1 /* dir.c: AFS filesystem directory handling
2 *
3 * Copyright (C) 2002, 2018 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/fs.h>
14 #include <linux/namei.h>
15 #include <linux/pagemap.h>
16 #include <linux/swap.h>
17 #include <linux/ctype.h>
18 #include <linux/sched.h>
19 #include <linux/task_io_accounting_ops.h>
20 #include "internal.h"
21 #include "xdr_fs.h"
22
23 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
24 unsigned int flags);
25 static int afs_dir_open(struct inode *inode, struct file *file);
26 static int afs_readdir(struct file *file, struct dir_context *ctx);
27 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
28 static int afs_d_delete(const struct dentry *dentry);
29 static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen,
30 loff_t fpos, u64 ino, unsigned dtype);
31 static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
32 loff_t fpos, u64 ino, unsigned dtype);
33 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
34 bool excl);
35 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
36 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
37 static int afs_unlink(struct inode *dir, struct dentry *dentry);
38 static int afs_link(struct dentry *from, struct inode *dir,
39 struct dentry *dentry);
40 static int afs_symlink(struct inode *dir, struct dentry *dentry,
41 const char *content);
42 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
43 struct inode *new_dir, struct dentry *new_dentry,
44 unsigned int flags);
45 static int afs_dir_releasepage(struct page *page, gfp_t gfp_flags);
46 static void afs_dir_invalidatepage(struct page *page, unsigned int offset,
47 unsigned int length);
48
afs_dir_set_page_dirty(struct page * page)49 static int afs_dir_set_page_dirty(struct page *page)
50 {
51 BUG(); /* This should never happen. */
52 }
53
54 const struct file_operations afs_dir_file_operations = {
55 .open = afs_dir_open,
56 .release = afs_release,
57 .iterate_shared = afs_readdir,
58 .lock = afs_lock,
59 .llseek = generic_file_llseek,
60 };
61
62 const struct inode_operations afs_dir_inode_operations = {
63 .create = afs_create,
64 .lookup = afs_lookup,
65 .link = afs_link,
66 .unlink = afs_unlink,
67 .symlink = afs_symlink,
68 .mkdir = afs_mkdir,
69 .rmdir = afs_rmdir,
70 .rename = afs_rename,
71 .permission = afs_permission,
72 .getattr = afs_getattr,
73 .setattr = afs_setattr,
74 .listxattr = afs_listxattr,
75 };
76
77 const struct address_space_operations afs_dir_aops = {
78 .set_page_dirty = afs_dir_set_page_dirty,
79 .releasepage = afs_dir_releasepage,
80 .invalidatepage = afs_dir_invalidatepage,
81 };
82
83 const struct dentry_operations afs_fs_dentry_operations = {
84 .d_revalidate = afs_d_revalidate,
85 .d_delete = afs_d_delete,
86 .d_release = afs_d_release,
87 .d_automount = afs_d_automount,
88 };
89
90 struct afs_lookup_one_cookie {
91 struct dir_context ctx;
92 struct qstr name;
93 bool found;
94 struct afs_fid fid;
95 };
96
97 struct afs_lookup_cookie {
98 struct dir_context ctx;
99 struct qstr name;
100 bool found;
101 bool one_only;
102 unsigned short nr_fids;
103 struct afs_file_status *statuses;
104 struct afs_callback *callbacks;
105 struct afs_fid fids[50];
106 };
107
108 /*
109 * check that a directory page is valid
110 */
afs_dir_check_page(struct afs_vnode * dvnode,struct page * page,loff_t i_size)111 static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
112 loff_t i_size)
113 {
114 struct afs_xdr_dir_page *dbuf;
115 loff_t latter, off;
116 int tmp, qty;
117
118 /* Determine how many magic numbers there should be in this page, but
119 * we must take care because the directory may change size under us.
120 */
121 off = page_offset(page);
122 if (i_size <= off)
123 goto checked;
124
125 latter = i_size - off;
126 if (latter >= PAGE_SIZE)
127 qty = PAGE_SIZE;
128 else
129 qty = latter;
130 qty /= sizeof(union afs_xdr_dir_block);
131
132 /* check them */
133 dbuf = kmap(page);
134 for (tmp = 0; tmp < qty; tmp++) {
135 if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
136 printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
137 __func__, dvnode->vfs_inode.i_ino, tmp, qty,
138 ntohs(dbuf->blocks[tmp].hdr.magic));
139 trace_afs_dir_check_failed(dvnode, off, i_size);
140 kunmap(page);
141 goto error;
142 }
143
144 /* Make sure each block is NUL terminated so we can reasonably
145 * use string functions on it. The filenames in the page
146 * *should* be NUL-terminated anyway.
147 */
148 ((u8 *)&dbuf->blocks[tmp])[AFS_DIR_BLOCK_SIZE - 1] = 0;
149 }
150
151 kunmap(page);
152
153 checked:
154 afs_stat_v(dvnode, n_read_dir);
155 return true;
156
157 error:
158 return false;
159 }
160
161 /*
162 * open an AFS directory file
163 */
afs_dir_open(struct inode * inode,struct file * file)164 static int afs_dir_open(struct inode *inode, struct file *file)
165 {
166 _enter("{%lu}", inode->i_ino);
167
168 BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
169 BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
170
171 if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
172 return -ENOENT;
173
174 return afs_open(inode, file);
175 }
176
177 /*
178 * Read the directory into the pagecache in one go, scrubbing the previous
179 * contents. The list of pages is returned, pinning them so that they don't
180 * get reclaimed during the iteration.
181 */
afs_read_dir(struct afs_vnode * dvnode,struct key * key)182 static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
183 __acquires(&dvnode->validate_lock)
184 {
185 struct afs_read *req;
186 loff_t i_size;
187 int nr_pages, nr_inline, i, n;
188 int ret = -ENOMEM;
189
190 retry:
191 i_size = i_size_read(&dvnode->vfs_inode);
192 if (i_size < 2048)
193 return ERR_PTR(-EIO);
194 if (i_size > 2048 * 1024)
195 return ERR_PTR(-EFBIG);
196
197 _enter("%llu", i_size);
198
199 /* Get a request record to hold the page list. We want to hold it
200 * inline if we can, but we don't want to make an order 1 allocation.
201 */
202 nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;
203 nr_inline = nr_pages;
204 if (nr_inline > (PAGE_SIZE - sizeof(*req)) / sizeof(struct page *))
205 nr_inline = 0;
206
207 req = kzalloc(sizeof(*req) + sizeof(struct page *) * nr_inline,
208 GFP_KERNEL);
209 if (!req)
210 return ERR_PTR(-ENOMEM);
211
212 refcount_set(&req->usage, 1);
213 req->nr_pages = nr_pages;
214 req->actual_len = i_size; /* May change */
215 req->len = nr_pages * PAGE_SIZE; /* We can ask for more than there is */
216 req->data_version = dvnode->status.data_version; /* May change */
217 if (nr_inline > 0) {
218 req->pages = req->array;
219 } else {
220 req->pages = kcalloc(nr_pages, sizeof(struct page *),
221 GFP_KERNEL);
222 if (!req->pages)
223 goto error;
224 }
225
226 /* Get a list of all the pages that hold or will hold the directory
227 * content. We need to fill in any gaps that we might find where the
228 * memory reclaimer has been at work. If there are any gaps, we will
229 * need to reread the entire directory contents.
230 */
231 i = 0;
232 do {
233 n = find_get_pages_contig(dvnode->vfs_inode.i_mapping, i,
234 req->nr_pages - i,
235 req->pages + i);
236 _debug("find %u at %u/%u", n, i, req->nr_pages);
237 if (n == 0) {
238 gfp_t gfp = dvnode->vfs_inode.i_mapping->gfp_mask;
239
240 if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
241 afs_stat_v(dvnode, n_inval);
242
243 ret = -ENOMEM;
244 req->pages[i] = __page_cache_alloc(gfp);
245 if (!req->pages[i])
246 goto error;
247 ret = add_to_page_cache_lru(req->pages[i],
248 dvnode->vfs_inode.i_mapping,
249 i, gfp);
250 if (ret < 0)
251 goto error;
252
253 set_page_private(req->pages[i], 1);
254 SetPagePrivate(req->pages[i]);
255 unlock_page(req->pages[i]);
256 i++;
257 } else {
258 i += n;
259 }
260 } while (i < req->nr_pages);
261
262 /* If we're going to reload, we need to lock all the pages to prevent
263 * races.
264 */
265 ret = -ERESTARTSYS;
266 if (down_read_killable(&dvnode->validate_lock) < 0)
267 goto error;
268
269 if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
270 goto success;
271
272 up_read(&dvnode->validate_lock);
273 if (down_write_killable(&dvnode->validate_lock) < 0)
274 goto error;
275
276 if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
277 ret = afs_fetch_data(dvnode, key, req);
278 if (ret < 0)
279 goto error_unlock;
280
281 task_io_account_read(PAGE_SIZE * req->nr_pages);
282
283 if (req->len < req->file_size)
284 goto content_has_grown;
285
286 /* Validate the data we just read. */
287 ret = -EIO;
288 for (i = 0; i < req->nr_pages; i++)
289 if (!afs_dir_check_page(dvnode, req->pages[i],
290 req->actual_len))
291 goto error_unlock;
292
293 // TODO: Trim excess pages
294
295 set_bit(AFS_VNODE_DIR_VALID, &dvnode->flags);
296 }
297
298 downgrade_write(&dvnode->validate_lock);
299 success:
300 return req;
301
302 error_unlock:
303 up_write(&dvnode->validate_lock);
304 error:
305 afs_put_read(req);
306 _leave(" = %d", ret);
307 return ERR_PTR(ret);
308
309 content_has_grown:
310 up_write(&dvnode->validate_lock);
311 afs_put_read(req);
312 goto retry;
313 }
314
315 /*
316 * deal with one block in an AFS directory
317 */
afs_dir_iterate_block(struct dir_context * ctx,union afs_xdr_dir_block * block,unsigned blkoff)318 static int afs_dir_iterate_block(struct dir_context *ctx,
319 union afs_xdr_dir_block *block,
320 unsigned blkoff)
321 {
322 union afs_xdr_dirent *dire;
323 unsigned offset, next, curr;
324 size_t nlen;
325 int tmp;
326
327 _enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block);
328
329 curr = (ctx->pos - blkoff) / sizeof(union afs_xdr_dirent);
330
331 /* walk through the block, an entry at a time */
332 for (offset = (blkoff == 0 ? AFS_DIR_RESV_BLOCKS0 : AFS_DIR_RESV_BLOCKS);
333 offset < AFS_DIR_SLOTS_PER_BLOCK;
334 offset = next
335 ) {
336 next = offset + 1;
337
338 /* skip entries marked unused in the bitmap */
339 if (!(block->hdr.bitmap[offset / 8] &
340 (1 << (offset % 8)))) {
341 _debug("ENT[%zu.%u]: unused",
342 blkoff / sizeof(union afs_xdr_dir_block), offset);
343 if (offset >= curr)
344 ctx->pos = blkoff +
345 next * sizeof(union afs_xdr_dirent);
346 continue;
347 }
348
349 /* got a valid entry */
350 dire = &block->dirents[offset];
351 nlen = strnlen(dire->u.name,
352 sizeof(*block) -
353 offset * sizeof(union afs_xdr_dirent));
354
355 _debug("ENT[%zu.%u]: %s %zu \"%s\"",
356 blkoff / sizeof(union afs_xdr_dir_block), offset,
357 (offset < curr ? "skip" : "fill"),
358 nlen, dire->u.name);
359
360 /* work out where the next possible entry is */
361 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_xdr_dirent)) {
362 if (next >= AFS_DIR_SLOTS_PER_BLOCK) {
363 _debug("ENT[%zu.%u]:"
364 " %u travelled beyond end dir block"
365 " (len %u/%zu)",
366 blkoff / sizeof(union afs_xdr_dir_block),
367 offset, next, tmp, nlen);
368 return -EIO;
369 }
370 if (!(block->hdr.bitmap[next / 8] &
371 (1 << (next % 8)))) {
372 _debug("ENT[%zu.%u]:"
373 " %u unmarked extension (len %u/%zu)",
374 blkoff / sizeof(union afs_xdr_dir_block),
375 offset, next, tmp, nlen);
376 return -EIO;
377 }
378
379 _debug("ENT[%zu.%u]: ext %u/%zu",
380 blkoff / sizeof(union afs_xdr_dir_block),
381 next, tmp, nlen);
382 next++;
383 }
384
385 /* skip if starts before the current position */
386 if (offset < curr)
387 continue;
388
389 /* found the next entry */
390 if (!dir_emit(ctx, dire->u.name, nlen,
391 ntohl(dire->u.vnode),
392 (ctx->actor == afs_lookup_filldir ||
393 ctx->actor == afs_lookup_one_filldir)?
394 ntohl(dire->u.unique) : DT_UNKNOWN)) {
395 _leave(" = 0 [full]");
396 return 0;
397 }
398
399 ctx->pos = blkoff + next * sizeof(union afs_xdr_dirent);
400 }
401
402 _leave(" = 1 [more]");
403 return 1;
404 }
405
406 /*
407 * iterate through the data blob that lists the contents of an AFS directory
408 */
afs_dir_iterate(struct inode * dir,struct dir_context * ctx,struct key * key)409 static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
410 struct key *key)
411 {
412 struct afs_vnode *dvnode = AFS_FS_I(dir);
413 struct afs_xdr_dir_page *dbuf;
414 union afs_xdr_dir_block *dblock;
415 struct afs_read *req;
416 struct page *page;
417 unsigned blkoff, limit;
418 int ret;
419
420 _enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
421
422 if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
423 _leave(" = -ESTALE");
424 return -ESTALE;
425 }
426
427 req = afs_read_dir(dvnode, key);
428 if (IS_ERR(req))
429 return PTR_ERR(req);
430
431 /* round the file position up to the next entry boundary */
432 ctx->pos += sizeof(union afs_xdr_dirent) - 1;
433 ctx->pos &= ~(sizeof(union afs_xdr_dirent) - 1);
434
435 /* walk through the blocks in sequence */
436 ret = 0;
437 while (ctx->pos < req->actual_len) {
438 blkoff = ctx->pos & ~(sizeof(union afs_xdr_dir_block) - 1);
439
440 /* Fetch the appropriate page from the directory and re-add it
441 * to the LRU.
442 */
443 page = req->pages[blkoff / PAGE_SIZE];
444 if (!page) {
445 ret = -EIO;
446 break;
447 }
448 mark_page_accessed(page);
449
450 limit = blkoff & ~(PAGE_SIZE - 1);
451
452 dbuf = kmap(page);
453
454 /* deal with the individual blocks stashed on this page */
455 do {
456 dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
457 sizeof(union afs_xdr_dir_block)];
458 ret = afs_dir_iterate_block(ctx, dblock, blkoff);
459 if (ret != 1) {
460 kunmap(page);
461 goto out;
462 }
463
464 blkoff += sizeof(union afs_xdr_dir_block);
465
466 } while (ctx->pos < dir->i_size && blkoff < limit);
467
468 kunmap(page);
469 ret = 0;
470 }
471
472 out:
473 up_read(&dvnode->validate_lock);
474 afs_put_read(req);
475 _leave(" = %d", ret);
476 return ret;
477 }
478
479 /*
480 * read an AFS directory
481 */
afs_readdir(struct file * file,struct dir_context * ctx)482 static int afs_readdir(struct file *file, struct dir_context *ctx)
483 {
484 return afs_dir_iterate(file_inode(file), ctx, afs_file_key(file));
485 }
486
487 /*
488 * Search the directory for a single name
489 * - if afs_dir_iterate_block() spots this function, it'll pass the FID
490 * uniquifier through dtype
491 */
afs_lookup_one_filldir(struct dir_context * ctx,const char * name,int nlen,loff_t fpos,u64 ino,unsigned dtype)492 static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name,
493 int nlen, loff_t fpos, u64 ino, unsigned dtype)
494 {
495 struct afs_lookup_one_cookie *cookie =
496 container_of(ctx, struct afs_lookup_one_cookie, ctx);
497
498 _enter("{%s,%u},%s,%u,,%llu,%u",
499 cookie->name.name, cookie->name.len, name, nlen,
500 (unsigned long long) ino, dtype);
501
502 /* insanity checks first */
503 BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
504 BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
505
506 if (cookie->name.len != nlen ||
507 memcmp(cookie->name.name, name, nlen) != 0) {
508 _leave(" = 0 [no]");
509 return 0;
510 }
511
512 cookie->fid.vnode = ino;
513 cookie->fid.unique = dtype;
514 cookie->found = 1;
515
516 _leave(" = -1 [found]");
517 return -1;
518 }
519
520 /*
521 * Do a lookup of a single name in a directory
522 * - just returns the FID the dentry name maps to if found
523 */
afs_do_lookup_one(struct inode * dir,struct dentry * dentry,struct afs_fid * fid,struct key * key)524 static int afs_do_lookup_one(struct inode *dir, struct dentry *dentry,
525 struct afs_fid *fid, struct key *key)
526 {
527 struct afs_super_info *as = dir->i_sb->s_fs_info;
528 struct afs_lookup_one_cookie cookie = {
529 .ctx.actor = afs_lookup_one_filldir,
530 .name = dentry->d_name,
531 .fid.vid = as->volume->vid
532 };
533 int ret;
534
535 _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
536
537 /* search the directory */
538 ret = afs_dir_iterate(dir, &cookie.ctx, key);
539 if (ret < 0) {
540 _leave(" = %d [iter]", ret);
541 return ret;
542 }
543
544 ret = -ENOENT;
545 if (!cookie.found) {
546 _leave(" = -ENOENT [not found]");
547 return -ENOENT;
548 }
549
550 *fid = cookie.fid;
551 _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
552 return 0;
553 }
554
555 /*
556 * search the directory for a name
557 * - if afs_dir_iterate_block() spots this function, it'll pass the FID
558 * uniquifier through dtype
559 */
afs_lookup_filldir(struct dir_context * ctx,const char * name,int nlen,loff_t fpos,u64 ino,unsigned dtype)560 static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
561 int nlen, loff_t fpos, u64 ino, unsigned dtype)
562 {
563 struct afs_lookup_cookie *cookie =
564 container_of(ctx, struct afs_lookup_cookie, ctx);
565 int ret;
566
567 _enter("{%s,%u},%s,%u,,%llu,%u",
568 cookie->name.name, cookie->name.len, name, nlen,
569 (unsigned long long) ino, dtype);
570
571 /* insanity checks first */
572 BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
573 BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
574
575 if (cookie->found) {
576 if (cookie->nr_fids < 50) {
577 cookie->fids[cookie->nr_fids].vnode = ino;
578 cookie->fids[cookie->nr_fids].unique = dtype;
579 cookie->nr_fids++;
580 }
581 } else if (cookie->name.len == nlen &&
582 memcmp(cookie->name.name, name, nlen) == 0) {
583 cookie->fids[0].vnode = ino;
584 cookie->fids[0].unique = dtype;
585 cookie->found = 1;
586 if (cookie->one_only)
587 return -1;
588 }
589
590 ret = cookie->nr_fids >= 50 ? -1 : 0;
591 _leave(" = %d", ret);
592 return ret;
593 }
594
595 /*
596 * Do a lookup in a directory. We make use of bulk lookup to query a slew of
597 * files in one go and create inodes for them. The inode of the file we were
598 * asked for is returned.
599 */
afs_do_lookup(struct inode * dir,struct dentry * dentry,struct key * key)600 static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry,
601 struct key *key)
602 {
603 struct afs_lookup_cookie *cookie;
604 struct afs_cb_interest *cbi = NULL;
605 struct afs_super_info *as = dir->i_sb->s_fs_info;
606 struct afs_iget_data data;
607 struct afs_fs_cursor fc;
608 struct afs_vnode *dvnode = AFS_FS_I(dir);
609 struct inode *inode = NULL;
610 int ret, i;
611
612 _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
613
614 cookie = kzalloc(sizeof(struct afs_lookup_cookie), GFP_KERNEL);
615 if (!cookie)
616 return ERR_PTR(-ENOMEM);
617
618 cookie->ctx.actor = afs_lookup_filldir;
619 cookie->name = dentry->d_name;
620 cookie->nr_fids = 1; /* slot 0 is saved for the fid we actually want */
621
622 read_seqlock_excl(&dvnode->cb_lock);
623 if (dvnode->cb_interest &&
624 dvnode->cb_interest->server &&
625 test_bit(AFS_SERVER_FL_NO_IBULK, &dvnode->cb_interest->server->flags))
626 cookie->one_only = true;
627 read_sequnlock_excl(&dvnode->cb_lock);
628
629 for (i = 0; i < 50; i++)
630 cookie->fids[i].vid = as->volume->vid;
631
632 /* search the directory */
633 ret = afs_dir_iterate(dir, &cookie->ctx, key);
634 if (ret < 0) {
635 inode = ERR_PTR(ret);
636 goto out;
637 }
638
639 inode = ERR_PTR(-ENOENT);
640 if (!cookie->found)
641 goto out;
642
643 /* Check to see if we already have an inode for the primary fid. */
644 data.volume = dvnode->volume;
645 data.fid = cookie->fids[0];
646 inode = ilookup5(dir->i_sb, cookie->fids[0].vnode, afs_iget5_test, &data);
647 if (inode)
648 goto out;
649
650 /* Need space for examining all the selected files */
651 inode = ERR_PTR(-ENOMEM);
652 cookie->statuses = kcalloc(cookie->nr_fids, sizeof(struct afs_file_status),
653 GFP_KERNEL);
654 if (!cookie->statuses)
655 goto out;
656
657 cookie->callbacks = kcalloc(cookie->nr_fids, sizeof(struct afs_callback),
658 GFP_KERNEL);
659 if (!cookie->callbacks)
660 goto out_s;
661
662 /* Try FS.InlineBulkStatus first. Abort codes for the individual
663 * lookups contained therein are stored in the reply without aborting
664 * the whole operation.
665 */
666 if (cookie->one_only)
667 goto no_inline_bulk_status;
668
669 inode = ERR_PTR(-ERESTARTSYS);
670 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
671 while (afs_select_fileserver(&fc)) {
672 if (test_bit(AFS_SERVER_FL_NO_IBULK,
673 &fc.cbi->server->flags)) {
674 fc.ac.abort_code = RX_INVALID_OPERATION;
675 fc.ac.error = -ECONNABORTED;
676 break;
677 }
678 afs_fs_inline_bulk_status(&fc,
679 afs_v2net(dvnode),
680 cookie->fids,
681 cookie->statuses,
682 cookie->callbacks,
683 cookie->nr_fids, NULL);
684 }
685
686 if (fc.ac.error == 0)
687 cbi = afs_get_cb_interest(fc.cbi);
688 if (fc.ac.abort_code == RX_INVALID_OPERATION)
689 set_bit(AFS_SERVER_FL_NO_IBULK, &fc.cbi->server->flags);
690 inode = ERR_PTR(afs_end_vnode_operation(&fc));
691 }
692
693 if (!IS_ERR(inode))
694 goto success;
695 if (fc.ac.abort_code != RX_INVALID_OPERATION)
696 goto out_c;
697
698 no_inline_bulk_status:
699 /* We could try FS.BulkStatus next, but this aborts the entire op if
700 * any of the lookups fails - so, for the moment, revert to
701 * FS.FetchStatus for just the primary fid.
702 */
703 cookie->nr_fids = 1;
704 inode = ERR_PTR(-ERESTARTSYS);
705 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
706 while (afs_select_fileserver(&fc)) {
707 afs_fs_fetch_status(&fc,
708 afs_v2net(dvnode),
709 cookie->fids,
710 cookie->statuses,
711 cookie->callbacks,
712 NULL);
713 }
714
715 if (fc.ac.error == 0)
716 cbi = afs_get_cb_interest(fc.cbi);
717 inode = ERR_PTR(afs_end_vnode_operation(&fc));
718 }
719
720 if (IS_ERR(inode))
721 goto out_c;
722
723 for (i = 0; i < cookie->nr_fids; i++)
724 cookie->statuses[i].abort_code = 0;
725
726 success:
727 /* Turn all the files into inodes and save the first one - which is the
728 * one we actually want.
729 */
730 if (cookie->statuses[0].abort_code != 0)
731 inode = ERR_PTR(afs_abort_to_error(cookie->statuses[0].abort_code));
732
733 for (i = 0; i < cookie->nr_fids; i++) {
734 struct inode *ti;
735
736 if (cookie->statuses[i].abort_code != 0)
737 continue;
738
739 ti = afs_iget(dir->i_sb, key, &cookie->fids[i],
740 &cookie->statuses[i],
741 &cookie->callbacks[i],
742 cbi);
743 if (i == 0) {
744 inode = ti;
745 } else {
746 if (!IS_ERR(ti))
747 iput(ti);
748 }
749 }
750
751 out_c:
752 afs_put_cb_interest(afs_v2net(dvnode), cbi);
753 kfree(cookie->callbacks);
754 out_s:
755 kfree(cookie->statuses);
756 out:
757 kfree(cookie);
758 return inode;
759 }
760
761 /*
762 * Look up an entry in a directory with @sys substitution.
763 */
afs_lookup_atsys(struct inode * dir,struct dentry * dentry,struct key * key)764 static struct dentry *afs_lookup_atsys(struct inode *dir, struct dentry *dentry,
765 struct key *key)
766 {
767 struct afs_sysnames *subs;
768 struct afs_net *net = afs_i2net(dir);
769 struct dentry *ret;
770 char *buf, *p, *name;
771 int len, i;
772
773 _enter("");
774
775 ret = ERR_PTR(-ENOMEM);
776 p = buf = kmalloc(AFSNAMEMAX, GFP_KERNEL);
777 if (!buf)
778 goto out_p;
779 if (dentry->d_name.len > 4) {
780 memcpy(p, dentry->d_name.name, dentry->d_name.len - 4);
781 p += dentry->d_name.len - 4;
782 }
783
784 /* There is an ordered list of substitutes that we have to try. */
785 read_lock(&net->sysnames_lock);
786 subs = net->sysnames;
787 refcount_inc(&subs->usage);
788 read_unlock(&net->sysnames_lock);
789
790 for (i = 0; i < subs->nr; i++) {
791 name = subs->subs[i];
792 len = dentry->d_name.len - 4 + strlen(name);
793 if (len >= AFSNAMEMAX) {
794 ret = ERR_PTR(-ENAMETOOLONG);
795 goto out_s;
796 }
797
798 strcpy(p, name);
799 ret = lookup_one_len(buf, dentry->d_parent, len);
800 if (IS_ERR(ret) || d_is_positive(ret))
801 goto out_s;
802 dput(ret);
803 }
804
805 /* We don't want to d_add() the @sys dentry here as we don't want to
806 * the cached dentry to hide changes to the sysnames list.
807 */
808 ret = NULL;
809 out_s:
810 afs_put_sysnames(subs);
811 kfree(buf);
812 out_p:
813 key_put(key);
814 return ret;
815 }
816
817 /*
818 * look up an entry in a directory
819 */
afs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)820 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
821 unsigned int flags)
822 {
823 struct afs_vnode *dvnode = AFS_FS_I(dir);
824 struct inode *inode;
825 struct dentry *d;
826 struct key *key;
827 int ret;
828
829 _enter("{%x:%u},%p{%pd},",
830 dvnode->fid.vid, dvnode->fid.vnode, dentry, dentry);
831
832 ASSERTCMP(d_inode(dentry), ==, NULL);
833
834 if (dentry->d_name.len >= AFSNAMEMAX) {
835 _leave(" = -ENAMETOOLONG");
836 return ERR_PTR(-ENAMETOOLONG);
837 }
838
839 if (test_bit(AFS_VNODE_DELETED, &dvnode->flags)) {
840 _leave(" = -ESTALE");
841 return ERR_PTR(-ESTALE);
842 }
843
844 key = afs_request_key(dvnode->volume->cell);
845 if (IS_ERR(key)) {
846 _leave(" = %ld [key]", PTR_ERR(key));
847 return ERR_CAST(key);
848 }
849
850 ret = afs_validate(dvnode, key);
851 if (ret < 0) {
852 key_put(key);
853 _leave(" = %d [val]", ret);
854 return ERR_PTR(ret);
855 }
856
857 if (dentry->d_name.len >= 4 &&
858 dentry->d_name.name[dentry->d_name.len - 4] == '@' &&
859 dentry->d_name.name[dentry->d_name.len - 3] == 's' &&
860 dentry->d_name.name[dentry->d_name.len - 2] == 'y' &&
861 dentry->d_name.name[dentry->d_name.len - 1] == 's')
862 return afs_lookup_atsys(dir, dentry, key);
863
864 afs_stat_v(dvnode, n_lookup);
865 inode = afs_do_lookup(dir, dentry, key);
866 key_put(key);
867 if (inode == ERR_PTR(-ENOENT)) {
868 inode = afs_try_auto_mntpt(dentry, dir);
869 } else {
870 dentry->d_fsdata =
871 (void *)(unsigned long)dvnode->status.data_version;
872 }
873 d = d_splice_alias(inode, dentry);
874 if (!IS_ERR_OR_NULL(d))
875 d->d_fsdata = dentry->d_fsdata;
876 return d;
877 }
878
879 /*
880 * check that a dentry lookup hit has found a valid entry
881 * - NOTE! the hit can be a negative hit too, so we can't assume we have an
882 * inode
883 */
afs_d_revalidate(struct dentry * dentry,unsigned int flags)884 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
885 {
886 struct afs_vnode *vnode, *dir;
887 struct afs_fid uninitialized_var(fid);
888 struct dentry *parent;
889 struct inode *inode;
890 struct key *key;
891 long dir_version, de_version;
892 int ret;
893
894 if (flags & LOOKUP_RCU)
895 return -ECHILD;
896
897 if (d_really_is_positive(dentry)) {
898 vnode = AFS_FS_I(d_inode(dentry));
899 _enter("{v={%x:%u} n=%pd fl=%lx},",
900 vnode->fid.vid, vnode->fid.vnode, dentry,
901 vnode->flags);
902 } else {
903 _enter("{neg n=%pd}", dentry);
904 }
905
906 key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
907 if (IS_ERR(key))
908 key = NULL;
909
910 if (d_really_is_positive(dentry)) {
911 inode = d_inode(dentry);
912 if (inode) {
913 vnode = AFS_FS_I(inode);
914 afs_validate(vnode, key);
915 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
916 goto out_bad;
917 }
918 }
919
920 /* lock down the parent dentry so we can peer at it */
921 parent = dget_parent(dentry);
922 dir = AFS_FS_I(d_inode(parent));
923
924 /* validate the parent directory */
925 afs_validate(dir, key);
926
927 if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
928 _debug("%pd: parent dir deleted", dentry);
929 goto out_bad_parent;
930 }
931
932 /* We only need to invalidate a dentry if the server's copy changed
933 * behind our back. If we made the change, it's no problem. Note that
934 * on a 32-bit system, we only have 32 bits in the dentry to store the
935 * version.
936 */
937 dir_version = (long)dir->status.data_version;
938 de_version = (long)dentry->d_fsdata;
939 if (de_version == dir_version)
940 goto out_valid_noupdate;
941
942 dir_version = (long)dir->invalid_before;
943 if (de_version - dir_version >= 0)
944 goto out_valid;
945
946 _debug("dir modified");
947 afs_stat_v(dir, n_reval);
948
949 /* search the directory for this vnode */
950 ret = afs_do_lookup_one(&dir->vfs_inode, dentry, &fid, key);
951 switch (ret) {
952 case 0:
953 /* the filename maps to something */
954 if (d_really_is_negative(dentry))
955 goto out_bad_parent;
956 inode = d_inode(dentry);
957 if (is_bad_inode(inode)) {
958 printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n",
959 dentry);
960 goto out_bad_parent;
961 }
962
963 vnode = AFS_FS_I(inode);
964
965 /* if the vnode ID has changed, then the dirent points to a
966 * different file */
967 if (fid.vnode != vnode->fid.vnode) {
968 _debug("%pd: dirent changed [%u != %u]",
969 dentry, fid.vnode,
970 vnode->fid.vnode);
971 goto not_found;
972 }
973
974 /* if the vnode ID uniqifier has changed, then the file has
975 * been deleted and replaced, and the original vnode ID has
976 * been reused */
977 if (fid.unique != vnode->fid.unique) {
978 _debug("%pd: file deleted (uq %u -> %u I:%u)",
979 dentry, fid.unique,
980 vnode->fid.unique,
981 vnode->vfs_inode.i_generation);
982 write_seqlock(&vnode->cb_lock);
983 set_bit(AFS_VNODE_DELETED, &vnode->flags);
984 write_sequnlock(&vnode->cb_lock);
985 goto not_found;
986 }
987 goto out_valid;
988
989 case -ENOENT:
990 /* the filename is unknown */
991 _debug("%pd: dirent not found", dentry);
992 if (d_really_is_positive(dentry))
993 goto not_found;
994 goto out_valid;
995
996 default:
997 _debug("failed to iterate dir %pd: %d",
998 parent, ret);
999 goto out_bad_parent;
1000 }
1001
1002 out_valid:
1003 dentry->d_fsdata = (void *)dir_version;
1004 out_valid_noupdate:
1005 dput(parent);
1006 key_put(key);
1007 _leave(" = 1 [valid]");
1008 return 1;
1009
1010 /* the dirent, if it exists, now points to a different vnode */
1011 not_found:
1012 spin_lock(&dentry->d_lock);
1013 dentry->d_flags |= DCACHE_NFSFS_RENAMED;
1014 spin_unlock(&dentry->d_lock);
1015
1016 out_bad_parent:
1017 _debug("dropping dentry %pd2", dentry);
1018 dput(parent);
1019 out_bad:
1020 key_put(key);
1021
1022 _leave(" = 0 [bad]");
1023 return 0;
1024 }
1025
1026 /*
1027 * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
1028 * sleep)
1029 * - called from dput() when d_count is going to 0.
1030 * - return 1 to request dentry be unhashed, 0 otherwise
1031 */
afs_d_delete(const struct dentry * dentry)1032 static int afs_d_delete(const struct dentry *dentry)
1033 {
1034 _enter("%pd", dentry);
1035
1036 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1037 goto zap;
1038
1039 if (d_really_is_positive(dentry) &&
1040 (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(d_inode(dentry))->flags) ||
1041 test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->flags)))
1042 goto zap;
1043
1044 _leave(" = 0 [keep]");
1045 return 0;
1046
1047 zap:
1048 _leave(" = 1 [zap]");
1049 return 1;
1050 }
1051
1052 /*
1053 * handle dentry release
1054 */
afs_d_release(struct dentry * dentry)1055 void afs_d_release(struct dentry *dentry)
1056 {
1057 _enter("%pd", dentry);
1058 }
1059
1060 /*
1061 * Create a new inode for create/mkdir/symlink
1062 */
afs_vnode_new_inode(struct afs_fs_cursor * fc,struct dentry * new_dentry,struct afs_fid * newfid,struct afs_file_status * newstatus,struct afs_callback * newcb)1063 static void afs_vnode_new_inode(struct afs_fs_cursor *fc,
1064 struct dentry *new_dentry,
1065 struct afs_fid *newfid,
1066 struct afs_file_status *newstatus,
1067 struct afs_callback *newcb)
1068 {
1069 struct afs_vnode *vnode;
1070 struct inode *inode;
1071
1072 if (fc->ac.error < 0)
1073 return;
1074
1075 d_drop(new_dentry);
1076
1077 inode = afs_iget(fc->vnode->vfs_inode.i_sb, fc->key,
1078 newfid, newstatus, newcb, fc->cbi);
1079 if (IS_ERR(inode)) {
1080 /* ENOMEM or EINTR at a really inconvenient time - just abandon
1081 * the new directory on the server.
1082 */
1083 fc->ac.error = PTR_ERR(inode);
1084 return;
1085 }
1086
1087 vnode = AFS_FS_I(inode);
1088 set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
1089 d_add(new_dentry, inode);
1090 }
1091
1092 /*
1093 * create a directory on an AFS filesystem
1094 */
afs_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)1095 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
1096 {
1097 struct afs_file_status newstatus;
1098 struct afs_fs_cursor fc;
1099 struct afs_callback newcb;
1100 struct afs_vnode *dvnode = AFS_FS_I(dir);
1101 struct afs_fid newfid;
1102 struct key *key;
1103 u64 data_version = dvnode->status.data_version;
1104 int ret;
1105
1106 mode |= S_IFDIR;
1107
1108 _enter("{%x:%u},{%pd},%ho",
1109 dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
1110
1111 key = afs_request_key(dvnode->volume->cell);
1112 if (IS_ERR(key)) {
1113 ret = PTR_ERR(key);
1114 goto error;
1115 }
1116
1117 ret = -ERESTARTSYS;
1118 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
1119 while (afs_select_fileserver(&fc)) {
1120 fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1121 afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
1122 &newfid, &newstatus, &newcb);
1123 }
1124
1125 afs_check_for_remote_deletion(&fc, fc.vnode);
1126 afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
1127 afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, &newcb);
1128 ret = afs_end_vnode_operation(&fc);
1129 if (ret < 0)
1130 goto error_key;
1131 } else {
1132 goto error_key;
1133 }
1134
1135 if (ret == 0 &&
1136 test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1137 afs_edit_dir_add(dvnode, &dentry->d_name, &newfid,
1138 afs_edit_dir_for_create);
1139
1140 key_put(key);
1141 _leave(" = 0");
1142 return 0;
1143
1144 error_key:
1145 key_put(key);
1146 error:
1147 d_drop(dentry);
1148 _leave(" = %d", ret);
1149 return ret;
1150 }
1151
1152 /*
1153 * Remove a subdir from a directory.
1154 */
afs_dir_remove_subdir(struct dentry * dentry)1155 static void afs_dir_remove_subdir(struct dentry *dentry)
1156 {
1157 if (d_really_is_positive(dentry)) {
1158 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
1159
1160 clear_nlink(&vnode->vfs_inode);
1161 set_bit(AFS_VNODE_DELETED, &vnode->flags);
1162 clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
1163 clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
1164 }
1165 }
1166
1167 /*
1168 * remove a directory from an AFS filesystem
1169 */
afs_rmdir(struct inode * dir,struct dentry * dentry)1170 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
1171 {
1172 struct afs_fs_cursor fc;
1173 struct afs_vnode *dvnode = AFS_FS_I(dir);
1174 struct key *key;
1175 u64 data_version = dvnode->status.data_version;
1176 int ret;
1177
1178 _enter("{%x:%u},{%pd}",
1179 dvnode->fid.vid, dvnode->fid.vnode, dentry);
1180
1181 key = afs_request_key(dvnode->volume->cell);
1182 if (IS_ERR(key)) {
1183 ret = PTR_ERR(key);
1184 goto error;
1185 }
1186
1187 ret = -ERESTARTSYS;
1188 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
1189 while (afs_select_fileserver(&fc)) {
1190 fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1191 afs_fs_remove(&fc, dentry->d_name.name, true,
1192 data_version);
1193 }
1194
1195 afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
1196 ret = afs_end_vnode_operation(&fc);
1197 if (ret == 0) {
1198 afs_dir_remove_subdir(dentry);
1199 if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1200 afs_edit_dir_remove(dvnode, &dentry->d_name,
1201 afs_edit_dir_for_rmdir);
1202 }
1203 }
1204
1205 key_put(key);
1206 error:
1207 return ret;
1208 }
1209
1210 /*
1211 * Remove a link to a file or symlink from a directory.
1212 *
1213 * If the file was not deleted due to excess hard links, the fileserver will
1214 * break the callback promise on the file - if it had one - before it returns
1215 * to us, and if it was deleted, it won't
1216 *
1217 * However, if we didn't have a callback promise outstanding, or it was
1218 * outstanding on a different server, then it won't break it either...
1219 */
afs_dir_remove_link(struct dentry * dentry,struct key * key,unsigned long d_version_before,unsigned long d_version_after)1220 static int afs_dir_remove_link(struct dentry *dentry, struct key *key,
1221 unsigned long d_version_before,
1222 unsigned long d_version_after)
1223 {
1224 bool dir_valid;
1225 int ret = 0;
1226
1227 /* There were no intervening changes on the server if the version
1228 * number we got back was incremented by exactly 1.
1229 */
1230 dir_valid = (d_version_after == d_version_before + 1);
1231
1232 if (d_really_is_positive(dentry)) {
1233 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
1234
1235 if (dir_valid) {
1236 drop_nlink(&vnode->vfs_inode);
1237 if (vnode->vfs_inode.i_nlink == 0) {
1238 set_bit(AFS_VNODE_DELETED, &vnode->flags);
1239 clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
1240 }
1241 ret = 0;
1242 } else {
1243 clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
1244
1245 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
1246 kdebug("AFS_VNODE_DELETED");
1247
1248 ret = afs_validate(vnode, key);
1249 if (ret == -ESTALE)
1250 ret = 0;
1251 }
1252 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
1253 }
1254
1255 return ret;
1256 }
1257
1258 /*
1259 * Remove a file or symlink from an AFS filesystem.
1260 */
afs_unlink(struct inode * dir,struct dentry * dentry)1261 static int afs_unlink(struct inode *dir, struct dentry *dentry)
1262 {
1263 struct afs_fs_cursor fc;
1264 struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode;
1265 struct key *key;
1266 unsigned long d_version = (unsigned long)dentry->d_fsdata;
1267 u64 data_version = dvnode->status.data_version;
1268 int ret;
1269
1270 _enter("{%x:%u},{%pd}",
1271 dvnode->fid.vid, dvnode->fid.vnode, dentry);
1272
1273 if (dentry->d_name.len >= AFSNAMEMAX)
1274 return -ENAMETOOLONG;
1275
1276 key = afs_request_key(dvnode->volume->cell);
1277 if (IS_ERR(key)) {
1278 ret = PTR_ERR(key);
1279 goto error;
1280 }
1281
1282 /* Try to make sure we have a callback promise on the victim. */
1283 if (d_really_is_positive(dentry)) {
1284 vnode = AFS_FS_I(d_inode(dentry));
1285 ret = afs_validate(vnode, key);
1286 if (ret < 0)
1287 goto error_key;
1288 }
1289
1290 ret = -ERESTARTSYS;
1291 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
1292 while (afs_select_fileserver(&fc)) {
1293 fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1294 afs_fs_remove(&fc, dentry->d_name.name, false,
1295 data_version);
1296 }
1297
1298 afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
1299 ret = afs_end_vnode_operation(&fc);
1300 if (ret == 0)
1301 ret = afs_dir_remove_link(
1302 dentry, key, d_version,
1303 (unsigned long)dvnode->status.data_version);
1304 if (ret == 0 &&
1305 test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1306 afs_edit_dir_remove(dvnode, &dentry->d_name,
1307 afs_edit_dir_for_unlink);
1308 }
1309
1310 error_key:
1311 key_put(key);
1312 error:
1313 _leave(" = %d", ret);
1314 return ret;
1315 }
1316
1317 /*
1318 * create a regular file on an AFS filesystem
1319 */
afs_create(struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)1320 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
1321 bool excl)
1322 {
1323 struct afs_fs_cursor fc;
1324 struct afs_file_status newstatus;
1325 struct afs_callback newcb;
1326 struct afs_vnode *dvnode = AFS_FS_I(dir);
1327 struct afs_fid newfid;
1328 struct key *key;
1329 u64 data_version = dvnode->status.data_version;
1330 int ret;
1331
1332 mode |= S_IFREG;
1333
1334 _enter("{%x:%u},{%pd},%ho,",
1335 dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
1336
1337 ret = -ENAMETOOLONG;
1338 if (dentry->d_name.len >= AFSNAMEMAX)
1339 goto error;
1340
1341 key = afs_request_key(dvnode->volume->cell);
1342 if (IS_ERR(key)) {
1343 ret = PTR_ERR(key);
1344 goto error;
1345 }
1346
1347 ret = -ERESTARTSYS;
1348 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
1349 while (afs_select_fileserver(&fc)) {
1350 fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1351 afs_fs_create(&fc, dentry->d_name.name, mode, data_version,
1352 &newfid, &newstatus, &newcb);
1353 }
1354
1355 afs_check_for_remote_deletion(&fc, fc.vnode);
1356 afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
1357 afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, &newcb);
1358 ret = afs_end_vnode_operation(&fc);
1359 if (ret < 0)
1360 goto error_key;
1361 } else {
1362 goto error_key;
1363 }
1364
1365 if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1366 afs_edit_dir_add(dvnode, &dentry->d_name, &newfid,
1367 afs_edit_dir_for_create);
1368
1369 key_put(key);
1370 _leave(" = 0");
1371 return 0;
1372
1373 error_key:
1374 key_put(key);
1375 error:
1376 d_drop(dentry);
1377 _leave(" = %d", ret);
1378 return ret;
1379 }
1380
1381 /*
1382 * create a hard link between files in an AFS filesystem
1383 */
afs_link(struct dentry * from,struct inode * dir,struct dentry * dentry)1384 static int afs_link(struct dentry *from, struct inode *dir,
1385 struct dentry *dentry)
1386 {
1387 struct afs_fs_cursor fc;
1388 struct afs_vnode *dvnode, *vnode;
1389 struct key *key;
1390 u64 data_version;
1391 int ret;
1392
1393 vnode = AFS_FS_I(d_inode(from));
1394 dvnode = AFS_FS_I(dir);
1395 data_version = dvnode->status.data_version;
1396
1397 _enter("{%x:%u},{%x:%u},{%pd}",
1398 vnode->fid.vid, vnode->fid.vnode,
1399 dvnode->fid.vid, dvnode->fid.vnode,
1400 dentry);
1401
1402 ret = -ENAMETOOLONG;
1403 if (dentry->d_name.len >= AFSNAMEMAX)
1404 goto error;
1405
1406 key = afs_request_key(dvnode->volume->cell);
1407 if (IS_ERR(key)) {
1408 ret = PTR_ERR(key);
1409 goto error;
1410 }
1411
1412 ret = -ERESTARTSYS;
1413 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
1414 if (mutex_lock_interruptible_nested(&vnode->io_lock, 1) < 0) {
1415 afs_end_vnode_operation(&fc);
1416 goto error_key;
1417 }
1418
1419 while (afs_select_fileserver(&fc)) {
1420 fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1421 fc.cb_break_2 = afs_calc_vnode_cb_break(vnode);
1422 afs_fs_link(&fc, vnode, dentry->d_name.name, data_version);
1423 }
1424
1425 afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
1426 afs_vnode_commit_status(&fc, vnode, fc.cb_break_2);
1427 ihold(&vnode->vfs_inode);
1428 d_instantiate(dentry, &vnode->vfs_inode);
1429
1430 mutex_unlock(&vnode->io_lock);
1431 ret = afs_end_vnode_operation(&fc);
1432 if (ret < 0)
1433 goto error_key;
1434 } else {
1435 goto error_key;
1436 }
1437
1438 if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1439 afs_edit_dir_add(dvnode, &dentry->d_name, &vnode->fid,
1440 afs_edit_dir_for_link);
1441
1442 key_put(key);
1443 _leave(" = 0");
1444 return 0;
1445
1446 error_key:
1447 key_put(key);
1448 error:
1449 d_drop(dentry);
1450 _leave(" = %d", ret);
1451 return ret;
1452 }
1453
1454 /*
1455 * create a symlink in an AFS filesystem
1456 */
afs_symlink(struct inode * dir,struct dentry * dentry,const char * content)1457 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1458 const char *content)
1459 {
1460 struct afs_fs_cursor fc;
1461 struct afs_file_status newstatus;
1462 struct afs_vnode *dvnode = AFS_FS_I(dir);
1463 struct afs_fid newfid;
1464 struct key *key;
1465 u64 data_version = dvnode->status.data_version;
1466 int ret;
1467
1468 _enter("{%x:%u},{%pd},%s",
1469 dvnode->fid.vid, dvnode->fid.vnode, dentry,
1470 content);
1471
1472 ret = -ENAMETOOLONG;
1473 if (dentry->d_name.len >= AFSNAMEMAX)
1474 goto error;
1475
1476 ret = -EINVAL;
1477 if (strlen(content) >= AFSPATHMAX)
1478 goto error;
1479
1480 key = afs_request_key(dvnode->volume->cell);
1481 if (IS_ERR(key)) {
1482 ret = PTR_ERR(key);
1483 goto error;
1484 }
1485
1486 ret = -ERESTARTSYS;
1487 if (afs_begin_vnode_operation(&fc, dvnode, key)) {
1488 while (afs_select_fileserver(&fc)) {
1489 fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1490 afs_fs_symlink(&fc, dentry->d_name.name,
1491 content, data_version,
1492 &newfid, &newstatus);
1493 }
1494
1495 afs_check_for_remote_deletion(&fc, fc.vnode);
1496 afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
1497 afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, NULL);
1498 ret = afs_end_vnode_operation(&fc);
1499 if (ret < 0)
1500 goto error_key;
1501 } else {
1502 goto error_key;
1503 }
1504
1505 if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1506 afs_edit_dir_add(dvnode, &dentry->d_name, &newfid,
1507 afs_edit_dir_for_symlink);
1508
1509 key_put(key);
1510 _leave(" = 0");
1511 return 0;
1512
1513 error_key:
1514 key_put(key);
1515 error:
1516 d_drop(dentry);
1517 _leave(" = %d", ret);
1518 return ret;
1519 }
1520
1521 /*
1522 * rename a file in an AFS filesystem and/or move it between directories
1523 */
afs_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)1524 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1525 struct inode *new_dir, struct dentry *new_dentry,
1526 unsigned int flags)
1527 {
1528 struct afs_fs_cursor fc;
1529 struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1530 struct key *key;
1531 u64 orig_data_version, new_data_version;
1532 bool new_negative = d_is_negative(new_dentry);
1533 int ret;
1534
1535 if (flags)
1536 return -EINVAL;
1537
1538 vnode = AFS_FS_I(d_inode(old_dentry));
1539 orig_dvnode = AFS_FS_I(old_dir);
1540 new_dvnode = AFS_FS_I(new_dir);
1541 orig_data_version = orig_dvnode->status.data_version;
1542 new_data_version = new_dvnode->status.data_version;
1543
1544 _enter("{%x:%u},{%x:%u},{%x:%u},{%pd}",
1545 orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1546 vnode->fid.vid, vnode->fid.vnode,
1547 new_dvnode->fid.vid, new_dvnode->fid.vnode,
1548 new_dentry);
1549
1550 key = afs_request_key(orig_dvnode->volume->cell);
1551 if (IS_ERR(key)) {
1552 ret = PTR_ERR(key);
1553 goto error;
1554 }
1555
1556 ret = -ERESTARTSYS;
1557 if (afs_begin_vnode_operation(&fc, orig_dvnode, key)) {
1558 if (orig_dvnode != new_dvnode) {
1559 if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
1560 afs_end_vnode_operation(&fc);
1561 goto error_key;
1562 }
1563 }
1564 while (afs_select_fileserver(&fc)) {
1565 fc.cb_break = afs_calc_vnode_cb_break(orig_dvnode);
1566 fc.cb_break_2 = afs_calc_vnode_cb_break(new_dvnode);
1567 afs_fs_rename(&fc, old_dentry->d_name.name,
1568 new_dvnode, new_dentry->d_name.name,
1569 orig_data_version, new_data_version);
1570 }
1571
1572 afs_vnode_commit_status(&fc, orig_dvnode, fc.cb_break);
1573 afs_vnode_commit_status(&fc, new_dvnode, fc.cb_break_2);
1574 if (orig_dvnode != new_dvnode)
1575 mutex_unlock(&new_dvnode->io_lock);
1576 ret = afs_end_vnode_operation(&fc);
1577 if (ret < 0)
1578 goto error_key;
1579 }
1580
1581 if (ret == 0) {
1582 if (test_bit(AFS_VNODE_DIR_VALID, &orig_dvnode->flags))
1583 afs_edit_dir_remove(orig_dvnode, &old_dentry->d_name,
1584 afs_edit_dir_for_rename);
1585
1586 if (!new_negative &&
1587 test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
1588 afs_edit_dir_remove(new_dvnode, &new_dentry->d_name,
1589 afs_edit_dir_for_rename);
1590
1591 if (test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
1592 afs_edit_dir_add(new_dvnode, &new_dentry->d_name,
1593 &vnode->fid, afs_edit_dir_for_rename);
1594 }
1595
1596 error_key:
1597 key_put(key);
1598 error:
1599 _leave(" = %d", ret);
1600 return ret;
1601 }
1602
1603 /*
1604 * Release a directory page and clean up its private state if it's not busy
1605 * - return true if the page can now be released, false if not
1606 */
afs_dir_releasepage(struct page * page,gfp_t gfp_flags)1607 static int afs_dir_releasepage(struct page *page, gfp_t gfp_flags)
1608 {
1609 struct afs_vnode *dvnode = AFS_FS_I(page->mapping->host);
1610
1611 _enter("{{%x:%u}[%lu]}", dvnode->fid.vid, dvnode->fid.vnode, page->index);
1612
1613 set_page_private(page, 0);
1614 ClearPagePrivate(page);
1615
1616 /* The directory will need reloading. */
1617 if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1618 afs_stat_v(dvnode, n_relpg);
1619 return 1;
1620 }
1621
1622 /*
1623 * invalidate part or all of a page
1624 * - release a page and clean up its private data if offset is 0 (indicating
1625 * the entire page)
1626 */
afs_dir_invalidatepage(struct page * page,unsigned int offset,unsigned int length)1627 static void afs_dir_invalidatepage(struct page *page, unsigned int offset,
1628 unsigned int length)
1629 {
1630 struct afs_vnode *dvnode = AFS_FS_I(page->mapping->host);
1631
1632 _enter("{%lu},%u,%u", page->index, offset, length);
1633
1634 BUG_ON(!PageLocked(page));
1635
1636 /* The directory will need reloading. */
1637 if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
1638 afs_stat_v(dvnode, n_inval);
1639
1640 /* we clean up only if the entire page is being invalidated */
1641 if (offset == 0 && length == PAGE_SIZE) {
1642 set_page_private(page, 0);
1643 ClearPagePrivate(page);
1644 }
1645 }
1646