WSL2-Linux-Kernel/fs/afs/inode.c

288 строки
6.8 KiB
C

/*
* Copyright (c) 2002 Red Hat, Inc. All rights reserved.
*
* This software may be freely redistributed under the terms of the
* GNU General Public License.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Authors: David Woodhouse <dwmw2@cambridge.redhat.com>
* David Howells <dhowells@redhat.com>
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include "volume.h"
#include "vnode.h"
#include "super.h"
#include "internal.h"
struct afs_iget_data {
struct afs_fid fid;
struct afs_volume *volume; /* volume on which resides */
};
/*****************************************************************************/
/*
* map the AFS file status to the inode member variables
*/
static int afs_inode_map_status(struct afs_vnode *vnode)
{
struct inode *inode = AFS_VNODE_TO_I(vnode);
_debug("FS: ft=%d lk=%d sz=%Zu ver=%Lu mod=%hu",
vnode->status.type,
vnode->status.nlink,
vnode->status.size,
vnode->status.version,
vnode->status.mode);
switch (vnode->status.type) {
case AFS_FTYPE_FILE:
inode->i_mode = S_IFREG | vnode->status.mode;
inode->i_op = &afs_file_inode_operations;
inode->i_fop = &generic_ro_fops;
break;
case AFS_FTYPE_DIR:
inode->i_mode = S_IFDIR | vnode->status.mode;
inode->i_op = &afs_dir_inode_operations;
inode->i_fop = &afs_dir_file_operations;
break;
case AFS_FTYPE_SYMLINK:
inode->i_mode = S_IFLNK | vnode->status.mode;
inode->i_op = &page_symlink_inode_operations;
break;
default:
printk("kAFS: AFS vnode with undefined type\n");
return -EBADMSG;
}
inode->i_nlink = vnode->status.nlink;
inode->i_uid = vnode->status.owner;
inode->i_gid = 0;
inode->i_size = vnode->status.size;
inode->i_ctime.tv_sec = vnode->status.mtime_server;
inode->i_ctime.tv_nsec = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_version = vnode->fid.unique;
inode->i_mapping->a_ops = &afs_fs_aops;
/* check to see whether a symbolic link is really a mountpoint */
if (vnode->status.type == AFS_FTYPE_SYMLINK) {
afs_mntpt_check_symlink(vnode);
if (vnode->flags & AFS_VNODE_MOUNTPOINT) {
inode->i_mode = S_IFDIR | vnode->status.mode;
inode->i_op = &afs_mntpt_inode_operations;
inode->i_fop = &afs_mntpt_file_operations;
}
}
return 0;
} /* end afs_inode_map_status() */
/*****************************************************************************/
/*
* attempt to fetch the status of an inode, coelescing multiple simultaneous
* fetches
*/
static int afs_inode_fetch_status(struct inode *inode)
{
struct afs_vnode *vnode;
int ret;
vnode = AFS_FS_I(inode);
ret = afs_vnode_fetch_status(vnode);
if (ret == 0)
ret = afs_inode_map_status(vnode);
return ret;
} /* end afs_inode_fetch_status() */
/*****************************************************************************/
/*
* iget5() comparator
*/
static int afs_iget5_test(struct inode *inode, void *opaque)
{
struct afs_iget_data *data = opaque;
return inode->i_ino == data->fid.vnode &&
inode->i_version == data->fid.unique;
} /* end afs_iget5_test() */
/*****************************************************************************/
/*
* iget5() inode initialiser
*/
static int afs_iget5_set(struct inode *inode, void *opaque)
{
struct afs_iget_data *data = opaque;
struct afs_vnode *vnode = AFS_FS_I(inode);
inode->i_ino = data->fid.vnode;
inode->i_version = data->fid.unique;
vnode->fid = data->fid;
vnode->volume = data->volume;
return 0;
} /* end afs_iget5_set() */
/*****************************************************************************/
/*
* inode retrieval
*/
inline int afs_iget(struct super_block *sb, struct afs_fid *fid,
struct inode **_inode)
{
struct afs_iget_data data = { .fid = *fid };
struct afs_super_info *as;
struct afs_vnode *vnode;
struct inode *inode;
int ret;
_enter(",{%u,%u,%u},,", fid->vid, fid->vnode, fid->unique);
as = sb->s_fs_info;
data.volume = as->volume;
inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
&data);
if (!inode) {
_leave(" = -ENOMEM");
return -ENOMEM;
}
vnode = AFS_FS_I(inode);
/* deal with an existing inode */
if (!(inode->i_state & I_NEW)) {
ret = afs_vnode_fetch_status(vnode);
if (ret==0)
*_inode = inode;
else
iput(inode);
_leave(" = %d", ret);
return ret;
}
#ifdef AFS_CACHING_SUPPORT
/* set up caching before reading the status, as fetch-status reads the
* first page of symlinks to see if they're really mntpts */
cachefs_acquire_cookie(vnode->volume->cache,
NULL,
vnode,
&vnode->cache);
#endif
/* okay... it's a new inode */
inode->i_flags |= S_NOATIME;
vnode->flags |= AFS_VNODE_CHANGED;
ret = afs_inode_fetch_status(inode);
if (ret<0)
goto bad_inode;
/* success */
unlock_new_inode(inode);
*_inode = inode;
_leave(" = 0 [CB { v=%u x=%lu t=%u }]",
vnode->cb_version,
vnode->cb_timeout.timo_jif,
vnode->cb_type);
return 0;
/* failure */
bad_inode:
make_bad_inode(inode);
unlock_new_inode(inode);
iput(inode);
_leave(" = %d [bad]", ret);
return ret;
} /* end afs_iget() */
/*****************************************************************************/
/*
* read the attributes of an inode
*/
int afs_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
struct afs_vnode *vnode;
struct inode *inode;
int ret;
inode = dentry->d_inode;
_enter("{ ino=%lu v=%lu }", inode->i_ino, inode->i_version);
vnode = AFS_FS_I(inode);
ret = afs_inode_fetch_status(inode);
if (ret == -ENOENT) {
_leave(" = %d [%d %p]",
ret, atomic_read(&dentry->d_count), dentry->d_inode);
return ret;
}
else if (ret < 0) {
make_bad_inode(inode);
_leave(" = %d", ret);
return ret;
}
/* transfer attributes from the inode structure to the stat
* structure */
generic_fillattr(inode, stat);
_leave(" = 0 CB { v=%u x=%u t=%u }",
vnode->cb_version,
vnode->cb_expiry,
vnode->cb_type);
return 0;
} /* end afs_inode_getattr() */
/*****************************************************************************/
/*
* clear an AFS inode
*/
void afs_clear_inode(struct inode *inode)
{
struct afs_vnode *vnode;
vnode = AFS_FS_I(inode);
_enter("ino=%lu { vn=%08x v=%u x=%u t=%u }",
inode->i_ino,
vnode->fid.vnode,
vnode->cb_version,
vnode->cb_expiry,
vnode->cb_type
);
BUG_ON(inode->i_ino != vnode->fid.vnode);
afs_vnode_give_up_callback(vnode);
#ifdef AFS_CACHING_SUPPORT
cachefs_relinquish_cookie(vnode->cache, 0);
vnode->cache = NULL;
#endif
_leave("");
} /* end afs_clear_inode() */