// SPDX-License-Identifier: GPL-2.0

  #include <linux/ceph/ceph_debug.h>

  
  #include <linux/module.h>
  #include <linux/fs.h>

  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/uaccess.h>
  #include <linux/kernel.h>

  #include <linux/writeback.h>
  #include <linux/vmalloc.h>

  #include <linux/xattr.h>

  #include <linux/posix_acl.h>

  #include <linux/random.h>

  #include <linux/sort.h>

  
  #include "super.h"

  #include "mds_client.h"

  #include "cache.h"

  #include <linux/ceph/decode.h>

  
  /*
   * Ceph inode operations
   *
   * Implement basic inode helpers (get, alloc) and inode ops (getattr,
   * setattr, etc.), xattr helpers, and helpers for assimilating
   * metadata returned by the MDS into our cache.
   *
   * Also define helpers for doing asynchronous writeback, invalidation,
   * and truncation for the benefit of those who can't afford to block
   * (typically because they are in the message handler path).
   */
  
  static const struct inode_operations ceph_symlink_iops;

  static void ceph_invalidate_work(struct work_struct *work);
  static void ceph_writeback_work(struct work_struct *work);
  static void ceph_vmtruncate_work(struct work_struct *work);

  
  /*
   * find or create an inode, given the ceph ino number
   */

  static int ceph_set_ino_cb(struct inode *inode, void *data)
  {
  	ceph_inode(inode)->i_vino = *(struct ceph_vino *)data;
  	inode->i_ino = ceph_vino_to_ino(*(struct ceph_vino *)data);
  	return 0;
  }

  struct inode *ceph_get_inode(struct super_block *sb, struct ceph_vino vino)
  {
  	struct inode *inode;
  	ino_t t = ceph_vino_to_ino(vino);
  
  	inode = iget5_locked(sb, t, ceph_ino_compare, ceph_set_ino_cb, &vino);

  	if (!inode)

  		return ERR_PTR(-ENOMEM);
  	if (inode->i_state & I_NEW) {
  		dout("get_inode created new inode %p %llx.%llx ino %llx
  ",
  		     inode, ceph_vinop(inode), (u64)inode->i_ino);
  		unlock_new_inode(inode);
  	}
  
  	dout("get_inode on %lu=%llx.%llx got %p
  ", inode->i_ino, vino.ino,
  	     vino.snap, inode);
  	return inode;
  }
  
  /*
   * get/constuct snapdir inode for a given directory
   */
  struct inode *ceph_get_snapdir(struct inode *parent)
  {
  	struct ceph_vino vino = {
  		.ino = ceph_ino(parent),
  		.snap = CEPH_SNAPDIR,
  	};
  	struct inode *inode = ceph_get_inode(parent->i_sb, vino);

  	struct ceph_inode_info *ci = ceph_inode(inode);

  
  	BUG_ON(!S_ISDIR(parent->i_mode));
  	if (IS_ERR(inode))

  		return inode;

  	inode->i_mode = parent->i_mode;
  	inode->i_uid = parent->i_uid;
  	inode->i_gid = parent->i_gid;

  	inode->i_op = &ceph_snapdir_iops;
  	inode->i_fop = &ceph_snapdir_fops;

  	ci->i_snap_caps = CEPH_CAP_PIN; /* so we can open */
  	ci->i_rbytes = 0;

  	return inode;
  }
  
  const struct inode_operations ceph_file_iops = {
  	.permission = ceph_permission,
  	.setattr = ceph_setattr,
  	.getattr = ceph_getattr,

  	.listxattr = ceph_listxattr,

  	.get_acl = ceph_get_acl,

  	.set_acl = ceph_set_acl,

  };
  
  
  /*
   * We use a 'frag tree' to keep track of the MDS's directory fragments
   * for a given inode (usually there is just a single fragment).  We
   * need to know when a child frag is delegated to a new MDS, or when
   * it is flagged as replicated, so we can direct our requests
   * accordingly.
   */
  
  /*
   * find/create a frag in the tree
   */
  static struct ceph_inode_frag *__get_or_create_frag(struct ceph_inode_info *ci,
  						    u32 f)
  {
  	struct rb_node **p;
  	struct rb_node *parent = NULL;
  	struct ceph_inode_frag *frag;
  	int c;
  
  	p = &ci->i_fragtree.rb_node;
  	while (*p) {
  		parent = *p;
  		frag = rb_entry(parent, struct ceph_inode_frag, node);
  		c = ceph_frag_compare(f, frag->frag);
  		if (c < 0)
  			p = &(*p)->rb_left;
  		else if (c > 0)
  			p = &(*p)->rb_right;
  		else
  			return frag;
  	}
  
  	frag = kmalloc(sizeof(*frag), GFP_NOFS);

  	if (!frag)

  		return ERR_PTR(-ENOMEM);

  	frag->frag = f;
  	frag->split_by = 0;
  	frag->mds = -1;
  	frag->ndist = 0;
  
  	rb_link_node(&frag->node, parent, p);
  	rb_insert_color(&frag->node, &ci->i_fragtree);
  
  	dout("get_or_create_frag added %llx.%llx frag %x
  ",
  	     ceph_vinop(&ci->vfs_inode), f);
  	return frag;
  }
  
  /*
   * find a specific frag @f
   */
  struct ceph_inode_frag *__ceph_find_frag(struct ceph_inode_info *ci, u32 f)
  {
  	struct rb_node *n = ci->i_fragtree.rb_node;
  
  	while (n) {
  		struct ceph_inode_frag *frag =
  			rb_entry(n, struct ceph_inode_frag, node);
  		int c = ceph_frag_compare(f, frag->frag);
  		if (c < 0)
  			n = n->rb_left;
  		else if (c > 0)
  			n = n->rb_right;
  		else
  			return frag;
  	}
  	return NULL;
  }
  
  /*
   * Choose frag containing the given value @v.  If @pfrag is
   * specified, copy the frag delegation info to the caller if
   * it is present.
   */

  static u32 __ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
  			      struct ceph_inode_frag *pfrag, int *found)

  {
  	u32 t = ceph_frag_make(0, 0);
  	struct ceph_inode_frag *frag;
  	unsigned nway, i;
  	u32 n;
  
  	if (found)
  		*found = 0;

  	while (1) {
  		WARN_ON(!ceph_frag_contains_value(t, v));
  		frag = __ceph_find_frag(ci, t);
  		if (!frag)
  			break; /* t is a leaf */
  		if (frag->split_by == 0) {
  			if (pfrag)
  				memcpy(pfrag, frag, sizeof(*pfrag));
  			if (found)
  				*found = 1;
  			break;
  		}
  
  		/* choose child */
  		nway = 1 << frag->split_by;
  		dout("choose_frag(%x) %x splits by %d (%d ways)
  ", v, t,
  		     frag->split_by, nway);
  		for (i = 0; i < nway; i++) {
  			n = ceph_frag_make_child(t, frag->split_by, i);
  			if (ceph_frag_contains_value(n, v)) {
  				t = n;
  				break;
  			}
  		}
  		BUG_ON(i == nway);
  	}
  	dout("choose_frag(%x) = %x
  ", v, t);

  	return t;
  }

  u32 ceph_choose_frag(struct ceph_inode_info *ci, u32 v,
  		     struct ceph_inode_frag *pfrag, int *found)
  {
  	u32 ret;
  	mutex_lock(&ci->i_fragtree_mutex);
  	ret = __ceph_choose_frag(ci, v, pfrag, found);
  	mutex_unlock(&ci->i_fragtree_mutex);
  	return ret;
  }

  /*
   * Process dirfrag (delegation) info from the mds.  Include leaf
   * fragment in tree ONLY if ndist > 0.  Otherwise, only
   * branches/splits are included in i_fragtree)
   */
  static int ceph_fill_dirfrag(struct inode *inode,
  			     struct ceph_mds_reply_dirfrag *dirinfo)
  {
  	struct ceph_inode_info *ci = ceph_inode(inode);
  	struct ceph_inode_frag *frag;
  	u32 id = le32_to_cpu(dirinfo->frag);
  	int mds = le32_to_cpu(dirinfo->auth);
  	int ndist = le32_to_cpu(dirinfo->ndist);

  	int diri_auth = -1;

  	int i;
  	int err = 0;

  	spin_lock(&ci->i_ceph_lock);
  	if (ci->i_auth_cap)
  		diri_auth = ci->i_auth_cap->mds;
  	spin_unlock(&ci->i_ceph_lock);

  	if (mds == -1) /* CDIR_AUTH_PARENT */
  		mds = diri_auth;

  	mutex_lock(&ci->i_fragtree_mutex);

  	if (ndist == 0 && mds == diri_auth) {

  		/* no delegation info needed. */
  		frag = __ceph_find_frag(ci, id);
  		if (!frag)
  			goto out;
  		if (frag->split_by == 0) {
  			/* tree leaf, remove */
  			dout("fill_dirfrag removed %llx.%llx frag %x"
  			     " (no ref)
  ", ceph_vinop(inode), id);
  			rb_erase(&frag->node, &ci->i_fragtree);
  			kfree(frag);
  		} else {
  			/* tree branch, keep and clear */
  			dout("fill_dirfrag cleared %llx.%llx frag %x"
  			     " referral
  ", ceph_vinop(inode), id);
  			frag->mds = -1;
  			frag->ndist = 0;
  		}
  		goto out;
  	}
  
  
  	/* find/add this frag to store mds delegation info */
  	frag = __get_or_create_frag(ci, id);
  	if (IS_ERR(frag)) {
  		/* this is not the end of the world; we can continue
  		   with bad/inaccurate delegation info */
  		pr_err("fill_dirfrag ENOMEM on mds ref %llx.%llx fg %x
  ",
  		       ceph_vinop(inode), le32_to_cpu(dirinfo->frag));
  		err = -ENOMEM;
  		goto out;
  	}
  
  	frag->mds = mds;
  	frag->ndist = min_t(u32, ndist, CEPH_MAX_DIRFRAG_REP);
  	for (i = 0; i < frag->ndist; i++)
  		frag->dist[i] = le32_to_cpu(dirinfo->dist[i]);
  	dout("fill_dirfrag %llx.%llx frag %x ndist=%d
  ",
  	     ceph_vinop(inode), frag->frag, frag->ndist);
  
  out:
  	mutex_unlock(&ci->i_fragtree_mutex);
  	return err;
  }

  static int frag_tree_split_cmp(const void *l, const void *r)
  {
  	struct ceph_frag_tree_split *ls = (struct ceph_frag_tree_split*)l;
  	struct ceph_frag_tree_split *rs = (struct ceph_frag_tree_split*)r;

  	return ceph_frag_compare(le32_to_cpu(ls->frag),
  				 le32_to_cpu(rs->frag));

  }

  static bool is_frag_child(u32 f, struct ceph_inode_frag *frag)
  {
  	if (!frag)
  		return f == ceph_frag_make(0, 0);
  	if (ceph_frag_bits(f) != ceph_frag_bits(frag->frag) + frag->split_by)
  		return false;
  	return ceph_frag_contains_value(frag->frag, ceph_frag_value(f));
  }

  static int ceph_fill_fragtree(struct inode *inode,
  			      struct ceph_frag_tree_head *fragtree,
  			      struct ceph_mds_reply_dirfrag *dirinfo)
  {
  	struct ceph_inode_info *ci = ceph_inode(inode);

  	struct ceph_inode_frag *frag, *prev_frag = NULL;

  	struct rb_node *rb_node;

  	unsigned i, split_by, nsplits;
  	u32 id;

  	bool update = false;
  
  	mutex_lock(&ci->i_fragtree_mutex);
  	nsplits = le32_to_cpu(fragtree->nsplits);

  	if (nsplits != ci->i_fragtree_nsplits) {
  		update = true;
  	} else if (nsplits) {

  		i = prandom_u32() % nsplits;
  		id = le32_to_cpu(fragtree->splits[i].frag);
  		if (!__ceph_find_frag(ci, id))
  			update = true;
  	} else if (!RB_EMPTY_ROOT(&ci->i_fragtree)) {
  		rb_node = rb_first(&ci->i_fragtree);
  		frag = rb_entry(rb_node, struct ceph_inode_frag, node);
  		if (frag->frag != ceph_frag_make(0, 0) || rb_next(rb_node))
  			update = true;
  	}
  	if (!update && dirinfo) {
  		id = le32_to_cpu(dirinfo->frag);
  		if (id != __ceph_choose_frag(ci, id, NULL, NULL))
  			update = true;
  	}
  	if (!update)
  		goto out_unlock;

  	if (nsplits > 1) {
  		sort(fragtree->splits, nsplits, sizeof(fragtree->splits[0]),
  		     frag_tree_split_cmp, NULL);
  	}

  	dout("fill_fragtree %llx.%llx
  ", ceph_vinop(inode));
  	rb_node = rb_first(&ci->i_fragtree);
  	for (i = 0; i < nsplits; i++) {
  		id = le32_to_cpu(fragtree->splits[i].frag);

  		split_by = le32_to_cpu(fragtree->splits[i].by);
  		if (split_by == 0 || ceph_frag_bits(id) + split_by > 24) {
  			pr_err("fill_fragtree %llx.%llx invalid split %d/%u, "
  			       "frag %x split by %d
  ", ceph_vinop(inode),
  			       i, nsplits, id, split_by);
  			continue;
  		}

  		frag = NULL;
  		while (rb_node) {
  			frag = rb_entry(rb_node, struct ceph_inode_frag, node);
  			if (ceph_frag_compare(frag->frag, id) >= 0) {
  				if (frag->frag != id)
  					frag = NULL;
  				else
  					rb_node = rb_next(rb_node);
  				break;
  			}
  			rb_node = rb_next(rb_node);

  			/* delete stale split/leaf node */
  			if (frag->split_by > 0 ||
  			    !is_frag_child(frag->frag, prev_frag)) {
  				rb_erase(&frag->node, &ci->i_fragtree);

  				if (frag->split_by > 0)
  					ci->i_fragtree_nsplits--;

  				kfree(frag);
  			}

  			frag = NULL;
  		}
  		if (!frag) {
  			frag = __get_or_create_frag(ci, id);
  			if (IS_ERR(frag))
  				continue;
  		}

  		if (frag->split_by == 0)
  			ci->i_fragtree_nsplits++;
  		frag->split_by = split_by;

  		dout(" frag %x split by %d
  ", frag->frag, frag->split_by);

  		prev_frag = frag;

  	}
  	while (rb_node) {
  		frag = rb_entry(rb_node, struct ceph_inode_frag, node);
  		rb_node = rb_next(rb_node);

  		/* delete stale split/leaf node */
  		if (frag->split_by > 0 ||
  		    !is_frag_child(frag->frag, prev_frag)) {
  			rb_erase(&frag->node, &ci->i_fragtree);

  			if (frag->split_by > 0)
  				ci->i_fragtree_nsplits--;

  			kfree(frag);
  		}

  	}
  out_unlock:
  	mutex_unlock(&ci->i_fragtree_mutex);
  	return 0;
  }

  
  /*
   * initialize a newly allocated inode.
   */
  struct inode *ceph_alloc_inode(struct super_block *sb)
  {
  	struct ceph_inode_info *ci;
  	int i;
  
  	ci = kmem_cache_alloc(ceph_inode_cachep, GFP_NOFS);
  	if (!ci)
  		return NULL;
  
  	dout("alloc_inode %p
  ", &ci->vfs_inode);

  	spin_lock_init(&ci->i_ceph_lock);

  	ci->i_version = 0;

  	ci->i_inline_version = 0;

  	ci->i_time_warp_seq = 0;
  	ci->i_ceph_flags = 0;

  	atomic64_set(&ci->i_ordered_count, 1);
  	atomic64_set(&ci->i_release_count, 1);
  	atomic64_set(&ci->i_complete_seq[0], 0);
  	atomic64_set(&ci->i_complete_seq[1], 0);

  	ci->i_symlink = NULL;

  	memset(&ci->i_dir_layout, 0, sizeof(ci->i_dir_layout));

  	RCU_INIT_POINTER(ci->i_layout.pool_ns, NULL);

  	ci->i_fragtree = RB_ROOT;
  	mutex_init(&ci->i_fragtree_mutex);
  
  	ci->i_xattrs.blob = NULL;
  	ci->i_xattrs.prealloc_blob = NULL;
  	ci->i_xattrs.dirty = false;
  	ci->i_xattrs.index = RB_ROOT;
  	ci->i_xattrs.count = 0;
  	ci->i_xattrs.names_size = 0;
  	ci->i_xattrs.vals_size = 0;
  	ci->i_xattrs.version = 0;
  	ci->i_xattrs.index_version = 0;
  
  	ci->i_caps = RB_ROOT;
  	ci->i_auth_cap = NULL;
  	ci->i_dirty_caps = 0;
  	ci->i_flushing_caps = 0;
  	INIT_LIST_HEAD(&ci->i_dirty_item);
  	INIT_LIST_HEAD(&ci->i_flushing_item);

  	ci->i_prealloc_cap_flush = NULL;

  	INIT_LIST_HEAD(&ci->i_cap_flush_list);

  	init_waitqueue_head(&ci->i_cap_wq);
  	ci->i_hold_caps_min = 0;
  	ci->i_hold_caps_max = 0;
  	INIT_LIST_HEAD(&ci->i_cap_delay_list);

  	INIT_LIST_HEAD(&ci->i_cap_snaps);
  	ci->i_head_snapc = NULL;
  	ci->i_snap_caps = 0;

  	for (i = 0; i < CEPH_FILE_MODE_BITS; i++)

  		ci->i_nr_by_mode[i] = 0;

  	mutex_init(&ci->i_truncate_mutex);

  	ci->i_truncate_seq = 0;
  	ci->i_truncate_size = 0;
  	ci->i_truncate_pending = 0;
  
  	ci->i_max_size = 0;
  	ci->i_reported_size = 0;
  	ci->i_wanted_max_size = 0;
  	ci->i_requested_max_size = 0;
  
  	ci->i_pin_ref = 0;
  	ci->i_rd_ref = 0;
  	ci->i_rdcache_ref = 0;
  	ci->i_wr_ref = 0;

  	ci->i_wb_ref = 0;

  	ci->i_wrbuffer_ref = 0;
  	ci->i_wrbuffer_ref_head = 0;
  	ci->i_shared_gen = 0;
  	ci->i_rdcache_gen = 0;
  	ci->i_rdcache_revoking = 0;

  	INIT_LIST_HEAD(&ci->i_unsafe_dirops);

  	INIT_LIST_HEAD(&ci->i_unsafe_iops);

  	spin_lock_init(&ci->i_unsafe_lock);
  
  	ci->i_snap_realm = NULL;
  	INIT_LIST_HEAD(&ci->i_snap_realm_item);
  	INIT_LIST_HEAD(&ci->i_snap_flush_item);

  	INIT_WORK(&ci->i_wb_work, ceph_writeback_work);
  	INIT_WORK(&ci->i_pg_inv_work, ceph_invalidate_work);

  
  	INIT_WORK(&ci->i_vmtruncate_work, ceph_vmtruncate_work);

  	ceph_fscache_inode_init(ci);

  	return &ci->vfs_inode;
  }

  static void ceph_i_callback(struct rcu_head *head)
  {
  	struct inode *inode = container_of(head, struct inode, i_rcu);
  	struct ceph_inode_info *ci = ceph_inode(inode);

  	kmem_cache_free(ceph_inode_cachep, ci);
  }

  void ceph_destroy_inode(struct inode *inode)
  {
  	struct ceph_inode_info *ci = ceph_inode(inode);
  	struct ceph_inode_frag *frag;
  	struct rb_node *n;
  
  	dout("destroy_inode %p ino %llx.%llx
  ", inode, ceph_vinop(inode));

  	ceph_fscache_unregister_inode_cookie(ci);

  	ceph_queue_caps_release(inode);

  	/*
  	 * we may still have a snap_realm reference if there are stray

  	 * caps in i_snap_caps.

  	 */
  	if (ci->i_snap_realm) {
  		struct ceph_mds_client *mdsc =

  			ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;

  		struct ceph_snap_realm *realm = ci->i_snap_realm;
  
  		dout(" dropping residual ref to snap realm %p
  ", realm);
  		spin_lock(&realm->inodes_with_caps_lock);
  		list_del_init(&ci->i_snap_realm_item);
  		spin_unlock(&realm->inodes_with_caps_lock);
  		ceph_put_snap_realm(mdsc, realm);
  	}

  	kfree(ci->i_symlink);
  	while ((n = rb_first(&ci->i_fragtree)) != NULL) {
  		frag = rb_entry(n, struct ceph_inode_frag, node);
  		rb_erase(n, &ci->i_fragtree);
  		kfree(frag);
  	}

  	ci->i_fragtree_nsplits = 0;

  
  	__ceph_destroy_xattrs(ci);

  	if (ci->i_xattrs.blob)
  		ceph_buffer_put(ci->i_xattrs.blob);
  	if (ci->i_xattrs.prealloc_blob)
  		ceph_buffer_put(ci->i_xattrs.prealloc_blob);

  	ceph_put_string(rcu_dereference_raw(ci->i_layout.pool_ns));

  	call_rcu(&inode->i_rcu, ceph_i_callback);

  }

  int ceph_drop_inode(struct inode *inode)
  {
  	/*
  	 * Positve dentry and corresponding inode are always accompanied
  	 * in MDS reply. So no need to keep inode in the cache after
  	 * dropping all its aliases.
  	 */
  	return 1;
  }

  static inline blkcnt_t calc_inode_blocks(u64 size)
  {
  	return (size + (1<<9) - 1) >> 9;
  }

  /*
   * Helpers to fill in size, ctime, mtime, and atime.  We have to be
   * careful because either the client or MDS may have more up to date
   * info, depending on which capabilities are held, and whether
   * time_warp_seq or truncate_seq have increased.  (Ordinarily, mtime
   * and size are monotonically increasing, except when utimes() or
   * truncate() increments the corresponding _seq values.)
   */
  int ceph_fill_file_size(struct inode *inode, int issued,
  			u32 truncate_seq, u64 truncate_size, u64 size)
  {
  	struct ceph_inode_info *ci = ceph_inode(inode);
  	int queue_trunc = 0;
  
  	if (ceph_seq_cmp(truncate_seq, ci->i_truncate_seq) > 0 ||
  	    (truncate_seq == ci->i_truncate_seq && size > inode->i_size)) {
  		dout("size %lld -> %llu
  ", inode->i_size, size);

  		if (size > 0 && S_ISDIR(inode->i_mode)) {
  			pr_err("fill_file_size non-zero size for directory
  ");
  			size = 0;
  		}

  		i_size_write(inode, size);

  		inode->i_blocks = calc_inode_blocks(size);

  		ci->i_reported_size = size;
  		if (truncate_seq != ci->i_truncate_seq) {
  			dout("truncate_seq %u -> %u
  ",
  			     ci->i_truncate_seq, truncate_seq);
  			ci->i_truncate_seq = truncate_seq;

  
  			/* the MDS should have revoked these caps */
  			WARN_ON_ONCE(issued & (CEPH_CAP_FILE_EXCL |
  					       CEPH_CAP_FILE_RD |
  					       CEPH_CAP_FILE_WR |
  					       CEPH_CAP_FILE_LAZYIO));

  			/*
  			 * If we hold relevant caps, or in the case where we're
  			 * not the only client referencing this file and we
  			 * don't hold those caps, then we need to check whether
  			 * the file is either opened or mmaped
  			 */

  			if ((issued & (CEPH_CAP_FILE_CACHE|
  				       CEPH_CAP_FILE_BUFFER)) ||

  			    mapping_mapped(inode->i_mapping) ||
  			    __ceph_caps_file_wanted(ci)) {

  				ci->i_truncate_pending++;
  				queue_trunc = 1;
  			}
  		}
  	}
  	if (ceph_seq_cmp(truncate_seq, ci->i_truncate_seq) >= 0 &&
  	    ci->i_truncate_size != truncate_size) {
  		dout("truncate_size %lld -> %llu
  ", ci->i_truncate_size,
  		     truncate_size);
  		ci->i_truncate_size = truncate_size;
  	}

  
  	if (queue_trunc)
  		ceph_fscache_invalidate(inode);

  	return queue_trunc;
  }
  
  void ceph_fill_file_time(struct inode *inode, int issued,
  			 u64 time_warp_seq, struct timespec *ctime,
  			 struct timespec *mtime, struct timespec *atime)
  {
  	struct ceph_inode_info *ci = ceph_inode(inode);
  	int warn = 0;
  
  	if (issued & (CEPH_CAP_FILE_EXCL|
  		      CEPH_CAP_FILE_WR|

  		      CEPH_CAP_FILE_BUFFER|
  		      CEPH_CAP_AUTH_EXCL|
  		      CEPH_CAP_XATTR_EXCL)) {

  		if (timespec_compare(ctime, &inode->i_ctime) > 0) {
  			dout("ctime %ld.%09ld -> %ld.%09ld inc w/ cap
  ",
  			     inode->i_ctime.tv_sec, inode->i_ctime.tv_nsec,
  			     ctime->tv_sec, ctime->tv_nsec);
  			inode->i_ctime = *ctime;
  		}
  		if (ceph_seq_cmp(time_warp_seq, ci->i_time_warp_seq) > 0) {
  			/* the MDS did a utimes() */
  			dout("mtime %ld.%09ld -> %ld.%09ld "
  			     "tw %d -> %d
  ",
  			     inode->i_mtime.tv_sec, inode->i_mtime.tv_nsec,
  			     mtime->tv_sec, mtime->tv_nsec,
  			     ci->i_time_warp_seq, (int)time_warp_seq);
  
  			inode->i_mtime = *mtime;
  			inode->i_atime = *atime;
  			ci->i_time_warp_seq = time_warp_seq;
  		} else if (time_warp_seq == ci->i_time_warp_seq) {
  			/* nobody did utimes(); take the max */
  			if (timespec_compare(mtime, &inode->i_mtime) > 0) {
  				dout("mtime %ld.%09ld -> %ld.%09ld inc
  ",
  				     inode->i_mtime.tv_sec,
  				     inode->i_mtime.tv_nsec,
  				     mtime->tv_sec, mtime->tv_nsec);
  				inode->i_mtime = *mtime;
  			}
  			if (timespec_compare(atime, &inode->i_atime) > 0) {
  				dout("atime %ld.%09ld -> %ld.%09ld inc
  ",
  				     inode->i_atime.tv_sec,
  				     inode->i_atime.tv_nsec,
  				     atime->tv_sec, atime->tv_nsec);
  				inode->i_atime = *atime;
  			}
  		} else if (issued & CEPH_CAP_FILE_EXCL) {
  			/* we did a utimes(); ignore mds values */
  		} else {
  			warn = 1;
  		}
  	} else {

  		/* we have no write|excl caps; whatever the MDS says is true */

  		if (ceph_seq_cmp(time_warp_seq, ci->i_time_warp_seq) >= 0) {
  			inode->i_ctime = *ctime;
  			inode->i_mtime = *mtime;
  			inode->i_atime = *atime;
  			ci->i_time_warp_seq = time_warp_seq;
  		} else {
  			warn = 1;
  		}
  	}
  	if (warn) /* time_warp_seq shouldn't go backwards */
  		dout("%p mds time_warp_seq %llu < %u
  ",
  		     inode, time_warp_seq, ci->i_time_warp_seq);
  }
  
  /*
   * Populate an inode based on info from mds.  May be called on new or
   * existing inodes.
   */

  static int fill_inode(struct inode *inode, struct page *locked_page,

  		      struct ceph_mds_reply_info_in *iinfo,
  		      struct ceph_mds_reply_dirfrag *dirinfo,
  		      struct ceph_mds_session *session,
  		      unsigned long ttl_from, int cap_fmode,
  		      struct ceph_cap_reservation *caps_reservation)
  {

  	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;

  	struct ceph_mds_reply_inode *info = iinfo->in;
  	struct ceph_inode_info *ci = ceph_inode(inode);

  	int issued = 0, implemented, new_issued;

  	struct timespec mtime, atime, ctime;

  	struct ceph_buffer *xattr_blob = NULL;

  	struct ceph_string *pool_ns = NULL;

  	struct ceph_cap *new_cap = NULL;

  	int err = 0;

  	bool wake = false;

  	bool queue_trunc = false;
  	bool new_version = false;

  	bool fill_inline = false;

  
  	dout("fill_inode %p ino %llx.%llx v %llu had %llu
  ",
  	     inode, ceph_vinop(inode), le64_to_cpu(info->version),
  	     ci->i_version);

  	/* prealloc new cap struct */
  	if (info->cap.caps && ceph_snap(inode) == CEPH_NOSNAP)
  		new_cap = ceph_get_cap(mdsc, caps_reservation);

  	/*
  	 * prealloc xattr data, if it looks like we'll need it.  only
  	 * if len > 4 (meaning there are actually xattrs; the first 4
  	 * bytes are the xattr count).
  	 */
  	if (iinfo->xattr_len > 4) {

  		xattr_blob = ceph_buffer_new(iinfo->xattr_len, GFP_NOFS);

  		if (!xattr_blob)
  			pr_err("fill_inode ENOMEM xattr blob %d bytes
  ",
  			       iinfo->xattr_len);
  	}

  	if (iinfo->pool_ns_len > 0)
  		pool_ns = ceph_find_or_create_string(iinfo->pool_ns_data,
  						     iinfo->pool_ns_len);

  	spin_lock(&ci->i_ceph_lock);

  
  	/*
  	 * provided version will be odd if inode value is projected,

  	 * even if stable.  skip the update if we have newer stable
  	 * info (ours>=theirs, e.g. due to racing mds replies), unless
  	 * we are getting projected (unstable) info (in which case the
  	 * version is odd, and we want ours>theirs).
  	 *   us   them
  	 *   2    2     skip
  	 *   3    2     skip
  	 *   3    3     update

  	 */

  	if (ci->i_version == 0 ||
  	    ((info->cap.flags & CEPH_CAP_FLAG_AUTH) &&
  	     le64_to_cpu(info->version) > (ci->i_version & ~1)))
  		new_version = true;

  	issued = __ceph_caps_issued(ci, &implemented);
  	issued |= implemented | __ceph_caps_dirty(ci);

  	new_issued = ~issued & le32_to_cpu(info->cap.caps);

  
  	/* update inode */
  	ci->i_version = le64_to_cpu(info->version);
  	inode->i_version++;
  	inode->i_rdev = le32_to_cpu(info->rdev);

  	inode->i_blkbits = fls(le32_to_cpu(info->layout.fl_stripe_unit)) - 1;

  	if ((new_version || (new_issued & CEPH_CAP_AUTH_SHARED)) &&
  	    (issued & CEPH_CAP_AUTH_EXCL) == 0) {

  		inode->i_mode = le32_to_cpu(info->mode);

  		inode->i_uid = make_kuid(&init_user_ns, le32_to_cpu(info->uid));
  		inode->i_gid = make_kgid(&init_user_ns, le32_to_cpu(info->gid));

  		dout("%p mode 0%o uid.gid %d.%d
  ", inode, inode->i_mode,

  		     from_kuid(&init_user_ns, inode->i_uid),
  		     from_kgid(&init_user_ns, inode->i_gid));

  	}

  	if ((new_version || (new_issued & CEPH_CAP_LINK_SHARED)) &&
  	    (issued & CEPH_CAP_LINK_EXCL) == 0)

  		set_nlink(inode, le32_to_cpu(info->nlink));

  	if (new_version || (new_issued & CEPH_CAP_ANY_RD)) {
  		/* be careful with mtime, atime, size */
  		ceph_decode_timespec(&atime, &info->atime);
  		ceph_decode_timespec(&mtime, &info->mtime);
  		ceph_decode_timespec(&ctime, &info->ctime);
  		ceph_fill_file_time(inode, issued,
  				le32_to_cpu(info->time_warp_seq),
  				&ctime, &mtime, &atime);
  	}
  
  	if (new_version ||
  	    (new_issued & (CEPH_CAP_ANY_FILE_RD | CEPH_CAP_ANY_FILE_WR))) {

  		s64 old_pool = ci->i_layout.pool_id;

  		struct ceph_string *old_ns;

  		ceph_file_layout_from_legacy(&ci->i_layout, &info->layout);

  		old_ns = rcu_dereference_protected(ci->i_layout.pool_ns,
  					lockdep_is_held(&ci->i_ceph_lock));
  		rcu_assign_pointer(ci->i_layout.pool_ns, pool_ns);
  
  		if (ci->i_layout.pool_id != old_pool || pool_ns != old_ns)

  			ci->i_ceph_flags &= ~CEPH_I_POOL_PERM;

  		pool_ns = old_ns;

  		queue_trunc = ceph_fill_file_size(inode, issued,
  					le32_to_cpu(info->truncate_seq),
  					le64_to_cpu(info->truncate_size),
  					le64_to_cpu(info->size));
  		/* only update max_size on auth cap */
  		if ((info->cap.flags & CEPH_CAP_FLAG_AUTH) &&
  		    ci->i_max_size != le64_to_cpu(info->max_size)) {
  			dout("max_size %lld -> %llu
  ", ci->i_max_size,
  					le64_to_cpu(info->max_size));
  			ci->i_max_size = le64_to_cpu(info->max_size);
  		}
  	}

  
  	/* xattrs */
  	/* note that if i_xattrs.len <= 4, i_xattrs.data will still be NULL. */

  	if ((ci->i_xattrs.version == 0 || !(issued & CEPH_CAP_XATTR_EXCL))  &&

  	    le64_to_cpu(info->xattr_version) > ci->i_xattrs.version) {
  		if (ci->i_xattrs.blob)
  			ceph_buffer_put(ci->i_xattrs.blob);
  		ci->i_xattrs.blob = xattr_blob;
  		if (xattr_blob)
  			memcpy(ci->i_xattrs.blob->vec.iov_base,
  			       iinfo->xattr_data, iinfo->xattr_len);
  		ci->i_xattrs.version = le64_to_cpu(info->xattr_version);

  		ceph_forget_all_cached_acls(inode);

  		xattr_blob = NULL;

  	}
  
  	inode->i_mapping->a_ops = &ceph_aops;

  
  	switch (inode->i_mode & S_IFMT) {
  	case S_IFIFO:
  	case S_IFBLK:
  	case S_IFCHR:
  	case S_IFSOCK:
  		init_special_inode(inode, inode->i_mode, inode->i_rdev);
  		inode->i_op = &ceph_file_iops;
  		break;
  	case S_IFREG:
  		inode->i_op = &ceph_file_iops;
  		inode->i_fop = &ceph_file_fops;
  		break;
  	case S_IFLNK:
  		inode->i_op = &ceph_symlink_iops;
  		if (!ci->i_symlink) {

  			u32 symlen = iinfo->symlink_len;

  			char *sym;

  			spin_unlock(&ci->i_ceph_lock);

  			if (symlen != i_size_read(inode)) {
  				pr_err("fill_inode %llx.%llx BAD symlink "
  					"size %lld
  ", ceph_vinop(inode),
  					i_size_read(inode));
  				i_size_write(inode, symlen);
  				inode->i_blocks = calc_inode_blocks(symlen);
  			}

  			err = -ENOMEM;

  			sym = kstrndup(iinfo->symlink, symlen, GFP_NOFS);

  			if (!sym)
  				goto out;

  			spin_lock(&ci->i_ceph_lock);

  			if (!ci->i_symlink)
  				ci->i_symlink = sym;
  			else
  				kfree(sym); /* lost a race */
  		}

  		inode->i_link = ci->i_symlink;

  		break;
  	case S_IFDIR:
  		inode->i_op = &ceph_dir_iops;
  		inode->i_fop = &ceph_dir_fops;

  		ci->i_dir_layout = iinfo->dir_layout;

  		ci->i_files = le64_to_cpu(info->files);
  		ci->i_subdirs = le64_to_cpu(info->subdirs);
  		ci->i_rbytes = le64_to_cpu(info->rbytes);
  		ci->i_rfiles = le64_to_cpu(info->rfiles);
  		ci->i_rsubdirs = le64_to_cpu(info->rsubdirs);
  		ceph_decode_timespec(&ci->i_rctime, &info->rctime);

  		break;
  	default:
  		pr_err("fill_inode %llx.%llx BAD mode 0%o
  ",
  		       ceph_vinop(inode), inode->i_mode);
  	}

  	/* were we issued a capability? */
  	if (info->cap.caps) {
  		if (ceph_snap(inode) == CEPH_NOSNAP) {

  			unsigned caps = le32_to_cpu(info->cap.caps);

  			ceph_add_cap(inode, session,
  				     le64_to_cpu(info->cap.cap_id),

  				     cap_fmode, caps,

  				     le32_to_cpu(info->cap.wanted),
  				     le32_to_cpu(info->cap.seq),
  				     le32_to_cpu(info->cap.mseq),
  				     le64_to_cpu(info->cap.realm),

  				     info->cap.flags, &new_cap);

  
  			/* set dir completion flag? */
  			if (S_ISDIR(inode->i_mode) &&
  			    ci->i_files == 0 && ci->i_subdirs == 0 &&
  			    (caps & CEPH_CAP_FILE_SHARED) &&
  			    (issued & CEPH_CAP_FILE_EXCL) == 0 &&
  			    !__ceph_dir_is_complete(ci)) {
  				dout(" marking %p complete (empty)
  ", inode);

  				i_size_write(inode, 0);

  				__ceph_dir_set_complete(ci,

  					atomic64_read(&ci->i_release_count),
  					atomic64_read(&ci->i_ordered_count));

  			}

  			wake = true;

  		} else {

  			dout(" %p got snap_caps %s
  ", inode,
  			     ceph_cap_string(le32_to_cpu(info->cap.caps)));
  			ci->i_snap_caps |= le32_to_cpu(info->cap.caps);
  			if (cap_fmode >= 0)
  				__ceph_get_fmode(ci, cap_fmode);

  		}

  	} else if (cap_fmode >= 0) {

  		pr_warn("mds issued no caps on %llx.%llx
  ",

  			   ceph_vinop(inode));
  		__ceph_get_fmode(ci, cap_fmode);

  	}

  
  	if (iinfo->inline_version > 0 &&
  	    iinfo->inline_version >= ci->i_inline_version) {
  		int cache_caps = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
  		ci->i_inline_version = iinfo->inline_version;
  		if (ci->i_inline_version != CEPH_INLINE_NONE &&

  		    (locked_page ||
  		     (le32_to_cpu(info->cap.caps) & cache_caps)))

  			fill_inline = true;
  	}

  	spin_unlock(&ci->i_ceph_lock);

  	if (fill_inline)

  		ceph_fill_inline_data(inode, locked_page,

  				      iinfo->inline_data, iinfo->inline_len);

  	if (wake)
  		wake_up_all(&ci->i_cap_wq);

  	/* queue truncate if we saw i_size decrease */
  	if (queue_trunc)

  		ceph_queue_vmtruncate(inode);

  
  	/* populate frag tree */

  	if (S_ISDIR(inode->i_mode))
  		ceph_fill_fragtree(inode, &info->fragtree, dirinfo);

  
  	/* update delegation info? */
  	if (dirinfo)
  		ceph_fill_dirfrag(inode, dirinfo);
  
  	err = 0;

  out:

  	if (new_cap)
  		ceph_put_cap(mdsc, new_cap);

  	if (xattr_blob)
  		ceph_buffer_put(xattr_blob);

  	ceph_put_string(pool_ns);

  	return err;
  }
  
  /*
   * caller should hold session s_mutex.
   */
  static void update_dentry_lease(struct dentry *dentry,
  				struct ceph_mds_reply_lease *lease,
  				struct ceph_mds_session *session,

  				unsigned long from_time,
  				struct ceph_vino *tgt_vino,
  				struct ceph_vino *dir_vino)

  {
  	struct ceph_dentry_info *di = ceph_dentry(dentry);
  	long unsigned duration = le32_to_cpu(lease->duration_ms);
  	long unsigned ttl = from_time + (duration * HZ) / 1000;
  	long unsigned half_ttl = from_time + (duration * HZ / 2) / 1000;
  	struct inode *dir;

  	struct ceph_mds_session *old_lease_session = NULL;

  	/*
  	 * Make sure dentry's inode matches tgt_vino. NULL tgt_vino means that
  	 * we expect a negative dentry.
  	 */
  	if (!tgt_vino && d_really_is_positive(dentry))
  		return;
  
  	if (tgt_vino && (d_really_is_negative(dentry) ||
  			!ceph_ino_compare(d_inode(dentry), tgt_vino)))
  		return;

  	spin_lock(&dentry->d_lock);

  	dout("update_dentry_lease %p duration %lu ms ttl %lu
  ",
  	     dentry, duration, ttl);

  	dir = d_inode(dentry->d_parent);

  	/* make sure parent matches dir_vino */
  	if (!ceph_ino_compare(dir, dir_vino))
  		goto out_unlock;

  	/* only track leases on regular dentries */
  	if (ceph_snap(dir) != CEPH_NOSNAP)
  		goto out_unlock;

  	di->lease_shared_gen = ceph_inode(dir)->i_shared_gen;

  	if (duration == 0)

  		goto out_unlock;
  
  	if (di->lease_gen == session->s_cap_gen &&

  	    time_before(ttl, di->time))

  		goto out_unlock;  /* we already have a newer lease. */

  	if (di->lease_session && di->lease_session != session) {
  		old_lease_session = di->lease_session;
  		di->lease_session = NULL;
  	}

  
  	ceph_dentry_lru_touch(dentry);
  
  	if (!di->lease_session)
  		di->lease_session = ceph_get_mds_session(session);
  	di->lease_gen = session->s_cap_gen;
  	di->lease_seq = le32_to_cpu(lease->seq);
  	di->lease_renew_after = half_ttl;
  	di->lease_renew_from = 0;

  	di->time = ttl;

  out_unlock:
  	spin_unlock(&dentry->d_lock);

  	if (old_lease_session)
  		ceph_put_mds_session(old_lease_session);

  }
  
  /*
   * splice a dentry to an inode.
   * caller must hold directory i_mutex for this to be safe.

   */

  static struct dentry *splice_dentry(struct dentry *dn, struct inode *in)

  {
  	struct dentry *realdn;

  	BUG_ON(d_inode(dn));

  	/* dn must be unhashed */
  	if (!d_unhashed(dn))
  		d_drop(dn);

  	realdn = d_splice_alias(in, dn);

  	if (IS_ERR(realdn)) {

  		pr_err("splice_dentry error %ld %p inode %p ino %llx.%llx
  ",
  		       PTR_ERR(realdn), dn, in, ceph_vinop(in));

  		dn = realdn;
  		/*
  		 * Caller should release 'dn' in the case of error.
  		 * If 'req->r_dentry' is passed to this function,
  		 * caller should leave 'req->r_dentry' untouched.
  		 */

  		goto out;
  	} else if (realdn) {
  		dout("dn %p (%d) spliced with %p (%d) "
  		     "inode %p ino %llx.%llx
  ",

  		     dn, d_count(dn),
  		     realdn, d_count(realdn),

  		     d_inode(realdn), ceph_vinop(d_inode(realdn)));

  		dput(dn);
  		dn = realdn;
  	} else {
  		BUG_ON(!ceph_dentry(dn));

  		dout("dn %p attached to %p ino %llx.%llx
  ",

  		     dn, d_inode(dn), ceph_vinop(d_inode(dn)));

  	}

  out:
  	return dn;
  }
  
  /*
   * Incorporate results into the local cache.  This is either just
   * one inode, or a directory, dentry, and possibly linked-to inode (e.g.,
   * after a lookup).
   *
   * A reply may contain
   *         a directory inode along with a dentry.
   *  and/or a target inode
   *
   * Called with snap_rwsem (read).
   */

  int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)

  {

  	struct ceph_mds_session *session = req->r_session;

  	struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
  	struct inode *in = NULL;

  	struct ceph_vino tvino, dvino;

  	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);

  	int err = 0;
  
  	dout("fill_trace %p is_dentry %d is_target %d
  ", req,
  	     rinfo->head->is_dentry, rinfo->head->is_target);

  	if (!rinfo->head->is_target && !rinfo->head->is_dentry) {
  		dout("fill_trace reply is empty!
  ");

  		if (rinfo->head->result == 0 && req->r_parent)

  			ceph_invalidate_dir_request(req);

  		return 0;
  	}
  
  	if (rinfo->head->is_dentry) {

  		struct inode *dir = req->r_parent;

  		if (dir) {

  			err = fill_inode(dir, NULL,
  					 &rinfo->diri, rinfo->dirfrag,

  					 session, req->r_request_started, -1,
  					 &req->r_caps_reservation);
  			if (err < 0)

  				goto done;

  		} else {
  			WARN_ON_ONCE(1);
  		}

  
  		if (dir && req->r_op == CEPH_MDS_OP_LOOKUPNAME) {
  			struct qstr dname;
  			struct dentry *dn, *parent;
  
  			BUG_ON(!rinfo->head->is_target);
  			BUG_ON(req->r_dentry);
  
  			parent = d_find_any_alias(dir);
  			BUG_ON(!parent);
  
  			dname.name = rinfo->dname;
  			dname.len = rinfo->dname_len;

  			dname.hash = full_name_hash(parent, dname.name, dname.len);

  			tvino.ino = le64_to_cpu(rinfo->targeti.in->ino);
  			tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid);

  retry_lookup:
  			dn = d_lookup(parent, &dname);
  			dout("d_lookup on parent=%p name=%.*s got %p
  ",
  			     parent, dname.len, dname.name, dn);
  
  			if (!dn) {
  				dn = d_alloc(parent, &dname);
  				dout("d_alloc %p '%.*s' = %p
  ", parent,
  				     dname.len, dname.name, dn);

  				if (!dn) {

  					dput(parent);
  					err = -ENOMEM;
  					goto done;
  				}

  				err = 0;

  			} else if (d_really_is_positive(dn) &&

  				   (ceph_ino(d_inode(dn)) != tvino.ino ||
  				    ceph_snap(d_inode(dn)) != tvino.snap)) {

  				dout(" dn %p points to wrong inode %p
  ",

  				     dn, d_inode(dn));

  				d_delete(dn);
  				dput(dn);
  				goto retry_lookup;
  			}
  
  			req->r_dentry = dn;
  			dput(parent);
  		}

  	}

  	if (rinfo->head->is_target) {

  		tvino.ino = le64_to_cpu(rinfo->targeti.in->ino);
  		tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid);

  		in = ceph_get_inode(sb, tvino);

  		if (IS_ERR(in)) {
  			err = PTR_ERR(in);
  			goto done;
  		}
  		req->r_target_inode = in;

  		err = fill_inode(in, req->r_locked_page, &rinfo->targeti, NULL,

  				session, req->r_request_started,

  				(!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags) &&
  				rinfo->head->result == 0) ?  req->r_fmode : -1,

  				&req->r_caps_reservation);
  		if (err < 0) {
  			pr_err("fill_inode badness %p %llx.%llx
  ",
  				in, ceph_vinop(in));
  			goto done;
  		}
  	}

  	/*
  	 * ignore null lease/binding on snapdir ENOENT, or else we
  	 * will have trouble splicing in the virtual snapdir later
  	 */

  	if (rinfo->head->is_dentry &&
              !test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags) &&
  	    test_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags) &&

  	    (rinfo->head->is_target || strncmp(req->r_dentry->d_name.name,

  					       fsc->mount_options->snapdir_name,

  					       req->r_dentry->d_name.len))) {

  		/*
  		 * lookup link rename   : null -> possibly existing inode
  		 * mknod symlink mkdir  : null -> new inode
  		 * unlink               : linked -> null
  		 */

  		struct inode *dir = req->r_parent;

  		struct dentry *dn = req->r_dentry;
  		bool have_dir_cap, have_lease;
  
  		BUG_ON(!dn);
  		BUG_ON(!dir);

  		BUG_ON(d_inode(dn->d_parent) != dir);

  
  		dvino.ino = le64_to_cpu(rinfo->diri.in->ino);
  		dvino.snap = le64_to_cpu(rinfo->diri.in->snapid);
  
  		BUG_ON(ceph_ino(dir) != dvino.ino);
  		BUG_ON(ceph_snap(dir) != dvino.snap);

  		/* do we have a lease on the whole dir? */
  		have_dir_cap =
  			(le32_to_cpu(rinfo->diri.in->cap.caps) &
  			 CEPH_CAP_FILE_SHARED);
  
  		/* do we have a dn lease? */
  		have_lease = have_dir_cap ||

  			le32_to_cpu(rinfo->dlease->duration_ms);

  		if (!have_lease)
  			dout("fill_trace  no dentry lease or dir cap
  ");
  
  		/* rename? */
  		if (req->r_old_dentry && req->r_op == CEPH_MDS_OP_RENAME) {

  			struct inode *olddir = req->r_old_dentry_dir;
  			BUG_ON(!olddir);

  			dout(" src %p '%pd' dst %p '%pd'
  ",

  			     req->r_old_dentry,

  			     req->r_old_dentry,
  			     dn, dn);

  			dout("fill_trace doing d_move %p -> %p
  ",
  			     req->r_old_dentry, dn);

  			/* d_move screws up sibling dentries' offsets */
  			ceph_dir_clear_ordered(dir);
  			ceph_dir_clear_ordered(olddir);

  			d_move(req->r_old_dentry, dn);

  			dout(" src %p '%pd' dst %p '%pd'
  ",
  			     req->r_old_dentry,

  			     req->r_old_dentry,

  			     dn, dn);

  			/* ensure target dentry is invalidated, despite
  			   rehashing bug in vfs_rename_dir */

  			ceph_invalidate_dentry_lease(dn);

  			dout("dn %p gets new offset %lld
  ", req->r_old_dentry,

  			     ceph_dentry(req->r_old_dentry)->offset);

  			dn = req->r_old_dentry;  /* use old_dentry */

  		}
  
  		/* null dentry? */
  		if (!rinfo->head->is_target) {
  			dout("fill_trace null dentry
  ");

  			if (d_really_is_positive(dn)) {

  				ceph_dir_clear_ordered(dir);

  				dout("d_delete %p
  ", dn);
  				d_delete(dn);

  			} else if (have_lease) {
  				if (d_unhashed(dn))

  					d_add(dn, NULL);

  				update_dentry_lease(dn, rinfo->dlease,
  						    session,

  						    req->r_request_started,
  						    NULL, &dvino);

  			}
  			goto done;
  		}
  
  		/* attach proper inode */

  		if (d_really_is_negative(dn)) {

  			ceph_dir_clear_ordered(dir);

  			ihold(in);

  			dn = splice_dentry(dn, in);

  			if (IS_ERR(dn)) {
  				err = PTR_ERR(dn);
  				goto done;
  			}
  			req->r_dentry = dn;  /* may have spliced */

  		} else if (d_really_is_positive(dn) && d_inode(dn) != in) {

  			dout(" %p links to %p %llx.%llx, not %llx.%llx
  ",

  			     dn, d_inode(dn), ceph_vinop(d_inode(dn)),

  			     ceph_vinop(in));

  			d_invalidate(dn);

  			have_lease = false;

  		}

  		if (have_lease) {
  			tvino.ino = le64_to_cpu(rinfo->targeti.in->ino);
  			tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid);

  			update_dentry_lease(dn, rinfo->dlease, session,

  					    req->r_request_started,
  					    &tvino, &dvino);
  		}

  		dout(" final dn %p
  ", dn);

  	} else if ((req->r_op == CEPH_MDS_OP_LOOKUPSNAP ||
  		    req->r_op == CEPH_MDS_OP_MKSNAP) &&
  		   !test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {

  		struct dentry *dn = req->r_dentry;

  		struct inode *dir = req->r_parent;

  
  		/* fill out a snapdir LOOKUPSNAP dentry */
  		BUG_ON(!dn);

  		BUG_ON(!dir);
  		BUG_ON(ceph_snap(dir) != CEPH_SNAPDIR);

  		dout(" linking snapped dir %p to dn %p
  ", in, dn);

  		ceph_dir_clear_ordered(dir);

  		ihold(in);

  		dn = splice_dentry(dn, in);

  		if (IS_ERR(dn)) {
  			err = PTR_ERR(dn);
  			goto done;
  		}
  		req->r_dentry = dn;  /* may have spliced */

  	} else if (rinfo->head->is_dentry) {
  		struct ceph_vino *ptvino = NULL;
  
  		if ((le32_to_cpu(rinfo->diri.in->cap.caps) & CEPH_CAP_FILE_SHARED) ||
  		    le32_to_cpu(rinfo->dlease->duration_ms)) {
  			dvino.ino = le64_to_cpu(rinfo->diri.in->ino);
  			dvino.snap = le64_to_cpu(rinfo->diri.in->snapid);
  
  			if (rinfo->head->is_target) {
  				tvino.ino = le64_to_cpu(rinfo->targeti.in->ino);
  				tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid);
  				ptvino = &tvino;
  			}
  
  			update_dentry_lease(req->r_dentry, rinfo->dlease,
  				session, req->r_request_started, ptvino,
  				&dvino);
  		} else {
  			dout("%s: no dentry lease or dir cap
  ", __func__);
  		}

  	}

  done:
  	dout("fill_trace done err=%d
  ", err);
  	return err;
  }
  
  /*
   * Prepopulate our cache with readdir results, leases, etc.
   */

  static int readdir_prepopulate_inodes_only(struct ceph_mds_request *req,
  					   struct ceph_mds_session *session)
  {
  	struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
  	int i, err = 0;
  
  	for (i = 0; i < rinfo->dir_nr; i++) {

  		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;

  		struct ceph_vino vino;
  		struct inode *in;
  		int rc;

  		vino.ino = le64_to_cpu(rde->inode.in->ino);
  		vino.snap = le64_to_cpu(rde->inode.in->snapid);

  
  		in = ceph_get_inode(req->r_dentry->d_sb, vino);
  		if (IS_ERR(in)) {
  			err = PTR_ERR(in);
  			dout("new_inode badness got %d
  ", err);
  			continue;
  		}

  		rc = fill_inode(in, NULL, &rde->inode, NULL, session,

  				req->r_request_started, -1,
  				&req->r_caps_reservation);
  		if (rc < 0) {
  			pr_err("fill_inode badness on %p got %d
  ", in, rc);
  			err = rc;

  		}

  		iput(in);

  	}
  
  	return err;
  }

  void ceph_readdir_cache_release(struct ceph_readdir_cache_control *ctl)
  {
  	if (ctl->page) {
  		kunmap(ctl->page);

  		put_page(ctl->page);

  		ctl->page = NULL;
  	}
  }
  
  static int fill_readdir_cache(struct inode *dir, struct dentry *dn,
  			      struct ceph_readdir_cache_control *ctl,
  			      struct ceph_mds_request *req)
  {
  	struct ceph_inode_info *ci = ceph_inode(dir);

  	unsigned nsize = PAGE_SIZE / sizeof(struct dentry*);

  	unsigned idx = ctl->index % nsize;
  	pgoff_t pgoff = ctl->index / nsize;
  
  	if (!ctl->page || pgoff != page_index(ctl->page)) {
  		ceph_readdir_cache_release(ctl);

  		if (idx == 0)
  			ctl->page = grab_cache_page(&dir->i_data, pgoff);
  		else
  			ctl->page = find_lock_page(&dir->i_data, pgoff);

  		if (!ctl->page) {
  			ctl->index = -1;

  			return idx == 0 ? -ENOMEM : 0;

  		}
  		/* reading/filling the cache are serialized by
  		 * i_mutex, no need to use page lock */
  		unlock_page(ctl->page);
  		ctl->dentries = kmap(ctl->page);

  		if (idx == 0)

  			memset(ctl->dentries, 0, PAGE_SIZE);

  	}
  
  	if (req->r_dir_release_cnt == atomic64_read(&ci->i_release_count) &&
  	    req->r_dir_ordered_cnt == atomic64_read(&ci->i_ordered_count)) {
  		dout("readdir cache dn %p idx %d
  ", dn, ctl->index);
  		ctl->dentries[idx] = dn;
  		ctl->index++;
  	} else {
  		dout("disable readdir cache
  ");
  		ctl->index = -1;
  	}
  	return 0;
  }

  int ceph_readdir_prepopulate(struct ceph_mds_request *req,
  			     struct ceph_mds_session *session)
  {
  	struct dentry *parent = req->r_dentry;

  	struct ceph_inode_info *ci = ceph_inode(d_inode(parent));

  	struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
  	struct qstr dname;
  	struct dentry *dn;
  	struct inode *in;

  	int err = 0, skipped = 0, ret, i;

  	struct ceph_mds_request_head *rhead = req->r_request->front.iov_base;

  	u32 frag = le32_to_cpu(rhead->args.readdir.frag);

  	u32 last_hash = 0;
  	u32 fpos_offset;

  	struct ceph_readdir_cache_control cache_ctl = {};

  	if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))

  		return readdir_prepopulate_inodes_only(req, session);

  	if (rinfo->hash_order) {
  		if (req->r_path2) {
  			last_hash = ceph_str_hash(ci->i_dir_layout.dl_dir_hash,
  						  req->r_path2,
  						  strlen(req->r_path2));
  			last_hash = ceph_frag_value(last_hash);
  		} else if (rinfo->offset_hash) {
  			/* mds understands offset_hash */
  			WARN_ON_ONCE(req->r_readdir_offset != 2);
  			last_hash = le32_to_cpu(rhead->args.readdir.offset_hash);
  		}

  	}

  	if (rinfo->dir_dir &&
  	    le32_to_cpu(rinfo->dir_dir->frag) != frag) {
  		dout("readdir_prepopulate got new frag %x -> %x
  ",
  		     frag, le32_to_cpu(rinfo->dir_dir->frag));
  		frag = le32_to_cpu(rinfo->dir_dir->frag);

  		if (!rinfo->hash_order)

  			req->r_readdir_offset = 2;

  	}

  
  	if (le32_to_cpu(rinfo->head->op) == CEPH_MDS_OP_LSSNAP) {

  		dout("readdir_prepopulate %d items under SNAPDIR dn %p
  ",
  		     rinfo->dir_nr, parent);
  	} else {
  		dout("readdir_prepopulate %d items under dn %p
  ",
  		     rinfo->dir_nr, parent);
  		if (rinfo->dir_dir)

  			ceph_fill_dirfrag(d_inode(parent), rinfo->dir_dir);

  		if (ceph_frag_is_leftmost(frag) &&
  		    req->r_readdir_offset == 2 &&
  		    !(rinfo->hash_order && last_hash)) {
  			/* note dir version at start of readdir so we can
  			 * tell if any dentries get dropped */
  			req->r_dir_release_cnt =
  				atomic64_read(&ci->i_release_count);
  			req->r_dir_ordered_cnt =
  				atomic64_read(&ci->i_ordered_count);
  			req->r_readdir_cache_idx = 0;
  		}

  	}
  
  	cache_ctl.index = req->r_readdir_cache_idx;

  	fpos_offset = req->r_readdir_offset;

  	/* FIXME: release caps/leases if error occurs */

  	for (i = 0; i < rinfo->dir_nr; i++) {

  		struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;

  		struct ceph_vino tvino, dvino;

  		dname.name = rde->name;
  		dname.len = rde->name_len;

  		dname.hash = full_name_hash(parent, dname.name, dname.len);

  		tvino.ino = le64_to_cpu(rde->inode.in->ino);
  		tvino.snap = le64_to_cpu(rde->inode.in->snapid);

  		if (rinfo->hash_order) {
  			u32 hash = ceph_str_hash(ci->i_dir_layout.dl_dir_hash,
  						 rde->name, rde->name_len);
  			hash = ceph_frag_value(hash);
  			if (hash != last_hash)
  				fpos_offset = 2;
  			last_hash = hash;
  			rde->offset = ceph_make_fpos(hash, fpos_offset++, true);
  		} else {
  			rde->offset = ceph_make_fpos(frag, fpos_offset++, false);
  		}

  
  retry_lookup:
  		dn = d_lookup(parent, &dname);
  		dout("d_lookup on parent=%p name=%.*s got %p
  ",
  		     parent, dname.len, dname.name, dn);
  
  		if (!dn) {
  			dn = d_alloc(parent, &dname);
  			dout("d_alloc %p '%.*s' = %p
  ", parent,
  			     dname.len, dname.name, dn);

  			if (!dn) {

  				dout("d_alloc badness
  ");
  				err = -ENOMEM;
  				goto out;
  			}

  		} else if (d_really_is_positive(dn) &&

  			   (ceph_ino(d_inode(dn)) != tvino.ino ||
  			    ceph_snap(d_inode(dn)) != tvino.snap)) {

  			dout(" dn %p points to wrong inode %p
  ",

  			     dn, d_inode(dn));

  			d_delete(dn);
  			dput(dn);
  			goto retry_lookup;

  		}

  		/* inode */

  		if (d_really_is_positive(dn)) {
  			in = d_inode(dn);

  		} else {

  			in = ceph_get_inode(parent->d_sb, tvino);

  			if (IS_ERR(in)) {

  				dout("new_inode badness
  ");

  				d_drop(dn);

  				dput(dn);

  				err = PTR_ERR(in);

  				goto out;
  			}

  		}

  		ret = fill_inode(in, NULL, &rde->inode, NULL, session,

  				 req->r_request_started, -1,
  				 &req->r_caps_reservation);
  		if (ret < 0) {

  			pr_err("fill_inode badness on %p
  ", in);

  			if (d_really_is_negative(dn))

  				iput(in);
  			d_drop(dn);

  			err = ret;

  			goto next_item;

  		}

  		if (d_really_is_negative(dn)) {

  			struct dentry *realdn;
  
  			if (ceph_security_xattr_deadlock(in)) {
  				dout(" skip splicing dn %p to inode %p"
  				     " (security xattr deadlock)
  ", dn, in);
  				iput(in);
  				skipped++;
  				goto next_item;
  			}
  
  			realdn = splice_dentry(dn, in);

  			if (IS_ERR(realdn)) {
  				err = PTR_ERR(realdn);
  				d_drop(dn);

  				dn = NULL;
  				goto next_item;
  			}

  			dn = realdn;

  		}

  		ceph_dentry(dn)->offset = rde->offset;

  		dvino = ceph_vino(d_inode(parent));

  		update_dentry_lease(dn, rde->lease, req->r_session,

  				    req->r_request_started, &tvino, &dvino);

  		if (err == 0 && skipped == 0 && cache_ctl.index >= 0) {

  			ret = fill_readdir_cache(d_inode(parent), dn,
  						 &cache_ctl, req);
  			if (ret < 0)
  				err = ret;
  		}

  next_item:
  		if (dn)
  			dput(dn);

  	}

  out:

  	if (err == 0 && skipped == 0) {

  		set_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags);

  		req->r_readdir_cache_idx = cache_ctl.index;
  	}
  	ceph_readdir_cache_release(&cache_ctl);

  	dout("readdir_prepopulate done
  ");
  	return err;
  }

  bool ceph_inode_set_size(struct inode *inode, loff_t size)

  {
  	struct ceph_inode_info *ci = ceph_inode(inode);

  	bool ret;

  	spin_lock(&ci->i_ceph_lock);

  	dout("set_size %p %llu -> %llu
  ", inode, inode->i_size, size);

  	i_size_write(inode, size);

  	inode->i_blocks = calc_inode_blocks(size);

  	ret = __ceph_should_report_size(ci);

  	spin_unlock(&ci->i_ceph_lock);

  	return ret;
  }
  
  /*
   * Write back inode data in a worker thread.  (This can't be done
   * in the message handler context.)
   */

  void ceph_queue_writeback(struct inode *inode)
  {

  	ihold(inode);

  	if (queue_work(ceph_inode_to_client(inode)->wb_wq,
  		       &ceph_inode(inode)->i_wb_work)) {

  		dout("ceph_queue_writeback %p
  ", inode);

  	} else {

  		dout("ceph_queue_writeback %p failed
  ", inode);

  		iput(inode);

  	}
  }
  
  static void ceph_writeback_work(struct work_struct *work)

  {
  	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
  						  i_wb_work);
  	struct inode *inode = &ci->vfs_inode;
  
  	dout("writeback %p
  ", inode);
  	filemap_fdatawrite(&inode->i_data);
  	iput(inode);
  }
  
  /*

   * queue an async invalidation
   */
  void ceph_queue_invalidate(struct inode *inode)
  {

  	ihold(inode);

  	if (queue_work(ceph_inode_to_client(inode)->pg_inv_wq,
  		       &ceph_inode(inode)->i_pg_inv_work)) {
  		dout("ceph_queue_invalidate %p
  ", inode);

  	} else {
  		dout("ceph_queue_invalidate %p failed
  ", inode);

  		iput(inode);

  	}
  }
  
  /*

   * Invalidate inode pages in a worker thread.  (This can't be done
   * in the message handler context.)
   */

  static void ceph_invalidate_work(struct work_struct *work)

  {
  	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
  						  i_pg_inv_work);
  	struct inode *inode = &ci->vfs_inode;

  	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);

  	u32 orig_gen;
  	int check = 0;

  	mutex_lock(&ci->i_truncate_mutex);

  	if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {

  		pr_warn_ratelimited("invalidate_pages %p %lld forced umount
  ",
  				    inode, ceph_ino(inode));
  		mapping_set_error(inode->i_mapping, -EIO);
  		truncate_pagecache(inode, 0);
  		mutex_unlock(&ci->i_truncate_mutex);
  		goto out;
  	}

  	spin_lock(&ci->i_ceph_lock);

  	dout("invalidate_pages %p gen %d revoking %d
  ", inode,
  	     ci->i_rdcache_gen, ci->i_rdcache_revoking);

  	if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {

  		if (__ceph_caps_revoking_other(ci, NULL, CEPH_CAP_FILE_CACHE))
  			check = 1;

  		spin_unlock(&ci->i_ceph_lock);

  		mutex_unlock(&ci->i_truncate_mutex);

  		goto out;
  	}
  	orig_gen = ci->i_rdcache_gen;

  	spin_unlock(&ci->i_ceph_lock);

  	if (invalidate_inode_pages2(inode->i_mapping) < 0) {
  		pr_err("invalidate_pages %p fails
  ", inode);
  	}

  	spin_lock(&ci->i_ceph_lock);

  	if (orig_gen == ci->i_rdcache_gen &&
  	    orig_gen == ci->i_rdcache_revoking) {

  		dout("invalidate_pages %p gen %d successful
  ", inode,
  		     ci->i_rdcache_gen);

  		ci->i_rdcache_revoking--;

  		check = 1;
  	} else {

  		dout("invalidate_pages %p gen %d raced, now %d revoking %d
  ",
  		     inode, orig_gen, ci->i_rdcache_gen,
  		     ci->i_rdcache_revoking);

  		if (__ceph_caps_revoking_other(ci, NULL, CEPH_CAP_FILE_CACHE))
  			check = 1;

  	}

  	spin_unlock(&ci->i_ceph_lock);

  	mutex_unlock(&ci->i_truncate_mutex);

  out:

  	if (check)
  		ceph_check_caps(ci, 0, NULL);

  	iput(inode);
  }
  
  
  /*

   * called by trunc_wq;

   *
   * We also truncate in a separate thread as well.
   */

  static void ceph_vmtruncate_work(struct work_struct *work)

  {
  	struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info,
  						  i_vmtruncate_work);
  	struct inode *inode = &ci->vfs_inode;
  
  	dout("vmtruncate_work %p
  ", inode);

  	__ceph_do_pending_vmtruncate(inode);

  	iput(inode);
  }
  
  /*

   * Queue an async vmtruncate.  If we fail to queue work, we will handle
   * the truncation the next time we call __ceph_do_pending_vmtruncate.
   */
  void ceph_queue_vmtruncate(struct inode *inode)
  {
  	struct ceph_inode_info *ci = ceph_inode(inode);

  	ihold(inode);

  	if (queue_work(ceph_sb_to_client(inode->i_sb)->trunc_wq,

  		       &ci->i_vmtruncate_work)) {
  		dout("ceph_queue_vmtruncate %p
  ", inode);

  	} else {
  		dout("ceph_queue_vmtruncate %p failed, pending=%d
  ",
  		     inode, ci->i_truncate_pending);

  		iput(inode);

  	}
  }
  
  /*

   * Make sure any pending truncation is applied before doing anything
   * that may depend on it.
   */

  void __ceph_do_pending_vmtruncate(struct inode *inode)

  {
  	struct ceph_inode_info *ci = ceph_inode(inode);
  	u64 to;

  	int wrbuffer_refs, finish = 0;

  	mutex_lock(&ci->i_truncate_mutex);

  retry:

  	spin_lock(&ci->i_ceph_lock);

  	if (ci->i_truncate_pending == 0) {
  		dout("__do_pending_vmtruncate %p none pending
  ", inode);

  		spin_unlock(&ci->i_ceph_lock);

  		mutex_unlock(&ci->i_truncate_mutex);

  		return;
  	}
  
  	/*
  	 * make sure any dirty snapped pages are flushed before we
  	 * possibly truncate them.. so write AND block!
  	 */
  	if (ci->i_wrbuffer_ref_head < ci->i_wrbuffer_ref) {

  		struct ceph_cap_snap *capsnap;
  		to = ci->i_truncate_size;
  		list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
  			// MDS should have revoked Frw caps
  			WARN_ON_ONCE(capsnap->writing);
  			if (capsnap->dirty_pages && capsnap->size > to)
  				to = capsnap->size;
  		}
  		spin_unlock(&ci->i_ceph_lock);

  		dout("__do_pending_vmtruncate %p flushing snaps first
  ",
  		     inode);

  
  		truncate_pagecache(inode, to);

  		filemap_write_and_wait_range(&inode->i_data, 0,
  					     inode->i_sb->s_maxbytes);
  		goto retry;
  	}

  	/* there should be no reader or writer */
  	WARN_ON_ONCE(ci->i_rd_ref || ci->i_wr_ref);

  	to = ci->i_truncate_size;
  	wrbuffer_refs = ci->i_wrbuffer_ref;
  	dout("__do_pending_vmtruncate %p (%d) to %lld
  ", inode,
  	     ci->i_truncate_pending, to);

  	spin_unlock(&ci->i_ceph_lock);

  	truncate_pagecache(inode, to);

  	spin_lock(&ci->i_ceph_lock);

  	if (to == ci->i_truncate_size) {
  		ci->i_truncate_pending = 0;
  		finish = 1;
  	}

  	spin_unlock(&ci->i_ceph_lock);

  	if (!finish)
  		goto retry;

  	mutex_unlock(&ci->i_truncate_mutex);

  	if (wrbuffer_refs == 0)
  		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);

  
  	wake_up_all(&ci->i_cap_wq);

  }

  /*
   * symlinks
   */

  static const struct inode_operations ceph_symlink_iops = {

  	.get_link = simple_get_link,

  	.setattr = ceph_setattr,
  	.getattr = ceph_getattr,

  	.listxattr = ceph_listxattr,

  };

  int __ceph_setattr(struct inode *inode, struct iattr *attr)

  {

  	struct ceph_inode_info *ci = ceph_inode(inode);

  	const unsigned int ia_valid = attr->ia_valid;
  	struct ceph_mds_request *req;

  	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;

  	struct ceph_cap_flush *prealloc_cf;

  	int issued;
  	int release = 0, dirtied = 0;
  	int mask = 0;
  	int err = 0;

  	int inode_dirty_flags = 0;

  	bool lock_snap_rwsem = false;

  	prealloc_cf = ceph_alloc_cap_flush();
  	if (!prealloc_cf)
  		return -ENOMEM;

  	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETATTR,
  				       USE_AUTH_MDS);

  	if (IS_ERR(req)) {
  		ceph_free_cap_flush(prealloc_cf);

  		return PTR_ERR(req);

  	}

  	spin_lock(&ci->i_ceph_lock);

  	issued = __ceph_caps_issued(ci, NULL);

  
  	if (!ci->i_head_snapc &&
  	    (issued & (CEPH_CAP_ANY_EXCL | CEPH_CAP_FILE_WR))) {
  		lock_snap_rwsem = true;
  		if (!down_read_trylock(&mdsc->snap_rwsem)) {
  			spin_unlock(&ci->i_ceph_lock);
  			down_read(&mdsc->snap_rwsem);
  			spin_lock(&ci->i_ceph_lock);
  			issued = __ceph_caps_issued(ci, NULL);
  		}
  	}

  	dout("setattr %p issued %s
  ", inode, ceph_cap_string(issued));
  
  	if (ia_valid & ATTR_UID) {
  		dout("setattr %p uid %d -> %d
  ", inode,

  		     from_kuid(&init_user_ns, inode->i_uid),
  		     from_kuid(&init_user_ns, attr->ia_uid));

  		if (issued & CEPH_CAP_AUTH_EXCL) {
  			inode->i_uid = attr->ia_uid;
  			dirtied |= CEPH_CAP_AUTH_EXCL;
  		} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||

  			   !uid_eq(attr->ia_uid, inode->i_uid)) {
  			req->r_args.setattr.uid = cpu_to_le32(
  				from_kuid(&init_user_ns, attr->ia_uid));

  			mask |= CEPH_SETATTR_UID;
  			release |= CEPH_CAP_AUTH_SHARED;
  		}
  	}
  	if (ia_valid & ATTR_GID) {
  		dout("setattr %p gid %d -> %d
  ", inode,

  		     from_kgid(&init_user_ns, inode->i_gid),
  		     from_kgid(&init_user_ns, attr->ia_gid));

  		if (issued & CEPH_CAP_AUTH_EXCL) {
  			inode->i_gid = attr->ia_gid;
  			dirtied |= CEPH_CAP_AUTH_EXCL;
  		} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||

  			   !gid_eq(attr->ia_gid, inode->i_gid)) {
  			req->r_args.setattr.gid = cpu_to_le32(
  				from_kgid(&init_user_ns, attr->ia_gid));

  			mask |= CEPH_SETATTR_GID;
  			release |= CEPH_CAP_AUTH_SHARED;
  		}
  	}
  	if (ia_valid & ATTR_MODE) {
  		dout("setattr %p mode 0%o -> 0%o
  ", inode, inode->i_mode,
  		     attr->ia_mode);
  		if (issued & CEPH_CAP_AUTH_EXCL) {
  			inode->i_mode = attr->ia_mode;
  			dirtied |= CEPH_CAP_AUTH_EXCL;
  		} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
  			   attr->ia_mode != inode->i_mode) {

  			inode->i_mode = attr->ia_mode;

  			req->r_args.setattr.mode = cpu_to_le32(attr->ia_mode);
  			mask |= CEPH_SETATTR_MODE;
  			release |= CEPH_CAP_AUTH_SHARED;
  		}
  	}
  
  	if (ia_valid & ATTR_ATIME) {
  		dout("setattr %p atime %ld.%ld -> %ld.%ld
  ", inode,
  		     inode->i_atime.tv_sec, inode->i_atime.tv_nsec,
  		     attr->ia_atime.tv_sec, attr->ia_atime.tv_nsec);
  		if (issued & CEPH_CAP_FILE_EXCL) {
  			ci->i_time_warp_seq++;
  			inode->i_atime = attr->ia_atime;
  			dirtied |= CEPH_CAP_FILE_EXCL;
  		} else if ((issued & CEPH_CAP_FILE_WR) &&
  			   timespec_compare(&inode->i_atime,
  					    &attr->ia_atime) < 0) {
  			inode->i_atime = attr->ia_atime;
  			dirtied |= CEPH_CAP_FILE_WR;
  		} else if ((issued & CEPH_CAP_FILE_SHARED) == 0 ||
  			   !timespec_equal(&inode->i_atime, &attr->ia_atime)) {
  			ceph_encode_timespec(&req->r_args.setattr.atime,
  					     &attr->ia_atime);
  			mask |= CEPH_SETATTR_ATIME;
  			release |= CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_RD |
  				CEPH_CAP_FILE_WR;
  		}
  	}
  	if (ia_valid & ATTR_MTIME) {
  		dout("setattr %p mtime %ld.%ld -> %ld.%ld
  ", inode,
  		     inode->i_mtime.tv_sec, inode->i_mtime.tv_nsec,
  		     attr->ia_mtime.tv_sec, attr->ia_mtime.tv_nsec);
  		if (issued & CEPH_CAP_FILE_EXCL) {
  			ci->i_time_warp_seq++;
  			inode->i_mtime = attr->ia_mtime;
  			dirtied |= CEPH_CAP_FILE_EXCL;
  		} else if ((issued & CEPH_CAP_FILE_WR) &&
  			   timespec_compare(&inode->i_mtime,
  					    &attr->ia_mtime) < 0) {
  			inode->i_mtime = attr->ia_mtime;
  			dirtied |= CEPH_CAP_FILE_WR;
  		} else if ((issued & CEPH_CAP_FILE_SHARED) == 0 ||
  			   !timespec_equal(&inode->i_mtime, &attr->ia_mtime)) {
  			ceph_encode_timespec(&req->r_args.setattr.mtime,
  					     &attr->ia_mtime);
  			mask |= CEPH_SETATTR_MTIME;
  			release |= CEPH_CAP_FILE_SHARED | CEPH_CAP_FILE_RD |
  				CEPH_CAP_FILE_WR;
  		}
  	}
  	if (ia_valid & ATTR_SIZE) {
  		dout("setattr %p size %lld -> %lld
  ", inode,
  		     inode->i_size, attr->ia_size);

  		if ((issued & CEPH_CAP_FILE_EXCL) &&
  		    attr->ia_size > inode->i_size) {

  			i_size_write(inode, attr->ia_size);

  			inode->i_blocks = calc_inode_blocks(attr->ia_size);

  			ci->i_reported_size = attr->ia_size;
  			dirtied |= CEPH_CAP_FILE_EXCL;
  		} else if ((issued & CEPH_CAP_FILE_SHARED) == 0 ||
  			   attr->ia_size != inode->i_size) {
  			req->r_args.setattr.size = cpu_to_le64(attr->ia_size);
  			req->r_args.setattr.old_size =
  				cpu_to_le64(inode->i_size);
  			mask |= CEPH_SETATTR_SIZE;
  			release |= CEPH_CAP_FILE_SHARED | CEPH_CAP_FILE_RD |
  				CEPH_CAP_FILE_WR;
  		}
  	}
  
  	/* these do nothing */
  	if (ia_valid & ATTR_CTIME) {
  		bool only = (ia_valid & (ATTR_SIZE|ATTR_MTIME|ATTR_ATIME|
  					 ATTR_MODE|ATTR_UID|ATTR_GID)) == 0;
  		dout("setattr %p ctime %ld.%ld -> %ld.%ld (%s)
  ", inode,
  		     inode->i_ctime.tv_sec, inode->i_ctime.tv_nsec,
  		     attr->ia_ctime.tv_sec, attr->ia_ctime.tv_nsec,
  		     only ? "ctime only" : "ignored");

  		if (only) {
  			/*
  			 * if kernel wants to dirty ctime but nothing else,
  			 * we need to choose a cap to dirty under, or do
  			 * a almost-no-op setattr
  			 */
  			if (issued & CEPH_CAP_AUTH_EXCL)
  				dirtied |= CEPH_CAP_AUTH_EXCL;
  			else if (issued & CEPH_CAP_FILE_EXCL)
  				dirtied |= CEPH_CAP_FILE_EXCL;
  			else if (issued & CEPH_CAP_XATTR_EXCL)
  				dirtied |= CEPH_CAP_XATTR_EXCL;
  			else
  				mask |= CEPH_SETATTR_CTIME;
  		}
  	}
  	if (ia_valid & ATTR_FILE)
  		dout("setattr %p ATTR_FILE ... hrm!
  ", inode);
  
  	if (dirtied) {

  		inode_dirty_flags = __ceph_mark_dirty_caps(ci, dirtied,
  							   &prealloc_cf);

  		inode->i_ctime = attr->ia_ctime;

  	}
  
  	release &= issued;

  	spin_unlock(&ci->i_ceph_lock);

  	if (lock_snap_rwsem)
  		up_read(&mdsc->snap_rwsem);

  	if (inode_dirty_flags)
  		__mark_inode_dirty(inode, inode_dirty_flags);