1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Functions to handle the cached directory entries
4 *
5 * Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
6 */
7
8 #include <linux/namei.h>
9 #include "cifsglob.h"
10 #include "cifsproto.h"
11 #include "cifs_debug.h"
12 #include "smb2proto.h"
13 #include "cached_dir.h"
14
15 static struct cached_fid *init_cached_dir(const char *path);
16 static void free_cached_dir(struct cached_fid *cfid);
17 static void smb2_close_cached_fid(struct kref *ref);
18 static void cfids_laundromat_worker(struct work_struct *work);
19 static void close_cached_dir_locked(struct cached_fid *cfid);
20
21 struct cached_dir_dentry {
22 struct list_head entry;
23 struct dentry *dentry;
24 };
25
find_or_create_cached_dir(struct cached_fids * cfids,const char * path,bool lookup_only,__u32 max_cached_dirs)26 static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
27 const char *path,
28 bool lookup_only,
29 __u32 max_cached_dirs)
30 {
31 struct cached_fid *cfid;
32
33 list_for_each_entry(cfid, &cfids->entries, entry) {
34 if (!strcmp(cfid->path, path)) {
35 /*
36 * If it doesn't have a lease it is either not yet
37 * fully cached or it may be in the process of
38 * being deleted due to a lease break.
39 */
40 if (!is_valid_cached_dir(cfid))
41 return NULL;
42 kref_get(&cfid->refcount);
43 return cfid;
44 }
45 }
46 if (lookup_only) {
47 return NULL;
48 }
49 if (cfids->num_entries >= max_cached_dirs) {
50 return NULL;
51 }
52 cfid = init_cached_dir(path);
53 if (cfid == NULL) {
54 return NULL;
55 }
56 cfid->cfids = cfids;
57 cfids->num_entries++;
58 list_add(&cfid->entry, &cfids->entries);
59 cfid->on_list = true;
60 kref_get(&cfid->refcount);
61 /*
62 * Set @cfid->has_lease to true during construction so that the lease
63 * reference can be put in cached_dir_lease_break() due to a potential
64 * lease break right after the request is sent or while @cfid is still
65 * being cached, or if a reconnection is triggered during construction.
66 * Concurrent processes won't be to use it yet due to @cfid->time being
67 * zero.
68 */
69 cfid->has_lease = true;
70
71 return cfid;
72 }
73
74 static struct dentry *
path_to_dentry(struct cifs_sb_info * cifs_sb,const char * path)75 path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path)
76 {
77 struct dentry *dentry;
78 const char *s, *p;
79 char sep;
80
81 sep = CIFS_DIR_SEP(cifs_sb);
82 dentry = dget(cifs_sb->root);
83 s = path;
84
85 do {
86 struct inode *dir = d_inode(dentry);
87 struct dentry *child;
88
89 if (!S_ISDIR(dir->i_mode)) {
90 dput(dentry);
91 dentry = ERR_PTR(-ENOTDIR);
92 break;
93 }
94
95 /* skip separators */
96 while (*s == sep)
97 s++;
98 if (!*s)
99 break;
100 p = s++;
101 /* next separator */
102 while (*s && *s != sep)
103 s++;
104
105 child = lookup_noperm_positive_unlocked(&QSTR_LEN(p, s - p),
106 dentry);
107 dput(dentry);
108 dentry = child;
109 } while (!IS_ERR(dentry));
110 return dentry;
111 }
112
path_no_prefix(struct cifs_sb_info * cifs_sb,const char * path)113 static const char *path_no_prefix(struct cifs_sb_info *cifs_sb,
114 const char *path)
115 {
116 size_t len = 0;
117
118 if (!*path)
119 return path;
120
121 if ((cifs_sb_flags(cifs_sb) & CIFS_MOUNT_USE_PREFIX_PATH) &&
122 cifs_sb->prepath) {
123 len = strlen(cifs_sb->prepath) + 1;
124 if (unlikely(len > strlen(path)))
125 return ERR_PTR(-EINVAL);
126 }
127 return path + len;
128 }
129
130 /*
131 * Open the and cache a directory handle.
132 * If error then *cfid is not initialized.
133 */
open_cached_dir(unsigned int xid,struct cifs_tcon * tcon,const char * path,struct cifs_sb_info * cifs_sb,bool lookup_only,struct cached_fid ** ret_cfid)134 int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
135 const char *path,
136 struct cifs_sb_info *cifs_sb,
137 bool lookup_only, struct cached_fid **ret_cfid)
138 {
139 struct cifs_ses *ses;
140 struct TCP_Server_Info *server;
141 struct cifs_open_parms oparms;
142 struct smb2_create_rsp *o_rsp = NULL;
143 struct smb2_query_info_rsp *qi_rsp = NULL;
144 int resp_buftype[2];
145 struct smb_rqst rqst[2];
146 struct kvec rsp_iov[2];
147 struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
148 struct kvec qi_iov[1];
149 int rc, flags = 0;
150 __le16 *utf16_path = NULL;
151 u8 oplock = SMB2_OPLOCK_LEVEL_II;
152 struct cifs_fid *pfid;
153 struct dentry *dentry = NULL;
154 struct cached_fid *cfid;
155 struct cached_fids *cfids;
156 const char *npath;
157 int retries = 0, cur_sleep = 0;
158 __le32 lease_flags = 0;
159
160 if (cifs_sb->root == NULL)
161 return -ENOENT;
162
163 if (tcon == NULL)
164 return -EOPNOTSUPP;
165
166 ses = tcon->ses;
167 cfids = tcon->cfids;
168
169 if (cfids == NULL)
170 return -EOPNOTSUPP;
171
172 replay_again:
173 /* reinitialize for possible replay */
174 flags = 0;
175 oplock = SMB2_OPLOCK_LEVEL_II;
176 server = cifs_pick_channel(ses);
177
178 if (!server->ops->new_lease_key)
179 return smb_EIO(smb_eio_trace_no_lease_key);
180
181 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
182 if (!utf16_path)
183 return -ENOMEM;
184
185 spin_lock(&cfids->cfid_list_lock);
186 cfid = find_or_create_cached_dir(cfids, path, lookup_only, tcon->max_cached_dirs);
187 if (cfid == NULL) {
188 spin_unlock(&cfids->cfid_list_lock);
189 kfree(utf16_path);
190 return -ENOENT;
191 }
192 /*
193 * Return cached fid if it is valid (has a lease and has a time).
194 * Otherwise, it is either a new entry or laundromat worker removed it
195 * from @cfids->entries. Caller will put last reference if the latter.
196 */
197 if (is_valid_cached_dir(cfid)) {
198 cfid->last_access_time = jiffies;
199 spin_unlock(&cfids->cfid_list_lock);
200 *ret_cfid = cfid;
201 kfree(utf16_path);
202 return 0;
203 }
204 spin_unlock(&cfids->cfid_list_lock);
205
206 pfid = &cfid->fid;
207
208 /*
209 * Skip any prefix paths in @path as lookup_noperm_positive_unlocked() ends up
210 * calling ->lookup() which already adds those through
211 * build_path_from_dentry(). Also, do it earlier as we might reconnect
212 * below when trying to send compounded request and then potentially
213 * having a different prefix path (e.g. after DFS failover).
214 */
215 npath = path_no_prefix(cifs_sb, path);
216 if (IS_ERR(npath)) {
217 rc = PTR_ERR(npath);
218 goto out;
219 }
220
221 if (!npath[0]) {
222 dentry = dget(cifs_sb->root);
223 } else {
224 dentry = path_to_dentry(cifs_sb, npath);
225 if (IS_ERR(dentry)) {
226 rc = -ENOENT;
227 goto out;
228 }
229 if (dentry->d_parent && server->dialect >= SMB30_PROT_ID) {
230 struct cached_fid *parent_cfid;
231
232 spin_lock(&cfids->cfid_list_lock);
233 list_for_each_entry(parent_cfid, &cfids->entries, entry) {
234 if (parent_cfid->dentry == dentry->d_parent) {
235 cifs_dbg(FYI, "found a parent cached file handle\n");
236 if (is_valid_cached_dir(parent_cfid)) {
237 lease_flags
238 |= SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE;
239 memcpy(pfid->parent_lease_key,
240 parent_cfid->fid.lease_key,
241 SMB2_LEASE_KEY_SIZE);
242 }
243 break;
244 }
245 }
246 spin_unlock(&cfids->cfid_list_lock);
247 }
248 }
249 cfid->dentry = dentry;
250 cfid->tcon = tcon;
251
252 /*
253 * We do not hold the lock for the open because in case
254 * SMB2_open needs to reconnect.
255 * This is safe because no other thread will be able to get a ref
256 * to the cfid until we have finished opening the file and (possibly)
257 * acquired a lease.
258 */
259 if (smb3_encryption_required(tcon))
260 flags |= CIFS_TRANSFORM_REQ;
261
262 server->ops->new_lease_key(pfid);
263
264 memset(rqst, 0, sizeof(rqst));
265 resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
266 memset(rsp_iov, 0, sizeof(rsp_iov));
267
268 /* Open */
269 memset(&open_iov, 0, sizeof(open_iov));
270 rqst[0].rq_iov = open_iov;
271 rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
272
273 oparms = (struct cifs_open_parms) {
274 .tcon = tcon,
275 .path = path,
276 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE),
277 .desired_access = FILE_READ_DATA | FILE_READ_ATTRIBUTES |
278 FILE_READ_EA,
279 .disposition = FILE_OPEN,
280 .fid = pfid,
281 .lease_flags = lease_flags,
282 .replay = !!(retries),
283 };
284
285 rc = SMB2_open_init(tcon, server,
286 &rqst[0], &oplock, &oparms, utf16_path);
287 if (rc)
288 goto oshr_free;
289
290 if (oplock != SMB2_OPLOCK_LEVEL_II) {
291 rc = -EINVAL;
292 cifs_dbg(FYI, "%s: Oplock level %d not suitable for cached directory\n",
293 __func__, oplock);
294 goto oshr_free;
295 }
296
297 smb2_set_next_command(tcon, &rqst[0]);
298
299 memset(&qi_iov, 0, sizeof(qi_iov));
300 rqst[1].rq_iov = qi_iov;
301 rqst[1].rq_nvec = 1;
302
303 rc = SMB2_query_info_init(tcon, server,
304 &rqst[1], COMPOUND_FID,
305 COMPOUND_FID, FILE_ALL_INFORMATION,
306 SMB2_O_INFO_FILE, 0,
307 sizeof(struct smb2_file_all_info) +
308 PATH_MAX * 2, 0, NULL);
309 if (rc)
310 goto oshr_free;
311
312 smb2_set_related(&rqst[1]);
313
314 if (retries) {
315 /* Back-off before retry */
316 if (cur_sleep)
317 msleep(cur_sleep);
318
319 smb2_set_replay(server, &rqst[0]);
320 smb2_set_replay(server, &rqst[1]);
321 }
322
323 rc = compound_send_recv(xid, ses, server,
324 flags, 2, rqst,
325 resp_buftype, rsp_iov);
326 if (rc) {
327 if (rc == -EREMCHG) {
328 tcon->need_reconnect = true;
329 pr_warn_once("server share %s deleted\n",
330 tcon->tree_name);
331 }
332 goto oshr_free;
333 }
334 cfid->is_open = true;
335
336 spin_lock(&cfids->cfid_list_lock);
337
338 o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
339 oparms.fid->persistent_fid = o_rsp->PersistentFileId;
340 oparms.fid->volatile_fid = o_rsp->VolatileFileId;
341 #ifdef CONFIG_CIFS_DEBUG2
342 oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
343 #endif /* CIFS_DEBUG2 */
344
345
346 if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
347 spin_unlock(&cfids->cfid_list_lock);
348 rc = -EINVAL;
349 goto oshr_free;
350 }
351
352 rc = smb2_parse_contexts(server, rsp_iov,
353 &oparms.fid->epoch,
354 oparms.fid->lease_key,
355 &oplock, NULL, NULL);
356 if (rc) {
357 spin_unlock(&cfids->cfid_list_lock);
358 goto oshr_free;
359 }
360
361 rc = -EINVAL;
362 if (!(oplock & SMB2_LEASE_READ_CACHING_HE)) {
363 spin_unlock(&cfids->cfid_list_lock);
364 goto oshr_free;
365 }
366 qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
367 if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) {
368 spin_unlock(&cfids->cfid_list_lock);
369 goto oshr_free;
370 }
371 if (!smb2_validate_and_copy_iov(
372 le16_to_cpu(qi_rsp->OutputBufferOffset),
373 sizeof(struct smb2_file_all_info),
374 &rsp_iov[1], sizeof(struct smb2_file_all_info),
375 (char *)&cfid->file_all_info))
376 cfid->file_all_info_is_valid = true;
377
378 cfid->time = jiffies;
379 cfid->last_access_time = jiffies;
380 spin_unlock(&cfids->cfid_list_lock);
381 /* At this point the directory handle is fully cached */
382 rc = 0;
383
384 oshr_free:
385 SMB2_open_free(&rqst[0]);
386 SMB2_query_info_free(&rqst[1]);
387 free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
388 free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
389 out:
390 if (rc) {
391 spin_lock(&cfids->cfid_list_lock);
392 if (cfid->on_list) {
393 list_del(&cfid->entry);
394 cfid->on_list = false;
395 cfids->num_entries--;
396 }
397 if (cfid->has_lease) {
398 /*
399 * We are guaranteed to have two references at this
400 * point. One for the caller and one for a potential
401 * lease. Release one here, and the second below.
402 */
403 cfid->has_lease = false;
404 close_cached_dir_locked(cfid);
405 }
406 spin_unlock(&cfids->cfid_list_lock);
407
408 close_cached_dir(cfid);
409 } else {
410 *ret_cfid = cfid;
411 atomic_inc(&tcon->num_remote_opens);
412 }
413 kfree(utf16_path);
414
415 if (is_replayable_error(rc) &&
416 smb2_should_replay(tcon, &retries, &cur_sleep))
417 goto replay_again;
418
419 return rc;
420 }
421
open_cached_dir_by_dentry(struct cifs_tcon * tcon,struct dentry * dentry,struct cached_fid ** ret_cfid)422 int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
423 struct dentry *dentry,
424 struct cached_fid **ret_cfid)
425 {
426 struct cached_fid *cfid;
427 struct cached_fids *cfids = tcon->cfids;
428
429 if (cfids == NULL)
430 return -EOPNOTSUPP;
431
432 if (!dentry)
433 return -ENOENT;
434
435 spin_lock(&cfids->cfid_list_lock);
436 list_for_each_entry(cfid, &cfids->entries, entry) {
437 if (cfid->dentry == dentry) {
438 if (!is_valid_cached_dir(cfid))
439 break;
440 cifs_dbg(FYI, "found a cached file handle by dentry\n");
441 kref_get(&cfid->refcount);
442 *ret_cfid = cfid;
443 cfid->last_access_time = jiffies;
444 spin_unlock(&cfids->cfid_list_lock);
445 return 0;
446 }
447 }
448 spin_unlock(&cfids->cfid_list_lock);
449 return -ENOENT;
450 }
451
452 static void
smb2_close_cached_fid(struct kref * ref)453 smb2_close_cached_fid(struct kref *ref)
454 __releases(&cfid->cfids->cfid_list_lock)
455 {
456 struct cached_fid *cfid = container_of(ref, struct cached_fid,
457 refcount);
458 int rc;
459
460 lockdep_assert_held(&cfid->cfids->cfid_list_lock);
461
462 if (cfid->on_list) {
463 list_del(&cfid->entry);
464 cfid->on_list = false;
465 cfid->cfids->num_entries--;
466 }
467 spin_unlock(&cfid->cfids->cfid_list_lock);
468
469 dput(cfid->dentry);
470 cfid->dentry = NULL;
471
472 if (cfid->is_open) {
473 rc = SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
474 cfid->fid.volatile_fid);
475 if (rc) /* should we retry on -EBUSY or -EAGAIN? */
476 cifs_dbg(VFS, "close cached dir rc %d\n", rc);
477 }
478
479 free_cached_dir(cfid);
480 }
481
drop_cached_dir_by_name(const unsigned int xid,struct cifs_tcon * tcon,const char * name,struct cifs_sb_info * cifs_sb)482 void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
483 const char *name, struct cifs_sb_info *cifs_sb)
484 {
485 struct cached_fid *cfid = NULL;
486 int rc;
487
488 rc = open_cached_dir(xid, tcon, name, cifs_sb, true, &cfid);
489 if (rc) {
490 cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
491 return;
492 }
493 spin_lock(&cfid->cfids->cfid_list_lock);
494 if (cfid->has_lease) {
495 cfid->has_lease = false;
496 close_cached_dir_locked(cfid);
497 }
498 spin_unlock(&cfid->cfids->cfid_list_lock);
499 close_cached_dir(cfid);
500 }
501
502 /**
503 * close_cached_dir - drop a reference of a cached dir
504 *
505 * The release function will be called with cfid_list_lock held to remove the
506 * cached dirs from the list before any other thread can take another @cfid
507 * ref. Must not be called with cfid_list_lock held; use
508 * close_cached_dir_locked() called instead.
509 *
510 * @cfid: cached dir
511 */
close_cached_dir(struct cached_fid * cfid)512 void close_cached_dir(struct cached_fid *cfid)
513 {
514 lockdep_assert_not_held(&cfid->cfids->cfid_list_lock);
515 kref_put_lock(&cfid->refcount, smb2_close_cached_fid, &cfid->cfids->cfid_list_lock);
516 }
517
518 /**
519 * close_cached_dir_locked - put a reference of a cached dir with
520 * cfid_list_lock held
521 *
522 * Calling close_cached_dir() with cfid_list_lock held has the potential effect
523 * of causing a deadlock if the invariant of refcount >= 2 is false.
524 *
525 * This function is used in paths that hold cfid_list_lock and expect at least
526 * two references. If that invariant is violated, WARNs and returns without
527 * dropping a reference; the final put must still go through
528 * close_cached_dir().
529 *
530 * @cfid: cached dir
531 */
close_cached_dir_locked(struct cached_fid * cfid)532 static void close_cached_dir_locked(struct cached_fid *cfid)
533 {
534 lockdep_assert_held(&cfid->cfids->cfid_list_lock);
535
536 if (WARN_ON(kref_read(&cfid->refcount) < 2))
537 return;
538
539 kref_put(&cfid->refcount, smb2_close_cached_fid);
540 }
541
542 /*
543 * Called from cifs_kill_sb when we unmount a share
544 */
close_all_cached_dirs(struct cifs_sb_info * cifs_sb)545 void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
546 {
547 struct rb_root *root = &cifs_sb->tlink_tree;
548 struct rb_node *node;
549 struct cached_fid *cfid;
550 struct cifs_tcon *tcon;
551 struct tcon_link *tlink;
552 struct cached_fids *cfids;
553 struct cached_dir_dentry *tmp_list, *q;
554 LIST_HEAD(entry);
555
556 spin_lock(&cifs_sb->tlink_tree_lock);
557 for (node = rb_first(root); node; node = rb_next(node)) {
558 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
559 tcon = tlink_tcon(tlink);
560 if (IS_ERR(tcon))
561 continue;
562 cfids = tcon->cfids;
563 if (cfids == NULL)
564 continue;
565 spin_lock(&cfids->cfid_list_lock);
566 list_for_each_entry(cfid, &cfids->entries, entry) {
567 tmp_list = kmalloc_obj(*tmp_list, GFP_ATOMIC);
568 if (tmp_list == NULL) {
569 /*
570 * If the malloc() fails, we won't drop all
571 * dentries, and unmounting is likely to trigger
572 * a 'Dentry still in use' error.
573 */
574 cifs_tcon_dbg(VFS, "Out of memory while dropping dentries\n");
575 spin_unlock(&cfids->cfid_list_lock);
576 spin_unlock(&cifs_sb->tlink_tree_lock);
577 goto done;
578 }
579
580 tmp_list->dentry = cfid->dentry;
581 cfid->dentry = NULL;
582
583 list_add_tail(&tmp_list->entry, &entry);
584 }
585 spin_unlock(&cfids->cfid_list_lock);
586 }
587 spin_unlock(&cifs_sb->tlink_tree_lock);
588
589 done:
590 list_for_each_entry_safe(tmp_list, q, &entry, entry) {
591 list_del(&tmp_list->entry);
592 dput(tmp_list->dentry);
593 kfree(tmp_list);
594 }
595
596 /* Flush any pending work that will drop dentries */
597 flush_workqueue(cfid_put_wq);
598 }
599
600 /*
601 * Invalidate all cached dirs when a TCON has been reset
602 * due to a session loss.
603 */
invalidate_all_cached_dirs(struct cifs_tcon * tcon,bool sync)604 void invalidate_all_cached_dirs(struct cifs_tcon *tcon, bool sync)
605 {
606 struct cached_fids *cfids = tcon->cfids;
607 struct cached_fid *cfid, *q;
608
609 if (cfids == NULL)
610 return;
611
612 /*
613 * Mark all the cfids as closed, and move them to the cfids->dying list.
614 * They'll be cleaned up by laundromat. Take a reference to each cfid
615 * during this process.
616 */
617 spin_lock(&cfids->cfid_list_lock);
618 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
619 list_move(&cfid->entry, &cfids->dying);
620 cfids->num_entries--;
621 cfid->is_open = false;
622 cfid->on_list = false;
623 if (cfid->has_lease) {
624 /*
625 * The lease was never cancelled from the server,
626 * so steal that reference.
627 */
628 cfid->has_lease = false;
629 } else
630 kref_get(&cfid->refcount);
631 }
632 spin_unlock(&cfids->cfid_list_lock);
633
634 /* run laundromat unconditionally now as there might have been previously queued work */
635 mod_delayed_work(cfid_put_wq, &cfids->laundromat_work, 0);
636 if (sync)
637 flush_delayed_work(&cfids->laundromat_work);
638 }
639
640 static void
cached_dir_offload_close(struct work_struct * work)641 cached_dir_offload_close(struct work_struct *work)
642 {
643 struct cached_fid *cfid = container_of(work,
644 struct cached_fid, close_work);
645 struct cifs_tcon *tcon = cfid->tcon;
646
647 WARN_ON(cfid->on_list);
648
649 close_cached_dir(cfid);
650 cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cached_close);
651 }
652
653 /*
654 * Release the cached directory's dentry, and then queue work to drop cached
655 * directory itself (closing on server if needed).
656 *
657 * Must be called with a reference to the cached_fid and a reference to the
658 * tcon.
659 */
cached_dir_put_work(struct work_struct * work)660 static void cached_dir_put_work(struct work_struct *work)
661 {
662 struct cached_fid *cfid = container_of(work, struct cached_fid,
663 put_work);
664 dput(cfid->dentry);
665 cfid->dentry = NULL;
666
667 queue_work(serverclose_wq, &cfid->close_work);
668 }
669
cached_dir_lease_break(struct cifs_tcon * tcon,__u8 lease_key[16])670 bool cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
671 {
672 struct cached_fids *cfids = tcon->cfids;
673 struct cached_fid *cfid;
674
675 if (cfids == NULL)
676 return false;
677
678 spin_lock(&cfids->cfid_list_lock);
679 list_for_each_entry(cfid, &cfids->entries, entry) {
680 if (cfid->has_lease &&
681 !memcmp(lease_key,
682 cfid->fid.lease_key,
683 SMB2_LEASE_KEY_SIZE)) {
684 cfid->has_lease = false;
685 cfid->time = 0;
686 /*
687 * We found a lease remove it from the list
688 * so no threads can access it.
689 */
690 list_del(&cfid->entry);
691 cfid->on_list = false;
692 cfids->num_entries--;
693
694 ++tcon->tc_count;
695 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
696 netfs_trace_tcon_ref_get_cached_lease_break);
697 queue_work(cfid_put_wq, &cfid->put_work);
698 spin_unlock(&cfids->cfid_list_lock);
699 return true;
700 }
701 }
702 spin_unlock(&cfids->cfid_list_lock);
703 return false;
704 }
705
init_cached_dir(const char * path)706 static struct cached_fid *init_cached_dir(const char *path)
707 {
708 struct cached_fid *cfid;
709
710 cfid = kzalloc_obj(*cfid, GFP_ATOMIC);
711 if (!cfid)
712 return NULL;
713 cfid->path = kstrdup(path, GFP_ATOMIC);
714 if (!cfid->path) {
715 kfree(cfid);
716 return NULL;
717 }
718
719 INIT_WORK(&cfid->close_work, cached_dir_offload_close);
720 INIT_WORK(&cfid->put_work, cached_dir_put_work);
721 INIT_LIST_HEAD(&cfid->entry);
722 INIT_LIST_HEAD(&cfid->dirents.entries);
723 mutex_init(&cfid->dirents.de_mutex);
724 kref_init(&cfid->refcount);
725 return cfid;
726 }
727
free_cached_dir(struct cached_fid * cfid)728 static void free_cached_dir(struct cached_fid *cfid)
729 {
730 struct cached_dirent *dirent, *q;
731
732 WARN_ON(work_pending(&cfid->close_work));
733 WARN_ON(work_pending(&cfid->put_work));
734
735 dput(cfid->dentry);
736 cfid->dentry = NULL;
737
738 /*
739 * Delete all cached dirent names
740 */
741 list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
742 list_del(&dirent->entry);
743 kfree(dirent->name);
744 kfree(dirent);
745 }
746
747 /* adjust tcon-level counters and reset per-dir accounting */
748 if (cfid->cfids) {
749 if (cfid->dirents.entries_count)
750 atomic_long_sub((long)cfid->dirents.entries_count,
751 &cfid->cfids->total_dirents_entries);
752 if (cfid->dirents.bytes_used) {
753 atomic64_sub((long long)cfid->dirents.bytes_used,
754 &cfid->cfids->total_dirents_bytes);
755 atomic64_sub((long long)cfid->dirents.bytes_used,
756 &cifs_dircache_bytes_used);
757 }
758 }
759 cfid->dirents.entries_count = 0;
760 cfid->dirents.bytes_used = 0;
761
762 kfree(cfid->path);
763 cfid->path = NULL;
764 kfree(cfid);
765 }
766
cfids_laundromat_worker(struct work_struct * work)767 static void cfids_laundromat_worker(struct work_struct *work)
768 {
769 struct cached_fids *cfids;
770 struct cached_fid *cfid, *q;
771 LIST_HEAD(entry);
772
773 cfids = container_of(work, struct cached_fids, laundromat_work.work);
774
775 spin_lock(&cfids->cfid_list_lock);
776 /* move cfids->dying to the local list */
777 list_cut_before(&entry, &cfids->dying, &cfids->dying);
778
779 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
780 if (cfid->last_access_time &&
781 time_after(jiffies, cfid->last_access_time + HZ * dir_cache_timeout)) {
782 cfid->on_list = false;
783 list_move(&cfid->entry, &entry);
784 cfids->num_entries--;
785 if (cfid->has_lease) {
786 /*
787 * Our lease has not yet been cancelled from the
788 * server. Steal that reference.
789 */
790 cfid->has_lease = false;
791 } else
792 kref_get(&cfid->refcount);
793 }
794 }
795 spin_unlock(&cfids->cfid_list_lock);
796
797 list_for_each_entry_safe(cfid, q, &entry, entry) {
798 list_del(&cfid->entry);
799
800 dput(cfid->dentry);
801 cfid->dentry = NULL;
802
803 if (cfid->is_open) {
804 spin_lock(&cfid->tcon->tc_lock);
805 ++cfid->tcon->tc_count;
806 trace_smb3_tcon_ref(cfid->tcon->debug_id, cfid->tcon->tc_count,
807 netfs_trace_tcon_ref_get_cached_laundromat);
808 spin_unlock(&cfid->tcon->tc_lock);
809 queue_work(serverclose_wq, &cfid->close_work);
810 } else
811 /*
812 * Drop the ref-count from above, either the lease-ref (if there
813 * was one) or the extra one acquired.
814 */
815 close_cached_dir(cfid);
816 }
817 queue_delayed_work(cfid_put_wq, &cfids->laundromat_work,
818 dir_cache_timeout * HZ);
819 }
820
init_cached_dirs(void)821 struct cached_fids *init_cached_dirs(void)
822 {
823 struct cached_fids *cfids;
824
825 cfids = kzalloc_obj(*cfids);
826 if (!cfids)
827 return NULL;
828 spin_lock_init(&cfids->cfid_list_lock);
829 INIT_LIST_HEAD(&cfids->entries);
830 INIT_LIST_HEAD(&cfids->dying);
831
832 INIT_DELAYED_WORK(&cfids->laundromat_work, cfids_laundromat_worker);
833 queue_delayed_work(cfid_put_wq, &cfids->laundromat_work,
834 dir_cache_timeout * HZ);
835
836 atomic_long_set(&cfids->total_dirents_entries, 0);
837 atomic64_set(&cfids->total_dirents_bytes, 0);
838
839 return cfids;
840 }
841
842 /*
843 * Called from tconInfoFree when we are tearing down the tcon.
844 * There are no active users or open files/directories at this point.
845 */
free_cached_dirs(struct cached_fids * cfids)846 void free_cached_dirs(struct cached_fids *cfids)
847 {
848 struct cached_fid *cfid, *q;
849 LIST_HEAD(entry);
850
851 if (cfids == NULL)
852 return;
853
854 cancel_delayed_work_sync(&cfids->laundromat_work);
855
856 spin_lock(&cfids->cfid_list_lock);
857 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
858 cfid->on_list = false;
859 cfid->is_open = false;
860 list_move(&cfid->entry, &entry);
861 }
862 list_for_each_entry_safe(cfid, q, &cfids->dying, entry) {
863 cfid->on_list = false;
864 cfid->is_open = false;
865 list_move(&cfid->entry, &entry);
866 }
867 spin_unlock(&cfids->cfid_list_lock);
868
869 list_for_each_entry_safe(cfid, q, &entry, entry) {
870 list_del(&cfid->entry);
871 free_cached_dir(cfid);
872 }
873
874 kfree(cfids);
875 }
876