android_kernel_motorola_sm6225/fs/9p/fid.h
Eric Van Hensbergen da977b2c7e [PATCH] 9p: fix segfault caused by race condition in meta-data operations
Running dbench multithreaded exposed a race condition where fid structures
were removed while in use.  This patch adds semaphores to meta-data operations
to protect the fid structure.  Some cleanup of error-case handling in the
inode operations is also included.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26 13:51:00 -08:00

62 lines
1.9 KiB
C

/*
* 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 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
* 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/list.h>
#define FID_OP 0
#define FID_WALK 1
#define FID_CREATE 2
struct v9fs_fid {
struct list_head list; /* list of fids associated with a dentry */
struct list_head active; /* XXX - debug */
struct semaphore lock;
u32 fid;
unsigned char fidopen; /* set when fid is opened */
unsigned char fidclunked; /* set when fid has already been clunked */
struct v9fs_qid qid;
u32 iounit;
/* readdir stuff */
int rdir_fpos;
loff_t rdir_pos;
struct v9fs_fcall *rdir_fcall;
/* management stuff */
uid_t uid; /* user associated with this fid */
/* private data */
struct file *filp; /* backpointer to File struct for open files */
struct v9fs_session_info *v9ses; /* session info for this FID */
};
struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry);
struct v9fs_fid *v9fs_fid_get_created(struct dentry *);
void v9fs_fid_destroy(struct v9fs_fid *fid);
struct v9fs_fid *v9fs_fid_create(struct v9fs_session_info *, int fid);
int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry);
struct v9fs_fid *v9fs_fid_clone(struct dentry *dentry);
void v9fs_fid_clunk(struct v9fs_session_info *v9ses, struct v9fs_fid *fid);