1 files changed, 969 insertions, 0 deletions

diff --git a/api/src/glfs-resolve.c b/api/src/glfs-resolve.c
new file mode 100644
index 000000000..4ca2eb6fc
--- /dev/null
+++ b/api/src/glfs-resolve.c
@@ -0,0 +1,969 @@
+/*
+  Copyright (c) 2012 Red Hat, Inc. <http://www.redhat.com>
+  This file is part of GlusterFS.
+
+  This file is licensed to you under your choice of the GNU Lesser
+  General Public License, version 3 or any later version (LGPLv3 or
+  later), or the GNU General Public License, version 2 (GPLv2), in all
+  cases as published by the Free Software Foundation.
+*/
+
+
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <limits.h>
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "glusterfs.h"
+#include "logging.h"
+#include "stack.h"
+#include "event.h"
+#include "glfs-mem-types.h"
+#include "common-utils.h"
+#include "syncop.h"
+#include "call-stub.h"
+
+#include "glfs-internal.h"
+
+#define graphid_str(subvol) (uuid_utoa((unsigned char *)subvol->graph->graph_uuid))
+
+
+int
+glfs_first_lookup_safe (xlator_t *subvol)
+{
+	loc_t  loc = {0, };
+	int    ret = -1;
+
+	loc.inode = subvol->itable->root;
+	memset (loc.gfid, 0, 16);
+	loc.gfid[15] = 1;
+	loc.path = "/";
+	loc.name = "";
+
+	ret = syncop_lookup (subvol, &loc, 0, 0, 0, 0);
+
+	gf_log (subvol->name, GF_LOG_DEBUG, "first lookup complete %d", ret);
+
+	return ret;
+}
+
+
+int
+__glfs_first_lookup (struct glfs *fs, xlator_t *subvol)
+{
+	int ret = -1;
+
+	fs->migration_in_progress = 1;
+	pthread_mutex_unlock (&fs->mutex);
+	{
+		ret = glfs_first_lookup_safe (subvol);
+	}
+	pthread_mutex_lock (&fs->mutex);
+	fs->migration_in_progress = 0;
+	pthread_cond_broadcast (&fs->cond);
+
+	return ret;
+}
+
+
+inode_t *
+glfs_refresh_inode_safe (xlator_t *subvol, inode_t *oldinode)
+{
+	loc_t        loc = {0, };
+	int          ret = -1;
+	struct iatt  iatt = {0, };
+	inode_t     *newinode = NULL;
+
+
+	if (!oldinode)
+		return NULL;
+
+	if (oldinode->table->xl == subvol)
+		return inode_ref (oldinode);
+
+	newinode = inode_find (subvol->itable, oldinode->gfid);
+	if (newinode)
+		return newinode;
+
+	uuid_copy (loc.gfid, oldinode->gfid);
+	loc.inode = inode_new (subvol->itable);
+	if (!loc.inode)
+		return NULL;
+
+	ret = syncop_lookup (subvol, &loc, 0, &iatt, 0, 0);
+
+	if (ret) {
+		gf_log (subvol->name, GF_LOG_WARNING,
+			"inode refresh of %s failed: %s",
+			uuid_utoa (oldinode->gfid), strerror (errno));
+		loc_wipe (&loc);
+		return NULL;
+	}
+
+	newinode = inode_link (loc.inode, 0, 0, &iatt);
+	if (newinode)
+		inode_lookup (newinode);
+
+	loc_wipe (&loc);
+
+	return newinode;
+}
+
+
+inode_t *
+__glfs_refresh_inode (struct glfs *fs, xlator_t *subvol, inode_t *inode)
+{
+	inode_t *newinode = NULL;
+
+	fs->migration_in_progress = 1;
+	pthread_mutex_unlock (&fs->mutex);
+	{
+		newinode = glfs_refresh_inode_safe (subvol, inode);
+	}
+	pthread_mutex_lock (&fs->mutex);
+	fs->migration_in_progress = 0;
+	pthread_cond_broadcast (&fs->cond);
+
+	return newinode;
+}
+
+int
+glfs_loc_touchup (loc_t *loc)
+{
+	char *path = NULL;
+	int   ret = -1;
+	char *bn = NULL;
+
+	if (loc->parent)
+		ret = inode_path (loc->parent, loc->name, &path);
+	else
+		ret = inode_path (loc->inode, 0, &path);
+
+	loc->path = path;
+
+	if (ret < 0 || !path) {
+		ret = -1;
+		errno = ENOMEM;
+		goto out;
+	}
+
+	bn = strrchr (path, '/');
+	if (bn)
+		bn++;
+	loc->name = bn;
+	ret = 0;
+out:
+	return ret;
+}
+
+
+int
+glfs_resolve_symlink (struct glfs *fs, xlator_t *subvol, inode_t *inode,
+		      char **lpath)
+{
+	loc_t  loc = {0, };
+	char  *path = NULL;
+	char  *rpath = NULL;
+	int    ret = -1;
+
+	loc.inode = inode_ref (inode);
+	uuid_copy (loc.gfid, inode->gfid);
+	ret = inode_path (inode, NULL, &rpath);
+	if (ret < 0)
+		goto out;
+	loc.path = rpath;
+
+	ret = syncop_readlink (subvol, &loc, &path, 4096);
+
+	if (ret < 0)
+		goto out;
+
+	if (lpath)
+		*lpath = path;
+out:
+	loc_wipe (&loc);
+	return ret;
+}
+
+
+int
+glfs_resolve_base (struct glfs *fs, xlator_t *subvol, inode_t *inode,
+		   struct iatt *iatt)
+{
+	loc_t       loc = {0, };
+	int         ret = -1;
+	char       *path = NULL;
+
+	loc.inode = inode_ref (inode);
+	uuid_copy (loc.gfid, inode->gfid);
+
+	ret = inode_path (loc.inode, NULL, &path);
+	loc.path = path;
+	if (ret < 0)
+		goto out;
+
+	ret = syncop_lookup (subvol, &loc, NULL, iatt, NULL, NULL);
+out:
+	loc_wipe (&loc);
+
+	return ret;
+}
+
+
+inode_t *
+glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent,
+			const char *component, struct iatt *iatt,
+			int force_lookup)
+{
+	loc_t        loc = {0, };
+	inode_t     *inode = NULL;
+	int          reval = 0;
+	int          ret = -1;
+	int          glret = -1;
+	struct iatt  ciatt = {0, };
+	uuid_t       gfid;
+	dict_t      *xattr_req = NULL;
+
+	loc.name = component;
+
+	loc.parent = inode_ref (parent);
+	uuid_copy (loc.pargfid, parent->gfid);
+
+
+	if (strcmp (component, ".") == 0)
+		loc.inode = inode_ref (parent);
+	else if (strcmp (component, "..") == 0)
+		loc.inode = inode_parent (parent, 0, 0);
+	else
+		loc.inode = inode_grep (parent->table, parent, component);
+
+	if (loc.inode) {
+		uuid_copy (loc.gfid, loc.inode->gfid);
+		reval = 1;
+
+		if (!force_lookup) {
+			inode = inode_ref (loc.inode);
+			ciatt.ia_type = inode->ia_type;
+			goto found;
+		}
+	} else {
+		uuid_generate (gfid);
+		loc.inode = inode_new (parent->table);
+	}
+
+	if (!loc.inode)
+		goto out;
+
+	glret = glfs_loc_touchup (&loc);
+	if (glret < 0) {
+		ret = -1;
+		goto out;
+	}
+
+	ret = syncop_lookup (subvol, &loc, NULL, &ciatt, NULL, NULL);
+	if (ret && reval) {
+		inode_unref (loc.inode);
+		loc.inode = inode_new (parent->table);
+		if (!loc.inode) {
+			errno = ENOMEM;
+			goto out;
+		}
+
+		xattr_req = dict_new ();
+		if (!xattr_req) {
+			errno = ENOMEM;
+			goto out;
+		}
+
+		uuid_generate (gfid);
+
+		ret = dict_set_static_bin (xattr_req, "gfid-req", gfid, 16);
+		if (ret) {
+			errno = ENOMEM;
+			goto out;
+		}
+
+		ret = syncop_lookup (subvol, &loc, xattr_req, &ciatt,
+				     NULL, NULL);
+	}
+	if (ret)
+		goto out;
+
+	inode = inode_link (loc.inode, loc.parent, component, &ciatt);
+found:
+	if (inode)
+		inode_lookup (inode);
+	if (iatt)
+		*iatt = ciatt;
+out:
+	if (xattr_req)
+		dict_unref (xattr_req);
+
+	loc_wipe (&loc);
+
+	return inode;
+}
+
+
+int
+glfs_resolve_at (struct glfs *fs, xlator_t *subvol, inode_t *at,
+		 const char *origpath, loc_t *loc, struct iatt *iatt,
+		 int follow, int reval)
+{
+	inode_t    *inode = NULL;
+	inode_t    *parent = NULL;
+	char       *saveptr = NULL;
+	char       *path = NULL;
+	char       *component = NULL;
+	char       *next_component = NULL;
+	int         ret = -1;
+	struct iatt ciatt = {0, };
+
+	path = gf_strdup (origpath);
+	if (!path) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	parent = NULL;
+	if (at && path[0] != '/') {
+		/* A relative resolution of a path which starts with '/'
+		   is equal to an absolute path resolution.
+		*/
+		inode = inode_ref (at);
+	} else {
+		inode = inode_ref (subvol->itable->root);
+
+		if (strcmp (path, "/") == 0)
+			glfs_resolve_base (fs, subvol, inode, &ciatt);
+	}
+
+	for (component = strtok_r (path, "/", &saveptr);
+	     component; component = next_component) {
+
+		next_component = strtok_r (NULL, "/", &saveptr);
+
+		if (parent)
+			inode_unref (parent);
+
+		parent = inode;
+
+		inode = glfs_resolve_component (fs, subvol, parent,
+						component, &ciatt,
+						/* force hard lookup on the last
+						   component, as the caller
+						   wants proper iatt filled
+						*/
+						(reval || (!next_component &&
+						iatt)));
+		if (!inode)
+			break;
+
+		if (IA_ISLNK (ciatt.ia_type) && (next_component || follow)) {
+			/* If the component is not the last piece,
+			   then following it is necessary even if
+			   not requested by the caller
+			*/
+			char *lpath = NULL;
+			loc_t sym_loc = {0,};
+
+			if (follow > GLFS_SYMLINK_MAX_FOLLOW) {
+				errno = ELOOP;
+				ret = -1;
+				if (inode) {
+					inode_unref (inode);
+					inode = NULL;
+				}
+				break;
+			}
+
+			ret = glfs_resolve_symlink (fs, subvol, inode, &lpath);
+			inode_unref (inode);
+			inode = NULL;
+			if (ret < 0)
+				break;
+
+			ret = glfs_resolve_at (fs, subvol, parent, lpath,
+					       &sym_loc,
+					       /* followed iatt becomes the
+						  component iatt
+					       */
+					       &ciatt,
+					       /* always recurisvely follow while
+						  following symlink
+					       */
+					       follow + 1, reval);
+			if (ret == 0)
+				inode = inode_ref (sym_loc.inode);
+			loc_wipe (&sym_loc);
+			GF_FREE (lpath);
+		}
+
+		if (!next_component)
+			break;
+
+		if (!IA_ISDIR (ciatt.ia_type)) {
+			/* next_component exists and this component is
+			   not a directory
+			*/
+			inode_unref (inode);
+			inode = NULL;
+			ret = -1;
+			errno = ENOTDIR;
+			break;
+		}
+	}
+
+	if (parent && next_component)
+		/* resolution failed mid-way */
+		goto out;
+
+	/* At this point, all components up to the last parent directory
+	   have been resolved successfully (@parent). Resolution of basename
+	   might have failed (@inode) if at all.
+	*/
+
+	loc->parent = parent;
+	if (parent) {
+		uuid_copy (loc->pargfid, parent->gfid);
+		loc->name = component;
+	}
+
+	loc->inode = inode;
+	if (inode) {
+		uuid_copy (loc->gfid, inode->gfid);
+		if (iatt)
+			*iatt = ciatt;
+		ret = 0;
+	}
+
+	glfs_loc_touchup (loc);
+out:
+	GF_FREE (path);
+
+	/* do NOT loc_wipe here as only last component might be missing */
+
+	return ret;
+}
+
+
+int
+glfs_resolve_path (struct glfs *fs, xlator_t *subvol, const char *origpath,
+		   loc_t *loc, struct iatt *iatt, int follow, int reval)
+{
+	int ret = -1;
+	inode_t *cwd = NULL;
+
+	if (origpath[0] == '/')
+		return glfs_resolve_at (fs, subvol, NULL, origpath, loc, iatt,
+					follow, reval);
+
+	cwd = glfs_cwd_get (fs);
+
+	ret = glfs_resolve_at (fs, subvol, cwd, origpath, loc, iatt,
+			       follow, reval);
+	if (cwd)
+		inode_unref (cwd);
+
+	return ret;
+}
+
+
+int
+glfs_resolve (struct glfs *fs, xlator_t *subvol, const char *origpath,
+	      loc_t *loc, struct iatt *iatt, int reval)
+{
+	int ret = -1;
+
+	ret = glfs_resolve_path (fs, subvol, origpath, loc, iatt, 1, reval);
+
+	return ret;
+}
+
+
+int
+glfs_lresolve (struct glfs *fs, xlator_t *subvol, const char *origpath,
+	       loc_t *loc, struct iatt *iatt, int reval)
+{
+	int ret = -1;
+
+	ret = glfs_resolve_path (fs, subvol, origpath, loc, iatt, 0, reval);
+
+	return ret;
+}
+
+
+int
+glfs_migrate_fd_locks_safe (struct glfs *fs, xlator_t *oldsubvol, fd_t *oldfd,
+			    xlator_t *newsubvol, fd_t *newfd)
+{
+	dict_t *lockinfo = NULL;
+	int ret = 0;
+	char uuid1[64];
+
+	if (!oldfd->lk_ctx || fd_lk_ctx_empty (oldfd->lk_ctx))
+		return 0;
+
+	newfd->lk_ctx = fd_lk_ctx_ref (oldfd->lk_ctx);
+
+	ret = syncop_fgetxattr (oldsubvol, oldfd, &lockinfo,
+				GF_XATTR_LOCKINFO_KEY);
+	if (ret < 0) {
+		gf_log (fs->volname, GF_LOG_WARNING,
+			"fgetxattr (%s) failed (%s) on graph %s (%d)",
+			uuid_utoa_r (oldfd->inode->gfid, uuid1),
+			strerror (errno),
+			graphid_str (oldsubvol), oldsubvol->graph->id);
+		goto out;
+	}
+
+	if (!dict_get (lockinfo, GF_XATTR_LOCKINFO_KEY)) {
+		gf_log (fs->volname, GF_LOG_WARNING,
+			"missing lokinfo key (%s) on graph %s (%d)",
+			uuid_utoa_r (oldfd->inode->gfid, uuid1),
+			graphid_str (oldsubvol), oldsubvol->graph->id);
+		goto out;
+	}
+
+	ret = syncop_fsetxattr (newsubvol, newfd, lockinfo, 0);
+	if (ret < 0) {
+		gf_log (fs->volname, GF_LOG_WARNING,
+			"fsetxattr (%s) failed (%s) on graph %s (%d)",
+			uuid_utoa_r (newfd->inode->gfid, uuid1),
+			strerror (errno),
+			graphid_str (newsubvol), newsubvol->graph->id);
+		goto out;
+	}
+out:
+	if (lockinfo)
+		dict_unref (lockinfo);
+	return ret;
+}
+
+
+fd_t *
+glfs_migrate_fd_safe (struct glfs *fs, xlator_t *newsubvol, fd_t *oldfd)
+{
+	fd_t *newfd = NULL;
+	inode_t *oldinode = NULL;
+	inode_t *newinode = NULL;
+	xlator_t *oldsubvol = NULL;
+	int ret = -1;
+	loc_t loc = {0, };
+	char uuid1[64];
+
+
+	oldinode = oldfd->inode;
+	oldsubvol = oldinode->table->xl;
+
+	if (oldsubvol == newsubvol)
+		return fd_ref (oldfd);
+
+	if (!oldsubvol->switched) {
+		ret = syncop_fsync (oldsubvol, oldfd, 0);
+		if (ret) {
+			gf_log (fs->volname, GF_LOG_WARNING,
+				"fsync() failed (%s) on %s graph %s (%d)",
+				strerror (errno),
+				uuid_utoa_r (oldfd->inode->gfid, uuid1),
+				graphid_str (oldsubvol), oldsubvol->graph->id);
+		}
+	}
+
+	newinode = glfs_refresh_inode_safe (newsubvol, oldinode);
+	if (!newinode) {
+		gf_log (fs->volname, GF_LOG_WARNING,
+			"inode (%s) refresh failed (%s) on graph %s (%d)",
+			uuid_utoa_r (oldinode->gfid, uuid1),
+			strerror (errno),
+			graphid_str (newsubvol), newsubvol->graph->id);
+		goto out;
+	}
+
+	newfd = fd_create (newinode, getpid());
+	if (!newfd) {
+		gf_log (fs->volname, GF_LOG_WARNING,
+			"fd_create (%s) failed (%s) on graph %s (%d)",
+			uuid_utoa_r (newinode->gfid, uuid1),
+			strerror (errno),
+			graphid_str (newsubvol), newsubvol->graph->id);
+		goto out;
+	}
+
+	loc.inode = inode_ref (newinode);
+
+        ret = inode_path (oldfd->inode, NULL, (char **)&loc.path);
+        if (ret < 0) {
+                gf_log (fs->volname, GF_LOG_INFO, "inode_path failed");
+                goto out;
+        }
+
+        uuid_copy (loc.gfid, oldinode->gfid);
+
+
+	if (IA_ISDIR (oldinode->ia_type))
+		ret = syncop_opendir (newsubvol, &loc, newfd);
+	else
+		ret = syncop_open (newsubvol, &loc,
+				   oldfd->flags & ~(O_TRUNC|O_EXCL|O_CREAT),
+				   newfd);
+	loc_wipe (&loc);
+
+	if (ret) {
+		gf_log (fs->volname, GF_LOG_WARNING,
+			"syncop_open%s (%s) failed (%s) on graph %s (%d)",
+			IA_ISDIR (oldinode->ia_type) ? "dir" : "",
+			uuid_utoa_r (newinode->gfid, uuid1),
+			strerror (errno),
+			graphid_str (newsubvol), newsubvol->graph->id);
+		goto out;
+	}
+
+	ret = glfs_migrate_fd_locks_safe (fs, oldsubvol, oldfd, newsubvol,
+					  newfd);
+
+	if (ret) {
+		gf_log (fs->volname, GF_LOG_WARNING,
+			"lock migration (%s) failed (%s) on graph %s (%d)",
+			uuid_utoa_r (newinode->gfid, uuid1),
+			strerror (errno),
+			graphid_str (newsubvol), newsubvol->graph->id);
+		goto out;
+	}
+
+        newfd->flags = oldfd->flags;
+	fd_bind (newfd);
+out:
+	if (newinode)
+		inode_unref (newinode);
+
+	if (ret) {
+		fd_unref (newfd);
+		newfd = NULL;
+	}
+
+	return newfd;
+}
+
+
+fd_t *
+__glfs_migrate_fd (struct glfs *fs, xlator_t *newsubvol, struct glfs_fd *glfd)
+{
+	fd_t *oldfd = NULL;
+	fd_t *newfd = NULL;
+
+	oldfd = glfd->fd;
+
+	fs->migration_in_progress = 1;
+	pthread_mutex_unlock (&fs->mutex);
+	{
+		newfd = glfs_migrate_fd_safe (fs, newsubvol, oldfd);
+	}
+	pthread_mutex_lock (&fs->mutex);
+	fs->migration_in_progress = 0;
+	pthread_cond_broadcast (&fs->cond);
+
+	return newfd;
+}
+
+
+fd_t *
+__glfs_resolve_fd (struct glfs *fs, xlator_t *subvol, struct glfs_fd *glfd)
+{
+	fd_t *fd = NULL;
+
+	if (glfd->fd->inode->table->xl == subvol)
+		return fd_ref (glfd->fd);
+
+	fd = __glfs_migrate_fd (fs, subvol, glfd);
+	if (!fd)
+		return NULL;
+
+	if (subvol == fs->active_subvol) {
+		fd_unref (glfd->fd);
+		glfd->fd = fd_ref (fd);
+	}
+
+	return fd;
+}
+
+
+fd_t *
+glfs_resolve_fd (struct glfs *fs, xlator_t *subvol, struct glfs_fd *glfd)
+{
+	fd_t *fd = NULL;
+
+	glfs_lock (fs);
+	{
+		fd = __glfs_resolve_fd (fs, subvol, glfd);
+	}
+	glfs_unlock (fs);
+
+	return fd;
+}
+
+
+void
+__glfs_migrate_openfds (struct glfs *fs, xlator_t *subvol)
+{
+	struct glfs_fd *glfd = NULL;
+	fd_t *fd = NULL;
+
+	list_for_each_entry (glfd, &fs->openfds, openfds) {
+		if (uuid_is_null (glfd->fd->inode->gfid)) {
+			gf_log (fs->volname, GF_LOG_INFO,
+				"skipping openfd %p/%p in graph %s (%d)",
+				glfd, glfd->fd,	graphid_str(subvol),
+				subvol->graph->id);
+			/* create in progress, defer */
+			continue;
+		}
+
+		fd = __glfs_migrate_fd (fs, subvol, glfd);
+		if (fd) {
+			fd_unref (glfd->fd);
+			glfd->fd = fd;
+		}
+	}
+}
+
+
+xlator_t *
+__glfs_active_subvol (struct glfs *fs)
+{
+	xlator_t      *new_subvol = NULL;
+	int            ret = -1;
+	inode_t       *new_cwd = NULL;
+
+	if (!fs->next_subvol)
+		return fs->active_subvol;
+
+	new_subvol = fs->next_subvol;
+
+	ret = __glfs_first_lookup (fs, new_subvol);
+	if (ret) {
+		gf_log (fs->volname, GF_LOG_INFO,
+			"first lookup on graph %s (%d) failed (%s)",
+			graphid_str (new_subvol), new_subvol->graph->id,
+			strerror (errno));
+		return NULL;
+	}
+
+	if (fs->cwd) {
+		new_cwd = __glfs_refresh_inode (fs, new_subvol, fs->cwd);
+
+		if (!new_cwd) {
+			char buf1[64];
+			gf_log (fs->volname, GF_LOG_INFO,
+				"cwd refresh of %s graph %s (%d) failed (%s)",
+				uuid_utoa_r (fs->cwd->gfid, buf1),
+				graphid_str (new_subvol),
+				new_subvol->graph->id, strerror (errno));
+			return NULL;
+		}
+	}
+
+	__glfs_migrate_openfds (fs, new_subvol);
+
+	/* switching @active_subvol and @cwd
+	   should be atomic
+	*/
+	fs->old_subvol = fs->active_subvol;
+	fs->active_subvol = fs->next_subvol;
+	fs->next_subvol = NULL;
+
+	if (new_cwd) {
+		__glfs_cwd_set (fs, new_cwd);
+		inode_unref (new_cwd);
+	}
+
+	gf_log (fs->volname, GF_LOG_INFO, "switched to graph %s (%d)",
+		graphid_str (new_subvol), new_subvol->graph->id);
+
+	return new_subvol;
+}
+
+xlator_t *
+glfs_active_subvol (struct glfs *fs)
+{
+	xlator_t      *subvol = NULL;
+	xlator_t      *old_subvol = NULL;
+
+	glfs_lock (fs);
+	{
+		subvol = __glfs_active_subvol (fs);
+
+		if (subvol)
+			subvol->winds++;
+
+		if (fs->old_subvol) {
+			old_subvol = fs->old_subvol;
+			fs->old_subvol = NULL;
+			old_subvol->switched = 1;
+		}
+	}
+	glfs_unlock (fs);
+
+	if (old_subvol)
+		glfs_subvol_done (fs, old_subvol);
+
+	return subvol;
+}
+
+
+void
+glfs_subvol_done (struct glfs *fs, xlator_t *subvol)
+{
+	int ref = 0;
+	xlator_t *active_subvol = NULL;
+
+	if (!subvol)
+		return;
+
+	glfs_lock (fs);
+	{
+		ref = (--subvol->winds);
+		active_subvol = fs->active_subvol;
+	}
+	glfs_unlock (fs);
+
+	if (ref == 0) {
+		assert (subvol != active_subvol);
+		xlator_notify (subvol, GF_EVENT_PARENT_DOWN, subvol, NULL);
+	}
+}
+
+
+int
+__glfs_cwd_set (struct glfs *fs, inode_t *inode)
+{
+	if (inode->table->xl != fs->active_subvol) {
+		inode = __glfs_refresh_inode (fs, fs->active_subvol, inode);
+		if (!inode)
+			return -1;
+	} else {
+		inode_ref (inode);
+	}
+
+	if (fs->cwd)
+		inode_unref (fs->cwd);
+
+	fs->cwd = inode;
+
+	return 0;
+}
+
+
+int
+glfs_cwd_set (struct glfs *fs, inode_t *inode)
+{
+	int ret = 0;
+
+	glfs_lock (fs);
+	{
+		ret = __glfs_cwd_set (fs, inode);
+	}
+	glfs_unlock (fs);
+
+	return ret;
+}
+
+
+inode_t *
+__glfs_cwd_get (struct glfs *fs)
+{
+	inode_t *cwd = NULL;
+
+	if (!fs->cwd)
+		return NULL;
+
+	if (fs->cwd->table->xl == fs->active_subvol) {
+		cwd = inode_ref (fs->cwd);
+		return cwd;
+	}
+
+	cwd = __glfs_refresh_inode (fs, fs->active_subvol, fs->cwd);
+
+	return cwd;
+}
+
+inode_t *
+glfs_cwd_get (struct glfs *fs)
+{
+	inode_t *cwd = NULL;
+
+	glfs_lock (fs);
+	{
+		cwd = __glfs_cwd_get (fs);
+	}
+	glfs_unlock (fs);
+
+	return cwd;
+}
+
+inode_t *
+__glfs_resolve_inode (struct glfs *fs, xlator_t *subvol,
+		    struct glfs_object *object)
+{
+	inode_t *inode = NULL;
+
+	if (object->inode->table->xl == subvol)
+		return inode_ref (object->inode);
+
+	inode = __glfs_refresh_inode (fs, fs->active_subvol,
+					object->inode);
+	if (!inode)
+		return NULL;
+
+	if (subvol == fs->active_subvol) {
+		inode_unref (object->inode);
+		object->inode = inode_ref (inode);
+	}
+
+	return inode;
+}
+
+inode_t *
+glfs_resolve_inode (struct glfs *fs, xlator_t *subvol,
+		    struct glfs_object *object)
+{
+	inode_t *inode = NULL;
+
+	glfs_lock (fs);
+	{
+		inode = __glfs_resolve_inode(fs, subvol, object);
+	}
+	glfs_unlock (fs);
+
+	return inode;
+}
+
+int
+glfs_create_object (loc_t *loc, struct glfs_object **retobject)
+{
+	struct glfs_object *object = NULL;
+
+	object = GF_CALLOC (1, sizeof(struct glfs_object),
+			    glfs_mt_glfs_object_t);
+	if (object == NULL) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	object->inode = loc->inode;
+	uuid_copy (object->gfid, object->inode->gfid);
+
+	/* we hold the reference */
+	loc->inode = NULL;
+
+	*retobject = object;
+
+	return 0;
+}