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 <linux/magic.h> 43 #include <net/9p/9p.h> 44 #include <net/9p/client.h> 45 46 #include "v9fs.h" 47 #include "v9fs_vfs.h" 48 #include "fid.h" 49 #include "xattr.h" 50 #include "acl.h" 51 52 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 53 54 /** 55 * v9fs_set_super - set the superblock 56 * @s: super block 57 * @data: file system specific data 58 * 59 */ 60 61 static int v9fs_set_super(struct super_block *s, void *data) 62 { 63 s->s_fs_info = data; 64 return set_anon_super(s, data); 65 } 66 67 /** 68 * v9fs_fill_super - populate superblock with info 69 * @sb: superblock 70 * @v9ses: session information 71 * @flags: flags propagated from v9fs_mount() 72 * 73 */ 74 75 static void 76 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 77 int flags, void *data) 78 { 79 sb->s_maxbytes = MAX_LFS_FILESIZE; 80 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 81 sb->s_blocksize = 1 << sb->s_blocksize_bits; 82 sb->s_magic = V9FS_MAGIC; 83 if (v9fs_proto_dotl(v9ses)) { 84 sb->s_op = &v9fs_super_ops_dotl; 85 sb->s_xattr = v9fs_xattr_handlers; 86 } else 87 sb->s_op = &v9fs_super_ops; 88 sb->s_bdi = &v9ses->bdi; 89 90 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 91 MS_NOATIME; 92 93 #ifdef CONFIG_9P_FS_POSIX_ACL 94 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT) 95 sb->s_flags |= MS_POSIXACL; 96 #endif 97 98 save_mount_options(sb, data); 99 } 100 101 /** 102 * v9fs_mount - mount a superblock 103 * @fs_type: file system type 104 * @flags: mount flags 105 * @dev_name: device name that was mounted 106 * @data: mount options 107 * 108 */ 109 110 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 111 const char *dev_name, void *data) 112 { 113 struct super_block *sb = NULL; 114 struct inode *inode = NULL; 115 struct dentry *root = NULL; 116 struct v9fs_session_info *v9ses = NULL; 117 int mode = S_IRWXUGO | S_ISVTX; 118 struct p9_fid *fid; 119 int retval = 0; 120 121 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 122 123 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 124 if (!v9ses) 125 return ERR_PTR(-ENOMEM); 126 127 fid = v9fs_session_init(v9ses, dev_name, data); 128 if (IS_ERR(fid)) { 129 retval = PTR_ERR(fid); 130 /* 131 * we need to call session_close to tear down some 132 * of the data structure setup by session_init 133 */ 134 goto close_session; 135 } 136 137 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 138 if (IS_ERR(sb)) { 139 retval = PTR_ERR(sb); 140 goto clunk_fid; 141 } 142 v9fs_fill_super(sb, v9ses, flags, data); 143 144 if (v9ses->cache) 145 sb->s_d_op = &v9fs_cached_dentry_operations; 146 else 147 sb->s_d_op = &v9fs_dentry_operations; 148 149 inode = v9fs_get_inode(sb, S_IFDIR | mode); 150 if (IS_ERR(inode)) { 151 retval = PTR_ERR(inode); 152 goto release_sb; 153 } 154 155 root = d_alloc_root(inode); 156 if (!root) { 157 iput(inode); 158 retval = -ENOMEM; 159 goto release_sb; 160 } 161 sb->s_root = root; 162 if (v9fs_proto_dotl(v9ses)) { 163 struct p9_stat_dotl *st = NULL; 164 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 165 if (IS_ERR(st)) { 166 retval = PTR_ERR(st); 167 goto release_sb; 168 } 169 170 v9fs_stat2inode_dotl(st, root->d_inode); 171 kfree(st); 172 } else { 173 struct p9_wstat *st = NULL; 174 st = p9_client_stat(fid); 175 if (IS_ERR(st)) { 176 retval = PTR_ERR(st); 177 goto release_sb; 178 } 179 180 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 181 v9fs_stat2inode(st, root->d_inode, sb); 182 183 p9stat_free(st); 184 kfree(st); 185 } 186 retval = v9fs_get_acl(inode, fid); 187 if (retval) 188 goto release_sb; 189 v9fs_fid_add(root, fid); 190 191 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 192 return dget(sb->s_root); 193 194 clunk_fid: 195 p9_client_clunk(fid); 196 close_session: 197 v9fs_session_close(v9ses); 198 kfree(v9ses); 199 return ERR_PTR(retval); 200 201 release_sb: 202 /* 203 * we will do the session_close and root dentry release 204 * in the below call. But we need to clunk fid, because we haven't 205 * attached the fid to dentry so it won't get clunked 206 * automatically. 207 */ 208 p9_client_clunk(fid); 209 deactivate_locked_super(sb); 210 return ERR_PTR(retval); 211 } 212 213 /** 214 * v9fs_kill_super - Kill Superblock 215 * @s: superblock 216 * 217 */ 218 219 static void v9fs_kill_super(struct super_block *s) 220 { 221 struct v9fs_session_info *v9ses = s->s_fs_info; 222 223 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 224 225 kill_anon_super(s); 226 227 v9fs_session_cancel(v9ses); 228 v9fs_session_close(v9ses); 229 kfree(v9ses); 230 s->s_fs_info = NULL; 231 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 232 } 233 234 static void 235 v9fs_umount_begin(struct super_block *sb) 236 { 237 struct v9fs_session_info *v9ses; 238 239 v9ses = sb->s_fs_info; 240 v9fs_session_begin_cancel(v9ses); 241 } 242 243 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 244 { 245 struct v9fs_session_info *v9ses; 246 struct p9_fid *fid; 247 struct p9_rstatfs rs; 248 int res; 249 250 fid = v9fs_fid_lookup(dentry); 251 if (IS_ERR(fid)) { 252 res = PTR_ERR(fid); 253 goto done; 254 } 255 256 v9ses = v9fs_inode2v9ses(dentry->d_inode); 257 if (v9fs_proto_dotl(v9ses)) { 258 res = p9_client_statfs(fid, &rs); 259 if (res == 0) { 260 buf->f_type = V9FS_MAGIC; 261 buf->f_bsize = rs.bsize; 262 buf->f_blocks = rs.blocks; 263 buf->f_bfree = rs.bfree; 264 buf->f_bavail = rs.bavail; 265 buf->f_files = rs.files; 266 buf->f_ffree = rs.ffree; 267 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 268 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 269 buf->f_namelen = rs.namelen; 270 } 271 if (res != -ENOSYS) 272 goto done; 273 } 274 res = simple_statfs(dentry, buf); 275 done: 276 return res; 277 } 278 279 static const struct super_operations v9fs_super_ops = { 280 #ifdef CONFIG_9P_FSCACHE 281 .alloc_inode = v9fs_alloc_inode, 282 .destroy_inode = v9fs_destroy_inode, 283 #endif 284 .statfs = simple_statfs, 285 .evict_inode = v9fs_evict_inode, 286 .show_options = generic_show_options, 287 .umount_begin = v9fs_umount_begin, 288 }; 289 290 static const struct super_operations v9fs_super_ops_dotl = { 291 #ifdef CONFIG_9P_FSCACHE 292 .alloc_inode = v9fs_alloc_inode, 293 .destroy_inode = v9fs_destroy_inode, 294 #endif 295 .statfs = v9fs_statfs, 296 .evict_inode = v9fs_evict_inode, 297 .show_options = generic_show_options, 298 .umount_begin = v9fs_umount_begin, 299 }; 300 301 struct file_system_type v9fs_fs_type = { 302 .name = "9p", 303 .mount = v9fs_mount, 304 .kill_sb = v9fs_kill_super, 305 .owner = THIS_MODULE, 306 .fs_flags = FS_RENAME_DOES_D_MOVE, 307 }; 308