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->mnt_cifs_flags & 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 = 1;
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 -EIO;
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 smb2_set_next_command(tcon, &rqst[0]);
290
291 memset(&qi_iov, 0, sizeof(qi_iov));
292 rqst[1].rq_iov = qi_iov;
293 rqst[1].rq_nvec = 1;
294
295 rc = SMB2_query_info_init(tcon, server,
296 &rqst[1], COMPOUND_FID,
297 COMPOUND_FID, FILE_ALL_INFORMATION,
298 SMB2_O_INFO_FILE, 0,
299 sizeof(struct smb2_file_all_info) +
300 PATH_MAX * 2, 0, NULL);
301 if (rc)
302 goto oshr_free;
303
304 smb2_set_related(&rqst[1]);
305
306 if (retries) {
307 smb2_set_replay(server, &rqst[0]);
308 smb2_set_replay(server, &rqst[1]);
309 }
310
311 rc = compound_send_recv(xid, ses, server,
312 flags, 2, rqst,
313 resp_buftype, rsp_iov);
314 if (rc) {
315 if (rc == -EREMCHG) {
316 tcon->need_reconnect = true;
317 pr_warn_once("server share %s deleted\n",
318 tcon->tree_name);
319 }
320 goto oshr_free;
321 }
322 cfid->is_open = true;
323
324 spin_lock(&cfids->cfid_list_lock);
325
326 o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
327 oparms.fid->persistent_fid = o_rsp->PersistentFileId;
328 oparms.fid->volatile_fid = o_rsp->VolatileFileId;
329 #ifdef CONFIG_CIFS_DEBUG2
330 oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
331 #endif /* CIFS_DEBUG2 */
332
333
334 if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
335 spin_unlock(&cfids->cfid_list_lock);
336 rc = -EINVAL;
337 goto oshr_free;
338 }
339
340 rc = smb2_parse_contexts(server, rsp_iov,
341 &oparms.fid->epoch,
342 oparms.fid->lease_key,
343 &oplock, NULL, NULL);
344 if (rc) {
345 spin_unlock(&cfids->cfid_list_lock);
346 goto oshr_free;
347 }
348
349 rc = -EINVAL;
350 if (!(oplock & SMB2_LEASE_READ_CACHING_HE)) {
351 spin_unlock(&cfids->cfid_list_lock);
352 goto oshr_free;
353 }
354 qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
355 if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) {
356 spin_unlock(&cfids->cfid_list_lock);
357 goto oshr_free;
358 }
359 if (!smb2_validate_and_copy_iov(
360 le16_to_cpu(qi_rsp->OutputBufferOffset),
361 sizeof(struct smb2_file_all_info),
362 &rsp_iov[1], sizeof(struct smb2_file_all_info),
363 (char *)&cfid->file_all_info))
364 cfid->file_all_info_is_valid = true;
365
366 cfid->time = jiffies;
367 cfid->last_access_time = jiffies;
368 spin_unlock(&cfids->cfid_list_lock);
369 /* At this point the directory handle is fully cached */
370 rc = 0;
371
372 oshr_free:
373 SMB2_open_free(&rqst[0]);
374 SMB2_query_info_free(&rqst[1]);
375 free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
376 free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
377 out:
378 if (rc) {
379 spin_lock(&cfids->cfid_list_lock);
380 if (cfid->on_list) {
381 list_del(&cfid->entry);
382 cfid->on_list = false;
383 cfids->num_entries--;
384 }
385 if (cfid->has_lease) {
386 /*
387 * We are guaranteed to have two references at this
388 * point. One for the caller and one for a potential
389 * lease. Release one here, and the second below.
390 */
391 cfid->has_lease = false;
392 close_cached_dir_locked(cfid);
393 }
394 spin_unlock(&cfids->cfid_list_lock);
395
396 close_cached_dir(cfid);
397 } else {
398 *ret_cfid = cfid;
399 atomic_inc(&tcon->num_remote_opens);
400 }
401 kfree(utf16_path);
402
403 if (is_replayable_error(rc) &&
404 smb2_should_replay(tcon, &retries, &cur_sleep))
405 goto replay_again;
406
407 return rc;
408 }
409
open_cached_dir_by_dentry(struct cifs_tcon * tcon,struct dentry * dentry,struct cached_fid ** ret_cfid)410 int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
411 struct dentry *dentry,
412 struct cached_fid **ret_cfid)
413 {
414 struct cached_fid *cfid;
415 struct cached_fids *cfids = tcon->cfids;
416
417 if (cfids == NULL)
418 return -EOPNOTSUPP;
419
420 if (!dentry)
421 return -ENOENT;
422
423 spin_lock(&cfids->cfid_list_lock);
424 list_for_each_entry(cfid, &cfids->entries, entry) {
425 if (cfid->dentry == dentry) {
426 if (!is_valid_cached_dir(cfid))
427 break;
428 cifs_dbg(FYI, "found a cached file handle by dentry\n");
429 kref_get(&cfid->refcount);
430 *ret_cfid = cfid;
431 cfid->last_access_time = jiffies;
432 spin_unlock(&cfids->cfid_list_lock);
433 return 0;
434 }
435 }
436 spin_unlock(&cfids->cfid_list_lock);
437 return -ENOENT;
438 }
439
440 static void
smb2_close_cached_fid(struct kref * ref)441 smb2_close_cached_fid(struct kref *ref)
442 __releases(&cfid->cfids->cfid_list_lock)
443 {
444 struct cached_fid *cfid = container_of(ref, struct cached_fid,
445 refcount);
446 int rc;
447
448 lockdep_assert_held(&cfid->cfids->cfid_list_lock);
449
450 if (cfid->on_list) {
451 list_del(&cfid->entry);
452 cfid->on_list = false;
453 cfid->cfids->num_entries--;
454 }
455 spin_unlock(&cfid->cfids->cfid_list_lock);
456
457 dput(cfid->dentry);
458 cfid->dentry = NULL;
459
460 if (cfid->is_open) {
461 rc = SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
462 cfid->fid.volatile_fid);
463 if (rc) /* should we retry on -EBUSY or -EAGAIN? */
464 cifs_dbg(VFS, "close cached dir rc %d\n", rc);
465 }
466
467 free_cached_dir(cfid);
468 }
469
drop_cached_dir_by_name(const unsigned int xid,struct cifs_tcon * tcon,const char * name,struct cifs_sb_info * cifs_sb)470 void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
471 const char *name, struct cifs_sb_info *cifs_sb)
472 {
473 struct cached_fid *cfid = NULL;
474 int rc;
475
476 rc = open_cached_dir(xid, tcon, name, cifs_sb, true, &cfid);
477 if (rc) {
478 cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
479 return;
480 }
481 spin_lock(&cfid->cfids->cfid_list_lock);
482 if (cfid->has_lease) {
483 cfid->has_lease = false;
484 close_cached_dir_locked(cfid);
485 }
486 spin_unlock(&cfid->cfids->cfid_list_lock);
487 close_cached_dir(cfid);
488 }
489
490 /**
491 * close_cached_dir - drop a reference of a cached dir
492 *
493 * The release function will be called with cfid_list_lock held to remove the
494 * cached dirs from the list before any other thread can take another @cfid
495 * ref. Must not be called with cfid_list_lock held; use
496 * close_cached_dir_locked() called instead.
497 *
498 * @cfid: cached dir
499 */
close_cached_dir(struct cached_fid * cfid)500 void close_cached_dir(struct cached_fid *cfid)
501 {
502 lockdep_assert_not_held(&cfid->cfids->cfid_list_lock);
503 kref_put_lock(&cfid->refcount, smb2_close_cached_fid, &cfid->cfids->cfid_list_lock);
504 }
505
506 /**
507 * close_cached_dir_locked - put a reference of a cached dir with
508 * cfid_list_lock held
509 *
510 * Calling close_cached_dir() with cfid_list_lock held has the potential effect
511 * of causing a deadlock if the invariant of refcount >= 2 is false.
512 *
513 * This function is used in paths that hold cfid_list_lock and expect at least
514 * two references. If that invariant is violated, WARNs and returns without
515 * dropping a reference; the final put must still go through
516 * close_cached_dir().
517 *
518 * @cfid: cached dir
519 */
close_cached_dir_locked(struct cached_fid * cfid)520 static void close_cached_dir_locked(struct cached_fid *cfid)
521 {
522 lockdep_assert_held(&cfid->cfids->cfid_list_lock);
523
524 if (WARN_ON(kref_read(&cfid->refcount) < 2))
525 return;
526
527 kref_put(&cfid->refcount, smb2_close_cached_fid);
528 }
529
530 /*
531 * Called from cifs_kill_sb when we unmount a share
532 */
close_all_cached_dirs(struct cifs_sb_info * cifs_sb)533 void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
534 {
535 struct rb_root *root = &cifs_sb->tlink_tree;
536 struct rb_node *node;
537 struct cached_fid *cfid;
538 struct cifs_tcon *tcon;
539 struct tcon_link *tlink;
540 struct cached_fids *cfids;
541 struct cached_dir_dentry *tmp_list, *q;
542 LIST_HEAD(entry);
543
544 spin_lock(&cifs_sb->tlink_tree_lock);
545 for (node = rb_first(root); node; node = rb_next(node)) {
546 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
547 tcon = tlink_tcon(tlink);
548 if (IS_ERR(tcon))
549 continue;
550 cfids = tcon->cfids;
551 if (cfids == NULL)
552 continue;
553 spin_lock(&cfids->cfid_list_lock);
554 list_for_each_entry(cfid, &cfids->entries, entry) {
555 tmp_list = kmalloc(sizeof(*tmp_list), GFP_ATOMIC);
556 if (tmp_list == NULL) {
557 /*
558 * If the malloc() fails, we won't drop all
559 * dentries, and unmounting is likely to trigger
560 * a 'Dentry still in use' error.
561 */
562 cifs_tcon_dbg(VFS, "Out of memory while dropping dentries\n");
563 spin_unlock(&cfids->cfid_list_lock);
564 spin_unlock(&cifs_sb->tlink_tree_lock);
565 goto done;
566 }
567
568 tmp_list->dentry = cfid->dentry;
569 cfid->dentry = NULL;
570
571 list_add_tail(&tmp_list->entry, &entry);
572 }
573 spin_unlock(&cfids->cfid_list_lock);
574 }
575 spin_unlock(&cifs_sb->tlink_tree_lock);
576
577 done:
578 list_for_each_entry_safe(tmp_list, q, &entry, entry) {
579 list_del(&tmp_list->entry);
580 dput(tmp_list->dentry);
581 kfree(tmp_list);
582 }
583
584 /* Flush any pending work that will drop dentries */
585 flush_workqueue(cfid_put_wq);
586 }
587
588 /*
589 * Invalidate all cached dirs when a TCON has been reset
590 * due to a session loss.
591 */
invalidate_all_cached_dirs(struct cifs_tcon * tcon)592 void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
593 {
594 struct cached_fids *cfids = tcon->cfids;
595 struct cached_fid *cfid, *q;
596
597 if (cfids == NULL)
598 return;
599
600 /*
601 * Mark all the cfids as closed, and move them to the cfids->dying list.
602 * They'll be cleaned up by laundromat. Take a reference to each cfid
603 * during this process.
604 */
605 spin_lock(&cfids->cfid_list_lock);
606 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
607 list_move(&cfid->entry, &cfids->dying);
608 cfids->num_entries--;
609 cfid->is_open = false;
610 cfid->on_list = false;
611 if (cfid->has_lease) {
612 /*
613 * The lease was never cancelled from the server,
614 * so steal that reference.
615 */
616 cfid->has_lease = false;
617 } else
618 kref_get(&cfid->refcount);
619 }
620 spin_unlock(&cfids->cfid_list_lock);
621
622 /* run laundromat unconditionally now as there might have been previously queued work */
623 mod_delayed_work(cfid_put_wq, &cfids->laundromat_work, 0);
624 flush_delayed_work(&cfids->laundromat_work);
625 }
626
627 static void
cached_dir_offload_close(struct work_struct * work)628 cached_dir_offload_close(struct work_struct *work)
629 {
630 struct cached_fid *cfid = container_of(work,
631 struct cached_fid, close_work);
632 struct cifs_tcon *tcon = cfid->tcon;
633
634 WARN_ON(cfid->on_list);
635
636 close_cached_dir(cfid);
637 cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cached_close);
638 }
639
640 /*
641 * Release the cached directory's dentry, and then queue work to drop cached
642 * directory itself (closing on server if needed).
643 *
644 * Must be called with a reference to the cached_fid and a reference to the
645 * tcon.
646 */
cached_dir_put_work(struct work_struct * work)647 static void cached_dir_put_work(struct work_struct *work)
648 {
649 struct cached_fid *cfid = container_of(work, struct cached_fid,
650 put_work);
651 dput(cfid->dentry);
652 cfid->dentry = NULL;
653
654 queue_work(serverclose_wq, &cfid->close_work);
655 }
656
cached_dir_lease_break(struct cifs_tcon * tcon,__u8 lease_key[16])657 bool cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
658 {
659 struct cached_fids *cfids = tcon->cfids;
660 struct cached_fid *cfid;
661
662 if (cfids == NULL)
663 return false;
664
665 spin_lock(&cfids->cfid_list_lock);
666 list_for_each_entry(cfid, &cfids->entries, entry) {
667 if (cfid->has_lease &&
668 !memcmp(lease_key,
669 cfid->fid.lease_key,
670 SMB2_LEASE_KEY_SIZE)) {
671 cfid->has_lease = false;
672 cfid->time = 0;
673 /*
674 * We found a lease remove it from the list
675 * so no threads can access it.
676 */
677 list_del(&cfid->entry);
678 cfid->on_list = false;
679 cfids->num_entries--;
680
681 ++tcon->tc_count;
682 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
683 netfs_trace_tcon_ref_get_cached_lease_break);
684 queue_work(cfid_put_wq, &cfid->put_work);
685 spin_unlock(&cfids->cfid_list_lock);
686 return true;
687 }
688 }
689 spin_unlock(&cfids->cfid_list_lock);
690 return false;
691 }
692
init_cached_dir(const char * path)693 static struct cached_fid *init_cached_dir(const char *path)
694 {
695 struct cached_fid *cfid;
696
697 cfid = kzalloc(sizeof(*cfid), GFP_ATOMIC);
698 if (!cfid)
699 return NULL;
700 cfid->path = kstrdup(path, GFP_ATOMIC);
701 if (!cfid->path) {
702 kfree(cfid);
703 return NULL;
704 }
705
706 INIT_WORK(&cfid->close_work, cached_dir_offload_close);
707 INIT_WORK(&cfid->put_work, cached_dir_put_work);
708 INIT_LIST_HEAD(&cfid->entry);
709 INIT_LIST_HEAD(&cfid->dirents.entries);
710 mutex_init(&cfid->dirents.de_mutex);
711 kref_init(&cfid->refcount);
712 return cfid;
713 }
714
free_cached_dir(struct cached_fid * cfid)715 static void free_cached_dir(struct cached_fid *cfid)
716 {
717 struct cached_dirent *dirent, *q;
718
719 WARN_ON(work_pending(&cfid->close_work));
720 WARN_ON(work_pending(&cfid->put_work));
721
722 dput(cfid->dentry);
723 cfid->dentry = NULL;
724
725 /*
726 * Delete all cached dirent names
727 */
728 list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
729 list_del(&dirent->entry);
730 kfree(dirent->name);
731 kfree(dirent);
732 }
733
734 /* adjust tcon-level counters and reset per-dir accounting */
735 if (cfid->cfids) {
736 if (cfid->dirents.entries_count)
737 atomic_long_sub((long)cfid->dirents.entries_count,
738 &cfid->cfids->total_dirents_entries);
739 if (cfid->dirents.bytes_used) {
740 atomic64_sub((long long)cfid->dirents.bytes_used,
741 &cfid->cfids->total_dirents_bytes);
742 atomic64_sub((long long)cfid->dirents.bytes_used,
743 &cifs_dircache_bytes_used);
744 }
745 }
746 cfid->dirents.entries_count = 0;
747 cfid->dirents.bytes_used = 0;
748
749 kfree(cfid->path);
750 cfid->path = NULL;
751 kfree(cfid);
752 }
753
cfids_laundromat_worker(struct work_struct * work)754 static void cfids_laundromat_worker(struct work_struct *work)
755 {
756 struct cached_fids *cfids;
757 struct cached_fid *cfid, *q;
758 LIST_HEAD(entry);
759
760 cfids = container_of(work, struct cached_fids, laundromat_work.work);
761
762 spin_lock(&cfids->cfid_list_lock);
763 /* move cfids->dying to the local list */
764 list_cut_before(&entry, &cfids->dying, &cfids->dying);
765
766 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
767 if (cfid->last_access_time &&
768 time_after(jiffies, cfid->last_access_time + HZ * dir_cache_timeout)) {
769 cfid->on_list = false;
770 list_move(&cfid->entry, &entry);
771 cfids->num_entries--;
772 if (cfid->has_lease) {
773 /*
774 * Our lease has not yet been cancelled from the
775 * server. Steal that reference.
776 */
777 cfid->has_lease = false;
778 } else
779 kref_get(&cfid->refcount);
780 }
781 }
782 spin_unlock(&cfids->cfid_list_lock);
783
784 list_for_each_entry_safe(cfid, q, &entry, entry) {
785 list_del(&cfid->entry);
786
787 dput(cfid->dentry);
788 cfid->dentry = NULL;
789
790 if (cfid->is_open) {
791 spin_lock(&cifs_tcp_ses_lock);
792 ++cfid->tcon->tc_count;
793 trace_smb3_tcon_ref(cfid->tcon->debug_id, cfid->tcon->tc_count,
794 netfs_trace_tcon_ref_get_cached_laundromat);
795 spin_unlock(&cifs_tcp_ses_lock);
796 queue_work(serverclose_wq, &cfid->close_work);
797 } else
798 /*
799 * Drop the ref-count from above, either the lease-ref (if there
800 * was one) or the extra one acquired.
801 */
802 close_cached_dir(cfid);
803 }
804 queue_delayed_work(cfid_put_wq, &cfids->laundromat_work,
805 dir_cache_timeout * HZ);
806 }
807
init_cached_dirs(void)808 struct cached_fids *init_cached_dirs(void)
809 {
810 struct cached_fids *cfids;
811
812 cfids = kzalloc(sizeof(*cfids), GFP_KERNEL);
813 if (!cfids)
814 return NULL;
815 spin_lock_init(&cfids->cfid_list_lock);
816 INIT_LIST_HEAD(&cfids->entries);
817 INIT_LIST_HEAD(&cfids->dying);
818
819 INIT_DELAYED_WORK(&cfids->laundromat_work, cfids_laundromat_worker);
820 queue_delayed_work(cfid_put_wq, &cfids->laundromat_work,
821 dir_cache_timeout * HZ);
822
823 atomic_long_set(&cfids->total_dirents_entries, 0);
824 atomic64_set(&cfids->total_dirents_bytes, 0);
825
826 return cfids;
827 }
828
829 /*
830 * Called from tconInfoFree when we are tearing down the tcon.
831 * There are no active users or open files/directories at this point.
832 */
free_cached_dirs(struct cached_fids * cfids)833 void free_cached_dirs(struct cached_fids *cfids)
834 {
835 struct cached_fid *cfid, *q;
836 LIST_HEAD(entry);
837
838 if (cfids == NULL)
839 return;
840
841 cancel_delayed_work_sync(&cfids->laundromat_work);
842
843 spin_lock(&cfids->cfid_list_lock);
844 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
845 cfid->on_list = false;
846 cfid->is_open = false;
847 list_move(&cfid->entry, &entry);
848 }
849 list_for_each_entry_safe(cfid, q, &cfids->dying, entry) {
850 cfid->on_list = false;
851 cfid->is_open = false;
852 list_move(&cfid->entry, &entry);
853 }
854 spin_unlock(&cfids->cfid_list_lock);
855
856 list_for_each_entry_safe(cfid, q, &entry, entry) {
857 list_del(&cfid->entry);
858 free_cached_dir(cfid);
859 }
860
861 kfree(cfids);
862 }
863