xref: /kernel/linux/linux-5.10/fs/ceph/dir.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/ceph/ceph_debug.h>
3
4#include <linux/spinlock.h>
5#include <linux/namei.h>
6#include <linux/slab.h>
7#include <linux/sched.h>
8#include <linux/xattr.h>
9
10#include "super.h"
11#include "mds_client.h"
12
13/*
14 * Directory operations: readdir, lookup, create, link, unlink,
15 * rename, etc.
16 */
17
18/*
19 * Ceph MDS operations are specified in terms of a base ino and
20 * relative path.  Thus, the client can specify an operation on a
21 * specific inode (e.g., a getattr due to fstat(2)), or as a path
22 * relative to, say, the root directory.
23 *
24 * Normally, we limit ourselves to strict inode ops (no path component)
25 * or dentry operations (a single path component relative to an ino).  The
26 * exception to this is open_root_dentry(), which will open the mount
27 * point by name.
28 */
29
30const struct dentry_operations ceph_dentry_ops;
31
32static bool __dentry_lease_is_valid(struct ceph_dentry_info *di);
33static int __dir_lease_try_check(const struct dentry *dentry);
34
35/*
36 * Initialize ceph dentry state.
37 */
38static int ceph_d_init(struct dentry *dentry)
39{
40	struct ceph_dentry_info *di;
41	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dentry->d_sb);
42
43	di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
44	if (!di)
45		return -ENOMEM;          /* oh well */
46
47	di->dentry = dentry;
48	di->lease_session = NULL;
49	di->time = jiffies;
50	dentry->d_fsdata = di;
51	INIT_LIST_HEAD(&di->lease_list);
52
53	atomic64_inc(&mdsc->metric.total_dentries);
54
55	return 0;
56}
57
58/*
59 * for f_pos for readdir:
60 * - hash order:
61 *	(0xff << 52) | ((24 bits hash) << 28) |
62 *	(the nth entry has hash collision);
63 * - frag+name order;
64 *	((frag value) << 28) | (the nth entry in frag);
65 */
66#define OFFSET_BITS	28
67#define OFFSET_MASK	((1 << OFFSET_BITS) - 1)
68#define HASH_ORDER	(0xffull << (OFFSET_BITS + 24))
69loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
70{
71	loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
72	if (hash_order)
73		fpos |= HASH_ORDER;
74	return fpos;
75}
76
77static bool is_hash_order(loff_t p)
78{
79	return (p & HASH_ORDER) == HASH_ORDER;
80}
81
82static unsigned fpos_frag(loff_t p)
83{
84	return p >> OFFSET_BITS;
85}
86
87static unsigned fpos_hash(loff_t p)
88{
89	return ceph_frag_value(fpos_frag(p));
90}
91
92static unsigned fpos_off(loff_t p)
93{
94	return p & OFFSET_MASK;
95}
96
97static int fpos_cmp(loff_t l, loff_t r)
98{
99	int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
100	if (v)
101		return v;
102	return (int)(fpos_off(l) - fpos_off(r));
103}
104
105/*
106 * make note of the last dentry we read, so we can
107 * continue at the same lexicographical point,
108 * regardless of what dir changes take place on the
109 * server.
110 */
111static int note_last_dentry(struct ceph_dir_file_info *dfi, const char *name,
112		            int len, unsigned next_offset)
113{
114	char *buf = kmalloc(len+1, GFP_KERNEL);
115	if (!buf)
116		return -ENOMEM;
117	kfree(dfi->last_name);
118	dfi->last_name = buf;
119	memcpy(dfi->last_name, name, len);
120	dfi->last_name[len] = 0;
121	dfi->next_offset = next_offset;
122	dout("note_last_dentry '%s'\n", dfi->last_name);
123	return 0;
124}
125
126
127static struct dentry *
128__dcache_find_get_entry(struct dentry *parent, u64 idx,
129			struct ceph_readdir_cache_control *cache_ctl)
130{
131	struct inode *dir = d_inode(parent);
132	struct dentry *dentry;
133	unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
134	loff_t ptr_pos = idx * sizeof(struct dentry *);
135	pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
136
137	if (ptr_pos >= i_size_read(dir))
138		return NULL;
139
140	if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
141		ceph_readdir_cache_release(cache_ctl);
142		cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
143		if (!cache_ctl->page) {
144			dout(" page %lu not found\n", ptr_pgoff);
145			return ERR_PTR(-EAGAIN);
146		}
147		/* reading/filling the cache are serialized by
148		   i_mutex, no need to use page lock */
149		unlock_page(cache_ctl->page);
150		cache_ctl->dentries = kmap(cache_ctl->page);
151	}
152
153	cache_ctl->index = idx & idx_mask;
154
155	rcu_read_lock();
156	spin_lock(&parent->d_lock);
157	/* check i_size again here, because empty directory can be
158	 * marked as complete while not holding the i_mutex. */
159	if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
160		dentry = cache_ctl->dentries[cache_ctl->index];
161	else
162		dentry = NULL;
163	spin_unlock(&parent->d_lock);
164	if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
165		dentry = NULL;
166	rcu_read_unlock();
167	return dentry ? : ERR_PTR(-EAGAIN);
168}
169
170/*
171 * When possible, we try to satisfy a readdir by peeking at the
172 * dcache.  We make this work by carefully ordering dentries on
173 * d_child when we initially get results back from the MDS, and
174 * falling back to a "normal" sync readdir if any dentries in the dir
175 * are dropped.
176 *
177 * Complete dir indicates that we have all dentries in the dir.  It is
178 * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
179 * the MDS if/when the directory is modified).
180 */
181static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
182			    int shared_gen)
183{
184	struct ceph_dir_file_info *dfi = file->private_data;
185	struct dentry *parent = file->f_path.dentry;
186	struct inode *dir = d_inode(parent);
187	struct dentry *dentry, *last = NULL;
188	struct ceph_dentry_info *di;
189	struct ceph_readdir_cache_control cache_ctl = {};
190	u64 idx = 0;
191	int err = 0;
192
193	dout("__dcache_readdir %p v%u at %llx\n", dir, (unsigned)shared_gen, ctx->pos);
194
195	/* search start position */
196	if (ctx->pos > 2) {
197		u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
198		while (count > 0) {
199			u64 step = count >> 1;
200			dentry = __dcache_find_get_entry(parent, idx + step,
201							 &cache_ctl);
202			if (!dentry) {
203				/* use linar search */
204				idx = 0;
205				break;
206			}
207			if (IS_ERR(dentry)) {
208				err = PTR_ERR(dentry);
209				goto out;
210			}
211			di = ceph_dentry(dentry);
212			spin_lock(&dentry->d_lock);
213			if (fpos_cmp(di->offset, ctx->pos) < 0) {
214				idx += step + 1;
215				count -= step + 1;
216			} else {
217				count = step;
218			}
219			spin_unlock(&dentry->d_lock);
220			dput(dentry);
221		}
222
223		dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
224	}
225
226
227	for (;;) {
228		bool emit_dentry = false;
229		dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
230		if (!dentry) {
231			dfi->file_info.flags |= CEPH_F_ATEND;
232			err = 0;
233			break;
234		}
235		if (IS_ERR(dentry)) {
236			err = PTR_ERR(dentry);
237			goto out;
238		}
239
240		spin_lock(&dentry->d_lock);
241		di = ceph_dentry(dentry);
242		if (d_unhashed(dentry) ||
243		    d_really_is_negative(dentry) ||
244		    di->lease_shared_gen != shared_gen) {
245			spin_unlock(&dentry->d_lock);
246			dput(dentry);
247			err = -EAGAIN;
248			goto out;
249		}
250		if (fpos_cmp(ctx->pos, di->offset) <= 0) {
251			__ceph_dentry_dir_lease_touch(di);
252			emit_dentry = true;
253		}
254		spin_unlock(&dentry->d_lock);
255
256		if (emit_dentry) {
257			dout(" %llx dentry %p %pd %p\n", di->offset,
258			     dentry, dentry, d_inode(dentry));
259			ctx->pos = di->offset;
260			if (!dir_emit(ctx, dentry->d_name.name,
261				      dentry->d_name.len, ceph_present_inode(d_inode(dentry)),
262				      d_inode(dentry)->i_mode >> 12)) {
263				dput(dentry);
264				err = 0;
265				break;
266			}
267			ctx->pos++;
268
269			if (last)
270				dput(last);
271			last = dentry;
272		} else {
273			dput(dentry);
274		}
275	}
276out:
277	ceph_readdir_cache_release(&cache_ctl);
278	if (last) {
279		int ret;
280		di = ceph_dentry(last);
281		ret = note_last_dentry(dfi, last->d_name.name, last->d_name.len,
282				       fpos_off(di->offset) + 1);
283		if (ret < 0)
284			err = ret;
285		dput(last);
286		/* last_name no longer match cache index */
287		if (dfi->readdir_cache_idx >= 0) {
288			dfi->readdir_cache_idx = -1;
289			dfi->dir_release_count = 0;
290		}
291	}
292	return err;
293}
294
295static bool need_send_readdir(struct ceph_dir_file_info *dfi, loff_t pos)
296{
297	if (!dfi->last_readdir)
298		return true;
299	if (is_hash_order(pos))
300		return !ceph_frag_contains_value(dfi->frag, fpos_hash(pos));
301	else
302		return dfi->frag != fpos_frag(pos);
303}
304
305static int ceph_readdir(struct file *file, struct dir_context *ctx)
306{
307	struct ceph_dir_file_info *dfi = file->private_data;
308	struct inode *inode = file_inode(file);
309	struct ceph_inode_info *ci = ceph_inode(inode);
310	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
311	struct ceph_mds_client *mdsc = fsc->mdsc;
312	int i;
313	int err;
314	unsigned frag = -1;
315	struct ceph_mds_reply_info_parsed *rinfo;
316
317	dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
318	if (dfi->file_info.flags & CEPH_F_ATEND)
319		return 0;
320
321	/* always start with . and .. */
322	if (ctx->pos == 0) {
323		dout("readdir off 0 -> '.'\n");
324		if (!dir_emit(ctx, ".", 1, ceph_present_inode(inode),
325			    inode->i_mode >> 12))
326			return 0;
327		ctx->pos = 1;
328	}
329	if (ctx->pos == 1) {
330		u64 ino;
331		struct dentry *dentry = file->f_path.dentry;
332
333		spin_lock(&dentry->d_lock);
334		ino = ceph_present_inode(dentry->d_parent->d_inode);
335		spin_unlock(&dentry->d_lock);
336
337		dout("readdir off 1 -> '..'\n");
338		if (!dir_emit(ctx, "..", 2, ino, inode->i_mode >> 12))
339			return 0;
340		ctx->pos = 2;
341	}
342
343	spin_lock(&ci->i_ceph_lock);
344	/* request Fx cap. if have Fx, we don't need to release Fs cap
345	 * for later create/unlink. */
346	__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_WR);
347	/* can we use the dcache? */
348	if (ceph_test_mount_opt(fsc, DCACHE) &&
349	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
350	    ceph_snap(inode) != CEPH_SNAPDIR &&
351	    __ceph_dir_is_complete_ordered(ci) &&
352	    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
353		int shared_gen = atomic_read(&ci->i_shared_gen);
354
355		spin_unlock(&ci->i_ceph_lock);
356		err = __dcache_readdir(file, ctx, shared_gen);
357		if (err != -EAGAIN)
358			return err;
359	} else {
360		spin_unlock(&ci->i_ceph_lock);
361	}
362
363	/* proceed with a normal readdir */
364more:
365	/* do we have the correct frag content buffered? */
366	if (need_send_readdir(dfi, ctx->pos)) {
367		struct ceph_mds_request *req;
368		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
369			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
370
371		/* discard old result, if any */
372		if (dfi->last_readdir) {
373			ceph_mdsc_put_request(dfi->last_readdir);
374			dfi->last_readdir = NULL;
375		}
376
377		if (is_hash_order(ctx->pos)) {
378			/* fragtree isn't always accurate. choose frag
379			 * based on previous reply when possible. */
380			if (frag == (unsigned)-1)
381				frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
382							NULL, NULL);
383		} else {
384			frag = fpos_frag(ctx->pos);
385		}
386
387		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
388		     ceph_vinop(inode), frag, dfi->last_name);
389		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
390		if (IS_ERR(req))
391			return PTR_ERR(req);
392		err = ceph_alloc_readdir_reply_buffer(req, inode);
393		if (err) {
394			ceph_mdsc_put_request(req);
395			return err;
396		}
397		/* hints to request -> mds selection code */
398		req->r_direct_mode = USE_AUTH_MDS;
399		if (op == CEPH_MDS_OP_READDIR) {
400			req->r_direct_hash = ceph_frag_value(frag);
401			__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
402			req->r_inode_drop = CEPH_CAP_FILE_EXCL;
403		}
404		if (dfi->last_name) {
405			req->r_path2 = kstrdup(dfi->last_name, GFP_KERNEL);
406			if (!req->r_path2) {
407				ceph_mdsc_put_request(req);
408				return -ENOMEM;
409			}
410		} else if (is_hash_order(ctx->pos)) {
411			req->r_args.readdir.offset_hash =
412				cpu_to_le32(fpos_hash(ctx->pos));
413		}
414
415		req->r_dir_release_cnt = dfi->dir_release_count;
416		req->r_dir_ordered_cnt = dfi->dir_ordered_count;
417		req->r_readdir_cache_idx = dfi->readdir_cache_idx;
418		req->r_readdir_offset = dfi->next_offset;
419		req->r_args.readdir.frag = cpu_to_le32(frag);
420		req->r_args.readdir.flags =
421				cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
422
423		req->r_inode = inode;
424		ihold(inode);
425		req->r_dentry = dget(file->f_path.dentry);
426		err = ceph_mdsc_do_request(mdsc, NULL, req);
427		if (err < 0) {
428			ceph_mdsc_put_request(req);
429			return err;
430		}
431		dout("readdir got and parsed readdir result=%d on "
432		     "frag %x, end=%d, complete=%d, hash_order=%d\n",
433		     err, frag,
434		     (int)req->r_reply_info.dir_end,
435		     (int)req->r_reply_info.dir_complete,
436		     (int)req->r_reply_info.hash_order);
437
438		rinfo = &req->r_reply_info;
439		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
440			frag = le32_to_cpu(rinfo->dir_dir->frag);
441			if (!rinfo->hash_order) {
442				dfi->next_offset = req->r_readdir_offset;
443				/* adjust ctx->pos to beginning of frag */
444				ctx->pos = ceph_make_fpos(frag,
445							  dfi->next_offset,
446							  false);
447			}
448		}
449
450		dfi->frag = frag;
451		dfi->last_readdir = req;
452
453		if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
454			dfi->readdir_cache_idx = req->r_readdir_cache_idx;
455			if (dfi->readdir_cache_idx < 0) {
456				/* preclude from marking dir ordered */
457				dfi->dir_ordered_count = 0;
458			} else if (ceph_frag_is_leftmost(frag) &&
459				   dfi->next_offset == 2) {
460				/* note dir version at start of readdir so
461				 * we can tell if any dentries get dropped */
462				dfi->dir_release_count = req->r_dir_release_cnt;
463				dfi->dir_ordered_count = req->r_dir_ordered_cnt;
464			}
465		} else {
466			dout("readdir !did_prepopulate\n");
467			/* disable readdir cache */
468			dfi->readdir_cache_idx = -1;
469			/* preclude from marking dir complete */
470			dfi->dir_release_count = 0;
471		}
472
473		/* note next offset and last dentry name */
474		if (rinfo->dir_nr > 0) {
475			struct ceph_mds_reply_dir_entry *rde =
476					rinfo->dir_entries + (rinfo->dir_nr-1);
477			unsigned next_offset = req->r_reply_info.dir_end ?
478					2 : (fpos_off(rde->offset) + 1);
479			err = note_last_dentry(dfi, rde->name, rde->name_len,
480					       next_offset);
481			if (err) {
482				ceph_mdsc_put_request(dfi->last_readdir);
483				dfi->last_readdir = NULL;
484				return err;
485			}
486		} else if (req->r_reply_info.dir_end) {
487			dfi->next_offset = 2;
488			/* keep last name */
489		}
490	}
491
492	rinfo = &dfi->last_readdir->r_reply_info;
493	dout("readdir frag %x num %d pos %llx chunk first %llx\n",
494	     dfi->frag, rinfo->dir_nr, ctx->pos,
495	     rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
496
497	i = 0;
498	/* search start position */
499	if (rinfo->dir_nr > 0) {
500		int step, nr = rinfo->dir_nr;
501		while (nr > 0) {
502			step = nr >> 1;
503			if (rinfo->dir_entries[i + step].offset < ctx->pos) {
504				i +=  step + 1;
505				nr -= step + 1;
506			} else {
507				nr = step;
508			}
509		}
510	}
511	for (; i < rinfo->dir_nr; i++) {
512		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
513
514		BUG_ON(rde->offset < ctx->pos);
515
516		ctx->pos = rde->offset;
517		dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
518		     i, rinfo->dir_nr, ctx->pos,
519		     rde->name_len, rde->name, &rde->inode.in);
520
521		BUG_ON(!rde->inode.in);
522
523		if (!dir_emit(ctx, rde->name, rde->name_len,
524			      ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
525			      le32_to_cpu(rde->inode.in->mode) >> 12)) {
526			/*
527			 * NOTE: Here no need to put the 'dfi->last_readdir',
528			 * because when dir_emit stops us it's most likely
529			 * doesn't have enough memory, etc. So for next readdir
530			 * it will continue.
531			 */
532			dout("filldir stopping us...\n");
533			return 0;
534		}
535		ctx->pos++;
536	}
537
538	ceph_mdsc_put_request(dfi->last_readdir);
539	dfi->last_readdir = NULL;
540
541	if (dfi->next_offset > 2) {
542		frag = dfi->frag;
543		goto more;
544	}
545
546	/* more frags? */
547	if (!ceph_frag_is_rightmost(dfi->frag)) {
548		frag = ceph_frag_next(dfi->frag);
549		if (is_hash_order(ctx->pos)) {
550			loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
551							dfi->next_offset, true);
552			if (new_pos > ctx->pos)
553				ctx->pos = new_pos;
554			/* keep last_name */
555		} else {
556			ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
557							false);
558			kfree(dfi->last_name);
559			dfi->last_name = NULL;
560		}
561		dout("readdir next frag is %x\n", frag);
562		goto more;
563	}
564	dfi->file_info.flags |= CEPH_F_ATEND;
565
566	/*
567	 * if dir_release_count still matches the dir, no dentries
568	 * were released during the whole readdir, and we should have
569	 * the complete dir contents in our cache.
570	 */
571	if (atomic64_read(&ci->i_release_count) ==
572					dfi->dir_release_count) {
573		spin_lock(&ci->i_ceph_lock);
574		if (dfi->dir_ordered_count ==
575				atomic64_read(&ci->i_ordered_count)) {
576			dout(" marking %p complete and ordered\n", inode);
577			/* use i_size to track number of entries in
578			 * readdir cache */
579			BUG_ON(dfi->readdir_cache_idx < 0);
580			i_size_write(inode, dfi->readdir_cache_idx *
581				     sizeof(struct dentry*));
582		} else {
583			dout(" marking %p complete\n", inode);
584		}
585		__ceph_dir_set_complete(ci, dfi->dir_release_count,
586					dfi->dir_ordered_count);
587		spin_unlock(&ci->i_ceph_lock);
588	}
589
590	dout("readdir %p file %p done.\n", inode, file);
591	return 0;
592}
593
594static void reset_readdir(struct ceph_dir_file_info *dfi)
595{
596	if (dfi->last_readdir) {
597		ceph_mdsc_put_request(dfi->last_readdir);
598		dfi->last_readdir = NULL;
599	}
600	kfree(dfi->last_name);
601	dfi->last_name = NULL;
602	dfi->dir_release_count = 0;
603	dfi->readdir_cache_idx = -1;
604	dfi->next_offset = 2;  /* compensate for . and .. */
605	dfi->file_info.flags &= ~CEPH_F_ATEND;
606}
607
608/*
609 * discard buffered readdir content on seekdir(0), or seek to new frag,
610 * or seek prior to current chunk
611 */
612static bool need_reset_readdir(struct ceph_dir_file_info *dfi, loff_t new_pos)
613{
614	struct ceph_mds_reply_info_parsed *rinfo;
615	loff_t chunk_offset;
616	if (new_pos == 0)
617		return true;
618	if (is_hash_order(new_pos)) {
619		/* no need to reset last_name for a forward seek when
620		 * dentries are sotred in hash order */
621	} else if (dfi->frag != fpos_frag(new_pos)) {
622		return true;
623	}
624	rinfo = dfi->last_readdir ? &dfi->last_readdir->r_reply_info : NULL;
625	if (!rinfo || !rinfo->dir_nr)
626		return true;
627	chunk_offset = rinfo->dir_entries[0].offset;
628	return new_pos < chunk_offset ||
629	       is_hash_order(new_pos) != is_hash_order(chunk_offset);
630}
631
632static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
633{
634	struct ceph_dir_file_info *dfi = file->private_data;
635	struct inode *inode = file->f_mapping->host;
636	loff_t retval;
637
638	inode_lock(inode);
639	retval = -EINVAL;
640	switch (whence) {
641	case SEEK_CUR:
642		offset += file->f_pos;
643	case SEEK_SET:
644		break;
645	case SEEK_END:
646		retval = -EOPNOTSUPP;
647	default:
648		goto out;
649	}
650
651	if (offset >= 0) {
652		if (need_reset_readdir(dfi, offset)) {
653			dout("dir_llseek dropping %p content\n", file);
654			reset_readdir(dfi);
655		} else if (is_hash_order(offset) && offset > file->f_pos) {
656			/* for hash offset, we don't know if a forward seek
657			 * is within same frag */
658			dfi->dir_release_count = 0;
659			dfi->readdir_cache_idx = -1;
660		}
661
662		if (offset != file->f_pos) {
663			file->f_pos = offset;
664			file->f_version = 0;
665			dfi->file_info.flags &= ~CEPH_F_ATEND;
666		}
667		retval = offset;
668	}
669out:
670	inode_unlock(inode);
671	return retval;
672}
673
674/*
675 * Handle lookups for the hidden .snap directory.
676 */
677int ceph_handle_snapdir(struct ceph_mds_request *req,
678			struct dentry *dentry, int err)
679{
680	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
681	struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
682
683	/* .snap dir? */
684	if (err == -ENOENT &&
685	    ceph_snap(parent) == CEPH_NOSNAP &&
686	    strcmp(dentry->d_name.name,
687		   fsc->mount_options->snapdir_name) == 0) {
688		struct inode *inode = ceph_get_snapdir(parent);
689		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
690		     dentry, dentry, inode);
691		BUG_ON(!d_unhashed(dentry));
692		d_add(dentry, inode);
693		err = 0;
694	}
695	return err;
696}
697
698/*
699 * Figure out final result of a lookup/open request.
700 *
701 * Mainly, make sure we return the final req->r_dentry (if it already
702 * existed) in place of the original VFS-provided dentry when they
703 * differ.
704 *
705 * Gracefully handle the case where the MDS replies with -ENOENT and
706 * no trace (which it may do, at its discretion, e.g., if it doesn't
707 * care to issue a lease on the negative dentry).
708 */
709struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
710				  struct dentry *dentry, int err)
711{
712	if (err == -ENOENT) {
713		/* no trace? */
714		err = 0;
715		if (!req->r_reply_info.head->is_dentry) {
716			dout("ENOENT and no trace, dentry %p inode %p\n",
717			     dentry, d_inode(dentry));
718			if (d_really_is_positive(dentry)) {
719				d_drop(dentry);
720				err = -ENOENT;
721			} else {
722				d_add(dentry, NULL);
723			}
724		}
725	}
726	if (err)
727		dentry = ERR_PTR(err);
728	else if (dentry != req->r_dentry)
729		dentry = dget(req->r_dentry);   /* we got spliced */
730	else
731		dentry = NULL;
732	return dentry;
733}
734
735static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
736{
737	return ceph_ino(inode) == CEPH_INO_ROOT &&
738		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
739}
740
741/*
742 * Look up a single dir entry.  If there is a lookup intent, inform
743 * the MDS so that it gets our 'caps wanted' value in a single op.
744 */
745static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
746				  unsigned int flags)
747{
748	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
749	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
750	struct ceph_mds_request *req;
751	int op;
752	int mask;
753	int err;
754
755	dout("lookup %p dentry %p '%pd'\n",
756	     dir, dentry, dentry);
757
758	if (dentry->d_name.len > NAME_MAX)
759		return ERR_PTR(-ENAMETOOLONG);
760
761	/* can we conclude ENOENT locally? */
762	if (d_really_is_negative(dentry)) {
763		struct ceph_inode_info *ci = ceph_inode(dir);
764		struct ceph_dentry_info *di = ceph_dentry(dentry);
765
766		spin_lock(&ci->i_ceph_lock);
767		dout(" dir %p flags are 0x%lx\n", dir, ci->i_ceph_flags);
768		if (strncmp(dentry->d_name.name,
769			    fsc->mount_options->snapdir_name,
770			    dentry->d_name.len) &&
771		    !is_root_ceph_dentry(dir, dentry) &&
772		    ceph_test_mount_opt(fsc, DCACHE) &&
773		    __ceph_dir_is_complete(ci) &&
774		    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
775			__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
776			spin_unlock(&ci->i_ceph_lock);
777			dout(" dir %p complete, -ENOENT\n", dir);
778			d_add(dentry, NULL);
779			di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
780			return NULL;
781		}
782		spin_unlock(&ci->i_ceph_lock);
783	}
784
785	op = ceph_snap(dir) == CEPH_SNAPDIR ?
786		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
787	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
788	if (IS_ERR(req))
789		return ERR_CAST(req);
790	req->r_dentry = dget(dentry);
791	req->r_num_caps = 2;
792
793	mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
794	if (ceph_security_xattr_wanted(dir))
795		mask |= CEPH_CAP_XATTR_SHARED;
796	req->r_args.getattr.mask = cpu_to_le32(mask);
797
798	req->r_parent = dir;
799	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
800	err = ceph_mdsc_do_request(mdsc, NULL, req);
801	err = ceph_handle_snapdir(req, dentry, err);
802	dentry = ceph_finish_lookup(req, dentry, err);
803	ceph_mdsc_put_request(req);  /* will dput(dentry) */
804	dout("lookup result=%p\n", dentry);
805	return dentry;
806}
807
808/*
809 * If we do a create but get no trace back from the MDS, follow up with
810 * a lookup (the VFS expects us to link up the provided dentry).
811 */
812int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
813{
814	struct dentry *result = ceph_lookup(dir, dentry, 0);
815
816	if (result && !IS_ERR(result)) {
817		/*
818		 * We created the item, then did a lookup, and found
819		 * it was already linked to another inode we already
820		 * had in our cache (and thus got spliced). To not
821		 * confuse VFS (especially when inode is a directory),
822		 * we don't link our dentry to that inode, return an
823		 * error instead.
824		 *
825		 * This event should be rare and it happens only when
826		 * we talk to old MDS. Recent MDS does not send traceless
827		 * reply for request that creates new inode.
828		 */
829		d_drop(result);
830		return -ESTALE;
831	}
832	return PTR_ERR(result);
833}
834
835static int ceph_mknod(struct inode *dir, struct dentry *dentry,
836		      umode_t mode, dev_t rdev)
837{
838	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
839	struct ceph_mds_request *req;
840	struct ceph_acl_sec_ctx as_ctx = {};
841	int err;
842
843	if (ceph_snap(dir) != CEPH_NOSNAP)
844		return -EROFS;
845
846	if (ceph_quota_is_max_files_exceeded(dir)) {
847		err = -EDQUOT;
848		goto out;
849	}
850
851	err = ceph_pre_init_acls(dir, &mode, &as_ctx);
852	if (err < 0)
853		goto out;
854	err = ceph_security_init_secctx(dentry, mode, &as_ctx);
855	if (err < 0)
856		goto out;
857
858	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
859	     dir, dentry, mode, rdev);
860	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
861	if (IS_ERR(req)) {
862		err = PTR_ERR(req);
863		goto out;
864	}
865	req->r_dentry = dget(dentry);
866	req->r_num_caps = 2;
867	req->r_parent = dir;
868	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
869	req->r_args.mknod.mode = cpu_to_le32(mode);
870	req->r_args.mknod.rdev = cpu_to_le32(rdev);
871	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
872	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
873	if (as_ctx.pagelist) {
874		req->r_pagelist = as_ctx.pagelist;
875		as_ctx.pagelist = NULL;
876	}
877	err = ceph_mdsc_do_request(mdsc, dir, req);
878	if (!err && !req->r_reply_info.head->is_dentry)
879		err = ceph_handle_notrace_create(dir, dentry);
880	ceph_mdsc_put_request(req);
881out:
882	if (!err)
883		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
884	else
885		d_drop(dentry);
886	ceph_release_acl_sec_ctx(&as_ctx);
887	return err;
888}
889
890static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
891		       bool excl)
892{
893	return ceph_mknod(dir, dentry, mode, 0);
894}
895
896static int ceph_symlink(struct inode *dir, struct dentry *dentry,
897			    const char *dest)
898{
899	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
900	struct ceph_mds_request *req;
901	struct ceph_acl_sec_ctx as_ctx = {};
902	int err;
903
904	if (ceph_snap(dir) != CEPH_NOSNAP)
905		return -EROFS;
906
907	if (ceph_quota_is_max_files_exceeded(dir)) {
908		err = -EDQUOT;
909		goto out;
910	}
911
912	err = ceph_security_init_secctx(dentry, S_IFLNK | 0777, &as_ctx);
913	if (err < 0)
914		goto out;
915
916	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
917	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
918	if (IS_ERR(req)) {
919		err = PTR_ERR(req);
920		goto out;
921	}
922	req->r_path2 = kstrdup(dest, GFP_KERNEL);
923	if (!req->r_path2) {
924		err = -ENOMEM;
925		ceph_mdsc_put_request(req);
926		goto out;
927	}
928	req->r_parent = dir;
929	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
930	req->r_dentry = dget(dentry);
931	req->r_num_caps = 2;
932	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
933	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
934	if (as_ctx.pagelist) {
935		req->r_pagelist = as_ctx.pagelist;
936		as_ctx.pagelist = NULL;
937	}
938	err = ceph_mdsc_do_request(mdsc, dir, req);
939	if (!err && !req->r_reply_info.head->is_dentry)
940		err = ceph_handle_notrace_create(dir, dentry);
941	ceph_mdsc_put_request(req);
942out:
943	if (err)
944		d_drop(dentry);
945	ceph_release_acl_sec_ctx(&as_ctx);
946	return err;
947}
948
949static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
950{
951	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
952	struct ceph_mds_request *req;
953	struct ceph_acl_sec_ctx as_ctx = {};
954	int err = -EROFS;
955	int op;
956
957	if (ceph_snap(dir) == CEPH_SNAPDIR) {
958		/* mkdir .snap/foo is a MKSNAP */
959		op = CEPH_MDS_OP_MKSNAP;
960		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
961		     dentry, dentry);
962	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
963		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
964		op = CEPH_MDS_OP_MKDIR;
965	} else {
966		goto out;
967	}
968
969	if (op == CEPH_MDS_OP_MKDIR &&
970	    ceph_quota_is_max_files_exceeded(dir)) {
971		err = -EDQUOT;
972		goto out;
973	}
974
975	mode |= S_IFDIR;
976	err = ceph_pre_init_acls(dir, &mode, &as_ctx);
977	if (err < 0)
978		goto out;
979	err = ceph_security_init_secctx(dentry, mode, &as_ctx);
980	if (err < 0)
981		goto out;
982
983	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
984	if (IS_ERR(req)) {
985		err = PTR_ERR(req);
986		goto out;
987	}
988
989	req->r_dentry = dget(dentry);
990	req->r_num_caps = 2;
991	req->r_parent = dir;
992	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
993	req->r_args.mkdir.mode = cpu_to_le32(mode);
994	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
995	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
996	if (as_ctx.pagelist) {
997		req->r_pagelist = as_ctx.pagelist;
998		as_ctx.pagelist = NULL;
999	}
1000	err = ceph_mdsc_do_request(mdsc, dir, req);
1001	if (!err &&
1002	    !req->r_reply_info.head->is_target &&
1003	    !req->r_reply_info.head->is_dentry)
1004		err = ceph_handle_notrace_create(dir, dentry);
1005	ceph_mdsc_put_request(req);
1006out:
1007	if (!err)
1008		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
1009	else
1010		d_drop(dentry);
1011	ceph_release_acl_sec_ctx(&as_ctx);
1012	return err;
1013}
1014
1015static int ceph_link(struct dentry *old_dentry, struct inode *dir,
1016		     struct dentry *dentry)
1017{
1018	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
1019	struct ceph_mds_request *req;
1020	int err;
1021
1022	if (ceph_snap(dir) != CEPH_NOSNAP)
1023		return -EROFS;
1024
1025	dout("link in dir %p old_dentry %p dentry %p\n", dir,
1026	     old_dentry, dentry);
1027	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
1028	if (IS_ERR(req)) {
1029		d_drop(dentry);
1030		return PTR_ERR(req);
1031	}
1032	req->r_dentry = dget(dentry);
1033	req->r_num_caps = 2;
1034	req->r_old_dentry = dget(old_dentry);
1035	req->r_parent = dir;
1036	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1037	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1038	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1039	/* release LINK_SHARED on source inode (mds will lock it) */
1040	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1041	err = ceph_mdsc_do_request(mdsc, dir, req);
1042	if (err) {
1043		d_drop(dentry);
1044	} else if (!req->r_reply_info.head->is_dentry) {
1045		ihold(d_inode(old_dentry));
1046		d_instantiate(dentry, d_inode(old_dentry));
1047	}
1048	ceph_mdsc_put_request(req);
1049	return err;
1050}
1051
1052static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
1053				 struct ceph_mds_request *req)
1054{
1055	int result = req->r_err ? req->r_err :
1056			le32_to_cpu(req->r_reply_info.head->result);
1057
1058	if (result == -EJUKEBOX)
1059		goto out;
1060
1061	/* If op failed, mark everyone involved for errors */
1062	if (result) {
1063		int pathlen = 0;
1064		u64 base = 0;
1065		char *path = ceph_mdsc_build_path(req->r_dentry, &pathlen,
1066						  &base, 0);
1067
1068		/* mark error on parent + clear complete */
1069		mapping_set_error(req->r_parent->i_mapping, result);
1070		ceph_dir_clear_complete(req->r_parent);
1071
1072		/* drop the dentry -- we don't know its status */
1073		if (!d_unhashed(req->r_dentry))
1074			d_drop(req->r_dentry);
1075
1076		/* mark inode itself for an error (since metadata is bogus) */
1077		mapping_set_error(req->r_old_inode->i_mapping, result);
1078
1079		pr_warn("ceph: async unlink failure path=(%llx)%s result=%d!\n",
1080			base, IS_ERR(path) ? "<<bad>>" : path, result);
1081		ceph_mdsc_free_path(path, pathlen);
1082	}
1083out:
1084	iput(req->r_old_inode);
1085	ceph_mdsc_release_dir_caps(req);
1086}
1087
1088static int get_caps_for_async_unlink(struct inode *dir, struct dentry *dentry)
1089{
1090	struct ceph_inode_info *ci = ceph_inode(dir);
1091	struct ceph_dentry_info *di;
1092	int got = 0, want = CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_UNLINK;
1093
1094	spin_lock(&ci->i_ceph_lock);
1095	if ((__ceph_caps_issued(ci, NULL) & want) == want) {
1096		ceph_take_cap_refs(ci, want, false);
1097		got = want;
1098	}
1099	spin_unlock(&ci->i_ceph_lock);
1100
1101	/* If we didn't get anything, return 0 */
1102	if (!got)
1103		return 0;
1104
1105        spin_lock(&dentry->d_lock);
1106        di = ceph_dentry(dentry);
1107	/*
1108	 * - We are holding Fx, which implies Fs caps.
1109	 * - Only support async unlink for primary linkage
1110	 */
1111	if (atomic_read(&ci->i_shared_gen) != di->lease_shared_gen ||
1112	    !(di->flags & CEPH_DENTRY_PRIMARY_LINK))
1113		want = 0;
1114        spin_unlock(&dentry->d_lock);
1115
1116	/* Do we still want what we've got? */
1117	if (want == got)
1118		return got;
1119
1120	ceph_put_cap_refs(ci, got);
1121	return 0;
1122}
1123
1124/*
1125 * rmdir and unlink are differ only by the metadata op code
1126 */
1127static int ceph_unlink(struct inode *dir, struct dentry *dentry)
1128{
1129	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
1130	struct ceph_mds_client *mdsc = fsc->mdsc;
1131	struct inode *inode = d_inode(dentry);
1132	struct ceph_mds_request *req;
1133	bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
1134	int err = -EROFS;
1135	int op;
1136
1137	if (ceph_snap(dir) == CEPH_SNAPDIR) {
1138		/* rmdir .snap/foo is RMSNAP */
1139		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
1140		op = CEPH_MDS_OP_RMSNAP;
1141	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
1142		dout("unlink/rmdir dir %p dn %p inode %p\n",
1143		     dir, dentry, inode);
1144		op = d_is_dir(dentry) ?
1145			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
1146	} else
1147		goto out;
1148retry:
1149	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1150	if (IS_ERR(req)) {
1151		err = PTR_ERR(req);
1152		goto out;
1153	}
1154	req->r_dentry = dget(dentry);
1155	req->r_num_caps = 2;
1156	req->r_parent = dir;
1157	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1158	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1159	req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
1160
1161	if (try_async && op == CEPH_MDS_OP_UNLINK &&
1162	    (req->r_dir_caps = get_caps_for_async_unlink(dir, dentry))) {
1163		dout("async unlink on %llu/%.*s caps=%s", ceph_ino(dir),
1164		     dentry->d_name.len, dentry->d_name.name,
1165		     ceph_cap_string(req->r_dir_caps));
1166		set_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags);
1167		req->r_callback = ceph_async_unlink_cb;
1168		req->r_old_inode = d_inode(dentry);
1169		ihold(req->r_old_inode);
1170		err = ceph_mdsc_submit_request(mdsc, dir, req);
1171		if (!err) {
1172			/*
1173			 * We have enough caps, so we assume that the unlink
1174			 * will succeed. Fix up the target inode and dcache.
1175			 */
1176			drop_nlink(inode);
1177			d_delete(dentry);
1178		} else if (err == -EJUKEBOX) {
1179			try_async = false;
1180			ceph_mdsc_put_request(req);
1181			goto retry;
1182		}
1183	} else {
1184		set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1185		err = ceph_mdsc_do_request(mdsc, dir, req);
1186		if (!err && !req->r_reply_info.head->is_dentry)
1187			d_delete(dentry);
1188	}
1189
1190	ceph_mdsc_put_request(req);
1191out:
1192	return err;
1193}
1194
1195static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
1196		       struct inode *new_dir, struct dentry *new_dentry,
1197		       unsigned int flags)
1198{
1199	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(old_dir->i_sb);
1200	struct ceph_mds_request *req;
1201	int op = CEPH_MDS_OP_RENAME;
1202	int err;
1203
1204	if (flags)
1205		return -EINVAL;
1206
1207	if (ceph_snap(old_dir) != ceph_snap(new_dir))
1208		return -EXDEV;
1209	if (ceph_snap(old_dir) != CEPH_NOSNAP) {
1210		if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
1211			op = CEPH_MDS_OP_RENAMESNAP;
1212		else
1213			return -EROFS;
1214	} else if (old_dir != new_dir) {
1215		err = ceph_quota_check_rename(mdsc, d_inode(old_dentry),
1216					      new_dir);
1217		if (err)
1218			return err;
1219	}
1220
1221	dout("rename dir %p dentry %p to dir %p dentry %p\n",
1222	     old_dir, old_dentry, new_dir, new_dentry);
1223	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1224	if (IS_ERR(req))
1225		return PTR_ERR(req);
1226	ihold(old_dir);
1227	req->r_dentry = dget(new_dentry);
1228	req->r_num_caps = 2;
1229	req->r_old_dentry = dget(old_dentry);
1230	req->r_old_dentry_dir = old_dir;
1231	req->r_parent = new_dir;
1232	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1233	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
1234	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
1235	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1236	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1237	/* release LINK_RDCACHE on source inode (mds will lock it) */
1238	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1239	if (d_really_is_positive(new_dentry)) {
1240		req->r_inode_drop =
1241			ceph_drop_caps_for_unlink(d_inode(new_dentry));
1242	}
1243	err = ceph_mdsc_do_request(mdsc, old_dir, req);
1244	if (!err && !req->r_reply_info.head->is_dentry) {
1245		/*
1246		 * Normally d_move() is done by fill_trace (called by
1247		 * do_request, above).  If there is no trace, we need
1248		 * to do it here.
1249		 */
1250		d_move(old_dentry, new_dentry);
1251	}
1252	ceph_mdsc_put_request(req);
1253	return err;
1254}
1255
1256/*
1257 * Move dentry to tail of mdsc->dentry_leases list when lease is updated.
1258 * Leases at front of the list will expire first. (Assume all leases have
1259 * similar duration)
1260 *
1261 * Called under dentry->d_lock.
1262 */
1263void __ceph_dentry_lease_touch(struct ceph_dentry_info *di)
1264{
1265	struct dentry *dn = di->dentry;
1266	struct ceph_mds_client *mdsc;
1267
1268	dout("dentry_lease_touch %p %p '%pd'\n", di, dn, dn);
1269
1270	di->flags |= CEPH_DENTRY_LEASE_LIST;
1271	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1272		di->flags |= CEPH_DENTRY_REFERENCED;
1273		return;
1274	}
1275
1276	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1277	spin_lock(&mdsc->dentry_list_lock);
1278	list_move_tail(&di->lease_list, &mdsc->dentry_leases);
1279	spin_unlock(&mdsc->dentry_list_lock);
1280}
1281
1282static void __dentry_dir_lease_touch(struct ceph_mds_client* mdsc,
1283				     struct ceph_dentry_info *di)
1284{
1285	di->flags &= ~(CEPH_DENTRY_LEASE_LIST | CEPH_DENTRY_REFERENCED);
1286	di->lease_gen = 0;
1287	di->time = jiffies;
1288	list_move_tail(&di->lease_list, &mdsc->dentry_dir_leases);
1289}
1290
1291/*
1292 * When dir lease is used, add dentry to tail of mdsc->dentry_dir_leases
1293 * list if it's not in the list, otherwise set 'referenced' flag.
1294 *
1295 * Called under dentry->d_lock.
1296 */
1297void __ceph_dentry_dir_lease_touch(struct ceph_dentry_info *di)
1298{
1299	struct dentry *dn = di->dentry;
1300	struct ceph_mds_client *mdsc;
1301
1302	dout("dentry_dir_lease_touch %p %p '%pd' (offset 0x%llx)\n",
1303	     di, dn, dn, di->offset);
1304
1305	if (!list_empty(&di->lease_list)) {
1306		if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1307			/* don't remove dentry from dentry lease list
1308			 * if its lease is valid */
1309			if (__dentry_lease_is_valid(di))
1310				return;
1311		} else {
1312			di->flags |= CEPH_DENTRY_REFERENCED;
1313			return;
1314		}
1315	}
1316
1317	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1318		di->flags |= CEPH_DENTRY_REFERENCED;
1319		di->flags &= ~CEPH_DENTRY_LEASE_LIST;
1320		return;
1321	}
1322
1323	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1324	spin_lock(&mdsc->dentry_list_lock);
1325	__dentry_dir_lease_touch(mdsc, di),
1326	spin_unlock(&mdsc->dentry_list_lock);
1327}
1328
1329static void __dentry_lease_unlist(struct ceph_dentry_info *di)
1330{
1331	struct ceph_mds_client *mdsc;
1332	if (di->flags & CEPH_DENTRY_SHRINK_LIST)
1333		return;
1334	if (list_empty(&di->lease_list))
1335		return;
1336
1337	mdsc = ceph_sb_to_client(di->dentry->d_sb)->mdsc;
1338	spin_lock(&mdsc->dentry_list_lock);
1339	list_del_init(&di->lease_list);
1340	spin_unlock(&mdsc->dentry_list_lock);
1341}
1342
1343enum {
1344	KEEP	= 0,
1345	DELETE	= 1,
1346	TOUCH	= 2,
1347	STOP	= 4,
1348};
1349
1350struct ceph_lease_walk_control {
1351	bool dir_lease;
1352	bool expire_dir_lease;
1353	unsigned long nr_to_scan;
1354	unsigned long dir_lease_ttl;
1355};
1356
1357static unsigned long
1358__dentry_leases_walk(struct ceph_mds_client *mdsc,
1359		     struct ceph_lease_walk_control *lwc,
1360		     int (*check)(struct dentry*, void*))
1361{
1362	struct ceph_dentry_info *di, *tmp;
1363	struct dentry *dentry, *last = NULL;
1364	struct list_head* list;
1365        LIST_HEAD(dispose);
1366	unsigned long freed = 0;
1367	int ret = 0;
1368
1369	list = lwc->dir_lease ? &mdsc->dentry_dir_leases : &mdsc->dentry_leases;
1370	spin_lock(&mdsc->dentry_list_lock);
1371	list_for_each_entry_safe(di, tmp, list, lease_list) {
1372		if (!lwc->nr_to_scan)
1373			break;
1374		--lwc->nr_to_scan;
1375
1376		dentry = di->dentry;
1377		if (last == dentry)
1378			break;
1379
1380		if (!spin_trylock(&dentry->d_lock))
1381			continue;
1382
1383		if (__lockref_is_dead(&dentry->d_lockref)) {
1384			list_del_init(&di->lease_list);
1385			goto next;
1386		}
1387
1388		ret = check(dentry, lwc);
1389		if (ret & TOUCH) {
1390			/* move it into tail of dir lease list */
1391			__dentry_dir_lease_touch(mdsc, di);
1392			if (!last)
1393				last = dentry;
1394		}
1395		if (ret & DELETE) {
1396			/* stale lease */
1397			di->flags &= ~CEPH_DENTRY_REFERENCED;
1398			if (dentry->d_lockref.count > 0) {
1399				/* update_dentry_lease() will re-add
1400				 * it to lease list, or
1401				 * ceph_d_delete() will return 1 when
1402				 * last reference is dropped */
1403				list_del_init(&di->lease_list);
1404			} else {
1405				di->flags |= CEPH_DENTRY_SHRINK_LIST;
1406				list_move_tail(&di->lease_list, &dispose);
1407				dget_dlock(dentry);
1408			}
1409		}
1410next:
1411		spin_unlock(&dentry->d_lock);
1412		if (ret & STOP)
1413			break;
1414	}
1415	spin_unlock(&mdsc->dentry_list_lock);
1416
1417	while (!list_empty(&dispose)) {
1418		di = list_first_entry(&dispose, struct ceph_dentry_info,
1419				      lease_list);
1420		dentry = di->dentry;
1421		spin_lock(&dentry->d_lock);
1422
1423		list_del_init(&di->lease_list);
1424		di->flags &= ~CEPH_DENTRY_SHRINK_LIST;
1425		if (di->flags & CEPH_DENTRY_REFERENCED) {
1426			spin_lock(&mdsc->dentry_list_lock);
1427			if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1428				list_add_tail(&di->lease_list,
1429					      &mdsc->dentry_leases);
1430			} else {
1431				__dentry_dir_lease_touch(mdsc, di);
1432			}
1433			spin_unlock(&mdsc->dentry_list_lock);
1434		} else {
1435			freed++;
1436		}
1437
1438		spin_unlock(&dentry->d_lock);
1439		/* ceph_d_delete() does the trick */
1440		dput(dentry);
1441	}
1442	return freed;
1443}
1444
1445static int __dentry_lease_check(struct dentry *dentry, void *arg)
1446{
1447	struct ceph_dentry_info *di = ceph_dentry(dentry);
1448	int ret;
1449
1450	if (__dentry_lease_is_valid(di))
1451		return STOP;
1452	ret = __dir_lease_try_check(dentry);
1453	if (ret == -EBUSY)
1454		return KEEP;
1455	if (ret > 0)
1456		return TOUCH;
1457	return DELETE;
1458}
1459
1460static int __dir_lease_check(struct dentry *dentry, void *arg)
1461{
1462	struct ceph_lease_walk_control *lwc = arg;
1463	struct ceph_dentry_info *di = ceph_dentry(dentry);
1464
1465	int ret = __dir_lease_try_check(dentry);
1466	if (ret == -EBUSY)
1467		return KEEP;
1468	if (ret > 0) {
1469		if (time_before(jiffies, di->time + lwc->dir_lease_ttl))
1470			return STOP;
1471		/* Move dentry to tail of dir lease list if we don't want
1472		 * to delete it. So dentries in the list are checked in a
1473		 * round robin manner */
1474		if (!lwc->expire_dir_lease)
1475			return TOUCH;
1476		if (dentry->d_lockref.count > 0 ||
1477		    (di->flags & CEPH_DENTRY_REFERENCED))
1478			return TOUCH;
1479		/* invalidate dir lease */
1480		di->lease_shared_gen = 0;
1481	}
1482	return DELETE;
1483}
1484
1485int ceph_trim_dentries(struct ceph_mds_client *mdsc)
1486{
1487	struct ceph_lease_walk_control lwc;
1488	unsigned long count;
1489	unsigned long freed;
1490
1491	spin_lock(&mdsc->caps_list_lock);
1492        if (mdsc->caps_use_max > 0 &&
1493            mdsc->caps_use_count > mdsc->caps_use_max)
1494		count = mdsc->caps_use_count - mdsc->caps_use_max;
1495	else
1496		count = 0;
1497        spin_unlock(&mdsc->caps_list_lock);
1498
1499	lwc.dir_lease = false;
1500	lwc.nr_to_scan  = CEPH_CAPS_PER_RELEASE * 2;
1501	freed = __dentry_leases_walk(mdsc, &lwc, __dentry_lease_check);
1502	if (!lwc.nr_to_scan) /* more invalid leases */
1503		return -EAGAIN;
1504
1505	if (lwc.nr_to_scan < CEPH_CAPS_PER_RELEASE)
1506		lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE;
1507
1508	lwc.dir_lease = true;
1509	lwc.expire_dir_lease = freed < count;
1510	lwc.dir_lease_ttl = mdsc->fsc->mount_options->caps_wanted_delay_max * HZ;
1511	freed +=__dentry_leases_walk(mdsc, &lwc, __dir_lease_check);
1512	if (!lwc.nr_to_scan) /* more to check */
1513		return -EAGAIN;
1514
1515	return freed > 0 ? 1 : 0;
1516}
1517
1518/*
1519 * Ensure a dentry lease will no longer revalidate.
1520 */
1521void ceph_invalidate_dentry_lease(struct dentry *dentry)
1522{
1523	struct ceph_dentry_info *di = ceph_dentry(dentry);
1524	spin_lock(&dentry->d_lock);
1525	di->time = jiffies;
1526	di->lease_shared_gen = 0;
1527	di->flags &= ~CEPH_DENTRY_PRIMARY_LINK;
1528	__dentry_lease_unlist(di);
1529	spin_unlock(&dentry->d_lock);
1530}
1531
1532/*
1533 * Check if dentry lease is valid.  If not, delete the lease.  Try to
1534 * renew if the least is more than half up.
1535 */
1536static bool __dentry_lease_is_valid(struct ceph_dentry_info *di)
1537{
1538	struct ceph_mds_session *session;
1539
1540	if (!di->lease_gen)
1541		return false;
1542
1543	session = di->lease_session;
1544	if (session) {
1545		u32 gen;
1546		unsigned long ttl;
1547
1548		spin_lock(&session->s_gen_ttl_lock);
1549		gen = session->s_cap_gen;
1550		ttl = session->s_cap_ttl;
1551		spin_unlock(&session->s_gen_ttl_lock);
1552
1553		if (di->lease_gen == gen &&
1554		    time_before(jiffies, ttl) &&
1555		    time_before(jiffies, di->time))
1556			return true;
1557	}
1558	di->lease_gen = 0;
1559	return false;
1560}
1561
1562static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags)
1563{
1564	struct ceph_dentry_info *di;
1565	struct ceph_mds_session *session = NULL;
1566	u32 seq = 0;
1567	int valid = 0;
1568
1569	spin_lock(&dentry->d_lock);
1570	di = ceph_dentry(dentry);
1571	if (di && __dentry_lease_is_valid(di)) {
1572		valid = 1;
1573
1574		if (di->lease_renew_after &&
1575		    time_after(jiffies, di->lease_renew_after)) {
1576			/*
1577			 * We should renew. If we're in RCU walk mode
1578			 * though, we can't do that so just return
1579			 * -ECHILD.
1580			 */
1581			if (flags & LOOKUP_RCU) {
1582				valid = -ECHILD;
1583			} else {
1584				session = ceph_get_mds_session(di->lease_session);
1585				seq = di->lease_seq;
1586				di->lease_renew_after = 0;
1587				di->lease_renew_from = jiffies;
1588			}
1589		}
1590	}
1591	spin_unlock(&dentry->d_lock);
1592
1593	if (session) {
1594		ceph_mdsc_lease_send_msg(session, dentry,
1595					 CEPH_MDS_LEASE_RENEW, seq);
1596		ceph_put_mds_session(session);
1597	}
1598	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1599	return valid;
1600}
1601
1602/*
1603 * Called under dentry->d_lock.
1604 */
1605static int __dir_lease_try_check(const struct dentry *dentry)
1606{
1607	struct ceph_dentry_info *di = ceph_dentry(dentry);
1608	struct inode *dir;
1609	struct ceph_inode_info *ci;
1610	int valid = 0;
1611
1612	if (!di->lease_shared_gen)
1613		return 0;
1614	if (IS_ROOT(dentry))
1615		return 0;
1616
1617	dir = d_inode(dentry->d_parent);
1618	ci = ceph_inode(dir);
1619
1620	if (spin_trylock(&ci->i_ceph_lock)) {
1621		if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen &&
1622		    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 0))
1623			valid = 1;
1624		spin_unlock(&ci->i_ceph_lock);
1625	} else {
1626		valid = -EBUSY;
1627	}
1628
1629	if (!valid)
1630		di->lease_shared_gen = 0;
1631	return valid;
1632}
1633
1634/*
1635 * Check if directory-wide content lease/cap is valid.
1636 */
1637static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry,
1638			      struct ceph_mds_client *mdsc)
1639{
1640	struct ceph_inode_info *ci = ceph_inode(dir);
1641	int valid;
1642	int shared_gen;
1643
1644	spin_lock(&ci->i_ceph_lock);
1645	valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1646	if (valid) {
1647		__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
1648		shared_gen = atomic_read(&ci->i_shared_gen);
1649	}
1650	spin_unlock(&ci->i_ceph_lock);
1651	if (valid) {
1652		struct ceph_dentry_info *di;
1653		spin_lock(&dentry->d_lock);
1654		di = ceph_dentry(dentry);
1655		if (dir == d_inode(dentry->d_parent) &&
1656		    di && di->lease_shared_gen == shared_gen)
1657			__ceph_dentry_dir_lease_touch(di);
1658		else
1659			valid = 0;
1660		spin_unlock(&dentry->d_lock);
1661	}
1662	dout("dir_lease_is_valid dir %p v%u dentry %p = %d\n",
1663	     dir, (unsigned)atomic_read(&ci->i_shared_gen), dentry, valid);
1664	return valid;
1665}
1666
1667/*
1668 * Check if cached dentry can be trusted.
1669 */
1670static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1671{
1672	int valid = 0;
1673	struct dentry *parent;
1674	struct inode *dir, *inode;
1675	struct ceph_mds_client *mdsc;
1676
1677	if (flags & LOOKUP_RCU) {
1678		parent = READ_ONCE(dentry->d_parent);
1679		dir = d_inode_rcu(parent);
1680		if (!dir)
1681			return -ECHILD;
1682		inode = d_inode_rcu(dentry);
1683	} else {
1684		parent = dget_parent(dentry);
1685		dir = d_inode(parent);
1686		inode = d_inode(dentry);
1687	}
1688
1689	dout("d_revalidate %p '%pd' inode %p offset 0x%llx\n", dentry,
1690	     dentry, inode, ceph_dentry(dentry)->offset);
1691
1692	mdsc = ceph_sb_to_client(dir->i_sb)->mdsc;
1693
1694	/* always trust cached snapped dentries, snapdir dentry */
1695	if (ceph_snap(dir) != CEPH_NOSNAP) {
1696		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1697		     dentry, inode);
1698		valid = 1;
1699	} else if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1700		valid = 1;
1701	} else {
1702		valid = dentry_lease_is_valid(dentry, flags);
1703		if (valid == -ECHILD)
1704			return valid;
1705		if (valid || dir_lease_is_valid(dir, dentry, mdsc)) {
1706			if (inode)
1707				valid = ceph_is_any_caps(inode);
1708			else
1709				valid = 1;
1710		}
1711	}
1712
1713	if (!valid) {
1714		struct ceph_mds_request *req;
1715		int op, err;
1716		u32 mask;
1717
1718		if (flags & LOOKUP_RCU)
1719			return -ECHILD;
1720
1721		percpu_counter_inc(&mdsc->metric.d_lease_mis);
1722
1723		op = ceph_snap(dir) == CEPH_SNAPDIR ?
1724			CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
1725		req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1726		if (!IS_ERR(req)) {
1727			req->r_dentry = dget(dentry);
1728			req->r_num_caps = 2;
1729			req->r_parent = dir;
1730
1731			mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1732			if (ceph_security_xattr_wanted(dir))
1733				mask |= CEPH_CAP_XATTR_SHARED;
1734			req->r_args.getattr.mask = cpu_to_le32(mask);
1735
1736			err = ceph_mdsc_do_request(mdsc, NULL, req);
1737			switch (err) {
1738			case 0:
1739				if (d_really_is_positive(dentry) &&
1740				    d_inode(dentry) == req->r_target_inode)
1741					valid = 1;
1742				break;
1743			case -ENOENT:
1744				if (d_really_is_negative(dentry))
1745					valid = 1;
1746				fallthrough;
1747			default:
1748				break;
1749			}
1750			ceph_mdsc_put_request(req);
1751			dout("d_revalidate %p lookup result=%d\n",
1752			     dentry, err);
1753		}
1754	} else {
1755		percpu_counter_inc(&mdsc->metric.d_lease_hit);
1756	}
1757
1758	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1759	if (!valid)
1760		ceph_dir_clear_complete(dir);
1761
1762	if (!(flags & LOOKUP_RCU))
1763		dput(parent);
1764	return valid;
1765}
1766
1767/*
1768 * Delete unused dentry that doesn't have valid lease
1769 *
1770 * Called under dentry->d_lock.
1771 */
1772static int ceph_d_delete(const struct dentry *dentry)
1773{
1774	struct ceph_dentry_info *di;
1775
1776	/* won't release caps */
1777	if (d_really_is_negative(dentry))
1778		return 0;
1779	if (ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
1780		return 0;
1781	/* vaild lease? */
1782	di = ceph_dentry(dentry);
1783	if (di) {
1784		if (__dentry_lease_is_valid(di))
1785			return 0;
1786		if (__dir_lease_try_check(dentry))
1787			return 0;
1788	}
1789	return 1;
1790}
1791
1792/*
1793 * Release our ceph_dentry_info.
1794 */
1795static void ceph_d_release(struct dentry *dentry)
1796{
1797	struct ceph_dentry_info *di = ceph_dentry(dentry);
1798	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
1799
1800	dout("d_release %p\n", dentry);
1801
1802	atomic64_dec(&fsc->mdsc->metric.total_dentries);
1803
1804	spin_lock(&dentry->d_lock);
1805	__dentry_lease_unlist(di);
1806	dentry->d_fsdata = NULL;
1807	spin_unlock(&dentry->d_lock);
1808
1809	ceph_put_mds_session(di->lease_session);
1810	kmem_cache_free(ceph_dentry_cachep, di);
1811}
1812
1813/*
1814 * When the VFS prunes a dentry from the cache, we need to clear the
1815 * complete flag on the parent directory.
1816 *
1817 * Called under dentry->d_lock.
1818 */
1819static void ceph_d_prune(struct dentry *dentry)
1820{
1821	struct ceph_inode_info *dir_ci;
1822	struct ceph_dentry_info *di;
1823
1824	dout("ceph_d_prune %pd %p\n", dentry, dentry);
1825
1826	/* do we have a valid parent? */
1827	if (IS_ROOT(dentry))
1828		return;
1829
1830	/* we hold d_lock, so d_parent is stable */
1831	dir_ci = ceph_inode(d_inode(dentry->d_parent));
1832	if (dir_ci->i_vino.snap == CEPH_SNAPDIR)
1833		return;
1834
1835	/* who calls d_delete() should also disable dcache readdir */
1836	if (d_really_is_negative(dentry))
1837		return;
1838
1839	/* d_fsdata does not get cleared until d_release */
1840	if (!d_unhashed(dentry)) {
1841		__ceph_dir_clear_complete(dir_ci);
1842		return;
1843	}
1844
1845	/* Disable dcache readdir just in case that someone called d_drop()
1846	 * or d_invalidate(), but MDS didn't revoke CEPH_CAP_FILE_SHARED
1847	 * properly (dcache readdir is still enabled) */
1848	di = ceph_dentry(dentry);
1849	if (di->offset > 0 &&
1850	    di->lease_shared_gen == atomic_read(&dir_ci->i_shared_gen))
1851		__ceph_dir_clear_ordered(dir_ci);
1852}
1853
1854/*
1855 * read() on a dir.  This weird interface hack only works if mounted
1856 * with '-o dirstat'.
1857 */
1858static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1859			     loff_t *ppos)
1860{
1861	struct ceph_dir_file_info *dfi = file->private_data;
1862	struct inode *inode = file_inode(file);
1863	struct ceph_inode_info *ci = ceph_inode(inode);
1864	int left;
1865	const int bufsize = 1024;
1866
1867	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1868		return -EISDIR;
1869
1870	if (!dfi->dir_info) {
1871		dfi->dir_info = kmalloc(bufsize, GFP_KERNEL);
1872		if (!dfi->dir_info)
1873			return -ENOMEM;
1874		dfi->dir_info_len =
1875			snprintf(dfi->dir_info, bufsize,
1876				"entries:   %20lld\n"
1877				" files:    %20lld\n"
1878				" subdirs:  %20lld\n"
1879				"rentries:  %20lld\n"
1880				" rfiles:   %20lld\n"
1881				" rsubdirs: %20lld\n"
1882				"rbytes:    %20lld\n"
1883				"rctime:    %10lld.%09ld\n",
1884				ci->i_files + ci->i_subdirs,
1885				ci->i_files,
1886				ci->i_subdirs,
1887				ci->i_rfiles + ci->i_rsubdirs,
1888				ci->i_rfiles,
1889				ci->i_rsubdirs,
1890				ci->i_rbytes,
1891				ci->i_rctime.tv_sec,
1892				ci->i_rctime.tv_nsec);
1893	}
1894
1895	if (*ppos >= dfi->dir_info_len)
1896		return 0;
1897	size = min_t(unsigned, size, dfi->dir_info_len-*ppos);
1898	left = copy_to_user(buf, dfi->dir_info + *ppos, size);
1899	if (left == size)
1900		return -EFAULT;
1901	*ppos += (size - left);
1902	return size - left;
1903}
1904
1905
1906
1907/*
1908 * Return name hash for a given dentry.  This is dependent on
1909 * the parent directory's hash function.
1910 */
1911unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1912{
1913	struct ceph_inode_info *dci = ceph_inode(dir);
1914	unsigned hash;
1915
1916	switch (dci->i_dir_layout.dl_dir_hash) {
1917	case 0:	/* for backward compat */
1918	case CEPH_STR_HASH_LINUX:
1919		return dn->d_name.hash;
1920
1921	default:
1922		spin_lock(&dn->d_lock);
1923		hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1924				     dn->d_name.name, dn->d_name.len);
1925		spin_unlock(&dn->d_lock);
1926		return hash;
1927	}
1928}
1929
1930const struct file_operations ceph_dir_fops = {
1931	.read = ceph_read_dir,
1932	.iterate = ceph_readdir,
1933	.llseek = ceph_dir_llseek,
1934	.open = ceph_open,
1935	.release = ceph_release,
1936	.unlocked_ioctl = ceph_ioctl,
1937	.compat_ioctl = compat_ptr_ioctl,
1938	.fsync = ceph_fsync,
1939	.lock = ceph_lock,
1940	.flock = ceph_flock,
1941};
1942
1943const struct file_operations ceph_snapdir_fops = {
1944	.iterate = ceph_readdir,
1945	.llseek = ceph_dir_llseek,
1946	.open = ceph_open,
1947	.release = ceph_release,
1948};
1949
1950const struct inode_operations ceph_dir_iops = {
1951	.lookup = ceph_lookup,
1952	.permission = ceph_permission,
1953	.getattr = ceph_getattr,
1954	.setattr = ceph_setattr,
1955	.listxattr = ceph_listxattr,
1956	.get_acl = ceph_get_acl,
1957	.set_acl = ceph_set_acl,
1958	.mknod = ceph_mknod,
1959	.symlink = ceph_symlink,
1960	.mkdir = ceph_mkdir,
1961	.link = ceph_link,
1962	.unlink = ceph_unlink,
1963	.rmdir = ceph_unlink,
1964	.rename = ceph_rename,
1965	.create = ceph_create,
1966	.atomic_open = ceph_atomic_open,
1967};
1968
1969const struct inode_operations ceph_snapdir_iops = {
1970	.lookup = ceph_lookup,
1971	.permission = ceph_permission,
1972	.getattr = ceph_getattr,
1973	.mkdir = ceph_mkdir,
1974	.rmdir = ceph_unlink,
1975	.rename = ceph_rename,
1976};
1977
1978const struct dentry_operations ceph_dentry_ops = {
1979	.d_revalidate = ceph_d_revalidate,
1980	.d_delete = ceph_d_delete,
1981	.d_release = ceph_d_release,
1982	.d_prune = ceph_d_prune,
1983	.d_init = ceph_d_init,
1984};
1985