Commit | Line | Data |
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b991bc2d JSP |
1 | /* |
2 | * Copyright (c) 1994 Jan-Simon Pendry | |
3 | * Copyright (c) 1994 | |
4 | * The Regents of the University of California. All rights reserved. | |
5 | * | |
6 | * This code is derived from software contributed to Berkeley by | |
7 | * Jan-Simon Pendry. | |
8 | * | |
9 | * %sccs.include.redist.c% | |
10 | * | |
c93d29a8 | 11 | * @(#)union_subr.c 8.5 (Berkeley) %G% |
b991bc2d JSP |
12 | */ |
13 | ||
14 | #include <sys/param.h> | |
15 | #include <sys/systm.h> | |
16 | #include <sys/time.h> | |
17 | #include <sys/kernel.h> | |
18 | #include <sys/vnode.h> | |
19 | #include <sys/namei.h> | |
20 | #include <sys/malloc.h> | |
81be6ee0 | 21 | #include <sys/file.h> |
3b293975 | 22 | #include <sys/filedesc.h> |
58572fc0 | 23 | #include <sys/queue.h> |
c93d29a8 | 24 | #include <sys/mount.h> |
2e1ae99e | 25 | #include <miscfs/union/union.h> |
b991bc2d | 26 | |
79f80c71 JSP |
27 | #ifdef DIAGNOSTIC |
28 | #include <sys/proc.h> | |
29 | #endif | |
30 | ||
58572fc0 JSP |
31 | /* must be power of two, otherwise change UNION_HASH() */ |
32 | #define NHASH 32 | |
33 | ||
34 | /* unsigned int ... */ | |
35 | #define UNION_HASH(u, l) \ | |
36 | (((((unsigned long) (u)) + ((unsigned long) l)) >> 8) & (NHASH-1)) | |
37 | ||
38 | static LIST_HEAD(unhead, union_node) unhead[NHASH]; | |
39 | static int unvplock[NHASH]; | |
b991bc2d JSP |
40 | |
41 | int | |
42 | union_init() | |
43 | { | |
58572fc0 JSP |
44 | int i; |
45 | ||
46 | for (i = 0; i < NHASH; i++) | |
47 | LIST_INIT(&unhead[i]); | |
48 | bzero((caddr_t) unvplock, sizeof(unvplock)); | |
49 | } | |
50 | ||
51 | static int | |
52 | union_list_lock(ix) | |
53 | int ix; | |
54 | { | |
55 | ||
56 | if (unvplock[ix] & UN_LOCKED) { | |
57 | unvplock[ix] |= UN_WANT; | |
58 | sleep((caddr_t) &unvplock[ix], PINOD); | |
59 | return (1); | |
60 | } | |
b991bc2d | 61 | |
58572fc0 JSP |
62 | unvplock[ix] |= UN_LOCKED; |
63 | ||
64 | return (0); | |
b991bc2d JSP |
65 | } |
66 | ||
e2a2f3a7 | 67 | static void |
58572fc0 JSP |
68 | union_list_unlock(ix) |
69 | int ix; | |
70 | { | |
71 | ||
72 | unvplock[ix] &= ~UN_LOCKED; | |
73 | ||
74 | if (unvplock[ix] & UN_WANT) { | |
75 | unvplock[ix] &= ~UN_WANT; | |
76 | wakeup((caddr_t) &unvplock[ix]); | |
77 | } | |
78 | } | |
79 | ||
80 | void | |
81 | union_updatevp(un, uppervp, lowervp) | |
e2a2f3a7 | 82 | struct union_node *un; |
58572fc0 JSP |
83 | struct vnode *uppervp; |
84 | struct vnode *lowervp; | |
e2a2f3a7 | 85 | { |
58572fc0 JSP |
86 | int ohash = UNION_HASH(un->un_uppervp, un->un_lowervp); |
87 | int nhash = UNION_HASH(uppervp, lowervp); | |
e2a2f3a7 | 88 | |
58572fc0 JSP |
89 | if (ohash != nhash) { |
90 | /* | |
91 | * Ensure locking is ordered from lower to higher | |
92 | * to avoid deadlocks. | |
93 | */ | |
94 | if (nhash < ohash) { | |
95 | int t = ohash; | |
96 | ohash = nhash; | |
97 | nhash = t; | |
98 | } | |
99 | ||
100 | while (union_list_lock(ohash)) | |
101 | continue; | |
102 | ||
103 | while (union_list_lock(nhash)) | |
104 | continue; | |
105 | ||
106 | LIST_REMOVE(un, un_cache); | |
107 | union_list_unlock(ohash); | |
108 | } else { | |
109 | while (union_list_lock(nhash)) | |
110 | continue; | |
111 | } | |
112 | ||
113 | if (un->un_lowervp != lowervp) { | |
114 | if (un->un_lowervp) { | |
115 | vrele(un->un_lowervp); | |
116 | if (un->un_path) { | |
117 | free(un->un_path, M_TEMP); | |
118 | un->un_path = 0; | |
119 | } | |
120 | if (un->un_dirvp) { | |
121 | vrele(un->un_dirvp); | |
122 | un->un_dirvp = NULLVP; | |
123 | } | |
e2a2f3a7 | 124 | } |
58572fc0 JSP |
125 | un->un_lowervp = lowervp; |
126 | } | |
127 | ||
128 | if (un->un_uppervp != uppervp) { | |
129 | if (un->un_uppervp) | |
130 | vrele(un->un_uppervp); | |
131 | ||
132 | un->un_uppervp = uppervp; | |
e2a2f3a7 | 133 | } |
58572fc0 JSP |
134 | |
135 | if (ohash != nhash) | |
136 | LIST_INSERT_HEAD(&unhead[nhash], un, un_cache); | |
137 | ||
138 | union_list_unlock(nhash); | |
139 | } | |
140 | ||
141 | void | |
142 | union_newlower(un, lowervp) | |
143 | struct union_node *un; | |
144 | struct vnode *lowervp; | |
145 | { | |
146 | ||
147 | union_updatevp(un, un->un_uppervp, lowervp); | |
148 | } | |
149 | ||
150 | void | |
151 | union_newupper(un, uppervp) | |
152 | struct union_node *un; | |
153 | struct vnode *uppervp; | |
154 | { | |
155 | ||
156 | union_updatevp(un, uppervp, un->un_lowervp); | |
e2a2f3a7 JSP |
157 | } |
158 | ||
b991bc2d JSP |
159 | /* |
160 | * allocate a union_node/vnode pair. the vnode is | |
01dac67e JSP |
161 | * referenced and locked. the new vnode is returned |
162 | * via (vpp). (mp) is the mountpoint of the union filesystem, | |
163 | * (dvp) is the parent directory where the upper layer object | |
164 | * should exist (but doesn't) and (cnp) is the componentname | |
165 | * information which is partially copied to allow the upper | |
166 | * layer object to be created at a later time. (uppervp) | |
167 | * and (lowervp) reference the upper and lower layer objects | |
168 | * being mapped. either, but not both, can be nil. | |
e2a2f3a7 | 169 | * if supplied, (uppervp) is locked. |
3b293975 JSP |
170 | * the reference is either maintained in the new union_node |
171 | * object which is allocated, or they are vrele'd. | |
b991bc2d JSP |
172 | * |
173 | * all union_nodes are maintained on a singly-linked | |
174 | * list. new nodes are only allocated when they cannot | |
175 | * be found on this list. entries on the list are | |
176 | * removed when the vfs reclaim entry is called. | |
177 | * | |
178 | * a single lock is kept for the entire list. this is | |
179 | * needed because the getnewvnode() function can block | |
180 | * waiting for a vnode to become free, in which case there | |
181 | * may be more than one process trying to get the same | |
182 | * vnode. this lock is only taken if we are going to | |
183 | * call getnewvnode, since the kernel itself is single-threaded. | |
184 | * | |
185 | * if an entry is found on the list, then call vget() to | |
186 | * take a reference. this is done because there may be | |
187 | * zero references to it and so it needs to removed from | |
188 | * the vnode free list. | |
189 | */ | |
190 | int | |
79f80c71 | 191 | union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp) |
b991bc2d JSP |
192 | struct vnode **vpp; |
193 | struct mount *mp; | |
79f80c71 | 194 | struct vnode *undvp; |
b991bc2d JSP |
195 | struct vnode *dvp; /* may be null */ |
196 | struct componentname *cnp; /* may be null */ | |
197 | struct vnode *uppervp; /* may be null */ | |
198 | struct vnode *lowervp; /* may be null */ | |
199 | { | |
200 | int error; | |
201 | struct union_node *un; | |
202 | struct union_node **pp; | |
58572fc0 | 203 | struct vnode *xlowervp = NULLVP; |
c93d29a8 | 204 | struct union_mount *um = MOUNTTOUNIONMOUNT(mp); |
58572fc0 | 205 | int hash; |
c93d29a8 | 206 | int vflag; |
58572fc0 | 207 | int try; |
01dac67e | 208 | |
58572fc0 | 209 | if (uppervp == NULLVP && lowervp == NULLVP) |
01dac67e JSP |
210 | panic("union: unidentifiable allocation"); |
211 | ||
212 | if (uppervp && lowervp && (uppervp->v_type != lowervp->v_type)) { | |
213 | xlowervp = lowervp; | |
58572fc0 | 214 | lowervp = NULLVP; |
01dac67e | 215 | } |
b991bc2d | 216 | |
c93d29a8 JSP |
217 | /* detect the root vnode (and aliases) */ |
218 | vflag = 0; | |
219 | if ((uppervp == um->um_uppervp) && | |
220 | ((lowervp == NULLVP) || lowervp == um->um_lowervp)) { | |
221 | if (lowervp == NULLVP) { | |
222 | lowervp = um->um_lowervp; | |
223 | VREF(lowervp); | |
224 | } | |
225 | vflag = VROOT; | |
226 | } | |
227 | ||
b991bc2d | 228 | loop: |
58572fc0 JSP |
229 | for (try = 0; try < 3; try++) { |
230 | switch (try) { | |
231 | case 0: | |
232 | if (lowervp == NULLVP) | |
233 | continue; | |
234 | hash = UNION_HASH(uppervp, lowervp); | |
e2a2f3a7 | 235 | break; |
58572fc0 JSP |
236 | |
237 | case 1: | |
238 | if (uppervp == NULLVP) | |
239 | continue; | |
240 | hash = UNION_HASH(uppervp, NULLVP); | |
241 | break; | |
242 | ||
243 | case 2: | |
244 | if (lowervp == NULLVP) | |
245 | continue; | |
246 | hash = UNION_HASH(NULLVP, lowervp); | |
247 | break; | |
248 | } | |
249 | ||
250 | while (union_list_lock(hash)) | |
251 | continue; | |
252 | ||
253 | for (un = unhead[hash].lh_first; un != 0; | |
254 | un = un->un_cache.le_next) { | |
255 | if ((un->un_lowervp == lowervp || | |
256 | un->un_lowervp == NULLVP) && | |
257 | (un->un_uppervp == uppervp || | |
258 | un->un_uppervp == NULLVP) && | |
259 | (UNIONTOV(un)->v_mount == mp)) { | |
260 | if (vget(UNIONTOV(un), 0)) { | |
261 | union_list_unlock(hash); | |
262 | goto loop; | |
263 | } | |
264 | break; | |
265 | } | |
e2a2f3a7 | 266 | } |
58572fc0 JSP |
267 | |
268 | union_list_unlock(hash); | |
269 | ||
270 | if (un) | |
271 | break; | |
e2a2f3a7 | 272 | } |
ed5969c8 | 273 | |
e2a2f3a7 JSP |
274 | if (un) { |
275 | /* | |
276 | * Obtain a lock on the union_node. | |
277 | * uppervp is locked, though un->un_uppervp | |
278 | * may not be. this doesn't break the locking | |
279 | * hierarchy since in the case that un->un_uppervp | |
280 | * is not yet locked it will be vrele'd and replaced | |
281 | * with uppervp. | |
282 | */ | |
283 | ||
284 | if ((dvp != NULLVP) && (uppervp == dvp)) { | |
ed5969c8 | 285 | /* |
e2a2f3a7 JSP |
286 | * Access ``.'', so (un) will already |
287 | * be locked. Since this process has | |
288 | * the lock on (uppervp) no other | |
289 | * process can hold the lock on (un). | |
ed5969c8 | 290 | */ |
e2a2f3a7 JSP |
291 | #ifdef DIAGNOSTIC |
292 | if ((un->un_flags & UN_LOCKED) == 0) | |
293 | panic("union: . not locked"); | |
294 | else if (curproc && un->un_pid != curproc->p_pid && | |
295 | un->un_pid > -1 && curproc->p_pid > -1) | |
296 | panic("union: allocvp not lock owner"); | |
297 | #endif | |
298 | } else { | |
299 | if (un->un_flags & UN_LOCKED) { | |
300 | vrele(UNIONTOV(un)); | |
301 | un->un_flags |= UN_WANT; | |
302 | sleep((caddr_t) &un->un_flags, PINOD); | |
303 | goto loop; | |
79f80c71 | 304 | } |
e2a2f3a7 | 305 | un->un_flags |= UN_LOCKED; |
ed5969c8 | 306 | |
e2a2f3a7 JSP |
307 | #ifdef DIAGNOSTIC |
308 | if (curproc) | |
309 | un->un_pid = curproc->p_pid; | |
310 | else | |
311 | un->un_pid = -1; | |
312 | #endif | |
313 | } | |
314 | ||
315 | /* | |
316 | * At this point, the union_node is locked, | |
317 | * un->un_uppervp may not be locked, and uppervp | |
318 | * is locked or nil. | |
319 | */ | |
320 | ||
321 | /* | |
322 | * Save information about the upper layer. | |
323 | */ | |
324 | if (uppervp != un->un_uppervp) { | |
58572fc0 | 325 | union_newupper(un, uppervp); |
e2a2f3a7 JSP |
326 | } else if (uppervp) { |
327 | vrele(uppervp); | |
328 | } | |
329 | ||
330 | if (un->un_uppervp) { | |
331 | un->un_flags |= UN_ULOCK; | |
332 | un->un_flags &= ~UN_KLOCK; | |
333 | } | |
334 | ||
335 | /* | |
336 | * Save information about the lower layer. | |
337 | * This needs to keep track of pathname | |
338 | * and directory information which union_vn_create | |
339 | * might need. | |
340 | */ | |
341 | if (lowervp != un->un_lowervp) { | |
58572fc0 | 342 | union_newlower(un, lowervp); |
e2a2f3a7 JSP |
343 | if (cnp && (lowervp != NULLVP) && |
344 | (lowervp->v_type == VREG)) { | |
345 | un->un_hash = cnp->cn_hash; | |
346 | un->un_path = malloc(cnp->cn_namelen+1, | |
347 | M_TEMP, M_WAITOK); | |
348 | bcopy(cnp->cn_nameptr, un->un_path, | |
349 | cnp->cn_namelen); | |
350 | un->un_path[cnp->cn_namelen] = '\0'; | |
351 | VREF(dvp); | |
352 | un->un_dirvp = dvp; | |
79f80c71 | 353 | } |
e2a2f3a7 JSP |
354 | } else if (lowervp) { |
355 | vrele(lowervp); | |
b991bc2d | 356 | } |
e2a2f3a7 JSP |
357 | *vpp = UNIONTOV(un); |
358 | return (0); | |
b991bc2d JSP |
359 | } |
360 | ||
361 | /* | |
362 | * otherwise lock the vp list while we call getnewvnode | |
363 | * since that can block. | |
364 | */ | |
58572fc0 JSP |
365 | hash = UNION_HASH(uppervp, lowervp); |
366 | ||
367 | if (union_list_lock(hash)) | |
b991bc2d | 368 | goto loop; |
b991bc2d JSP |
369 | |
370 | error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp); | |
e2a2f3a7 JSP |
371 | if (error) { |
372 | if (uppervp) { | |
373 | if (dvp == uppervp) | |
374 | vrele(uppervp); | |
375 | else | |
376 | vput(uppervp); | |
377 | } | |
378 | if (lowervp) | |
379 | vrele(lowervp); | |
380 | ||
b991bc2d | 381 | goto out; |
e2a2f3a7 | 382 | } |
b991bc2d JSP |
383 | |
384 | MALLOC((*vpp)->v_data, void *, sizeof(struct union_node), | |
385 | M_TEMP, M_WAITOK); | |
386 | ||
c93d29a8 | 387 | (*vpp)->v_flag |= vflag; |
01dac67e JSP |
388 | if (uppervp) |
389 | (*vpp)->v_type = uppervp->v_type; | |
390 | else | |
391 | (*vpp)->v_type = lowervp->v_type; | |
b991bc2d | 392 | un = VTOUNION(*vpp); |
79f80c71 | 393 | un->un_vnode = *vpp; |
b991bc2d JSP |
394 | un->un_uppervp = uppervp; |
395 | un->un_lowervp = lowervp; | |
15a86f7e | 396 | un->un_openl = 0; |
e2a2f3a7 JSP |
397 | un->un_flags = UN_LOCKED; |
398 | if (un->un_uppervp) | |
399 | un->un_flags |= UN_ULOCK; | |
400 | #ifdef DIAGNOSTIC | |
401 | if (curproc) | |
402 | un->un_pid = curproc->p_pid; | |
403 | else | |
404 | un->un_pid = -1; | |
405 | #endif | |
ed5969c8 JSP |
406 | if (cnp && (lowervp != NULLVP) && (lowervp->v_type == VREG)) { |
407 | un->un_hash = cnp->cn_hash; | |
b991bc2d JSP |
408 | un->un_path = malloc(cnp->cn_namelen+1, M_TEMP, M_WAITOK); |
409 | bcopy(cnp->cn_nameptr, un->un_path, cnp->cn_namelen); | |
410 | un->un_path[cnp->cn_namelen] = '\0'; | |
01dac67e JSP |
411 | VREF(dvp); |
412 | un->un_dirvp = dvp; | |
b991bc2d | 413 | } else { |
ed5969c8 | 414 | un->un_hash = 0; |
b991bc2d | 415 | un->un_path = 0; |
01dac67e | 416 | un->un_dirvp = 0; |
b991bc2d JSP |
417 | } |
418 | ||
58572fc0 | 419 | LIST_INSERT_HEAD(&unhead[hash], un, un_cache); |
b991bc2d | 420 | |
01dac67e JSP |
421 | if (xlowervp) |
422 | vrele(xlowervp); | |
423 | ||
b991bc2d | 424 | out: |
58572fc0 | 425 | union_list_unlock(hash); |
b991bc2d | 426 | |
b991bc2d JSP |
427 | return (error); |
428 | } | |
429 | ||
430 | int | |
431 | union_freevp(vp) | |
432 | struct vnode *vp; | |
433 | { | |
b991bc2d JSP |
434 | struct union_node *un = VTOUNION(vp); |
435 | ||
58572fc0 JSP |
436 | LIST_REMOVE(un, un_cache); |
437 | ||
438 | if (un->un_uppervp) | |
439 | vrele(un->un_uppervp); | |
440 | if (un->un_lowervp) | |
441 | vrele(un->un_lowervp); | |
442 | if (un->un_dirvp) | |
443 | vrele(un->un_dirvp); | |
444 | if (un->un_path) | |
445 | free(un->un_path, M_TEMP); | |
b991bc2d | 446 | |
b991bc2d JSP |
447 | FREE(vp->v_data, M_TEMP); |
448 | vp->v_data = 0; | |
58572fc0 | 449 | |
b991bc2d JSP |
450 | return (0); |
451 | } | |
81be6ee0 JSP |
452 | |
453 | /* | |
454 | * copyfile. copy the vnode (fvp) to the vnode (tvp) | |
455 | * using a sequence of reads and writes. both (fvp) | |
456 | * and (tvp) are locked on entry and exit. | |
457 | */ | |
458 | int | |
459 | union_copyfile(p, cred, fvp, tvp) | |
460 | struct proc *p; | |
461 | struct ucred *cred; | |
462 | struct vnode *fvp; | |
463 | struct vnode *tvp; | |
464 | { | |
465 | char *buf; | |
466 | struct uio uio; | |
467 | struct iovec iov; | |
468 | int error = 0; | |
469 | ||
470 | /* | |
471 | * strategy: | |
472 | * allocate a buffer of size MAXBSIZE. | |
473 | * loop doing reads and writes, keeping track | |
474 | * of the current uio offset. | |
475 | * give up at the first sign of trouble. | |
476 | */ | |
477 | ||
478 | uio.uio_procp = p; | |
479 | uio.uio_segflg = UIO_SYSSPACE; | |
480 | uio.uio_offset = 0; | |
481 | ||
482 | VOP_UNLOCK(fvp); /* XXX */ | |
483 | LEASE_CHECK(fvp, p, cred, LEASE_READ); | |
484 | VOP_LOCK(fvp); /* XXX */ | |
485 | VOP_UNLOCK(tvp); /* XXX */ | |
486 | LEASE_CHECK(tvp, p, cred, LEASE_WRITE); | |
487 | VOP_LOCK(tvp); /* XXX */ | |
488 | ||
489 | buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); | |
490 | ||
491 | /* ugly loop follows... */ | |
492 | do { | |
493 | off_t offset = uio.uio_offset; | |
494 | ||
495 | uio.uio_iov = &iov; | |
496 | uio.uio_iovcnt = 1; | |
497 | iov.iov_base = buf; | |
498 | iov.iov_len = MAXBSIZE; | |
499 | uio.uio_resid = iov.iov_len; | |
500 | uio.uio_rw = UIO_READ; | |
501 | error = VOP_READ(fvp, &uio, 0, cred); | |
502 | ||
503 | if (error == 0) { | |
504 | uio.uio_iov = &iov; | |
505 | uio.uio_iovcnt = 1; | |
506 | iov.iov_base = buf; | |
507 | iov.iov_len = MAXBSIZE - uio.uio_resid; | |
508 | uio.uio_offset = offset; | |
509 | uio.uio_rw = UIO_WRITE; | |
510 | uio.uio_resid = iov.iov_len; | |
511 | ||
512 | if (uio.uio_resid == 0) | |
513 | break; | |
514 | ||
515 | do { | |
516 | error = VOP_WRITE(tvp, &uio, 0, cred); | |
517 | } while ((uio.uio_resid > 0) && (error == 0)); | |
518 | } | |
519 | ||
520 | } while (error == 0); | |
521 | ||
522 | free(buf, M_TEMP); | |
523 | return (error); | |
524 | } | |
525 | ||
3b293975 JSP |
526 | /* |
527 | * Create a shadow directory in the upper layer. | |
528 | * The new vnode is returned locked. | |
529 | * | |
530 | * (um) points to the union mount structure for access to the | |
531 | * the mounting process's credentials. | |
532 | * (dvp) is the directory in which to create the shadow directory. | |
533 | * it is unlocked on entry and exit. | |
534 | * (cnp) is the componentname to be created. | |
535 | * (vpp) is the returned newly created shadow directory, which | |
536 | * is returned locked. | |
537 | */ | |
538 | int | |
539 | union_mkshadow(um, dvp, cnp, vpp) | |
540 | struct union_mount *um; | |
541 | struct vnode *dvp; | |
542 | struct componentname *cnp; | |
543 | struct vnode **vpp; | |
544 | { | |
545 | int error; | |
546 | struct vattr va; | |
547 | struct proc *p = cnp->cn_proc; | |
548 | struct componentname cn; | |
549 | ||
550 | /* | |
551 | * policy: when creating the shadow directory in the | |
692a90df JSP |
552 | * upper layer, create it owned by the user who did |
553 | * the mount, group from parent directory, and mode | |
554 | * 777 modified by umask (ie mostly identical to the | |
555 | * mkdir syscall). (jsp, kb) | |
3b293975 JSP |
556 | */ |
557 | ||
558 | /* | |
559 | * A new componentname structure must be faked up because | |
560 | * there is no way to know where the upper level cnp came | |
561 | * from or what it is being used for. This must duplicate | |
562 | * some of the work done by NDINIT, some of the work done | |
563 | * by namei, some of the work done by lookup and some of | |
564 | * the work done by VOP_LOOKUP when given a CREATE flag. | |
565 | * Conclusion: Horrible. | |
566 | * | |
567 | * The pathname buffer will be FREEed by VOP_MKDIR. | |
568 | */ | |
569 | cn.cn_pnbuf = malloc(cnp->cn_namelen+1, M_NAMEI, M_WAITOK); | |
ed5969c8 JSP |
570 | bcopy(cnp->cn_nameptr, cn.cn_pnbuf, cnp->cn_namelen); |
571 | cn.cn_pnbuf[cnp->cn_namelen] = '\0'; | |
3b293975 JSP |
572 | |
573 | cn.cn_nameiop = CREATE; | |
bf006388 | 574 | cn.cn_flags = (LOCKPARENT|HASBUF|SAVENAME|SAVESTART|ISLASTCN); |
3b293975 | 575 | cn.cn_proc = cnp->cn_proc; |
c1b204a8 JSP |
576 | if (um->um_op == UNMNT_ABOVE) |
577 | cn.cn_cred = cnp->cn_cred; | |
578 | else | |
579 | cn.cn_cred = um->um_cred; | |
3b293975 JSP |
580 | cn.cn_nameptr = cn.cn_pnbuf; |
581 | cn.cn_namelen = cnp->cn_namelen; | |
582 | cn.cn_hash = cnp->cn_hash; | |
583 | cn.cn_consume = cnp->cn_consume; | |
584 | ||
ed5969c8 | 585 | VREF(dvp); |
3b293975 JSP |
586 | if (error = relookup(dvp, vpp, &cn)) |
587 | return (error); | |
ed5969c8 | 588 | vrele(dvp); |
3b293975 JSP |
589 | |
590 | if (*vpp) { | |
591 | VOP_ABORTOP(dvp, &cn); | |
592 | VOP_UNLOCK(dvp); | |
593 | vrele(*vpp); | |
594 | *vpp = NULLVP; | |
595 | return (EEXIST); | |
596 | } | |
597 | ||
598 | VATTR_NULL(&va); | |
599 | va.va_type = VDIR; | |
692a90df | 600 | va.va_mode = um->um_cmode; |
3b293975 JSP |
601 | |
602 | /* LEASE_CHECK: dvp is locked */ | |
603 | LEASE_CHECK(dvp, p, p->p_ucred, LEASE_WRITE); | |
604 | ||
3b293975 JSP |
605 | error = VOP_MKDIR(dvp, vpp, &cn, &va); |
606 | return (error); | |
607 | } | |
608 | ||
81be6ee0 JSP |
609 | /* |
610 | * union_vn_create: creates and opens a new shadow file | |
611 | * on the upper union layer. this function is similar | |
612 | * in spirit to calling vn_open but it avoids calling namei(). | |
613 | * the problem with calling namei is that a) it locks too many | |
614 | * things, and b) it doesn't start at the "right" directory, | |
615 | * whereas relookup is told where to start. | |
616 | */ | |
617 | int | |
3b293975 | 618 | union_vn_create(vpp, un, p) |
81be6ee0 JSP |
619 | struct vnode **vpp; |
620 | struct union_node *un; | |
81be6ee0 JSP |
621 | struct proc *p; |
622 | { | |
623 | struct vnode *vp; | |
624 | struct ucred *cred = p->p_ucred; | |
625 | struct vattr vat; | |
626 | struct vattr *vap = &vat; | |
627 | int fmode = FFLAGS(O_WRONLY|O_CREAT|O_TRUNC|O_EXCL); | |
628 | int error; | |
ed5969c8 | 629 | int cmode = UN_FILEMODE & ~p->p_fd->fd_cmask; |
81be6ee0 JSP |
630 | char *cp; |
631 | struct componentname cn; | |
632 | ||
633 | *vpp = NULLVP; | |
634 | ||
692a90df JSP |
635 | /* |
636 | * Build a new componentname structure (for the same | |
637 | * reasons outlines in union_mkshadow). | |
638 | * The difference here is that the file is owned by | |
639 | * the current user, rather than by the person who | |
640 | * did the mount, since the current user needs to be | |
641 | * able to write the file (that's why it is being | |
642 | * copied in the first place). | |
643 | */ | |
81be6ee0 JSP |
644 | cn.cn_namelen = strlen(un->un_path); |
645 | cn.cn_pnbuf = (caddr_t) malloc(cn.cn_namelen, M_NAMEI, M_WAITOK); | |
646 | bcopy(un->un_path, cn.cn_pnbuf, cn.cn_namelen+1); | |
647 | cn.cn_nameiop = CREATE; | |
bf006388 | 648 | cn.cn_flags = (LOCKPARENT|HASBUF|SAVENAME|SAVESTART|ISLASTCN); |
81be6ee0 JSP |
649 | cn.cn_proc = p; |
650 | cn.cn_cred = p->p_ucred; | |
651 | cn.cn_nameptr = cn.cn_pnbuf; | |
ed5969c8 | 652 | cn.cn_hash = un->un_hash; |
81be6ee0 JSP |
653 | cn.cn_consume = 0; |
654 | ||
ed5969c8 | 655 | VREF(un->un_dirvp); |
81be6ee0 JSP |
656 | if (error = relookup(un->un_dirvp, &vp, &cn)) |
657 | return (error); | |
ed5969c8 JSP |
658 | vrele(un->un_dirvp); |
659 | ||
bf006388 | 660 | if (vp) { |
81be6ee0 JSP |
661 | VOP_ABORTOP(un->un_dirvp, &cn); |
662 | if (un->un_dirvp == vp) | |
663 | vrele(un->un_dirvp); | |
664 | else | |
bf006388 JSP |
665 | vput(un->un_dirvp); |
666 | vrele(vp); | |
667 | return (EEXIST); | |
81be6ee0 JSP |
668 | } |
669 | ||
bf006388 JSP |
670 | /* |
671 | * Good - there was no race to create the file | |
672 | * so go ahead and create it. The permissions | |
673 | * on the file will be 0666 modified by the | |
674 | * current user's umask. Access to the file, while | |
675 | * it is unioned, will require access to the top *and* | |
676 | * bottom files. Access when not unioned will simply | |
677 | * require access to the top-level file. | |
678 | * TODO: confirm choice of access permissions. | |
679 | */ | |
81be6ee0 | 680 | VATTR_NULL(vap); |
bf006388 JSP |
681 | vap->va_type = VREG; |
682 | vap->va_mode = cmode; | |
683 | LEASE_CHECK(un->un_dirvp, p, cred, LEASE_WRITE); | |
684 | if (error = VOP_CREATE(un->un_dirvp, &vp, &cn, vap)) | |
685 | return (error); | |
81be6ee0 | 686 | |
bf006388 JSP |
687 | if (error = VOP_OPEN(vp, fmode, cred, p)) { |
688 | vput(vp); | |
689 | return (error); | |
690 | } | |
81be6ee0 JSP |
691 | |
692 | vp->v_writecount++; | |
693 | *vpp = vp; | |
694 | return (0); | |
81be6ee0 | 695 | } |
ed5969c8 JSP |
696 | |
697 | int | |
15a86f7e | 698 | union_vn_close(vp, fmode, cred, p) |
ed5969c8 JSP |
699 | struct vnode *vp; |
700 | int fmode; | |
15a86f7e JSP |
701 | struct ucred *cred; |
702 | struct proc *p; | |
ed5969c8 JSP |
703 | { |
704 | if (fmode & FWRITE) | |
705 | --vp->v_writecount; | |
706 | return (VOP_CLOSE(vp, fmode)); | |
707 | } | |
708 | ||
709 | void | |
710 | union_removed_upper(un) | |
711 | struct union_node *un; | |
712 | { | |
e2a2f3a7 JSP |
713 | if (un->un_flags & UN_ULOCK) { |
714 | un->un_flags &= ~UN_ULOCK; | |
58572fc0 | 715 | VOP_UNLOCK(un->un_uppervp); |
e2a2f3a7 | 716 | } |
58572fc0 JSP |
717 | |
718 | union_newupper(un, NULLVP); | |
ed5969c8 | 719 | } |
15a86f7e JSP |
720 | |
721 | struct vnode * | |
722 | union_lowervp(vp) | |
723 | struct vnode *vp; | |
724 | { | |
725 | struct union_node *un = VTOUNION(vp); | |
726 | ||
727 | if (un->un_lowervp && (vp->v_type == un->un_lowervp->v_type)) { | |
728 | if (vget(un->un_lowervp, 0)) | |
729 | return (NULLVP); | |
730 | } | |
731 | ||
732 | return (un->un_lowervp); | |
733 | } |