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 <linux/statfs.h> 42 #include <net/9p/9p.h> 43 #include <net/9p/client.h> 44 45 #include "v9fs.h" 46 #include "v9fs_vfs.h" 47 #include "fid.h" 48 #include "xattr.h" 49 50 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 51 52 /** 53 * v9fs_set_super - set the superblock 54 * @s: super block 55 * @data: file system specific data 56 * 57 */ 58 59 static int v9fs_set_super(struct super_block *s, void *data) 60 { 61 s->s_fs_info = data; 62 return set_anon_super(s, data); 63 } 64 65 /** 66 * v9fs_fill_super - populate superblock with info 67 * @sb: superblock 68 * @v9ses: session information 69 * @flags: flags propagated from v9fs_get_sb() 70 * 71 */ 72 73 static void 74 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 75 int flags, void *data) 76 { 77 sb->s_maxbytes = MAX_LFS_FILESIZE; 78 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 79 sb->s_blocksize = 1 << sb->s_blocksize_bits; 80 sb->s_magic = V9FS_MAGIC; 81 if (v9fs_proto_dotl(v9ses)) { 82 sb->s_op = &v9fs_super_ops_dotl; 83 sb->s_xattr = v9fs_xattr_handlers; 84 } else 85 sb->s_op = &v9fs_super_ops; 86 sb->s_bdi = &v9ses->bdi; 87 88 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 89 MS_NOATIME; 90 91 save_mount_options(sb, data); 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 inode *inode = NULL; 110 struct dentry *root = NULL; 111 struct v9fs_session_info *v9ses = NULL; 112 int mode = S_IRWXUGO | S_ISVTX; 113 struct p9_fid *fid; 114 int retval = 0; 115 116 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 117 118 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 119 if (!v9ses) 120 return -ENOMEM; 121 122 fid = v9fs_session_init(v9ses, dev_name, data); 123 if (IS_ERR(fid)) { 124 retval = PTR_ERR(fid); 125 goto close_session; 126 } 127 128 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 129 if (IS_ERR(sb)) { 130 retval = PTR_ERR(sb); 131 goto clunk_fid; 132 } 133 v9fs_fill_super(sb, v9ses, flags, data); 134 135 inode = v9fs_get_inode(sb, S_IFDIR | mode); 136 if (IS_ERR(inode)) { 137 retval = PTR_ERR(inode); 138 goto release_sb; 139 } 140 141 root = d_alloc_root(inode); 142 if (!root) { 143 iput(inode); 144 retval = -ENOMEM; 145 goto release_sb; 146 } 147 148 sb->s_root = root; 149 150 if (v9fs_proto_dotl(v9ses)) { 151 struct p9_stat_dotl *st = NULL; 152 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 153 if (IS_ERR(st)) { 154 retval = PTR_ERR(st); 155 goto clunk_fid; 156 } 157 158 v9fs_stat2inode_dotl(st, root->d_inode); 159 kfree(st); 160 } else { 161 struct p9_wstat *st = NULL; 162 st = p9_client_stat(fid); 163 if (IS_ERR(st)) { 164 retval = PTR_ERR(st); 165 goto clunk_fid; 166 } 167 168 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 169 v9fs_stat2inode(st, root->d_inode, sb); 170 171 p9stat_free(st); 172 kfree(st); 173 } 174 175 v9fs_fid_add(root, fid); 176 177 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 178 simple_set_mnt(mnt, sb); 179 return 0; 180 181 clunk_fid: 182 p9_client_clunk(fid); 183 184 close_session: 185 v9fs_session_close(v9ses); 186 kfree(v9ses); 187 return retval; 188 189 release_sb: 190 deactivate_locked_super(sb); 191 return retval; 192 } 193 194 /** 195 * v9fs_kill_super - Kill Superblock 196 * @s: superblock 197 * 198 */ 199 200 static void v9fs_kill_super(struct super_block *s) 201 { 202 struct v9fs_session_info *v9ses = s->s_fs_info; 203 204 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 205 206 if (s->s_root) 207 v9fs_dentry_release(s->s_root); /* clunk root */ 208 209 kill_anon_super(s); 210 211 v9fs_session_cancel(v9ses); 212 v9fs_session_close(v9ses); 213 kfree(v9ses); 214 s->s_fs_info = NULL; 215 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 216 } 217 218 static void 219 v9fs_umount_begin(struct super_block *sb) 220 { 221 struct v9fs_session_info *v9ses; 222 223 v9ses = sb->s_fs_info; 224 v9fs_session_begin_cancel(v9ses); 225 } 226 227 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 228 { 229 struct v9fs_session_info *v9ses; 230 struct p9_fid *fid; 231 struct p9_rstatfs rs; 232 int res; 233 234 fid = v9fs_fid_lookup(dentry); 235 if (IS_ERR(fid)) { 236 res = PTR_ERR(fid); 237 goto done; 238 } 239 240 v9ses = v9fs_inode2v9ses(dentry->d_inode); 241 if (v9fs_proto_dotl(v9ses)) { 242 res = p9_client_statfs(fid, &rs); 243 if (res == 0) { 244 buf->f_type = rs.type; 245 buf->f_bsize = rs.bsize; 246 buf->f_blocks = rs.blocks; 247 buf->f_bfree = rs.bfree; 248 buf->f_bavail = rs.bavail; 249 buf->f_files = rs.files; 250 buf->f_ffree = rs.ffree; 251 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 252 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 253 buf->f_namelen = rs.namelen; 254 } 255 if (res != -ENOSYS) 256 goto done; 257 } 258 res = simple_statfs(dentry, buf); 259 done: 260 return res; 261 } 262 263 static const struct super_operations v9fs_super_ops = { 264 #ifdef CONFIG_9P_FSCACHE 265 .alloc_inode = v9fs_alloc_inode, 266 .destroy_inode = v9fs_destroy_inode, 267 #endif 268 .statfs = simple_statfs, 269 .evict_inode = v9fs_evict_inode, 270 .show_options = generic_show_options, 271 .umount_begin = v9fs_umount_begin, 272 }; 273 274 static const struct super_operations v9fs_super_ops_dotl = { 275 #ifdef CONFIG_9P_FSCACHE 276 .alloc_inode = v9fs_alloc_inode, 277 .destroy_inode = v9fs_destroy_inode, 278 #endif 279 .statfs = v9fs_statfs, 280 .evict_inode = v9fs_evict_inode, 281 .show_options = generic_show_options, 282 .umount_begin = v9fs_umount_begin, 283 }; 284 285 struct file_system_type v9fs_fs_type = { 286 .name = "9p", 287 .get_sb = v9fs_get_sb, 288 .kill_sb = v9fs_kill_super, 289 .owner = THIS_MODULE, 290 .fs_flags = FS_RENAME_DOES_D_MOVE, 291 }; 292