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/inet.h> 35 #include <linux/pagemap.h> 36 #include <linux/seq_file.h> 37 #include <linux/mount.h> 38 #include <linux/idr.h> 39 40 #include "debug.h" 41 #include "v9fs.h" 42 #include "9p.h" 43 #include "v9fs_vfs.h" 44 #include "fid.h" 45 46 static void v9fs_clear_inode(struct inode *); 47 static const struct super_operations v9fs_super_ops; 48 49 /** 50 * v9fs_clear_inode - release an inode 51 * @inode: inode to release 52 * 53 */ 54 55 static void v9fs_clear_inode(struct inode *inode) 56 { 57 filemap_fdatawrite(inode->i_mapping); 58 } 59 60 /** 61 * v9fs_set_super - set the superblock 62 * @s: super block 63 * @data: file system specific data 64 * 65 */ 66 67 static int v9fs_set_super(struct super_block *s, void *data) 68 { 69 s->s_fs_info = data; 70 return set_anon_super(s, data); 71 } 72 73 /** 74 * v9fs_fill_super - populate superblock with info 75 * @sb: superblock 76 * @v9ses: session information 77 * 78 */ 79 80 static void 81 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 82 int flags) 83 { 84 sb->s_maxbytes = MAX_LFS_FILESIZE; 85 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 86 sb->s_blocksize = 1 << sb->s_blocksize_bits; 87 sb->s_magic = V9FS_MAGIC; 88 sb->s_op = &v9fs_super_ops; 89 90 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 91 MS_NOATIME; 92 } 93 94 /** 95 * v9fs_get_sb - mount a superblock 96 * @fs_type: file system type 97 * @flags: mount flags 98 * @dev_name: device name that was mounted 99 * @data: mount options 100 * @mnt: mountpoint record to be instantiated 101 * 102 */ 103 104 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 105 const char *dev_name, void *data, 106 struct vfsmount *mnt) 107 { 108 struct super_block *sb = NULL; 109 struct v9fs_fcall *fcall = NULL; 110 struct inode *inode = NULL; 111 struct dentry *root = NULL; 112 struct v9fs_session_info *v9ses = NULL; 113 struct v9fs_fid *root_fid = NULL; 114 int mode = S_IRWXUGO | S_ISVTX; 115 uid_t uid = current->fsuid; 116 gid_t gid = current->fsgid; 117 int stat_result = 0; 118 int newfid = 0; 119 int retval = 0; 120 121 dprintk(DEBUG_VFS, " \n"); 122 123 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 124 if (!v9ses) 125 return -ENOMEM; 126 127 if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) { 128 dprintk(DEBUG_ERROR, "problem initiating session\n"); 129 retval = newfid; 130 goto out_free_session; 131 } 132 133 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 134 if (IS_ERR(sb)) { 135 retval = PTR_ERR(sb); 136 goto out_close_session; 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 if (!root) { 151 retval = -ENOMEM; 152 goto put_back_sb; 153 } 154 155 sb->s_root = root; 156 157 stat_result = v9fs_t_stat(v9ses, newfid, &fcall); 158 if (stat_result < 0) { 159 dprintk(DEBUG_ERROR, "stat error\n"); 160 v9fs_t_clunk(v9ses, newfid); 161 } else { 162 /* Setup the Root Inode */ 163 root_fid = v9fs_fid_create(v9ses, newfid); 164 if (root_fid == NULL) { 165 retval = -ENOMEM; 166 goto put_back_sb; 167 } 168 169 retval = v9fs_fid_insert(root_fid, root); 170 if (retval < 0) { 171 kfree(fcall); 172 goto put_back_sb; 173 } 174 175 root_fid->qid = fcall->params.rstat.stat.qid; 176 root->d_inode->i_ino = 177 v9fs_qid2ino(&fcall->params.rstat.stat.qid); 178 v9fs_stat2inode(&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 put_back_sb; 186 } 187 188 return simple_set_mnt(mnt, sb); 189 190 out_close_session: 191 v9fs_session_close(v9ses); 192 out_free_session: 193 kfree(v9ses); 194 return retval; 195 196 put_back_sb: 197 /* deactivate_super calls v9fs_kill_super which will frees the rest */ 198 up_write(&sb->s_umount); 199 deactivate_super(sb); 200 return retval; 201 } 202 203 /** 204 * v9fs_kill_super - Kill Superblock 205 * @s: superblock 206 * 207 */ 208 209 static void v9fs_kill_super(struct super_block *s) 210 { 211 struct v9fs_session_info *v9ses = s->s_fs_info; 212 213 dprintk(DEBUG_VFS, " %p\n", s); 214 215 v9fs_dentry_release(s->s_root); /* clunk root */ 216 217 kill_anon_super(s); 218 219 v9fs_session_close(v9ses); 220 kfree(v9ses); 221 dprintk(DEBUG_VFS, "exiting kill_super\n"); 222 } 223 224 /** 225 * v9fs_show_options - Show mount options in /proc/mounts 226 * @m: seq_file to write to 227 * @mnt: mount descriptor 228 * 229 */ 230 231 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt) 232 { 233 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info; 234 235 if (v9ses->debug != 0) 236 seq_printf(m, ",debug=%u", v9ses->debug); 237 if (v9ses->port != V9FS_PORT) 238 seq_printf(m, ",port=%u", v9ses->port); 239 if (v9ses->maxdata != 9000) 240 seq_printf(m, ",msize=%u", v9ses->maxdata); 241 if (v9ses->afid != ~0) 242 seq_printf(m, ",afid=%u", v9ses->afid); 243 if (v9ses->proto == PROTO_UNIX) 244 seq_puts(m, ",proto=unix"); 245 if (v9ses->extended == 0) 246 seq_puts(m, ",noextend"); 247 if (v9ses->nodev == 1) 248 seq_puts(m, ",nodevmap"); 249 seq_printf(m, ",name=%s", v9ses->name); 250 seq_printf(m, ",aname=%s", v9ses->remotename); 251 seq_printf(m, ",uid=%u", v9ses->uid); 252 seq_printf(m, ",gid=%u", v9ses->gid); 253 return 0; 254 } 255 256 static void 257 v9fs_umount_begin(struct vfsmount *vfsmnt, int flags) 258 { 259 struct v9fs_session_info *v9ses = vfsmnt->mnt_sb->s_fs_info; 260 261 if (flags & MNT_FORCE) 262 v9fs_session_cancel(v9ses); 263 } 264 265 static const struct super_operations v9fs_super_ops = { 266 .statfs = simple_statfs, 267 .clear_inode = v9fs_clear_inode, 268 .show_options = v9fs_show_options, 269 .umount_begin = v9fs_umount_begin, 270 }; 271 272 struct file_system_type v9fs_fs_type = { 273 .name = "9p", 274 .get_sb = v9fs_get_sb, 275 .kill_sb = v9fs_kill_super, 276 .owner = THIS_MODULE, 277 }; 278