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 const struct super_operations v9fs_super_ops; 48 49 /** 50 * v9fs_set_super - set the superblock 51 * @s: super block 52 * @data: file system specific data 53 * 54 */ 55 56 static int v9fs_set_super(struct super_block *s, void *data) 57 { 58 s->s_fs_info = data; 59 return set_anon_super(s, data); 60 } 61 62 /** 63 * v9fs_fill_super - populate superblock with info 64 * @sb: superblock 65 * @v9ses: session information 66 * @flags: flags propagated from v9fs_get_sb() 67 * 68 */ 69 70 static void 71 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 72 int flags, void *data) 73 { 74 sb->s_maxbytes = MAX_LFS_FILESIZE; 75 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 76 sb->s_blocksize = 1 << sb->s_blocksize_bits; 77 sb->s_magic = V9FS_MAGIC; 78 sb->s_op = &v9fs_super_ops; 79 80 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 81 MS_NOATIME; 82 83 save_mount_options(sb, data); 84 } 85 86 /** 87 * v9fs_get_sb - mount a superblock 88 * @fs_type: file system type 89 * @flags: mount flags 90 * @dev_name: device name that was mounted 91 * @data: mount options 92 * @mnt: mountpoint record to be instantiated 93 * 94 */ 95 96 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 97 const char *dev_name, void *data, 98 struct vfsmount *mnt) 99 { 100 struct super_block *sb = NULL; 101 struct inode *inode = NULL; 102 struct dentry *root = NULL; 103 struct v9fs_session_info *v9ses = NULL; 104 struct p9_wstat *st = NULL; 105 int mode = S_IRWXUGO | S_ISVTX; 106 struct p9_fid *fid; 107 int retval = 0; 108 109 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 110 111 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 112 if (!v9ses) 113 return -ENOMEM; 114 115 fid = v9fs_session_init(v9ses, dev_name, data); 116 if (IS_ERR(fid)) { 117 retval = PTR_ERR(fid); 118 goto close_session; 119 } 120 121 st = p9_client_stat(fid); 122 if (IS_ERR(st)) { 123 retval = PTR_ERR(st); 124 goto clunk_fid; 125 } 126 127 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 128 if (IS_ERR(sb)) { 129 retval = PTR_ERR(sb); 130 goto free_stat; 131 } 132 v9fs_fill_super(sb, v9ses, flags, data); 133 134 inode = v9fs_get_inode(sb, S_IFDIR | mode); 135 if (IS_ERR(inode)) { 136 retval = PTR_ERR(inode); 137 goto release_sb; 138 } 139 140 root = d_alloc_root(inode); 141 if (!root) { 142 iput(inode); 143 retval = -ENOMEM; 144 goto release_sb; 145 } 146 147 sb->s_root = root; 148 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 149 150 v9fs_stat2inode(st, root->d_inode, sb); 151 152 v9fs_fid_add(root, fid); 153 p9stat_free(st); 154 kfree(st); 155 156 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n"); 157 simple_set_mnt(mnt, sb); 158 return 0; 159 160 free_stat: 161 p9stat_free(st); 162 kfree(st); 163 164 clunk_fid: 165 p9_client_clunk(fid); 166 167 close_session: 168 v9fs_session_close(v9ses); 169 kfree(v9ses); 170 return retval; 171 172 release_sb: 173 p9stat_free(st); 174 kfree(st); 175 deactivate_locked_super(sb); 176 return retval; 177 } 178 179 /** 180 * v9fs_kill_super - Kill Superblock 181 * @s: superblock 182 * 183 */ 184 185 static void v9fs_kill_super(struct super_block *s) 186 { 187 struct v9fs_session_info *v9ses = s->s_fs_info; 188 189 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 190 191 v9fs_dentry_release(s->s_root); /* clunk root */ 192 193 kill_anon_super(s); 194 195 v9fs_session_close(v9ses); 196 kfree(v9ses); 197 s->s_fs_info = NULL; 198 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 199 } 200 201 static void 202 v9fs_umount_begin(struct super_block *sb) 203 { 204 struct v9fs_session_info *v9ses; 205 206 v9ses = sb->s_fs_info; 207 v9fs_session_cancel(v9ses); 208 } 209 210 static const struct super_operations v9fs_super_ops = { 211 #ifdef CONFIG_9P_FSCACHE 212 .alloc_inode = v9fs_alloc_inode, 213 .destroy_inode = v9fs_destroy_inode, 214 #endif 215 .statfs = simple_statfs, 216 .clear_inode = v9fs_clear_inode, 217 .show_options = generic_show_options, 218 .umount_begin = v9fs_umount_begin, 219 }; 220 221 struct file_system_type v9fs_fs_type = { 222 .name = "9p", 223 .get_sb = v9fs_get_sb, 224 .kill_sb = v9fs_kill_super, 225 .owner = THIS_MODULE, 226 }; 227