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 version 2 12 * as published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to: 21 * Free Software Foundation 22 * 51 Franklin Street, Fifth Floor 23 * Boston, MA 02111-1301 USA 24 * 25 */ 26 27 #include <linux/kernel.h> 28 #include <linux/module.h> 29 #include <linux/errno.h> 30 #include <linux/fs.h> 31 #include <linux/file.h> 32 #include <linux/stat.h> 33 #include <linux/string.h> 34 #include <linux/smp_lock.h> 35 #include <linux/inet.h> 36 #include <linux/pagemap.h> 37 #include <linux/seq_file.h> 38 #include <linux/mount.h> 39 #include <linux/idr.h> 40 41 #include "debug.h" 42 #include "v9fs.h" 43 #include "9p.h" 44 #include "v9fs_vfs.h" 45 #include "fid.h" 46 47 static void v9fs_clear_inode(struct inode *); 48 static struct super_operations v9fs_super_ops; 49 50 /** 51 * v9fs_clear_inode - release an inode 52 * @inode: inode to release 53 * 54 */ 55 56 static void v9fs_clear_inode(struct inode *inode) 57 { 58 filemap_fdatawrite(inode->i_mapping); 59 } 60 61 /** 62 * v9fs_set_super - set the superblock 63 * @s: super block 64 * @data: file system specific data 65 * 66 */ 67 68 static int v9fs_set_super(struct super_block *s, void *data) 69 { 70 s->s_fs_info = data; 71 return set_anon_super(s, data); 72 } 73 74 /** 75 * v9fs_fill_super - populate superblock with info 76 * @sb: superblock 77 * @v9ses: session information 78 * 79 */ 80 81 static void 82 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 83 int flags) 84 { 85 sb->s_maxbytes = MAX_LFS_FILESIZE; 86 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 87 sb->s_blocksize = 1 << sb->s_blocksize_bits; 88 sb->s_magic = V9FS_MAGIC; 89 sb->s_op = &v9fs_super_ops; 90 91 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 92 MS_NOATIME; 93 } 94 95 /** 96 * v9fs_get_sb - mount a superblock 97 * @fs_type: file system type 98 * @flags: mount flags 99 * @dev_name: device name that was mounted 100 * @data: mount options 101 * @mnt: mountpoint record to be instantiated 102 * 103 */ 104 105 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 106 const char *dev_name, void *data, 107 struct vfsmount *mnt) 108 { 109 struct super_block *sb = NULL; 110 struct v9fs_fcall *fcall = NULL; 111 struct inode *inode = NULL; 112 struct dentry *root = NULL; 113 struct v9fs_session_info *v9ses = NULL; 114 struct v9fs_fid *root_fid = NULL; 115 int mode = S_IRWXUGO | S_ISVTX; 116 uid_t uid = current->fsuid; 117 gid_t gid = current->fsgid; 118 int stat_result = 0; 119 int newfid = 0; 120 int retval = 0; 121 122 dprintk(DEBUG_VFS, " \n"); 123 124 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 125 if (!v9ses) 126 return -ENOMEM; 127 128 if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) { 129 dprintk(DEBUG_ERROR, "problem initiating session\n"); 130 retval = newfid; 131 goto out_free_session; 132 } 133 134 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 135 if (IS_ERR(sb)) { 136 retval = PTR_ERR(sb); 137 goto out_close_session; 138 } 139 v9fs_fill_super(sb, v9ses, flags); 140 141 inode = v9fs_get_inode(sb, S_IFDIR | mode); 142 if (IS_ERR(inode)) { 143 retval = PTR_ERR(inode); 144 goto put_back_sb; 145 } 146 147 inode->i_uid = uid; 148 inode->i_gid = gid; 149 150 root = d_alloc_root(inode); 151 if (!root) { 152 retval = -ENOMEM; 153 goto put_back_sb; 154 } 155 156 sb->s_root = root; 157 158 stat_result = v9fs_t_stat(v9ses, newfid, &fcall); 159 if (stat_result < 0) { 160 dprintk(DEBUG_ERROR, "stat error\n"); 161 v9fs_t_clunk(v9ses, newfid); 162 } else { 163 /* Setup the Root Inode */ 164 root_fid = v9fs_fid_create(v9ses, newfid); 165 if (root_fid == NULL) { 166 retval = -ENOMEM; 167 goto put_back_sb; 168 } 169 170 retval = v9fs_fid_insert(root_fid, root); 171 if (retval < 0) { 172 kfree(fcall); 173 goto put_back_sb; 174 } 175 176 root_fid->qid = fcall->params.rstat.stat.qid; 177 root->d_inode->i_ino = 178 v9fs_qid2ino(&fcall->params.rstat.stat.qid); 179 v9fs_stat2inode(&fcall->params.rstat.stat, root->d_inode, sb); 180 } 181 182 kfree(fcall); 183 184 if (stat_result < 0) { 185 retval = stat_result; 186 goto put_back_sb; 187 } 188 189 return simple_set_mnt(mnt, sb); 190 191 out_close_session: 192 v9fs_session_close(v9ses); 193 out_free_session: 194 kfree(v9ses); 195 return retval; 196 197 put_back_sb: 198 /* deactivate_super calls v9fs_kill_super which will frees the rest */ 199 up_write(&sb->s_umount); 200 deactivate_super(sb); 201 return retval; 202 } 203 204 /** 205 * v9fs_kill_super - Kill Superblock 206 * @s: superblock 207 * 208 */ 209 210 static void v9fs_kill_super(struct super_block *s) 211 { 212 struct v9fs_session_info *v9ses = s->s_fs_info; 213 214 dprintk(DEBUG_VFS, " %p\n", s); 215 216 v9fs_dentry_release(s->s_root); /* clunk root */ 217 218 kill_anon_super(s); 219 220 v9fs_session_close(v9ses); 221 kfree(v9ses); 222 dprintk(DEBUG_VFS, "exiting kill_super\n"); 223 } 224 225 /** 226 * v9fs_show_options - Show mount options in /proc/mounts 227 * @m: seq_file to write to 228 * @mnt: mount descriptor 229 * 230 */ 231 232 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt) 233 { 234 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info; 235 236 if (v9ses->debug != 0) 237 seq_printf(m, ",debug=%u", v9ses->debug); 238 if (v9ses->port != V9FS_PORT) 239 seq_printf(m, ",port=%u", v9ses->port); 240 if (v9ses->maxdata != 9000) 241 seq_printf(m, ",msize=%u", v9ses->maxdata); 242 if (v9ses->afid != ~0) 243 seq_printf(m, ",afid=%u", v9ses->afid); 244 if (v9ses->proto == PROTO_UNIX) 245 seq_puts(m, ",proto=unix"); 246 if (v9ses->extended == 0) 247 seq_puts(m, ",noextend"); 248 if (v9ses->nodev == 1) 249 seq_puts(m, ",nodevmap"); 250 seq_printf(m, ",name=%s", v9ses->name); 251 seq_printf(m, ",aname=%s", v9ses->remotename); 252 seq_printf(m, ",uid=%u", v9ses->uid); 253 seq_printf(m, ",gid=%u", v9ses->gid); 254 return 0; 255 } 256 257 static void 258 v9fs_umount_begin(struct vfsmount *vfsmnt, int flags) 259 { 260 struct v9fs_session_info *v9ses = vfsmnt->mnt_sb->s_fs_info; 261 262 if (flags & MNT_FORCE) 263 v9fs_session_cancel(v9ses); 264 } 265 266 static struct super_operations v9fs_super_ops = { 267 .statfs = simple_statfs, 268 .clear_inode = v9fs_clear_inode, 269 .show_options = v9fs_show_options, 270 .umount_begin = v9fs_umount_begin, 271 }; 272 273 struct file_system_type v9fs_fs_type = { 274 .name = "9p", 275 .get_sb = v9fs_get_sb, 276 .kill_sb = v9fs_kill_super, 277 .owner = THIS_MODULE, 278 }; 279