/* * 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 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/module.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/sched.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" /* 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_uname, 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=%x"}, {Opt_uname, "uname=%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_uname) { 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_uname: 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; } /* no need to store exactly p, we just need something non-null */ error = idr_get_new(&p->pool, p, &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_check_idpool - check if the specified id is available * @id - id to check * @p - pool */ int v9fs_check_idpool(int id, struct v9fs_idpool *p) { return idr_find(&p->pool, id) != NULL; } /** * 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; struct v9fs_str *version; 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 tags */ idr_init(&v9ses->fidpool.pool); init_MUTEX(&v9ses->fidpool.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; break; default: printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto); retval = -ENOPROTOOPT; goto SessCleanUp; }; v9ses->transport = kmalloc(sizeof(*v9ses->transport), GFP_KERNEL); if (!v9ses->transport) { retval = -ENOMEM; goto SessCleanUp; } memmove(v9ses->transport, trans_proto, sizeof(*v9ses->transport)); 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; v9ses->mux = v9fs_mux_init(v9ses->transport, v9ses->maxdata + V9FS_IOHDRSZ, &v9ses->extended); if (IS_ERR(v9ses->mux)) { retval = PTR_ERR(v9ses->mux); v9ses->mux = NULL; 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; } version = &fcall->params.rversion.version; if (version->len==8 && !memcmp(version->str, "9P2000.u", 8)) { dprintk(DEBUG_9P, "9P2000 UNIX extensions enabled\n"); v9ses->extended = 1; } else if (version->len==6 && !memcmp(version->str, "9P2000", 6)) { dprintk(DEBUG_9P, "9P2000 legacy mode enabled\n"); v9ses->extended = 0; } else { retval = -EREMOTEIO; goto FreeFcall; } 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) { dprintk(DEBUG_ERROR, "afid not equal to ~0\n"); if (v9fs_t_clunk(v9ses, v9ses->afid)) 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->mux) { v9fs_mux_destroy(v9ses->mux); v9ses->mux = NULL; } if (v9ses->transport) { v9ses->transport->close(v9ses->transport); kfree(v9ses->transport); v9ses->transport = NULL; } __putname(v9ses->name); __putname(v9ses->remotename); } /** * v9fs_session_cancel - mark transport as disconnected * and cancel all pending requests. */ void v9fs_session_cancel(struct v9fs_session_info *v9ses) { dprintk(DEBUG_ERROR, "cancel session %p\n", v9ses); v9ses->transport->status = Disconnected; v9fs_mux_cancel(v9ses->mux, -EIO); } extern int v9fs_error_init(void); /** * v9fs_init - Initialize module * */ static int __init init_v9fs(void) { int ret; v9fs_error_init(); printk(KERN_INFO "Installing v9fs 9P2000 file system support\n"); ret = v9fs_mux_global_init(); if (!ret) return ret; ret = register_filesystem(&v9fs_fs_type); if (!ret) v9fs_mux_global_exit(); return ret; } /** * v9fs_init - shutdown module * */ static void __exit exit_v9fs(void) { v9fs_mux_global_exit(); 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");