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/mount.h> 37 #include <linux/idr.h> 38 #include <linux/sched.h> 39 #include <linux/slab.h> 40 #include <linux/statfs.h> 41 #include <linux/magic.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 #include "acl.h" 50 51 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 52 53 /** 54 * v9fs_set_super - set the superblock 55 * @s: super block 56 * @data: file system specific data 57 * 58 */ 59 60 static int v9fs_set_super(struct super_block *s, void *data) 61 { 62 s->s_fs_info = data; 63 return set_anon_super(s, data); 64 } 65 66 /** 67 * v9fs_fill_super - populate superblock with info 68 * @sb: superblock 69 * @v9ses: session information 70 * @flags: flags propagated from v9fs_mount() 71 * 72 */ 73 74 static int 75 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 76 int flags, void *data) 77 { 78 int ret; 79 80 sb->s_maxbytes = MAX_LFS_FILESIZE; 81 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 82 sb->s_blocksize = 1 << sb->s_blocksize_bits; 83 sb->s_magic = V9FS_MAGIC; 84 if (v9fs_proto_dotl(v9ses)) { 85 sb->s_op = &v9fs_super_ops_dotl; 86 sb->s_xattr = v9fs_xattr_handlers; 87 } else 88 sb->s_op = &v9fs_super_ops; 89 90 ret = super_setup_bdi(sb); 91 if (ret) 92 return ret; 93 94 if (v9ses->cache) 95 sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE; 96 97 sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME; 98 if (!v9ses->cache) 99 sb->s_flags |= SB_SYNCHRONOUS; 100 101 #ifdef CONFIG_9P_FS_POSIX_ACL 102 if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) 103 sb->s_flags |= SB_POSIXACL; 104 #endif 105 106 return 0; 107 } 108 109 /** 110 * v9fs_mount - mount a superblock 111 * @fs_type: file system type 112 * @flags: mount flags 113 * @dev_name: device name that was mounted 114 * @data: mount options 115 * 116 */ 117 118 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 119 const char *dev_name, void *data) 120 { 121 struct super_block *sb = NULL; 122 struct inode *inode = NULL; 123 struct dentry *root = NULL; 124 struct v9fs_session_info *v9ses = NULL; 125 umode_t mode = S_IRWXUGO | S_ISVTX; 126 struct p9_fid *fid; 127 int retval = 0; 128 129 p9_debug(P9_DEBUG_VFS, "\n"); 130 131 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 132 if (!v9ses) 133 return ERR_PTR(-ENOMEM); 134 135 fid = v9fs_session_init(v9ses, dev_name, data); 136 if (IS_ERR(fid)) { 137 retval = PTR_ERR(fid); 138 goto free_session; 139 } 140 141 sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); 142 if (IS_ERR(sb)) { 143 retval = PTR_ERR(sb); 144 goto clunk_fid; 145 } 146 retval = v9fs_fill_super(sb, v9ses, flags, data); 147 if (retval) 148 goto release_sb; 149 150 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 151 sb->s_d_op = &v9fs_cached_dentry_operations; 152 else 153 sb->s_d_op = &v9fs_dentry_operations; 154 155 inode = v9fs_get_inode(sb, S_IFDIR | mode, 0); 156 if (IS_ERR(inode)) { 157 retval = PTR_ERR(inode); 158 goto release_sb; 159 } 160 161 root = d_make_root(inode); 162 if (!root) { 163 retval = -ENOMEM; 164 goto release_sb; 165 } 166 sb->s_root = root; 167 if (v9fs_proto_dotl(v9ses)) { 168 struct p9_stat_dotl *st = NULL; 169 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 170 if (IS_ERR(st)) { 171 retval = PTR_ERR(st); 172 goto release_sb; 173 } 174 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 175 v9fs_stat2inode_dotl(st, d_inode(root)); 176 kfree(st); 177 } else { 178 struct p9_wstat *st = NULL; 179 st = p9_client_stat(fid); 180 if (IS_ERR(st)) { 181 retval = PTR_ERR(st); 182 goto release_sb; 183 } 184 185 d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); 186 v9fs_stat2inode(st, d_inode(root), sb); 187 188 p9stat_free(st); 189 kfree(st); 190 } 191 retval = v9fs_get_acl(inode, fid); 192 if (retval) 193 goto release_sb; 194 v9fs_fid_add(root, fid); 195 196 p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); 197 return dget(sb->s_root); 198 199 clunk_fid: 200 p9_client_clunk(fid); 201 v9fs_session_close(v9ses); 202 free_session: 203 kfree(v9ses); 204 return ERR_PTR(retval); 205 206 release_sb: 207 /* 208 * we will do the session_close and root dentry release 209 * in the below call. But we need to clunk fid, because we haven't 210 * attached the fid to dentry so it won't get clunked 211 * automatically. 212 */ 213 p9_client_clunk(fid); 214 deactivate_locked_super(sb); 215 return ERR_PTR(retval); 216 } 217 218 /** 219 * v9fs_kill_super - Kill Superblock 220 * @s: superblock 221 * 222 */ 223 224 static void v9fs_kill_super(struct super_block *s) 225 { 226 struct v9fs_session_info *v9ses = s->s_fs_info; 227 228 p9_debug(P9_DEBUG_VFS, " %p\n", s); 229 230 kill_anon_super(s); 231 232 v9fs_session_cancel(v9ses); 233 v9fs_session_close(v9ses); 234 kfree(v9ses); 235 s->s_fs_info = NULL; 236 p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); 237 } 238 239 static void 240 v9fs_umount_begin(struct super_block *sb) 241 { 242 struct v9fs_session_info *v9ses; 243 244 v9ses = sb->s_fs_info; 245 v9fs_session_begin_cancel(v9ses); 246 } 247 248 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 249 { 250 struct v9fs_session_info *v9ses; 251 struct p9_fid *fid; 252 struct p9_rstatfs rs; 253 int res; 254 255 fid = v9fs_fid_lookup(dentry); 256 if (IS_ERR(fid)) { 257 res = PTR_ERR(fid); 258 goto done; 259 } 260 261 v9ses = v9fs_dentry2v9ses(dentry); 262 if (v9fs_proto_dotl(v9ses)) { 263 res = p9_client_statfs(fid, &rs); 264 if (res == 0) { 265 buf->f_type = rs.type; 266 buf->f_bsize = rs.bsize; 267 buf->f_blocks = rs.blocks; 268 buf->f_bfree = rs.bfree; 269 buf->f_bavail = rs.bavail; 270 buf->f_files = rs.files; 271 buf->f_ffree = rs.ffree; 272 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 273 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 274 buf->f_namelen = rs.namelen; 275 } 276 if (res != -ENOSYS) 277 goto done; 278 } 279 res = simple_statfs(dentry, buf); 280 done: 281 return res; 282 } 283 284 static int v9fs_drop_inode(struct inode *inode) 285 { 286 struct v9fs_session_info *v9ses; 287 v9ses = v9fs_inode2v9ses(inode); 288 if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) 289 return generic_drop_inode(inode); 290 /* 291 * in case of non cached mode always drop the 292 * the inode because we want the inode attribute 293 * to always match that on the server. 294 */ 295 return 1; 296 } 297 298 static int v9fs_write_inode(struct inode *inode, 299 struct writeback_control *wbc) 300 { 301 int ret; 302 struct p9_wstat wstat; 303 struct v9fs_inode *v9inode; 304 /* 305 * send an fsync request to server irrespective of 306 * wbc->sync_mode. 307 */ 308 p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 309 v9inode = V9FS_I(inode); 310 if (!v9inode->writeback_fid) 311 return 0; 312 v9fs_blank_wstat(&wstat); 313 314 ret = p9_client_wstat(v9inode->writeback_fid, &wstat); 315 if (ret < 0) { 316 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 317 return ret; 318 } 319 return 0; 320 } 321 322 static int v9fs_write_inode_dotl(struct inode *inode, 323 struct writeback_control *wbc) 324 { 325 int ret; 326 struct v9fs_inode *v9inode; 327 /* 328 * send an fsync request to server irrespective of 329 * wbc->sync_mode. 330 */ 331 v9inode = V9FS_I(inode); 332 p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n", 333 __func__, inode, v9inode->writeback_fid); 334 if (!v9inode->writeback_fid) 335 return 0; 336 337 ret = p9_client_fsync(v9inode->writeback_fid, 0); 338 if (ret < 0) { 339 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 340 return ret; 341 } 342 return 0; 343 } 344 345 static const struct super_operations v9fs_super_ops = { 346 .alloc_inode = v9fs_alloc_inode, 347 .destroy_inode = v9fs_destroy_inode, 348 .statfs = simple_statfs, 349 .evict_inode = v9fs_evict_inode, 350 .show_options = v9fs_show_options, 351 .umount_begin = v9fs_umount_begin, 352 .write_inode = v9fs_write_inode, 353 }; 354 355 static const struct super_operations v9fs_super_ops_dotl = { 356 .alloc_inode = v9fs_alloc_inode, 357 .destroy_inode = v9fs_destroy_inode, 358 .statfs = v9fs_statfs, 359 .drop_inode = v9fs_drop_inode, 360 .evict_inode = v9fs_evict_inode, 361 .show_options = v9fs_show_options, 362 .umount_begin = v9fs_umount_begin, 363 .write_inode = v9fs_write_inode_dotl, 364 }; 365 366 struct file_system_type v9fs_fs_type = { 367 .name = "9p", 368 .mount = v9fs_mount, 369 .kill_sb = v9fs_kill_super, 370 .owner = THIS_MODULE, 371 .fs_flags = FS_RENAME_DOES_D_MOVE, 372 }; 373 MODULE_ALIAS_FS("9p"); 374