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