fs/afs/inode.c

   1 /*
   2  * Copyright (c) 2002 Red Hat, Inc. All rights reserved.
   3  *
   4  * This software may be freely redistributed under the terms of the
   5  * GNU General Public License.
   6  *
   7  * You should have received a copy of the GNU General Public License
   8  * along with this program; if not, write to the Free Software
   9  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  10  *
  11  * Authors: David Woodhouse <dwmw2@cambridge.redhat.com>
  12  *          David Howells <dhowells@redhat.com>
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/fs.h>
  21 #include <linux/pagemap.h>
  22 #include "volume.h"
  23 #include "vnode.h"
  24 #include "super.h"
  25 #include "internal.h"
  26
  27 struct afs_iget_data {
  28         struct afs_fid          fid;
  29         struct afs_volume       *volume;        /* volume on which resides */
  30 };
  31
  32 /*****************************************************************************/
  33 /*
  34  * map the AFS file status to the inode member variables
  35  */
  36 static int afs_inode_map_status(struct afs_vnode *vnode)
  37 {
  38         struct inode *inode = AFS_VNODE_TO_I(vnode);
  39
  40         _debug("FS: ft=%d lk=%d sz=%Zu ver=%Lu mod=%hu",
  41                vnode->status.type,
  42                vnode->status.nlink,
  43                vnode->status.size,
  44                vnode->status.version,
  45                vnode->status.mode);
  46
  47         switch (vnode->status.type) {
  48         case AFS_FTYPE_FILE:
  49                 inode->i_mode   = S_IFREG | vnode->status.mode;
  50                 inode->i_op     = &afs_file_inode_operations;
  51                 inode->i_fop    = &generic_ro_fops;
  52                 break;
  53         case AFS_FTYPE_DIR:
  54                 inode->i_mode   = S_IFDIR | vnode->status.mode;
  55                 inode->i_op     = &afs_dir_inode_operations;
  56                 inode->i_fop    = &afs_dir_file_operations;
  57                 break;
  58         case AFS_FTYPE_SYMLINK:
  59                 inode->i_mode   = S_IFLNK | vnode->status.mode;
  60                 inode->i_op     = &page_symlink_inode_operations;
  61                 break;
  62         default:
  63                 printk("kAFS: AFS vnode with undefined type\n");
  64                 return -EBADMSG;
  65         }
  66
  67         inode->i_nlink          = vnode->status.nlink;
  68         inode->i_uid            = vnode->status.owner;
  69         inode->i_gid            = 0;
  70         inode->i_size           = vnode->status.size;
  71         inode->i_ctime.tv_sec   = vnode->status.mtime_server;
  72         inode->i_ctime.tv_nsec  = 0;
  73         inode->i_atime          = inode->i_mtime = inode->i_ctime;
  74         inode->i_blocks         = 0;
  75         inode->i_version        = vnode->fid.unique;
  76         inode->i_mapping->a_ops = &afs_fs_aops;
  77
  78         /* check to see whether a symbolic link is really a mountpoint */
  79         if (vnode->status.type == AFS_FTYPE_SYMLINK) {
  80                 afs_mntpt_check_symlink(vnode);
  81
  82                 if (vnode->flags & AFS_VNODE_MOUNTPOINT) {
  83                         inode->i_mode   = S_IFDIR | vnode->status.mode;
  84                         inode->i_op     = &afs_mntpt_inode_operations;
  85                         inode->i_fop    = &afs_mntpt_file_operations;
  86                 }
  87         }
  88
  89         return 0;
  90 } /* end afs_inode_map_status() */
  91
  92 /*****************************************************************************/
  93 /*
  94  * attempt to fetch the status of an inode, coelescing multiple simultaneous
  95  * fetches
  96  */
  97 static int afs_inode_fetch_status(struct inode *inode)
  98 {
  99         struct afs_vnode *vnode;
 100         int ret;
 101
 102         vnode = AFS_FS_I(inode);
 103
 104         ret = afs_vnode_fetch_status(vnode);
 105
 106         if (ret == 0)
 107                 ret = afs_inode_map_status(vnode);
 108
 109         return ret;
 110
 111 } /* end afs_inode_fetch_status() */
 112
 113 /*****************************************************************************/
 114 /*
 115  * iget5() comparator
 116  */
 117 static int afs_iget5_test(struct inode *inode, void *opaque)
 118 {
 119         struct afs_iget_data *data = opaque;
 120
 121         return inode->i_ino == data->fid.vnode &&
 122                 inode->i_version == data->fid.unique;
 123 } /* end afs_iget5_test() */
 124
 125 /*****************************************************************************/
 126 /*
 127  * iget5() inode initialiser
 128  */
 129 static int afs_iget5_set(struct inode *inode, void *opaque)
 130 {
 131         struct afs_iget_data *data = opaque;
 132         struct afs_vnode *vnode = AFS_FS_I(inode);
 133
 134         inode->i_ino = data->fid.vnode;
 135         inode->i_version = data->fid.unique;
 136         vnode->fid = data->fid;
 137         vnode->volume = data->volume;
 138
 139         return 0;
 140 } /* end afs_iget5_set() */
 141
 142 /*****************************************************************************/
 143 /*
 144  * inode retrieval
 145  */
 146 inline int afs_iget(struct super_block *sb, struct afs_fid *fid,
 147                     struct inode **_inode)
 148 {
 149         struct afs_iget_data data = { .fid = *fid };
 150         struct afs_super_info *as;
 151         struct afs_vnode *vnode;
 152         struct inode *inode;
 153         int ret;
 154
 155         _enter(",{%u,%u,%u},,", fid->vid, fid->vnode, fid->unique);
 156
 157         as = sb->s_fs_info;
 158         data.volume = as->volume;
 159
 160         inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
 161                              &data);
 162         if (!inode) {
 163                 _leave(" = -ENOMEM");
 164                 return -ENOMEM;
 165         }
 166
 167         vnode = AFS_FS_I(inode);
 168
 169         /* deal with an existing inode */
 170         if (!(inode->i_state & I_NEW)) {
 171                 ret = afs_vnode_fetch_status(vnode);
 172                 if (ret==0)
 173                         *_inode = inode;
 174                 else
 175                         iput(inode);
 176                 _leave(" = %d", ret);
 177                 return ret;
 178         }
 179
 180 #ifdef AFS_CACHING_SUPPORT
 181         /* set up caching before reading the status, as fetch-status reads the
 182          * first page of symlinks to see if they're really mntpts */
 183         cachefs_acquire_cookie(vnode->volume->cache,
 184                                NULL,
 185                                vnode,
 186                                &vnode->cache);
 187 #endif
 188
 189         /* okay... it's a new inode */
 190         inode->i_flags |= S_NOATIME;
 191         vnode->flags |= AFS_VNODE_CHANGED;
 192         ret = afs_inode_fetch_status(inode);
 193         if (ret<0)
 194                 goto bad_inode;
 195
 196         /* success */
 197         unlock_new_inode(inode);
 198
 199         *_inode = inode;
 200         _leave(" = 0 [CB { v=%u x=%lu t=%u }]",
 201                vnode->cb_version,
 202                vnode->cb_timeout.timo_jif,
 203                vnode->cb_type);
 204         return 0;
 205
 206         /* failure */
 207  bad_inode:
 208         make_bad_inode(inode);
 209         unlock_new_inode(inode);
 210         iput(inode);
 211
 212         _leave(" = %d [bad]", ret);
 213         return ret;
 214 } /* end afs_iget() */
 215
 216 /*****************************************************************************/
 217 /*
 218  * read the attributes of an inode
 219  */
 220 int afs_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
 221                       struct kstat *stat)
 222 {
 223         struct afs_vnode *vnode;
 224         struct inode *inode;
 225         int ret;
 226
 227         inode = dentry->d_inode;
 228
 229         _enter("{ ino=%lu v=%lu }", inode->i_ino, inode->i_version);
 230
 231         vnode = AFS_FS_I(inode);
 232
 233         ret = afs_inode_fetch_status(inode);
 234         if (ret == -ENOENT) {
 235                 _leave(" = %d [%d %p]",
 236                        ret, atomic_read(&dentry->d_count), dentry->d_inode);
 237                 return ret;
 238         }
 239         else if (ret < 0) {
 240                 make_bad_inode(inode);
 241                 _leave(" = %d", ret);
 242                 return ret;
 243         }
 244
 245         /* transfer attributes from the inode structure to the stat
 246          * structure */
 247         generic_fillattr(inode, stat);
 248
 249         _leave(" = 0 CB { v=%u x=%u t=%u }",
 250                vnode->cb_version,
 251                vnode->cb_expiry,
 252                vnode->cb_type);
 253
 254         return 0;
 255 } /* end afs_inode_getattr() */
 256
 257 /*****************************************************************************/
 258 /*
 259  * clear an AFS inode
 260  */
 261 void afs_clear_inode(struct inode *inode)
 262 {
 263         struct afs_vnode *vnode;
 264
 265         vnode = AFS_FS_I(inode);
 266
 267         _enter("ino=%lu { vn=%08x v=%u x=%u t=%u }",
 268                inode->i_ino,
 269                vnode->fid.vnode,
 270                vnode->cb_version,
 271                vnode->cb_expiry,
 272                vnode->cb_type
 273                );
 274
 275         BUG_ON(inode->i_ino != vnode->fid.vnode);
 276
 277         afs_vnode_give_up_callback(vnode);
 278
 279 #ifdef AFS_CACHING_SUPPORT
 280         cachefs_relinquish_cookie(vnode->cache, 0);
 281         vnode->cache = NULL;
 282 #endif
 283
 284         _leave("");
 285 } /* end afs_clear_inode() */