488 lines
10 KiB
C
488 lines
10 KiB
C
/*
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* linux/fs/9p/v9fs.c
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*
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* This file contains functions assisting in mapping VFS to 9P2000
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*
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* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
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* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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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/parser.h>
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#include <linux/idr.h>
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#include "debug.h"
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#include "v9fs.h"
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#include "9p.h"
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#include "v9fs_vfs.h"
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#include "transport.h"
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#include "mux.h"
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/* TODO: sysfs or debugfs interface */
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int v9fs_debug_level = 0; /* feature-rific global debug level */
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/*
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* Option Parsing (code inspired by NFS code)
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*
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*/
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enum {
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/* Options that take integer arguments */
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Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid, Opt_debug,
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Opt_rfdno, Opt_wfdno,
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/* String options */
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Opt_uname, Opt_remotename,
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/* Options that take no arguments */
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Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd,
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/* Error token */
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Opt_err
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};
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static match_table_t tokens = {
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{Opt_port, "port=%u"},
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{Opt_msize, "msize=%u"},
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{Opt_uid, "uid=%u"},
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{Opt_gid, "gid=%u"},
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{Opt_afid, "afid=%u"},
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{Opt_rfdno, "rfdno=%u"},
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{Opt_wfdno, "wfdno=%u"},
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{Opt_debug, "debug=%x"},
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{Opt_uname, "uname=%s"},
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{Opt_remotename, "aname=%s"},
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{Opt_unix, "proto=unix"},
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{Opt_tcp, "proto=tcp"},
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{Opt_fd, "proto=fd"},
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{Opt_tcp, "tcp"},
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{Opt_unix, "unix"},
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{Opt_fd, "fd"},
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{Opt_legacy, "noextend"},
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{Opt_nodevmap, "nodevmap"},
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{Opt_err, NULL}
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};
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/*
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* Parse option string.
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*/
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/**
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* v9fs_parse_options - parse mount options into session structure
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* @options: options string passed from mount
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* @v9ses: existing v9fs session information
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*
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*/
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static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
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{
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char *p;
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substring_t args[MAX_OPT_ARGS];
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int option;
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int ret;
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/* setup defaults */
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v9ses->port = V9FS_PORT;
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v9ses->maxdata = 9000;
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v9ses->proto = PROTO_TCP;
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v9ses->extended = 1;
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v9ses->afid = ~0;
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v9ses->debug = 0;
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v9ses->rfdno = ~0;
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v9ses->wfdno = ~0;
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if (!options)
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return;
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while ((p = strsep(&options, ",")) != NULL) {
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int token;
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if (!*p)
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continue;
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token = match_token(p, tokens, args);
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if (token < Opt_uname) {
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if ((ret = match_int(&args[0], &option)) < 0) {
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dprintk(DEBUG_ERROR,
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"integer field, but no integer?\n");
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continue;
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}
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}
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switch (token) {
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case Opt_port:
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v9ses->port = option;
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break;
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case Opt_msize:
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v9ses->maxdata = option;
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break;
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case Opt_uid:
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v9ses->uid = option;
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break;
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case Opt_gid:
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v9ses->gid = option;
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break;
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case Opt_afid:
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v9ses->afid = option;
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break;
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case Opt_rfdno:
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v9ses->rfdno = option;
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break;
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case Opt_wfdno:
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v9ses->wfdno = option;
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break;
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case Opt_debug:
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v9ses->debug = option;
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break;
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case Opt_tcp:
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v9ses->proto = PROTO_TCP;
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break;
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case Opt_unix:
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v9ses->proto = PROTO_UNIX;
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break;
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case Opt_fd:
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v9ses->proto = PROTO_FD;
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break;
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case Opt_uname:
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match_strcpy(v9ses->name, &args[0]);
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break;
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case Opt_remotename:
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match_strcpy(v9ses->remotename, &args[0]);
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break;
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case Opt_legacy:
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v9ses->extended = 0;
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break;
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case Opt_nodevmap:
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v9ses->nodev = 1;
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break;
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default:
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continue;
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}
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}
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}
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/**
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* v9fs_inode2v9ses - safely extract v9fs session info from super block
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* @inode: inode to extract information from
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*
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* Paranoid function to extract v9ses information from superblock,
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* if anything is missing it will report an error.
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*
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*/
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struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
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{
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return (inode->i_sb->s_fs_info);
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}
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/**
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* v9fs_get_idpool - allocate numeric id from pool
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* @p - pool to allocate from
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*
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* XXX - This seems to be an awful generic function, should it be in idr.c with
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* the lock included in struct idr?
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*/
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int v9fs_get_idpool(struct v9fs_idpool *p)
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{
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int i = 0;
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int error;
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retry:
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if (idr_pre_get(&p->pool, GFP_KERNEL) == 0)
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return 0;
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if (down_interruptible(&p->lock) == -EINTR) {
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eprintk(KERN_WARNING, "Interrupted while locking\n");
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return -1;
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}
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/* no need to store exactly p, we just need something non-null */
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error = idr_get_new(&p->pool, p, &i);
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up(&p->lock);
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if (error == -EAGAIN)
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goto retry;
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else if (error)
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return -1;
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return i;
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}
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/**
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* v9fs_put_idpool - release numeric id from pool
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* @p - pool to allocate from
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*
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* XXX - This seems to be an awful generic function, should it be in idr.c with
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* the lock included in struct idr?
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*/
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void v9fs_put_idpool(int id, struct v9fs_idpool *p)
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{
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if (down_interruptible(&p->lock) == -EINTR) {
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eprintk(KERN_WARNING, "Interrupted while locking\n");
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return;
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}
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idr_remove(&p->pool, id);
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up(&p->lock);
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}
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/**
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* v9fs_check_idpool - check if the specified id is available
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* @id - id to check
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* @p - pool
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*/
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int v9fs_check_idpool(int id, struct v9fs_idpool *p)
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{
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return idr_find(&p->pool, id) != NULL;
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}
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/**
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* v9fs_session_init - initialize session
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* @v9ses: session information structure
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* @dev_name: device being mounted
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* @data: options
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*
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*/
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int
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v9fs_session_init(struct v9fs_session_info *v9ses,
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const char *dev_name, char *data)
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{
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struct v9fs_fcall *fcall = NULL;
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struct v9fs_transport *trans_proto;
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int n = 0;
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int newfid = -1;
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int retval = -EINVAL;
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struct v9fs_str *version;
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v9ses->name = __getname();
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if (!v9ses->name)
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return -ENOMEM;
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v9ses->remotename = __getname();
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if (!v9ses->remotename) {
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__putname(v9ses->name);
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return -ENOMEM;
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}
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strcpy(v9ses->name, V9FS_DEFUSER);
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strcpy(v9ses->remotename, V9FS_DEFANAME);
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v9fs_parse_options(data, v9ses);
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/* set global debug level */
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v9fs_debug_level = v9ses->debug;
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/* id pools that are session-dependent: fids and tags */
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idr_init(&v9ses->fidpool.pool);
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init_MUTEX(&v9ses->fidpool.lock);
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switch (v9ses->proto) {
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case PROTO_TCP:
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trans_proto = &v9fs_trans_tcp;
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break;
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case PROTO_UNIX:
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trans_proto = &v9fs_trans_unix;
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*v9ses->remotename = 0;
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break;
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case PROTO_FD:
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trans_proto = &v9fs_trans_fd;
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*v9ses->remotename = 0;
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break;
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default:
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printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
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retval = -ENOPROTOOPT;
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goto SessCleanUp;
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};
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v9ses->transport = kmalloc(sizeof(*v9ses->transport), GFP_KERNEL);
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if (!v9ses->transport) {
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retval = -ENOMEM;
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goto SessCleanUp;
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}
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memmove(v9ses->transport, trans_proto, sizeof(*v9ses->transport));
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if ((retval = v9ses->transport->init(v9ses, dev_name, data)) < 0) {
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eprintk(KERN_ERR, "problem initializing transport\n");
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goto SessCleanUp;
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}
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v9ses->inprogress = 0;
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v9ses->shutdown = 0;
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v9ses->session_hung = 0;
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v9ses->mux = v9fs_mux_init(v9ses->transport, v9ses->maxdata + V9FS_IOHDRSZ,
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&v9ses->extended);
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if (IS_ERR(v9ses->mux)) {
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retval = PTR_ERR(v9ses->mux);
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v9ses->mux = NULL;
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dprintk(DEBUG_ERROR, "problem initializing mux\n");
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goto SessCleanUp;
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}
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if (v9ses->afid == ~0) {
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if (v9ses->extended)
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retval =
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v9fs_t_version(v9ses, v9ses->maxdata, "9P2000.u",
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&fcall);
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else
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retval = v9fs_t_version(v9ses, v9ses->maxdata, "9P2000",
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&fcall);
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if (retval < 0) {
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dprintk(DEBUG_ERROR, "v9fs_t_version failed\n");
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goto FreeFcall;
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}
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version = &fcall->params.rversion.version;
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if (version->len==8 && !memcmp(version->str, "9P2000.u", 8)) {
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dprintk(DEBUG_9P, "9P2000 UNIX extensions enabled\n");
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v9ses->extended = 1;
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} else if (version->len==6 && !memcmp(version->str, "9P2000", 6)) {
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dprintk(DEBUG_9P, "9P2000 legacy mode enabled\n");
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v9ses->extended = 0;
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} else {
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retval = -EREMOTEIO;
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goto FreeFcall;
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}
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n = fcall->params.rversion.msize;
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kfree(fcall);
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if (n < v9ses->maxdata)
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v9ses->maxdata = n;
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}
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newfid = v9fs_get_idpool(&v9ses->fidpool);
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if (newfid < 0) {
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eprintk(KERN_WARNING, "couldn't allocate FID\n");
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retval = -ENOMEM;
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goto SessCleanUp;
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}
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/* it is a little bit ugly, but we have to prevent newfid */
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/* being the same as afid, so if it is, get a new fid */
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if (v9ses->afid != ~0 && newfid == v9ses->afid) {
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newfid = v9fs_get_idpool(&v9ses->fidpool);
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if (newfid < 0) {
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eprintk(KERN_WARNING, "couldn't allocate FID\n");
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retval = -ENOMEM;
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goto SessCleanUp;
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}
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}
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if ((retval =
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v9fs_t_attach(v9ses, v9ses->name, v9ses->remotename, newfid,
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v9ses->afid, NULL))
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< 0) {
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dprintk(DEBUG_ERROR, "cannot attach\n");
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goto SessCleanUp;
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}
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if (v9ses->afid != ~0) {
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dprintk(DEBUG_ERROR, "afid not equal to ~0\n");
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if (v9fs_t_clunk(v9ses, v9ses->afid))
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dprintk(DEBUG_ERROR, "clunk failed\n");
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}
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return newfid;
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FreeFcall:
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kfree(fcall);
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SessCleanUp:
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v9fs_session_close(v9ses);
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return retval;
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}
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/**
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* v9fs_session_close - shutdown a session
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* @v9ses: session information structure
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*
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*/
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void v9fs_session_close(struct v9fs_session_info *v9ses)
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{
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if (v9ses->mux) {
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v9fs_mux_destroy(v9ses->mux);
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v9ses->mux = NULL;
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}
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if (v9ses->transport) {
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v9ses->transport->close(v9ses->transport);
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kfree(v9ses->transport);
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v9ses->transport = NULL;
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}
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__putname(v9ses->name);
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__putname(v9ses->remotename);
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}
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/**
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* v9fs_session_cancel - mark transport as disconnected
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* and cancel all pending requests.
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*/
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void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
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dprintk(DEBUG_ERROR, "cancel session %p\n", v9ses);
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v9ses->transport->status = Disconnected;
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v9fs_mux_cancel(v9ses->mux, -EIO);
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}
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extern int v9fs_error_init(void);
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/**
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* v9fs_init - Initialize module
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*
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*/
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static int __init init_v9fs(void)
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{
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int ret;
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v9fs_error_init();
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printk(KERN_INFO "Installing v9fs 9P2000 file system support\n");
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ret = v9fs_mux_global_init();
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if (!ret)
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return ret;
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ret = register_filesystem(&v9fs_fs_type);
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if (!ret)
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v9fs_mux_global_exit();
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return ret;
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}
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/**
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* v9fs_init - shutdown module
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*
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*/
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static void __exit exit_v9fs(void)
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{
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v9fs_mux_global_exit();
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unregister_filesystem(&v9fs_fs_type);
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}
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module_init(init_v9fs)
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module_exit(exit_v9fs)
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MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
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MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
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MODULE_LICENSE("GPL");
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