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1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ceph/ceph_debug.h>
3
4 #include <linux/spinlock.h>
5 #include <linux/namei.h>
6 #include <linux/slab.h>
7 #include <linux/sched.h>
8 #include <linux/xattr.h>
9
10 #include "super.h"
11 #include "mds_client.h"
12
13 /*
14 * Directory operations: readdir, lookup, create, link, unlink,
15 * rename, etc.
16 */
17
18 /*
19 * Ceph MDS operations are specified in terms of a base ino and
20 * relative path. Thus, the client can specify an operation on a
21 * specific inode (e.g., a getattr due to fstat(2)), or as a path
22 * relative to, say, the root directory.
23 *
24 * Normally, we limit ourselves to strict inode ops (no path component)
25 * or dentry operations (a single path component relative to an ino). The
26 * exception to this is open_root_dentry(), which will open the mount
27 * point by name.
28 */
29
30 const struct dentry_operations ceph_dentry_ops;
31
32 static bool __dentry_lease_is_valid(struct ceph_dentry_info *di);
33 static int __dir_lease_try_check(const struct dentry *dentry);
34
35 /*
36 * Initialize ceph dentry state.
37 */
38 static int ceph_d_init(struct dentry *dentry)
39 {
40 struct ceph_dentry_info *di;
41
42 di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
43 if (!di)
44 return -ENOMEM; /* oh well */
45
46 di->dentry = dentry;
47 di->lease_session = NULL;
48 di->time = jiffies;
49 dentry->d_fsdata = di;
50 INIT_LIST_HEAD(&di->lease_list);
51 return 0;
52 }
53
54 /*
55 * for f_pos for readdir:
56 * - hash order:
57 * (0xff << 52) | ((24 bits hash) << 28) |
58 * (the nth entry has hash collision);
59 * - frag+name order;
60 * ((frag value) << 28) | (the nth entry in frag);
61 */
62 #define OFFSET_BITS 28
63 #define OFFSET_MASK ((1 << OFFSET_BITS) - 1)
64 #define HASH_ORDER (0xffull << (OFFSET_BITS + 24))
65 loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
66 {
67 loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
68 if (hash_order)
69 fpos |= HASH_ORDER;
70 return fpos;
71 }
72
73 static bool is_hash_order(loff_t p)
74 {
75 return (p & HASH_ORDER) == HASH_ORDER;
76 }
77
78 static unsigned fpos_frag(loff_t p)
79 {
80 return p >> OFFSET_BITS;
81 }
82
83 static unsigned fpos_hash(loff_t p)
84 {
85 return ceph_frag_value(fpos_frag(p));
86 }
87
88 static unsigned fpos_off(loff_t p)
89 {
90 return p & OFFSET_MASK;
91 }
92
93 static int fpos_cmp(loff_t l, loff_t r)
94 {
95 int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
96 if (v)
97 return v;
98 return (int)(fpos_off(l) - fpos_off(r));
99 }
100
101 /*
102 * make note of the last dentry we read, so we can
103 * continue at the same lexicographical point,
104 * regardless of what dir changes take place on the
105 * server.
106 */
107 static int note_last_dentry(struct ceph_dir_file_info *dfi, const char *name,
108 int len, unsigned next_offset)
109 {
110 char *buf = kmalloc(len+1, GFP_KERNEL);
111 if (!buf)
112 return -ENOMEM;
113 kfree(dfi->last_name);
114 dfi->last_name = buf;
115 memcpy(dfi->last_name, name, len);
116 dfi->last_name[len] = 0;
117 dfi->next_offset = next_offset;
118 dout("note_last_dentry '%s'\n", dfi->last_name);
119 return 0;
120 }
121
122
123 static struct dentry *
124 __dcache_find_get_entry(struct dentry *parent, u64 idx,
125 struct ceph_readdir_cache_control *cache_ctl)
126 {
127 struct inode *dir = d_inode(parent);
128 struct dentry *dentry;
129 unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
130 loff_t ptr_pos = idx * sizeof(struct dentry *);
131 pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
132
133 if (ptr_pos >= i_size_read(dir))
134 return NULL;
135
136 if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
137 ceph_readdir_cache_release(cache_ctl);
138 cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
139 if (!cache_ctl->page) {
140 dout(" page %lu not found\n", ptr_pgoff);
141 return ERR_PTR(-EAGAIN);
142 }
143 /* reading/filling the cache are serialized by
144 i_mutex, no need to use page lock */
145 unlock_page(cache_ctl->page);
146 cache_ctl->dentries = kmap(cache_ctl->page);
147 }
148
149 cache_ctl->index = idx & idx_mask;
150
151 rcu_read_lock();
152 spin_lock(&parent->d_lock);
153 /* check i_size again here, because empty directory can be
154 * marked as complete while not holding the i_mutex. */
155 if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
156 dentry = cache_ctl->dentries[cache_ctl->index];
157 else
158 dentry = NULL;
159 spin_unlock(&parent->d_lock);
160 if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
161 dentry = NULL;
162 rcu_read_unlock();
163 return dentry ? : ERR_PTR(-EAGAIN);
164 }
165
166 /*
167 * When possible, we try to satisfy a readdir by peeking at the
168 * dcache. We make this work by carefully ordering dentries on
169 * d_child when we initially get results back from the MDS, and
170 * falling back to a "normal" sync readdir if any dentries in the dir
171 * are dropped.
172 *
173 * Complete dir indicates that we have all dentries in the dir. It is
174 * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
175 * the MDS if/when the directory is modified).
176 */
177 static int __dcache_readdir(struct file *file, struct dir_context *ctx,
178 int shared_gen)
179 {
180 struct ceph_dir_file_info *dfi = file->private_data;
181 struct dentry *parent = file->f_path.dentry;
182 struct inode *dir = d_inode(parent);
183 struct dentry *dentry, *last = NULL;
184 struct ceph_dentry_info *di;
185 struct ceph_readdir_cache_control cache_ctl = {};
186 u64 idx = 0;
187 int err = 0;
188
189 dout("__dcache_readdir %p v%u at %llx\n", dir, (unsigned)shared_gen, ctx->pos);
190
191 /* search start position */
192 if (ctx->pos > 2) {
193 u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
194 while (count > 0) {
195 u64 step = count >> 1;
196 dentry = __dcache_find_get_entry(parent, idx + step,
197 &cache_ctl);
198 if (!dentry) {
199 /* use linar search */
200 idx = 0;
201 break;
202 }
203 if (IS_ERR(dentry)) {
204 err = PTR_ERR(dentry);
205 goto out;
206 }
207 di = ceph_dentry(dentry);
208 spin_lock(&dentry->d_lock);
209 if (fpos_cmp(di->offset, ctx->pos) < 0) {
210 idx += step + 1;
211 count -= step + 1;
212 } else {
213 count = step;
214 }
215 spin_unlock(&dentry->d_lock);
216 dput(dentry);
217 }
218
219 dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
220 }
221
222
223 for (;;) {
224 bool emit_dentry = false;
225 dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
226 if (!dentry) {
227 dfi->file_info.flags |= CEPH_F_ATEND;
228 err = 0;
229 break;
230 }
231 if (IS_ERR(dentry)) {
232 err = PTR_ERR(dentry);
233 goto out;
234 }
235
236 spin_lock(&dentry->d_lock);
237 di = ceph_dentry(dentry);
238 if (d_unhashed(dentry) ||
239 d_really_is_negative(dentry) ||
240 di->lease_shared_gen != shared_gen) {
241 spin_unlock(&dentry->d_lock);
242 dput(dentry);
243 err = -EAGAIN;
244 goto out;
245 }
246 if (fpos_cmp(ctx->pos, di->offset) <= 0) {
247 __ceph_dentry_dir_lease_touch(di);
248 emit_dentry = true;
249 }
250 spin_unlock(&dentry->d_lock);
251
252 if (emit_dentry) {
253 dout(" %llx dentry %p %pd %p\n", di->offset,
254 dentry, dentry, d_inode(dentry));
255 ctx->pos = di->offset;
256 if (!dir_emit(ctx, dentry->d_name.name,
257 dentry->d_name.len,
258 ceph_translate_ino(dentry->d_sb,
259 d_inode(dentry)->i_ino),
260 d_inode(dentry)->i_mode >> 12)) {
261 dput(dentry);
262 err = 0;
263 break;
264 }
265 ctx->pos++;
266
267 if (last)
268 dput(last);
269 last = dentry;
270 } else {
271 dput(dentry);
272 }
273 }
274 out:
275 ceph_readdir_cache_release(&cache_ctl);
276 if (last) {
277 int ret;
278 di = ceph_dentry(last);
279 ret = note_last_dentry(dfi, last->d_name.name, last->d_name.len,
280 fpos_off(di->offset) + 1);
281 if (ret < 0)
282 err = ret;
283 dput(last);
284 /* last_name no longer match cache index */
285 if (dfi->readdir_cache_idx >= 0) {
286 dfi->readdir_cache_idx = -1;
287 dfi->dir_release_count = 0;
288 }
289 }
290 return err;
291 }
292
293 static bool need_send_readdir(struct ceph_dir_file_info *dfi, loff_t pos)
294 {
295 if (!dfi->last_readdir)
296 return true;
297 if (is_hash_order(pos))
298 return !ceph_frag_contains_value(dfi->frag, fpos_hash(pos));
299 else
300 return dfi->frag != fpos_frag(pos);
301 }
302
303 static int ceph_readdir(struct file *file, struct dir_context *ctx)
304 {
305 struct ceph_dir_file_info *dfi = file->private_data;
306 struct inode *inode = file_inode(file);
307 struct ceph_inode_info *ci = ceph_inode(inode);
308 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
309 struct ceph_mds_client *mdsc = fsc->mdsc;
310 int i;
311 int err;
312 unsigned frag = -1;
313 struct ceph_mds_reply_info_parsed *rinfo;
314
315 dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
316 if (dfi->file_info.flags & CEPH_F_ATEND)
317 return 0;
318
319 /* always start with . and .. */
320 if (ctx->pos == 0) {
321 dout("readdir off 0 -> '.'\n");
322 if (!dir_emit(ctx, ".", 1,
323 ceph_translate_ino(inode->i_sb, inode->i_ino),
324 inode->i_mode >> 12))
325 return 0;
326 ctx->pos = 1;
327 }
328 if (ctx->pos == 1) {
329 ino_t ino = parent_ino(file->f_path.dentry);
330 dout("readdir off 1 -> '..'\n");
331 if (!dir_emit(ctx, "..", 2,
332 ceph_translate_ino(inode->i_sb, ino),
333 inode->i_mode >> 12))
334 return 0;
335 ctx->pos = 2;
336 }
337
338 /* can we use the dcache? */
339 spin_lock(&ci->i_ceph_lock);
340 if (ceph_test_mount_opt(fsc, DCACHE) &&
341 !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
342 ceph_snap(inode) != CEPH_SNAPDIR &&
343 __ceph_dir_is_complete_ordered(ci) &&
344 __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
345 int shared_gen = atomic_read(&ci->i_shared_gen);
346 spin_unlock(&ci->i_ceph_lock);
347 err = __dcache_readdir(file, ctx, shared_gen);
348 if (err != -EAGAIN)
349 return err;
350 } else {
351 spin_unlock(&ci->i_ceph_lock);
352 }
353
354 /* proceed with a normal readdir */
355 more:
356 /* do we have the correct frag content buffered? */
357 if (need_send_readdir(dfi, ctx->pos)) {
358 struct ceph_mds_request *req;
359 int op = ceph_snap(inode) == CEPH_SNAPDIR ?
360 CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
361
362 /* discard old result, if any */
363 if (dfi->last_readdir) {
364 ceph_mdsc_put_request(dfi->last_readdir);
365 dfi->last_readdir = NULL;
366 }
367
368 if (is_hash_order(ctx->pos)) {
369 /* fragtree isn't always accurate. choose frag
370 * based on previous reply when possible. */
371 if (frag == (unsigned)-1)
372 frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
373 NULL, NULL);
374 } else {
375 frag = fpos_frag(ctx->pos);
376 }
377
378 dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
379 ceph_vinop(inode), frag, dfi->last_name);
380 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
381 if (IS_ERR(req))
382 return PTR_ERR(req);
383 err = ceph_alloc_readdir_reply_buffer(req, inode);
384 if (err) {
385 ceph_mdsc_put_request(req);
386 return err;
387 }
388 /* hints to request -> mds selection code */
389 req->r_direct_mode = USE_AUTH_MDS;
390 if (op == CEPH_MDS_OP_READDIR) {
391 req->r_direct_hash = ceph_frag_value(frag);
392 __set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
393 req->r_inode_drop = CEPH_CAP_FILE_EXCL;
394 }
395 if (dfi->last_name) {
396 req->r_path2 = kstrdup(dfi->last_name, GFP_KERNEL);
397 if (!req->r_path2) {
398 ceph_mdsc_put_request(req);
399 return -ENOMEM;
400 }
401 } else if (is_hash_order(ctx->pos)) {
402 req->r_args.readdir.offset_hash =
403 cpu_to_le32(fpos_hash(ctx->pos));
404 }
405
406 req->r_dir_release_cnt = dfi->dir_release_count;
407 req->r_dir_ordered_cnt = dfi->dir_ordered_count;
408 req->r_readdir_cache_idx = dfi->readdir_cache_idx;
409 req->r_readdir_offset = dfi->next_offset;
410 req->r_args.readdir.frag = cpu_to_le32(frag);
411 req->r_args.readdir.flags =
412 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
413
414 req->r_inode = inode;
415 ihold(inode);
416 req->r_dentry = dget(file->f_path.dentry);
417 err = ceph_mdsc_do_request(mdsc, NULL, req);
418 if (err < 0) {
419 ceph_mdsc_put_request(req);
420 return err;
421 }
422 dout("readdir got and parsed readdir result=%d on "
423 "frag %x, end=%d, complete=%d, hash_order=%d\n",
424 err, frag,
425 (int)req->r_reply_info.dir_end,
426 (int)req->r_reply_info.dir_complete,
427 (int)req->r_reply_info.hash_order);
428
429 rinfo = &req->r_reply_info;
430 if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
431 frag = le32_to_cpu(rinfo->dir_dir->frag);
432 if (!rinfo->hash_order) {
433 dfi->next_offset = req->r_readdir_offset;
434 /* adjust ctx->pos to beginning of frag */
435 ctx->pos = ceph_make_fpos(frag,
436 dfi->next_offset,
437 false);
438 }
439 }
440
441 dfi->frag = frag;
442 dfi->last_readdir = req;
443
444 if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
445 dfi->readdir_cache_idx = req->r_readdir_cache_idx;
446 if (dfi->readdir_cache_idx < 0) {
447 /* preclude from marking dir ordered */
448 dfi->dir_ordered_count = 0;
449 } else if (ceph_frag_is_leftmost(frag) &&
450 dfi->next_offset == 2) {
451 /* note dir version at start of readdir so
452 * we can tell if any dentries get dropped */
453 dfi->dir_release_count = req->r_dir_release_cnt;
454 dfi->dir_ordered_count = req->r_dir_ordered_cnt;
455 }
456 } else {
457 dout("readdir !did_prepopulate\n");
458 /* disable readdir cache */
459 dfi->readdir_cache_idx = -1;
460 /* preclude from marking dir complete */
461 dfi->dir_release_count = 0;
462 }
463
464 /* note next offset and last dentry name */
465 if (rinfo->dir_nr > 0) {
466 struct ceph_mds_reply_dir_entry *rde =
467 rinfo->dir_entries + (rinfo->dir_nr-1);
468 unsigned next_offset = req->r_reply_info.dir_end ?
469 2 : (fpos_off(rde->offset) + 1);
470 err = note_last_dentry(dfi, rde->name, rde->name_len,
471 next_offset);
472 if (err)
473 return err;
474 } else if (req->r_reply_info.dir_end) {
475 dfi->next_offset = 2;
476 /* keep last name */
477 }
478 }
479
480 rinfo = &dfi->last_readdir->r_reply_info;
481 dout("readdir frag %x num %d pos %llx chunk first %llx\n",
482 dfi->frag, rinfo->dir_nr, ctx->pos,
483 rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
484
485 i = 0;
486 /* search start position */
487 if (rinfo->dir_nr > 0) {
488 int step, nr = rinfo->dir_nr;
489 while (nr > 0) {
490 step = nr >> 1;
491 if (rinfo->dir_entries[i + step].offset < ctx->pos) {
492 i += step + 1;
493 nr -= step + 1;
494 } else {
495 nr = step;
496 }
497 }
498 }
499 for (; i < rinfo->dir_nr; i++) {
500 struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
501 struct ceph_vino vino;
502 ino_t ino;
503 u32 ftype;
504
505 BUG_ON(rde->offset < ctx->pos);
506
507 ctx->pos = rde->offset;
508 dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
509 i, rinfo->dir_nr, ctx->pos,
510 rde->name_len, rde->name, &rde->inode.in);
511
512 BUG_ON(!rde->inode.in);
513 ftype = le32_to_cpu(rde->inode.in->mode) >> 12;
514 vino.ino = le64_to_cpu(rde->inode.in->ino);
515 vino.snap = le64_to_cpu(rde->inode.in->snapid);
516 ino = ceph_vino_to_ino(vino);
517
518 if (!dir_emit(ctx, rde->name, rde->name_len,
519 ceph_translate_ino(inode->i_sb, ino), ftype)) {
520 dout("filldir stopping us...\n");
521 return 0;
522 }
523 ctx->pos++;
524 }
525
526 ceph_mdsc_put_request(dfi->last_readdir);
527 dfi->last_readdir = NULL;
528
529 if (dfi->next_offset > 2) {
530 frag = dfi->frag;
531 goto more;
532 }
533
534 /* more frags? */
535 if (!ceph_frag_is_rightmost(dfi->frag)) {
536 frag = ceph_frag_next(dfi->frag);
537 if (is_hash_order(ctx->pos)) {
538 loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
539 dfi->next_offset, true);
540 if (new_pos > ctx->pos)
541 ctx->pos = new_pos;
542 /* keep last_name */
543 } else {
544 ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
545 false);
546 kfree(dfi->last_name);
547 dfi->last_name = NULL;
548 }
549 dout("readdir next frag is %x\n", frag);
550 goto more;
551 }
552 dfi->file_info.flags |= CEPH_F_ATEND;
553
554 /*
555 * if dir_release_count still matches the dir, no dentries
556 * were released during the whole readdir, and we should have
557 * the complete dir contents in our cache.
558 */
559 if (atomic64_read(&ci->i_release_count) ==
560 dfi->dir_release_count) {
561 spin_lock(&ci->i_ceph_lock);
562 if (dfi->dir_ordered_count ==
563 atomic64_read(&ci->i_ordered_count)) {
564 dout(" marking %p complete and ordered\n", inode);
565 /* use i_size to track number of entries in
566 * readdir cache */
567 BUG_ON(dfi->readdir_cache_idx < 0);
568 i_size_write(inode, dfi->readdir_cache_idx *
569 sizeof(struct dentry*));
570 } else {
571 dout(" marking %p complete\n", inode);
572 }
573 __ceph_dir_set_complete(ci, dfi->dir_release_count,
574 dfi->dir_ordered_count);
575 spin_unlock(&ci->i_ceph_lock);
576 }
577
578 dout("readdir %p file %p done.\n", inode, file);
579 return 0;
580 }
581
582 static void reset_readdir(struct ceph_dir_file_info *dfi)
583 {
584 if (dfi->last_readdir) {
585 ceph_mdsc_put_request(dfi->last_readdir);
586 dfi->last_readdir = NULL;
587 }
588 kfree(dfi->last_name);
589 dfi->last_name = NULL;
590 dfi->dir_release_count = 0;
591 dfi->readdir_cache_idx = -1;
592 dfi->next_offset = 2; /* compensate for . and .. */
593 dfi->file_info.flags &= ~CEPH_F_ATEND;
594 }
595
596 /*
597 * discard buffered readdir content on seekdir(0), or seek to new frag,
598 * or seek prior to current chunk
599 */
600 static bool need_reset_readdir(struct ceph_dir_file_info *dfi, loff_t new_pos)
601 {
602 struct ceph_mds_reply_info_parsed *rinfo;
603 loff_t chunk_offset;
604 if (new_pos == 0)
605 return true;
606 if (is_hash_order(new_pos)) {
607 /* no need to reset last_name for a forward seek when
608 * dentries are sotred in hash order */
609 } else if (dfi->frag != fpos_frag(new_pos)) {
610 return true;
611 }
612 rinfo = dfi->last_readdir ? &dfi->last_readdir->r_reply_info : NULL;
613 if (!rinfo || !rinfo->dir_nr)
614 return true;
615 chunk_offset = rinfo->dir_entries[0].offset;
616 return new_pos < chunk_offset ||
617 is_hash_order(new_pos) != is_hash_order(chunk_offset);
618 }
619
620 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
621 {
622 struct ceph_dir_file_info *dfi = file->private_data;
623 struct inode *inode = file->f_mapping->host;
624 loff_t retval;
625
626 inode_lock(inode);
627 retval = -EINVAL;
628 switch (whence) {
629 case SEEK_CUR:
630 offset += file->f_pos;
631 case SEEK_SET:
632 break;
633 case SEEK_END:
634 retval = -EOPNOTSUPP;
635 default:
636 goto out;
637 }
638
639 if (offset >= 0) {
640 if (need_reset_readdir(dfi, offset)) {
641 dout("dir_llseek dropping %p content\n", file);
642 reset_readdir(dfi);
643 } else if (is_hash_order(offset) && offset > file->f_pos) {
644 /* for hash offset, we don't know if a forward seek
645 * is within same frag */
646 dfi->dir_release_count = 0;
647 dfi->readdir_cache_idx = -1;
648 }
649
650 if (offset != file->f_pos) {
651 file->f_pos = offset;
652 file->f_version = 0;
653 dfi->file_info.flags &= ~CEPH_F_ATEND;
654 }
655 retval = offset;
656 }
657 out:
658 inode_unlock(inode);
659 return retval;
660 }
661
662 /*
663 * Handle lookups for the hidden .snap directory.
664 */
665 int ceph_handle_snapdir(struct ceph_mds_request *req,
666 struct dentry *dentry, int err)
667 {
668 struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
669 struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
670
671 /* .snap dir? */
672 if (err == -ENOENT &&
673 ceph_snap(parent) == CEPH_NOSNAP &&
674 strcmp(dentry->d_name.name,
675 fsc->mount_options->snapdir_name) == 0) {
676 struct inode *inode = ceph_get_snapdir(parent);
677 dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
678 dentry, dentry, inode);
679 BUG_ON(!d_unhashed(dentry));
680 d_add(dentry, inode);
681 err = 0;
682 }
683 return err;
684 }
685
686 /*
687 * Figure out final result of a lookup/open request.
688 *
689 * Mainly, make sure we return the final req->r_dentry (if it already
690 * existed) in place of the original VFS-provided dentry when they
691 * differ.
692 *
693 * Gracefully handle the case where the MDS replies with -ENOENT and
694 * no trace (which it may do, at its discretion, e.g., if it doesn't
695 * care to issue a lease on the negative dentry).
696 */
697 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
698 struct dentry *dentry, int err)
699 {
700 if (err == -ENOENT) {
701 /* no trace? */
702 err = 0;
703 if (!req->r_reply_info.head->is_dentry) {
704 dout("ENOENT and no trace, dentry %p inode %p\n",
705 dentry, d_inode(dentry));
706 if (d_really_is_positive(dentry)) {
707 d_drop(dentry);
708 err = -ENOENT;
709 } else {
710 d_add(dentry, NULL);
711 }
712 }
713 }
714 if (err)
715 dentry = ERR_PTR(err);
716 else if (dentry != req->r_dentry)
717 dentry = dget(req->r_dentry); /* we got spliced */
718 else
719 dentry = NULL;
720 return dentry;
721 }
722
723 static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
724 {
725 return ceph_ino(inode) == CEPH_INO_ROOT &&
726 strncmp(dentry->d_name.name, ".ceph", 5) == 0;
727 }
728
729 /*
730 * Look up a single dir entry. If there is a lookup intent, inform
731 * the MDS so that it gets our 'caps wanted' value in a single op.
732 */
733 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
734 unsigned int flags)
735 {
736 struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
737 struct ceph_mds_client *mdsc = fsc->mdsc;
738 struct ceph_mds_request *req;
739 int op;
740 int mask;
741 int err;
742
743 dout("lookup %p dentry %p '%pd'\n",
744 dir, dentry, dentry);
745
746 if (dentry->d_name.len > NAME_MAX)
747 return ERR_PTR(-ENAMETOOLONG);
748
749 /* can we conclude ENOENT locally? */
750 if (d_really_is_negative(dentry)) {
751 struct ceph_inode_info *ci = ceph_inode(dir);
752 struct ceph_dentry_info *di = ceph_dentry(dentry);
753
754 spin_lock(&ci->i_ceph_lock);
755 dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
756 if (strncmp(dentry->d_name.name,
757 fsc->mount_options->snapdir_name,
758 dentry->d_name.len) &&
759 !is_root_ceph_dentry(dir, dentry) &&
760 ceph_test_mount_opt(fsc, DCACHE) &&
761 __ceph_dir_is_complete(ci) &&
762 (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
763 spin_unlock(&ci->i_ceph_lock);
764 dout(" dir %p complete, -ENOENT\n", dir);
765 d_add(dentry, NULL);
766 di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
767 return NULL;
768 }
769 spin_unlock(&ci->i_ceph_lock);
770 }
771
772 op = ceph_snap(dir) == CEPH_SNAPDIR ?
773 CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
774 req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
775 if (IS_ERR(req))
776 return ERR_CAST(req);
777 req->r_dentry = dget(dentry);
778 req->r_num_caps = 2;
779
780 mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
781 if (ceph_security_xattr_wanted(dir))
782 mask |= CEPH_CAP_XATTR_SHARED;
783 req->r_args.getattr.mask = cpu_to_le32(mask);
784
785 req->r_parent = dir;
786 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
787 err = ceph_mdsc_do_request(mdsc, NULL, req);
788 err = ceph_handle_snapdir(req, dentry, err);
789 dentry = ceph_finish_lookup(req, dentry, err);
790 ceph_mdsc_put_request(req); /* will dput(dentry) */
791 dout("lookup result=%p\n", dentry);
792 return dentry;
793 }
794
795 /*
796 * If we do a create but get no trace back from the MDS, follow up with
797 * a lookup (the VFS expects us to link up the provided dentry).
798 */
799 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
800 {
801 struct dentry *result = ceph_lookup(dir, dentry, 0);
802
803 if (result && !IS_ERR(result)) {
804 /*
805 * We created the item, then did a lookup, and found
806 * it was already linked to another inode we already
807 * had in our cache (and thus got spliced). To not
808 * confuse VFS (especially when inode is a directory),
809 * we don't link our dentry to that inode, return an
810 * error instead.
811 *
812 * This event should be rare and it happens only when
813 * we talk to old MDS. Recent MDS does not send traceless
814 * reply for request that creates new inode.
815 */
816 d_drop(result);
817 return -ESTALE;
818 }
819 return PTR_ERR(result);
820 }
821
822 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
823 umode_t mode, dev_t rdev)
824 {
825 struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
826 struct ceph_mds_client *mdsc = fsc->mdsc;
827 struct ceph_mds_request *req;
828 struct ceph_acls_info acls = {};
829 int err;
830
831 if (ceph_snap(dir) != CEPH_NOSNAP)
832 return -EROFS;
833
834 if (ceph_quota_is_max_files_exceeded(dir)) {
835 err = -EDQUOT;
836 goto out;
837 }
838
839 err = ceph_pre_init_acls(dir, &mode, &acls);
840 if (err < 0)
841 goto out;
842
843 dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
844 dir, dentry, mode, rdev);
845 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
846 if (IS_ERR(req)) {
847 err = PTR_ERR(req);
848 goto out;
849 }
850 req->r_dentry = dget(dentry);
851 req->r_num_caps = 2;
852 req->r_parent = dir;
853 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
854 req->r_args.mknod.mode = cpu_to_le32(mode);
855 req->r_args.mknod.rdev = cpu_to_le32(rdev);
856 req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
857 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
858 if (acls.pagelist) {
859 req->r_pagelist = acls.pagelist;
860 acls.pagelist = NULL;
861 }
862 err = ceph_mdsc_do_request(mdsc, dir, req);
863 if (!err && !req->r_reply_info.head->is_dentry)
864 err = ceph_handle_notrace_create(dir, dentry);
865 ceph_mdsc_put_request(req);
866 out:
867 if (!err)
868 ceph_init_inode_acls(d_inode(dentry), &acls);
869 else
870 d_drop(dentry);
871 ceph_release_acls_info(&acls);
872 return err;
873 }
874
875 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
876 bool excl)
877 {
878 return ceph_mknod(dir, dentry, mode, 0);
879 }
880
881 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
882 const char *dest)
883 {
884 struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
885 struct ceph_mds_client *mdsc = fsc->mdsc;
886 struct ceph_mds_request *req;
887 int err;
888
889 if (ceph_snap(dir) != CEPH_NOSNAP)
890 return -EROFS;
891
892 if (ceph_quota_is_max_files_exceeded(dir)) {
893 err = -EDQUOT;
894 goto out;
895 }
896
897 dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
898 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
899 if (IS_ERR(req)) {
900 err = PTR_ERR(req);
901 goto out;
902 }
903 req->r_path2 = kstrdup(dest, GFP_KERNEL);
904 if (!req->r_path2) {
905 err = -ENOMEM;
906 ceph_mdsc_put_request(req);
907 goto out;
908 }
909 req->r_parent = dir;
910 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
911 req->r_dentry = dget(dentry);
912 req->r_num_caps = 2;
913 req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
914 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
915 err = ceph_mdsc_do_request(mdsc, dir, req);
916 if (!err && !req->r_reply_info.head->is_dentry)
917 err = ceph_handle_notrace_create(dir, dentry);
918 ceph_mdsc_put_request(req);
919 out:
920 if (err)
921 d_drop(dentry);
922 return err;
923 }
924
925 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
926 {
927 struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
928 struct ceph_mds_client *mdsc = fsc->mdsc;
929 struct ceph_mds_request *req;
930 struct ceph_acls_info acls = {};
931 int err = -EROFS;
932 int op;
933
934 if (ceph_snap(dir) == CEPH_SNAPDIR) {
935 /* mkdir .snap/foo is a MKSNAP */
936 op = CEPH_MDS_OP_MKSNAP;
937 dout("mksnap dir %p snap '%pd' dn %p\n", dir,
938 dentry, dentry);
939 } else if (ceph_snap(dir) == CEPH_NOSNAP) {
940 dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
941 op = CEPH_MDS_OP_MKDIR;
942 } else {
943 goto out;
944 }
945
946 if (op == CEPH_MDS_OP_MKDIR &&
947 ceph_quota_is_max_files_exceeded(dir)) {
948 err = -EDQUOT;
949 goto out;
950 }
951
952 mode |= S_IFDIR;
953 err = ceph_pre_init_acls(dir, &mode, &acls);
954 if (err < 0)
955 goto out;
956
957 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
958 if (IS_ERR(req)) {
959 err = PTR_ERR(req);
960 goto out;
961 }
962
963 req->r_dentry = dget(dentry);
964 req->r_num_caps = 2;
965 req->r_parent = dir;
966 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
967 req->r_args.mkdir.mode = cpu_to_le32(mode);
968 req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
969 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
970 if (acls.pagelist) {
971 req->r_pagelist = acls.pagelist;
972 acls.pagelist = NULL;
973 }
974 err = ceph_mdsc_do_request(mdsc, dir, req);
975 if (!err &&
976 !req->r_reply_info.head->is_target &&
977 !req->r_reply_info.head->is_dentry)
978 err = ceph_handle_notrace_create(dir, dentry);
979 ceph_mdsc_put_request(req);
980 out:
981 if (!err)
982 ceph_init_inode_acls(d_inode(dentry), &acls);
983 else
984 d_drop(dentry);
985 ceph_release_acls_info(&acls);
986 return err;
987 }
988
989 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
990 struct dentry *dentry)
991 {
992 struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
993 struct ceph_mds_client *mdsc = fsc->mdsc;
994 struct ceph_mds_request *req;
995 int err;
996
997 if (ceph_snap(dir) != CEPH_NOSNAP)
998 return -EROFS;
999
1000 dout("link in dir %p old_dentry %p dentry %p\n", dir,
1001 old_dentry, dentry);
1002 req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
1003 if (IS_ERR(req)) {
1004 d_drop(dentry);
1005 return PTR_ERR(req);
1006 }
1007 req->r_dentry = dget(dentry);
1008 req->r_num_caps = 2;
1009 req->r_old_dentry = dget(old_dentry);
1010 req->r_parent = dir;
1011 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1012 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1013 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1014 /* release LINK_SHARED on source inode (mds will lock it) */
1015 req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1016 err = ceph_mdsc_do_request(mdsc, dir, req);
1017 if (err) {
1018 d_drop(dentry);
1019 } else if (!req->r_reply_info.head->is_dentry) {
1020 ihold(d_inode(old_dentry));
1021 d_instantiate(dentry, d_inode(old_dentry));
1022 }
1023 ceph_mdsc_put_request(req);
1024 return err;
1025 }
1026
1027 /*
1028 * rmdir and unlink are differ only by the metadata op code
1029 */
1030 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
1031 {
1032 struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
1033 struct ceph_mds_client *mdsc = fsc->mdsc;
1034 struct inode *inode = d_inode(dentry);
1035 struct ceph_mds_request *req;
1036 int err = -EROFS;
1037 int op;
1038
1039 if (ceph_snap(dir) == CEPH_SNAPDIR) {
1040 /* rmdir .snap/foo is RMSNAP */
1041 dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
1042 op = CEPH_MDS_OP_RMSNAP;
1043 } else if (ceph_snap(dir) == CEPH_NOSNAP) {
1044 dout("unlink/rmdir dir %p dn %p inode %p\n",
1045 dir, dentry, inode);
1046 op = d_is_dir(dentry) ?
1047 CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
1048 } else
1049 goto out;
1050 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1051 if (IS_ERR(req)) {
1052 err = PTR_ERR(req);
1053 goto out;
1054 }
1055 req->r_dentry = dget(dentry);
1056 req->r_num_caps = 2;
1057 req->r_parent = dir;
1058 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1059 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1060 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1061 req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
1062 err = ceph_mdsc_do_request(mdsc, dir, req);
1063 if (!err && !req->r_reply_info.head->is_dentry)
1064 d_delete(dentry);
1065 ceph_mdsc_put_request(req);
1066 out:
1067 return err;
1068 }
1069
1070 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
1071 struct inode *new_dir, struct dentry *new_dentry,
1072 unsigned int flags)
1073 {
1074 struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
1075 struct ceph_mds_client *mdsc = fsc->mdsc;
1076 struct ceph_mds_request *req;
1077 int op = CEPH_MDS_OP_RENAME;
1078 int err;
1079
1080 if (flags)
1081 return -EINVAL;
1082
1083 if (ceph_snap(old_dir) != ceph_snap(new_dir))
1084 return -EXDEV;
1085 if (ceph_snap(old_dir) != CEPH_NOSNAP) {
1086 if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
1087 op = CEPH_MDS_OP_RENAMESNAP;
1088 else
1089 return -EROFS;
1090 }
1091 /* don't allow cross-quota renames */
1092 if ((old_dir != new_dir) &&
1093 (!ceph_quota_is_same_realm(old_dir, new_dir)))
1094 return -EXDEV;
1095
1096 dout("rename dir %p dentry %p to dir %p dentry %p\n",
1097 old_dir, old_dentry, new_dir, new_dentry);
1098 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1099 if (IS_ERR(req))
1100 return PTR_ERR(req);
1101 ihold(old_dir);
1102 req->r_dentry = dget(new_dentry);
1103 req->r_num_caps = 2;
1104 req->r_old_dentry = dget(old_dentry);
1105 req->r_old_dentry_dir = old_dir;
1106 req->r_parent = new_dir;
1107 set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1108 req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
1109 req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
1110 req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1111 req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1112 /* release LINK_RDCACHE on source inode (mds will lock it) */
1113 req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1114 if (d_really_is_positive(new_dentry)) {
1115 req->r_inode_drop =
1116 ceph_drop_caps_for_unlink(d_inode(new_dentry));
1117 }
1118 err = ceph_mdsc_do_request(mdsc, old_dir, req);
1119 if (!err && !req->r_reply_info.head->is_dentry) {
1120 /*
1121 * Normally d_move() is done by fill_trace (called by
1122 * do_request, above). If there is no trace, we need
1123 * to do it here.
1124 */
1125 d_move(old_dentry, new_dentry);
1126 }
1127 ceph_mdsc_put_request(req);
1128 return err;
1129 }
1130
1131 /*
1132 * Move dentry to tail of mdsc->dentry_leases list when lease is updated.
1133 * Leases at front of the list will expire first. (Assume all leases have
1134 * similar duration)
1135 *
1136 * Called under dentry->d_lock.
1137 */
1138 void __ceph_dentry_lease_touch(struct ceph_dentry_info *di)
1139 {
1140 struct dentry *dn = di->dentry;
1141 struct ceph_mds_client *mdsc;
1142
1143 dout("dentry_lease_touch %p %p '%pd'\n", di, dn, dn);
1144
1145 di->flags |= CEPH_DENTRY_LEASE_LIST;
1146 if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1147 di->flags |= CEPH_DENTRY_REFERENCED;
1148 return;
1149 }
1150
1151 mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1152 spin_lock(&mdsc->dentry_list_lock);
1153 list_move_tail(&di->lease_list, &mdsc->dentry_leases);
1154 spin_unlock(&mdsc->dentry_list_lock);
1155 }
1156
1157 static void __dentry_dir_lease_touch(struct ceph_mds_client* mdsc,
1158 struct ceph_dentry_info *di)
1159 {
1160 di->flags &= ~(CEPH_DENTRY_LEASE_LIST | CEPH_DENTRY_REFERENCED);
1161 di->lease_gen = 0;
1162 di->time = jiffies;
1163 list_move_tail(&di->lease_list, &mdsc->dentry_dir_leases);
1164 }
1165
1166 /*
1167 * When dir lease is used, add dentry to tail of mdsc->dentry_dir_leases
1168 * list if it's not in the list, otherwise set 'referenced' flag.
1169 *
1170 * Called under dentry->d_lock.
1171 */
1172 void __ceph_dentry_dir_lease_touch(struct ceph_dentry_info *di)
1173 {
1174 struct dentry *dn = di->dentry;
1175 struct ceph_mds_client *mdsc;
1176
1177 dout("dentry_dir_lease_touch %p %p '%pd' (offset %lld)\n",
1178 di, dn, dn, di->offset);
1179
1180 if (!list_empty(&di->lease_list)) {
1181 if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1182 /* don't remove dentry from dentry lease list
1183 * if its lease is valid */
1184 if (__dentry_lease_is_valid(di))
1185 return;
1186 } else {
1187 di->flags |= CEPH_DENTRY_REFERENCED;
1188 return;
1189 }
1190 }
1191
1192 if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1193 di->flags |= CEPH_DENTRY_REFERENCED;
1194 di->flags &= ~CEPH_DENTRY_LEASE_LIST;
1195 return;
1196 }
1197
1198 mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1199 spin_lock(&mdsc->dentry_list_lock);
1200 __dentry_dir_lease_touch(mdsc, di),
1201 spin_unlock(&mdsc->dentry_list_lock);
1202 }
1203
1204 static void __dentry_lease_unlist(struct ceph_dentry_info *di)
1205 {
1206 struct ceph_mds_client *mdsc;
1207 if (di->flags & CEPH_DENTRY_SHRINK_LIST)
1208 return;
1209 if (list_empty(&di->lease_list))
1210 return;
1211
1212 mdsc = ceph_sb_to_client(di->dentry->d_sb)->mdsc;
1213 spin_lock(&mdsc->dentry_list_lock);
1214 list_del_init(&di->lease_list);
1215 spin_unlock(&mdsc->dentry_list_lock);
1216 }
1217
1218 enum {
1219 KEEP = 0,
1220 DELETE = 1,
1221 TOUCH = 2,
1222 STOP = 4,
1223 };
1224
1225 struct ceph_lease_walk_control {
1226 bool dir_lease;
1227 bool expire_dir_lease;
1228 unsigned long nr_to_scan;
1229 unsigned long dir_lease_ttl;
1230 };
1231
1232 static unsigned long
1233 __dentry_leases_walk(struct ceph_mds_client *mdsc,
1234 struct ceph_lease_walk_control *lwc,
1235 int (*check)(struct dentry*, void*))
1236 {
1237 struct ceph_dentry_info *di, *tmp;
1238 struct dentry *dentry, *last = NULL;
1239 struct list_head* list;
1240 LIST_HEAD(dispose);
1241 unsigned long freed = 0;
1242 int ret = 0;
1243
1244 list = lwc->dir_lease ? &mdsc->dentry_dir_leases : &mdsc->dentry_leases;
1245 spin_lock(&mdsc->dentry_list_lock);
1246 list_for_each_entry_safe(di, tmp, list, lease_list) {
1247 if (!lwc->nr_to_scan)
1248 break;
1249 --lwc->nr_to_scan;
1250
1251 dentry = di->dentry;
1252 if (last == dentry)
1253 break;
1254
1255 if (!spin_trylock(&dentry->d_lock))
1256 continue;
1257
1258 if (dentry->d_lockref.count < 0) {
1259 list_del_init(&di->lease_list);
1260 goto next;
1261 }
1262
1263 ret = check(dentry, lwc);
1264 if (ret & TOUCH) {
1265 /* move it into tail of dir lease list */
1266 __dentry_dir_lease_touch(mdsc, di);
1267 if (!last)
1268 last = dentry;
1269 }
1270 if (ret & DELETE) {
1271 /* stale lease */
1272 di->flags &= ~CEPH_DENTRY_REFERENCED;
1273 if (dentry->d_lockref.count > 0) {
1274 /* update_dentry_lease() will re-add
1275 * it to lease list, or
1276 * ceph_d_delete() will return 1 when
1277 * last reference is dropped */
1278 list_del_init(&di->lease_list);
1279 } else {
1280 di->flags |= CEPH_DENTRY_SHRINK_LIST;
1281 list_move_tail(&di->lease_list, &dispose);
1282 dget_dlock(dentry);
1283 }
1284 }
1285 next:
1286 spin_unlock(&dentry->d_lock);
1287 if (ret & STOP)
1288 break;
1289 }
1290 spin_unlock(&mdsc->dentry_list_lock);
1291
1292 while (!list_empty(&dispose)) {
1293 di = list_first_entry(&dispose, struct ceph_dentry_info,
1294 lease_list);
1295 dentry = di->dentry;
1296 spin_lock(&dentry->d_lock);
1297
1298 list_del_init(&di->lease_list);
1299 di->flags &= ~CEPH_DENTRY_SHRINK_LIST;
1300 if (di->flags & CEPH_DENTRY_REFERENCED) {
1301 spin_lock(&mdsc->dentry_list_lock);
1302 if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1303 list_add_tail(&di->lease_list,
1304 &mdsc->dentry_leases);
1305 } else {
1306 __dentry_dir_lease_touch(mdsc, di);
1307 }
1308 spin_unlock(&mdsc->dentry_list_lock);
1309 } else {
1310 freed++;
1311 }
1312
1313 spin_unlock(&dentry->d_lock);
1314 /* ceph_d_delete() does the trick */
1315 dput(dentry);
1316 }
1317 return freed;
1318 }
1319
1320 static int __dentry_lease_check(struct dentry *dentry, void *arg)
1321 {
1322 struct ceph_dentry_info *di = ceph_dentry(dentry);
1323 int ret;
1324
1325 if (__dentry_lease_is_valid(di))
1326 return STOP;
1327 ret = __dir_lease_try_check(dentry);
1328 if (ret == -EBUSY)
1329 return KEEP;
1330 if (ret > 0)
1331 return TOUCH;
1332 return DELETE;
1333 }
1334
1335 static int __dir_lease_check(struct dentry *dentry, void *arg)
1336 {
1337 struct ceph_lease_walk_control *lwc = arg;
1338 struct ceph_dentry_info *di = ceph_dentry(dentry);
1339
1340 int ret = __dir_lease_try_check(dentry);
1341 if (ret == -EBUSY)
1342 return KEEP;
1343 if (ret > 0) {
1344 if (time_before(jiffies, di->time + lwc->dir_lease_ttl))
1345 return STOP;
1346 /* Move dentry to tail of dir lease list if we don't want
1347 * to delete it. So dentries in the list are checked in a
1348 * round robin manner */
1349 if (!lwc->expire_dir_lease)
1350 return TOUCH;
1351 if (dentry->d_lockref.count > 0 ||
1352 (di->flags & CEPH_DENTRY_REFERENCED))
1353 return TOUCH;
1354 /* invalidate dir lease */
1355 di->lease_shared_gen = 0;
1356 }
1357 return DELETE;
1358 }
1359
1360 int ceph_trim_dentries(struct ceph_mds_client *mdsc)
1361 {
1362 struct ceph_lease_walk_control lwc;
1363 unsigned long count;
1364 unsigned long freed;
1365
1366 spin_lock(&mdsc->caps_list_lock);
1367 if (mdsc->caps_use_max > 0 &&
1368 mdsc->caps_use_count > mdsc->caps_use_max)
1369 count = mdsc->caps_use_count - mdsc->caps_use_max;
1370 else
1371 count = 0;
1372 spin_unlock(&mdsc->caps_list_lock);
1373
1374 lwc.dir_lease = false;
1375 lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE * 2;
1376 freed = __dentry_leases_walk(mdsc, &lwc, __dentry_lease_check);
1377 if (!lwc.nr_to_scan) /* more invalid leases */
1378 return -EAGAIN;
1379
1380 if (lwc.nr_to_scan < CEPH_CAPS_PER_RELEASE)
1381 lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE;
1382
1383 lwc.dir_lease = true;
1384 lwc.expire_dir_lease = freed < count;
1385 lwc.dir_lease_ttl = mdsc->fsc->mount_options->caps_wanted_delay_max * HZ;
1386 freed +=__dentry_leases_walk(mdsc, &lwc, __dir_lease_check);
1387 if (!lwc.nr_to_scan) /* more to check */
1388 return -EAGAIN;
1389
1390 return freed > 0 ? 1 : 0;
1391 }
1392
1393 /*
1394 * Ensure a dentry lease will no longer revalidate.
1395 */
1396 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1397 {
1398 struct ceph_dentry_info *di = ceph_dentry(dentry);
1399 spin_lock(&dentry->d_lock);
1400 di->time = jiffies;
1401 di->lease_shared_gen = 0;
1402 __dentry_lease_unlist(di);
1403 spin_unlock(&dentry->d_lock);
1404 }
1405
1406 /*
1407 * Check if dentry lease is valid. If not, delete the lease. Try to
1408 * renew if the least is more than half up.
1409 */
1410 static bool __dentry_lease_is_valid(struct ceph_dentry_info *di)
1411 {
1412 struct ceph_mds_session *session;
1413
1414 if (!di->lease_gen)
1415 return false;
1416
1417 session = di->lease_session;
1418 if (session) {
1419 u32 gen;
1420 unsigned long ttl;
1421
1422 spin_lock(&session->s_gen_ttl_lock);
1423 gen = session->s_cap_gen;
1424 ttl = session->s_cap_ttl;
1425 spin_unlock(&session->s_gen_ttl_lock);
1426
1427 if (di->lease_gen == gen &&
1428 time_before(jiffies, ttl) &&
1429 time_before(jiffies, di->time))
1430 return true;
1431 }
1432 di->lease_gen = 0;
1433 return false;
1434 }
1435
1436 static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags,
1437 struct inode *dir)
1438 {
1439 struct ceph_dentry_info *di;
1440 struct ceph_mds_session *session = NULL;
1441 u32 seq = 0;
1442 int valid = 0;
1443
1444 spin_lock(&dentry->d_lock);
1445 di = ceph_dentry(dentry);
1446 if (di && __dentry_lease_is_valid(di)) {
1447 valid = 1;
1448
1449 if (di->lease_renew_after &&
1450 time_after(jiffies, di->lease_renew_after)) {
1451 /*
1452 * We should renew. If we're in RCU walk mode
1453 * though, we can't do that so just return
1454 * -ECHILD.
1455 */
1456 if (flags & LOOKUP_RCU) {
1457 valid = -ECHILD;
1458 } else {
1459 session = ceph_get_mds_session(di->lease_session);
1460 seq = di->lease_seq;
1461 di->lease_renew_after = 0;
1462 di->lease_renew_from = jiffies;
1463 }
1464 }
1465 }
1466 spin_unlock(&dentry->d_lock);
1467
1468 if (session) {
1469 ceph_mdsc_lease_send_msg(session, dir, dentry,
1470 CEPH_MDS_LEASE_RENEW, seq);
1471 ceph_put_mds_session(session);
1472 }
1473 dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1474 return valid;
1475 }
1476
1477 /*
1478 * Called under dentry->d_lock.
1479 */
1480 static int __dir_lease_try_check(const struct dentry *dentry)
1481 {
1482 struct ceph_dentry_info *di = ceph_dentry(dentry);
1483 struct inode *dir;
1484 struct ceph_inode_info *ci;
1485 int valid = 0;
1486
1487 if (!di->lease_shared_gen)
1488 return 0;
1489 if (IS_ROOT(dentry))
1490 return 0;
1491
1492 dir = d_inode(dentry->d_parent);
1493 ci = ceph_inode(dir);
1494
1495 if (spin_trylock(&ci->i_ceph_lock)) {
1496 if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen &&
1497 __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 0))
1498 valid = 1;
1499 spin_unlock(&ci->i_ceph_lock);
1500 } else {
1501 valid = -EBUSY;
1502 }
1503
1504 if (!valid)
1505 di->lease_shared_gen = 0;
1506 return valid;
1507 }
1508
1509 /*
1510 * Check if directory-wide content lease/cap is valid.
1511 */
1512 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1513 {
1514 struct ceph_inode_info *ci = ceph_inode(dir);
1515 int valid;
1516 int shared_gen;
1517
1518 spin_lock(&ci->i_ceph_lock);
1519 valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1520 shared_gen = atomic_read(&ci->i_shared_gen);
1521 spin_unlock(&ci->i_ceph_lock);
1522 if (valid) {
1523 struct ceph_dentry_info *di;
1524 spin_lock(&dentry->d_lock);
1525 di = ceph_dentry(dentry);
1526 if (dir == d_inode(dentry->d_parent) &&
1527 di && di->lease_shared_gen == shared_gen)
1528 __ceph_dentry_dir_lease_touch(di);
1529 else
1530 valid = 0;
1531 spin_unlock(&dentry->d_lock);
1532 }
1533 dout("dir_lease_is_valid dir %p v%u dentry %p = %d\n",
1534 dir, (unsigned)atomic_read(&ci->i_shared_gen), dentry, valid);
1535 return valid;
1536 }
1537
1538 /*
1539 * Check if cached dentry can be trusted.
1540 */
1541 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1542 {
1543 int valid = 0;
1544 struct dentry *parent;
1545 struct inode *dir;
1546
1547 if (flags & LOOKUP_RCU) {
1548 parent = READ_ONCE(dentry->d_parent);
1549 dir = d_inode_rcu(parent);
1550 if (!dir)
1551 return -ECHILD;
1552 } else {
1553 parent = dget_parent(dentry);
1554 dir = d_inode(parent);
1555 }
1556
1557 dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1558 dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1559
1560 /* always trust cached snapped dentries, snapdir dentry */
1561 if (ceph_snap(dir) != CEPH_NOSNAP) {
1562 dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1563 dentry, d_inode(dentry));
1564 valid = 1;
1565 } else if (d_really_is_positive(dentry) &&
1566 ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1567 valid = 1;
1568 } else {
1569 valid = dentry_lease_is_valid(dentry, flags, dir);
1570 if (valid == -ECHILD)
1571 return valid;
1572 if (valid || dir_lease_is_valid(dir, dentry)) {
1573 if (d_really_is_positive(dentry))
1574 valid = ceph_is_any_caps(d_inode(dentry));
1575 else
1576 valid = 1;
1577 }
1578 }
1579
1580 if (!valid) {
1581 struct ceph_mds_client *mdsc =
1582 ceph_sb_to_client(dir->i_sb)->mdsc;
1583 struct ceph_mds_request *req;
1584 int op, err;
1585 u32 mask;
1586
1587 if (flags & LOOKUP_RCU)
1588 return -ECHILD;
1589
1590 op = ceph_snap(dir) == CEPH_SNAPDIR ?
1591 CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
1592 req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1593 if (!IS_ERR(req)) {
1594 req->r_dentry = dget(dentry);
1595 req->r_num_caps = 2;
1596 req->r_parent = dir;
1597
1598 mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1599 if (ceph_security_xattr_wanted(dir))
1600 mask |= CEPH_CAP_XATTR_SHARED;
1601 req->r_args.getattr.mask = cpu_to_le32(mask);
1602
1603 err = ceph_mdsc_do_request(mdsc, NULL, req);
1604 switch (err) {
1605 case 0:
1606 if (d_really_is_positive(dentry) &&
1607 d_inode(dentry) == req->r_target_inode)
1608 valid = 1;
1609 break;
1610 case -ENOENT:
1611 if (d_really_is_negative(dentry))
1612 valid = 1;
1613 /* Fallthrough */
1614 default:
1615 break;
1616 }
1617 ceph_mdsc_put_request(req);
1618 dout("d_revalidate %p lookup result=%d\n",
1619 dentry, err);
1620 }
1621 }
1622
1623 dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1624 if (!valid)
1625 ceph_dir_clear_complete(dir);
1626
1627 if (!(flags & LOOKUP_RCU))
1628 dput(parent);
1629 return valid;
1630 }
1631
1632 /*
1633 * Delete unused dentry that doesn't have valid lease
1634 *
1635 * Called under dentry->d_lock.
1636 */
1637 static int ceph_d_delete(const struct dentry *dentry)
1638 {
1639 struct ceph_dentry_info *di;
1640
1641 /* won't release caps */
1642 if (d_really_is_negative(dentry))
1643 return 0;
1644 if (ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
1645 return 0;
1646 /* vaild lease? */
1647 di = ceph_dentry(dentry);
1648 if (di) {
1649 if (__dentry_lease_is_valid(di))
1650 return 0;
1651 if (__dir_lease_try_check(dentry))
1652 return 0;
1653 }
1654 return 1;
1655 }
1656
1657 /*
1658 * Release our ceph_dentry_info.
1659 */
1660 static void ceph_d_release(struct dentry *dentry)
1661 {
1662 struct ceph_dentry_info *di = ceph_dentry(dentry);
1663
1664 dout("d_release %p\n", dentry);
1665
1666 spin_lock(&dentry->d_lock);
1667 __dentry_lease_unlist(di);
1668 dentry->d_fsdata = NULL;
1669 spin_unlock(&dentry->d_lock);
1670
1671 if (di->lease_session)
1672 ceph_put_mds_session(di->lease_session);
1673 kmem_cache_free(ceph_dentry_cachep, di);
1674 }
1675
1676 /*
1677 * When the VFS prunes a dentry from the cache, we need to clear the
1678 * complete flag on the parent directory.
1679 *
1680 * Called under dentry->d_lock.
1681 */
1682 static void ceph_d_prune(struct dentry *dentry)
1683 {
1684 struct ceph_inode_info *dir_ci;
1685 struct ceph_dentry_info *di;
1686
1687 dout("ceph_d_prune %pd %p\n", dentry, dentry);
1688
1689 /* do we have a valid parent? */
1690 if (IS_ROOT(dentry))
1691 return;
1692
1693 /* we hold d_lock, so d_parent is stable */
1694 dir_ci = ceph_inode(d_inode(dentry->d_parent));
1695 if (dir_ci->i_vino.snap == CEPH_SNAPDIR)
1696 return;
1697
1698 /* who calls d_delete() should also disable dcache readdir */
1699 if (d_really_is_negative(dentry))
1700 return;
1701
1702 /* d_fsdata does not get cleared until d_release */
1703 if (!d_unhashed(dentry)) {
1704 __ceph_dir_clear_complete(dir_ci);
1705 return;
1706 }
1707
1708 /* Disable dcache readdir just in case that someone called d_drop()
1709 * or d_invalidate(), but MDS didn't revoke CEPH_CAP_FILE_SHARED
1710 * properly (dcache readdir is still enabled) */
1711 di = ceph_dentry(dentry);
1712 if (di->offset > 0 &&
1713 di->lease_shared_gen == atomic_read(&dir_ci->i_shared_gen))
1714 __ceph_dir_clear_ordered(dir_ci);
1715 }
1716
1717 /*
1718 * read() on a dir. This weird interface hack only works if mounted
1719 * with '-o dirstat'.
1720 */
1721 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1722 loff_t *ppos)
1723 {
1724 struct ceph_dir_file_info *dfi = file->private_data;
1725 struct inode *inode = file_inode(file);
1726 struct ceph_inode_info *ci = ceph_inode(inode);
1727 int left;
1728 const int bufsize = 1024;
1729
1730 if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1731 return -EISDIR;
1732
1733 if (!dfi->dir_info) {
1734 dfi->dir_info = kmalloc(bufsize, GFP_KERNEL);
1735 if (!dfi->dir_info)
1736 return -ENOMEM;
1737 dfi->dir_info_len =
1738 snprintf(dfi->dir_info, bufsize,
1739 "entries: %20lld\n"
1740 " files: %20lld\n"
1741 " subdirs: %20lld\n"
1742 "rentries: %20lld\n"
1743 " rfiles: %20lld\n"
1744 " rsubdirs: %20lld\n"
1745 "rbytes: %20lld\n"
1746 "rctime: %10lld.%09ld\n",
1747 ci->i_files + ci->i_subdirs,
1748 ci->i_files,
1749 ci->i_subdirs,
1750 ci->i_rfiles + ci->i_rsubdirs,
1751 ci->i_rfiles,
1752 ci->i_rsubdirs,
1753 ci->i_rbytes,
1754 ci->i_rctime.tv_sec,
1755 ci->i_rctime.tv_nsec);
1756 }
1757
1758 if (*ppos >= dfi->dir_info_len)
1759 return 0;
1760 size = min_t(unsigned, size, dfi->dir_info_len-*ppos);
1761 left = copy_to_user(buf, dfi->dir_info + *ppos, size);
1762 if (left == size)
1763 return -EFAULT;
1764 *ppos += (size - left);
1765 return size - left;
1766 }
1767
1768
1769
1770 /*
1771 * Return name hash for a given dentry. This is dependent on
1772 * the parent directory's hash function.
1773 */
1774 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1775 {
1776 struct ceph_inode_info *dci = ceph_inode(dir);
1777 unsigned hash;
1778
1779 switch (dci->i_dir_layout.dl_dir_hash) {
1780 case 0: /* for backward compat */
1781 case CEPH_STR_HASH_LINUX:
1782 return dn->d_name.hash;
1783
1784 default:
1785 spin_lock(&dn->d_lock);
1786 hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1787 dn->d_name.name, dn->d_name.len);
1788 spin_unlock(&dn->d_lock);
1789 return hash;
1790 }
1791 }
1792
1793 const struct file_operations ceph_dir_fops = {
1794 .read = ceph_read_dir,
1795 .iterate = ceph_readdir,
1796 .llseek = ceph_dir_llseek,
1797 .open = ceph_open,
1798 .release = ceph_release,
1799 .unlocked_ioctl = ceph_ioctl,
1800 .fsync = ceph_fsync,
1801 .lock = ceph_lock,
1802 .flock = ceph_flock,
1803 };
1804
1805 const struct file_operations ceph_snapdir_fops = {
1806 .iterate = ceph_readdir,
1807 .llseek = ceph_dir_llseek,
1808 .open = ceph_open,
1809 .release = ceph_release,
1810 };
1811
1812 const struct inode_operations ceph_dir_iops = {
1813 .lookup = ceph_lookup,
1814 .permission = ceph_permission,
1815 .getattr = ceph_getattr,
1816 .setattr = ceph_setattr,
1817 .listxattr = ceph_listxattr,
1818 .get_acl = ceph_get_acl,
1819 .set_acl = ceph_set_acl,
1820 .mknod = ceph_mknod,
1821 .symlink = ceph_symlink,
1822 .mkdir = ceph_mkdir,
1823 .link = ceph_link,
1824 .unlink = ceph_unlink,
1825 .rmdir = ceph_unlink,
1826 .rename = ceph_rename,
1827 .create = ceph_create,
1828 .atomic_open = ceph_atomic_open,
1829 };
1830
1831 const struct inode_operations ceph_snapdir_iops = {
1832 .lookup = ceph_lookup,
1833 .permission = ceph_permission,
1834 .getattr = ceph_getattr,
1835 .mkdir = ceph_mkdir,
1836 .rmdir = ceph_unlink,
1837 .rename = ceph_rename,
1838 };
1839
1840 const struct dentry_operations ceph_dentry_ops = {
1841 .d_revalidate = ceph_d_revalidate,
1842 .d_delete = ceph_d_delete,
1843 .d_release = ceph_d_release,
1844 .d_prune = ceph_d_prune,
1845 .d_init = ceph_d_init,
1846 };
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