135 lines
3.1 KiB
C
135 lines
3.1 KiB
C
/*
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* V9FS FID Management
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*
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* Copyright (C) 2005, 2006 by Eric Van Hensbergen <ericvh@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to:
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* Free Software Foundation
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* 51 Franklin Street, Fifth Floor
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* Boston, MA 02111-1301 USA
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*
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/sched.h>
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#include <linux/idr.h>
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#include <asm/semaphore.h>
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#include <net/9p/9p.h>
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#include <net/9p/client.h>
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#include "v9fs.h"
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#include "v9fs_vfs.h"
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#include "fid.h"
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/**
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* v9fs_fid_insert - add a fid to a dentry
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* @fid: fid to add
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* @dentry: dentry that it is being added to
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*
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*/
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int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
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{
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struct v9fs_dentry *dent;
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P9_DPRINTK(P9_DEBUG_VFS, "fid %d dentry %s\n",
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fid->fid, dentry->d_iname);
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dent = dentry->d_fsdata;
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if (!dent) {
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dent = kmalloc(sizeof(struct v9fs_dentry), GFP_KERNEL);
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if (!dent)
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return -ENOMEM;
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spin_lock_init(&dent->lock);
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INIT_LIST_HEAD(&dent->fidlist);
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dentry->d_fsdata = dent;
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}
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spin_lock(&dent->lock);
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list_add(&fid->dlist, &dent->fidlist);
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spin_unlock(&dent->lock);
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return 0;
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}
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/**
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* v9fs_fid_lookup - return a locked fid from a dentry
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* @dentry: dentry to look for fid in
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*
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* find a fid in the dentry, obtain its semaphore and return a reference to it.
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* code calling lookup is responsible for releasing lock
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*
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* TODO: only match fids that have the same uid as current user
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*
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*/
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struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
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{
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struct v9fs_dentry *dent;
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struct p9_fid *fid;
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P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
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dent = dentry->d_fsdata;
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if (dent)
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fid = list_entry(dent->fidlist.next, struct p9_fid, dlist);
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else
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fid = ERR_PTR(-EBADF);
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P9_DPRINTK(P9_DEBUG_VFS, " fid: %p\n", fid);
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return fid;
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}
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struct p9_fid *v9fs_fid_lookup_remove(struct dentry *dentry)
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{
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struct p9_fid *fid;
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struct v9fs_dentry *dent;
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dent = dentry->d_fsdata;
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fid = v9fs_fid_lookup(dentry);
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if (!IS_ERR(fid)) {
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spin_lock(&dent->lock);
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list_del(&fid->dlist);
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spin_unlock(&dent->lock);
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}
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return fid;
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}
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/**
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* v9fs_fid_clone - lookup the fid for a dentry, clone a private copy and
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* release it
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* @dentry: dentry to look for fid in
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*
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* find a fid in the dentry and then clone to a new private fid
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*
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* TODO: only match fids that have the same uid as current user
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*
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*/
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struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
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{
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struct p9_fid *ofid, *fid;
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P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
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ofid = v9fs_fid_lookup(dentry);
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if (IS_ERR(ofid))
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return ofid;
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fid = p9_client_walk(ofid, 0, NULL, 1);
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return fid;
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}
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