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 <linux/magic.h>
  43 #include <net/9p/9p.h>
  44 #include <net/9p/client.h>
  45
  46 #include "v9fs.h"
  47 #include "v9fs_vfs.h"
  48 #include "fid.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51
  52 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
  53
  54 /**
  55  * v9fs_set_super - set the superblock
  56  * @s: super block
  57  * @data: file system specific data
  58  *
  59  */
  60
  61 static int v9fs_set_super(struct super_block *s, void *data)
  62 {
  63         s->s_fs_info = data;
  64         return set_anon_super(s, data);
  65 }
  66
  67 /**
  68  * v9fs_fill_super - populate superblock with info
  69  * @sb: superblock
  70  * @v9ses: session information
  71  * @flags: flags propagated from v9fs_mount()
  72  *
  73  */
  74
  75 static void
  76 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
  77                 int flags, void *data)
  78 {
  79         sb->s_maxbytes = MAX_LFS_FILESIZE;
  80         sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
  81         sb->s_blocksize = 1 << sb->s_blocksize_bits;
  82         sb->s_magic = V9FS_MAGIC;
  83         if (v9fs_proto_dotl(v9ses)) {
  84                 sb->s_op = &v9fs_super_ops_dotl;
  85                 sb->s_xattr = v9fs_xattr_handlers;
  86         } else
  87                 sb->s_op = &v9fs_super_ops;
  88         sb->s_bdi = &v9ses->bdi;
  89
  90         sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
  91             MS_NOATIME;
  92
  93 #ifdef CONFIG_9P_FS_POSIX_ACL
  94         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)
  95                 sb->s_flags |= MS_POSIXACL;
  96 #endif
  97
  98         save_mount_options(sb, data);
  99 }
 100
 101 /**
 102  * v9fs_mount - mount a superblock
 103  * @fs_type: file system type
 104  * @flags: mount flags
 105  * @dev_name: device name that was mounted
 106  * @data: mount options
 107  *
 108  */
 109
 110 static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
 111                        const char *dev_name, void *data)
 112 {
 113         struct super_block *sb = NULL;
 114         struct inode *inode = NULL;
 115         struct dentry *root = NULL;
 116         struct v9fs_session_info *v9ses = 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 ERR_PTR(-ENOMEM);
 126
 127         fid = v9fs_session_init(v9ses, dev_name, data);
 128         if (IS_ERR(fid)) {
 129                 retval = PTR_ERR(fid);
 130                 /*
 131                  * we need to call session_close to tear down some
 132                  * of the data structure setup by session_init
 133                  */
 134                 goto close_session;
 135         }
 136
 137         sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
 138         if (IS_ERR(sb)) {
 139                 retval = PTR_ERR(sb);
 140                 goto clunk_fid;
 141         }
 142         v9fs_fill_super(sb, v9ses, flags, data);
 143
 144         inode = v9fs_get_inode(sb, S_IFDIR | mode);
 145         if (IS_ERR(inode)) {
 146                 retval = PTR_ERR(inode);
 147                 goto release_sb;
 148         }
 149
 150         root = d_alloc_root(inode);
 151         if (!root) {
 152                 iput(inode);
 153                 retval = -ENOMEM;
 154                 goto release_sb;
 155         }
 156         sb->s_root = root;
 157         if (v9fs_proto_dotl(v9ses)) {
 158                 struct p9_stat_dotl *st = NULL;
 159                 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
 160                 if (IS_ERR(st)) {
 161                         retval = PTR_ERR(st);
 162                         goto release_sb;
 163                 }
 164
 165                 v9fs_stat2inode_dotl(st, root->d_inode);
 166                 kfree(st);
 167         } else {
 168                 struct p9_wstat *st = NULL;
 169                 st = p9_client_stat(fid);
 170                 if (IS_ERR(st)) {
 171                         retval = PTR_ERR(st);
 172                         goto release_sb;
 173                 }
 174
 175                 root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
 176                 v9fs_stat2inode(st, root->d_inode, sb);
 177
 178                 p9stat_free(st);
 179                 kfree(st);
 180         }
 181         retval = v9fs_get_acl(inode, fid);
 182         if (retval)
 183                 goto release_sb;
 184         v9fs_fid_add(root, fid);
 185
 186         P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
 187         return dget(sb->s_root);
 188
 189 clunk_fid:
 190         p9_client_clunk(fid);
 191 close_session:
 192         v9fs_session_close(v9ses);
 193         kfree(v9ses);
 194         return ERR_PTR(retval);
 195
 196 release_sb:
 197         /*
 198          * we will do the session_close and root dentry release
 199          * in the below call. But we need to clunk fid, because we haven't
 200          * attached the fid to dentry so it won't get clunked
 201          * automatically.
 202          */
 203         p9_client_clunk(fid);
 204         deactivate_locked_super(sb);
 205         return ERR_PTR(retval);
 206 }
 207
 208 /**
 209  * v9fs_kill_super - Kill Superblock
 210  * @s: superblock
 211  *
 212  */
 213
 214 static void v9fs_kill_super(struct super_block *s)
 215 {
 216         struct v9fs_session_info *v9ses = s->s_fs_info;
 217
 218         P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
 219
 220         if (s->s_root)
 221                 v9fs_dentry_release(s->s_root); /* clunk root */
 222
 223         kill_anon_super(s);
 224
 225         v9fs_session_cancel(v9ses);
 226         v9fs_session_close(v9ses);
 227         kfree(v9ses);
 228         s->s_fs_info = NULL;
 229         P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
 230 }
 231
 232 static void
 233 v9fs_umount_begin(struct super_block *sb)
 234 {
 235         struct v9fs_session_info *v9ses;
 236
 237         v9ses = sb->s_fs_info;
 238         v9fs_session_begin_cancel(v9ses);
 239 }
 240
 241 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 242 {
 243         struct v9fs_session_info *v9ses;
 244         struct p9_fid *fid;
 245         struct p9_rstatfs rs;
 246         int res;
 247
 248         fid = v9fs_fid_lookup(dentry);
 249         if (IS_ERR(fid)) {
 250                 res = PTR_ERR(fid);
 251                 goto done;
 252         }
 253
 254         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 255         if (v9fs_proto_dotl(v9ses)) {
 256                 res = p9_client_statfs(fid, &rs);
 257                 if (res == 0) {
 258                         buf->f_type = V9FS_MAGIC;
 259                         buf->f_bsize = rs.bsize;
 260                         buf->f_blocks = rs.blocks;
 261                         buf->f_bfree = rs.bfree;
 262                         buf->f_bavail = rs.bavail;
 263                         buf->f_files = rs.files;
 264                         buf->f_ffree = rs.ffree;
 265                         buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL;
 266                         buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL;
 267                         buf->f_namelen = rs.namelen;
 268                 }
 269                 if (res != -ENOSYS)
 270                         goto done;
 271         }
 272         res = simple_statfs(dentry, buf);
 273 done:
 274         return res;
 275 }
 276
 277 static const struct super_operations v9fs_super_ops = {
 278 #ifdef CONFIG_9P_FSCACHE
 279         .alloc_inode = v9fs_alloc_inode,
 280         .destroy_inode = v9fs_destroy_inode,
 281 #endif
 282         .statfs = simple_statfs,
 283         .evict_inode = v9fs_evict_inode,
 284         .show_options = generic_show_options,
 285         .umount_begin = v9fs_umount_begin,
 286 };
 287
 288 static const struct super_operations v9fs_super_ops_dotl = {
 289 #ifdef CONFIG_9P_FSCACHE
 290         .alloc_inode = v9fs_alloc_inode,
 291         .destroy_inode = v9fs_destroy_inode,
 292 #endif
 293         .statfs = v9fs_statfs,
 294         .evict_inode = v9fs_evict_inode,
 295         .show_options = generic_show_options,
 296         .umount_begin = v9fs_umount_begin,
 297 };
 298
 299 struct file_system_type v9fs_fs_type = {
 300         .name = "9p",
 301         .mount = v9fs_mount,
 302         .kill_sb = v9fs_kill_super,
 303         .owner = THIS_MODULE,
 304         .fs_flags = FS_RENAME_DOES_D_MOVE,
 305 };