/*
* V9FS FID Management
*
- * Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
+ * Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
+ * Copyright (C) 2005, 2006 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.
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
*
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
+#include <linux/sched.h>
#include <linux/idr.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.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
+ * v9fs_fid_add - add a fid to a dentry
+ * @dentry: dentry that the fid is being added to
* @fid: fid to add
- * @dentry: dentry that it is being added to
*
*/
-static int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry)
+int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
{
- 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");
+ struct v9fs_dentry *dent;
+
+ P9_DPRINTK(P9_DEBUG_VFS, "fid %d dentry %s\n",
+ fid->fid, dentry->d_name.name);
+
+ dent = dentry->d_fsdata;
+ if (!dent) {
+ dent = kmalloc(sizeof(struct v9fs_dentry), GFP_KERNEL);
+ if (!dent)
return -ENOMEM;
- }
- fid_list = (struct list_head *)dentry->d_fsdata;
- INIT_LIST_HEAD(fid_list); /* Initialize list head */
+
+ spin_lock_init(&dent->lock);
+ INIT_LIST_HEAD(&dent->fidlist);
+ dentry->d_fsdata = dent;
}
- fid->uid = current->uid;
- fid->pid = current->pid;
- list_add(&fid->list, fid_list);
+ spin_lock(&dent->lock);
+ list_add(&fid->dlist, &dent->fidlist);
+ spin_unlock(&dent->lock);
+
return 0;
}
/**
- * v9fs_fid_create - allocate a FID structure
- * @dentry - dentry to link newly created fid to
+ * v9fs_fid_find - retrieve a fid that belongs to the specified uid
+ * @dentry: dentry to look for fid in
+ * @uid: return fid that belongs to the specified user
+ * @any: if non-zero, return any fid associated with the dentry
*
*/
-struct v9fs_fid *v9fs_fid_create(struct dentry *dentry)
+static struct p9_fid *v9fs_fid_find(struct dentry *dentry, u32 uid, int any)
{
- 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;
+ struct v9fs_dentry *dent;
+ struct p9_fid *fid, *ret;
+
+ P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p) uid %d any %d\n",
+ dentry->d_name.name, dentry, uid, any);
+ dent = (struct v9fs_dentry *) dentry->d_fsdata;
+ ret = NULL;
+ if (dent) {
+ spin_lock(&dent->lock);
+ list_for_each_entry(fid, &dent->fidlist, dlist) {
+ if (any || fid->uid == uid) {
+ ret = fid;
+ break;
+ }
+ }
+ spin_unlock(&dent->lock);
}
-}
-
-/**
- * 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);
+ return ret;
}
/**
- * v9fs_fid_lookup - retrieve the right fid from a particular dentry
+ * v9fs_fid_lookup - lookup for a fid, try to walk if not found
* @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.
*
+ * Look for a fid in the specified dentry for the current user.
+ * If no fid is found, try to create one walking from a fid from the parent
+ * dentry (if it has one), or the root dentry. If the user haven't accessed
+ * the fs yet, attach now and walk from the root.
*/
-struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry, int type)
+struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
{
- 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;
- }
- }
- }
+ int i, n, l, clone, any, access;
+ u32 uid;
+ struct p9_fid *fid;
+ struct dentry *d, *ds;
+ struct v9fs_session_info *v9ses;
+ char **wnames, *uname;
+
+ v9ses = v9fs_inode2v9ses(dentry->d_inode);
+ access = v9ses->flags & V9FS_ACCESS_MASK;
+ switch (access) {
+ case V9FS_ACCESS_SINGLE:
+ case V9FS_ACCESS_USER:
+ uid = current_fsuid();
+ any = 0;
+ break;
+
+ case V9FS_ACCESS_ANY:
+ uid = v9ses->uid;
+ any = 1;
+ break;
+
+ default:
+ uid = ~0;
+ any = 0;
+ break;
}
- /* 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;
- }
+ fid = v9fs_fid_find(dentry, uid, any);
+ if (fid)
+ return 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;
+ ds = dentry->d_parent;
+ fid = v9fs_fid_find(ds, uid, any);
+ if (!fid) { /* walk from the root */
+ n = 0;
+ for (ds = dentry; !IS_ROOT(ds); ds = ds->d_parent)
+ n++;
+
+ fid = v9fs_fid_find(ds, uid, any);
+ if (!fid) { /* the user is not attached to the fs yet */
+ if (access == V9FS_ACCESS_SINGLE)
+ return ERR_PTR(-EPERM);
+
+ if (v9fs_extended(v9ses))
+ uname = NULL;
+ else
+ uname = v9ses->uname;
+
+ fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
+ v9ses->aname);
+
+ if (IS_ERR(fid))
+ return fid;
+
+ v9fs_fid_add(ds, fid);
}
+ } else /* walk from the parent */
+ n = 1;
-/* 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;
- }
+ if (ds == dentry)
+ 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;
- }
+ wnames = kmalloc(sizeof(char *) * n, GFP_KERNEL);
+ if (!wnames)
+ return ERR_PTR(-ENOMEM);
+
+ for (d = dentry, i = (n-1); i >= 0; i--, d = d->d_parent)
+ wnames[i] = (char *) d->d_name.name;
+
+ clone = 1;
+ i = 0;
+ while (i < n) {
+ l = min(n - i, P9_MAXWELEM);
+ fid = p9_client_walk(fid, l, &wnames[i], clone);
+ if (IS_ERR(fid)) {
+ kfree(wnames);
+ return fid;
}
+
+ i += l;
+ clone = 0;
}
- return return_fid;
+ kfree(wnames);
+ v9fs_fid_add(dentry, fid);
+ return fid;
+}
+
+struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
+{
+ struct p9_fid *fid, *ret;
+
+ fid = v9fs_fid_lookup(dentry);
+ if (IS_ERR(fid))
+ return fid;
+
+ ret = p9_client_walk(fid, 0, NULL, 1);
+ return ret;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff