fs/9p/vfs_super.c

   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
  50 static 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
  59 static 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
  73 static void
  74 v9fs_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
 104 static 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
 184 clunk_fid:
 185         p9_client_clunk(fid);
 186 close_session:
 187         v9fs_session_close(v9ses);
 188         kfree(v9ses);
 189         return retval;
 190 release_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
 208 static 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
 226 static void
 227 v9fs_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
 235 static 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);
 267 done:
 268         return res;
 269 }
 270
 271 static 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
 282 static 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
 293 struct 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 };