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 = 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 int mode = S_IRWXUGO | S_ISVTX; 121 struct p9_fid *fid; 122 int retval = 0; 123 124 P9_DPRINTK(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, 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); 153 if (IS_ERR(inode)) { 154 retval = PTR_ERR(inode); 155 goto release_sb; 156 } 157 158 root = d_alloc_root(inode); 159 if (!root) { 160 iput(inode); 161 retval = -ENOMEM; 162 goto release_sb; 163 } 164 sb->s_root = root; 165 if (v9fs_proto_dotl(v9ses)) { 166 struct p9_stat_dotl *st = NULL; 167 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 168 if (IS_ERR(st)) { 169 retval = PTR_ERR(st); 170 goto release_sb; 171 } 172 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 173 v9fs_stat2inode_dotl(st, root->d_inode); 174 kfree(st); 175 } else { 176 struct p9_wstat *st = NULL; 177 st = p9_client_stat(fid); 178 if (IS_ERR(st)) { 179 retval = PTR_ERR(st); 180 goto release_sb; 181 } 182 183 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 184 v9fs_stat2inode(st, root->d_inode, sb); 185 186 p9stat_free(st); 187 kfree(st); 188 } 189 retval = v9fs_get_acl(inode, fid); 190 if (retval) 191 goto release_sb; 192 v9fs_fid_add(root, fid); 193 194 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 195 return dget(sb->s_root); 196 197 clunk_fid: 198 p9_client_clunk(fid); 199 close_session: 200 v9fs_session_close(v9ses); 201 kfree(v9ses); 202 return ERR_PTR(retval); 203 204 release_sb: 205 /* 206 * we will do the session_close and root dentry release 207 * in the below call. But we need to clunk fid, because we haven't 208 * attached the fid to dentry so it won't get clunked 209 * automatically. 210 */ 211 p9_client_clunk(fid); 212 deactivate_locked_super(sb); 213 return ERR_PTR(retval); 214 } 215 216 /** 217 * v9fs_kill_super - Kill Superblock 218 * @s: superblock 219 * 220 */ 221 222 static void v9fs_kill_super(struct super_block *s) 223 { 224 struct v9fs_session_info *v9ses = s->s_fs_info; 225 226 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 227 228 kill_anon_super(s); 229 230 v9fs_session_cancel(v9ses); 231 v9fs_session_close(v9ses); 232 kfree(v9ses); 233 s->s_fs_info = NULL; 234 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 235 } 236 237 static void 238 v9fs_umount_begin(struct super_block *sb) 239 { 240 struct v9fs_session_info *v9ses; 241 242 v9ses = sb->s_fs_info; 243 v9fs_session_begin_cancel(v9ses); 244 } 245 246 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 247 { 248 struct v9fs_session_info *v9ses; 249 struct p9_fid *fid; 250 struct p9_rstatfs rs; 251 int res; 252 253 fid = v9fs_fid_lookup(dentry); 254 if (IS_ERR(fid)) { 255 res = PTR_ERR(fid); 256 goto done; 257 } 258 259 v9ses = v9fs_dentry2v9ses(dentry); 260 if (v9fs_proto_dotl(v9ses)) { 261 res = p9_client_statfs(fid, &rs); 262 if (res == 0) { 263 buf->f_type = V9FS_MAGIC; 264 buf->f_bsize = rs.bsize; 265 buf->f_blocks = rs.blocks; 266 buf->f_bfree = rs.bfree; 267 buf->f_bavail = rs.bavail; 268 buf->f_files = rs.files; 269 buf->f_ffree = rs.ffree; 270 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 271 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 272 buf->f_namelen = rs.namelen; 273 } 274 if (res != -ENOSYS) 275 goto done; 276 } 277 res = simple_statfs(dentry, buf); 278 done: 279 return res; 280 } 281 282 static int v9fs_drop_inode(struct inode *inode) 283 { 284 struct v9fs_session_info *v9ses; 285 v9ses = v9fs_inode2v9ses(inode); 286 if (v9ses->cache) 287 return generic_drop_inode(inode); 288 /* 289 * in case of non cached mode always drop the 290 * the inode because we want the inode attribute 291 * to always match that on the server. 292 */ 293 return 1; 294 } 295 296 static int v9fs_write_inode(struct inode *inode, 297 struct writeback_control *wbc) 298 { 299 int ret; 300 struct p9_wstat wstat; 301 struct v9fs_inode *v9inode; 302 /* 303 * send an fsync request to server irrespective of 304 * wbc->sync_mode. 305 */ 306 P9_DPRINTK(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 307 v9inode = V9FS_I(inode); 308 if (!v9inode->writeback_fid) 309 return 0; 310 v9fs_blank_wstat(&wstat); 311 312 ret = p9_client_wstat(v9inode->writeback_fid, &wstat); 313 if (ret < 0) { 314 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 315 return ret; 316 } 317 return 0; 318 } 319 320 static int v9fs_write_inode_dotl(struct inode *inode, 321 struct writeback_control *wbc) 322 { 323 int ret; 324 struct v9fs_inode *v9inode; 325 /* 326 * send an fsync request to server irrespective of 327 * wbc->sync_mode. 328 */ 329 P9_DPRINTK(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); 330 v9inode = V9FS_I(inode); 331 if (!v9inode->writeback_fid) 332 return 0; 333 ret = p9_client_fsync(v9inode->writeback_fid, 0); 334 if (ret < 0) { 335 __mark_inode_dirty(inode, I_DIRTY_DATASYNC); 336 return ret; 337 } 338 return 0; 339 } 340 341 static const struct super_operations v9fs_super_ops = { 342 .alloc_inode = v9fs_alloc_inode, 343 .destroy_inode = v9fs_destroy_inode, 344 .statfs = simple_statfs, 345 .evict_inode = v9fs_evict_inode, 346 .show_options = generic_show_options, 347 .umount_begin = v9fs_umount_begin, 348 .write_inode = v9fs_write_inode, 349 }; 350 351 static const struct super_operations v9fs_super_ops_dotl = { 352 .alloc_inode = v9fs_alloc_inode, 353 .destroy_inode = v9fs_destroy_inode, 354 .statfs = v9fs_statfs, 355 .drop_inode = v9fs_drop_inode, 356 .evict_inode = v9fs_evict_inode, 357 .show_options = generic_show_options, 358 .umount_begin = v9fs_umount_begin, 359 .write_inode = v9fs_write_inode_dotl, 360 }; 361 362 struct file_system_type v9fs_fs_type = { 363 .name = "9p", 364 .mount = v9fs_mount, 365 .kill_sb = v9fs_kill_super, 366 .owner = THIS_MODULE, 367 .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT, 368 }; 369