1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ceph/ceph_debug.h>
3
4 #include <linux/exportfs.h>
5 #include <linux/slab.h>
6 #include <asm/unaligned.h>
7
8 #include "super.h"
9 #include "mds_client.h"
10 #include "crypto.h"
11
12 /*
13 * Basic fh
14 */
15 struct ceph_nfs_fh {
16 u64 ino;
17 } __attribute__ ((packed));
18
19 /*
20 * Larger fh that includes parent ino.
21 */
22 struct ceph_nfs_confh {
23 u64 ino, parent_ino;
24 } __attribute__ ((packed));
25
26 /*
27 * fh for snapped inode
28 */
29 struct ceph_nfs_snapfh {
30 u64 ino;
31 u64 snapid;
32 u64 parent_ino;
33 u32 hash;
34 } __attribute__ ((packed));
35
36 static int ceph_encode_snapfh(struct inode *inode, u32 *rawfh, int *max_len,
37 struct inode *parent_inode)
38 {
39 struct ceph_client *cl = ceph_inode_to_client(inode);
40 static const int snap_handle_length =
41 sizeof(struct ceph_nfs_snapfh) >> 2;
42 struct ceph_nfs_snapfh *sfh = (void *)rawfh;
43 u64 snapid = ceph_snap(inode);
44 int ret;
45 bool no_parent = true;
46
47 if (*max_len < snap_handle_length) {
48 *max_len = snap_handle_length;
49 ret = FILEID_INVALID;
50 goto out;
51 }
52
53 ret = -EINVAL;
54 if (snapid != CEPH_SNAPDIR) {
55 struct inode *dir;
56 struct dentry *dentry = d_find_alias(inode);
57 if (!dentry)
58 goto out;
59
60 rcu_read_lock();
61 dir = d_inode_rcu(dentry->d_parent);
62 if (ceph_snap(dir) != CEPH_SNAPDIR) {
63 sfh->parent_ino = ceph_ino(dir);
64 sfh->hash = ceph_dentry_hash(dir, dentry);
65 no_parent = false;
66 }
67 rcu_read_unlock();
68 dput(dentry);
69 }
70
71 if (no_parent) {
72 if (!S_ISDIR(inode->i_mode))
73 goto out;
74 sfh->parent_ino = sfh->ino;
75 sfh->hash = 0;
76 }
77 sfh->ino = ceph_ino(inode);
78 sfh->snapid = snapid;
79
80 *max_len = snap_handle_length;
81 ret = FILEID_BTRFS_WITH_PARENT;
82 out:
83 doutc(cl, "%p %llx.%llx ret=%d\n", inode, ceph_vinop(inode), ret);
84 return ret;
85 }
86
87 static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
88 struct inode *parent_inode)
89 {
90 struct ceph_client *cl = ceph_inode_to_client(inode);
91 static const int handle_length =
92 sizeof(struct ceph_nfs_fh) >> 2;
93 static const int connected_handle_length =
94 sizeof(struct ceph_nfs_confh) >> 2;
95 int type;
96
97 if (ceph_snap(inode) != CEPH_NOSNAP)
98 return ceph_encode_snapfh(inode, rawfh, max_len, parent_inode);
99
100 if (parent_inode && (*max_len < connected_handle_length)) {
101 *max_len = connected_handle_length;
102 return FILEID_INVALID;
103 } else if (*max_len < handle_length) {
104 *max_len = handle_length;
105 return FILEID_INVALID;
106 }
107
108 if (parent_inode) {
109 struct ceph_nfs_confh *cfh = (void *)rawfh;
110 doutc(cl, "%p %llx.%llx with parent %p %llx.%llx\n", inode,
111 ceph_vinop(inode), parent_inode, ceph_vinop(parent_inode));
112 cfh->ino = ceph_ino(inode);
113 cfh->parent_ino = ceph_ino(parent_inode);
114 *max_len = connected_handle_length;
115 type = FILEID_INO32_GEN_PARENT;
116 } else {
117 struct ceph_nfs_fh *fh = (void *)rawfh;
118 doutc(cl, "%p %llx.%llx\n", inode, ceph_vinop(inode));
119 fh->ino = ceph_ino(inode);
120 *max_len = handle_length;
121 type = FILEID_INO32_GEN;
122 }
123 return type;
124 }
125
126 static struct inode *__lookup_inode(struct super_block *sb, u64 ino)
127 {
128 struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(sb)->mdsc;
129 struct inode *inode;
130 struct ceph_vino vino;
131 int err;
132
133 vino.ino = ino;
134 vino.snap = CEPH_NOSNAP;
135
136 if (ceph_vino_is_reserved(vino))
137 return ERR_PTR(-ESTALE);
138
139 inode = ceph_find_inode(sb, vino);
140 if (!inode) {
141 struct ceph_mds_request *req;
142 int mask;
143
144 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
145 USE_ANY_MDS);
146 if (IS_ERR(req))
147 return ERR_CAST(req);
148
149 mask = CEPH_STAT_CAP_INODE;
150 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
151 mask |= CEPH_CAP_XATTR_SHARED;
152 req->r_args.lookupino.mask = cpu_to_le32(mask);
153
154 req->r_ino1 = vino;
155 req->r_num_caps = 1;
156 err = ceph_mdsc_do_request(mdsc, NULL, req);
157 inode = req->r_target_inode;
158 if (inode)
159 ihold(inode);
160 ceph_mdsc_put_request(req);
161 if (!inode)
162 return err < 0 ? ERR_PTR(err) : ERR_PTR(-ESTALE);
163 } else {
164 if (ceph_inode_is_shutdown(inode)) {
165 iput(inode);
166 return ERR_PTR(-ESTALE);
167 }
168 }
169 return inode;
170 }
171
172 struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino)
173 {
174 struct inode *inode = __lookup_inode(sb, ino);
175 if (IS_ERR(inode))
176 return inode;
177 if (inode->i_nlink == 0) {
178 iput(inode);
179 return ERR_PTR(-ESTALE);
180 }
181 return inode;
182 }
183
184 static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino)
185 {
186 struct inode *inode = __lookup_inode(sb, ino);
187 struct ceph_inode_info *ci = ceph_inode(inode);
188 int err;
189
190 if (IS_ERR(inode))
191 return ERR_CAST(inode);
192 /* We need LINK caps to reliably check i_nlink */
193 err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false);
194 if (err) {
195 iput(inode);
196 return ERR_PTR(err);
197 }
198 /* -ESTALE if inode as been unlinked and no file is open */
199 if ((inode->i_nlink == 0) && !__ceph_is_file_opened(ci)) {
200 iput(inode);
201 return ERR_PTR(-ESTALE);
202 }
203 return d_obtain_alias(inode);
204 }
205
206 static struct dentry *__snapfh_to_dentry(struct super_block *sb,
207 struct ceph_nfs_snapfh *sfh,
208 bool want_parent)
209 {
210 struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(sb)->mdsc;
211 struct ceph_client *cl = mdsc->fsc->client;
212 struct ceph_mds_request *req;
213 struct inode *inode;
214 struct ceph_vino vino;
215 int mask;
216 int err;
217 bool unlinked = false;
218
219 if (want_parent) {
220 vino.ino = sfh->parent_ino;
221 if (sfh->snapid == CEPH_SNAPDIR)
222 vino.snap = CEPH_NOSNAP;
223 else if (sfh->ino == sfh->parent_ino)
224 vino.snap = CEPH_SNAPDIR;
225 else
226 vino.snap = sfh->snapid;
227 } else {
228 vino.ino = sfh->ino;
229 vino.snap = sfh->snapid;
230 }
231
232 if (ceph_vino_is_reserved(vino))
233 return ERR_PTR(-ESTALE);
234
235 inode = ceph_find_inode(sb, vino);
236 if (inode) {
237 if (ceph_inode_is_shutdown(inode)) {
238 iput(inode);
239 return ERR_PTR(-ESTALE);
240 }
241 return d_obtain_alias(inode);
242 }
243
244 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
245 USE_ANY_MDS);
246 if (IS_ERR(req))
247 return ERR_CAST(req);
248
249 mask = CEPH_STAT_CAP_INODE;
250 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
251 mask |= CEPH_CAP_XATTR_SHARED;
252 req->r_args.lookupino.mask = cpu_to_le32(mask);
253 if (vino.snap < CEPH_NOSNAP) {
254 req->r_args.lookupino.snapid = cpu_to_le64(vino.snap);
255 if (!want_parent && sfh->ino != sfh->parent_ino) {
256 req->r_args.lookupino.parent =
257 cpu_to_le64(sfh->parent_ino);
258 req->r_args.lookupino.hash =
259 cpu_to_le32(sfh->hash);
260 }
261 }
262
263 req->r_ino1 = vino;
264 req->r_num_caps = 1;
265 err = ceph_mdsc_do_request(mdsc, NULL, req);
266 inode = req->r_target_inode;
267 if (inode) {
268 if (vino.snap == CEPH_SNAPDIR) {
269 if (inode->i_nlink == 0)
270 unlinked = true;
271 inode = ceph_get_snapdir(inode);
272 } else if (ceph_snap(inode) == vino.snap) {
273 ihold(inode);
274 } else {
275 /* mds does not support lookup snapped inode */
276 inode = ERR_PTR(-EOPNOTSUPP);
277 }
278 } else {
279 inode = ERR_PTR(-ESTALE);
280 }
281 ceph_mdsc_put_request(req);
282
283 if (want_parent) {
284 doutc(cl, "%llx.%llx\n err=%d\n", vino.ino, vino.snap, err);
285 } else {
286 doutc(cl, "%llx.%llx parent %llx hash %x err=%d", vino.ino,
287 vino.snap, sfh->parent_ino, sfh->hash, err);
288 }
289 /* see comments in ceph_get_parent() */
290 return unlinked ? d_obtain_root(inode) : d_obtain_alias(inode);
291 }
292
293 /*
294 * convert regular fh to dentry
295 */
296 static struct dentry *ceph_fh_to_dentry(struct super_block *sb,
297 struct fid *fid,
298 int fh_len, int fh_type)
299 {
300 struct ceph_fs_client *fsc = ceph_sb_to_fs_client(sb);
301 struct ceph_nfs_fh *fh = (void *)fid->raw;
302
303 if (fh_type == FILEID_BTRFS_WITH_PARENT) {
304 struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
305 return __snapfh_to_dentry(sb, sfh, false);
306 }
307
308 if (fh_type != FILEID_INO32_GEN &&
309 fh_type != FILEID_INO32_GEN_PARENT)
310 return NULL;
311 if (fh_len < sizeof(*fh) / 4)
312 return NULL;
313
314 doutc(fsc->client, "%llx\n", fh->ino);
315 return __fh_to_dentry(sb, fh->ino);
316 }
317
318 static struct dentry *__get_parent(struct super_block *sb,
319 struct dentry *child, u64 ino)
320 {
321 struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(sb)->mdsc;
322 struct ceph_mds_request *req;
323 struct inode *inode;
324 int mask;
325 int err;
326
327 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT,
328 USE_ANY_MDS);
329 if (IS_ERR(req))
330 return ERR_CAST(req);
331
332 if (child) {
333 req->r_inode = d_inode(child);
334 ihold(d_inode(child));
335 } else {
336 req->r_ino1 = (struct ceph_vino) {
337 .ino = ino,
338 .snap = CEPH_NOSNAP,
339 };
340 }
341
342 mask = CEPH_STAT_CAP_INODE;
343 if (ceph_security_xattr_wanted(d_inode(sb->s_root)))
344 mask |= CEPH_CAP_XATTR_SHARED;
345 req->r_args.getattr.mask = cpu_to_le32(mask);
346
347 req->r_num_caps = 1;
348 err = ceph_mdsc_do_request(mdsc, NULL, req);
349 if (err) {
350 ceph_mdsc_put_request(req);
351 return ERR_PTR(err);
352 }
353
354 inode = req->r_target_inode;
355 if (inode)
356 ihold(inode);
357 ceph_mdsc_put_request(req);
358 if (!inode)
359 return ERR_PTR(-ENOENT);
360
361 return d_obtain_alias(inode);
362 }
363
364 static struct dentry *ceph_get_parent(struct dentry *child)
365 {
366 struct inode *inode = d_inode(child);
367 struct ceph_client *cl = ceph_inode_to_client(inode);
368 struct dentry *dn;
369
370 if (ceph_snap(inode) != CEPH_NOSNAP) {
371 struct inode* dir;
372 bool unlinked = false;
373 /* do not support non-directory */
374 if (!d_is_dir(child)) {
375 dn = ERR_PTR(-EINVAL);
376 goto out;
377 }
378 dir = __lookup_inode(inode->i_sb, ceph_ino(inode));
379 if (IS_ERR(dir)) {
380 dn = ERR_CAST(dir);
381 goto out;
382 }
383 /* There can be multiple paths to access snapped inode.
384 * For simplicity, treat snapdir of head inode as parent */
385 if (ceph_snap(inode) != CEPH_SNAPDIR) {
386 struct inode *snapdir = ceph_get_snapdir(dir);
387 if (dir->i_nlink == 0)
388 unlinked = true;
389 iput(dir);
390 if (IS_ERR(snapdir)) {
391 dn = ERR_CAST(snapdir);
392 goto out;
393 }
394 dir = snapdir;
395 }
396 /* If directory has already been deleted, futher get_parent
397 * will fail. Do not mark snapdir dentry as disconnected,
398 * this prevent exportfs from doing futher get_parent. */
399 if (unlinked)
400 dn = d_obtain_root(dir);
401 else
402 dn = d_obtain_alias(dir);
403 } else {
404 dn = __get_parent(child->d_sb, child, 0);
405 }
406 out:
407 doutc(cl, "child %p %p %llx.%llx err=%ld\n", child, inode,
408 ceph_vinop(inode), (long)PTR_ERR_OR_ZERO(dn));
409 return dn;
410 }
411
412 /*
413 * convert regular fh to parent
414 */
415 static struct dentry *ceph_fh_to_parent(struct super_block *sb,
416 struct fid *fid,
417 int fh_len, int fh_type)
418 {
419 struct ceph_fs_client *fsc = ceph_sb_to_fs_client(sb);
420 struct ceph_nfs_confh *cfh = (void *)fid->raw;
421 struct dentry *dentry;
422
423 if (fh_type == FILEID_BTRFS_WITH_PARENT) {
424 struct ceph_nfs_snapfh *sfh = (void *)fid->raw;
425 return __snapfh_to_dentry(sb, sfh, true);
426 }
427
428 if (fh_type != FILEID_INO32_GEN_PARENT)
429 return NULL;
430 if (fh_len < sizeof(*cfh) / 4)
431 return NULL;
432
433 doutc(fsc->client, "%llx\n", cfh->parent_ino);
434 dentry = __get_parent(sb, NULL, cfh->ino);
435 if (unlikely(dentry == ERR_PTR(-ENOENT)))
436 dentry = __fh_to_dentry(sb, cfh->parent_ino);
437 return dentry;
438 }
439
440 static int __get_snap_name(struct dentry *parent, char *name,
441 struct dentry *child)
442 {
443 struct inode *inode = d_inode(child);
444 struct inode *dir = d_inode(parent);
445 struct ceph_fs_client *fsc = ceph_inode_to_fs_client(inode);
446 struct ceph_mds_request *req = NULL;
447 char *last_name = NULL;
448 unsigned next_offset = 2;
449 int err = -EINVAL;
450
451 if (ceph_ino(inode) != ceph_ino(dir))
452 goto out;
453 if (ceph_snap(inode) == CEPH_SNAPDIR) {
454 if (ceph_snap(dir) == CEPH_NOSNAP) {
455 strcpy(name, fsc->mount_options->snapdir_name);
456 err = 0;
457 }
458 goto out;
459 }
460 if (ceph_snap(dir) != CEPH_SNAPDIR)
461 goto out;
462
463 while (1) {
464 struct ceph_mds_reply_info_parsed *rinfo;
465 struct ceph_mds_reply_dir_entry *rde;
466 int i;
467
468 req = ceph_mdsc_create_request(fsc->mdsc, CEPH_MDS_OP_LSSNAP,
469 USE_AUTH_MDS);
470 if (IS_ERR(req)) {
471 err = PTR_ERR(req);
472 req = NULL;
473 goto out;
474 }
475 err = ceph_alloc_readdir_reply_buffer(req, inode);
476 if (err)
477 goto out;
478
479 req->r_direct_mode = USE_AUTH_MDS;
480 req->r_readdir_offset = next_offset;
481 req->r_args.readdir.flags =
482 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
483 if (last_name) {
484 req->r_path2 = last_name;
485 last_name = NULL;
486 }
487
488 req->r_inode = dir;
489 ihold(dir);
490 req->r_dentry = dget(parent);
491
492 inode_lock(dir);
493 err = ceph_mdsc_do_request(fsc->mdsc, NULL, req);
494 inode_unlock(dir);
495
496 if (err < 0)
497 goto out;
498
499 rinfo = &req->r_reply_info;
500 for (i = 0; i < rinfo->dir_nr; i++) {
501 rde = rinfo->dir_entries + i;
502 BUG_ON(!rde->inode.in);
503 if (ceph_snap(inode) ==
504 le64_to_cpu(rde->inode.in->snapid)) {
505 memcpy(name, rde->name, rde->name_len);
506 name[rde->name_len] = '\0';
507 err = 0;
508 goto out;
509 }
510 }
511
512 if (rinfo->dir_end)
513 break;
514
515 BUG_ON(rinfo->dir_nr <= 0);
516 rde = rinfo->dir_entries + (rinfo->dir_nr - 1);
517 next_offset += rinfo->dir_nr;
518 last_name = kstrndup(rde->name, rde->name_len, GFP_KERNEL);
519 if (!last_name) {
520 err = -ENOMEM;
521 goto out;
522 }
523
524 ceph_mdsc_put_request(req);
525 req = NULL;
526 }
527 err = -ENOENT;
528 out:
529 if (req)
530 ceph_mdsc_put_request(req);
531 kfree(last_name);
532 doutc(fsc->client, "child dentry %p %p %llx.%llx err=%d\n", child,
533 inode, ceph_vinop(inode), err);
534 return err;
535 }
536
537 static int ceph_get_name(struct dentry *parent, char *name,
538 struct dentry *child)
539 {
540 struct ceph_mds_client *mdsc;
541 struct ceph_mds_request *req;
542 struct inode *dir = d_inode(parent);
543 struct inode *inode = d_inode(child);
544 struct ceph_mds_reply_info_parsed *rinfo;
545 int err;
546
547 if (ceph_snap(inode) != CEPH_NOSNAP)
548 return __get_snap_name(parent, name, child);
549
550 mdsc = ceph_inode_to_fs_client(inode)->mdsc;
551 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME,
552 USE_ANY_MDS);
553 if (IS_ERR(req))
554 return PTR_ERR(req);
555
556 inode_lock(dir);
557 req->r_inode = inode;
558 ihold(inode);
559 req->r_ino2 = ceph_vino(d_inode(parent));
560 req->r_parent = dir;
561 ihold(dir);
562 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
563 req->r_num_caps = 2;
564 err = ceph_mdsc_do_request(mdsc, NULL, req);
565 inode_unlock(dir);
566
567 if (err)
568 goto out;
569
570 rinfo = &req->r_reply_info;
571 if (!IS_ENCRYPTED(dir)) {
572 memcpy(name, rinfo->dname, rinfo->dname_len);
573 name[rinfo->dname_len] = 0;
574 } else {
575 struct fscrypt_str oname = FSTR_INIT(NULL, 0);
576 struct ceph_fname fname = { .dir = dir,
577 .name = rinfo->dname,
578 .ctext = rinfo->altname,
579 .name_len = rinfo->dname_len,
580 .ctext_len = rinfo->altname_len };
581
582 err = ceph_fname_alloc_buffer(dir, &oname);
583 if (err < 0)
584 goto out;
585
586 err = ceph_fname_to_usr(&fname, NULL, &oname, NULL);
587 if (!err) {
588 memcpy(name, oname.name, oname.len);
589 name[oname.len] = 0;
590 }
591 ceph_fname_free_buffer(dir, &oname);
592 }
593 out:
594 doutc(mdsc->fsc->client, "child dentry %p %p %llx.%llx err %d %s%s\n",
595 child, inode, ceph_vinop(inode), err, err ? "" : "name ",
596 err ? "" : name);
597 ceph_mdsc_put_request(req);
598 return err;
599 }
600
601 const struct export_operations ceph_export_ops = {
602 .encode_fh = ceph_encode_fh,
603 .fh_to_dentry = ceph_fh_to_dentry,
604 .fh_to_parent = ceph_fh_to_parent,
605 .get_parent = ceph_get_parent,
606 .get_name = ceph_get_name,
607 };
608
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