xref: /linux/fs/ceph/dir.c (revision 0d08df6c493898e679d9c517e77ea95c063d40ec)
1 #include <linux/ceph/ceph_debug.h>
2 
3 #include <linux/spinlock.h>
4 #include <linux/fs_struct.h>
5 #include <linux/namei.h>
6 #include <linux/slab.h>
7 #include <linux/sched.h>
8 #include <linux/xattr.h>
9 
10 #include "super.h"
11 #include "mds_client.h"
12 
13 /*
14  * Directory operations: readdir, lookup, create, link, unlink,
15  * rename, etc.
16  */
17 
18 /*
19  * Ceph MDS operations are specified in terms of a base ino and
20  * relative path.  Thus, the client can specify an operation on a
21  * specific inode (e.g., a getattr due to fstat(2)), or as a path
22  * relative to, say, the root directory.
23  *
24  * Normally, we limit ourselves to strict inode ops (no path component)
25  * or dentry operations (a single path component relative to an ino).  The
26  * exception to this is open_root_dentry(), which will open the mount
27  * point by name.
28  */
29 
30 const struct dentry_operations ceph_dentry_ops;
31 
32 /*
33  * Initialize ceph dentry state.
34  */
35 int ceph_init_dentry(struct dentry *dentry)
36 {
37 	struct ceph_dentry_info *di;
38 
39 	if (dentry->d_fsdata)
40 		return 0;
41 
42 	di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
43 	if (!di)
44 		return -ENOMEM;          /* oh well */
45 
46 	spin_lock(&dentry->d_lock);
47 	if (dentry->d_fsdata) {
48 		/* lost a race */
49 		kmem_cache_free(ceph_dentry_cachep, di);
50 		goto out_unlock;
51 	}
52 
53 	if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP)
54 		d_set_d_op(dentry, &ceph_dentry_ops);
55 	else if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_SNAPDIR)
56 		d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
57 	else
58 		d_set_d_op(dentry, &ceph_snap_dentry_ops);
59 
60 	di->dentry = dentry;
61 	di->lease_session = NULL;
62 	dentry->d_time = jiffies;
63 	/* avoid reordering d_fsdata setup so that the check above is safe */
64 	smp_mb();
65 	dentry->d_fsdata = di;
66 	ceph_dentry_lru_add(dentry);
67 out_unlock:
68 	spin_unlock(&dentry->d_lock);
69 	return 0;
70 }
71 
72 /*
73  * for readdir, we encode the directory frag and offset within that
74  * frag into f_pos.
75  */
76 static unsigned fpos_frag(loff_t p)
77 {
78 	return p >> 32;
79 }
80 static unsigned fpos_off(loff_t p)
81 {
82 	return p & 0xffffffff;
83 }
84 
85 static int fpos_cmp(loff_t l, loff_t r)
86 {
87 	int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
88 	if (v)
89 		return v;
90 	return (int)(fpos_off(l) - fpos_off(r));
91 }
92 
93 /*
94  * make note of the last dentry we read, so we can
95  * continue at the same lexicographical point,
96  * regardless of what dir changes take place on the
97  * server.
98  */
99 static int note_last_dentry(struct ceph_file_info *fi, const char *name,
100 		            int len, unsigned next_offset)
101 {
102 	char *buf = kmalloc(len+1, GFP_KERNEL);
103 	if (!buf)
104 		return -ENOMEM;
105 	kfree(fi->last_name);
106 	fi->last_name = buf;
107 	memcpy(fi->last_name, name, len);
108 	fi->last_name[len] = 0;
109 	fi->next_offset = next_offset;
110 	dout("note_last_dentry '%s'\n", fi->last_name);
111 	return 0;
112 }
113 
114 /*
115  * When possible, we try to satisfy a readdir by peeking at the
116  * dcache.  We make this work by carefully ordering dentries on
117  * d_child when we initially get results back from the MDS, and
118  * falling back to a "normal" sync readdir if any dentries in the dir
119  * are dropped.
120  *
121  * Complete dir indicates that we have all dentries in the dir.  It is
122  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
123  * the MDS if/when the directory is modified).
124  */
125 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
126 			    u32 shared_gen)
127 {
128 	struct ceph_file_info *fi = file->private_data;
129 	struct dentry *parent = file->f_path.dentry;
130 	struct inode *dir = d_inode(parent);
131 	struct dentry *dentry, *last = NULL;
132 	struct ceph_dentry_info *di;
133 	unsigned nsize = PAGE_SIZE / sizeof(struct dentry *);
134 	int err = 0;
135 	loff_t ptr_pos = 0;
136 	struct ceph_readdir_cache_control cache_ctl = {};
137 
138 	dout("__dcache_readdir %p v%u at %llu\n", dir, shared_gen, ctx->pos);
139 
140 	/* we can calculate cache index for the first dirfrag */
141 	if (ceph_frag_is_leftmost(fpos_frag(ctx->pos))) {
142 		cache_ctl.index = fpos_off(ctx->pos) - 2;
143 		BUG_ON(cache_ctl.index < 0);
144 		ptr_pos = cache_ctl.index * sizeof(struct dentry *);
145 	}
146 
147 	while (true) {
148 		pgoff_t pgoff;
149 		bool emit_dentry;
150 
151 		if (ptr_pos >= i_size_read(dir)) {
152 			fi->flags |= CEPH_F_ATEND;
153 			err = 0;
154 			break;
155 		}
156 
157 		err = -EAGAIN;
158 		pgoff = ptr_pos >> PAGE_SHIFT;
159 		if (!cache_ctl.page || pgoff != page_index(cache_ctl.page)) {
160 			ceph_readdir_cache_release(&cache_ctl);
161 			cache_ctl.page = find_lock_page(&dir->i_data, pgoff);
162 			if (!cache_ctl.page) {
163 				dout(" page %lu not found\n", pgoff);
164 				break;
165 			}
166 			/* reading/filling the cache are serialized by
167 			 * i_mutex, no need to use page lock */
168 			unlock_page(cache_ctl.page);
169 			cache_ctl.dentries = kmap(cache_ctl.page);
170 		}
171 
172 		rcu_read_lock();
173 		spin_lock(&parent->d_lock);
174 		/* check i_size again here, because empty directory can be
175 		 * marked as complete while not holding the i_mutex. */
176 		if (ceph_dir_is_complete_ordered(dir) &&
177 		    ptr_pos < i_size_read(dir))
178 			dentry = cache_ctl.dentries[cache_ctl.index % nsize];
179 		else
180 			dentry = NULL;
181 		spin_unlock(&parent->d_lock);
182 		if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
183 			dentry = NULL;
184 		rcu_read_unlock();
185 		if (!dentry)
186 			break;
187 
188 		emit_dentry = false;
189 		di = ceph_dentry(dentry);
190 		spin_lock(&dentry->d_lock);
191 		if (di->lease_shared_gen == shared_gen &&
192 		    d_really_is_positive(dentry) &&
193 		    ceph_snap(d_inode(dentry)) != CEPH_SNAPDIR &&
194 		    ceph_ino(d_inode(dentry)) != CEPH_INO_CEPH &&
195 		    fpos_cmp(ctx->pos, di->offset) <= 0) {
196 			emit_dentry = true;
197 		}
198 		spin_unlock(&dentry->d_lock);
199 
200 		if (emit_dentry) {
201 			dout(" %llu (%llu) dentry %p %pd %p\n", di->offset, ctx->pos,
202 			     dentry, dentry, d_inode(dentry));
203 			ctx->pos = di->offset;
204 			if (!dir_emit(ctx, dentry->d_name.name,
205 				      dentry->d_name.len,
206 				      ceph_translate_ino(dentry->d_sb,
207 							 d_inode(dentry)->i_ino),
208 				      d_inode(dentry)->i_mode >> 12)) {
209 				dput(dentry);
210 				err = 0;
211 				break;
212 			}
213 			ctx->pos++;
214 
215 			if (last)
216 				dput(last);
217 			last = dentry;
218 		} else {
219 			dput(dentry);
220 		}
221 
222 		cache_ctl.index++;
223 		ptr_pos += sizeof(struct dentry *);
224 	}
225 	ceph_readdir_cache_release(&cache_ctl);
226 	if (last) {
227 		int ret;
228 		di = ceph_dentry(last);
229 		ret = note_last_dentry(fi, last->d_name.name, last->d_name.len,
230 				       fpos_off(di->offset) + 1);
231 		if (ret < 0)
232 			err = ret;
233 		dput(last);
234 	}
235 	return err;
236 }
237 
238 static int ceph_readdir(struct file *file, struct dir_context *ctx)
239 {
240 	struct ceph_file_info *fi = file->private_data;
241 	struct inode *inode = file_inode(file);
242 	struct ceph_inode_info *ci = ceph_inode(inode);
243 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
244 	struct ceph_mds_client *mdsc = fsc->mdsc;
245 	unsigned frag = fpos_frag(ctx->pos);
246 	int off = fpos_off(ctx->pos);
247 	int err;
248 	u32 ftype;
249 	struct ceph_mds_reply_info_parsed *rinfo;
250 
251 	dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
252 	if (fi->flags & CEPH_F_ATEND)
253 		return 0;
254 
255 	/* always start with . and .. */
256 	if (ctx->pos == 0) {
257 		dout("readdir off 0 -> '.'\n");
258 		if (!dir_emit(ctx, ".", 1,
259 			    ceph_translate_ino(inode->i_sb, inode->i_ino),
260 			    inode->i_mode >> 12))
261 			return 0;
262 		ctx->pos = 1;
263 		off = 1;
264 	}
265 	if (ctx->pos == 1) {
266 		ino_t ino = parent_ino(file->f_path.dentry);
267 		dout("readdir off 1 -> '..'\n");
268 		if (!dir_emit(ctx, "..", 2,
269 			    ceph_translate_ino(inode->i_sb, ino),
270 			    inode->i_mode >> 12))
271 			return 0;
272 		ctx->pos = 2;
273 		off = 2;
274 	}
275 
276 	/* can we use the dcache? */
277 	spin_lock(&ci->i_ceph_lock);
278 	if (ceph_test_mount_opt(fsc, DCACHE) &&
279 	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
280 	    ceph_snap(inode) != CEPH_SNAPDIR &&
281 	    __ceph_dir_is_complete_ordered(ci) &&
282 	    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
283 		u32 shared_gen = ci->i_shared_gen;
284 		spin_unlock(&ci->i_ceph_lock);
285 		err = __dcache_readdir(file, ctx, shared_gen);
286 		if (err != -EAGAIN)
287 			return err;
288 		frag = fpos_frag(ctx->pos);
289 		off = fpos_off(ctx->pos);
290 	} else {
291 		spin_unlock(&ci->i_ceph_lock);
292 	}
293 
294 	/* proceed with a normal readdir */
295 more:
296 	/* do we have the correct frag content buffered? */
297 	if (fi->frag != frag || fi->last_readdir == NULL) {
298 		struct ceph_mds_request *req;
299 		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
300 			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
301 
302 		/* discard old result, if any */
303 		if (fi->last_readdir) {
304 			ceph_mdsc_put_request(fi->last_readdir);
305 			fi->last_readdir = NULL;
306 		}
307 
308 		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
309 		     ceph_vinop(inode), frag, fi->last_name);
310 		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
311 		if (IS_ERR(req))
312 			return PTR_ERR(req);
313 		err = ceph_alloc_readdir_reply_buffer(req, inode);
314 		if (err) {
315 			ceph_mdsc_put_request(req);
316 			return err;
317 		}
318 		/* hints to request -> mds selection code */
319 		req->r_direct_mode = USE_AUTH_MDS;
320 		req->r_direct_hash = ceph_frag_value(frag);
321 		req->r_direct_is_hash = true;
322 		if (fi->last_name) {
323 			req->r_path2 = kstrdup(fi->last_name, GFP_KERNEL);
324 			if (!req->r_path2) {
325 				ceph_mdsc_put_request(req);
326 				return -ENOMEM;
327 			}
328 		}
329 		req->r_dir_release_cnt = fi->dir_release_count;
330 		req->r_dir_ordered_cnt = fi->dir_ordered_count;
331 		req->r_readdir_cache_idx = fi->readdir_cache_idx;
332 		req->r_readdir_offset = fi->next_offset;
333 		req->r_args.readdir.frag = cpu_to_le32(frag);
334 
335 		req->r_inode = inode;
336 		ihold(inode);
337 		req->r_dentry = dget(file->f_path.dentry);
338 		err = ceph_mdsc_do_request(mdsc, NULL, req);
339 		if (err < 0) {
340 			ceph_mdsc_put_request(req);
341 			return err;
342 		}
343 		dout("readdir got and parsed readdir result=%d"
344 		     " on frag %x, end=%d, complete=%d\n", err, frag,
345 		     (int)req->r_reply_info.dir_end,
346 		     (int)req->r_reply_info.dir_complete);
347 
348 
349 		/* note next offset and last dentry name */
350 		rinfo = &req->r_reply_info;
351 		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
352 			frag = le32_to_cpu(rinfo->dir_dir->frag);
353 			off = req->r_readdir_offset;
354 			fi->next_offset = off;
355 		}
356 
357 		fi->frag = frag;
358 		fi->offset = fi->next_offset;
359 		fi->last_readdir = req;
360 
361 		if (req->r_did_prepopulate) {
362 			fi->readdir_cache_idx = req->r_readdir_cache_idx;
363 			if (fi->readdir_cache_idx < 0) {
364 				/* preclude from marking dir ordered */
365 				fi->dir_ordered_count = 0;
366 			} else if (ceph_frag_is_leftmost(frag) && off == 2) {
367 				/* note dir version at start of readdir so
368 				 * we can tell if any dentries get dropped */
369 				fi->dir_release_count = req->r_dir_release_cnt;
370 				fi->dir_ordered_count = req->r_dir_ordered_cnt;
371 			}
372 		} else {
373 			dout("readdir !did_prepopulate");
374 			/* disable readdir cache */
375 			fi->readdir_cache_idx = -1;
376 			/* preclude from marking dir complete */
377 			fi->dir_release_count = 0;
378 		}
379 
380 		if (req->r_reply_info.dir_end) {
381 			kfree(fi->last_name);
382 			fi->last_name = NULL;
383 			if (ceph_frag_is_rightmost(frag))
384 				fi->next_offset = 2;
385 			else
386 				fi->next_offset = 0;
387 		} else {
388 			err = note_last_dentry(fi,
389 				       rinfo->dir_dname[rinfo->dir_nr-1],
390 				       rinfo->dir_dname_len[rinfo->dir_nr-1],
391 				       fi->next_offset + rinfo->dir_nr);
392 			if (err)
393 				return err;
394 		}
395 	}
396 
397 	rinfo = &fi->last_readdir->r_reply_info;
398 	dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
399 	     rinfo->dir_nr, off, fi->offset);
400 
401 	ctx->pos = ceph_make_fpos(frag, off);
402 	while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
403 		struct ceph_mds_reply_inode *in =
404 			rinfo->dir_in[off - fi->offset].in;
405 		struct ceph_vino vino;
406 		ino_t ino;
407 
408 		dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
409 		     off, off - fi->offset, rinfo->dir_nr, ctx->pos,
410 		     rinfo->dir_dname_len[off - fi->offset],
411 		     rinfo->dir_dname[off - fi->offset], in);
412 		BUG_ON(!in);
413 		ftype = le32_to_cpu(in->mode) >> 12;
414 		vino.ino = le64_to_cpu(in->ino);
415 		vino.snap = le64_to_cpu(in->snapid);
416 		ino = ceph_vino_to_ino(vino);
417 		if (!dir_emit(ctx,
418 			    rinfo->dir_dname[off - fi->offset],
419 			    rinfo->dir_dname_len[off - fi->offset],
420 			    ceph_translate_ino(inode->i_sb, ino), ftype)) {
421 			dout("filldir stopping us...\n");
422 			return 0;
423 		}
424 		off++;
425 		ctx->pos++;
426 	}
427 
428 	if (fi->last_name) {
429 		ceph_mdsc_put_request(fi->last_readdir);
430 		fi->last_readdir = NULL;
431 		goto more;
432 	}
433 
434 	/* more frags? */
435 	if (!ceph_frag_is_rightmost(frag)) {
436 		frag = ceph_frag_next(frag);
437 		off = 0;
438 		ctx->pos = ceph_make_fpos(frag, off);
439 		dout("readdir next frag is %x\n", frag);
440 		goto more;
441 	}
442 	fi->flags |= CEPH_F_ATEND;
443 
444 	/*
445 	 * if dir_release_count still matches the dir, no dentries
446 	 * were released during the whole readdir, and we should have
447 	 * the complete dir contents in our cache.
448 	 */
449 	if (atomic64_read(&ci->i_release_count) == fi->dir_release_count) {
450 		spin_lock(&ci->i_ceph_lock);
451 		if (fi->dir_ordered_count == atomic64_read(&ci->i_ordered_count)) {
452 			dout(" marking %p complete and ordered\n", inode);
453 			/* use i_size to track number of entries in
454 			 * readdir cache */
455 			BUG_ON(fi->readdir_cache_idx < 0);
456 			i_size_write(inode, fi->readdir_cache_idx *
457 				     sizeof(struct dentry*));
458 		} else {
459 			dout(" marking %p complete\n", inode);
460 		}
461 		__ceph_dir_set_complete(ci, fi->dir_release_count,
462 					fi->dir_ordered_count);
463 		spin_unlock(&ci->i_ceph_lock);
464 	}
465 
466 	dout("readdir %p file %p done.\n", inode, file);
467 	return 0;
468 }
469 
470 static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
471 {
472 	if (fi->last_readdir) {
473 		ceph_mdsc_put_request(fi->last_readdir);
474 		fi->last_readdir = NULL;
475 	}
476 	kfree(fi->last_name);
477 	fi->last_name = NULL;
478 	fi->dir_release_count = 0;
479 	fi->readdir_cache_idx = -1;
480 	if (ceph_frag_is_leftmost(frag))
481 		fi->next_offset = 2;  /* compensate for . and .. */
482 	else
483 		fi->next_offset = 0;
484 	fi->flags &= ~CEPH_F_ATEND;
485 }
486 
487 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
488 {
489 	struct ceph_file_info *fi = file->private_data;
490 	struct inode *inode = file->f_mapping->host;
491 	loff_t old_offset = ceph_make_fpos(fi->frag, fi->next_offset);
492 	loff_t retval;
493 
494 	inode_lock(inode);
495 	retval = -EINVAL;
496 	switch (whence) {
497 	case SEEK_CUR:
498 		offset += file->f_pos;
499 	case SEEK_SET:
500 		break;
501 	case SEEK_END:
502 		retval = -EOPNOTSUPP;
503 	default:
504 		goto out;
505 	}
506 
507 	if (offset >= 0) {
508 		if (offset != file->f_pos) {
509 			file->f_pos = offset;
510 			file->f_version = 0;
511 			fi->flags &= ~CEPH_F_ATEND;
512 		}
513 		retval = offset;
514 
515 		if (offset == 0 ||
516 		    fpos_frag(offset) != fi->frag ||
517 		    fpos_off(offset) < fi->offset) {
518 			/* discard buffered readdir content on seekdir(0), or
519 			 * seek to new frag, or seek prior to current chunk */
520 			dout("dir_llseek dropping %p content\n", file);
521 			reset_readdir(fi, fpos_frag(offset));
522 		} else if (fpos_cmp(offset, old_offset) > 0) {
523 			/* reset dir_release_count if we did a forward seek */
524 			fi->dir_release_count = 0;
525 			fi->readdir_cache_idx = -1;
526 		}
527 	}
528 out:
529 	inode_unlock(inode);
530 	return retval;
531 }
532 
533 /*
534  * Handle lookups for the hidden .snap directory.
535  */
536 int ceph_handle_snapdir(struct ceph_mds_request *req,
537 			struct dentry *dentry, int err)
538 {
539 	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
540 	struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
541 
542 	/* .snap dir? */
543 	if (err == -ENOENT &&
544 	    ceph_snap(parent) == CEPH_NOSNAP &&
545 	    strcmp(dentry->d_name.name,
546 		   fsc->mount_options->snapdir_name) == 0) {
547 		struct inode *inode = ceph_get_snapdir(parent);
548 		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
549 		     dentry, dentry, inode);
550 		BUG_ON(!d_unhashed(dentry));
551 		d_add(dentry, inode);
552 		err = 0;
553 	}
554 	return err;
555 }
556 
557 /*
558  * Figure out final result of a lookup/open request.
559  *
560  * Mainly, make sure we return the final req->r_dentry (if it already
561  * existed) in place of the original VFS-provided dentry when they
562  * differ.
563  *
564  * Gracefully handle the case where the MDS replies with -ENOENT and
565  * no trace (which it may do, at its discretion, e.g., if it doesn't
566  * care to issue a lease on the negative dentry).
567  */
568 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
569 				  struct dentry *dentry, int err)
570 {
571 	if (err == -ENOENT) {
572 		/* no trace? */
573 		err = 0;
574 		if (!req->r_reply_info.head->is_dentry) {
575 			dout("ENOENT and no trace, dentry %p inode %p\n",
576 			     dentry, d_inode(dentry));
577 			if (d_really_is_positive(dentry)) {
578 				d_drop(dentry);
579 				err = -ENOENT;
580 			} else {
581 				d_add(dentry, NULL);
582 			}
583 		}
584 	}
585 	if (err)
586 		dentry = ERR_PTR(err);
587 	else if (dentry != req->r_dentry)
588 		dentry = dget(req->r_dentry);   /* we got spliced */
589 	else
590 		dentry = NULL;
591 	return dentry;
592 }
593 
594 static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
595 {
596 	return ceph_ino(inode) == CEPH_INO_ROOT &&
597 		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
598 }
599 
600 /*
601  * Look up a single dir entry.  If there is a lookup intent, inform
602  * the MDS so that it gets our 'caps wanted' value in a single op.
603  */
604 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
605 				  unsigned int flags)
606 {
607 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
608 	struct ceph_mds_client *mdsc = fsc->mdsc;
609 	struct ceph_mds_request *req;
610 	int op;
611 	int mask;
612 	int err;
613 
614 	dout("lookup %p dentry %p '%pd'\n",
615 	     dir, dentry, dentry);
616 
617 	if (dentry->d_name.len > NAME_MAX)
618 		return ERR_PTR(-ENAMETOOLONG);
619 
620 	err = ceph_init_dentry(dentry);
621 	if (err < 0)
622 		return ERR_PTR(err);
623 
624 	/* can we conclude ENOENT locally? */
625 	if (d_really_is_negative(dentry)) {
626 		struct ceph_inode_info *ci = ceph_inode(dir);
627 		struct ceph_dentry_info *di = ceph_dentry(dentry);
628 
629 		spin_lock(&ci->i_ceph_lock);
630 		dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
631 		if (strncmp(dentry->d_name.name,
632 			    fsc->mount_options->snapdir_name,
633 			    dentry->d_name.len) &&
634 		    !is_root_ceph_dentry(dir, dentry) &&
635 		    ceph_test_mount_opt(fsc, DCACHE) &&
636 		    __ceph_dir_is_complete(ci) &&
637 		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
638 			spin_unlock(&ci->i_ceph_lock);
639 			dout(" dir %p complete, -ENOENT\n", dir);
640 			d_add(dentry, NULL);
641 			di->lease_shared_gen = ci->i_shared_gen;
642 			return NULL;
643 		}
644 		spin_unlock(&ci->i_ceph_lock);
645 	}
646 
647 	op = ceph_snap(dir) == CEPH_SNAPDIR ?
648 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
649 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
650 	if (IS_ERR(req))
651 		return ERR_CAST(req);
652 	req->r_dentry = dget(dentry);
653 	req->r_num_caps = 2;
654 
655 	mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
656 	if (ceph_security_xattr_wanted(dir))
657 		mask |= CEPH_CAP_XATTR_SHARED;
658 	req->r_args.getattr.mask = cpu_to_le32(mask);
659 
660 	req->r_locked_dir = dir;
661 	err = ceph_mdsc_do_request(mdsc, NULL, req);
662 	err = ceph_handle_snapdir(req, dentry, err);
663 	dentry = ceph_finish_lookup(req, dentry, err);
664 	ceph_mdsc_put_request(req);  /* will dput(dentry) */
665 	dout("lookup result=%p\n", dentry);
666 	return dentry;
667 }
668 
669 /*
670  * If we do a create but get no trace back from the MDS, follow up with
671  * a lookup (the VFS expects us to link up the provided dentry).
672  */
673 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
674 {
675 	struct dentry *result = ceph_lookup(dir, dentry, 0);
676 
677 	if (result && !IS_ERR(result)) {
678 		/*
679 		 * We created the item, then did a lookup, and found
680 		 * it was already linked to another inode we already
681 		 * had in our cache (and thus got spliced). To not
682 		 * confuse VFS (especially when inode is a directory),
683 		 * we don't link our dentry to that inode, return an
684 		 * error instead.
685 		 *
686 		 * This event should be rare and it happens only when
687 		 * we talk to old MDS. Recent MDS does not send traceless
688 		 * reply for request that creates new inode.
689 		 */
690 		d_drop(result);
691 		return -ESTALE;
692 	}
693 	return PTR_ERR(result);
694 }
695 
696 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
697 		      umode_t mode, dev_t rdev)
698 {
699 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
700 	struct ceph_mds_client *mdsc = fsc->mdsc;
701 	struct ceph_mds_request *req;
702 	struct ceph_acls_info acls = {};
703 	int err;
704 
705 	if (ceph_snap(dir) != CEPH_NOSNAP)
706 		return -EROFS;
707 
708 	err = ceph_pre_init_acls(dir, &mode, &acls);
709 	if (err < 0)
710 		return err;
711 
712 	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
713 	     dir, dentry, mode, rdev);
714 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
715 	if (IS_ERR(req)) {
716 		err = PTR_ERR(req);
717 		goto out;
718 	}
719 	req->r_dentry = dget(dentry);
720 	req->r_num_caps = 2;
721 	req->r_locked_dir = dir;
722 	req->r_args.mknod.mode = cpu_to_le32(mode);
723 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
724 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
725 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
726 	if (acls.pagelist) {
727 		req->r_pagelist = acls.pagelist;
728 		acls.pagelist = NULL;
729 	}
730 	err = ceph_mdsc_do_request(mdsc, dir, req);
731 	if (!err && !req->r_reply_info.head->is_dentry)
732 		err = ceph_handle_notrace_create(dir, dentry);
733 	ceph_mdsc_put_request(req);
734 out:
735 	if (!err)
736 		ceph_init_inode_acls(d_inode(dentry), &acls);
737 	else
738 		d_drop(dentry);
739 	ceph_release_acls_info(&acls);
740 	return err;
741 }
742 
743 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
744 		       bool excl)
745 {
746 	return ceph_mknod(dir, dentry, mode, 0);
747 }
748 
749 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
750 			    const char *dest)
751 {
752 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
753 	struct ceph_mds_client *mdsc = fsc->mdsc;
754 	struct ceph_mds_request *req;
755 	int err;
756 
757 	if (ceph_snap(dir) != CEPH_NOSNAP)
758 		return -EROFS;
759 
760 	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
761 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
762 	if (IS_ERR(req)) {
763 		err = PTR_ERR(req);
764 		goto out;
765 	}
766 	req->r_path2 = kstrdup(dest, GFP_KERNEL);
767 	if (!req->r_path2) {
768 		err = -ENOMEM;
769 		ceph_mdsc_put_request(req);
770 		goto out;
771 	}
772 	req->r_locked_dir = dir;
773 	req->r_dentry = dget(dentry);
774 	req->r_num_caps = 2;
775 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
776 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
777 	err = ceph_mdsc_do_request(mdsc, dir, req);
778 	if (!err && !req->r_reply_info.head->is_dentry)
779 		err = ceph_handle_notrace_create(dir, dentry);
780 	ceph_mdsc_put_request(req);
781 out:
782 	if (err)
783 		d_drop(dentry);
784 	return err;
785 }
786 
787 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
788 {
789 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
790 	struct ceph_mds_client *mdsc = fsc->mdsc;
791 	struct ceph_mds_request *req;
792 	struct ceph_acls_info acls = {};
793 	int err = -EROFS;
794 	int op;
795 
796 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
797 		/* mkdir .snap/foo is a MKSNAP */
798 		op = CEPH_MDS_OP_MKSNAP;
799 		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
800 		     dentry, dentry);
801 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
802 		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
803 		op = CEPH_MDS_OP_MKDIR;
804 	} else {
805 		goto out;
806 	}
807 
808 	mode |= S_IFDIR;
809 	err = ceph_pre_init_acls(dir, &mode, &acls);
810 	if (err < 0)
811 		goto out;
812 
813 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
814 	if (IS_ERR(req)) {
815 		err = PTR_ERR(req);
816 		goto out;
817 	}
818 
819 	req->r_dentry = dget(dentry);
820 	req->r_num_caps = 2;
821 	req->r_locked_dir = dir;
822 	req->r_args.mkdir.mode = cpu_to_le32(mode);
823 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
824 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
825 	if (acls.pagelist) {
826 		req->r_pagelist = acls.pagelist;
827 		acls.pagelist = NULL;
828 	}
829 	err = ceph_mdsc_do_request(mdsc, dir, req);
830 	if (!err &&
831 	    !req->r_reply_info.head->is_target &&
832 	    !req->r_reply_info.head->is_dentry)
833 		err = ceph_handle_notrace_create(dir, dentry);
834 	ceph_mdsc_put_request(req);
835 out:
836 	if (!err)
837 		ceph_init_inode_acls(d_inode(dentry), &acls);
838 	else
839 		d_drop(dentry);
840 	ceph_release_acls_info(&acls);
841 	return err;
842 }
843 
844 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
845 		     struct dentry *dentry)
846 {
847 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
848 	struct ceph_mds_client *mdsc = fsc->mdsc;
849 	struct ceph_mds_request *req;
850 	int err;
851 
852 	if (ceph_snap(dir) != CEPH_NOSNAP)
853 		return -EROFS;
854 
855 	dout("link in dir %p old_dentry %p dentry %p\n", dir,
856 	     old_dentry, dentry);
857 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
858 	if (IS_ERR(req)) {
859 		d_drop(dentry);
860 		return PTR_ERR(req);
861 	}
862 	req->r_dentry = dget(dentry);
863 	req->r_num_caps = 2;
864 	req->r_old_dentry = dget(old_dentry);
865 	req->r_locked_dir = dir;
866 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
867 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
868 	/* release LINK_SHARED on source inode (mds will lock it) */
869 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
870 	err = ceph_mdsc_do_request(mdsc, dir, req);
871 	if (err) {
872 		d_drop(dentry);
873 	} else if (!req->r_reply_info.head->is_dentry) {
874 		ihold(d_inode(old_dentry));
875 		d_instantiate(dentry, d_inode(old_dentry));
876 	}
877 	ceph_mdsc_put_request(req);
878 	return err;
879 }
880 
881 /*
882  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
883  * looks like the link count will hit 0, drop any other caps (other
884  * than PIN) we don't specifically want (due to the file still being
885  * open).
886  */
887 static int drop_caps_for_unlink(struct inode *inode)
888 {
889 	struct ceph_inode_info *ci = ceph_inode(inode);
890 	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
891 
892 	spin_lock(&ci->i_ceph_lock);
893 	if (inode->i_nlink == 1) {
894 		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
895 		ci->i_ceph_flags |= CEPH_I_NODELAY;
896 	}
897 	spin_unlock(&ci->i_ceph_lock);
898 	return drop;
899 }
900 
901 /*
902  * rmdir and unlink are differ only by the metadata op code
903  */
904 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
905 {
906 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
907 	struct ceph_mds_client *mdsc = fsc->mdsc;
908 	struct inode *inode = d_inode(dentry);
909 	struct ceph_mds_request *req;
910 	int err = -EROFS;
911 	int op;
912 
913 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
914 		/* rmdir .snap/foo is RMSNAP */
915 		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
916 		op = CEPH_MDS_OP_RMSNAP;
917 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
918 		dout("unlink/rmdir dir %p dn %p inode %p\n",
919 		     dir, dentry, inode);
920 		op = d_is_dir(dentry) ?
921 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
922 	} else
923 		goto out;
924 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
925 	if (IS_ERR(req)) {
926 		err = PTR_ERR(req);
927 		goto out;
928 	}
929 	req->r_dentry = dget(dentry);
930 	req->r_num_caps = 2;
931 	req->r_locked_dir = dir;
932 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
933 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
934 	req->r_inode_drop = drop_caps_for_unlink(inode);
935 	err = ceph_mdsc_do_request(mdsc, dir, req);
936 	if (!err && !req->r_reply_info.head->is_dentry)
937 		d_delete(dentry);
938 	ceph_mdsc_put_request(req);
939 out:
940 	return err;
941 }
942 
943 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
944 		       struct inode *new_dir, struct dentry *new_dentry)
945 {
946 	struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
947 	struct ceph_mds_client *mdsc = fsc->mdsc;
948 	struct ceph_mds_request *req;
949 	int op = CEPH_MDS_OP_RENAME;
950 	int err;
951 
952 	if (ceph_snap(old_dir) != ceph_snap(new_dir))
953 		return -EXDEV;
954 	if (ceph_snap(old_dir) != CEPH_NOSNAP) {
955 		if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
956 			op = CEPH_MDS_OP_RENAMESNAP;
957 		else
958 			return -EROFS;
959 	}
960 	dout("rename dir %p dentry %p to dir %p dentry %p\n",
961 	     old_dir, old_dentry, new_dir, new_dentry);
962 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
963 	if (IS_ERR(req))
964 		return PTR_ERR(req);
965 	ihold(old_dir);
966 	req->r_dentry = dget(new_dentry);
967 	req->r_num_caps = 2;
968 	req->r_old_dentry = dget(old_dentry);
969 	req->r_old_dentry_dir = old_dir;
970 	req->r_locked_dir = new_dir;
971 	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
972 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
973 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
974 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
975 	/* release LINK_RDCACHE on source inode (mds will lock it) */
976 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
977 	if (d_really_is_positive(new_dentry))
978 		req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
979 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
980 	if (!err && !req->r_reply_info.head->is_dentry) {
981 		/*
982 		 * Normally d_move() is done by fill_trace (called by
983 		 * do_request, above).  If there is no trace, we need
984 		 * to do it here.
985 		 */
986 
987 		/* d_move screws up sibling dentries' offsets */
988 		ceph_dir_clear_complete(old_dir);
989 		ceph_dir_clear_complete(new_dir);
990 
991 		d_move(old_dentry, new_dentry);
992 
993 		/* ensure target dentry is invalidated, despite
994 		   rehashing bug in vfs_rename_dir */
995 		ceph_invalidate_dentry_lease(new_dentry);
996 	}
997 	ceph_mdsc_put_request(req);
998 	return err;
999 }
1000 
1001 /*
1002  * Ensure a dentry lease will no longer revalidate.
1003  */
1004 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1005 {
1006 	spin_lock(&dentry->d_lock);
1007 	dentry->d_time = jiffies;
1008 	ceph_dentry(dentry)->lease_shared_gen = 0;
1009 	spin_unlock(&dentry->d_lock);
1010 }
1011 
1012 /*
1013  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1014  * renew if the least is more than half up.
1015  */
1016 static int dentry_lease_is_valid(struct dentry *dentry)
1017 {
1018 	struct ceph_dentry_info *di;
1019 	struct ceph_mds_session *s;
1020 	int valid = 0;
1021 	u32 gen;
1022 	unsigned long ttl;
1023 	struct ceph_mds_session *session = NULL;
1024 	struct inode *dir = NULL;
1025 	u32 seq = 0;
1026 
1027 	spin_lock(&dentry->d_lock);
1028 	di = ceph_dentry(dentry);
1029 	if (di->lease_session) {
1030 		s = di->lease_session;
1031 		spin_lock(&s->s_gen_ttl_lock);
1032 		gen = s->s_cap_gen;
1033 		ttl = s->s_cap_ttl;
1034 		spin_unlock(&s->s_gen_ttl_lock);
1035 
1036 		if (di->lease_gen == gen &&
1037 		    time_before(jiffies, dentry->d_time) &&
1038 		    time_before(jiffies, ttl)) {
1039 			valid = 1;
1040 			if (di->lease_renew_after &&
1041 			    time_after(jiffies, di->lease_renew_after)) {
1042 				/* we should renew */
1043 				dir = d_inode(dentry->d_parent);
1044 				session = ceph_get_mds_session(s);
1045 				seq = di->lease_seq;
1046 				di->lease_renew_after = 0;
1047 				di->lease_renew_from = jiffies;
1048 			}
1049 		}
1050 	}
1051 	spin_unlock(&dentry->d_lock);
1052 
1053 	if (session) {
1054 		ceph_mdsc_lease_send_msg(session, dir, dentry,
1055 					 CEPH_MDS_LEASE_RENEW, seq);
1056 		ceph_put_mds_session(session);
1057 	}
1058 	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1059 	return valid;
1060 }
1061 
1062 /*
1063  * Check if directory-wide content lease/cap is valid.
1064  */
1065 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1066 {
1067 	struct ceph_inode_info *ci = ceph_inode(dir);
1068 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1069 	int valid = 0;
1070 
1071 	spin_lock(&ci->i_ceph_lock);
1072 	if (ci->i_shared_gen == di->lease_shared_gen)
1073 		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1074 	spin_unlock(&ci->i_ceph_lock);
1075 	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1076 	     dir, (unsigned)ci->i_shared_gen, dentry,
1077 	     (unsigned)di->lease_shared_gen, valid);
1078 	return valid;
1079 }
1080 
1081 /*
1082  * Check if cached dentry can be trusted.
1083  */
1084 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1085 {
1086 	int valid = 0;
1087 	struct dentry *parent;
1088 	struct inode *dir;
1089 
1090 	if (flags & LOOKUP_RCU)
1091 		return -ECHILD;
1092 
1093 	dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1094 	     dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1095 
1096 	parent = dget_parent(dentry);
1097 	dir = d_inode(parent);
1098 
1099 	/* always trust cached snapped dentries, snapdir dentry */
1100 	if (ceph_snap(dir) != CEPH_NOSNAP) {
1101 		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1102 		     dentry, d_inode(dentry));
1103 		valid = 1;
1104 	} else if (d_really_is_positive(dentry) &&
1105 		   ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1106 		valid = 1;
1107 	} else if (dentry_lease_is_valid(dentry) ||
1108 		   dir_lease_is_valid(dir, dentry)) {
1109 		if (d_really_is_positive(dentry))
1110 			valid = ceph_is_any_caps(d_inode(dentry));
1111 		else
1112 			valid = 1;
1113 	}
1114 
1115 	if (!valid) {
1116 		struct ceph_mds_client *mdsc =
1117 			ceph_sb_to_client(dir->i_sb)->mdsc;
1118 		struct ceph_mds_request *req;
1119 		int op, mask, err;
1120 
1121 		op = ceph_snap(dir) == CEPH_SNAPDIR ?
1122 			CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
1123 		req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1124 		if (!IS_ERR(req)) {
1125 			req->r_dentry = dget(dentry);
1126 			req->r_num_caps = 2;
1127 
1128 			mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1129 			if (ceph_security_xattr_wanted(dir))
1130 				mask |= CEPH_CAP_XATTR_SHARED;
1131 			req->r_args.getattr.mask = mask;
1132 
1133 			req->r_locked_dir = dir;
1134 			err = ceph_mdsc_do_request(mdsc, NULL, req);
1135 			if (err == 0 || err == -ENOENT) {
1136 				if (dentry == req->r_dentry) {
1137 					valid = !d_unhashed(dentry);
1138 				} else {
1139 					d_invalidate(req->r_dentry);
1140 					err = -EAGAIN;
1141 				}
1142 			}
1143 			ceph_mdsc_put_request(req);
1144 			dout("d_revalidate %p lookup result=%d\n",
1145 			     dentry, err);
1146 		}
1147 	}
1148 
1149 	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1150 	if (valid) {
1151 		ceph_dentry_lru_touch(dentry);
1152 	} else {
1153 		ceph_dir_clear_complete(dir);
1154 	}
1155 
1156 	dput(parent);
1157 	return valid;
1158 }
1159 
1160 /*
1161  * Release our ceph_dentry_info.
1162  */
1163 static void ceph_d_release(struct dentry *dentry)
1164 {
1165 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1166 
1167 	dout("d_release %p\n", dentry);
1168 	ceph_dentry_lru_del(dentry);
1169 	if (di->lease_session)
1170 		ceph_put_mds_session(di->lease_session);
1171 	kmem_cache_free(ceph_dentry_cachep, di);
1172 	dentry->d_fsdata = NULL;
1173 }
1174 
1175 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1176 					  unsigned int flags)
1177 {
1178 	/*
1179 	 * Eventually, we'll want to revalidate snapped metadata
1180 	 * too... probably...
1181 	 */
1182 	return 1;
1183 }
1184 
1185 /*
1186  * When the VFS prunes a dentry from the cache, we need to clear the
1187  * complete flag on the parent directory.
1188  *
1189  * Called under dentry->d_lock.
1190  */
1191 static void ceph_d_prune(struct dentry *dentry)
1192 {
1193 	dout("ceph_d_prune %p\n", dentry);
1194 
1195 	/* do we have a valid parent? */
1196 	if (IS_ROOT(dentry))
1197 		return;
1198 
1199 	/* if we are not hashed, we don't affect dir's completeness */
1200 	if (d_unhashed(dentry))
1201 		return;
1202 
1203 	/*
1204 	 * we hold d_lock, so d_parent is stable, and d_fsdata is never
1205 	 * cleared until d_release
1206 	 */
1207 	ceph_dir_clear_complete(d_inode(dentry->d_parent));
1208 }
1209 
1210 /*
1211  * read() on a dir.  This weird interface hack only works if mounted
1212  * with '-o dirstat'.
1213  */
1214 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1215 			     loff_t *ppos)
1216 {
1217 	struct ceph_file_info *cf = file->private_data;
1218 	struct inode *inode = file_inode(file);
1219 	struct ceph_inode_info *ci = ceph_inode(inode);
1220 	int left;
1221 	const int bufsize = 1024;
1222 
1223 	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1224 		return -EISDIR;
1225 
1226 	if (!cf->dir_info) {
1227 		cf->dir_info = kmalloc(bufsize, GFP_KERNEL);
1228 		if (!cf->dir_info)
1229 			return -ENOMEM;
1230 		cf->dir_info_len =
1231 			snprintf(cf->dir_info, bufsize,
1232 				"entries:   %20lld\n"
1233 				" files:    %20lld\n"
1234 				" subdirs:  %20lld\n"
1235 				"rentries:  %20lld\n"
1236 				" rfiles:   %20lld\n"
1237 				" rsubdirs: %20lld\n"
1238 				"rbytes:    %20lld\n"
1239 				"rctime:    %10ld.%09ld\n",
1240 				ci->i_files + ci->i_subdirs,
1241 				ci->i_files,
1242 				ci->i_subdirs,
1243 				ci->i_rfiles + ci->i_rsubdirs,
1244 				ci->i_rfiles,
1245 				ci->i_rsubdirs,
1246 				ci->i_rbytes,
1247 				(long)ci->i_rctime.tv_sec,
1248 				(long)ci->i_rctime.tv_nsec);
1249 	}
1250 
1251 	if (*ppos >= cf->dir_info_len)
1252 		return 0;
1253 	size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1254 	left = copy_to_user(buf, cf->dir_info + *ppos, size);
1255 	if (left == size)
1256 		return -EFAULT;
1257 	*ppos += (size - left);
1258 	return size - left;
1259 }
1260 
1261 /*
1262  * We maintain a private dentry LRU.
1263  *
1264  * FIXME: this needs to be changed to a per-mds lru to be useful.
1265  */
1266 void ceph_dentry_lru_add(struct dentry *dn)
1267 {
1268 	struct ceph_dentry_info *di = ceph_dentry(dn);
1269 	struct ceph_mds_client *mdsc;
1270 
1271 	dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1272 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1273 	spin_lock(&mdsc->dentry_lru_lock);
1274 	list_add_tail(&di->lru, &mdsc->dentry_lru);
1275 	mdsc->num_dentry++;
1276 	spin_unlock(&mdsc->dentry_lru_lock);
1277 }
1278 
1279 void ceph_dentry_lru_touch(struct dentry *dn)
1280 {
1281 	struct ceph_dentry_info *di = ceph_dentry(dn);
1282 	struct ceph_mds_client *mdsc;
1283 
1284 	dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1285 	     di->offset);
1286 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1287 	spin_lock(&mdsc->dentry_lru_lock);
1288 	list_move_tail(&di->lru, &mdsc->dentry_lru);
1289 	spin_unlock(&mdsc->dentry_lru_lock);
1290 }
1291 
1292 void ceph_dentry_lru_del(struct dentry *dn)
1293 {
1294 	struct ceph_dentry_info *di = ceph_dentry(dn);
1295 	struct ceph_mds_client *mdsc;
1296 
1297 	dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1298 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1299 	spin_lock(&mdsc->dentry_lru_lock);
1300 	list_del_init(&di->lru);
1301 	mdsc->num_dentry--;
1302 	spin_unlock(&mdsc->dentry_lru_lock);
1303 }
1304 
1305 /*
1306  * Return name hash for a given dentry.  This is dependent on
1307  * the parent directory's hash function.
1308  */
1309 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1310 {
1311 	struct ceph_inode_info *dci = ceph_inode(dir);
1312 
1313 	switch (dci->i_dir_layout.dl_dir_hash) {
1314 	case 0:	/* for backward compat */
1315 	case CEPH_STR_HASH_LINUX:
1316 		return dn->d_name.hash;
1317 
1318 	default:
1319 		return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1320 				     dn->d_name.name, dn->d_name.len);
1321 	}
1322 }
1323 
1324 const struct file_operations ceph_dir_fops = {
1325 	.read = ceph_read_dir,
1326 	.iterate = ceph_readdir,
1327 	.llseek = ceph_dir_llseek,
1328 	.open = ceph_open,
1329 	.release = ceph_release,
1330 	.unlocked_ioctl = ceph_ioctl,
1331 	.fsync = ceph_fsync,
1332 };
1333 
1334 const struct file_operations ceph_snapdir_fops = {
1335 	.iterate = ceph_readdir,
1336 	.llseek = ceph_dir_llseek,
1337 	.open = ceph_open,
1338 	.release = ceph_release,
1339 };
1340 
1341 const struct inode_operations ceph_dir_iops = {
1342 	.lookup = ceph_lookup,
1343 	.permission = ceph_permission,
1344 	.getattr = ceph_getattr,
1345 	.setattr = ceph_setattr,
1346 	.setxattr = generic_setxattr,
1347 	.getxattr = generic_getxattr,
1348 	.listxattr = ceph_listxattr,
1349 	.removexattr = generic_removexattr,
1350 	.get_acl = ceph_get_acl,
1351 	.set_acl = ceph_set_acl,
1352 	.mknod = ceph_mknod,
1353 	.symlink = ceph_symlink,
1354 	.mkdir = ceph_mkdir,
1355 	.link = ceph_link,
1356 	.unlink = ceph_unlink,
1357 	.rmdir = ceph_unlink,
1358 	.rename = ceph_rename,
1359 	.create = ceph_create,
1360 	.atomic_open = ceph_atomic_open,
1361 };
1362 
1363 const struct inode_operations ceph_snapdir_iops = {
1364 	.lookup = ceph_lookup,
1365 	.permission = ceph_permission,
1366 	.getattr = ceph_getattr,
1367 	.mkdir = ceph_mkdir,
1368 	.rmdir = ceph_unlink,
1369 	.rename = ceph_rename,
1370 };
1371 
1372 const struct dentry_operations ceph_dentry_ops = {
1373 	.d_revalidate = ceph_d_revalidate,
1374 	.d_release = ceph_d_release,
1375 	.d_prune = ceph_d_prune,
1376 };
1377 
1378 const struct dentry_operations ceph_snapdir_dentry_ops = {
1379 	.d_revalidate = ceph_snapdir_d_revalidate,
1380 	.d_release = ceph_d_release,
1381 };
1382 
1383 const struct dentry_operations ceph_snap_dentry_ops = {
1384 	.d_release = ceph_d_release,
1385 	.d_prune = ceph_d_prune,
1386 };
1387