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 if (v9ses->cache) 90 sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_CACHE_SIZE; 91 92 sb->s_flags |= MS_ACTIVE | MS_DIRSYNC | MS_NOATIME; 93 if (!v9ses->cache) 94 sb->s_flags |= MS_SYNCHRONOUS; 95 96 #ifdef CONFIG_9P_FS_POSIX_ACL 97 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) 98 sb->s_flags |= MS_POSIXACL; 99 #endif 100 101 save_mount_options(sb, data); 102 } 103 104 /** 105 * v9fs_mount - mount a superblock 106 * @fs_type: file system type 107 * @flags: mount flags 108 * @dev_name: device name that was mounted 109 * @data: mount options 110 * 111 */ 112 113 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 114 const char *dev_name, void *data) 115 { 116 struct super_block *sb = NULL; 117 struct inode *inode = NULL; 118 struct dentry *root = NULL; 119 struct v9fs_session_info *v9ses = NULL; 120 umode_t mode = S_IRWXUGO | S_ISVTX; 121 struct p9_fid *fid; 122 int retval = 0; 123 124 p9_debug(P9_DEBUG_VFS, "\n"); 125 126 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 127 if (!v9ses) 128 return ERR_PTR(-ENOMEM); 129 130 fid = v9fs_session_init(v9ses, dev_name, data); 131 if (IS_ERR(fid)) { 132 retval = PTR_ERR(fid); 133 /* 134 * we need to call session_close to tear down some 135 * of the data structure setup by session_init 136 */ 137 goto close_session; 138 } 139 140 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); 141 if (IS_ERR(sb)) { 142 retval = PTR_ERR(sb); 143 goto clunk_fid; 144 } 145 v9fs_fill_super(sb, v9ses, flags, data); 146 147 if (v9ses->cache) 148 sb->s_d_op = &v9fs_cached_dentry_operations; 149 else 150 sb->s_d_op = &v9fs_dentry_operations; 151 152 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0); 153 if (IS_ERR(inode)) { 154 retval = PTR_ERR(inode); 155 goto release_sb; 156 } 157 158 root = d_make_root(inode); 159 if (!root) { 160 retval = -ENOMEM; 161 goto release_sb; 162 } 163 sb->s_root = root; 164 if (v9fs_proto_dotl(v9ses)) { 165 struct p9_stat_dotl *st = NULL; 166 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 167 if (IS_ERR(st)) { 168 retval = PTR_ERR(st); 169 goto release_sb; 170 } 171 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 172 v9fs_stat2inode_dotl(st, root->d_inode); 173 kfree(st); 174 } else { 175 struct p9_wstat *st = NULL; 176 st = p9_client_stat(fid); 177 if (IS_ERR(st)) { 178 retval = PTR_ERR(st); 179 goto release_sb; 180 } 181 182 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 183 v9fs_stat2inode(st, root->d_inode, sb); 184 185 p9stat_free(st); 186 kfree(st); 187 } 188 retval = v9fs_get_acl(inode, fid); 189 if (retval) 190 goto release_sb; 191 v9fs_fid_add(root, fid); 192 193 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 194 return dget(sb->s_root); 195 196 clunk_fid: 197 p9_client_clunk(fid); 198 close_session: 199 v9fs_session_close(v9ses); 200 kfree(v9ses); 201 return ERR_PTR(retval); 202 203 release_sb: 204 /* 205 * we will do the session_close and root dentry release 206 * in the below call. But we need to clunk fid, because we haven't 207 * attached the fid to dentry so it won't get clunked 208 * automatically. 209 */ 210 p9_client_clunk(fid); 211 deactivate_locked_super(sb); 212 return ERR_PTR(retval); 213 } 214 215 /** 216 * v9fs_kill_super - Kill Superblock 217 * @s: superblock 218 * 219 */ 220 221 static void v9fs_kill_super(struct super_block *s) 222 { 223 struct v9fs_session_info *v9ses = s->s_fs_info; 224 225 p9_debug(P9_DEBUG_VFS, " %p\n", s); 226 227 kill_anon_super(s); 228 229 v9fs_session_cancel(v9ses); 230 v9fs_session_close(v9ses); 231 kfree(v9ses); 232 s->s_fs_info = NULL; 233 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 234 } 235 236 static void 237 v9fs_umount_begin(struct super_block *sb) 238 { 239 struct v9fs_session_info *v9ses; 240 241 v9ses = sb->s_fs_info; 242 v9fs_session_begin_cancel(v9ses); 243 } 244 245 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 246 { 247 struct v9fs_session_info *v9ses; 248 struct p9_fid *fid; 249 struct p9_rstatfs rs; 250 int res; 251 252 fid = v9fs_fid_lookup(dentry); 253 if (IS_ERR(fid)) { 254 res = PTR_ERR(fid); 255 goto done; 256 } 257 258 v9ses = v9fs_dentry2v9ses(dentry); 259 if (v9fs_proto_dotl(v9ses)) { 260 res = p9_client_statfs(fid, &rs); 261 if (res == 0) { 262 buf->f_type = rs.type; 263 buf->f_bsize = rs.bsize; 264 buf->f_blocks = rs.blocks; 265 buf->f_bfree = rs.bfree; 266 buf->f_bavail = rs.bavail; 267 buf->f_files = rs.files; 268 buf->f_ffree = rs.ffree; 269 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 270 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 271 buf->f_namelen = rs.namelen; 272 } 273 if (res != -ENOSYS) 274 goto done; 275 } 276 res = simple_statfs(dentry, buf); 277 done: 278 return res; 279 } 280 281 static int v9fs_drop_inode(struct inode *inode) 282 { 283 struct v9fs_session_info *v9ses; 284 v9ses = v9fs_inode2v9ses(inode); 285 if (v9ses->cache) 286 return generic_drop_inode(inode); 287 /* 288 * in case of non cached mode always drop the 289 * the inode because we want the inode attribute 290 * to always match that on the server. 291 */ 292 return 1; 293 } 294 295 static int v9fs_write_inode(struct inode *inode, 296 struct writeback_control *wbc) 297 { 298 int ret; 299 struct p9_wstat wstat; 300 struct v9fs_inode *v9inode; 301 /* 302 * send an fsync request to server irrespective of 303 * wbc->sync_mode. 304 */ 305 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 306 v9inode = V9FS_I(inode); 307 if (!v9inode->writeback_fid) 308 return 0; 309 v9fs_blank_wstat(&wstat); 310 311 ret = p9_client_wstat(v9inode->writeback_fid, &wstat); 312 if (ret < 0) { 313 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 314 return ret; 315 } 316 return 0; 317 } 318 319 static int v9fs_write_inode_dotl(struct inode *inode, 320 struct writeback_control *wbc) 321 { 322 int ret; 323 struct v9fs_inode *v9inode; 324 /* 325 * send an fsync request to server irrespective of 326 * wbc->sync_mode. 327 */ 328 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 329 v9inode = V9FS_I(inode); 330 if (!v9inode->writeback_fid) 331 return 0; 332 ret = p9_client_fsync(v9inode->writeback_fid, 0); 333 if (ret < 0) { 334 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 335 return ret; 336 } 337 return 0; 338 } 339 340 static const struct super_operations v9fs_super_ops = { 341 .alloc_inode = v9fs_alloc_inode, 342 .destroy_inode = v9fs_destroy_inode, 343 .statfs = simple_statfs, 344 .evict_inode = v9fs_evict_inode, 345 .show_options = generic_show_options, 346 .umount_begin = v9fs_umount_begin, 347 .write_inode = v9fs_write_inode, 348 }; 349 350 static const struct super_operations v9fs_super_ops_dotl = { 351 .alloc_inode = v9fs_alloc_inode, 352 .destroy_inode = v9fs_destroy_inode, 353 .statfs = v9fs_statfs, 354 .drop_inode = v9fs_drop_inode, 355 .evict_inode = v9fs_evict_inode, 356 .show_options = generic_show_options, 357 .umount_begin = v9fs_umount_begin, 358 .write_inode = v9fs_write_inode_dotl, 359 }; 360 361 struct file_system_type v9fs_fs_type = { 362 .name = "9p", 363 .mount = v9fs_mount, 364 .kill_sb = v9fs_kill_super, 365 .owner = THIS_MODULE, 366 .fs_flags = FS_RENAME_DOES_D_MOVE, 367 }; 368 MODULE_ALIAS_FS("9p"); 369