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 * 79 */ 80 81 static void 82 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, 83 int flags) 84 { 85 sb->s_maxbytes = MAX_LFS_FILESIZE; 86 sb->s_blocksize_bits = fls(v9ses->maxdata - 1); 87 sb->s_blocksize = 1 << sb->s_blocksize_bits; 88 sb->s_magic = V9FS_MAGIC; 89 sb->s_op = &v9fs_super_ops; 90 91 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | 92 MS_NOATIME; 93 } 94 95 /** 96 * v9fs_get_sb - mount a superblock 97 * @fs_type: file system type 98 * @flags: mount flags 99 * @dev_name: device name that was mounted 100 * @data: mount options 101 * @mnt: mountpoint record to be instantiated 102 * 103 */ 104 105 static int v9fs_get_sb(struct file_system_type *fs_type, int flags, 106 const char *dev_name, void *data, 107 struct vfsmount *mnt) 108 { 109 struct super_block *sb = NULL; 110 struct inode *inode = NULL; 111 struct dentry *root = NULL; 112 struct v9fs_session_info *v9ses = NULL; 113 struct p9_stat *st = NULL; 114 int mode = S_IRWXUGO | S_ISVTX; 115 uid_t uid = current->fsuid; 116 gid_t gid = current->fsgid; 117 struct p9_fid *fid; 118 int retval = 0; 119 120 P9_DPRINTK(P9_DEBUG_VFS, " \n"); 121 122 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); 123 if (!v9ses) 124 return -ENOMEM; 125 126 fid = v9fs_session_init(v9ses, dev_name, data); 127 if (IS_ERR(fid)) { 128 retval = PTR_ERR(fid); 129 fid = NULL; 130 kfree(v9ses); 131 v9ses = NULL; 132 goto error; 133 } 134 135 st = p9_client_stat(fid); 136 if (IS_ERR(st)) { 137 retval = PTR_ERR(st); 138 goto error; 139 } 140 141 sb = sget(fs_type, NULL, v9fs_set_super, v9ses); 142 if (IS_ERR(sb)) { 143 retval = PTR_ERR(sb); 144 goto error; 145 } 146 v9fs_fill_super(sb, v9ses, flags); 147 148 inode = v9fs_get_inode(sb, S_IFDIR | mode); 149 if (IS_ERR(inode)) { 150 retval = PTR_ERR(inode); 151 goto error; 152 } 153 154 inode->i_uid = uid; 155 inode->i_gid = gid; 156 157 root = d_alloc_root(inode); 158 if (!root) { 159 retval = -ENOMEM; 160 goto error; 161 } 162 163 sb->s_root = root; 164 root->d_inode->i_ino = v9fs_qid2ino(&st->qid); 165 v9fs_stat2inode(st, root->d_inode, sb); 166 v9fs_fid_add(root, fid); 167 168 return simple_set_mnt(mnt, sb); 169 170 error: 171 if (fid) 172 p9_client_clunk(fid); 173 174 if (v9ses) { 175 v9fs_session_close(v9ses); 176 kfree(v9ses); 177 } 178 179 if (sb) { 180 up_write(&sb->s_umount); 181 deactivate_super(sb); 182 } 183 184 return retval; 185 } 186 187 /** 188 * v9fs_kill_super - Kill Superblock 189 * @s: superblock 190 * 191 */ 192 193 static void v9fs_kill_super(struct super_block *s) 194 { 195 struct v9fs_session_info *v9ses = s->s_fs_info; 196 197 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s); 198 199 v9fs_dentry_release(s->s_root); /* clunk root */ 200 201 kill_anon_super(s); 202 203 v9fs_session_close(v9ses); 204 kfree(v9ses); 205 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n"); 206 } 207 208 /** 209 * v9fs_show_options - Show mount options in /proc/mounts 210 * @m: seq_file to write to 211 * @mnt: mount descriptor 212 * 213 */ 214 215 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt) 216 { 217 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info; 218 219 seq_printf(m, "%s", v9ses->options); 220 return 0; 221 } 222 223 static void 224 v9fs_umount_begin(struct vfsmount *vfsmnt, int flags) 225 { 226 struct v9fs_session_info *v9ses = vfsmnt->mnt_sb->s_fs_info; 227 228 if (flags & MNT_FORCE) 229 v9fs_session_cancel(v9ses); 230 } 231 232 static const struct super_operations v9fs_super_ops = { 233 .statfs = simple_statfs, 234 .clear_inode = v9fs_clear_inode, 235 .show_options = v9fs_show_options, 236 .umount_begin = v9fs_umount_begin, 237 }; 238 239 struct file_system_type v9fs_fs_type = { 240 .name = "9p", 241 .get_sb = v9fs_get_sb, 242 .kill_sb = v9fs_kill_super, 243 .owner = THIS_MODULE, 244 }; 245