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/slab.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 const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 49 50 /** 51 * v9fs_set_super - set the superblock 52 * @s: super block 53 * @data: file system specific data 54 * 55 */ 56 57 static int v9fs_set_super(struct super_block *s, void *data) 58 { 59 s->s_fs_info = data; 60 return set_anon_super(s, data); 61 } 62 63 /** 64 * v9fs_fill_super - populate superblock with info 65 * @sb: superblock 66 * @v9ses: session information 67 * @flags: flags propagated from v9fs_get_sb() 68 * 69 */ 70 71 static void 72 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 73 int flags, void *data) 74 { 75 sb->s_maxbytes = MAX_LFS_FILESIZE; 76 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 77 sb->s_blocksize = 1 << sb->s_blocksize_bits; 78 sb->s_magic = V9FS_MAGIC; 79 if (v9fs_proto_dotl(v9ses)) 80 sb->s_op = &v9fs_super_ops_dotl; 81 else 82 sb->s_op = &v9fs_super_ops; 83 sb->s_bdi = &v9ses->bdi; 84 85 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 86 MS_NOATIME; 87 88 save_mount_options(sb, data); 89 } 90 91 /** 92 * v9fs_get_sb - mount a superblock 93 * @fs_type: file system type 94 * @flags: mount flags 95 * @dev_name: device name that was mounted 96 * @data: mount options 97 * @mnt: mountpoint record to be instantiated 98 * 99 */ 100 101 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 102 const char *dev_name, void *data, 103 struct vfsmount *mnt) 104 { 105 struct super_block *sb = NULL; 106 struct inode *inode = NULL; 107 struct dentry *root = NULL; 108 struct v9fs_session_info *v9ses = NULL; 109 struct p9_wstat *st = NULL; 110 int mode = S_IRWXUGO | S_ISVTX; 111 struct p9_fid *fid; 112 int retval = 0; 113 114 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 115 116 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 117 if (!v9ses) 118 return -ENOMEM; 119 120 fid = v9fs_session_init(v9ses, dev_name, data); 121 if (IS_ERR(fid)) { 122 retval = PTR_ERR(fid); 123 goto close_session; 124 } 125 126 st = p9_client_stat(fid); 127 if (IS_ERR(st)) { 128 retval = PTR_ERR(st); 129 goto clunk_fid; 130 } 131 132 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 133 if (IS_ERR(sb)) { 134 retval = PTR_ERR(sb); 135 goto free_stat; 136 } 137 v9fs_fill_super(sb, v9ses, flags, data); 138 139 inode = v9fs_get_inode(sb, S_IFDIR | mode); 140 if (IS_ERR(inode)) { 141 retval = PTR_ERR(inode); 142 goto release_sb; 143 } 144 145 root = d_alloc_root(inode); 146 if (!root) { 147 iput(inode); 148 retval = -ENOMEM; 149 goto release_sb; 150 } 151 152 sb->s_root = root; 153 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 154 155 v9fs_stat2inode(st, root->d_inode, sb); 156 157 v9fs_fid_add(root, fid); 158 p9stat_free(st); 159 kfree(st); 160 161 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 162 simple_set_mnt(mnt, sb); 163 return 0; 164 165 free_stat: 166 p9stat_free(st); 167 kfree(st); 168 169 clunk_fid: 170 p9_client_clunk(fid); 171 172 close_session: 173 v9fs_session_close(v9ses); 174 kfree(v9ses); 175 return retval; 176 177 release_sb: 178 p9stat_free(st); 179 kfree(st); 180 deactivate_locked_super(sb); 181 return retval; 182 } 183 184 /** 185 * v9fs_kill_super - Kill Superblock 186 * @s: superblock 187 * 188 */ 189 190 static void v9fs_kill_super(struct super_block *s) 191 { 192 struct v9fs_session_info *v9ses = s->s_fs_info; 193 194 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 195 196 if (s->s_root) 197 v9fs_dentry_release(s->s_root); /* clunk root */ 198 199 kill_anon_super(s); 200 201 v9fs_session_cancel(v9ses); 202 v9fs_session_close(v9ses); 203 kfree(v9ses); 204 s->s_fs_info = NULL; 205 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 206 } 207 208 static void 209 v9fs_umount_begin(struct super_block *sb) 210 { 211 struct v9fs_session_info *v9ses; 212 213 v9ses = sb->s_fs_info; 214 v9fs_session_begin_cancel(v9ses); 215 } 216 217 static const struct super_operations v9fs_super_ops = { 218 #ifdef CONFIG_9P_FSCACHE 219 .alloc_inode = v9fs_alloc_inode, 220 .destroy_inode = v9fs_destroy_inode, 221 #endif 222 .statfs = simple_statfs, 223 .clear_inode = v9fs_clear_inode, 224 .show_options = generic_show_options, 225 .umount_begin = v9fs_umount_begin, 226 }; 227 228 static const struct super_operations v9fs_super_ops_dotl = { 229 #ifdef CONFIG_9P_FSCACHE 230 .alloc_inode = v9fs_alloc_inode, 231 .destroy_inode = v9fs_destroy_inode, 232 #endif 233 .statfs = simple_statfs, 234 .clear_inode = v9fs_clear_inode, 235 .show_options = generic_show_options, 236 .umount_begin = v9fs_umount_begin, 237 }; 238 239 struct file_system_type v9fs_fs_type = { 240 .name = "9p", 241 .get_sb = v9fs_get_sb, 242 .kill_sb = v9fs_kill_super, 243 .owner = THIS_MODULE, 244 }; 245