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 <net/9p/9p.h>
  42 #include <net/9p/client.h>
  43
  44 #include "v9fs.h"
  45 #include "v9fs_vfs.h"
  46 #include "fid.h"
  47
  48 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
  49
  50 /**
  51  * v9fs_set_super - set the superblock
  52  * @s: super block
  53  * @data: file system specific data
  54  *
  55  */
  56
  57 static int v9fs_set_super(struct super_block *s, void *data)
  58 {
  59         s->s_fs_info = data;
  60         return set_anon_super(s, data);
  61 }
  62
  63 /**
  64  * v9fs_fill_super - populate superblock with info
  65  * @sb: superblock
  66  * @v9ses: session information
  67  * @flags: flags propagated from v9fs_get_sb()
  68  *
  69  */
  70
  71 static void
  72 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
  73                 int flags, void *data)
  74 {
  75         sb->s_maxbytes = MAX_LFS_FILESIZE;
  76         sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
  77         sb->s_blocksize = 1 << sb->s_blocksize_bits;
  78         sb->s_magic = V9FS_MAGIC;
  79         if (v9fs_proto_dotl(v9ses))
  80                 sb->s_op = &v9fs_super_ops_dotl;
  81         else
  82                 sb->s_op = &v9fs_super_ops;
  83         sb->s_bdi = &v9ses->bdi;
  84
  85         sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
  86             MS_NOATIME;
  87
  88         save_mount_options(sb, data);
  89 }
  90
  91 /**
  92  * v9fs_get_sb - mount a superblock
  93  * @fs_type: file system type
  94  * @flags: mount flags
  95  * @dev_name: device name that was mounted
  96  * @data: mount options
  97  * @mnt: mountpoint record to be instantiated
  98  *
  99  */
 100
 101 static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
 102                        const char *dev_name, void *data,
 103                        struct vfsmount *mnt)
 104 {
 105         struct super_block *sb = NULL;
 106         struct inode *inode = NULL;
 107         struct dentry *root = NULL;
 108         struct v9fs_session_info *v9ses = NULL;
 109         struct p9_wstat *st = NULL;
 110         int mode = S_IRWXUGO | S_ISVTX;
 111         struct p9_fid *fid;
 112         int retval = 0;
 113
 114         P9_DPRINTK(P9_DEBUG_VFS, " \n");
 115
 116         v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
 117         if (!v9ses)
 118                 return -ENOMEM;
 119
 120         fid = v9fs_session_init(v9ses, dev_name, data);
 121         if (IS_ERR(fid)) {
 122                 retval = PTR_ERR(fid);
 123                 goto close_session;
 124         }
 125
 126         st = p9_client_stat(fid);
 127         if (IS_ERR(st)) {
 128                 retval = PTR_ERR(st);
 129                 goto clunk_fid;
 130         }
 131
 132         sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
 133         if (IS_ERR(sb)) {
 134                 retval = PTR_ERR(sb);
 135                 goto free_stat;
 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
 152         sb->s_root = root;
 153         root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
 154
 155         v9fs_stat2inode(st, root->d_inode, sb);
 156
 157         v9fs_fid_add(root, fid);
 158         p9stat_free(st);
 159         kfree(st);
 160
 161 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
 162         simple_set_mnt(mnt, sb);
 163         return 0;
 164
 165 free_stat:
 166         p9stat_free(st);
 167         kfree(st);
 168
 169 clunk_fid:
 170         p9_client_clunk(fid);
 171
 172 close_session:
 173         v9fs_session_close(v9ses);
 174         kfree(v9ses);
 175         return retval;
 176
 177 release_sb:
 178         p9stat_free(st);
 179         kfree(st);
 180         deactivate_locked_super(sb);
 181         return retval;
 182 }
 183
 184 /**
 185  * v9fs_kill_super - Kill Superblock
 186  * @s: superblock
 187  *
 188  */
 189
 190 static void v9fs_kill_super(struct super_block *s)
 191 {
 192         struct v9fs_session_info *v9ses = s->s_fs_info;
 193
 194         P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
 195
 196         if (s->s_root)
 197                 v9fs_dentry_release(s->s_root); /* clunk root */
 198
 199         kill_anon_super(s);
 200
 201         v9fs_session_cancel(v9ses);
 202         v9fs_session_close(v9ses);
 203         kfree(v9ses);
 204         s->s_fs_info = NULL;
 205         P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
 206 }
 207
 208 static void
 209 v9fs_umount_begin(struct super_block *sb)
 210 {
 211         struct v9fs_session_info *v9ses;
 212
 213         v9ses = sb->s_fs_info;
 214         v9fs_session_begin_cancel(v9ses);
 215 }
 216
 217 static const struct super_operations v9fs_super_ops = {
 218 #ifdef CONFIG_9P_FSCACHE
 219         .alloc_inode = v9fs_alloc_inode,
 220         .destroy_inode = v9fs_destroy_inode,
 221 #endif
 222         .statfs = simple_statfs,
 223         .clear_inode = v9fs_clear_inode,
 224         .show_options = generic_show_options,
 225         .umount_begin = v9fs_umount_begin,
 226 };
 227
 228 static const struct super_operations v9fs_super_ops_dotl = {
 229 #ifdef CONFIG_9P_FSCACHE
 230         .alloc_inode = v9fs_alloc_inode,
 231         .destroy_inode = v9fs_destroy_inode,
 232 #endif
 233         .statfs = simple_statfs,
 234         .clear_inode = v9fs_clear_inode,
 235         .show_options = generic_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 };