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 return ERR_PTR(newfid); 133 } 134 135 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 136 137 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); 149 150 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, NULL); 161 v9fs_put_idpool(newfid, &v9ses->fidpool); 162 } else { 163 /* Setup the Root Inode */ 164 root_fid = v9fs_fid_create(root, v9ses, newfid, 0); 165 if (root_fid == NULL) { 166 retval = -ENOMEM; 167 goto put_back_sb; 168 } 169 170 root_fid->qid = fcall->params.rstat.stat->qid; 171 root->d_inode->i_ino = 172 v9fs_qid2ino(&fcall->params.rstat.stat->qid); 173 v9fs_mistat2inode(fcall->params.rstat.stat, root->d_inode, sb); 174 } 175 176 kfree(fcall); 177 178 if (stat_result < 0) { 179 retval = stat_result; 180 goto put_back_sb; 181 } 182 183 return sb; 184 185 put_back_sb: 186 /* deactivate_super calls v9fs_kill_super which will frees the rest */ 187 up_write(&sb->s_umount); 188 deactivate_super(sb); 189 return ERR_PTR(retval); 190 } 191 192 /** 193 * v9fs_kill_super - Kill Superblock 194 * @s: superblock 195 * 196 */ 197 198 static void v9fs_kill_super(struct super_block *s) 199 { 200 struct v9fs_session_info *v9ses = s->s_fs_info; 201 202 dprintk(DEBUG_VFS, " %p\n", s); 203 204 v9fs_dentry_release(s->s_root); /* clunk root */ 205 206 kill_anon_super(s); 207 208 v9fs_session_close(v9ses); 209 kfree(v9ses); 210 dprintk(DEBUG_VFS, "exiting kill_super\n"); 211 } 212 213 /** 214 * v9fs_show_options - Show mount options in /proc/mounts 215 * @m: seq_file to write to 216 * @mnt: mount descriptor 217 * 218 */ 219 220 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt) 221 { 222 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info; 223 224 if (v9ses->debug != 0) 225 seq_printf(m, ",debug=%u", v9ses->debug); 226 if (v9ses->port != V9FS_PORT) 227 seq_printf(m, ",port=%u", v9ses->port); 228 if (v9ses->maxdata != 9000) 229 seq_printf(m, ",msize=%u", v9ses->maxdata); 230 if (v9ses->afid != ~0) 231 seq_printf(m, ",afid=%u", v9ses->afid); 232 if (v9ses->proto == PROTO_UNIX) 233 seq_puts(m, ",proto=unix"); 234 if (v9ses->extended == 0) 235 seq_puts(m, ",noextend"); 236 if (v9ses->nodev == 1) 237 seq_puts(m, ",nodevmap"); 238 seq_printf(m, ",name=%s", v9ses->name); 239 seq_printf(m, ",aname=%s", v9ses->remotename); 240 seq_printf(m, ",uid=%u", v9ses->uid); 241 seq_printf(m, ",gid=%u", v9ses->gid); 242 return 0; 243 } 244 245 static void 246 v9fs_umount_begin(struct super_block *sb) 247 { 248 struct v9fs_session_info *v9ses = sb->s_fs_info; 249 250 v9fs_session_cancel(v9ses); 251 } 252 253 static struct super_operations v9fs_super_ops = { 254 .statfs = simple_statfs, 255 .clear_inode = v9fs_clear_inode, 256 .show_options = v9fs_show_options, 257 .umount_begin = v9fs_umount_begin, 258 }; 259 260 struct file_system_type v9fs_fs_type = { 261 .name = "9P", 262 .get_sb = v9fs_get_sb, 263 .kill_sb = v9fs_kill_super, 264 .owner = THIS_MODULE, 265 }; 266