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 <net/9p/9p.h> 41 #include <net/9p/client.h> 42 43 #include "v9fs.h" 44 #include "v9fs_vfs.h" 45 #include "fid.h" 46 47 static void v9fs_clear_inode(struct inode *); 48 static const struct super_operations v9fs_super_ops; 49 50 /** 51 * v9fs_clear_inode - release an inode 52 * @inode: inode to release 53 * 54 */ 55 56 static void v9fs_clear_inode(struct inode *inode) 57 { 58 filemap_fdatawrite(inode->i_mapping); 59 } 60 61 /** 62 * v9fs_set_super - set the superblock 63 * @s: super block 64 * @data: file system specific data 65 * 66 */ 67 68 static int v9fs_set_super(struct super_block *s, void *data) 69 { 70 s->s_fs_info = data; 71 return set_anon_super(s, data); 72 } 73 74 /** 75 * v9fs_fill_super - populate superblock with info 76 * @sb: superblock 77 * @v9ses: session information 78 * @flags: flags propagated from v9fs_get_sb() 79 * 80 */ 81 82 static void 83 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 84 int flags, void *data) 85 { 86 sb->s_maxbytes = MAX_LFS_FILESIZE; 87 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 88 sb->s_blocksize = 1 << sb->s_blocksize_bits; 89 sb->s_magic = V9FS_MAGIC; 90 sb->s_op = &v9fs_super_ops; 91 92 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 93 MS_NOATIME; 94 95 save_mount_options(sb, data); 96 } 97 98 /** 99 * v9fs_get_sb - mount a superblock 100 * @fs_type: file system type 101 * @flags: mount flags 102 * @dev_name: device name that was mounted 103 * @data: mount options 104 * @mnt: mountpoint record to be instantiated 105 * 106 */ 107 108 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 109 const char *dev_name, void *data, 110 struct vfsmount *mnt) 111 { 112 struct super_block *sb = NULL; 113 struct inode *inode = NULL; 114 struct dentry *root = NULL; 115 struct v9fs_session_info *v9ses = NULL; 116 struct p9_wstat *st = NULL; 117 int mode = S_IRWXUGO | S_ISVTX; 118 struct p9_fid *fid; 119 int retval = 0; 120 121 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 122 123 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 124 if (!v9ses) 125 return -ENOMEM; 126 127 fid = v9fs_session_init(v9ses, dev_name, data); 128 if (IS_ERR(fid)) { 129 retval = PTR_ERR(fid); 130 goto close_session; 131 } 132 133 st = p9_client_stat(fid); 134 if (IS_ERR(st)) { 135 retval = PTR_ERR(st); 136 goto clunk_fid; 137 } 138 139 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 140 if (IS_ERR(sb)) { 141 retval = PTR_ERR(sb); 142 goto free_stat; 143 } 144 v9fs_fill_super(sb, v9ses, flags, data); 145 146 inode = v9fs_get_inode(sb, S_IFDIR | mode); 147 if (IS_ERR(inode)) { 148 retval = PTR_ERR(inode); 149 goto release_sb; 150 } 151 152 root = d_alloc_root(inode); 153 if (!root) { 154 iput(inode); 155 retval = -ENOMEM; 156 goto release_sb; 157 } 158 159 sb->s_root = root; 160 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 161 162 v9fs_stat2inode(st, root->d_inode, sb); 163 164 v9fs_fid_add(root, fid); 165 p9stat_free(st); 166 kfree(st); 167 168 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 169 simple_set_mnt(mnt, sb); 170 return 0; 171 172 free_stat: 173 p9stat_free(st); 174 kfree(st); 175 176 clunk_fid: 177 p9_client_clunk(fid); 178 179 close_session: 180 v9fs_session_close(v9ses); 181 kfree(v9ses); 182 return retval; 183 184 release_sb: 185 p9stat_free(st); 186 kfree(st); 187 deactivate_locked_super(sb); 188 return retval; 189 } 190 191 /** 192 * v9fs_kill_super - Kill Superblock 193 * @s: superblock 194 * 195 */ 196 197 static void v9fs_kill_super(struct super_block *s) 198 { 199 struct v9fs_session_info *v9ses = s->s_fs_info; 200 201 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 202 203 v9fs_dentry_release(s->s_root); /* clunk root */ 204 205 kill_anon_super(s); 206 207 v9fs_session_close(v9ses); 208 kfree(v9ses); 209 s->s_fs_info = NULL; 210 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 211 } 212 213 static void 214 v9fs_umount_begin(struct super_block *sb) 215 { 216 struct v9fs_session_info *v9ses; 217 218 v9ses = sb->s_fs_info; 219 v9fs_session_cancel(v9ses); 220 } 221 222 static const struct super_operations v9fs_super_ops = { 223 .statfs = simple_statfs, 224 .clear_inode = v9fs_clear_inode, 225 .show_options = generic_show_options, 226 .umount_begin = v9fs_umount_begin, 227 }; 228 229 struct file_system_type v9fs_fs_type = { 230 .name = "9p", 231 .get_sb = v9fs_get_sb, 232 .kill_sb = v9fs_kill_super, 233 .owner = THIS_MODULE, 234 }; 235