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_blksize        = PAGE_CACHE_SIZE;
  76         inode->i_blocks         = 0;
  77         inode->i_version        = vnode->fid.unique;
  78         inode->i_mapping->a_ops = &afs_fs_aops;
  79
  80         /* check to see whether a symbolic link is really a mountpoint */
  81         if (vnode->status.type == AFS_FTYPE_SYMLINK) {
  82                 afs_mntpt_check_symlink(vnode);
  83
  84                 if (vnode->flags & AFS_VNODE_MOUNTPOINT) {
  85                         inode->i_mode   = S_IFDIR | vnode->status.mode;
  86                         inode->i_op     = &afs_mntpt_inode_operations;
  87                         inode->i_fop    = &afs_mntpt_file_operations;
  88                 }
  89         }
  90
  91         return 0;
  92 } /* end afs_inode_map_status() */
  93
  94 /*****************************************************************************/
  95 /*
  96  * attempt to fetch the status of an inode, coelescing multiple simultaneous
  97  * fetches
  98  */
  99 static int afs_inode_fetch_status(struct inode *inode)
 100 {
 101         struct afs_vnode *vnode;
 102         int ret;
 103
 104         vnode = AFS_FS_I(inode);
 105
 106         ret = afs_vnode_fetch_status(vnode);
 107
 108         if (ret == 0)
 109                 ret = afs_inode_map_status(vnode);
 110
 111         return ret;
 112
 113 } /* end afs_inode_fetch_status() */
 114
 115 /*****************************************************************************/
 116 /*
 117  * iget5() comparator
 118  */
 119 static int afs_iget5_test(struct inode *inode, void *opaque)
 120 {
 121         struct afs_iget_data *data = opaque;
 122
 123         return inode->i_ino == data->fid.vnode &&
 124                 inode->i_version == data->fid.unique;
 125 } /* end afs_iget5_test() */
 126
 127 /*****************************************************************************/
 128 /*
 129  * iget5() inode initialiser
 130  */
 131 static int afs_iget5_set(struct inode *inode, void *opaque)
 132 {
 133         struct afs_iget_data *data = opaque;
 134         struct afs_vnode *vnode = AFS_FS_I(inode);
 135
 136         inode->i_ino = data->fid.vnode;
 137         inode->i_version = data->fid.unique;
 138         vnode->fid = data->fid;
 139         vnode->volume = data->volume;
 140
 141         return 0;
 142 } /* end afs_iget5_set() */
 143
 144 /*****************************************************************************/
 145 /*
 146  * inode retrieval
 147  */
 148 inline int afs_iget(struct super_block *sb, struct afs_fid *fid,
 149                     struct inode **_inode)
 150 {
 151         struct afs_iget_data data = { .fid = *fid };
 152         struct afs_super_info *as;
 153         struct afs_vnode *vnode;
 154         struct inode *inode;
 155         int ret;
 156
 157         _enter(",{%u,%u,%u},,", fid->vid, fid->vnode, fid->unique);
 158
 159         as = sb->s_fs_info;
 160         data.volume = as->volume;
 161
 162         inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
 163                              &data);
 164         if (!inode) {
 165                 _leave(" = -ENOMEM");
 166                 return -ENOMEM;
 167         }
 168
 169         vnode = AFS_FS_I(inode);
 170
 171         /* deal with an existing inode */
 172         if (!(inode->i_state & I_NEW)) {
 173                 ret = afs_vnode_fetch_status(vnode);
 174                 if (ret==0)
 175                         *_inode = inode;
 176                 else
 177                         iput(inode);
 178                 _leave(" = %d", ret);
 179                 return ret;
 180         }
 181
 182 #ifdef AFS_CACHING_SUPPORT
 183         /* set up caching before reading the status, as fetch-status reads the
 184          * first page of symlinks to see if they're really mntpts */
 185         cachefs_acquire_cookie(vnode->volume->cache,
 186                                NULL,
 187                                vnode,
 188                                &vnode->cache);
 189 #endif
 190
 191         /* okay... it's a new inode */
 192         inode->i_flags |= S_NOATIME;
 193         vnode->flags |= AFS_VNODE_CHANGED;
 194         ret = afs_inode_fetch_status(inode);
 195         if (ret<0)
 196                 goto bad_inode;
 197
 198         /* success */
 199         unlock_new_inode(inode);
 200
 201         *_inode = inode;
 202         _leave(" = 0 [CB { v=%u x=%lu t=%u }]",
 203                vnode->cb_version,
 204                vnode->cb_timeout.timo_jif,
 205                vnode->cb_type);
 206         return 0;
 207
 208         /* failure */
 209  bad_inode:
 210         make_bad_inode(inode);
 211         unlock_new_inode(inode);
 212         iput(inode);
 213
 214         _leave(" = %d [bad]", ret);
 215         return ret;
 216 } /* end afs_iget() */
 217
 218 /*****************************************************************************/
 219 /*
 220  * read the attributes of an inode
 221  */
 222 int afs_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
 223                       struct kstat *stat)
 224 {
 225         struct afs_vnode *vnode;
 226         struct inode *inode;
 227         int ret;
 228
 229         inode = dentry->d_inode;
 230
 231         _enter("{ ino=%lu v=%lu }", inode->i_ino, inode->i_version);
 232
 233         vnode = AFS_FS_I(inode);
 234
 235         ret = afs_inode_fetch_status(inode);
 236         if (ret == -ENOENT) {
 237                 _leave(" = %d [%d %p]",
 238                        ret, atomic_read(&dentry->d_count), dentry->d_inode);
 239                 return ret;
 240         }
 241         else if (ret < 0) {
 242                 make_bad_inode(inode);
 243                 _leave(" = %d", ret);
 244                 return ret;
 245         }
 246
 247         /* transfer attributes from the inode structure to the stat
 248          * structure */
 249         generic_fillattr(inode, stat);
 250
 251         _leave(" = 0 CB { v=%u x=%u t=%u }",
 252                vnode->cb_version,
 253                vnode->cb_expiry,
 254                vnode->cb_type);
 255
 256         return 0;
 257 } /* end afs_inode_getattr() */
 258
 259 /*****************************************************************************/
 260 /*
 261  * clear an AFS inode
 262  */
 263 void afs_clear_inode(struct inode *inode)
 264 {
 265         struct afs_vnode *vnode;
 266
 267         vnode = AFS_FS_I(inode);
 268
 269         _enter("ino=%lu { vn=%08x v=%u x=%u t=%u }",
 270                inode->i_ino,
 271                vnode->fid.vnode,
 272                vnode->cb_version,
 273                vnode->cb_expiry,
 274                vnode->cb_type
 275                );
 276
 277         BUG_ON(inode->i_ino != vnode->fid.vnode);
 278
 279         afs_vnode_give_up_callback(vnode);
 280
 281 #ifdef AFS_CACHING_SUPPORT
 282         cachefs_relinquish_cookie(vnode->cache, 0);
 283         vnode->cache = NULL;
 284 #endif
 285
 286         _leave("");
 287 } /* end afs_clear_inode() */