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 49 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; 50 51 /** 52 * v9fs_set_super - set the superblock 53 * @s: super block 54 * @data: file system specific data 55 * 56 */ 57 58 static int v9fs_set_super(struct super_block *s, void *data) 59 { 60 s->s_fs_info = data; 61 return set_anon_super(s, data); 62 } 63 64 /** 65 * v9fs_fill_super - populate superblock with info 66 * @sb: superblock 67 * @v9ses: session information 68 * @flags: flags propagated from v9fs_get_sb() 69 * 70 */ 71 72 static void 73 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 74 int flags, void *data) 75 { 76 sb->s_maxbytes = MAX_LFS_FILESIZE; 77 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 78 sb->s_blocksize = 1 << sb->s_blocksize_bits; 79 sb->s_magic = V9FS_MAGIC; 80 if (v9fs_proto_dotl(v9ses)) 81 sb->s_op = &v9fs_super_ops_dotl; 82 else 83 sb->s_op = &v9fs_super_ops; 84 sb->s_bdi = &v9ses->bdi; 85 86 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 87 MS_NOATIME; 88 89 save_mount_options(sb, data); 90 } 91 92 /** 93 * v9fs_get_sb - mount a superblock 94 * @fs_type: file system type 95 * @flags: mount flags 96 * @dev_name: device name that was mounted 97 * @data: mount options 98 * @mnt: mountpoint record to be instantiated 99 * 100 */ 101 102 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 103 const char *dev_name, void *data, 104 struct vfsmount *mnt) 105 { 106 struct super_block *sb = NULL; 107 struct inode *inode = NULL; 108 struct dentry *root = NULL; 109 struct v9fs_session_info *v9ses = NULL; 110 struct p9_wstat *st = NULL; 111 int mode = S_IRWXUGO | S_ISVTX; 112 struct p9_fid *fid; 113 int retval = 0; 114 115 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 116 117 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 118 if (!v9ses) 119 return -ENOMEM; 120 121 fid = v9fs_session_init(v9ses, dev_name, data); 122 if (IS_ERR(fid)) { 123 retval = PTR_ERR(fid); 124 goto close_session; 125 } 126 127 st = p9_client_stat(fid); 128 if (IS_ERR(st)) { 129 retval = PTR_ERR(st); 130 goto clunk_fid; 131 } 132 133 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 134 if (IS_ERR(sb)) { 135 retval = PTR_ERR(sb); 136 goto free_stat; 137 } 138 v9fs_fill_super(sb, v9ses, flags, data); 139 140 inode = v9fs_get_inode(sb, S_IFDIR | mode); 141 if (IS_ERR(inode)) { 142 retval = PTR_ERR(inode); 143 goto release_sb; 144 } 145 146 root = d_alloc_root(inode); 147 if (!root) { 148 iput(inode); 149 retval = -ENOMEM; 150 goto release_sb; 151 } 152 153 sb->s_root = root; 154 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 155 156 v9fs_stat2inode(st, root->d_inode, sb); 157 158 v9fs_fid_add(root, fid); 159 p9stat_free(st); 160 kfree(st); 161 162 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 163 simple_set_mnt(mnt, sb); 164 return 0; 165 166 free_stat: 167 p9stat_free(st); 168 kfree(st); 169 170 clunk_fid: 171 p9_client_clunk(fid); 172 173 close_session: 174 v9fs_session_close(v9ses); 175 kfree(v9ses); 176 return retval; 177 178 release_sb: 179 p9stat_free(st); 180 kfree(st); 181 deactivate_locked_super(sb); 182 return retval; 183 } 184 185 /** 186 * v9fs_kill_super - Kill Superblock 187 * @s: superblock 188 * 189 */ 190 191 static void v9fs_kill_super(struct super_block *s) 192 { 193 struct v9fs_session_info *v9ses = s->s_fs_info; 194 195 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 196 197 if (s->s_root) 198 v9fs_dentry_release(s->s_root); /* clunk root */ 199 200 kill_anon_super(s); 201 202 v9fs_session_cancel(v9ses); 203 v9fs_session_close(v9ses); 204 kfree(v9ses); 205 s->s_fs_info = NULL; 206 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 207 } 208 209 static void 210 v9fs_umount_begin(struct super_block *sb) 211 { 212 struct v9fs_session_info *v9ses; 213 214 v9ses = sb->s_fs_info; 215 v9fs_session_begin_cancel(v9ses); 216 } 217 218 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) 219 { 220 struct v9fs_session_info *v9ses; 221 struct p9_fid *fid; 222 struct p9_rstatfs rs; 223 int res; 224 225 fid = v9fs_fid_lookup(dentry); 226 if (IS_ERR(fid)) { 227 res = PTR_ERR(fid); 228 goto done; 229 } 230 231 v9ses = v9fs_inode2v9ses(dentry->d_inode); 232 if (v9fs_proto_dotl(v9ses)) { 233 res = p9_client_statfs(fid, &rs); 234 if (res == 0) { 235 buf->f_type = rs.type; 236 buf->f_bsize = rs.bsize; 237 buf->f_blocks = rs.blocks; 238 buf->f_bfree = rs.bfree; 239 buf->f_bavail = rs.bavail; 240 buf->f_files = rs.files; 241 buf->f_ffree = rs.ffree; 242 buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL; 243 buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL; 244 buf->f_namelen = rs.namelen; 245 } 246 if (res != -ENOSYS) 247 goto done; 248 } 249 res = simple_statfs(dentry, buf); 250 done: 251 return res; 252 } 253 254 static const struct super_operations v9fs_super_ops = { 255 #ifdef CONFIG_9P_FSCACHE 256 .alloc_inode = v9fs_alloc_inode, 257 .destroy_inode = v9fs_destroy_inode, 258 #endif 259 .statfs = simple_statfs, 260 .clear_inode = v9fs_clear_inode, 261 .show_options = generic_show_options, 262 .umount_begin = v9fs_umount_begin, 263 }; 264 265 static const struct super_operations v9fs_super_ops_dotl = { 266 #ifdef CONFIG_9P_FSCACHE 267 .alloc_inode = v9fs_alloc_inode, 268 .destroy_inode = v9fs_destroy_inode, 269 #endif 270 .statfs = v9fs_statfs, 271 .clear_inode = v9fs_clear_inode, 272 .show_options = generic_show_options, 273 .umount_begin = v9fs_umount_begin, 274 }; 275 276 struct file_system_type v9fs_fs_type = { 277 .name = "9p", 278 .get_sb = v9fs_get_sb, 279 .kill_sb = v9fs_kill_super, 280 .owner = THIS_MODULE, 281 }; 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