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 #include <linux/sched.h> 40 #include <linux/smp_lock.h> 41 #include <net/9p/9p.h> 42 #include <net/9p/client.h> 43 44 #include "v9fs.h" 45 #include "v9fs_vfs.h" 46 #include "fid.h" 47 48 static void v9fs_clear_inode(struct inode *); 49 static const 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 * @flags: flags propagated from v9fs_get_sb() 80 * 81 */ 82 83 static void 84 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 85 int flags) 86 { 87 sb->s_maxbytes = MAX_LFS_FILESIZE; 88 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 89 sb->s_blocksize = 1 << sb->s_blocksize_bits; 90 sb->s_magic = V9FS_MAGIC; 91 sb->s_op = &v9fs_super_ops; 92 93 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 94 MS_NOATIME; 95 } 96 97 /** 98 * v9fs_get_sb - mount a superblock 99 * @fs_type: file system type 100 * @flags: mount flags 101 * @dev_name: device name that was mounted 102 * @data: mount options 103 * @mnt: mountpoint record to be instantiated 104 * 105 */ 106 107 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 108 const char *dev_name, void *data, 109 struct vfsmount *mnt) 110 { 111 struct super_block *sb = NULL; 112 struct inode *inode = NULL; 113 struct dentry *root = NULL; 114 struct v9fs_session_info *v9ses = NULL; 115 struct p9_wstat *st = NULL; 116 int mode = S_IRWXUGO | S_ISVTX; 117 uid_t uid = current_fsuid(); 118 gid_t gid = current_fsgid(); 119 struct p9_fid *fid; 120 int retval = 0; 121 122 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 123 124 st = NULL; 125 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 126 if (!v9ses) 127 return -ENOMEM; 128 129 fid = v9fs_session_init(v9ses, dev_name, data); 130 if (IS_ERR(fid)) { 131 retval = PTR_ERR(fid); 132 goto close_session; 133 } 134 135 st = p9_client_stat(fid); 136 if (IS_ERR(st)) { 137 retval = PTR_ERR(st); 138 goto clunk_fid; 139 } 140 141 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 142 if (IS_ERR(sb)) { 143 retval = PTR_ERR(sb); 144 goto free_stat; 145 } 146 v9fs_fill_super(sb, v9ses, flags); 147 148 inode = v9fs_get_inode(sb, S_IFDIR | mode); 149 if (IS_ERR(inode)) { 150 retval = PTR_ERR(inode); 151 goto release_sb; 152 } 153 154 inode->i_uid = uid; 155 inode->i_gid = gid; 156 157 root = d_alloc_root(inode); 158 if (!root) { 159 iput(inode); 160 retval = -ENOMEM; 161 goto release_sb; 162 } 163 164 sb->s_root = root; 165 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 166 167 v9fs_stat2inode(st, root->d_inode, sb); 168 169 v9fs_fid_add(root, fid); 170 p9stat_free(st); 171 kfree(st); 172 173 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 174 simple_set_mnt(mnt, sb); 175 return 0; 176 177 release_sb: 178 deactivate_locked_super(sb); 179 180 free_stat: 181 kfree(st); 182 183 clunk_fid: 184 p9_client_clunk(fid); 185 186 close_session: 187 v9fs_session_close(v9ses); 188 kfree(v9ses); 189 190 return retval; 191 } 192 193 /** 194 * v9fs_kill_super - Kill Superblock 195 * @s: superblock 196 * 197 */ 198 199 static void v9fs_kill_super(struct super_block *s) 200 { 201 struct v9fs_session_info *v9ses = s->s_fs_info; 202 203 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 204 205 v9fs_dentry_release(s->s_root); /* clunk root */ 206 207 kill_anon_super(s); 208 209 v9fs_session_close(v9ses); 210 kfree(v9ses); 211 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 212 } 213 214 /** 215 * v9fs_show_options - Show mount options in /proc/mounts 216 * @m: seq_file to write to 217 * @mnt: mount descriptor 218 * 219 */ 220 221 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt) 222 { 223 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info; 224 225 seq_printf(m, "%s", v9ses->options); 226 return 0; 227 } 228 229 static void 230 v9fs_umount_begin(struct super_block *sb) 231 { 232 struct v9fs_session_info *v9ses; 233 234 lock_kernel(); 235 v9ses = sb->s_fs_info; 236 v9fs_session_cancel(v9ses); 237 unlock_kernel(); 238 } 239 240 static const struct super_operations v9fs_super_ops = { 241 .statfs = simple_statfs, 242 .clear_inode = v9fs_clear_inode, 243 .show_options = v9fs_show_options, 244 .umount_begin = v9fs_umount_begin, 245 }; 246 247 struct file_system_type v9fs_fs_type = { 248 .name = "9p", 249 .get_sb = v9fs_get_sb, 250 .kill_sb = v9fs_kill_super, 251 .owner = THIS_MODULE, 252 }; 253