Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / fs / ceph / dir.c
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
30 const struct dentry_operations ceph_dentry_ops;
31
32 static bool __dentry_lease_is_valid(struct ceph_dentry_info *di);
33 static int __dir_lease_try_check(const struct dentry *dentry);
34
35 /*
36  * Initialize ceph dentry state.
37  */
38 static int ceph_d_init(struct dentry *dentry)
39 {
40         struct ceph_dentry_info *di;
41
42         di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
43         if (!di)
44                 return -ENOMEM;          /* oh well */
45
46         di->dentry = dentry;
47         di->lease_session = NULL;
48         di->time = jiffies;
49         dentry->d_fsdata = di;
50         INIT_LIST_HEAD(&di->lease_list);
51         return 0;
52 }
53
54 /*
55  * for f_pos for readdir:
56  * - hash order:
57  *      (0xff << 52) | ((24 bits hash) << 28) |
58  *      (the nth entry has hash collision);
59  * - frag+name order;
60  *      ((frag value) << 28) | (the nth entry in frag);
61  */
62 #define OFFSET_BITS     28
63 #define OFFSET_MASK     ((1 << OFFSET_BITS) - 1)
64 #define HASH_ORDER      (0xffull << (OFFSET_BITS + 24))
65 loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
66 {
67         loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
68         if (hash_order)
69                 fpos |= HASH_ORDER;
70         return fpos;
71 }
72
73 static bool is_hash_order(loff_t p)
74 {
75         return (p & HASH_ORDER) == HASH_ORDER;
76 }
77
78 static unsigned fpos_frag(loff_t p)
79 {
80         return p >> OFFSET_BITS;
81 }
82
83 static unsigned fpos_hash(loff_t p)
84 {
85         return ceph_frag_value(fpos_frag(p));
86 }
87
88 static unsigned fpos_off(loff_t p)
89 {
90         return p & OFFSET_MASK;
91 }
92
93 static int fpos_cmp(loff_t l, loff_t r)
94 {
95         int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
96         if (v)
97                 return v;
98         return (int)(fpos_off(l) - fpos_off(r));
99 }
100
101 /*
102  * make note of the last dentry we read, so we can
103  * continue at the same lexicographical point,
104  * regardless of what dir changes take place on the
105  * server.
106  */
107 static int note_last_dentry(struct ceph_dir_file_info *dfi, const char *name,
108                             int len, unsigned next_offset)
109 {
110         char *buf = kmalloc(len+1, GFP_KERNEL);
111         if (!buf)
112                 return -ENOMEM;
113         kfree(dfi->last_name);
114         dfi->last_name = buf;
115         memcpy(dfi->last_name, name, len);
116         dfi->last_name[len] = 0;
117         dfi->next_offset = next_offset;
118         dout("note_last_dentry '%s'\n", dfi->last_name);
119         return 0;
120 }
121
122
123 static struct dentry *
124 __dcache_find_get_entry(struct dentry *parent, u64 idx,
125                         struct ceph_readdir_cache_control *cache_ctl)
126 {
127         struct inode *dir = d_inode(parent);
128         struct dentry *dentry;
129         unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
130         loff_t ptr_pos = idx * sizeof(struct dentry *);
131         pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
132
133         if (ptr_pos >= i_size_read(dir))
134                 return NULL;
135
136         if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
137                 ceph_readdir_cache_release(cache_ctl);
138                 cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
139                 if (!cache_ctl->page) {
140                         dout(" page %lu not found\n", ptr_pgoff);
141                         return ERR_PTR(-EAGAIN);
142                 }
143                 /* reading/filling the cache are serialized by
144                    i_mutex, no need to use page lock */
145                 unlock_page(cache_ctl->page);
146                 cache_ctl->dentries = kmap(cache_ctl->page);
147         }
148
149         cache_ctl->index = idx & idx_mask;
150
151         rcu_read_lock();
152         spin_lock(&parent->d_lock);
153         /* check i_size again here, because empty directory can be
154          * marked as complete while not holding the i_mutex. */
155         if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
156                 dentry = cache_ctl->dentries[cache_ctl->index];
157         else
158                 dentry = NULL;
159         spin_unlock(&parent->d_lock);
160         if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
161                 dentry = NULL;
162         rcu_read_unlock();
163         return dentry ? : ERR_PTR(-EAGAIN);
164 }
165
166 /*
167  * When possible, we try to satisfy a readdir by peeking at the
168  * dcache.  We make this work by carefully ordering dentries on
169  * d_child when we initially get results back from the MDS, and
170  * falling back to a "normal" sync readdir if any dentries in the dir
171  * are dropped.
172  *
173  * Complete dir indicates that we have all dentries in the dir.  It is
174  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
175  * the MDS if/when the directory is modified).
176  */
177 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
178                             int shared_gen)
179 {
180         struct ceph_dir_file_info *dfi = file->private_data;
181         struct dentry *parent = file->f_path.dentry;
182         struct inode *dir = d_inode(parent);
183         struct dentry *dentry, *last = NULL;
184         struct ceph_dentry_info *di;
185         struct ceph_readdir_cache_control cache_ctl = {};
186         u64 idx = 0;
187         int err = 0;
188
189         dout("__dcache_readdir %p v%u at %llx\n", dir, (unsigned)shared_gen, ctx->pos);
190
191         /* search start position */
192         if (ctx->pos > 2) {
193                 u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
194                 while (count > 0) {
195                         u64 step = count >> 1;
196                         dentry = __dcache_find_get_entry(parent, idx + step,
197                                                          &cache_ctl);
198                         if (!dentry) {
199                                 /* use linar search */
200                                 idx = 0;
201                                 break;
202                         }
203                         if (IS_ERR(dentry)) {
204                                 err = PTR_ERR(dentry);
205                                 goto out;
206                         }
207                         di = ceph_dentry(dentry);
208                         spin_lock(&dentry->d_lock);
209                         if (fpos_cmp(di->offset, ctx->pos) < 0) {
210                                 idx += step + 1;
211                                 count -= step + 1;
212                         } else {
213                                 count = step;
214                         }
215                         spin_unlock(&dentry->d_lock);
216                         dput(dentry);
217                 }
218
219                 dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
220         }
221
222
223         for (;;) {
224                 bool emit_dentry = false;
225                 dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
226                 if (!dentry) {
227                         dfi->file_info.flags |= CEPH_F_ATEND;
228                         err = 0;
229                         break;
230                 }
231                 if (IS_ERR(dentry)) {
232                         err = PTR_ERR(dentry);
233                         goto out;
234                 }
235
236                 spin_lock(&dentry->d_lock);
237                 di = ceph_dentry(dentry);
238                 if (d_unhashed(dentry) ||
239                     d_really_is_negative(dentry) ||
240                     di->lease_shared_gen != shared_gen) {
241                         spin_unlock(&dentry->d_lock);
242                         dput(dentry);
243                         err = -EAGAIN;
244                         goto out;
245                 }
246                 if (fpos_cmp(ctx->pos, di->offset) <= 0) {
247                         __ceph_dentry_dir_lease_touch(di);
248                         emit_dentry = true;
249                 }
250                 spin_unlock(&dentry->d_lock);
251
252                 if (emit_dentry) {
253                         dout(" %llx dentry %p %pd %p\n", di->offset,
254                              dentry, dentry, d_inode(dentry));
255                         ctx->pos = di->offset;
256                         if (!dir_emit(ctx, dentry->d_name.name,
257                                       dentry->d_name.len,
258                                       ceph_translate_ino(dentry->d_sb,
259                                                          d_inode(dentry)->i_ino),
260                                       d_inode(dentry)->i_mode >> 12)) {
261                                 dput(dentry);
262                                 err = 0;
263                                 break;
264                         }
265                         ctx->pos++;
266
267                         if (last)
268                                 dput(last);
269                         last = dentry;
270                 } else {
271                         dput(dentry);
272                 }
273         }
274 out:
275         ceph_readdir_cache_release(&cache_ctl);
276         if (last) {
277                 int ret;
278                 di = ceph_dentry(last);
279                 ret = note_last_dentry(dfi, last->d_name.name, last->d_name.len,
280                                        fpos_off(di->offset) + 1);
281                 if (ret < 0)
282                         err = ret;
283                 dput(last);
284                 /* last_name no longer match cache index */
285                 if (dfi->readdir_cache_idx >= 0) {
286                         dfi->readdir_cache_idx = -1;
287                         dfi->dir_release_count = 0;
288                 }
289         }
290         return err;
291 }
292
293 static bool need_send_readdir(struct ceph_dir_file_info *dfi, loff_t pos)
294 {
295         if (!dfi->last_readdir)
296                 return true;
297         if (is_hash_order(pos))
298                 return !ceph_frag_contains_value(dfi->frag, fpos_hash(pos));
299         else
300                 return dfi->frag != fpos_frag(pos);
301 }
302
303 static int ceph_readdir(struct file *file, struct dir_context *ctx)
304 {
305         struct ceph_dir_file_info *dfi = file->private_data;
306         struct inode *inode = file_inode(file);
307         struct ceph_inode_info *ci = ceph_inode(inode);
308         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
309         struct ceph_mds_client *mdsc = fsc->mdsc;
310         int i;
311         int err;
312         unsigned frag = -1;
313         struct ceph_mds_reply_info_parsed *rinfo;
314
315         dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
316         if (dfi->file_info.flags & CEPH_F_ATEND)
317                 return 0;
318
319         /* always start with . and .. */
320         if (ctx->pos == 0) {
321                 dout("readdir off 0 -> '.'\n");
322                 if (!dir_emit(ctx, ".", 1, 
323                             ceph_translate_ino(inode->i_sb, inode->i_ino),
324                             inode->i_mode >> 12))
325                         return 0;
326                 ctx->pos = 1;
327         }
328         if (ctx->pos == 1) {
329                 ino_t ino = parent_ino(file->f_path.dentry);
330                 dout("readdir off 1 -> '..'\n");
331                 if (!dir_emit(ctx, "..", 2,
332                             ceph_translate_ino(inode->i_sb, ino),
333                             inode->i_mode >> 12))
334                         return 0;
335                 ctx->pos = 2;
336         }
337
338         /* can we use the dcache? */
339         spin_lock(&ci->i_ceph_lock);
340         if (ceph_test_mount_opt(fsc, DCACHE) &&
341             !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
342             ceph_snap(inode) != CEPH_SNAPDIR &&
343             __ceph_dir_is_complete_ordered(ci) &&
344             __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
345                 int shared_gen = atomic_read(&ci->i_shared_gen);
346                 spin_unlock(&ci->i_ceph_lock);
347                 err = __dcache_readdir(file, ctx, shared_gen);
348                 if (err != -EAGAIN)
349                         return err;
350         } else {
351                 spin_unlock(&ci->i_ceph_lock);
352         }
353
354         /* proceed with a normal readdir */
355 more:
356         /* do we have the correct frag content buffered? */
357         if (need_send_readdir(dfi, ctx->pos)) {
358                 struct ceph_mds_request *req;
359                 int op = ceph_snap(inode) == CEPH_SNAPDIR ?
360                         CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
361
362                 /* discard old result, if any */
363                 if (dfi->last_readdir) {
364                         ceph_mdsc_put_request(dfi->last_readdir);
365                         dfi->last_readdir = NULL;
366                 }
367
368                 if (is_hash_order(ctx->pos)) {
369                         /* fragtree isn't always accurate. choose frag
370                          * based on previous reply when possible. */
371                         if (frag == (unsigned)-1)
372                                 frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
373                                                         NULL, NULL);
374                 } else {
375                         frag = fpos_frag(ctx->pos);
376                 }
377
378                 dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
379                      ceph_vinop(inode), frag, dfi->last_name);
380                 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
381                 if (IS_ERR(req))
382                         return PTR_ERR(req);
383                 err = ceph_alloc_readdir_reply_buffer(req, inode);
384                 if (err) {
385                         ceph_mdsc_put_request(req);
386                         return err;
387                 }
388                 /* hints to request -> mds selection code */
389                 req->r_direct_mode = USE_AUTH_MDS;
390                 if (op == CEPH_MDS_OP_READDIR) {
391                         req->r_direct_hash = ceph_frag_value(frag);
392                         __set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
393                         req->r_inode_drop = CEPH_CAP_FILE_EXCL;
394                 }
395                 if (dfi->last_name) {
396                         req->r_path2 = kstrdup(dfi->last_name, GFP_KERNEL);
397                         if (!req->r_path2) {
398                                 ceph_mdsc_put_request(req);
399                                 return -ENOMEM;
400                         }
401                 } else if (is_hash_order(ctx->pos)) {
402                         req->r_args.readdir.offset_hash =
403                                 cpu_to_le32(fpos_hash(ctx->pos));
404                 }
405
406                 req->r_dir_release_cnt = dfi->dir_release_count;
407                 req->r_dir_ordered_cnt = dfi->dir_ordered_count;
408                 req->r_readdir_cache_idx = dfi->readdir_cache_idx;
409                 req->r_readdir_offset = dfi->next_offset;
410                 req->r_args.readdir.frag = cpu_to_le32(frag);
411                 req->r_args.readdir.flags =
412                                 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
413
414                 req->r_inode = inode;
415                 ihold(inode);
416                 req->r_dentry = dget(file->f_path.dentry);
417                 err = ceph_mdsc_do_request(mdsc, NULL, req);
418                 if (err < 0) {
419                         ceph_mdsc_put_request(req);
420                         return err;
421                 }
422                 dout("readdir got and parsed readdir result=%d on "
423                      "frag %x, end=%d, complete=%d, hash_order=%d\n",
424                      err, frag,
425                      (int)req->r_reply_info.dir_end,
426                      (int)req->r_reply_info.dir_complete,
427                      (int)req->r_reply_info.hash_order);
428
429                 rinfo = &req->r_reply_info;
430                 if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
431                         frag = le32_to_cpu(rinfo->dir_dir->frag);
432                         if (!rinfo->hash_order) {
433                                 dfi->next_offset = req->r_readdir_offset;
434                                 /* adjust ctx->pos to beginning of frag */
435                                 ctx->pos = ceph_make_fpos(frag,
436                                                           dfi->next_offset,
437                                                           false);
438                         }
439                 }
440
441                 dfi->frag = frag;
442                 dfi->last_readdir = req;
443
444                 if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
445                         dfi->readdir_cache_idx = req->r_readdir_cache_idx;
446                         if (dfi->readdir_cache_idx < 0) {
447                                 /* preclude from marking dir ordered */
448                                 dfi->dir_ordered_count = 0;
449                         } else if (ceph_frag_is_leftmost(frag) &&
450                                    dfi->next_offset == 2) {
451                                 /* note dir version at start of readdir so
452                                  * we can tell if any dentries get dropped */
453                                 dfi->dir_release_count = req->r_dir_release_cnt;
454                                 dfi->dir_ordered_count = req->r_dir_ordered_cnt;
455                         }
456                 } else {
457                         dout("readdir !did_prepopulate\n");
458                         /* disable readdir cache */
459                         dfi->readdir_cache_idx = -1;
460                         /* preclude from marking dir complete */
461                         dfi->dir_release_count = 0;
462                 }
463
464                 /* note next offset and last dentry name */
465                 if (rinfo->dir_nr > 0) {
466                         struct ceph_mds_reply_dir_entry *rde =
467                                         rinfo->dir_entries + (rinfo->dir_nr-1);
468                         unsigned next_offset = req->r_reply_info.dir_end ?
469                                         2 : (fpos_off(rde->offset) + 1);
470                         err = note_last_dentry(dfi, rde->name, rde->name_len,
471                                                next_offset);
472                         if (err)
473                                 return err;
474                 } else if (req->r_reply_info.dir_end) {
475                         dfi->next_offset = 2;
476                         /* keep last name */
477                 }
478         }
479
480         rinfo = &dfi->last_readdir->r_reply_info;
481         dout("readdir frag %x num %d pos %llx chunk first %llx\n",
482              dfi->frag, rinfo->dir_nr, ctx->pos,
483              rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
484
485         i = 0;
486         /* search start position */
487         if (rinfo->dir_nr > 0) {
488                 int step, nr = rinfo->dir_nr;
489                 while (nr > 0) {
490                         step = nr >> 1;
491                         if (rinfo->dir_entries[i + step].offset < ctx->pos) {
492                                 i +=  step + 1;
493                                 nr -= step + 1;
494                         } else {
495                                 nr = step;
496                         }
497                 }
498         }
499         for (; i < rinfo->dir_nr; i++) {
500                 struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
501                 struct ceph_vino vino;
502                 ino_t ino;
503                 u32 ftype;
504
505                 BUG_ON(rde->offset < ctx->pos);
506
507                 ctx->pos = rde->offset;
508                 dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
509                      i, rinfo->dir_nr, ctx->pos,
510                      rde->name_len, rde->name, &rde->inode.in);
511
512                 BUG_ON(!rde->inode.in);
513                 ftype = le32_to_cpu(rde->inode.in->mode) >> 12;
514                 vino.ino = le64_to_cpu(rde->inode.in->ino);
515                 vino.snap = le64_to_cpu(rde->inode.in->snapid);
516                 ino = ceph_vino_to_ino(vino);
517
518                 if (!dir_emit(ctx, rde->name, rde->name_len,
519                               ceph_translate_ino(inode->i_sb, ino), ftype)) {
520                         dout("filldir stopping us...\n");
521                         return 0;
522                 }
523                 ctx->pos++;
524         }
525
526         ceph_mdsc_put_request(dfi->last_readdir);
527         dfi->last_readdir = NULL;
528
529         if (dfi->next_offset > 2) {
530                 frag = dfi->frag;
531                 goto more;
532         }
533
534         /* more frags? */
535         if (!ceph_frag_is_rightmost(dfi->frag)) {
536                 frag = ceph_frag_next(dfi->frag);
537                 if (is_hash_order(ctx->pos)) {
538                         loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
539                                                         dfi->next_offset, true);
540                         if (new_pos > ctx->pos)
541                                 ctx->pos = new_pos;
542                         /* keep last_name */
543                 } else {
544                         ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
545                                                         false);
546                         kfree(dfi->last_name);
547                         dfi->last_name = NULL;
548                 }
549                 dout("readdir next frag is %x\n", frag);
550                 goto more;
551         }
552         dfi->file_info.flags |= CEPH_F_ATEND;
553
554         /*
555          * if dir_release_count still matches the dir, no dentries
556          * were released during the whole readdir, and we should have
557          * the complete dir contents in our cache.
558          */
559         if (atomic64_read(&ci->i_release_count) ==
560                                         dfi->dir_release_count) {
561                 spin_lock(&ci->i_ceph_lock);
562                 if (dfi->dir_ordered_count ==
563                                 atomic64_read(&ci->i_ordered_count)) {
564                         dout(" marking %p complete and ordered\n", inode);
565                         /* use i_size to track number of entries in
566                          * readdir cache */
567                         BUG_ON(dfi->readdir_cache_idx < 0);
568                         i_size_write(inode, dfi->readdir_cache_idx *
569                                      sizeof(struct dentry*));
570                 } else {
571                         dout(" marking %p complete\n", inode);
572                 }
573                 __ceph_dir_set_complete(ci, dfi->dir_release_count,
574                                         dfi->dir_ordered_count);
575                 spin_unlock(&ci->i_ceph_lock);
576         }
577
578         dout("readdir %p file %p done.\n", inode, file);
579         return 0;
580 }
581
582 static void reset_readdir(struct ceph_dir_file_info *dfi)
583 {
584         if (dfi->last_readdir) {
585                 ceph_mdsc_put_request(dfi->last_readdir);
586                 dfi->last_readdir = NULL;
587         }
588         kfree(dfi->last_name);
589         dfi->last_name = NULL;
590         dfi->dir_release_count = 0;
591         dfi->readdir_cache_idx = -1;
592         dfi->next_offset = 2;  /* compensate for . and .. */
593         dfi->file_info.flags &= ~CEPH_F_ATEND;
594 }
595
596 /*
597  * discard buffered readdir content on seekdir(0), or seek to new frag,
598  * or seek prior to current chunk
599  */
600 static bool need_reset_readdir(struct ceph_dir_file_info *dfi, loff_t new_pos)
601 {
602         struct ceph_mds_reply_info_parsed *rinfo;
603         loff_t chunk_offset;
604         if (new_pos == 0)
605                 return true;
606         if (is_hash_order(new_pos)) {
607                 /* no need to reset last_name for a forward seek when
608                  * dentries are sotred in hash order */
609         } else if (dfi->frag != fpos_frag(new_pos)) {
610                 return true;
611         }
612         rinfo = dfi->last_readdir ? &dfi->last_readdir->r_reply_info : NULL;
613         if (!rinfo || !rinfo->dir_nr)
614                 return true;
615         chunk_offset = rinfo->dir_entries[0].offset;
616         return new_pos < chunk_offset ||
617                is_hash_order(new_pos) != is_hash_order(chunk_offset);
618 }
619
620 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
621 {
622         struct ceph_dir_file_info *dfi = file->private_data;
623         struct inode *inode = file->f_mapping->host;
624         loff_t retval;
625
626         inode_lock(inode);
627         retval = -EINVAL;
628         switch (whence) {
629         case SEEK_CUR:
630                 offset += file->f_pos;
631         case SEEK_SET:
632                 break;
633         case SEEK_END:
634                 retval = -EOPNOTSUPP;
635         default:
636                 goto out;
637         }
638
639         if (offset >= 0) {
640                 if (need_reset_readdir(dfi, offset)) {
641                         dout("dir_llseek dropping %p content\n", file);
642                         reset_readdir(dfi);
643                 } else if (is_hash_order(offset) && offset > file->f_pos) {
644                         /* for hash offset, we don't know if a forward seek
645                          * is within same frag */
646                         dfi->dir_release_count = 0;
647                         dfi->readdir_cache_idx = -1;
648                 }
649
650                 if (offset != file->f_pos) {
651                         file->f_pos = offset;
652                         file->f_version = 0;
653                         dfi->file_info.flags &= ~CEPH_F_ATEND;
654                 }
655                 retval = offset;
656         }
657 out:
658         inode_unlock(inode);
659         return retval;
660 }
661
662 /*
663  * Handle lookups for the hidden .snap directory.
664  */
665 int ceph_handle_snapdir(struct ceph_mds_request *req,
666                         struct dentry *dentry, int err)
667 {
668         struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
669         struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
670
671         /* .snap dir? */
672         if (err == -ENOENT &&
673             ceph_snap(parent) == CEPH_NOSNAP &&
674             strcmp(dentry->d_name.name,
675                    fsc->mount_options->snapdir_name) == 0) {
676                 struct inode *inode = ceph_get_snapdir(parent);
677                 dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
678                      dentry, dentry, inode);
679                 BUG_ON(!d_unhashed(dentry));
680                 d_add(dentry, inode);
681                 err = 0;
682         }
683         return err;
684 }
685
686 /*
687  * Figure out final result of a lookup/open request.
688  *
689  * Mainly, make sure we return the final req->r_dentry (if it already
690  * existed) in place of the original VFS-provided dentry when they
691  * differ.
692  *
693  * Gracefully handle the case where the MDS replies with -ENOENT and
694  * no trace (which it may do, at its discretion, e.g., if it doesn't
695  * care to issue a lease on the negative dentry).
696  */
697 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
698                                   struct dentry *dentry, int err)
699 {
700         if (err == -ENOENT) {
701                 /* no trace? */
702                 err = 0;
703                 if (!req->r_reply_info.head->is_dentry) {
704                         dout("ENOENT and no trace, dentry %p inode %p\n",
705                              dentry, d_inode(dentry));
706                         if (d_really_is_positive(dentry)) {
707                                 d_drop(dentry);
708                                 err = -ENOENT;
709                         } else {
710                                 d_add(dentry, NULL);
711                         }
712                 }
713         }
714         if (err)
715                 dentry = ERR_PTR(err);
716         else if (dentry != req->r_dentry)
717                 dentry = dget(req->r_dentry);   /* we got spliced */
718         else
719                 dentry = NULL;
720         return dentry;
721 }
722
723 static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
724 {
725         return ceph_ino(inode) == CEPH_INO_ROOT &&
726                 strncmp(dentry->d_name.name, ".ceph", 5) == 0;
727 }
728
729 /*
730  * Look up a single dir entry.  If there is a lookup intent, inform
731  * the MDS so that it gets our 'caps wanted' value in a single op.
732  */
733 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
734                                   unsigned int flags)
735 {
736         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
737         struct ceph_mds_client *mdsc = fsc->mdsc;
738         struct ceph_mds_request *req;
739         int op;
740         int mask;
741         int err;
742
743         dout("lookup %p dentry %p '%pd'\n",
744              dir, dentry, dentry);
745
746         if (dentry->d_name.len > NAME_MAX)
747                 return ERR_PTR(-ENAMETOOLONG);
748
749         /* can we conclude ENOENT locally? */
750         if (d_really_is_negative(dentry)) {
751                 struct ceph_inode_info *ci = ceph_inode(dir);
752                 struct ceph_dentry_info *di = ceph_dentry(dentry);
753
754                 spin_lock(&ci->i_ceph_lock);
755                 dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
756                 if (strncmp(dentry->d_name.name,
757                             fsc->mount_options->snapdir_name,
758                             dentry->d_name.len) &&
759                     !is_root_ceph_dentry(dir, dentry) &&
760                     ceph_test_mount_opt(fsc, DCACHE) &&
761                     __ceph_dir_is_complete(ci) &&
762                     (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
763                         spin_unlock(&ci->i_ceph_lock);
764                         dout(" dir %p complete, -ENOENT\n", dir);
765                         d_add(dentry, NULL);
766                         di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
767                         return NULL;
768                 }
769                 spin_unlock(&ci->i_ceph_lock);
770         }
771
772         op = ceph_snap(dir) == CEPH_SNAPDIR ?
773                 CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
774         req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
775         if (IS_ERR(req))
776                 return ERR_CAST(req);
777         req->r_dentry = dget(dentry);
778         req->r_num_caps = 2;
779
780         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
781         if (ceph_security_xattr_wanted(dir))
782                 mask |= CEPH_CAP_XATTR_SHARED;
783         req->r_args.getattr.mask = cpu_to_le32(mask);
784
785         req->r_parent = dir;
786         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
787         err = ceph_mdsc_do_request(mdsc, NULL, req);
788         err = ceph_handle_snapdir(req, dentry, err);
789         dentry = ceph_finish_lookup(req, dentry, err);
790         ceph_mdsc_put_request(req);  /* will dput(dentry) */
791         dout("lookup result=%p\n", dentry);
792         return dentry;
793 }
794
795 /*
796  * If we do a create but get no trace back from the MDS, follow up with
797  * a lookup (the VFS expects us to link up the provided dentry).
798  */
799 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
800 {
801         struct dentry *result = ceph_lookup(dir, dentry, 0);
802
803         if (result && !IS_ERR(result)) {
804                 /*
805                  * We created the item, then did a lookup, and found
806                  * it was already linked to another inode we already
807                  * had in our cache (and thus got spliced). To not
808                  * confuse VFS (especially when inode is a directory),
809                  * we don't link our dentry to that inode, return an
810                  * error instead.
811                  *
812                  * This event should be rare and it happens only when
813                  * we talk to old MDS. Recent MDS does not send traceless
814                  * reply for request that creates new inode.
815                  */
816                 d_drop(result);
817                 return -ESTALE;
818         }
819         return PTR_ERR(result);
820 }
821
822 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
823                       umode_t mode, dev_t rdev)
824 {
825         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
826         struct ceph_mds_client *mdsc = fsc->mdsc;
827         struct ceph_mds_request *req;
828         struct ceph_acl_sec_ctx as_ctx = {};
829         int err;
830
831         if (ceph_snap(dir) != CEPH_NOSNAP)
832                 return -EROFS;
833
834         if (ceph_quota_is_max_files_exceeded(dir)) {
835                 err = -EDQUOT;
836                 goto out;
837         }
838
839         err = ceph_pre_init_acls(dir, &mode, &as_ctx);
840         if (err < 0)
841                 goto out;
842         err = ceph_security_init_secctx(dentry, mode, &as_ctx);
843         if (err < 0)
844                 goto out;
845
846         dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
847              dir, dentry, mode, rdev);
848         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
849         if (IS_ERR(req)) {
850                 err = PTR_ERR(req);
851                 goto out;
852         }
853         req->r_dentry = dget(dentry);
854         req->r_num_caps = 2;
855         req->r_parent = dir;
856         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
857         req->r_args.mknod.mode = cpu_to_le32(mode);
858         req->r_args.mknod.rdev = cpu_to_le32(rdev);
859         req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
860         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
861         if (as_ctx.pagelist) {
862                 req->r_pagelist = as_ctx.pagelist;
863                 as_ctx.pagelist = NULL;
864         }
865         err = ceph_mdsc_do_request(mdsc, dir, req);
866         if (!err && !req->r_reply_info.head->is_dentry)
867                 err = ceph_handle_notrace_create(dir, dentry);
868         ceph_mdsc_put_request(req);
869 out:
870         if (!err)
871                 ceph_init_inode_acls(d_inode(dentry), &as_ctx);
872         else
873                 d_drop(dentry);
874         ceph_release_acl_sec_ctx(&as_ctx);
875         return err;
876 }
877
878 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
879                        bool excl)
880 {
881         return ceph_mknod(dir, dentry, mode, 0);
882 }
883
884 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
885                             const char *dest)
886 {
887         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
888         struct ceph_mds_client *mdsc = fsc->mdsc;
889         struct ceph_mds_request *req;
890         struct ceph_acl_sec_ctx as_ctx = {};
891         int err;
892
893         if (ceph_snap(dir) != CEPH_NOSNAP)
894                 return -EROFS;
895
896         if (ceph_quota_is_max_files_exceeded(dir)) {
897                 err = -EDQUOT;
898                 goto out;
899         }
900
901         err = ceph_security_init_secctx(dentry, S_IFLNK | 0777, &as_ctx);
902         if (err < 0)
903                 goto out;
904
905         dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
906         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
907         if (IS_ERR(req)) {
908                 err = PTR_ERR(req);
909                 goto out;
910         }
911         req->r_path2 = kstrdup(dest, GFP_KERNEL);
912         if (!req->r_path2) {
913                 err = -ENOMEM;
914                 ceph_mdsc_put_request(req);
915                 goto out;
916         }
917         req->r_parent = dir;
918         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
919         req->r_dentry = dget(dentry);
920         req->r_num_caps = 2;
921         req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
922         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
923         err = ceph_mdsc_do_request(mdsc, dir, req);
924         if (!err && !req->r_reply_info.head->is_dentry)
925                 err = ceph_handle_notrace_create(dir, dentry);
926         ceph_mdsc_put_request(req);
927 out:
928         if (err)
929                 d_drop(dentry);
930         ceph_release_acl_sec_ctx(&as_ctx);
931         return err;
932 }
933
934 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
935 {
936         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
937         struct ceph_mds_client *mdsc = fsc->mdsc;
938         struct ceph_mds_request *req;
939         struct ceph_acl_sec_ctx as_ctx = {};
940         int err = -EROFS;
941         int op;
942
943         if (ceph_snap(dir) == CEPH_SNAPDIR) {
944                 /* mkdir .snap/foo is a MKSNAP */
945                 op = CEPH_MDS_OP_MKSNAP;
946                 dout("mksnap dir %p snap '%pd' dn %p\n", dir,
947                      dentry, dentry);
948         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
949                 dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
950                 op = CEPH_MDS_OP_MKDIR;
951         } else {
952                 goto out;
953         }
954
955         if (op == CEPH_MDS_OP_MKDIR &&
956             ceph_quota_is_max_files_exceeded(dir)) {
957                 err = -EDQUOT;
958                 goto out;
959         }
960
961         mode |= S_IFDIR;
962         err = ceph_pre_init_acls(dir, &mode, &as_ctx);
963         if (err < 0)
964                 goto out;
965         err = ceph_security_init_secctx(dentry, mode, &as_ctx);
966         if (err < 0)
967                 goto out;
968
969         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
970         if (IS_ERR(req)) {
971                 err = PTR_ERR(req);
972                 goto out;
973         }
974
975         req->r_dentry = dget(dentry);
976         req->r_num_caps = 2;
977         req->r_parent = dir;
978         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
979         req->r_args.mkdir.mode = cpu_to_le32(mode);
980         req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
981         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
982         if (as_ctx.pagelist) {
983                 req->r_pagelist = as_ctx.pagelist;
984                 as_ctx.pagelist = NULL;
985         }
986         err = ceph_mdsc_do_request(mdsc, dir, req);
987         if (!err &&
988             !req->r_reply_info.head->is_target &&
989             !req->r_reply_info.head->is_dentry)
990                 err = ceph_handle_notrace_create(dir, dentry);
991         ceph_mdsc_put_request(req);
992 out:
993         if (!err)
994                 ceph_init_inode_acls(d_inode(dentry), &as_ctx);
995         else
996                 d_drop(dentry);
997         ceph_release_acl_sec_ctx(&as_ctx);
998         return err;
999 }
1000
1001 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
1002                      struct dentry *dentry)
1003 {
1004         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
1005         struct ceph_mds_client *mdsc = fsc->mdsc;
1006         struct ceph_mds_request *req;
1007         int err;
1008
1009         if (ceph_snap(dir) != CEPH_NOSNAP)
1010                 return -EROFS;
1011
1012         dout("link in dir %p old_dentry %p dentry %p\n", dir,
1013              old_dentry, dentry);
1014         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
1015         if (IS_ERR(req)) {
1016                 d_drop(dentry);
1017                 return PTR_ERR(req);
1018         }
1019         req->r_dentry = dget(dentry);
1020         req->r_num_caps = 2;
1021         req->r_old_dentry = dget(old_dentry);
1022         req->r_parent = dir;
1023         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1024         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1025         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1026         /* release LINK_SHARED on source inode (mds will lock it) */
1027         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1028         err = ceph_mdsc_do_request(mdsc, dir, req);
1029         if (err) {
1030                 d_drop(dentry);
1031         } else if (!req->r_reply_info.head->is_dentry) {
1032                 ihold(d_inode(old_dentry));
1033                 d_instantiate(dentry, d_inode(old_dentry));
1034         }
1035         ceph_mdsc_put_request(req);
1036         return err;
1037 }
1038
1039 /*
1040  * rmdir and unlink are differ only by the metadata op code
1041  */
1042 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
1043 {
1044         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
1045         struct ceph_mds_client *mdsc = fsc->mdsc;
1046         struct inode *inode = d_inode(dentry);
1047         struct ceph_mds_request *req;
1048         int err = -EROFS;
1049         int op;
1050
1051         if (ceph_snap(dir) == CEPH_SNAPDIR) {
1052                 /* rmdir .snap/foo is RMSNAP */
1053                 dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
1054                 op = CEPH_MDS_OP_RMSNAP;
1055         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
1056                 dout("unlink/rmdir dir %p dn %p inode %p\n",
1057                      dir, dentry, inode);
1058                 op = d_is_dir(dentry) ?
1059                         CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
1060         } else
1061                 goto out;
1062         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1063         if (IS_ERR(req)) {
1064                 err = PTR_ERR(req);
1065                 goto out;
1066         }
1067         req->r_dentry = dget(dentry);
1068         req->r_num_caps = 2;
1069         req->r_parent = dir;
1070         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1071         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1072         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1073         req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
1074         err = ceph_mdsc_do_request(mdsc, dir, req);
1075         if (!err && !req->r_reply_info.head->is_dentry)
1076                 d_delete(dentry);
1077         ceph_mdsc_put_request(req);
1078 out:
1079         return err;
1080 }
1081
1082 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
1083                        struct inode *new_dir, struct dentry *new_dentry,
1084                        unsigned int flags)
1085 {
1086         struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
1087         struct ceph_mds_client *mdsc = fsc->mdsc;
1088         struct ceph_mds_request *req;
1089         int op = CEPH_MDS_OP_RENAME;
1090         int err;
1091
1092         if (flags)
1093                 return -EINVAL;
1094
1095         if (ceph_snap(old_dir) != ceph_snap(new_dir))
1096                 return -EXDEV;
1097         if (ceph_snap(old_dir) != CEPH_NOSNAP) {
1098                 if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
1099                         op = CEPH_MDS_OP_RENAMESNAP;
1100                 else
1101                         return -EROFS;
1102         }
1103         /* don't allow cross-quota renames */
1104         if ((old_dir != new_dir) &&
1105             (!ceph_quota_is_same_realm(old_dir, new_dir)))
1106                 return -EXDEV;
1107
1108         dout("rename dir %p dentry %p to dir %p dentry %p\n",
1109              old_dir, old_dentry, new_dir, new_dentry);
1110         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1111         if (IS_ERR(req))
1112                 return PTR_ERR(req);
1113         ihold(old_dir);
1114         req->r_dentry = dget(new_dentry);
1115         req->r_num_caps = 2;
1116         req->r_old_dentry = dget(old_dentry);
1117         req->r_old_dentry_dir = old_dir;
1118         req->r_parent = new_dir;
1119         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1120         req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
1121         req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
1122         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1123         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1124         /* release LINK_RDCACHE on source inode (mds will lock it) */
1125         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1126         if (d_really_is_positive(new_dentry)) {
1127                 req->r_inode_drop =
1128                         ceph_drop_caps_for_unlink(d_inode(new_dentry));
1129         }
1130         err = ceph_mdsc_do_request(mdsc, old_dir, req);
1131         if (!err && !req->r_reply_info.head->is_dentry) {
1132                 /*
1133                  * Normally d_move() is done by fill_trace (called by
1134                  * do_request, above).  If there is no trace, we need
1135                  * to do it here.
1136                  */
1137                 d_move(old_dentry, new_dentry);
1138         }
1139         ceph_mdsc_put_request(req);
1140         return err;
1141 }
1142
1143 /*
1144  * Move dentry to tail of mdsc->dentry_leases list when lease is updated.
1145  * Leases at front of the list will expire first. (Assume all leases have
1146  * similar duration)
1147  *
1148  * Called under dentry->d_lock.
1149  */
1150 void __ceph_dentry_lease_touch(struct ceph_dentry_info *di)
1151 {
1152         struct dentry *dn = di->dentry;
1153         struct ceph_mds_client *mdsc;
1154
1155         dout("dentry_lease_touch %p %p '%pd'\n", di, dn, dn);
1156
1157         di->flags |= CEPH_DENTRY_LEASE_LIST;
1158         if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1159                 di->flags |= CEPH_DENTRY_REFERENCED;
1160                 return;
1161         }
1162
1163         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1164         spin_lock(&mdsc->dentry_list_lock);
1165         list_move_tail(&di->lease_list, &mdsc->dentry_leases);
1166         spin_unlock(&mdsc->dentry_list_lock);
1167 }
1168
1169 static void __dentry_dir_lease_touch(struct ceph_mds_client* mdsc,
1170                                      struct ceph_dentry_info *di)
1171 {
1172         di->flags &= ~(CEPH_DENTRY_LEASE_LIST | CEPH_DENTRY_REFERENCED);
1173         di->lease_gen = 0;
1174         di->time = jiffies;
1175         list_move_tail(&di->lease_list, &mdsc->dentry_dir_leases);
1176 }
1177
1178 /*
1179  * When dir lease is used, add dentry to tail of mdsc->dentry_dir_leases
1180  * list if it's not in the list, otherwise set 'referenced' flag.
1181  *
1182  * Called under dentry->d_lock.
1183  */
1184 void __ceph_dentry_dir_lease_touch(struct ceph_dentry_info *di)
1185 {
1186         struct dentry *dn = di->dentry;
1187         struct ceph_mds_client *mdsc;
1188
1189         dout("dentry_dir_lease_touch %p %p '%pd' (offset %lld)\n",
1190              di, dn, dn, di->offset);
1191
1192         if (!list_empty(&di->lease_list)) {
1193                 if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1194                         /* don't remove dentry from dentry lease list
1195                          * if its lease is valid */
1196                         if (__dentry_lease_is_valid(di))
1197                                 return;
1198                 } else {
1199                         di->flags |= CEPH_DENTRY_REFERENCED;
1200                         return;
1201                 }
1202         }
1203
1204         if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
1205                 di->flags |= CEPH_DENTRY_REFERENCED;
1206                 di->flags &= ~CEPH_DENTRY_LEASE_LIST;
1207                 return;
1208         }
1209
1210         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1211         spin_lock(&mdsc->dentry_list_lock);
1212         __dentry_dir_lease_touch(mdsc, di),
1213         spin_unlock(&mdsc->dentry_list_lock);
1214 }
1215
1216 static void __dentry_lease_unlist(struct ceph_dentry_info *di)
1217 {
1218         struct ceph_mds_client *mdsc;
1219         if (di->flags & CEPH_DENTRY_SHRINK_LIST)
1220                 return;
1221         if (list_empty(&di->lease_list))
1222                 return;
1223
1224         mdsc = ceph_sb_to_client(di->dentry->d_sb)->mdsc;
1225         spin_lock(&mdsc->dentry_list_lock);
1226         list_del_init(&di->lease_list);
1227         spin_unlock(&mdsc->dentry_list_lock);
1228 }
1229
1230 enum {
1231         KEEP    = 0,
1232         DELETE  = 1,
1233         TOUCH   = 2,
1234         STOP    = 4,
1235 };
1236
1237 struct ceph_lease_walk_control {
1238         bool dir_lease;
1239         bool expire_dir_lease;
1240         unsigned long nr_to_scan;
1241         unsigned long dir_lease_ttl;
1242 };
1243
1244 static unsigned long
1245 __dentry_leases_walk(struct ceph_mds_client *mdsc,
1246                      struct ceph_lease_walk_control *lwc,
1247                      int (*check)(struct dentry*, void*))
1248 {
1249         struct ceph_dentry_info *di, *tmp;
1250         struct dentry *dentry, *last = NULL;
1251         struct list_head* list;
1252         LIST_HEAD(dispose);
1253         unsigned long freed = 0;
1254         int ret = 0;
1255
1256         list = lwc->dir_lease ? &mdsc->dentry_dir_leases : &mdsc->dentry_leases;
1257         spin_lock(&mdsc->dentry_list_lock);
1258         list_for_each_entry_safe(di, tmp, list, lease_list) {
1259                 if (!lwc->nr_to_scan)
1260                         break;
1261                 --lwc->nr_to_scan;
1262
1263                 dentry = di->dentry;
1264                 if (last == dentry)
1265                         break;
1266
1267                 if (!spin_trylock(&dentry->d_lock))
1268                         continue;
1269
1270                 if (__lockref_is_dead(&dentry->d_lockref)) {
1271                         list_del_init(&di->lease_list);
1272                         goto next;
1273                 }
1274
1275                 ret = check(dentry, lwc);
1276                 if (ret & TOUCH) {
1277                         /* move it into tail of dir lease list */
1278                         __dentry_dir_lease_touch(mdsc, di);
1279                         if (!last)
1280                                 last = dentry;
1281                 }
1282                 if (ret & DELETE) {
1283                         /* stale lease */
1284                         di->flags &= ~CEPH_DENTRY_REFERENCED;
1285                         if (dentry->d_lockref.count > 0) {
1286                                 /* update_dentry_lease() will re-add
1287                                  * it to lease list, or
1288                                  * ceph_d_delete() will return 1 when
1289                                  * last reference is dropped */
1290                                 list_del_init(&di->lease_list);
1291                         } else {
1292                                 di->flags |= CEPH_DENTRY_SHRINK_LIST;
1293                                 list_move_tail(&di->lease_list, &dispose);
1294                                 dget_dlock(dentry);
1295                         }
1296                 }
1297 next:
1298                 spin_unlock(&dentry->d_lock);
1299                 if (ret & STOP)
1300                         break;
1301         }
1302         spin_unlock(&mdsc->dentry_list_lock);
1303
1304         while (!list_empty(&dispose)) {
1305                 di = list_first_entry(&dispose, struct ceph_dentry_info,
1306                                       lease_list);
1307                 dentry = di->dentry;
1308                 spin_lock(&dentry->d_lock);
1309
1310                 list_del_init(&di->lease_list);
1311                 di->flags &= ~CEPH_DENTRY_SHRINK_LIST;
1312                 if (di->flags & CEPH_DENTRY_REFERENCED) {
1313                         spin_lock(&mdsc->dentry_list_lock);
1314                         if (di->flags & CEPH_DENTRY_LEASE_LIST) {
1315                                 list_add_tail(&di->lease_list,
1316                                               &mdsc->dentry_leases);
1317                         } else {
1318                                 __dentry_dir_lease_touch(mdsc, di);
1319                         }
1320                         spin_unlock(&mdsc->dentry_list_lock);
1321                 } else {
1322                         freed++;
1323                 }
1324
1325                 spin_unlock(&dentry->d_lock);
1326                 /* ceph_d_delete() does the trick */
1327                 dput(dentry);
1328         }
1329         return freed;
1330 }
1331
1332 static int __dentry_lease_check(struct dentry *dentry, void *arg)
1333 {
1334         struct ceph_dentry_info *di = ceph_dentry(dentry);
1335         int ret;
1336
1337         if (__dentry_lease_is_valid(di))
1338                 return STOP;
1339         ret = __dir_lease_try_check(dentry);
1340         if (ret == -EBUSY)
1341                 return KEEP;
1342         if (ret > 0)
1343                 return TOUCH;
1344         return DELETE;
1345 }
1346
1347 static int __dir_lease_check(struct dentry *dentry, void *arg)
1348 {
1349         struct ceph_lease_walk_control *lwc = arg;
1350         struct ceph_dentry_info *di = ceph_dentry(dentry);
1351
1352         int ret = __dir_lease_try_check(dentry);
1353         if (ret == -EBUSY)
1354                 return KEEP;
1355         if (ret > 0) {
1356                 if (time_before(jiffies, di->time + lwc->dir_lease_ttl))
1357                         return STOP;
1358                 /* Move dentry to tail of dir lease list if we don't want
1359                  * to delete it. So dentries in the list are checked in a
1360                  * round robin manner */
1361                 if (!lwc->expire_dir_lease)
1362                         return TOUCH;
1363                 if (dentry->d_lockref.count > 0 ||
1364                     (di->flags & CEPH_DENTRY_REFERENCED))
1365                         return TOUCH;
1366                 /* invalidate dir lease */
1367                 di->lease_shared_gen = 0;
1368         }
1369         return DELETE;
1370 }
1371
1372 int ceph_trim_dentries(struct ceph_mds_client *mdsc)
1373 {
1374         struct ceph_lease_walk_control lwc;
1375         unsigned long count;
1376         unsigned long freed;
1377
1378         spin_lock(&mdsc->caps_list_lock);
1379         if (mdsc->caps_use_max > 0 &&
1380             mdsc->caps_use_count > mdsc->caps_use_max)
1381                 count = mdsc->caps_use_count - mdsc->caps_use_max;
1382         else
1383                 count = 0;
1384         spin_unlock(&mdsc->caps_list_lock);
1385
1386         lwc.dir_lease = false;
1387         lwc.nr_to_scan  = CEPH_CAPS_PER_RELEASE * 2;
1388         freed = __dentry_leases_walk(mdsc, &lwc, __dentry_lease_check);
1389         if (!lwc.nr_to_scan) /* more invalid leases */
1390                 return -EAGAIN;
1391
1392         if (lwc.nr_to_scan < CEPH_CAPS_PER_RELEASE)
1393                 lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE;
1394
1395         lwc.dir_lease = true;
1396         lwc.expire_dir_lease = freed < count;
1397         lwc.dir_lease_ttl = mdsc->fsc->mount_options->caps_wanted_delay_max * HZ;
1398         freed +=__dentry_leases_walk(mdsc, &lwc, __dir_lease_check);
1399         if (!lwc.nr_to_scan) /* more to check */
1400                 return -EAGAIN;
1401
1402         return freed > 0 ? 1 : 0;
1403 }
1404
1405 /*
1406  * Ensure a dentry lease will no longer revalidate.
1407  */
1408 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1409 {
1410         struct ceph_dentry_info *di = ceph_dentry(dentry);
1411         spin_lock(&dentry->d_lock);
1412         di->time = jiffies;
1413         di->lease_shared_gen = 0;
1414         __dentry_lease_unlist(di);
1415         spin_unlock(&dentry->d_lock);
1416 }
1417
1418 /*
1419  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1420  * renew if the least is more than half up.
1421  */
1422 static bool __dentry_lease_is_valid(struct ceph_dentry_info *di)
1423 {
1424         struct ceph_mds_session *session;
1425
1426         if (!di->lease_gen)
1427                 return false;
1428
1429         session = di->lease_session;
1430         if (session) {
1431                 u32 gen;
1432                 unsigned long ttl;
1433
1434                 spin_lock(&session->s_gen_ttl_lock);
1435                 gen = session->s_cap_gen;
1436                 ttl = session->s_cap_ttl;
1437                 spin_unlock(&session->s_gen_ttl_lock);
1438
1439                 if (di->lease_gen == gen &&
1440                     time_before(jiffies, ttl) &&
1441                     time_before(jiffies, di->time))
1442                         return true;
1443         }
1444         di->lease_gen = 0;
1445         return false;
1446 }
1447
1448 static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags)
1449 {
1450         struct ceph_dentry_info *di;
1451         struct ceph_mds_session *session = NULL;
1452         u32 seq = 0;
1453         int valid = 0;
1454
1455         spin_lock(&dentry->d_lock);
1456         di = ceph_dentry(dentry);
1457         if (di && __dentry_lease_is_valid(di)) {
1458                 valid = 1;
1459
1460                 if (di->lease_renew_after &&
1461                     time_after(jiffies, di->lease_renew_after)) {
1462                         /*
1463                          * We should renew. If we're in RCU walk mode
1464                          * though, we can't do that so just return
1465                          * -ECHILD.
1466                          */
1467                         if (flags & LOOKUP_RCU) {
1468                                 valid = -ECHILD;
1469                         } else {
1470                                 session = ceph_get_mds_session(di->lease_session);
1471                                 seq = di->lease_seq;
1472                                 di->lease_renew_after = 0;
1473                                 di->lease_renew_from = jiffies;
1474                         }
1475                 }
1476         }
1477         spin_unlock(&dentry->d_lock);
1478
1479         if (session) {
1480                 ceph_mdsc_lease_send_msg(session, dentry,
1481                                          CEPH_MDS_LEASE_RENEW, seq);
1482                 ceph_put_mds_session(session);
1483         }
1484         dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1485         return valid;
1486 }
1487
1488 /*
1489  * Called under dentry->d_lock.
1490  */
1491 static int __dir_lease_try_check(const struct dentry *dentry)
1492 {
1493         struct ceph_dentry_info *di = ceph_dentry(dentry);
1494         struct inode *dir;
1495         struct ceph_inode_info *ci;
1496         int valid = 0;
1497
1498         if (!di->lease_shared_gen)
1499                 return 0;
1500         if (IS_ROOT(dentry))
1501                 return 0;
1502
1503         dir = d_inode(dentry->d_parent);
1504         ci = ceph_inode(dir);
1505
1506         if (spin_trylock(&ci->i_ceph_lock)) {
1507                 if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen &&
1508                     __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 0))
1509                         valid = 1;
1510                 spin_unlock(&ci->i_ceph_lock);
1511         } else {
1512                 valid = -EBUSY;
1513         }
1514
1515         if (!valid)
1516                 di->lease_shared_gen = 0;
1517         return valid;
1518 }
1519
1520 /*
1521  * Check if directory-wide content lease/cap is valid.
1522  */
1523 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1524 {
1525         struct ceph_inode_info *ci = ceph_inode(dir);
1526         int valid;
1527         int shared_gen;
1528
1529         spin_lock(&ci->i_ceph_lock);
1530         valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1531         shared_gen = atomic_read(&ci->i_shared_gen);
1532         spin_unlock(&ci->i_ceph_lock);
1533         if (valid) {
1534                 struct ceph_dentry_info *di;
1535                 spin_lock(&dentry->d_lock);
1536                 di = ceph_dentry(dentry);
1537                 if (dir == d_inode(dentry->d_parent) &&
1538                     di && di->lease_shared_gen == shared_gen)
1539                         __ceph_dentry_dir_lease_touch(di);
1540                 else
1541                         valid = 0;
1542                 spin_unlock(&dentry->d_lock);
1543         }
1544         dout("dir_lease_is_valid dir %p v%u dentry %p = %d\n",
1545              dir, (unsigned)atomic_read(&ci->i_shared_gen), dentry, valid);
1546         return valid;
1547 }
1548
1549 /*
1550  * Check if cached dentry can be trusted.
1551  */
1552 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1553 {
1554         int valid = 0;
1555         struct dentry *parent;
1556         struct inode *dir;
1557
1558         if (flags & LOOKUP_RCU) {
1559                 parent = READ_ONCE(dentry->d_parent);
1560                 dir = d_inode_rcu(parent);
1561                 if (!dir)
1562                         return -ECHILD;
1563         } else {
1564                 parent = dget_parent(dentry);
1565                 dir = d_inode(parent);
1566         }
1567
1568         dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1569              dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1570
1571         /* always trust cached snapped dentries, snapdir dentry */
1572         if (ceph_snap(dir) != CEPH_NOSNAP) {
1573                 dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1574                      dentry, d_inode(dentry));
1575                 valid = 1;
1576         } else if (d_really_is_positive(dentry) &&
1577                    ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1578                 valid = 1;
1579         } else {
1580                 valid = dentry_lease_is_valid(dentry, flags);
1581                 if (valid == -ECHILD)
1582                         return valid;
1583                 if (valid || dir_lease_is_valid(dir, dentry)) {
1584                         if (d_really_is_positive(dentry))
1585                                 valid = ceph_is_any_caps(d_inode(dentry));
1586                         else
1587                                 valid = 1;
1588                 }
1589         }
1590
1591         if (!valid) {
1592                 struct ceph_mds_client *mdsc =
1593                         ceph_sb_to_client(dir->i_sb)->mdsc;
1594                 struct ceph_mds_request *req;
1595                 int op, err;
1596                 u32 mask;
1597
1598                 if (flags & LOOKUP_RCU)
1599                         return -ECHILD;
1600
1601                 op = ceph_snap(dir) == CEPH_SNAPDIR ?
1602                         CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
1603                 req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1604                 if (!IS_ERR(req)) {
1605                         req->r_dentry = dget(dentry);
1606                         req->r_num_caps = 2;
1607                         req->r_parent = dir;
1608
1609                         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1610                         if (ceph_security_xattr_wanted(dir))
1611                                 mask |= CEPH_CAP_XATTR_SHARED;
1612                         req->r_args.getattr.mask = cpu_to_le32(mask);
1613
1614                         err = ceph_mdsc_do_request(mdsc, NULL, req);
1615                         switch (err) {
1616                         case 0:
1617                                 if (d_really_is_positive(dentry) &&
1618                                     d_inode(dentry) == req->r_target_inode)
1619                                         valid = 1;
1620                                 break;
1621                         case -ENOENT:
1622                                 if (d_really_is_negative(dentry))
1623                                         valid = 1;
1624                                 /* Fallthrough */
1625                         default:
1626                                 break;
1627                         }
1628                         ceph_mdsc_put_request(req);
1629                         dout("d_revalidate %p lookup result=%d\n",
1630                              dentry, err);
1631                 }
1632         }
1633
1634         dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1635         if (!valid)
1636                 ceph_dir_clear_complete(dir);
1637
1638         if (!(flags & LOOKUP_RCU))
1639                 dput(parent);
1640         return valid;
1641 }
1642
1643 /*
1644  * Delete unused dentry that doesn't have valid lease
1645  *
1646  * Called under dentry->d_lock.
1647  */
1648 static int ceph_d_delete(const struct dentry *dentry)
1649 {
1650         struct ceph_dentry_info *di;
1651
1652         /* won't release caps */
1653         if (d_really_is_negative(dentry))
1654                 return 0;
1655         if (ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
1656                 return 0;
1657         /* vaild lease? */
1658         di = ceph_dentry(dentry);
1659         if (di) {
1660                 if (__dentry_lease_is_valid(di))
1661                         return 0;
1662                 if (__dir_lease_try_check(dentry))
1663                         return 0;
1664         }
1665         return 1;
1666 }
1667
1668 /*
1669  * Release our ceph_dentry_info.
1670  */
1671 static void ceph_d_release(struct dentry *dentry)
1672 {
1673         struct ceph_dentry_info *di = ceph_dentry(dentry);
1674
1675         dout("d_release %p\n", dentry);
1676
1677         spin_lock(&dentry->d_lock);
1678         __dentry_lease_unlist(di);
1679         dentry->d_fsdata = NULL;
1680         spin_unlock(&dentry->d_lock);
1681
1682         if (di->lease_session)
1683                 ceph_put_mds_session(di->lease_session);
1684         kmem_cache_free(ceph_dentry_cachep, di);
1685 }
1686
1687 /*
1688  * When the VFS prunes a dentry from the cache, we need to clear the
1689  * complete flag on the parent directory.
1690  *
1691  * Called under dentry->d_lock.
1692  */
1693 static void ceph_d_prune(struct dentry *dentry)
1694 {
1695         struct ceph_inode_info *dir_ci;
1696         struct ceph_dentry_info *di;
1697
1698         dout("ceph_d_prune %pd %p\n", dentry, dentry);
1699
1700         /* do we have a valid parent? */
1701         if (IS_ROOT(dentry))
1702                 return;
1703
1704         /* we hold d_lock, so d_parent is stable */
1705         dir_ci = ceph_inode(d_inode(dentry->d_parent));
1706         if (dir_ci->i_vino.snap == CEPH_SNAPDIR)
1707                 return;
1708
1709         /* who calls d_delete() should also disable dcache readdir */
1710         if (d_really_is_negative(dentry))
1711                 return;
1712
1713         /* d_fsdata does not get cleared until d_release */
1714         if (!d_unhashed(dentry)) {
1715                 __ceph_dir_clear_complete(dir_ci);
1716                 return;
1717         }
1718
1719         /* Disable dcache readdir just in case that someone called d_drop()
1720          * or d_invalidate(), but MDS didn't revoke CEPH_CAP_FILE_SHARED
1721          * properly (dcache readdir is still enabled) */
1722         di = ceph_dentry(dentry);
1723         if (di->offset > 0 &&
1724             di->lease_shared_gen == atomic_read(&dir_ci->i_shared_gen))
1725                 __ceph_dir_clear_ordered(dir_ci);
1726 }
1727
1728 /*
1729  * read() on a dir.  This weird interface hack only works if mounted
1730  * with '-o dirstat'.
1731  */
1732 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1733                              loff_t *ppos)
1734 {
1735         struct ceph_dir_file_info *dfi = file->private_data;
1736         struct inode *inode = file_inode(file);
1737         struct ceph_inode_info *ci = ceph_inode(inode);
1738         int left;
1739         const int bufsize = 1024;
1740
1741         if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1742                 return -EISDIR;
1743
1744         if (!dfi->dir_info) {
1745                 dfi->dir_info = kmalloc(bufsize, GFP_KERNEL);
1746                 if (!dfi->dir_info)
1747                         return -ENOMEM;
1748                 dfi->dir_info_len =
1749                         snprintf(dfi->dir_info, bufsize,
1750                                 "entries:   %20lld\n"
1751                                 " files:    %20lld\n"
1752                                 " subdirs:  %20lld\n"
1753                                 "rentries:  %20lld\n"
1754                                 " rfiles:   %20lld\n"
1755                                 " rsubdirs: %20lld\n"
1756                                 "rbytes:    %20lld\n"
1757                                 "rctime:    %10lld.%09ld\n",
1758                                 ci->i_files + ci->i_subdirs,
1759                                 ci->i_files,
1760                                 ci->i_subdirs,
1761                                 ci->i_rfiles + ci->i_rsubdirs,
1762                                 ci->i_rfiles,
1763                                 ci->i_rsubdirs,
1764                                 ci->i_rbytes,
1765                                 ci->i_rctime.tv_sec,
1766                                 ci->i_rctime.tv_nsec);
1767         }
1768
1769         if (*ppos >= dfi->dir_info_len)
1770                 return 0;
1771         size = min_t(unsigned, size, dfi->dir_info_len-*ppos);
1772         left = copy_to_user(buf, dfi->dir_info + *ppos, size);
1773         if (left == size)
1774                 return -EFAULT;
1775         *ppos += (size - left);
1776         return size - left;
1777 }
1778
1779
1780
1781 /*
1782  * Return name hash for a given dentry.  This is dependent on
1783  * the parent directory's hash function.
1784  */
1785 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1786 {
1787         struct ceph_inode_info *dci = ceph_inode(dir);
1788         unsigned hash;
1789
1790         switch (dci->i_dir_layout.dl_dir_hash) {
1791         case 0: /* for backward compat */
1792         case CEPH_STR_HASH_LINUX:
1793                 return dn->d_name.hash;
1794
1795         default:
1796                 spin_lock(&dn->d_lock);
1797                 hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1798                                      dn->d_name.name, dn->d_name.len);
1799                 spin_unlock(&dn->d_lock);
1800                 return hash;
1801         }
1802 }
1803
1804 const struct file_operations ceph_dir_fops = {
1805         .read = ceph_read_dir,
1806         .iterate = ceph_readdir,
1807         .llseek = ceph_dir_llseek,
1808         .open = ceph_open,
1809         .release = ceph_release,
1810         .unlocked_ioctl = ceph_ioctl,
1811         .fsync = ceph_fsync,
1812         .lock = ceph_lock,
1813         .flock = ceph_flock,
1814 };
1815
1816 const struct file_operations ceph_snapdir_fops = {
1817         .iterate = ceph_readdir,
1818         .llseek = ceph_dir_llseek,
1819         .open = ceph_open,
1820         .release = ceph_release,
1821 };
1822
1823 const struct inode_operations ceph_dir_iops = {
1824         .lookup = ceph_lookup,
1825         .permission = ceph_permission,
1826         .getattr = ceph_getattr,
1827         .setattr = ceph_setattr,
1828         .listxattr = ceph_listxattr,
1829         .get_acl = ceph_get_acl,
1830         .set_acl = ceph_set_acl,
1831         .mknod = ceph_mknod,
1832         .symlink = ceph_symlink,
1833         .mkdir = ceph_mkdir,
1834         .link = ceph_link,
1835         .unlink = ceph_unlink,
1836         .rmdir = ceph_unlink,
1837         .rename = ceph_rename,
1838         .create = ceph_create,
1839         .atomic_open = ceph_atomic_open,
1840 };
1841
1842 const struct inode_operations ceph_snapdir_iops = {
1843         .lookup = ceph_lookup,
1844         .permission = ceph_permission,
1845         .getattr = ceph_getattr,
1846         .mkdir = ceph_mkdir,
1847         .rmdir = ceph_unlink,
1848         .rename = ceph_rename,
1849 };
1850
1851 const struct dentry_operations ceph_dentry_ops = {
1852         .d_revalidate = ceph_d_revalidate,
1853         .d_delete = ceph_d_delete,
1854         .d_release = ceph_d_release,
1855         .d_prune = ceph_d_prune,
1856         .d_init = ceph_d_init,
1857 };