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         if (v9ses->cache)
 145                 sb->s_d_op = &v9fs_cached_dentry_operations;
 146         else
 147                 sb->s_d_op = &v9fs_dentry_operations;
 148
 149         inode = v9fs_get_inode(sb, S_IFDIR | mode);
 150         if (IS_ERR(inode)) {
 151                 retval = PTR_ERR(inode);
 152                 goto release_sb;
 153         }
 154
 155         root = d_alloc_root(inode);
 156         if (!root) {
 157                 iput(inode);
 158                 retval = -ENOMEM;
 159                 goto release_sb;
 160         }
 161         sb->s_root = root;
 162         if (v9fs_proto_dotl(v9ses)) {
 163                 struct p9_stat_dotl *st = NULL;
 164                 st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
 165                 if (IS_ERR(st)) {
 166                         retval = PTR_ERR(st);
 167                         goto release_sb;
 168                 }
 169
 170                 v9fs_stat2inode_dotl(st, root->d_inode);
 171                 kfree(st);
 172         } else {
 173                 struct p9_wstat *st = NULL;
 174                 st = p9_client_stat(fid);
 175                 if (IS_ERR(st)) {
 176                         retval = PTR_ERR(st);
 177                         goto release_sb;
 178                 }
 179
 180                 root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
 181                 v9fs_stat2inode(st, root->d_inode, sb);
 182
 183                 p9stat_free(st);
 184                 kfree(st);
 185         }
 186         retval = v9fs_get_acl(inode, fid);
 187         if (retval)
 188                 goto release_sb;
 189         v9fs_fid_add(root, fid);
 190
 191         P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
 192         return dget(sb->s_root);
 193
 194 clunk_fid:
 195         p9_client_clunk(fid);
 196 close_session:
 197         v9fs_session_close(v9ses);
 198         kfree(v9ses);
 199         return ERR_PTR(retval);
 200
 201 release_sb:
 202         /*
 203          * we will do the session_close and root dentry release
 204          * in the below call. But we need to clunk fid, because we haven't
 205          * attached the fid to dentry so it won't get clunked
 206          * automatically.
 207          */
 208         p9_client_clunk(fid);
 209         deactivate_locked_super(sb);
 210         return ERR_PTR(retval);
 211 }
 212
 213 /**
 214  * v9fs_kill_super - Kill Superblock
 215  * @s: superblock
 216  *
 217  */
 218
 219 static void v9fs_kill_super(struct super_block *s)
 220 {
 221         struct v9fs_session_info *v9ses = s->s_fs_info;
 222
 223         P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
 224
 225         kill_anon_super(s);
 226
 227         v9fs_session_cancel(v9ses);
 228         v9fs_session_close(v9ses);
 229         kfree(v9ses);
 230         s->s_fs_info = NULL;
 231         P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
 232 }
 233
 234 static void
 235 v9fs_umount_begin(struct super_block *sb)
 236 {
 237         struct v9fs_session_info *v9ses;
 238
 239         v9ses = sb->s_fs_info;
 240         v9fs_session_begin_cancel(v9ses);
 241 }
 242
 243 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 244 {
 245         struct v9fs_session_info *v9ses;
 246         struct p9_fid *fid;
 247         struct p9_rstatfs rs;
 248         int res;
 249
 250         fid = v9fs_fid_lookup(dentry);
 251         if (IS_ERR(fid)) {
 252                 res = PTR_ERR(fid);
 253                 goto done;
 254         }
 255
 256         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 257         if (v9fs_proto_dotl(v9ses)) {
 258                 res = p9_client_statfs(fid, &rs);
 259                 if (res == 0) {
 260                         buf->f_type = V9FS_MAGIC;
 261                         buf->f_bsize = rs.bsize;
 262                         buf->f_blocks = rs.blocks;
 263                         buf->f_bfree = rs.bfree;
 264                         buf->f_bavail = rs.bavail;
 265                         buf->f_files = rs.files;
 266                         buf->f_ffree = rs.ffree;
 267                         buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL;
 268                         buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL;
 269                         buf->f_namelen = rs.namelen;
 270                 }
 271                 if (res != -ENOSYS)
 272                         goto done;
 273         }
 274         res = simple_statfs(dentry, buf);
 275 done:
 276         return res;
 277 }
 278
 279 static const struct super_operations v9fs_super_ops = {
 280 #ifdef CONFIG_9P_FSCACHE
 281         .alloc_inode = v9fs_alloc_inode,
 282         .destroy_inode = v9fs_destroy_inode,
 283 #endif
 284         .statfs = simple_statfs,
 285         .evict_inode = v9fs_evict_inode,
 286         .show_options = generic_show_options,
 287         .umount_begin = v9fs_umount_begin,
 288 };
 289
 290 static const struct super_operations v9fs_super_ops_dotl = {
 291 #ifdef CONFIG_9P_FSCACHE
 292         .alloc_inode = v9fs_alloc_inode,
 293         .destroy_inode = v9fs_destroy_inode,
 294 #endif
 295         .statfs = v9fs_statfs,
 296         .evict_inode = v9fs_evict_inode,
 297         .show_options = generic_show_options,
 298         .umount_begin = v9fs_umount_begin,
 299 };
 300
 301 struct file_system_type v9fs_fs_type = {
 302         .name = "9p",
 303         .mount = v9fs_mount,
 304         .kill_sb = v9fs_kill_super,
 305         .owner = THIS_MODULE,
 306         .fs_flags = FS_RENAME_DOES_D_MOVE,
 307 };