[PATCH] v9fs: debug and support routines
This part of the patch contains debug and other misc routines.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
new file mode 100644
index 0000000..821c9c4
--- /dev/null
+++ b/fs/9p/fid.c
@@ -0,0 +1,241 @@
+/*
+ * V9FS FID Management
+ *
+ * Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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, write to:
+ * Free Software Foundation
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA 02111-1301 USA
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+
+#include "debug.h"
+#include "v9fs.h"
+#include "9p.h"
+#include "v9fs_vfs.h"
+#include "transport.h"
+#include "mux.h"
+#include "conv.h"
+#include "fid.h"
+
+/**
+ * v9fs_fid_insert - add a fid to a dentry
+ * @fid: fid to add
+ * @dentry: dentry that it is being added to
+ *
+ */
+
+static int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry)
+{
+ struct list_head *fid_list = (struct list_head *)dentry->d_fsdata;
+ dprintk(DEBUG_9P, "fid %d (%p) dentry %s (%p)\n", fid->fid, fid,
+ dentry->d_iname, dentry);
+ if (dentry->d_fsdata == NULL) {
+ dentry->d_fsdata =
+ kmalloc(sizeof(struct list_head), GFP_KERNEL);
+ if (dentry->d_fsdata == NULL) {
+ dprintk(DEBUG_ERROR, "Out of memory\n");
+ return -ENOMEM;
+ }
+ fid_list = (struct list_head *)dentry->d_fsdata;
+ INIT_LIST_HEAD(fid_list); /* Initialize list head */
+ }
+
+ fid->uid = current->uid;
+ fid->pid = current->pid;
+ list_add(&fid->list, fid_list);
+ return 0;
+}
+
+/**
+ * v9fs_fid_create - allocate a FID structure
+ * @dentry - dentry to link newly created fid to
+ *
+ */
+
+struct v9fs_fid *v9fs_fid_create(struct dentry *dentry)
+{
+ struct v9fs_fid *new;
+
+ new = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL);
+ if (new == NULL) {
+ dprintk(DEBUG_ERROR, "Out of Memory\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ new->fid = -1;
+ new->fidopen = 0;
+ new->fidcreate = 0;
+ new->fidclunked = 0;
+ new->iounit = 0;
+
+ if (v9fs_fid_insert(new, dentry) == 0)
+ return new;
+ else {
+ dprintk(DEBUG_ERROR, "Problems inserting to dentry\n");
+ kfree(new);
+ return NULL;
+ }
+}
+
+/**
+ * v9fs_fid_destroy - deallocate a FID structure
+ * @fid: fid to destroy
+ *
+ */
+
+void v9fs_fid_destroy(struct v9fs_fid *fid)
+{
+ list_del(&fid->list);
+ kfree(fid);
+}
+
+/**
+ * v9fs_fid_lookup - retrieve the right fid from a particular dentry
+ * @dentry: dentry to look for fid in
+ * @type: intent of lookup (operation or traversal)
+ *
+ * search list of fids associated with a dentry for a fid with a matching
+ * thread id or uid. If that fails, look up the dentry's parents to see if you
+ * can find a matching fid.
+ *
+ */
+
+struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry, int type)
+{
+ struct list_head *fid_list = (struct list_head *)dentry->d_fsdata;
+ struct v9fs_fid *current_fid = NULL;
+ struct v9fs_fid *temp = NULL;
+ struct v9fs_fid *return_fid = NULL;
+ int found_parent = 0;
+ int found_user = 0;
+
+ dprintk(DEBUG_9P, " dentry: %s (%p) type %d\n", dentry->d_iname, dentry,
+ type);
+
+ if (fid_list && !list_empty(fid_list)) {
+ list_for_each_entry_safe(current_fid, temp, fid_list, list) {
+ if (current_fid->uid == current->uid) {
+ if (return_fid == NULL) {
+ if ((type == FID_OP)
+ || (!current_fid->fidopen)) {
+ return_fid = current_fid;
+ found_user = 1;
+ }
+ }
+ }
+ if (current_fid->pid == current->real_parent->pid) {
+ if ((return_fid == NULL) || (found_parent)
+ || (found_user)) {
+ if ((type == FID_OP)
+ || (!current_fid->fidopen)) {
+ return_fid = current_fid;
+ found_parent = 1;
+ found_user = 0;
+ }
+ }
+ }
+ if (current_fid->pid == current->pid) {
+ if ((type == FID_OP) ||
+ (!current_fid->fidopen)) {
+ return_fid = current_fid;
+ found_parent = 0;
+ found_user = 0;
+ }
+ }
+ }
+ }
+
+ /* we are at the root but didn't match */
+ if ((!return_fid) && (dentry->d_parent == dentry)) {
+ /* TODO: clone attach with new uid */
+ return_fid = current_fid;
+ }
+
+ if (!return_fid) {
+ struct dentry *par = current->fs->pwd->d_parent;
+ int count = 1;
+ while (par != NULL) {
+ if (par == dentry)
+ break;
+ count++;
+ if (par == par->d_parent) {
+ dprintk(DEBUG_ERROR,
+ "got to root without finding dentry\n");
+ break;
+ }
+ par = par->d_parent;
+ }
+
+/* XXX - there may be some duplication we can get rid of */
+ if (par == dentry) {
+ /* we need to fid_lookup the starting point */
+ int fidnum = -1;
+ int oldfid = -1;
+ int result = -1;
+ struct v9fs_session_info *v9ses =
+ v9fs_inode2v9ses(current->fs->pwd->d_inode);
+
+ current_fid =
+ v9fs_fid_lookup(current->fs->pwd, FID_WALK);
+ if (current_fid == NULL) {
+ dprintk(DEBUG_ERROR,
+ "process cwd doesn't have a fid\n");
+ return return_fid;
+ }
+ oldfid = current_fid->fid;
+ par = current->fs->pwd;
+ /* TODO: take advantage of multiwalk */
+
+ fidnum = v9fs_get_idpool(&v9ses->fidpool);
+ if (fidnum < 0) {
+ dprintk(DEBUG_ERROR,
+ "could not get a new fid num\n");
+ return return_fid;
+ }
+
+ while (par != dentry) {
+ result =
+ v9fs_t_walk(v9ses, oldfid, fidnum, "..",
+ NULL);
+ if (result < 0) {
+ dprintk(DEBUG_ERROR,
+ "problem walking to parent\n");
+
+ break;
+ }
+ oldfid = fidnum;
+ if (par == par->d_parent) {
+ dprintk(DEBUG_ERROR,
+ "can't find dentry\n");
+ break;
+ }
+ par = par->d_parent;
+ }
+ if (par == dentry) {
+ return_fid = v9fs_fid_create(dentry);
+ return_fid->fid = fidnum;
+ }
+ }
+ }
+
+ return return_fid;
+}