fs/9p/vfs_super.c

   1 /*
   2  *  linux/fs/9p/vfs_super.c
   3  *
   4  * This file contians superblock ops for 9P2000. It is intended that
   5  * you mount this file system on directories.
   6  *
   7  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   8  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to:
  22  *  Free Software Foundation
  23  *  51 Franklin Street, Fifth Floor
  24  *  Boston, MA  02111-1301  USA
  25  *
  26  */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/config.h>
  30 #include <linux/module.h>
  31 #include <linux/errno.h>
  32 #include <linux/fs.h>
  33 #include <linux/file.h>
  34 #include <linux/stat.h>
  35 #include <linux/string.h>
  36 #include <linux/smp_lock.h>
  37 #include <linux/inet.h>
  38 #include <linux/pagemap.h>
  39 #include <linux/seq_file.h>
  40 #include <linux/mount.h>
  41 #include <linux/idr.h>
  42
  43 #include "debug.h"
  44 #include "v9fs.h"
  45 #include "9p.h"
  46 #include "v9fs_vfs.h"
  47 #include "conv.h"
  48 #include "fid.h"
  49
  50 static void v9fs_clear_inode(struct inode *);
  51 static struct super_operations v9fs_super_ops;
  52
  53 /**
  54  * v9fs_clear_inode - release an inode
  55  * @inode: inode to release
  56  *
  57  */
  58
  59 static void v9fs_clear_inode(struct inode *inode)
  60 {
  61         filemap_fdatawrite(inode->i_mapping);
  62 }
  63
  64 /**
  65  * v9fs_set_super - set the superblock
  66  * @s: super block
  67  * @data: file system specific data
  68  *
  69  */
  70
  71 static int v9fs_set_super(struct super_block *s, void *data)
  72 {
  73         s->s_fs_info = data;
  74         return set_anon_super(s, data);
  75 }
  76
  77 /**
  78  * v9fs_fill_super - populate superblock with info
  79  * @sb: superblock
  80  * @v9ses: session information
  81  *
  82  */
  83
  84 static void
  85 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
  86                 int flags)
  87 {
  88         sb->s_maxbytes = MAX_LFS_FILESIZE;
  89         sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
  90         sb->s_blocksize = 1 << sb->s_blocksize_bits;
  91         sb->s_magic = V9FS_MAGIC;
  92         sb->s_op = &v9fs_super_ops;
  93
  94         sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
  95             MS_NODIRATIME | MS_NOATIME;
  96 }
  97
  98 /**
  99  * v9fs_get_sb - mount a superblock
 100  * @fs_type: file system type
 101  * @flags: mount flags
 102  * @dev_name: device name that was mounted
 103  * @data: mount options
 104  *
 105  */
 106
 107 static struct super_block *v9fs_get_sb(struct file_system_type
 108                                        *fs_type, int flags,
 109                                        const char *dev_name, void *data)
 110 {
 111         struct super_block *sb = NULL;
 112         struct v9fs_fcall *fcall = NULL;
 113         struct inode *inode = NULL;
 114         struct dentry *root = NULL;
 115         struct v9fs_session_info *v9ses = NULL;
 116         struct v9fs_fid *root_fid = NULL;
 117         int mode = S_IRWXUGO | S_ISVTX;
 118         uid_t uid = current->fsuid;
 119         gid_t gid = current->fsgid;
 120         int stat_result = 0;
 121         int newfid = 0;
 122         int retval = 0;
 123
 124         dprintk(DEBUG_VFS, " \n");
 125
 126         v9ses = kcalloc(1, sizeof(struct v9fs_session_info), GFP_KERNEL);
 127         if (!v9ses)
 128                 return ERR_PTR(-ENOMEM);
 129
 130         if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) {
 131                 dprintk(DEBUG_ERROR, "problem initiating session\n");
 132                 retval = newfid;
 133                 goto free_session;
 134         }
 135
 136         sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
 137
 138         v9fs_fill_super(sb, v9ses, flags);
 139
 140         inode = v9fs_get_inode(sb, S_IFDIR | mode);
 141         if (IS_ERR(inode)) {
 142                 retval = PTR_ERR(inode);
 143                 goto put_back_sb;
 144         }
 145
 146         inode->i_uid = uid;
 147         inode->i_gid = gid;
 148
 149         root = d_alloc_root(inode);
 150
 151         if (!root) {
 152                 retval = -ENOMEM;
 153                 goto release_inode;
 154         }
 155
 156         sb->s_root = root;
 157
 158         /* Setup the Root Inode */
 159         root_fid = v9fs_fid_create(root);
 160         if (root_fid == NULL) {
 161                 retval = -ENOMEM;
 162                 goto release_dentry;
 163         }
 164
 165         root_fid->fidopen = 0;
 166         root_fid->v9ses = v9ses;
 167
 168         stat_result = v9fs_t_stat(v9ses, newfid, &fcall);
 169         if (stat_result < 0) {
 170                 dprintk(DEBUG_ERROR, "stat error\n");
 171                 v9fs_t_clunk(v9ses, newfid, NULL);
 172                 v9fs_put_idpool(newfid, &v9ses->fidpool);
 173         } else {
 174                 root_fid->fid = newfid;
 175                 root_fid->qid = fcall->params.rstat.stat->qid;
 176                 root->d_inode->i_ino =
 177                     v9fs_qid2ino(&fcall->params.rstat.stat->qid);
 178                 v9fs_mistat2inode(fcall->params.rstat.stat, root->d_inode, sb);
 179         }
 180
 181         kfree(fcall);
 182
 183         if (stat_result < 0) {
 184                 retval = stat_result;
 185                 goto release_dentry;
 186         }
 187
 188         return sb;
 189
 190       release_dentry:
 191         dput(sb->s_root);
 192
 193       release_inode:
 194         iput(inode);
 195
 196       put_back_sb:
 197         up_write(&sb->s_umount);
 198         deactivate_super(sb);
 199         v9fs_session_close(v9ses);
 200
 201       free_session:
 202         kfree(v9ses);
 203
 204         return ERR_PTR(retval);
 205 }
 206
 207 /**
 208  * v9fs_kill_super - Kill Superblock
 209  * @s: superblock
 210  *
 211  */
 212
 213 static void v9fs_kill_super(struct super_block *s)
 214 {
 215         struct v9fs_session_info *v9ses = s->s_fs_info;
 216
 217         dprintk(DEBUG_VFS, " %p\n", s);
 218
 219         v9fs_dentry_release(s->s_root); /* clunk root */
 220
 221         kill_anon_super(s);
 222
 223         v9fs_session_close(v9ses);
 224         kfree(v9ses);
 225         dprintk(DEBUG_VFS, "exiting kill_super\n");
 226 }
 227
 228 /**
 229  * v9fs_show_options - Show mount options in /proc/mounts
 230  * @m: seq_file to write to
 231  * @mnt: mount descriptor
 232  *
 233  */
 234
 235 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
 236 {
 237         struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
 238
 239         if (v9ses->debug != 0)
 240                 seq_printf(m, ",debug=%u", v9ses->debug);
 241         if (v9ses->port != V9FS_PORT)
 242                 seq_printf(m, ",port=%u", v9ses->port);
 243         if (v9ses->maxdata != 9000)
 244                 seq_printf(m, ",msize=%u", v9ses->maxdata);
 245         if (v9ses->afid != ~0)
 246                 seq_printf(m, ",afid=%u", v9ses->afid);
 247         if (v9ses->proto == PROTO_UNIX)
 248                 seq_puts(m, ",proto=unix");
 249         if (v9ses->extended == 0)
 250                 seq_puts(m, ",noextend");
 251         if (v9ses->nodev == 1)
 252                 seq_puts(m, ",nodevmap");
 253         seq_printf(m, ",name=%s", v9ses->name);
 254         seq_printf(m, ",aname=%s", v9ses->remotename);
 255         seq_printf(m, ",uid=%u", v9ses->uid);
 256         seq_printf(m, ",gid=%u", v9ses->gid);
 257         return 0;
 258 }
 259
 260 static void
 261 v9fs_umount_begin(struct super_block *sb)
 262 {
 263         struct v9fs_session_info *v9ses = sb->s_fs_info;
 264
 265         v9fs_session_cancel(v9ses);
 266 }
 267
 268 static struct super_operations v9fs_super_ops = {
 269         .statfs = simple_statfs,
 270         .clear_inode = v9fs_clear_inode,
 271         .show_options = v9fs_show_options,
 272         .umount_begin = v9fs_umount_begin,
 273 };
 274
 275 struct file_system_type v9fs_fs_type = {
 276         .name = "9P",
 277         .get_sb = v9fs_get_sb,
 278         .kill_sb = v9fs_kill_super,
 279         .owner = THIS_MODULE,
 280 };