f71626a461
If error occurs while in v9fs_get_sb after it calles sget, the dentry object of the root and its inode may be freed twice -- once while handling the error in v9fs_get_sb, and second time when v9fs_get_sb calles deactivate_super (which in turn calls v9fs_kill_super) The patch removes the unnecessary code that frees the root dentry and its inode. Signed-off-by: Latchesar Ionkov <lucho@ionkov.net> Cc: Eric Van Hensbergen <ericvh@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
270 lines
6.2 KiB
C
270 lines
6.2 KiB
C
/*
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* linux/fs/9p/vfs_super.c
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*
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* This file contians superblock ops for 9P2000. It is intended that
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* you mount this file system on directories.
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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/kernel.h>
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#include <linux/config.h>
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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/file.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <linux/smp_lock.h>
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#include <linux/inet.h>
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#include <linux/pagemap.h>
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#include <linux/seq_file.h>
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#include <linux/mount.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 "conv.h"
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#include "fid.h"
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static void v9fs_clear_inode(struct inode *);
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static struct super_operations v9fs_super_ops;
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/**
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* v9fs_clear_inode - release an inode
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* @inode: inode to release
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*
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*/
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static void v9fs_clear_inode(struct inode *inode)
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{
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filemap_fdatawrite(inode->i_mapping);
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}
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/**
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* v9fs_set_super - set the superblock
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* @s: super block
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* @data: file system specific data
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*
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*/
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static int v9fs_set_super(struct super_block *s, void *data)
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{
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s->s_fs_info = data;
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return set_anon_super(s, data);
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}
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/**
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* v9fs_fill_super - populate superblock with info
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* @sb: superblock
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* @v9ses: session information
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*
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*/
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static void
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v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
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int flags)
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{
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sb->s_maxbytes = MAX_LFS_FILESIZE;
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sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
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sb->s_blocksize = 1 << sb->s_blocksize_bits;
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sb->s_magic = V9FS_MAGIC;
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sb->s_op = &v9fs_super_ops;
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sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
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MS_NODIRATIME | MS_NOATIME;
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}
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/**
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* v9fs_get_sb - mount a superblock
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* @fs_type: file system type
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* @flags: mount flags
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* @dev_name: device name that was mounted
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* @data: mount options
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*
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*/
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static struct super_block *v9fs_get_sb(struct file_system_type
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*fs_type, int flags,
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const char *dev_name, void *data)
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{
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struct super_block *sb = NULL;
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struct v9fs_fcall *fcall = NULL;
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struct inode *inode = NULL;
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struct dentry *root = NULL;
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struct v9fs_session_info *v9ses = NULL;
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struct v9fs_fid *root_fid = NULL;
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int mode = S_IRWXUGO | S_ISVTX;
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uid_t uid = current->fsuid;
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gid_t gid = current->fsgid;
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int stat_result = 0;
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int newfid = 0;
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int retval = 0;
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dprintk(DEBUG_VFS, " \n");
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v9ses = kcalloc(1, sizeof(struct v9fs_session_info), GFP_KERNEL);
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if (!v9ses)
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return ERR_PTR(-ENOMEM);
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if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) {
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dprintk(DEBUG_ERROR, "problem initiating session\n");
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kfree(v9ses);
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return ERR_PTR(newfid);
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}
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sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
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v9fs_fill_super(sb, v9ses, flags);
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inode = v9fs_get_inode(sb, S_IFDIR | mode);
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if (IS_ERR(inode)) {
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retval = PTR_ERR(inode);
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goto put_back_sb;
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}
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inode->i_uid = uid;
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inode->i_gid = gid;
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root = d_alloc_root(inode);
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if (!root) {
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retval = -ENOMEM;
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goto put_back_sb;
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}
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sb->s_root = root;
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/* Setup the Root Inode */
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root_fid = v9fs_fid_create(root);
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if (root_fid == NULL) {
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retval = -ENOMEM;
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goto put_back_sb;
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}
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root_fid->fidopen = 0;
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root_fid->v9ses = v9ses;
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stat_result = v9fs_t_stat(v9ses, newfid, &fcall);
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if (stat_result < 0) {
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dprintk(DEBUG_ERROR, "stat error\n");
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v9fs_t_clunk(v9ses, newfid, NULL);
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v9fs_put_idpool(newfid, &v9ses->fidpool);
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} else {
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root_fid->fid = newfid;
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root_fid->qid = fcall->params.rstat.stat->qid;
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root->d_inode->i_ino =
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v9fs_qid2ino(&fcall->params.rstat.stat->qid);
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v9fs_mistat2inode(fcall->params.rstat.stat, root->d_inode, sb);
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}
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kfree(fcall);
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if (stat_result < 0) {
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retval = stat_result;
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goto put_back_sb;
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}
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return sb;
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put_back_sb:
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/* deactivate_super calls v9fs_kill_super which will frees the rest */
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up_write(&sb->s_umount);
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deactivate_super(sb);
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return ERR_PTR(retval);
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}
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/**
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* v9fs_kill_super - Kill Superblock
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* @s: superblock
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*
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*/
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static void v9fs_kill_super(struct super_block *s)
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{
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struct v9fs_session_info *v9ses = s->s_fs_info;
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dprintk(DEBUG_VFS, " %p\n", s);
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v9fs_dentry_release(s->s_root); /* clunk root */
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kill_anon_super(s);
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v9fs_session_close(v9ses);
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kfree(v9ses);
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dprintk(DEBUG_VFS, "exiting kill_super\n");
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}
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/**
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* v9fs_show_options - Show mount options in /proc/mounts
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* @m: seq_file to write to
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* @mnt: mount descriptor
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*
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*/
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static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
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{
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struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
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if (v9ses->debug != 0)
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seq_printf(m, ",debug=%u", v9ses->debug);
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if (v9ses->port != V9FS_PORT)
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seq_printf(m, ",port=%u", v9ses->port);
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if (v9ses->maxdata != 9000)
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seq_printf(m, ",msize=%u", v9ses->maxdata);
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if (v9ses->afid != ~0)
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seq_printf(m, ",afid=%u", v9ses->afid);
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if (v9ses->proto == PROTO_UNIX)
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seq_puts(m, ",proto=unix");
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if (v9ses->extended == 0)
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seq_puts(m, ",noextend");
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if (v9ses->nodev == 1)
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seq_puts(m, ",nodevmap");
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seq_printf(m, ",name=%s", v9ses->name);
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seq_printf(m, ",aname=%s", v9ses->remotename);
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seq_printf(m, ",uid=%u", v9ses->uid);
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seq_printf(m, ",gid=%u", v9ses->gid);
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return 0;
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}
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static void
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v9fs_umount_begin(struct super_block *sb)
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{
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struct v9fs_session_info *v9ses = sb->s_fs_info;
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v9fs_session_cancel(v9ses);
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}
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static struct super_operations v9fs_super_ops = {
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.statfs = simple_statfs,
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.clear_inode = v9fs_clear_inode,
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.show_options = v9fs_show_options,
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.umount_begin = v9fs_umount_begin,
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};
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struct file_system_type v9fs_fs_type = {
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.name = "9P",
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.get_sb = v9fs_get_sb,
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.kill_sb = v9fs_kill_super,
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.owner = THIS_MODULE,
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};
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