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1 #include <linux/ceph/ceph_debug.h>
2 
3 #include <linux/spinlock.h>
4 #include <linux/fs_struct.h>
5 #include <linux/namei.h>
6 #include <linux/slab.h>
7 #include <linux/sched.h>
8 
9 #include "super.h"
10 #include "mds_client.h"
11 
12 /*
13  * Directory operations: readdir, lookup, create, link, unlink,
14  * rename, etc.
15  */
16 
17 /*
18  * Ceph MDS operations are specified in terms of a base ino and
19  * relative path.  Thus, the client can specify an operation on a
20  * specific inode (e.g., a getattr due to fstat(2)), or as a path
21  * relative to, say, the root directory.
22  *
23  * Normally, we limit ourselves to strict inode ops (no path component)
24  * or dentry operations (a single path component relative to an ino).  The
25  * exception to this is open_root_dentry(), which will open the mount
26  * point by name.
27  */
28 
29 const struct dentry_operations ceph_dentry_ops;
30 
31 /*
32  * Initialize ceph dentry state.
33  */
ceph_init_dentry(struct dentry * dentry)34 int ceph_init_dentry(struct dentry *dentry)
35 {
36 	struct ceph_dentry_info *di;
37 
38 	if (dentry->d_fsdata)
39 		return 0;
40 
41 	di = kmem_cache_alloc(ceph_dentry_cachep, GFP_KERNEL | __GFP_ZERO);
42 	if (!di)
43 		return -ENOMEM;          /* oh well */
44 
45 	spin_lock(&dentry->d_lock);
46 	if (dentry->d_fsdata) {
47 		/* lost a race */
48 		kmem_cache_free(ceph_dentry_cachep, di);
49 		goto out_unlock;
50 	}
51 
52 	if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP)
53 		d_set_d_op(dentry, &ceph_dentry_ops);
54 	else if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_SNAPDIR)
55 		d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
56 	else
57 		d_set_d_op(dentry, &ceph_snap_dentry_ops);
58 
59 	di->dentry = dentry;
60 	di->lease_session = NULL;
61 	dentry->d_time = jiffies;
62 	/* avoid reordering d_fsdata setup so that the check above is safe */
63 	smp_mb();
64 	dentry->d_fsdata = di;
65 	ceph_dentry_lru_add(dentry);
66 out_unlock:
67 	spin_unlock(&dentry->d_lock);
68 	return 0;
69 }
70 
ceph_get_dentry_parent_inode(struct dentry * dentry)71 struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry)
72 {
73 	struct inode *inode = NULL;
74 
75 	if (!dentry)
76 		return NULL;
77 
78 	spin_lock(&dentry->d_lock);
79 	if (!IS_ROOT(dentry)) {
80 		inode = 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  */
fpos_frag(loff_t p)92 static unsigned fpos_frag(loff_t p)
93 {
94 	return p >> 32;
95 }
fpos_off(loff_t p)96 static unsigned fpos_off(loff_t p)
97 {
98 	return p & 0xffffffff;
99 }
100 
fpos_cmp(loff_t l,loff_t r)101 static int fpos_cmp(loff_t l, loff_t r)
102 {
103 	int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
104 	if (v)
105 		return v;
106 	return (int)(fpos_off(l) - fpos_off(r));
107 }
108 
109 /*
110  * make note of the last dentry we read, so we can
111  * continue at the same lexicographical point,
112  * regardless of what dir changes take place on the
113  * server.
114  */
note_last_dentry(struct ceph_file_info * fi,const char * name,int len,unsigned next_offset)115 static int note_last_dentry(struct ceph_file_info *fi, const char *name,
116 		            int len, unsigned next_offset)
117 {
118 	char *buf = kmalloc(len+1, GFP_KERNEL);
119 	if (!buf)
120 		return -ENOMEM;
121 	kfree(fi->last_name);
122 	fi->last_name = buf;
123 	memcpy(fi->last_name, name, len);
124 	fi->last_name[len] = 0;
125 	fi->next_offset = next_offset;
126 	dout("note_last_dentry '%s'\n", fi->last_name);
127 	return 0;
128 }
129 
130 /*
131  * When possible, we try to satisfy a readdir by peeking at the
132  * dcache.  We make this work by carefully ordering dentries on
133  * d_child when we initially get results back from the MDS, and
134  * falling back to a "normal" sync readdir if any dentries in the dir
135  * are dropped.
136  *
137  * Complete dir indicates that we have all dentries in the dir.  It is
138  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
139  * the MDS if/when the directory is modified).
140  */
__dcache_readdir(struct file * file,struct dir_context * ctx,u32 shared_gen)141 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
142 			    u32 shared_gen)
143 {
144 	struct ceph_file_info *fi = file->private_data;
145 	struct dentry *parent = file->f_path.dentry;
146 	struct inode *dir = d_inode(parent);
147 	struct dentry *dentry, *last = NULL;
148 	struct ceph_dentry_info *di;
149 	unsigned nsize = PAGE_CACHE_SIZE / sizeof(struct dentry *);
150 	int err = 0;
151 	loff_t ptr_pos = 0;
152 	struct ceph_readdir_cache_control cache_ctl = {};
153 
154 	dout("__dcache_readdir %p v%u at %llu\n", dir, shared_gen, ctx->pos);
155 
156 	/* we can calculate cache index for the first dirfrag */
157 	if (ceph_frag_is_leftmost(fpos_frag(ctx->pos))) {
158 		cache_ctl.index = fpos_off(ctx->pos) - 2;
159 		BUG_ON(cache_ctl.index < 0);
160 		ptr_pos = cache_ctl.index * sizeof(struct dentry *);
161 	}
162 
163 	while (true) {
164 		pgoff_t pgoff;
165 		bool emit_dentry;
166 
167 		if (ptr_pos >= i_size_read(dir)) {
168 			fi->flags |= CEPH_F_ATEND;
169 			err = 0;
170 			break;
171 		}
172 
173 		err = -EAGAIN;
174 		pgoff = ptr_pos >> PAGE_CACHE_SHIFT;
175 		if (!cache_ctl.page || pgoff != page_index(cache_ctl.page)) {
176 			ceph_readdir_cache_release(&cache_ctl);
177 			cache_ctl.page = find_lock_page(&dir->i_data, pgoff);
178 			if (!cache_ctl.page) {
179 				dout(" page %lu not found\n", pgoff);
180 				break;
181 			}
182 			/* reading/filling the cache are serialized by
183 			 * i_mutex, no need to use page lock */
184 			unlock_page(cache_ctl.page);
185 			cache_ctl.dentries = kmap(cache_ctl.page);
186 		}
187 
188 		rcu_read_lock();
189 		spin_lock(&parent->d_lock);
190 		/* check i_size again here, because empty directory can be
191 		 * marked as complete while not holding the i_mutex. */
192 		if (ceph_dir_is_complete_ordered(dir) &&
193 		    ptr_pos < i_size_read(dir))
194 			dentry = cache_ctl.dentries[cache_ctl.index % nsize];
195 		else
196 			dentry = NULL;
197 		spin_unlock(&parent->d_lock);
198 		if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
199 			dentry = NULL;
200 		rcu_read_unlock();
201 		if (!dentry)
202 			break;
203 
204 		emit_dentry = false;
205 		di = ceph_dentry(dentry);
206 		spin_lock(&dentry->d_lock);
207 		if (di->lease_shared_gen == shared_gen &&
208 		    d_really_is_positive(dentry) &&
209 		    ceph_snap(d_inode(dentry)) != CEPH_SNAPDIR &&
210 		    ceph_ino(d_inode(dentry)) != CEPH_INO_CEPH &&
211 		    fpos_cmp(ctx->pos, di->offset) <= 0) {
212 			emit_dentry = true;
213 		}
214 		spin_unlock(&dentry->d_lock);
215 
216 		if (emit_dentry) {
217 			dout(" %llu (%llu) dentry %p %pd %p\n", di->offset, ctx->pos,
218 			     dentry, dentry, d_inode(dentry));
219 			ctx->pos = di->offset;
220 			if (!dir_emit(ctx, dentry->d_name.name,
221 				      dentry->d_name.len,
222 				      ceph_translate_ino(dentry->d_sb,
223 							 d_inode(dentry)->i_ino),
224 				      d_inode(dentry)->i_mode >> 12)) {
225 				dput(dentry);
226 				err = 0;
227 				break;
228 			}
229 			ctx->pos++;
230 
231 			if (last)
232 				dput(last);
233 			last = dentry;
234 		} else {
235 			dput(dentry);
236 		}
237 
238 		cache_ctl.index++;
239 		ptr_pos += sizeof(struct dentry *);
240 	}
241 	ceph_readdir_cache_release(&cache_ctl);
242 	if (last) {
243 		int ret;
244 		di = ceph_dentry(last);
245 		ret = note_last_dentry(fi, last->d_name.name, last->d_name.len,
246 				       fpos_off(di->offset) + 1);
247 		if (ret < 0)
248 			err = ret;
249 		dput(last);
250 		/* last_name no longer match cache index */
251 		if (fi->readdir_cache_idx >= 0) {
252 			fi->readdir_cache_idx = -1;
253 			fi->dir_release_count = 0;
254 		}
255 	}
256 	return err;
257 }
258 
ceph_readdir(struct file * file,struct dir_context * ctx)259 static int ceph_readdir(struct file *file, struct dir_context *ctx)
260 {
261 	struct ceph_file_info *fi = file->private_data;
262 	struct inode *inode = file_inode(file);
263 	struct ceph_inode_info *ci = ceph_inode(inode);
264 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
265 	struct ceph_mds_client *mdsc = fsc->mdsc;
266 	unsigned frag = fpos_frag(ctx->pos);
267 	int off = fpos_off(ctx->pos);
268 	int err;
269 	u32 ftype;
270 	struct ceph_mds_reply_info_parsed *rinfo;
271 
272 	dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
273 	if (fi->flags & CEPH_F_ATEND)
274 		return 0;
275 
276 	/* always start with . and .. */
277 	if (ctx->pos == 0) {
278 		dout("readdir off 0 -> '.'\n");
279 		if (!dir_emit(ctx, ".", 1,
280 			    ceph_translate_ino(inode->i_sb, inode->i_ino),
281 			    inode->i_mode >> 12))
282 			return 0;
283 		ctx->pos = 1;
284 		off = 1;
285 	}
286 	if (ctx->pos == 1) {
287 		ino_t ino = parent_ino(file->f_path.dentry);
288 		dout("readdir off 1 -> '..'\n");
289 		if (!dir_emit(ctx, "..", 2,
290 			    ceph_translate_ino(inode->i_sb, ino),
291 			    inode->i_mode >> 12))
292 			return 0;
293 		ctx->pos = 2;
294 		off = 2;
295 	}
296 
297 	/* can we use the dcache? */
298 	spin_lock(&ci->i_ceph_lock);
299 	if (ceph_test_mount_opt(fsc, DCACHE) &&
300 	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
301 	    ceph_snap(inode) != CEPH_SNAPDIR &&
302 	    __ceph_dir_is_complete_ordered(ci) &&
303 	    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
304 		u32 shared_gen = ci->i_shared_gen;
305 		spin_unlock(&ci->i_ceph_lock);
306 		err = __dcache_readdir(file, ctx, shared_gen);
307 		if (err != -EAGAIN)
308 			return err;
309 		frag = fpos_frag(ctx->pos);
310 		off = fpos_off(ctx->pos);
311 	} else {
312 		spin_unlock(&ci->i_ceph_lock);
313 	}
314 
315 	/* proceed with a normal readdir */
316 more:
317 	/* do we have the correct frag content buffered? */
318 	if (fi->frag != frag || fi->last_readdir == NULL) {
319 		struct ceph_mds_request *req;
320 		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
321 			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
322 
323 		/* discard old result, if any */
324 		if (fi->last_readdir) {
325 			ceph_mdsc_put_request(fi->last_readdir);
326 			fi->last_readdir = NULL;
327 		}
328 
329 		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
330 		     ceph_vinop(inode), frag, fi->last_name);
331 		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
332 		if (IS_ERR(req))
333 			return PTR_ERR(req);
334 		err = ceph_alloc_readdir_reply_buffer(req, inode);
335 		if (err) {
336 			ceph_mdsc_put_request(req);
337 			return err;
338 		}
339 		/* hints to request -> mds selection code */
340 		req->r_direct_mode = USE_AUTH_MDS;
341 		req->r_direct_hash = ceph_frag_value(frag);
342 		req->r_direct_is_hash = true;
343 		if (fi->last_name) {
344 			req->r_path2 = kstrdup(fi->last_name, GFP_KERNEL);
345 			if (!req->r_path2) {
346 				ceph_mdsc_put_request(req);
347 				return -ENOMEM;
348 			}
349 		}
350 		req->r_dir_release_cnt = fi->dir_release_count;
351 		req->r_dir_ordered_cnt = fi->dir_ordered_count;
352 		req->r_readdir_cache_idx = fi->readdir_cache_idx;
353 		req->r_readdir_offset = fi->next_offset;
354 		req->r_args.readdir.frag = cpu_to_le32(frag);
355 
356 		req->r_inode = inode;
357 		ihold(inode);
358 		req->r_dentry = dget(file->f_path.dentry);
359 		err = ceph_mdsc_do_request(mdsc, NULL, req);
360 		if (err < 0) {
361 			ceph_mdsc_put_request(req);
362 			return err;
363 		}
364 		dout("readdir got and parsed readdir result=%d"
365 		     " on frag %x, end=%d, complete=%d\n", err, frag,
366 		     (int)req->r_reply_info.dir_end,
367 		     (int)req->r_reply_info.dir_complete);
368 
369 
370 		/* note next offset and last dentry name */
371 		rinfo = &req->r_reply_info;
372 		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
373 			frag = le32_to_cpu(rinfo->dir_dir->frag);
374 			off = req->r_readdir_offset;
375 			fi->next_offset = off;
376 		}
377 
378 		fi->frag = frag;
379 		fi->offset = fi->next_offset;
380 		fi->last_readdir = req;
381 
382 		if (req->r_did_prepopulate) {
383 			fi->readdir_cache_idx = req->r_readdir_cache_idx;
384 			if (fi->readdir_cache_idx < 0) {
385 				/* preclude from marking dir ordered */
386 				fi->dir_ordered_count = 0;
387 			} else if (ceph_frag_is_leftmost(frag) && off == 2) {
388 				/* note dir version at start of readdir so
389 				 * we can tell if any dentries get dropped */
390 				fi->dir_release_count = req->r_dir_release_cnt;
391 				fi->dir_ordered_count = req->r_dir_ordered_cnt;
392 			}
393 		} else {
394 			dout("readdir !did_prepopulate");
395 			/* disable readdir cache */
396 			fi->readdir_cache_idx = -1;
397 			/* preclude from marking dir complete */
398 			fi->dir_release_count = 0;
399 		}
400 
401 		if (req->r_reply_info.dir_end) {
402 			kfree(fi->last_name);
403 			fi->last_name = NULL;
404 			if (ceph_frag_is_rightmost(frag))
405 				fi->next_offset = 2;
406 			else
407 				fi->next_offset = 0;
408 		} else {
409 			err = note_last_dentry(fi,
410 				       rinfo->dir_dname[rinfo->dir_nr-1],
411 				       rinfo->dir_dname_len[rinfo->dir_nr-1],
412 				       fi->next_offset + rinfo->dir_nr);
413 			if (err)
414 				return err;
415 		}
416 	}
417 
418 	rinfo = &fi->last_readdir->r_reply_info;
419 	dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
420 	     rinfo->dir_nr, off, fi->offset);
421 
422 	ctx->pos = ceph_make_fpos(frag, off);
423 	while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
424 		struct ceph_mds_reply_inode *in =
425 			rinfo->dir_in[off - fi->offset].in;
426 		struct ceph_vino vino;
427 		ino_t ino;
428 
429 		dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
430 		     off, off - fi->offset, rinfo->dir_nr, ctx->pos,
431 		     rinfo->dir_dname_len[off - fi->offset],
432 		     rinfo->dir_dname[off - fi->offset], in);
433 		BUG_ON(!in);
434 		ftype = le32_to_cpu(in->mode) >> 12;
435 		vino.ino = le64_to_cpu(in->ino);
436 		vino.snap = le64_to_cpu(in->snapid);
437 		ino = ceph_vino_to_ino(vino);
438 		if (!dir_emit(ctx,
439 			    rinfo->dir_dname[off - fi->offset],
440 			    rinfo->dir_dname_len[off - fi->offset],
441 			    ceph_translate_ino(inode->i_sb, ino), ftype)) {
442 			dout("filldir stopping us...\n");
443 			return 0;
444 		}
445 		off++;
446 		ctx->pos++;
447 	}
448 
449 	if (fi->last_name) {
450 		ceph_mdsc_put_request(fi->last_readdir);
451 		fi->last_readdir = NULL;
452 		goto more;
453 	}
454 
455 	/* more frags? */
456 	if (!ceph_frag_is_rightmost(frag)) {
457 		frag = ceph_frag_next(frag);
458 		off = 0;
459 		ctx->pos = ceph_make_fpos(frag, off);
460 		dout("readdir next frag is %x\n", frag);
461 		goto more;
462 	}
463 	fi->flags |= CEPH_F_ATEND;
464 
465 	/*
466 	 * if dir_release_count still matches the dir, no dentries
467 	 * were released during the whole readdir, and we should have
468 	 * the complete dir contents in our cache.
469 	 */
470 	if (atomic64_read(&ci->i_release_count) == fi->dir_release_count) {
471 		spin_lock(&ci->i_ceph_lock);
472 		if (fi->dir_ordered_count == atomic64_read(&ci->i_ordered_count)) {
473 			dout(" marking %p complete and ordered\n", inode);
474 			/* use i_size to track number of entries in
475 			 * readdir cache */
476 			BUG_ON(fi->readdir_cache_idx < 0);
477 			i_size_write(inode, fi->readdir_cache_idx *
478 				     sizeof(struct dentry*));
479 		} else {
480 			dout(" marking %p complete\n", inode);
481 		}
482 		__ceph_dir_set_complete(ci, fi->dir_release_count,
483 					fi->dir_ordered_count);
484 		spin_unlock(&ci->i_ceph_lock);
485 	}
486 
487 	dout("readdir %p file %p done.\n", inode, file);
488 	return 0;
489 }
490 
reset_readdir(struct ceph_file_info * fi,unsigned frag)491 static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
492 {
493 	if (fi->last_readdir) {
494 		ceph_mdsc_put_request(fi->last_readdir);
495 		fi->last_readdir = NULL;
496 	}
497 	kfree(fi->last_name);
498 	fi->last_name = NULL;
499 	fi->dir_release_count = 0;
500 	fi->readdir_cache_idx = -1;
501 	if (ceph_frag_is_leftmost(frag))
502 		fi->next_offset = 2;  /* compensate for . and .. */
503 	else
504 		fi->next_offset = 0;
505 	fi->flags &= ~CEPH_F_ATEND;
506 }
507 
ceph_dir_llseek(struct file * file,loff_t offset,int whence)508 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
509 {
510 	struct ceph_file_info *fi = file->private_data;
511 	struct inode *inode = file->f_mapping->host;
512 	loff_t old_offset = ceph_make_fpos(fi->frag, fi->next_offset);
513 	loff_t retval;
514 
515 	mutex_lock(&inode->i_mutex);
516 	retval = -EINVAL;
517 	switch (whence) {
518 	case SEEK_CUR:
519 		offset += file->f_pos;
520 	case SEEK_SET:
521 		break;
522 	case SEEK_END:
523 		retval = -EOPNOTSUPP;
524 	default:
525 		goto out;
526 	}
527 
528 	if (offset >= 0) {
529 		if (offset != file->f_pos) {
530 			file->f_pos = offset;
531 			file->f_version = 0;
532 			fi->flags &= ~CEPH_F_ATEND;
533 		}
534 		retval = offset;
535 
536 		if (offset == 0 ||
537 		    fpos_frag(offset) != fi->frag ||
538 		    fpos_off(offset) < fi->offset) {
539 			/* discard buffered readdir content on seekdir(0), or
540 			 * seek to new frag, or seek prior to current chunk */
541 			dout("dir_llseek dropping %p content\n", file);
542 			reset_readdir(fi, fpos_frag(offset));
543 		} else if (fpos_cmp(offset, old_offset) > 0) {
544 			/* reset dir_release_count if we did a forward seek */
545 			fi->dir_release_count = 0;
546 			fi->readdir_cache_idx = -1;
547 		}
548 	}
549 out:
550 	mutex_unlock(&inode->i_mutex);
551 	return retval;
552 }
553 
554 /*
555  * Handle lookups for the hidden .snap directory.
556  */
ceph_handle_snapdir(struct ceph_mds_request * req,struct dentry * dentry,int err)557 int ceph_handle_snapdir(struct ceph_mds_request *req,
558 			struct dentry *dentry, int err)
559 {
560 	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
561 	struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
562 
563 	/* .snap dir? */
564 	if (err == -ENOENT &&
565 	    ceph_snap(parent) == CEPH_NOSNAP &&
566 	    strcmp(dentry->d_name.name,
567 		   fsc->mount_options->snapdir_name) == 0) {
568 		struct inode *inode = ceph_get_snapdir(parent);
569 		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
570 		     dentry, dentry, inode);
571 		BUG_ON(!d_unhashed(dentry));
572 		d_add(dentry, inode);
573 		err = 0;
574 	}
575 	return err;
576 }
577 
578 /*
579  * Figure out final result of a lookup/open request.
580  *
581  * Mainly, make sure we return the final req->r_dentry (if it already
582  * existed) in place of the original VFS-provided dentry when they
583  * differ.
584  *
585  * Gracefully handle the case where the MDS replies with -ENOENT and
586  * no trace (which it may do, at its discretion, e.g., if it doesn't
587  * care to issue a lease on the negative dentry).
588  */
ceph_finish_lookup(struct ceph_mds_request * req,struct dentry * dentry,int err)589 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
590 				  struct dentry *dentry, int err)
591 {
592 	if (err == -ENOENT) {
593 		/* no trace? */
594 		err = 0;
595 		if (!req->r_reply_info.head->is_dentry) {
596 			dout("ENOENT and no trace, dentry %p inode %p\n",
597 			     dentry, d_inode(dentry));
598 			if (d_really_is_positive(dentry)) {
599 				d_drop(dentry);
600 				err = -ENOENT;
601 			} else {
602 				d_add(dentry, NULL);
603 			}
604 		}
605 	}
606 	if (err)
607 		dentry = ERR_PTR(err);
608 	else if (dentry != req->r_dentry)
609 		dentry = dget(req->r_dentry);   /* we got spliced */
610 	else
611 		dentry = NULL;
612 	return dentry;
613 }
614 
is_root_ceph_dentry(struct inode * inode,struct dentry * dentry)615 static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
616 {
617 	return ceph_ino(inode) == CEPH_INO_ROOT &&
618 		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
619 }
620 
621 /*
622  * Look up a single dir entry.  If there is a lookup intent, inform
623  * the MDS so that it gets our 'caps wanted' value in a single op.
624  */
ceph_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)625 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
626 				  unsigned int flags)
627 {
628 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
629 	struct ceph_mds_client *mdsc = fsc->mdsc;
630 	struct ceph_mds_request *req;
631 	int op;
632 	int err;
633 
634 	dout("lookup %p dentry %p '%pd'\n",
635 	     dir, dentry, dentry);
636 
637 	if (dentry->d_name.len > NAME_MAX)
638 		return ERR_PTR(-ENAMETOOLONG);
639 
640 	err = ceph_init_dentry(dentry);
641 	if (err < 0)
642 		return ERR_PTR(err);
643 
644 	/* can we conclude ENOENT locally? */
645 	if (d_really_is_negative(dentry)) {
646 		struct ceph_inode_info *ci = ceph_inode(dir);
647 		struct ceph_dentry_info *di = ceph_dentry(dentry);
648 
649 		spin_lock(&ci->i_ceph_lock);
650 		dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
651 		if (strncmp(dentry->d_name.name,
652 			    fsc->mount_options->snapdir_name,
653 			    dentry->d_name.len) &&
654 		    !is_root_ceph_dentry(dir, dentry) &&
655 		    ceph_test_mount_opt(fsc, DCACHE) &&
656 		    __ceph_dir_is_complete(ci) &&
657 		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
658 			spin_unlock(&ci->i_ceph_lock);
659 			dout(" dir %p complete, -ENOENT\n", dir);
660 			d_add(dentry, NULL);
661 			di->lease_shared_gen = ci->i_shared_gen;
662 			return NULL;
663 		}
664 		spin_unlock(&ci->i_ceph_lock);
665 	}
666 
667 	op = ceph_snap(dir) == CEPH_SNAPDIR ?
668 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
669 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
670 	if (IS_ERR(req))
671 		return ERR_CAST(req);
672 	req->r_dentry = dget(dentry);
673 	req->r_num_caps = 2;
674 	/* we only need inode linkage */
675 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
676 	req->r_locked_dir = dir;
677 	err = ceph_mdsc_do_request(mdsc, NULL, req);
678 	err = ceph_handle_snapdir(req, dentry, err);
679 	dentry = ceph_finish_lookup(req, dentry, err);
680 	ceph_mdsc_put_request(req);  /* will dput(dentry) */
681 	dout("lookup result=%p\n", dentry);
682 	return dentry;
683 }
684 
685 /*
686  * If we do a create but get no trace back from the MDS, follow up with
687  * a lookup (the VFS expects us to link up the provided dentry).
688  */
ceph_handle_notrace_create(struct inode * dir,struct dentry * dentry)689 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
690 {
691 	struct dentry *result = ceph_lookup(dir, dentry, 0);
692 
693 	if (result && !IS_ERR(result)) {
694 		/*
695 		 * We created the item, then did a lookup, and found
696 		 * it was already linked to another inode we already
697 		 * had in our cache (and thus got spliced). To not
698 		 * confuse VFS (especially when inode is a directory),
699 		 * we don't link our dentry to that inode, return an
700 		 * error instead.
701 		 *
702 		 * This event should be rare and it happens only when
703 		 * we talk to old MDS. Recent MDS does not send traceless
704 		 * reply for request that creates new inode.
705 		 */
706 		d_drop(result);
707 		return -ESTALE;
708 	}
709 	return PTR_ERR(result);
710 }
711 
ceph_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)712 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
713 		      umode_t mode, dev_t rdev)
714 {
715 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
716 	struct ceph_mds_client *mdsc = fsc->mdsc;
717 	struct ceph_mds_request *req;
718 	struct ceph_acls_info acls = {};
719 	int err;
720 
721 	if (ceph_snap(dir) != CEPH_NOSNAP)
722 		return -EROFS;
723 
724 	err = ceph_pre_init_acls(dir, &mode, &acls);
725 	if (err < 0)
726 		return err;
727 
728 	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
729 	     dir, dentry, mode, rdev);
730 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
731 	if (IS_ERR(req)) {
732 		err = PTR_ERR(req);
733 		goto out;
734 	}
735 	req->r_dentry = dget(dentry);
736 	req->r_num_caps = 2;
737 	req->r_locked_dir = dir;
738 	req->r_args.mknod.mode = cpu_to_le32(mode);
739 	req->r_args.mknod.rdev = cpu_to_le32(rdev);
740 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
741 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
742 	if (acls.pagelist) {
743 		req->r_pagelist = acls.pagelist;
744 		acls.pagelist = NULL;
745 	}
746 	err = ceph_mdsc_do_request(mdsc, dir, req);
747 	if (!err && !req->r_reply_info.head->is_dentry)
748 		err = ceph_handle_notrace_create(dir, dentry);
749 	ceph_mdsc_put_request(req);
750 out:
751 	if (!err)
752 		ceph_init_inode_acls(d_inode(dentry), &acls);
753 	else
754 		d_drop(dentry);
755 	ceph_release_acls_info(&acls);
756 	return err;
757 }
758 
ceph_create(struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)759 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
760 		       bool excl)
761 {
762 	return ceph_mknod(dir, dentry, mode, 0);
763 }
764 
ceph_symlink(struct inode * dir,struct dentry * dentry,const char * dest)765 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
766 			    const char *dest)
767 {
768 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
769 	struct ceph_mds_client *mdsc = fsc->mdsc;
770 	struct ceph_mds_request *req;
771 	int err;
772 
773 	if (ceph_snap(dir) != CEPH_NOSNAP)
774 		return -EROFS;
775 
776 	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
777 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
778 	if (IS_ERR(req)) {
779 		err = PTR_ERR(req);
780 		goto out;
781 	}
782 	req->r_path2 = kstrdup(dest, GFP_KERNEL);
783 	if (!req->r_path2) {
784 		err = -ENOMEM;
785 		ceph_mdsc_put_request(req);
786 		goto out;
787 	}
788 	req->r_locked_dir = dir;
789 	req->r_dentry = dget(dentry);
790 	req->r_num_caps = 2;
791 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
792 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
793 	err = ceph_mdsc_do_request(mdsc, dir, req);
794 	if (!err && !req->r_reply_info.head->is_dentry)
795 		err = ceph_handle_notrace_create(dir, dentry);
796 	ceph_mdsc_put_request(req);
797 out:
798 	if (err)
799 		d_drop(dentry);
800 	return err;
801 }
802 
ceph_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)803 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
804 {
805 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
806 	struct ceph_mds_client *mdsc = fsc->mdsc;
807 	struct ceph_mds_request *req;
808 	struct ceph_acls_info acls = {};
809 	int err = -EROFS;
810 	int op;
811 
812 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
813 		/* mkdir .snap/foo is a MKSNAP */
814 		op = CEPH_MDS_OP_MKSNAP;
815 		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
816 		     dentry, dentry);
817 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
818 		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
819 		op = CEPH_MDS_OP_MKDIR;
820 	} else {
821 		goto out;
822 	}
823 
824 	mode |= S_IFDIR;
825 	err = ceph_pre_init_acls(dir, &mode, &acls);
826 	if (err < 0)
827 		goto out;
828 
829 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
830 	if (IS_ERR(req)) {
831 		err = PTR_ERR(req);
832 		goto out;
833 	}
834 
835 	req->r_dentry = dget(dentry);
836 	req->r_num_caps = 2;
837 	req->r_locked_dir = dir;
838 	req->r_args.mkdir.mode = cpu_to_le32(mode);
839 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
840 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
841 	if (acls.pagelist) {
842 		req->r_pagelist = acls.pagelist;
843 		acls.pagelist = NULL;
844 	}
845 	err = ceph_mdsc_do_request(mdsc, dir, req);
846 	if (!err &&
847 	    !req->r_reply_info.head->is_target &&
848 	    !req->r_reply_info.head->is_dentry)
849 		err = ceph_handle_notrace_create(dir, dentry);
850 	ceph_mdsc_put_request(req);
851 out:
852 	if (!err)
853 		ceph_init_inode_acls(d_inode(dentry), &acls);
854 	else
855 		d_drop(dentry);
856 	ceph_release_acls_info(&acls);
857 	return err;
858 }
859 
ceph_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)860 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
861 		     struct dentry *dentry)
862 {
863 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
864 	struct ceph_mds_client *mdsc = fsc->mdsc;
865 	struct ceph_mds_request *req;
866 	int err;
867 
868 	if (ceph_snap(dir) != CEPH_NOSNAP)
869 		return -EROFS;
870 
871 	dout("link in dir %p old_dentry %p dentry %p\n", dir,
872 	     old_dentry, dentry);
873 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
874 	if (IS_ERR(req)) {
875 		d_drop(dentry);
876 		return PTR_ERR(req);
877 	}
878 	req->r_dentry = dget(dentry);
879 	req->r_num_caps = 2;
880 	req->r_old_dentry = dget(old_dentry);
881 	req->r_locked_dir = dir;
882 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
883 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
884 	/* release LINK_SHARED on source inode (mds will lock it) */
885 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
886 	err = ceph_mdsc_do_request(mdsc, dir, req);
887 	if (err) {
888 		d_drop(dentry);
889 	} else if (!req->r_reply_info.head->is_dentry) {
890 		ihold(d_inode(old_dentry));
891 		d_instantiate(dentry, d_inode(old_dentry));
892 	}
893 	ceph_mdsc_put_request(req);
894 	return err;
895 }
896 
897 /*
898  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
899  * looks like the link count will hit 0, drop any other caps (other
900  * than PIN) we don't specifically want (due to the file still being
901  * open).
902  */
drop_caps_for_unlink(struct inode * inode)903 static int drop_caps_for_unlink(struct inode *inode)
904 {
905 	struct ceph_inode_info *ci = ceph_inode(inode);
906 	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
907 
908 	spin_lock(&ci->i_ceph_lock);
909 	if (inode->i_nlink == 1) {
910 		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
911 		ci->i_ceph_flags |= CEPH_I_NODELAY;
912 	}
913 	spin_unlock(&ci->i_ceph_lock);
914 	return drop;
915 }
916 
917 /*
918  * rmdir and unlink are differ only by the metadata op code
919  */
ceph_unlink(struct inode * dir,struct dentry * dentry)920 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
921 {
922 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
923 	struct ceph_mds_client *mdsc = fsc->mdsc;
924 	struct inode *inode = d_inode(dentry);
925 	struct ceph_mds_request *req;
926 	int err = -EROFS;
927 	int op;
928 
929 	if (ceph_snap(dir) == CEPH_SNAPDIR) {
930 		/* rmdir .snap/foo is RMSNAP */
931 		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
932 		op = CEPH_MDS_OP_RMSNAP;
933 	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
934 		dout("unlink/rmdir dir %p dn %p inode %p\n",
935 		     dir, dentry, inode);
936 		op = d_is_dir(dentry) ?
937 			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
938 	} else
939 		goto out;
940 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
941 	if (IS_ERR(req)) {
942 		err = PTR_ERR(req);
943 		goto out;
944 	}
945 	req->r_dentry = dget(dentry);
946 	req->r_num_caps = 2;
947 	req->r_locked_dir = dir;
948 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
949 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
950 	req->r_inode_drop = drop_caps_for_unlink(inode);
951 	err = ceph_mdsc_do_request(mdsc, dir, req);
952 	if (!err && !req->r_reply_info.head->is_dentry)
953 		d_delete(dentry);
954 	ceph_mdsc_put_request(req);
955 out:
956 	return err;
957 }
958 
ceph_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)959 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
960 		       struct inode *new_dir, struct dentry *new_dentry)
961 {
962 	struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
963 	struct ceph_mds_client *mdsc = fsc->mdsc;
964 	struct ceph_mds_request *req;
965 	int op = CEPH_MDS_OP_RENAME;
966 	int err;
967 
968 	if (ceph_snap(old_dir) != ceph_snap(new_dir))
969 		return -EXDEV;
970 	if (ceph_snap(old_dir) != CEPH_NOSNAP) {
971 		if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
972 			op = CEPH_MDS_OP_RENAMESNAP;
973 		else
974 			return -EROFS;
975 	}
976 	dout("rename dir %p dentry %p to dir %p dentry %p\n",
977 	     old_dir, old_dentry, new_dir, new_dentry);
978 	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
979 	if (IS_ERR(req))
980 		return PTR_ERR(req);
981 	ihold(old_dir);
982 	req->r_dentry = dget(new_dentry);
983 	req->r_num_caps = 2;
984 	req->r_old_dentry = dget(old_dentry);
985 	req->r_old_dentry_dir = old_dir;
986 	req->r_locked_dir = new_dir;
987 	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
988 	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
989 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
990 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
991 	/* release LINK_RDCACHE on source inode (mds will lock it) */
992 	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
993 	if (d_really_is_positive(new_dentry))
994 		req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
995 	err = ceph_mdsc_do_request(mdsc, old_dir, req);
996 	if (!err && !req->r_reply_info.head->is_dentry) {
997 		/*
998 		 * Normally d_move() is done by fill_trace (called by
999 		 * do_request, above).  If there is no trace, we need
1000 		 * to do it here.
1001 		 */
1002 
1003 		/* d_move screws up sibling dentries' offsets */
1004 		ceph_dir_clear_complete(old_dir);
1005 		ceph_dir_clear_complete(new_dir);
1006 
1007 		d_move(old_dentry, new_dentry);
1008 
1009 		/* ensure target dentry is invalidated, despite
1010 		   rehashing bug in vfs_rename_dir */
1011 		ceph_invalidate_dentry_lease(new_dentry);
1012 	}
1013 	ceph_mdsc_put_request(req);
1014 	return err;
1015 }
1016 
1017 /*
1018  * Ensure a dentry lease will no longer revalidate.
1019  */
ceph_invalidate_dentry_lease(struct dentry * dentry)1020 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1021 {
1022 	spin_lock(&dentry->d_lock);
1023 	dentry->d_time = jiffies;
1024 	ceph_dentry(dentry)->lease_shared_gen = 0;
1025 	spin_unlock(&dentry->d_lock);
1026 }
1027 
1028 /*
1029  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1030  * renew if the least is more than half up.
1031  */
dentry_lease_is_valid(struct dentry * dentry)1032 static int dentry_lease_is_valid(struct dentry *dentry)
1033 {
1034 	struct ceph_dentry_info *di;
1035 	struct ceph_mds_session *s;
1036 	int valid = 0;
1037 	u32 gen;
1038 	unsigned long ttl;
1039 	struct ceph_mds_session *session = NULL;
1040 	struct inode *dir = NULL;
1041 	u32 seq = 0;
1042 
1043 	spin_lock(&dentry->d_lock);
1044 	di = ceph_dentry(dentry);
1045 	if (di->lease_session) {
1046 		s = di->lease_session;
1047 		spin_lock(&s->s_gen_ttl_lock);
1048 		gen = s->s_cap_gen;
1049 		ttl = s->s_cap_ttl;
1050 		spin_unlock(&s->s_gen_ttl_lock);
1051 
1052 		if (di->lease_gen == gen &&
1053 		    time_before(jiffies, dentry->d_time) &&
1054 		    time_before(jiffies, ttl)) {
1055 			valid = 1;
1056 			if (di->lease_renew_after &&
1057 			    time_after(jiffies, di->lease_renew_after)) {
1058 				/* we should renew */
1059 				dir = d_inode(dentry->d_parent);
1060 				session = ceph_get_mds_session(s);
1061 				seq = di->lease_seq;
1062 				di->lease_renew_after = 0;
1063 				di->lease_renew_from = jiffies;
1064 			}
1065 		}
1066 	}
1067 	spin_unlock(&dentry->d_lock);
1068 
1069 	if (session) {
1070 		ceph_mdsc_lease_send_msg(session, dir, dentry,
1071 					 CEPH_MDS_LEASE_RENEW, seq);
1072 		ceph_put_mds_session(session);
1073 	}
1074 	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1075 	return valid;
1076 }
1077 
1078 /*
1079  * Check if directory-wide content lease/cap is valid.
1080  */
dir_lease_is_valid(struct inode * dir,struct dentry * dentry)1081 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1082 {
1083 	struct ceph_inode_info *ci = ceph_inode(dir);
1084 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1085 	int valid = 0;
1086 
1087 	spin_lock(&ci->i_ceph_lock);
1088 	if (ci->i_shared_gen == di->lease_shared_gen)
1089 		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1090 	spin_unlock(&ci->i_ceph_lock);
1091 	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1092 	     dir, (unsigned)ci->i_shared_gen, dentry,
1093 	     (unsigned)di->lease_shared_gen, valid);
1094 	return valid;
1095 }
1096 
1097 /*
1098  * Check if cached dentry can be trusted.
1099  */
ceph_d_revalidate(struct dentry * dentry,unsigned int flags)1100 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1101 {
1102 	int valid = 0;
1103 	struct inode *dir;
1104 
1105 	if (flags & LOOKUP_RCU)
1106 		return -ECHILD;
1107 
1108 	dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1109 	     dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1110 
1111 	dir = ceph_get_dentry_parent_inode(dentry);
1112 
1113 	/* always trust cached snapped dentries, snapdir dentry */
1114 	if (ceph_snap(dir) != CEPH_NOSNAP) {
1115 		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1116 		     dentry, d_inode(dentry));
1117 		valid = 1;
1118 	} else if (d_really_is_positive(dentry) &&
1119 		   ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1120 		valid = 1;
1121 	} else if (dentry_lease_is_valid(dentry) ||
1122 		   dir_lease_is_valid(dir, dentry)) {
1123 		if (d_really_is_positive(dentry))
1124 			valid = ceph_is_any_caps(d_inode(dentry));
1125 		else
1126 			valid = 1;
1127 	}
1128 
1129 	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1130 	if (valid) {
1131 		ceph_dentry_lru_touch(dentry);
1132 	} else {
1133 		ceph_dir_clear_complete(dir);
1134 	}
1135 	iput(dir);
1136 	return valid;
1137 }
1138 
1139 /*
1140  * Release our ceph_dentry_info.
1141  */
ceph_d_release(struct dentry * dentry)1142 static void ceph_d_release(struct dentry *dentry)
1143 {
1144 	struct ceph_dentry_info *di = ceph_dentry(dentry);
1145 
1146 	dout("d_release %p\n", dentry);
1147 	ceph_dentry_lru_del(dentry);
1148 	if (di->lease_session)
1149 		ceph_put_mds_session(di->lease_session);
1150 	kmem_cache_free(ceph_dentry_cachep, di);
1151 	dentry->d_fsdata = NULL;
1152 }
1153 
ceph_snapdir_d_revalidate(struct dentry * dentry,unsigned int flags)1154 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1155 					  unsigned int flags)
1156 {
1157 	/*
1158 	 * Eventually, we'll want to revalidate snapped metadata
1159 	 * too... probably...
1160 	 */
1161 	return 1;
1162 }
1163 
1164 /*
1165  * When the VFS prunes a dentry from the cache, we need to clear the
1166  * complete flag on the parent directory.
1167  *
1168  * Called under dentry->d_lock.
1169  */
ceph_d_prune(struct dentry * dentry)1170 static void ceph_d_prune(struct dentry *dentry)
1171 {
1172 	dout("ceph_d_prune %p\n", dentry);
1173 
1174 	/* do we have a valid parent? */
1175 	if (IS_ROOT(dentry))
1176 		return;
1177 
1178 	/* if we are not hashed, we don't affect dir's completeness */
1179 	if (d_unhashed(dentry))
1180 		return;
1181 
1182 	/*
1183 	 * we hold d_lock, so d_parent is stable, and d_fsdata is never
1184 	 * cleared until d_release
1185 	 */
1186 	ceph_dir_clear_complete(d_inode(dentry->d_parent));
1187 }
1188 
1189 /*
1190  * read() on a dir.  This weird interface hack only works if mounted
1191  * with '-o dirstat'.
1192  */
ceph_read_dir(struct file * file,char __user * buf,size_t size,loff_t * ppos)1193 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1194 			     loff_t *ppos)
1195 {
1196 	struct ceph_file_info *cf = file->private_data;
1197 	struct inode *inode = file_inode(file);
1198 	struct ceph_inode_info *ci = ceph_inode(inode);
1199 	int left;
1200 	const int bufsize = 1024;
1201 
1202 	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1203 		return -EISDIR;
1204 
1205 	if (!cf->dir_info) {
1206 		cf->dir_info = kmalloc(bufsize, GFP_KERNEL);
1207 		if (!cf->dir_info)
1208 			return -ENOMEM;
1209 		cf->dir_info_len =
1210 			snprintf(cf->dir_info, bufsize,
1211 				"entries:   %20lld\n"
1212 				" files:    %20lld\n"
1213 				" subdirs:  %20lld\n"
1214 				"rentries:  %20lld\n"
1215 				" rfiles:   %20lld\n"
1216 				" rsubdirs: %20lld\n"
1217 				"rbytes:    %20lld\n"
1218 				"rctime:    %10ld.%09ld\n",
1219 				ci->i_files + ci->i_subdirs,
1220 				ci->i_files,
1221 				ci->i_subdirs,
1222 				ci->i_rfiles + ci->i_rsubdirs,
1223 				ci->i_rfiles,
1224 				ci->i_rsubdirs,
1225 				ci->i_rbytes,
1226 				(long)ci->i_rctime.tv_sec,
1227 				(long)ci->i_rctime.tv_nsec);
1228 	}
1229 
1230 	if (*ppos >= cf->dir_info_len)
1231 		return 0;
1232 	size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1233 	left = copy_to_user(buf, cf->dir_info + *ppos, size);
1234 	if (left == size)
1235 		return -EFAULT;
1236 	*ppos += (size - left);
1237 	return size - left;
1238 }
1239 
1240 /*
1241  * We maintain a private dentry LRU.
1242  *
1243  * FIXME: this needs to be changed to a per-mds lru to be useful.
1244  */
ceph_dentry_lru_add(struct dentry * dn)1245 void ceph_dentry_lru_add(struct dentry *dn)
1246 {
1247 	struct ceph_dentry_info *di = ceph_dentry(dn);
1248 	struct ceph_mds_client *mdsc;
1249 
1250 	dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1251 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1252 	spin_lock(&mdsc->dentry_lru_lock);
1253 	list_add_tail(&di->lru, &mdsc->dentry_lru);
1254 	mdsc->num_dentry++;
1255 	spin_unlock(&mdsc->dentry_lru_lock);
1256 }
1257 
ceph_dentry_lru_touch(struct dentry * dn)1258 void ceph_dentry_lru_touch(struct dentry *dn)
1259 {
1260 	struct ceph_dentry_info *di = ceph_dentry(dn);
1261 	struct ceph_mds_client *mdsc;
1262 
1263 	dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1264 	     di->offset);
1265 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1266 	spin_lock(&mdsc->dentry_lru_lock);
1267 	list_move_tail(&di->lru, &mdsc->dentry_lru);
1268 	spin_unlock(&mdsc->dentry_lru_lock);
1269 }
1270 
ceph_dentry_lru_del(struct dentry * dn)1271 void ceph_dentry_lru_del(struct dentry *dn)
1272 {
1273 	struct ceph_dentry_info *di = ceph_dentry(dn);
1274 	struct ceph_mds_client *mdsc;
1275 
1276 	dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1277 	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1278 	spin_lock(&mdsc->dentry_lru_lock);
1279 	list_del_init(&di->lru);
1280 	mdsc->num_dentry--;
1281 	spin_unlock(&mdsc->dentry_lru_lock);
1282 }
1283 
1284 /*
1285  * Return name hash for a given dentry.  This is dependent on
1286  * the parent directory's hash function.
1287  */
ceph_dentry_hash(struct inode * dir,struct dentry * dn)1288 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1289 {
1290 	struct ceph_inode_info *dci = ceph_inode(dir);
1291 	unsigned hash;
1292 
1293 	switch (dci->i_dir_layout.dl_dir_hash) {
1294 	case 0:	/* for backward compat */
1295 	case CEPH_STR_HASH_LINUX:
1296 		return dn->d_name.hash;
1297 
1298 	default:
1299 		spin_lock(&dn->d_lock);
1300 		hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1301 				     dn->d_name.name, dn->d_name.len);
1302 		spin_unlock(&dn->d_lock);
1303 		return hash;
1304 	}
1305 }
1306 
1307 const struct file_operations ceph_dir_fops = {
1308 	.read = ceph_read_dir,
1309 	.iterate = ceph_readdir,
1310 	.llseek = ceph_dir_llseek,
1311 	.open = ceph_open,
1312 	.release = ceph_release,
1313 	.unlocked_ioctl = ceph_ioctl,
1314 	.fsync = ceph_fsync,
1315 };
1316 
1317 const struct file_operations ceph_snapdir_fops = {
1318 	.iterate = ceph_readdir,
1319 	.llseek = ceph_dir_llseek,
1320 	.open = ceph_open,
1321 	.release = ceph_release,
1322 };
1323 
1324 const struct inode_operations ceph_dir_iops = {
1325 	.lookup = ceph_lookup,
1326 	.permission = ceph_permission,
1327 	.getattr = ceph_getattr,
1328 	.setattr = ceph_setattr,
1329 	.setxattr = ceph_setxattr,
1330 	.getxattr = ceph_getxattr,
1331 	.listxattr = ceph_listxattr,
1332 	.removexattr = ceph_removexattr,
1333 	.get_acl = ceph_get_acl,
1334 	.set_acl = ceph_set_acl,
1335 	.mknod = ceph_mknod,
1336 	.symlink = ceph_symlink,
1337 	.mkdir = ceph_mkdir,
1338 	.link = ceph_link,
1339 	.unlink = ceph_unlink,
1340 	.rmdir = ceph_unlink,
1341 	.rename = ceph_rename,
1342 	.create = ceph_create,
1343 	.atomic_open = ceph_atomic_open,
1344 };
1345 
1346 const struct inode_operations ceph_snapdir_iops = {
1347 	.lookup = ceph_lookup,
1348 	.permission = ceph_permission,
1349 	.getattr = ceph_getattr,
1350 	.mkdir = ceph_mkdir,
1351 	.rmdir = ceph_unlink,
1352 	.rename = ceph_rename,
1353 };
1354 
1355 const struct dentry_operations ceph_dentry_ops = {
1356 	.d_revalidate = ceph_d_revalidate,
1357 	.d_release = ceph_d_release,
1358 	.d_prune = ceph_d_prune,
1359 };
1360 
1361 const struct dentry_operations ceph_snapdir_dentry_ops = {
1362 	.d_revalidate = ceph_snapdir_d_revalidate,
1363 	.d_release = ceph_d_release,
1364 };
1365 
1366 const struct dentry_operations ceph_snap_dentry_ops = {
1367 	.d_release = ceph_d_release,
1368 	.d_prune = ceph_d_prune,
1369 };
1370