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/config.h> 29 #include <linux/module.h> 30 #include <linux/errno.h> 31 #include <linux/fs.h> 32 #include <linux/file.h> 33 #include <linux/stat.h> 34 #include <linux/string.h> 35 #include <linux/smp_lock.h> 36 #include <linux/inet.h> 37 #include <linux/pagemap.h> 38 #include <linux/seq_file.h> 39 #include <linux/mount.h> 40 #include <linux/idr.h> 41 42 #include "debug.h" 43 #include "v9fs.h" 44 #include "9p.h" 45 #include "v9fs_vfs.h" 46 #include "fid.h" 47 48 static void v9fs_clear_inode(struct inode *); 49 static struct super_operations v9fs_super_ops; 50 51 /** 52 * v9fs_clear_inode - release an inode 53 * @inode: inode to release 54 * 55 */ 56 57 static void v9fs_clear_inode(struct inode *inode) 58 { 59 filemap_fdatawrite(inode->i_mapping); 60 } 61 62 /** 63 * v9fs_set_super - set the superblock 64 * @s: super block 65 * @data: file system specific data 66 * 67 */ 68 69 static int v9fs_set_super(struct super_block *s, void *data) 70 { 71 s->s_fs_info = data; 72 return set_anon_super(s, data); 73 } 74 75 /** 76 * v9fs_fill_super - populate superblock with info 77 * @sb: superblock 78 * @v9ses: session information 79 * 80 */ 81 82 static void 83 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 84 int flags) 85 { 86 sb->s_maxbytes = MAX_LFS_FILESIZE; 87 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 88 sb->s_blocksize = 1 << sb->s_blocksize_bits; 89 sb->s_magic = V9FS_MAGIC; 90 sb->s_op = &v9fs_super_ops; 91 92 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 93 MS_NOATIME; 94 } 95 96 /** 97 * v9fs_get_sb - mount a superblock 98 * @fs_type: file system type 99 * @flags: mount flags 100 * @dev_name: device name that was mounted 101 * @data: mount options 102 * 103 */ 104 105 static struct super_block *v9fs_get_sb(struct file_system_type 106 *fs_type, int flags, 107 const char *dev_name, void *data) 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 ERR_PTR(-ENOMEM); 127 128 if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) { 129 dprintk(DEBUG_ERROR, "problem initiating session\n"); 130 sb = ERR_PTR(newfid); 131 goto out_free_session; 132 } 133 134 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 135 if (IS_ERR(sb)) 136 goto out_close_session; 137 v9fs_fill_super(sb, v9ses, flags); 138 139 inode = v9fs_get_inode(sb, S_IFDIR | mode); 140 if (IS_ERR(inode)) { 141 retval = PTR_ERR(inode); 142 goto put_back_sb; 143 } 144 145 inode->i_uid = uid; 146 inode->i_gid = gid; 147 148 root = d_alloc_root(inode); 149 if (!root) { 150 retval = -ENOMEM; 151 goto put_back_sb; 152 } 153 154 sb->s_root = root; 155 156 stat_result = v9fs_t_stat(v9ses, newfid, &fcall); 157 if (stat_result < 0) { 158 dprintk(DEBUG_ERROR, "stat error\n"); 159 v9fs_t_clunk(v9ses, newfid); 160 } else { 161 /* Setup the Root Inode */ 162 root_fid = v9fs_fid_create(v9ses, newfid); 163 if (root_fid == NULL) { 164 retval = -ENOMEM; 165 goto put_back_sb; 166 } 167 168 retval = v9fs_fid_insert(root_fid, root); 169 if (retval < 0) { 170 kfree(fcall); 171 goto put_back_sb; 172 } 173 174 root_fid->qid = fcall->params.rstat.stat.qid; 175 root->d_inode->i_ino = 176 v9fs_qid2ino(&fcall->params.rstat.stat.qid); 177 v9fs_stat2inode(&fcall->params.rstat.stat, root->d_inode, sb); 178 } 179 180 kfree(fcall); 181 182 if (stat_result < 0) { 183 retval = stat_result; 184 goto put_back_sb; 185 } 186 187 return sb; 188 189 out_close_session: 190 v9fs_session_close(v9ses); 191 out_free_session: 192 kfree(v9ses); 193 return sb; 194 195 put_back_sb: 196 /* deactivate_super calls v9fs_kill_super which will frees the rest */ 197 up_write(&sb->s_umount); 198 deactivate_super(sb); 199 return ERR_PTR(retval); 200 } 201 202 /** 203 * v9fs_kill_super - Kill Superblock 204 * @s: superblock 205 * 206 */ 207 208 static void v9fs_kill_super(struct super_block *s) 209 { 210 struct v9fs_session_info *v9ses = s->s_fs_info; 211 212 dprintk(DEBUG_VFS, " %p\n", s); 213 214 v9fs_dentry_release(s->s_root); /* clunk root */ 215 216 kill_anon_super(s); 217 218 v9fs_session_close(v9ses); 219 kfree(v9ses); 220 dprintk(DEBUG_VFS, "exiting kill_super\n"); 221 } 222 223 /** 224 * v9fs_show_options - Show mount options in /proc/mounts 225 * @m: seq_file to write to 226 * @mnt: mount descriptor 227 * 228 */ 229 230 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt) 231 { 232 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info; 233 234 if (v9ses->debug != 0) 235 seq_printf(m, ",debug=%u", v9ses->debug); 236 if (v9ses->port != V9FS_PORT) 237 seq_printf(m, ",port=%u", v9ses->port); 238 if (v9ses->maxdata != 9000) 239 seq_printf(m, ",msize=%u", v9ses->maxdata); 240 if (v9ses->afid != ~0) 241 seq_printf(m, ",afid=%u", v9ses->afid); 242 if (v9ses->proto == PROTO_UNIX) 243 seq_puts(m, ",proto=unix"); 244 if (v9ses->extended == 0) 245 seq_puts(m, ",noextend"); 246 if (v9ses->nodev == 1) 247 seq_puts(m, ",nodevmap"); 248 seq_printf(m, ",name=%s", v9ses->name); 249 seq_printf(m, ",aname=%s", v9ses->remotename); 250 seq_printf(m, ",uid=%u", v9ses->uid); 251 seq_printf(m, ",gid=%u", v9ses->gid); 252 return 0; 253 } 254 255 static void 256 v9fs_umount_begin(struct super_block *sb) 257 { 258 struct v9fs_session_info *v9ses = sb->s_fs_info; 259 260 v9fs_session_cancel(v9ses); 261 } 262 263 static struct super_operations v9fs_super_ops = { 264 .statfs = simple_statfs, 265 .clear_inode = v9fs_clear_inode, 266 .show_options = v9fs_show_options, 267 .umount_begin = v9fs_umount_begin, 268 }; 269 270 struct file_system_type v9fs_fs_type = { 271 .name = "9p", 272 .get_sb = v9fs_get_sb, 273 .kill_sb = v9fs_kill_super, 274 .owner = THIS_MODULE, 275 }; 276