Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2064 insertions, 0 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
new file mode 100644
index 000000000..e7e2ebac3
--- /dev/null
+++ b/fs/ceph/dir.c
@@ -0,0 +1,2064 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/spinlock.h>
+#include <linux/namei.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/xattr.h>
+
+#include "super.h"
+#include "mds_client.h"
+
+/*
+ * Directory operations: readdir, lookup, create, link, unlink,
+ * rename, etc.
+ */
+
+/*
+ * Ceph MDS operations are specified in terms of a base ino and
+ * relative path.  Thus, the client can specify an operation on a
+ * specific inode (e.g., a getattr due to fstat(2)), or as a path
+ * relative to, say, the root directory.
+ *
+ * Normally, we limit ourselves to strict inode ops (no path component)
+ * or dentry operations (a single path component relative to an ino).  The
+ * exception to this is open_root_dentry(), which will open the mount
+ * point by name.
+ */
+
+const struct dentry_operations ceph_dentry_ops;
+
+static bool __dentry_lease_is_valid(struct ceph_dentry_info *di);
+static int __dir_lease_try_check(const struct dentry *dentry);
+
+/*
+ * Initialize ceph dentry state.
+ */
+static int ceph_d_init(struct dentry *dentry)
+{
+	struct ceph_dentry_info *di;
+	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dentry->d_sb);
+
+	di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
+	if (!di)
+		return -ENOMEM;          /* oh well */
+
+	di->dentry = dentry;
+	di->lease_session = NULL;
+	di->time = jiffies;
+	dentry->d_fsdata = di;
+	INIT_LIST_HEAD(&di->lease_list);
+
+	atomic64_inc(&mdsc->metric.total_dentries);
+
+	return 0;
+}
+
+/*
+ * for f_pos for readdir:
+ * - hash order:
+ *	(0xff << 52) | ((24 bits hash) << 28) |
+ *	(the nth entry has hash collision);
+ * - frag+name order;
+ *	((frag value) << 28) | (the nth entry in frag);
+ */
+#define OFFSET_BITS	28
+#define OFFSET_MASK	((1 << OFFSET_BITS) - 1)
+#define HASH_ORDER	(0xffull << (OFFSET_BITS + 24))
+loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
+{
+	loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
+	if (hash_order)
+		fpos |= HASH_ORDER;
+	return fpos;
+}
+
+static bool is_hash_order(loff_t p)
+{
+	return (p & HASH_ORDER) == HASH_ORDER;
+}
+
+static unsigned fpos_frag(loff_t p)
+{
+	return p >> OFFSET_BITS;
+}
+
+static unsigned fpos_hash(loff_t p)
+{
+	return ceph_frag_value(fpos_frag(p));
+}
+
+static unsigned fpos_off(loff_t p)
+{
+	return p & OFFSET_MASK;
+}
+
+static int fpos_cmp(loff_t l, loff_t r)
+{
+	int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
+	if (v)
+		return v;
+	return (int)(fpos_off(l) - fpos_off(r));
+}
+
+/*
+ * make note of the last dentry we read, so we can
+ * continue at the same lexicographical point,
+ * regardless of what dir changes take place on the
+ * server.
+ */
+static int note_last_dentry(struct ceph_dir_file_info *dfi, const char *name,
+		            int len, unsigned next_offset)
+{
+	char *buf = kmalloc(len+1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	kfree(dfi->last_name);
+	dfi->last_name = buf;
+	memcpy(dfi->last_name, name, len);
+	dfi->last_name[len] = 0;
+	dfi->next_offset = next_offset;
+	dout("note_last_dentry '%s'\n", dfi->last_name);
+	return 0;
+}
+
+
+static struct dentry *
+__dcache_find_get_entry(struct dentry *parent, u64 idx,
+			struct ceph_readdir_cache_control *cache_ctl)
+{
+	struct inode *dir = d_inode(parent);
+	struct dentry *dentry;
+	unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
+	loff_t ptr_pos = idx * sizeof(struct dentry *);
+	pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
+
+	if (ptr_pos >= i_size_read(dir))
+		return NULL;
+
+	if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
+		ceph_readdir_cache_release(cache_ctl);
+		cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
+		if (!cache_ctl->page) {
+			dout(" page %lu not found\n", ptr_pgoff);
+			return ERR_PTR(-EAGAIN);
+		}
+		/* reading/filling the cache are serialized by
+		   i_rwsem, no need to use page lock */
+		unlock_page(cache_ctl->page);
+		cache_ctl->dentries = kmap(cache_ctl->page);
+	}
+
+	cache_ctl->index = idx & idx_mask;
+
+	rcu_read_lock();
+	spin_lock(&parent->d_lock);
+	/* check i_size again here, because empty directory can be
+	 * marked as complete while not holding the i_rwsem. */
+	if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
+		dentry = cache_ctl->dentries[cache_ctl->index];
+	else
+		dentry = NULL;
+	spin_unlock(&parent->d_lock);
+	if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
+		dentry = NULL;
+	rcu_read_unlock();
+	return dentry ? : ERR_PTR(-EAGAIN);
+}
+
+/*
+ * When possible, we try to satisfy a readdir by peeking at the
+ * dcache.  We make this work by carefully ordering dentries on
+ * d_child when we initially get results back from the MDS, and
+ * falling back to a "normal" sync readdir if any dentries in the dir
+ * are dropped.
+ *
+ * Complete dir indicates that we have all dentries in the dir.  It is
+ * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
+ * the MDS if/when the directory is modified).
+ */
+static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
+			    int shared_gen)
+{
+	struct ceph_dir_file_info *dfi = file->private_data;
+	struct dentry *parent = file->f_path.dentry;
+	struct inode *dir = d_inode(parent);
+	struct dentry *dentry, *last = NULL;
+	struct ceph_dentry_info *di;
+	struct ceph_readdir_cache_control cache_ctl = {};
+	u64 idx = 0;
+	int err = 0;
+
+	dout("__dcache_readdir %p v%u at %llx\n", dir, (unsigned)shared_gen, ctx->pos);
+
+	/* search start position */
+	if (ctx->pos > 2) {
+		u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
+		while (count > 0) {
+			u64 step = count >> 1;
+			dentry = __dcache_find_get_entry(parent, idx + step,
+							 &cache_ctl);
+			if (!dentry) {
+				/* use linar search */
+				idx = 0;
+				break;
+			}
+			if (IS_ERR(dentry)) {
+				err = PTR_ERR(dentry);
+				goto out;
+			}
+			di = ceph_dentry(dentry);
+			spin_lock(&dentry->d_lock);
+			if (fpos_cmp(di->offset, ctx->pos) < 0) {
+				idx += step + 1;
+				count -= step + 1;
+			} else {
+				count = step;
+			}
+			spin_unlock(&dentry->d_lock);
+			dput(dentry);
+		}
+
+		dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
+	}
+
+
+	for (;;) {
+		bool emit_dentry = false;
+		dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
+		if (!dentry) {
+			dfi->file_info.flags |= CEPH_F_ATEND;
+			err = 0;
+			break;
+		}
+		if (IS_ERR(dentry)) {
+			err = PTR_ERR(dentry);
+			goto out;
+		}
+
+		spin_lock(&dentry->d_lock);
+		di = ceph_dentry(dentry);
+		if (d_unhashed(dentry) ||
+		    d_really_is_negative(dentry) ||
+		    di->lease_shared_gen != shared_gen) {
+			spin_unlock(&dentry->d_lock);
+			dput(dentry);
+			err = -EAGAIN;
+			goto out;
+		}
+		if (fpos_cmp(ctx->pos, di->offset) <= 0) {
+			__ceph_dentry_dir_lease_touch(di);
+			emit_dentry = true;
+		}
+		spin_unlock(&dentry->d_lock);
+
+		if (emit_dentry) {
+			dout(" %llx dentry %p %pd %p\n", di->offset,
+			     dentry, dentry, d_inode(dentry));
+			ctx->pos = di->offset;
+			if (!dir_emit(ctx, dentry->d_name.name,
+				      dentry->d_name.len, ceph_present_inode(d_inode(dentry)),
+				      d_inode(dentry)->i_mode >> 12)) {
+				dput(dentry);
+				err = 0;
+				break;
+			}
+			ctx->pos++;
+
+			if (last)
+				dput(last);
+			last = dentry;
+		} else {
+			dput(dentry);
+		}
+	}
+out:
+	ceph_readdir_cache_release(&cache_ctl);
+	if (last) {
+		int ret;
+		di = ceph_dentry(last);
+		ret = note_last_dentry(dfi, last->d_name.name, last->d_name.len,
+				       fpos_off(di->offset) + 1);
+		if (ret < 0)
+			err = ret;
+		dput(last);
+		/* last_name no longer match cache index */
+		if (dfi->readdir_cache_idx >= 0) {
+			dfi->readdir_cache_idx = -1;
+			dfi->dir_release_count = 0;
+		}
+	}
+	return err;
+}
+
+static bool need_send_readdir(struct ceph_dir_file_info *dfi, loff_t pos)
+{
+	if (!dfi->last_readdir)
+		return true;
+	if (is_hash_order(pos))
+		return !ceph_frag_contains_value(dfi->frag, fpos_hash(pos));
+	else
+		return dfi->frag != fpos_frag(pos);
+}
+
+static int ceph_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct ceph_dir_file_info *dfi = file->private_data;
+	struct inode *inode = file_inode(file);
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+	struct ceph_mds_client *mdsc = fsc->mdsc;
+	int i;
+	int err;
+	unsigned frag = -1;
+	struct ceph_mds_reply_info_parsed *rinfo;
+
+	dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
+	if (dfi->file_info.flags & CEPH_F_ATEND)
+		return 0;
+
+	/* always start with . and .. */
+	if (ctx->pos == 0) {
+		dout("readdir off 0 -> '.'\n");
+		if (!dir_emit(ctx, ".", 1, ceph_present_inode(inode),
+			    inode->i_mode >> 12))
+			return 0;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		u64 ino;
+		struct dentry *dentry = file->f_path.dentry;
+
+		spin_lock(&dentry->d_lock);
+		ino = ceph_present_inode(dentry->d_parent->d_inode);
+		spin_unlock(&dentry->d_lock);
+
+		dout("readdir off 1 -> '..'\n");
+		if (!dir_emit(ctx, "..", 2, ino, inode->i_mode >> 12))
+			return 0;
+		ctx->pos = 2;
+	}
+
+	spin_lock(&ci->i_ceph_lock);
+	/* request Fx cap. if have Fx, we don't need to release Fs cap
+	 * for later create/unlink. */
+	__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_WR);
+	/* can we use the dcache? */
+	if (ceph_test_mount_opt(fsc, DCACHE) &&
+	    !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
+	    ceph_snap(inode) != CEPH_SNAPDIR &&
+	    __ceph_dir_is_complete_ordered(ci) &&
+	    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
+		int shared_gen = atomic_read(&ci->i_shared_gen);
+
+		spin_unlock(&ci->i_ceph_lock);
+		err = __dcache_readdir(file, ctx, shared_gen);
+		if (err != -EAGAIN)
+			return err;
+	} else {
+		spin_unlock(&ci->i_ceph_lock);
+	}
+
+	/* proceed with a normal readdir */
+more:
+	/* do we have the correct frag content buffered? */
+	if (need_send_readdir(dfi, ctx->pos)) {
+		struct ceph_mds_request *req;
+		int op = ceph_snap(inode) == CEPH_SNAPDIR ?
+			CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
+
+		/* discard old result, if any */
+		if (dfi->last_readdir) {
+			ceph_mdsc_put_request(dfi->last_readdir);
+			dfi->last_readdir = NULL;
+		}
+
+		if (is_hash_order(ctx->pos)) {
+			/* fragtree isn't always accurate. choose frag
+			 * based on previous reply when possible. */
+			if (frag == (unsigned)-1)
+				frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
+							NULL, NULL);
+		} else {
+			frag = fpos_frag(ctx->pos);
+		}
+
+		dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
+		     ceph_vinop(inode), frag, dfi->last_name);
+		req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
+		if (IS_ERR(req))
+			return PTR_ERR(req);
+		err = ceph_alloc_readdir_reply_buffer(req, inode);
+		if (err) {
+			ceph_mdsc_put_request(req);
+			return err;
+		}
+		/* hints to request -> mds selection code */
+		req->r_direct_mode = USE_AUTH_MDS;
+		if (op == CEPH_MDS_OP_READDIR) {
+			req->r_direct_hash = ceph_frag_value(frag);
+			__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
+			req->r_inode_drop = CEPH_CAP_FILE_EXCL;
+		}
+		if (dfi->last_name) {
+			req->r_path2 = kstrdup(dfi->last_name, GFP_KERNEL);
+			if (!req->r_path2) {
+				ceph_mdsc_put_request(req);
+				return -ENOMEM;
+			}
+		} else if (is_hash_order(ctx->pos)) {
+			req->r_args.readdir.offset_hash =
+				cpu_to_le32(fpos_hash(ctx->pos));
+		}
+
+		req->r_dir_release_cnt = dfi->dir_release_count;
+		req->r_dir_ordered_cnt = dfi->dir_ordered_count;
+		req->r_readdir_cache_idx = dfi->readdir_cache_idx;
+		req->r_readdir_offset = dfi->next_offset;
+		req->r_args.readdir.frag = cpu_to_le32(frag);
+		req->r_args.readdir.flags =
+				cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
+
+		req->r_inode = inode;
+		ihold(inode);
+		req->r_dentry = dget(file->f_path.dentry);
+		err = ceph_mdsc_do_request(mdsc, NULL, req);
+		if (err < 0) {
+			ceph_mdsc_put_request(req);
+			return err;
+		}
+		dout("readdir got and parsed readdir result=%d on "
+		     "frag %x, end=%d, complete=%d, hash_order=%d\n",
+		     err, frag,
+		     (int)req->r_reply_info.dir_end,
+		     (int)req->r_reply_info.dir_complete,
+		     (int)req->r_reply_info.hash_order);
+
+		rinfo = &req->r_reply_info;
+		if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
+			frag = le32_to_cpu(rinfo->dir_dir->frag);
+			if (!rinfo->hash_order) {
+				dfi->next_offset = req->r_readdir_offset;
+				/* adjust ctx->pos to beginning of frag */
+				ctx->pos = ceph_make_fpos(frag,
+							  dfi->next_offset,
+							  false);
+			}
+		}
+
+		dfi->frag = frag;
+		dfi->last_readdir = req;
+
+		if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
+			dfi->readdir_cache_idx = req->r_readdir_cache_idx;
+			if (dfi->readdir_cache_idx < 0) {
+				/* preclude from marking dir ordered */
+				dfi->dir_ordered_count = 0;
+			} else if (ceph_frag_is_leftmost(frag) &&
+				   dfi->next_offset == 2) {
+				/* note dir version at start of readdir so
+				 * we can tell if any dentries get dropped */
+				dfi->dir_release_count = req->r_dir_release_cnt;
+				dfi->dir_ordered_count = req->r_dir_ordered_cnt;
+			}
+		} else {
+			dout("readdir !did_prepopulate\n");
+			/* disable readdir cache */
+			dfi->readdir_cache_idx = -1;
+			/* preclude from marking dir complete */
+			dfi->dir_release_count = 0;
+		}
+
+		/* note next offset and last dentry name */
+		if (rinfo->dir_nr > 0) {
+			struct ceph_mds_reply_dir_entry *rde =
+					rinfo->dir_entries + (rinfo->dir_nr-1);
+			unsigned next_offset = req->r_reply_info.dir_end ?
+					2 : (fpos_off(rde->offset) + 1);
+			err = note_last_dentry(dfi, rde->name, rde->name_len,
+					       next_offset);
+			if (err) {
+				ceph_mdsc_put_request(dfi->last_readdir);
+				dfi->last_readdir = NULL;
+				return err;
+			}
+		} else if (req->r_reply_info.dir_end) {
+			dfi->next_offset = 2;
+			/* keep last name */
+		}
+	}
+
+	rinfo = &dfi->last_readdir->r_reply_info;
+	dout("readdir frag %x num %d pos %llx chunk first %llx\n",
+	     dfi->frag, rinfo->dir_nr, ctx->pos,
+	     rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
+
+	i = 0;
+	/* search start position */
+	if (rinfo->dir_nr > 0) {
+		int step, nr = rinfo->dir_nr;
+		while (nr > 0) {
+			step = nr >> 1;
+			if (rinfo->dir_entries[i + step].offset < ctx->pos) {
+				i +=  step + 1;
+				nr -= step + 1;
+			} else {
+				nr = step;
+			}
+		}
+	}
+	for (; i < rinfo->dir_nr; i++) {
+		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
+
+		BUG_ON(rde->offset < ctx->pos);
+
+		ctx->pos = rde->offset;
+		dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
+		     i, rinfo->dir_nr, ctx->pos,
+		     rde->name_len, rde->name, &rde->inode.in);
+
+		BUG_ON(!rde->inode.in);
+
+		if (!dir_emit(ctx, rde->name, rde->name_len,
+			      ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
+			      le32_to_cpu(rde->inode.in->mode) >> 12)) {
+			/*
+			 * NOTE: Here no need to put the 'dfi->last_readdir',
+			 * because when dir_emit stops us it's most likely
+			 * doesn't have enough memory, etc. So for next readdir
+			 * it will continue.
+			 */
+			dout("filldir stopping us...\n");
+			return 0;
+		}
+		ctx->pos++;
+	}
+
+	ceph_mdsc_put_request(dfi->last_readdir);
+	dfi->last_readdir = NULL;
+
+	if (dfi->next_offset > 2) {
+		frag = dfi->frag;
+		goto more;
+	}
+
+	/* more frags? */
+	if (!ceph_frag_is_rightmost(dfi->frag)) {
+		frag = ceph_frag_next(dfi->frag);
+		if (is_hash_order(ctx->pos)) {
+			loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
+							dfi->next_offset, true);
+			if (new_pos > ctx->pos)
+				ctx->pos = new_pos;
+			/* keep last_name */
+		} else {
+			ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
+							false);
+			kfree(dfi->last_name);
+			dfi->last_name = NULL;
+		}
+		dout("readdir next frag is %x\n", frag);
+		goto more;
+	}
+	dfi->file_info.flags |= CEPH_F_ATEND;
+
+	/*
+	 * if dir_release_count still matches the dir, no dentries
+	 * were released during the whole readdir, and we should have
+	 * the complete dir contents in our cache.
+	 */
+	if (atomic64_read(&ci->i_release_count) ==
+					dfi->dir_release_count) {
+		spin_lock(&ci->i_ceph_lock);
+		if (dfi->dir_ordered_count ==
+				atomic64_read(&ci->i_ordered_count)) {
+			dout(" marking %p complete and ordered\n", inode);
+			/* use i_size to track number of entries in
+			 * readdir cache */
+			BUG_ON(dfi->readdir_cache_idx < 0);
+			i_size_write(inode, dfi->readdir_cache_idx *
+				     sizeof(struct dentry*));
+		} else {
+			dout(" marking %p complete\n", inode);
+		}
+		__ceph_dir_set_complete(ci, dfi->dir_release_count,
+					dfi->dir_ordered_count);
+		spin_unlock(&ci->i_ceph_lock);
+	}
+
+	dout("readdir %p file %p done.\n", inode, file);
+	return 0;
+}
+
+static void reset_readdir(struct ceph_dir_file_info *dfi)
+{
+	if (dfi->last_readdir) {
+		ceph_mdsc_put_request(dfi->last_readdir);
+		dfi->last_readdir = NULL;
+	}
+	kfree(dfi->last_name);
+	dfi->last_name = NULL;
+	dfi->dir_release_count = 0;
+	dfi->readdir_cache_idx = -1;
+	dfi->next_offset = 2;  /* compensate for . and .. */
+	dfi->file_info.flags &= ~CEPH_F_ATEND;
+}
+
+/*
+ * discard buffered readdir content on seekdir(0), or seek to new frag,
+ * or seek prior to current chunk
+ */
+static bool need_reset_readdir(struct ceph_dir_file_info *dfi, loff_t new_pos)
+{
+	struct ceph_mds_reply_info_parsed *rinfo;
+	loff_t chunk_offset;
+	if (new_pos == 0)
+		return true;
+	if (is_hash_order(new_pos)) {
+		/* no need to reset last_name for a forward seek when
+		 * dentries are sotred in hash order */
+	} else if (dfi->frag != fpos_frag(new_pos)) {
+		return true;
+	}
+	rinfo = dfi->last_readdir ? &dfi->last_readdir->r_reply_info : NULL;
+	if (!rinfo || !rinfo->dir_nr)
+		return true;
+	chunk_offset = rinfo->dir_entries[0].offset;
+	return new_pos < chunk_offset ||
+	       is_hash_order(new_pos) != is_hash_order(chunk_offset);
+}
+
+static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct ceph_dir_file_info *dfi = file->private_data;
+	struct inode *inode = file->f_mapping->host;
+	loff_t retval;
+
+	inode_lock(inode);
+	retval = -EINVAL;
+	switch (whence) {
+	case SEEK_CUR:
+		offset += file->f_pos;
+		break;
+	case SEEK_SET:
+		break;
+	case SEEK_END:
+		retval = -EOPNOTSUPP;
+		goto out;
+	default:
+		goto out;
+	}
+
+	if (offset >= 0) {
+		if (need_reset_readdir(dfi, offset)) {
+			dout("dir_llseek dropping %p content\n", file);
+			reset_readdir(dfi);
+		} else if (is_hash_order(offset) && offset > file->f_pos) {
+			/* for hash offset, we don't know if a forward seek
+			 * is within same frag */
+			dfi->dir_release_count = 0;
+			dfi->readdir_cache_idx = -1;
+		}
+
+		if (offset != file->f_pos) {
+			file->f_pos = offset;
+			file->f_version = 0;
+			dfi->file_info.flags &= ~CEPH_F_ATEND;
+		}
+		retval = offset;
+	}
+out:
+	inode_unlock(inode);
+	return retval;
+}
+
+/*
+ * Handle lookups for the hidden .snap directory.
+ */
+struct dentry *ceph_handle_snapdir(struct ceph_mds_request *req,
+				   struct dentry *dentry)
+{
+	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
+	struct inode *parent = d_inode(dentry->d_parent); /* we hold i_rwsem */
+
+	/* .snap dir? */
+	if (ceph_snap(parent) == CEPH_NOSNAP &&
+	    strcmp(dentry->d_name.name, fsc->mount_options->snapdir_name) == 0) {
+		struct dentry *res;
+		struct inode *inode = ceph_get_snapdir(parent);
+
+		res = d_splice_alias(inode, dentry);
+		dout("ENOENT on snapdir %p '%pd', linking to snapdir %p. Spliced dentry %p\n",
+		     dentry, dentry, inode, res);
+		if (res)
+			dentry = res;
+	}
+	return dentry;
+}
+
+/*
+ * Figure out final result of a lookup/open request.
+ *
+ * Mainly, make sure we return the final req->r_dentry (if it already
+ * existed) in place of the original VFS-provided dentry when they
+ * differ.
+ *
+ * Gracefully handle the case where the MDS replies with -ENOENT and
+ * no trace (which it may do, at its discretion, e.g., if it doesn't
+ * care to issue a lease on the negative dentry).
+ */
+struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
+				  struct dentry *dentry, int err)
+{
+	if (err == -ENOENT) {
+		/* no trace? */
+		err = 0;
+		if (!req->r_reply_info.head->is_dentry) {
+			dout("ENOENT and no trace, dentry %p inode %p\n",
+			     dentry, d_inode(dentry));
+			if (d_really_is_positive(dentry)) {
+				d_drop(dentry);
+				err = -ENOENT;
+			} else {
+				d_add(dentry, NULL);
+			}
+		}
+	}
+	if (err)
+		dentry = ERR_PTR(err);
+	else if (dentry != req->r_dentry)
+		dentry = dget(req->r_dentry);   /* we got spliced */
+	else
+		dentry = NULL;
+	return dentry;
+}
+
+static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
+{
+	return ceph_ino(inode) == CEPH_INO_ROOT &&
+		strncmp(dentry->d_name.name, ".ceph", 5) == 0;
+}
+
+/*
+ * Look up a single dir entry.  If there is a lookup intent, inform
+ * the MDS so that it gets our 'caps wanted' value in a single op.
+ */
+static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
+				  unsigned int flags)
+{
+	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
+	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
+	struct ceph_mds_request *req;
+	int op;
+	int mask;
+	int err;
+
+	dout("lookup %p dentry %p '%pd'\n",
+	     dir, dentry, dentry);
+
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	/* can we conclude ENOENT locally? */
+	if (d_really_is_negative(dentry)) {
+		struct ceph_inode_info *ci = ceph_inode(dir);
+		struct ceph_dentry_info *di = ceph_dentry(dentry);
+
+		spin_lock(&ci->i_ceph_lock);
+		dout(" dir %p flags are 0x%lx\n", dir, ci->i_ceph_flags);
+		if (strncmp(dentry->d_name.name,
+			    fsc->mount_options->snapdir_name,
+			    dentry->d_name.len) &&
+		    !is_root_ceph_dentry(dir, dentry) &&
+		    ceph_test_mount_opt(fsc, DCACHE) &&
+		    __ceph_dir_is_complete(ci) &&
+		    __ceph_caps_issued_mask_metric(ci, CEPH_CAP_FILE_SHARED, 1)) {
+			__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
+			spin_unlock(&ci->i_ceph_lock);
+			dout(" dir %p complete, -ENOENT\n", dir);
+			d_add(dentry, NULL);
+			di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
+			return NULL;
+		}
+		spin_unlock(&ci->i_ceph_lock);
+	}
+
+	op = ceph_snap(dir) == CEPH_SNAPDIR ?
+		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
+	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
+	if (IS_ERR(req))
+		return ERR_CAST(req);
+	req->r_dentry = dget(dentry);
+	req->r_num_caps = 2;
+
+	mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
+	if (ceph_security_xattr_wanted(dir))
+		mask |= CEPH_CAP_XATTR_SHARED;
+	req->r_args.getattr.mask = cpu_to_le32(mask);
+
+	ihold(dir);
+	req->r_parent = dir;
+	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+	err = ceph_mdsc_do_request(mdsc, NULL, req);
+	if (err == -ENOENT) {
+		struct dentry *res;
+
+		res = ceph_handle_snapdir(req, dentry);
+		if (IS_ERR(res)) {
+			err = PTR_ERR(res);
+		} else {
+			dentry = res;
+			err = 0;
+		}
+	}
+	dentry = ceph_finish_lookup(req, dentry, err);
+	ceph_mdsc_put_request(req);  /* will dput(dentry) */
+	dout("lookup result=%p\n", dentry);
+	return dentry;
+}
+
+/*
+ * If we do a create but get no trace back from the MDS, follow up with
+ * a lookup (the VFS expects us to link up the provided dentry).
+ */
+int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
+{
+	struct dentry *result = ceph_lookup(dir, dentry, 0);
+
+	if (result && !IS_ERR(result)) {
+		/*
+		 * We created the item, then did a lookup, and found
+		 * it was already linked to another inode we already
+		 * had in our cache (and thus got spliced). To not
+		 * confuse VFS (especially when inode is a directory),
+		 * we don't link our dentry to that inode, return an
+		 * error instead.
+		 *
+		 * This event should be rare and it happens only when
+		 * we talk to old MDS. Recent MDS does not send traceless
+		 * reply for request that creates new inode.
+		 */
+		d_drop(result);
+		return -ESTALE;
+	}
+	return PTR_ERR(result);
+}
+
+static int ceph_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+		      struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
+	struct ceph_mds_request *req;
+	struct ceph_acl_sec_ctx as_ctx = {};
+	int err;
+
+	if (ceph_snap(dir) != CEPH_NOSNAP)
+		return -EROFS;
+
+	err = ceph_wait_on_conflict_unlink(dentry);
+	if (err)
+		return err;
+
+	if (ceph_quota_is_max_files_exceeded(dir)) {
+		err = -EDQUOT;
+		goto out;
+	}
+
+	err = ceph_pre_init_acls(dir, &mode, &as_ctx);
+	if (err < 0)
+		goto out;
+	err = ceph_security_init_secctx(dentry, mode, &as_ctx);
+	if (err < 0)
+		goto out;
+
+	dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
+	     dir, dentry, mode, rdev);
+	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		goto out;
+	}
+	req->r_dentry = dget(dentry);
+	req->r_num_caps = 2;
+	req->r_parent = dir;
+	ihold(dir);
+	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+	req->r_args.mknod.mode = cpu_to_le32(mode);
+	req->r_args.mknod.rdev = cpu_to_le32(rdev);
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
+	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+	if (as_ctx.pagelist) {
+		req->r_pagelist = as_ctx.pagelist;
+		as_ctx.pagelist = NULL;
+	}
+	err = ceph_mdsc_do_request(mdsc, dir, req);
+	if (!err && !req->r_reply_info.head->is_dentry)
+		err = ceph_handle_notrace_create(dir, dentry);
+	ceph_mdsc_put_request(req);
+out:
+	if (!err)
+		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
+	else
+		d_drop(dentry);
+	ceph_release_acl_sec_ctx(&as_ctx);
+	return err;
+}
+
+static int ceph_create(struct user_namespace *mnt_userns, struct inode *dir,
+		       struct dentry *dentry, umode_t mode, bool excl)
+{
+	return ceph_mknod(mnt_userns, dir, dentry, mode, 0);
+}
+
+static int ceph_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+			struct dentry *dentry, const char *dest)
+{
+	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
+	struct ceph_mds_request *req;
+	struct ceph_acl_sec_ctx as_ctx = {};
+	int err;
+
+	if (ceph_snap(dir) != CEPH_NOSNAP)
+		return -EROFS;
+
+	err = ceph_wait_on_conflict_unlink(dentry);
+	if (err)
+		return err;
+
+	if (ceph_quota_is_max_files_exceeded(dir)) {
+		err = -EDQUOT;
+		goto out;
+	}
+
+	err = ceph_security_init_secctx(dentry, S_IFLNK | 0777, &as_ctx);
+	if (err < 0)
+		goto out;
+
+	dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
+	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		goto out;
+	}
+	req->r_path2 = kstrdup(dest, GFP_KERNEL);
+	if (!req->r_path2) {
+		err = -ENOMEM;
+		ceph_mdsc_put_request(req);
+		goto out;
+	}
+	req->r_parent = dir;
+	ihold(dir);
+
+	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+	req->r_dentry = dget(dentry);
+	req->r_num_caps = 2;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
+	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+	if (as_ctx.pagelist) {
+		req->r_pagelist = as_ctx.pagelist;
+		as_ctx.pagelist = NULL;
+	}
+	err = ceph_mdsc_do_request(mdsc, dir, req);
+	if (!err && !req->r_reply_info.head->is_dentry)
+		err = ceph_handle_notrace_create(dir, dentry);
+	ceph_mdsc_put_request(req);
+out:
+	if (err)
+		d_drop(dentry);
+	ceph_release_acl_sec_ctx(&as_ctx);
+	return err;
+}
+
+static int ceph_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+		      struct dentry *dentry, umode_t mode)
+{
+	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
+	struct ceph_mds_request *req;
+	struct ceph_acl_sec_ctx as_ctx = {};
+	int err;
+	int op;
+
+	err = ceph_wait_on_conflict_unlink(dentry);
+	if (err)
+		return err;
+
+	if (ceph_snap(dir) == CEPH_SNAPDIR) {
+		/* mkdir .snap/foo is a MKSNAP */
+		op = CEPH_MDS_OP_MKSNAP;
+		dout("mksnap dir %p snap '%pd' dn %p\n", dir,
+		     dentry, dentry);
+	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
+		dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
+		op = CEPH_MDS_OP_MKDIR;
+	} else {
+		err = -EROFS;
+		goto out;
+	}
+
+	if (op == CEPH_MDS_OP_MKDIR &&
+	    ceph_quota_is_max_files_exceeded(dir)) {
+		err = -EDQUOT;
+		goto out;
+	}
+
+	mode |= S_IFDIR;
+	err = ceph_pre_init_acls(dir, &mode, &as_ctx);
+	if (err < 0)
+		goto out;
+	err = ceph_security_init_secctx(dentry, mode, &as_ctx);
+	if (err < 0)
+		goto out;
+
+	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		goto out;
+	}
+
+	req->r_dentry = dget(dentry);
+	req->r_num_caps = 2;
+	req->r_parent = dir;
+	ihold(dir);
+	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+	req->r_args.mkdir.mode = cpu_to_le32(mode);
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
+	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+	if (as_ctx.pagelist) {
+		req->r_pagelist = as_ctx.pagelist;
+		as_ctx.pagelist = NULL;
+	}
+	err = ceph_mdsc_do_request(mdsc, dir, req);
+	if (!err &&
+	    !req->r_reply_info.head->is_target &&
+	    !req->r_reply_info.head->is_dentry)
+		err = ceph_handle_notrace_create(dir, dentry);
+	ceph_mdsc_put_request(req);
+out:
+	if (!err)
+		ceph_init_inode_acls(d_inode(dentry), &as_ctx);
+	else
+		d_drop(dentry);
+	ceph_release_acl_sec_ctx(&as_ctx);
+	return err;
+}
+
+static int ceph_link(struct dentry *old_dentry, struct inode *dir,
+		     struct dentry *dentry)
+{
+	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
+	struct ceph_mds_request *req;
+	int err;
+
+	err = ceph_wait_on_conflict_unlink(dentry);
+	if (err)
+		return err;
+
+	if (ceph_snap(dir) != CEPH_NOSNAP)
+		return -EROFS;
+
+	dout("link in dir %p old_dentry %p dentry %p\n", dir,
+	     old_dentry, dentry);
+	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
+	if (IS_ERR(req)) {
+		d_drop(dentry);
+		return PTR_ERR(req);
+	}
+	req->r_dentry = dget(dentry);
+	req->r_num_caps = 2;
+	req->r_old_dentry = dget(old_dentry);
+	req->r_parent = dir;
+	ihold(dir);
+	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+	/* release LINK_SHARED on source inode (mds will lock it) */
+	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
+	err = ceph_mdsc_do_request(mdsc, dir, req);
+	if (err) {
+		d_drop(dentry);
+	} else if (!req->r_reply_info.head->is_dentry) {
+		ihold(d_inode(old_dentry));
+		d_instantiate(dentry, d_inode(old_dentry));
+	}
+	ceph_mdsc_put_request(req);
+	return err;
+}
+
+static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
+				 struct ceph_mds_request *req)
+{
+	struct dentry *dentry = req->r_dentry;
+	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
+	struct ceph_dentry_info *di = ceph_dentry(dentry);
+	int result = req->r_err ? req->r_err :
+			le32_to_cpu(req->r_reply_info.head->result);
+
+	if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
+		pr_warn("%s dentry %p:%pd async unlink bit is not set\n",
+			__func__, dentry, dentry);
+
+	spin_lock(&fsc->async_unlink_conflict_lock);
+	hash_del_rcu(&di->hnode);
+	spin_unlock(&fsc->async_unlink_conflict_lock);
+
+	spin_lock(&dentry->d_lock);
+	di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
+	wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT);
+	spin_unlock(&dentry->d_lock);
+
+	synchronize_rcu();
+
+	if (result == -EJUKEBOX)
+		goto out;
+
+	/* If op failed, mark everyone involved for errors */
+	if (result) {
+		int pathlen = 0;
+		u64 base = 0;
+		char *path = ceph_mdsc_build_path(dentry, &pathlen,
+						  &base, 0);
+
+		/* mark error on parent + clear complete */
+		mapping_set_error(req->r_parent->i_mapping, result);
+		ceph_dir_clear_complete(req->r_parent);
+
+		/* drop the dentry -- we don't know its status */
+		if (!d_unhashed(dentry))
+			d_drop(dentry);
+
+		/* mark inode itself for an error (since metadata is bogus) */
+		mapping_set_error(req->r_old_inode->i_mapping, result);
+
+		pr_warn("async unlink failure path=(%llx)%s result=%d!\n",
+			base, IS_ERR(path) ? "<<bad>>" : path, result);
+		ceph_mdsc_free_path(path, pathlen);
+	}
+out:
+	iput(req->r_old_inode);
+	ceph_mdsc_release_dir_caps(req);
+}
+
+static int get_caps_for_async_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct ceph_inode_info *ci = ceph_inode(dir);
+	struct ceph_dentry_info *di;
+	int got = 0, want = CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_UNLINK;
+
+	spin_lock(&ci->i_ceph_lock);
+	if ((__ceph_caps_issued(ci, NULL) & want) == want) {
+		ceph_take_cap_refs(ci, want, false);
+		got = want;
+	}
+	spin_unlock(&ci->i_ceph_lock);
+
+	/* If we didn't get anything, return 0 */
+	if (!got)
+		return 0;
+
+        spin_lock(&dentry->d_lock);
+        di = ceph_dentry(dentry);
+	/*
+	 * - We are holding Fx, which implies Fs caps.
+	 * - Only support async unlink for primary linkage
+	 */
+	if (atomic_read(&ci->i_shared_gen) != di->lease_shared_gen ||
+	    !(di->flags & CEPH_DENTRY_PRIMARY_LINK))
+		want = 0;
+        spin_unlock(&dentry->d_lock);
+
+	/* Do we still want what we've got? */
+	if (want == got)
+		return got;
+
+	ceph_put_cap_refs(ci, got);
+	return 0;
+}
+
+/*
+ * rmdir and unlink are differ only by the metadata op code
+ */
+static int ceph_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
+	struct ceph_mds_client *mdsc = fsc->mdsc;
+	struct inode *inode = d_inode(dentry);
+	struct ceph_mds_request *req;
+	bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
+	int err = -EROFS;
+	int op;
+
+	if (ceph_snap(dir) == CEPH_SNAPDIR) {
+		/* rmdir .snap/foo is RMSNAP */
+		dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
+		op = CEPH_MDS_OP_RMSNAP;
+	} else if (ceph_snap(dir) == CEPH_NOSNAP) {
+		dout("unlink/rmdir dir %p dn %p inode %p\n",
+		     dir, dentry, inode);
+		op = d_is_dir(dentry) ?
+			CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
+	} else
+		goto out;
+retry:
+	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		goto out;
+	}
+	req->r_dentry = dget(dentry);
+	req->r_num_caps = 2;
+	req->r_parent = dir;
+	ihold(dir);
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+	req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
+
+	if (try_async && op == CEPH_MDS_OP_UNLINK &&
+	    (req->r_dir_caps = get_caps_for_async_unlink(dir, dentry))) {
+		struct ceph_dentry_info *di = ceph_dentry(dentry);
+
+		dout("async unlink on %llu/%.*s caps=%s", ceph_ino(dir),
+		     dentry->d_name.len, dentry->d_name.name,
+		     ceph_cap_string(req->r_dir_caps));
+		set_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags);
+		req->r_callback = ceph_async_unlink_cb;
+		req->r_old_inode = d_inode(dentry);
+		ihold(req->r_old_inode);
+
+		spin_lock(&dentry->d_lock);
+		di->flags |= CEPH_DENTRY_ASYNC_UNLINK;
+		spin_unlock(&dentry->d_lock);
+
+		spin_lock(&fsc->async_unlink_conflict_lock);
+		hash_add_rcu(fsc->async_unlink_conflict, &di->hnode,
+			     dentry->d_name.hash);
+		spin_unlock(&fsc->async_unlink_conflict_lock);
+
+		err = ceph_mdsc_submit_request(mdsc, dir, req);
+		if (!err) {
+			/*
+			 * We have enough caps, so we assume that the unlink
+			 * will succeed. Fix up the target inode and dcache.
+			 */
+			drop_nlink(inode);
+			d_delete(dentry);
+		} else {
+			spin_lock(&fsc->async_unlink_conflict_lock);
+			hash_del_rcu(&di->hnode);
+			spin_unlock(&fsc->async_unlink_conflict_lock);
+
+			spin_lock(&dentry->d_lock);
+			di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
+			spin_unlock(&dentry->d_lock);
+
+			if (err == -EJUKEBOX) {
+				try_async = false;
+				ceph_mdsc_put_request(req);
+				goto retry;
+			}
+		}
+	} else {
+		set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+		err = ceph_mdsc_do_request(mdsc, dir, req);
+		if (!err && !req->r_reply_info.head->is_dentry)
+			d_delete(dentry);
+	}
+
+	ceph_mdsc_put_request(req);
+out:
+	return err;
+}
+
+static int ceph_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+		       struct dentry *old_dentry, struct inode *new_dir,
+		       struct dentry *new_dentry, unsigned int flags)
+{
+	struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(old_dir->i_sb);
+	struct ceph_mds_request *req;
+	int op = CEPH_MDS_OP_RENAME;
+	int err;
+
+	if (flags)
+		return -EINVAL;
+
+	if (ceph_snap(old_dir) != ceph_snap(new_dir))
+		return -EXDEV;
+	if (ceph_snap(old_dir) != CEPH_NOSNAP) {
+		if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
+			op = CEPH_MDS_OP_RENAMESNAP;
+		else
+			return -EROFS;
+	}
+	/* don't allow cross-quota renames */
+	if ((old_dir != new_dir) &&
+	    (!ceph_quota_is_same_realm(old_dir, new_dir)))
+		return -EXDEV;
+
+	err = ceph_wait_on_conflict_unlink(new_dentry);
+	if (err)
+		return err;
+
+	dout("rename dir %p dentry %p to dir %p dentry %p\n",
+	     old_dir, old_dentry, new_dir, new_dentry);
+	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+	ihold(old_dir);
+	req->r_dentry = dget(new_dentry);
+	req->r_num_caps = 2;
+	req->r_old_dentry = dget(old_dentry);
+	req->r_old_dentry_dir = old_dir;
+	req->r_parent = new_dir;
+	ihold(new_dir);
+	set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
+	req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
+	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+	/* release LINK_RDCACHE on source inode (mds will lock it) */
+	req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
+	if (d_really_is_positive(new_dentry)) {
+		req->r_inode_drop =
+			ceph_drop_caps_for_unlink(d_inode(new_dentry));
+	}
+	err = ceph_mdsc_do_request(mdsc, old_dir, req);
+	if (!err && !req->r_reply_info.head->is_dentry) {
+		/*
+		 * Normally d_move() is done by fill_trace (called by
+		 * do_request, above).  If there is no trace, we need
+		 * to do it here.
+		 */
+		d_move(old_dentry, new_dentry);
+	}
+	ceph_mdsc_put_request(req);
+	return err;
+}
+
+/*
+ * Move dentry to tail of mdsc->dentry_leases list when lease is updated.
+ * Leases at front of the list will expire first. (Assume all leases have
+ * similar duration)
+ *
+ * Called under dentry->d_lock.
+ */
+void __ceph_dentry_lease_touch(struct ceph_dentry_info *di)
+{
+	struct dentry *dn = di->dentry;
+	struct ceph_mds_client *mdsc;
+
+	dout("dentry_lease_touch %p %p '%pd'\n", di, dn, dn);
+
+	di->flags |= CEPH_DENTRY_LEASE_LIST;
+	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
+		di->flags |= CEPH_DENTRY_REFERENCED;
+		return;
+	}
+
+	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
+	spin_lock(&mdsc->dentry_list_lock);
+	list_move_tail(&di->lease_list, &mdsc->dentry_leases);
+	spin_unlock(&mdsc->dentry_list_lock);
+}
+
+static void __dentry_dir_lease_touch(struct ceph_mds_client* mdsc,
+				     struct ceph_dentry_info *di)
+{
+	di->flags &= ~(CEPH_DENTRY_LEASE_LIST | CEPH_DENTRY_REFERENCED);
+	di->lease_gen = 0;
+	di->time = jiffies;
+	list_move_tail(&di->lease_list, &mdsc->dentry_dir_leases);
+}
+
+/*
+ * When dir lease is used, add dentry to tail of mdsc->dentry_dir_leases
+ * list if it's not in the list, otherwise set 'referenced' flag.
+ *
+ * Called under dentry->d_lock.
+ */
+void __ceph_dentry_dir_lease_touch(struct ceph_dentry_info *di)
+{
+	struct dentry *dn = di->dentry;
+	struct ceph_mds_client *mdsc;
+
+	dout("dentry_dir_lease_touch %p %p '%pd' (offset 0x%llx)\n",
+	     di, dn, dn, di->offset);
+
+	if (!list_empty(&di->lease_list)) {
+		if (di->flags & CEPH_DENTRY_LEASE_LIST) {
+			/* don't remove dentry from dentry lease list
+			 * if its lease is valid */
+			if (__dentry_lease_is_valid(di))
+				return;
+		} else {
+			di->flags |= CEPH_DENTRY_REFERENCED;
+			return;
+		}
+	}
+
+	if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
+		di->flags |= CEPH_DENTRY_REFERENCED;
+		di->flags &= ~CEPH_DENTRY_LEASE_LIST;
+		return;
+	}
+
+	mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
+	spin_lock(&mdsc->dentry_list_lock);
+	__dentry_dir_lease_touch(mdsc, di),
+	spin_unlock(&mdsc->dentry_list_lock);
+}
+
+static void __dentry_lease_unlist(struct ceph_dentry_info *di)
+{
+	struct ceph_mds_client *mdsc;
+	if (di->flags & CEPH_DENTRY_SHRINK_LIST)
+		return;
+	if (list_empty(&di->lease_list))
+		return;
+
+	mdsc = ceph_sb_to_client(di->dentry->d_sb)->mdsc;
+	spin_lock(&mdsc->dentry_list_lock);
+	list_del_init(&di->lease_list);
+	spin_unlock(&mdsc->dentry_list_lock);
+}
+
+enum {
+	KEEP	= 0,
+	DELETE	= 1,
+	TOUCH	= 2,
+	STOP	= 4,
+};
+
+struct ceph_lease_walk_control {
+	bool dir_lease;
+	bool expire_dir_lease;
+	unsigned long nr_to_scan;
+	unsigned long dir_lease_ttl;
+};
+
+static unsigned long
+__dentry_leases_walk(struct ceph_mds_client *mdsc,
+		     struct ceph_lease_walk_control *lwc,
+		     int (*check)(struct dentry*, void*))
+{
+	struct ceph_dentry_info *di, *tmp;
+	struct dentry *dentry, *last = NULL;
+	struct list_head* list;
+        LIST_HEAD(dispose);
+	unsigned long freed = 0;
+	int ret = 0;
+
+	list = lwc->dir_lease ? &mdsc->dentry_dir_leases : &mdsc->dentry_leases;
+	spin_lock(&mdsc->dentry_list_lock);
+	list_for_each_entry_safe(di, tmp, list, lease_list) {
+		if (!lwc->nr_to_scan)
+			break;
+		--lwc->nr_to_scan;
+
+		dentry = di->dentry;
+		if (last == dentry)
+			break;
+
+		if (!spin_trylock(&dentry->d_lock))
+			continue;
+
+		if (__lockref_is_dead(&dentry->d_lockref)) {
+			list_del_init(&di->lease_list);
+			goto next;
+		}
+
+		ret = check(dentry, lwc);
+		if (ret & TOUCH) {
+			/* move it into tail of dir lease list */
+			__dentry_dir_lease_touch(mdsc, di);
+			if (!last)
+				last = dentry;
+		}
+		if (ret & DELETE) {
+			/* stale lease */
+			di->flags &= ~CEPH_DENTRY_REFERENCED;
+			if (dentry->d_lockref.count > 0) {
+				/* update_dentry_lease() will re-add
+				 * it to lease list, or
+				 * ceph_d_delete() will return 1 when
+				 * last reference is dropped */
+				list_del_init(&di->lease_list);
+			} else {
+				di->flags |= CEPH_DENTRY_SHRINK_LIST;
+				list_move_tail(&di->lease_list, &dispose);
+				dget_dlock(dentry);
+			}
+		}
+next:
+		spin_unlock(&dentry->d_lock);
+		if (ret & STOP)
+			break;
+	}
+	spin_unlock(&mdsc->dentry_list_lock);
+
+	while (!list_empty(&dispose)) {
+		di = list_first_entry(&dispose, struct ceph_dentry_info,
+				      lease_list);
+		dentry = di->dentry;
+		spin_lock(&dentry->d_lock);
+
+		list_del_init(&di->lease_list);
+		di->flags &= ~CEPH_DENTRY_SHRINK_LIST;
+		if (di->flags & CEPH_DENTRY_REFERENCED) {
+			spin_lock(&mdsc->dentry_list_lock);
+			if (di->flags & CEPH_DENTRY_LEASE_LIST) {
+				list_add_tail(&di->lease_list,
+					      &mdsc->dentry_leases);
+			} else {
+				__dentry_dir_lease_touch(mdsc, di);
+			}
+			spin_unlock(&mdsc->dentry_list_lock);
+		} else {
+			freed++;
+		}
+
+		spin_unlock(&dentry->d_lock);
+		/* ceph_d_delete() does the trick */
+		dput(dentry);
+	}
+	return freed;
+}
+
+static int __dentry_lease_check(struct dentry *dentry, void *arg)
+{
+	struct ceph_dentry_info *di = ceph_dentry(dentry);
+	int ret;
+
+	if (__dentry_lease_is_valid(di))
+		return STOP;
+	ret = __dir_lease_try_check(dentry);
+	if (ret == -EBUSY)
+		return KEEP;
+	if (ret > 0)
+		return TOUCH;
+	return DELETE;
+}
+
+static int __dir_lease_check(struct dentry *dentry, void *arg)
+{
+	struct ceph_lease_walk_control *lwc = arg;
+	struct ceph_dentry_info *di = ceph_dentry(dentry);
+
+	int ret = __dir_lease_try_check(dentry);
+	if (ret == -EBUSY)
+		return KEEP;
+	if (ret > 0) {
+		if (time_before(jiffies, di->time + lwc->dir_lease_ttl))
+			return STOP;
+		/* Move dentry to tail of dir lease list if we don't want
+		 * to delete it. So dentries in the list are checked in a
+		 * round robin manner */
+		if (!lwc->expire_dir_lease)
+			return TOUCH;
+		if (dentry->d_lockref.count > 0 ||
+		    (di->flags & CEPH_DENTRY_REFERENCED))
+			return TOUCH;
+		/* invalidate dir lease */
+		di->lease_shared_gen = 0;
+	}
+	return DELETE;
+}
+
+int ceph_trim_dentries(struct ceph_mds_client *mdsc)
+{
+	struct ceph_lease_walk_control lwc;
+	unsigned long count;
+	unsigned long freed;
+
+	spin_lock(&mdsc->caps_list_lock);
+        if (mdsc->caps_use_max > 0 &&
+            mdsc->caps_use_count > mdsc->caps_use_max)
+		count = mdsc->caps_use_count - mdsc->caps_use_max;
+	else
+		count = 0;
+        spin_unlock(&mdsc->caps_list_lock);
+
+	lwc.dir_lease = false;
+	lwc.nr_to_scan  = CEPH_CAPS_PER_RELEASE * 2;
+	freed = __dentry_leases_walk(mdsc, &lwc, __dentry_lease_check);
+	if (!lwc.nr_to_scan) /* more invalid leases */
+		return -EAGAIN;
+
+	if (lwc.nr_to_scan < CEPH_CAPS_PER_RELEASE)
+		lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE;
+
+	lwc.dir_lease = true;
+	lwc.expire_dir_lease = freed < count;
+	lwc.dir_lease_ttl = mdsc->fsc->mount_options->caps_wanted_delay_max * HZ;
+	freed +=__dentry_leases_walk(mdsc, &lwc, __dir_lease_check);
+	if (!lwc.nr_to_scan) /* more to check */
+		return -EAGAIN;
+
+	return freed > 0 ? 1 : 0;
+}
+
+/*
+ * Ensure a dentry lease will no longer revalidate.
+ */
+void ceph_invalidate_dentry_lease(struct dentry *dentry)
+{
+	struct ceph_dentry_info *di = ceph_dentry(dentry);
+	spin_lock(&dentry->d_lock);
+	di->time = jiffies;
+	di->lease_shared_gen = 0;
+	di->flags &= ~CEPH_DENTRY_PRIMARY_LINK;
+	__dentry_lease_unlist(di);
+	spin_unlock(&dentry->d_lock);
+}
+
+/*
+ * Check if dentry lease is valid.  If not, delete the lease.  Try to
+ * renew if the least is more than half up.
+ */
+static bool __dentry_lease_is_valid(struct ceph_dentry_info *di)
+{
+	struct ceph_mds_session *session;
+
+	if (!di->lease_gen)
+		return false;
+
+	session = di->lease_session;
+	if (session) {
+		u32 gen;
+		unsigned long ttl;
+
+		gen = atomic_read(&session->s_cap_gen);
+		ttl = session->s_cap_ttl;
+
+		if (di->lease_gen == gen &&
+		    time_before(jiffies, ttl) &&
+		    time_before(jiffies, di->time))
+			return true;
+	}
+	di->lease_gen = 0;
+	return false;
+}
+
+static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags)
+{
+	struct ceph_dentry_info *di;
+	struct ceph_mds_session *session = NULL;
+	u32 seq = 0;
+	int valid = 0;
+
+	spin_lock(&dentry->d_lock);
+	di = ceph_dentry(dentry);
+	if (di && __dentry_lease_is_valid(di)) {
+		valid = 1;
+
+		if (di->lease_renew_after &&
+		    time_after(jiffies, di->lease_renew_after)) {
+			/*
+			 * We should renew. If we're in RCU walk mode
+			 * though, we can't do that so just return
+			 * -ECHILD.
+			 */
+			if (flags & LOOKUP_RCU) {
+				valid = -ECHILD;
+			} else {
+				session = ceph_get_mds_session(di->lease_session);
+				seq = di->lease_seq;
+				di->lease_renew_after = 0;
+				di->lease_renew_from = jiffies;
+			}
+		}
+	}
+	spin_unlock(&dentry->d_lock);
+
+	if (session) {
+		ceph_mdsc_lease_send_msg(session, dentry,
+					 CEPH_MDS_LEASE_RENEW, seq);
+		ceph_put_mds_session(session);
+	}
+	dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
+	return valid;
+}
+
+/*
+ * Called under dentry->d_lock.
+ */
+static int __dir_lease_try_check(const struct dentry *dentry)
+{
+	struct ceph_dentry_info *di = ceph_dentry(dentry);
+	struct inode *dir;
+	struct ceph_inode_info *ci;
+	int valid = 0;
+
+	if (!di->lease_shared_gen)
+		return 0;
+	if (IS_ROOT(dentry))
+		return 0;
+
+	dir = d_inode(dentry->d_parent);
+	ci = ceph_inode(dir);
+
+	if (spin_trylock(&ci->i_ceph_lock)) {
+		if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen &&
+		    __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 0))
+			valid = 1;
+		spin_unlock(&ci->i_ceph_lock);
+	} else {
+		valid = -EBUSY;
+	}
+
+	if (!valid)
+		di->lease_shared_gen = 0;
+	return valid;
+}
+
+/*
+ * Check if directory-wide content lease/cap is valid.
+ */
+static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry,
+			      struct ceph_mds_client *mdsc)
+{
+	struct ceph_inode_info *ci = ceph_inode(dir);
+	int valid;
+	int shared_gen;
+
+	spin_lock(&ci->i_ceph_lock);
+	valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
+	if (valid) {
+		__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
+		shared_gen = atomic_read(&ci->i_shared_gen);
+	}
+	spin_unlock(&ci->i_ceph_lock);
+	if (valid) {
+		struct ceph_dentry_info *di;
+		spin_lock(&dentry->d_lock);
+		di = ceph_dentry(dentry);
+		if (dir == d_inode(dentry->d_parent) &&
+		    di && di->lease_shared_gen == shared_gen)
+			__ceph_dentry_dir_lease_touch(di);
+		else
+			valid = 0;
+		spin_unlock(&dentry->d_lock);
+	}
+	dout("dir_lease_is_valid dir %p v%u dentry %p = %d\n",
+	     dir, (unsigned)atomic_read(&ci->i_shared_gen), dentry, valid);
+	return valid;
+}
+
+/*
+ * Check if cached dentry can be trusted.
+ */
+static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	int valid = 0;
+	struct dentry *parent;
+	struct inode *dir, *inode;
+	struct ceph_mds_client *mdsc;
+
+	if (flags & LOOKUP_RCU) {
+		parent = READ_ONCE(dentry->d_parent);
+		dir = d_inode_rcu(parent);
+		if (!dir)
+			return -ECHILD;
+		inode = d_inode_rcu(dentry);
+	} else {
+		parent = dget_parent(dentry);
+		dir = d_inode(parent);
+		inode = d_inode(dentry);
+	}
+
+	dout("d_revalidate %p '%pd' inode %p offset 0x%llx\n", dentry,
+	     dentry, inode, ceph_dentry(dentry)->offset);
+
+	mdsc = ceph_sb_to_client(dir->i_sb)->mdsc;
+
+	/* always trust cached snapped dentries, snapdir dentry */
+	if (ceph_snap(dir) != CEPH_NOSNAP) {
+		dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
+		     dentry, inode);
+		valid = 1;
+	} else if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
+		valid = 1;
+	} else {
+		valid = dentry_lease_is_valid(dentry, flags);
+		if (valid == -ECHILD)
+			return valid;
+		if (valid || dir_lease_is_valid(dir, dentry, mdsc)) {
+			if (inode)
+				valid = ceph_is_any_caps(inode);
+			else
+				valid = 1;
+		}
+	}
+
+	if (!valid) {
+		struct ceph_mds_request *req;
+		int op, err;
+		u32 mask;
+
+		if (flags & LOOKUP_RCU)
+			return -ECHILD;
+
+		percpu_counter_inc(&mdsc->metric.d_lease_mis);
+
+		op = ceph_snap(dir) == CEPH_SNAPDIR ?
+			CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
+		req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
+		if (!IS_ERR(req)) {
+			req->r_dentry = dget(dentry);
+			req->r_num_caps = 2;
+			req->r_parent = dir;
+			ihold(dir);
+
+			mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
+			if (ceph_security_xattr_wanted(dir))
+				mask |= CEPH_CAP_XATTR_SHARED;
+			req->r_args.getattr.mask = cpu_to_le32(mask);
+
+			err = ceph_mdsc_do_request(mdsc, NULL, req);
+			switch (err) {
+			case 0:
+				if (d_really_is_positive(dentry) &&
+				    d_inode(dentry) == req->r_target_inode)
+					valid = 1;
+				break;
+			case -ENOENT:
+				if (d_really_is_negative(dentry))
+					valid = 1;
+				fallthrough;
+			default:
+				break;
+			}
+			ceph_mdsc_put_request(req);
+			dout("d_revalidate %p lookup result=%d\n",
+			     dentry, err);
+		}
+	} else {
+		percpu_counter_inc(&mdsc->metric.d_lease_hit);
+	}
+
+	dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
+	if (!valid)
+		ceph_dir_clear_complete(dir);
+
+	if (!(flags & LOOKUP_RCU))
+		dput(parent);
+	return valid;
+}
+
+/*
+ * Delete unused dentry that doesn't have valid lease
+ *
+ * Called under dentry->d_lock.
+ */
+static int ceph_d_delete(const struct dentry *dentry)
+{
+	struct ceph_dentry_info *di;
+
+	/* won't release caps */
+	if (d_really_is_negative(dentry))
+		return 0;
+	if (ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
+		return 0;
+	/* vaild lease? */
+	di = ceph_dentry(dentry);
+	if (di) {
+		if (__dentry_lease_is_valid(di))
+			return 0;
+		if (__dir_lease_try_check(dentry))
+			return 0;
+	}
+	return 1;
+}
+
+/*
+ * Release our ceph_dentry_info.
+ */
+static void ceph_d_release(struct dentry *dentry)
+{
+	struct ceph_dentry_info *di = ceph_dentry(dentry);
+	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
+
+	dout("d_release %p\n", dentry);
+
+	atomic64_dec(&fsc->mdsc->metric.total_dentries);
+
+	spin_lock(&dentry->d_lock);
+	__dentry_lease_unlist(di);
+	dentry->d_fsdata = NULL;
+	spin_unlock(&dentry->d_lock);
+
+	ceph_put_mds_session(di->lease_session);
+	kmem_cache_free(ceph_dentry_cachep, di);
+}
+
+/*
+ * When the VFS prunes a dentry from the cache, we need to clear the
+ * complete flag on the parent directory.
+ *
+ * Called under dentry->d_lock.
+ */
+static void ceph_d_prune(struct dentry *dentry)
+{
+	struct ceph_inode_info *dir_ci;
+	struct ceph_dentry_info *di;
+
+	dout("ceph_d_prune %pd %p\n", dentry, dentry);
+
+	/* do we have a valid parent? */
+	if (IS_ROOT(dentry))
+		return;
+
+	/* we hold d_lock, so d_parent is stable */
+	dir_ci = ceph_inode(d_inode(dentry->d_parent));
+	if (dir_ci->i_vino.snap == CEPH_SNAPDIR)
+		return;
+
+	/* who calls d_delete() should also disable dcache readdir */
+	if (d_really_is_negative(dentry))
+		return;
+
+	/* d_fsdata does not get cleared until d_release */
+	if (!d_unhashed(dentry)) {
+		__ceph_dir_clear_complete(dir_ci);
+		return;
+	}
+
+	/* Disable dcache readdir just in case that someone called d_drop()
+	 * or d_invalidate(), but MDS didn't revoke CEPH_CAP_FILE_SHARED
+	 * properly (dcache readdir is still enabled) */
+	di = ceph_dentry(dentry);
+	if (di->offset > 0 &&
+	    di->lease_shared_gen == atomic_read(&dir_ci->i_shared_gen))
+		__ceph_dir_clear_ordered(dir_ci);
+}
+
+/*
+ * read() on a dir.  This weird interface hack only works if mounted
+ * with '-o dirstat'.
+ */
+static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
+			     loff_t *ppos)
+{
+	struct ceph_dir_file_info *dfi = file->private_data;
+	struct inode *inode = file_inode(file);
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	int left;
+	const int bufsize = 1024;
+
+	if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
+		return -EISDIR;
+
+	if (!dfi->dir_info) {
+		dfi->dir_info = kmalloc(bufsize, GFP_KERNEL);
+		if (!dfi->dir_info)
+			return -ENOMEM;
+		dfi->dir_info_len =
+			snprintf(dfi->dir_info, bufsize,
+				"entries:   %20lld\n"
+				" files:    %20lld\n"
+				" subdirs:  %20lld\n"
+				"rentries:  %20lld\n"
+				" rfiles:   %20lld\n"
+				" rsubdirs: %20lld\n"
+				"rbytes:    %20lld\n"
+				"rctime:    %10lld.%09ld\n",
+				ci->i_files + ci->i_subdirs,
+				ci->i_files,
+				ci->i_subdirs,
+				ci->i_rfiles + ci->i_rsubdirs,
+				ci->i_rfiles,
+				ci->i_rsubdirs,
+				ci->i_rbytes,
+				ci->i_rctime.tv_sec,
+				ci->i_rctime.tv_nsec);
+	}
+
+	if (*ppos >= dfi->dir_info_len)
+		return 0;
+	size = min_t(unsigned, size, dfi->dir_info_len-*ppos);
+	left = copy_to_user(buf, dfi->dir_info + *ppos, size);
+	if (left == size)
+		return -EFAULT;
+	*ppos += (size - left);
+	return size - left;
+}
+
+
+
+/*
+ * Return name hash for a given dentry.  This is dependent on
+ * the parent directory's hash function.
+ */
+unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
+{
+	struct ceph_inode_info *dci = ceph_inode(dir);
+	unsigned hash;
+
+	switch (dci->i_dir_layout.dl_dir_hash) {
+	case 0:	/* for backward compat */
+	case CEPH_STR_HASH_LINUX:
+		return dn->d_name.hash;
+
+	default:
+		spin_lock(&dn->d_lock);
+		hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
+				     dn->d_name.name, dn->d_name.len);
+		spin_unlock(&dn->d_lock);
+		return hash;
+	}
+}
+
+const struct file_operations ceph_dir_fops = {
+	.read = ceph_read_dir,
+	.iterate = ceph_readdir,
+	.llseek = ceph_dir_llseek,
+	.open = ceph_open,
+	.release = ceph_release,
+	.unlocked_ioctl = ceph_ioctl,
+	.compat_ioctl = compat_ptr_ioctl,
+	.fsync = ceph_fsync,
+	.lock = ceph_lock,
+	.flock = ceph_flock,
+};
+
+const struct file_operations ceph_snapdir_fops = {
+	.iterate = ceph_readdir,
+	.llseek = ceph_dir_llseek,
+	.open = ceph_open,
+	.release = ceph_release,
+};
+
+const struct inode_operations ceph_dir_iops = {
+	.lookup = ceph_lookup,
+	.permission = ceph_permission,
+	.getattr = ceph_getattr,
+	.setattr = ceph_setattr,
+	.listxattr = ceph_listxattr,
+	.get_acl = ceph_get_acl,
+	.set_acl = ceph_set_acl,
+	.mknod = ceph_mknod,
+	.symlink = ceph_symlink,
+	.mkdir = ceph_mkdir,
+	.link = ceph_link,
+	.unlink = ceph_unlink,
+	.rmdir = ceph_unlink,
+	.rename = ceph_rename,
+	.create = ceph_create,
+	.atomic_open = ceph_atomic_open,
+};
+
+const struct inode_operations ceph_snapdir_iops = {
+	.lookup = ceph_lookup,
+	.permission = ceph_permission,
+	.getattr = ceph_getattr,
+	.mkdir = ceph_mkdir,
+	.rmdir = ceph_unlink,
+	.rename = ceph_rename,
+};
+
+const struct dentry_operations ceph_dentry_ops = {
+	.d_revalidate = ceph_d_revalidate,
+	.d_delete = ceph_d_delete,
+	.d_release = ceph_d_release,
+	.d_prune = ceph_d_prune,
+	.d_init = ceph_d_init,
+};