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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
  29const struct inode_operations ceph_dir_iops;
  30const struct file_operations ceph_dir_fops;
  31const struct dentry_operations ceph_dentry_ops;
  32
  33/*
  34 * Initialize ceph dentry state.
  35 */
  36int ceph_init_dentry(struct dentry *dentry)
  37{
  38	struct ceph_dentry_info *di;
  39
  40	if (dentry->d_fsdata)
  41		return 0;
  42
  43	di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS | __GFP_ZERO);
  44	if (!di)
  45		return -ENOMEM;          /* oh well */
  46
  47	spin_lock(&dentry->d_lock);
  48	if (dentry->d_fsdata) {
  49		/* lost a race */
  50		kmem_cache_free(ceph_dentry_cachep, di);
  51		goto out_unlock;
  52	}
  53
  54	if (dentry->d_parent == NULL ||   /* nfs fh_to_dentry */
  55	    ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
  56		d_set_d_op(dentry, &ceph_dentry_ops);
  57	else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
  58		d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
  59	else
  60		d_set_d_op(dentry, &ceph_snap_dentry_ops);
  61
  62	di->dentry = dentry;
  63	di->lease_session = NULL;
  64	dentry->d_time = jiffies;
  65	/* avoid reordering d_fsdata setup so that the check above is safe */
  66	smp_mb();
  67	dentry->d_fsdata = di;
  68	ceph_dentry_lru_add(dentry);
  69out_unlock:
  70	spin_unlock(&dentry->d_lock);
  71	return 0;
  72}
  73
  74struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry)
  75{
  76	struct inode *inode = NULL;
  77
  78	if (!dentry)
  79		return NULL;
  80
  81	spin_lock(&dentry->d_lock);
  82	if (dentry->d_parent) {
  83		inode = dentry->d_parent->d_inode;
  84		ihold(inode);
  85	}
  86	spin_unlock(&dentry->d_lock);
  87	return inode;
  88}
  89
  90
  91/*
  92 * for readdir, we encode the directory frag and offset within that
  93 * frag into f_pos.
  94 */
  95static unsigned fpos_frag(loff_t p)
  96{
  97	return p >> 32;
  98}
  99static unsigned fpos_off(loff_t p)
 100{
 101	return p & 0xffffffff;
 102}
 103
 104/*
 105 * When possible, we try to satisfy a readdir by peeking at the
 106 * dcache.  We make this work by carefully ordering dentries on
 107 * d_u.d_child when we initially get results back from the MDS, and
 108 * falling back to a "normal" sync readdir if any dentries in the dir
 109 * are dropped.
 110 *
 111 * D_COMPLETE tells indicates we have all dentries in the dir.  It is
 112 * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
 113 * the MDS if/when the directory is modified).
 114 */
 115static int __dcache_readdir(struct file *filp,
 116			    void *dirent, filldir_t filldir)
 117{
 118	struct ceph_file_info *fi = filp->private_data;
 119	struct dentry *parent = filp->f_dentry;
 120	struct inode *dir = parent->d_inode;
 121	struct list_head *p;
 122	struct dentry *dentry, *last;
 123	struct ceph_dentry_info *di;
 124	int err = 0;
 125
 126	/* claim ref on last dentry we returned */
 127	last = fi->dentry;
 128	fi->dentry = NULL;
 129
 130	dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos,
 131	     last);
 132
 133	spin_lock(&parent->d_lock);
 134
 135	/* start at beginning? */
 136	if (filp->f_pos == 2 || last == NULL ||
 137	    filp->f_pos < ceph_dentry(last)->offset) {
 138		if (list_empty(&parent->d_subdirs))
 139			goto out_unlock;
 140		p = parent->d_subdirs.prev;
 141		dout(" initial p %p/%p\n", p->prev, p->next);
 142	} else {
 143		p = last->d_u.d_child.prev;
 144	}
 145
 146more:
 147	dentry = list_entry(p, struct dentry, d_u.d_child);
 148	di = ceph_dentry(dentry);
 149	while (1) {
 150		dout(" p %p/%p %s d_subdirs %p/%p\n", p->prev, p->next,
 151		     d_unhashed(dentry) ? "!hashed" : "hashed",
 152		     parent->d_subdirs.prev, parent->d_subdirs.next);
 153		if (p == &parent->d_subdirs) {
 154			fi->flags |= CEPH_F_ATEND;
 155			goto out_unlock;
 156		}
 157		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
 158		if (!d_unhashed(dentry) && dentry->d_inode &&
 159		    ceph_snap(dentry->d_inode) != CEPH_SNAPDIR &&
 160		    ceph_ino(dentry->d_inode) != CEPH_INO_CEPH &&
 161		    filp->f_pos <= di->offset)
 162			break;
 163		dout(" skipping %p %.*s at %llu (%llu)%s%s\n", dentry,
 164		     dentry->d_name.len, dentry->d_name.name, di->offset,
 165		     filp->f_pos, d_unhashed(dentry) ? " unhashed" : "",
 166		     !dentry->d_inode ? " null" : "");
 167		spin_unlock(&dentry->d_lock);
 168		p = p->prev;
 169		dentry = list_entry(p, struct dentry, d_u.d_child);
 170		di = ceph_dentry(dentry);
 171	}
 172
 173	dget_dlock(dentry);
 174	spin_unlock(&dentry->d_lock);
 175	spin_unlock(&parent->d_lock);
 176
 177	dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos,
 178	     dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
 179	filp->f_pos = di->offset;
 180	err = filldir(dirent, dentry->d_name.name,
 181		      dentry->d_name.len, di->offset,
 182		      ceph_translate_ino(dentry->d_sb, dentry->d_inode->i_ino),
 183		      dentry->d_inode->i_mode >> 12);
 184
 185	if (last) {
 186		if (err < 0) {
 187			/* remember our position */
 188			fi->dentry = last;
 189			fi->next_offset = di->offset;
 190		} else {
 191			dput(last);
 192		}
 193	}
 194	last = dentry;
 195
 196	if (err < 0)
 197		goto out;
 198
 199	filp->f_pos++;
 200
 201	/* make sure a dentry wasn't dropped while we didn't have parent lock */
 202	if (!ceph_dir_test_complete(dir)) {
 203		dout(" lost D_COMPLETE on %p; falling back to mds\n", dir);
 204		err = -EAGAIN;
 205		goto out;
 206	}
 207
 208	spin_lock(&parent->d_lock);
 209	p = p->prev;	/* advance to next dentry */
 210	goto more;
 211
 212out_unlock:
 213	spin_unlock(&parent->d_lock);
 214out:
 215	if (last)
 216		dput(last);
 217	return err;
 218}
 219
 220/*
 221 * make note of the last dentry we read, so we can
 222 * continue at the same lexicographical point,
 223 * regardless of what dir changes take place on the
 224 * server.
 225 */
 226static int note_last_dentry(struct ceph_file_info *fi, const char *name,
 227			    int len)
 228{
 229	kfree(fi->last_name);
 230	fi->last_name = kmalloc(len+1, GFP_NOFS);
 231	if (!fi->last_name)
 232		return -ENOMEM;
 233	memcpy(fi->last_name, name, len);
 234	fi->last_name[len] = 0;
 235	dout("note_last_dentry '%s'\n", fi->last_name);
 236	return 0;
 237}
 238
 239static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
 240{
 241	struct ceph_file_info *fi = filp->private_data;
 242	struct inode *inode = filp->f_dentry->d_inode;
 243	struct ceph_inode_info *ci = ceph_inode(inode);
 244	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 245	struct ceph_mds_client *mdsc = fsc->mdsc;
 246	unsigned frag = fpos_frag(filp->f_pos);
 247	int off = fpos_off(filp->f_pos);
 248	int err;
 249	u32 ftype;
 250	struct ceph_mds_reply_info_parsed *rinfo;
 251	const int max_entries = fsc->mount_options->max_readdir;
 252	const int max_bytes = fsc->mount_options->max_readdir_bytes;
 253
 254	dout("readdir %p filp %p frag %u off %u\n", inode, filp, frag, off);
 255	if (fi->flags & CEPH_F_ATEND)
 256		return 0;
 257
 258	/* always start with . and .. */
 259	if (filp->f_pos == 0) {
 260		/* note dir version at start of readdir so we can tell
 261		 * if any dentries get dropped */
 262		fi->dir_release_count = ci->i_release_count;
 263
 264		dout("readdir off 0 -> '.'\n");
 265		if (filldir(dirent, ".", 1, ceph_make_fpos(0, 0),
 266			    ceph_translate_ino(inode->i_sb, inode->i_ino),
 267			    inode->i_mode >> 12) < 0)
 268			return 0;
 269		filp->f_pos = 1;
 270		off = 1;
 271	}
 272	if (filp->f_pos == 1) {
 273		ino_t ino = parent_ino(filp->f_dentry);
 274		dout("readdir off 1 -> '..'\n");
 275		if (filldir(dirent, "..", 2, ceph_make_fpos(0, 1),
 276			    ceph_translate_ino(inode->i_sb, ino),
 277			    inode->i_mode >> 12) < 0)
 278			return 0;
 279		filp->f_pos = 2;
 280		off = 2;
 281	}
 282
 283	/* can we use the dcache? */
 284	spin_lock(&ci->i_ceph_lock);
 285	if ((filp->f_pos == 2 || fi->dentry) &&
 286	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
 287	    ceph_snap(inode) != CEPH_SNAPDIR &&
 288	    ceph_dir_test_complete(inode) &&
 289	    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
 290		spin_unlock(&ci->i_ceph_lock);
 291		err = __dcache_readdir(filp, dirent, filldir);
 292		if (err != -EAGAIN)
 293			return err;
 294	} else {
 295		spin_unlock(&ci->i_ceph_lock);
 296	}
 297	if (fi->dentry) {
 298		err = note_last_dentry(fi, fi->dentry->d_name.name,
 299				       fi->dentry->d_name.len);
 300		if (err)
 301			return err;
 302		dput(fi->dentry);
 303		fi->dentry = NULL;
 304	}
 305
 306	/* proceed with a normal readdir */
 307
 308more:
 309	/* do we have the correct frag content buffered? */
 310	if (fi->frag != frag || fi->last_readdir == NULL) {
 311		struct ceph_mds_request *req;
 312		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
 313			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
 314
 315		/* discard old result, if any */
 316		if (fi->last_readdir) {
 317			ceph_mdsc_put_request(fi->last_readdir);
 318			fi->last_readdir = NULL;
 319		}
 320
 321		/* requery frag tree, as the frag topology may have changed */
 322		frag = ceph_choose_frag(ceph_inode(inode), frag, NULL, NULL);
 323
 324		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
 325		     ceph_vinop(inode), frag, fi->last_name);
 326		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 327		if (IS_ERR(req))
 328			return PTR_ERR(req);
 329		req->r_inode = inode;
 330		ihold(inode);
 331		req->r_dentry = dget(filp->f_dentry);
 332		/* hints to request -> mds selection code */
 333		req->r_direct_mode = USE_AUTH_MDS;
 334		req->r_direct_hash = ceph_frag_value(frag);
 335		req->r_direct_is_hash = true;
 336		req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
 337		req->r_readdir_offset = fi->next_offset;
 338		req->r_args.readdir.frag = cpu_to_le32(frag);
 339		req->r_args.readdir.max_entries = cpu_to_le32(max_entries);
 340		req->r_args.readdir.max_bytes = cpu_to_le32(max_bytes);
 341		req->r_num_caps = max_entries + 1;
 342		err = ceph_mdsc_do_request(mdsc, NULL, req);
 343		if (err < 0) {
 344			ceph_mdsc_put_request(req);
 345			return err;
 346		}
 347		dout("readdir got and parsed readdir result=%d"
 348		     " on frag %x, end=%d, complete=%d\n", err, frag,
 349		     (int)req->r_reply_info.dir_end,
 350		     (int)req->r_reply_info.dir_complete);
 351
 352		if (!req->r_did_prepopulate) {
 353			dout("readdir !did_prepopulate");
 354			fi->dir_release_count--;    /* preclude D_COMPLETE */
 355		}
 356
 357		/* note next offset and last dentry name */
 358		fi->offset = fi->next_offset;
 359		fi->last_readdir = req;
 360
 361		if (req->r_reply_info.dir_end) {
 362			kfree(fi->last_name);
 363			fi->last_name = NULL;
 364			if (ceph_frag_is_rightmost(frag))
 365				fi->next_offset = 2;
 366			else
 367				fi->next_offset = 0;
 368		} else {
 369			rinfo = &req->r_reply_info;
 370			err = note_last_dentry(fi,
 371				       rinfo->dir_dname[rinfo->dir_nr-1],
 372				       rinfo->dir_dname_len[rinfo->dir_nr-1]);
 373			if (err)
 374				return err;
 375			fi->next_offset += rinfo->dir_nr;
 376		}
 377	}
 378
 379	rinfo = &fi->last_readdir->r_reply_info;
 380	dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
 381	     rinfo->dir_nr, off, fi->offset);
 382	while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
 383		u64 pos = ceph_make_fpos(frag, off);
 384		struct ceph_mds_reply_inode *in =
 385			rinfo->dir_in[off - fi->offset].in;
 386		struct ceph_vino vino;
 387		ino_t ino;
 388
 389		dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
 390		     off, off - fi->offset, rinfo->dir_nr, pos,
 391		     rinfo->dir_dname_len[off - fi->offset],
 392		     rinfo->dir_dname[off - fi->offset], in);
 393		BUG_ON(!in);
 394		ftype = le32_to_cpu(in->mode) >> 12;
 395		vino.ino = le64_to_cpu(in->ino);
 396		vino.snap = le64_to_cpu(in->snapid);
 397		ino = ceph_vino_to_ino(vino);
 398		if (filldir(dirent,
 399			    rinfo->dir_dname[off - fi->offset],
 400			    rinfo->dir_dname_len[off - fi->offset],
 401			    pos,
 402			    ceph_translate_ino(inode->i_sb, ino), ftype) < 0) {
 403			dout("filldir stopping us...\n");
 404			return 0;
 405		}
 406		off++;
 407		filp->f_pos = pos + 1;
 408	}
 409
 410	if (fi->last_name) {
 411		ceph_mdsc_put_request(fi->last_readdir);
 412		fi->last_readdir = NULL;
 413		goto more;
 414	}
 415
 416	/* more frags? */
 417	if (!ceph_frag_is_rightmost(frag)) {
 418		frag = ceph_frag_next(frag);
 419		off = 0;
 420		filp->f_pos = ceph_make_fpos(frag, off);
 421		dout("readdir next frag is %x\n", frag);
 422		goto more;
 423	}
 424	fi->flags |= CEPH_F_ATEND;
 425
 426	/*
 427	 * if dir_release_count still matches the dir, no dentries
 428	 * were released during the whole readdir, and we should have
 429	 * the complete dir contents in our cache.
 430	 */
 431	spin_lock(&ci->i_ceph_lock);
 432	if (ci->i_release_count == fi->dir_release_count) {
 433		ceph_dir_set_complete(inode);
 434		ci->i_max_offset = filp->f_pos;
 435	}
 436	spin_unlock(&ci->i_ceph_lock);
 437
 438	dout("readdir %p filp %p done.\n", inode, filp);
 439	return 0;
 440}
 441
 442static void reset_readdir(struct ceph_file_info *fi)
 443{
 444	if (fi->last_readdir) {
 445		ceph_mdsc_put_request(fi->last_readdir);
 446		fi->last_readdir = NULL;
 447	}
 448	kfree(fi->last_name);
 449	fi->last_name = NULL;
 450	fi->next_offset = 2;  /* compensate for . and .. */
 451	if (fi->dentry) {
 452		dput(fi->dentry);
 453		fi->dentry = NULL;
 454	}
 455	fi->flags &= ~CEPH_F_ATEND;
 456}
 457
 458static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int origin)
 459{
 460	struct ceph_file_info *fi = file->private_data;
 461	struct inode *inode = file->f_mapping->host;
 462	loff_t old_offset = offset;
 463	loff_t retval;
 464
 465	mutex_lock(&inode->i_mutex);
 466	retval = -EINVAL;
 467	switch (origin) {
 468	case SEEK_END:
 469		offset += inode->i_size + 2;   /* FIXME */
 470		break;
 471	case SEEK_CUR:
 472		offset += file->f_pos;
 473	case SEEK_SET:
 474		break;
 475	default:
 476		goto out;
 477	}
 478
 479	if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
 480		if (offset != file->f_pos) {
 481			file->f_pos = offset;
 482			file->f_version = 0;
 483			fi->flags &= ~CEPH_F_ATEND;
 484		}
 485		retval = offset;
 486
 487		/*
 488		 * discard buffered readdir content on seekdir(0), or
 489		 * seek to new frag, or seek prior to current chunk.
 490		 */
 491		if (offset == 0 ||
 492		    fpos_frag(offset) != fpos_frag(old_offset) ||
 493		    fpos_off(offset) < fi->offset) {
 494			dout("dir_llseek dropping %p content\n", file);
 495			reset_readdir(fi);
 496		}
 497
 498		/* bump dir_release_count if we did a forward seek */
 499		if (offset > old_offset)
 500			fi->dir_release_count--;
 501	}
 502out:
 503	mutex_unlock(&inode->i_mutex);
 504	return retval;
 505}
 506
 507/*
 508 * Handle lookups for the hidden .snap directory.
 509 */
 510int ceph_handle_snapdir(struct ceph_mds_request *req,
 511			struct dentry *dentry, int err)
 512{
 513	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
 514	struct inode *parent = dentry->d_parent->d_inode; /* we hold i_mutex */
 515
 516	/* .snap dir? */
 517	if (err == -ENOENT &&
 518	    ceph_snap(parent) == CEPH_NOSNAP &&
 519	    strcmp(dentry->d_name.name,
 520		   fsc->mount_options->snapdir_name) == 0) {
 521		struct inode *inode = ceph_get_snapdir(parent);
 522		dout("ENOENT on snapdir %p '%.*s', linking to snapdir %p\n",
 523		     dentry, dentry->d_name.len, dentry->d_name.name, inode);
 524		BUG_ON(!d_unhashed(dentry));
 525		d_add(dentry, inode);
 526		err = 0;
 527	}
 528	return err;
 529}
 530
 531/*
 532 * Figure out final result of a lookup/open request.
 533 *
 534 * Mainly, make sure we return the final req->r_dentry (if it already
 535 * existed) in place of the original VFS-provided dentry when they
 536 * differ.
 537 *
 538 * Gracefully handle the case where the MDS replies with -ENOENT and
 539 * no trace (which it may do, at its discretion, e.g., if it doesn't
 540 * care to issue a lease on the negative dentry).
 541 */
 542struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
 543				  struct dentry *dentry, int err)
 544{
 545	if (err == -ENOENT) {
 546		/* no trace? */
 547		err = 0;
 548		if (!req->r_reply_info.head->is_dentry) {
 549			dout("ENOENT and no trace, dentry %p inode %p\n",
 550			     dentry, dentry->d_inode);
 551			if (dentry->d_inode) {
 552				d_drop(dentry);
 553				err = -ENOENT;
 554			} else {
 555				d_add(dentry, NULL);
 556			}
 557		}
 558	}
 559	if (err)
 560		dentry = ERR_PTR(err);
 561	else if (dentry != req->r_dentry)
 562		dentry = dget(req->r_dentry);   /* we got spliced */
 563	else
 564		dentry = NULL;
 565	return dentry;
 566}
 567
 568static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
 569{
 570	return ceph_ino(inode) == CEPH_INO_ROOT &&
 571		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
 572}
 573
 574/*
 575 * Look up a single dir entry.  If there is a lookup intent, inform
 576 * the MDS so that it gets our 'caps wanted' value in a single op.
 577 */
 578static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 579				  struct nameidata *nd)
 580{
 581	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 582	struct ceph_mds_client *mdsc = fsc->mdsc;
 583	struct ceph_mds_request *req;
 584	int op;
 585	int err;
 586
 587	dout("lookup %p dentry %p '%.*s'\n",
 588	     dir, dentry, dentry->d_name.len, dentry->d_name.name);
 589
 590	if (dentry->d_name.len > NAME_MAX)
 591		return ERR_PTR(-ENAMETOOLONG);
 592
 593	err = ceph_init_dentry(dentry);
 594	if (err < 0)
 595		return ERR_PTR(err);
 596
 597	/* open (but not create!) intent? */
 598	if (nd &&
 599	    (nd->flags & LOOKUP_OPEN) &&
 600	    !(nd->intent.open.flags & O_CREAT)) {
 601		int mode = nd->intent.open.create_mode & ~current->fs->umask;
 602		return ceph_lookup_open(dir, dentry, nd, mode, 1);
 603	}
 604
 605	/* can we conclude ENOENT locally? */
 606	if (dentry->d_inode == NULL) {
 607		struct ceph_inode_info *ci = ceph_inode(dir);
 608		struct ceph_dentry_info *di = ceph_dentry(dentry);
 609
 610		spin_lock(&ci->i_ceph_lock);
 611		dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
 612		if (strncmp(dentry->d_name.name,
 613			    fsc->mount_options->snapdir_name,
 614			    dentry->d_name.len) &&
 615		    !is_root_ceph_dentry(dir, dentry) &&
 616		    ceph_dir_test_complete(dir) &&
 617		    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
 618			spin_unlock(&ci->i_ceph_lock);
 619			dout(" dir %p complete, -ENOENT\n", dir);
 620			d_add(dentry, NULL);
 621			di->lease_shared_gen = ci->i_shared_gen;
 622			return NULL;
 623		}
 624		spin_unlock(&ci->i_ceph_lock);
 625	}
 626
 627	op = ceph_snap(dir) == CEPH_SNAPDIR ?
 628		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
 629	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
 630	if (IS_ERR(req))
 631		return ERR_CAST(req);
 632	req->r_dentry = dget(dentry);
 633	req->r_num_caps = 2;
 634	/* we only need inode linkage */
 635	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
 636	req->r_locked_dir = dir;
 637	err = ceph_mdsc_do_request(mdsc, NULL, req);
 638	err = ceph_handle_snapdir(req, dentry, err);
 639	dentry = ceph_finish_lookup(req, dentry, err);
 640	ceph_mdsc_put_request(req);  /* will dput(dentry) */
 641	dout("lookup result=%p\n", dentry);
 642	return dentry;
 643}
 644
 645/*
 646 * If we do a create but get no trace back from the MDS, follow up with
 647 * a lookup (the VFS expects us to link up the provided dentry).
 648 */
 649int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
 650{
 651	struct dentry *result = ceph_lookup(dir, dentry, NULL);
 652
 653	if (result && !IS_ERR(result)) {
 654		/*
 655		 * We created the item, then did a lookup, and found
 656		 * it was already linked to another inode we already
 657		 * had in our cache (and thus got spliced).  Link our
 658		 * dentry to that inode, but don't hash it, just in
 659		 * case the VFS wants to dereference it.
 660		 */
 661		BUG_ON(!result->d_inode);
 662		d_instantiate(dentry, result->d_inode);
 663		return 0;
 664	}
 665	return PTR_ERR(result);
 666}
 667
 668static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 669		      umode_t mode, dev_t rdev)
 670{
 671	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 672	struct ceph_mds_client *mdsc = fsc->mdsc;
 673	struct ceph_mds_request *req;
 674	int err;
 675
 676	if (ceph_snap(dir) != CEPH_NOSNAP)
 677		return -EROFS;
 678
 679	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
 680	     dir, dentry, mode, rdev);
 681	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
 682	if (IS_ERR(req)) {
 683		d_drop(dentry);
 684		return PTR_ERR(req);
 685	}
 686	req->r_dentry = dget(dentry);
 687	req->r_num_caps = 2;
 688	req->r_locked_dir = dir;
 689	req->r_args.mknod.mode = cpu_to_le32(mode);
 690	req->r_args.mknod.rdev = cpu_to_le32(rdev);
 691	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 692	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 693	err = ceph_mdsc_do_request(mdsc, dir, req);
 694	if (!err && !req->r_reply_info.head->is_dentry)
 695		err = ceph_handle_notrace_create(dir, dentry);
 696	ceph_mdsc_put_request(req);
 697	if (err)
 698		d_drop(dentry);
 699	return err;
 700}
 701
 702static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 703		       struct nameidata *nd)
 704{
 705	dout("create in dir %p dentry %p name '%.*s'\n",
 706	     dir, dentry, dentry->d_name.len, dentry->d_name.name);
 707
 708	if (ceph_snap(dir) != CEPH_NOSNAP)
 709		return -EROFS;
 710
 711	if (nd) {
 712		BUG_ON((nd->flags & LOOKUP_OPEN) == 0);
 713		dentry = ceph_lookup_open(dir, dentry, nd, mode, 0);
 714		/* hrm, what should i do here if we get aliased? */
 715		if (IS_ERR(dentry))
 716			return PTR_ERR(dentry);
 717		return 0;
 718	}
 719
 720	/* fall back to mknod */
 721	return ceph_mknod(dir, dentry, (mode & ~S_IFMT) | S_IFREG, 0);
 722}
 723
 724static int ceph_symlink(struct inode *dir, struct dentry *dentry,
 725			    const char *dest)
 726{
 727	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 728	struct ceph_mds_client *mdsc = fsc->mdsc;
 729	struct ceph_mds_request *req;
 730	int err;
 731
 732	if (ceph_snap(dir) != CEPH_NOSNAP)
 733		return -EROFS;
 734
 735	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
 736	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
 737	if (IS_ERR(req)) {
 738		d_drop(dentry);
 739		return PTR_ERR(req);
 740	}
 741	req->r_dentry = dget(dentry);
 742	req->r_num_caps = 2;
 743	req->r_path2 = kstrdup(dest, GFP_NOFS);
 744	req->r_locked_dir = dir;
 745	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 746	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 747	err = ceph_mdsc_do_request(mdsc, dir, req);
 748	if (!err && !req->r_reply_info.head->is_dentry)
 749		err = ceph_handle_notrace_create(dir, dentry);
 750	ceph_mdsc_put_request(req);
 751	if (err)
 752		d_drop(dentry);
 753	return err;
 754}
 755
 756static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 757{
 758	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 759	struct ceph_mds_client *mdsc = fsc->mdsc;
 760	struct ceph_mds_request *req;
 761	int err = -EROFS;
 762	int op;
 763
 764	if (ceph_snap(dir) == CEPH_SNAPDIR) {
 765		/* mkdir .snap/foo is a MKSNAP */
 766		op = CEPH_MDS_OP_MKSNAP;
 767		dout("mksnap dir %p snap '%.*s' dn %p\n", dir,
 768		     dentry->d_name.len, dentry->d_name.name, dentry);
 769	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
 770		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
 771		op = CEPH_MDS_OP_MKDIR;
 772	} else {
 773		goto out;
 774	}
 775	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 776	if (IS_ERR(req)) {
 777		err = PTR_ERR(req);
 778		goto out;
 779	}
 780
 781	req->r_dentry = dget(dentry);
 782	req->r_num_caps = 2;
 783	req->r_locked_dir = dir;
 784	req->r_args.mkdir.mode = cpu_to_le32(mode);
 785	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 786	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 787	err = ceph_mdsc_do_request(mdsc, dir, req);
 788	if (!err && !req->r_reply_info.head->is_dentry)
 789		err = ceph_handle_notrace_create(dir, dentry);
 790	ceph_mdsc_put_request(req);
 791out:
 792	if (err < 0)
 793		d_drop(dentry);
 794	return err;
 795}
 796
 797static int ceph_link(struct dentry *old_dentry, struct inode *dir,
 798		     struct dentry *dentry)
 799{
 800	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 801	struct ceph_mds_client *mdsc = fsc->mdsc;
 802	struct ceph_mds_request *req;
 803	int err;
 804
 805	if (ceph_snap(dir) != CEPH_NOSNAP)
 806		return -EROFS;
 807
 808	dout("link in dir %p old_dentry %p dentry %p\n", dir,
 809	     old_dentry, dentry);
 810	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
 811	if (IS_ERR(req)) {
 812		d_drop(dentry);
 813		return PTR_ERR(req);
 814	}
 815	req->r_dentry = dget(dentry);
 816	req->r_num_caps = 2;
 817	req->r_old_dentry = dget(old_dentry); /* or inode? hrm. */
 818	req->r_old_dentry_dir = ceph_get_dentry_parent_inode(old_dentry);
 819	req->r_locked_dir = dir;
 820	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 821	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 822	err = ceph_mdsc_do_request(mdsc, dir, req);
 823	if (err) {
 824		d_drop(dentry);
 825	} else if (!req->r_reply_info.head->is_dentry) {
 826		ihold(old_dentry->d_inode);
 827		d_instantiate(dentry, old_dentry->d_inode);
 828	}
 829	ceph_mdsc_put_request(req);
 830	return err;
 831}
 832
 833/*
 834 * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
 835 * looks like the link count will hit 0, drop any other caps (other
 836 * than PIN) we don't specifically want (due to the file still being
 837 * open).
 838 */
 839static int drop_caps_for_unlink(struct inode *inode)
 840{
 841	struct ceph_inode_info *ci = ceph_inode(inode);
 842	int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
 843
 844	spin_lock(&ci->i_ceph_lock);
 845	if (inode->i_nlink == 1) {
 846		drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
 847		ci->i_ceph_flags |= CEPH_I_NODELAY;
 848	}
 849	spin_unlock(&ci->i_ceph_lock);
 850	return drop;
 851}
 852
 853/*
 854 * rmdir and unlink are differ only by the metadata op code
 855 */
 856static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 857{
 858	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 859	struct ceph_mds_client *mdsc = fsc->mdsc;
 860	struct inode *inode = dentry->d_inode;
 861	struct ceph_mds_request *req;
 862	int err = -EROFS;
 863	int op;
 864
 865	if (ceph_snap(dir) == CEPH_SNAPDIR) {
 866		/* rmdir .snap/foo is RMSNAP */
 867		dout("rmsnap dir %p '%.*s' dn %p\n", dir, dentry->d_name.len,
 868		     dentry->d_name.name, dentry);
 869		op = CEPH_MDS_OP_RMSNAP;
 870	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
 871		dout("unlink/rmdir dir %p dn %p inode %p\n",
 872		     dir, dentry, inode);
 873		op = S_ISDIR(dentry->d_inode->i_mode) ?
 874			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
 875	} else
 876		goto out;
 877	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 878	if (IS_ERR(req)) {
 879		err = PTR_ERR(req);
 880		goto out;
 881	}
 882	req->r_dentry = dget(dentry);
 883	req->r_num_caps = 2;
 884	req->r_locked_dir = dir;
 885	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 886	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 887	req->r_inode_drop = drop_caps_for_unlink(inode);
 888	err = ceph_mdsc_do_request(mdsc, dir, req);
 889	if (!err && !req->r_reply_info.head->is_dentry)
 890		d_delete(dentry);
 891	ceph_mdsc_put_request(req);
 892out:
 893	return err;
 894}
 895
 896static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
 897		       struct inode *new_dir, struct dentry *new_dentry)
 898{
 899	struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
 900	struct ceph_mds_client *mdsc = fsc->mdsc;
 901	struct ceph_mds_request *req;
 902	int err;
 903
 904	if (ceph_snap(old_dir) != ceph_snap(new_dir))
 905		return -EXDEV;
 906	if (ceph_snap(old_dir) != CEPH_NOSNAP ||
 907	    ceph_snap(new_dir) != CEPH_NOSNAP)
 908		return -EROFS;
 909	dout("rename dir %p dentry %p to dir %p dentry %p\n",
 910	     old_dir, old_dentry, new_dir, new_dentry);
 911	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_RENAME, USE_AUTH_MDS);
 912	if (IS_ERR(req))
 913		return PTR_ERR(req);
 914	req->r_dentry = dget(new_dentry);
 915	req->r_num_caps = 2;
 916	req->r_old_dentry = dget(old_dentry);
 917	req->r_old_dentry_dir = ceph_get_dentry_parent_inode(old_dentry);
 918	req->r_locked_dir = new_dir;
 919	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
 920	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
 921	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 922	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 923	/* release LINK_RDCACHE on source inode (mds will lock it) */
 924	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
 925	if (new_dentry->d_inode)
 926		req->r_inode_drop = drop_caps_for_unlink(new_dentry->d_inode);
 927	err = ceph_mdsc_do_request(mdsc, old_dir, req);
 928	if (!err && !req->r_reply_info.head->is_dentry) {
 929		/*
 930		 * Normally d_move() is done by fill_trace (called by
 931		 * do_request, above).  If there is no trace, we need
 932		 * to do it here.
 933		 */
 934
 935		/* d_move screws up d_subdirs order */
 936		ceph_dir_clear_complete(new_dir);
 937
 938		d_move(old_dentry, new_dentry);
 939
 940		/* ensure target dentry is invalidated, despite
 941		   rehashing bug in vfs_rename_dir */
 942		ceph_invalidate_dentry_lease(new_dentry);
 943	}
 944	ceph_mdsc_put_request(req);
 945	return err;
 946}
 947
 948/*
 949 * Ensure a dentry lease will no longer revalidate.
 950 */
 951void ceph_invalidate_dentry_lease(struct dentry *dentry)
 952{
 953	spin_lock(&dentry->d_lock);
 954	dentry->d_time = jiffies;
 955	ceph_dentry(dentry)->lease_shared_gen = 0;
 956	spin_unlock(&dentry->d_lock);
 957}
 958
 959/*
 960 * Check if dentry lease is valid.  If not, delete the lease.  Try to
 961 * renew if the least is more than half up.
 962 */
 963static int dentry_lease_is_valid(struct dentry *dentry)
 964{
 965	struct ceph_dentry_info *di;
 966	struct ceph_mds_session *s;
 967	int valid = 0;
 968	u32 gen;
 969	unsigned long ttl;
 970	struct ceph_mds_session *session = NULL;
 971	struct inode *dir = NULL;
 972	u32 seq = 0;
 973
 974	spin_lock(&dentry->d_lock);
 975	di = ceph_dentry(dentry);
 976	if (di->lease_session) {
 977		s = di->lease_session;
 978		spin_lock(&s->s_gen_ttl_lock);
 979		gen = s->s_cap_gen;
 980		ttl = s->s_cap_ttl;
 981		spin_unlock(&s->s_gen_ttl_lock);
 982
 983		if (di->lease_gen == gen &&
 984		    time_before(jiffies, dentry->d_time) &&
 985		    time_before(jiffies, ttl)) {
 986			valid = 1;
 987			if (di->lease_renew_after &&
 988			    time_after(jiffies, di->lease_renew_after)) {
 989				/* we should renew */
 990				dir = dentry->d_parent->d_inode;
 991				session = ceph_get_mds_session(s);
 992				seq = di->lease_seq;
 993				di->lease_renew_after = 0;
 994				di->lease_renew_from = jiffies;
 995			}
 996		}
 997	}
 998	spin_unlock(&dentry->d_lock);
 999
1000	if (session) {
1001		ceph_mdsc_lease_send_msg(session, dir, dentry,
1002					 CEPH_MDS_LEASE_RENEW, seq);
1003		ceph_put_mds_session(session);
1004	}
1005	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1006	return valid;
1007}
1008
1009/*
1010 * Check if directory-wide content lease/cap is valid.
1011 */
1012static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1013{
1014	struct ceph_inode_info *ci = ceph_inode(dir);
1015	struct ceph_dentry_info *di = ceph_dentry(dentry);
1016	int valid = 0;
1017
1018	spin_lock(&ci->i_ceph_lock);
1019	if (ci->i_shared_gen == di->lease_shared_gen)
1020		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1021	spin_unlock(&ci->i_ceph_lock);
1022	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1023	     dir, (unsigned)ci->i_shared_gen, dentry,
1024	     (unsigned)di->lease_shared_gen, valid);
1025	return valid;
1026}
1027
1028/*
1029 * Check if cached dentry can be trusted.
1030 */
1031static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
1032{
1033	int valid = 0;
1034	struct inode *dir;
1035
1036	if (nd && nd->flags & LOOKUP_RCU)
1037		return -ECHILD;
1038
1039	dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
1040	     dentry->d_name.len, dentry->d_name.name, dentry->d_inode,
1041	     ceph_dentry(dentry)->offset);
1042
1043	dir = ceph_get_dentry_parent_inode(dentry);
1044
1045	/* always trust cached snapped dentries, snapdir dentry */
1046	if (ceph_snap(dir) != CEPH_NOSNAP) {
1047		dout("d_revalidate %p '%.*s' inode %p is SNAPPED\n", dentry,
1048		     dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
1049		valid = 1;
1050	} else if (dentry->d_inode &&
1051		   ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) {
1052		valid = 1;
1053	} else if (dentry_lease_is_valid(dentry) ||
1054		   dir_lease_is_valid(dir, dentry)) {
1055		valid = 1;
1056	}
1057
1058	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1059	if (valid)
1060		ceph_dentry_lru_touch(dentry);
1061	else
1062		d_drop(dentry);
1063	iput(dir);
1064	return valid;
1065}
1066
1067/*
1068 * Release our ceph_dentry_info.
1069 */
1070static void ceph_d_release(struct dentry *dentry)
1071{
1072	struct ceph_dentry_info *di = ceph_dentry(dentry);
1073
1074	dout("d_release %p\n", dentry);
1075	ceph_dentry_lru_del(dentry);
1076	if (di->lease_session)
1077		ceph_put_mds_session(di->lease_session);
1078	kmem_cache_free(ceph_dentry_cachep, di);
1079	dentry->d_fsdata = NULL;
1080}
1081
1082static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1083					  struct nameidata *nd)
1084{
1085	/*
1086	 * Eventually, we'll want to revalidate snapped metadata
1087	 * too... probably...
1088	 */
1089	return 1;
1090}
1091
1092/*
1093 * Set/clear/test dir complete flag on the dir's dentry.
1094 */
1095void ceph_dir_set_complete(struct inode *inode)
1096{
1097	struct dentry *dentry = d_find_any_alias(inode);
1098	
1099	if (dentry && ceph_dentry(dentry) &&
1100	    ceph_test_mount_opt(ceph_sb_to_client(dentry->d_sb), DCACHE)) {
1101		dout(" marking %p (%p) complete\n", inode, dentry);
1102		set_bit(CEPH_D_COMPLETE, &ceph_dentry(dentry)->flags);
1103	}
1104	dput(dentry);
1105}
1106
1107void ceph_dir_clear_complete(struct inode *inode)
1108{
1109	struct dentry *dentry = d_find_any_alias(inode);
1110
1111	if (dentry && ceph_dentry(dentry)) {
1112		dout(" marking %p (%p) complete\n", inode, dentry);
1113		set_bit(CEPH_D_COMPLETE, &ceph_dentry(dentry)->flags);
1114	}
1115	dput(dentry);
1116}
1117
1118bool ceph_dir_test_complete(struct inode *inode)
1119{
1120	struct dentry *dentry = d_find_any_alias(inode);
1121
1122	if (dentry && ceph_dentry(dentry)) {
1123		dout(" marking %p (%p) NOT complete\n", inode, dentry);
1124		clear_bit(CEPH_D_COMPLETE, &ceph_dentry(dentry)->flags);
1125	}
1126	dput(dentry);
1127	return false;
1128}
1129
1130/*
1131 * When the VFS prunes a dentry from the cache, we need to clear the
1132 * complete flag on the parent directory.
1133 *
1134 * Called under dentry->d_lock.
1135 */
1136static void ceph_d_prune(struct dentry *dentry)
1137{
1138	struct ceph_dentry_info *di;
1139
1140	dout("ceph_d_prune %p\n", dentry);
1141
1142	/* do we have a valid parent? */
1143	if (!dentry->d_parent || IS_ROOT(dentry))
1144		return;
1145
1146	/* if we are not hashed, we don't affect D_COMPLETE */
1147	if (d_unhashed(dentry))
1148		return;
1149
1150	/*
1151	 * we hold d_lock, so d_parent is stable, and d_fsdata is never
1152	 * cleared until d_release
1153	 */
1154	di = ceph_dentry(dentry->d_parent);
1155	clear_bit(CEPH_D_COMPLETE, &di->flags);
1156}
1157
1158/*
1159 * read() on a dir.  This weird interface hack only works if mounted
1160 * with '-o dirstat'.
1161 */
1162static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1163			     loff_t *ppos)
1164{
1165	struct ceph_file_info *cf = file->private_data;
1166	struct inode *inode = file->f_dentry->d_inode;
1167	struct ceph_inode_info *ci = ceph_inode(inode);
1168	int left;
1169	const int bufsize = 1024;
1170
1171	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1172		return -EISDIR;
1173
1174	if (!cf->dir_info) {
1175		cf->dir_info = kmalloc(bufsize, GFP_NOFS);
1176		if (!cf->dir_info)
1177			return -ENOMEM;
1178		cf->dir_info_len =
1179			snprintf(cf->dir_info, bufsize,
1180				"entries:   %20lld\n"
1181				" files:    %20lld\n"
1182				" subdirs:  %20lld\n"
1183				"rentries:  %20lld\n"
1184				" rfiles:   %20lld\n"
1185				" rsubdirs: %20lld\n"
1186				"rbytes:    %20lld\n"
1187				"rctime:    %10ld.%09ld\n",
1188				ci->i_files + ci->i_subdirs,
1189				ci->i_files,
1190				ci->i_subdirs,
1191				ci->i_rfiles + ci->i_rsubdirs,
1192				ci->i_rfiles,
1193				ci->i_rsubdirs,
1194				ci->i_rbytes,
1195				(long)ci->i_rctime.tv_sec,
1196				(long)ci->i_rctime.tv_nsec);
1197	}
1198
1199	if (*ppos >= cf->dir_info_len)
1200		return 0;
1201	size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1202	left = copy_to_user(buf, cf->dir_info + *ppos, size);
1203	if (left == size)
1204		return -EFAULT;
1205	*ppos += (size - left);
1206	return size - left;
1207}
1208
1209/*
1210 * an fsync() on a dir will wait for any uncommitted directory
1211 * operations to commit.
1212 */
1213static int ceph_dir_fsync(struct file *file, loff_t start, loff_t end,
1214			  int datasync)
1215{
1216	struct inode *inode = file->f_path.dentry->d_inode;
1217	struct ceph_inode_info *ci = ceph_inode(inode);
1218	struct list_head *head = &ci->i_unsafe_dirops;
1219	struct ceph_mds_request *req;
1220	u64 last_tid;
1221	int ret = 0;
1222
1223	dout("dir_fsync %p\n", inode);
1224	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
1225	if (ret)
1226		return ret;
1227	mutex_lock(&inode->i_mutex);
1228
1229	spin_lock(&ci->i_unsafe_lock);
1230	if (list_empty(head))
1231		goto out;
1232
1233	req = list_entry(head->prev,
1234			 struct ceph_mds_request, r_unsafe_dir_item);
1235	last_tid = req->r_tid;
1236
1237	do {
1238		ceph_mdsc_get_request(req);
1239		spin_unlock(&ci->i_unsafe_lock);
1240
1241		dout("dir_fsync %p wait on tid %llu (until %llu)\n",
1242		     inode, req->r_tid, last_tid);
1243		if (req->r_timeout) {
1244			ret = wait_for_completion_timeout(
1245				&req->r_safe_completion, req->r_timeout);
1246			if (ret > 0)
1247				ret = 0;
1248			else if (ret == 0)
1249				ret = -EIO;  /* timed out */
1250		} else {
1251			wait_for_completion(&req->r_safe_completion);
1252		}
1253		ceph_mdsc_put_request(req);
1254
1255		spin_lock(&ci->i_unsafe_lock);
1256		if (ret || list_empty(head))
1257			break;
1258		req = list_entry(head->next,
1259				 struct ceph_mds_request, r_unsafe_dir_item);
1260	} while (req->r_tid < last_tid);
1261out:
1262	spin_unlock(&ci->i_unsafe_lock);
1263	mutex_unlock(&inode->i_mutex);
1264
1265	return ret;
1266}
1267
1268/*
1269 * We maintain a private dentry LRU.
1270 *
1271 * FIXME: this needs to be changed to a per-mds lru to be useful.
1272 */
1273void ceph_dentry_lru_add(struct dentry *dn)
1274{
1275	struct ceph_dentry_info *di = ceph_dentry(dn);
1276	struct ceph_mds_client *mdsc;
1277
1278	dout("dentry_lru_add %p %p '%.*s'\n", di, dn,
1279	     dn->d_name.len, dn->d_name.name);
1280	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1281	spin_lock(&mdsc->dentry_lru_lock);
1282	list_add_tail(&di->lru, &mdsc->dentry_lru);
1283	mdsc->num_dentry++;
1284	spin_unlock(&mdsc->dentry_lru_lock);
1285}
1286
1287void ceph_dentry_lru_touch(struct dentry *dn)
1288{
1289	struct ceph_dentry_info *di = ceph_dentry(dn);
1290	struct ceph_mds_client *mdsc;
1291
1292	dout("dentry_lru_touch %p %p '%.*s' (offset %lld)\n", di, dn,
1293	     dn->d_name.len, dn->d_name.name, di->offset);
1294	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1295	spin_lock(&mdsc->dentry_lru_lock);
1296	list_move_tail(&di->lru, &mdsc->dentry_lru);
1297	spin_unlock(&mdsc->dentry_lru_lock);
1298}
1299
1300void ceph_dentry_lru_del(struct dentry *dn)
1301{
1302	struct ceph_dentry_info *di = ceph_dentry(dn);
1303	struct ceph_mds_client *mdsc;
1304
1305	dout("dentry_lru_del %p %p '%.*s'\n", di, dn,
1306	     dn->d_name.len, dn->d_name.name);
1307	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1308	spin_lock(&mdsc->dentry_lru_lock);
1309	list_del_init(&di->lru);
1310	mdsc->num_dentry--;
1311	spin_unlock(&mdsc->dentry_lru_lock);
1312}
1313
1314/*
1315 * Return name hash for a given dentry.  This is dependent on
1316 * the parent directory's hash function.
1317 */
1318unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1319{
1320	struct ceph_inode_info *dci = ceph_inode(dir);
1321
1322	switch (dci->i_dir_layout.dl_dir_hash) {
1323	case 0:	/* for backward compat */
1324	case CEPH_STR_HASH_LINUX:
1325		return dn->d_name.hash;
1326
1327	default:
1328		return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1329				     dn->d_name.name, dn->d_name.len);
1330	}
1331}
1332
1333const struct file_operations ceph_dir_fops = {
1334	.read = ceph_read_dir,
1335	.readdir = ceph_readdir,
1336	.llseek = ceph_dir_llseek,
1337	.open = ceph_open,
1338	.release = ceph_release,
1339	.unlocked_ioctl = ceph_ioctl,
1340	.fsync = ceph_dir_fsync,
1341};
1342
1343const struct inode_operations ceph_dir_iops = {
1344	.lookup = ceph_lookup,
1345	.permission = ceph_permission,
1346	.getattr = ceph_getattr,
1347	.setattr = ceph_setattr,
1348	.setxattr = ceph_setxattr,
1349	.getxattr = ceph_getxattr,
1350	.listxattr = ceph_listxattr,
1351	.removexattr = ceph_removexattr,
1352	.mknod = ceph_mknod,
1353	.symlink = ceph_symlink,
1354	.mkdir = ceph_mkdir,
1355	.link = ceph_link,
1356	.unlink = ceph_unlink,
1357	.rmdir = ceph_unlink,
1358	.rename = ceph_rename,
1359	.create = ceph_create,
1360};
1361
1362const struct dentry_operations ceph_dentry_ops = {
1363	.d_revalidate = ceph_d_revalidate,
1364	.d_release = ceph_d_release,
1365	.d_prune = ceph_d_prune,
1366};
1367
1368const struct dentry_operations ceph_snapdir_dentry_ops = {
1369	.d_revalidate = ceph_snapdir_d_revalidate,
1370	.d_release = ceph_d_release,
1371};
1372
1373const struct dentry_operations ceph_snap_dentry_ops = {
1374	.d_release = ceph_d_release,
1375	.d_prune = ceph_d_prune,
1376};