xref: /linux/fs/ceph/dir.c (revision 894b3c35d1de9cfa4f72b21e280d80d278879c20)
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_fs_client * fsc,struct ceph_dir_file_info * dfi,const char * name,int len,unsigned next_offset)112 static int note_last_dentry(struct ceph_fs_client *fsc,
113 			    struct ceph_dir_file_info *dfi,
114 			    const char *name,
115 		            int len, unsigned next_offset)
116 {
117 	char *buf = kmalloc(len+1, GFP_KERNEL);
118 	if (!buf)
119 		return -ENOMEM;
120 	kfree(dfi->last_name);
121 	dfi->last_name = buf;
122 	memcpy(dfi->last_name, name, len);
123 	dfi->last_name[len] = 0;
124 	dfi->next_offset = next_offset;
125 	doutc(fsc->client, "'%s'\n", dfi->last_name);
126 	return 0;
127 }
128 
129 
130 static struct dentry *
__dcache_find_get_entry(struct dentry * parent,u64 idx,struct ceph_readdir_cache_control * cache_ctl)131 __dcache_find_get_entry(struct dentry *parent, u64 idx,
132 			struct ceph_readdir_cache_control *cache_ctl)
133 {
134 	struct inode *dir = d_inode(parent);
135 	struct ceph_client *cl = ceph_inode_to_client(dir);
136 	struct dentry *dentry;
137 	unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
138 	loff_t ptr_pos = idx * sizeof(struct dentry *);
139 	pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
140 
141 	if (ptr_pos >= i_size_read(dir))
142 		return NULL;
143 
144 	if (!cache_ctl->page || ptr_pgoff != cache_ctl->page->index) {
145 		ceph_readdir_cache_release(cache_ctl);
146 		cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
147 		if (!cache_ctl->page) {
148 			doutc(cl, " page %lu not found\n", ptr_pgoff);
149 			return ERR_PTR(-EAGAIN);
150 		}
151 		/* reading/filling the cache are serialized by
152 		   i_rwsem, no need to use page lock */
153 		unlock_page(cache_ctl->page);
154 		cache_ctl->dentries = kmap(cache_ctl->page);
155 	}
156 
157 	cache_ctl->index = idx & idx_mask;
158 
159 	rcu_read_lock();
160 	spin_lock(&parent->d_lock);
161 	/* check i_size again here, because empty directory can be
162 	 * marked as complete while not holding the i_rwsem. */
163 	if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
164 		dentry = cache_ctl->dentries[cache_ctl->index];
165 	else
166 		dentry = NULL;
167 	spin_unlock(&parent->d_lock);
168 	if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
169 		dentry = NULL;
170 	rcu_read_unlock();
171 	return dentry ? : ERR_PTR(-EAGAIN);
172 }
173 
174 /*
175  * When possible, we try to satisfy a readdir by peeking at the
176  * dcache.  We make this work by carefully ordering dentries on
177  * d_children when we initially get results back from the MDS, and
178  * falling back to a "normal" sync readdir if any dentries in the dir
179  * are dropped.
180  *
181  * Complete dir indicates that we have all dentries in the dir.  It is
182  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
183  * the MDS if/when the directory is modified).
184  */
__dcache_readdir(struct file * file,struct dir_context * ctx,int shared_gen)185 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
186 			    int shared_gen)
187 {
188 	struct ceph_dir_file_info *dfi = file->private_data;
189 	struct dentry *parent = file->f_path.dentry;
190 	struct inode *dir = d_inode(parent);
191 	struct ceph_fs_client *fsc = ceph_inode_to_fs_client(dir);
192 	struct ceph_client *cl = ceph_inode_to_client(dir);
193 	struct dentry *dentry, *last = NULL;
194 	struct ceph_dentry_info *di;
195 	struct ceph_readdir_cache_control cache_ctl = {};
196 	u64 idx = 0;
197 	int err = 0;
198 
199 	doutc(cl, "%p %llx.%llx v%u at %llx\n", dir, ceph_vinop(dir),
200 	      (unsigned)shared_gen, ctx->pos);
201 
202 	/* search start position */
203 	if (ctx->pos > 2) {
204 		u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
205 		while (count > 0) {
206 			u64 step = count >> 1;
207 			dentry = __dcache_find_get_entry(parent, idx + step,
208 							 &cache_ctl);
209 			if (!dentry) {
210 				/* use linar search */
211 				idx = 0;
212 				break;
213 			}
214 			if (IS_ERR(dentry)) {
215 				err = PTR_ERR(dentry);
216 				goto out;
217 			}
218 			di = ceph_dentry(dentry);
219 			spin_lock(&dentry->d_lock);
220 			if (fpos_cmp(di->offset, ctx->pos) < 0) {
221 				idx += step + 1;
222 				count -= step + 1;
223 			} else {
224 				count = step;
225 			}
226 			spin_unlock(&dentry->d_lock);
227 			dput(dentry);
228 		}
229 
230 		doutc(cl, "%p %llx.%llx cache idx %llu\n", dir,
231 		      ceph_vinop(dir), idx);
232 	}
233 
234 
235 	for (;;) {
236 		bool emit_dentry = false;
237 		dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
238 		if (!dentry) {
239 			dfi->file_info.flags |= CEPH_F_ATEND;
240 			err = 0;
241 			break;
242 		}
243 		if (IS_ERR(dentry)) {
244 			err = PTR_ERR(dentry);
245 			goto out;
246 		}
247 
248 		spin_lock(&dentry->d_lock);
249 		di = ceph_dentry(dentry);
250 		if (d_unhashed(dentry) ||
251 		    d_really_is_negative(dentry) ||
252 		    di->lease_shared_gen != shared_gen ||
253 		    ((dentry->d_flags & DCACHE_NOKEY_NAME) &&
254 		     fscrypt_has_encryption_key(dir))) {
255 			spin_unlock(&dentry->d_lock);
256 			dput(dentry);
257 			err = -EAGAIN;
258 			goto out;
259 		}
260 		if (fpos_cmp(ctx->pos, di->offset) <= 0) {
261 			__ceph_dentry_dir_lease_touch(di);
262 			emit_dentry = true;
263 		}
264 		spin_unlock(&dentry->d_lock);
265 
266 		if (emit_dentry) {
267 			doutc(cl, " %llx dentry %p %pd %p\n", di->offset,
268 			      dentry, dentry, d_inode(dentry));
269 			ctx->pos = di->offset;
270 			if (!dir_emit(ctx, dentry->d_name.name,
271 				      dentry->d_name.len, ceph_present_inode(d_inode(dentry)),
272 				      d_inode(dentry)->i_mode >> 12)) {
273 				dput(dentry);
274 				err = 0;
275 				break;
276 			}
277 			ctx->pos++;
278 
279 			if (last)
280 				dput(last);
281 			last = dentry;
282 		} else {
283 			dput(dentry);
284 		}
285 	}
286 out:
287 	ceph_readdir_cache_release(&cache_ctl);
288 	if (last) {
289 		int ret;
290 		di = ceph_dentry(last);
291 		ret = note_last_dentry(fsc, dfi, last->d_name.name,
292 				       last->d_name.len,
293 				       fpos_off(di->offset) + 1);
294 		if (ret < 0)
295 			err = ret;
296 		dput(last);
297 		/* last_name no longer match cache index */
298 		if (dfi->readdir_cache_idx >= 0) {
299 			dfi->readdir_cache_idx = -1;
300 			dfi->dir_release_count = 0;
301 		}
302 	}
303 	return err;
304 }
305 
need_send_readdir(struct ceph_dir_file_info * dfi,loff_t pos)306 static bool need_send_readdir(struct ceph_dir_file_info *dfi, loff_t pos)
307 {
308 	if (!dfi->last_readdir)
309 		return true;
310 	if (is_hash_order(pos))
311 		return !ceph_frag_contains_value(dfi->frag, fpos_hash(pos));
312 	else
313 		return dfi->frag != fpos_frag(pos);
314 }
315 
ceph_readdir(struct file * file,struct dir_context * ctx)316 static int ceph_readdir(struct file *file, struct dir_context *ctx)
317 {
318 	struct ceph_dir_file_info *dfi = file->private_data;
319 	struct inode *inode = file_inode(file);
320 	struct ceph_inode_info *ci = ceph_inode(inode);
321 	struct ceph_fs_client *fsc = ceph_inode_to_fs_client(inode);
322 	struct ceph_mds_client *mdsc = fsc->mdsc;
323 	struct ceph_client *cl = fsc->client;
324 	int i;
325 	int err;
326 	unsigned frag = -1;
327 	struct ceph_mds_reply_info_parsed *rinfo;
328 
329 	doutc(cl, "%p %llx.%llx file %p pos %llx\n", inode,
330 	      ceph_vinop(inode), file, ctx->pos);
331 	if (dfi->file_info.flags & CEPH_F_ATEND)
332 		return 0;
333 
334 	/* always start with . and .. */
335 	if (ctx->pos == 0) {
336 		doutc(cl, "%p %llx.%llx off 0 -> '.'\n", inode,
337 		      ceph_vinop(inode));
338 		if (!dir_emit(ctx, ".", 1, ceph_present_inode(inode),
339 			    inode->i_mode >> 12))
340 			return 0;
341 		ctx->pos = 1;
342 	}
343 	if (ctx->pos == 1) {
344 		u64 ino;
345 		struct dentry *dentry = file->f_path.dentry;
346 
347 		spin_lock(&dentry->d_lock);
348 		ino = ceph_present_inode(dentry->d_parent->d_inode);
349 		spin_unlock(&dentry->d_lock);
350 
351 		doutc(cl, "%p %llx.%llx off 1 -> '..'\n", inode,
352 		      ceph_vinop(inode));
353 		if (!dir_emit(ctx, "..", 2, ino, inode->i_mode >> 12))
354 			return 0;
355 		ctx->pos = 2;
356 	}
357 
358 	err = ceph_fscrypt_prepare_readdir(inode);
359 	if (err < 0)
360 		return err;
361 
362 	spin_lock(&ci->i_ceph_lock);
363 	/* request Fx cap. if have Fx, we don't need to release Fs cap
364 	 * for later create/unlink. */
365 	__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_WR);
366 	/* can we use the dcache? */
367 	if (ceph_test_mount_opt(fsc, DCACHE) &&
368 	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
369 	    ceph_snap(inode) != CEPH_SNAPDIR &&
370 	    __ceph_dir_is_complete_ordered(ci) &&
371 	    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
372 		int shared_gen = atomic_read(&ci->i_shared_gen);
373 
374 		spin_unlock(&ci->i_ceph_lock);
375 		err = __dcache_readdir(file, ctx, shared_gen);
376 		if (err != -EAGAIN)
377 			return err;
378 	} else {
379 		spin_unlock(&ci->i_ceph_lock);
380 	}
381 
382 	/* proceed with a normal readdir */
383 more:
384 	/* do we have the correct frag content buffered? */
385 	if (need_send_readdir(dfi, ctx->pos)) {
386 		struct ceph_mds_request *req;
387 		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
388 			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
389 
390 		/* discard old result, if any */
391 		if (dfi->last_readdir) {
392 			ceph_mdsc_put_request(dfi->last_readdir);
393 			dfi->last_readdir = NULL;
394 		}
395 
396 		if (is_hash_order(ctx->pos)) {
397 			/* fragtree isn't always accurate. choose frag
398 			 * based on previous reply when possible. */
399 			if (frag == (unsigned)-1)
400 				frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
401 							NULL, NULL);
402 		} else {
403 			frag = fpos_frag(ctx->pos);
404 		}
405 
406 		doutc(cl, "fetching %p %llx.%llx frag %x offset '%s'\n",
407 		      inode, ceph_vinop(inode), frag, dfi->last_name);
408 		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
409 		if (IS_ERR(req))
410 			return PTR_ERR(req);
411 
412 		err = ceph_alloc_readdir_reply_buffer(req, inode);
413 		if (err) {
414 			ceph_mdsc_put_request(req);
415 			return err;
416 		}
417 		/* hints to request -> mds selection code */
418 		req->r_direct_mode = USE_AUTH_MDS;
419 		if (op == CEPH_MDS_OP_READDIR) {
420 			req->r_direct_hash = ceph_frag_value(frag);
421 			__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
422 			req->r_inode_drop = CEPH_CAP_FILE_EXCL;
423 		}
424 		if (dfi->last_name) {
425 			struct qstr d_name = { .name = dfi->last_name,
426 					       .len = strlen(dfi->last_name) };
427 
428 			req->r_path2 = kzalloc(NAME_MAX + 1, GFP_KERNEL);
429 			if (!req->r_path2) {
430 				ceph_mdsc_put_request(req);
431 				return -ENOMEM;
432 			}
433 
434 			err = ceph_encode_encrypted_dname(inode, &d_name,
435 							  req->r_path2);
436 			if (err < 0) {
437 				ceph_mdsc_put_request(req);
438 				return err;
439 			}
440 		} else if (is_hash_order(ctx->pos)) {
441 			req->r_args.readdir.offset_hash =
442 				cpu_to_le32(fpos_hash(ctx->pos));
443 		}
444 
445 		req->r_dir_release_cnt = dfi->dir_release_count;
446 		req->r_dir_ordered_cnt = dfi->dir_ordered_count;
447 		req->r_readdir_cache_idx = dfi->readdir_cache_idx;
448 		req->r_readdir_offset = dfi->next_offset;
449 		req->r_args.readdir.frag = cpu_to_le32(frag);
450 		req->r_args.readdir.flags =
451 				cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
452 
453 		req->r_inode = inode;
454 		ihold(inode);
455 		req->r_dentry = dget(file->f_path.dentry);
456 		err = ceph_mdsc_do_request(mdsc, NULL, req);
457 		if (err < 0) {
458 			ceph_mdsc_put_request(req);
459 			return err;
460 		}
461 		doutc(cl, "%p %llx.%llx got and parsed readdir result=%d"
462 		      "on frag %x, end=%d, complete=%d, hash_order=%d\n",
463 		      inode, ceph_vinop(inode), err, frag,
464 		      (int)req->r_reply_info.dir_end,
465 		      (int)req->r_reply_info.dir_complete,
466 		      (int)req->r_reply_info.hash_order);
467 
468 		rinfo = &req->r_reply_info;
469 		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
470 			frag = le32_to_cpu(rinfo->dir_dir->frag);
471 			if (!rinfo->hash_order) {
472 				dfi->next_offset = req->r_readdir_offset;
473 				/* adjust ctx->pos to beginning of frag */
474 				ctx->pos = ceph_make_fpos(frag,
475 							  dfi->next_offset,
476 							  false);
477 			}
478 		}
479 
480 		dfi->frag = frag;
481 		dfi->last_readdir = req;
482 
483 		if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
484 			dfi->readdir_cache_idx = req->r_readdir_cache_idx;
485 			if (dfi->readdir_cache_idx < 0) {
486 				/* preclude from marking dir ordered */
487 				dfi->dir_ordered_count = 0;
488 			} else if (ceph_frag_is_leftmost(frag) &&
489 				   dfi->next_offset == 2) {
490 				/* note dir version at start of readdir so
491 				 * we can tell if any dentries get dropped */
492 				dfi->dir_release_count = req->r_dir_release_cnt;
493 				dfi->dir_ordered_count = req->r_dir_ordered_cnt;
494 			}
495 		} else {
496 			doutc(cl, "%p %llx.%llx !did_prepopulate\n", inode,
497 			      ceph_vinop(inode));
498 			/* disable readdir cache */
499 			dfi->readdir_cache_idx = -1;
500 			/* preclude from marking dir complete */
501 			dfi->dir_release_count = 0;
502 		}
503 
504 		/* note next offset and last dentry name */
505 		if (rinfo->dir_nr > 0) {
506 			struct ceph_mds_reply_dir_entry *rde =
507 					rinfo->dir_entries + (rinfo->dir_nr-1);
508 			unsigned next_offset = req->r_reply_info.dir_end ?
509 					2 : (fpos_off(rde->offset) + 1);
510 			err = note_last_dentry(fsc, dfi, rde->name,
511 					       rde->name_len, next_offset);
512 			if (err) {
513 				ceph_mdsc_put_request(dfi->last_readdir);
514 				dfi->last_readdir = NULL;
515 				return err;
516 			}
517 		} else if (req->r_reply_info.dir_end) {
518 			dfi->next_offset = 2;
519 			/* keep last name */
520 		}
521 	}
522 
523 	rinfo = &dfi->last_readdir->r_reply_info;
524 	doutc(cl, "%p %llx.%llx frag %x num %d pos %llx chunk first %llx\n",
525 	      inode, ceph_vinop(inode), dfi->frag, rinfo->dir_nr, ctx->pos,
526 	      rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
527 
528 	i = 0;
529 	/* search start position */
530 	if (rinfo->dir_nr > 0) {
531 		int step, nr = rinfo->dir_nr;
532 		while (nr > 0) {
533 			step = nr >> 1;
534 			if (rinfo->dir_entries[i + step].offset < ctx->pos) {
535 				i +=  step + 1;
536 				nr -= step + 1;
537 			} else {
538 				nr = step;
539 			}
540 		}
541 	}
542 	for (; i < rinfo->dir_nr; i++) {
543 		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
544 
545 		if (rde->offset < ctx->pos) {
546 			pr_warn_client(cl,
547 				"%p %llx.%llx rde->offset 0x%llx ctx->pos 0x%llx\n",
548 				inode, ceph_vinop(inode), rde->offset, ctx->pos);
549 			return -EIO;
550 		}
551 
552 		if (WARN_ON_ONCE(!rde->inode.in))
553 			return -EIO;
554 
555 		ctx->pos = rde->offset;
556 		doutc(cl, "%p %llx.%llx (%d/%d) -> %llx '%.*s' %p\n", inode,
557 		      ceph_vinop(inode), i, rinfo->dir_nr, ctx->pos,
558 		      rde->name_len, rde->name, &rde->inode.in);
559 
560 		if (!dir_emit(ctx, rde->name, rde->name_len,
561 			      ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
562 			      le32_to_cpu(rde->inode.in->mode) >> 12)) {
563 			/*
564 			 * NOTE: Here no need to put the 'dfi->last_readdir',
565 			 * because when dir_emit stops us it's most likely
566 			 * doesn't have enough memory, etc. So for next readdir
567 			 * it will continue.
568 			 */
569 			doutc(cl, "filldir stopping us...\n");
570 			return 0;
571 		}
572 
573 		/* Reset the lengths to their original allocated vals */
574 		ctx->pos++;
575 	}
576 
577 	ceph_mdsc_put_request(dfi->last_readdir);
578 	dfi->last_readdir = NULL;
579 
580 	if (dfi->next_offset > 2) {
581 		frag = dfi->frag;
582 		goto more;
583 	}
584 
585 	/* more frags? */
586 	if (!ceph_frag_is_rightmost(dfi->frag)) {
587 		frag = ceph_frag_next(dfi->frag);
588 		if (is_hash_order(ctx->pos)) {
589 			loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
590 							dfi->next_offset, true);
591 			if (new_pos > ctx->pos)
592 				ctx->pos = new_pos;
593 			/* keep last_name */
594 		} else {
595 			ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
596 							false);
597 			kfree(dfi->last_name);
598 			dfi->last_name = NULL;
599 		}
600 		doutc(cl, "%p %llx.%llx next frag is %x\n", inode,
601 		      ceph_vinop(inode), frag);
602 		goto more;
603 	}
604 	dfi->file_info.flags |= CEPH_F_ATEND;
605 
606 	/*
607 	 * if dir_release_count still matches the dir, no dentries
608 	 * were released during the whole readdir, and we should have
609 	 * the complete dir contents in our cache.
610 	 */
611 	if (atomic64_read(&ci->i_release_count) ==
612 					dfi->dir_release_count) {
613 		spin_lock(&ci->i_ceph_lock);
614 		if (dfi->dir_ordered_count ==
615 				atomic64_read(&ci->i_ordered_count)) {
616 			doutc(cl, " marking %p %llx.%llx complete and ordered\n",
617 			      inode, ceph_vinop(inode));
618 			/* use i_size to track number of entries in
619 			 * readdir cache */
620 			BUG_ON(dfi->readdir_cache_idx < 0);
621 			i_size_write(inode, dfi->readdir_cache_idx *
622 				     sizeof(struct dentry*));
623 		} else {
624 			doutc(cl, " marking %llx.%llx complete\n",
625 			      ceph_vinop(inode));
626 		}
627 		__ceph_dir_set_complete(ci, dfi->dir_release_count,
628 					dfi->dir_ordered_count);
629 		spin_unlock(&ci->i_ceph_lock);
630 	}
631 	doutc(cl, "%p %llx.%llx file %p done.\n", inode, ceph_vinop(inode),
632 	      file);
633 	return 0;
634 }
635 
reset_readdir(struct ceph_dir_file_info * dfi)636 static void reset_readdir(struct ceph_dir_file_info *dfi)
637 {
638 	if (dfi->last_readdir) {
639 		ceph_mdsc_put_request(dfi->last_readdir);
640 		dfi->last_readdir = NULL;
641 	}
642 	kfree(dfi->last_name);
643 	dfi->last_name = NULL;
644 	dfi->dir_release_count = 0;
645 	dfi->readdir_cache_idx = -1;
646 	dfi->next_offset = 2;  /* compensate for . and .. */
647 	dfi->file_info.flags &= ~CEPH_F_ATEND;
648 }
649 
650 /*
651  * discard buffered readdir content on seekdir(0), or seek to new frag,
652  * or seek prior to current chunk
653  */
need_reset_readdir(struct ceph_dir_file_info * dfi,loff_t new_pos)654 static bool need_reset_readdir(struct ceph_dir_file_info *dfi, loff_t new_pos)
655 {
656 	struct ceph_mds_reply_info_parsed *rinfo;
657 	loff_t chunk_offset;
658 	if (new_pos == 0)
659 		return true;
660 	if (is_hash_order(new_pos)) {
661 		/* no need to reset last_name for a forward seek when
662 		 * dentries are sotred in hash order */
663 	} else if (dfi->frag != fpos_frag(new_pos)) {
664 		return true;
665 	}
666 	rinfo = dfi->last_readdir ? &dfi->last_readdir->r_reply_info : NULL;
667 	if (!rinfo || !rinfo->dir_nr)
668 		return true;
669 	chunk_offset = rinfo->dir_entries[0].offset;
670 	return new_pos < chunk_offset ||
671 	       is_hash_order(new_pos) != is_hash_order(chunk_offset);
672 }
673 
ceph_dir_llseek(struct file * file,loff_t offset,int whence)674 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
675 {
676 	struct ceph_dir_file_info *dfi = file->private_data;
677 	struct inode *inode = file->f_mapping->host;
678 	struct ceph_client *cl = ceph_inode_to_client(inode);
679 	loff_t retval;
680 
681 	inode_lock(inode);
682 	retval = -EINVAL;
683 	switch (whence) {
684 	case SEEK_CUR:
685 		offset += file->f_pos;
686 		break;
687 	case SEEK_SET:
688 		break;
689 	case SEEK_END:
690 		retval = -EOPNOTSUPP;
691 		goto out;
692 	default:
693 		goto out;
694 	}
695 
696 	if (offset >= 0) {
697 		if (need_reset_readdir(dfi, offset)) {
698 			doutc(cl, "%p %llx.%llx dropping %p content\n",
699 			      inode, ceph_vinop(inode), file);
700 			reset_readdir(dfi);
701 		} else if (is_hash_order(offset) && offset > file->f_pos) {
702 			/* for hash offset, we don't know if a forward seek
703 			 * is within same frag */
704 			dfi->dir_release_count = 0;
705 			dfi->readdir_cache_idx = -1;
706 		}
707 
708 		if (offset != file->f_pos) {
709 			file->f_pos = offset;
710 			dfi->file_info.flags &= ~CEPH_F_ATEND;
711 		}
712 		retval = offset;
713 	}
714 out:
715 	inode_unlock(inode);
716 	return retval;
717 }
718 
719 /*
720  * Handle lookups for the hidden .snap directory.
721  */
ceph_handle_snapdir(struct ceph_mds_request * req,struct dentry * dentry)722 struct dentry *ceph_handle_snapdir(struct ceph_mds_request *req,
723 				   struct dentry *dentry)
724 {
725 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dentry->d_sb);
726 	struct inode *parent = d_inode(dentry->d_parent); /* we hold i_rwsem */
727 	struct ceph_client *cl = ceph_inode_to_client(parent);
728 
729 	/* .snap dir? */
730 	if (ceph_snap(parent) == CEPH_NOSNAP &&
731 	    strcmp(dentry->d_name.name, fsc->mount_options->snapdir_name) == 0) {
732 		struct dentry *res;
733 		struct inode *inode = ceph_get_snapdir(parent);
734 
735 		res = d_splice_alias(inode, dentry);
736 		doutc(cl, "ENOENT on snapdir %p '%pd', linking to "
737 		      "snapdir %p %llx.%llx. Spliced dentry %p\n",
738 		      dentry, dentry, inode, ceph_vinop(inode), res);
739 		if (res)
740 			dentry = res;
741 	}
742 	return dentry;
743 }
744 
745 /*
746  * Figure out final result of a lookup/open request.
747  *
748  * Mainly, make sure we return the final req->r_dentry (if it already
749  * existed) in place of the original VFS-provided dentry when they
750  * differ.
751  *
752  * Gracefully handle the case where the MDS replies with -ENOENT and
753  * no trace (which it may do, at its discretion, e.g., if it doesn't
754  * care to issue a lease on the negative dentry).
755  */
ceph_finish_lookup(struct ceph_mds_request * req,struct dentry * dentry,int err)756 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
757 				  struct dentry *dentry, int err)
758 {
759 	struct ceph_client *cl = req->r_mdsc->fsc->client;
760 
761 	if (err == -ENOENT) {
762 		/* no trace? */
763 		err = 0;
764 		if (!req->r_reply_info.head->is_dentry) {
765 			doutc(cl,
766 			      "ENOENT and no trace, dentry %p inode %llx.%llx\n",
767 			      dentry, ceph_vinop(d_inode(dentry)));
768 			if (d_really_is_positive(dentry)) {
769 				d_drop(dentry);
770 				err = -ENOENT;
771 			} else {
772 				d_add(dentry, NULL);
773 			}
774 		}
775 	}
776 	if (err)
777 		dentry = ERR_PTR(err);
778 	else if (dentry != req->r_dentry)
779 		dentry = dget(req->r_dentry);   /* we got spliced */
780 	else
781 		dentry = NULL;
782 	return dentry;
783 }
784 
is_root_ceph_dentry(struct inode * inode,struct dentry * dentry)785 static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
786 {
787 	return ceph_ino(inode) == CEPH_INO_ROOT &&
788 		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
789 }
790 
791 /*
792  * Look up a single dir entry.  If there is a lookup intent, inform
793  * the MDS so that it gets our 'caps wanted' value in a single op.
794  */
ceph_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)795 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
796 				  unsigned int flags)
797 {
798 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dir->i_sb);
799 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
800 	struct ceph_client *cl = fsc->client;
801 	struct ceph_mds_request *req;
802 	int op;
803 	int mask;
804 	int err;
805 
806 	doutc(cl, "%p %llx.%llx/'%pd' dentry %p\n", dir, ceph_vinop(dir),
807 	      dentry, dentry);
808 
809 	if (dentry->d_name.len > NAME_MAX)
810 		return ERR_PTR(-ENAMETOOLONG);
811 
812 	if (IS_ENCRYPTED(dir)) {
813 		bool had_key = fscrypt_has_encryption_key(dir);
814 
815 		err = fscrypt_prepare_lookup_partial(dir, dentry);
816 		if (err < 0)
817 			return ERR_PTR(err);
818 
819 		/* mark directory as incomplete if it has been unlocked */
820 		if (!had_key && fscrypt_has_encryption_key(dir))
821 			ceph_dir_clear_complete(dir);
822 	}
823 
824 	/* can we conclude ENOENT locally? */
825 	if (d_really_is_negative(dentry)) {
826 		struct ceph_inode_info *ci = ceph_inode(dir);
827 		struct ceph_dentry_info *di = ceph_dentry(dentry);
828 
829 		spin_lock(&ci->i_ceph_lock);
830 		doutc(cl, " dir %llx.%llx flags are 0x%lx\n",
831 		      ceph_vinop(dir), ci->i_ceph_flags);
832 		if (strncmp(dentry->d_name.name,
833 			    fsc->mount_options->snapdir_name,
834 			    dentry->d_name.len) &&
835 		    !is_root_ceph_dentry(dir, dentry) &&
836 		    ceph_test_mount_opt(fsc, DCACHE) &&
837 		    __ceph_dir_is_complete(ci) &&
838 		    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
839 			__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
840 			spin_unlock(&ci->i_ceph_lock);
841 			doutc(cl, " dir %llx.%llx complete, -ENOENT\n",
842 			      ceph_vinop(dir));
843 			d_add(dentry, NULL);
844 			di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
845 			return NULL;
846 		}
847 		spin_unlock(&ci->i_ceph_lock);
848 	}
849 
850 	op = ceph_snap(dir) == CEPH_SNAPDIR ?
851 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
852 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
853 	if (IS_ERR(req))
854 		return ERR_CAST(req);
855 	req->r_dentry = dget(dentry);
856 	req->r_num_caps = 2;
857 
858 	mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
859 	if (ceph_security_xattr_wanted(dir))
860 		mask |= CEPH_CAP_XATTR_SHARED;
861 	req->r_args.getattr.mask = cpu_to_le32(mask);
862 
863 	ihold(dir);
864 	req->r_parent = dir;
865 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
866 	err = ceph_mdsc_do_request(mdsc, NULL, req);
867 	if (err == -ENOENT) {
868 		struct dentry *res;
869 
870 		res = ceph_handle_snapdir(req, dentry);
871 		if (IS_ERR(res)) {
872 			err = PTR_ERR(res);
873 		} else {
874 			dentry = res;
875 			err = 0;
876 		}
877 	}
878 	dentry = ceph_finish_lookup(req, dentry, err);
879 	ceph_mdsc_put_request(req);  /* will dput(dentry) */
880 	doutc(cl, "result=%p\n", dentry);
881 	return dentry;
882 }
883 
884 /*
885  * If we do a create but get no trace back from the MDS, follow up with
886  * a lookup (the VFS expects us to link up the provided dentry).
887  */
ceph_handle_notrace_create(struct inode * dir,struct dentry * dentry)888 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
889 {
890 	struct dentry *result = ceph_lookup(dir, dentry, 0);
891 
892 	if (result && !IS_ERR(result)) {
893 		/*
894 		 * We created the item, then did a lookup, and found
895 		 * it was already linked to another inode we already
896 		 * had in our cache (and thus got spliced). To not
897 		 * confuse VFS (especially when inode is a directory),
898 		 * we don't link our dentry to that inode, return an
899 		 * error instead.
900 		 *
901 		 * This event should be rare and it happens only when
902 		 * we talk to old MDS. Recent MDS does not send traceless
903 		 * reply for request that creates new inode.
904 		 */
905 		d_drop(result);
906 		return -ESTALE;
907 	}
908 	return PTR_ERR(result);
909 }
910 
ceph_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)911 static int ceph_mknod(struct mnt_idmap *idmap, struct inode *dir,
912 		      struct dentry *dentry, umode_t mode, dev_t rdev)
913 {
914 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
915 	struct ceph_client *cl = mdsc->fsc->client;
916 	struct ceph_mds_request *req;
917 	struct ceph_acl_sec_ctx as_ctx = {};
918 	int err;
919 
920 	if (ceph_snap(dir) != CEPH_NOSNAP)
921 		return -EROFS;
922 
923 	err = ceph_wait_on_conflict_unlink(dentry);
924 	if (err)
925 		return err;
926 
927 	if (ceph_quota_is_max_files_exceeded(dir)) {
928 		err = -EDQUOT;
929 		goto out;
930 	}
931 
932 	doutc(cl, "%p %llx.%llx/'%pd' dentry %p mode 0%ho rdev %d\n",
933 	      dir, ceph_vinop(dir), dentry, dentry, mode, rdev);
934 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
935 	if (IS_ERR(req)) {
936 		err = PTR_ERR(req);
937 		goto out;
938 	}
939 
940 	req->r_new_inode = ceph_new_inode(dir, dentry, &mode, &as_ctx);
941 	if (IS_ERR(req->r_new_inode)) {
942 		err = PTR_ERR(req->r_new_inode);
943 		req->r_new_inode = NULL;
944 		goto out_req;
945 	}
946 
947 	if (S_ISREG(mode) && IS_ENCRYPTED(dir))
948 		set_bit(CEPH_MDS_R_FSCRYPT_FILE, &req->r_req_flags);
949 
950 	req->r_dentry = dget(dentry);
951 	req->r_num_caps = 2;
952 	req->r_parent = dir;
953 	ihold(dir);
954 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
955 	req->r_mnt_idmap = mnt_idmap_get(idmap);
956 	req->r_args.mknod.mode = cpu_to_le32(mode);
957 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
958 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
959 			     CEPH_CAP_XATTR_EXCL;
960 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
961 
962 	ceph_as_ctx_to_req(req, &as_ctx);
963 
964 	err = ceph_mdsc_do_request(mdsc, dir, req);
965 	if (!err && !req->r_reply_info.head->is_dentry)
966 		err = ceph_handle_notrace_create(dir, dentry);
967 out_req:
968 	ceph_mdsc_put_request(req);
969 out:
970 	if (!err)
971 		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
972 	else
973 		d_drop(dentry);
974 	ceph_release_acl_sec_ctx(&as_ctx);
975 	return err;
976 }
977 
ceph_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)978 static int ceph_create(struct mnt_idmap *idmap, struct inode *dir,
979 		       struct dentry *dentry, umode_t mode, bool excl)
980 {
981 	return ceph_mknod(idmap, dir, dentry, mode, 0);
982 }
983 
984 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
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 	int err;
989 	int len = strlen(dest);
990 	struct fscrypt_str osd_link = FSTR_INIT(NULL, 0);
991 
992 	err = fscrypt_prepare_symlink(req->r_parent, dest, len, PATH_MAX,
993 				      &osd_link);
994 	if (err)
995 		goto out;
996 
997 	err = fscrypt_encrypt_symlink(req->r_new_inode, dest, len, &osd_link);
998 	if (err)
999 		goto out;
1000 
1001 	req->r_path2 = kmalloc(CEPH_BASE64_CHARS(osd_link.len) + 1, GFP_KERNEL);
1002 	if (!req->r_path2) {
1003 		err = -ENOMEM;
1004 		goto out;
1005 	}
1006 
1007 	len = ceph_base64_encode(osd_link.name, osd_link.len, req->r_path2);
1008 	req->r_path2[len] = '\0';
1009 out:
1010 	fscrypt_fname_free_buffer(&osd_link);
1011 	return err;
1012 }
1013 #else
prep_encrypted_symlink_target(struct ceph_mds_request * req,const char * dest)1014 static int prep_encrypted_symlink_target(struct ceph_mds_request *req,
1015 					 const char *dest)
1016 {
1017 	return -EOPNOTSUPP;
1018 }
1019 #endif
1020 
ceph_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * dest)1021 static int ceph_symlink(struct mnt_idmap *idmap, struct inode *dir,
1022 			struct dentry *dentry, const char *dest)
1023 {
1024 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
1025 	struct ceph_client *cl = mdsc->fsc->client;
1026 	struct ceph_mds_request *req;
1027 	struct ceph_acl_sec_ctx as_ctx = {};
1028 	umode_t mode = S_IFLNK | 0777;
1029 	int err;
1030 
1031 	if (ceph_snap(dir) != CEPH_NOSNAP)
1032 		return -EROFS;
1033 
1034 	err = ceph_wait_on_conflict_unlink(dentry);
1035 	if (err)
1036 		return err;
1037 
1038 	if (ceph_quota_is_max_files_exceeded(dir)) {
1039 		err = -EDQUOT;
1040 		goto out;
1041 	}
1042 
1043 	doutc(cl, "%p %llx.%llx/'%pd' to '%s'\n", dir, ceph_vinop(dir), dentry,
1044 	      dest);
1045 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
1046 	if (IS_ERR(req)) {
1047 		err = PTR_ERR(req);
1048 		goto out;
1049 	}
1050 
1051 	req->r_new_inode = ceph_new_inode(dir, dentry, &mode, &as_ctx);
1052 	if (IS_ERR(req->r_new_inode)) {
1053 		err = PTR_ERR(req->r_new_inode);
1054 		req->r_new_inode = NULL;
1055 		goto out_req;
1056 	}
1057 
1058 	req->r_parent = dir;
1059 	ihold(dir);
1060 
1061 	if (IS_ENCRYPTED(req->r_new_inode)) {
1062 		err = prep_encrypted_symlink_target(req, dest);
1063 		if (err)
1064 			goto out_req;
1065 	} else {
1066 		req->r_path2 = kstrdup(dest, GFP_KERNEL);
1067 		if (!req->r_path2) {
1068 			err = -ENOMEM;
1069 			goto out_req;
1070 		}
1071 	}
1072 
1073 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1074 	req->r_mnt_idmap = mnt_idmap_get(idmap);
1075 	req->r_dentry = dget(dentry);
1076 	req->r_num_caps = 2;
1077 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
1078 			     CEPH_CAP_XATTR_EXCL;
1079 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1080 
1081 	ceph_as_ctx_to_req(req, &as_ctx);
1082 
1083 	err = ceph_mdsc_do_request(mdsc, dir, req);
1084 	if (!err && !req->r_reply_info.head->is_dentry)
1085 		err = ceph_handle_notrace_create(dir, dentry);
1086 out_req:
1087 	ceph_mdsc_put_request(req);
1088 out:
1089 	if (err)
1090 		d_drop(dentry);
1091 	ceph_release_acl_sec_ctx(&as_ctx);
1092 	return err;
1093 }
1094 
ceph_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)1095 static int ceph_mkdir(struct mnt_idmap *idmap, struct inode *dir,
1096 		      struct dentry *dentry, umode_t mode)
1097 {
1098 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
1099 	struct ceph_client *cl = mdsc->fsc->client;
1100 	struct ceph_mds_request *req;
1101 	struct ceph_acl_sec_ctx as_ctx = {};
1102 	int err;
1103 	int op;
1104 
1105 	err = ceph_wait_on_conflict_unlink(dentry);
1106 	if (err)
1107 		return err;
1108 
1109 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
1110 		/* mkdir .snap/foo is a MKSNAP */
1111 		op = CEPH_MDS_OP_MKSNAP;
1112 		doutc(cl, "mksnap %llx.%llx/'%pd' dentry %p\n",
1113 		      ceph_vinop(dir), dentry, dentry);
1114 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
1115 		doutc(cl, "mkdir %llx.%llx/'%pd' dentry %p mode 0%ho\n",
1116 		      ceph_vinop(dir), dentry, dentry, mode);
1117 		op = CEPH_MDS_OP_MKDIR;
1118 	} else {
1119 		err = -EROFS;
1120 		goto out;
1121 	}
1122 
1123 	if (op == CEPH_MDS_OP_MKDIR &&
1124 	    ceph_quota_is_max_files_exceeded(dir)) {
1125 		err = -EDQUOT;
1126 		goto out;
1127 	}
1128 	if ((op == CEPH_MDS_OP_MKSNAP) && IS_ENCRYPTED(dir) &&
1129 	    !fscrypt_has_encryption_key(dir)) {
1130 		err = -ENOKEY;
1131 		goto out;
1132 	}
1133 
1134 
1135 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1136 	if (IS_ERR(req)) {
1137 		err = PTR_ERR(req);
1138 		goto out;
1139 	}
1140 
1141 	mode |= S_IFDIR;
1142 	req->r_new_inode = ceph_new_inode(dir, dentry, &mode, &as_ctx);
1143 	if (IS_ERR(req->r_new_inode)) {
1144 		err = PTR_ERR(req->r_new_inode);
1145 		req->r_new_inode = NULL;
1146 		goto out_req;
1147 	}
1148 
1149 	req->r_dentry = dget(dentry);
1150 	req->r_num_caps = 2;
1151 	req->r_parent = dir;
1152 	ihold(dir);
1153 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1154 	if (op == CEPH_MDS_OP_MKDIR)
1155 		req->r_mnt_idmap = mnt_idmap_get(idmap);
1156 	req->r_args.mkdir.mode = cpu_to_le32(mode);
1157 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL |
1158 			     CEPH_CAP_XATTR_EXCL;
1159 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1160 
1161 	ceph_as_ctx_to_req(req, &as_ctx);
1162 
1163 	err = ceph_mdsc_do_request(mdsc, dir, req);
1164 	if (!err &&
1165 	    !req->r_reply_info.head->is_target &&
1166 	    !req->r_reply_info.head->is_dentry)
1167 		err = ceph_handle_notrace_create(dir, dentry);
1168 out_req:
1169 	ceph_mdsc_put_request(req);
1170 out:
1171 	if (!err)
1172 		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
1173 	else
1174 		d_drop(dentry);
1175 	ceph_release_acl_sec_ctx(&as_ctx);
1176 	return err;
1177 }
1178 
ceph_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)1179 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
1180 		     struct dentry *dentry)
1181 {
1182 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
1183 	struct ceph_client *cl = mdsc->fsc->client;
1184 	struct ceph_mds_request *req;
1185 	int err;
1186 
1187 	if (dentry->d_flags & DCACHE_DISCONNECTED)
1188 		return -EINVAL;
1189 
1190 	err = ceph_wait_on_conflict_unlink(dentry);
1191 	if (err)
1192 		return err;
1193 
1194 	if (ceph_snap(dir) != CEPH_NOSNAP)
1195 		return -EROFS;
1196 
1197 	err = fscrypt_prepare_link(old_dentry, dir, dentry);
1198 	if (err)
1199 		return err;
1200 
1201 	doutc(cl, "%p %llx.%llx/'%pd' to '%pd'\n", dir, ceph_vinop(dir),
1202 	      old_dentry, dentry);
1203 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
1204 	if (IS_ERR(req)) {
1205 		d_drop(dentry);
1206 		return PTR_ERR(req);
1207 	}
1208 	req->r_dentry = dget(dentry);
1209 	req->r_num_caps = 2;
1210 	req->r_old_dentry = dget(old_dentry);
1211 	/*
1212 	 * The old_dentry maybe a DCACHE_DISCONNECTED dentry, then we
1213 	 * will just pass the ino# to MDSs.
1214 	 */
1215 	if (old_dentry->d_flags & DCACHE_DISCONNECTED)
1216 		req->r_ino2 = ceph_vino(d_inode(old_dentry));
1217 	req->r_parent = dir;
1218 	ihold(dir);
1219 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1220 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1221 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1222 	/* release LINK_SHARED on source inode (mds will lock it) */
1223 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1224 	err = ceph_mdsc_do_request(mdsc, dir, req);
1225 	if (err) {
1226 		d_drop(dentry);
1227 	} else if (!req->r_reply_info.head->is_dentry) {
1228 		ihold(d_inode(old_dentry));
1229 		d_instantiate(dentry, d_inode(old_dentry));
1230 	}
1231 	ceph_mdsc_put_request(req);
1232 	return err;
1233 }
1234 
ceph_async_unlink_cb(struct ceph_mds_client * mdsc,struct ceph_mds_request * req)1235 static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
1236 				 struct ceph_mds_request *req)
1237 {
1238 	struct dentry *dentry = req->r_dentry;
1239 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dentry->d_sb);
1240 	struct ceph_client *cl = fsc->client;
1241 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1242 	int result = req->r_err ? req->r_err :
1243 			le32_to_cpu(req->r_reply_info.head->result);
1244 
1245 	if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
1246 		pr_warn_client(cl,
1247 			"dentry %p:%pd async unlink bit is not set\n",
1248 			dentry, dentry);
1249 
1250 	spin_lock(&fsc->async_unlink_conflict_lock);
1251 	hash_del_rcu(&di->hnode);
1252 	spin_unlock(&fsc->async_unlink_conflict_lock);
1253 
1254 	spin_lock(&dentry->d_lock);
1255 	di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
1256 	wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT);
1257 	spin_unlock(&dentry->d_lock);
1258 
1259 	synchronize_rcu();
1260 
1261 	if (result == -EJUKEBOX)
1262 		goto out;
1263 
1264 	/* If op failed, mark everyone involved for errors */
1265 	if (result) {
1266 		int pathlen = 0;
1267 		u64 base = 0;
1268 		char *path = ceph_mdsc_build_path(mdsc, dentry, &pathlen,
1269 						  &base, 0);
1270 
1271 		/* mark error on parent + clear complete */
1272 		mapping_set_error(req->r_parent->i_mapping, result);
1273 		ceph_dir_clear_complete(req->r_parent);
1274 
1275 		/* drop the dentry -- we don't know its status */
1276 		if (!d_unhashed(dentry))
1277 			d_drop(dentry);
1278 
1279 		/* mark inode itself for an error (since metadata is bogus) */
1280 		mapping_set_error(req->r_old_inode->i_mapping, result);
1281 
1282 		pr_warn_client(cl, "failure path=(%llx)%s result=%d!\n",
1283 			       base, IS_ERR(path) ? "<<bad>>" : path, result);
1284 		ceph_mdsc_free_path(path, pathlen);
1285 	}
1286 out:
1287 	iput(req->r_old_inode);
1288 	ceph_mdsc_release_dir_caps(req);
1289 }
1290 
get_caps_for_async_unlink(struct inode * dir,struct dentry * dentry)1291 static int get_caps_for_async_unlink(struct inode *dir, struct dentry *dentry)
1292 {
1293 	struct ceph_inode_info *ci = ceph_inode(dir);
1294 	struct ceph_dentry_info *di;
1295 	int got = 0, want = CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_UNLINK;
1296 
1297 	spin_lock(&ci->i_ceph_lock);
1298 	if ((__ceph_caps_issued(ci, NULL) & want) == want) {
1299 		ceph_take_cap_refs(ci, want, false);
1300 		got = want;
1301 	}
1302 	spin_unlock(&ci->i_ceph_lock);
1303 
1304 	/* If we didn't get anything, return 0 */
1305 	if (!got)
1306 		return 0;
1307 
1308         spin_lock(&dentry->d_lock);
1309         di = ceph_dentry(dentry);
1310 	/*
1311 	 * - We are holding Fx, which implies Fs caps.
1312 	 * - Only support async unlink for primary linkage
1313 	 */
1314 	if (atomic_read(&ci->i_shared_gen) != di->lease_shared_gen ||
1315 	    !(di->flags & CEPH_DENTRY_PRIMARY_LINK))
1316 		want = 0;
1317         spin_unlock(&dentry->d_lock);
1318 
1319 	/* Do we still want what we've got? */
1320 	if (want == got)
1321 		return got;
1322 
1323 	ceph_put_cap_refs(ci, got);
1324 	return 0;
1325 }
1326 
1327 /*
1328  * rmdir and unlink are differ only by the metadata op code
1329  */
ceph_unlink(struct inode * dir,struct dentry * dentry)1330 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
1331 {
1332 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dir->i_sb);
1333 	struct ceph_client *cl = fsc->client;
1334 	struct ceph_mds_client *mdsc = fsc->mdsc;
1335 	struct inode *inode = d_inode(dentry);
1336 	struct ceph_mds_request *req;
1337 	bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
1338 	struct dentry *dn;
1339 	int err = -EROFS;
1340 	int op;
1341 	char *path;
1342 	int pathlen;
1343 	u64 pathbase;
1344 
1345 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
1346 		/* rmdir .snap/foo is RMSNAP */
1347 		doutc(cl, "rmsnap %llx.%llx/'%pd' dn\n", ceph_vinop(dir),
1348 		      dentry);
1349 		op = CEPH_MDS_OP_RMSNAP;
1350 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
1351 		doutc(cl, "unlink/rmdir %llx.%llx/'%pd' inode %llx.%llx\n",
1352 		      ceph_vinop(dir), dentry, ceph_vinop(inode));
1353 		op = d_is_dir(dentry) ?
1354 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
1355 	} else
1356 		goto out;
1357 
1358 	dn = d_find_alias(dir);
1359 	if (!dn) {
1360 		try_async = false;
1361 	} else {
1362 		path = ceph_mdsc_build_path(mdsc, dn, &pathlen, &pathbase, 0);
1363 		if (IS_ERR(path)) {
1364 			try_async = false;
1365 			err = 0;
1366 		} else {
1367 			err = ceph_mds_check_access(mdsc, path, MAY_WRITE);
1368 		}
1369 		ceph_mdsc_free_path(path, pathlen);
1370 		dput(dn);
1371 
1372 		/* For none EACCES cases will let the MDS do the mds auth check */
1373 		if (err == -EACCES) {
1374 			return err;
1375 		} else if (err < 0) {
1376 			try_async = false;
1377 			err = 0;
1378 		}
1379 	}
1380 
1381 retry:
1382 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1383 	if (IS_ERR(req)) {
1384 		err = PTR_ERR(req);
1385 		goto out;
1386 	}
1387 	req->r_dentry = dget(dentry);
1388 	req->r_num_caps = 2;
1389 	req->r_parent = dir;
1390 	ihold(dir);
1391 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1392 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1393 	req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
1394 
1395 	if (try_async && op == CEPH_MDS_OP_UNLINK &&
1396 	    (req->r_dir_caps = get_caps_for_async_unlink(dir, dentry))) {
1397 		struct ceph_dentry_info *di = ceph_dentry(dentry);
1398 
1399 		doutc(cl, "async unlink on %llx.%llx/'%pd' caps=%s",
1400 		      ceph_vinop(dir), dentry,
1401 		      ceph_cap_string(req->r_dir_caps));
1402 		set_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags);
1403 		req->r_callback = ceph_async_unlink_cb;
1404 		req->r_old_inode = d_inode(dentry);
1405 		ihold(req->r_old_inode);
1406 
1407 		spin_lock(&dentry->d_lock);
1408 		di->flags |= CEPH_DENTRY_ASYNC_UNLINK;
1409 		spin_unlock(&dentry->d_lock);
1410 
1411 		spin_lock(&fsc->async_unlink_conflict_lock);
1412 		hash_add_rcu(fsc->async_unlink_conflict, &di->hnode,
1413 			     dentry->d_name.hash);
1414 		spin_unlock(&fsc->async_unlink_conflict_lock);
1415 
1416 		err = ceph_mdsc_submit_request(mdsc, dir, req);
1417 		if (!err) {
1418 			/*
1419 			 * We have enough caps, so we assume that the unlink
1420 			 * will succeed. Fix up the target inode and dcache.
1421 			 */
1422 			drop_nlink(inode);
1423 			d_delete(dentry);
1424 		} else {
1425 			spin_lock(&fsc->async_unlink_conflict_lock);
1426 			hash_del_rcu(&di->hnode);
1427 			spin_unlock(&fsc->async_unlink_conflict_lock);
1428 
1429 			spin_lock(&dentry->d_lock);
1430 			di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
1431 			spin_unlock(&dentry->d_lock);
1432 
1433 			if (err == -EJUKEBOX) {
1434 				try_async = false;
1435 				ceph_mdsc_put_request(req);
1436 				goto retry;
1437 			}
1438 		}
1439 	} else {
1440 		set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1441 		err = ceph_mdsc_do_request(mdsc, dir, req);
1442 		if (!err && !req->r_reply_info.head->is_dentry)
1443 			d_delete(dentry);
1444 	}
1445 
1446 	ceph_mdsc_put_request(req);
1447 out:
1448 	return err;
1449 }
1450 
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)1451 static int ceph_rename(struct mnt_idmap *idmap, struct inode *old_dir,
1452 		       struct dentry *old_dentry, struct inode *new_dir,
1453 		       struct dentry *new_dentry, unsigned int flags)
1454 {
1455 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(old_dir->i_sb);
1456 	struct ceph_client *cl = mdsc->fsc->client;
1457 	struct ceph_mds_request *req;
1458 	int op = CEPH_MDS_OP_RENAME;
1459 	int err;
1460 
1461 	if (flags)
1462 		return -EINVAL;
1463 
1464 	if (ceph_snap(old_dir) != ceph_snap(new_dir))
1465 		return -EXDEV;
1466 	if (ceph_snap(old_dir) != CEPH_NOSNAP) {
1467 		if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
1468 			op = CEPH_MDS_OP_RENAMESNAP;
1469 		else
1470 			return -EROFS;
1471 	}
1472 	/* don't allow cross-quota renames */
1473 	if ((old_dir != new_dir) &&
1474 	    (!ceph_quota_is_same_realm(old_dir, new_dir)))
1475 		return -EXDEV;
1476 
1477 	err = ceph_wait_on_conflict_unlink(new_dentry);
1478 	if (err)
1479 		return err;
1480 
1481 	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
1482 				     flags);
1483 	if (err)
1484 		return err;
1485 
1486 	doutc(cl, "%llx.%llx/'%pd' to %llx.%llx/'%pd'\n",
1487 	      ceph_vinop(old_dir), old_dentry, ceph_vinop(new_dir),
1488 	      new_dentry);
1489 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1490 	if (IS_ERR(req))
1491 		return PTR_ERR(req);
1492 	ihold(old_dir);
1493 	req->r_dentry = dget(new_dentry);
1494 	req->r_num_caps = 2;
1495 	req->r_old_dentry = dget(old_dentry);
1496 	req->r_old_dentry_dir = old_dir;
1497 	req->r_parent = new_dir;
1498 	ihold(new_dir);
1499 	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1500 	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1501 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
1502 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_XATTR_EXCL;
1503 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1504 	/* release LINK_RDCACHE on source inode (mds will lock it) */
1505 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1506 	if (d_really_is_positive(new_dentry)) {
1507 		req->r_inode_drop =
1508 			ceph_drop_caps_for_unlink(d_inode(new_dentry));
1509 	}
1510 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
1511 	if (!err && !req->r_reply_info.head->is_dentry) {
1512 		/*
1513 		 * Normally d_move() is done by fill_trace (called by
1514 		 * do_request, above).  If there is no trace, we need
1515 		 * to do it here.
1516 		 */
1517 		d_move(old_dentry, new_dentry);
1518 	}
1519 	ceph_mdsc_put_request(req);
1520 	return err;
1521 }
1522 
1523 /*
1524  * Move dentry to tail of mdsc->dentry_leases list when lease is updated.
1525  * Leases at front of the list will expire first. (Assume all leases have
1526  * similar duration)
1527  *
1528  * Called under dentry->d_lock.
1529  */
__ceph_dentry_lease_touch(struct ceph_dentry_info * di)1530 void __ceph_dentry_lease_touch(struct ceph_dentry_info *di)
1531 {
1532 	struct dentry *dn = di->dentry;
1533 	struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(dn->d_sb)->mdsc;
1534 	struct ceph_client *cl = mdsc->fsc->client;
1535 
1536 	doutc(cl, "%p %p '%pd'\n", di, dn, dn);
1537 
1538 	di->flags |= CEPH_DENTRY_LEASE_LIST;
1539 	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1540 		di->flags |= CEPH_DENTRY_REFERENCED;
1541 		return;
1542 	}
1543 
1544 	spin_lock(&mdsc->dentry_list_lock);
1545 	list_move_tail(&di->lease_list, &mdsc->dentry_leases);
1546 	spin_unlock(&mdsc->dentry_list_lock);
1547 }
1548 
__dentry_dir_lease_touch(struct ceph_mds_client * mdsc,struct ceph_dentry_info * di)1549 static void __dentry_dir_lease_touch(struct ceph_mds_client* mdsc,
1550 				     struct ceph_dentry_info *di)
1551 {
1552 	di->flags &= ~(CEPH_DENTRY_LEASE_LIST | CEPH_DENTRY_REFERENCED);
1553 	di->lease_gen = 0;
1554 	di->time = jiffies;
1555 	list_move_tail(&di->lease_list, &mdsc->dentry_dir_leases);
1556 }
1557 
1558 /*
1559  * When dir lease is used, add dentry to tail of mdsc->dentry_dir_leases
1560  * list if it's not in the list, otherwise set 'referenced' flag.
1561  *
1562  * Called under dentry->d_lock.
1563  */
__ceph_dentry_dir_lease_touch(struct ceph_dentry_info * di)1564 void __ceph_dentry_dir_lease_touch(struct ceph_dentry_info *di)
1565 {
1566 	struct dentry *dn = di->dentry;
1567 	struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(dn->d_sb)->mdsc;
1568 	struct ceph_client *cl = mdsc->fsc->client;
1569 
1570 	doutc(cl, "%p %p '%pd' (offset 0x%llx)\n", di, dn, dn, di->offset);
1571 
1572 	if (!list_empty(&di->lease_list)) {
1573 		if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1574 			/* don't remove dentry from dentry lease list
1575 			 * if its lease is valid */
1576 			if (__dentry_lease_is_valid(di))
1577 				return;
1578 		} else {
1579 			di->flags |= CEPH_DENTRY_REFERENCED;
1580 			return;
1581 		}
1582 	}
1583 
1584 	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1585 		di->flags |= CEPH_DENTRY_REFERENCED;
1586 		di->flags &= ~CEPH_DENTRY_LEASE_LIST;
1587 		return;
1588 	}
1589 
1590 	spin_lock(&mdsc->dentry_list_lock);
1591 	__dentry_dir_lease_touch(mdsc, di);
1592 	spin_unlock(&mdsc->dentry_list_lock);
1593 }
1594 
__dentry_lease_unlist(struct ceph_dentry_info * di)1595 static void __dentry_lease_unlist(struct ceph_dentry_info *di)
1596 {
1597 	struct ceph_mds_client *mdsc;
1598 	if (di->flags & CEPH_DENTRY_SHRINK_LIST)
1599 		return;
1600 	if (list_empty(&di->lease_list))
1601 		return;
1602 
1603 	mdsc = ceph_sb_to_fs_client(di->dentry->d_sb)->mdsc;
1604 	spin_lock(&mdsc->dentry_list_lock);
1605 	list_del_init(&di->lease_list);
1606 	spin_unlock(&mdsc->dentry_list_lock);
1607 }
1608 
1609 enum {
1610 	KEEP	= 0,
1611 	DELETE	= 1,
1612 	TOUCH	= 2,
1613 	STOP	= 4,
1614 };
1615 
1616 struct ceph_lease_walk_control {
1617 	bool dir_lease;
1618 	bool expire_dir_lease;
1619 	unsigned long nr_to_scan;
1620 	unsigned long dir_lease_ttl;
1621 };
1622 
1623 static int __dir_lease_check(const struct dentry *, struct ceph_lease_walk_control *);
1624 static int __dentry_lease_check(const struct dentry *);
1625 
1626 static unsigned long
__dentry_leases_walk(struct ceph_mds_client * mdsc,struct ceph_lease_walk_control * lwc)1627 __dentry_leases_walk(struct ceph_mds_client *mdsc,
1628 		     struct ceph_lease_walk_control *lwc)
1629 {
1630 	struct ceph_dentry_info *di, *tmp;
1631 	struct dentry *dentry, *last = NULL;
1632 	struct list_head* list;
1633         LIST_HEAD(dispose);
1634 	unsigned long freed = 0;
1635 	int ret = 0;
1636 
1637 	list = lwc->dir_lease ? &mdsc->dentry_dir_leases : &mdsc->dentry_leases;
1638 	spin_lock(&mdsc->dentry_list_lock);
1639 	list_for_each_entry_safe(di, tmp, list, lease_list) {
1640 		if (!lwc->nr_to_scan)
1641 			break;
1642 		--lwc->nr_to_scan;
1643 
1644 		dentry = di->dentry;
1645 		if (last == dentry)
1646 			break;
1647 
1648 		if (!spin_trylock(&dentry->d_lock))
1649 			continue;
1650 
1651 		if (__lockref_is_dead(&dentry->d_lockref)) {
1652 			list_del_init(&di->lease_list);
1653 			goto next;
1654 		}
1655 
1656 		if (lwc->dir_lease)
1657 			ret = __dir_lease_check(dentry, lwc);
1658 		else
1659 			ret = __dentry_lease_check(dentry);
1660 		if (ret & TOUCH) {
1661 			/* move it into tail of dir lease list */
1662 			__dentry_dir_lease_touch(mdsc, di);
1663 			if (!last)
1664 				last = dentry;
1665 		}
1666 		if (ret & DELETE) {
1667 			/* stale lease */
1668 			di->flags &= ~CEPH_DENTRY_REFERENCED;
1669 			if (dentry->d_lockref.count > 0) {
1670 				/* update_dentry_lease() will re-add
1671 				 * it to lease list, or
1672 				 * ceph_d_delete() will return 1 when
1673 				 * last reference is dropped */
1674 				list_del_init(&di->lease_list);
1675 			} else {
1676 				di->flags |= CEPH_DENTRY_SHRINK_LIST;
1677 				list_move_tail(&di->lease_list, &dispose);
1678 				dget_dlock(dentry);
1679 			}
1680 		}
1681 next:
1682 		spin_unlock(&dentry->d_lock);
1683 		if (ret & STOP)
1684 			break;
1685 	}
1686 	spin_unlock(&mdsc->dentry_list_lock);
1687 
1688 	while (!list_empty(&dispose)) {
1689 		di = list_first_entry(&dispose, struct ceph_dentry_info,
1690 				      lease_list);
1691 		dentry = di->dentry;
1692 		spin_lock(&dentry->d_lock);
1693 
1694 		list_del_init(&di->lease_list);
1695 		di->flags &= ~CEPH_DENTRY_SHRINK_LIST;
1696 		if (di->flags & CEPH_DENTRY_REFERENCED) {
1697 			spin_lock(&mdsc->dentry_list_lock);
1698 			if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1699 				list_add_tail(&di->lease_list,
1700 					      &mdsc->dentry_leases);
1701 			} else {
1702 				__dentry_dir_lease_touch(mdsc, di);
1703 			}
1704 			spin_unlock(&mdsc->dentry_list_lock);
1705 		} else {
1706 			freed++;
1707 		}
1708 
1709 		spin_unlock(&dentry->d_lock);
1710 		/* ceph_d_delete() does the trick */
1711 		dput(dentry);
1712 	}
1713 	return freed;
1714 }
1715 
__dentry_lease_check(const struct dentry * dentry)1716 static int __dentry_lease_check(const struct dentry *dentry)
1717 {
1718 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1719 	int ret;
1720 
1721 	if (__dentry_lease_is_valid(di))
1722 		return STOP;
1723 	ret = __dir_lease_try_check(dentry);
1724 	if (ret == -EBUSY)
1725 		return KEEP;
1726 	if (ret > 0)
1727 		return TOUCH;
1728 	return DELETE;
1729 }
1730 
__dir_lease_check(const struct dentry * dentry,struct ceph_lease_walk_control * lwc)1731 static int __dir_lease_check(const struct dentry *dentry,
1732 			     struct ceph_lease_walk_control *lwc)
1733 {
1734 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1735 
1736 	int ret = __dir_lease_try_check(dentry);
1737 	if (ret == -EBUSY)
1738 		return KEEP;
1739 	if (ret > 0) {
1740 		if (time_before(jiffies, di->time + lwc->dir_lease_ttl))
1741 			return STOP;
1742 		/* Move dentry to tail of dir lease list if we don't want
1743 		 * to delete it. So dentries in the list are checked in a
1744 		 * round robin manner */
1745 		if (!lwc->expire_dir_lease)
1746 			return TOUCH;
1747 		if (dentry->d_lockref.count > 0 ||
1748 		    (di->flags & CEPH_DENTRY_REFERENCED))
1749 			return TOUCH;
1750 		/* invalidate dir lease */
1751 		di->lease_shared_gen = 0;
1752 	}
1753 	return DELETE;
1754 }
1755 
ceph_trim_dentries(struct ceph_mds_client * mdsc)1756 int ceph_trim_dentries(struct ceph_mds_client *mdsc)
1757 {
1758 	struct ceph_lease_walk_control lwc;
1759 	unsigned long count;
1760 	unsigned long freed;
1761 
1762 	spin_lock(&mdsc->caps_list_lock);
1763         if (mdsc->caps_use_max > 0 &&
1764             mdsc->caps_use_count > mdsc->caps_use_max)
1765 		count = mdsc->caps_use_count - mdsc->caps_use_max;
1766 	else
1767 		count = 0;
1768         spin_unlock(&mdsc->caps_list_lock);
1769 
1770 	lwc.dir_lease = false;
1771 	lwc.nr_to_scan  = CEPH_CAPS_PER_RELEASE * 2;
1772 	freed = __dentry_leases_walk(mdsc, &lwc);
1773 	if (!lwc.nr_to_scan) /* more invalid leases */
1774 		return -EAGAIN;
1775 
1776 	if (lwc.nr_to_scan < CEPH_CAPS_PER_RELEASE)
1777 		lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE;
1778 
1779 	lwc.dir_lease = true;
1780 	lwc.expire_dir_lease = freed < count;
1781 	lwc.dir_lease_ttl = mdsc->fsc->mount_options->caps_wanted_delay_max * HZ;
1782 	freed +=__dentry_leases_walk(mdsc, &lwc);
1783 	if (!lwc.nr_to_scan) /* more to check */
1784 		return -EAGAIN;
1785 
1786 	return freed > 0 ? 1 : 0;
1787 }
1788 
1789 /*
1790  * Ensure a dentry lease will no longer revalidate.
1791  */
ceph_invalidate_dentry_lease(struct dentry * dentry)1792 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1793 {
1794 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1795 	spin_lock(&dentry->d_lock);
1796 	di->time = jiffies;
1797 	di->lease_shared_gen = 0;
1798 	di->flags &= ~CEPH_DENTRY_PRIMARY_LINK;
1799 	__dentry_lease_unlist(di);
1800 	spin_unlock(&dentry->d_lock);
1801 }
1802 
1803 /*
1804  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1805  * renew if the least is more than half up.
1806  */
__dentry_lease_is_valid(struct ceph_dentry_info * di)1807 static bool __dentry_lease_is_valid(struct ceph_dentry_info *di)
1808 {
1809 	struct ceph_mds_session *session;
1810 
1811 	if (!di->lease_gen)
1812 		return false;
1813 
1814 	session = di->lease_session;
1815 	if (session) {
1816 		u32 gen;
1817 		unsigned long ttl;
1818 
1819 		gen = atomic_read(&session->s_cap_gen);
1820 		ttl = session->s_cap_ttl;
1821 
1822 		if (di->lease_gen == gen &&
1823 		    time_before(jiffies, ttl) &&
1824 		    time_before(jiffies, di->time))
1825 			return true;
1826 	}
1827 	di->lease_gen = 0;
1828 	return false;
1829 }
1830 
dentry_lease_is_valid(struct dentry * dentry,unsigned int flags)1831 static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags)
1832 {
1833 	struct ceph_dentry_info *di;
1834 	struct ceph_mds_session *session = NULL;
1835 	struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(dentry->d_sb)->mdsc;
1836 	struct ceph_client *cl = mdsc->fsc->client;
1837 	u32 seq = 0;
1838 	int valid = 0;
1839 
1840 	spin_lock(&dentry->d_lock);
1841 	di = ceph_dentry(dentry);
1842 	if (di && __dentry_lease_is_valid(di)) {
1843 		valid = 1;
1844 
1845 		if (di->lease_renew_after &&
1846 		    time_after(jiffies, di->lease_renew_after)) {
1847 			/*
1848 			 * We should renew. If we're in RCU walk mode
1849 			 * though, we can't do that so just return
1850 			 * -ECHILD.
1851 			 */
1852 			if (flags & LOOKUP_RCU) {
1853 				valid = -ECHILD;
1854 			} else {
1855 				session = ceph_get_mds_session(di->lease_session);
1856 				seq = di->lease_seq;
1857 				di->lease_renew_after = 0;
1858 				di->lease_renew_from = jiffies;
1859 			}
1860 		}
1861 	}
1862 	spin_unlock(&dentry->d_lock);
1863 
1864 	if (session) {
1865 		ceph_mdsc_lease_send_msg(session, dentry,
1866 					 CEPH_MDS_LEASE_RENEW, seq);
1867 		ceph_put_mds_session(session);
1868 	}
1869 	doutc(cl, "dentry %p = %d\n", dentry, valid);
1870 	return valid;
1871 }
1872 
1873 /*
1874  * Called under dentry->d_lock.
1875  */
__dir_lease_try_check(const struct dentry * dentry)1876 static int __dir_lease_try_check(const struct dentry *dentry)
1877 {
1878 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1879 	struct inode *dir;
1880 	struct ceph_inode_info *ci;
1881 	int valid = 0;
1882 
1883 	if (!di->lease_shared_gen)
1884 		return 0;
1885 	if (IS_ROOT(dentry))
1886 		return 0;
1887 
1888 	dir = d_inode(dentry->d_parent);
1889 	ci = ceph_inode(dir);
1890 
1891 	if (spin_trylock(&ci->i_ceph_lock)) {
1892 		if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen &&
1893 		    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 0))
1894 			valid = 1;
1895 		spin_unlock(&ci->i_ceph_lock);
1896 	} else {
1897 		valid = -EBUSY;
1898 	}
1899 
1900 	if (!valid)
1901 		di->lease_shared_gen = 0;
1902 	return valid;
1903 }
1904 
1905 /*
1906  * Check if directory-wide content lease/cap is valid.
1907  */
dir_lease_is_valid(struct inode * dir,struct dentry * dentry,struct ceph_mds_client * mdsc)1908 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry,
1909 			      struct ceph_mds_client *mdsc)
1910 {
1911 	struct ceph_inode_info *ci = ceph_inode(dir);
1912 	struct ceph_client *cl = mdsc->fsc->client;
1913 	int valid;
1914 	int shared_gen;
1915 
1916 	spin_lock(&ci->i_ceph_lock);
1917 	valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1918 	if (valid) {
1919 		__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
1920 		shared_gen = atomic_read(&ci->i_shared_gen);
1921 	}
1922 	spin_unlock(&ci->i_ceph_lock);
1923 	if (valid) {
1924 		struct ceph_dentry_info *di;
1925 		spin_lock(&dentry->d_lock);
1926 		di = ceph_dentry(dentry);
1927 		if (dir == d_inode(dentry->d_parent) &&
1928 		    di && di->lease_shared_gen == shared_gen)
1929 			__ceph_dentry_dir_lease_touch(di);
1930 		else
1931 			valid = 0;
1932 		spin_unlock(&dentry->d_lock);
1933 	}
1934 	doutc(cl, "dir %p %llx.%llx v%u dentry %p '%pd' = %d\n", dir,
1935 	      ceph_vinop(dir), (unsigned)atomic_read(&ci->i_shared_gen),
1936 	      dentry, dentry, valid);
1937 	return valid;
1938 }
1939 
1940 /*
1941  * Check if cached dentry can be trusted.
1942  */
ceph_d_revalidate(struct dentry * dentry,unsigned int flags)1943 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1944 {
1945 	struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(dentry->d_sb)->mdsc;
1946 	struct ceph_client *cl = mdsc->fsc->client;
1947 	int valid = 0;
1948 	struct dentry *parent;
1949 	struct inode *dir, *inode;
1950 
1951 	valid = fscrypt_d_revalidate(dentry, flags);
1952 	if (valid <= 0)
1953 		return valid;
1954 
1955 	if (flags & LOOKUP_RCU) {
1956 		parent = READ_ONCE(dentry->d_parent);
1957 		dir = d_inode_rcu(parent);
1958 		if (!dir)
1959 			return -ECHILD;
1960 		inode = d_inode_rcu(dentry);
1961 	} else {
1962 		parent = dget_parent(dentry);
1963 		dir = d_inode(parent);
1964 		inode = d_inode(dentry);
1965 	}
1966 
1967 	doutc(cl, "%p '%pd' inode %p offset 0x%llx nokey %d\n",
1968 	      dentry, dentry, inode, ceph_dentry(dentry)->offset,
1969 	      !!(dentry->d_flags & DCACHE_NOKEY_NAME));
1970 
1971 	mdsc = ceph_sb_to_fs_client(dir->i_sb)->mdsc;
1972 
1973 	/* always trust cached snapped dentries, snapdir dentry */
1974 	if (ceph_snap(dir) != CEPH_NOSNAP) {
1975 		doutc(cl, "%p '%pd' inode %p is SNAPPED\n", dentry,
1976 		      dentry, inode);
1977 		valid = 1;
1978 	} else if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1979 		valid = 1;
1980 	} else {
1981 		valid = dentry_lease_is_valid(dentry, flags);
1982 		if (valid == -ECHILD)
1983 			return valid;
1984 		if (valid || dir_lease_is_valid(dir, dentry, mdsc)) {
1985 			if (inode)
1986 				valid = ceph_is_any_caps(inode);
1987 			else
1988 				valid = 1;
1989 		}
1990 	}
1991 
1992 	if (!valid) {
1993 		struct ceph_mds_request *req;
1994 		int op, err;
1995 		u32 mask;
1996 
1997 		if (flags & LOOKUP_RCU)
1998 			return -ECHILD;
1999 
2000 		percpu_counter_inc(&mdsc->metric.d_lease_mis);
2001 
2002 		op = ceph_snap(dir) == CEPH_SNAPDIR ?
2003 			CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
2004 		req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
2005 		if (!IS_ERR(req)) {
2006 			req->r_dentry = dget(dentry);
2007 			req->r_num_caps = 2;
2008 			req->r_parent = dir;
2009 			ihold(dir);
2010 
2011 			mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
2012 			if (ceph_security_xattr_wanted(dir))
2013 				mask |= CEPH_CAP_XATTR_SHARED;
2014 			req->r_args.getattr.mask = cpu_to_le32(mask);
2015 
2016 			err = ceph_mdsc_do_request(mdsc, NULL, req);
2017 			switch (err) {
2018 			case 0:
2019 				if (d_really_is_positive(dentry) &&
2020 				    d_inode(dentry) == req->r_target_inode)
2021 					valid = 1;
2022 				break;
2023 			case -ENOENT:
2024 				if (d_really_is_negative(dentry))
2025 					valid = 1;
2026 				fallthrough;
2027 			default:
2028 				break;
2029 			}
2030 			ceph_mdsc_put_request(req);
2031 			doutc(cl, "%p '%pd', lookup result=%d\n", dentry,
2032 			      dentry, err);
2033 		}
2034 	} else {
2035 		percpu_counter_inc(&mdsc->metric.d_lease_hit);
2036 	}
2037 
2038 	doutc(cl, "%p '%pd' %s\n", dentry, dentry, valid ? "valid" : "invalid");
2039 	if (!valid)
2040 		ceph_dir_clear_complete(dir);
2041 
2042 	if (!(flags & LOOKUP_RCU))
2043 		dput(parent);
2044 	return valid;
2045 }
2046 
2047 /*
2048  * Delete unused dentry that doesn't have valid lease
2049  *
2050  * Called under dentry->d_lock.
2051  */
ceph_d_delete(const struct dentry * dentry)2052 static int ceph_d_delete(const struct dentry *dentry)
2053 {
2054 	struct ceph_dentry_info *di;
2055 
2056 	/* won't release caps */
2057 	if (d_really_is_negative(dentry))
2058 		return 0;
2059 	if (ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
2060 		return 0;
2061 	/* valid lease? */
2062 	di = ceph_dentry(dentry);
2063 	if (di) {
2064 		if (__dentry_lease_is_valid(di))
2065 			return 0;
2066 		if (__dir_lease_try_check(dentry))
2067 			return 0;
2068 	}
2069 	return 1;
2070 }
2071 
2072 /*
2073  * Release our ceph_dentry_info.
2074  */
ceph_d_release(struct dentry * dentry)2075 static void ceph_d_release(struct dentry *dentry)
2076 {
2077 	struct ceph_dentry_info *di = ceph_dentry(dentry);
2078 	struct ceph_fs_client *fsc = ceph_sb_to_fs_client(dentry->d_sb);
2079 
2080 	doutc(fsc->client, "dentry %p '%pd'\n", dentry, dentry);
2081 
2082 	atomic64_dec(&fsc->mdsc->metric.total_dentries);
2083 
2084 	spin_lock(&dentry->d_lock);
2085 	__dentry_lease_unlist(di);
2086 	dentry->d_fsdata = NULL;
2087 	spin_unlock(&dentry->d_lock);
2088 
2089 	ceph_put_mds_session(di->lease_session);
2090 	kmem_cache_free(ceph_dentry_cachep, di);
2091 }
2092 
2093 /*
2094  * When the VFS prunes a dentry from the cache, we need to clear the
2095  * complete flag on the parent directory.
2096  *
2097  * Called under dentry->d_lock.
2098  */
ceph_d_prune(struct dentry * dentry)2099 static void ceph_d_prune(struct dentry *dentry)
2100 {
2101 	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dentry->d_sb);
2102 	struct ceph_client *cl = mdsc->fsc->client;
2103 	struct ceph_inode_info *dir_ci;
2104 	struct ceph_dentry_info *di;
2105 
2106 	doutc(cl, "dentry %p '%pd'\n", dentry, dentry);
2107 
2108 	/* do we have a valid parent? */
2109 	if (IS_ROOT(dentry))
2110 		return;
2111 
2112 	/* we hold d_lock, so d_parent is stable */
2113 	dir_ci = ceph_inode(d_inode(dentry->d_parent));
2114 	if (dir_ci->i_vino.snap == CEPH_SNAPDIR)
2115 		return;
2116 
2117 	/* who calls d_delete() should also disable dcache readdir */
2118 	if (d_really_is_negative(dentry))
2119 		return;
2120 
2121 	/* d_fsdata does not get cleared until d_release */
2122 	if (!d_unhashed(dentry)) {
2123 		__ceph_dir_clear_complete(dir_ci);
2124 		return;
2125 	}
2126 
2127 	/* Disable dcache readdir just in case that someone called d_drop()
2128 	 * or d_invalidate(), but MDS didn't revoke CEPH_CAP_FILE_SHARED
2129 	 * properly (dcache readdir is still enabled) */
2130 	di = ceph_dentry(dentry);
2131 	if (di->offset > 0 &&
2132 	    di->lease_shared_gen == atomic_read(&dir_ci->i_shared_gen))
2133 		__ceph_dir_clear_ordered(dir_ci);
2134 }
2135 
2136 /*
2137  * read() on a dir.  This weird interface hack only works if mounted
2138  * with '-o dirstat'.
2139  */
ceph_read_dir(struct file * file,char __user * buf,size_t size,loff_t * ppos)2140 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
2141 			     loff_t *ppos)
2142 {
2143 	struct ceph_dir_file_info *dfi = file->private_data;
2144 	struct inode *inode = file_inode(file);
2145 	struct ceph_inode_info *ci = ceph_inode(inode);
2146 	int left;
2147 	const int bufsize = 1024;
2148 
2149 	if (!ceph_test_mount_opt(ceph_sb_to_fs_client(inode->i_sb), DIRSTAT))
2150 		return -EISDIR;
2151 
2152 	if (!dfi->dir_info) {
2153 		dfi->dir_info = kmalloc(bufsize, GFP_KERNEL);
2154 		if (!dfi->dir_info)
2155 			return -ENOMEM;
2156 		dfi->dir_info_len =
2157 			snprintf(dfi->dir_info, bufsize,
2158 				"entries:   %20lld\n"
2159 				" files:    %20lld\n"
2160 				" subdirs:  %20lld\n"
2161 				"rentries:  %20lld\n"
2162 				" rfiles:   %20lld\n"
2163 				" rsubdirs: %20lld\n"
2164 				"rbytes:    %20lld\n"
2165 				"rctime:    %10lld.%09ld\n",
2166 				ci->i_files + ci->i_subdirs,
2167 				ci->i_files,
2168 				ci->i_subdirs,
2169 				ci->i_rfiles + ci->i_rsubdirs,
2170 				ci->i_rfiles,
2171 				ci->i_rsubdirs,
2172 				ci->i_rbytes,
2173 				ci->i_rctime.tv_sec,
2174 				ci->i_rctime.tv_nsec);
2175 	}
2176 
2177 	if (*ppos >= dfi->dir_info_len)
2178 		return 0;
2179 	size = min_t(unsigned, size, dfi->dir_info_len-*ppos);
2180 	left = copy_to_user(buf, dfi->dir_info + *ppos, size);
2181 	if (left == size)
2182 		return -EFAULT;
2183 	*ppos += (size - left);
2184 	return size - left;
2185 }
2186 
2187 
2188 
2189 /*
2190  * Return name hash for a given dentry.  This is dependent on
2191  * the parent directory's hash function.
2192  */
ceph_dentry_hash(struct inode * dir,struct dentry * dn)2193 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
2194 {
2195 	struct ceph_inode_info *dci = ceph_inode(dir);
2196 	unsigned hash;
2197 
2198 	switch (dci->i_dir_layout.dl_dir_hash) {
2199 	case 0:	/* for backward compat */
2200 	case CEPH_STR_HASH_LINUX:
2201 		return dn->d_name.hash;
2202 
2203 	default:
2204 		spin_lock(&dn->d_lock);
2205 		hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
2206 				     dn->d_name.name, dn->d_name.len);
2207 		spin_unlock(&dn->d_lock);
2208 		return hash;
2209 	}
2210 }
2211 
2212 WRAP_DIR_ITER(ceph_readdir) // FIXME!
2213 const struct file_operations ceph_dir_fops = {
2214 	.read = ceph_read_dir,
2215 	.iterate_shared = shared_ceph_readdir,
2216 	.llseek = ceph_dir_llseek,
2217 	.open = ceph_open,
2218 	.release = ceph_release,
2219 	.unlocked_ioctl = ceph_ioctl,
2220 	.compat_ioctl = compat_ptr_ioctl,
2221 	.fsync = ceph_fsync,
2222 	.lock = ceph_lock,
2223 	.flock = ceph_flock,
2224 };
2225 
2226 const struct file_operations ceph_snapdir_fops = {
2227 	.iterate_shared = shared_ceph_readdir,
2228 	.llseek = ceph_dir_llseek,
2229 	.open = ceph_open,
2230 	.release = ceph_release,
2231 };
2232 
2233 const struct inode_operations ceph_dir_iops = {
2234 	.lookup = ceph_lookup,
2235 	.permission = ceph_permission,
2236 	.getattr = ceph_getattr,
2237 	.setattr = ceph_setattr,
2238 	.listxattr = ceph_listxattr,
2239 	.get_inode_acl = ceph_get_acl,
2240 	.set_acl = ceph_set_acl,
2241 	.mknod = ceph_mknod,
2242 	.symlink = ceph_symlink,
2243 	.mkdir = ceph_mkdir,
2244 	.link = ceph_link,
2245 	.unlink = ceph_unlink,
2246 	.rmdir = ceph_unlink,
2247 	.rename = ceph_rename,
2248 	.create = ceph_create,
2249 	.atomic_open = ceph_atomic_open,
2250 };
2251 
2252 const struct inode_operations ceph_snapdir_iops = {
2253 	.lookup = ceph_lookup,
2254 	.permission = ceph_permission,
2255 	.getattr = ceph_getattr,
2256 	.mkdir = ceph_mkdir,
2257 	.rmdir = ceph_unlink,
2258 	.rename = ceph_rename,
2259 };
2260 
2261 const struct dentry_operations ceph_dentry_ops = {
2262 	.d_revalidate = ceph_d_revalidate,
2263 	.d_delete = ceph_d_delete,
2264 	.d_release = ceph_d_release,
2265 	.d_prune = ceph_d_prune,
2266 	.d_init = ceph_d_init,
2267 };
2268