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