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 <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 50static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 51 52/** 53 * v9fs_set_super - set the superblock 54 * @s: super block 55 * @data: file system specific data 56 * 57 */ 58 59static int v9fs_set_super(struct super_block *s, void *data) 60{ 61 s->s_fs_info = data; 62 return set_anon_super(s, data); 63} 64 65/** 66 * v9fs_fill_super - populate superblock with info 67 * @sb: superblock 68 * @v9ses: session information 69 * @flags: flags propagated from v9fs_get_sb() 70 * 71 */ 72 73static void 74v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 75 int flags, void *data) 76{ 77 sb->s_maxbytes = MAX_LFS_FILESIZE; 78 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 79 sb->s_blocksize = 1 << sb->s_blocksize_bits; 80 sb->s_magic = V9FS_MAGIC; 81 if (v9fs_proto_dotl(v9ses)) { 82 sb->s_op = &v9fs_super_ops_dotl; 83 sb->s_xattr = v9fs_xattr_handlers; 84 } else 85 sb->s_op = &v9fs_super_ops; 86 sb->s_bdi = &v9ses->bdi; 87 88 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 89 MS_NOATIME; 90 91 save_mount_options(sb, data); 92} 93 94/** 95 * v9fs_get_sb - mount a superblock 96 * @fs_type: file system type 97 * @flags: mount flags 98 * @dev_name: device name that was mounted 99 * @data: mount options 100 * @mnt: mountpoint record to be instantiated 101 * 102 */ 103 104static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 105 const char *dev_name, void *data, 106 struct vfsmount *mnt) 107{ 108 struct super_block *sb = NULL; 109 struct inode *inode = NULL; 110 struct dentry *root = NULL; 111 struct v9fs_session_info *v9ses = NULL; 112 int mode = S_IRWXUGO | S_ISVTX; 113 struct p9_fid *fid; 114 int retval = 0; 115 116 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 117 118 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 119 if (!v9ses) 120 return -ENOMEM; 121 122 fid = v9fs_session_init(v9ses, dev_name, data); 123 if (IS_ERR(fid)) { 124 retval = PTR_ERR(fid); 125 /* 126 * we need to call session_close to tear down some 127 * of the data structure setup by session_init 128 */ 129 goto close_session; 130 } 131 132 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 133 if (IS_ERR(sb)) { 134 retval = PTR_ERR(sb); 135 goto clunk_fid; 136 } 137 v9fs_fill_super(sb, v9ses, flags, data); 138 139 inode = v9fs_get_inode(sb, S_IFDIR | mode); 140 if (IS_ERR(inode)) { 141 retval = PTR_ERR(inode); 142 goto release_sb; 143 } 144 145 root = d_alloc_root(inode); 146 if (!root) { 147 iput(inode); 148 retval = -ENOMEM; 149 goto release_sb; 150 } 151 sb->s_root = root; 152 153 if (v9fs_proto_dotl(v9ses)) { 154 struct p9_stat_dotl *st = NULL; 155 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); 156 if (IS_ERR(st)) { 157 retval = PTR_ERR(st); 158 goto release_sb; 159 } 160 161 v9fs_stat2inode_dotl(st, root->d_inode); 162 kfree(st); 163 } else { 164 struct p9_wstat *st = NULL; 165 st = p9_client_stat(fid); 166 if (IS_ERR(st)) { 167 retval = PTR_ERR(st); 168 goto release_sb; 169 } 170 171 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 172 v9fs_stat2inode(st, root->d_inode, sb); 173 174 p9stat_free(st); 175 kfree(st); 176 } 177 178 v9fs_fid_add(root, fid); 179 180 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 181 simple_set_mnt(mnt, sb); 182 return 0; 183 184clunk_fid: 185 p9_client_clunk(fid); 186close_session: 187 v9fs_session_close(v9ses); 188 kfree(v9ses); 189 return retval; 190release_sb: 191 /* 192 * we will do the session_close and root dentry release 193 * in the below call. But we need to clunk fid, because we haven't 194 * attached the fid to dentry so it won't get clunked 195 * automatically. 196 */ 197 p9_client_clunk(fid); 198 deactivate_locked_super(sb); 199 return retval; 200} 201 202/** 203 * v9fs_kill_super - Kill Superblock 204 * @s: superblock 205 * 206 */ 207 208static void v9fs_kill_super(struct super_block *s) 209{ 210 struct v9fs_session_info *v9ses = s->s_fs_info; 211 212 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 213 214 if (s->s_root) 215 v9fs_dentry_release(s->s_root); /* clunk root */ 216 217 kill_anon_super(s); 218 219 v9fs_session_cancel(v9ses); 220 v9fs_session_close(v9ses); 221 kfree(v9ses); 222 s->s_fs_info = NULL; 223 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 224} 225 226static void 227v9fs_umount_begin(struct super_block *sb) 228{ 229 struct v9fs_session_info *v9ses; 230 231 v9ses = sb->s_fs_info; 232 v9fs_session_begin_cancel(v9ses); 233} 234 235static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 236{ 237 struct v9fs_session_info *v9ses; 238 struct p9_fid *fid; 239 struct p9_rstatfs rs; 240 int res; 241 242 fid = v9fs_fid_lookup(dentry); 243 if (IS_ERR(fid)) { 244 res = PTR_ERR(fid); 245 goto done; 246 } 247 248 v9ses = v9fs_inode2v9ses(dentry->d_inode); 249 if (v9fs_proto_dotl(v9ses)) { 250 res = p9_client_statfs(fid, &rs); 251 if (res == 0) { 252 buf->f_type = rs.type; 253 buf->f_bsize = rs.bsize; 254 buf->f_blocks = rs.blocks; 255 buf->f_bfree = rs.bfree; 256 buf->f_bavail = rs.bavail; 257 buf->f_files = rs.files; 258 buf->f_ffree = rs.ffree; 259 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 260 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 261 buf->f_namelen = rs.namelen; 262 } 263 if (res != -ENOSYS) 264 goto done; 265 } 266 res = simple_statfs(dentry, buf); 267done: 268 return res; 269} 270 271static const struct super_operations v9fs_super_ops = { 272#ifdef CONFIG_9P_FSCACHE 273 .alloc_inode = v9fs_alloc_inode, 274 .destroy_inode = v9fs_destroy_inode, 275#endif 276 .statfs = simple_statfs, 277 .evict_inode = v9fs_evict_inode, 278 .show_options = generic_show_options, 279 .umount_begin = v9fs_umount_begin, 280}; 281 282static const struct super_operations v9fs_super_ops_dotl = { 283#ifdef CONFIG_9P_FSCACHE 284 .alloc_inode = v9fs_alloc_inode, 285 .destroy_inode = v9fs_destroy_inode, 286#endif 287 .statfs = v9fs_statfs, 288 .evict_inode = v9fs_evict_inode, 289 .show_options = generic_show_options, 290 .umount_begin = v9fs_umount_begin, 291}; 292 293struct file_system_type v9fs_fs_type = { 294 .name = "9p", 295 .get_sb = v9fs_get_sb, 296 .kill_sb = v9fs_kill_super, 297 .owner = THIS_MODULE, 298 .fs_flags = FS_RENAME_DOES_D_MOVE, 299}; 300