |
776 | } | |
d36096be | 777 | ovbcopy(cp, nbp->b_un.b_addr + dp->i_size, pathlen); |
a6b6f679 | 778 | u.u_error = |
4f083fd7 | 779 | rdwri(UIO_READ, dp, nbp->b_un.b_addr, (int)dp->i_size, |
8011f5df | 780 | (off_t)0, 1, (int *)0); |
6bd0bb92 BJ |
781 | if (u.u_error) |
782 | goto bad2; | |
783 | cp = nbp->b_un.b_addr; | |
784 | iput(dp); | |
f5039631 | 785 | if (*cp == '/') { |
6bd0bb92 | 786 | irele(pdp); |
f5039631 BJ |
787 | while (*cp == '/') |
788 | cp++; | |
6bd0bb92 BJ |
789 | if ((dp = u.u_rdir) == NULL) |
790 | dp = rootdir; | |
56700195 | 791 | ILOCK(dp); |
6bd0bb92 BJ |
792 | dp->i_count++; |
793 | } else { | |
794 | dp = pdp; | |
56700195 | 795 | ILOCK(dp); |
f5039631 | 796 | } |
6bd0bb92 BJ |
797 | fs = dp->i_fs; |
798 | goto dirloop; | |
10873320 | 799 | } |
6bd0bb92 | 800 | |
10873320 | 801 | /* |
6bd0bb92 BJ |
802 | * Not a symbolic link. If more pathname, |
803 | * continue at next component, else return. | |
10873320 | 804 | */ |
6bd0bb92 BJ |
805 | if (*cp == '/') { |
806 | while (*cp == '/') | |
807 | cp++; | |
4f083fd7 | 808 | irele(pdp); |
6bd0bb92 | 809 | goto dirloop; |
10873320 | 810 | } |
db9631a2 KM |
811 | nbp->av_forw = freenamebuf; |
812 | freenamebuf = nbp; | |
4f083fd7 | 813 | if (lockparent) |
d870be74 | 814 | ndp->ni_pdir = pdp; |
4f083fd7 SL |
815 | else |
816 | irele(pdp); | |
6bd0bb92 BJ |
817 | return (dp); |
818 | bad2: | |
819 | irele(pdp); | |
820 | bad: | |
821 | if (bp) | |
822 | brelse(bp); | |
823 | if (dp) | |
824 | iput(dp); | |
db9631a2 KM |
825 | nbp->av_forw = freenamebuf; |
826 | freenamebuf = nbp; | |
6459ebe0 | 827 | return (NULL); |
10873320 BJ |
828 | } |
829 | ||
f93197fc | 830 | |
d870be74 | 831 | dirbad(ip, offset, how) |
6bd0bb92 | 832 | struct inode *ip; |
d870be74 | 833 | off_t offset; |
6bd0bb92 BJ |
834 | char *how; |
835 | { | |
836 | ||
837 | printf("%s: bad dir ino %d at offset %d: %s\n", | |
d870be74 | 838 | ip->i_fs->fs_fsmnt, ip->i_number, offset, how); |
6bd0bb92 BJ |
839 | } |
840 | ||
d82d5deb KM |
841 | /* |
842 | * Do consistency checking on a directory entry: | |
843 | * record length must be multiple of 4 | |
d82d5deb KM |
844 | * entry must fit in rest of its DIRBLKSIZ block |
845 | * record must be large enough to contain entry | |
846 | * name is not longer than MAXNAMLEN | |
847 | * name must be as long as advertised, and null terminated | |
848 | */ | |
849 | dirbadentry(ep, entryoffsetinblock) | |
6bd0bb92 | 850 | register struct direct *ep; |
d82d5deb | 851 | int entryoffsetinblock; |
6bd0bb92 | 852 | { |
6bd0bb92 BJ |
853 | register int i; |
854 | ||
a5e62f37 | 855 | if ((ep->d_reclen & 0x3) != 0 || |
d82d5deb KM |
856 | ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) || |
857 | ep->d_reclen < DIRSIZ(ep) || ep->d_namlen > MAXNAMLEN) | |
858 | return (1); | |
6bd0bb92 | 859 | for (i = 0; i < ep->d_namlen; i++) |
d870be74 | 860 | if (ep->d_name[i] == '\0') |
6bd0bb92 BJ |
861 | return (1); |
862 | return (ep->d_name[i]); | |
863 | } | |
864 | ||
6bd0bb92 BJ |
865 | /* |
866 | * Write a directory entry after a call to namei, using the parameters | |
867 | * which it left in the u. area. The argument ip is the inode which | |
d870be74 | 868 | * the new directory entry will refer to. The u. area field ndp->ni_pdir is |
6bd0bb92 | 869 | * a pointer to the directory to be written, which was left locked by |
d870be74 | 870 | * namei. Remaining parameters (ndp->ni_offset, ndp->ni_count) indicate |
6bd0bb92 BJ |
871 | * how the space for the new entry is to be gotten. |
872 | */ | |
d870be74 | 873 | direnter(ip, ndp) |
6bd0bb92 | 874 | struct inode *ip; |
d870be74 | 875 | register struct nameidata *ndp; |
f5039631 | 876 | { |
6bd0bb92 | 877 | register struct direct *ep, *nep; |
9e7c949b | 878 | register struct inode *dp = ndp->ni_pdir; |
6bd0bb92 | 879 | struct buf *bp; |
efa3a91c | 880 | int loc, spacefree, error = 0; |
b32450f4 BJ |
881 | u_int dsize; |
882 | int newentrysize; | |
6bd0bb92 | 883 | char *dirbuf; |
f5039631 | 884 | |
d870be74 KM |
885 | ndp->ni_dent.d_ino = ip->i_number; |
886 | newentrysize = DIRSIZ(&ndp->ni_dent); | |
887 | if (ndp->ni_count == 0) { | |
6bd0bb92 | 888 | /* |
d870be74 KM |
889 | * If ndp->ni_count is 0, then namei could find no space in the |
890 | * directory. In this case ndp->ni_offset will be on a directory | |
6bd0bb92 BJ |
891 | * block boundary and we will write the new entry into a fresh |
892 | * block. | |
893 | */ | |
d870be74 | 894 | if (ndp->ni_offset&(DIRBLKSIZ-1)) |
6bd0bb92 | 895 | panic("wdir: newblk"); |
d870be74 | 896 | ndp->ni_dent.d_reclen = DIRBLKSIZ; |
9e7c949b | 897 | error = rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, |
d870be74 | 898 | newentrysize, ndp->ni_offset, 1, (int *)0); |
23de9f20 KM |
899 | if (DIRBLKSIZ > dp->i_fs->fs_fsize) |
900 | panic("wdir: blksize"); /* XXX - should grow w/bmap() */ | |
901 | else | |
902 | dp->i_size = roundup(dp->i_size, DIRBLKSIZ); | |
9e7c949b | 903 | iput(dp); |
f2a5ad78 | 904 | return (error); |
6bd0bb92 BJ |
905 | } |
906 | ||
907 | /* | |
d870be74 KM |
908 | * If ndp->ni_count is non-zero, then namei found space for the new |
909 | * entry in the range ndp->ni_offset to ndp->ni_offset + ndp->ni_count. | |
6bd0bb92 BJ |
910 | * in the directory. To use this space, we may have to compact |
911 | * the entries located there, by copying them together towards | |
912 | * the beginning of the block, leaving the free space in | |
913 | * one usable chunk at the end. | |
914 | */ | |
915 | ||
916 | /* | |
917 | * Increase size of directory if entry eats into new space. | |
918 | * This should never push the size past a new multiple of | |
919 | * DIRBLKSIZE. | |
23de9f20 KM |
920 | * |
921 | * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. | |
6bd0bb92 | 922 | */ |
9e7c949b KM |
923 | if (ndp->ni_offset + ndp->ni_count > dp->i_size) |
924 | dp->i_size = ndp->ni_offset + ndp->ni_count; | |
6bd0bb92 BJ |
925 | /* |
926 | * Get the block containing the space for the new directory | |
f2a5ad78 | 927 | * entry. Should return error by result instead of u.u_error. |
6bd0bb92 | 928 | */ |
9e7c949b | 929 | bp = blkatoff(dp, ndp->ni_offset, (char **)&dirbuf); |
4f083fd7 | 930 | if (bp == 0) { |
9e7c949b | 931 | iput(dp); |
f2a5ad78 | 932 | return (u.u_error); |
4f083fd7 | 933 | } |
6bd0bb92 BJ |
934 | /* |
935 | * Find space for the new entry. In the simple case, the | |
936 | * entry at offset base will have the space. If it does | |
937 | * not, then namei arranged that compacting the region | |
d870be74 | 938 | * ndp->ni_offset to ndp->ni_offset+ndp->ni_count would yield the space. |
6bd0bb92 BJ |
939 | */ |
940 | ep = (struct direct *)dirbuf; | |
941 | dsize = DIRSIZ(ep); | |
efa3a91c | 942 | spacefree = ep->d_reclen - dsize; |
d870be74 | 943 | for (loc = ep->d_reclen; loc < ndp->ni_count; ) { |
6bd0bb92 BJ |
944 | nep = (struct direct *)(dirbuf + loc); |
945 | if (ep->d_ino) { | |
946 | /* trim the existing slot */ | |
947 | ep->d_reclen = dsize; | |
948 | ep = (struct direct *)((char *)ep + dsize); | |
949 | } else { | |
950 | /* overwrite; nothing there; header is ours */ | |
efa3a91c | 951 | spacefree += dsize; |
6bd0bb92 BJ |
952 | } |
953 | dsize = DIRSIZ(nep); | |
efa3a91c | 954 | spacefree += nep->d_reclen - dsize; |
6bd0bb92 | 955 | loc += nep->d_reclen; |
9f024ffc | 956 | bcopy((caddr_t)nep, (caddr_t)ep, dsize); |
6bd0bb92 BJ |
957 | } |
958 | /* | |
959 | * Update the pointer fields in the previous entry (if any), | |
960 | * copy in the new entry, and write out the block. | |
961 | */ | |
962 | if (ep->d_ino == 0) { | |
efa3a91c | 963 | if (spacefree + dsize < newentrysize) |
6bd0bb92 | 964 | panic("wdir: compact1"); |
d870be74 | 965 | ndp->ni_dent.d_reclen = spacefree + dsize; |
6bd0bb92 | 966 | } else { |
efa3a91c | 967 | if (spacefree < newentrysize) |
6bd0bb92 | 968 | panic("wdir: compact2"); |
d870be74 | 969 | ndp->ni_dent.d_reclen = spacefree; |
6bd0bb92 BJ |
970 | ep->d_reclen = dsize; |
971 | ep = (struct direct *)((char *)ep + dsize); | |
972 | } | |
d870be74 | 973 | bcopy((caddr_t)&ndp->ni_dent, (caddr_t)ep, (u_int)newentrysize); |
6bd0bb92 | 974 | bwrite(bp); |
9e7c949b KM |
975 | dp->i_flag |= IUPD|ICHG; |
976 | if (ndp->ni_endoff && ndp->ni_endoff < dp->i_size) | |
a5e62f37 | 977 | itrunc(dp, (u_long)ndp->ni_endoff); |
9e7c949b | 978 | iput(dp); |
f2a5ad78 | 979 | return (error); |
6bd0bb92 BJ |
980 | } |
981 | ||
4f083fd7 SL |
982 | /* |
983 | * Remove a directory entry after a call to namei, using the | |
984 | * parameters which it left in the u. area. The u. entry | |
d870be74 KM |
985 | * ni_offset contains the offset into the directory of the |
986 | * entry to be eliminated. The ni_count field contains the | |
4f083fd7 SL |
987 | * size of the previous record in the directory. If this |
988 | * is 0, the first entry is being deleted, so we need only | |
989 | * zero the inode number to mark the entry as free. If the | |
990 | * entry isn't the first in the directory, we must reclaim | |
991 | * the space of the now empty record by adding the record size | |
992 | * to the size of the previous entry. | |
993 | */ | |
d870be74 KM |
994 | dirremove(ndp) |
995 | register struct nameidata *ndp; | |
6bd0bb92 | 996 | { |
d870be74 | 997 | register struct inode *dp = ndp->ni_pdir; |
6bd0bb92 BJ |
998 | register struct buf *bp; |
999 | struct direct *ep; | |
1000 | ||
d870be74 | 1001 | if (ndp->ni_count == 0) { |
6bd0bb92 BJ |
1002 | /* |
1003 | * First entry in block: set d_ino to zero. | |
1004 | */ | |
d870be74 KM |
1005 | ndp->ni_dent.d_ino = 0; |
1006 | (void) rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1007 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
36d4ed87 | 1008 | } else { |
6bd0bb92 BJ |
1009 | /* |
1010 | * Collapse new free space into previous entry. | |
1011 | */ | |
8011f5df | 1012 | bp = blkatoff(dp, ndp->ni_offset - ndp->ni_count, (char **)&ep); |
6bd0bb92 BJ |
1013 | if (bp == 0) |
1014 | return (0); | |
d870be74 | 1015 | ep->d_reclen += ndp->ni_dent.d_reclen; |
6bd0bb92 BJ |
1016 | bwrite(bp); |
1017 | dp->i_flag |= IUPD|ICHG; | |
1018 | } | |
1019 | return (1); | |
10873320 | 1020 | } |
6459ebe0 | 1021 | |
4f083fd7 SL |
1022 | /* |
1023 | * Rewrite an existing directory entry to point at the inode | |
1024 | * supplied. The parameters describing the directory entry are | |
1025 | * set up by a call to namei. | |
1026 | */ | |
d870be74 | 1027 | dirrewrite(dp, ip, ndp) |
4f083fd7 | 1028 | struct inode *dp, *ip; |
d870be74 | 1029 | struct nameidata *ndp; |
4f083fd7 SL |
1030 | { |
1031 | ||
d870be74 KM |
1032 | ndp->ni_dent.d_ino = ip->i_number; |
1033 | u.u_error = rdwri(UIO_WRITE, dp, (caddr_t)&ndp->ni_dent, | |
1034 | (int)DIRSIZ(&ndp->ni_dent), ndp->ni_offset, 1, (int *)0); | |
4f083fd7 SL |
1035 | iput(dp); |
1036 | } | |
1037 | ||
4a0415d6 SL |
1038 | /* |
1039 | * Return buffer with contents of block "offset" | |
1040 | * from the beginning of directory "ip". If "res" | |
1041 | * is non-zero, fill it in with a pointer to the | |
1042 | * remaining space in the directory. | |
1043 | */ | |
6bd0bb92 | 1044 | struct buf * |
4a0415d6 | 1045 | blkatoff(ip, offset, res) |
6bd0bb92 BJ |
1046 | struct inode *ip; |
1047 | off_t offset; | |
1048 | char **res; | |
6459ebe0 | 1049 | { |
6bd0bb92 | 1050 | register struct fs *fs = ip->i_fs; |
3fd23f5c | 1051 | daddr_t lbn = lblkno(fs, offset); |
6bd0bb92 | 1052 | int bsize = blksize(fs, ip, lbn); |
6bd0bb92 | 1053 | register struct buf *bp; |
7e4f159c | 1054 | daddr_t bn; |
6459ebe0 | 1055 | |
7e4f159c | 1056 | bn = bmap(ip, lbn, B_READ, bsize); |
6bd0bb92 BJ |
1057 | if (u.u_error) |
1058 | return (0); | |
7e4f159c KM |
1059 | if (bn == (daddr_t)-1) { |
1060 | dirbad(ip, offset, "hole in dir"); | |
1061 | return (0); | |
1062 | } | |
ec67a3ce MK |
1063 | #ifdef SECSIZE |
1064 | bp = bread(ip->i_dev, fsbtodb(fs, bn), bsize, fs->fs_dbsize); | |
1065 | #else SECSIZE | |
7e4f159c | 1066 | bp = bread(ip->i_dev, fsbtodb(fs, bn), bsize); |
ec67a3ce | 1067 | #endif SECSIZE |
6bd0bb92 BJ |
1068 | if (bp->b_flags & B_ERROR) { |
1069 | brelse(bp); | |
1070 | return (0); | |
1071 | } | |
1072 | if (res) | |
7e4f159c | 1073 | *res = bp->b_un.b_addr + blkoff(fs, offset); |
6bd0bb92 | 1074 | return (bp); |
6459ebe0 | 1075 | } |
4f083fd7 SL |
1076 | |
1077 | /* | |
1078 | * Check if a directory is empty or not. | |
1079 | * Inode supplied must be locked. | |
17d11193 SL |
1080 | * |
1081 | * Using a struct dirtemplate here is not precisely | |
1082 | * what we want, but better than using a struct direct. | |
1083 | * | |
1084 | * NB: does not handle corrupted directories. | |
4f083fd7 | 1085 | */ |
68f21562 | 1086 | dirempty(ip, parentino) |
05d2bbce | 1087 | register struct inode *ip; |
68f21562 | 1088 | ino_t parentino; |
4f083fd7 SL |
1089 | { |
1090 | register off_t off; | |
17d11193 SL |
1091 | struct dirtemplate dbuf; |
1092 | register struct direct *dp = (struct direct *)&dbuf; | |
05d2bbce | 1093 | int error, count; |
17d11193 | 1094 | #define MINDIRSIZ (sizeof (struct dirtemplate) / 2) |
4f083fd7 SL |
1095 | |
1096 | for (off = 0; off < ip->i_size; off += dp->d_reclen) { | |
17d11193 SL |
1097 | error = rdwri(UIO_READ, ip, (caddr_t)dp, MINDIRSIZ, |
1098 | off, 1, &count); | |
1099 | /* | |
1100 | * Since we read MINDIRSIZ, residual must | |
1101 | * be 0 unless we're at end of file. | |
1102 | */ | |
1103 | if (error || count != 0) | |
4f083fd7 | 1104 | return (0); |
d14b14c3 | 1105 | /* avoid infinite loops */ |
a5e62f37 | 1106 | if (dp->d_reclen == 0) |
d14b14c3 | 1107 | return (0); |
17d11193 | 1108 | /* skip empty entries */ |
4f083fd7 SL |
1109 | if (dp->d_ino == 0) |
1110 | continue; | |
17d11193 SL |
1111 | /* accept only "." and ".." */ |
1112 | if (dp->d_namlen > 2) | |
1113 | return (0); | |
4f083fd7 SL |
1114 | if (dp->d_name[0] != '.') |
1115 | return (0); | |
17d11193 SL |
1116 | /* |
1117 | * At this point d_namlen must be 1 or 2. | |
1118 | * 1 implies ".", 2 implies ".." if second | |
1119 | * char is also "." | |
1120 | */ | |
68f21562 KM |
1121 | if (dp->d_namlen == 1) |
1122 | continue; | |
1123 | if (dp->d_name[1] == '.' && dp->d_ino == parentino) | |
4f083fd7 SL |
1124 | continue; |
1125 | return (0); | |
1126 | } | |
1127 | return (1); | |
1128 | } | |
b1aa93b9 KM |
1129 | |
1130 | /* | |
1131 | * Check if source directory is in the path of the target directory. | |
1132 | * Target is supplied locked, source is unlocked. | |
1133 | * The target is always iput() before returning. | |
1134 | */ | |
1135 | checkpath(source, target) | |
1136 | struct inode *source, *target; | |
1137 | { | |
1138 | struct dirtemplate dirbuf; | |
1139 | register struct inode *ip; | |
1140 | int error = 0; | |
1141 | ||
1142 | ip = target; | |
1143 | if (ip->i_number == source->i_number) { | |
1144 | error = EEXIST; | |
1145 | goto out; | |
1146 | } | |
1147 | if (ip->i_number == ROOTINO) | |
1148 | goto out; | |
1149 | ||
1150 | for (;;) { | |
1151 | if ((ip->i_mode&IFMT) != IFDIR) { | |
1152 | error = ENOTDIR; | |
1153 | break; | |
1154 | } | |
1155 | error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, | |
1156 | sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); | |
1157 | if (error != 0) | |
1158 | break; | |
1159 | if (dirbuf.dotdot_namlen != 2 || | |
4a287f19 KM |
1160 | dirbuf.dotdot_name[0] != '.' || |
1161 | dirbuf.dotdot_name[1] != '.') { | |
b1aa93b9 KM |
1162 | error = ENOTDIR; |
1163 | break; | |
1164 | } | |
1165 | if (dirbuf.dotdot_ino == source->i_number) { | |
1166 | error = EINVAL; | |
1167 | break; | |
1168 | } | |
1169 | if (dirbuf.dotdot_ino == ROOTINO) | |
1170 | break; | |
1171 | iput(ip); | |
1172 | ip = iget(ip->i_dev, ip->i_fs, dirbuf.dotdot_ino); | |
1173 | if (ip == NULL) { | |
1174 | error = u.u_error; | |
1175 | break; | |
1176 | } | |
1177 | } | |
1178 | ||
1179 | out: | |
1180 | if (error == ENOTDIR) | |
1181 | printf("checkpath: .. not a directory\n"); | |
1182 | if (ip != NULL) | |
1183 | iput(ip); | |
1184 | return (error); | |
1185 | } | |
f93197fc KM |
1186 | |
1187 | /* | |
1188 | * Name cache initialization, from main() when we are booting | |
1189 | */ | |
1190 | nchinit() | |
1191 | { | |
1192 | register union nchash *nchp; | |
7dba1c03 | 1193 | register struct namecache *ncp; |
f93197fc KM |
1194 | |
1195 | nchhead = 0; | |
1196 | nchtail = &nchhead; | |
7dba1c03 | 1197 | for (ncp = namecache; ncp < &namecache[nchsize]; ncp++) { |
f93197fc KM |
1198 | ncp->nc_forw = ncp; /* hash chain */ |
1199 | ncp->nc_back = ncp; | |
f93197fc KM |
1200 | ncp->nc_nxt = NULL; /* lru chain */ |
1201 | *nchtail = ncp; | |
1202 | ncp->nc_prev = nchtail; | |
1203 | nchtail = &ncp->nc_nxt; | |
f93197fc KM |
1204 | /* all else is zero already */ |
1205 | } | |
f93197fc KM |
1206 | for (nchp = nchash; nchp < &nchash[NCHHASH]; nchp++) { |
1207 | nchp->nch_head[0] = nchp; | |
1208 | nchp->nch_head[1] = nchp; | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | /* | |
1213 | * Cache flush, called when filesys is umounted to | |
1214 | * remove entries that would now be invalid | |
1215 | * | |
1216 | * The line "nxtcp = nchhead" near the end is to avoid potential problems | |
1217 | * if the cache lru chain is modified while we are dumping the | |
1218 | * inode. This makes the algorithm O(n^2), but do you think I care? | |
1219 | */ | |
1220 | nchinval(dev) | |
1221 | register dev_t dev; | |
1222 | { | |
7dba1c03 | 1223 | register struct namecache *ncp, *nxtcp; |
f93197fc KM |
1224 | |
1225 | for (ncp = nchhead; ncp; ncp = nxtcp) { | |
1226 | nxtcp = ncp->nc_nxt; | |
f93197fc KM |
1227 | if (ncp->nc_ip == NULL || |
1228 | (ncp->nc_idev != dev && ncp->nc_dev != dev)) | |
1229 | continue; | |
a5e62f37 | 1230 | /* free the resources we had */ |
f93197fc KM |
1231 | ncp->nc_idev = NODEV; |
1232 | ncp->nc_dev = NODEV; | |
4a287f19 | 1233 | ncp->nc_id = NULL; |
f93197fc | 1234 | ncp->nc_ino = 0; |
4a287f19 | 1235 | ncp->nc_ip = NULL; |
a5e62f37 MK |
1236 | remque(ncp); /* remove entry from its hash chain */ |
1237 | ncp->nc_forw = ncp; /* and make a dummy one */ | |
f93197fc | 1238 | ncp->nc_back = ncp; |
a5e62f37 | 1239 | /* delete this entry from LRU chain */ |
f93197fc KM |
1240 | *ncp->nc_prev = nxtcp; |
1241 | if (nxtcp) | |
1242 | nxtcp->nc_prev = ncp->nc_prev; | |
1243 | else | |
1244 | nchtail = ncp->nc_prev; | |
a5e62f37 | 1245 | /* cause rescan of list, it may have altered */ |
f93197fc | 1246 | nxtcp = nchhead; |
a5e62f37 | 1247 | /* put the now-free entry at head of LRU */ |
f93197fc KM |
1248 | ncp->nc_nxt = nxtcp; |
1249 | ncp->nc_prev = &nchhead; | |
1250 | nxtcp->nc_prev = &ncp->nc_nxt; | |
1251 | nchhead = ncp; | |
1252 | } | |
1253 | } | |
9ffa8d54 KM |
1254 | |
1255 | /* | |
1256 | * Name cache invalidation of all entries. | |
1257 | */ | |
1258 | cacheinvalall() | |
1259 | { | |
7dba1c03 | 1260 | register struct namecache *ncp; |
9ffa8d54 | 1261 | |
7dba1c03 | 1262 | for (ncp = namecache; ncp < &namecache[nchsize]; ncp++) |
9ffa8d54 | 1263 | ncp->nc_id = 0; |
9ffa8d54 | 1264 | } |