xref: /openbmc/linux/fs/ceph/dir.c (revision e2c3de04)
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 dentry_operations ceph_dentry_ops;
30 
31 /*
32  * Initialize ceph dentry state.
33  */
34 int ceph_init_dentry(struct dentry *dentry)
35 {
36 	struct ceph_dentry_info *di;
37 
38 	if (dentry->d_fsdata)
39 		return 0;
40 
41 	di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO);
42 	if (!di)
43 		return -ENOMEM;          /* oh well */
44 
45 	spin_lock(&dentry->d_lock);
46 	if (dentry->d_fsdata) {
47 		/* lost a race */
48 		kmem_cache_free(ceph_dentry_cachep, di);
49 		goto out_unlock;
50 	}
51 
52 	if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
53 		d_set_d_op(dentry, &ceph_dentry_ops);
54 	else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
55 		d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
56 	else
57 		d_set_d_op(dentry, &ceph_snap_dentry_ops);
58 
59 	di->dentry = dentry;
60 	di->lease_session = NULL;
61 	dentry->d_time = jiffies;
62 	/* avoid reordering d_fsdata setup so that the check above is safe */
63 	smp_mb();
64 	dentry->d_fsdata = di;
65 	ceph_dentry_lru_add(dentry);
66 out_unlock:
67 	spin_unlock(&dentry->d_lock);
68 	return 0;
69 }
70 
71 struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry)
72 {
73 	struct inode *inode = NULL;
74 
75 	if (!dentry)
76 		return NULL;
77 
78 	spin_lock(&dentry->d_lock);
79 	if (!IS_ROOT(dentry)) {
80 		inode = dentry->d_parent->d_inode;
81 		ihold(inode);
82 	}
83 	spin_unlock(&dentry->d_lock);
84 	return inode;
85 }
86 
87 
88 /*
89  * for readdir, we encode the directory frag and offset within that
90  * frag into f_pos.
91  */
92 static unsigned fpos_frag(loff_t p)
93 {
94 	return p >> 32;
95 }
96 static unsigned fpos_off(loff_t p)
97 {
98 	return p & 0xffffffff;
99 }
100 
101 static int fpos_cmp(loff_t l, loff_t r)
102 {
103 	int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
104 	if (v)
105 		return v;
106 	return (int)(fpos_off(l) - fpos_off(r));
107 }
108 
109 /*
110  * When possible, we try to satisfy a readdir by peeking at the
111  * dcache.  We make this work by carefully ordering dentries on
112  * d_child when we initially get results back from the MDS, and
113  * falling back to a "normal" sync readdir if any dentries in the dir
114  * are dropped.
115  *
116  * Complete dir indicates that we have all dentries in the dir.  It is
117  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
118  * the MDS if/when the directory is modified).
119  */
120 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
121 			    u32 shared_gen)
122 {
123 	struct ceph_file_info *fi = file->private_data;
124 	struct dentry *parent = file->f_path.dentry;
125 	struct inode *dir = parent->d_inode;
126 	struct list_head *p;
127 	struct dentry *dentry, *last;
128 	struct ceph_dentry_info *di;
129 	int err = 0;
130 
131 	/* claim ref on last dentry we returned */
132 	last = fi->dentry;
133 	fi->dentry = NULL;
134 
135 	dout("__dcache_readdir %p v%u at %llu (last %p)\n",
136 	     dir, shared_gen, ctx->pos, last);
137 
138 	spin_lock(&parent->d_lock);
139 
140 	/* start at beginning? */
141 	if (ctx->pos == 2 || last == NULL ||
142 	    fpos_cmp(ctx->pos, ceph_dentry(last)->offset) < 0) {
143 		if (list_empty(&parent->d_subdirs))
144 			goto out_unlock;
145 		p = parent->d_subdirs.prev;
146 		dout(" initial p %p/%p\n", p->prev, p->next);
147 	} else {
148 		p = last->d_child.prev;
149 	}
150 
151 more:
152 	dentry = list_entry(p, struct dentry, d_child);
153 	di = ceph_dentry(dentry);
154 	while (1) {
155 		dout(" p %p/%p %s d_subdirs %p/%p\n", p->prev, p->next,
156 		     d_unhashed(dentry) ? "!hashed" : "hashed",
157 		     parent->d_subdirs.prev, parent->d_subdirs.next);
158 		if (p == &parent->d_subdirs) {
159 			fi->flags |= CEPH_F_ATEND;
160 			goto out_unlock;
161 		}
162 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
163 		if (di->lease_shared_gen == shared_gen &&
164 		    !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 %pd at %llu (%llu)%s%s\n", dentry,
170 		     dentry, 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_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 	/* make sure a dentry wasn't dropped while we didn't have parent lock */
184 	if (!ceph_dir_is_complete_ordered(dir)) {
185 		dout(" lost dir complete on %p; falling back to mds\n", dir);
186 		dput(dentry);
187 		err = -EAGAIN;
188 		goto out;
189 	}
190 
191 	dout(" %llu (%llu) dentry %p %pd %p\n", di->offset, ctx->pos,
192 	     dentry, dentry, dentry->d_inode);
193 	if (!dir_emit(ctx, dentry->d_name.name,
194 		      dentry->d_name.len,
195 		      ceph_translate_ino(dentry->d_sb, dentry->d_inode->i_ino),
196 		      dentry->d_inode->i_mode >> 12)) {
197 		if (last) {
198 			/* remember our position */
199 			fi->dentry = last;
200 			fi->next_offset = fpos_off(di->offset);
201 		}
202 		dput(dentry);
203 		return 0;
204 	}
205 
206 	ctx->pos = di->offset + 1;
207 
208 	if (last)
209 		dput(last);
210 	last = dentry;
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 
256 	dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
257 	if (fi->flags & CEPH_F_ATEND)
258 		return 0;
259 
260 	/* always start with . and .. */
261 	if (ctx->pos == 0) {
262 		dout("readdir off 0 -> '.'\n");
263 		if (!dir_emit(ctx, ".", 1,
264 			    ceph_translate_ino(inode->i_sb, inode->i_ino),
265 			    inode->i_mode >> 12))
266 			return 0;
267 		ctx->pos = 1;
268 		off = 1;
269 	}
270 	if (ctx->pos == 1) {
271 		ino_t ino = parent_ino(file->f_path.dentry);
272 		dout("readdir off 1 -> '..'\n");
273 		if (!dir_emit(ctx, "..", 2,
274 			    ceph_translate_ino(inode->i_sb, ino),
275 			    inode->i_mode >> 12))
276 			return 0;
277 		ctx->pos = 2;
278 		off = 2;
279 	}
280 
281 	/* can we use the dcache? */
282 	spin_lock(&ci->i_ceph_lock);
283 	if ((ctx->pos == 2 || fi->dentry) &&
284 	    ceph_test_mount_opt(fsc, DCACHE) &&
285 	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
286 	    ceph_snap(inode) != CEPH_SNAPDIR &&
287 	    __ceph_dir_is_complete_ordered(ci) &&
288 	    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
289 		u32 shared_gen = ci->i_shared_gen;
290 		spin_unlock(&ci->i_ceph_lock);
291 		err = __dcache_readdir(file, ctx, shared_gen);
292 		if (err != -EAGAIN)
293 			return err;
294 		frag = fpos_frag(ctx->pos);
295 		off = fpos_off(ctx->pos);
296 	} else {
297 		spin_unlock(&ci->i_ceph_lock);
298 	}
299 	if (fi->dentry) {
300 		err = note_last_dentry(fi, fi->dentry->d_name.name,
301 				       fi->dentry->d_name.len);
302 		if (err)
303 			return err;
304 		dput(fi->dentry);
305 		fi->dentry = NULL;
306 	}
307 
308 	/* proceed with a normal readdir */
309 
310 	if (ctx->pos == 2) {
311 		/* note dir version at start of readdir so we can tell
312 		 * if any dentries get dropped */
313 		fi->dir_release_count = atomic_read(&ci->i_release_count);
314 		fi->dir_ordered_count = ci->i_ordered_count;
315 	}
316 
317 more:
318 	/* do we have the correct frag content buffered? */
319 	if (fi->frag != frag || fi->last_readdir == NULL) {
320 		struct ceph_mds_request *req;
321 		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
322 			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
323 
324 		/* discard old result, if any */
325 		if (fi->last_readdir) {
326 			ceph_mdsc_put_request(fi->last_readdir);
327 			fi->last_readdir = NULL;
328 		}
329 
330 		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
331 		     ceph_vinop(inode), frag, fi->last_name);
332 		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
333 		if (IS_ERR(req))
334 			return PTR_ERR(req);
335 		err = ceph_alloc_readdir_reply_buffer(req, inode);
336 		if (err) {
337 			ceph_mdsc_put_request(req);
338 			return err;
339 		}
340 		req->r_inode = inode;
341 		ihold(inode);
342 		req->r_dentry = dget(file->f_path.dentry);
343 		/* hints to request -> mds selection code */
344 		req->r_direct_mode = USE_AUTH_MDS;
345 		req->r_direct_hash = ceph_frag_value(frag);
346 		req->r_direct_is_hash = true;
347 		req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
348 		req->r_readdir_offset = fi->next_offset;
349 		req->r_args.readdir.frag = cpu_to_le32(frag);
350 		err = ceph_mdsc_do_request(mdsc, NULL, req);
351 		if (err < 0) {
352 			ceph_mdsc_put_request(req);
353 			return err;
354 		}
355 		dout("readdir got and parsed readdir result=%d"
356 		     " on frag %x, end=%d, complete=%d\n", err, frag,
357 		     (int)req->r_reply_info.dir_end,
358 		     (int)req->r_reply_info.dir_complete);
359 
360 		if (!req->r_did_prepopulate) {
361 			dout("readdir !did_prepopulate");
362 			/* preclude from marking dir complete */
363 			fi->dir_release_count--;
364 		}
365 
366 		/* note next offset and last dentry name */
367 		rinfo = &req->r_reply_info;
368 		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
369 			frag = le32_to_cpu(rinfo->dir_dir->frag);
370 			if (ceph_frag_is_leftmost(frag))
371 				fi->next_offset = 2;
372 			else
373 				fi->next_offset = 0;
374 			off = fi->next_offset;
375 		}
376 		fi->frag = frag;
377 		fi->offset = fi->next_offset;
378 		fi->last_readdir = req;
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 			if (err)
392 				return err;
393 			fi->next_offset += rinfo->dir_nr;
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 	spin_lock(&ci->i_ceph_lock);
450 	if (atomic_read(&ci->i_release_count) == fi->dir_release_count) {
451 		if (ci->i_ordered_count == fi->dir_ordered_count)
452 			dout(" marking %p complete and ordered\n", inode);
453 		else
454 			dout(" marking %p complete\n", inode);
455 		__ceph_dir_set_complete(ci, fi->dir_release_count,
456 					fi->dir_ordered_count);
457 	}
458 	spin_unlock(&ci->i_ceph_lock);
459 
460 	dout("readdir %p file %p done.\n", inode, file);
461 	return 0;
462 }
463 
464 static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
465 {
466 	if (fi->last_readdir) {
467 		ceph_mdsc_put_request(fi->last_readdir);
468 		fi->last_readdir = NULL;
469 	}
470 	kfree(fi->last_name);
471 	fi->last_name = NULL;
472 	if (ceph_frag_is_leftmost(frag))
473 		fi->next_offset = 2;  /* compensate for . and .. */
474 	else
475 		fi->next_offset = 0;
476 	if (fi->dentry) {
477 		dput(fi->dentry);
478 		fi->dentry = NULL;
479 	}
480 	fi->flags &= ~CEPH_F_ATEND;
481 }
482 
483 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
484 {
485 	struct ceph_file_info *fi = file->private_data;
486 	struct inode *inode = file->f_mapping->host;
487 	loff_t old_offset = ceph_make_fpos(fi->frag, fi->next_offset);
488 	loff_t retval;
489 
490 	mutex_lock(&inode->i_mutex);
491 	retval = -EINVAL;
492 	switch (whence) {
493 	case SEEK_END:
494 		offset += inode->i_size + 2;   /* FIXME */
495 		break;
496 	case SEEK_CUR:
497 		offset += file->f_pos;
498 	case SEEK_SET:
499 		break;
500 	default:
501 		goto out;
502 	}
503 
504 	if (offset >= 0) {
505 		if (offset != file->f_pos) {
506 			file->f_pos = offset;
507 			file->f_version = 0;
508 			fi->flags &= ~CEPH_F_ATEND;
509 		}
510 		retval = offset;
511 
512 		/*
513 		 * discard buffered readdir content on seekdir(0), or
514 		 * seek to new frag, or seek prior to current chunk.
515 		 */
516 		if (offset == 0 ||
517 		    fpos_frag(offset) != fi->frag ||
518 		    fpos_off(offset) < fi->offset) {
519 			dout("dir_llseek dropping %p content\n", file);
520 			reset_readdir(fi, fpos_frag(offset));
521 		}
522 
523 		/* bump dir_release_count if we did a forward seek */
524 		if (fpos_cmp(offset, old_offset) > 0)
525 			fi->dir_release_count--;
526 	}
527 out:
528 	mutex_unlock(&inode->i_mutex);
529 	return retval;
530 }
531 
532 /*
533  * Handle lookups for the hidden .snap directory.
534  */
535 int ceph_handle_snapdir(struct ceph_mds_request *req,
536 			struct dentry *dentry, int err)
537 {
538 	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
539 	struct inode *parent = dentry->d_parent->d_inode; /* we hold i_mutex */
540 
541 	/* .snap dir? */
542 	if (err == -ENOENT &&
543 	    ceph_snap(parent) == CEPH_NOSNAP &&
544 	    strcmp(dentry->d_name.name,
545 		   fsc->mount_options->snapdir_name) == 0) {
546 		struct inode *inode = ceph_get_snapdir(parent);
547 		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
548 		     dentry, dentry, inode);
549 		BUG_ON(!d_unhashed(dentry));
550 		d_add(dentry, inode);
551 		err = 0;
552 	}
553 	return err;
554 }
555 
556 /*
557  * Figure out final result of a lookup/open request.
558  *
559  * Mainly, make sure we return the final req->r_dentry (if it already
560  * existed) in place of the original VFS-provided dentry when they
561  * differ.
562  *
563  * Gracefully handle the case where the MDS replies with -ENOENT and
564  * no trace (which it may do, at its discretion, e.g., if it doesn't
565  * care to issue a lease on the negative dentry).
566  */
567 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
568 				  struct dentry *dentry, int err)
569 {
570 	if (err == -ENOENT) {
571 		/* no trace? */
572 		err = 0;
573 		if (!req->r_reply_info.head->is_dentry) {
574 			dout("ENOENT and no trace, dentry %p inode %p\n",
575 			     dentry, dentry->d_inode);
576 			if (dentry->d_inode) {
577 				d_drop(dentry);
578 				err = -ENOENT;
579 			} else {
580 				d_add(dentry, NULL);
581 			}
582 		}
583 	}
584 	if (err)
585 		dentry = ERR_PTR(err);
586 	else if (dentry != req->r_dentry)
587 		dentry = dget(req->r_dentry);   /* we got spliced */
588 	else
589 		dentry = NULL;
590 	return dentry;
591 }
592 
593 static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
594 {
595 	return ceph_ino(inode) == CEPH_INO_ROOT &&
596 		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
597 }
598 
599 /*
600  * Look up a single dir entry.  If there is a lookup intent, inform
601  * the MDS so that it gets our 'caps wanted' value in a single op.
602  */
603 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
604 				  unsigned int flags)
605 {
606 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
607 	struct ceph_mds_client *mdsc = fsc->mdsc;
608 	struct ceph_mds_request *req;
609 	int op;
610 	int err;
611 
612 	dout("lookup %p dentry %p '%pd'\n",
613 	     dir, dentry, dentry);
614 
615 	if (dentry->d_name.len > NAME_MAX)
616 		return ERR_PTR(-ENAMETOOLONG);
617 
618 	err = ceph_init_dentry(dentry);
619 	if (err < 0)
620 		return ERR_PTR(err);
621 
622 	/* can we conclude ENOENT locally? */
623 	if (dentry->d_inode == NULL) {
624 		struct ceph_inode_info *ci = ceph_inode(dir);
625 		struct ceph_dentry_info *di = ceph_dentry(dentry);
626 
627 		spin_lock(&ci->i_ceph_lock);
628 		dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
629 		if (strncmp(dentry->d_name.name,
630 			    fsc->mount_options->snapdir_name,
631 			    dentry->d_name.len) &&
632 		    !is_root_ceph_dentry(dir, dentry) &&
633 		    ceph_test_mount_opt(fsc, DCACHE) &&
634 		    __ceph_dir_is_complete(ci) &&
635 		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
636 			spin_unlock(&ci->i_ceph_lock);
637 			dout(" dir %p complete, -ENOENT\n", dir);
638 			d_add(dentry, NULL);
639 			di->lease_shared_gen = ci->i_shared_gen;
640 			return NULL;
641 		}
642 		spin_unlock(&ci->i_ceph_lock);
643 	}
644 
645 	op = ceph_snap(dir) == CEPH_SNAPDIR ?
646 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
647 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
648 	if (IS_ERR(req))
649 		return ERR_CAST(req);
650 	req->r_dentry = dget(dentry);
651 	req->r_num_caps = 2;
652 	/* we only need inode linkage */
653 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
654 	req->r_locked_dir = dir;
655 	err = ceph_mdsc_do_request(mdsc, NULL, req);
656 	err = ceph_handle_snapdir(req, dentry, err);
657 	dentry = ceph_finish_lookup(req, dentry, err);
658 	ceph_mdsc_put_request(req);  /* will dput(dentry) */
659 	dout("lookup result=%p\n", dentry);
660 	return dentry;
661 }
662 
663 /*
664  * If we do a create but get no trace back from the MDS, follow up with
665  * a lookup (the VFS expects us to link up the provided dentry).
666  */
667 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
668 {
669 	struct dentry *result = ceph_lookup(dir, dentry, 0);
670 
671 	if (result && !IS_ERR(result)) {
672 		/*
673 		 * We created the item, then did a lookup, and found
674 		 * it was already linked to another inode we already
675 		 * had in our cache (and thus got spliced). To not
676 		 * confuse VFS (especially when inode is a directory),
677 		 * we don't link our dentry to that inode, return an
678 		 * error instead.
679 		 *
680 		 * This event should be rare and it happens only when
681 		 * we talk to old MDS. Recent MDS does not send traceless
682 		 * reply for request that creates new inode.
683 		 */
684 		d_drop(result);
685 		return -ESTALE;
686 	}
687 	return PTR_ERR(result);
688 }
689 
690 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
691 		      umode_t mode, dev_t rdev)
692 {
693 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
694 	struct ceph_mds_client *mdsc = fsc->mdsc;
695 	struct ceph_mds_request *req;
696 	struct ceph_acls_info acls = {};
697 	int err;
698 
699 	if (ceph_snap(dir) != CEPH_NOSNAP)
700 		return -EROFS;
701 
702 	err = ceph_pre_init_acls(dir, &mode, &acls);
703 	if (err < 0)
704 		return err;
705 
706 	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
707 	     dir, dentry, mode, rdev);
708 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
709 	if (IS_ERR(req)) {
710 		err = PTR_ERR(req);
711 		goto out;
712 	}
713 	req->r_dentry = dget(dentry);
714 	req->r_num_caps = 2;
715 	req->r_locked_dir = dir;
716 	req->r_args.mknod.mode = cpu_to_le32(mode);
717 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
718 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
719 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
720 	if (acls.pagelist) {
721 		req->r_pagelist = acls.pagelist;
722 		acls.pagelist = NULL;
723 	}
724 	err = ceph_mdsc_do_request(mdsc, dir, req);
725 	if (!err && !req->r_reply_info.head->is_dentry)
726 		err = ceph_handle_notrace_create(dir, dentry);
727 	ceph_mdsc_put_request(req);
728 out:
729 	if (!err)
730 		ceph_init_inode_acls(dentry->d_inode, &acls);
731 	else
732 		d_drop(dentry);
733 	ceph_release_acls_info(&acls);
734 	return err;
735 }
736 
737 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
738 		       bool excl)
739 {
740 	return ceph_mknod(dir, dentry, mode, 0);
741 }
742 
743 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
744 			    const char *dest)
745 {
746 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
747 	struct ceph_mds_client *mdsc = fsc->mdsc;
748 	struct ceph_mds_request *req;
749 	int err;
750 
751 	if (ceph_snap(dir) != CEPH_NOSNAP)
752 		return -EROFS;
753 
754 	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
755 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
756 	if (IS_ERR(req)) {
757 		err = PTR_ERR(req);
758 		goto out;
759 	}
760 	req->r_dentry = dget(dentry);
761 	req->r_num_caps = 2;
762 	req->r_path2 = kstrdup(dest, GFP_NOFS);
763 	req->r_locked_dir = dir;
764 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
765 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
766 	err = ceph_mdsc_do_request(mdsc, dir, req);
767 	if (!err && !req->r_reply_info.head->is_dentry)
768 		err = ceph_handle_notrace_create(dir, dentry);
769 	ceph_mdsc_put_request(req);
770 out:
771 	if (err)
772 		d_drop(dentry);
773 	return err;
774 }
775 
776 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
777 {
778 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
779 	struct ceph_mds_client *mdsc = fsc->mdsc;
780 	struct ceph_mds_request *req;
781 	struct ceph_acls_info acls = {};
782 	int err = -EROFS;
783 	int op;
784 
785 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
786 		/* mkdir .snap/foo is a MKSNAP */
787 		op = CEPH_MDS_OP_MKSNAP;
788 		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
789 		     dentry, dentry);
790 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
791 		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
792 		op = CEPH_MDS_OP_MKDIR;
793 	} else {
794 		goto out;
795 	}
796 
797 	mode |= S_IFDIR;
798 	err = ceph_pre_init_acls(dir, &mode, &acls);
799 	if (err < 0)
800 		goto out;
801 
802 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
803 	if (IS_ERR(req)) {
804 		err = PTR_ERR(req);
805 		goto out;
806 	}
807 
808 	req->r_dentry = dget(dentry);
809 	req->r_num_caps = 2;
810 	req->r_locked_dir = dir;
811 	req->r_args.mkdir.mode = cpu_to_le32(mode);
812 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
813 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
814 	if (acls.pagelist) {
815 		req->r_pagelist = acls.pagelist;
816 		acls.pagelist = NULL;
817 	}
818 	err = ceph_mdsc_do_request(mdsc, dir, req);
819 	if (!err &&
820 	    !req->r_reply_info.head->is_target &&
821 	    !req->r_reply_info.head->is_dentry)
822 		err = ceph_handle_notrace_create(dir, dentry);
823 	ceph_mdsc_put_request(req);
824 out:
825 	if (!err)
826 		ceph_init_inode_acls(dentry->d_inode, &acls);
827 	else
828 		d_drop(dentry);
829 	ceph_release_acls_info(&acls);
830 	return err;
831 }
832 
833 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
834 		     struct dentry *dentry)
835 {
836 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
837 	struct ceph_mds_client *mdsc = fsc->mdsc;
838 	struct ceph_mds_request *req;
839 	int err;
840 
841 	if (ceph_snap(dir) != CEPH_NOSNAP)
842 		return -EROFS;
843 
844 	dout("link in dir %p old_dentry %p dentry %p\n", dir,
845 	     old_dentry, dentry);
846 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
847 	if (IS_ERR(req)) {
848 		d_drop(dentry);
849 		return PTR_ERR(req);
850 	}
851 	req->r_dentry = dget(dentry);
852 	req->r_num_caps = 2;
853 	req->r_old_dentry = dget(old_dentry);
854 	req->r_locked_dir = dir;
855 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
856 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
857 	/* release LINK_SHARED on source inode (mds will lock it) */
858 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
859 	err = ceph_mdsc_do_request(mdsc, dir, req);
860 	if (err) {
861 		d_drop(dentry);
862 	} else if (!req->r_reply_info.head->is_dentry) {
863 		ihold(old_dentry->d_inode);
864 		d_instantiate(dentry, old_dentry->d_inode);
865 	}
866 	ceph_mdsc_put_request(req);
867 	return err;
868 }
869 
870 /*
871  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
872  * looks like the link count will hit 0, drop any other caps (other
873  * than PIN) we don't specifically want (due to the file still being
874  * open).
875  */
876 static int drop_caps_for_unlink(struct inode *inode)
877 {
878 	struct ceph_inode_info *ci = ceph_inode(inode);
879 	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
880 
881 	spin_lock(&ci->i_ceph_lock);
882 	if (inode->i_nlink == 1) {
883 		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
884 		ci->i_ceph_flags |= CEPH_I_NODELAY;
885 	}
886 	spin_unlock(&ci->i_ceph_lock);
887 	return drop;
888 }
889 
890 /*
891  * rmdir and unlink are differ only by the metadata op code
892  */
893 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
894 {
895 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
896 	struct ceph_mds_client *mdsc = fsc->mdsc;
897 	struct inode *inode = dentry->d_inode;
898 	struct ceph_mds_request *req;
899 	int err = -EROFS;
900 	int op;
901 
902 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
903 		/* rmdir .snap/foo is RMSNAP */
904 		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
905 		op = CEPH_MDS_OP_RMSNAP;
906 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
907 		dout("unlink/rmdir dir %p dn %p inode %p\n",
908 		     dir, dentry, inode);
909 		op = d_is_dir(dentry) ?
910 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
911 	} else
912 		goto out;
913 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
914 	if (IS_ERR(req)) {
915 		err = PTR_ERR(req);
916 		goto out;
917 	}
918 	req->r_dentry = dget(dentry);
919 	req->r_num_caps = 2;
920 	req->r_locked_dir = dir;
921 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
922 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
923 	req->r_inode_drop = drop_caps_for_unlink(inode);
924 	err = ceph_mdsc_do_request(mdsc, dir, req);
925 	if (!err && !req->r_reply_info.head->is_dentry)
926 		d_delete(dentry);
927 	ceph_mdsc_put_request(req);
928 out:
929 	return err;
930 }
931 
932 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
933 		       struct inode *new_dir, struct dentry *new_dentry)
934 {
935 	struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
936 	struct ceph_mds_client *mdsc = fsc->mdsc;
937 	struct ceph_mds_request *req;
938 	int err;
939 
940 	if (ceph_snap(old_dir) != ceph_snap(new_dir))
941 		return -EXDEV;
942 	if (ceph_snap(old_dir) != CEPH_NOSNAP ||
943 	    ceph_snap(new_dir) != CEPH_NOSNAP)
944 		return -EROFS;
945 	dout("rename dir %p dentry %p to dir %p dentry %p\n",
946 	     old_dir, old_dentry, new_dir, new_dentry);
947 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_RENAME, USE_AUTH_MDS);
948 	if (IS_ERR(req))
949 		return PTR_ERR(req);
950 	ihold(old_dir);
951 	req->r_dentry = dget(new_dentry);
952 	req->r_num_caps = 2;
953 	req->r_old_dentry = dget(old_dentry);
954 	req->r_old_dentry_dir = old_dir;
955 	req->r_locked_dir = new_dir;
956 	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
957 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
958 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
959 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
960 	/* release LINK_RDCACHE on source inode (mds will lock it) */
961 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
962 	if (new_dentry->d_inode)
963 		req->r_inode_drop = drop_caps_for_unlink(new_dentry->d_inode);
964 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
965 	if (!err && !req->r_reply_info.head->is_dentry) {
966 		/*
967 		 * Normally d_move() is done by fill_trace (called by
968 		 * do_request, above).  If there is no trace, we need
969 		 * to do it here.
970 		 */
971 
972 		d_move(old_dentry, new_dentry);
973 
974 		/* ensure target dentry is invalidated, despite
975 		   rehashing bug in vfs_rename_dir */
976 		ceph_invalidate_dentry_lease(new_dentry);
977 
978 		/* d_move screws up sibling dentries' offsets */
979 		ceph_dir_clear_complete(old_dir);
980 		ceph_dir_clear_complete(new_dir);
981 
982 	}
983 	ceph_mdsc_put_request(req);
984 	return err;
985 }
986 
987 /*
988  * Ensure a dentry lease will no longer revalidate.
989  */
990 void ceph_invalidate_dentry_lease(struct dentry *dentry)
991 {
992 	spin_lock(&dentry->d_lock);
993 	dentry->d_time = jiffies;
994 	ceph_dentry(dentry)->lease_shared_gen = 0;
995 	spin_unlock(&dentry->d_lock);
996 }
997 
998 /*
999  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1000  * renew if the least is more than half up.
1001  */
1002 static int dentry_lease_is_valid(struct dentry *dentry)
1003 {
1004 	struct ceph_dentry_info *di;
1005 	struct ceph_mds_session *s;
1006 	int valid = 0;
1007 	u32 gen;
1008 	unsigned long ttl;
1009 	struct ceph_mds_session *session = NULL;
1010 	struct inode *dir = NULL;
1011 	u32 seq = 0;
1012 
1013 	spin_lock(&dentry->d_lock);
1014 	di = ceph_dentry(dentry);
1015 	if (di->lease_session) {
1016 		s = di->lease_session;
1017 		spin_lock(&s->s_gen_ttl_lock);
1018 		gen = s->s_cap_gen;
1019 		ttl = s->s_cap_ttl;
1020 		spin_unlock(&s->s_gen_ttl_lock);
1021 
1022 		if (di->lease_gen == gen &&
1023 		    time_before(jiffies, dentry->d_time) &&
1024 		    time_before(jiffies, ttl)) {
1025 			valid = 1;
1026 			if (di->lease_renew_after &&
1027 			    time_after(jiffies, di->lease_renew_after)) {
1028 				/* we should renew */
1029 				dir = dentry->d_parent->d_inode;
1030 				session = ceph_get_mds_session(s);
1031 				seq = di->lease_seq;
1032 				di->lease_renew_after = 0;
1033 				di->lease_renew_from = jiffies;
1034 			}
1035 		}
1036 	}
1037 	spin_unlock(&dentry->d_lock);
1038 
1039 	if (session) {
1040 		ceph_mdsc_lease_send_msg(session, dir, dentry,
1041 					 CEPH_MDS_LEASE_RENEW, seq);
1042 		ceph_put_mds_session(session);
1043 	}
1044 	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1045 	return valid;
1046 }
1047 
1048 /*
1049  * Check if directory-wide content lease/cap is valid.
1050  */
1051 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1052 {
1053 	struct ceph_inode_info *ci = ceph_inode(dir);
1054 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1055 	int valid = 0;
1056 
1057 	spin_lock(&ci->i_ceph_lock);
1058 	if (ci->i_shared_gen == di->lease_shared_gen)
1059 		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1060 	spin_unlock(&ci->i_ceph_lock);
1061 	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1062 	     dir, (unsigned)ci->i_shared_gen, dentry,
1063 	     (unsigned)di->lease_shared_gen, valid);
1064 	return valid;
1065 }
1066 
1067 /*
1068  * Check if cached dentry can be trusted.
1069  */
1070 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1071 {
1072 	int valid = 0;
1073 	struct inode *dir;
1074 
1075 	if (flags & LOOKUP_RCU)
1076 		return -ECHILD;
1077 
1078 	dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1079 	     dentry, dentry->d_inode, ceph_dentry(dentry)->offset);
1080 
1081 	dir = ceph_get_dentry_parent_inode(dentry);
1082 
1083 	/* always trust cached snapped dentries, snapdir dentry */
1084 	if (ceph_snap(dir) != CEPH_NOSNAP) {
1085 		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1086 		     dentry, dentry->d_inode);
1087 		valid = 1;
1088 	} else if (dentry->d_inode &&
1089 		   ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) {
1090 		valid = 1;
1091 	} else if (dentry_lease_is_valid(dentry) ||
1092 		   dir_lease_is_valid(dir, dentry)) {
1093 		if (dentry->d_inode)
1094 			valid = ceph_is_any_caps(dentry->d_inode);
1095 		else
1096 			valid = 1;
1097 	}
1098 
1099 	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1100 	if (valid) {
1101 		ceph_dentry_lru_touch(dentry);
1102 	} else {
1103 		ceph_dir_clear_complete(dir);
1104 	}
1105 	iput(dir);
1106 	return valid;
1107 }
1108 
1109 /*
1110  * Release our ceph_dentry_info.
1111  */
1112 static void ceph_d_release(struct dentry *dentry)
1113 {
1114 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1115 
1116 	dout("d_release %p\n", dentry);
1117 	ceph_dentry_lru_del(dentry);
1118 	if (di->lease_session)
1119 		ceph_put_mds_session(di->lease_session);
1120 	kmem_cache_free(ceph_dentry_cachep, di);
1121 	dentry->d_fsdata = NULL;
1122 }
1123 
1124 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1125 					  unsigned int flags)
1126 {
1127 	/*
1128 	 * Eventually, we'll want to revalidate snapped metadata
1129 	 * too... probably...
1130 	 */
1131 	return 1;
1132 }
1133 
1134 /*
1135  * When the VFS prunes a dentry from the cache, we need to clear the
1136  * complete flag on the parent directory.
1137  *
1138  * Called under dentry->d_lock.
1139  */
1140 static void ceph_d_prune(struct dentry *dentry)
1141 {
1142 	dout("ceph_d_prune %p\n", dentry);
1143 
1144 	/* do we have a valid parent? */
1145 	if (IS_ROOT(dentry))
1146 		return;
1147 
1148 	/* if we are not hashed, we don't affect dir's completeness */
1149 	if (d_unhashed(dentry))
1150 		return;
1151 
1152 	/*
1153 	 * we hold d_lock, so d_parent is stable, and d_fsdata is never
1154 	 * cleared until d_release
1155 	 */
1156 	ceph_dir_clear_complete(dentry->d_parent->d_inode);
1157 }
1158 
1159 /*
1160  * read() on a dir.  This weird interface hack only works if mounted
1161  * with '-o dirstat'.
1162  */
1163 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1164 			     loff_t *ppos)
1165 {
1166 	struct ceph_file_info *cf = file->private_data;
1167 	struct inode *inode = file_inode(file);
1168 	struct ceph_inode_info *ci = ceph_inode(inode);
1169 	int left;
1170 	const int bufsize = 1024;
1171 
1172 	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1173 		return -EISDIR;
1174 
1175 	if (!cf->dir_info) {
1176 		cf->dir_info = kmalloc(bufsize, GFP_NOFS);
1177 		if (!cf->dir_info)
1178 			return -ENOMEM;
1179 		cf->dir_info_len =
1180 			snprintf(cf->dir_info, bufsize,
1181 				"entries:   %20lld\n"
1182 				" files:    %20lld\n"
1183 				" subdirs:  %20lld\n"
1184 				"rentries:  %20lld\n"
1185 				" rfiles:   %20lld\n"
1186 				" rsubdirs: %20lld\n"
1187 				"rbytes:    %20lld\n"
1188 				"rctime:    %10ld.%09ld\n",
1189 				ci->i_files + ci->i_subdirs,
1190 				ci->i_files,
1191 				ci->i_subdirs,
1192 				ci->i_rfiles + ci->i_rsubdirs,
1193 				ci->i_rfiles,
1194 				ci->i_rsubdirs,
1195 				ci->i_rbytes,
1196 				(long)ci->i_rctime.tv_sec,
1197 				(long)ci->i_rctime.tv_nsec);
1198 	}
1199 
1200 	if (*ppos >= cf->dir_info_len)
1201 		return 0;
1202 	size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1203 	left = copy_to_user(buf, cf->dir_info + *ppos, size);
1204 	if (left == size)
1205 		return -EFAULT;
1206 	*ppos += (size - left);
1207 	return size - left;
1208 }
1209 
1210 /*
1211  * an fsync() on a dir will wait for any uncommitted directory
1212  * operations to commit.
1213  */
1214 static int ceph_dir_fsync(struct file *file, loff_t start, loff_t end,
1215 			  int datasync)
1216 {
1217 	struct inode *inode = file_inode(file);
1218 	struct ceph_inode_info *ci = ceph_inode(inode);
1219 	struct list_head *head = &ci->i_unsafe_dirops;
1220 	struct ceph_mds_request *req;
1221 	u64 last_tid;
1222 	int ret = 0;
1223 
1224 	dout("dir_fsync %p\n", inode);
1225 	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
1226 	if (ret)
1227 		return ret;
1228 	mutex_lock(&inode->i_mutex);
1229 
1230 	spin_lock(&ci->i_unsafe_lock);
1231 	if (list_empty(head))
1232 		goto out;
1233 
1234 	req = list_entry(head->prev,
1235 			 struct ceph_mds_request, r_unsafe_dir_item);
1236 	last_tid = req->r_tid;
1237 
1238 	do {
1239 		ceph_mdsc_get_request(req);
1240 		spin_unlock(&ci->i_unsafe_lock);
1241 
1242 		dout("dir_fsync %p wait on tid %llu (until %llu)\n",
1243 		     inode, req->r_tid, last_tid);
1244 		if (req->r_timeout) {
1245 			ret = wait_for_completion_timeout(
1246 				&req->r_safe_completion, req->r_timeout);
1247 			if (ret > 0)
1248 				ret = 0;
1249 			else if (ret == 0)
1250 				ret = -EIO;  /* timed out */
1251 		} else {
1252 			wait_for_completion(&req->r_safe_completion);
1253 		}
1254 		ceph_mdsc_put_request(req);
1255 
1256 		spin_lock(&ci->i_unsafe_lock);
1257 		if (ret || list_empty(head))
1258 			break;
1259 		req = list_entry(head->next,
1260 				 struct ceph_mds_request, r_unsafe_dir_item);
1261 	} while (req->r_tid < last_tid);
1262 out:
1263 	spin_unlock(&ci->i_unsafe_lock);
1264 	mutex_unlock(&inode->i_mutex);
1265 
1266 	return ret;
1267 }
1268 
1269 /*
1270  * We maintain a private dentry LRU.
1271  *
1272  * FIXME: this needs to be changed to a per-mds lru to be useful.
1273  */
1274 void ceph_dentry_lru_add(struct dentry *dn)
1275 {
1276 	struct ceph_dentry_info *di = ceph_dentry(dn);
1277 	struct ceph_mds_client *mdsc;
1278 
1279 	dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1280 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1281 	spin_lock(&mdsc->dentry_lru_lock);
1282 	list_add_tail(&di->lru, &mdsc->dentry_lru);
1283 	mdsc->num_dentry++;
1284 	spin_unlock(&mdsc->dentry_lru_lock);
1285 }
1286 
1287 void ceph_dentry_lru_touch(struct dentry *dn)
1288 {
1289 	struct ceph_dentry_info *di = ceph_dentry(dn);
1290 	struct ceph_mds_client *mdsc;
1291 
1292 	dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1293 	     di->offset);
1294 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1295 	spin_lock(&mdsc->dentry_lru_lock);
1296 	list_move_tail(&di->lru, &mdsc->dentry_lru);
1297 	spin_unlock(&mdsc->dentry_lru_lock);
1298 }
1299 
1300 void ceph_dentry_lru_del(struct dentry *dn)
1301 {
1302 	struct ceph_dentry_info *di = ceph_dentry(dn);
1303 	struct ceph_mds_client *mdsc;
1304 
1305 	dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1306 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1307 	spin_lock(&mdsc->dentry_lru_lock);
1308 	list_del_init(&di->lru);
1309 	mdsc->num_dentry--;
1310 	spin_unlock(&mdsc->dentry_lru_lock);
1311 }
1312 
1313 /*
1314  * Return name hash for a given dentry.  This is dependent on
1315  * the parent directory's hash function.
1316  */
1317 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1318 {
1319 	struct ceph_inode_info *dci = ceph_inode(dir);
1320 
1321 	switch (dci->i_dir_layout.dl_dir_hash) {
1322 	case 0:	/* for backward compat */
1323 	case CEPH_STR_HASH_LINUX:
1324 		return dn->d_name.hash;
1325 
1326 	default:
1327 		return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1328 				     dn->d_name.name, dn->d_name.len);
1329 	}
1330 }
1331 
1332 const struct file_operations ceph_dir_fops = {
1333 	.read = ceph_read_dir,
1334 	.iterate = ceph_readdir,
1335 	.llseek = ceph_dir_llseek,
1336 	.open = ceph_open,
1337 	.release = ceph_release,
1338 	.unlocked_ioctl = ceph_ioctl,
1339 	.fsync = ceph_dir_fsync,
1340 };
1341 
1342 const struct file_operations ceph_snapdir_fops = {
1343 	.iterate = ceph_readdir,
1344 	.llseek = ceph_dir_llseek,
1345 	.open = ceph_open,
1346 	.release = ceph_release,
1347 };
1348 
1349 const struct inode_operations ceph_dir_iops = {
1350 	.lookup = ceph_lookup,
1351 	.permission = ceph_permission,
1352 	.getattr = ceph_getattr,
1353 	.setattr = ceph_setattr,
1354 	.setxattr = ceph_setxattr,
1355 	.getxattr = ceph_getxattr,
1356 	.listxattr = ceph_listxattr,
1357 	.removexattr = ceph_removexattr,
1358 	.get_acl = ceph_get_acl,
1359 	.set_acl = ceph_set_acl,
1360 	.mknod = ceph_mknod,
1361 	.symlink = ceph_symlink,
1362 	.mkdir = ceph_mkdir,
1363 	.link = ceph_link,
1364 	.unlink = ceph_unlink,
1365 	.rmdir = ceph_unlink,
1366 	.rename = ceph_rename,
1367 	.create = ceph_create,
1368 	.atomic_open = ceph_atomic_open,
1369 };
1370 
1371 const struct inode_operations ceph_snapdir_iops = {
1372 	.lookup = ceph_lookup,
1373 	.permission = ceph_permission,
1374 	.getattr = ceph_getattr,
1375 	.mkdir = ceph_mkdir,
1376 	.rmdir = ceph_unlink,
1377 };
1378 
1379 const struct dentry_operations ceph_dentry_ops = {
1380 	.d_revalidate = ceph_d_revalidate,
1381 	.d_release = ceph_d_release,
1382 	.d_prune = ceph_d_prune,
1383 };
1384 
1385 const struct dentry_operations ceph_snapdir_dentry_ops = {
1386 	.d_revalidate = ceph_snapdir_d_revalidate,
1387 	.d_release = ceph_d_release,
1388 };
1389 
1390 const struct dentry_operations ceph_snap_dentry_ops = {
1391 	.d_release = ceph_d_release,
1392 	.d_prune = ceph_d_prune,
1393 };
1394