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author | Eric Van Hensbergen <ericvh@gmail.com> | 2005-09-09 20:04:20 (GMT) |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-09 20:57:56 (GMT) |
commit | 9e82cf6a802a72f0f447eb4c76d6a3fc8736a31d (patch) | |
tree | 69bab629bd530930470fded8f04ca57566680668 /fs/9p/v9fs.c | |
parent | 2bad8471511ce5cc3ea90d0940622bd4b56b9cce (diff) | |
download | linux-9e82cf6a802a72f0f447eb4c76d6a3fc8736a31d.tar.xz |
[PATCH] v9fs: VFS superblock operations and glue
This part of the patch contains VFS superblock and mapping code.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/9p/v9fs.c')
-rw-r--r-- | fs/9p/v9fs.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c new file mode 100644 index 0000000..14d663e --- /dev/null +++ b/fs/9p/v9fs.c @@ -0,0 +1,448 @@ +/* + * 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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