/*
   Copyright (c) 2006-2010 Gluster, Inc. <http://www.gluster.com>
   This file is part of GlusterFS.

   GlusterFS is free software; you can redistribute it and/or modify
   it under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation; either version 3 of the License,
   or (at your option) any later version.

   GlusterFS is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program.  If not, see
   <http://www.gnu.org/licenses/>.
*/

/*
 * TODO:
 * Need to free_state() when fuse_reply_err() + return.
 * Check loc->path for "" after fuse_loc_fill in all fops
 * (now being done in getattr, lookup) or better - make
 * fuse_loc_fill() and inode_path() return success/failure.
 */

#include "fuse-bridge.h"

static int gf_fuse_conn_err_log;
static int gf_fuse_xattr_enotsup_log;


/*
 * iov_out should contain a fuse_out_header at zeroth position.
 * The error value of this header is sent to kernel.
 */
static int
send_fuse_iov (xlator_t *this, fuse_in_header_t *finh, struct iovec *iov_out,
               int count)
{
        fuse_private_t *priv = NULL;
        struct fuse_out_header *fouh = NULL;
        int res, i;

        if (!this || !finh || !iov_out) {
                gf_log ("send_fuse_iov", GF_LOG_ERROR,"Invalid arguments");
                return -1;
        }
        priv = this->private;

        fouh = iov_out[0].iov_base;
        iov_out[0].iov_len = sizeof (*fouh);
        fouh->len = 0;
        for (i = 0; i < count; i++)
                fouh->len += iov_out[i].iov_len;
        fouh->unique = finh->unique;

        res = writev (priv->fd, iov_out, count);

        if (res == -1)
                return errno;
        if (res != fouh->len)
                return EINVAL;

        if (priv->fuse_dump_fd != -1) {
                char w = 'W';

                pthread_mutex_lock (&priv->fuse_dump_mutex);
                res = write (priv->fuse_dump_fd, &w, 1);
                if (res != -1)
                        res = writev (priv->fuse_dump_fd, iov_out, count);
                pthread_mutex_unlock (&priv->fuse_dump_mutex);

                if (res == -1)
                        gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                                "failed to dump fuse message (W): %s",
                                strerror (errno));
        }

        return 0;
}

static int
send_fuse_data (xlator_t *this, fuse_in_header_t *finh, void *data, size_t size)
{
        struct fuse_out_header fouh = {0, };
        struct iovec iov_out[2];

        fouh.error = 0;
        iov_out[0].iov_base = &fouh;
        iov_out[1].iov_base = data;
        iov_out[1].iov_len = size;

        return send_fuse_iov (this, finh, iov_out, 2);
}

#define send_fuse_obj(this, finh, obj) \
        send_fuse_data (this, finh, obj, sizeof (*(obj)))

int
send_fuse_err (xlator_t *this, fuse_in_header_t *finh, int error)
{
        struct fuse_out_header fouh = {0, };
        struct iovec iov_out;

        fouh.error = -error;
        iov_out.iov_base = &fouh;

        return send_fuse_iov (this, finh, &iov_out, 1);
}

static int
fuse_entry_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                int32_t op_ret, int32_t op_errno,
                inode_t *inode, struct iatt *buf)
{
        fuse_state_t            *state = NULL;
        fuse_in_header_t        *finh = NULL;
        struct fuse_entry_out    feo = {0, };
        fuse_private_t          *priv = NULL;
        inode_t                 *linked_inode = NULL;

        priv = this->private;
        state = frame->root->state;
        finh = state->finh;

        if (!op_ret && state->loc.ino == 1) {
                buf->ia_ino = 1;
        }

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => %"PRId64" (%"PRId64")",
                        frame->root->unique, gf_fop_list[frame->root->op],
                        state->loc.path, buf->ia_ino, state->loc.ino);

                buf->ia_blksize = this->ctx->page_size;
                gf_fuse_stat2attr (buf, &feo.attr);

                if (!buf->ia_ino) {
                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                "%"PRIu64": %s() %s returning inode 0",
                                frame->root->unique,
                                gf_fop_list[frame->root->op], state->loc.path);
                }

                linked_inode = inode_link (inode, state->loc.parent,
                                           state->loc.name, buf);

                if (linked_inode != inode) {
                }

                inode_lookup (linked_inode);

                /* TODO: make these timeouts configurable (via meta?) */
                /* should we do linked_node or inode */
                feo.nodeid = inode_to_fuse_nodeid (linked_inode);

                inode_unref (linked_inode);

                feo.entry_valid =
                        calc_timeout_sec (priv->entry_timeout);
                feo.entry_valid_nsec =
                        calc_timeout_nsec (priv->entry_timeout);
                feo.attr_valid =
                        calc_timeout_sec (priv->attribute_timeout);
                feo.attr_valid_nsec =
                        calc_timeout_nsec (priv->attribute_timeout);

#if FUSE_KERNEL_MINOR_VERSION >= 9
                priv->proto_minor >= 9 ?
                send_fuse_obj (this, finh, &feo) :
                send_fuse_data (this, finh, &feo,
                                FUSE_COMPAT_ENTRY_OUT_SIZE);
#else
                send_fuse_obj (this, finh, &feo);
#endif
        } else {
                gf_log ("glusterfs-fuse",
                        (op_errno == ENOENT ? GF_LOG_TRACE : GF_LOG_WARNING),
                        "%"PRIu64": %s() %s => -1 (%s)", frame->root->unique,
                        gf_fop_list[frame->root->op], state->loc.path,
                        strerror (op_errno));
                send_fuse_err (this, state->finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);
        return 0;
}


static int
fuse_newentry_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno,
                   inode_t *inode, struct iatt *buf, struct iatt *preparent,
                   struct iatt *postparent)
{
        fuse_entry_cbk (frame, cookie, this, op_ret, op_errno, inode, buf);
        return 0;
}


static int
fuse_lookup_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 int32_t op_ret, int32_t op_errno,
                 inode_t *inode, struct iatt *stat, dict_t *dict,
                 struct iatt *postparent)
{
        fuse_state_t            *state = NULL;
        call_frame_t            *prev = NULL;
        inode_table_t           *itable = NULL;

        state = frame->root->state;
        prev  = cookie;

        if (op_ret == -1 && state->is_revalidate == 1) {
                itable = state->loc.inode->table;
                inode_unref (state->loc.inode);
                state->loc.inode = inode_new (itable);
                state->is_revalidate = 2;

                STACK_WIND (frame, fuse_lookup_cbk,
                            prev->this, prev->this->fops->lookup,
                            &state->loc, state->dict);
                return 0;
        }

        fuse_entry_cbk (frame, cookie, this, op_ret, op_errno, inode, stat);
        return 0;
}

void
fuse_lookup_resume (fuse_state_t *state)
{
        if (!state->loc.parent && !state->loc.inode) {
                gf_log ("fuse", GF_LOG_ERROR, "failed to resolve path %s",
                        state->loc.path);
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        if (state->loc.inode) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": LOOKUP %s(%"PRId64")", state->finh->unique,
                        state->loc.path, state->loc.inode->ino);
                state->is_revalidate = 1;
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": LOOKUP %s", state->finh->unique,
                        state->loc.path);
                state->loc.inode = inode_new (state->loc.parent->table);
        }

        FUSE_FOP (state, fuse_lookup_cbk, GF_FOP_LOOKUP,
                  lookup, &state->loc, state->dict);
}

static void
fuse_lookup (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        char         *name      = msg;
        fuse_state_t *state     = NULL;
        int32_t       ret       = -1;

        GET_STATE (this, finh, state);

        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": LOOKUP %"PRIu64"/%s (fuse_loc_fill() failed)",
                        finh->unique, finh->nodeid, name);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        if (state->loc.inode) {
                uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        } else {
                uuid_generate (state->gfid);
        }

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_lookup_resume);

}


static void
fuse_forget (xlator_t *this, fuse_in_header_t *finh, void *msg)

{
        struct fuse_forget_in *ffi = msg;

        inode_t      *fuse_inode;

        if (finh->nodeid == 1) {
                GF_FREE (finh);
                return;
        }

        fuse_inode = fuse_ino_to_inode (finh->nodeid, this);

        inode_forget (fuse_inode, ffi->nlookup);
        inode_unref (fuse_inode);

        GF_FREE (finh);
}


static int
fuse_truncate_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno, struct iatt *prebuf,
                   struct iatt *postbuf)
{
        fuse_state_t     *state;
        fuse_in_header_t *finh;
        fuse_private_t   *priv = NULL;
        struct fuse_attr_out fao;

        priv  = this->private;
        state = frame->root->state;
        finh  = state->finh;

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => %"PRId64, frame->root->unique,
                        gf_fop_list[frame->root->op],
                        state->loc.path ? state->loc.path : "ERR",
                        prebuf->ia_ino);

                /* TODO: make these timeouts configurable via meta */
                /* TODO: what if the inode number has changed by now */
                postbuf->ia_blksize = this->ctx->page_size;
                gf_fuse_stat2attr (postbuf, &fao.attr);

                fao.attr_valid = calc_timeout_sec (priv->attribute_timeout);
                fao.attr_valid_nsec =
                  calc_timeout_nsec (priv->attribute_timeout);

#if FUSE_KERNEL_MINOR_VERSION >= 9
                priv->proto_minor >= 9 ?
                send_fuse_obj (this, finh, &fao) :
                send_fuse_data (this, finh, &fao,
                                FUSE_COMPAT_ATTR_OUT_SIZE);
#else
                send_fuse_obj (this, finh, &fao);
#endif
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": %s() %s => -1 (%s)", frame->root->unique,
                        gf_fop_list[frame->root->op],
                        state->loc.path ? state->loc.path : "ERR",
                        strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}


static int
fuse_attr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
               int32_t op_ret, int32_t op_errno, struct iatt *buf)
{
        fuse_state_t     *state;
        fuse_in_header_t *finh;
        fuse_private_t   *priv = NULL;
        struct fuse_attr_out fao;

        priv  = this->private;
        state = frame->root->state;
        finh  = state->finh;

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => %"PRId64, frame->root->unique,
                        gf_fop_list[frame->root->op],
                        state->loc.path ? state->loc.path : "ERR",
                        buf->ia_ino);

                /* TODO: make these timeouts configurable via meta */
                /* TODO: what if the inode number has changed by now */
                buf->ia_blksize = this->ctx->page_size;
                gf_fuse_stat2attr (buf, &fao.attr);

                fao.attr_valid = calc_timeout_sec (priv->attribute_timeout);
                fao.attr_valid_nsec =
                  calc_timeout_nsec (priv->attribute_timeout);

#if FUSE_KERNEL_MINOR_VERSION >= 9
                priv->proto_minor >= 9 ?
                send_fuse_obj (this, finh, &fao) :
                send_fuse_data (this, finh, &fao,
                                FUSE_COMPAT_ATTR_OUT_SIZE);
#else
                send_fuse_obj (this, finh, &fao);
#endif
        } else {
                GF_LOG_OCCASIONALLY ( gf_fuse_conn_err_log, "glusterfs-fuse", 
                                      GF_LOG_WARNING, 
                                      "%"PRIu64": %s() %s => -1 (%s)", 
                                      frame->root->unique,
                                      gf_fop_list[frame->root->op],
                                      state->loc.path ? state->loc.path : "ERR",
                                      strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}


static int
fuse_root_lookup_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                      int32_t op_ret, int32_t op_errno,
                      inode_t *inode, struct iatt *stat, dict_t *dict,
                      struct iatt *postparent)
{
        fuse_attr_cbk (frame, cookie, this, op_ret, op_errno, stat);

        return 0;
}

void
fuse_getattr_resume (fuse_state_t *state)
{
        if (!state->fd || IA_ISDIR (state->loc.inode->ia_type)) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": GETATTR %"PRIu64" (%s)",
                        state->finh->unique, state->finh->nodeid,
                        state->loc.path);

                FUSE_FOP (state, fuse_attr_cbk, GF_FOP_STAT,
                          stat, &state->loc);
        } else {

                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": FGETATTR %"PRIu64" (%s/%p)",
                        state->finh->unique, state->finh->nodeid,
                        state->loc.path, state->fd);

                FUSE_FOP (state, fuse_attr_cbk, GF_FOP_FSTAT,
                          fstat, state->fd);
        }
}

static void
fuse_getattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        fuse_state_t *state;
        fd_t         *fd = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);

        if (finh->nodeid == 1) {
                state->gfid[15] = 1;

                ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
                if (ret < 0) {
                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                "%"PRIu64": GETATTR on / (fuse_loc_fill() failed)",
                                finh->unique);
                        send_fuse_err (this, finh, ENOENT);
                        free_fuse_state (state);
                        return;
                }

                fuse_gfid_set (state);

                FUSE_FOP (state, fuse_root_lookup_cbk, GF_FOP_LOOKUP,
                          lookup, &state->loc, state->dict);
                return;
        }

        ret = fuse_loc_fill (&state->loc, state, state->finh->nodeid, 0, NULL);

        if (!state->loc.inode) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": GETATTR %"PRIu64" (%s) (fuse_loc_fill() returned NULL inode)",
                        state->finh->unique, state->finh->nodeid, state->loc.path);
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        fd = fd_lookup (state->loc.inode, state->finh->pid);
        state->fd = fd;
        if (!fd || IA_ISDIR (state->loc.inode->ia_type)) {
                /* this is the @ret of fuse_loc_fill, checked here
                   to permit fstat() to happen even when fuse_loc_fill fails
                */
                if (ret < 0) {
                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                "%"PRIu64": GETATTR %"PRIu64" (fuse_loc_fill() failed)",
                                state->finh->unique, state->finh->nodeid);
                        send_fuse_err (state->this, state->finh, ENOENT);
                        free_fuse_state (state);
                        return;
                }

                if (state->fd)
                        fd_unref (state->fd);

                state->fd = NULL;
        }

        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        if (state->loc.path)
                state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_getattr_resume);
}


static int
fuse_fd_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
             int32_t op_ret, int32_t op_errno, fd_t *fd)
{
        fuse_state_t          *state;
        fuse_in_header_t      *finh;
        fuse_private_t        *priv = NULL;
        struct fuse_open_out   foo = {0, };

        priv = this->private;
        state = frame->root->state;
        finh = state->finh;

        if (op_ret >= 0) {
                foo.fh = (uintptr_t) fd;
                foo.open_flags = 0;

                if (!IA_ISDIR (fd->inode->ia_type)) {
                        if (((priv->direct_io_mode == 2)
                             && ((state->flags & O_ACCMODE) != O_RDONLY))
                            || (priv->direct_io_mode == 1))
                                foo.open_flags |= FOPEN_DIRECT_IO;
#ifdef GF_DARWIN_HOST_OS
                                /* In Linux: by default, buffer cache
                                 * is purged upon open, setting
                                 * FOPEN_KEEP_CACHE implies no-purge
                                 *
                                 * In MacFUSE: by default, buffer cache
                                 * is left intact upon open, setting
                                 * FOPEN_PURGE_UBC implies purge
                                 *
                                 * [[Innnnteresting...]]
                                 */
                                foo.open_flags |= FOPEN_PURGE_UBC;
#endif
                }

                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => %p", frame->root->unique,
                        gf_fop_list[frame->root->op], state->loc.path, fd);

                fd_ref (fd);
                if (send_fuse_obj (this, finh, &foo) == ENOENT) {
                        gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
                                "open(%s) got EINTR", state->loc.path);
                        fd_unref (fd);
                                goto out;
                }

                fd_bind (fd);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": %s() %s => -1 (%s)", frame->root->unique,
                        gf_fop_list[frame->root->op], state->loc.path,
                        strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }
out:
        free_fuse_state (state);
        STACK_DESTROY (frame->root);
        return 0;
}


static void
fuse_do_truncate (fuse_state_t *state, size_t size)
{
        if (state->fd) {
                FUSE_FOP (state, fuse_truncate_cbk, GF_FOP_FTRUNCATE,
                          ftruncate, state->fd, size);
        } else {
                FUSE_FOP (state, fuse_truncate_cbk, GF_FOP_TRUNCATE,
                          truncate, &state->loc, size);
        }

        return;
}


static int
fuse_setattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                  int32_t op_ret, int32_t op_errno,
                  struct iatt *statpre, struct iatt *statpost)
{
        fuse_state_t     *state;
        fuse_in_header_t *finh;
        fuse_private_t   *priv = NULL;
        struct fuse_attr_out fao;

        int op_done = 0;

        priv  = this->private;
        state = frame->root->state;
        finh  = state->finh;

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => %"PRId64, frame->root->unique,
                        gf_fop_list[frame->root->op],
                        state->loc.path ? state->loc.path : "ERR",
                        statpost->ia_ino);

                /* TODO: make these timeouts configurable via meta */
                /* TODO: what if the inode number has changed by now */

                statpost->ia_blksize = this->ctx->page_size;

                gf_fuse_stat2attr (statpost, &fao.attr);

                fao.attr_valid = calc_timeout_sec (priv->attribute_timeout);
                fao.attr_valid_nsec =
                        calc_timeout_nsec (priv->attribute_timeout);

                if (state->truncate_needed) {
                        fuse_do_truncate (state, state->size);
                } else {
#if FUSE_KERNEL_MINOR_VERSION >= 9
                        priv->proto_minor >= 9 ?
                        send_fuse_obj (this, finh, &fao) :
                        send_fuse_data (this, finh, &fao,
                                        FUSE_COMPAT_ATTR_OUT_SIZE);
#else
                        send_fuse_obj (this, finh, &fao);
#endif
                        op_done = 1;
                }
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": %s() %s => -1 (%s)", frame->root->unique,
                        gf_fop_list[frame->root->op],
                        state->loc.path ? state->loc.path : "ERR",
                        strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
                op_done = 1;
        }

        if (op_done) {
                free_fuse_state (state);
        }

        STACK_DESTROY (frame->root);

        return 0;
}


static int32_t
fattr_to_gf_set_attr (int32_t valid)
{
        int32_t gf_valid = 0;

        if (valid & FATTR_MODE)
                gf_valid |= GF_SET_ATTR_MODE;

        if (valid & FATTR_UID)
                gf_valid |= GF_SET_ATTR_UID;

        if (valid & FATTR_GID)
                gf_valid |= GF_SET_ATTR_GID;

        if (valid & FATTR_ATIME)
                gf_valid |= GF_SET_ATTR_ATIME;

        if (valid & FATTR_MTIME)
                gf_valid |= GF_SET_ATTR_MTIME;

        if (valid & FATTR_SIZE)
                gf_valid |= GF_SET_ATTR_SIZE;

        return gf_valid;
}


#define FATTR_MASK   (FATTR_SIZE                        \
                      | FATTR_UID | FATTR_GID           \
                      | FATTR_ATIME | FATTR_MTIME       \
                      | FATTR_MODE)

void
fuse_setattr_resume (fuse_state_t *state)
{
        if ((state->valid & (FATTR_MASK)) != FATTR_SIZE) {
                if (state->fd &&
                    !((state->valid & FATTR_ATIME) ||
                      (state->valid & FATTR_MTIME))) {
                        /*
                            there is no "futimes" call, so don't send
                            fsetattr if ATIME or MTIME is set
                         */

                        FUSE_FOP (state, fuse_setattr_cbk, GF_FOP_FSETATTR,
                                  fsetattr, state->fd, &state->attr,
                                  fattr_to_gf_set_attr (state->valid));
                } else {
                        FUSE_FOP (state, fuse_setattr_cbk, GF_FOP_SETATTR,
                                  setattr, &state->loc, &state->attr,
                                  fattr_to_gf_set_attr (state->valid));
                }
        } else {
                fuse_do_truncate (state, state->size);
        }

}

static void
fuse_setattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_setattr_in *fsi = msg;

        fuse_private_t  *priv = NULL;
        fuse_state_t *state = NULL;
        int32_t       ret   = -1;

        GET_STATE (this, finh, state);

        if (fsi->valid & FATTR_FH &&
            !(fsi->valid & (FATTR_ATIME|FATTR_MTIME)))
                /* We need no loc if kernel sent us an fd and
                 * we are not fiddling with times */
                ret = 1;
        else
                ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0,
                                     NULL);

        /*
         * This is just stub code demonstrating how to retrieve
         * lock_owner in setattr, according to the FUSE proto.
         * We do not make use of ATM. Its purpose is supporting
         * mandatory locking, but getting that right is further
         * down the road. Cf.
         *
         * http://thread.gmane.org/gmane.comp.file-systems.fuse.devel/
         * 4962/focus=4982
         *
         * http://git.kernel.org/?p=linux/kernel/git/torvalds/
         * linux-2.6.git;a=commit;h=v2.6.23-5896-gf333211
         */
        priv = this->private;
#if FUSE_KERNEL_MINOR_VERSION >= 9
        if (priv->proto_minor >= 9 && fsi->valid & FATTR_LOCKOWNER)
                state->lk_owner = fsi->lock_owner;
#endif

        if ((state->loc.inode == NULL && ret == 0) ||
            (ret < 0)) {

                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": SETATTR %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);

                return;
        }

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": SETATTR (%"PRIu64")%s", finh->unique,
                finh->nodeid, state->loc.path);

        state->valid = fsi->valid;

        if (fsi->valid & FATTR_FH) {
                state->fd = FH_TO_FD (fsi->fh);
        }

        if ((fsi->valid & (FATTR_MASK)) != FATTR_SIZE) {
                if (fsi->valid & FATTR_SIZE) {
                        state->size            = fsi->size;
                        state->truncate_needed = _gf_true;
                }

                state->attr.ia_size  = fsi->size;
                state->attr.ia_atime = fsi->atime;
                state->attr.ia_mtime = fsi->mtime;
                state->attr.ia_atime_nsec = fsi->atimensec;
                state->attr.ia_mtime_nsec = fsi->mtimensec;

                state->attr.ia_prot = ia_prot_from_st_mode (fsi->mode);
                state->attr.ia_uid  = fsi->uid;
                state->attr.ia_gid  = fsi->gid;
        } else {
                state->size = fsi->size;
        }

        if (!state->fd) {
                uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
                state->resolve.path = gf_strdup (state->loc.path);
        }

        fuse_resolve_and_resume (state, fuse_setattr_resume);
}


static int
fuse_err_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
              int32_t op_ret, int32_t op_errno)
{
        fuse_state_t *state = frame->root->state;
        fuse_in_header_t *finh = state->finh;

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => 0", frame->root->unique,
                        gf_fop_list[frame->root->op],
                        state->loc.path ? state->loc.path : "ERR");

                send_fuse_err (this, finh, 0);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": %s() %s => -1 (%s)",
                        frame->root->unique,
                        gf_fop_list[frame->root->op],
                        state->loc.path ? state->loc.path : "ERR",
                        strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}


static int
fuse_fsync_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                int32_t op_ret, int32_t op_errno, struct iatt *prebuf,
                struct iatt *postbuf)
{
        return fuse_err_cbk (frame, cookie, this, op_ret, op_errno);
}


static int
fuse_setxattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno)
{
        if (op_ret == -1 && op_errno == ENOTSUP)
                GF_LOG_OCCASIONALLY (gf_fuse_xattr_enotsup_log,
                                     "glusterfs-fuse", GF_LOG_CRITICAL,
                                     "extended attribute not supported "
                                     "by the backend storage");

        return fuse_err_cbk (frame, cookie, this, op_ret, op_errno);
}


static int
fuse_unlink_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 int32_t op_ret, int32_t op_errno, struct iatt *preparent,
                 struct iatt *postparent)
{
        fuse_state_t     *state = NULL;
        fuse_in_header_t *finh = NULL;

        state = frame->root->state;
        finh = state->finh;

        if (op_ret == 0)
                inode_unlink (state->loc.inode, state->loc.parent,
                              state->loc.name);

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => 0", frame->root->unique,
                        gf_fop_list[frame->root->op], state->loc.path);

                send_fuse_err (this, finh, 0);
        } else {
                gf_log ("glusterfs-fuse",
                        op_errno == ENOTEMPTY ? GF_LOG_DEBUG : GF_LOG_WARNING,
                        "%"PRIu64": %s() %s => -1 (%s)", frame->root->unique,
                        gf_fop_list[frame->root->op], state->loc.path,
                        strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

void
fuse_access_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64" ACCESS %s/%"PRIu64" mask=%d",
                state->finh->unique, state->loc.path,
                state->finh->nodeid, state->mask);

        FUSE_FOP (state, fuse_err_cbk, GF_FOP_ACCESS, access,
                  &state->loc, state->mask);

}

static void
fuse_access (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_access_in *fai = msg;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);

        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": ACCESS %"PRIu64" (%s) (fuse_loc_fill() failed)",
                        finh->unique, finh->nodeid, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->mask = fai->mask;

        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_access_resume);
        return;
}


static int
fuse_readlink_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno, const char *linkname,
                   struct iatt *buf)
{
        fuse_state_t     *state = NULL;
        fuse_in_header_t *finh = NULL;

        state = frame->root->state;
        finh = state->finh;

        if (op_ret > 0) {
                ((char *)linkname)[op_ret] = '\0';

                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s => %s", frame->root->unique,
                        state->loc.path, linkname);

                send_fuse_data (this, finh, (void *)linkname, op_ret + 1);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": %s => -1 (%s)", frame->root->unique,
                        state->loc.path, strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

void
fuse_readlink_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64" READLINK %s/%"PRId64, state->finh->unique,
                state->loc.path, state->loc.inode->ino);

        FUSE_FOP (state, fuse_readlink_cbk, GF_FOP_READLINK,
                  readlink, &state->loc, 4096);

}

static void
fuse_readlink (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);
        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64" READLINK %s (fuse_loc_fill() returned NULL inode)",
                        finh->unique, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_readlink_resume);

        return;
}

void
fuse_mknod_resume (fuse_state_t *state)
{
        if (!state->loc.parent) {
                gf_log ("fuse", GF_LOG_ERROR, "failed to resolve path %s",
                        state->loc.path);
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        if (state->loc.inode) {
                gf_log (state->this->name, GF_LOG_DEBUG, "inode already present");
                inode_unref (state->loc.inode);
        }

        state->loc.inode = inode_new (state->loc.parent->table);

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": MKNOD %s", state->finh->unique,
                state->loc.path);

        FUSE_FOP (state, fuse_newentry_cbk, GF_FOP_MKNOD,
                  mknod, &state->loc, state->mode, state->rdev, state->dict);

}

static void
fuse_mknod (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_mknod_in *fmi = msg;
        char         *name = (char *)(fmi + 1);

        fuse_state_t   *state = NULL;
        fuse_private_t *priv = NULL;
        int32_t         ret = -1;

        priv = this->private;
#if FUSE_KERNEL_MINOR_VERSION >= 12
        if (priv->proto_minor < 12)
                name = (char *)msg + FUSE_COMPAT_MKNOD_IN_SIZE;
#endif

        GET_STATE (this, finh, state);

        uuid_generate (state->gfid);

        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64" MKNOD %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->mode = fmi->mode;
        state->rdev = fmi->rdev;

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_mknod_resume);

        return;
}

void
fuse_mkdir_resume (fuse_state_t *state)
{
        if (!state->loc.parent) {
                gf_log ("fuse", GF_LOG_ERROR, "failed to resolve path %s",
                        state->loc.path);
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        if (state->loc.inode) {
                gf_log (state->this->name, GF_LOG_DEBUG, "inode already present");
                inode_unref (state->loc.inode);
        }

        state->loc.inode = inode_new (state->loc.parent->table);

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": MKDIR %s", state->finh->unique,
                state->loc.path);

        FUSE_FOP (state, fuse_newentry_cbk, GF_FOP_MKDIR,
                  mkdir, &state->loc, state->mode, state->dict);
}

static void
fuse_mkdir (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_mkdir_in *fmi = msg;
        char *name = (char *)(fmi + 1);

        fuse_state_t *state;
        int32_t ret = -1;

        GET_STATE (this, finh, state);

        uuid_generate (state->gfid);

        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64" MKDIR %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->mode = fmi->mode;

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_mkdir_resume);

        return;
}

void
fuse_unlink_resume (fuse_state_t *state)
{
        if (!state->loc.inode) {
                gf_log ("fuse", GF_LOG_WARNING, "path resolving failed");
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": UNLINK %s", state->finh->unique,
                state->loc.path);

        FUSE_FOP (state, fuse_unlink_cbk, GF_FOP_UNLINK,
                  unlink, &state->loc);

}

static void
fuse_unlink (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        char         *name = msg;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);
        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": UNLINK %s (fuse_loc_fill() returned NULL inode)",
                        finh->unique, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_unlink_resume);

        return;
}

void
fuse_rmdir_resume (fuse_state_t *state)
{
        if (!state->loc.inode) {
                gf_log ("fuse", GF_LOG_WARNING, "path resolving failed");
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": RMDIR %s", state->finh->unique,
                state->loc.path);

        FUSE_FOP (state, fuse_unlink_cbk, GF_FOP_RMDIR,
                  rmdir, &state->loc, 0);
}

static void
fuse_rmdir (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        char         *name = msg;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);
        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": RMDIR %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_rmdir_resume);
        return;
}

void
fuse_symlink_resume (fuse_state_t *state)
{
        if (!state->loc.parent) {
                gf_log ("fuse", GF_LOG_ERROR, "failed to resolve path %s",
                        state->loc.path);
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        if (state->loc.inode) {
                gf_log (state->this->name, GF_LOG_DEBUG, "inode already present");
                inode_unref (state->loc.inode);
        }

        state->loc.inode = inode_new (state->loc.parent->table);

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": SYMLINK %s -> %s", state->finh->unique,
                state->loc.path, state->name);

        FUSE_FOP (state, fuse_newentry_cbk, GF_FOP_SYMLINK,
                  symlink, state->name, &state->loc, state->dict);
}

static void
fuse_symlink (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        char *name = msg;
        char *linkname = name + strlen (name) + 1;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);

        uuid_generate (state->gfid);

        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64" SYMLINK %s -> %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path, linkname);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->name = gf_strdup (linkname);

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_symlink_resume);
        return;
}


int
fuse_rename_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 int32_t op_ret, int32_t op_errno, struct iatt *buf,
                 struct iatt *preoldparent, struct iatt *postoldparent,
                 struct iatt *prenewparent, struct iatt *postnewparent)
{
        fuse_state_t     *state = NULL;
        fuse_in_header_t *finh = NULL;

        state = frame->root->state;
        finh  = state->finh;

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s -> %s => 0 (buf->ia_ino=%"PRId64" , loc->ino=%"PRId64")",
                        frame->root->unique, state->loc.path, state->loc2.path,
                        buf->ia_ino, state->loc.ino);

                {
                        /* ugly ugly - to stay blind to situation where
                           rename happens on a new inode
                        */
                        buf->ia_ino = state->loc.ino;
                        buf->ia_type = state->loc.inode->ia_type;
                }
                buf->ia_blksize = this->ctx->page_size;

                inode_rename (state->loc.parent->table,
                              state->loc.parent, state->loc.name,
                              state->loc2.parent, state->loc2.name,
                              state->loc.inode, buf);

                send_fuse_err (this, finh, 0);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": %s -> %s => -1 (%s)", frame->root->unique,
                        state->loc.path, state->loc2.path,
                        strerror (op_errno));
                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);
        return 0;
}

void
fuse_rename_resume (fuse_state_t *state)
{
        if (!state->loc.inode) {
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": RENAME `%s (%"PRId64")' -> `%s (%"PRId64")'",
                state->finh->unique, state->loc.path, state->loc.ino,
                state->loc2.path, state->loc2.ino);

        FUSE_FOP (state, fuse_rename_cbk, GF_FOP_RENAME,
                  rename, &state->loc, &state->loc2);
}

static void
fuse_rename (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_rename_in  *fri = msg;
        char *oldname = (char *)(fri + 1);
        char *newname = oldname + strlen (oldname) + 1;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);

        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, oldname);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "for %s %"PRIu64": RENAME `%s' -> `%s' (fuse_loc_fill() failed)",
                        state->loc.path, finh->unique, state->loc.path,
                        state->loc2.path);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        ret = fuse_loc_fill (&state->loc2, state, 0, fri->newdir, newname);
        if (!state->loc2.parent && (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "for %s %"PRIu64": RENAME `%s' -> `%s' (fuse_loc_fill() failed)",
                        state->loc.path, finh->unique, state->loc.path,
                        state->loc2.path);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (oldname);
        state->resolve.path = gf_strdup (state->loc.path);

        uuid_copy (state->resolve2.pargfid, state->loc2.parent->gfid);
        state->resolve2.bname = gf_strdup (newname);
        state->resolve2.path = gf_strdup (state->loc2.path);

        fuse_resolve_and_resume (state, fuse_rename_resume);

        return;
}

void
fuse_link_resume (fuse_state_t *state)
{
        if (state->loc.inode) {
                gf_log (state->this->name, GF_LOG_DEBUG, "inode already present");
                inode_unref (state->loc.inode);
        }

        state->loc.inode = inode_ref (state->loc2.inode);

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": LINK() %s (%"PRId64") -> %s (%"PRId64")",
                state->finh->unique, state->loc2.path, state->loc2.ino,
                state->loc.path, state->loc.ino);

        FUSE_FOP (state, fuse_newentry_cbk, GF_FOP_LINK,
                  link, &state->loc2, &state->loc);
}

static void
fuse_link (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_link_in *fli = msg;
        char         *name = (char *)(fli + 1);

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);

        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (ret == 0)
                ret = fuse_loc_fill (&state->loc2, state, fli->oldnodeid, 0,
                                     NULL);

        if (!state->loc2.inode || (ret < 0) || !state->loc.parent) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "fuse_loc_fill() failed %"PRIu64": LINK %s %s",
                        finh->unique, state->loc2.path, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        uuid_copy (state->resolve2.gfid, state->loc2.inode->gfid);
        state->resolve2.path = gf_strdup (state->loc2.path);

        fuse_resolve_and_resume (state, fuse_link_resume);

        return;
}


static int
fuse_create_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 int32_t op_ret, int32_t op_errno,
                 fd_t *fd, inode_t *inode, struct iatt *buf,
                 struct iatt *preparent, struct iatt *postparent)
{
        fuse_state_t            *state = NULL;
        fuse_in_header_t        *finh = NULL;
        fuse_private_t          *priv = NULL;
        struct fuse_out_header   fouh = {0, };
        struct fuse_entry_out    feo = {0, };
        struct fuse_open_out     foo = {0, };
        struct iovec             iov_out[3];
        inode_t                 *linked_inode = NULL;

        state    = frame->root->state;
        priv     = this->private;
        finh     = state->finh;
        foo.open_flags = 0;

        if (op_ret >= 0) {
                foo.fh = (uintptr_t) fd;

                if (((priv->direct_io_mode == 2)
                     && ((state->flags & O_ACCMODE) != O_RDONLY))
                    || (priv->direct_io_mode == 1))
                        foo.open_flags |= FOPEN_DIRECT_IO;

                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => %p (ino=%"PRId64")",
                        frame->root->unique, gf_fop_list[frame->root->op],
                        state->loc.path, fd, buf->ia_ino);

                buf->ia_blksize = this->ctx->page_size;
                gf_fuse_stat2attr (buf, &feo.attr);

                linked_inode = inode_link (inode, state->loc.parent,
                                           state->loc.name, buf);

                if (linked_inode != inode) {
                        /*
                           VERY racy code (if used anywhere else)
                           -- don't do this without understanding
                        */
                        inode_unref (fd->inode);
                        fd->inode = inode_ref (linked_inode);
                }

                inode_lookup (linked_inode);

                inode_unref (linked_inode);

                fd_ref (fd);

                feo.nodeid = inode_to_fuse_nodeid (linked_inode);

                feo.entry_valid = calc_timeout_sec (priv->entry_timeout);
                feo.entry_valid_nsec = calc_timeout_nsec (priv->entry_timeout);
                feo.attr_valid = calc_timeout_sec (priv->attribute_timeout);
                feo.attr_valid_nsec =
                  calc_timeout_nsec (priv->attribute_timeout);

                fouh.error = 0;
                iov_out[0].iov_base = &fouh;
                iov_out[1].iov_base = &feo;
#if FUSE_KERNEL_MINOR_VERSION >= 9
                iov_out[1].iov_len = priv->proto_minor >= 9 ?
                                     sizeof (feo) :
                                     FUSE_COMPAT_ENTRY_OUT_SIZE;
#else
                iov_out[1].iov_len = sizeof (feo);
#endif
                iov_out[2].iov_base = &foo;
                iov_out[2].iov_len = sizeof (foo);
                if (send_fuse_iov (this, finh, iov_out, 3) == ENOENT) {
                        gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
                                "create(%s) got EINTR", state->loc.path);
                        inode_forget (inode, 1);
                        fd_unref (fd);
                        goto out;
                }

                fd_bind (fd);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": %s => -1 (%s)", finh->unique,
                        state->loc.path, strerror (op_errno));
                send_fuse_err (this, finh, op_errno);
        }
out:
        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

void
fuse_create_resume (fuse_state_t *state)
{
        fd_t *fd = NULL;

        if (!state->loc.parent) {
                gf_log ("fuse", GF_LOG_ERROR, "failed to resolve path %s",
                        state->loc.path);
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        if (state->loc.inode) {
                gf_log (state->this->name, GF_LOG_DEBUG, "inode already present");
                inode_unref (state->loc.inode);
        }

        state->loc.inode = inode_new (state->loc.parent->table);

        fd = fd_create (state->loc.inode, state->finh->pid);
        state->fd = fd;
        fd->flags = state->flags;

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": CREATE %s", state->finh->unique,
                state->loc.path);

        FUSE_FOP (state, fuse_create_cbk, GF_FOP_CREATE,
                  create, &state->loc, state->flags, state->mode,
                  fd, state->dict);

}

static void
fuse_create (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
#if FUSE_KERNEL_MINOR_VERSION >= 12
        struct fuse_create_in *fci = msg;
#else
        struct fuse_open_in *fci = msg;
#endif
        char         *name = (char *)(fci + 1);

        fuse_private_t        *priv = NULL;
        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        priv = this->private;
#if FUSE_KERNEL_MINOR_VERSION >= 12
        if (priv->proto_minor < 12)
                name = (char *)((struct fuse_open_in *)msg + 1);
#endif

        GET_STATE (this, finh, state);

        uuid_generate (state->gfid);

        ret = fuse_loc_fill (&state->loc, state, 0, finh->nodeid, name);
        if (!state->loc.parent || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64" CREATE %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path);
                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->mode = fci->mode;
        state->flags = fci->flags;

        uuid_copy (state->resolve.pargfid, state->loc.parent->gfid);
        state->resolve.bname = gf_strdup (name);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_create_resume);

        return;
}

void
fuse_open_resume (fuse_state_t *state)
{
        fd_t *fd = NULL;

        fd = fd_create (state->loc.inode, state->finh->pid);
        if (!fd) {
                gf_log ("fuse", GF_LOG_ERROR,
                        "fd is NULL");
                send_fuse_err (state->this, state->finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->fd = fd;
        fd->flags = state->flags;

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": OPEN %s", state->finh->unique,
                state->loc.path);

        FUSE_FOP (state, fuse_fd_cbk, GF_FOP_OPEN,
                  open, &state->loc, state->flags, fd, 0);
}

static void
fuse_open (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_open_in *foi = msg;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);

        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": OPEN %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->flags = foi->flags;

        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_open_resume);

        return;
}


static int
fuse_readv_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                int32_t op_ret, int32_t op_errno,
                struct iovec *vector, int32_t count,
                struct iatt *stbuf, struct iobref *iobref)
{
        fuse_state_t *state = NULL;
        fuse_in_header_t *finh = NULL;
        struct fuse_out_header fouh = {0, };
        struct iovec *iov_out = NULL;

        state = frame->root->state;
        finh = state->finh;

        if (op_ret >= 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": READ => %d/%"GF_PRI_SIZET",%"PRId64"/%"PRId64,
                        frame->root->unique,
                        op_ret, state->size, state->off, stbuf->ia_size);

                iov_out = GF_CALLOC (count + 1, sizeof (*iov_out),
                                     gf_fuse_mt_iovec);
                if (iov_out) {
                        fouh.error = 0;
                        iov_out[0].iov_base = &fouh;
                        memcpy (iov_out + 1, vector, count * sizeof (*iov_out));
                        send_fuse_iov (this, finh, iov_out, count + 1);
                        GF_FREE (iov_out);
                } else
                        send_fuse_err (this, finh, ENOMEM);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": READ => %d (%s)", frame->root->unique,
                        op_ret, strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

void
fuse_readv_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": READ (%p, size=%zu, offset=%"PRIu64")",
                state->finh->unique, state->fd, state->size, state->off);

        FUSE_FOP (state, fuse_readv_cbk, GF_FOP_READ,
                  readv, state->fd, state->size, state->off);
}

static void
fuse_readv (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_read_in *fri = msg;

        fuse_private_t  *priv = NULL;
        fuse_state_t *state = NULL;
        fd_t         *fd = NULL;

        GET_STATE (this, finh, state);


        fd = FH_TO_FD (fri->fh);
        state->fd = fd;

        /* See comment by similar code in fuse_settatr */
        priv = this->private;
#if FUSE_KERNEL_MINOR_VERSION >= 9
        if (priv->proto_minor >= 9 && fri->read_flags & FUSE_READ_LOCKOWNER)
                state->lk_owner = fri->lock_owner;
#endif

        state->size = fri->size;
        state->off = fri->offset;

        fuse_resolve_and_resume (state, fuse_readv_resume);
}


static int
fuse_writev_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 int32_t op_ret, int32_t op_errno,
                 struct iatt *stbuf, struct iatt *postbuf)
{
        fuse_state_t *state = NULL;
        fuse_in_header_t *finh = NULL;
        struct fuse_write_out fwo = {0, };

        state = frame->root->state;
        finh = state->finh;

        if (op_ret >= 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": WRITE => %d/%"GF_PRI_SIZET",%"PRId64"/%"PRId64,
                        frame->root->unique,
                        op_ret, state->size, state->off, stbuf->ia_size);

                fwo.size = op_ret;
                send_fuse_obj (this, finh, &fwo);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": WRITE => -1 (%s)", frame->root->unique,
                        strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

void
fuse_write_resume (fuse_state_t *state)
{
        struct iobref *iobref = NULL;
        struct iobuf  *iobuf = NULL;

        if (!state->fd || !state->fd->inode) {
                send_fuse_err (state->this, state->finh, EBADFD);
                free_fuse_state (state);
                return;
        }

        iobref = iobref_new ();
        if (!iobref) {
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "%"PRIu64": WRITE iobref allocation failed",
                        state->finh->unique);
                send_fuse_err (state->this, state->finh, ENOMEM);

                free_fuse_state (state);
                return;
        }

        iobuf = ((fuse_private_t *) (state->this->private))->iobuf;
        iobref_add (iobref, iobuf);

        FUSE_FOP (state, fuse_writev_cbk, GF_FOP_WRITE, writev, state->fd,
                  &state->vector, 1, state->off, iobref);

        iobref_unref (iobref);
}

static void
fuse_write (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        /* WRITE is special, metadata is attached to in_header,
         * and msg is the payload as-is.
         */
        struct fuse_write_in *fwi = (struct fuse_write_in *)
                                      (finh + 1);

        fuse_private_t  *priv = NULL;
        fuse_state_t    *state = NULL;
        fd_t            *fd = NULL;

        priv = this->private;

        GET_STATE (this, finh, state);
        fd          = FH_TO_FD (fwi->fh);
        state->fd   = fd;
        state->size = fwi->size;
        state->off  = fwi->offset;

        /* See comment by similar code in fuse_settatr */
        priv = this->private;
#if FUSE_KERNEL_MINOR_VERSION >= 9
        if (priv->proto_minor >= 9 && fwi->write_flags & FUSE_WRITE_LOCKOWNER)
                state->lk_owner = fwi->lock_owner;
#endif

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": WRITE (%p, size=%"PRIu32", offset=%"PRId64")",
                finh->unique, fd, fwi->size, fwi->offset);

        state->vector.iov_base = msg;
        state->vector.iov_len  = fwi->size;

        fuse_resolve_and_resume (state, fuse_write_resume);

        return;
}

void
fuse_flush_resume (fuse_state_t *state)
{
        FUSE_FOP (state, fuse_err_cbk, GF_FOP_FLUSH,
                  flush, state->fd);
}

static void
fuse_flush (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_flush_in *ffi = msg;

        fuse_state_t *state = NULL;
        fd_t         *fd = NULL;

        GET_STATE (this, finh, state);
        fd = FH_TO_FD (ffi->fh);
        state->fd = fd;

        state->lk_owner = ffi->lock_owner;

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": FLUSH %p", finh->unique, fd);

        fuse_resolve_and_resume (state, fuse_flush_resume);

        return;
}

static void
fuse_release (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_release_in *fri        = msg;
        fd_t                   *new_fd     = NULL;
        fd_t                   *fd         = NULL;
        uint64_t                tmp_fd_ctx = 0;
        int                     ret        = 0;
        fuse_state_t           *state      = NULL;

        GET_STATE (this, finh, state);
        fd = FH_TO_FD (fri->fh);
        state->fd = fd;

        /* TODO */
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": RELEASE %p", finh->unique, state->fd);

        ret = fd_ctx_get (fd, this, &tmp_fd_ctx);
        if (!ret) {
                new_fd = (fd_t *)(long)tmp_fd_ctx;
                fd_unref (new_fd);
        }
        fd_unref (fd);

        send_fuse_err (this, finh, 0);

        free_fuse_state (state);
        return;
}

void
fuse_fsync_resume (fuse_state_t *state)
{
        /* fsync_flags: 1 means "datasync" (no defines for this) */
        FUSE_FOP (state, fuse_fsync_cbk, GF_FOP_FSYNC,
                  fsync, state->fd, state->flags & 1);
}

static void
fuse_fsync (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_fsync_in *fsi = msg;

        fuse_state_t *state = NULL;
        fd_t         *fd = NULL;

        GET_STATE (this, finh, state);
        fd = FH_TO_FD (fsi->fh);
        state->fd = fd;

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": FSYNC %p", finh->unique, fd);

        state->flags = fsi->fsync_flags;
        fuse_resolve_and_resume (state, fuse_fsync_resume);
        return;
}

void
fuse_opendir_resume (fuse_state_t *state)
{
        fd_t *fd = NULL;

        fd = fd_create (state->loc.inode, state->finh->pid);
        state->fd = fd;

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": OPENDIR %s", state->finh->unique,
                state->loc.path);

        FUSE_FOP (state, fuse_fd_cbk, GF_FOP_OPENDIR,
                  opendir, &state->loc, fd);
}

static void
fuse_opendir (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        /*
        struct fuse_open_in *foi = msg;
         */

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);
        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) || (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": OPENDIR %s (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_opendir_resume);
}


unsigned char
d_type_from_stat (struct iatt *buf)
{
        unsigned char d_type;

        if (IA_ISLNK (buf->ia_type)) {
                d_type = DT_LNK;

        } else if (IA_ISDIR (buf->ia_type)) {
                d_type = DT_DIR;

        } else if (IA_ISFIFO (buf->ia_type)) {
                d_type = DT_FIFO;

        } else if (IA_ISSOCK (buf->ia_type)) {
                d_type = DT_SOCK;

        } else if (IA_ISCHR (buf->ia_type)) {
                d_type = DT_CHR;

        } else if (IA_ISBLK (buf->ia_type)) {
                d_type = DT_BLK;

        } else if (IA_ISREG (buf->ia_type)) {
                d_type = DT_REG;

        } else {
                d_type = DT_UNKNOWN;
        }

        return d_type;
}


static int
fuse_readdir_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                  int32_t op_ret, int32_t op_errno, gf_dirent_t *entries)
{
        fuse_state_t *state = NULL;
        fuse_in_header_t *finh = NULL;
        int           size = 0;
        char         *buf = NULL;
        gf_dirent_t  *entry = NULL;
        struct fuse_dirent *fde = NULL;

        state = frame->root->state;
        finh  = state->finh;

        if (op_ret < 0) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": READDIR => -1 (%s)", frame->root->unique,
                        strerror (op_errno));

                send_fuse_err (this, finh, op_errno);
                goto out;
        }

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": READDIR => %d/%"GF_PRI_SIZET",%"PRId64,
                frame->root->unique, op_ret, state->size, state->off);

        list_for_each_entry (entry, &entries->list, list) {
                size += FUSE_DIRENT_ALIGN (FUSE_NAME_OFFSET +
                                           strlen (entry->d_name));
        }

        buf = GF_CALLOC (1, size, gf_fuse_mt_char);
        if (!buf) {
                gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
                        "%"PRIu64": READDIR => -1 (%s)", frame->root->unique,
                        strerror (ENOMEM));
                send_fuse_err (this, finh, ENOMEM);
                goto out;
        }

        size = 0;
        list_for_each_entry (entry, &entries->list, list) {
                fde = (struct fuse_dirent *)(buf + size);
                fde->ino = entry->d_ino;
                fde->off = entry->d_off;
                fde->namelen = strlen (entry->d_name);
                strncpy (fde->name, entry->d_name, fde->namelen);
                size += FUSE_DIRENT_SIZE (fde);
        }

        send_fuse_data (this, finh, buf, size);

out:
        free_fuse_state (state);
        STACK_DESTROY (frame->root);
        if (buf)
                GF_FREE (buf);
        return 0;

}

void
fuse_readdir_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": READDIR (%p, size=%zu, offset=%"PRId64")",
                state->finh->unique, state->fd, state->size, state->off);

        FUSE_FOP (state, fuse_readdir_cbk, GF_FOP_READDIR,
                  readdir, state->fd, state->size, state->off);
}

static void
fuse_readdir (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_read_in *fri = msg;

        fuse_state_t *state = NULL;
        fd_t         *fd = NULL;

        GET_STATE (this, finh, state);
        state->size = fri->size;
        state->off = fri->offset;
        fd = FH_TO_FD (fri->fh);
        state->fd = fd;

        fuse_resolve_and_resume (state, fuse_readdir_resume);
}


static void
fuse_releasedir (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_release_in *fri        = msg;
        fd_t                   *new_fd     = NULL;
        uint64_t                tmp_fd_ctx = 0;
        int                     ret        = 0;
        fuse_state_t           *state      = NULL;

        GET_STATE (this, finh, state);
        state->fd = FH_TO_FD (fri->fh);

        /* TODO: free 'new-fd' in the ctx */
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": RELEASEDIR %p", finh->unique, state->fd);

        ret = fd_ctx_get (state->fd, this, &tmp_fd_ctx);
        if (!ret) {
                new_fd = (fd_t *)(long)tmp_fd_ctx;
                fd_unref (new_fd);
        }

        fd_unref (state->fd);

        send_fuse_err (this, finh, 0);

        free_fuse_state (state);

        return;
}

void
fuse_fsyncdir_resume (fuse_state_t *state)
{
        FUSE_FOP (state, fuse_err_cbk, GF_FOP_FSYNCDIR,
                  fsyncdir, state->fd, state->flags & 1);

}

static void
fuse_fsyncdir (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_fsync_in *fsi = msg;

        fuse_state_t *state = NULL;
        fd_t         *fd = NULL;

        fd = FH_TO_FD (fsi->fh);

        GET_STATE (this, finh, state);
        state->fd = fd;

        state->flags = fsi->fsync_flags;
        fuse_resolve_and_resume (state, fuse_fsyncdir_resume);

        return;
}


static int
fuse_statfs_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 int32_t op_ret, int32_t op_errno, struct statvfs *buf)
{
        fuse_state_t *state = NULL;
        fuse_in_header_t *finh = NULL;
        fuse_private_t   *priv = NULL;
        struct fuse_statfs_out fso = {{0, }, };

        state = frame->root->state;
        priv  = this->private;
        finh  = state->finh;
        /*
          Filesystems (like ZFS on solaris) reports
          different ->f_frsize and ->f_bsize. Old coreutils
          df tools use statfs() and do not see ->f_frsize.
          the ->f_blocks, ->f_bavail and ->f_bfree are
          w.r.t ->f_frsize and not ->f_bsize which makes the
          df tools report wrong values.

          Scale the block counts to match ->f_bsize.
        */
        /* TODO: with old coreutils, f_bsize is taken from stat()'s ia_blksize
         * so the df with old coreutils this wont work :(
         */

        if (op_ret == 0) {
#ifndef GF_DARWIN_HOST_OS
                /* MacFUSE doesn't respect anyof these tweaks */
                buf->f_blocks *= buf->f_frsize;
                buf->f_blocks /= this->ctx->page_size;

                buf->f_bavail *= buf->f_frsize;
                buf->f_bavail /= this->ctx->page_size;

                buf->f_bfree *= buf->f_frsize;
                buf->f_bfree /= this->ctx->page_size;

                buf->f_frsize = buf->f_bsize =this->ctx->page_size;
#endif /* GF_DARWIN_HOST_OS */
                fso.st.bsize   = buf->f_bsize;
                fso.st.frsize  = buf->f_frsize;
                fso.st.blocks  = buf->f_blocks;
                fso.st.bfree   = buf->f_bfree;
                fso.st.bavail  = buf->f_bavail;
                fso.st.files   = buf->f_files;
                fso.st.ffree   = buf->f_ffree;
                fso.st.namelen = buf->f_namemax;

                priv->proto_minor >= 4 ?
                send_fuse_obj (this, finh, &fso) :
                send_fuse_data (this, finh, &fso, FUSE_COMPAT_STATFS_SIZE);
        } else {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": ERR => -1 (%s)", frame->root->unique,
                        strerror (op_errno));
                send_fuse_err (this, finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

static void
fuse_statfs (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);
        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": STATFS (fuse_loc_fill() fail)",
                        finh->unique);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": STATFS", finh->unique);

        FUSE_FOP (state, fuse_statfs_cbk, GF_FOP_STATFS,
                  statfs, &state->loc);
}

void
fuse_setxattr_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": SETXATTR %s/%"PRIu64" (%s)", state->finh->unique,
                state->loc.path, state->finh->nodeid, state->name);

        FUSE_FOP (state, fuse_setxattr_cbk, GF_FOP_SETXATTR,
                  setxattr, &state->loc, state->dict, state->flags);
}

static void
fuse_setxattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_setxattr_in *fsi = msg;
        char         *name = (char *)(fsi + 1);
        char         *value = name + strlen (name) + 1;
        struct fuse_private *priv = NULL;

        fuse_state_t *state = NULL;
        char         *dict_value = NULL;
        int32_t       ret = -1;

        priv = this->private;

#ifdef GF_DARWIN_HOST_OS
        if (fsi->position) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": SETXATTR %s/%"PRIu64" (%s):"
                        "refusing positioned setxattr",
                        finh->unique, state->loc.path, finh->nodeid, name);
                send_fuse_err (this, finh, EINVAL);
                FREE (finh);
                return;
        }
#endif

        if (!priv->acl) {
                if ((strcmp (name, "system.posix_acl_access") == 0) ||
                    (strcmp (name, "system.posix_acl_default") == 0)) {
                        send_fuse_err (this, finh, EOPNOTSUPP);
                        GF_FREE (finh);
                        return;
                }
        }

#ifdef DISABLE_SELINUX
        if (!strncmp (name, "security.", 9)) {
                send_fuse_err (this, finh, EOPNOTSUPP);
                GF_FREE (finh);
                return;
        }
#endif

        /* Check if the command is for changing the log
           level of process or specific xlator */
        ret = is_gf_log_command (this, name, value);
        if (ret >= 0) {
                send_fuse_err (this, finh, ret);
                GF_FREE (finh);
                return;
        }

        GET_STATE (this, finh, state);
        state->size = fsi->size;
        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": SETXATTR %s/%"PRIu64" (%s) (fuse_loc_fill() failed)",
                        finh->unique,
                        state->loc.path, finh->nodeid, name);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->dict = get_new_dict ();
        if (!state->dict) {
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "%"PRIu64": SETXATTR dict allocation failed",
                        finh->unique);

                send_fuse_err (this, finh, ENOMEM);
                free_fuse_state (state);
                return;
        }

        dict_value = memdup (value, fsi->size);
        dict_set (state->dict, (char *)name,
                  data_from_dynptr ((void *)dict_value, fsi->size));
        dict_ref (state->dict);

        state->flags = fsi->flags;
        state->name = gf_strdup (name);

        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_setxattr_resume);

        return;
}

static void
send_fuse_xattr (xlator_t *this, fuse_in_header_t *finh, const char *value,
                 size_t size, size_t expected)
{
        struct fuse_getxattr_out fgxo;

        /* linux kernel limits the size of xattr value to 64k */
        if (size > GLUSTERFS_XATTR_LEN_MAX)
                send_fuse_err (this, finh, E2BIG);
        else if (expected) {
                /* if callback for getxattr and asks for value */
                if (size > expected)
                        /* reply would be bigger than
                         * what was asked by kernel */
                        send_fuse_err (this, finh, ERANGE);
                else
                        send_fuse_data (this, finh, (void *)value, size);
        } else {
                fgxo.size = size;
                send_fuse_obj (this, finh, &fgxo);
        }
}

static int
fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                int32_t op_ret, int32_t op_errno, dict_t *dict)
{
        int             need_to_free_dict = 0;
        char           *value = "";
        fuse_state_t   *state = NULL;
        fuse_in_header_t *finh = NULL;
        data_t         *value_data = NULL;
        int             ret = -1;
        int32_t         len = 0;
        data_pair_t    *trav = NULL;

        state = frame->root->state;
        finh  = state->finh;

        if (op_ret >= 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": %s() %s => %d", frame->root->unique,
                        gf_fop_list[frame->root->op], state->loc.path, op_ret);

                /* if successful */
                if (state->name) {
                        /* if callback for getxattr */
                        value_data = dict_get (dict, state->name);
                        if (value_data) {

                                ret = value_data->len; /* Don't return the value for '\0' */
                                value = value_data->data;

                                send_fuse_xattr (this, finh, value, ret, state->size);
                                /* if(ret >...)...else if...else */
                        } else {
                                send_fuse_err (this, finh, ENODATA);
                        } /* if(value_data)...else */
                } else {
                        /* if callback for listxattr */
                        trav = dict->members_list;
                        while (trav) {
                                len += strlen (trav->key) + 1;
                                trav = trav->next;
                        } /* while(trav) */
                        value = alloca (len + 1);
                        if (!value)
                                goto out;
                        len = 0;
                        trav = dict->members_list;
                        while (trav) {
                                strcpy (value + len, trav->key);
                                value[len + strlen (trav->key)] = '\0';
                                len += strlen (trav->key) + 1;
                                trav = trav->next;
                        } /* while(trav) */
                        send_fuse_xattr (this, finh, value, len, state->size);
                } /* if(state->name)...else */
        } else {
                /* if failure - no need to check if listxattr or getxattr */
                if (op_errno != ENODATA) {
                        if (op_errno == ENOTSUP) {
                                GF_LOG_OCCASIONALLY (gf_fuse_xattr_enotsup_log,
                                                     "glusterfs-fuse",
                                                     GF_LOG_ERROR,
                                                     "extended attribute not "
                                                     "supported by the backend "
                                                     "storage");
                        } else {
                                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                        "%"PRIu64": %s(%s) %s => -1 (%s)",
                                        frame->root->unique,
                                        gf_fop_list[frame->root->op], state->name,
                                        state->loc.path, strerror (op_errno));
                        }
                } else {
                        gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
                                "%"PRIu64": %s(%s) %s => -1 (%s)",
                                frame->root->unique,
                                gf_fop_list[frame->root->op], state->name,
                                state->loc.path, strerror (op_errno));
                } /* if(op_errno!= ENODATA)...else */

                send_fuse_err (this, finh, op_errno);
        } /* if(op_ret>=0)...else */

out:
        if (need_to_free_dict)
                dict_unref (dict);

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

void
fuse_getxattr_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": GETXATTR %s/%"PRIu64" (%s)", state->finh->unique,
                state->loc.path, state->finh->nodeid, state->name);

        FUSE_FOP (state, fuse_xattr_cbk, GF_FOP_GETXATTR,
                  getxattr, &state->loc, state->name);
}

static void
fuse_getxattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_getxattr_in *fgxi = msg;
        char         *name = (char *)(fgxi + 1);

        fuse_state_t *state = NULL;
        int32_t       ret = -1;
        struct fuse_private *priv = NULL;

        priv = this->private;

#ifdef GF_DARWIN_HOST_OS
        if (fgxi->position) {
                /* position can be used only for
                 * resource fork queries which we
                 * don't support anyway... so handling
                 * it separately is just sort of a
                 * matter of aesthetics, not strictly
                 * necessary.
                 */

                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": GETXATTR %s/%"PRIu64" (%s):"
                        "refusing positioned getxattr",
                        finh->unique, state->loc.path, finh->nodeid, name);
                send_fuse_err (this, finh, EINVAL);
                FREE (finh);
                return;
        }
#endif

        if (!priv->acl) {
                if ((strcmp (name, "system.posix_acl_access") == 0) ||
                    (strcmp (name, "system.posix_acl_default") == 0)) {
                        send_fuse_err (this, finh, ENOTSUP);
                        GF_FREE (finh);
                        return;
                }
        }

#ifdef DISABLE_SELINUX
        if (!strncmp (name, "security.", 9)) {
                send_fuse_err (this, finh, ENODATA);
                GF_FREE (finh);
                return;
        }
#endif

        GET_STATE (this, finh, state);

        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": GETXATTR %s/%"PRIu64" (%s) (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path, finh->nodeid, name);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->size = fgxi->size;
        state->name = gf_strdup (name);

        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_getxattr_resume);
        return;
}

void
fuse_listxattr_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": LISTXATTR %s/%"PRIu64, state->finh->unique,
                state->loc.path, state->finh->nodeid);

        FUSE_FOP (state, fuse_xattr_cbk, GF_FOP_GETXATTR,
                  getxattr, &state->loc, NULL);
}

static void
fuse_listxattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_getxattr_in *fgxi = msg;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);

        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                        "%"PRIu64": LISTXATTR %s/%"PRIu64" (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path, finh->nodeid);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->size = fgxi->size;
        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_listxattr_resume);

        return;
}

void
fuse_removexattr_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": REMOVEXATTR %s/%"PRIu64" (%s)", state->finh->unique,
                state->loc.path, state->finh->nodeid, state->name);

        FUSE_FOP (state, fuse_err_cbk, GF_FOP_REMOVEXATTR,
                  removexattr, &state->loc, state->name);
}

static void
fuse_removexattr (xlator_t *this, fuse_in_header_t *finh, void *msg)

{
        char *name = msg;

        fuse_state_t *state = NULL;
        int32_t       ret = -1;

        GET_STATE (this, finh, state);
        ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
        if ((state->loc.inode == NULL) ||
            (ret < 0)) {
                gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
                        "%"PRIu64": REMOVEXATTR %s/%"PRIu64" (%s) (fuse_loc_fill() failed)",
                        finh->unique, state->loc.path, finh->nodeid, name);

                send_fuse_err (this, finh, ENOENT);
                free_fuse_state (state);
                return;
        }

        state->name = gf_strdup (name);
        uuid_copy (state->resolve.gfid, state->loc.inode->gfid);
        state->resolve.path = gf_strdup (state->loc.path);

        fuse_resolve_and_resume (state, fuse_removexattr_resume);
        return;
}


static int gf_fuse_lk_enosys_log;

static int
fuse_getlk_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                int32_t op_ret, int32_t op_errno, struct gf_flock *lock)
{
        fuse_state_t *state = NULL;

        state = frame->root->state;
        struct fuse_lk_out flo = {{0, }, };

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": ERR => 0", frame->root->unique);
                flo.lk.type = lock->l_type;
                flo.lk.pid  = lock->l_pid;
                if (lock->l_type == F_UNLCK)
                        flo.lk.start = flo.lk.end = 0;
                else {
                        flo.lk.start = lock->l_start;
                        flo.lk.end = lock->l_len ?
                                     (lock->l_start + lock->l_len - 1) :
                                     OFFSET_MAX;
                }
                send_fuse_obj (this, state->finh, &flo);
        } else {
                if (op_errno == ENOSYS) {
                        gf_fuse_lk_enosys_log++;
                        if (!(gf_fuse_lk_enosys_log % GF_UNIVERSAL_ANSWER)) {
                                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                                        "GETLK not supported. loading "
                                        "'features/posix-locks' on server side "
                                        "will add GETLK support.");
                        }
                } else {
                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                "%"PRIu64": ERR => -1 (%s)",
                                frame->root->unique, strerror (op_errno));
                }
                send_fuse_err (this, state->finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}

void
fuse_getlk_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": GETLK %p", state->finh->unique, state->fd);

        FUSE_FOP (state, fuse_getlk_cbk, GF_FOP_LK,
                  lk, state->fd, F_GETLK, &state->lk_lock);
}

static void
fuse_getlk (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_lk_in *fli = msg;

        fuse_state_t *state = NULL;
        fd_t         *fd = NULL;

        fd = FH_TO_FD (fli->fh);
        GET_STATE (this, finh, state);
        state->fd = fd;
        convert_fuse_file_lock (&fli->lk, &state->lk_lock,
                                fli->owner);

        state->lk_owner = fli->owner;

        fuse_resolve_and_resume (state, fuse_getlk_resume);

        return;
}


static int
fuse_setlk_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                int32_t op_ret, int32_t op_errno, struct gf_flock *lock)
{
        fuse_state_t *state = NULL;

        state = frame->root->state;

        if (op_ret == 0) {
                gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                        "%"PRIu64": ERR => 0", frame->root->unique);
                send_fuse_err (this, state->finh, 0);
        } else {
                if (op_errno == ENOSYS) {
                        gf_fuse_lk_enosys_log++;
                        if (!(gf_fuse_lk_enosys_log % GF_UNIVERSAL_ANSWER)) {
                                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                                        "SETLK not supported. loading "
                                        "'features/posix-locks' on server side "
                                        "will add SETLK support.");
                        }
                } else if (op_errno == EAGAIN) {
                        gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
                                "Returning EAGAIN Flock: "
                                "start=%llu, len=%llu, pid=%llu, lk-owner=%llu",
                                (unsigned long long) lock->l_start,
                                (unsigned long long) lock->l_len,
                                (unsigned long long) lock->l_pid,
                                (unsigned long long) frame->root->lk_owner);

                } else  {
                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                "%"PRIu64": ERR => -1 (%s)",
                                frame->root->unique, strerror (op_errno));
                }

                send_fuse_err (this, state->finh, op_errno);
        }

        free_fuse_state (state);
        STACK_DESTROY (frame->root);

        return 0;
}


void
fuse_setlk_resume (fuse_state_t *state)
{
        gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                "%"PRIu64": SETLK%s %p", state->finh->unique,
                state->finh->opcode == FUSE_SETLK ? "" : "W", state->fd);

        FUSE_FOP (state, fuse_setlk_cbk, GF_FOP_LK, lk, state->fd,
                  state->finh->opcode == FUSE_SETLK ? F_SETLK : F_SETLKW,
                  &state->lk_lock);
}

static void
fuse_setlk (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_lk_in *fli = msg;

        fuse_state_t *state = NULL;
        fd_t         *fd = NULL;

        fd = FH_TO_FD (fli->fh);
        GET_STATE (this, finh, state);
        state->finh = finh;
        state->fd = fd;
        convert_fuse_file_lock (&fli->lk, &state->lk_lock,
                                fli->owner);

        state->lk_owner = fli->owner;

        fuse_resolve_and_resume (state, fuse_setlk_resume);

        return;
}

static void
fuse_init (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        struct fuse_init_in *fini = msg;

        struct fuse_init_out fino;
        fuse_private_t *priv = NULL;
        int ret;

        priv = this->private;

        if (priv->init_recvd) {
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "got INIT after first message");

                close (priv->fd);
                goto out;
        }

        priv->init_recvd = 1;

        if (fini->major != FUSE_KERNEL_VERSION) {
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "unsupported FUSE protocol version %d.%d",
                        fini->major, fini->minor);

                close (priv->fd);
                goto out;
        }
        priv->proto_minor = fini->minor;

        fino.major = FUSE_KERNEL_VERSION;
        fino.minor = FUSE_KERNEL_MINOR_VERSION;
        fino.max_readahead = 1 << 17;
        fino.max_write = 1 << 17;
        fino.flags = FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
#if FUSE_KERNEL_MINOR_VERSION >= 9
        if (fini->minor >= 6 /* fuse_init_in has flags */ &&
            fini->flags & FUSE_BIG_WRITES) {
                /* no need for direct I/O mode by default if big writes are supported */
                if (priv->direct_io_mode == 2)
                        priv->direct_io_mode = 0;
                fino.flags |= FUSE_BIG_WRITES;
        }
        if (fini->minor >= 13) {
                /* these values seemed to work fine during testing */

                fino.max_background = 64;
                fino.congestion_threshold = 48;
        }
        if (fini->minor < 9)
                *priv->msg0_len_p = sizeof(*finh) + FUSE_COMPAT_WRITE_IN_SIZE;
#endif
        ret = send_fuse_obj (this, finh, &fino);
        if (ret == 0)
                gf_log ("glusterfs-fuse", GF_LOG_INFO,
                        "FUSE inited with protocol versions:"
                        " glusterfs %d.%d kernel %d.%d",
                        FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION,
                        fini->major, fini->minor);
        else {
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "FUSE init failed (%s)", strerror (ret));

                close (priv->fd);
        }

 out:
        GF_FREE (finh);
}


static void
fuse_enosys (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        send_fuse_err (this, finh, ENOSYS);

        GF_FREE (finh);
}


static void
fuse_destroy (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        send_fuse_err (this, finh, 0);

        GF_FREE (finh);
}



struct fuse_first_lookup {
        pthread_mutex_t  mutex;
        pthread_cond_t   cond;
        char             fin;
};

int
fuse_first_lookup_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                       int32_t op_ret, int32_t op_errno,
                       inode_t *inode, struct iatt *buf, dict_t *xattr,
                       struct iatt *postparent)
{
        struct fuse_first_lookup *stub = NULL;

        stub = frame->local;

        if (op_ret == 0) {
                gf_log (this->name, GF_LOG_TRACE,
                        "first lookup on root succeeded.");
        } else {
                gf_log (this->name, GF_LOG_DEBUG,
                        "first lookup on root failed.");
        }

        pthread_mutex_lock (&stub->mutex);
        {
                stub->fin = 1;
                pthread_cond_broadcast (&stub->cond);
        }
        pthread_mutex_unlock (&stub->mutex);

        return 0;
}


int
fuse_first_lookup (xlator_t *this)
{
        fuse_private_t            *priv = NULL;
        loc_t                      loc = {0, };
        call_frame_t              *frame = NULL;
        xlator_t                  *xl = NULL;
        dict_t                    *dict = NULL;
        struct fuse_first_lookup   stub;
        uuid_t                     gfid;
        int                        ret;

        priv = this->private;

        loc.path = "/";
        loc.name = "";
        loc.ino = 1;
        loc.inode = fuse_ino_to_inode (1, this);
        loc.parent = NULL;

        dict = dict_new ();
        frame = create_frame (this, this->ctx->pool);
        frame->root->type = GF_OP_TYPE_FOP;

        xl = priv->active_subvol;

        pthread_mutex_init (&stub.mutex, NULL);
        pthread_cond_init (&stub.cond, NULL);
        stub.fin = 0;

        frame->local = &stub;

        memset (gfid, 0, 16);
        gfid[15] = 1;
        ret = dict_set_static_bin (dict, "gfid-req", gfid, 16);

        STACK_WIND (frame, fuse_first_lookup_cbk, xl, xl->fops->lookup,
                    &loc, dict);
        dict_unref (dict);

        pthread_mutex_lock (&stub.mutex);
        {
                while (!stub.fin) {
                        pthread_cond_wait (&stub.cond, &stub.mutex);
                }
        }
        pthread_mutex_unlock (&stub.mutex);

        pthread_mutex_destroy (&stub.mutex);
        pthread_cond_destroy (&stub.cond);

        frame->local = NULL;
        STACK_DESTROY (frame->root);

        return 0;
}


int
fuse_graph_sync (xlator_t *this)
{
        fuse_private_t   *priv = NULL;
        int               need_first_lookup = 0;
        int               ret = 0;

        priv = this->private;

        pthread_mutex_lock (&priv->sync_mutex);
        {
                if (!priv->next_graph)
                        goto unlock;

                priv->active_subvol = priv->next_graph->top;
                priv->next_graph = NULL;
                need_first_lookup = 1;

                while (!priv->event_recvd) {
                        ret = pthread_cond_wait (&priv->sync_cond,
                                                 &priv->sync_mutex);
                        if (ret != 0) {
			          gf_log (this->name, GF_LOG_DEBUG,
					  "timedwait returned non zero value "
					  "ret: %d errno: %d", ret, errno);
				  break;
			}
                }
        }
unlock:
        pthread_mutex_unlock (&priv->sync_mutex);

        if (need_first_lookup) {
                fuse_first_lookup (this);
        }

        return 0;
}


static void *
fuse_thread_proc (void *data)
{
        char           *mount_point = NULL;
        xlator_t       *this = NULL;
        fuse_private_t *priv = NULL;
        ssize_t         res = 0;
        struct iobuf   *iobuf = NULL;
        fuse_in_header_t *finh;
        struct iovec iov_in[2];
        void *msg = NULL;
        const size_t msg0_size = sizeof (*finh) + 128;
        fuse_handler_t **fuse_ops = NULL;

        this = data;
        priv = this->private;
        fuse_ops = priv->fuse_ops;

        THIS = this;

        iov_in[0].iov_len = sizeof (*finh) + sizeof (struct fuse_write_in);
        iov_in[1].iov_len = ((struct iobuf_pool *)this->ctx->iobuf_pool)
                              ->page_size;
        priv->msg0_len_p = &iov_in[0].iov_len;

        for (;;) {
                /* THIS has to be reset here */
                THIS = this;

                if (priv->init_recvd)
                        fuse_graph_sync (this);

                iobuf = iobuf_get (this->ctx->iobuf_pool);
                /* Add extra 128 byte to the first iov so that it can
                 * accomodate "ordinary" non-write requests. It's not
                 * guaranteed to be big enough, as SETXATTR and namespace
                 * operations with very long names may grow behind it,
                 * but it's good enough in most cases (and we can handle
                 * rest via realloc).
                 */
                iov_in[0].iov_base = GF_CALLOC (1, msg0_size,
                                                gf_fuse_mt_iov_base);

                if (!iobuf || !iov_in[0].iov_base) {
                        gf_log (this->name, GF_LOG_ERROR,
                                "Out of memory");
                        if (iobuf)
                                iobuf_unref (iobuf);
                        GF_FREE (iov_in[0].iov_base);
                        sleep (10);
                        continue;
                }

                iov_in[1].iov_base = iobuf->ptr;

                res = readv (priv->fd, iov_in, 2);

                if (res == -1) {
                        if (errno == ENODEV || errno == EBADF) {
                                gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
                                        "terminating upon getting %s when "
                                        "reading /dev/fuse",
                                        errno == ENODEV ? "ENODEV" : "EBADF");

                                break;
                        }
                        if (errno != EINTR) {
                                gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                        "read from /dev/fuse returned -1 (%s)",
                                        strerror (errno));
                        }

                        goto cont_err;
                }
                if (res < sizeof (finh)) {
                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                "short read on /dev/fuse");
                        break;
                }

                finh = (fuse_in_header_t *)iov_in[0].iov_base;

                if (res != finh->len
#ifdef GF_DARWIN_HOST_OS
                    /* work around fuse4bsd/MacFUSE msg size miscalculation bug,
                     * that is, payload size is not taken into account for
                     * buffered writes
                     */
                    && !(finh->opcode == FUSE_WRITE &&
                         finh->len == sizeof(*finh) + sizeof(struct fuse_write_in) &&
                         res == finh->len + ((struct fuse_write_in *)(finh + 1))->size)
#endif
                   ) {
                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                                "inconsistent read on /dev/fuse");
                        break;
                }

                priv->iobuf = iobuf;

                if (finh->opcode == FUSE_WRITE)
                        msg = iov_in[1].iov_base;
                else {
                        if (res > msg0_size) {
                                iov_in[0].iov_base =
                                  GF_REALLOC (iov_in[0].iov_base, res);
                                if (iov_in[0].iov_base)
                                        finh = (fuse_in_header_t *)
                                                 iov_in[0].iov_base;
                                else {
                                        gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                                                "Out of memory");
                                        send_fuse_err (this, finh, ENOMEM);

                                        goto cont_err;
                                }
                        }

                        if (res > iov_in[0].iov_len)
                                memcpy (iov_in[0].iov_base + iov_in[0].iov_len,
                                        iov_in[1].iov_base,
                                        res - iov_in[0].iov_len);

                        msg = finh + 1;
                }
#ifdef GF_DARWIN_HOST_OS
                if (finh->opcode >= FUSE_OP_HIGH)
                        /* turn down MacFUSE specific messages */
                        fuse_enosys (this, finh, msg);
                else
#endif
                fuse_ops[finh->opcode] (this, finh, msg);

                iobuf_unref (iobuf);
                continue;

 cont_err:
                iobuf_unref (iobuf);
                GF_FREE (iov_in[0].iov_base);
        }

        iobuf_unref (iobuf);
        GF_FREE (iov_in[0].iov_base);

        if (dict_get (this->options, ZR_MOUNTPOINT_OPT))
                mount_point = data_to_str (dict_get (this->options,
                                                     ZR_MOUNTPOINT_OPT));
        if (mount_point) {
                gf_log (this->name, GF_LOG_INFO,
                        "unmounting %s", mount_point);
                dict_del (this->options, ZR_MOUNTPOINT_OPT);
        }

        kill (getpid(), SIGTERM);

        return NULL;
}

int32_t
fuse_itable_dump (xlator_t  *this)
{
        if (!this)
                 return -1;

        gf_proc_dump_add_section("xlator.mount.fuse.itable");
        inode_table_dump(this->itable, "xlator.mount.fuse.itable");

	return 0;
}

int32_t
fuse_priv_dump (xlator_t  *this)
{
        fuse_private_t  *private = NULL;

        if (!this)
                return -1;

        private = this->private;

        if (!private)
                return -1;

        gf_proc_dump_add_section("xlator.mount.fuse.priv");

        gf_proc_dump_write("xlator.mount.fuse.priv.fd", "%d", private->fd);
        gf_proc_dump_write("xlator.mount.fuse.priv.proto_minor", "%u",
                            private->proto_minor);
        gf_proc_dump_write("xlator.mount.fuse.priv.volfile", "%s",
                            private->volfile?private->volfile:"None");
        gf_proc_dump_write("xlator.mount.fuse.volfile_size", "%d",
                            private->volfile_size);
        gf_proc_dump_write("xlator.mount.fuse.mount_point", "%s",
                            private->mount_point);
        gf_proc_dump_write("xlator.mount.fuse.iobuf", "%u",
                            private->iobuf);
        gf_proc_dump_write("xlator.mount.fuse.fuse_thread_started", "%d",
                            (int)private->fuse_thread_started);
        gf_proc_dump_write("xlator.mount.fuse.direct_io_mode", "%d",
                            private->direct_io_mode);
        gf_proc_dump_write("xlator.mount.fuse.entry_timeout", "%lf",
                            private->entry_timeout);
        gf_proc_dump_write("xlator.mount.fuse.attribute_timeout", "%lf",
                            private->attribute_timeout);
        gf_proc_dump_write("xlator.mount.fuse.init_recvd", "%d",
                            (int)private->init_recvd);
        gf_proc_dump_write("xlator.mount.fuse.strict_volfile_check", "%d",
                            (int)private->strict_volfile_check);

        return 0;
}


int
fuse_graph_setup (xlator_t *this, glusterfs_graph_t *graph)
{
        inode_table_t  *itable = NULL;
        int             ret = 0;
        fuse_private_t *priv = NULL;

        priv = this->private;

        /* handle the case of more than one CHILD_UP on same graph */
        if (priv->active_subvol == graph->top)
                return 0; /* This is a valid case */

        if (graph->used)
                return 0;

        graph->used = 1;

        itable = inode_table_new (0, graph->top);
        if (!itable)
                return -1;

        ((xlator_t *)graph->top)->itable = itable;

        pthread_mutex_lock (&priv->sync_mutex);
        {
                priv->next_graph = graph;
                priv->event_recvd = 0;

                pthread_cond_signal (&priv->sync_cond);
        }
        pthread_mutex_unlock (&priv->sync_mutex);

        gf_log ("fuse", GF_LOG_INFO, "switched to graph %d",
                ((graph) ? graph->id : 0));

        return ret;
}


int
notify (xlator_t *this, int32_t event, void *data, ...)
{
        int32_t             ret     = 0;
        fuse_private_t     *private = NULL;
        glusterfs_graph_t  *graph = NULL;

        private = this->private;

        graph = data;

        gf_log ("fuse", GF_LOG_DEBUG, "got event %d on graph %d",
                event, ((graph) ? graph->id : 0));

        switch (event)
        {
        case GF_EVENT_GRAPH_NEW:
                break;

        case GF_EVENT_CHILD_UP:
        case GF_EVENT_CHILD_DOWN:
        case GF_EVENT_CHILD_CONNECTING:
        {
                if (graph) {
                        ret = fuse_graph_setup (this, graph);
                        if (ret)
                                gf_log (this->name, GF_LOG_WARNING,
                                        "failed to setup the graph");
                }

                if ((event == GF_EVENT_CHILD_UP)
                    || (event == GF_EVENT_CHILD_DOWN)) {
                        pthread_mutex_lock (&private->sync_mutex);
                        {
                                private->event_recvd = 1;
                                pthread_cond_broadcast (&private->sync_cond);
                        }
                        pthread_mutex_unlock (&private->sync_mutex);
                }

                if (!private->fuse_thread_started) {
                        private->fuse_thread_started = 1;

                        ret = pthread_create (&private->fuse_thread, NULL,
                                              fuse_thread_proc, this);
                        if (ret != 0) {
                                gf_log (this->name, GF_LOG_DEBUG,
                                        "pthread_create() failed (%s)",
                                        strerror (errno));
                                break;
                        }
                }

                break;
        }

        default:
                break;
        }

        return ret;
}

int32_t
mem_acct_init (xlator_t *this)
{
        int     ret = -1;

        if (!this)
                return ret;

        ret = xlator_mem_acct_init (this, gf_fuse_mt_end + 1);

        if (ret != 0) {
                gf_log (this->name, GF_LOG_ERROR, "Memory accounting init"
                                "failed");
                return ret;
        }

        return ret;
}


static fuse_handler_t *fuse_std_ops[FUSE_OP_HIGH] = {
        [FUSE_INIT]        = fuse_init,
        [FUSE_DESTROY]     = fuse_destroy,
        [FUSE_LOOKUP]      = fuse_lookup,
        [FUSE_FORGET]      = fuse_forget,
        [FUSE_GETATTR]     = fuse_getattr,
        [FUSE_SETATTR]     = fuse_setattr,
        [FUSE_OPENDIR]     = fuse_opendir,
        [FUSE_READDIR]     = fuse_readdir,
        [FUSE_RELEASEDIR]  = fuse_releasedir,
        [FUSE_ACCESS]      = fuse_access,
        [FUSE_READLINK]    = fuse_readlink,
        [FUSE_MKNOD]       = fuse_mknod,
        [FUSE_MKDIR]       = fuse_mkdir,
        [FUSE_UNLINK]      = fuse_unlink,
        [FUSE_RMDIR]       = fuse_rmdir,
        [FUSE_SYMLINK]     = fuse_symlink,
        [FUSE_RENAME]      = fuse_rename,
        [FUSE_LINK]        = fuse_link,
        [FUSE_CREATE]      = fuse_create,
        [FUSE_OPEN]        = fuse_open,
        [FUSE_READ]        = fuse_readv,
        [FUSE_WRITE]       = fuse_write,
        [FUSE_FLUSH]       = fuse_flush,
        [FUSE_RELEASE]     = fuse_release,
        [FUSE_FSYNC]       = fuse_fsync,
        [FUSE_FSYNCDIR]    = fuse_fsyncdir,
        [FUSE_STATFS]      = fuse_statfs,
        [FUSE_SETXATTR]    = fuse_setxattr,
        [FUSE_GETXATTR]    = fuse_getxattr,
        [FUSE_LISTXATTR]   = fuse_listxattr,
        [FUSE_REMOVEXATTR] = fuse_removexattr,
        [FUSE_GETLK]       = fuse_getlk,
        [FUSE_SETLK]       = fuse_setlk,
        [FUSE_SETLKW]      = fuse_setlk,
};


static fuse_handler_t *fuse_dump_ops[FUSE_OP_HIGH] = {
};


static void
fuse_dumper (xlator_t *this, fuse_in_header_t *finh, void *msg)
{
        fuse_private_t *priv = NULL;
        struct iovec diov[3];
        char r = 'R';
        int ret = 0;

        priv = this->private;

        diov[0].iov_base = &r;
        diov[0].iov_len  = 1;
        diov[1].iov_base = finh;
        diov[1].iov_len  = sizeof (*finh);
        diov[2].iov_base = msg;
        diov[2].iov_len  = finh->len - sizeof (*finh);

        pthread_mutex_lock (&priv->fuse_dump_mutex);
        ret = writev (priv->fuse_dump_fd, diov, 3);
        pthread_mutex_unlock (&priv->fuse_dump_mutex);
        if (ret == -1)
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "failed to dump fuse message (R): %s",
                        strerror (errno));

        return priv->fuse_ops0[finh->opcode] (this, finh, msg);
}


int
init (xlator_t *this_xl)
{
        int                ret = 0;
        dict_t            *options = NULL;
        char              *value_string = NULL;
        cmd_args_t        *cmd_args = NULL;
        char              *fsname = NULL;
        fuse_private_t    *priv = NULL;
        struct stat        stbuf = {0,};
        int                i = 0;
        int                xl_name_allocated = 0;
        int                fsname_allocated = 0;
        glusterfs_ctx_t   *ctx = NULL;
        gf_boolean_t       sync_mtab = _gf_false;

        if (this_xl == NULL)
                return -1;

        if (this_xl->options == NULL)
                return -1;

        ctx = glusterfs_ctx_get ();
        if (!ctx)
                return -1;

        options = this_xl->options;

        if (this_xl->name == NULL) {
                this_xl->name = gf_strdup ("fuse");
                if (!this_xl->name) {
                        gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                                "Out of memory");

                        goto cleanup_exit;
                }
                xl_name_allocated = 1;
        }

        priv = GF_CALLOC (1, sizeof (*priv), gf_fuse_mt_fuse_private_t);
        if (!priv) {
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "Out of memory");

                goto cleanup_exit;
        }
        this_xl->private = (void *) priv;
        priv->mount_point = NULL;
        priv->fd = -1;

        /* get options from option dictionary */
        ret = dict_get_str (options, ZR_MOUNTPOINT_OPT, &value_string);
        if (ret == -1 || value_string == NULL) {
                gf_log ("fuse", GF_LOG_ERROR,
                        "Mandatory option 'mountpoint' is not specified.");
                goto cleanup_exit;
        }

        if (stat (value_string, &stbuf) != 0) {
                if (errno == ENOENT) {
                        gf_log (this_xl->name, GF_LOG_ERROR,
                                "%s %s does not exist",
                                ZR_MOUNTPOINT_OPT, value_string);
                } else if (errno == ENOTCONN) {
                        gf_log (this_xl->name, GF_LOG_ERROR,
                                "Mountpoint %s seems to have a stale "
                                "mount, run 'umount %s' and try again.",
                                value_string, value_string);
                } else {
                        gf_log (this_xl->name, GF_LOG_DEBUG,
                                "%s %s : stat returned %s",
                                ZR_MOUNTPOINT_OPT,
                                value_string, strerror (errno));
                }
                goto cleanup_exit;
        }

        if (S_ISDIR (stbuf.st_mode) == 0) {
                gf_log (this_xl->name, GF_LOG_ERROR,
                        "%s %s is not a directory",
                        ZR_MOUNTPOINT_OPT, value_string);
                goto cleanup_exit;
        }
        priv->mount_point = gf_strdup (value_string);
        if (!priv->mount_point) {
                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                        "Out of memory");

                goto cleanup_exit;
        }

        ret = dict_get_double (options, "attribute-timeout",
                               &priv->attribute_timeout);
        if (ret != 0)
                priv->attribute_timeout = 1.0; /* default */

        ret = dict_get_double (options, "entry-timeout",
                               &priv->entry_timeout);
        if (ret != 0)
                priv->entry_timeout = 1.0; /* default */

        ret = dict_get_int32 (options, "client-pid",
                              &priv->client_pid);
        if (ret == 0)
                priv->client_pid_set = _gf_true;

        priv->direct_io_mode = 2;
        ret = dict_get_str (options, ZR_DIRECT_IO_OPT, &value_string);
        if (ret == 0) {
                ret = gf_string2boolean (value_string, &priv->direct_io_mode);
                GF_ASSERT (ret == 0);
        }

        priv->strict_volfile_check = 0;
        ret = dict_get_str (options, ZR_STRICT_VOLFILE_CHECK, &value_string);
        if (ret == 0) {
                ret = gf_string2boolean (value_string,
                                         &priv->strict_volfile_check);
                GF_ASSERT (ret == 0);
        }

        priv->acl = 0;
        ret = dict_get_str (options, "acl", &value_string);
        if (ret == 0) {
                ret = gf_string2boolean (value_string, &priv->acl);
                GF_ASSERT (ret == 0);
        }


        priv->fuse_dump_fd = -1;
        ret = dict_get_str (options, "dump-fuse", &value_string);
        if (ret == 0) {
                ret = unlink (value_string);
                if (ret != -1 || errno == ENOENT)
                        ret = open (value_string, O_RDWR|O_CREAT|O_EXCL,
                                    S_IRUSR|S_IWUSR);
                if (ret == -1) {
                        gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                                "cannot open fuse dump file %s",
                                 value_string);

                        goto cleanup_exit;
                }
                priv->fuse_dump_fd = ret;
        }

        sync_mtab = _gf_false;
        ret = dict_get_str (options, "sync-mtab", &value_string);
        if (ret == 0) {
                ret = gf_string2boolean (value_string,
                                         &sync_mtab);
                GF_ASSERT (ret == 0);
        }

        cmd_args = &this_xl->ctx->cmd_args;
        fsname = cmd_args->volfile;
        if (!fsname && cmd_args->volfile_server) {
                if (cmd_args->volfile_id) {
                        fsname = GF_MALLOC (
                                   strlen (cmd_args->volfile_server) + 1 +
                                   strlen (cmd_args->volfile_id) + 1,
                                   gf_fuse_mt_fuse_private_t);
                        if (!fsname) {
                                gf_log ("glusterfs-fuse", GF_LOG_ERROR,
                                        "Out of memory");
                                goto cleanup_exit;
                        }
                        fsname_allocated = 1;
                        strcpy (fsname, cmd_args->volfile_server);
                        strcat (fsname, ":");
                        strcat (fsname, cmd_args->volfile_id);
                } else
                        fsname = cmd_args->volfile_server;
        }
        if (!fsname)
                fsname = "glusterfs";


        if (priv->acl) {
                priv->fd = gf_fuse_mount (priv->mount_point, fsname,
                                          "allow_other,"
                                          "max_read=131072",
                                          sync_mtab ? &ctx->mtab_pid : NULL);
        } else {
                priv->fd = gf_fuse_mount (priv->mount_point, fsname,
                                          "allow_other,default_permissions,"
                                          "max_read=131072",
                                          sync_mtab ? &ctx->mtab_pid : NULL);
        }

        if (priv->fd == -1)
                goto cleanup_exit;

        pthread_mutex_init (&priv->fuse_dump_mutex, NULL);
        pthread_cond_init (&priv->sync_cond, NULL);
        pthread_mutex_init (&priv->sync_mutex, NULL);
        priv->event_recvd = 0;

        for (i = 0; i < FUSE_OP_HIGH; i++) {
                if (!fuse_std_ops[i])
                        fuse_std_ops[i] = fuse_enosys;
                if (!fuse_dump_ops[i])
                        fuse_dump_ops[i] = fuse_dumper;
        }
        priv->fuse_ops = fuse_std_ops;
        if (priv->fuse_dump_fd != -1) {
                priv->fuse_ops0 = priv->fuse_ops;
                priv->fuse_ops  = fuse_dump_ops;
        }

        return 0;

cleanup_exit:
        if (xl_name_allocated)
                GF_FREE (this_xl->name);
        if (fsname_allocated)
                GF_FREE (fsname);
        if (priv) {
                GF_FREE (priv->mount_point);
                close (priv->fd);
                close (priv->fuse_dump_fd);
                GF_FREE (priv);
        }
        return -1;
}


void
fini (xlator_t *this_xl)
{
        fuse_private_t *priv = NULL;
        char *mount_point = NULL;

        if (this_xl == NULL)
                return;

        if ((priv = this_xl->private) == NULL)
                return;

        if (dict_get (this_xl->options, ZR_MOUNTPOINT_OPT))
                mount_point = data_to_str (dict_get (this_xl->options,
                                                     ZR_MOUNTPOINT_OPT));
        if (mount_point != NULL) {
                gf_log (this_xl->name, GF_LOG_INFO,
                        "Unmounting '%s'.", mount_point);

                dict_del (this_xl->options, ZR_MOUNTPOINT_OPT);
                gf_fuse_unmount (mount_point, priv->fd);
                close (priv->fuse_dump_fd);
        }
}

struct xlator_fops fops = {
};

struct xlator_cbks cbks = {
};


struct xlator_dumpops dumpops = {
        .priv  = fuse_priv_dump,
        .inode = fuse_itable_dump,
};

struct volume_options options[] = {
        { .key  = {"direct-io-mode"},
          .type = GF_OPTION_TYPE_BOOL
        },
        { .key  = {ZR_MOUNTPOINT_OPT, "mount-point"},
          .type = GF_OPTION_TYPE_PATH
        },
        { .key  = {ZR_DUMP_FUSE, "fuse-dumpfile"},
          .type = GF_OPTION_TYPE_PATH
        },
        { .key  = {ZR_ATTR_TIMEOUT_OPT},
          .type = GF_OPTION_TYPE_DOUBLE
        },
        { .key  = {ZR_ENTRY_TIMEOUT_OPT},
          .type = GF_OPTION_TYPE_DOUBLE
        },
        { .key  = {ZR_STRICT_VOLFILE_CHECK},
          .type = GF_OPTION_TYPE_BOOL
        },
        { .key  = {"client-pid"},
          .type = GF_OPTION_TYPE_INT
        },
        { .key  = {"sync-mtab"},
          .type = GF_OPTION_TYPE_BOOL
        },
        { .key = {NULL} },
};