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-rw-r--r--fs/9p/v9fs.c448
1 files changed, 448 insertions, 0 deletions
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
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+++ b/fs/9p/v9fs.c
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+/*
+ * 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");
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