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 <net/9p/9p.h> 41 #include <net/9p/client.h> 42 43 #include "v9fs.h" 44 #include "v9fs_vfs.h" 45 #include "fid.h" 46 47 static void v9fs_clear_inode(struct inode *); 48 static const 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 * @flags: flags propagated from v9fs_get_sb() 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 * @mnt: mountpoint record to be instantiated 103 * 104 */ 105 106 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 107 const char *dev_name, void *data, 108 struct vfsmount *mnt) 109 { 110 struct super_block *sb = NULL; 111 struct inode *inode = NULL; 112 struct dentry *root = NULL; 113 struct v9fs_session_info *v9ses = NULL; 114 struct p9_stat *st = NULL; 115 int mode = S_IRWXUGO | S_ISVTX; 116 uid_t uid = current->fsuid; 117 gid_t gid = current->fsgid; 118 struct p9_fid *fid; 119 int retval = 0; 120 121 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 122 123 st = NULL; 124 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 125 if (!v9ses) 126 return -ENOMEM; 127 128 fid = v9fs_session_init(v9ses, dev_name, data); 129 if (IS_ERR(fid)) { 130 retval = PTR_ERR(fid); 131 goto close_session; 132 } 133 134 st = p9_client_stat(fid); 135 if (IS_ERR(st)) { 136 retval = PTR_ERR(st); 137 goto clunk_fid; 138 } 139 140 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 141 if (IS_ERR(sb)) { 142 retval = PTR_ERR(sb); 143 goto free_stat; 144 } 145 v9fs_fill_super(sb, v9ses, flags); 146 147 inode = v9fs_get_inode(sb, S_IFDIR | mode); 148 if (IS_ERR(inode)) { 149 retval = PTR_ERR(inode); 150 goto release_sb; 151 } 152 153 inode->i_uid = uid; 154 inode->i_gid = gid; 155 156 root = d_alloc_root(inode); 157 if (!root) { 158 retval = -ENOMEM; 159 goto release_sb; 160 } 161 162 sb->s_root = root; 163 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 164 v9fs_stat2inode(st, root->d_inode, sb); 165 v9fs_fid_add(root, fid); 166 kfree(st); 167 168 return simple_set_mnt(mnt, sb); 169 170 release_sb: 171 if (sb) { 172 up_write(&sb->s_umount); 173 deactivate_super(sb); 174 } 175 176 free_stat: 177 kfree(st); 178 179 clunk_fid: 180 p9_client_clunk(fid); 181 182 close_session: 183 v9fs_session_close(v9ses); 184 kfree(v9ses); 185 186 return retval; 187 } 188 189 /** 190 * v9fs_kill_super - Kill Superblock 191 * @s: superblock 192 * 193 */ 194 195 static void v9fs_kill_super(struct super_block *s) 196 { 197 struct v9fs_session_info *v9ses = s->s_fs_info; 198 199 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 200 201 v9fs_dentry_release(s->s_root); /* clunk root */ 202 203 kill_anon_super(s); 204 205 v9fs_session_close(v9ses); 206 kfree(v9ses); 207 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 208 } 209 210 /** 211 * v9fs_show_options - Show mount options in /proc/mounts 212 * @m: seq_file to write to 213 * @mnt: mount descriptor 214 * 215 */ 216 217 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt) 218 { 219 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info; 220 221 seq_printf(m, "%s", v9ses->options); 222 return 0; 223 } 224 225 static void 226 v9fs_umount_begin(struct super_block *sb) 227 { 228 struct v9fs_session_info *v9ses = sb->s_fs_info; 229 230 v9fs_session_cancel(v9ses); 231 } 232 233 static const struct super_operations v9fs_super_ops = { 234 .statfs = simple_statfs, 235 .clear_inode = v9fs_clear_inode, 236 .show_options = v9fs_show_options, 237 .umount_begin = v9fs_umount_begin, 238 }; 239 240 struct file_system_type v9fs_fs_type = { 241 .name = "9p", 242 .get_sb = v9fs_get_sb, 243 .kill_sb = v9fs_kill_super, 244 .owner = THIS_MODULE, 245 }; 246