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 | * | |
88edbcd4 | 11 | * @(#)union_subr.c 8.12 (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> |
8a9c17f6 | 25 | #include <vm/vm.h> /* for vnode_pager_setsize */ |
2e1ae99e | 26 | #include <miscfs/union/union.h> |
b991bc2d | 27 | |
79f80c71 JSP |
28 | #ifdef DIAGNOSTIC |
29 | #include <sys/proc.h> | |
30 | #endif | |
31 | ||
58572fc0 JSP |
32 | /* must be power of two, otherwise change UNION_HASH() */ |
33 | #define NHASH 32 | |
34 | ||
35 | /* unsigned int ... */ | |
36 | #define UNION_HASH(u, l) \ | |
37 | (((((unsigned long) (u)) + ((unsigned long) l)) >> 8) & (NHASH-1)) | |
38 | ||
39 | static LIST_HEAD(unhead, union_node) unhead[NHASH]; | |
40 | static int unvplock[NHASH]; | |
b991bc2d JSP |
41 | |
42 | int | |
43 | union_init() | |
44 | { | |
58572fc0 JSP |
45 | int i; |
46 | ||
47 | for (i = 0; i < NHASH; i++) | |
48 | LIST_INIT(&unhead[i]); | |
49 | bzero((caddr_t) unvplock, sizeof(unvplock)); | |
50 | } | |
51 | ||
52 | static int | |
53 | union_list_lock(ix) | |
54 | int ix; | |
55 | { | |
56 | ||
57 | if (unvplock[ix] & UN_LOCKED) { | |
58 | unvplock[ix] |= UN_WANT; | |
59 | sleep((caddr_t) &unvplock[ix], PINOD); | |
60 | return (1); | |
61 | } | |
b991bc2d | 62 | |
58572fc0 JSP |
63 | unvplock[ix] |= UN_LOCKED; |
64 | ||
65 | return (0); | |
b991bc2d JSP |
66 | } |
67 | ||
e2a2f3a7 | 68 | static void |
58572fc0 JSP |
69 | union_list_unlock(ix) |
70 | int ix; | |
71 | { | |
72 | ||
73 | unvplock[ix] &= ~UN_LOCKED; | |
74 | ||
75 | if (unvplock[ix] & UN_WANT) { | |
76 | unvplock[ix] &= ~UN_WANT; | |
77 | wakeup((caddr_t) &unvplock[ix]); | |
78 | } | |
79 | } | |
80 | ||
81 | void | |
82 | union_updatevp(un, uppervp, lowervp) | |
e2a2f3a7 | 83 | struct union_node *un; |
58572fc0 JSP |
84 | struct vnode *uppervp; |
85 | struct vnode *lowervp; | |
e2a2f3a7 | 86 | { |
58572fc0 JSP |
87 | int ohash = UNION_HASH(un->un_uppervp, un->un_lowervp); |
88 | int nhash = UNION_HASH(uppervp, lowervp); | |
b5b5f291 | 89 | int docache = (lowervp != NULLVP || uppervp != NULLVP); |
e2a2f3a7 | 90 | |
b5b5f291 JSP |
91 | /* |
92 | * Ensure locking is ordered from lower to higher | |
93 | * to avoid deadlocks. | |
94 | */ | |
95 | if (nhash < ohash) { | |
96 | int t = ohash; | |
97 | ohash = nhash; | |
98 | nhash = t; | |
99 | } | |
58572fc0 | 100 | |
b5b5f291 | 101 | if (ohash != nhash) |
58572fc0 JSP |
102 | while (union_list_lock(ohash)) |
103 | continue; | |
104 | ||
b5b5f291 JSP |
105 | while (union_list_lock(nhash)) |
106 | continue; | |
58572fc0 | 107 | |
b5b5f291 JSP |
108 | if (ohash != nhash || !docache) { |
109 | if (un->un_flags & UN_CACHED) { | |
b5b5f291 | 110 | un->un_flags &= ~UN_CACHED; |
233b9c0e | 111 | LIST_REMOVE(un, un_cache); |
b5b5f291 | 112 | } |
58572fc0 JSP |
113 | } |
114 | ||
b5b5f291 JSP |
115 | if (ohash != nhash) |
116 | union_list_unlock(ohash); | |
117 | ||
58572fc0 JSP |
118 | if (un->un_lowervp != lowervp) { |
119 | if (un->un_lowervp) { | |
120 | vrele(un->un_lowervp); | |
121 | if (un->un_path) { | |
122 | free(un->un_path, M_TEMP); | |
123 | un->un_path = 0; | |
124 | } | |
125 | if (un->un_dirvp) { | |
126 | vrele(un->un_dirvp); | |
127 | un->un_dirvp = NULLVP; | |
128 | } | |
e2a2f3a7 | 129 | } |
58572fc0 | 130 | un->un_lowervp = lowervp; |
8a9c17f6 | 131 | un->un_lowersz = VNOVAL; |
58572fc0 JSP |
132 | } |
133 | ||
134 | if (un->un_uppervp != uppervp) { | |
135 | if (un->un_uppervp) | |
136 | vrele(un->un_uppervp); | |
137 | ||
138 | un->un_uppervp = uppervp; | |
8a9c17f6 | 139 | un->un_uppersz = VNOVAL; |
e2a2f3a7 | 140 | } |
58572fc0 | 141 | |
b5b5f291 | 142 | if (docache && (ohash != nhash)) { |
58572fc0 | 143 | LIST_INSERT_HEAD(&unhead[nhash], un, un_cache); |
b5b5f291 JSP |
144 | un->un_flags |= UN_CACHED; |
145 | } | |
58572fc0 JSP |
146 | |
147 | union_list_unlock(nhash); | |
148 | } | |
149 | ||
150 | void | |
151 | union_newlower(un, lowervp) | |
152 | struct union_node *un; | |
153 | struct vnode *lowervp; | |
154 | { | |
155 | ||
156 | union_updatevp(un, un->un_uppervp, lowervp); | |
157 | } | |
158 | ||
159 | void | |
160 | union_newupper(un, uppervp) | |
161 | struct union_node *un; | |
162 | struct vnode *uppervp; | |
163 | { | |
164 | ||
165 | union_updatevp(un, uppervp, un->un_lowervp); | |
e2a2f3a7 JSP |
166 | } |
167 | ||
8a9c17f6 JSP |
168 | /* |
169 | * Keep track of size changes in the underlying vnodes. | |
170 | * If the size changes, then callback to the vm layer | |
171 | * giving priority to the upper layer size. | |
172 | */ | |
173 | void | |
174 | union_newsize(vp, uppersz, lowersz) | |
175 | struct vnode *vp; | |
176 | off_t uppersz, lowersz; | |
177 | { | |
178 | struct union_node *un; | |
179 | off_t sz; | |
180 | ||
181 | /* only interested in regular files */ | |
182 | if (vp->v_type != VREG) | |
183 | return; | |
184 | ||
185 | un = VTOUNION(vp); | |
186 | sz = VNOVAL; | |
187 | ||
188 | if ((uppersz != VNOVAL) && (un->un_uppersz != uppersz)) { | |
189 | un->un_uppersz = uppersz; | |
190 | if (sz == VNOVAL) | |
191 | sz = un->un_uppersz; | |
192 | } | |
193 | ||
194 | if ((lowersz != VNOVAL) && (un->un_lowersz != lowersz)) { | |
195 | un->un_lowersz = lowersz; | |
196 | if (sz == VNOVAL) | |
197 | sz = un->un_lowersz; | |
198 | } | |
199 | ||
200 | if (sz != VNOVAL) { | |
201 | #ifdef UNION_DIAGNOSTIC | |
202 | printf("union: %s size now %ld\n", | |
203 | uppersz != VNOVAL ? "upper" : "lower", (long) sz); | |
204 | #endif | |
205 | vnode_pager_setsize(vp, sz); | |
206 | } | |
207 | } | |
208 | ||
b991bc2d JSP |
209 | /* |
210 | * allocate a union_node/vnode pair. the vnode is | |
01dac67e JSP |
211 | * referenced and locked. the new vnode is returned |
212 | * via (vpp). (mp) is the mountpoint of the union filesystem, | |
213 | * (dvp) is the parent directory where the upper layer object | |
214 | * should exist (but doesn't) and (cnp) is the componentname | |
215 | * information which is partially copied to allow the upper | |
216 | * layer object to be created at a later time. (uppervp) | |
217 | * and (lowervp) reference the upper and lower layer objects | |
218 | * being mapped. either, but not both, can be nil. | |
e2a2f3a7 | 219 | * if supplied, (uppervp) is locked. |
3b293975 JSP |
220 | * the reference is either maintained in the new union_node |
221 | * object which is allocated, or they are vrele'd. | |
b991bc2d JSP |
222 | * |
223 | * all union_nodes are maintained on a singly-linked | |
224 | * list. new nodes are only allocated when they cannot | |
225 | * be found on this list. entries on the list are | |
226 | * removed when the vfs reclaim entry is called. | |
227 | * | |
228 | * a single lock is kept for the entire list. this is | |
229 | * needed because the getnewvnode() function can block | |
230 | * waiting for a vnode to become free, in which case there | |
231 | * may be more than one process trying to get the same | |
232 | * vnode. this lock is only taken if we are going to | |
233 | * call getnewvnode, since the kernel itself is single-threaded. | |
234 | * | |
235 | * if an entry is found on the list, then call vget() to | |
236 | * take a reference. this is done because there may be | |
237 | * zero references to it and so it needs to removed from | |
238 | * the vnode free list. | |
239 | */ | |
240 | int | |
79f80c71 | 241 | union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp) |
b991bc2d JSP |
242 | struct vnode **vpp; |
243 | struct mount *mp; | |
64c9fefc | 244 | struct vnode *undvp; /* parent union vnode */ |
b991bc2d JSP |
245 | struct vnode *dvp; /* may be null */ |
246 | struct componentname *cnp; /* may be null */ | |
247 | struct vnode *uppervp; /* may be null */ | |
248 | struct vnode *lowervp; /* may be null */ | |
249 | { | |
250 | int error; | |
251 | struct union_node *un; | |
252 | struct union_node **pp; | |
58572fc0 | 253 | struct vnode *xlowervp = NULLVP; |
c93d29a8 | 254 | struct union_mount *um = MOUNTTOUNIONMOUNT(mp); |
58572fc0 | 255 | int hash; |
c93d29a8 | 256 | int vflag; |
58572fc0 | 257 | int try; |
01dac67e | 258 | |
58572fc0 | 259 | if (uppervp == NULLVP && lowervp == NULLVP) |
01dac67e JSP |
260 | panic("union: unidentifiable allocation"); |
261 | ||
262 | if (uppervp && lowervp && (uppervp->v_type != lowervp->v_type)) { | |
263 | xlowervp = lowervp; | |
58572fc0 | 264 | lowervp = NULLVP; |
01dac67e | 265 | } |
b991bc2d | 266 | |
c93d29a8 JSP |
267 | /* detect the root vnode (and aliases) */ |
268 | vflag = 0; | |
269 | if ((uppervp == um->um_uppervp) && | |
270 | ((lowervp == NULLVP) || lowervp == um->um_lowervp)) { | |
271 | if (lowervp == NULLVP) { | |
272 | lowervp = um->um_lowervp; | |
0b870cc8 JSP |
273 | if (lowervp != NULLVP) |
274 | VREF(lowervp); | |
c93d29a8 JSP |
275 | } |
276 | vflag = VROOT; | |
277 | } | |
278 | ||
b991bc2d | 279 | loop: |
58572fc0 JSP |
280 | for (try = 0; try < 3; try++) { |
281 | switch (try) { | |
282 | case 0: | |
283 | if (lowervp == NULLVP) | |
284 | continue; | |
285 | hash = UNION_HASH(uppervp, lowervp); | |
e2a2f3a7 | 286 | break; |
58572fc0 JSP |
287 | |
288 | case 1: | |
289 | if (uppervp == NULLVP) | |
290 | continue; | |
291 | hash = UNION_HASH(uppervp, NULLVP); | |
292 | break; | |
293 | ||
294 | case 2: | |
295 | if (lowervp == NULLVP) | |
296 | continue; | |
297 | hash = UNION_HASH(NULLVP, lowervp); | |
298 | break; | |
299 | } | |
300 | ||
301 | while (union_list_lock(hash)) | |
302 | continue; | |
303 | ||
304 | for (un = unhead[hash].lh_first; un != 0; | |
305 | un = un->un_cache.le_next) { | |
306 | if ((un->un_lowervp == lowervp || | |
307 | un->un_lowervp == NULLVP) && | |
308 | (un->un_uppervp == uppervp || | |
309 | un->un_uppervp == NULLVP) && | |
310 | (UNIONTOV(un)->v_mount == mp)) { | |
311 | if (vget(UNIONTOV(un), 0)) { | |
312 | union_list_unlock(hash); | |
313 | goto loop; | |
314 | } | |
315 | break; | |
316 | } | |
e2a2f3a7 | 317 | } |
58572fc0 JSP |
318 | |
319 | union_list_unlock(hash); | |
320 | ||
321 | if (un) | |
322 | break; | |
e2a2f3a7 | 323 | } |
ed5969c8 | 324 | |
e2a2f3a7 JSP |
325 | if (un) { |
326 | /* | |
327 | * Obtain a lock on the union_node. | |
328 | * uppervp is locked, though un->un_uppervp | |
329 | * may not be. this doesn't break the locking | |
330 | * hierarchy since in the case that un->un_uppervp | |
331 | * is not yet locked it will be vrele'd and replaced | |
332 | * with uppervp. | |
333 | */ | |
334 | ||
335 | if ((dvp != NULLVP) && (uppervp == dvp)) { | |
ed5969c8 | 336 | /* |
e2a2f3a7 JSP |
337 | * Access ``.'', so (un) will already |
338 | * be locked. Since this process has | |
339 | * the lock on (uppervp) no other | |
340 | * process can hold the lock on (un). | |
ed5969c8 | 341 | */ |
e2a2f3a7 JSP |
342 | #ifdef DIAGNOSTIC |
343 | if ((un->un_flags & UN_LOCKED) == 0) | |
344 | panic("union: . not locked"); | |
345 | else if (curproc && un->un_pid != curproc->p_pid && | |
346 | un->un_pid > -1 && curproc->p_pid > -1) | |
347 | panic("union: allocvp not lock owner"); | |
348 | #endif | |
349 | } else { | |
350 | if (un->un_flags & UN_LOCKED) { | |
351 | vrele(UNIONTOV(un)); | |
352 | un->un_flags |= UN_WANT; | |
353 | sleep((caddr_t) &un->un_flags, PINOD); | |
354 | goto loop; | |
79f80c71 | 355 | } |
e2a2f3a7 | 356 | un->un_flags |= UN_LOCKED; |
ed5969c8 | 357 | |
e2a2f3a7 JSP |
358 | #ifdef DIAGNOSTIC |
359 | if (curproc) | |
360 | un->un_pid = curproc->p_pid; | |
361 | else | |
362 | un->un_pid = -1; | |
363 | #endif | |
364 | } | |
365 | ||
366 | /* | |
367 | * At this point, the union_node is locked, | |
368 | * un->un_uppervp may not be locked, and uppervp | |
369 | * is locked or nil. | |
370 | */ | |
371 | ||
372 | /* | |
373 | * Save information about the upper layer. | |
374 | */ | |
375 | if (uppervp != un->un_uppervp) { | |
58572fc0 | 376 | union_newupper(un, uppervp); |
e2a2f3a7 JSP |
377 | } else if (uppervp) { |
378 | vrele(uppervp); | |
379 | } | |
380 | ||
381 | if (un->un_uppervp) { | |
382 | un->un_flags |= UN_ULOCK; | |
383 | un->un_flags &= ~UN_KLOCK; | |
384 | } | |
385 | ||
386 | /* | |
387 | * Save information about the lower layer. | |
388 | * This needs to keep track of pathname | |
389 | * and directory information which union_vn_create | |
390 | * might need. | |
391 | */ | |
392 | if (lowervp != un->un_lowervp) { | |
58572fc0 | 393 | union_newlower(un, lowervp); |
88edbcd4 | 394 | if (cnp && (lowervp != NULLVP)) { |
e2a2f3a7 JSP |
395 | un->un_hash = cnp->cn_hash; |
396 | un->un_path = malloc(cnp->cn_namelen+1, | |
397 | M_TEMP, M_WAITOK); | |
398 | bcopy(cnp->cn_nameptr, un->un_path, | |
399 | cnp->cn_namelen); | |
400 | un->un_path[cnp->cn_namelen] = '\0'; | |
401 | VREF(dvp); | |
402 | un->un_dirvp = dvp; | |
79f80c71 | 403 | } |
e2a2f3a7 JSP |
404 | } else if (lowervp) { |
405 | vrele(lowervp); | |
b991bc2d | 406 | } |
e2a2f3a7 JSP |
407 | *vpp = UNIONTOV(un); |
408 | return (0); | |
b991bc2d JSP |
409 | } |
410 | ||
411 | /* | |
412 | * otherwise lock the vp list while we call getnewvnode | |
413 | * since that can block. | |
414 | */ | |
58572fc0 JSP |
415 | hash = UNION_HASH(uppervp, lowervp); |
416 | ||
417 | if (union_list_lock(hash)) | |
b991bc2d | 418 | goto loop; |
b991bc2d JSP |
419 | |
420 | error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp); | |
e2a2f3a7 JSP |
421 | if (error) { |
422 | if (uppervp) { | |
423 | if (dvp == uppervp) | |
424 | vrele(uppervp); | |
425 | else | |
426 | vput(uppervp); | |
427 | } | |
428 | if (lowervp) | |
429 | vrele(lowervp); | |
430 | ||
b991bc2d | 431 | goto out; |
e2a2f3a7 | 432 | } |
b991bc2d JSP |
433 | |
434 | MALLOC((*vpp)->v_data, void *, sizeof(struct union_node), | |
435 | M_TEMP, M_WAITOK); | |
436 | ||
c93d29a8 | 437 | (*vpp)->v_flag |= vflag; |
01dac67e JSP |
438 | if (uppervp) |
439 | (*vpp)->v_type = uppervp->v_type; | |
440 | else | |
441 | (*vpp)->v_type = lowervp->v_type; | |
b991bc2d | 442 | un = VTOUNION(*vpp); |
79f80c71 | 443 | un->un_vnode = *vpp; |
b991bc2d | 444 | un->un_uppervp = uppervp; |
8a9c17f6 | 445 | un->un_uppersz = VNOVAL; |
b991bc2d | 446 | un->un_lowervp = lowervp; |
8a9c17f6 | 447 | un->un_lowersz = VNOVAL; |
64c9fefc JSP |
448 | un->un_pvp = undvp; |
449 | if (undvp != NULLVP) | |
450 | VREF(undvp); | |
15a86f7e | 451 | un->un_openl = 0; |
e2a2f3a7 JSP |
452 | un->un_flags = UN_LOCKED; |
453 | if (un->un_uppervp) | |
454 | un->un_flags |= UN_ULOCK; | |
455 | #ifdef DIAGNOSTIC | |
456 | if (curproc) | |
457 | un->un_pid = curproc->p_pid; | |
458 | else | |
459 | un->un_pid = -1; | |
460 | #endif | |
88edbcd4 | 461 | if (cnp && (lowervp != NULLVP)) { |
ed5969c8 | 462 | un->un_hash = cnp->cn_hash; |
b991bc2d JSP |
463 | un->un_path = malloc(cnp->cn_namelen+1, M_TEMP, M_WAITOK); |
464 | bcopy(cnp->cn_nameptr, un->un_path, cnp->cn_namelen); | |
465 | un->un_path[cnp->cn_namelen] = '\0'; | |
01dac67e JSP |
466 | VREF(dvp); |
467 | un->un_dirvp = dvp; | |
b991bc2d | 468 | } else { |
ed5969c8 | 469 | un->un_hash = 0; |
b991bc2d | 470 | un->un_path = 0; |
01dac67e | 471 | un->un_dirvp = 0; |
b991bc2d JSP |
472 | } |
473 | ||
58572fc0 | 474 | LIST_INSERT_HEAD(&unhead[hash], un, un_cache); |
b5b5f291 | 475 | un->un_flags |= UN_CACHED; |
b991bc2d | 476 | |
01dac67e JSP |
477 | if (xlowervp) |
478 | vrele(xlowervp); | |
479 | ||
b991bc2d | 480 | out: |
58572fc0 | 481 | union_list_unlock(hash); |
b991bc2d | 482 | |
b991bc2d JSP |
483 | return (error); |
484 | } | |
485 | ||
486 | int | |
487 | union_freevp(vp) | |
488 | struct vnode *vp; | |
489 | { | |
b991bc2d JSP |
490 | struct union_node *un = VTOUNION(vp); |
491 | ||
b5b5f291 | 492 | if (un->un_flags & UN_CACHED) { |
b5b5f291 | 493 | un->un_flags &= ~UN_CACHED; |
233b9c0e | 494 | LIST_REMOVE(un, un_cache); |
b5b5f291 | 495 | } |
58572fc0 | 496 | |
64c9fefc JSP |
497 | if (un->un_pvp != NULLVP) |
498 | vrele(un->un_pvp); | |
b5b5f291 | 499 | if (un->un_uppervp != NULLVP) |
58572fc0 | 500 | vrele(un->un_uppervp); |
b5b5f291 | 501 | if (un->un_lowervp != NULLVP) |
58572fc0 | 502 | vrele(un->un_lowervp); |
b5b5f291 | 503 | if (un->un_dirvp != NULLVP) |
58572fc0 JSP |
504 | vrele(un->un_dirvp); |
505 | if (un->un_path) | |
506 | free(un->un_path, M_TEMP); | |
b991bc2d | 507 | |
b991bc2d JSP |
508 | FREE(vp->v_data, M_TEMP); |
509 | vp->v_data = 0; | |
58572fc0 | 510 | |
b991bc2d JSP |
511 | return (0); |
512 | } | |
81be6ee0 JSP |
513 | |
514 | /* | |
515 | * copyfile. copy the vnode (fvp) to the vnode (tvp) | |
516 | * using a sequence of reads and writes. both (fvp) | |
517 | * and (tvp) are locked on entry and exit. | |
518 | */ | |
519 | int | |
f8ee1df5 | 520 | union_copyfile(fvp, tvp, cred, p) |
81be6ee0 JSP |
521 | struct vnode *fvp; |
522 | struct vnode *tvp; | |
f8ee1df5 JSP |
523 | struct ucred *cred; |
524 | struct proc *p; | |
81be6ee0 JSP |
525 | { |
526 | char *buf; | |
527 | struct uio uio; | |
528 | struct iovec iov; | |
529 | int error = 0; | |
530 | ||
531 | /* | |
532 | * strategy: | |
533 | * allocate a buffer of size MAXBSIZE. | |
534 | * loop doing reads and writes, keeping track | |
535 | * of the current uio offset. | |
536 | * give up at the first sign of trouble. | |
537 | */ | |
538 | ||
539 | uio.uio_procp = p; | |
540 | uio.uio_segflg = UIO_SYSSPACE; | |
541 | uio.uio_offset = 0; | |
542 | ||
543 | VOP_UNLOCK(fvp); /* XXX */ | |
544 | LEASE_CHECK(fvp, p, cred, LEASE_READ); | |
545 | VOP_LOCK(fvp); /* XXX */ | |
546 | VOP_UNLOCK(tvp); /* XXX */ | |
547 | LEASE_CHECK(tvp, p, cred, LEASE_WRITE); | |
548 | VOP_LOCK(tvp); /* XXX */ | |
549 | ||
550 | buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); | |
551 | ||
552 | /* ugly loop follows... */ | |
553 | do { | |
554 | off_t offset = uio.uio_offset; | |
555 | ||
556 | uio.uio_iov = &iov; | |
557 | uio.uio_iovcnt = 1; | |
558 | iov.iov_base = buf; | |
559 | iov.iov_len = MAXBSIZE; | |
560 | uio.uio_resid = iov.iov_len; | |
561 | uio.uio_rw = UIO_READ; | |
562 | error = VOP_READ(fvp, &uio, 0, cred); | |
563 | ||
564 | if (error == 0) { | |
565 | uio.uio_iov = &iov; | |
566 | uio.uio_iovcnt = 1; | |
567 | iov.iov_base = buf; | |
568 | iov.iov_len = MAXBSIZE - uio.uio_resid; | |
569 | uio.uio_offset = offset; | |
570 | uio.uio_rw = UIO_WRITE; | |
571 | uio.uio_resid = iov.iov_len; | |
572 | ||
573 | if (uio.uio_resid == 0) | |
574 | break; | |
575 | ||
576 | do { | |
577 | error = VOP_WRITE(tvp, &uio, 0, cred); | |
578 | } while ((uio.uio_resid > 0) && (error == 0)); | |
579 | } | |
580 | ||
581 | } while (error == 0); | |
582 | ||
583 | free(buf, M_TEMP); | |
584 | return (error); | |
585 | } | |
586 | ||
f8ee1df5 JSP |
587 | /* |
588 | * (un) is assumed to be locked on entry and remains | |
589 | * locked on exit. | |
590 | */ | |
591 | int | |
592 | union_copyup(un, docopy, cred, p) | |
593 | struct union_node *un; | |
594 | int docopy; | |
595 | struct ucred *cred; | |
596 | struct proc *p; | |
597 | { | |
598 | int error; | |
599 | struct vnode *lvp, *uvp; | |
600 | ||
601 | error = union_vn_create(&uvp, un, p); | |
602 | if (error) | |
603 | return (error); | |
604 | ||
605 | /* at this point, uppervp is locked */ | |
606 | union_newupper(un, uvp); | |
607 | un->un_flags |= UN_ULOCK; | |
608 | ||
609 | lvp = un->un_lowervp; | |
610 | ||
611 | if (docopy) { | |
612 | /* | |
613 | * XX - should not ignore errors | |
614 | * from VOP_CLOSE | |
615 | */ | |
616 | VOP_LOCK(lvp); | |
617 | error = VOP_OPEN(lvp, FREAD, cred, p); | |
618 | if (error == 0) { | |
619 | error = union_copyfile(lvp, uvp, cred, p); | |
620 | VOP_UNLOCK(lvp); | |
621 | (void) VOP_CLOSE(lvp, FREAD); | |
622 | } | |
623 | #ifdef UNION_DIAGNOSTIC | |
624 | if (error == 0) | |
625 | uprintf("union: copied up %s\n", un->un_path); | |
626 | #endif | |
627 | ||
628 | } | |
629 | un->un_flags &= ~UN_ULOCK; | |
630 | VOP_UNLOCK(uvp); | |
631 | union_vn_close(uvp, FWRITE, cred, p); | |
632 | VOP_LOCK(uvp); | |
633 | un->un_flags |= UN_ULOCK; | |
634 | ||
635 | /* | |
636 | * Subsequent IOs will go to the top layer, so | |
637 | * call close on the lower vnode and open on the | |
638 | * upper vnode to ensure that the filesystem keeps | |
639 | * its references counts right. This doesn't do | |
640 | * the right thing with (cred) and (FREAD) though. | |
641 | * Ignoring error returns is not right, either. | |
642 | */ | |
643 | if (error == 0) { | |
644 | int i; | |
645 | ||
646 | for (i = 0; i < un->un_openl; i++) { | |
647 | (void) VOP_CLOSE(lvp, FREAD); | |
648 | (void) VOP_OPEN(uvp, FREAD, cred, p); | |
649 | } | |
650 | un->un_openl = 0; | |
651 | } | |
652 | ||
653 | return (error); | |
654 | ||
655 | } | |
656 | ||
88edbcd4 JSP |
657 | static int |
658 | union_relookup(um, dvp, vpp, cnp, cn, path) | |
659 | struct union_mount *um; | |
660 | struct vnode *dvp; | |
661 | struct vnode **vpp; | |
662 | struct componentname *cnp; | |
663 | struct componentname *cn; | |
664 | char *path; | |
665 | { | |
666 | int error; | |
667 | ||
668 | /* | |
669 | * A new componentname structure must be faked up because | |
670 | * there is no way to know where the upper level cnp came | |
671 | * from or what it is being used for. This must duplicate | |
672 | * some of the work done by NDINIT, some of the work done | |
673 | * by namei, some of the work done by lookup and some of | |
674 | * the work done by VOP_LOOKUP when given a CREATE flag. | |
675 | * Conclusion: Horrible. | |
676 | * | |
677 | * The pathname buffer will be FREEed by VOP_MKDIR. | |
678 | */ | |
679 | cn->cn_namelen = strlen(path); | |
680 | cn->cn_pnbuf = malloc(cn->cn_namelen+1, M_NAMEI, M_WAITOK); | |
681 | bcopy(path, cn->cn_pnbuf, cn->cn_namelen); | |
682 | cn->cn_pnbuf[cn->cn_namelen] = '\0'; | |
683 | ||
684 | cn->cn_nameiop = CREATE; | |
685 | cn->cn_flags = (LOCKPARENT|HASBUF|SAVENAME|SAVESTART|ISLASTCN); | |
686 | cn->cn_proc = cnp->cn_proc; | |
687 | if (um->um_op == UNMNT_ABOVE) | |
688 | cn->cn_cred = cnp->cn_cred; | |
689 | else | |
690 | cn->cn_cred = um->um_cred; | |
691 | cn->cn_nameptr = cn->cn_pnbuf; | |
692 | cn->cn_hash = cnp->cn_hash; | |
693 | cn->cn_consume = cnp->cn_consume; | |
694 | ||
695 | VREF(dvp); | |
696 | error = relookup(dvp, vpp, cn); | |
697 | if (!error) | |
698 | vrele(dvp); | |
699 | ||
700 | return (error); | |
701 | } | |
702 | ||
3b293975 JSP |
703 | /* |
704 | * Create a shadow directory in the upper layer. | |
705 | * The new vnode is returned locked. | |
706 | * | |
707 | * (um) points to the union mount structure for access to the | |
708 | * the mounting process's credentials. | |
709 | * (dvp) is the directory in which to create the shadow directory. | |
710 | * it is unlocked on entry and exit. | |
711 | * (cnp) is the componentname to be created. | |
712 | * (vpp) is the returned newly created shadow directory, which | |
713 | * is returned locked. | |
714 | */ | |
715 | int | |
716 | union_mkshadow(um, dvp, cnp, vpp) | |
717 | struct union_mount *um; | |
718 | struct vnode *dvp; | |
719 | struct componentname *cnp; | |
720 | struct vnode **vpp; | |
721 | { | |
722 | int error; | |
723 | struct vattr va; | |
724 | struct proc *p = cnp->cn_proc; | |
725 | struct componentname cn; | |
726 | ||
88edbcd4 JSP |
727 | error = union_relookup(um, dvp, vpp, cnp, &cn, cnp->cn_nameptr); |
728 | if (error) | |
729 | return (error); | |
730 | ||
731 | if (*vpp) { | |
732 | VOP_ABORTOP(dvp, &cn); | |
733 | VOP_UNLOCK(dvp); | |
734 | vrele(*vpp); | |
735 | *vpp = NULLVP; | |
736 | return (EEXIST); | |
737 | } | |
738 | ||
3b293975 JSP |
739 | /* |
740 | * policy: when creating the shadow directory in the | |
692a90df JSP |
741 | * upper layer, create it owned by the user who did |
742 | * the mount, group from parent directory, and mode | |
743 | * 777 modified by umask (ie mostly identical to the | |
744 | * mkdir syscall). (jsp, kb) | |
3b293975 JSP |
745 | */ |
746 | ||
88edbcd4 JSP |
747 | VATTR_NULL(&va); |
748 | va.va_type = VDIR; | |
749 | va.va_mode = um->um_cmode; | |
3b293975 | 750 | |
88edbcd4 JSP |
751 | /* LEASE_CHECK: dvp is locked */ |
752 | LEASE_CHECK(dvp, p, cn.cn_cred, LEASE_WRITE); | |
3b293975 | 753 | |
88edbcd4 JSP |
754 | error = VOP_MKDIR(dvp, vpp, &cn, &va); |
755 | return (error); | |
756 | } | |
757 | ||
758 | /* | |
759 | * Create a whiteout entry in the upper layer. | |
760 | * | |
761 | * (um) points to the union mount structure for access to the | |
762 | * the mounting process's credentials. | |
763 | * (dvp) is the directory in which to create the whiteout. | |
764 | * it is locked on entry and exit. | |
765 | * (cnp) is the componentname to be created. | |
766 | */ | |
767 | int | |
768 | union_mkwhiteout(um, dvp, cnp, path) | |
769 | struct union_mount *um; | |
770 | struct vnode *dvp; | |
771 | struct componentname *cnp; | |
772 | char *path; | |
773 | { | |
774 | int error; | |
775 | struct vattr va; | |
776 | struct proc *p = cnp->cn_proc; | |
777 | struct vnode **vpp; | |
778 | struct componentname cn; | |
779 | ||
780 | VOP_UNLOCK(dvp); | |
781 | error = union_relookup(um, dvp, vpp, cnp, &cn, path); | |
782 | if (error) | |
3b293975 JSP |
783 | return (error); |
784 | ||
785 | if (*vpp) { | |
786 | VOP_ABORTOP(dvp, &cn); | |
88edbcd4 | 787 | vrele(dvp); |
3b293975 JSP |
788 | vrele(*vpp); |
789 | *vpp = NULLVP; | |
790 | return (EEXIST); | |
791 | } | |
792 | ||
3b293975 JSP |
793 | /* LEASE_CHECK: dvp is locked */ |
794 | LEASE_CHECK(dvp, p, p->p_ucred, LEASE_WRITE); | |
795 | ||
88edbcd4 JSP |
796 | error = VOP_WHITEOUT(dvp, &cn, CREATE); |
797 | if (error != 0) | |
798 | VOP_ABORTOP(dvp, &cn); | |
799 | ||
800 | vrele(dvp); | |
801 | ||
3b293975 JSP |
802 | return (error); |
803 | } | |
804 | ||
81be6ee0 JSP |
805 | /* |
806 | * union_vn_create: creates and opens a new shadow file | |
807 | * on the upper union layer. this function is similar | |
808 | * in spirit to calling vn_open but it avoids calling namei(). | |
809 | * the problem with calling namei is that a) it locks too many | |
810 | * things, and b) it doesn't start at the "right" directory, | |
811 | * whereas relookup is told where to start. | |
812 | */ | |
813 | int | |
3b293975 | 814 | union_vn_create(vpp, un, p) |
81be6ee0 JSP |
815 | struct vnode **vpp; |
816 | struct union_node *un; | |
81be6ee0 JSP |
817 | struct proc *p; |
818 | { | |
819 | struct vnode *vp; | |
820 | struct ucred *cred = p->p_ucred; | |
821 | struct vattr vat; | |
822 | struct vattr *vap = &vat; | |
823 | int fmode = FFLAGS(O_WRONLY|O_CREAT|O_TRUNC|O_EXCL); | |
824 | int error; | |
ed5969c8 | 825 | int cmode = UN_FILEMODE & ~p->p_fd->fd_cmask; |
81be6ee0 JSP |
826 | char *cp; |
827 | struct componentname cn; | |
828 | ||
829 | *vpp = NULLVP; | |
830 | ||
692a90df JSP |
831 | /* |
832 | * Build a new componentname structure (for the same | |
833 | * reasons outlines in union_mkshadow). | |
834 | * The difference here is that the file is owned by | |
835 | * the current user, rather than by the person who | |
836 | * did the mount, since the current user needs to be | |
837 | * able to write the file (that's why it is being | |
838 | * copied in the first place). | |
839 | */ | |
81be6ee0 JSP |
840 | cn.cn_namelen = strlen(un->un_path); |
841 | cn.cn_pnbuf = (caddr_t) malloc(cn.cn_namelen, M_NAMEI, M_WAITOK); | |
842 | bcopy(un->un_path, cn.cn_pnbuf, cn.cn_namelen+1); | |
843 | cn.cn_nameiop = CREATE; | |
bf006388 | 844 | cn.cn_flags = (LOCKPARENT|HASBUF|SAVENAME|SAVESTART|ISLASTCN); |
81be6ee0 JSP |
845 | cn.cn_proc = p; |
846 | cn.cn_cred = p->p_ucred; | |
847 | cn.cn_nameptr = cn.cn_pnbuf; | |
ed5969c8 | 848 | cn.cn_hash = un->un_hash; |
81be6ee0 JSP |
849 | cn.cn_consume = 0; |
850 | ||
ed5969c8 | 851 | VREF(un->un_dirvp); |
81be6ee0 JSP |
852 | if (error = relookup(un->un_dirvp, &vp, &cn)) |
853 | return (error); | |
ed5969c8 JSP |
854 | vrele(un->un_dirvp); |
855 | ||
bf006388 | 856 | if (vp) { |
81be6ee0 JSP |
857 | VOP_ABORTOP(un->un_dirvp, &cn); |
858 | if (un->un_dirvp == vp) | |
859 | vrele(un->un_dirvp); | |
860 | else | |
bf006388 JSP |
861 | vput(un->un_dirvp); |
862 | vrele(vp); | |
863 | return (EEXIST); | |
81be6ee0 JSP |
864 | } |
865 | ||
bf006388 JSP |
866 | /* |
867 | * Good - there was no race to create the file | |
868 | * so go ahead and create it. The permissions | |
869 | * on the file will be 0666 modified by the | |
870 | * current user's umask. Access to the file, while | |
871 | * it is unioned, will require access to the top *and* | |
872 | * bottom files. Access when not unioned will simply | |
873 | * require access to the top-level file. | |
874 | * TODO: confirm choice of access permissions. | |
875 | */ | |
81be6ee0 | 876 | VATTR_NULL(vap); |
bf006388 JSP |
877 | vap->va_type = VREG; |
878 | vap->va_mode = cmode; | |
879 | LEASE_CHECK(un->un_dirvp, p, cred, LEASE_WRITE); | |
880 | if (error = VOP_CREATE(un->un_dirvp, &vp, &cn, vap)) | |
881 | return (error); | |
81be6ee0 | 882 | |
bf006388 JSP |
883 | if (error = VOP_OPEN(vp, fmode, cred, p)) { |
884 | vput(vp); | |
885 | return (error); | |
886 | } | |
81be6ee0 JSP |
887 | |
888 | vp->v_writecount++; | |
889 | *vpp = vp; | |
890 | return (0); | |
81be6ee0 | 891 | } |
ed5969c8 JSP |
892 | |
893 | int | |
15a86f7e | 894 | union_vn_close(vp, fmode, cred, p) |
ed5969c8 JSP |
895 | struct vnode *vp; |
896 | int fmode; | |
15a86f7e JSP |
897 | struct ucred *cred; |
898 | struct proc *p; | |
ed5969c8 | 899 | { |
88edbcd4 | 900 | |
ed5969c8 JSP |
901 | if (fmode & FWRITE) |
902 | --vp->v_writecount; | |
903 | return (VOP_CLOSE(vp, fmode)); | |
904 | } | |
905 | ||
906 | void | |
907 | union_removed_upper(un) | |
908 | struct union_node *un; | |
909 | { | |
233b9c0e | 910 | |
e2a2f3a7 JSP |
911 | if (un->un_flags & UN_ULOCK) { |
912 | un->un_flags &= ~UN_ULOCK; | |
58572fc0 | 913 | VOP_UNLOCK(un->un_uppervp); |
e2a2f3a7 | 914 | } |
58572fc0 | 915 | |
233b9c0e JSP |
916 | if (un->un_flags & UN_CACHED) { |
917 | un->un_flags &= ~UN_CACHED; | |
918 | LIST_REMOVE(un, un_cache); | |
919 | } | |
ed5969c8 | 920 | } |
15a86f7e JSP |
921 | |
922 | struct vnode * | |
923 | union_lowervp(vp) | |
924 | struct vnode *vp; | |
925 | { | |
926 | struct union_node *un = VTOUNION(vp); | |
927 | ||
f8ee1df5 JSP |
928 | if ((un->un_lowervp != NULLVP) && |
929 | (vp->v_type == un->un_lowervp->v_type)) { | |
930 | if (vget(un->un_lowervp, 0) == 0) | |
931 | return (un->un_lowervp); | |
15a86f7e JSP |
932 | } |
933 | ||
f8ee1df5 | 934 | return (NULLVP); |
15a86f7e | 935 | } |