fuse resolve related changes

Now fuse is fully complaint with DVM, as even if there is a fop
request on inode belonging to old graph, it will be resolved
corresponding to new graph and operations will be performed wrt.
new graph, which makes DVM truely spontaneous.

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 1240 (DVM: after graph change, inodes should resolve to new inode-table)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1240

1 files changed, 747 insertions, 0 deletions

diff --git a/xlators/mount/fuse/src/fuse-resolve.c b/xlators/mount/fuse/src/fuse-resolve.c
new file mode 100644
index 000000000..b90ef3d5f
--- /dev/null
+++ b/xlators/mount/fuse/src/fuse-resolve.c
@@ -0,0 +1,747 @@
+/*
+  Copyright (c) 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 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see
+  <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "fuse-bridge.h"
+
+static int
+gf_resolve_all (fuse_state_t *state);
+static int
+resolve_entry_simple (fuse_state_t *state);
+static int
+resolve_inode_simple (fuse_state_t *state);
+static int
+resolve_path_simple (fuse_state_t *state);
+
+static int
+component_count (const char *path)
+{
+        int         count = 0;
+        const char *trav = NULL;
+
+        for (trav = path; *trav; trav++) {
+                if (*trav == '/')
+                        count++;
+        }
+
+        return count + 2;
+}
+
+
+static int
+prepare_components (fuse_state_t *state)
+{
+        xlator_t               *active_xl  = NULL;
+        gf_resolve_t           *resolve    = NULL;
+        char                   *resolved   = NULL;
+        struct gf_resolve_comp *components = NULL;
+        char                   *trav       = NULL;
+        int                     count      = 0;
+        int                     i          = 0;
+
+        resolve = state->resolve_now;
+
+        resolved = gf_strdup (resolve->path);
+        resolve->resolved = resolved;
+
+        count = component_count (resolve->path);
+        components = GF_CALLOC (sizeof (*components), count, 0); //TODO
+        if (!components)
+                goto out;
+        resolve->components = components;
+
+        active_xl = fuse_active_subvol (state->this);
+
+        components[0].basename = "";
+        components[0].ino      = 1;
+        components[0].gen      = 0;
+        components[0].inode    = inode_ref (active_xl->itable->root);
+
+        i = 1;
+        for (trav = resolved; *trav; trav++) {
+                if (*trav == '/') {
+                        components[i].basename = trav + 1;
+                        *trav = 0;
+                        i++;
+                }
+        }
+out:
+        return 0;
+}
+
+
+static int
+resolve_loc_touchup (fuse_state_t *state)
+{
+        gf_resolve_t *resolve = NULL;
+        loc_t        *loc     = NULL;
+        char         *path    = NULL;
+        int           ret     = 0;
+
+        resolve = state->resolve_now;
+        loc     = state->loc_now;
+
+        if (!loc->path) {
+                if (loc->parent) {
+                        ret = inode_path (loc->parent, resolve->bname, &path);
+                } else if (loc->inode) {
+                        ret = inode_path (loc->inode, NULL, &path);
+                }
+                if (ret)
+                        gf_log ("", GF_LOG_TRACE,
+                                "return value inode_path %d", ret);
+
+                if (!path)
+                        path = gf_strdup (resolve->path);
+
+                loc->path = path;
+        }
+
+        loc->name = strrchr (loc->path, '/');
+        if (loc->name)
+                loc->name++;
+
+        if (!loc->parent && loc->inode) {
+                loc->parent = inode_parent (loc->inode, 0, NULL);
+        }
+
+        return 0;
+}
+
+static int
+fuse_resolve_newfd_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      = NULL;
+        gf_resolve_t *resolve    = NULL;
+        fd_t         *old_fd     = NULL;
+        fd_t         *tmp_fd     = NULL;
+        uint64_t      tmp_fd_ctx = 0;
+        int           ret        = 0;
+
+        state = frame->root->state;
+        resolve = state->resolve_now;
+
+        STACK_DESTROY (frame->root);
+
+        if (op_ret == -1) {
+                goto out;
+        }
+
+        old_fd = resolve->fd;
+
+        state->fd = fd_ref (fd);
+
+        fd_bind (fd);
+
+        resolve->fd = NULL;
+        ret = fd_ctx_del (old_fd, state->this, &tmp_fd_ctx);
+        if (!ret) {
+                tmp_fd = (fd_t *)(long)tmp_fd_ctx;
+                fd_unref (tmp_fd);
+        }
+        ret = fd_ctx_set (old_fd, state->this, (uint64_t)(long)fd);
+        if (ret)
+                gf_log ("resolve", GF_LOG_WARNING,
+                        "failed to set the fd ctx with resolved fd");
+out:
+        gf_resolve_all (state);
+        return 0;
+}
+
+static void
+gf_resolve_new_fd (fuse_state_t *state)
+{
+        gf_resolve_t *resolve = NULL;
+        fd_t         *new_fd  = NULL;
+        fd_t         *fd      = NULL;
+
+        resolve = state->resolve_now;
+        fd = resolve->fd;
+
+        new_fd = fd_create (state->loc.inode, state->finh->pid);
+        new_fd->flags = (fd->flags & ~O_TRUNC);
+
+        gf_log ("resolve", GF_LOG_DEBUG,
+                "%"PRIu64": OPEN %s", state->finh->unique,
+                state->loc.path);
+
+        FUSE_FOP (state, fuse_resolve_newfd_cbk, GF_FOP_OPEN,
+                  open, &state->loc, new_fd->flags, new_fd, 0);
+}
+
+static int
+resolve_deep_continue (fuse_state_t *state)
+{
+        gf_resolve_t     *resolve = NULL;
+        int               ret = 0;
+
+        resolve = state->resolve_now;
+
+        resolve->op_ret   = 0;
+        resolve->op_errno = 0;
+
+        if (resolve->par)
+                ret = resolve_entry_simple (state);
+        else if (resolve->ino)
+                ret = resolve_inode_simple (state);
+        else if (resolve->path)
+                ret = resolve_path_simple (state);
+        if (ret)
+                gf_log ("resolve", GF_LOG_TRACE,
+                        "return value of resolve_*_simple %d", ret);
+
+        resolve_loc_touchup (state);
+
+        /* This function is called by either fd resolve or inode resolve */
+        if (!resolve->fd)
+                gf_resolve_all (state);
+        else
+                gf_resolve_new_fd (state);
+
+        return 0;
+}
+
+
+static int
+resolve_deep_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                  int op_ret, int op_errno, inode_t *inode, struct iatt *buf,
+                  dict_t *xattr, struct iatt *postparent)
+{
+        xlator_t               *active_xl = NULL;
+        fuse_state_t           *state      = NULL;
+        gf_resolve_t           *resolve    = NULL;
+        struct gf_resolve_comp *components = NULL;
+        inode_t                *link_inode = NULL;
+        int                     i          = 0;
+
+        state = frame->root->state;
+        resolve = state->resolve_now;
+        components = resolve->components;
+
+        i = (long) cookie;
+
+        STACK_DESTROY (frame->root);
+
+        if (op_ret == -1) {
+                goto get_out_of_here;
+        }
+
+        if (i != 0) {
+                inode_ref (inode);
+                /* no linking for root inode */
+                link_inode = inode_link (inode, resolve->deep_loc.parent,
+                                         resolve->deep_loc.name, buf);
+                components[i].inode  = inode_ref (link_inode);
+                link_inode = NULL;
+        }
+        inode_ref (resolve->deep_loc.parent);
+        inode_ref (inode);
+        loc_wipe (&resolve->deep_loc);
+        i++; /* next component */
+
+        if (!components[i].basename) {
+                /* all components of the path are resolved */
+                goto get_out_of_here;
+        }
+
+        /* join the current component with the path resolved until now */
+        *(components[i].basename - 1) = '/';
+
+        active_xl = fuse_active_subvol (state->this);
+
+        resolve->deep_loc.path   = gf_strdup (resolve->resolved);
+        resolve->deep_loc.parent = inode_ref (components[i-1].inode);
+        resolve->deep_loc.inode  = inode_new (active_xl->itable);
+        resolve->deep_loc.name   = components[i].basename;
+
+        FUSE_FOP_COOKIE (state, active_xl, resolve_deep_cbk, (void *)(long)i,
+                         GF_FOP_LOOKUP, lookup, &resolve->deep_loc, NULL);
+        return 0;
+
+get_out_of_here:
+        resolve_deep_continue (state);
+        return 0;
+}
+
+
+static int
+resolve_path_deep (fuse_state_t *state)
+{
+        xlator_t               *active_xl  = NULL;
+        gf_resolve_t           *resolve    = NULL;
+        struct gf_resolve_comp *components = NULL;
+        inode_t                *inode      = NULL;
+        long                    i          = 0;
+
+        resolve = state->resolve_now;
+
+        prepare_components (state);
+
+        components = resolve->components;
+
+        /* start from the root */
+        active_xl = fuse_active_subvol (state->this);
+        resolve->deep_loc.inode = inode_ref (active_xl->itable->root);
+        resolve->deep_loc.path  = gf_strdup ("/");
+        resolve->deep_loc.name  = "";
+
+        for (i = 1; components[i].basename; i++) {
+                *(components[i].basename - 1) = '/';
+                inode = inode_grep (active_xl->itable, components[i-1].inode,
+                                    components[i].basename);
+                if (!inode)
+                        break;
+                components[i].inode = inode_ref (inode);
+        }
+
+        if (!components[i].basename)
+                goto resolved;
+
+        resolve->deep_loc.path   = gf_strdup (resolve->resolved);
+        resolve->deep_loc.parent = inode_ref (components[i-1].inode);
+        resolve->deep_loc.inode  = inode_new (active_xl->itable);
+        resolve->deep_loc.name   = components[i].basename;
+
+        FUSE_FOP_COOKIE (state, active_xl, resolve_deep_cbk, (void *)(long)i,
+                         GF_FOP_LOOKUP, lookup, &resolve->deep_loc, NULL);
+
+        return 0;
+resolved:
+        resolve_deep_continue (state);
+        return 0;
+}
+
+
+static int
+resolve_path_simple (fuse_state_t *state)
+{
+        gf_resolve_t           *resolve    = NULL;
+        struct gf_resolve_comp *components = NULL;
+        int                     ret        = -1;
+        int                     par_idx    = 0;
+        int                     ino_idx    = 0;
+        int                     i          = 0;
+
+        resolve = state->resolve_now;
+        components = resolve->components;
+
+        if (!components) {
+                resolve->op_ret   = -1;
+                resolve->op_errno = ENOENT;
+                goto out;
+        }
+
+        for (i = 0; components[i].basename; i++) {
+                par_idx = ino_idx;
+                ino_idx = i;
+        }
+
+        if (!components[par_idx].inode) {
+                resolve->op_ret    = -1;
+                resolve->op_errno  = ENOENT;
+                goto out;
+        }
+
+        if (!components[ino_idx].inode &&
+            (resolve->type == RESOLVE_MUST || resolve->type == RESOLVE_EXACT)) {
+                resolve->op_ret    = -1;
+                resolve->op_errno  = ENOENT;
+                goto out;
+        }
+
+        if (components[ino_idx].inode && resolve->type == RESOLVE_NOT) {
+                resolve->op_ret    = -1;
+                resolve->op_errno  = EEXIST;
+                goto out;
+        }
+
+        if (components[ino_idx].inode)
+                state->loc_now->inode  = inode_ref (components[ino_idx].inode);
+        state->loc_now->parent = inode_ref (components[par_idx].inode);
+
+        ret = 0;
+
+out:
+        return ret;
+}
+
+/*
+  Check if the requirements are fulfilled by entries in the inode cache itself
+  Return value:
+  <= 0 - simple resolution was decisive and complete (either success or failure)
+  > 0  - indecisive, need to perform deep resolution
+*/
+
+static int
+resolve_entry_simple (fuse_state_t *state)
+{
+        xlator_t     *this    = NULL;
+        xlator_t     *active_xl = NULL;
+        gf_resolve_t *resolve = NULL;
+        inode_t      *parent  = NULL;
+        inode_t      *inode   = NULL;
+        int           ret     = 0;
+
+        this  = state->this;
+        resolve = state->resolve_now;
+
+        active_xl = fuse_active_subvol (this);
+
+        parent = inode_get (active_xl->itable, resolve->par, 0);
+        if (!parent) {
+                /* simple resolution is indecisive. need to perform
+                   deep resolution */
+                resolve->op_ret   = -1;
+                resolve->op_errno = ENOENT;
+                ret = 1;
+
+                inode = inode_grep (active_xl->itable, parent, resolve->bname);
+                if (inode != NULL) {
+                        gf_log (this->name, GF_LOG_DEBUG, "%"PRId64": inode "
+                                "(pointer:%p ino: %"PRIu64") present but parent"
+                                " is NULL for path (%s)", 0L,
+                                inode, inode->ino, resolve->path);
+                        inode_unref (inode);
+                }
+                goto out;
+        }
+
+        /* expected @parent was found from the inode cache */
+        state->loc_now->parent = inode_ref (parent);
+
+        inode = inode_grep (active_xl->itable, parent, resolve->bname);
+        if (!inode) {
+                switch (resolve->type) {
+                case RESOLVE_DONTCARE:
+                case RESOLVE_NOT:
+                        ret = 0;
+                        break;
+                case RESOLVE_MAY:
+                        ret = 1;
+                        break;
+                default:
+                        resolve->op_ret   = -1;
+                        resolve->op_errno = ENOENT;
+                        ret = 1;
+                        break;
+                }
+
+                goto out;
+        }
+
+        if (resolve->type == RESOLVE_NOT) {
+                gf_log (this->name, GF_LOG_DEBUG, "inode (pointer: %p ino:%"
+                        PRIu64") found for path (%s) while type is RESOLVE_NOT",
+                        inode, inode->ino, resolve->path);
+                resolve->op_ret   = -1;
+                resolve->op_errno = EEXIST;
+                ret = -1;
+                goto out;
+        }
+
+        ret = 0;
+
+        state->loc_now->inode  = inode_ref (inode);
+
+out:
+        if (parent)
+                inode_unref (parent);
+
+        if (inode)
+                inode_unref (inode);
+
+        return ret;
+}
+
+
+static int
+gf_resolve_entry (fuse_state_t *state)
+{
+        int                 ret = 0;
+        loc_t              *loc = NULL;
+
+        loc  = state->loc_now;
+
+        ret = resolve_entry_simple (state);
+
+        if (ret > 0) {
+                loc_wipe (loc);
+                resolve_path_deep (state);
+                return 0;
+        }
+
+        if (ret == 0)
+                resolve_loc_touchup (state);
+
+        gf_resolve_all (state);
+
+        return 0;
+}
+
+
+static int
+resolve_inode_simple (fuse_state_t *state)
+{
+        xlator_t     *active_xl = NULL;
+        gf_resolve_t *resolve = NULL;
+        inode_t      *inode   = NULL;
+        int           ret     = 0;
+
+        resolve = state->resolve_now;
+
+        active_xl = fuse_active_subvol (state->this);
+
+        if (resolve->type == RESOLVE_EXACT) {
+                inode = inode_get (active_xl->itable, resolve->ino,
+                                   resolve->gen);
+        } else {
+                inode = inode_get (active_xl->itable, resolve->ino, 0);
+        }
+
+        if (!inode) {
+                resolve->op_ret   = -1;
+                resolve->op_errno = ENOENT;
+                ret = 1;
+                goto out;
+        }
+
+        ret = 0;
+
+        state->loc_now->inode = inode_ref (inode);
+
+out:
+        if (inode)
+                inode_unref (inode);
+
+        return ret;
+}
+
+
+static int
+gf_resolve_inode (fuse_state_t *state)
+{
+        int                 ret = 0;
+        loc_t              *loc = NULL;
+
+        loc  = state->loc_now;
+
+        ret = resolve_inode_simple (state);
+
+        if (ret > 0) {
+                loc_wipe (loc);
+                resolve_path_deep (state);
+                return 0;
+        }
+
+        if (ret == 0)
+                resolve_loc_touchup (state);
+
+        gf_resolve_all (state);
+
+        return 0;
+}
+
+
+static int
+gf_resolve_fd (fuse_state_t *state)
+{
+        gf_resolve_t  *resolve    = NULL;
+        fd_t          *fd         = NULL;
+        int            ret        = 0;
+        uint64_t       tmp_fd_ctx = 0;
+        char          *path       = NULL;
+        char          *name       = NULL;
+
+        resolve = state->resolve_now;
+
+        fd = resolve->fd;
+
+        ret = fd_ctx_get (fd, state->this, &tmp_fd_ctx);
+        if (!ret) {
+                state->fd = (fd_t *)(long)tmp_fd_ctx;
+                fd_ref (state->fd);
+                gf_resolve_all (state);
+                goto out;
+        }
+
+        ret = inode_path (fd->inode, 0, &path);
+        if (!ret || !path)
+                gf_log ("", GF_LOG_WARNING,
+                        "failed to do inode-path on fd %d %s", ret, path);
+
+        name = strrchr (path, '/');
+        if (name)
+                name++;
+
+        resolve->path = path;
+        resolve->bname = gf_strdup (name);
+
+        state->loc_now     = &state->loc;
+
+        resolve_path_deep (state);
+
+out:
+        return 0;
+}
+
+
+static int
+gf_resolve (fuse_state_t *state)
+ {
+        gf_resolve_t   *resolve = NULL;
+
+        resolve = state->resolve_now;
+
+        if (resolve->fd) {
+
+                gf_resolve_fd (state);
+
+        } else if (resolve->par) {
+
+                gf_resolve_entry (state);
+
+        } else if (resolve->ino) {
+
+                gf_resolve_inode (state);
+
+        } else if (resolve->path) {
+
+                resolve_path_deep (state);
+
+        } else  {
+
+                resolve->op_ret = -1;
+                resolve->op_errno = EINVAL;
+
+                gf_resolve_all (state);
+        }
+
+        return 0;
+}
+
+
+static int
+gf_resolve_done (fuse_state_t *state)
+{
+        fuse_resume_fn_t fn = NULL;
+
+        fn = state->resume_fn;
+        if (fn)
+                fn (state);
+
+        return 0;
+}
+
+
+/*
+ * This function is called multiple times, once per resolving one location/fd.
+ * state->resolve_now is used to decide which location/fd is to be resolved now
+ */
+static int
+gf_resolve_all (fuse_state_t *state)
+{
+        xlator_t     *this = NULL;
+
+        if (state->resolve_now == NULL) {
+
+                state->resolve_now = &state->resolve;
+                state->loc_now     = &state->loc;
+
+                gf_resolve (state);
+
+        } else if (state->resolve_now == &state->resolve) {
+
+                state->resolve_now = &state->resolve2;
+                state->loc_now     = &state->loc2;
+
+                gf_resolve (state);
+
+        } else if (state->resolve_now == &state->resolve2) {
+
+                gf_resolve_done (state);
+
+        } else {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Invalid pointer for state->resolve_now");
+        }
+
+        return 0;
+}
+
+
+int
+fuse_resolve_and_resume (fuse_state_t *state, fuse_resume_fn_t fn)
+{
+        xlator_t *inode_xl = NULL;
+        xlator_t *active_xl = NULL;
+
+        state->resume_fn = fn;
+
+        active_xl = fuse_active_subvol (state->this);
+        inode_xl = fuse_state_subvol (state);
+        if (!inode_xl && state->loc.parent)
+                inode_xl = state->loc.parent->table->xl;
+
+        /* If inode or fd is already in new graph, goto resume */
+        if (inode_xl == active_xl)
+                goto resume;
+
+        /* If the resolve is for 'fd' and its open with 'write' flag
+           set, don't switch to new graph yet */
+        if (state->fd && ((state->fd->flags & O_RDWR) ||
+                          (state->fd->flags & O_WRONLY)))
+                goto resume;
+
+        if (state->loc.path) {
+                state->resolve.path = gf_strdup (state->loc.path);
+                state->resolve.bname = gf_strdup (state->loc.name);
+                /* TODO: make sure there is no leaks in inode refs */
+                //loc_wipe (&state->loc);
+                state->loc.inode = NULL;
+                state->loc.parent = NULL;
+        }
+
+        /* Needed for rename and link */
+        if (state->loc2.path) {
+                state->resolve2.path = gf_strdup (state->loc2.path);
+                state->resolve2.bname = gf_strdup (state->loc2.name);
+                //loc_wipe (&state->loc2);
+                state->loc2.inode = NULL;
+                state->loc2.parent = NULL;
+        }
+
+        if (state->fd) {
+                state->resolve.fd = state->fd;
+                /* TODO: check if its a leak, if yes, then do 'unref' */
+                state->fd = NULL;
+        }
+
+        gf_resolve_all (state);
+
+        return 0;
+resume:
+        fn (state);
+
+        return 0;
+}