xref: /linux/fs/ceph/dir.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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, NOASYNCREADDIR) &&
285 	    ceph_snap(inode) != CEPH_SNAPDIR &&
286 	    __ceph_dir_is_complete_ordered(ci) &&
287 	    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
288 		u32 shared_gen = ci->i_shared_gen;
289 		spin_unlock(&ci->i_ceph_lock);
290 		err = __dcache_readdir(file, ctx, shared_gen);
291 		if (err != -EAGAIN)
292 			return err;
293 		frag = fpos_frag(ctx->pos);
294 		off = fpos_off(ctx->pos);
295 	} else {
296 		spin_unlock(&ci->i_ceph_lock);
297 	}
298 	if (fi->dentry) {
299 		err = note_last_dentry(fi, fi->dentry->d_name.name,
300 				       fi->dentry->d_name.len);
301 		if (err)
302 			return err;
303 		dput(fi->dentry);
304 		fi->dentry = NULL;
305 	}
306 
307 	/* proceed with a normal readdir */
308 
309 	if (ctx->pos == 2) {
310 		/* note dir version at start of readdir so we can tell
311 		 * if any dentries get dropped */
312 		fi->dir_release_count = atomic_read(&ci->i_release_count);
313 		fi->dir_ordered_count = ci->i_ordered_count;
314 	}
315 
316 more:
317 	/* do we have the correct frag content buffered? */
318 	if (fi->frag != frag || fi->last_readdir == NULL) {
319 		struct ceph_mds_request *req;
320 		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
321 			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
322 
323 		/* discard old result, if any */
324 		if (fi->last_readdir) {
325 			ceph_mdsc_put_request(fi->last_readdir);
326 			fi->last_readdir = NULL;
327 		}
328 
329 		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
330 		     ceph_vinop(inode), frag, fi->last_name);
331 		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
332 		if (IS_ERR(req))
333 			return PTR_ERR(req);
334 		err = ceph_alloc_readdir_reply_buffer(req, inode);
335 		if (err) {
336 			ceph_mdsc_put_request(req);
337 			return err;
338 		}
339 		req->r_inode = inode;
340 		ihold(inode);
341 		req->r_dentry = dget(file->f_path.dentry);
342 		/* hints to request -> mds selection code */
343 		req->r_direct_mode = USE_AUTH_MDS;
344 		req->r_direct_hash = ceph_frag_value(frag);
345 		req->r_direct_is_hash = true;
346 		req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
347 		req->r_readdir_offset = fi->next_offset;
348 		req->r_args.readdir.frag = cpu_to_le32(frag);
349 		err = ceph_mdsc_do_request(mdsc, NULL, req);
350 		if (err < 0) {
351 			ceph_mdsc_put_request(req);
352 			return err;
353 		}
354 		dout("readdir got and parsed readdir result=%d"
355 		     " on frag %x, end=%d, complete=%d\n", err, frag,
356 		     (int)req->r_reply_info.dir_end,
357 		     (int)req->r_reply_info.dir_complete);
358 
359 		if (!req->r_did_prepopulate) {
360 			dout("readdir !did_prepopulate");
361 			/* preclude from marking dir complete */
362 			fi->dir_release_count--;
363 		}
364 
365 		/* note next offset and last dentry name */
366 		rinfo = &req->r_reply_info;
367 		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
368 			frag = le32_to_cpu(rinfo->dir_dir->frag);
369 			if (ceph_frag_is_leftmost(frag))
370 				fi->next_offset = 2;
371 			else
372 				fi->next_offset = 0;
373 			off = fi->next_offset;
374 		}
375 		fi->frag = frag;
376 		fi->offset = fi->next_offset;
377 		fi->last_readdir = req;
378 
379 		if (req->r_reply_info.dir_end) {
380 			kfree(fi->last_name);
381 			fi->last_name = NULL;
382 			if (ceph_frag_is_rightmost(frag))
383 				fi->next_offset = 2;
384 			else
385 				fi->next_offset = 0;
386 		} else {
387 			err = note_last_dentry(fi,
388 				       rinfo->dir_dname[rinfo->dir_nr-1],
389 				       rinfo->dir_dname_len[rinfo->dir_nr-1]);
390 			if (err)
391 				return err;
392 			fi->next_offset += rinfo->dir_nr;
393 		}
394 	}
395 
396 	rinfo = &fi->last_readdir->r_reply_info;
397 	dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
398 	     rinfo->dir_nr, off, fi->offset);
399 
400 	ctx->pos = ceph_make_fpos(frag, off);
401 	while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
402 		struct ceph_mds_reply_inode *in =
403 			rinfo->dir_in[off - fi->offset].in;
404 		struct ceph_vino vino;
405 		ino_t ino;
406 
407 		dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
408 		     off, off - fi->offset, rinfo->dir_nr, ctx->pos,
409 		     rinfo->dir_dname_len[off - fi->offset],
410 		     rinfo->dir_dname[off - fi->offset], in);
411 		BUG_ON(!in);
412 		ftype = le32_to_cpu(in->mode) >> 12;
413 		vino.ino = le64_to_cpu(in->ino);
414 		vino.snap = le64_to_cpu(in->snapid);
415 		ino = ceph_vino_to_ino(vino);
416 		if (!dir_emit(ctx,
417 			    rinfo->dir_dname[off - fi->offset],
418 			    rinfo->dir_dname_len[off - fi->offset],
419 			    ceph_translate_ino(inode->i_sb, ino), ftype)) {
420 			dout("filldir stopping us...\n");
421 			return 0;
422 		}
423 		off++;
424 		ctx->pos++;
425 	}
426 
427 	if (fi->last_name) {
428 		ceph_mdsc_put_request(fi->last_readdir);
429 		fi->last_readdir = NULL;
430 		goto more;
431 	}
432 
433 	/* more frags? */
434 	if (!ceph_frag_is_rightmost(frag)) {
435 		frag = ceph_frag_next(frag);
436 		off = 0;
437 		ctx->pos = ceph_make_fpos(frag, off);
438 		dout("readdir next frag is %x\n", frag);
439 		goto more;
440 	}
441 	fi->flags |= CEPH_F_ATEND;
442 
443 	/*
444 	 * if dir_release_count still matches the dir, no dentries
445 	 * were released during the whole readdir, and we should have
446 	 * the complete dir contents in our cache.
447 	 */
448 	spin_lock(&ci->i_ceph_lock);
449 	if (atomic_read(&ci->i_release_count) == fi->dir_release_count) {
450 		if (ci->i_ordered_count == fi->dir_ordered_count)
451 			dout(" marking %p complete and ordered\n", inode);
452 		else
453 			dout(" marking %p complete\n", inode);
454 		__ceph_dir_set_complete(ci, fi->dir_release_count,
455 					fi->dir_ordered_count);
456 	}
457 	spin_unlock(&ci->i_ceph_lock);
458 
459 	dout("readdir %p file %p done.\n", inode, file);
460 	return 0;
461 }
462 
463 static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
464 {
465 	if (fi->last_readdir) {
466 		ceph_mdsc_put_request(fi->last_readdir);
467 		fi->last_readdir = NULL;
468 	}
469 	kfree(fi->last_name);
470 	fi->last_name = NULL;
471 	if (ceph_frag_is_leftmost(frag))
472 		fi->next_offset = 2;  /* compensate for . and .. */
473 	else
474 		fi->next_offset = 0;
475 	if (fi->dentry) {
476 		dput(fi->dentry);
477 		fi->dentry = NULL;
478 	}
479 	fi->flags &= ~CEPH_F_ATEND;
480 }
481 
482 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
483 {
484 	struct ceph_file_info *fi = file->private_data;
485 	struct inode *inode = file->f_mapping->host;
486 	loff_t old_offset = ceph_make_fpos(fi->frag, fi->next_offset);
487 	loff_t retval;
488 
489 	mutex_lock(&inode->i_mutex);
490 	retval = -EINVAL;
491 	switch (whence) {
492 	case SEEK_END:
493 		offset += inode->i_size + 2;   /* FIXME */
494 		break;
495 	case SEEK_CUR:
496 		offset += file->f_pos;
497 	case SEEK_SET:
498 		break;
499 	default:
500 		goto out;
501 	}
502 
503 	if (offset >= 0) {
504 		if (offset != file->f_pos) {
505 			file->f_pos = offset;
506 			file->f_version = 0;
507 			fi->flags &= ~CEPH_F_ATEND;
508 		}
509 		retval = offset;
510 
511 		/*
512 		 * discard buffered readdir content on seekdir(0), or
513 		 * seek to new frag, or seek prior to current chunk.
514 		 */
515 		if (offset == 0 ||
516 		    fpos_frag(offset) != fi->frag ||
517 		    fpos_off(offset) < fi->offset) {
518 			dout("dir_llseek dropping %p content\n", file);
519 			reset_readdir(fi, fpos_frag(offset));
520 		}
521 
522 		/* bump dir_release_count if we did a forward seek */
523 		if (fpos_cmp(offset, old_offset) > 0)
524 			fi->dir_release_count--;
525 	}
526 out:
527 	mutex_unlock(&inode->i_mutex);
528 	return retval;
529 }
530 
531 /*
532  * Handle lookups for the hidden .snap directory.
533  */
534 int ceph_handle_snapdir(struct ceph_mds_request *req,
535 			struct dentry *dentry, int err)
536 {
537 	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
538 	struct inode *parent = dentry->d_parent->d_inode; /* we hold i_mutex */
539 
540 	/* .snap dir? */
541 	if (err == -ENOENT &&
542 	    ceph_snap(parent) == CEPH_NOSNAP &&
543 	    strcmp(dentry->d_name.name,
544 		   fsc->mount_options->snapdir_name) == 0) {
545 		struct inode *inode = ceph_get_snapdir(parent);
546 		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
547 		     dentry, dentry, inode);
548 		BUG_ON(!d_unhashed(dentry));
549 		d_add(dentry, inode);
550 		err = 0;
551 	}
552 	return err;
553 }
554 
555 /*
556  * Figure out final result of a lookup/open request.
557  *
558  * Mainly, make sure we return the final req->r_dentry (if it already
559  * existed) in place of the original VFS-provided dentry when they
560  * differ.
561  *
562  * Gracefully handle the case where the MDS replies with -ENOENT and
563  * no trace (which it may do, at its discretion, e.g., if it doesn't
564  * care to issue a lease on the negative dentry).
565  */
566 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
567 				  struct dentry *dentry, int err)
568 {
569 	if (err == -ENOENT) {
570 		/* no trace? */
571 		err = 0;
572 		if (!req->r_reply_info.head->is_dentry) {
573 			dout("ENOENT and no trace, dentry %p inode %p\n",
574 			     dentry, dentry->d_inode);
575 			if (dentry->d_inode) {
576 				d_drop(dentry);
577 				err = -ENOENT;
578 			} else {
579 				d_add(dentry, NULL);
580 			}
581 		}
582 	}
583 	if (err)
584 		dentry = ERR_PTR(err);
585 	else if (dentry != req->r_dentry)
586 		dentry = dget(req->r_dentry);   /* we got spliced */
587 	else
588 		dentry = NULL;
589 	return dentry;
590 }
591 
592 static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
593 {
594 	return ceph_ino(inode) == CEPH_INO_ROOT &&
595 		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
596 }
597 
598 /*
599  * Look up a single dir entry.  If there is a lookup intent, inform
600  * the MDS so that it gets our 'caps wanted' value in a single op.
601  */
602 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
603 				  unsigned int flags)
604 {
605 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
606 	struct ceph_mds_client *mdsc = fsc->mdsc;
607 	struct ceph_mds_request *req;
608 	int op;
609 	int err;
610 
611 	dout("lookup %p dentry %p '%pd'\n",
612 	     dir, dentry, dentry);
613 
614 	if (dentry->d_name.len > NAME_MAX)
615 		return ERR_PTR(-ENAMETOOLONG);
616 
617 	err = ceph_init_dentry(dentry);
618 	if (err < 0)
619 		return ERR_PTR(err);
620 
621 	/* can we conclude ENOENT locally? */
622 	if (dentry->d_inode == NULL) {
623 		struct ceph_inode_info *ci = ceph_inode(dir);
624 		struct ceph_dentry_info *di = ceph_dentry(dentry);
625 
626 		spin_lock(&ci->i_ceph_lock);
627 		dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
628 		if (strncmp(dentry->d_name.name,
629 			    fsc->mount_options->snapdir_name,
630 			    dentry->d_name.len) &&
631 		    !is_root_ceph_dentry(dir, dentry) &&
632 		    __ceph_dir_is_complete(ci) &&
633 		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
634 			spin_unlock(&ci->i_ceph_lock);
635 			dout(" dir %p complete, -ENOENT\n", dir);
636 			d_add(dentry, NULL);
637 			di->lease_shared_gen = ci->i_shared_gen;
638 			return NULL;
639 		}
640 		spin_unlock(&ci->i_ceph_lock);
641 	}
642 
643 	op = ceph_snap(dir) == CEPH_SNAPDIR ?
644 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
645 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
646 	if (IS_ERR(req))
647 		return ERR_CAST(req);
648 	req->r_dentry = dget(dentry);
649 	req->r_num_caps = 2;
650 	/* we only need inode linkage */
651 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
652 	req->r_locked_dir = dir;
653 	err = ceph_mdsc_do_request(mdsc, NULL, req);
654 	err = ceph_handle_snapdir(req, dentry, err);
655 	dentry = ceph_finish_lookup(req, dentry, err);
656 	ceph_mdsc_put_request(req);  /* will dput(dentry) */
657 	dout("lookup result=%p\n", dentry);
658 	return dentry;
659 }
660 
661 /*
662  * If we do a create but get no trace back from the MDS, follow up with
663  * a lookup (the VFS expects us to link up the provided dentry).
664  */
665 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
666 {
667 	struct dentry *result = ceph_lookup(dir, dentry, 0);
668 
669 	if (result && !IS_ERR(result)) {
670 		/*
671 		 * We created the item, then did a lookup, and found
672 		 * it was already linked to another inode we already
673 		 * had in our cache (and thus got spliced). To not
674 		 * confuse VFS (especially when inode is a directory),
675 		 * we don't link our dentry to that inode, return an
676 		 * error instead.
677 		 *
678 		 * This event should be rare and it happens only when
679 		 * we talk to old MDS. Recent MDS does not send traceless
680 		 * reply for request that creates new inode.
681 		 */
682 		d_drop(result);
683 		return -ESTALE;
684 	}
685 	return PTR_ERR(result);
686 }
687 
688 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
689 		      umode_t mode, dev_t rdev)
690 {
691 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
692 	struct ceph_mds_client *mdsc = fsc->mdsc;
693 	struct ceph_mds_request *req;
694 	struct ceph_acls_info acls = {};
695 	int err;
696 
697 	if (ceph_snap(dir) != CEPH_NOSNAP)
698 		return -EROFS;
699 
700 	err = ceph_pre_init_acls(dir, &mode, &acls);
701 	if (err < 0)
702 		return err;
703 
704 	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
705 	     dir, dentry, mode, rdev);
706 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
707 	if (IS_ERR(req)) {
708 		err = PTR_ERR(req);
709 		goto out;
710 	}
711 	req->r_dentry = dget(dentry);
712 	req->r_num_caps = 2;
713 	req->r_locked_dir = dir;
714 	req->r_args.mknod.mode = cpu_to_le32(mode);
715 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
716 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
717 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
718 	if (acls.pagelist) {
719 		req->r_pagelist = acls.pagelist;
720 		acls.pagelist = NULL;
721 	}
722 	err = ceph_mdsc_do_request(mdsc, dir, req);
723 	if (!err && !req->r_reply_info.head->is_dentry)
724 		err = ceph_handle_notrace_create(dir, dentry);
725 	ceph_mdsc_put_request(req);
726 out:
727 	if (!err)
728 		ceph_init_inode_acls(dentry->d_inode, &acls);
729 	else
730 		d_drop(dentry);
731 	ceph_release_acls_info(&acls);
732 	return err;
733 }
734 
735 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
736 		       bool excl)
737 {
738 	return ceph_mknod(dir, dentry, mode, 0);
739 }
740 
741 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
742 			    const char *dest)
743 {
744 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
745 	struct ceph_mds_client *mdsc = fsc->mdsc;
746 	struct ceph_mds_request *req;
747 	int err;
748 
749 	if (ceph_snap(dir) != CEPH_NOSNAP)
750 		return -EROFS;
751 
752 	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
753 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
754 	if (IS_ERR(req)) {
755 		err = PTR_ERR(req);
756 		goto out;
757 	}
758 	req->r_dentry = dget(dentry);
759 	req->r_num_caps = 2;
760 	req->r_path2 = kstrdup(dest, GFP_NOFS);
761 	req->r_locked_dir = dir;
762 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
763 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
764 	err = ceph_mdsc_do_request(mdsc, dir, req);
765 	if (!err && !req->r_reply_info.head->is_dentry)
766 		err = ceph_handle_notrace_create(dir, dentry);
767 	ceph_mdsc_put_request(req);
768 out:
769 	if (err)
770 		d_drop(dentry);
771 	return err;
772 }
773 
774 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
775 {
776 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
777 	struct ceph_mds_client *mdsc = fsc->mdsc;
778 	struct ceph_mds_request *req;
779 	struct ceph_acls_info acls = {};
780 	int err = -EROFS;
781 	int op;
782 
783 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
784 		/* mkdir .snap/foo is a MKSNAP */
785 		op = CEPH_MDS_OP_MKSNAP;
786 		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
787 		     dentry, dentry);
788 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
789 		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
790 		op = CEPH_MDS_OP_MKDIR;
791 	} else {
792 		goto out;
793 	}
794 
795 	mode |= S_IFDIR;
796 	err = ceph_pre_init_acls(dir, &mode, &acls);
797 	if (err < 0)
798 		goto out;
799 
800 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
801 	if (IS_ERR(req)) {
802 		err = PTR_ERR(req);
803 		goto out;
804 	}
805 
806 	req->r_dentry = dget(dentry);
807 	req->r_num_caps = 2;
808 	req->r_locked_dir = dir;
809 	req->r_args.mkdir.mode = cpu_to_le32(mode);
810 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
811 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
812 	if (acls.pagelist) {
813 		req->r_pagelist = acls.pagelist;
814 		acls.pagelist = NULL;
815 	}
816 	err = ceph_mdsc_do_request(mdsc, dir, req);
817 	if (!err &&
818 	    !req->r_reply_info.head->is_target &&
819 	    !req->r_reply_info.head->is_dentry)
820 		err = ceph_handle_notrace_create(dir, dentry);
821 	ceph_mdsc_put_request(req);
822 out:
823 	if (!err)
824 		ceph_init_inode_acls(dentry->d_inode, &acls);
825 	else
826 		d_drop(dentry);
827 	ceph_release_acls_info(&acls);
828 	return err;
829 }
830 
831 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
832 		     struct dentry *dentry)
833 {
834 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
835 	struct ceph_mds_client *mdsc = fsc->mdsc;
836 	struct ceph_mds_request *req;
837 	int err;
838 
839 	if (ceph_snap(dir) != CEPH_NOSNAP)
840 		return -EROFS;
841 
842 	dout("link in dir %p old_dentry %p dentry %p\n", dir,
843 	     old_dentry, dentry);
844 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
845 	if (IS_ERR(req)) {
846 		d_drop(dentry);
847 		return PTR_ERR(req);
848 	}
849 	req->r_dentry = dget(dentry);
850 	req->r_num_caps = 2;
851 	req->r_old_dentry = dget(old_dentry);
852 	req->r_locked_dir = dir;
853 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
854 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
855 	/* release LINK_SHARED on source inode (mds will lock it) */
856 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
857 	err = ceph_mdsc_do_request(mdsc, dir, req);
858 	if (err) {
859 		d_drop(dentry);
860 	} else if (!req->r_reply_info.head->is_dentry) {
861 		ihold(old_dentry->d_inode);
862 		d_instantiate(dentry, old_dentry->d_inode);
863 	}
864 	ceph_mdsc_put_request(req);
865 	return err;
866 }
867 
868 /*
869  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
870  * looks like the link count will hit 0, drop any other caps (other
871  * than PIN) we don't specifically want (due to the file still being
872  * open).
873  */
874 static int drop_caps_for_unlink(struct inode *inode)
875 {
876 	struct ceph_inode_info *ci = ceph_inode(inode);
877 	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
878 
879 	spin_lock(&ci->i_ceph_lock);
880 	if (inode->i_nlink == 1) {
881 		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
882 		ci->i_ceph_flags |= CEPH_I_NODELAY;
883 	}
884 	spin_unlock(&ci->i_ceph_lock);
885 	return drop;
886 }
887 
888 /*
889  * rmdir and unlink are differ only by the metadata op code
890  */
891 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
892 {
893 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
894 	struct ceph_mds_client *mdsc = fsc->mdsc;
895 	struct inode *inode = dentry->d_inode;
896 	struct ceph_mds_request *req;
897 	int err = -EROFS;
898 	int op;
899 
900 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
901 		/* rmdir .snap/foo is RMSNAP */
902 		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
903 		op = CEPH_MDS_OP_RMSNAP;
904 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
905 		dout("unlink/rmdir dir %p dn %p inode %p\n",
906 		     dir, dentry, inode);
907 		op = d_is_dir(dentry) ?
908 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
909 	} else
910 		goto out;
911 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
912 	if (IS_ERR(req)) {
913 		err = PTR_ERR(req);
914 		goto out;
915 	}
916 	req->r_dentry = dget(dentry);
917 	req->r_num_caps = 2;
918 	req->r_locked_dir = dir;
919 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
920 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
921 	req->r_inode_drop = drop_caps_for_unlink(inode);
922 	err = ceph_mdsc_do_request(mdsc, dir, req);
923 	if (!err && !req->r_reply_info.head->is_dentry)
924 		d_delete(dentry);
925 	ceph_mdsc_put_request(req);
926 out:
927 	return err;
928 }
929 
930 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
931 		       struct inode *new_dir, struct dentry *new_dentry)
932 {
933 	struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
934 	struct ceph_mds_client *mdsc = fsc->mdsc;
935 	struct ceph_mds_request *req;
936 	int err;
937 
938 	if (ceph_snap(old_dir) != ceph_snap(new_dir))
939 		return -EXDEV;
940 	if (ceph_snap(old_dir) != CEPH_NOSNAP ||
941 	    ceph_snap(new_dir) != CEPH_NOSNAP)
942 		return -EROFS;
943 	dout("rename dir %p dentry %p to dir %p dentry %p\n",
944 	     old_dir, old_dentry, new_dir, new_dentry);
945 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_RENAME, USE_AUTH_MDS);
946 	if (IS_ERR(req))
947 		return PTR_ERR(req);
948 	ihold(old_dir);
949 	req->r_dentry = dget(new_dentry);
950 	req->r_num_caps = 2;
951 	req->r_old_dentry = dget(old_dentry);
952 	req->r_old_dentry_dir = old_dir;
953 	req->r_locked_dir = new_dir;
954 	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
955 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
956 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
957 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
958 	/* release LINK_RDCACHE on source inode (mds will lock it) */
959 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
960 	if (new_dentry->d_inode)
961 		req->r_inode_drop = drop_caps_for_unlink(new_dentry->d_inode);
962 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
963 	if (!err && !req->r_reply_info.head->is_dentry) {
964 		/*
965 		 * Normally d_move() is done by fill_trace (called by
966 		 * do_request, above).  If there is no trace, we need
967 		 * to do it here.
968 		 */
969 
970 		d_move(old_dentry, new_dentry);
971 
972 		/* ensure target dentry is invalidated, despite
973 		   rehashing bug in vfs_rename_dir */
974 		ceph_invalidate_dentry_lease(new_dentry);
975 
976 		/* d_move screws up sibling dentries' offsets */
977 		ceph_dir_clear_complete(old_dir);
978 		ceph_dir_clear_complete(new_dir);
979 
980 	}
981 	ceph_mdsc_put_request(req);
982 	return err;
983 }
984 
985 /*
986  * Ensure a dentry lease will no longer revalidate.
987  */
988 void ceph_invalidate_dentry_lease(struct dentry *dentry)
989 {
990 	spin_lock(&dentry->d_lock);
991 	dentry->d_time = jiffies;
992 	ceph_dentry(dentry)->lease_shared_gen = 0;
993 	spin_unlock(&dentry->d_lock);
994 }
995 
996 /*
997  * Check if dentry lease is valid.  If not, delete the lease.  Try to
998  * renew if the least is more than half up.
999  */
1000 static int dentry_lease_is_valid(struct dentry *dentry)
1001 {
1002 	struct ceph_dentry_info *di;
1003 	struct ceph_mds_session *s;
1004 	int valid = 0;
1005 	u32 gen;
1006 	unsigned long ttl;
1007 	struct ceph_mds_session *session = NULL;
1008 	struct inode *dir = NULL;
1009 	u32 seq = 0;
1010 
1011 	spin_lock(&dentry->d_lock);
1012 	di = ceph_dentry(dentry);
1013 	if (di->lease_session) {
1014 		s = di->lease_session;
1015 		spin_lock(&s->s_gen_ttl_lock);
1016 		gen = s->s_cap_gen;
1017 		ttl = s->s_cap_ttl;
1018 		spin_unlock(&s->s_gen_ttl_lock);
1019 
1020 		if (di->lease_gen == gen &&
1021 		    time_before(jiffies, dentry->d_time) &&
1022 		    time_before(jiffies, ttl)) {
1023 			valid = 1;
1024 			if (di->lease_renew_after &&
1025 			    time_after(jiffies, di->lease_renew_after)) {
1026 				/* we should renew */
1027 				dir = dentry->d_parent->d_inode;
1028 				session = ceph_get_mds_session(s);
1029 				seq = di->lease_seq;
1030 				di->lease_renew_after = 0;
1031 				di->lease_renew_from = jiffies;
1032 			}
1033 		}
1034 	}
1035 	spin_unlock(&dentry->d_lock);
1036 
1037 	if (session) {
1038 		ceph_mdsc_lease_send_msg(session, dir, dentry,
1039 					 CEPH_MDS_LEASE_RENEW, seq);
1040 		ceph_put_mds_session(session);
1041 	}
1042 	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1043 	return valid;
1044 }
1045 
1046 /*
1047  * Check if directory-wide content lease/cap is valid.
1048  */
1049 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1050 {
1051 	struct ceph_inode_info *ci = ceph_inode(dir);
1052 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1053 	int valid = 0;
1054 
1055 	spin_lock(&ci->i_ceph_lock);
1056 	if (ci->i_shared_gen == di->lease_shared_gen)
1057 		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1058 	spin_unlock(&ci->i_ceph_lock);
1059 	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1060 	     dir, (unsigned)ci->i_shared_gen, dentry,
1061 	     (unsigned)di->lease_shared_gen, valid);
1062 	return valid;
1063 }
1064 
1065 /*
1066  * Check if cached dentry can be trusted.
1067  */
1068 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1069 {
1070 	int valid = 0;
1071 	struct inode *dir;
1072 
1073 	if (flags & LOOKUP_RCU)
1074 		return -ECHILD;
1075 
1076 	dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1077 	     dentry, dentry->d_inode, ceph_dentry(dentry)->offset);
1078 
1079 	dir = ceph_get_dentry_parent_inode(dentry);
1080 
1081 	/* always trust cached snapped dentries, snapdir dentry */
1082 	if (ceph_snap(dir) != CEPH_NOSNAP) {
1083 		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1084 		     dentry, dentry->d_inode);
1085 		valid = 1;
1086 	} else if (dentry->d_inode &&
1087 		   ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) {
1088 		valid = 1;
1089 	} else if (dentry_lease_is_valid(dentry) ||
1090 		   dir_lease_is_valid(dir, dentry)) {
1091 		if (dentry->d_inode)
1092 			valid = ceph_is_any_caps(dentry->d_inode);
1093 		else
1094 			valid = 1;
1095 	}
1096 
1097 	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1098 	if (valid) {
1099 		ceph_dentry_lru_touch(dentry);
1100 	} else {
1101 		ceph_dir_clear_complete(dir);
1102 	}
1103 	iput(dir);
1104 	return valid;
1105 }
1106 
1107 /*
1108  * Release our ceph_dentry_info.
1109  */
1110 static void ceph_d_release(struct dentry *dentry)
1111 {
1112 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1113 
1114 	dout("d_release %p\n", dentry);
1115 	ceph_dentry_lru_del(dentry);
1116 	if (di->lease_session)
1117 		ceph_put_mds_session(di->lease_session);
1118 	kmem_cache_free(ceph_dentry_cachep, di);
1119 	dentry->d_fsdata = NULL;
1120 }
1121 
1122 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1123 					  unsigned int flags)
1124 {
1125 	/*
1126 	 * Eventually, we'll want to revalidate snapped metadata
1127 	 * too... probably...
1128 	 */
1129 	return 1;
1130 }
1131 
1132 /*
1133  * When the VFS prunes a dentry from the cache, we need to clear the
1134  * complete flag on the parent directory.
1135  *
1136  * Called under dentry->d_lock.
1137  */
1138 static void ceph_d_prune(struct dentry *dentry)
1139 {
1140 	dout("ceph_d_prune %p\n", dentry);
1141 
1142 	/* do we have a valid parent? */
1143 	if (IS_ROOT(dentry))
1144 		return;
1145 
1146 	/* if we are not hashed, we don't affect dir's completeness */
1147 	if (d_unhashed(dentry))
1148 		return;
1149 
1150 	/*
1151 	 * we hold d_lock, so d_parent is stable, and d_fsdata is never
1152 	 * cleared until d_release
1153 	 */
1154 	ceph_dir_clear_complete(dentry->d_parent->d_inode);
1155 }
1156 
1157 /*
1158  * read() on a dir.  This weird interface hack only works if mounted
1159  * with '-o dirstat'.
1160  */
1161 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1162 			     loff_t *ppos)
1163 {
1164 	struct ceph_file_info *cf = file->private_data;
1165 	struct inode *inode = file_inode(file);
1166 	struct ceph_inode_info *ci = ceph_inode(inode);
1167 	int left;
1168 	const int bufsize = 1024;
1169 
1170 	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1171 		return -EISDIR;
1172 
1173 	if (!cf->dir_info) {
1174 		cf->dir_info = kmalloc(bufsize, GFP_NOFS);
1175 		if (!cf->dir_info)
1176 			return -ENOMEM;
1177 		cf->dir_info_len =
1178 			snprintf(cf->dir_info, bufsize,
1179 				"entries:   %20lld\n"
1180 				" files:    %20lld\n"
1181 				" subdirs:  %20lld\n"
1182 				"rentries:  %20lld\n"
1183 				" rfiles:   %20lld\n"
1184 				" rsubdirs: %20lld\n"
1185 				"rbytes:    %20lld\n"
1186 				"rctime:    %10ld.%09ld\n",
1187 				ci->i_files + ci->i_subdirs,
1188 				ci->i_files,
1189 				ci->i_subdirs,
1190 				ci->i_rfiles + ci->i_rsubdirs,
1191 				ci->i_rfiles,
1192 				ci->i_rsubdirs,
1193 				ci->i_rbytes,
1194 				(long)ci->i_rctime.tv_sec,
1195 				(long)ci->i_rctime.tv_nsec);
1196 	}
1197 
1198 	if (*ppos >= cf->dir_info_len)
1199 		return 0;
1200 	size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1201 	left = copy_to_user(buf, cf->dir_info + *ppos, size);
1202 	if (left == size)
1203 		return -EFAULT;
1204 	*ppos += (size - left);
1205 	return size - left;
1206 }
1207 
1208 /*
1209  * an fsync() on a dir will wait for any uncommitted directory
1210  * operations to commit.
1211  */
1212 static int ceph_dir_fsync(struct file *file, loff_t start, loff_t end,
1213 			  int datasync)
1214 {
1215 	struct inode *inode = file_inode(file);
1216 	struct ceph_inode_info *ci = ceph_inode(inode);
1217 	struct list_head *head = &ci->i_unsafe_dirops;
1218 	struct ceph_mds_request *req;
1219 	u64 last_tid;
1220 	int ret = 0;
1221 
1222 	dout("dir_fsync %p\n", inode);
1223 	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
1224 	if (ret)
1225 		return ret;
1226 	mutex_lock(&inode->i_mutex);
1227 
1228 	spin_lock(&ci->i_unsafe_lock);
1229 	if (list_empty(head))
1230 		goto out;
1231 
1232 	req = list_entry(head->prev,
1233 			 struct ceph_mds_request, r_unsafe_dir_item);
1234 	last_tid = req->r_tid;
1235 
1236 	do {
1237 		ceph_mdsc_get_request(req);
1238 		spin_unlock(&ci->i_unsafe_lock);
1239 
1240 		dout("dir_fsync %p wait on tid %llu (until %llu)\n",
1241 		     inode, req->r_tid, last_tid);
1242 		if (req->r_timeout) {
1243 			ret = wait_for_completion_timeout(
1244 				&req->r_safe_completion, req->r_timeout);
1245 			if (ret > 0)
1246 				ret = 0;
1247 			else if (ret == 0)
1248 				ret = -EIO;  /* timed out */
1249 		} else {
1250 			wait_for_completion(&req->r_safe_completion);
1251 		}
1252 		ceph_mdsc_put_request(req);
1253 
1254 		spin_lock(&ci->i_unsafe_lock);
1255 		if (ret || list_empty(head))
1256 			break;
1257 		req = list_entry(head->next,
1258 				 struct ceph_mds_request, r_unsafe_dir_item);
1259 	} while (req->r_tid < last_tid);
1260 out:
1261 	spin_unlock(&ci->i_unsafe_lock);
1262 	mutex_unlock(&inode->i_mutex);
1263 
1264 	return ret;
1265 }
1266 
1267 /*
1268  * We maintain a private dentry LRU.
1269  *
1270  * FIXME: this needs to be changed to a per-mds lru to be useful.
1271  */
1272 void ceph_dentry_lru_add(struct dentry *dn)
1273 {
1274 	struct ceph_dentry_info *di = ceph_dentry(dn);
1275 	struct ceph_mds_client *mdsc;
1276 
1277 	dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1278 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1279 	spin_lock(&mdsc->dentry_lru_lock);
1280 	list_add_tail(&di->lru, &mdsc->dentry_lru);
1281 	mdsc->num_dentry++;
1282 	spin_unlock(&mdsc->dentry_lru_lock);
1283 }
1284 
1285 void ceph_dentry_lru_touch(struct dentry *dn)
1286 {
1287 	struct ceph_dentry_info *di = ceph_dentry(dn);
1288 	struct ceph_mds_client *mdsc;
1289 
1290 	dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1291 	     di->offset);
1292 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1293 	spin_lock(&mdsc->dentry_lru_lock);
1294 	list_move_tail(&di->lru, &mdsc->dentry_lru);
1295 	spin_unlock(&mdsc->dentry_lru_lock);
1296 }
1297 
1298 void ceph_dentry_lru_del(struct dentry *dn)
1299 {
1300 	struct ceph_dentry_info *di = ceph_dentry(dn);
1301 	struct ceph_mds_client *mdsc;
1302 
1303 	dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1304 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1305 	spin_lock(&mdsc->dentry_lru_lock);
1306 	list_del_init(&di->lru);
1307 	mdsc->num_dentry--;
1308 	spin_unlock(&mdsc->dentry_lru_lock);
1309 }
1310 
1311 /*
1312  * Return name hash for a given dentry.  This is dependent on
1313  * the parent directory's hash function.
1314  */
1315 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1316 {
1317 	struct ceph_inode_info *dci = ceph_inode(dir);
1318 
1319 	switch (dci->i_dir_layout.dl_dir_hash) {
1320 	case 0:	/* for backward compat */
1321 	case CEPH_STR_HASH_LINUX:
1322 		return dn->d_name.hash;
1323 
1324 	default:
1325 		return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1326 				     dn->d_name.name, dn->d_name.len);
1327 	}
1328 }
1329 
1330 const struct file_operations ceph_dir_fops = {
1331 	.read = ceph_read_dir,
1332 	.iterate = ceph_readdir,
1333 	.llseek = ceph_dir_llseek,
1334 	.open = ceph_open,
1335 	.release = ceph_release,
1336 	.unlocked_ioctl = ceph_ioctl,
1337 	.fsync = ceph_dir_fsync,
1338 };
1339 
1340 const struct file_operations ceph_snapdir_fops = {
1341 	.iterate = ceph_readdir,
1342 	.llseek = ceph_dir_llseek,
1343 	.open = ceph_open,
1344 	.release = ceph_release,
1345 };
1346 
1347 const struct inode_operations ceph_dir_iops = {
1348 	.lookup = ceph_lookup,
1349 	.permission = ceph_permission,
1350 	.getattr = ceph_getattr,
1351 	.setattr = ceph_setattr,
1352 	.setxattr = ceph_setxattr,
1353 	.getxattr = ceph_getxattr,
1354 	.listxattr = ceph_listxattr,
1355 	.removexattr = ceph_removexattr,
1356 	.get_acl = ceph_get_acl,
1357 	.set_acl = ceph_set_acl,
1358 	.mknod = ceph_mknod,
1359 	.symlink = ceph_symlink,
1360 	.mkdir = ceph_mkdir,
1361 	.link = ceph_link,
1362 	.unlink = ceph_unlink,
1363 	.rmdir = ceph_unlink,
1364 	.rename = ceph_rename,
1365 	.create = ceph_create,
1366 	.atomic_open = ceph_atomic_open,
1367 };
1368 
1369 const struct inode_operations ceph_snapdir_iops = {
1370 	.lookup = ceph_lookup,
1371 	.permission = ceph_permission,
1372 	.getattr = ceph_getattr,
1373 	.mkdir = ceph_mkdir,
1374 	.rmdir = ceph_unlink,
1375 };
1376 
1377 const struct dentry_operations ceph_dentry_ops = {
1378 	.d_revalidate = ceph_d_revalidate,
1379 	.d_release = ceph_d_release,
1380 	.d_prune = ceph_d_prune,
1381 };
1382 
1383 const struct dentry_operations ceph_snapdir_dentry_ops = {
1384 	.d_revalidate = ceph_snapdir_d_revalidate,
1385 	.d_release = ceph_d_release,
1386 };
1387 
1388 const struct dentry_operations ceph_snap_dentry_ops = {
1389 	.d_release = ceph_d_release,
1390 	.d_prune = ceph_d_prune,
1391 };
1392