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_NOFS | __GFP_ZERO);
42	if (!di)
43		return -ENOMEM;          /* oh well */
44
45	spin_lock(&dentry->d_lock);
46	if (dentry->d_fsdata) {
47		/* lost a race */
48		kmem_cache_free(ceph_dentry_cachep, di);
49		goto out_unlock;
50	}
51
52	if (ceph_snap(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 * When possible, we try to satisfy a readdir by peeking at the
111 * dcache.  We make this work by carefully ordering dentries on
112 * d_child when we initially get results back from the MDS, and
113 * falling back to a "normal" sync readdir if any dentries in the dir
114 * are dropped.
115 *
116 * Complete dir indicates that we have all dentries in the dir.  It is
117 * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
118 * the MDS if/when the directory is modified).
119 */
120static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
121			    u32 shared_gen)
122{
123	struct ceph_file_info *fi = file->private_data;
124	struct dentry *parent = file->f_path.dentry;
125	struct inode *dir = d_inode(parent);
126	struct list_head *p;
127	struct dentry *dentry, *last;
128	struct ceph_dentry_info *di;
129	int err = 0;
130
131	/* claim ref on last dentry we returned */
132	last = fi->dentry;
133	fi->dentry = NULL;
134
135	dout("__dcache_readdir %p v%u at %llu (last %p)\n",
136	     dir, shared_gen, ctx->pos, last);
137
138	spin_lock(&parent->d_lock);
139
140	/* start at beginning? */
141	if (ctx->pos == 2 || last == NULL ||
142	    fpos_cmp(ctx->pos, ceph_dentry(last)->offset) < 0) {
143		if (list_empty(&parent->d_subdirs))
144			goto out_unlock;
145		p = parent->d_subdirs.prev;
146		dout(" initial p %p/%p\n", p->prev, p->next);
147	} else {
148		p = last->d_child.prev;
149	}
150
151more:
152	dentry = list_entry(p, struct dentry, d_child);
153	di = ceph_dentry(dentry);
154	while (1) {
155		dout(" p %p/%p %s d_subdirs %p/%p\n", p->prev, p->next,
156		     d_unhashed(dentry) ? "!hashed" : "hashed",
157		     parent->d_subdirs.prev, parent->d_subdirs.next);
158		if (p == &parent->d_subdirs) {
159			fi->flags |= CEPH_F_ATEND;
160			goto out_unlock;
161		}
162		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
163		if (di->lease_shared_gen == shared_gen &&
164		    !d_unhashed(dentry) && d_really_is_positive(dentry) &&
165		    ceph_snap(d_inode(dentry)) != CEPH_SNAPDIR &&
166		    ceph_ino(d_inode(dentry)) != CEPH_INO_CEPH &&
167		    fpos_cmp(ctx->pos, di->offset) <= 0)
168			break;
169		dout(" skipping %p %pd at %llu (%llu)%s%s\n", dentry,
170		     dentry, di->offset,
171		     ctx->pos, d_unhashed(dentry) ? " unhashed" : "",
172		     !d_inode(dentry) ? " null" : "");
173		spin_unlock(&dentry->d_lock);
174		p = p->prev;
175		dentry = list_entry(p, struct dentry, d_child);
176		di = ceph_dentry(dentry);
177	}
178
179	dget_dlock(dentry);
180	spin_unlock(&dentry->d_lock);
181	spin_unlock(&parent->d_lock);
182
183	/* make sure a dentry wasn't dropped while we didn't have parent lock */
184	if (!ceph_dir_is_complete_ordered(dir)) {
185		dout(" lost dir complete on %p; falling back to mds\n", dir);
186		dput(dentry);
187		err = -EAGAIN;
188		goto out;
189	}
190
191	dout(" %llu (%llu) dentry %p %pd %p\n", di->offset, ctx->pos,
192	     dentry, dentry, d_inode(dentry));
193	if (!dir_emit(ctx, dentry->d_name.name,
194		      dentry->d_name.len,
195		      ceph_translate_ino(dentry->d_sb, d_inode(dentry)->i_ino),
196		      d_inode(dentry)->i_mode >> 12)) {
197		if (last) {
198			/* remember our position */
199			fi->dentry = last;
200			fi->next_offset = fpos_off(di->offset);
201		}
202		dput(dentry);
203		return 0;
204	}
205
206	ctx->pos = di->offset + 1;
207
208	if (last)
209		dput(last);
210	last = dentry;
211
212	spin_lock(&parent->d_lock);
213	p = p->prev;	/* advance to next dentry */
214	goto more;
215
216out_unlock:
217	spin_unlock(&parent->d_lock);
218out:
219	if (last)
220		dput(last);
221	return err;
222}
223
224/*
225 * make note of the last dentry we read, so we can
226 * continue at the same lexicographical point,
227 * regardless of what dir changes take place on the
228 * server.
229 */
230static int note_last_dentry(struct ceph_file_info *fi, const char *name,
231			    int len)
232{
233	kfree(fi->last_name);
234	fi->last_name = kmalloc(len+1, GFP_NOFS);
235	if (!fi->last_name)
236		return -ENOMEM;
237	memcpy(fi->last_name, name, len);
238	fi->last_name[len] = 0;
239	dout("note_last_dentry '%s'\n", fi->last_name);
240	return 0;
241}
242
243static int ceph_readdir(struct file *file, struct dir_context *ctx)
244{
245	struct ceph_file_info *fi = file->private_data;
246	struct inode *inode = file_inode(file);
247	struct ceph_inode_info *ci = ceph_inode(inode);
248	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
249	struct ceph_mds_client *mdsc = fsc->mdsc;
250	unsigned frag = fpos_frag(ctx->pos);
251	int off = fpos_off(ctx->pos);
252	int err;
253	u32 ftype;
254	struct ceph_mds_reply_info_parsed *rinfo;
255
256	dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
257	if (fi->flags & CEPH_F_ATEND)
258		return 0;
259
260	/* always start with . and .. */
261	if (ctx->pos == 0) {
262		dout("readdir off 0 -> '.'\n");
263		if (!dir_emit(ctx, ".", 1,
264			    ceph_translate_ino(inode->i_sb, inode->i_ino),
265			    inode->i_mode >> 12))
266			return 0;
267		ctx->pos = 1;
268		off = 1;
269	}
270	if (ctx->pos == 1) {
271		ino_t ino = parent_ino(file->f_path.dentry);
272		dout("readdir off 1 -> '..'\n");
273		if (!dir_emit(ctx, "..", 2,
274			    ceph_translate_ino(inode->i_sb, ino),
275			    inode->i_mode >> 12))
276			return 0;
277		ctx->pos = 2;
278		off = 2;
279	}
280
281	/* can we use the dcache? */
282	spin_lock(&ci->i_ceph_lock);
283	if ((ctx->pos == 2 || fi->dentry) &&
284	    ceph_test_mount_opt(fsc, DCACHE) &&
285	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
286	    ceph_snap(inode) != CEPH_SNAPDIR &&
287	    __ceph_dir_is_complete_ordered(ci) &&
288	    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
289		u32 shared_gen = ci->i_shared_gen;
290		spin_unlock(&ci->i_ceph_lock);
291		err = __dcache_readdir(file, ctx, shared_gen);
292		if (err != -EAGAIN)
293			return err;
294		frag = fpos_frag(ctx->pos);
295		off = fpos_off(ctx->pos);
296	} else {
297		spin_unlock(&ci->i_ceph_lock);
298	}
299	if (fi->dentry) {
300		err = note_last_dentry(fi, fi->dentry->d_name.name,
301				       fi->dentry->d_name.len);
302		if (err)
303			return err;
304		dput(fi->dentry);
305		fi->dentry = NULL;
306	}
307
308	/* proceed with a normal readdir */
309
310	if (ctx->pos == 2) {
311		/* note dir version at start of readdir so we can tell
312		 * if any dentries get dropped */
313		fi->dir_release_count = atomic_read(&ci->i_release_count);
314		fi->dir_ordered_count = ci->i_ordered_count;
315	}
316
317more:
318	/* do we have the correct frag content buffered? */
319	if (fi->frag != frag || fi->last_readdir == NULL) {
320		struct ceph_mds_request *req;
321		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
322			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
323
324		/* discard old result, if any */
325		if (fi->last_readdir) {
326			ceph_mdsc_put_request(fi->last_readdir);
327			fi->last_readdir = NULL;
328		}
329
330		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
331		     ceph_vinop(inode), frag, fi->last_name);
332		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
333		if (IS_ERR(req))
334			return PTR_ERR(req);
335		err = ceph_alloc_readdir_reply_buffer(req, inode);
336		if (err) {
337			ceph_mdsc_put_request(req);
338			return err;
339		}
340		/* hints to request -> mds selection code */
341		req->r_direct_mode = USE_AUTH_MDS;
342		req->r_direct_hash = ceph_frag_value(frag);
343		req->r_direct_is_hash = true;
344		if (fi->last_name) {
345			req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
346			if (!req->r_path2) {
347				ceph_mdsc_put_request(req);
348				return -ENOMEM;
349			}
350		}
351		req->r_readdir_offset = fi->next_offset;
352		req->r_args.readdir.frag = cpu_to_le32(frag);
353
354		req->r_inode = inode;
355		ihold(inode);
356		req->r_dentry = dget(file->f_path.dentry);
357		err = ceph_mdsc_do_request(mdsc, NULL, req);
358		if (err < 0) {
359			ceph_mdsc_put_request(req);
360			return err;
361		}
362		dout("readdir got and parsed readdir result=%d"
363		     " on frag %x, end=%d, complete=%d\n", err, frag,
364		     (int)req->r_reply_info.dir_end,
365		     (int)req->r_reply_info.dir_complete);
366
367		if (!req->r_did_prepopulate) {
368			dout("readdir !did_prepopulate");
369			/* preclude from marking dir complete */
370			fi->dir_release_count--;
371		}
372
373		/* note next offset and last dentry name */
374		rinfo = &req->r_reply_info;
375		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
376			frag = le32_to_cpu(rinfo->dir_dir->frag);
377			if (ceph_frag_is_leftmost(frag))
378				fi->next_offset = 2;
379			else
380				fi->next_offset = 0;
381			off = fi->next_offset;
382		}
383		fi->frag = frag;
384		fi->offset = fi->next_offset;
385		fi->last_readdir = req;
386
387		if (req->r_reply_info.dir_end) {
388			kfree(fi->last_name);
389			fi->last_name = NULL;
390			if (ceph_frag_is_rightmost(frag))
391				fi->next_offset = 2;
392			else
393				fi->next_offset = 0;
394		} else {
395			err = note_last_dentry(fi,
396				       rinfo->dir_dname[rinfo->dir_nr-1],
397				       rinfo->dir_dname_len[rinfo->dir_nr-1]);
398			if (err)
399				return err;
400			fi->next_offset += rinfo->dir_nr;
401		}
402	}
403
404	rinfo = &fi->last_readdir->r_reply_info;
405	dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
406	     rinfo->dir_nr, off, fi->offset);
407
408	ctx->pos = ceph_make_fpos(frag, off);
409	while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
410		struct ceph_mds_reply_inode *in =
411			rinfo->dir_in[off - fi->offset].in;
412		struct ceph_vino vino;
413		ino_t ino;
414
415		dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
416		     off, off - fi->offset, rinfo->dir_nr, ctx->pos,
417		     rinfo->dir_dname_len[off - fi->offset],
418		     rinfo->dir_dname[off - fi->offset], in);
419		BUG_ON(!in);
420		ftype = le32_to_cpu(in->mode) >> 12;
421		vino.ino = le64_to_cpu(in->ino);
422		vino.snap = le64_to_cpu(in->snapid);
423		ino = ceph_vino_to_ino(vino);
424		if (!dir_emit(ctx,
425			    rinfo->dir_dname[off - fi->offset],
426			    rinfo->dir_dname_len[off - fi->offset],
427			    ceph_translate_ino(inode->i_sb, ino), ftype)) {
428			dout("filldir stopping us...\n");
429			return 0;
430		}
431		off++;
432		ctx->pos++;
433	}
434
435	if (fi->last_name) {
436		ceph_mdsc_put_request(fi->last_readdir);
437		fi->last_readdir = NULL;
438		goto more;
439	}
440
441	/* more frags? */
442	if (!ceph_frag_is_rightmost(frag)) {
443		frag = ceph_frag_next(frag);
444		off = 0;
445		ctx->pos = ceph_make_fpos(frag, off);
446		dout("readdir next frag is %x\n", frag);
447		goto more;
448	}
449	fi->flags |= CEPH_F_ATEND;
450
451	/*
452	 * if dir_release_count still matches the dir, no dentries
453	 * were released during the whole readdir, and we should have
454	 * the complete dir contents in our cache.
455	 */
456	spin_lock(&ci->i_ceph_lock);
457	if (atomic_read(&ci->i_release_count) == fi->dir_release_count) {
458		if (ci->i_ordered_count == fi->dir_ordered_count)
459			dout(" marking %p complete and ordered\n", inode);
460		else
461			dout(" marking %p complete\n", inode);
462		__ceph_dir_set_complete(ci, fi->dir_release_count,
463					fi->dir_ordered_count);
464	}
465	spin_unlock(&ci->i_ceph_lock);
466
467	dout("readdir %p file %p done.\n", inode, file);
468	return 0;
469}
470
471static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
472{
473	if (fi->last_readdir) {
474		ceph_mdsc_put_request(fi->last_readdir);
475		fi->last_readdir = NULL;
476	}
477	kfree(fi->last_name);
478	fi->last_name = NULL;
479	if (ceph_frag_is_leftmost(frag))
480		fi->next_offset = 2;  /* compensate for . and .. */
481	else
482		fi->next_offset = 0;
483	if (fi->dentry) {
484		dput(fi->dentry);
485		fi->dentry = NULL;
486	}
487	fi->flags &= ~CEPH_F_ATEND;
488}
489
490static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
491{
492	struct ceph_file_info *fi = file->private_data;
493	struct inode *inode = file->f_mapping->host;
494	loff_t old_offset = ceph_make_fpos(fi->frag, fi->next_offset);
495	loff_t retval;
496
497	mutex_lock(&inode->i_mutex);
498	retval = -EINVAL;
499	switch (whence) {
500	case SEEK_END:
501		offset += inode->i_size + 2;   /* FIXME */
502		break;
503	case SEEK_CUR:
504		offset += file->f_pos;
505	case SEEK_SET:
506		break;
507	default:
508		goto out;
509	}
510
511	if (offset >= 0) {
512		if (offset != file->f_pos) {
513			file->f_pos = offset;
514			file->f_version = 0;
515			fi->flags &= ~CEPH_F_ATEND;
516		}
517		retval = offset;
518
519		/*
520		 * discard buffered readdir content on seekdir(0), or
521		 * seek to new frag, or seek prior to current chunk.
522		 */
523		if (offset == 0 ||
524		    fpos_frag(offset) != fi->frag ||
525		    fpos_off(offset) < fi->offset) {
526			dout("dir_llseek dropping %p content\n", file);
527			reset_readdir(fi, fpos_frag(offset));
528		}
529
530		/* bump dir_release_count if we did a forward seek */
531		if (fpos_cmp(offset, old_offset) > 0)
532			fi->dir_release_count--;
533	}
534out:
535	mutex_unlock(&inode->i_mutex);
536	return retval;
537}
538
539/*
540 * Handle lookups for the hidden .snap directory.
541 */
542int ceph_handle_snapdir(struct ceph_mds_request *req,
543			struct dentry *dentry, int err)
544{
545	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
546	struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
547
548	/* .snap dir? */
549	if (err == -ENOENT &&
550	    ceph_snap(parent) == CEPH_NOSNAP &&
551	    strcmp(dentry->d_name.name,
552		   fsc->mount_options->snapdir_name) == 0) {
553		struct inode *inode = ceph_get_snapdir(parent);
554		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
555		     dentry, dentry, inode);
556		BUG_ON(!d_unhashed(dentry));
557		d_add(dentry, inode);
558		err = 0;
559	}
560	return err;
561}
562
563/*
564 * Figure out final result of a lookup/open request.
565 *
566 * Mainly, make sure we return the final req->r_dentry (if it already
567 * existed) in place of the original VFS-provided dentry when they
568 * differ.
569 *
570 * Gracefully handle the case where the MDS replies with -ENOENT and
571 * no trace (which it may do, at its discretion, e.g., if it doesn't
572 * care to issue a lease on the negative dentry).
573 */
574struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
575				  struct dentry *dentry, int err)
576{
577	if (err == -ENOENT) {
578		/* no trace? */
579		err = 0;
580		if (!req->r_reply_info.head->is_dentry) {
581			dout("ENOENT and no trace, dentry %p inode %p\n",
582			     dentry, d_inode(dentry));
583			if (d_really_is_positive(dentry)) {
584				d_drop(dentry);
585				err = -ENOENT;
586			} else {
587				d_add(dentry, NULL);
588			}
589		}
590	}
591	if (err)
592		dentry = ERR_PTR(err);
593	else if (dentry != req->r_dentry)
594		dentry = dget(req->r_dentry);   /* we got spliced */
595	else
596		dentry = NULL;
597	return dentry;
598}
599
600static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
601{
602	return ceph_ino(inode) == CEPH_INO_ROOT &&
603		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
604}
605
606/*
607 * Look up a single dir entry.  If there is a lookup intent, inform
608 * the MDS so that it gets our 'caps wanted' value in a single op.
609 */
610static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
611				  unsigned int flags)
612{
613	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
614	struct ceph_mds_client *mdsc = fsc->mdsc;
615	struct ceph_mds_request *req;
616	int op;
617	int err;
618
619	dout("lookup %p dentry %p '%pd'\n",
620	     dir, dentry, dentry);
621
622	if (dentry->d_name.len > NAME_MAX)
623		return ERR_PTR(-ENAMETOOLONG);
624
625	err = ceph_init_dentry(dentry);
626	if (err < 0)
627		return ERR_PTR(err);
628
629	/* can we conclude ENOENT locally? */
630	if (d_really_is_negative(dentry)) {
631		struct ceph_inode_info *ci = ceph_inode(dir);
632		struct ceph_dentry_info *di = ceph_dentry(dentry);
633
634		spin_lock(&ci->i_ceph_lock);
635		dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
636		if (strncmp(dentry->d_name.name,
637			    fsc->mount_options->snapdir_name,
638			    dentry->d_name.len) &&
639		    !is_root_ceph_dentry(dir, dentry) &&
640		    ceph_test_mount_opt(fsc, DCACHE) &&
641		    __ceph_dir_is_complete(ci) &&
642		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
643			spin_unlock(&ci->i_ceph_lock);
644			dout(" dir %p complete, -ENOENT\n", dir);
645			d_add(dentry, NULL);
646			di->lease_shared_gen = ci->i_shared_gen;
647			return NULL;
648		}
649		spin_unlock(&ci->i_ceph_lock);
650	}
651
652	op = ceph_snap(dir) == CEPH_SNAPDIR ?
653		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
654	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
655	if (IS_ERR(req))
656		return ERR_CAST(req);
657	req->r_dentry = dget(dentry);
658	req->r_num_caps = 2;
659	/* we only need inode linkage */
660	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
661	req->r_locked_dir = dir;
662	err = ceph_mdsc_do_request(mdsc, NULL, req);
663	err = ceph_handle_snapdir(req, dentry, err);
664	dentry = ceph_finish_lookup(req, dentry, err);
665	ceph_mdsc_put_request(req);  /* will dput(dentry) */
666	dout("lookup result=%p\n", dentry);
667	return dentry;
668}
669
670/*
671 * If we do a create but get no trace back from the MDS, follow up with
672 * a lookup (the VFS expects us to link up the provided dentry).
673 */
674int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
675{
676	struct dentry *result = ceph_lookup(dir, dentry, 0);
677
678	if (result && !IS_ERR(result)) {
679		/*
680		 * We created the item, then did a lookup, and found
681		 * it was already linked to another inode we already
682		 * had in our cache (and thus got spliced). To not
683		 * confuse VFS (especially when inode is a directory),
684		 * we don't link our dentry to that inode, return an
685		 * error instead.
686		 *
687		 * This event should be rare and it happens only when
688		 * we talk to old MDS. Recent MDS does not send traceless
689		 * reply for request that creates new inode.
690		 */
691		d_drop(result);
692		return -ESTALE;
693	}
694	return PTR_ERR(result);
695}
696
697static int ceph_mknod(struct inode *dir, struct dentry *dentry,
698		      umode_t mode, dev_t rdev)
699{
700	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
701	struct ceph_mds_client *mdsc = fsc->mdsc;
702	struct ceph_mds_request *req;
703	struct ceph_acls_info acls = {};
704	int err;
705
706	if (ceph_snap(dir) != CEPH_NOSNAP)
707		return -EROFS;
708
709	err = ceph_pre_init_acls(dir, &mode, &acls);
710	if (err < 0)
711		return err;
712
713	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
714	     dir, dentry, mode, rdev);
715	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
716	if (IS_ERR(req)) {
717		err = PTR_ERR(req);
718		goto out;
719	}
720	req->r_dentry = dget(dentry);
721	req->r_num_caps = 2;
722	req->r_locked_dir = dir;
723	req->r_args.mknod.mode = cpu_to_le32(mode);
724	req->r_args.mknod.rdev = cpu_to_le32(rdev);
725	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
726	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
727	if (acls.pagelist) {
728		req->r_pagelist = acls.pagelist;
729		acls.pagelist = NULL;
730	}
731	err = ceph_mdsc_do_request(mdsc, dir, req);
732	if (!err && !req->r_reply_info.head->is_dentry)
733		err = ceph_handle_notrace_create(dir, dentry);
734	ceph_mdsc_put_request(req);
735out:
736	if (!err)
737		ceph_init_inode_acls(d_inode(dentry), &acls);
738	else
739		d_drop(dentry);
740	ceph_release_acls_info(&acls);
741	return err;
742}
743
744static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
745		       bool excl)
746{
747	return ceph_mknod(dir, dentry, mode, 0);
748}
749
750static int ceph_symlink(struct inode *dir, struct dentry *dentry,
751			    const char *dest)
752{
753	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
754	struct ceph_mds_client *mdsc = fsc->mdsc;
755	struct ceph_mds_request *req;
756	int err;
757
758	if (ceph_snap(dir) != CEPH_NOSNAP)
759		return -EROFS;
760
761	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
762	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
763	if (IS_ERR(req)) {
764		err = PTR_ERR(req);
765		goto out;
766	}
767	req->r_path2 = kstrdup(dest, GFP_NOFS);
768	if (!req->r_path2) {
769		err = -ENOMEM;
770		ceph_mdsc_put_request(req);
771		goto out;
772	}
773	req->r_locked_dir = dir;
774	req->r_dentry = dget(dentry);
775	req->r_num_caps = 2;
776	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
777	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
778	err = ceph_mdsc_do_request(mdsc, dir, req);
779	if (!err && !req->r_reply_info.head->is_dentry)
780		err = ceph_handle_notrace_create(dir, dentry);
781	ceph_mdsc_put_request(req);
782out:
783	if (err)
784		d_drop(dentry);
785	return err;
786}
787
788static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
789{
790	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
791	struct ceph_mds_client *mdsc = fsc->mdsc;
792	struct ceph_mds_request *req;
793	struct ceph_acls_info acls = {};
794	int err = -EROFS;
795	int op;
796
797	if (ceph_snap(dir) == CEPH_SNAPDIR) {
798		/* mkdir .snap/foo is a MKSNAP */
799		op = CEPH_MDS_OP_MKSNAP;
800		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
801		     dentry, dentry);
802	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
803		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
804		op = CEPH_MDS_OP_MKDIR;
805	} else {
806		goto out;
807	}
808
809	mode |= S_IFDIR;
810	err = ceph_pre_init_acls(dir, &mode, &acls);
811	if (err < 0)
812		goto out;
813
814	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
815	if (IS_ERR(req)) {
816		err = PTR_ERR(req);
817		goto out;
818	}
819
820	req->r_dentry = dget(dentry);
821	req->r_num_caps = 2;
822	req->r_locked_dir = dir;
823	req->r_args.mkdir.mode = cpu_to_le32(mode);
824	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
825	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
826	if (acls.pagelist) {
827		req->r_pagelist = acls.pagelist;
828		acls.pagelist = NULL;
829	}
830	err = ceph_mdsc_do_request(mdsc, dir, req);
831	if (!err &&
832	    !req->r_reply_info.head->is_target &&
833	    !req->r_reply_info.head->is_dentry)
834		err = ceph_handle_notrace_create(dir, dentry);
835	ceph_mdsc_put_request(req);
836out:
837	if (!err)
838		ceph_init_inode_acls(d_inode(dentry), &acls);
839	else
840		d_drop(dentry);
841	ceph_release_acls_info(&acls);
842	return err;
843}
844
845static int ceph_link(struct dentry *old_dentry, struct inode *dir,
846		     struct dentry *dentry)
847{
848	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
849	struct ceph_mds_client *mdsc = fsc->mdsc;
850	struct ceph_mds_request *req;
851	int err;
852
853	if (ceph_snap(dir) != CEPH_NOSNAP)
854		return -EROFS;
855
856	dout("link in dir %p old_dentry %p dentry %p\n", dir,
857	     old_dentry, dentry);
858	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
859	if (IS_ERR(req)) {
860		d_drop(dentry);
861		return PTR_ERR(req);
862	}
863	req->r_dentry = dget(dentry);
864	req->r_num_caps = 2;
865	req->r_old_dentry = dget(old_dentry);
866	req->r_locked_dir = dir;
867	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
868	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
869	/* release LINK_SHARED on source inode (mds will lock it) */
870	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
871	err = ceph_mdsc_do_request(mdsc, dir, req);
872	if (err) {
873		d_drop(dentry);
874	} else if (!req->r_reply_info.head->is_dentry) {
875		ihold(d_inode(old_dentry));
876		d_instantiate(dentry, d_inode(old_dentry));
877	}
878	ceph_mdsc_put_request(req);
879	return err;
880}
881
882/*
883 * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
884 * looks like the link count will hit 0, drop any other caps (other
885 * than PIN) we don't specifically want (due to the file still being
886 * open).
887 */
888static int drop_caps_for_unlink(struct inode *inode)
889{
890	struct ceph_inode_info *ci = ceph_inode(inode);
891	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
892
893	spin_lock(&ci->i_ceph_lock);
894	if (inode->i_nlink == 1) {
895		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
896		ci->i_ceph_flags |= CEPH_I_NODELAY;
897	}
898	spin_unlock(&ci->i_ceph_lock);
899	return drop;
900}
901
902/*
903 * rmdir and unlink are differ only by the metadata op code
904 */
905static int ceph_unlink(struct inode *dir, struct dentry *dentry)
906{
907	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
908	struct ceph_mds_client *mdsc = fsc->mdsc;
909	struct inode *inode = d_inode(dentry);
910	struct ceph_mds_request *req;
911	int err = -EROFS;
912	int op;
913
914	if (ceph_snap(dir) == CEPH_SNAPDIR) {
915		/* rmdir .snap/foo is RMSNAP */
916		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
917		op = CEPH_MDS_OP_RMSNAP;
918	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
919		dout("unlink/rmdir dir %p dn %p inode %p\n",
920		     dir, dentry, inode);
921		op = d_is_dir(dentry) ?
922			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
923	} else
924		goto out;
925	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
926	if (IS_ERR(req)) {
927		err = PTR_ERR(req);
928		goto out;
929	}
930	req->r_dentry = dget(dentry);
931	req->r_num_caps = 2;
932	req->r_locked_dir = dir;
933	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
934	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
935	req->r_inode_drop = drop_caps_for_unlink(inode);
936	err = ceph_mdsc_do_request(mdsc, dir, req);
937	if (!err && !req->r_reply_info.head->is_dentry)
938		d_delete(dentry);
939	ceph_mdsc_put_request(req);
940out:
941	return err;
942}
943
944static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
945		       struct inode *new_dir, struct dentry *new_dentry)
946{
947	struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
948	struct ceph_mds_client *mdsc = fsc->mdsc;
949	struct ceph_mds_request *req;
950	int op = CEPH_MDS_OP_RENAME;
951	int err;
952
953	if (ceph_snap(old_dir) != ceph_snap(new_dir))
954		return -EXDEV;
955	if (ceph_snap(old_dir) != CEPH_NOSNAP) {
956		if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
957			op = CEPH_MDS_OP_RENAMESNAP;
958		else
959			return -EROFS;
960	}
961	dout("rename dir %p dentry %p to dir %p dentry %p\n",
962	     old_dir, old_dentry, new_dir, new_dentry);
963	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
964	if (IS_ERR(req))
965		return PTR_ERR(req);
966	ihold(old_dir);
967	req->r_dentry = dget(new_dentry);
968	req->r_num_caps = 2;
969	req->r_old_dentry = dget(old_dentry);
970	req->r_old_dentry_dir = old_dir;
971	req->r_locked_dir = new_dir;
972	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
973	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
974	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
975	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
976	/* release LINK_RDCACHE on source inode (mds will lock it) */
977	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
978	if (d_really_is_positive(new_dentry))
979		req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
980	err = ceph_mdsc_do_request(mdsc, old_dir, req);
981	if (!err && !req->r_reply_info.head->is_dentry) {
982		/*
983		 * Normally d_move() is done by fill_trace (called by
984		 * do_request, above).  If there is no trace, we need
985		 * to do it here.
986		 */
987
988		d_move(old_dentry, new_dentry);
989
990		/* ensure target dentry is invalidated, despite
991		   rehashing bug in vfs_rename_dir */
992		ceph_invalidate_dentry_lease(new_dentry);
993
994		/* d_move screws up sibling dentries' offsets */
995		ceph_dir_clear_complete(old_dir);
996		ceph_dir_clear_complete(new_dir);
997
998	}
999	ceph_mdsc_put_request(req);
1000	return err;
1001}
1002
1003/*
1004 * Ensure a dentry lease will no longer revalidate.
1005 */
1006void ceph_invalidate_dentry_lease(struct dentry *dentry)
1007{
1008	spin_lock(&dentry->d_lock);
1009	dentry->d_time = jiffies;
1010	ceph_dentry(dentry)->lease_shared_gen = 0;
1011	spin_unlock(&dentry->d_lock);
1012}
1013
1014/*
1015 * Check if dentry lease is valid.  If not, delete the lease.  Try to
1016 * renew if the least is more than half up.
1017 */
1018static int dentry_lease_is_valid(struct dentry *dentry)
1019{
1020	struct ceph_dentry_info *di;
1021	struct ceph_mds_session *s;
1022	int valid = 0;
1023	u32 gen;
1024	unsigned long ttl;
1025	struct ceph_mds_session *session = NULL;
1026	struct inode *dir = NULL;
1027	u32 seq = 0;
1028
1029	spin_lock(&dentry->d_lock);
1030	di = ceph_dentry(dentry);
1031	if (di->lease_session) {
1032		s = di->lease_session;
1033		spin_lock(&s->s_gen_ttl_lock);
1034		gen = s->s_cap_gen;
1035		ttl = s->s_cap_ttl;
1036		spin_unlock(&s->s_gen_ttl_lock);
1037
1038		if (di->lease_gen == gen &&
1039		    time_before(jiffies, dentry->d_time) &&
1040		    time_before(jiffies, ttl)) {
1041			valid = 1;
1042			if (di->lease_renew_after &&
1043			    time_after(jiffies, di->lease_renew_after)) {
1044				/* we should renew */
1045				dir = d_inode(dentry->d_parent);
1046				session = ceph_get_mds_session(s);
1047				seq = di->lease_seq;
1048				di->lease_renew_after = 0;
1049				di->lease_renew_from = jiffies;
1050			}
1051		}
1052	}
1053	spin_unlock(&dentry->d_lock);
1054
1055	if (session) {
1056		ceph_mdsc_lease_send_msg(session, dir, dentry,
1057					 CEPH_MDS_LEASE_RENEW, seq);
1058		ceph_put_mds_session(session);
1059	}
1060	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1061	return valid;
1062}
1063
1064/*
1065 * Check if directory-wide content lease/cap is valid.
1066 */
1067static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1068{
1069	struct ceph_inode_info *ci = ceph_inode(dir);
1070	struct ceph_dentry_info *di = ceph_dentry(dentry);
1071	int valid = 0;
1072
1073	spin_lock(&ci->i_ceph_lock);
1074	if (ci->i_shared_gen == di->lease_shared_gen)
1075		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1076	spin_unlock(&ci->i_ceph_lock);
1077	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1078	     dir, (unsigned)ci->i_shared_gen, dentry,
1079	     (unsigned)di->lease_shared_gen, valid);
1080	return valid;
1081}
1082
1083/*
1084 * Check if cached dentry can be trusted.
1085 */
1086static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1087{
1088	int valid = 0;
1089	struct inode *dir;
1090
1091	if (flags & LOOKUP_RCU)
1092		return -ECHILD;
1093
1094	dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1095	     dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1096
1097	dir = ceph_get_dentry_parent_inode(dentry);
1098
1099	/* always trust cached snapped dentries, snapdir dentry */
1100	if (ceph_snap(dir) != CEPH_NOSNAP) {
1101		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1102		     dentry, d_inode(dentry));
1103		valid = 1;
1104	} else if (d_really_is_positive(dentry) &&
1105		   ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1106		valid = 1;
1107	} else if (dentry_lease_is_valid(dentry) ||
1108		   dir_lease_is_valid(dir, dentry)) {
1109		if (d_really_is_positive(dentry))
1110			valid = ceph_is_any_caps(d_inode(dentry));
1111		else
1112			valid = 1;
1113	}
1114
1115	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1116	if (valid) {
1117		ceph_dentry_lru_touch(dentry);
1118	} else {
1119		ceph_dir_clear_complete(dir);
1120	}
1121	iput(dir);
1122	return valid;
1123}
1124
1125/*
1126 * Release our ceph_dentry_info.
1127 */
1128static void ceph_d_release(struct dentry *dentry)
1129{
1130	struct ceph_dentry_info *di = ceph_dentry(dentry);
1131
1132	dout("d_release %p\n", dentry);
1133	ceph_dentry_lru_del(dentry);
1134	if (di->lease_session)
1135		ceph_put_mds_session(di->lease_session);
1136	kmem_cache_free(ceph_dentry_cachep, di);
1137	dentry->d_fsdata = NULL;
1138}
1139
1140static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1141					  unsigned int flags)
1142{
1143	/*
1144	 * Eventually, we'll want to revalidate snapped metadata
1145	 * too... probably...
1146	 */
1147	return 1;
1148}
1149
1150/*
1151 * When the VFS prunes a dentry from the cache, we need to clear the
1152 * complete flag on the parent directory.
1153 *
1154 * Called under dentry->d_lock.
1155 */
1156static void ceph_d_prune(struct dentry *dentry)
1157{
1158	dout("ceph_d_prune %p\n", dentry);
1159
1160	/* do we have a valid parent? */
1161	if (IS_ROOT(dentry))
1162		return;
1163
1164	/* if we are not hashed, we don't affect dir's completeness */
1165	if (d_unhashed(dentry))
1166		return;
1167
1168	/*
1169	 * we hold d_lock, so d_parent is stable, and d_fsdata is never
1170	 * cleared until d_release
1171	 */
1172	ceph_dir_clear_complete(d_inode(dentry->d_parent));
1173}
1174
1175/*
1176 * read() on a dir.  This weird interface hack only works if mounted
1177 * with '-o dirstat'.
1178 */
1179static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1180			     loff_t *ppos)
1181{
1182	struct ceph_file_info *cf = file->private_data;
1183	struct inode *inode = file_inode(file);
1184	struct ceph_inode_info *ci = ceph_inode(inode);
1185	int left;
1186	const int bufsize = 1024;
1187
1188	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1189		return -EISDIR;
1190
1191	if (!cf->dir_info) {
1192		cf->dir_info = kmalloc(bufsize, GFP_NOFS);
1193		if (!cf->dir_info)
1194			return -ENOMEM;
1195		cf->dir_info_len =
1196			snprintf(cf->dir_info, bufsize,
1197				"entries:   %20lld\n"
1198				" files:    %20lld\n"
1199				" subdirs:  %20lld\n"
1200				"rentries:  %20lld\n"
1201				" rfiles:   %20lld\n"
1202				" rsubdirs: %20lld\n"
1203				"rbytes:    %20lld\n"
1204				"rctime:    %10ld.%09ld\n",
1205				ci->i_files + ci->i_subdirs,
1206				ci->i_files,
1207				ci->i_subdirs,
1208				ci->i_rfiles + ci->i_rsubdirs,
1209				ci->i_rfiles,
1210				ci->i_rsubdirs,
1211				ci->i_rbytes,
1212				(long)ci->i_rctime.tv_sec,
1213				(long)ci->i_rctime.tv_nsec);
1214	}
1215
1216	if (*ppos >= cf->dir_info_len)
1217		return 0;
1218	size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1219	left = copy_to_user(buf, cf->dir_info + *ppos, size);
1220	if (left == size)
1221		return -EFAULT;
1222	*ppos += (size - left);
1223	return size - left;
1224}
1225
1226/*
1227 * an fsync() on a dir will wait for any uncommitted directory
1228 * operations to commit.
1229 */
1230static int ceph_dir_fsync(struct file *file, loff_t start, loff_t end,
1231			  int datasync)
1232{
1233	struct inode *inode = file_inode(file);
1234	struct ceph_inode_info *ci = ceph_inode(inode);
1235	struct list_head *head = &ci->i_unsafe_dirops;
1236	struct ceph_mds_request *req;
1237	u64 last_tid;
1238	int ret = 0;
1239
1240	dout("dir_fsync %p\n", inode);
1241	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
1242	if (ret)
1243		return ret;
1244	mutex_lock(&inode->i_mutex);
1245
1246	spin_lock(&ci->i_unsafe_lock);
1247	if (list_empty(head))
1248		goto out;
1249
1250	req = list_entry(head->prev,
1251			 struct ceph_mds_request, r_unsafe_dir_item);
1252	last_tid = req->r_tid;
1253
1254	do {
1255		ceph_mdsc_get_request(req);
1256		spin_unlock(&ci->i_unsafe_lock);
1257
1258		dout("dir_fsync %p wait on tid %llu (until %llu)\n",
1259		     inode, req->r_tid, last_tid);
1260		if (req->r_timeout) {
1261			unsigned long time_left = wait_for_completion_timeout(
1262							&req->r_safe_completion,
1263							req->r_timeout);
1264			if (time_left > 0)
1265				ret = 0;
1266			else
1267				ret = -EIO;  /* timed out */
1268		} else {
1269			wait_for_completion(&req->r_safe_completion);
1270		}
1271		ceph_mdsc_put_request(req);
1272
1273		spin_lock(&ci->i_unsafe_lock);
1274		if (ret || list_empty(head))
1275			break;
1276		req = list_entry(head->next,
1277				 struct ceph_mds_request, r_unsafe_dir_item);
1278	} while (req->r_tid < last_tid);
1279out:
1280	spin_unlock(&ci->i_unsafe_lock);
1281	mutex_unlock(&inode->i_mutex);
1282
1283	return ret;
1284}
1285
1286/*
1287 * We maintain a private dentry LRU.
1288 *
1289 * FIXME: this needs to be changed to a per-mds lru to be useful.
1290 */
1291void ceph_dentry_lru_add(struct dentry *dn)
1292{
1293	struct ceph_dentry_info *di = ceph_dentry(dn);
1294	struct ceph_mds_client *mdsc;
1295
1296	dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1297	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1298	spin_lock(&mdsc->dentry_lru_lock);
1299	list_add_tail(&di->lru, &mdsc->dentry_lru);
1300	mdsc->num_dentry++;
1301	spin_unlock(&mdsc->dentry_lru_lock);
1302}
1303
1304void ceph_dentry_lru_touch(struct dentry *dn)
1305{
1306	struct ceph_dentry_info *di = ceph_dentry(dn);
1307	struct ceph_mds_client *mdsc;
1308
1309	dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1310	     di->offset);
1311	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1312	spin_lock(&mdsc->dentry_lru_lock);
1313	list_move_tail(&di->lru, &mdsc->dentry_lru);
1314	spin_unlock(&mdsc->dentry_lru_lock);
1315}
1316
1317void ceph_dentry_lru_del(struct dentry *dn)
1318{
1319	struct ceph_dentry_info *di = ceph_dentry(dn);
1320	struct ceph_mds_client *mdsc;
1321
1322	dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1323	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1324	spin_lock(&mdsc->dentry_lru_lock);
1325	list_del_init(&di->lru);
1326	mdsc->num_dentry--;
1327	spin_unlock(&mdsc->dentry_lru_lock);
1328}
1329
1330/*
1331 * Return name hash for a given dentry.  This is dependent on
1332 * the parent directory's hash function.
1333 */
1334unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1335{
1336	struct ceph_inode_info *dci = ceph_inode(dir);
1337
1338	switch (dci->i_dir_layout.dl_dir_hash) {
1339	case 0:	/* for backward compat */
1340	case CEPH_STR_HASH_LINUX:
1341		return dn->d_name.hash;
1342
1343	default:
1344		return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1345				     dn->d_name.name, dn->d_name.len);
1346	}
1347}
1348
1349const struct file_operations ceph_dir_fops = {
1350	.read = ceph_read_dir,
1351	.iterate = ceph_readdir,
1352	.llseek = ceph_dir_llseek,
1353	.open = ceph_open,
1354	.release = ceph_release,
1355	.unlocked_ioctl = ceph_ioctl,
1356	.fsync = ceph_dir_fsync,
1357};
1358
1359const struct file_operations ceph_snapdir_fops = {
1360	.iterate = ceph_readdir,
1361	.llseek = ceph_dir_llseek,
1362	.open = ceph_open,
1363	.release = ceph_release,
1364};
1365
1366const struct inode_operations ceph_dir_iops = {
1367	.lookup = ceph_lookup,
1368	.permission = ceph_permission,
1369	.getattr = ceph_getattr,
1370	.setattr = ceph_setattr,
1371	.setxattr = ceph_setxattr,
1372	.getxattr = ceph_getxattr,
1373	.listxattr = ceph_listxattr,
1374	.removexattr = ceph_removexattr,
1375	.get_acl = ceph_get_acl,
1376	.set_acl = ceph_set_acl,
1377	.mknod = ceph_mknod,
1378	.symlink = ceph_symlink,
1379	.mkdir = ceph_mkdir,
1380	.link = ceph_link,
1381	.unlink = ceph_unlink,
1382	.rmdir = ceph_unlink,
1383	.rename = ceph_rename,
1384	.create = ceph_create,
1385	.atomic_open = ceph_atomic_open,
1386};
1387
1388const struct inode_operations ceph_snapdir_iops = {
1389	.lookup = ceph_lookup,
1390	.permission = ceph_permission,
1391	.getattr = ceph_getattr,
1392	.mkdir = ceph_mkdir,
1393	.rmdir = ceph_unlink,
1394	.rename = ceph_rename,
1395};
1396
1397const struct dentry_operations ceph_dentry_ops = {
1398	.d_revalidate = ceph_d_revalidate,
1399	.d_release = ceph_d_release,
1400	.d_prune = ceph_d_prune,
1401};
1402
1403const struct dentry_operations ceph_snapdir_dentry_ops = {
1404	.d_revalidate = ceph_snapdir_d_revalidate,
1405	.d_release = ceph_d_release,
1406};
1407
1408const struct dentry_operations ceph_snap_dentry_ops = {
1409	.d_release = ceph_d_release,
1410	.d_prune = ceph_d_prune,
1411};
1412