xref: /openbmc/linux/fs/ceph/dir.c (revision a2fb4d78)
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 
9 #include "super.h"
10 #include "mds_client.h"
11 
12 /*
13  * Directory operations: readdir, lookup, create, link, unlink,
14  * rename, etc.
15  */
16 
17 /*
18  * Ceph MDS operations are specified in terms of a base ino and
19  * relative path.  Thus, the client can specify an operation on a
20  * specific inode (e.g., a getattr due to fstat(2)), or as a path
21  * relative to, say, the root directory.
22  *
23  * Normally, we limit ourselves to strict inode ops (no path component)
24  * or dentry operations (a single path component relative to an ino).  The
25  * exception to this is open_root_dentry(), which will open the mount
26  * point by name.
27  */
28 
29 const struct inode_operations ceph_dir_iops;
30 const struct file_operations ceph_dir_fops;
31 const struct dentry_operations ceph_dentry_ops;
32 
33 /*
34  * Initialize ceph dentry state.
35  */
36 int ceph_init_dentry(struct dentry *dentry)
37 {
38 	struct ceph_dentry_info *di;
39 
40 	if (dentry->d_fsdata)
41 		return 0;
42 
43 	di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO);
44 	if (!di)
45 		return -ENOMEM;          /* oh well */
46 
47 	spin_lock(&dentry->d_lock);
48 	if (dentry->d_fsdata) {
49 		/* lost a race */
50 		kmem_cache_free(ceph_dentry_cachep, di);
51 		goto out_unlock;
52 	}
53 
54 	if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
55 		d_set_d_op(dentry, &ceph_dentry_ops);
56 	else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
57 		d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
58 	else
59 		d_set_d_op(dentry, &ceph_snap_dentry_ops);
60 
61 	di->dentry = dentry;
62 	di->lease_session = NULL;
63 	dentry->d_time = jiffies;
64 	/* avoid reordering d_fsdata setup so that the check above is safe */
65 	smp_mb();
66 	dentry->d_fsdata = di;
67 	ceph_dentry_lru_add(dentry);
68 out_unlock:
69 	spin_unlock(&dentry->d_lock);
70 	return 0;
71 }
72 
73 struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry)
74 {
75 	struct inode *inode = NULL;
76 
77 	if (!dentry)
78 		return NULL;
79 
80 	spin_lock(&dentry->d_lock);
81 	if (!IS_ROOT(dentry)) {
82 		inode = dentry->d_parent->d_inode;
83 		ihold(inode);
84 	}
85 	spin_unlock(&dentry->d_lock);
86 	return inode;
87 }
88 
89 
90 /*
91  * for readdir, we encode the directory frag and offset within that
92  * frag into f_pos.
93  */
94 static unsigned fpos_frag(loff_t p)
95 {
96 	return p >> 32;
97 }
98 static unsigned fpos_off(loff_t p)
99 {
100 	return p & 0xffffffff;
101 }
102 
103 static int fpos_cmp(loff_t l, loff_t r)
104 {
105 	int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
106 	if (v)
107 		return v;
108 	return (int)(fpos_off(l) - fpos_off(r));
109 }
110 
111 /*
112  * When possible, we try to satisfy a readdir by peeking at the
113  * dcache.  We make this work by carefully ordering dentries on
114  * d_u.d_child when we initially get results back from the MDS, and
115  * falling back to a "normal" sync readdir if any dentries in the dir
116  * are dropped.
117  *
118  * Complete dir indicates that we have all dentries in the dir.  It is
119  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
120  * the MDS if/when the directory is modified).
121  */
122 static int __dcache_readdir(struct file *file, struct dir_context *ctx)
123 {
124 	struct ceph_file_info *fi = file->private_data;
125 	struct dentry *parent = file->f_dentry;
126 	struct inode *dir = parent->d_inode;
127 	struct list_head *p;
128 	struct dentry *dentry, *last;
129 	struct ceph_dentry_info *di;
130 	int err = 0;
131 
132 	/* claim ref on last dentry we returned */
133 	last = fi->dentry;
134 	fi->dentry = NULL;
135 
136 	dout("__dcache_readdir %p at %llu (last %p)\n", dir, ctx->pos,
137 	     last);
138 
139 	spin_lock(&parent->d_lock);
140 
141 	/* start at beginning? */
142 	if (ctx->pos == 2 || last == NULL ||
143 	    ctx->pos < ceph_dentry(last)->offset) {
144 		if (list_empty(&parent->d_subdirs))
145 			goto out_unlock;
146 		p = parent->d_subdirs.prev;
147 		dout(" initial p %p/%p\n", p->prev, p->next);
148 	} else {
149 		p = last->d_u.d_child.prev;
150 	}
151 
152 more:
153 	dentry = list_entry(p, struct dentry, d_u.d_child);
154 	di = ceph_dentry(dentry);
155 	while (1) {
156 		dout(" p %p/%p %s d_subdirs %p/%p\n", p->prev, p->next,
157 		     d_unhashed(dentry) ? "!hashed" : "hashed",
158 		     parent->d_subdirs.prev, parent->d_subdirs.next);
159 		if (p == &parent->d_subdirs) {
160 			fi->flags |= CEPH_F_ATEND;
161 			goto out_unlock;
162 		}
163 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
164 		if (!d_unhashed(dentry) && dentry->d_inode &&
165 		    ceph_snap(dentry->d_inode) != CEPH_SNAPDIR &&
166 		    ceph_ino(dentry->d_inode) != CEPH_INO_CEPH &&
167 		    fpos_cmp(ctx->pos, di->offset) <= 0)
168 			break;
169 		dout(" skipping %p %.*s at %llu (%llu)%s%s\n", dentry,
170 		     dentry->d_name.len, dentry->d_name.name, di->offset,
171 		     ctx->pos, d_unhashed(dentry) ? " unhashed" : "",
172 		     !dentry->d_inode ? " null" : "");
173 		spin_unlock(&dentry->d_lock);
174 		p = p->prev;
175 		dentry = list_entry(p, struct dentry, d_u.d_child);
176 		di = ceph_dentry(dentry);
177 	}
178 
179 	dget_dlock(dentry);
180 	spin_unlock(&dentry->d_lock);
181 	spin_unlock(&parent->d_lock);
182 
183 	dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, ctx->pos,
184 	     dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
185 	ctx->pos = di->offset;
186 	if (!dir_emit(ctx, dentry->d_name.name,
187 		      dentry->d_name.len,
188 		      ceph_translate_ino(dentry->d_sb, dentry->d_inode->i_ino),
189 		      dentry->d_inode->i_mode >> 12)) {
190 		if (last) {
191 			/* remember our position */
192 			fi->dentry = last;
193 			fi->next_offset = di->offset;
194 		}
195 		dput(dentry);
196 		return 0;
197 	}
198 
199 	if (last)
200 		dput(last);
201 	last = dentry;
202 
203 	ctx->pos++;
204 
205 	/* make sure a dentry wasn't dropped while we didn't have parent lock */
206 	if (!ceph_dir_is_complete(dir)) {
207 		dout(" lost dir complete on %p; falling back to mds\n", dir);
208 		err = -EAGAIN;
209 		goto out;
210 	}
211 
212 	spin_lock(&parent->d_lock);
213 	p = p->prev;	/* advance to next dentry */
214 	goto more;
215 
216 out_unlock:
217 	spin_unlock(&parent->d_lock);
218 out:
219 	if (last)
220 		dput(last);
221 	return err;
222 }
223 
224 /*
225  * make note of the last dentry we read, so we can
226  * continue at the same lexicographical point,
227  * regardless of what dir changes take place on the
228  * server.
229  */
230 static int note_last_dentry(struct ceph_file_info *fi, const char *name,
231 			    int len)
232 {
233 	kfree(fi->last_name);
234 	fi->last_name = kmalloc(len+1, GFP_NOFS);
235 	if (!fi->last_name)
236 		return -ENOMEM;
237 	memcpy(fi->last_name, name, len);
238 	fi->last_name[len] = 0;
239 	dout("note_last_dentry '%s'\n", fi->last_name);
240 	return 0;
241 }
242 
243 static int ceph_readdir(struct file *file, struct dir_context *ctx)
244 {
245 	struct ceph_file_info *fi = file->private_data;
246 	struct inode *inode = file_inode(file);
247 	struct ceph_inode_info *ci = ceph_inode(inode);
248 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
249 	struct ceph_mds_client *mdsc = fsc->mdsc;
250 	unsigned frag = fpos_frag(ctx->pos);
251 	int off = fpos_off(ctx->pos);
252 	int err;
253 	u32 ftype;
254 	struct ceph_mds_reply_info_parsed *rinfo;
255 	const int max_entries = fsc->mount_options->max_readdir;
256 	const int max_bytes = fsc->mount_options->max_readdir_bytes;
257 
258 	dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
259 	if (fi->flags & CEPH_F_ATEND)
260 		return 0;
261 
262 	/* always start with . and .. */
263 	if (ctx->pos == 0) {
264 		/* note dir version at start of readdir so we can tell
265 		 * if any dentries get dropped */
266 		fi->dir_release_count = atomic_read(&ci->i_release_count);
267 
268 		dout("readdir off 0 -> '.'\n");
269 		if (!dir_emit(ctx, ".", 1,
270 			    ceph_translate_ino(inode->i_sb, inode->i_ino),
271 			    inode->i_mode >> 12))
272 			return 0;
273 		ctx->pos = 1;
274 		off = 1;
275 	}
276 	if (ctx->pos == 1) {
277 		ino_t ino = parent_ino(file->f_dentry);
278 		dout("readdir off 1 -> '..'\n");
279 		if (!dir_emit(ctx, "..", 2,
280 			    ceph_translate_ino(inode->i_sb, ino),
281 			    inode->i_mode >> 12))
282 			return 0;
283 		ctx->pos = 2;
284 		off = 2;
285 	}
286 
287 	/* can we use the dcache? */
288 	spin_lock(&ci->i_ceph_lock);
289 	if ((ctx->pos == 2 || fi->dentry) &&
290 	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
291 	    ceph_snap(inode) != CEPH_SNAPDIR &&
292 	    __ceph_dir_is_complete(ci) &&
293 	    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
294 		spin_unlock(&ci->i_ceph_lock);
295 		err = __dcache_readdir(file, ctx);
296 		if (err != -EAGAIN)
297 			return err;
298 	} else {
299 		spin_unlock(&ci->i_ceph_lock);
300 	}
301 	if (fi->dentry) {
302 		err = note_last_dentry(fi, fi->dentry->d_name.name,
303 				       fi->dentry->d_name.len);
304 		if (err)
305 			return err;
306 		dput(fi->dentry);
307 		fi->dentry = NULL;
308 	}
309 
310 	/* proceed with a normal readdir */
311 
312 more:
313 	/* do we have the correct frag content buffered? */
314 	if (fi->frag != frag || fi->last_readdir == NULL) {
315 		struct ceph_mds_request *req;
316 		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
317 			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
318 
319 		/* discard old result, if any */
320 		if (fi->last_readdir) {
321 			ceph_mdsc_put_request(fi->last_readdir);
322 			fi->last_readdir = NULL;
323 		}
324 
325 		/* requery frag tree, as the frag topology may have changed */
326 		frag = ceph_choose_frag(ceph_inode(inode), frag, NULL, NULL);
327 
328 		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
329 		     ceph_vinop(inode), frag, fi->last_name);
330 		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
331 		if (IS_ERR(req))
332 			return PTR_ERR(req);
333 		req->r_inode = inode;
334 		ihold(inode);
335 		req->r_dentry = dget(file->f_dentry);
336 		/* hints to request -> mds selection code */
337 		req->r_direct_mode = USE_AUTH_MDS;
338 		req->r_direct_hash = ceph_frag_value(frag);
339 		req->r_direct_is_hash = true;
340 		req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
341 		req->r_readdir_offset = fi->next_offset;
342 		req->r_args.readdir.frag = cpu_to_le32(frag);
343 		req->r_args.readdir.max_entries = cpu_to_le32(max_entries);
344 		req->r_args.readdir.max_bytes = cpu_to_le32(max_bytes);
345 		req->r_num_caps = max_entries + 1;
346 		err = ceph_mdsc_do_request(mdsc, NULL, req);
347 		if (err < 0) {
348 			ceph_mdsc_put_request(req);
349 			return err;
350 		}
351 		dout("readdir got and parsed readdir result=%d"
352 		     " on frag %x, end=%d, complete=%d\n", err, frag,
353 		     (int)req->r_reply_info.dir_end,
354 		     (int)req->r_reply_info.dir_complete);
355 
356 		if (!req->r_did_prepopulate) {
357 			dout("readdir !did_prepopulate");
358 			/* preclude from marking dir complete */
359 			fi->dir_release_count--;
360 		}
361 
362 		/* note next offset and last dentry name */
363 		rinfo = &req->r_reply_info;
364 		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
365 			frag = le32_to_cpu(rinfo->dir_dir->frag);
366 			if (ceph_frag_is_leftmost(frag))
367 				fi->next_offset = 2;
368 			else
369 				fi->next_offset = 0;
370 			off = fi->next_offset;
371 		}
372 		fi->offset = fi->next_offset;
373 		fi->last_readdir = req;
374 		fi->frag = frag;
375 
376 		if (req->r_reply_info.dir_end) {
377 			kfree(fi->last_name);
378 			fi->last_name = NULL;
379 			if (ceph_frag_is_rightmost(frag))
380 				fi->next_offset = 2;
381 			else
382 				fi->next_offset = 0;
383 		} else {
384 			err = note_last_dentry(fi,
385 				       rinfo->dir_dname[rinfo->dir_nr-1],
386 				       rinfo->dir_dname_len[rinfo->dir_nr-1]);
387 			if (err)
388 				return err;
389 			fi->next_offset += rinfo->dir_nr;
390 		}
391 	}
392 
393 	rinfo = &fi->last_readdir->r_reply_info;
394 	dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
395 	     rinfo->dir_nr, off, fi->offset);
396 
397 	ctx->pos = ceph_make_fpos(frag, off);
398 	while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
399 		struct ceph_mds_reply_inode *in =
400 			rinfo->dir_in[off - fi->offset].in;
401 		struct ceph_vino vino;
402 		ino_t ino;
403 
404 		dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
405 		     off, off - fi->offset, rinfo->dir_nr, ctx->pos,
406 		     rinfo->dir_dname_len[off - fi->offset],
407 		     rinfo->dir_dname[off - fi->offset], in);
408 		BUG_ON(!in);
409 		ftype = le32_to_cpu(in->mode) >> 12;
410 		vino.ino = le64_to_cpu(in->ino);
411 		vino.snap = le64_to_cpu(in->snapid);
412 		ino = ceph_vino_to_ino(vino);
413 		if (!dir_emit(ctx,
414 			    rinfo->dir_dname[off - fi->offset],
415 			    rinfo->dir_dname_len[off - fi->offset],
416 			    ceph_translate_ino(inode->i_sb, ino), ftype)) {
417 			dout("filldir stopping us...\n");
418 			return 0;
419 		}
420 		off++;
421 		ctx->pos++;
422 	}
423 
424 	if (fi->last_name) {
425 		ceph_mdsc_put_request(fi->last_readdir);
426 		fi->last_readdir = NULL;
427 		goto more;
428 	}
429 
430 	/* more frags? */
431 	if (!ceph_frag_is_rightmost(frag)) {
432 		frag = ceph_frag_next(frag);
433 		off = 0;
434 		ctx->pos = ceph_make_fpos(frag, off);
435 		dout("readdir next frag is %x\n", frag);
436 		goto more;
437 	}
438 	fi->flags |= CEPH_F_ATEND;
439 
440 	/*
441 	 * if dir_release_count still matches the dir, no dentries
442 	 * were released during the whole readdir, and we should have
443 	 * the complete dir contents in our cache.
444 	 */
445 	spin_lock(&ci->i_ceph_lock);
446 	if (atomic_read(&ci->i_release_count) == fi->dir_release_count) {
447 		dout(" marking %p complete\n", inode);
448 		__ceph_dir_set_complete(ci, fi->dir_release_count);
449 		ci->i_max_offset = ctx->pos;
450 	}
451 	spin_unlock(&ci->i_ceph_lock);
452 
453 	dout("readdir %p file %p done.\n", inode, file);
454 	return 0;
455 }
456 
457 static void reset_readdir(struct ceph_file_info *fi)
458 {
459 	if (fi->last_readdir) {
460 		ceph_mdsc_put_request(fi->last_readdir);
461 		fi->last_readdir = NULL;
462 	}
463 	kfree(fi->last_name);
464 	fi->last_name = NULL;
465 	fi->next_offset = 2;  /* compensate for . and .. */
466 	if (fi->dentry) {
467 		dput(fi->dentry);
468 		fi->dentry = NULL;
469 	}
470 	fi->flags &= ~CEPH_F_ATEND;
471 }
472 
473 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
474 {
475 	struct ceph_file_info *fi = file->private_data;
476 	struct inode *inode = file->f_mapping->host;
477 	loff_t old_offset = offset;
478 	loff_t retval;
479 
480 	mutex_lock(&inode->i_mutex);
481 	retval = -EINVAL;
482 	switch (whence) {
483 	case SEEK_END:
484 		offset += inode->i_size + 2;   /* FIXME */
485 		break;
486 	case SEEK_CUR:
487 		offset += file->f_pos;
488 	case SEEK_SET:
489 		break;
490 	default:
491 		goto out;
492 	}
493 
494 	if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
495 		if (offset != file->f_pos) {
496 			file->f_pos = offset;
497 			file->f_version = 0;
498 			fi->flags &= ~CEPH_F_ATEND;
499 		}
500 		retval = offset;
501 
502 		/*
503 		 * discard buffered readdir content on seekdir(0), or
504 		 * seek to new frag, or seek prior to current chunk.
505 		 */
506 		if (offset == 0 ||
507 		    fpos_frag(offset) != fpos_frag(old_offset) ||
508 		    fpos_off(offset) < fi->offset) {
509 			dout("dir_llseek dropping %p content\n", file);
510 			reset_readdir(fi);
511 		}
512 
513 		/* bump dir_release_count if we did a forward seek */
514 		if (offset > old_offset)
515 			fi->dir_release_count--;
516 	}
517 out:
518 	mutex_unlock(&inode->i_mutex);
519 	return retval;
520 }
521 
522 /*
523  * Handle lookups for the hidden .snap directory.
524  */
525 int ceph_handle_snapdir(struct ceph_mds_request *req,
526 			struct dentry *dentry, int err)
527 {
528 	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
529 	struct inode *parent = dentry->d_parent->d_inode; /* we hold i_mutex */
530 
531 	/* .snap dir? */
532 	if (err == -ENOENT &&
533 	    ceph_snap(parent) == CEPH_NOSNAP &&
534 	    strcmp(dentry->d_name.name,
535 		   fsc->mount_options->snapdir_name) == 0) {
536 		struct inode *inode = ceph_get_snapdir(parent);
537 		dout("ENOENT on snapdir %p '%.*s', linking to snapdir %p\n",
538 		     dentry, dentry->d_name.len, dentry->d_name.name, inode);
539 		BUG_ON(!d_unhashed(dentry));
540 		d_add(dentry, inode);
541 		err = 0;
542 	}
543 	return err;
544 }
545 
546 /*
547  * Figure out final result of a lookup/open request.
548  *
549  * Mainly, make sure we return the final req->r_dentry (if it already
550  * existed) in place of the original VFS-provided dentry when they
551  * differ.
552  *
553  * Gracefully handle the case where the MDS replies with -ENOENT and
554  * no trace (which it may do, at its discretion, e.g., if it doesn't
555  * care to issue a lease on the negative dentry).
556  */
557 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
558 				  struct dentry *dentry, int err)
559 {
560 	if (err == -ENOENT) {
561 		/* no trace? */
562 		err = 0;
563 		if (!req->r_reply_info.head->is_dentry) {
564 			dout("ENOENT and no trace, dentry %p inode %p\n",
565 			     dentry, dentry->d_inode);
566 			if (dentry->d_inode) {
567 				d_drop(dentry);
568 				err = -ENOENT;
569 			} else {
570 				d_add(dentry, NULL);
571 			}
572 		}
573 	}
574 	if (err)
575 		dentry = ERR_PTR(err);
576 	else if (dentry != req->r_dentry)
577 		dentry = dget(req->r_dentry);   /* we got spliced */
578 	else
579 		dentry = NULL;
580 	return dentry;
581 }
582 
583 static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
584 {
585 	return ceph_ino(inode) == CEPH_INO_ROOT &&
586 		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
587 }
588 
589 /*
590  * Look up a single dir entry.  If there is a lookup intent, inform
591  * the MDS so that it gets our 'caps wanted' value in a single op.
592  */
593 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
594 				  unsigned int flags)
595 {
596 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
597 	struct ceph_mds_client *mdsc = fsc->mdsc;
598 	struct ceph_mds_request *req;
599 	int op;
600 	int err;
601 
602 	dout("lookup %p dentry %p '%.*s'\n",
603 	     dir, dentry, dentry->d_name.len, dentry->d_name.name);
604 
605 	if (dentry->d_name.len > NAME_MAX)
606 		return ERR_PTR(-ENAMETOOLONG);
607 
608 	err = ceph_init_dentry(dentry);
609 	if (err < 0)
610 		return ERR_PTR(err);
611 
612 	/* can we conclude ENOENT locally? */
613 	if (dentry->d_inode == NULL) {
614 		struct ceph_inode_info *ci = ceph_inode(dir);
615 		struct ceph_dentry_info *di = ceph_dentry(dentry);
616 
617 		spin_lock(&ci->i_ceph_lock);
618 		dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
619 		if (strncmp(dentry->d_name.name,
620 			    fsc->mount_options->snapdir_name,
621 			    dentry->d_name.len) &&
622 		    !is_root_ceph_dentry(dir, dentry) &&
623 		    __ceph_dir_is_complete(ci) &&
624 		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
625 			spin_unlock(&ci->i_ceph_lock);
626 			dout(" dir %p complete, -ENOENT\n", dir);
627 			d_add(dentry, NULL);
628 			di->lease_shared_gen = ci->i_shared_gen;
629 			return NULL;
630 		}
631 		spin_unlock(&ci->i_ceph_lock);
632 	}
633 
634 	op = ceph_snap(dir) == CEPH_SNAPDIR ?
635 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
636 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
637 	if (IS_ERR(req))
638 		return ERR_CAST(req);
639 	req->r_dentry = dget(dentry);
640 	req->r_num_caps = 2;
641 	/* we only need inode linkage */
642 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
643 	req->r_locked_dir = dir;
644 	err = ceph_mdsc_do_request(mdsc, NULL, req);
645 	err = ceph_handle_snapdir(req, dentry, err);
646 	dentry = ceph_finish_lookup(req, dentry, err);
647 	ceph_mdsc_put_request(req);  /* will dput(dentry) */
648 	dout("lookup result=%p\n", dentry);
649 	return dentry;
650 }
651 
652 /*
653  * If we do a create but get no trace back from the MDS, follow up with
654  * a lookup (the VFS expects us to link up the provided dentry).
655  */
656 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
657 {
658 	struct dentry *result = ceph_lookup(dir, dentry, 0);
659 
660 	if (result && !IS_ERR(result)) {
661 		/*
662 		 * We created the item, then did a lookup, and found
663 		 * it was already linked to another inode we already
664 		 * had in our cache (and thus got spliced).  Link our
665 		 * dentry to that inode, but don't hash it, just in
666 		 * case the VFS wants to dereference it.
667 		 */
668 		BUG_ON(!result->d_inode);
669 		d_instantiate(dentry, result->d_inode);
670 		return 0;
671 	}
672 	return PTR_ERR(result);
673 }
674 
675 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
676 		      umode_t mode, dev_t rdev)
677 {
678 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
679 	struct ceph_mds_client *mdsc = fsc->mdsc;
680 	struct ceph_mds_request *req;
681 	int err;
682 
683 	if (ceph_snap(dir) != CEPH_NOSNAP)
684 		return -EROFS;
685 
686 	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
687 	     dir, dentry, mode, rdev);
688 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
689 	if (IS_ERR(req)) {
690 		d_drop(dentry);
691 		return PTR_ERR(req);
692 	}
693 	req->r_dentry = dget(dentry);
694 	req->r_num_caps = 2;
695 	req->r_locked_dir = dir;
696 	req->r_args.mknod.mode = cpu_to_le32(mode);
697 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
698 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
699 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
700 	err = ceph_mdsc_do_request(mdsc, dir, req);
701 	if (!err && !req->r_reply_info.head->is_dentry)
702 		err = ceph_handle_notrace_create(dir, dentry);
703 	ceph_mdsc_put_request(req);
704 
705 	if (!err)
706 		ceph_init_acl(dentry, dentry->d_inode, dir);
707 	else
708 		d_drop(dentry);
709 	return err;
710 }
711 
712 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
713 		       bool excl)
714 {
715 	return ceph_mknod(dir, dentry, mode, 0);
716 }
717 
718 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
719 			    const char *dest)
720 {
721 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
722 	struct ceph_mds_client *mdsc = fsc->mdsc;
723 	struct ceph_mds_request *req;
724 	int err;
725 
726 	if (ceph_snap(dir) != CEPH_NOSNAP)
727 		return -EROFS;
728 
729 	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
730 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
731 	if (IS_ERR(req)) {
732 		d_drop(dentry);
733 		return PTR_ERR(req);
734 	}
735 	req->r_dentry = dget(dentry);
736 	req->r_num_caps = 2;
737 	req->r_path2 = kstrdup(dest, GFP_NOFS);
738 	req->r_locked_dir = dir;
739 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
740 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
741 	err = ceph_mdsc_do_request(mdsc, dir, req);
742 	if (!err && !req->r_reply_info.head->is_dentry)
743 		err = ceph_handle_notrace_create(dir, dentry);
744 	ceph_mdsc_put_request(req);
745 	if (!err)
746 		ceph_init_acl(dentry, dentry->d_inode, dir);
747 	else
748 		d_drop(dentry);
749 	return err;
750 }
751 
752 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
753 {
754 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
755 	struct ceph_mds_client *mdsc = fsc->mdsc;
756 	struct ceph_mds_request *req;
757 	int err = -EROFS;
758 	int op;
759 
760 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
761 		/* mkdir .snap/foo is a MKSNAP */
762 		op = CEPH_MDS_OP_MKSNAP;
763 		dout("mksnap dir %p snap '%.*s' dn %p\n", dir,
764 		     dentry->d_name.len, dentry->d_name.name, dentry);
765 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
766 		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
767 		op = CEPH_MDS_OP_MKDIR;
768 	} else {
769 		goto out;
770 	}
771 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
772 	if (IS_ERR(req)) {
773 		err = PTR_ERR(req);
774 		goto out;
775 	}
776 
777 	req->r_dentry = dget(dentry);
778 	req->r_num_caps = 2;
779 	req->r_locked_dir = dir;
780 	req->r_args.mkdir.mode = cpu_to_le32(mode);
781 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
782 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
783 	err = ceph_mdsc_do_request(mdsc, dir, req);
784 	if (!err && !req->r_reply_info.head->is_dentry)
785 		err = ceph_handle_notrace_create(dir, dentry);
786 	ceph_mdsc_put_request(req);
787 out:
788 	if (!err)
789 		ceph_init_acl(dentry, dentry->d_inode, dir);
790 	else
791 		d_drop(dentry);
792 	return err;
793 }
794 
795 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
796 		     struct dentry *dentry)
797 {
798 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
799 	struct ceph_mds_client *mdsc = fsc->mdsc;
800 	struct ceph_mds_request *req;
801 	int err;
802 
803 	if (ceph_snap(dir) != CEPH_NOSNAP)
804 		return -EROFS;
805 
806 	dout("link in dir %p old_dentry %p dentry %p\n", dir,
807 	     old_dentry, dentry);
808 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
809 	if (IS_ERR(req)) {
810 		d_drop(dentry);
811 		return PTR_ERR(req);
812 	}
813 	req->r_dentry = dget(dentry);
814 	req->r_num_caps = 2;
815 	req->r_old_dentry = dget(old_dentry); /* or inode? hrm. */
816 	req->r_old_dentry_dir = ceph_get_dentry_parent_inode(old_dentry);
817 	req->r_locked_dir = dir;
818 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
819 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
820 	/* release LINK_SHARED on source inode (mds will lock it) */
821 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
822 	err = ceph_mdsc_do_request(mdsc, dir, req);
823 	if (err) {
824 		d_drop(dentry);
825 	} else if (!req->r_reply_info.head->is_dentry) {
826 		ihold(old_dentry->d_inode);
827 		d_instantiate(dentry, old_dentry->d_inode);
828 	}
829 	ceph_mdsc_put_request(req);
830 	return err;
831 }
832 
833 /*
834  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
835  * looks like the link count will hit 0, drop any other caps (other
836  * than PIN) we don't specifically want (due to the file still being
837  * open).
838  */
839 static int drop_caps_for_unlink(struct inode *inode)
840 {
841 	struct ceph_inode_info *ci = ceph_inode(inode);
842 	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
843 
844 	spin_lock(&ci->i_ceph_lock);
845 	if (inode->i_nlink == 1) {
846 		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
847 		ci->i_ceph_flags |= CEPH_I_NODELAY;
848 	}
849 	spin_unlock(&ci->i_ceph_lock);
850 	return drop;
851 }
852 
853 /*
854  * rmdir and unlink are differ only by the metadata op code
855  */
856 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
857 {
858 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
859 	struct ceph_mds_client *mdsc = fsc->mdsc;
860 	struct inode *inode = dentry->d_inode;
861 	struct ceph_mds_request *req;
862 	int err = -EROFS;
863 	int op;
864 
865 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
866 		/* rmdir .snap/foo is RMSNAP */
867 		dout("rmsnap dir %p '%.*s' dn %p\n", dir, dentry->d_name.len,
868 		     dentry->d_name.name, dentry);
869 		op = CEPH_MDS_OP_RMSNAP;
870 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
871 		dout("unlink/rmdir dir %p dn %p inode %p\n",
872 		     dir, dentry, inode);
873 		op = S_ISDIR(dentry->d_inode->i_mode) ?
874 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
875 	} else
876 		goto out;
877 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
878 	if (IS_ERR(req)) {
879 		err = PTR_ERR(req);
880 		goto out;
881 	}
882 	req->r_dentry = dget(dentry);
883 	req->r_num_caps = 2;
884 	req->r_locked_dir = dir;
885 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
886 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
887 	req->r_inode_drop = drop_caps_for_unlink(inode);
888 	err = ceph_mdsc_do_request(mdsc, dir, req);
889 	if (!err && !req->r_reply_info.head->is_dentry)
890 		d_delete(dentry);
891 	ceph_mdsc_put_request(req);
892 out:
893 	return err;
894 }
895 
896 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
897 		       struct inode *new_dir, struct dentry *new_dentry)
898 {
899 	struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
900 	struct ceph_mds_client *mdsc = fsc->mdsc;
901 	struct ceph_mds_request *req;
902 	int err;
903 
904 	if (ceph_snap(old_dir) != ceph_snap(new_dir))
905 		return -EXDEV;
906 	if (ceph_snap(old_dir) != CEPH_NOSNAP ||
907 	    ceph_snap(new_dir) != CEPH_NOSNAP)
908 		return -EROFS;
909 	dout("rename dir %p dentry %p to dir %p dentry %p\n",
910 	     old_dir, old_dentry, new_dir, new_dentry);
911 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_RENAME, USE_AUTH_MDS);
912 	if (IS_ERR(req))
913 		return PTR_ERR(req);
914 	req->r_dentry = dget(new_dentry);
915 	req->r_num_caps = 2;
916 	req->r_old_dentry = dget(old_dentry);
917 	req->r_old_dentry_dir = ceph_get_dentry_parent_inode(old_dentry);
918 	req->r_locked_dir = new_dir;
919 	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
920 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
921 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
922 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
923 	/* release LINK_RDCACHE on source inode (mds will lock it) */
924 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
925 	if (new_dentry->d_inode)
926 		req->r_inode_drop = drop_caps_for_unlink(new_dentry->d_inode);
927 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
928 	if (!err && !req->r_reply_info.head->is_dentry) {
929 		/*
930 		 * Normally d_move() is done by fill_trace (called by
931 		 * do_request, above).  If there is no trace, we need
932 		 * to do it here.
933 		 */
934 
935 		/* d_move screws up d_subdirs order */
936 		ceph_dir_clear_complete(new_dir);
937 
938 		d_move(old_dentry, new_dentry);
939 
940 		/* ensure target dentry is invalidated, despite
941 		   rehashing bug in vfs_rename_dir */
942 		ceph_invalidate_dentry_lease(new_dentry);
943 	}
944 	ceph_mdsc_put_request(req);
945 	return err;
946 }
947 
948 /*
949  * Ensure a dentry lease will no longer revalidate.
950  */
951 void ceph_invalidate_dentry_lease(struct dentry *dentry)
952 {
953 	spin_lock(&dentry->d_lock);
954 	dentry->d_time = jiffies;
955 	ceph_dentry(dentry)->lease_shared_gen = 0;
956 	spin_unlock(&dentry->d_lock);
957 }
958 
959 /*
960  * Check if dentry lease is valid.  If not, delete the lease.  Try to
961  * renew if the least is more than half up.
962  */
963 static int dentry_lease_is_valid(struct dentry *dentry)
964 {
965 	struct ceph_dentry_info *di;
966 	struct ceph_mds_session *s;
967 	int valid = 0;
968 	u32 gen;
969 	unsigned long ttl;
970 	struct ceph_mds_session *session = NULL;
971 	struct inode *dir = NULL;
972 	u32 seq = 0;
973 
974 	spin_lock(&dentry->d_lock);
975 	di = ceph_dentry(dentry);
976 	if (di->lease_session) {
977 		s = di->lease_session;
978 		spin_lock(&s->s_gen_ttl_lock);
979 		gen = s->s_cap_gen;
980 		ttl = s->s_cap_ttl;
981 		spin_unlock(&s->s_gen_ttl_lock);
982 
983 		if (di->lease_gen == gen &&
984 		    time_before(jiffies, dentry->d_time) &&
985 		    time_before(jiffies, ttl)) {
986 			valid = 1;
987 			if (di->lease_renew_after &&
988 			    time_after(jiffies, di->lease_renew_after)) {
989 				/* we should renew */
990 				dir = dentry->d_parent->d_inode;
991 				session = ceph_get_mds_session(s);
992 				seq = di->lease_seq;
993 				di->lease_renew_after = 0;
994 				di->lease_renew_from = jiffies;
995 			}
996 		}
997 	}
998 	spin_unlock(&dentry->d_lock);
999 
1000 	if (session) {
1001 		ceph_mdsc_lease_send_msg(session, dir, dentry,
1002 					 CEPH_MDS_LEASE_RENEW, seq);
1003 		ceph_put_mds_session(session);
1004 	}
1005 	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1006 	return valid;
1007 }
1008 
1009 /*
1010  * Check if directory-wide content lease/cap is valid.
1011  */
1012 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1013 {
1014 	struct ceph_inode_info *ci = ceph_inode(dir);
1015 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1016 	int valid = 0;
1017 
1018 	spin_lock(&ci->i_ceph_lock);
1019 	if (ci->i_shared_gen == di->lease_shared_gen)
1020 		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1021 	spin_unlock(&ci->i_ceph_lock);
1022 	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1023 	     dir, (unsigned)ci->i_shared_gen, dentry,
1024 	     (unsigned)di->lease_shared_gen, valid);
1025 	return valid;
1026 }
1027 
1028 /*
1029  * Check if cached dentry can be trusted.
1030  */
1031 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1032 {
1033 	int valid = 0;
1034 	struct inode *dir;
1035 
1036 	if (flags & LOOKUP_RCU)
1037 		return -ECHILD;
1038 
1039 	dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
1040 	     dentry->d_name.len, dentry->d_name.name, dentry->d_inode,
1041 	     ceph_dentry(dentry)->offset);
1042 
1043 	dir = ceph_get_dentry_parent_inode(dentry);
1044 
1045 	/* always trust cached snapped dentries, snapdir dentry */
1046 	if (ceph_snap(dir) != CEPH_NOSNAP) {
1047 		dout("d_revalidate %p '%.*s' inode %p is SNAPPED\n", dentry,
1048 		     dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
1049 		valid = 1;
1050 	} else if (dentry->d_inode &&
1051 		   ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) {
1052 		valid = 1;
1053 	} else if (dentry_lease_is_valid(dentry) ||
1054 		   dir_lease_is_valid(dir, dentry)) {
1055 		if (dentry->d_inode)
1056 			valid = ceph_is_any_caps(dentry->d_inode);
1057 		else
1058 			valid = 1;
1059 	}
1060 
1061 	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1062 	if (valid) {
1063 		ceph_dentry_lru_touch(dentry);
1064 	} else {
1065 		ceph_dir_clear_complete(dir);
1066 		d_drop(dentry);
1067 	}
1068 	iput(dir);
1069 	return valid;
1070 }
1071 
1072 /*
1073  * Release our ceph_dentry_info.
1074  */
1075 static void ceph_d_release(struct dentry *dentry)
1076 {
1077 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1078 
1079 	dout("d_release %p\n", dentry);
1080 	ceph_dentry_lru_del(dentry);
1081 	if (di->lease_session)
1082 		ceph_put_mds_session(di->lease_session);
1083 	kmem_cache_free(ceph_dentry_cachep, di);
1084 	dentry->d_fsdata = NULL;
1085 }
1086 
1087 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1088 					  unsigned int flags)
1089 {
1090 	/*
1091 	 * Eventually, we'll want to revalidate snapped metadata
1092 	 * too... probably...
1093 	 */
1094 	return 1;
1095 }
1096 
1097 /*
1098  * When the VFS prunes a dentry from the cache, we need to clear the
1099  * complete flag on the parent directory.
1100  *
1101  * Called under dentry->d_lock.
1102  */
1103 static void ceph_d_prune(struct dentry *dentry)
1104 {
1105 	dout("ceph_d_prune %p\n", dentry);
1106 
1107 	/* do we have a valid parent? */
1108 	if (IS_ROOT(dentry))
1109 		return;
1110 
1111 	/* if we are not hashed, we don't affect dir's completeness */
1112 	if (d_unhashed(dentry))
1113 		return;
1114 
1115 	/*
1116 	 * we hold d_lock, so d_parent is stable, and d_fsdata is never
1117 	 * cleared until d_release
1118 	 */
1119 	ceph_dir_clear_complete(dentry->d_parent->d_inode);
1120 }
1121 
1122 /*
1123  * read() on a dir.  This weird interface hack only works if mounted
1124  * with '-o dirstat'.
1125  */
1126 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1127 			     loff_t *ppos)
1128 {
1129 	struct ceph_file_info *cf = file->private_data;
1130 	struct inode *inode = file_inode(file);
1131 	struct ceph_inode_info *ci = ceph_inode(inode);
1132 	int left;
1133 	const int bufsize = 1024;
1134 
1135 	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1136 		return -EISDIR;
1137 
1138 	if (!cf->dir_info) {
1139 		cf->dir_info = kmalloc(bufsize, GFP_NOFS);
1140 		if (!cf->dir_info)
1141 			return -ENOMEM;
1142 		cf->dir_info_len =
1143 			snprintf(cf->dir_info, bufsize,
1144 				"entries:   %20lld\n"
1145 				" files:    %20lld\n"
1146 				" subdirs:  %20lld\n"
1147 				"rentries:  %20lld\n"
1148 				" rfiles:   %20lld\n"
1149 				" rsubdirs: %20lld\n"
1150 				"rbytes:    %20lld\n"
1151 				"rctime:    %10ld.%09ld\n",
1152 				ci->i_files + ci->i_subdirs,
1153 				ci->i_files,
1154 				ci->i_subdirs,
1155 				ci->i_rfiles + ci->i_rsubdirs,
1156 				ci->i_rfiles,
1157 				ci->i_rsubdirs,
1158 				ci->i_rbytes,
1159 				(long)ci->i_rctime.tv_sec,
1160 				(long)ci->i_rctime.tv_nsec);
1161 	}
1162 
1163 	if (*ppos >= cf->dir_info_len)
1164 		return 0;
1165 	size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1166 	left = copy_to_user(buf, cf->dir_info + *ppos, size);
1167 	if (left == size)
1168 		return -EFAULT;
1169 	*ppos += (size - left);
1170 	return size - left;
1171 }
1172 
1173 /*
1174  * an fsync() on a dir will wait for any uncommitted directory
1175  * operations to commit.
1176  */
1177 static int ceph_dir_fsync(struct file *file, loff_t start, loff_t end,
1178 			  int datasync)
1179 {
1180 	struct inode *inode = file_inode(file);
1181 	struct ceph_inode_info *ci = ceph_inode(inode);
1182 	struct list_head *head = &ci->i_unsafe_dirops;
1183 	struct ceph_mds_request *req;
1184 	u64 last_tid;
1185 	int ret = 0;
1186 
1187 	dout("dir_fsync %p\n", inode);
1188 	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
1189 	if (ret)
1190 		return ret;
1191 	mutex_lock(&inode->i_mutex);
1192 
1193 	spin_lock(&ci->i_unsafe_lock);
1194 	if (list_empty(head))
1195 		goto out;
1196 
1197 	req = list_entry(head->prev,
1198 			 struct ceph_mds_request, r_unsafe_dir_item);
1199 	last_tid = req->r_tid;
1200 
1201 	do {
1202 		ceph_mdsc_get_request(req);
1203 		spin_unlock(&ci->i_unsafe_lock);
1204 
1205 		dout("dir_fsync %p wait on tid %llu (until %llu)\n",
1206 		     inode, req->r_tid, last_tid);
1207 		if (req->r_timeout) {
1208 			ret = wait_for_completion_timeout(
1209 				&req->r_safe_completion, req->r_timeout);
1210 			if (ret > 0)
1211 				ret = 0;
1212 			else if (ret == 0)
1213 				ret = -EIO;  /* timed out */
1214 		} else {
1215 			wait_for_completion(&req->r_safe_completion);
1216 		}
1217 		ceph_mdsc_put_request(req);
1218 
1219 		spin_lock(&ci->i_unsafe_lock);
1220 		if (ret || list_empty(head))
1221 			break;
1222 		req = list_entry(head->next,
1223 				 struct ceph_mds_request, r_unsafe_dir_item);
1224 	} while (req->r_tid < last_tid);
1225 out:
1226 	spin_unlock(&ci->i_unsafe_lock);
1227 	mutex_unlock(&inode->i_mutex);
1228 
1229 	return ret;
1230 }
1231 
1232 /*
1233  * We maintain a private dentry LRU.
1234  *
1235  * FIXME: this needs to be changed to a per-mds lru to be useful.
1236  */
1237 void ceph_dentry_lru_add(struct dentry *dn)
1238 {
1239 	struct ceph_dentry_info *di = ceph_dentry(dn);
1240 	struct ceph_mds_client *mdsc;
1241 
1242 	dout("dentry_lru_add %p %p '%.*s'\n", di, dn,
1243 	     dn->d_name.len, dn->d_name.name);
1244 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1245 	spin_lock(&mdsc->dentry_lru_lock);
1246 	list_add_tail(&di->lru, &mdsc->dentry_lru);
1247 	mdsc->num_dentry++;
1248 	spin_unlock(&mdsc->dentry_lru_lock);
1249 }
1250 
1251 void ceph_dentry_lru_touch(struct dentry *dn)
1252 {
1253 	struct ceph_dentry_info *di = ceph_dentry(dn);
1254 	struct ceph_mds_client *mdsc;
1255 
1256 	dout("dentry_lru_touch %p %p '%.*s' (offset %lld)\n", di, dn,
1257 	     dn->d_name.len, dn->d_name.name, di->offset);
1258 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1259 	spin_lock(&mdsc->dentry_lru_lock);
1260 	list_move_tail(&di->lru, &mdsc->dentry_lru);
1261 	spin_unlock(&mdsc->dentry_lru_lock);
1262 }
1263 
1264 void ceph_dentry_lru_del(struct dentry *dn)
1265 {
1266 	struct ceph_dentry_info *di = ceph_dentry(dn);
1267 	struct ceph_mds_client *mdsc;
1268 
1269 	dout("dentry_lru_del %p %p '%.*s'\n", di, dn,
1270 	     dn->d_name.len, dn->d_name.name);
1271 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1272 	spin_lock(&mdsc->dentry_lru_lock);
1273 	list_del_init(&di->lru);
1274 	mdsc->num_dentry--;
1275 	spin_unlock(&mdsc->dentry_lru_lock);
1276 }
1277 
1278 /*
1279  * Return name hash for a given dentry.  This is dependent on
1280  * the parent directory's hash function.
1281  */
1282 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1283 {
1284 	struct ceph_inode_info *dci = ceph_inode(dir);
1285 
1286 	switch (dci->i_dir_layout.dl_dir_hash) {
1287 	case 0:	/* for backward compat */
1288 	case CEPH_STR_HASH_LINUX:
1289 		return dn->d_name.hash;
1290 
1291 	default:
1292 		return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1293 				     dn->d_name.name, dn->d_name.len);
1294 	}
1295 }
1296 
1297 const struct file_operations ceph_dir_fops = {
1298 	.read = ceph_read_dir,
1299 	.iterate = ceph_readdir,
1300 	.llseek = ceph_dir_llseek,
1301 	.open = ceph_open,
1302 	.release = ceph_release,
1303 	.unlocked_ioctl = ceph_ioctl,
1304 	.fsync = ceph_dir_fsync,
1305 };
1306 
1307 const struct inode_operations ceph_dir_iops = {
1308 	.lookup = ceph_lookup,
1309 	.permission = ceph_permission,
1310 	.getattr = ceph_getattr,
1311 	.setattr = ceph_setattr,
1312 	.setxattr = ceph_setxattr,
1313 	.getxattr = ceph_getxattr,
1314 	.listxattr = ceph_listxattr,
1315 	.removexattr = ceph_removexattr,
1316 	.get_acl = ceph_get_acl,
1317 	.set_acl = ceph_set_acl,
1318 	.mknod = ceph_mknod,
1319 	.symlink = ceph_symlink,
1320 	.mkdir = ceph_mkdir,
1321 	.link = ceph_link,
1322 	.unlink = ceph_unlink,
1323 	.rmdir = ceph_unlink,
1324 	.rename = ceph_rename,
1325 	.create = ceph_create,
1326 	.atomic_open = ceph_atomic_open,
1327 };
1328 
1329 const struct dentry_operations ceph_dentry_ops = {
1330 	.d_revalidate = ceph_d_revalidate,
1331 	.d_release = ceph_d_release,
1332 	.d_prune = ceph_d_prune,
1333 };
1334 
1335 const struct dentry_operations ceph_snapdir_dentry_ops = {
1336 	.d_revalidate = ceph_snapdir_d_revalidate,
1337 	.d_release = ceph_d_release,
1338 };
1339 
1340 const struct dentry_operations ceph_snap_dentry_ops = {
1341 	.d_release = ceph_d_release,
1342 	.d_prune = ceph_d_prune,
1343 };
1344