| 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 | root = d_alloc_root(inode); |
| 158 | if (!root) { |
| 159 | iput(inode); |
| 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 | v9fs_fid_add(root, fid); |
| 189 | retval = v9fs_get_acl(inode, fid); |
| 190 | if (retval) |
| 191 | goto release_sb; |
| 192 | /* |
| 193 | * Add the root fid to session info. This is used |
| 194 | * for file system sync. We want a cloned fid here |
| 195 | * so that we can do a sync_filesystem after a |
| 196 | * shrink_dcache_for_umount |
| 197 | */ |
| 198 | v9ses->root_fid = v9fs_fid_clone(root); |
| 199 | if (IS_ERR(v9ses->root_fid)) { |
| 200 | retval = PTR_ERR(v9ses->root_fid); |
| 201 | goto release_sb; |
| 202 | } |
| 203 | |
| 204 | P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); |
| 205 | return dget(sb->s_root); |
| 206 | |
| 207 | clunk_fid: |
| 208 | p9_client_clunk(fid); |
| 209 | close_session: |
| 210 | v9fs_session_close(v9ses); |
| 211 | kfree(v9ses); |
| 212 | return ERR_PTR(retval); |
| 213 | release_sb: |
| 214 | /* |
| 215 | * we will do the session_close and root dentry |
| 216 | * release in the below call. |
| 217 | */ |
| 218 | deactivate_locked_super(sb); |
| 219 | return ERR_PTR(retval); |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * v9fs_kill_super - Kill Superblock |
| 224 | * @s: superblock |
| 225 | * |
| 226 | */ |
| 227 | |
| 228 | static void v9fs_kill_super(struct super_block *s) |
| 229 | { |
| 230 | struct v9fs_session_info *v9ses = s->s_fs_info; |
| 231 | |
| 232 | P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); |
| 233 | |
| 234 | kill_anon_super(s); |
| 235 | p9_client_clunk(v9ses->root_fid); |
| 236 | v9fs_session_cancel(v9ses); |
| 237 | v9fs_session_close(v9ses); |
| 238 | kfree(v9ses); |
| 239 | s->s_fs_info = NULL; |
| 240 | P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); |
| 241 | } |
| 242 | |
| 243 | static void |
| 244 | v9fs_umount_begin(struct super_block *sb) |
| 245 | { |
| 246 | struct v9fs_session_info *v9ses; |
| 247 | |
| 248 | v9ses = sb->s_fs_info; |
| 249 | v9fs_session_begin_cancel(v9ses); |
| 250 | } |
| 251 | |
| 252 | static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 253 | { |
| 254 | struct v9fs_session_info *v9ses; |
| 255 | struct p9_fid *fid; |
| 256 | struct p9_rstatfs rs; |
| 257 | int res; |
| 258 | |
| 259 | fid = v9fs_fid_lookup(dentry); |
| 260 | if (IS_ERR(fid)) { |
| 261 | res = PTR_ERR(fid); |
| 262 | goto done; |
| 263 | } |
| 264 | |
| 265 | v9ses = v9fs_dentry2v9ses(dentry); |
| 266 | if (v9fs_proto_dotl(v9ses)) { |
| 267 | res = p9_client_statfs(fid, &rs); |
| 268 | if (res == 0) { |
| 269 | buf->f_type = V9FS_MAGIC; |
| 270 | buf->f_bsize = rs.bsize; |
| 271 | buf->f_blocks = rs.blocks; |
| 272 | buf->f_bfree = rs.bfree; |
| 273 | buf->f_bavail = rs.bavail; |
| 274 | buf->f_files = rs.files; |
| 275 | buf->f_ffree = rs.ffree; |
| 276 | buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; |
| 277 | buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; |
| 278 | buf->f_namelen = rs.namelen; |
| 279 | } |
| 280 | if (res != -ENOSYS) |
| 281 | goto done; |
| 282 | } |
| 283 | res = simple_statfs(dentry, buf); |
| 284 | done: |
| 285 | return res; |
| 286 | } |
| 287 | |
| 288 | static int v9fs_sync_fs(struct super_block *sb, int wait) |
| 289 | { |
| 290 | struct v9fs_session_info *v9ses = sb->s_fs_info; |
| 291 | |
| 292 | P9_DPRINTK(P9_DEBUG_VFS, "v9fs_sync_fs: super_block %p\n", sb); |
| 293 | return p9_client_sync_fs(v9ses->root_fid); |
| 294 | } |
| 295 | |
| 296 | static int v9fs_drop_inode(struct inode *inode) |
| 297 | { |
| 298 | struct v9fs_session_info *v9ses; |
| 299 | v9ses = v9fs_inode2v9ses(inode); |
| 300 | if (v9ses->cache) |
| 301 | return generic_drop_inode(inode); |
| 302 | /* |
| 303 | * in case of non cached mode always drop the |
| 304 | * the inode because we want the inode attribute |
| 305 | * to always match that on the server. |
| 306 | */ |
| 307 | return 1; |
| 308 | } |
| 309 | |
| 310 | static const struct super_operations v9fs_super_ops = { |
| 311 | .alloc_inode = v9fs_alloc_inode, |
| 312 | .destroy_inode = v9fs_destroy_inode, |
| 313 | .statfs = simple_statfs, |
| 314 | .evict_inode = v9fs_evict_inode, |
| 315 | .show_options = generic_show_options, |
| 316 | .umount_begin = v9fs_umount_begin, |
| 317 | }; |
| 318 | |
| 319 | static const struct super_operations v9fs_super_ops_dotl = { |
| 320 | .alloc_inode = v9fs_alloc_inode, |
| 321 | .destroy_inode = v9fs_destroy_inode, |
| 322 | .sync_fs = v9fs_sync_fs, |
| 323 | .statfs = v9fs_statfs, |
| 324 | .drop_inode = v9fs_drop_inode, |
| 325 | .evict_inode = v9fs_evict_inode, |
| 326 | .show_options = generic_show_options, |
| 327 | .umount_begin = v9fs_umount_begin, |
| 328 | }; |
| 329 | |
| 330 | struct file_system_type v9fs_fs_type = { |
| 331 | .name = "9p", |
| 332 | .mount = v9fs_mount, |
| 333 | .kill_sb = v9fs_kill_super, |
| 334 | .owner = THIS_MODULE, |
| 335 | .fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT, |
| 336 | }; |