Commit 9e82cf6a authored by Eric Van Hensbergen's avatar Eric Van Hensbergen Committed by Linus Torvalds
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[PATCH] v9fs: VFS superblock operations and glue



This part of the patch contains VFS superblock and mapping code.
Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 2bad8471
/*
* linux/fs/9p/v9fs.c
*
* This file contains functions assisting in mapping VFS to 9P2000
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* 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/parser.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"
/* TODO: sysfs or debugfs interface */
int v9fs_debug_level = 0; /* feature-rific global debug level */
/*
* Option Parsing (code inspired by NFS code)
*
*/
enum {
/* Options that take integer arguments */
Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid, Opt_debug,
Opt_rfdno, Opt_wfdno,
/* String options */
Opt_name, Opt_remotename,
/* Options that take no arguments */
Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd,
/* Error token */
Opt_err
};
static match_table_t tokens = {
{Opt_port, "port=%u"},
{Opt_msize, "msize=%u"},
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_afid, "afid=%u"},
{Opt_rfdno, "rfdno=%u"},
{Opt_wfdno, "wfdno=%u"},
{Opt_debug, "debug=%u"},
{Opt_name, "name=%s"},
{Opt_remotename, "aname=%s"},
{Opt_unix, "proto=unix"},
{Opt_tcp, "proto=tcp"},
{Opt_fd, "proto=fd"},
{Opt_tcp, "tcp"},
{Opt_unix, "unix"},
{Opt_fd, "fd"},
{Opt_legacy, "noextend"},
{Opt_nodevmap, "nodevmap"},
{Opt_err, NULL}
};
/*
* Parse option string.
*/
/**
* v9fs_parse_options - parse mount options into session structure
* @options: options string passed from mount
* @v9ses: existing v9fs session information
*
*/
static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
int ret;
/* setup defaults */
v9ses->port = V9FS_PORT;
v9ses->maxdata = 9000;
v9ses->proto = PROTO_TCP;
v9ses->extended = 1;
v9ses->afid = ~0;
v9ses->debug = 0;
v9ses->rfdno = ~0;
v9ses->wfdno = ~0;
if (!options)
return;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
if (token < Opt_name) {
if ((ret = match_int(&args[0], &option)) < 0) {
dprintk(DEBUG_ERROR,
"integer field, but no integer?\n");
continue;
}
}
switch (token) {
case Opt_port:
v9ses->port = option;
break;
case Opt_msize:
v9ses->maxdata = option;
break;
case Opt_uid:
v9ses->uid = option;
break;
case Opt_gid:
v9ses->gid = option;
break;
case Opt_afid:
v9ses->afid = option;
break;
case Opt_rfdno:
v9ses->rfdno = option;
break;
case Opt_wfdno:
v9ses->wfdno = option;
break;
case Opt_debug:
v9ses->debug = option;
break;
case Opt_tcp:
v9ses->proto = PROTO_TCP;
break;
case Opt_unix:
v9ses->proto = PROTO_UNIX;
break;
case Opt_fd:
v9ses->proto = PROTO_FD;
break;
case Opt_name:
match_strcpy(v9ses->name, &args[0]);
break;
case Opt_remotename:
match_strcpy(v9ses->remotename, &args[0]);
break;
case Opt_legacy:
v9ses->extended = 0;
break;
case Opt_nodevmap:
v9ses->nodev = 1;
break;
default:
continue;
}
}
}
/**
* v9fs_inode2v9ses - safely extract v9fs session info from super block
* @inode: inode to extract information from
*
* Paranoid function to extract v9ses information from superblock,
* if anything is missing it will report an error.
*
*/
struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
{
return (inode->i_sb->s_fs_info);
}
/**
* v9fs_get_idpool - allocate numeric id from pool
* @p - pool to allocate from
*
* XXX - This seems to be an awful generic function, should it be in idr.c with
* the lock included in struct idr?
*/
int v9fs_get_idpool(struct v9fs_idpool *p)
{
int i = 0;
int error;
retry:
if (idr_pre_get(&p->pool, GFP_KERNEL) == 0)
return 0;
if (down_interruptible(&p->lock) == -EINTR) {
eprintk(KERN_WARNING, "Interrupted while locking\n");
return -1;
}
error = idr_get_new(&p->pool, NULL, &i);
up(&p->lock);
if (error == -EAGAIN)
goto retry;
else if (error)
return -1;
return i;
}
/**
* v9fs_put_idpool - release numeric id from pool
* @p - pool to allocate from
*
* XXX - This seems to be an awful generic function, should it be in idr.c with
* the lock included in struct idr?
*/
void v9fs_put_idpool(int id, struct v9fs_idpool *p)
{
if (down_interruptible(&p->lock) == -EINTR) {
eprintk(KERN_WARNING, "Interrupted while locking\n");
return;
}
idr_remove(&p->pool, id);
up(&p->lock);
}
/**
* v9fs_session_init - initialize session
* @v9ses: session information structure
* @dev_name: device being mounted
* @data: options
*
*/
int
v9fs_session_init(struct v9fs_session_info *v9ses,
const char *dev_name, char *data)
{
struct v9fs_fcall *fcall = NULL;
struct v9fs_transport *trans_proto;
int n = 0;
int newfid = -1;
int retval = -EINVAL;
v9ses->name = __getname();
if (!v9ses->name)
return -ENOMEM;
v9ses->remotename = __getname();
if (!v9ses->remotename) {
putname(v9ses->name);
return -ENOMEM;
}
strcpy(v9ses->name, V9FS_DEFUSER);
strcpy(v9ses->remotename, V9FS_DEFANAME);
v9fs_parse_options(data, v9ses);
/* set global debug level */
v9fs_debug_level = v9ses->debug;
/* id pools that are session-dependent: FIDs and TIDs */
idr_init(&v9ses->fidpool.pool);
init_MUTEX(&v9ses->fidpool.lock);
idr_init(&v9ses->tidpool.pool);
init_MUTEX(&v9ses->tidpool.lock);
switch (v9ses->proto) {
case PROTO_TCP:
trans_proto = &v9fs_trans_tcp;
break;
case PROTO_UNIX:
trans_proto = &v9fs_trans_unix;
*v9ses->remotename = 0;
break;
case PROTO_FD:
trans_proto = &v9fs_trans_fd;
*v9ses->remotename = 0;
if((v9ses->wfdno == ~0) || (v9ses->rfdno == ~0)) {
printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
retval = -ENOPROTOOPT;
goto SessCleanUp;
}
break;
default:
printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
retval = -ENOPROTOOPT;
goto SessCleanUp;
};
v9ses->transport = trans_proto;
if ((retval = v9ses->transport->init(v9ses, dev_name, data)) < 0) {
eprintk(KERN_ERR, "problem initializing transport\n");
goto SessCleanUp;
}
v9ses->inprogress = 0;
v9ses->shutdown = 0;
v9ses->session_hung = 0;
if ((retval = v9fs_mux_init(v9ses, dev_name)) < 0) {
dprintk(DEBUG_ERROR, "problem initializing mux\n");
goto SessCleanUp;
}
if (v9ses->afid == ~0) {
if (v9ses->extended)
retval =
v9fs_t_version(v9ses, v9ses->maxdata, "9P2000.u",
&fcall);
else
retval = v9fs_t_version(v9ses, v9ses->maxdata, "9P2000",
&fcall);
if (retval < 0) {
dprintk(DEBUG_ERROR, "v9fs_t_version failed\n");
goto FreeFcall;
}
/* Really should check for 9P1 and report error */
if (!strcmp(fcall->params.rversion.version, "9P2000.u")) {
dprintk(DEBUG_9P, "9P2000 UNIX extensions enabled\n");
v9ses->extended = 1;
} else {
dprintk(DEBUG_9P, "9P2000 legacy mode enabled\n");
v9ses->extended = 0;
}
n = fcall->params.rversion.msize;
kfree(fcall);
if (n < v9ses->maxdata)
v9ses->maxdata = n;
}
newfid = v9fs_get_idpool(&v9ses->fidpool);
if (newfid < 0) {
eprintk(KERN_WARNING, "couldn't allocate FID\n");
retval = -ENOMEM;
goto SessCleanUp;
}
/* it is a little bit ugly, but we have to prevent newfid */
/* being the same as afid, so if it is, get a new fid */
if (v9ses->afid != ~0 && newfid == v9ses->afid) {
newfid = v9fs_get_idpool(&v9ses->fidpool);
if (newfid < 0) {
eprintk(KERN_WARNING, "couldn't allocate FID\n");
retval = -ENOMEM;
goto SessCleanUp;
}
}
if ((retval =
v9fs_t_attach(v9ses, v9ses->name, v9ses->remotename, newfid,
v9ses->afid, NULL))
< 0) {
dprintk(DEBUG_ERROR, "cannot attach\n");
goto SessCleanUp;
}
if (v9ses->afid != ~0) {
if (v9fs_t_clunk(v9ses, v9ses->afid, NULL))
dprintk(DEBUG_ERROR, "clunk failed\n");
}
return newfid;
FreeFcall:
kfree(fcall);
SessCleanUp:
v9fs_session_close(v9ses);
return retval;
}
/**
* v9fs_session_close - shutdown a session
* @v9ses: session information structure
*
*/
void v9fs_session_close(struct v9fs_session_info *v9ses)
{
if (v9ses->recvproc) {
send_sig(SIGKILL, v9ses->recvproc, 1);
wait_for_completion(&v9ses->proccmpl);
}
if (v9ses->transport)
v9ses->transport->close(v9ses->transport);
putname(v9ses->name);
putname(v9ses->remotename);
}
extern int v9fs_error_init(void);
/**
* v9fs_init - Initialize module
*
*/
static int __init init_v9fs(void)
{
v9fs_error_init();
printk(KERN_INFO "Installing v9fs 9P2000 file system support\n");
return register_filesystem(&v9fs_fs_type);
}
/**
* v9fs_init - shutdown module
*
*/
static void __exit exit_v9fs(void)
{
unregister_filesystem(&v9fs_fs_type);
}
module_init(init_v9fs)
module_exit(exit_v9fs)
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
MODULE_LICENSE("GPL");
/*
* V9FS definitions.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* 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
*
*/
/*
* Idpool structure provides lock and id management
*
*/
struct v9fs_idpool {
struct semaphore lock;
struct idr pool;
};
/*
* Session structure provides information for an opened session
*
*/
struct v9fs_session_info {
/* options */
unsigned int maxdata;
unsigned char extended; /* set to 1 if we are using UNIX extensions */
unsigned char nodev; /* set to 1 if no disable device mapping */
unsigned short port; /* port to connect to */
unsigned short debug; /* debug level */
unsigned short proto; /* protocol to use */
unsigned int afid; /* authentication fid */
unsigned int rfdno; /* read file descriptor number */
unsigned int wfdno; /* write file descriptor number */
char *name; /* user name to mount as */
char *remotename; /* name of remote hierarchy being mounted */
unsigned int uid; /* default uid/muid for legacy support */
unsigned int gid; /* default gid for legacy support */
/* book keeping */
struct v9fs_idpool fidpool; /* The FID pool for file descriptors */
struct v9fs_idpool tidpool; /* The TID pool for transactions ids */
/* transport information */
struct v9fs_transport *transport;
int inprogress; /* session in progress => true */
int shutdown; /* session shutting down. no more attaches. */
unsigned char session_hung;
/* mux private data */
struct v9fs_fcall *curfcall;
wait_queue_head_t read_wait;
struct completion fcread;
struct completion proccmpl;
struct task_struct *recvproc;
spinlock_t muxlock;
struct list_head mux_fcalls;
};
/* possible values of ->proto */
enum {
PROTO_TCP,
PROTO_UNIX,
PROTO_FD,
};
int v9fs_session_init(struct v9fs_session_info *, const char *, char *);
struct v9fs_session_info *v9fs_inode2v9ses(struct inode *);
void v9fs_session_close(struct v9fs_session_info *v9ses);
int v9fs_get_idpool(struct v9fs_idpool *p);
void v9fs_put_idpool(int id, struct v9fs_idpool *p);
int v9fs_get_option(char *opts, char *name, char *buf, int buflen);
long long v9fs_get_int_option(char *opts, char *name, long long dflt);
int v9fs_parse_tcp_devname(const char *devname, char **addr, char **remotename);
#define V9FS_MAGIC 0x01021997
/* other default globals */
#define V9FS_PORT 564
#define V9FS_DEFUSER "nobody"
#define V9FS_DEFANAME ""
/* inital pool sizes for fids and tags */
#define V9FS_START_FIDS 8192
#define V9FS_START_TIDS 256
/*
* V9FS VFS extensions.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* 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
*
*/
/* plan9 semantics are that created files are implicitly opened.
* But linux semantics are that you call create, then open.
* the plan9 approach is superior as it provides an atomic
* open.
* we track the create fid here. When the file is opened, if fidopen is
* non-zero, we use the fid and can skip some steps.
* there may be a better way to do this, but I don't know it.
* one BAD way is to clunk the fid on create, then open it again:
* you lose the atomicity of file open
*/
/* special case:
* unlink calls remove, which is an implicit clunk. So we have to track
* that kind of thing so that we don't try to clunk a dead fid.
*/
extern struct file_system_type v9fs_fs_type;
extern struct file_operations v9fs_file_operations;
extern struct file_operations v9fs_dir_operations;
extern struct dentry_operations v9fs_dentry_operations;
struct inode *v9fs_get_inode(struct super_block *sb, int mode);
ino_t v9fs_qid2ino(struct v9fs_qid *qid);
void v9fs_mistat2inode(struct v9fs_stat *, struct inode *,
struct super_block *);
int v9fs_dir_release(struct inode *inode, struct file *filp);
int v9fs_file_open(struct inode *inode, struct file *file);
void v9fs_inode2mistat(struct inode *inode, struct v9fs_stat *mistat);
void v9fs_dentry_release(struct dentry *);
/*
* linux/fs/9p/vfs_super.c
*
* This file contians superblock ops for 9P2000. It is intended that
* you mount this file system on directories.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* 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/kernel.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>