xref: /openbmc/linux/fs/ceph/dir.c (revision 985b9ee8)
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 #include "crypto.h"
13 
14 /*
15  * Directory operations: readdir, lookup, create, link, unlink,
16  * rename, etc.
17  */
18 
19 /*
20  * Ceph MDS operations are specified in terms of a base ino and
21  * relative path.  Thus, the client can specify an operation on a
22  * specific inode (e.g., a getattr due to fstat(2)), or as a path
23  * relative to, say, the root directory.
24  *
25  * Normally, we limit ourselves to strict inode ops (no path component)
26  * or dentry operations (a single path component relative to an ino).  The
27  * exception to this is open_root_dentry(), which will open the mount
28  * point by name.
29  */
30 
31 const struct dentry_operations ceph_dentry_ops;
32 
33 static bool __dentry_lease_is_valid(struct ceph_dentry_info *di);
34 static int __dir_lease_try_check(const struct dentry *dentry);
35 
36 /*
37  * Initialize ceph dentry state.
38  */
ceph_d_init(struct dentry * dentry)39 static int ceph_d_init(struct dentry *dentry)
40 {
41 	struct ceph_dentry_info *di;
42 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dentry->d_sb);
43 
44 	di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
45 	if (!di)
46 		return -ENOMEM;          /* oh well */
47 
48 	di->dentry = dentry;
49 	di->lease_session = NULL;
50 	di->time = jiffies;
51 	dentry->d_fsdata = di;
52 	INIT_LIST_HEAD(&di->lease_list);
53 
54 	atomic64_inc(&mdsc->metric.total_dentries);
55 
56 	return 0;
57 }
58 
59 /*
60  * for f_pos for readdir:
61  * - hash order:
62  *	(0xff << 52) | ((24 bits hash) << 28) |
63  *	(the nth entry has hash collision);
64  * - frag+name order;
65  *	((frag value) << 28) | (the nth entry in frag);
66  */
67 #define OFFSET_BITS	28
68 #define OFFSET_MASK	((1 << OFFSET_BITS) - 1)
69 #define HASH_ORDER	(0xffull << (OFFSET_BITS + 24))
ceph_make_fpos(unsigned high,unsigned off,bool hash_order)70 loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
71 {
72 	loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
73 	if (hash_order)
74 		fpos |= HASH_ORDER;
75 	return fpos;
76 }
77 
is_hash_order(loff_t p)78 static bool is_hash_order(loff_t p)
79 {
80 	return (p & HASH_ORDER) == HASH_ORDER;
81 }
82 
fpos_frag(loff_t p)83 static unsigned fpos_frag(loff_t p)
84 {
85 	return p >> OFFSET_BITS;
86 }
87 
fpos_hash(loff_t p)88 static unsigned fpos_hash(loff_t p)
89 {
90 	return ceph_frag_value(fpos_frag(p));
91 }
92 
fpos_off(loff_t p)93 static unsigned fpos_off(loff_t p)
94 {
95 	return p & OFFSET_MASK;
96 }
97 
fpos_cmp(loff_t l,loff_t r)98 static int fpos_cmp(loff_t l, loff_t r)
99 {
100 	int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
101 	if (v)
102 		return v;
103 	return (int)(fpos_off(l) - fpos_off(r));
104 }
105 
106 /*
107  * make note of the last dentry we read, so we can
108  * continue at the same lexicographical point,
109  * regardless of what dir changes take place on the
110  * server.
111  */
note_last_dentry(struct ceph_dir_file_info * dfi,const char * name,int len,unsigned next_offset)112 static int note_last_dentry(struct ceph_dir_file_info *dfi, const char *name,
113 		            int len, unsigned next_offset)
114 {
115 	char *buf = kmalloc(len+1, GFP_KERNEL);
116 	if (!buf)
117 		return -ENOMEM;
118 	kfree(dfi->last_name);
119 	dfi->last_name = buf;
120 	memcpy(dfi->last_name, name, len);
121 	dfi->last_name[len] = 0;
122 	dfi->next_offset = next_offset;
123 	dout("note_last_dentry '%s'\n", dfi->last_name);
124 	return 0;
125 }
126 
127 
128 static struct dentry *
__dcache_find_get_entry(struct dentry * parent,u64 idx,struct ceph_readdir_cache_control * cache_ctl)129 __dcache_find_get_entry(struct dentry *parent, u64 idx,
130 			struct ceph_readdir_cache_control *cache_ctl)
131 {
132 	struct inode *dir = d_inode(parent);
133 	struct dentry *dentry;
134 	unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
135 	loff_t ptr_pos = idx * sizeof(struct dentry *);
136 	pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
137 
138 	if (ptr_pos >= i_size_read(dir))
139 		return NULL;
140 
141 	if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
142 		ceph_readdir_cache_release(cache_ctl);
143 		cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
144 		if (!cache_ctl->page) {
145 			dout(" page %lu not found\n", ptr_pgoff);
146 			return ERR_PTR(-EAGAIN);
147 		}
148 		/* reading/filling the cache are serialized by
149 		   i_rwsem, no need to use page lock */
150 		unlock_page(cache_ctl->page);
151 		cache_ctl->dentries = kmap(cache_ctl->page);
152 	}
153 
154 	cache_ctl->index = idx & idx_mask;
155 
156 	rcu_read_lock();
157 	spin_lock(&parent->d_lock);
158 	/* check i_size again here, because empty directory can be
159 	 * marked as complete while not holding the i_rwsem. */
160 	if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
161 		dentry = cache_ctl->dentries[cache_ctl->index];
162 	else
163 		dentry = NULL;
164 	spin_unlock(&parent->d_lock);
165 	if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
166 		dentry = NULL;
167 	rcu_read_unlock();
168 	return dentry ? : ERR_PTR(-EAGAIN);
169 }
170 
171 /*
172  * When possible, we try to satisfy a readdir by peeking at the
173  * dcache.  We make this work by carefully ordering dentries on
174  * d_child when we initially get results back from the MDS, and
175  * falling back to a "normal" sync readdir if any dentries in the dir
176  * are dropped.
177  *
178  * Complete dir indicates that we have all dentries in the dir.  It is
179  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
180  * the MDS if/when the directory is modified).
181  */
__dcache_readdir(struct file * file,struct dir_context * ctx,int shared_gen)182 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
183 			    int shared_gen)
184 {
185 	struct ceph_dir_file_info *dfi = file->private_data;
186 	struct dentry *parent = file->f_path.dentry;
187 	struct inode *dir = d_inode(parent);
188 	struct dentry *dentry, *last = NULL;
189 	struct ceph_dentry_info *di;
190 	struct ceph_readdir_cache_control cache_ctl = {};
191 	u64 idx = 0;
192 	int err = 0;
193 
194 	dout("__dcache_readdir %p v%u at %llx\n", dir, (unsigned)shared_gen, ctx->pos);
195 
196 	/* search start position */
197 	if (ctx->pos > 2) {
198 		u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
199 		while (count > 0) {
200 			u64 step = count >> 1;
201 			dentry = __dcache_find_get_entry(parent, idx + step,
202 							 &cache_ctl);
203 			if (!dentry) {
204 				/* use linar search */
205 				idx = 0;
206 				break;
207 			}
208 			if (IS_ERR(dentry)) {
209 				err = PTR_ERR(dentry);
210 				goto out;
211 			}
212 			di = ceph_dentry(dentry);
213 			spin_lock(&dentry->d_lock);
214 			if (fpos_cmp(di->offset, ctx->pos) < 0) {
215 				idx += step + 1;
216 				count -= step + 1;
217 			} else {
218 				count = step;
219 			}
220 			spin_unlock(&dentry->d_lock);
221 			dput(dentry);
222 		}
223 
224 		dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
225 	}
226 
227 
228 	for (;;) {
229 		bool emit_dentry = false;
230 		dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
231 		if (!dentry) {
232 			dfi->file_info.flags |= CEPH_F_ATEND;
233 			err = 0;
234 			break;
235 		}
236 		if (IS_ERR(dentry)) {
237 			err = PTR_ERR(dentry);
238 			goto out;
239 		}
240 
241 		spin_lock(&dentry->d_lock);
242 		di = ceph_dentry(dentry);
243 		if (d_unhashed(dentry) ||
244 		    d_really_is_negative(dentry) ||
245 		    di->lease_shared_gen != shared_gen ||
246 		    ((dentry->d_flags & DCACHE_NOKEY_NAME) &&
247 		     fscrypt_has_encryption_key(dir))) {
248 			spin_unlock(&dentry->d_lock);
249 			dput(dentry);
250 			err = -EAGAIN;
251 			goto out;
252 		}
253 		if (fpos_cmp(ctx->pos, di->offset) <= 0) {
254 			__ceph_dentry_dir_lease_touch(di);
255 			emit_dentry = true;
256 		}
257 		spin_unlock(&dentry->d_lock);
258 
259 		if (emit_dentry) {
260 			dout(" %llx dentry %p %pd %p\n", di->offset,
261 			     dentry, dentry, d_inode(dentry));
262 			ctx->pos = di->offset;
263 			if (!dir_emit(ctx, dentry->d_name.name,
264 				      dentry->d_name.len, ceph_present_inode(d_inode(dentry)),
265 				      d_inode(dentry)->i_mode >> 12)) {
266 				dput(dentry);
267 				err = 0;
268 				break;
269 			}
270 			ctx->pos++;
271 
272 			if (last)
273 				dput(last);
274 			last = dentry;
275 		} else {
276 			dput(dentry);
277 		}
278 	}
279 out:
280 	ceph_readdir_cache_release(&cache_ctl);
281 	if (last) {
282 		int ret;
283 		di = ceph_dentry(last);
284 		ret = note_last_dentry(dfi, last->d_name.name, last->d_name.len,
285 				       fpos_off(di->offset) + 1);
286 		if (ret < 0)
287 			err = ret;
288 		dput(last);
289 		/* last_name no longer match cache index */
290 		if (dfi->readdir_cache_idx >= 0) {
291 			dfi->readdir_cache_idx = -1;
292 			dfi->dir_release_count = 0;
293 		}
294 	}
295 	return err;
296 }
297 
need_send_readdir(struct ceph_dir_file_info * dfi,loff_t pos)298 static bool need_send_readdir(struct ceph_dir_file_info *dfi, loff_t pos)
299 {
300 	if (!dfi->last_readdir)
301 		return true;
302 	if (is_hash_order(pos))
303 		return !ceph_frag_contains_value(dfi->frag, fpos_hash(pos));
304 	else
305 		return dfi->frag != fpos_frag(pos);
306 }
307 
ceph_readdir(struct file * file,struct dir_context * ctx)308 static int ceph_readdir(struct file *file, struct dir_context *ctx)
309 {
310 	struct ceph_dir_file_info *dfi = file->private_data;
311 	struct inode *inode = file_inode(file);
312 	struct ceph_inode_info *ci = ceph_inode(inode);
313 	struct ceph_fs_client *fsc = ceph_inode_to_fs_client(inode);
314 	struct ceph_mds_client *mdsc = fsc->mdsc;
315 	int i;
316 	int err;
317 	unsigned frag = -1;
318 	struct ceph_mds_reply_info_parsed *rinfo;
319 
320 	dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
321 	if (dfi->file_info.flags & CEPH_F_ATEND)
322 		return 0;
323 
324 	/* always start with . and .. */
325 	if (ctx->pos == 0) {
326 		dout("readdir off 0 -> '.'\n");
327 		if (!dir_emit(ctx, ".", 1, ceph_present_inode(inode),
328 			    inode->i_mode >> 12))
329 			return 0;
330 		ctx->pos = 1;
331 	}
332 	if (ctx->pos == 1) {
333 		u64 ino;
334 		struct dentry *dentry = file->f_path.dentry;
335 
336 		spin_lock(&dentry->d_lock);
337 		ino = ceph_present_inode(dentry->d_parent->d_inode);
338 		spin_unlock(&dentry->d_lock);
339 
340 		dout("readdir off 1 -> '..'\n");
341 		if (!dir_emit(ctx, "..", 2, ino, inode->i_mode >> 12))
342 			return 0;
343 		ctx->pos = 2;
344 	}
345 
346 	err = ceph_fscrypt_prepare_readdir(inode);
347 	if (err < 0)
348 		return err;
349 
350 	spin_lock(&ci->i_ceph_lock);
351 	/* request Fx cap. if have Fx, we don't need to release Fs cap
352 	 * for later create/unlink. */
353 	__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_WR);
354 	/* can we use the dcache? */
355 	if (ceph_test_mount_opt(fsc, DCACHE) &&
356 	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
357 	    ceph_snap(inode) != CEPH_SNAPDIR &&
358 	    __ceph_dir_is_complete_ordered(ci) &&
359 	    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
360 		int shared_gen = atomic_read(&ci->i_shared_gen);
361 
362 		spin_unlock(&ci->i_ceph_lock);
363 		err = __dcache_readdir(file, ctx, shared_gen);
364 		if (err != -EAGAIN)
365 			return err;
366 	} else {
367 		spin_unlock(&ci->i_ceph_lock);
368 	}
369 
370 	/* proceed with a normal readdir */
371 more:
372 	/* do we have the correct frag content buffered? */
373 	if (need_send_readdir(dfi, ctx->pos)) {
374 		struct ceph_mds_request *req;
375 		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
376 			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
377 
378 		/* discard old result, if any */
379 		if (dfi->last_readdir) {
380 			ceph_mdsc_put_request(dfi->last_readdir);
381 			dfi->last_readdir = NULL;
382 		}
383 
384 		if (is_hash_order(ctx->pos)) {
385 			/* fragtree isn't always accurate. choose frag
386 			 * based on previous reply when possible. */
387 			if (frag == (unsigned)-1)
388 				frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
389 							NULL, NULL);
390 		} else {
391 			frag = fpos_frag(ctx->pos);
392 		}
393 
394 		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
395 		     ceph_vinop(inode), frag, dfi->last_name);
396 		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
397 		if (IS_ERR(req))
398 			return PTR_ERR(req);
399 
400 		err = ceph_alloc_readdir_reply_buffer(req, inode);
401 		if (err) {
402 			ceph_mdsc_put_request(req);
403 			return err;
404 		}
405 		/* hints to request -> mds selection code */
406 		req->r_direct_mode = USE_AUTH_MDS;
407 		if (op == CEPH_MDS_OP_READDIR) {
408 			req->r_direct_hash = ceph_frag_value(frag);
409 			__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
410 			req->r_inode_drop = CEPH_CAP_FILE_EXCL;
411 		}
412 		if (dfi->last_name) {
413 			struct qstr d_name = { .name = dfi->last_name,
414 					       .len = strlen(dfi->last_name) };
415 
416 			req->r_path2 = kzalloc(NAME_MAX + 1, GFP_KERNEL);
417 			if (!req->r_path2) {
418 				ceph_mdsc_put_request(req);
419 				return -ENOMEM;
420 			}
421 
422 			err = ceph_encode_encrypted_dname(inode, &d_name,
423 							  req->r_path2);
424 			if (err < 0) {
425 				ceph_mdsc_put_request(req);
426 				return err;
427 			}
428 		} else if (is_hash_order(ctx->pos)) {
429 			req->r_args.readdir.offset_hash =
430 				cpu_to_le32(fpos_hash(ctx->pos));
431 		}
432 
433 		req->r_dir_release_cnt = dfi->dir_release_count;
434 		req->r_dir_ordered_cnt = dfi->dir_ordered_count;
435 		req->r_readdir_cache_idx = dfi->readdir_cache_idx;
436 		req->r_readdir_offset = dfi->next_offset;
437 		req->r_args.readdir.frag = cpu_to_le32(frag);
438 		req->r_args.readdir.flags =
439 				cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
440 
441 		req->r_inode = inode;
442 		ihold(inode);
443 		req->r_dentry = dget(file->f_path.dentry);
444 		err = ceph_mdsc_do_request(mdsc, NULL, req);
445 		if (err < 0) {
446 			ceph_mdsc_put_request(req);
447 			return err;
448 		}
449 		dout("readdir got and parsed readdir result=%d on "
450 		     "frag %x, end=%d, complete=%d, hash_order=%d\n",
451 		     err, frag,
452 		     (int)req->r_reply_info.dir_end,
453 		     (int)req->r_reply_info.dir_complete,
454 		     (int)req->r_reply_info.hash_order);
455 
456 		rinfo = &req->r_reply_info;
457 		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
458 			frag = le32_to_cpu(rinfo->dir_dir->frag);
459 			if (!rinfo->hash_order) {
460 				dfi->next_offset = req->r_readdir_offset;
461 				/* adjust ctx->pos to beginning of frag */
462 				ctx->pos = ceph_make_fpos(frag,
463 							  dfi->next_offset,
464 							  false);
465 			}
466 		}
467 
468 		dfi->frag = frag;
469 		dfi->last_readdir = req;
470 
471 		if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
472 			dfi->readdir_cache_idx = req->r_readdir_cache_idx;
473 			if (dfi->readdir_cache_idx < 0) {
474 				/* preclude from marking dir ordered */
475 				dfi->dir_ordered_count = 0;
476 			} else if (ceph_frag_is_leftmost(frag) &&
477 				   dfi->next_offset == 2) {
478 				/* note dir version at start of readdir so
479 				 * we can tell if any dentries get dropped */
480 				dfi->dir_release_count = req->r_dir_release_cnt;
481 				dfi->dir_ordered_count = req->r_dir_ordered_cnt;
482 			}
483 		} else {
484 			dout("readdir !did_prepopulate\n");
485 			/* disable readdir cache */
486 			dfi->readdir_cache_idx = -1;
487 			/* preclude from marking dir complete */
488 			dfi->dir_release_count = 0;
489 		}
490 
491 		/* note next offset and last dentry name */
492 		if (rinfo->dir_nr > 0) {
493 			struct ceph_mds_reply_dir_entry *rde =
494 					rinfo->dir_entries + (rinfo->dir_nr-1);
495 			unsigned next_offset = req->r_reply_info.dir_end ?
496 					2 : (fpos_off(rde->offset) + 1);
497 			err = note_last_dentry(dfi, rde->name, rde->name_len,
498 					       next_offset);
499 			if (err) {
500 				ceph_mdsc_put_request(dfi->last_readdir);
501 				dfi->last_readdir = NULL;
502 				return err;
503 			}
504 		} else if (req->r_reply_info.dir_end) {
505 			dfi->next_offset = 2;
506 			/* keep last name */
507 		}
508 	}
509 
510 	rinfo = &dfi->last_readdir->r_reply_info;
511 	dout("readdir frag %x num %d pos %llx chunk first %llx\n",
512 	     dfi->frag, rinfo->dir_nr, ctx->pos,
513 	     rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
514 
515 	i = 0;
516 	/* search start position */
517 	if (rinfo->dir_nr > 0) {
518 		int step, nr = rinfo->dir_nr;
519 		while (nr > 0) {
520 			step = nr >> 1;
521 			if (rinfo->dir_entries[i + step].offset < ctx->pos) {
522 				i +=  step + 1;
523 				nr -= step + 1;
524 			} else {
525 				nr = step;
526 			}
527 		}
528 	}
529 	for (; i < rinfo->dir_nr; i++) {
530 		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
531 
532 		if (rde->offset < ctx->pos) {
533 			pr_warn("%s: rde->offset 0x%llx ctx->pos 0x%llx\n",
534 				__func__, rde->offset, ctx->pos);
535 			return -EIO;
536 		}
537 
538 		if (WARN_ON_ONCE(!rde->inode.in))
539 			return -EIO;
540 
541 		ctx->pos = rde->offset;
542 		dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
543 		     i, rinfo->dir_nr, ctx->pos,
544 		     rde->name_len, rde->name, &rde->inode.in);
545 
546 		if (!dir_emit(ctx, rde->name, rde->name_len,
547 			      ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
548 			      le32_to_cpu(rde->inode.in->mode) >> 12)) {
549 			/*
550 			 * NOTE: Here no need to put the 'dfi->last_readdir',
551 			 * because when dir_emit stops us it's most likely
552 			 * doesn't have enough memory, etc. So for next readdir
553 			 * it will continue.
554 			 */
555 			dout("filldir stopping us...\n");
556 			return 0;
557 		}
558 
559 		/* Reset the lengths to their original allocated vals */
560 		ctx->pos++;
561 	}
562 
563 	ceph_mdsc_put_request(dfi->last_readdir);
564 	dfi->last_readdir = NULL;
565 
566 	if (dfi->next_offset > 2) {
567 		frag = dfi->frag;
568 		goto more;
569 	}
570 
571 	/* more frags? */
572 	if (!ceph_frag_is_rightmost(dfi->frag)) {
573 		frag = ceph_frag_next(dfi->frag);
574 		if (is_hash_order(ctx->pos)) {
575 			loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
576 							dfi->next_offset, true);
577 			if (new_pos > ctx->pos)
578 				ctx->pos = new_pos;
579 			/* keep last_name */
580 		} else {
581 			ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
582 							false);
583 			kfree(dfi->last_name);
584 			dfi->last_name = NULL;
585 		}
586 		dout("readdir next frag is %x\n", frag);
587 		goto more;
588 	}
589 	dfi->file_info.flags |= CEPH_F_ATEND;
590 
591 	/*
592 	 * if dir_release_count still matches the dir, no dentries
593 	 * were released during the whole readdir, and we should have
594 	 * the complete dir contents in our cache.
595 	 */
596 	if (atomic64_read(&ci->i_release_count) ==
597 					dfi->dir_release_count) {
598 		spin_lock(&ci->i_ceph_lock);
599 		if (dfi->dir_ordered_count ==
600 				atomic64_read(&ci->i_ordered_count)) {
601 			dout(" marking %p complete and ordered\n", inode);
602 			/* use i_size to track number of entries in
603 			 * readdir cache */
604 			BUG_ON(dfi->readdir_cache_idx < 0);
605 			i_size_write(inode, dfi->readdir_cache_idx *
606 				     sizeof(struct dentry*));
607 		} else {
608 			dout(" marking %p complete\n", inode);
609 		}
610 		__ceph_dir_set_complete(ci, dfi->dir_release_count,
611 					dfi->dir_ordered_count);
612 		spin_unlock(&ci->i_ceph_lock);
613 	}
614 	dout("readdir %p file %p done.\n", inode, file);
615 	return 0;
616 }
617 
reset_readdir(struct ceph_dir_file_info * dfi)618 static void reset_readdir(struct ceph_dir_file_info *dfi)
619 {
620 	if (dfi->last_readdir) {
621 		ceph_mdsc_put_request(dfi->last_readdir);
622 		dfi->last_readdir = NULL;
623 	}
624 	kfree(dfi->last_name);
625 	dfi->last_name = NULL;
626 	dfi->dir_release_count = 0;
627 	dfi->readdir_cache_idx = -1;
628 	dfi->next_offset = 2;  /* compensate for . and .. */
629 	dfi->file_info.flags &= ~CEPH_F_ATEND;
630 }
631 
632 /*
633  * discard buffered readdir content on seekdir(0), or seek to new frag,
634  * or seek prior to current chunk
635  */
need_reset_readdir(struct ceph_dir_file_info * dfi,loff_t new_pos)636 static bool need_reset_readdir(struct ceph_dir_file_info *dfi, loff_t new_pos)
637 {
638 	struct ceph_mds_reply_info_parsed *rinfo;
639 	loff_t chunk_offset;
640 	if (new_pos == 0)
641 		return true;
642 	if (is_hash_order(new_pos)) {
643 		/* no need to reset last_name for a forward seek when
644 		 * dentries are sotred in hash order */
645 	} else if (dfi->frag != fpos_frag(new_pos)) {
646 		return true;
647 	}
648 	rinfo = dfi->last_readdir ? &dfi->last_readdir->r_reply_info : NULL;
649 	if (!rinfo || !rinfo->dir_nr)
650 		return true;
651 	chunk_offset = rinfo->dir_entries[0].offset;
652 	return new_pos < chunk_offset ||
653 	       is_hash_order(new_pos) != is_hash_order(chunk_offset);
654 }
655 
ceph_dir_llseek(struct file * file,loff_t offset,int whence)656 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
657 {
658 	struct ceph_dir_file_info *dfi = file->private_data;
659 	struct inode *inode = file->f_mapping->host;
660 	loff_t retval;
661 
662 	inode_lock(inode);
663 	retval = -EINVAL;
664 	switch (whence) {
665 	case SEEK_CUR:
666 		offset += file->f_pos;
667 		break;
668 	case SEEK_SET:
669 		break;
670 	case SEEK_END:
671 		retval = -EOPNOTSUPP;
672 		goto out;
673 	default:
674 		goto out;
675 	}
676 
677 	if (offset >= 0) {
678 		if (need_reset_readdir(dfi, offset)) {
679 			dout("dir_llseek dropping %p content\n", file);
680 			reset_readdir(dfi);
681 		} else if (is_hash_order(offset) && offset > file->f_pos) {
682 			/* for hash offset, we don't know if a forward seek
683 			 * is within same frag */
684 			dfi->dir_release_count = 0;
685 			dfi->readdir_cache_idx = -1;
686 		}
687 
688 		if (offset != file->f_pos) {
689 			file->f_pos = offset;
690 			file->f_version = 0;
691 			dfi->file_info.flags &= ~CEPH_F_ATEND;
692 		}
693 		retval = offset;
694 	}
695 out:
696 	inode_unlock(inode);
697 	return retval;
698 }
699 
700 /*
701  * Handle lookups for the hidden .snap directory.
702  */
ceph_handle_snapdir(struct ceph_mds_request * req,struct dentry * dentry)703 struct dentry *ceph_handle_snapdir(struct ceph_mds_request *req,
704 				   struct dentry *dentry)
705 {
706 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dentry->d_sb);
707 	struct inode *parent = d_inode(dentry->d_parent); /* we hold i_rwsem */
708 
709 	/* .snap dir? */
710 	if (ceph_snap(parent) == CEPH_NOSNAP &&
711 	    strcmp(dentry->d_name.name, fsc->mount_options->snapdir_name) == 0) {
712 		struct dentry *res;
713 		struct inode *inode = ceph_get_snapdir(parent);
714 
715 		res = d_splice_alias(inode, dentry);
716 		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p. Spliced dentry %p\n",
717 		     dentry, dentry, inode, res);
718 		if (res)
719 			dentry = res;
720 	}
721 	return dentry;
722 }
723 
724 /*
725  * Figure out final result of a lookup/open request.
726  *
727  * Mainly, make sure we return the final req->r_dentry (if it already
728  * existed) in place of the original VFS-provided dentry when they
729  * differ.
730  *
731  * Gracefully handle the case where the MDS replies with -ENOENT and
732  * no trace (which it may do, at its discretion, e.g., if it doesn't
733  * care to issue a lease on the negative dentry).
734  */
ceph_finish_lookup(struct ceph_mds_request * req,struct dentry * dentry,int err)735 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
736 				  struct dentry *dentry, int err)
737 {
738 	if (err == -ENOENT) {
739 		/* no trace? */
740 		err = 0;
741 		if (!req->r_reply_info.head->is_dentry) {
742 			dout("ENOENT and no trace, dentry %p inode %p\n",
743 			     dentry, d_inode(dentry));
744 			if (d_really_is_positive(dentry)) {
745 				d_drop(dentry);
746 				err = -ENOENT;
747 			} else {
748 				d_add(dentry, NULL);
749 			}
750 		}
751 	}
752 	if (err)
753 		dentry = ERR_PTR(err);
754 	else if (dentry != req->r_dentry)
755 		dentry = dget(req->r_dentry);   /* we got spliced */
756 	else
757 		dentry = NULL;
758 	return dentry;
759 }
760 
is_root_ceph_dentry(struct inode * inode,struct dentry * dentry)761 static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
762 {
763 	return ceph_ino(inode) == CEPH_INO_ROOT &&
764 		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
765 }
766 
767 /*
768  * Look up a single dir entry.  If there is a lookup intent, inform
769  * the MDS so that it gets our 'caps wanted' value in a single op.
770  */
ceph_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)771 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
772 				  unsigned int flags)
773 {
774 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dir->i_sb);
775 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
776 	struct ceph_mds_request *req;
777 	int op;
778 	int mask;
779 	int err;
780 
781 	dout("lookup %p dentry %p '%pd'\n",
782 	     dir, dentry, dentry);
783 
784 	if (dentry->d_name.len > NAME_MAX)
785 		return ERR_PTR(-ENAMETOOLONG);
786 
787 	if (IS_ENCRYPTED(dir)) {
788 		bool had_key = fscrypt_has_encryption_key(dir);
789 
790 		err = fscrypt_prepare_lookup_partial(dir, dentry);
791 		if (err < 0)
792 			return ERR_PTR(err);
793 
794 		/* mark directory as incomplete if it has been unlocked */
795 		if (!had_key && fscrypt_has_encryption_key(dir))
796 			ceph_dir_clear_complete(dir);
797 	}
798 
799 	/* can we conclude ENOENT locally? */
800 	if (d_really_is_negative(dentry)) {
801 		struct ceph_inode_info *ci = ceph_inode(dir);
802 		struct ceph_dentry_info *di = ceph_dentry(dentry);
803 
804 		spin_lock(&ci->i_ceph_lock);
805 		dout(" dir %p flags are 0x%lx\n", dir, ci->i_ceph_flags);
806 		if (strncmp(dentry->d_name.name,
807 			    fsc->mount_options->snapdir_name,
808 			    dentry->d_name.len) &&
809 		    !is_root_ceph_dentry(dir, dentry) &&
810 		    ceph_test_mount_opt(fsc, DCACHE) &&
811 		    __ceph_dir_is_complete(ci) &&
812 		    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
813 			__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
814 			spin_unlock(&ci->i_ceph_lock);
815 			dout(" dir %p complete, -ENOENT\n", dir);
816 			d_add(dentry, NULL);
817 			di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
818 			return NULL;
819 		}
820 		spin_unlock(&ci->i_ceph_lock);
821 	}
822 
823 	op = ceph_snap(dir) == CEPH_SNAPDIR ?
824 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
825 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
826 	if (IS_ERR(req))
827 		return ERR_CAST(req);
828 	req->r_dentry = dget(dentry);
829 	req->r_num_caps = 2;
830 
831 	mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
832 	if (ceph_security_xattr_wanted(dir))
833 		mask |= CEPH_CAP_XATTR_SHARED;
834 	req->r_args.getattr.mask = cpu_to_le32(mask);
835 
836 	ihold(dir);
837 	req->r_parent = dir;
838 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
839 	err = ceph_mdsc_do_request(mdsc, NULL, req);
840 	if (err == -ENOENT) {
841 		struct dentry *res;
842 
843 		res = ceph_handle_snapdir(req, dentry);
844 		if (IS_ERR(res)) {
845 			err = PTR_ERR(res);
846 		} else {
847 			dentry = res;
848 			err = 0;
849 		}
850 	}
851 	dentry = ceph_finish_lookup(req, dentry, err);
852 	ceph_mdsc_put_request(req);  /* will dput(dentry) */
853 	dout("lookup result=%p\n", dentry);
854 	return dentry;
855 }
856 
857 /*
858  * If we do a create but get no trace back from the MDS, follow up with
859  * a lookup (the VFS expects us to link up the provided dentry).
860  */
ceph_handle_notrace_create(struct inode * dir,struct dentry * dentry)861 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
862 {
863 	struct dentry *result = ceph_lookup(dir, dentry, 0);
864 
865 	if (result && !IS_ERR(result)) {
866 		/*
867 		 * We created the item, then did a lookup, and found
868 		 * it was already linked to another inode we already
869 		 * had in our cache (and thus got spliced). To not
870 		 * confuse VFS (especially when inode is a directory),
871 		 * we don't link our dentry to that inode, return an
872 		 * error instead.
873 		 *
874 		 * This event should be rare and it happens only when
875 		 * we talk to old MDS. Recent MDS does not send traceless
876 		 * reply for request that creates new inode.
877 		 */
878 		d_drop(result);
879 		return -ESTALE;
880 	}
881 	return PTR_ERR(result);
882 }
883 
ceph_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)884 static int ceph_mknod(struct mnt_idmap *idmap, struct inode *dir,
885 		      struct dentry *dentry, umode_t mode, dev_t rdev)
886 {
887 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
888 	struct ceph_mds_request *req;
889 	struct ceph_acl_sec_ctx as_ctx = {};
890 	int err;
891 
892 	if (ceph_snap(dir) != CEPH_NOSNAP)
893 		return -EROFS;
894 
895 	err = ceph_wait_on_conflict_unlink(dentry);
896 	if (err)
897 		return err;
898 
899 	if (ceph_quota_is_max_files_exceeded(dir)) {
900 		err = -EDQUOT;
901 		goto out;
902 	}
903 
904 	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
905 	     dir, dentry, mode, rdev);
906 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
907 	if (IS_ERR(req)) {
908 		err = PTR_ERR(req);
909 		goto out;
910 	}
911 
912 	req->r_new_inode = ceph_new_inode(dir, dentry, &mode, &as_ctx);
913 	if (IS_ERR(req->r_new_inode)) {
914 		err = PTR_ERR(req->r_new_inode);
915 		req->r_new_inode = NULL;
916 		goto out_req;
917 	}
918 
919 	if (S_ISREG(mode) && IS_ENCRYPTED(dir))
920 		set_bit(CEPH_MDS_R_FSCRYPT_FILE, &req->r_req_flags);
921 
922 	req->r_dentry = dget(dentry);
923 	req->r_num_caps = 2;
924 	req->r_parent = dir;
925 	ihold(dir);
926 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
927 	req->r_args.mknod.mode = cpu_to_le32(mode);
928 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
929 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
930 			     CEPH_CAP_XATTR_EXCL;
931 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
932 
933 	ceph_as_ctx_to_req(req, &as_ctx);
934 
935 	err = ceph_mdsc_do_request(mdsc, dir, req);
936 	if (!err && !req->r_reply_info.head->is_dentry)
937 		err = ceph_handle_notrace_create(dir, dentry);
938 out_req:
939 	ceph_mdsc_put_request(req);
940 out:
941 	if (!err)
942 		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
943 	else
944 		d_drop(dentry);
945 	ceph_release_acl_sec_ctx(&as_ctx);
946 	return err;
947 }
948 
ceph_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)949 static int ceph_create(struct mnt_idmap *idmap, struct inode *dir,
950 		       struct dentry *dentry, umode_t mode, bool excl)
951 {
952 	return ceph_mknod(idmap, dir, dentry, mode, 0);
953 }
954 
955 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
prep_encrypted_symlink_target(struct ceph_mds_request * req,const char * dest)956 static int prep_encrypted_symlink_target(struct ceph_mds_request *req,
957 					 const char *dest)
958 {
959 	int err;
960 	int len = strlen(dest);
961 	struct fscrypt_str osd_link = FSTR_INIT(NULL, 0);
962 
963 	err = fscrypt_prepare_symlink(req->r_parent, dest, len, PATH_MAX,
964 				      &osd_link);
965 	if (err)
966 		goto out;
967 
968 	err = fscrypt_encrypt_symlink(req->r_new_inode, dest, len, &osd_link);
969 	if (err)
970 		goto out;
971 
972 	req->r_path2 = kmalloc(CEPH_BASE64_CHARS(osd_link.len) + 1, GFP_KERNEL);
973 	if (!req->r_path2) {
974 		err = -ENOMEM;
975 		goto out;
976 	}
977 
978 	len = ceph_base64_encode(osd_link.name, osd_link.len, req->r_path2);
979 	req->r_path2[len] = '\0';
980 out:
981 	fscrypt_fname_free_buffer(&osd_link);
982 	return err;
983 }
984 #else
prep_encrypted_symlink_target(struct ceph_mds_request * req,const char * dest)985 static int prep_encrypted_symlink_target(struct ceph_mds_request *req,
986 					 const char *dest)
987 {
988 	return -EOPNOTSUPP;
989 }
990 #endif
991 
ceph_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * dest)992 static int ceph_symlink(struct mnt_idmap *idmap, struct inode *dir,
993 			struct dentry *dentry, const char *dest)
994 {
995 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
996 	struct ceph_mds_request *req;
997 	struct ceph_acl_sec_ctx as_ctx = {};
998 	umode_t mode = S_IFLNK | 0777;
999 	int err;
1000 
1001 	if (ceph_snap(dir) != CEPH_NOSNAP)
1002 		return -EROFS;
1003 
1004 	err = ceph_wait_on_conflict_unlink(dentry);
1005 	if (err)
1006 		return err;
1007 
1008 	if (ceph_quota_is_max_files_exceeded(dir)) {
1009 		err = -EDQUOT;
1010 		goto out;
1011 	}
1012 
1013 	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
1014 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
1015 	if (IS_ERR(req)) {
1016 		err = PTR_ERR(req);
1017 		goto out;
1018 	}
1019 
1020 	req->r_new_inode = ceph_new_inode(dir, dentry, &mode, &as_ctx);
1021 	if (IS_ERR(req->r_new_inode)) {
1022 		err = PTR_ERR(req->r_new_inode);
1023 		req->r_new_inode = NULL;
1024 		goto out_req;
1025 	}
1026 
1027 	req->r_parent = dir;
1028 	ihold(dir);
1029 
1030 	if (IS_ENCRYPTED(req->r_new_inode)) {
1031 		err = prep_encrypted_symlink_target(req, dest);
1032 		if (err)
1033 			goto out_req;
1034 	} else {
1035 		req->r_path2 = kstrdup(dest, GFP_KERNEL);
1036 		if (!req->r_path2) {
1037 			err = -ENOMEM;
1038 			goto out_req;
1039 		}
1040 	}
1041 
1042 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1043 	req->r_dentry = dget(dentry);
1044 	req->r_num_caps = 2;
1045 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
1046 			     CEPH_CAP_XATTR_EXCL;
1047 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1048 
1049 	ceph_as_ctx_to_req(req, &as_ctx);
1050 
1051 	err = ceph_mdsc_do_request(mdsc, dir, req);
1052 	if (!err && !req->r_reply_info.head->is_dentry)
1053 		err = ceph_handle_notrace_create(dir, dentry);
1054 out_req:
1055 	ceph_mdsc_put_request(req);
1056 out:
1057 	if (err)
1058 		d_drop(dentry);
1059 	ceph_release_acl_sec_ctx(&as_ctx);
1060 	return err;
1061 }
1062 
ceph_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)1063 static int ceph_mkdir(struct mnt_idmap *idmap, struct inode *dir,
1064 		      struct dentry *dentry, umode_t mode)
1065 {
1066 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
1067 	struct ceph_mds_request *req;
1068 	struct ceph_acl_sec_ctx as_ctx = {};
1069 	int err;
1070 	int op;
1071 
1072 	err = ceph_wait_on_conflict_unlink(dentry);
1073 	if (err)
1074 		return err;
1075 
1076 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
1077 		/* mkdir .snap/foo is a MKSNAP */
1078 		op = CEPH_MDS_OP_MKSNAP;
1079 		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
1080 		     dentry, dentry);
1081 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
1082 		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
1083 		op = CEPH_MDS_OP_MKDIR;
1084 	} else {
1085 		err = -EROFS;
1086 		goto out;
1087 	}
1088 
1089 	if (op == CEPH_MDS_OP_MKDIR &&
1090 	    ceph_quota_is_max_files_exceeded(dir)) {
1091 		err = -EDQUOT;
1092 		goto out;
1093 	}
1094 	if ((op == CEPH_MDS_OP_MKSNAP) && IS_ENCRYPTED(dir) &&
1095 	    !fscrypt_has_encryption_key(dir)) {
1096 		err = -ENOKEY;
1097 		goto out;
1098 	}
1099 
1100 
1101 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1102 	if (IS_ERR(req)) {
1103 		err = PTR_ERR(req);
1104 		goto out;
1105 	}
1106 
1107 	mode |= S_IFDIR;
1108 	req->r_new_inode = ceph_new_inode(dir, dentry, &mode, &as_ctx);
1109 	if (IS_ERR(req->r_new_inode)) {
1110 		err = PTR_ERR(req->r_new_inode);
1111 		req->r_new_inode = NULL;
1112 		goto out_req;
1113 	}
1114 
1115 	req->r_dentry = dget(dentry);
1116 	req->r_num_caps = 2;
1117 	req->r_parent = dir;
1118 	ihold(dir);
1119 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1120 	req->r_args.mkdir.mode = cpu_to_le32(mode);
1121 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
1122 			     CEPH_CAP_XATTR_EXCL;
1123 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1124 
1125 	ceph_as_ctx_to_req(req, &as_ctx);
1126 
1127 	err = ceph_mdsc_do_request(mdsc, dir, req);
1128 	if (!err &&
1129 	    !req->r_reply_info.head->is_target &&
1130 	    !req->r_reply_info.head->is_dentry)
1131 		err = ceph_handle_notrace_create(dir, dentry);
1132 out_req:
1133 	ceph_mdsc_put_request(req);
1134 out:
1135 	if (!err)
1136 		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
1137 	else
1138 		d_drop(dentry);
1139 	ceph_release_acl_sec_ctx(&as_ctx);
1140 	return err;
1141 }
1142 
ceph_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)1143 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
1144 		     struct dentry *dentry)
1145 {
1146 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
1147 	struct ceph_mds_request *req;
1148 	int err;
1149 
1150 	if (dentry->d_flags & DCACHE_DISCONNECTED)
1151 		return -EINVAL;
1152 
1153 	err = ceph_wait_on_conflict_unlink(dentry);
1154 	if (err)
1155 		return err;
1156 
1157 	if (ceph_snap(dir) != CEPH_NOSNAP)
1158 		return -EROFS;
1159 
1160 	err = fscrypt_prepare_link(old_dentry, dir, dentry);
1161 	if (err)
1162 		return err;
1163 
1164 	dout("link in dir %p %llx.%llx old_dentry %p:'%pd' dentry %p:'%pd'\n",
1165 	     dir, ceph_vinop(dir), old_dentry, old_dentry, dentry, dentry);
1166 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
1167 	if (IS_ERR(req)) {
1168 		d_drop(dentry);
1169 		return PTR_ERR(req);
1170 	}
1171 	req->r_dentry = dget(dentry);
1172 	req->r_num_caps = 2;
1173 	req->r_old_dentry = dget(old_dentry);
1174 	/*
1175 	 * The old_dentry maybe a DCACHE_DISCONNECTED dentry, then we
1176 	 * will just pass the ino# to MDSs.
1177 	 */
1178 	if (old_dentry->d_flags & DCACHE_DISCONNECTED)
1179 		req->r_ino2 = ceph_vino(d_inode(old_dentry));
1180 	req->r_parent = dir;
1181 	ihold(dir);
1182 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1183 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1184 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1185 	/* release LINK_SHARED on source inode (mds will lock it) */
1186 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1187 	err = ceph_mdsc_do_request(mdsc, dir, req);
1188 	if (err) {
1189 		d_drop(dentry);
1190 	} else if (!req->r_reply_info.head->is_dentry) {
1191 		ihold(d_inode(old_dentry));
1192 		d_instantiate(dentry, d_inode(old_dentry));
1193 	}
1194 	ceph_mdsc_put_request(req);
1195 	return err;
1196 }
1197 
ceph_async_unlink_cb(struct ceph_mds_client * mdsc,struct ceph_mds_request * req)1198 static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
1199 				 struct ceph_mds_request *req)
1200 {
1201 	struct dentry *dentry = req->r_dentry;
1202 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dentry->d_sb);
1203 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1204 	int result = req->r_err ? req->r_err :
1205 			le32_to_cpu(req->r_reply_info.head->result);
1206 
1207 	if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
1208 		pr_warn("%s dentry %p:%pd async unlink bit is not set\n",
1209 			__func__, dentry, dentry);
1210 
1211 	spin_lock(&fsc->async_unlink_conflict_lock);
1212 	hash_del_rcu(&di->hnode);
1213 	spin_unlock(&fsc->async_unlink_conflict_lock);
1214 
1215 	spin_lock(&dentry->d_lock);
1216 	di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
1217 	wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT);
1218 	spin_unlock(&dentry->d_lock);
1219 
1220 	synchronize_rcu();
1221 
1222 	if (result == -EJUKEBOX)
1223 		goto out;
1224 
1225 	/* If op failed, mark everyone involved for errors */
1226 	if (result) {
1227 		int pathlen = 0;
1228 		u64 base = 0;
1229 		char *path = ceph_mdsc_build_path(mdsc, dentry, &pathlen,
1230 						  &base, 0);
1231 
1232 		/* mark error on parent + clear complete */
1233 		mapping_set_error(req->r_parent->i_mapping, result);
1234 		ceph_dir_clear_complete(req->r_parent);
1235 
1236 		/* drop the dentry -- we don't know its status */
1237 		if (!d_unhashed(dentry))
1238 			d_drop(dentry);
1239 
1240 		/* mark inode itself for an error (since metadata is bogus) */
1241 		mapping_set_error(req->r_old_inode->i_mapping, result);
1242 
1243 		pr_warn("async unlink failure path=(%llx)%s result=%d!\n",
1244 			base, IS_ERR(path) ? "<<bad>>" : path, result);
1245 		ceph_mdsc_free_path(path, pathlen);
1246 	}
1247 out:
1248 	iput(req->r_old_inode);
1249 	ceph_mdsc_release_dir_caps(req);
1250 }
1251 
get_caps_for_async_unlink(struct inode * dir,struct dentry * dentry)1252 static int get_caps_for_async_unlink(struct inode *dir, struct dentry *dentry)
1253 {
1254 	struct ceph_inode_info *ci = ceph_inode(dir);
1255 	struct ceph_dentry_info *di;
1256 	int got = 0, want = CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_UNLINK;
1257 
1258 	spin_lock(&ci->i_ceph_lock);
1259 	if ((__ceph_caps_issued(ci, NULL) & want) == want) {
1260 		ceph_take_cap_refs(ci, want, false);
1261 		got = want;
1262 	}
1263 	spin_unlock(&ci->i_ceph_lock);
1264 
1265 	/* If we didn't get anything, return 0 */
1266 	if (!got)
1267 		return 0;
1268 
1269         spin_lock(&dentry->d_lock);
1270         di = ceph_dentry(dentry);
1271 	/*
1272 	 * - We are holding Fx, which implies Fs caps.
1273 	 * - Only support async unlink for primary linkage
1274 	 */
1275 	if (atomic_read(&ci->i_shared_gen) != di->lease_shared_gen ||
1276 	    !(di->flags & CEPH_DENTRY_PRIMARY_LINK))
1277 		want = 0;
1278         spin_unlock(&dentry->d_lock);
1279 
1280 	/* Do we still want what we've got? */
1281 	if (want == got)
1282 		return got;
1283 
1284 	ceph_put_cap_refs(ci, got);
1285 	return 0;
1286 }
1287 
1288 /*
1289  * rmdir and unlink are differ only by the metadata op code
1290  */
ceph_unlink(struct inode * dir,struct dentry * dentry)1291 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
1292 {
1293 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dir->i_sb);
1294 	struct ceph_mds_client *mdsc = fsc->mdsc;
1295 	struct inode *inode = d_inode(dentry);
1296 	struct ceph_mds_request *req;
1297 	bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
1298 	int err = -EROFS;
1299 	int op;
1300 
1301 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
1302 		/* rmdir .snap/foo is RMSNAP */
1303 		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
1304 		op = CEPH_MDS_OP_RMSNAP;
1305 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
1306 		dout("unlink/rmdir dir %p dn %p inode %p\n",
1307 		     dir, dentry, inode);
1308 		op = d_is_dir(dentry) ?
1309 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
1310 	} else
1311 		goto out;
1312 retry:
1313 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1314 	if (IS_ERR(req)) {
1315 		err = PTR_ERR(req);
1316 		goto out;
1317 	}
1318 	req->r_dentry = dget(dentry);
1319 	req->r_num_caps = 2;
1320 	req->r_parent = dir;
1321 	ihold(dir);
1322 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1323 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1324 	req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
1325 
1326 	if (try_async && op == CEPH_MDS_OP_UNLINK &&
1327 	    (req->r_dir_caps = get_caps_for_async_unlink(dir, dentry))) {
1328 		struct ceph_dentry_info *di = ceph_dentry(dentry);
1329 
1330 		dout("async unlink on %llu/%.*s caps=%s", ceph_ino(dir),
1331 		     dentry->d_name.len, dentry->d_name.name,
1332 		     ceph_cap_string(req->r_dir_caps));
1333 		set_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags);
1334 		req->r_callback = ceph_async_unlink_cb;
1335 		req->r_old_inode = d_inode(dentry);
1336 		ihold(req->r_old_inode);
1337 
1338 		spin_lock(&dentry->d_lock);
1339 		di->flags |= CEPH_DENTRY_ASYNC_UNLINK;
1340 		spin_unlock(&dentry->d_lock);
1341 
1342 		spin_lock(&fsc->async_unlink_conflict_lock);
1343 		hash_add_rcu(fsc->async_unlink_conflict, &di->hnode,
1344 			     dentry->d_name.hash);
1345 		spin_unlock(&fsc->async_unlink_conflict_lock);
1346 
1347 		err = ceph_mdsc_submit_request(mdsc, dir, req);
1348 		if (!err) {
1349 			/*
1350 			 * We have enough caps, so we assume that the unlink
1351 			 * will succeed. Fix up the target inode and dcache.
1352 			 */
1353 			drop_nlink(inode);
1354 			d_delete(dentry);
1355 		} else {
1356 			spin_lock(&fsc->async_unlink_conflict_lock);
1357 			hash_del_rcu(&di->hnode);
1358 			spin_unlock(&fsc->async_unlink_conflict_lock);
1359 
1360 			spin_lock(&dentry->d_lock);
1361 			di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
1362 			spin_unlock(&dentry->d_lock);
1363 
1364 			if (err == -EJUKEBOX) {
1365 				try_async = false;
1366 				ceph_mdsc_put_request(req);
1367 				goto retry;
1368 			}
1369 		}
1370 	} else {
1371 		set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1372 		err = ceph_mdsc_do_request(mdsc, dir, req);
1373 		if (!err && !req->r_reply_info.head->is_dentry)
1374 			d_delete(dentry);
1375 	}
1376 
1377 	ceph_mdsc_put_request(req);
1378 out:
1379 	return err;
1380 }
1381 
ceph_rename(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)1382 static int ceph_rename(struct mnt_idmap *idmap, struct inode *old_dir,
1383 		       struct dentry *old_dentry, struct inode *new_dir,
1384 		       struct dentry *new_dentry, unsigned int flags)
1385 {
1386 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(old_dir->i_sb);
1387 	struct ceph_mds_request *req;
1388 	int op = CEPH_MDS_OP_RENAME;
1389 	int err;
1390 
1391 	if (flags)
1392 		return -EINVAL;
1393 
1394 	if (ceph_snap(old_dir) != ceph_snap(new_dir))
1395 		return -EXDEV;
1396 	if (ceph_snap(old_dir) != CEPH_NOSNAP) {
1397 		if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
1398 			op = CEPH_MDS_OP_RENAMESNAP;
1399 		else
1400 			return -EROFS;
1401 	}
1402 	/* don't allow cross-quota renames */
1403 	if ((old_dir != new_dir) &&
1404 	    (!ceph_quota_is_same_realm(old_dir, new_dir)))
1405 		return -EXDEV;
1406 
1407 	err = ceph_wait_on_conflict_unlink(new_dentry);
1408 	if (err)
1409 		return err;
1410 
1411 	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
1412 				     flags);
1413 	if (err)
1414 		return err;
1415 
1416 	dout("rename dir %p dentry %p to dir %p dentry %p\n",
1417 	     old_dir, old_dentry, new_dir, new_dentry);
1418 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1419 	if (IS_ERR(req))
1420 		return PTR_ERR(req);
1421 	ihold(old_dir);
1422 	req->r_dentry = dget(new_dentry);
1423 	req->r_num_caps = 2;
1424 	req->r_old_dentry = dget(old_dentry);
1425 	req->r_old_dentry_dir = old_dir;
1426 	req->r_parent = new_dir;
1427 	ihold(new_dir);
1428 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1429 	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1430 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
1431 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1432 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1433 	/* release LINK_RDCACHE on source inode (mds will lock it) */
1434 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1435 	if (d_really_is_positive(new_dentry)) {
1436 		req->r_inode_drop =
1437 			ceph_drop_caps_for_unlink(d_inode(new_dentry));
1438 	}
1439 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
1440 	if (!err && !req->r_reply_info.head->is_dentry) {
1441 		/*
1442 		 * Normally d_move() is done by fill_trace (called by
1443 		 * do_request, above).  If there is no trace, we need
1444 		 * to do it here.
1445 		 */
1446 		d_move(old_dentry, new_dentry);
1447 	}
1448 	ceph_mdsc_put_request(req);
1449 	return err;
1450 }
1451 
1452 /*
1453  * Move dentry to tail of mdsc->dentry_leases list when lease is updated.
1454  * Leases at front of the list will expire first. (Assume all leases have
1455  * similar duration)
1456  *
1457  * Called under dentry->d_lock.
1458  */
__ceph_dentry_lease_touch(struct ceph_dentry_info * di)1459 void __ceph_dentry_lease_touch(struct ceph_dentry_info *di)
1460 {
1461 	struct dentry *dn = di->dentry;
1462 	struct ceph_mds_client *mdsc;
1463 
1464 	dout("dentry_lease_touch %p %p '%pd'\n", di, dn, dn);
1465 
1466 	di->flags |= CEPH_DENTRY_LEASE_LIST;
1467 	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1468 		di->flags |= CEPH_DENTRY_REFERENCED;
1469 		return;
1470 	}
1471 
1472 	mdsc = ceph_sb_to_fs_client(dn->d_sb)->mdsc;
1473 	spin_lock(&mdsc->dentry_list_lock);
1474 	list_move_tail(&di->lease_list, &mdsc->dentry_leases);
1475 	spin_unlock(&mdsc->dentry_list_lock);
1476 }
1477 
__dentry_dir_lease_touch(struct ceph_mds_client * mdsc,struct ceph_dentry_info * di)1478 static void __dentry_dir_lease_touch(struct ceph_mds_client* mdsc,
1479 				     struct ceph_dentry_info *di)
1480 {
1481 	di->flags &= ~(CEPH_DENTRY_LEASE_LIST | CEPH_DENTRY_REFERENCED);
1482 	di->lease_gen = 0;
1483 	di->time = jiffies;
1484 	list_move_tail(&di->lease_list, &mdsc->dentry_dir_leases);
1485 }
1486 
1487 /*
1488  * When dir lease is used, add dentry to tail of mdsc->dentry_dir_leases
1489  * list if it's not in the list, otherwise set 'referenced' flag.
1490  *
1491  * Called under dentry->d_lock.
1492  */
__ceph_dentry_dir_lease_touch(struct ceph_dentry_info * di)1493 void __ceph_dentry_dir_lease_touch(struct ceph_dentry_info *di)
1494 {
1495 	struct dentry *dn = di->dentry;
1496 	struct ceph_mds_client *mdsc;
1497 
1498 	dout("dentry_dir_lease_touch %p %p '%pd' (offset 0x%llx)\n",
1499 	     di, dn, dn, di->offset);
1500 
1501 	if (!list_empty(&di->lease_list)) {
1502 		if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1503 			/* don't remove dentry from dentry lease list
1504 			 * if its lease is valid */
1505 			if (__dentry_lease_is_valid(di))
1506 				return;
1507 		} else {
1508 			di->flags |= CEPH_DENTRY_REFERENCED;
1509 			return;
1510 		}
1511 	}
1512 
1513 	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1514 		di->flags |= CEPH_DENTRY_REFERENCED;
1515 		di->flags &= ~CEPH_DENTRY_LEASE_LIST;
1516 		return;
1517 	}
1518 
1519 	mdsc = ceph_sb_to_fs_client(dn->d_sb)->mdsc;
1520 	spin_lock(&mdsc->dentry_list_lock);
1521 	__dentry_dir_lease_touch(mdsc, di),
1522 	spin_unlock(&mdsc->dentry_list_lock);
1523 }
1524 
__dentry_lease_unlist(struct ceph_dentry_info * di)1525 static void __dentry_lease_unlist(struct ceph_dentry_info *di)
1526 {
1527 	struct ceph_mds_client *mdsc;
1528 	if (di->flags & CEPH_DENTRY_SHRINK_LIST)
1529 		return;
1530 	if (list_empty(&di->lease_list))
1531 		return;
1532 
1533 	mdsc = ceph_sb_to_fs_client(di->dentry->d_sb)->mdsc;
1534 	spin_lock(&mdsc->dentry_list_lock);
1535 	list_del_init(&di->lease_list);
1536 	spin_unlock(&mdsc->dentry_list_lock);
1537 }
1538 
1539 enum {
1540 	KEEP	= 0,
1541 	DELETE	= 1,
1542 	TOUCH	= 2,
1543 	STOP	= 4,
1544 };
1545 
1546 struct ceph_lease_walk_control {
1547 	bool dir_lease;
1548 	bool expire_dir_lease;
1549 	unsigned long nr_to_scan;
1550 	unsigned long dir_lease_ttl;
1551 };
1552 
1553 static unsigned long
__dentry_leases_walk(struct ceph_mds_client * mdsc,struct ceph_lease_walk_control * lwc,int (* check)(struct dentry *,void *))1554 __dentry_leases_walk(struct ceph_mds_client *mdsc,
1555 		     struct ceph_lease_walk_control *lwc,
1556 		     int (*check)(struct dentry*, void*))
1557 {
1558 	struct ceph_dentry_info *di, *tmp;
1559 	struct dentry *dentry, *last = NULL;
1560 	struct list_head* list;
1561         LIST_HEAD(dispose);
1562 	unsigned long freed = 0;
1563 	int ret = 0;
1564 
1565 	list = lwc->dir_lease ? &mdsc->dentry_dir_leases : &mdsc->dentry_leases;
1566 	spin_lock(&mdsc->dentry_list_lock);
1567 	list_for_each_entry_safe(di, tmp, list, lease_list) {
1568 		if (!lwc->nr_to_scan)
1569 			break;
1570 		--lwc->nr_to_scan;
1571 
1572 		dentry = di->dentry;
1573 		if (last == dentry)
1574 			break;
1575 
1576 		if (!spin_trylock(&dentry->d_lock))
1577 			continue;
1578 
1579 		if (__lockref_is_dead(&dentry->d_lockref)) {
1580 			list_del_init(&di->lease_list);
1581 			goto next;
1582 		}
1583 
1584 		ret = check(dentry, lwc);
1585 		if (ret & TOUCH) {
1586 			/* move it into tail of dir lease list */
1587 			__dentry_dir_lease_touch(mdsc, di);
1588 			if (!last)
1589 				last = dentry;
1590 		}
1591 		if (ret & DELETE) {
1592 			/* stale lease */
1593 			di->flags &= ~CEPH_DENTRY_REFERENCED;
1594 			if (dentry->d_lockref.count > 0) {
1595 				/* update_dentry_lease() will re-add
1596 				 * it to lease list, or
1597 				 * ceph_d_delete() will return 1 when
1598 				 * last reference is dropped */
1599 				list_del_init(&di->lease_list);
1600 			} else {
1601 				di->flags |= CEPH_DENTRY_SHRINK_LIST;
1602 				list_move_tail(&di->lease_list, &dispose);
1603 				dget_dlock(dentry);
1604 			}
1605 		}
1606 next:
1607 		spin_unlock(&dentry->d_lock);
1608 		if (ret & STOP)
1609 			break;
1610 	}
1611 	spin_unlock(&mdsc->dentry_list_lock);
1612 
1613 	while (!list_empty(&dispose)) {
1614 		di = list_first_entry(&dispose, struct ceph_dentry_info,
1615 				      lease_list);
1616 		dentry = di->dentry;
1617 		spin_lock(&dentry->d_lock);
1618 
1619 		list_del_init(&di->lease_list);
1620 		di->flags &= ~CEPH_DENTRY_SHRINK_LIST;
1621 		if (di->flags & CEPH_DENTRY_REFERENCED) {
1622 			spin_lock(&mdsc->dentry_list_lock);
1623 			if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1624 				list_add_tail(&di->lease_list,
1625 					      &mdsc->dentry_leases);
1626 			} else {
1627 				__dentry_dir_lease_touch(mdsc, di);
1628 			}
1629 			spin_unlock(&mdsc->dentry_list_lock);
1630 		} else {
1631 			freed++;
1632 		}
1633 
1634 		spin_unlock(&dentry->d_lock);
1635 		/* ceph_d_delete() does the trick */
1636 		dput(dentry);
1637 	}
1638 	return freed;
1639 }
1640 
__dentry_lease_check(struct dentry * dentry,void * arg)1641 static int __dentry_lease_check(struct dentry *dentry, void *arg)
1642 {
1643 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1644 	int ret;
1645 
1646 	if (__dentry_lease_is_valid(di))
1647 		return STOP;
1648 	ret = __dir_lease_try_check(dentry);
1649 	if (ret == -EBUSY)
1650 		return KEEP;
1651 	if (ret > 0)
1652 		return TOUCH;
1653 	return DELETE;
1654 }
1655 
__dir_lease_check(struct dentry * dentry,void * arg)1656 static int __dir_lease_check(struct dentry *dentry, void *arg)
1657 {
1658 	struct ceph_lease_walk_control *lwc = arg;
1659 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1660 
1661 	int ret = __dir_lease_try_check(dentry);
1662 	if (ret == -EBUSY)
1663 		return KEEP;
1664 	if (ret > 0) {
1665 		if (time_before(jiffies, di->time + lwc->dir_lease_ttl))
1666 			return STOP;
1667 		/* Move dentry to tail of dir lease list if we don't want
1668 		 * to delete it. So dentries in the list are checked in a
1669 		 * round robin manner */
1670 		if (!lwc->expire_dir_lease)
1671 			return TOUCH;
1672 		if (dentry->d_lockref.count > 0 ||
1673 		    (di->flags & CEPH_DENTRY_REFERENCED))
1674 			return TOUCH;
1675 		/* invalidate dir lease */
1676 		di->lease_shared_gen = 0;
1677 	}
1678 	return DELETE;
1679 }
1680 
ceph_trim_dentries(struct ceph_mds_client * mdsc)1681 int ceph_trim_dentries(struct ceph_mds_client *mdsc)
1682 {
1683 	struct ceph_lease_walk_control lwc;
1684 	unsigned long count;
1685 	unsigned long freed;
1686 
1687 	spin_lock(&mdsc->caps_list_lock);
1688         if (mdsc->caps_use_max > 0 &&
1689             mdsc->caps_use_count > mdsc->caps_use_max)
1690 		count = mdsc->caps_use_count - mdsc->caps_use_max;
1691 	else
1692 		count = 0;
1693         spin_unlock(&mdsc->caps_list_lock);
1694 
1695 	lwc.dir_lease = false;
1696 	lwc.nr_to_scan  = CEPH_CAPS_PER_RELEASE * 2;
1697 	freed = __dentry_leases_walk(mdsc, &lwc, __dentry_lease_check);
1698 	if (!lwc.nr_to_scan) /* more invalid leases */
1699 		return -EAGAIN;
1700 
1701 	if (lwc.nr_to_scan < CEPH_CAPS_PER_RELEASE)
1702 		lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE;
1703 
1704 	lwc.dir_lease = true;
1705 	lwc.expire_dir_lease = freed < count;
1706 	lwc.dir_lease_ttl = mdsc->fsc->mount_options->caps_wanted_delay_max * HZ;
1707 	freed +=__dentry_leases_walk(mdsc, &lwc, __dir_lease_check);
1708 	if (!lwc.nr_to_scan) /* more to check */
1709 		return -EAGAIN;
1710 
1711 	return freed > 0 ? 1 : 0;
1712 }
1713 
1714 /*
1715  * Ensure a dentry lease will no longer revalidate.
1716  */
ceph_invalidate_dentry_lease(struct dentry * dentry)1717 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1718 {
1719 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1720 	spin_lock(&dentry->d_lock);
1721 	di->time = jiffies;
1722 	di->lease_shared_gen = 0;
1723 	di->flags &= ~CEPH_DENTRY_PRIMARY_LINK;
1724 	__dentry_lease_unlist(di);
1725 	spin_unlock(&dentry->d_lock);
1726 }
1727 
1728 /*
1729  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1730  * renew if the least is more than half up.
1731  */
__dentry_lease_is_valid(struct ceph_dentry_info * di)1732 static bool __dentry_lease_is_valid(struct ceph_dentry_info *di)
1733 {
1734 	struct ceph_mds_session *session;
1735 
1736 	if (!di->lease_gen)
1737 		return false;
1738 
1739 	session = di->lease_session;
1740 	if (session) {
1741 		u32 gen;
1742 		unsigned long ttl;
1743 
1744 		gen = atomic_read(&session->s_cap_gen);
1745 		ttl = session->s_cap_ttl;
1746 
1747 		if (di->lease_gen == gen &&
1748 		    time_before(jiffies, ttl) &&
1749 		    time_before(jiffies, di->time))
1750 			return true;
1751 	}
1752 	di->lease_gen = 0;
1753 	return false;
1754 }
1755 
dentry_lease_is_valid(struct dentry * dentry,unsigned int flags)1756 static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags)
1757 {
1758 	struct ceph_dentry_info *di;
1759 	struct ceph_mds_session *session = NULL;
1760 	u32 seq = 0;
1761 	int valid = 0;
1762 
1763 	spin_lock(&dentry->d_lock);
1764 	di = ceph_dentry(dentry);
1765 	if (di && __dentry_lease_is_valid(di)) {
1766 		valid = 1;
1767 
1768 		if (di->lease_renew_after &&
1769 		    time_after(jiffies, di->lease_renew_after)) {
1770 			/*
1771 			 * We should renew. If we're in RCU walk mode
1772 			 * though, we can't do that so just return
1773 			 * -ECHILD.
1774 			 */
1775 			if (flags & LOOKUP_RCU) {
1776 				valid = -ECHILD;
1777 			} else {
1778 				session = ceph_get_mds_session(di->lease_session);
1779 				seq = di->lease_seq;
1780 				di->lease_renew_after = 0;
1781 				di->lease_renew_from = jiffies;
1782 			}
1783 		}
1784 	}
1785 	spin_unlock(&dentry->d_lock);
1786 
1787 	if (session) {
1788 		ceph_mdsc_lease_send_msg(session, dentry,
1789 					 CEPH_MDS_LEASE_RENEW, seq);
1790 		ceph_put_mds_session(session);
1791 	}
1792 	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1793 	return valid;
1794 }
1795 
1796 /*
1797  * Called under dentry->d_lock.
1798  */
__dir_lease_try_check(const struct dentry * dentry)1799 static int __dir_lease_try_check(const struct dentry *dentry)
1800 {
1801 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1802 	struct inode *dir;
1803 	struct ceph_inode_info *ci;
1804 	int valid = 0;
1805 
1806 	if (!di->lease_shared_gen)
1807 		return 0;
1808 	if (IS_ROOT(dentry))
1809 		return 0;
1810 
1811 	dir = d_inode(dentry->d_parent);
1812 	ci = ceph_inode(dir);
1813 
1814 	if (spin_trylock(&ci->i_ceph_lock)) {
1815 		if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen &&
1816 		    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 0))
1817 			valid = 1;
1818 		spin_unlock(&ci->i_ceph_lock);
1819 	} else {
1820 		valid = -EBUSY;
1821 	}
1822 
1823 	if (!valid)
1824 		di->lease_shared_gen = 0;
1825 	return valid;
1826 }
1827 
1828 /*
1829  * Check if directory-wide content lease/cap is valid.
1830  */
dir_lease_is_valid(struct inode * dir,struct dentry * dentry,struct ceph_mds_client * mdsc)1831 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry,
1832 			      struct ceph_mds_client *mdsc)
1833 {
1834 	struct ceph_inode_info *ci = ceph_inode(dir);
1835 	int valid;
1836 	int shared_gen;
1837 
1838 	spin_lock(&ci->i_ceph_lock);
1839 	valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1840 	if (valid) {
1841 		__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
1842 		shared_gen = atomic_read(&ci->i_shared_gen);
1843 	}
1844 	spin_unlock(&ci->i_ceph_lock);
1845 	if (valid) {
1846 		struct ceph_dentry_info *di;
1847 		spin_lock(&dentry->d_lock);
1848 		di = ceph_dentry(dentry);
1849 		if (dir == d_inode(dentry->d_parent) &&
1850 		    di && di->lease_shared_gen == shared_gen)
1851 			__ceph_dentry_dir_lease_touch(di);
1852 		else
1853 			valid = 0;
1854 		spin_unlock(&dentry->d_lock);
1855 	}
1856 	dout("dir_lease_is_valid dir %p v%u dentry %p = %d\n",
1857 	     dir, (unsigned)atomic_read(&ci->i_shared_gen), dentry, valid);
1858 	return valid;
1859 }
1860 
1861 /*
1862  * Check if cached dentry can be trusted.
1863  */
ceph_d_revalidate(struct dentry * dentry,unsigned int flags)1864 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1865 {
1866 	int valid = 0;
1867 	struct dentry *parent;
1868 	struct inode *dir, *inode;
1869 	struct ceph_mds_client *mdsc;
1870 
1871 	valid = fscrypt_d_revalidate(dentry, flags);
1872 	if (valid <= 0)
1873 		return valid;
1874 
1875 	if (flags & LOOKUP_RCU) {
1876 		parent = READ_ONCE(dentry->d_parent);
1877 		dir = d_inode_rcu(parent);
1878 		if (!dir)
1879 			return -ECHILD;
1880 		inode = d_inode_rcu(dentry);
1881 	} else {
1882 		parent = dget_parent(dentry);
1883 		dir = d_inode(parent);
1884 		inode = d_inode(dentry);
1885 	}
1886 
1887 	dout("d_revalidate %p '%pd' inode %p offset 0x%llx nokey %d\n", dentry,
1888 	     dentry, inode, ceph_dentry(dentry)->offset,
1889 	     !!(dentry->d_flags & DCACHE_NOKEY_NAME));
1890 
1891 	mdsc = ceph_sb_to_fs_client(dir->i_sb)->mdsc;
1892 
1893 	/* always trust cached snapped dentries, snapdir dentry */
1894 	if (ceph_snap(dir) != CEPH_NOSNAP) {
1895 		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1896 		     dentry, inode);
1897 		valid = 1;
1898 	} else if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1899 		valid = 1;
1900 	} else {
1901 		valid = dentry_lease_is_valid(dentry, flags);
1902 		if (valid == -ECHILD)
1903 			return valid;
1904 		if (valid || dir_lease_is_valid(dir, dentry, mdsc)) {
1905 			if (inode)
1906 				valid = ceph_is_any_caps(inode);
1907 			else
1908 				valid = 1;
1909 		}
1910 	}
1911 
1912 	if (!valid) {
1913 		struct ceph_mds_request *req;
1914 		int op, err;
1915 		u32 mask;
1916 
1917 		if (flags & LOOKUP_RCU)
1918 			return -ECHILD;
1919 
1920 		percpu_counter_inc(&mdsc->metric.d_lease_mis);
1921 
1922 		op = ceph_snap(dir) == CEPH_SNAPDIR ?
1923 			CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
1924 		req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1925 		if (!IS_ERR(req)) {
1926 			req->r_dentry = dget(dentry);
1927 			req->r_num_caps = 2;
1928 			req->r_parent = dir;
1929 			ihold(dir);
1930 
1931 			mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1932 			if (ceph_security_xattr_wanted(dir))
1933 				mask |= CEPH_CAP_XATTR_SHARED;
1934 			req->r_args.getattr.mask = cpu_to_le32(mask);
1935 
1936 			err = ceph_mdsc_do_request(mdsc, NULL, req);
1937 			switch (err) {
1938 			case 0:
1939 				if (d_really_is_positive(dentry) &&
1940 				    d_inode(dentry) == req->r_target_inode)
1941 					valid = 1;
1942 				break;
1943 			case -ENOENT:
1944 				if (d_really_is_negative(dentry))
1945 					valid = 1;
1946 				fallthrough;
1947 			default:
1948 				break;
1949 			}
1950 			ceph_mdsc_put_request(req);
1951 			dout("d_revalidate %p lookup result=%d\n",
1952 			     dentry, err);
1953 		}
1954 	} else {
1955 		percpu_counter_inc(&mdsc->metric.d_lease_hit);
1956 	}
1957 
1958 	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1959 	if (!valid)
1960 		ceph_dir_clear_complete(dir);
1961 
1962 	if (!(flags & LOOKUP_RCU))
1963 		dput(parent);
1964 	return valid;
1965 }
1966 
1967 /*
1968  * Delete unused dentry that doesn't have valid lease
1969  *
1970  * Called under dentry->d_lock.
1971  */
ceph_d_delete(const struct dentry * dentry)1972 static int ceph_d_delete(const struct dentry *dentry)
1973 {
1974 	struct ceph_dentry_info *di;
1975 
1976 	/* won't release caps */
1977 	if (d_really_is_negative(dentry))
1978 		return 0;
1979 	if (ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
1980 		return 0;
1981 	/* vaild lease? */
1982 	di = ceph_dentry(dentry);
1983 	if (di) {
1984 		if (__dentry_lease_is_valid(di))
1985 			return 0;
1986 		if (__dir_lease_try_check(dentry))
1987 			return 0;
1988 	}
1989 	return 1;
1990 }
1991 
1992 /*
1993  * Release our ceph_dentry_info.
1994  */
ceph_d_release(struct dentry * dentry)1995 static void ceph_d_release(struct dentry *dentry)
1996 {
1997 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1998 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dentry->d_sb);
1999 
2000 	dout("d_release %p\n", dentry);
2001 
2002 	atomic64_dec(&fsc->mdsc->metric.total_dentries);
2003 
2004 	spin_lock(&dentry->d_lock);
2005 	__dentry_lease_unlist(di);
2006 	dentry->d_fsdata = NULL;
2007 	spin_unlock(&dentry->d_lock);
2008 
2009 	ceph_put_mds_session(di->lease_session);
2010 	kmem_cache_free(ceph_dentry_cachep, di);
2011 }
2012 
2013 /*
2014  * When the VFS prunes a dentry from the cache, we need to clear the
2015  * complete flag on the parent directory.
2016  *
2017  * Called under dentry->d_lock.
2018  */
ceph_d_prune(struct dentry * dentry)2019 static void ceph_d_prune(struct dentry *dentry)
2020 {
2021 	struct ceph_inode_info *dir_ci;
2022 	struct ceph_dentry_info *di;
2023 
2024 	dout("ceph_d_prune %pd %p\n", dentry, dentry);
2025 
2026 	/* do we have a valid parent? */
2027 	if (IS_ROOT(dentry))
2028 		return;
2029 
2030 	/* we hold d_lock, so d_parent is stable */
2031 	dir_ci = ceph_inode(d_inode(dentry->d_parent));
2032 	if (dir_ci->i_vino.snap == CEPH_SNAPDIR)
2033 		return;
2034 
2035 	/* who calls d_delete() should also disable dcache readdir */
2036 	if (d_really_is_negative(dentry))
2037 		return;
2038 
2039 	/* d_fsdata does not get cleared until d_release */
2040 	if (!d_unhashed(dentry)) {
2041 		__ceph_dir_clear_complete(dir_ci);
2042 		return;
2043 	}
2044 
2045 	/* Disable dcache readdir just in case that someone called d_drop()
2046 	 * or d_invalidate(), but MDS didn't revoke CEPH_CAP_FILE_SHARED
2047 	 * properly (dcache readdir is still enabled) */
2048 	di = ceph_dentry(dentry);
2049 	if (di->offset > 0 &&
2050 	    di->lease_shared_gen == atomic_read(&dir_ci->i_shared_gen))
2051 		__ceph_dir_clear_ordered(dir_ci);
2052 }
2053 
2054 /*
2055  * read() on a dir.  This weird interface hack only works if mounted
2056  * with '-o dirstat'.
2057  */
ceph_read_dir(struct file * file,char __user * buf,size_t size,loff_t * ppos)2058 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
2059 			     loff_t *ppos)
2060 {
2061 	struct ceph_dir_file_info *dfi = file->private_data;
2062 	struct inode *inode = file_inode(file);
2063 	struct ceph_inode_info *ci = ceph_inode(inode);
2064 	int left;
2065 	const int bufsize = 1024;
2066 
2067 	if (!ceph_test_mount_opt(ceph_sb_to_fs_client(inode->i_sb), DIRSTAT))
2068 		return -EISDIR;
2069 
2070 	if (!dfi->dir_info) {
2071 		dfi->dir_info = kmalloc(bufsize, GFP_KERNEL);
2072 		if (!dfi->dir_info)
2073 			return -ENOMEM;
2074 		dfi->dir_info_len =
2075 			snprintf(dfi->dir_info, bufsize,
2076 				"entries:   %20lld\n"
2077 				" files:    %20lld\n"
2078 				" subdirs:  %20lld\n"
2079 				"rentries:  %20lld\n"
2080 				" rfiles:   %20lld\n"
2081 				" rsubdirs: %20lld\n"
2082 				"rbytes:    %20lld\n"
2083 				"rctime:    %10lld.%09ld\n",
2084 				ci->i_files + ci->i_subdirs,
2085 				ci->i_files,
2086 				ci->i_subdirs,
2087 				ci->i_rfiles + ci->i_rsubdirs,
2088 				ci->i_rfiles,
2089 				ci->i_rsubdirs,
2090 				ci->i_rbytes,
2091 				ci->i_rctime.tv_sec,
2092 				ci->i_rctime.tv_nsec);
2093 	}
2094 
2095 	if (*ppos >= dfi->dir_info_len)
2096 		return 0;
2097 	size = min_t(unsigned, size, dfi->dir_info_len-*ppos);
2098 	left = copy_to_user(buf, dfi->dir_info + *ppos, size);
2099 	if (left == size)
2100 		return -EFAULT;
2101 	*ppos += (size - left);
2102 	return size - left;
2103 }
2104 
2105 
2106 
2107 /*
2108  * Return name hash for a given dentry.  This is dependent on
2109  * the parent directory's hash function.
2110  */
ceph_dentry_hash(struct inode * dir,struct dentry * dn)2111 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
2112 {
2113 	struct ceph_inode_info *dci = ceph_inode(dir);
2114 	unsigned hash;
2115 
2116 	switch (dci->i_dir_layout.dl_dir_hash) {
2117 	case 0:	/* for backward compat */
2118 	case CEPH_STR_HASH_LINUX:
2119 		return dn->d_name.hash;
2120 
2121 	default:
2122 		spin_lock(&dn->d_lock);
2123 		hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
2124 				     dn->d_name.name, dn->d_name.len);
2125 		spin_unlock(&dn->d_lock);
2126 		return hash;
2127 	}
2128 }
2129 
2130 WRAP_DIR_ITER(ceph_readdir) // FIXME!
2131 const struct file_operations ceph_dir_fops = {
2132 	.read = ceph_read_dir,
2133 	.iterate_shared = shared_ceph_readdir,
2134 	.llseek = ceph_dir_llseek,
2135 	.open = ceph_open,
2136 	.release = ceph_release,
2137 	.unlocked_ioctl = ceph_ioctl,
2138 	.compat_ioctl = compat_ptr_ioctl,
2139 	.fsync = ceph_fsync,
2140 	.lock = ceph_lock,
2141 	.flock = ceph_flock,
2142 };
2143 
2144 const struct file_operations ceph_snapdir_fops = {
2145 	.iterate_shared = shared_ceph_readdir,
2146 	.llseek = ceph_dir_llseek,
2147 	.open = ceph_open,
2148 	.release = ceph_release,
2149 };
2150 
2151 const struct inode_operations ceph_dir_iops = {
2152 	.lookup = ceph_lookup,
2153 	.permission = ceph_permission,
2154 	.getattr = ceph_getattr,
2155 	.setattr = ceph_setattr,
2156 	.listxattr = ceph_listxattr,
2157 	.get_inode_acl = ceph_get_acl,
2158 	.set_acl = ceph_set_acl,
2159 	.mknod = ceph_mknod,
2160 	.symlink = ceph_symlink,
2161 	.mkdir = ceph_mkdir,
2162 	.link = ceph_link,
2163 	.unlink = ceph_unlink,
2164 	.rmdir = ceph_unlink,
2165 	.rename = ceph_rename,
2166 	.create = ceph_create,
2167 	.atomic_open = ceph_atomic_open,
2168 };
2169 
2170 const struct inode_operations ceph_snapdir_iops = {
2171 	.lookup = ceph_lookup,
2172 	.permission = ceph_permission,
2173 	.getattr = ceph_getattr,
2174 	.mkdir = ceph_mkdir,
2175 	.rmdir = ceph_unlink,
2176 	.rename = ceph_rename,
2177 };
2178 
2179 const struct dentry_operations ceph_dentry_ops = {
2180 	.d_revalidate = ceph_d_revalidate,
2181 	.d_delete = ceph_d_delete,
2182 	.d_release = ceph_d_release,
2183 	.d_prune = ceph_d_prune,
2184 	.d_init = ceph_d_init,
2185 };
2186