1 // SPDX-License-Identifier: GPL-2.0
3 * Functions to handle the cached directory entries
5 * Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
8 #include <linux/namei.h>
10 #include "cifsproto.h"
11 #include "cifs_debug.h"
12 #include "smb2proto.h"
13 #include "cached_dir.h"
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);
19 static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
23 struct cached_fid *cfid;
25 spin_lock(&cfids->cfid_list_lock);
26 list_for_each_entry(cfid, &cfids->entries, entry) {
27 if (!strcmp(cfid->path, path)) {
29 * If it doesn't have a lease it is either not yet
30 * fully cached or it may be in the process of
31 * being deleted due to a lease break.
33 if (!cfid->has_lease) {
34 spin_unlock(&cfids->cfid_list_lock);
37 kref_get(&cfid->refcount);
38 spin_unlock(&cfids->cfid_list_lock);
43 spin_unlock(&cfids->cfid_list_lock);
46 if (cfids->num_entries >= MAX_CACHED_FIDS) {
47 spin_unlock(&cfids->cfid_list_lock);
50 cfid = init_cached_dir(path);
52 spin_unlock(&cfids->cfid_list_lock);
57 list_add(&cfid->entry, &cfids->entries);
59 kref_get(&cfid->refcount);
60 spin_unlock(&cfids->cfid_list_lock);
64 static struct dentry *
65 path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path)
67 struct dentry *dentry;
71 sep = CIFS_DIR_SEP(cifs_sb);
72 dentry = dget(cifs_sb->root);
76 struct inode *dir = d_inode(dentry);
79 if (!S_ISDIR(dir->i_mode)) {
81 dentry = ERR_PTR(-ENOTDIR);
92 while (*s && *s != sep)
95 child = lookup_positive_unlocked(p, dentry, s - p);
98 } while (!IS_ERR(dentry));
102 static const char *path_no_prefix(struct cifs_sb_info *cifs_sb,
110 if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
112 len = strlen(cifs_sb->prepath) + 1;
113 if (unlikely(len > strlen(path)))
114 return ERR_PTR(-EINVAL);
120 * Open the and cache a directory handle.
121 * If error then *cfid is not initialized.
123 int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
125 struct cifs_sb_info *cifs_sb,
126 bool lookup_only, struct cached_fid **ret_cfid)
128 struct cifs_ses *ses;
129 struct TCP_Server_Info *server;
130 struct cifs_open_parms oparms;
131 struct smb2_create_rsp *o_rsp = NULL;
132 struct smb2_query_info_rsp *qi_rsp = NULL;
134 struct smb_rqst rqst[2];
135 struct kvec rsp_iov[2];
136 struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
137 struct kvec qi_iov[1];
139 __le16 *utf16_path = NULL;
140 u8 oplock = SMB2_OPLOCK_LEVEL_II;
141 struct cifs_fid *pfid;
142 struct dentry *dentry = NULL;
143 struct cached_fid *cfid;
144 struct cached_fids *cfids;
147 if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache ||
148 is_smb1_server(tcon->ses->server))
152 server = cifs_pick_channel(ses);
155 if (!server->ops->new_lease_key)
158 if (cifs_sb->root == NULL)
161 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
165 cfid = find_or_create_cached_dir(cfids, path, lookup_only);
171 * At this point we either have a lease already and we can just
172 * return it. If not we are guaranteed to be the only thread accessing
175 if (cfid->has_lease) {
182 * Skip any prefix paths in @path as lookup_positive_unlocked() ends up
183 * calling ->lookup() which already adds those through
184 * build_path_from_dentry(). Also, do it earlier as we might reconnect
185 * below when trying to send compounded request and then potentially
186 * having a different prefix path (e.g. after DFS failover).
188 npath = path_no_prefix(cifs_sb, path);
196 * We do not hold the lock for the open because in case
197 * SMB2_open needs to reconnect.
198 * This is safe because no other thread will be able to get a ref
199 * to the cfid until we have finished opening the file and (possibly)
202 if (smb3_encryption_required(tcon))
203 flags |= CIFS_TRANSFORM_REQ;
206 server->ops->new_lease_key(pfid);
208 memset(rqst, 0, sizeof(rqst));
209 resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
210 memset(rsp_iov, 0, sizeof(rsp_iov));
213 memset(&open_iov, 0, sizeof(open_iov));
214 rqst[0].rq_iov = open_iov;
215 rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
217 oparms = (struct cifs_open_parms) {
220 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE),
221 .desired_access = FILE_READ_DATA | FILE_READ_ATTRIBUTES |
223 .disposition = FILE_OPEN,
227 rc = SMB2_open_init(tcon, server,
228 &rqst[0], &oplock, &oparms, utf16_path);
231 smb2_set_next_command(tcon, &rqst[0]);
233 memset(&qi_iov, 0, sizeof(qi_iov));
234 rqst[1].rq_iov = qi_iov;
237 rc = SMB2_query_info_init(tcon, server,
238 &rqst[1], COMPOUND_FID,
239 COMPOUND_FID, FILE_ALL_INFORMATION,
241 sizeof(struct smb2_file_all_info) +
242 PATH_MAX * 2, 0, NULL);
246 smb2_set_related(&rqst[1]);
248 rc = compound_send_recv(xid, ses, server,
250 resp_buftype, rsp_iov);
252 if (rc == -EREMCHG) {
253 tcon->need_reconnect = true;
254 pr_warn_once("server share %s deleted\n",
260 cfid->is_open = true;
262 o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
263 oparms.fid->persistent_fid = o_rsp->PersistentFileId;
264 oparms.fid->volatile_fid = o_rsp->VolatileFileId;
265 #ifdef CONFIG_CIFS_DEBUG2
266 oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
267 #endif /* CIFS_DEBUG2 */
269 if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE)
272 rc = smb2_parse_contexts(server, rsp_iov,
274 oparms.fid->lease_key,
275 &oplock, NULL, NULL);
278 if (!(oplock & SMB2_LEASE_READ_CACHING_HE))
280 qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
281 if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))
283 if (!smb2_validate_and_copy_iov(
284 le16_to_cpu(qi_rsp->OutputBufferOffset),
285 sizeof(struct smb2_file_all_info),
286 &rsp_iov[1], sizeof(struct smb2_file_all_info),
287 (char *)&cfid->file_all_info))
288 cfid->file_all_info_is_valid = true;
291 dentry = dget(cifs_sb->root);
293 dentry = path_to_dentry(cifs_sb, npath);
294 if (IS_ERR(dentry)) {
299 cfid->dentry = dentry;
300 cfid->time = jiffies;
301 cfid->has_lease = true;
305 SMB2_open_free(&rqst[0]);
306 SMB2_query_info_free(&rqst[1]);
307 free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
308 free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
309 spin_lock(&cfids->cfid_list_lock);
310 if (rc && !cfid->has_lease) {
312 list_del(&cfid->entry);
313 cfid->on_list = false;
314 cfids->num_entries--;
318 spin_unlock(&cfids->cfid_list_lock);
319 if (!rc && !cfid->has_lease) {
321 * We are guaranteed to have two references at this point.
322 * One for the caller and one for a potential lease.
323 * Release the Lease-ref so that the directory will be closed
324 * when the caller closes the cached handle.
326 kref_put(&cfid->refcount, smb2_close_cached_fid);
330 SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
331 cfid->fid.volatile_fid);
332 free_cached_dir(cfid);
338 atomic_inc(&tcon->num_remote_opens);
344 int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
345 struct dentry *dentry,
346 struct cached_fid **ret_cfid)
348 struct cached_fid *cfid;
349 struct cached_fids *cfids = tcon->cfids;
354 spin_lock(&cfids->cfid_list_lock);
355 list_for_each_entry(cfid, &cfids->entries, entry) {
356 if (dentry && cfid->dentry == dentry) {
357 cifs_dbg(FYI, "found a cached root file handle by dentry\n");
358 kref_get(&cfid->refcount);
360 spin_unlock(&cfids->cfid_list_lock);
364 spin_unlock(&cfids->cfid_list_lock);
369 smb2_close_cached_fid(struct kref *ref)
371 struct cached_fid *cfid = container_of(ref, struct cached_fid,
375 spin_lock(&cfid->cfids->cfid_list_lock);
377 list_del(&cfid->entry);
378 cfid->on_list = false;
379 cfid->cfids->num_entries--;
381 spin_unlock(&cfid->cfids->cfid_list_lock);
387 rc = SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
388 cfid->fid.volatile_fid);
389 if (rc != -EBUSY && rc != -EAGAIN)
390 atomic_dec(&cfid->tcon->num_remote_opens);
393 free_cached_dir(cfid);
396 void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
397 const char *name, struct cifs_sb_info *cifs_sb)
399 struct cached_fid *cfid = NULL;
402 rc = open_cached_dir(xid, tcon, name, cifs_sb, true, &cfid);
404 cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
407 spin_lock(&cfid->cfids->cfid_list_lock);
408 if (cfid->has_lease) {
409 cfid->has_lease = false;
410 kref_put(&cfid->refcount, smb2_close_cached_fid);
412 spin_unlock(&cfid->cfids->cfid_list_lock);
413 close_cached_dir(cfid);
417 void close_cached_dir(struct cached_fid *cfid)
419 kref_put(&cfid->refcount, smb2_close_cached_fid);
423 * Called from cifs_kill_sb when we unmount a share
425 void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
427 struct rb_root *root = &cifs_sb->tlink_tree;
428 struct rb_node *node;
429 struct cached_fid *cfid;
430 struct cifs_tcon *tcon;
431 struct tcon_link *tlink;
432 struct cached_fids *cfids;
434 for (node = rb_first(root); node; node = rb_next(node)) {
435 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
436 tcon = tlink_tcon(tlink);
442 list_for_each_entry(cfid, &cfids->entries, entry) {
450 * Invalidate all cached dirs when a TCON has been reset
451 * due to a session loss.
453 void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
455 struct cached_fids *cfids = tcon->cfids;
456 struct cached_fid *cfid, *q;
459 spin_lock(&cfids->cfid_list_lock);
460 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
461 list_move(&cfid->entry, &entry);
462 cfids->num_entries--;
463 cfid->is_open = false;
464 cfid->on_list = false;
465 /* To prevent race with smb2_cached_lease_break() */
466 kref_get(&cfid->refcount);
468 spin_unlock(&cfids->cfid_list_lock);
470 list_for_each_entry_safe(cfid, q, &entry, entry) {
471 list_del(&cfid->entry);
472 cancel_work_sync(&cfid->lease_break);
473 if (cfid->has_lease) {
475 * We lease was never cancelled from the server so we
476 * need to drop the reference.
478 spin_lock(&cfids->cfid_list_lock);
479 cfid->has_lease = false;
480 spin_unlock(&cfids->cfid_list_lock);
481 kref_put(&cfid->refcount, smb2_close_cached_fid);
483 /* Drop the extra reference opened above*/
484 kref_put(&cfid->refcount, smb2_close_cached_fid);
489 smb2_cached_lease_break(struct work_struct *work)
491 struct cached_fid *cfid = container_of(work,
492 struct cached_fid, lease_break);
494 spin_lock(&cfid->cfids->cfid_list_lock);
495 cfid->has_lease = false;
496 spin_unlock(&cfid->cfids->cfid_list_lock);
497 kref_put(&cfid->refcount, smb2_close_cached_fid);
500 int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
502 struct cached_fids *cfids = tcon->cfids;
503 struct cached_fid *cfid;
508 spin_lock(&cfids->cfid_list_lock);
509 list_for_each_entry(cfid, &cfids->entries, entry) {
510 if (cfid->has_lease &&
513 SMB2_LEASE_KEY_SIZE)) {
516 * We found a lease remove it from the list
517 * so no threads can access it.
519 list_del(&cfid->entry);
520 cfid->on_list = false;
521 cfids->num_entries--;
523 queue_work(cifsiod_wq,
525 spin_unlock(&cfids->cfid_list_lock);
529 spin_unlock(&cfids->cfid_list_lock);
533 static struct cached_fid *init_cached_dir(const char *path)
535 struct cached_fid *cfid;
537 cfid = kzalloc(sizeof(*cfid), GFP_ATOMIC);
540 cfid->path = kstrdup(path, GFP_ATOMIC);
546 INIT_WORK(&cfid->lease_break, smb2_cached_lease_break);
547 INIT_LIST_HEAD(&cfid->entry);
548 INIT_LIST_HEAD(&cfid->dirents.entries);
549 mutex_init(&cfid->dirents.de_mutex);
550 spin_lock_init(&cfid->fid_lock);
551 kref_init(&cfid->refcount);
555 static void free_cached_dir(struct cached_fid *cfid)
557 struct cached_dirent *dirent, *q;
563 * Delete all cached dirent names
565 list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
566 list_del(&dirent->entry);
576 struct cached_fids *init_cached_dirs(void)
578 struct cached_fids *cfids;
580 cfids = kzalloc(sizeof(*cfids), GFP_KERNEL);
583 spin_lock_init(&cfids->cfid_list_lock);
584 INIT_LIST_HEAD(&cfids->entries);
589 * Called from tconInfoFree when we are tearing down the tcon.
590 * There are no active users or open files/directories at this point.
592 void free_cached_dirs(struct cached_fids *cfids)
594 struct cached_fid *cfid, *q;
597 spin_lock(&cfids->cfid_list_lock);
598 list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
599 cfid->on_list = false;
600 cfid->is_open = false;
601 list_move(&cfid->entry, &entry);
603 spin_unlock(&cfids->cfid_list_lock);
605 list_for_each_entry_safe(cfid, q, &entry, entry) {
606 list_del(&cfid->entry);
607 free_cached_dir(cfid);