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 int 76 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 77 int flags, void *data) 78 { 79 int ret; 80 81 sb->s_maxbytes = MAX_LFS_FILESIZE; 82 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 83 sb->s_blocksize = 1 << sb->s_blocksize_bits; 84 sb->s_magic = V9FS_MAGIC; 85 if (v9fs_proto_dotl(v9ses)) { 86 sb->s_op = &v9fs_super_ops_dotl; 87 sb->s_xattr = v9fs_xattr_handlers; 88 } else 89 sb->s_op = &v9fs_super_ops; 90 91 ret = super_setup_bdi(sb); 92 if (ret) 93 return ret; 94 95 if (v9ses->cache) 96 sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE; 97 98 sb->s_flags |= MS_ACTIVE | MS_DIRSYNC | MS_NOATIME; 99 if (!v9ses->cache) 100 sb->s_flags |= MS_SYNCHRONOUS; 101 102 #ifdef CONFIG_9P_FS_POSIX_ACL 103 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) 104 sb->s_flags |= MS_POSIXACL; 105 #endif 106 107 save_mount_options(sb, data); 108 return 0; 109 } 110 111 /** 112 * v9fs_mount - mount a superblock 113 * @fs_type: file system type 114 * @flags: mount flags 115 * @dev_name: device name that was mounted 116 * @data: mount options 117 * 118 */ 119 120 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 121 const char *dev_name, void *data) 122 { 123 struct super_block *sb = NULL; 124 struct inode *inode = NULL; 125 struct dentry *root = NULL; 126 struct v9fs_session_info *v9ses = NULL; 127 umode_t mode = S_IRWXUGO | S_ISVTX; 128 struct p9_fid *fid; 129 int retval = 0; 130 131 p9_debug(P9_DEBUG_VFS, "\n"); 132 133 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 134 if (!v9ses) 135 return ERR_PTR(-ENOMEM); 136 137 fid = v9fs_session_init(v9ses, dev_name, data); 138 if (IS_ERR(fid)) { 139 retval = PTR_ERR(fid); 140 goto free_session; 141 } 142 143 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); 144 if (IS_ERR(sb)) { 145 retval = PTR_ERR(sb); 146 goto clunk_fid; 147 } 148 retval = v9fs_fill_super(sb, v9ses, flags, data); 149 if (retval) 150 goto release_sb; 151 152 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 153 sb->s_d_op = &v9fs_cached_dentry_operations; 154 else 155 sb->s_d_op = &v9fs_dentry_operations; 156 157 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0); 158 if (IS_ERR(inode)) { 159 retval = PTR_ERR(inode); 160 goto release_sb; 161 } 162 163 root = d_make_root(inode); 164 if (!root) { 165 retval = -ENOMEM; 166 goto release_sb; 167 } 168 sb->s_root = root; 169 if (v9fs_proto_dotl(v9ses)) { 170 struct p9_stat_dotl *st = NULL; 171 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 172 if (IS_ERR(st)) { 173 retval = PTR_ERR(st); 174 goto release_sb; 175 } 176 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 177 v9fs_stat2inode_dotl(st, d_inode(root)); 178 kfree(st); 179 } else { 180 struct p9_wstat *st = NULL; 181 st = p9_client_stat(fid); 182 if (IS_ERR(st)) { 183 retval = PTR_ERR(st); 184 goto release_sb; 185 } 186 187 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 188 v9fs_stat2inode(st, d_inode(root), sb); 189 190 p9stat_free(st); 191 kfree(st); 192 } 193 retval = v9fs_get_acl(inode, fid); 194 if (retval) 195 goto release_sb; 196 v9fs_fid_add(root, fid); 197 198 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 199 return dget(sb->s_root); 200 201 clunk_fid: 202 p9_client_clunk(fid); 203 v9fs_session_close(v9ses); 204 free_session: 205 kfree(v9ses); 206 return ERR_PTR(retval); 207 208 release_sb: 209 /* 210 * we will do the session_close and root dentry release 211 * in the below call. But we need to clunk fid, because we haven't 212 * attached the fid to dentry so it won't get clunked 213 * automatically. 214 */ 215 p9_client_clunk(fid); 216 deactivate_locked_super(sb); 217 return ERR_PTR(retval); 218 } 219 220 /** 221 * v9fs_kill_super - Kill Superblock 222 * @s: superblock 223 * 224 */ 225 226 static void v9fs_kill_super(struct super_block *s) 227 { 228 struct v9fs_session_info *v9ses = s->s_fs_info; 229 230 p9_debug(P9_DEBUG_VFS, " %p\n", s); 231 232 kill_anon_super(s); 233 234 v9fs_session_cancel(v9ses); 235 v9fs_session_close(v9ses); 236 kfree(v9ses); 237 s->s_fs_info = NULL; 238 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 239 } 240 241 static void 242 v9fs_umount_begin(struct super_block *sb) 243 { 244 struct v9fs_session_info *v9ses; 245 246 v9ses = sb->s_fs_info; 247 v9fs_session_begin_cancel(v9ses); 248 } 249 250 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 251 { 252 struct v9fs_session_info *v9ses; 253 struct p9_fid *fid; 254 struct p9_rstatfs rs; 255 int res; 256 257 fid = v9fs_fid_lookup(dentry); 258 if (IS_ERR(fid)) { 259 res = PTR_ERR(fid); 260 goto done; 261 } 262 263 v9ses = v9fs_dentry2v9ses(dentry); 264 if (v9fs_proto_dotl(v9ses)) { 265 res = p9_client_statfs(fid, &rs); 266 if (res == 0) { 267 buf->f_type = rs.type; 268 buf->f_bsize = rs.bsize; 269 buf->f_blocks = rs.blocks; 270 buf->f_bfree = rs.bfree; 271 buf->f_bavail = rs.bavail; 272 buf->f_files = rs.files; 273 buf->f_ffree = rs.ffree; 274 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 275 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 276 buf->f_namelen = rs.namelen; 277 } 278 if (res != -ENOSYS) 279 goto done; 280 } 281 res = simple_statfs(dentry, buf); 282 done: 283 return res; 284 } 285 286 static int v9fs_drop_inode(struct inode *inode) 287 { 288 struct v9fs_session_info *v9ses; 289 v9ses = v9fs_inode2v9ses(inode); 290 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 291 return generic_drop_inode(inode); 292 /* 293 * in case of non cached mode always drop the 294 * the inode because we want the inode attribute 295 * to always match that on the server. 296 */ 297 return 1; 298 } 299 300 static int v9fs_write_inode(struct inode *inode, 301 struct writeback_control *wbc) 302 { 303 int ret; 304 struct p9_wstat wstat; 305 struct v9fs_inode *v9inode; 306 /* 307 * send an fsync request to server irrespective of 308 * wbc->sync_mode. 309 */ 310 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 311 v9inode = V9FS_I(inode); 312 if (!v9inode->writeback_fid) 313 return 0; 314 v9fs_blank_wstat(&wstat); 315 316 ret = p9_client_wstat(v9inode->writeback_fid, &wstat); 317 if (ret < 0) { 318 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 319 return ret; 320 } 321 return 0; 322 } 323 324 static int v9fs_write_inode_dotl(struct inode *inode, 325 struct writeback_control *wbc) 326 { 327 int ret; 328 struct v9fs_inode *v9inode; 329 /* 330 * send an fsync request to server irrespective of 331 * wbc->sync_mode. 332 */ 333 v9inode = V9FS_I(inode); 334 p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n", 335 __func__, inode, v9inode->writeback_fid); 336 if (!v9inode->writeback_fid) 337 return 0; 338 339 ret = p9_client_fsync(v9inode->writeback_fid, 0); 340 if (ret < 0) { 341 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 342 return ret; 343 } 344 return 0; 345 } 346 347 static const struct super_operations v9fs_super_ops = { 348 .alloc_inode = v9fs_alloc_inode, 349 .destroy_inode = v9fs_destroy_inode, 350 .statfs = simple_statfs, 351 .evict_inode = v9fs_evict_inode, 352 .show_options = generic_show_options, 353 .umount_begin = v9fs_umount_begin, 354 .write_inode = v9fs_write_inode, 355 }; 356 357 static const struct super_operations v9fs_super_ops_dotl = { 358 .alloc_inode = v9fs_alloc_inode, 359 .destroy_inode = v9fs_destroy_inode, 360 .statfs = v9fs_statfs, 361 .drop_inode = v9fs_drop_inode, 362 .evict_inode = v9fs_evict_inode, 363 .show_options = generic_show_options, 364 .umount_begin = v9fs_umount_begin, 365 .write_inode = v9fs_write_inode_dotl, 366 }; 367 368 struct file_system_type v9fs_fs_type = { 369 .name = "9p", 370 .mount = v9fs_mount, 371 .kill_sb = v9fs_kill_super, 372 .owner = THIS_MODULE, 373 .fs_flags = FS_RENAME_DOES_D_MOVE, 374 }; 375 MODULE_ALIAS_FS("9p"); 376