// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2004-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_dir2.h"
#include "xfs_export.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_icache.h"
#include "xfs_pnfs.h"
/*
* Note that we only accept fileids which are long enough rather than allow
* the parent generation number to default to zero. XFS considers zero a
* valid generation number not an invalid/wildcard value.
*/
static int xfs_fileid_length(int fileid_type)
{
switch (fileid_type) {
case FILEID_INO32_GEN:
return 2;
case FILEID_INO32_GEN_PARENT:
return 4;
case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
return 3;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
return 6;
}
return FILEID_INVALID;
}
STATIC int
xfs_fs_encode_fh(
struct inode *inode,
__u32 *fh,
int *max_len,
struct inode *parent)
{
struct xfs_mount *mp = XFS_M(inode->i_sb);
struct fid *fid = (struct fid *)fh;
struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
int fileid_type;
int len;
/* Directories don't need their parent encoded, they have ".." */
if (!parent)
fileid_type = FILEID_INO32_GEN;
else
fileid_type = FILEID_INO32_GEN_PARENT;
/*
* If the filesystem may contain 64bit inode numbers, we need
* to use larger file handles that can represent them.
*
* While we only allocate inodes that do not fit into 32 bits any
* large enough filesystem may contain them, thus the slightly
* confusing looking conditional below.
*/
if (!xfs_has_small_inums(mp) || xfs_is_inode32(mp))
fileid_type |= XFS_FILEID_TYPE_64FLAG;
/*
* Only encode if there is enough space given. In practice
* this means we can't export a filesystem with 64bit inodes
* over NFSv2 with the subtree_check export option; the other
* seven combinations work. The real answer is "don't use v2".
*/
len = xfs_fileid_length(fileid_type);
if (*max_len < len) {
*max_len = len;
return FILEID_INVALID;
}
*max_len = len;
switch (fileid_type) {
case FILEID_INO32_GEN_PARENT:
fid->i32.parent_ino = XFS_I(parent)->i_ino;
fid->i32.parent_gen = parent->i_generation;
fallthrough;
case FILEID_INO32_GEN:
fid->i32.ino = XFS_I(inode)->i_ino;
fid->i32.gen = inode->i_generation;
break;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
fid64->parent_ino = XFS_I(parent)->i_ino;
fid64->parent_gen = parent->i_generation;
fallthrough;
case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
fid64->ino = XFS_I(inode)->i_ino;
fid64->gen = inode->i_generation;
break;
}
return fileid_type;
}
struct inode *
xfs_nfs_get_inode(
struct super_block *sb,
u64 ino,
u32 generation)
{
xfs_mount_t *mp = XFS_M(sb);
xfs_inode_t *ip;
int error;
/*
* NFS can sometimes send requests for ino 0. Fail them gracefully.
*/
if (ino == 0)
return ERR_PTR(-ESTALE);
/*
* The XFS_IGET_UNTRUSTED means that an invalid inode number is just
* fine and not an indication of a corrupted filesystem as clients can
* send invalid file handles and we have to handle it gracefully..
*/
error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
if (error) {
/*
* EINVAL means the inode cluster doesn't exist anymore.
* EFSCORRUPTED means the metadata pointing to the inode cluster
* or the inode cluster itself is corrupt. This implies the
* filehandle is stale, so we should translate it here.
* We don't use ESTALE directly down the chain to not
* confuse applications using bulkstat that expect EINVAL.
*/
switch (error) {
case -EINVAL:
case -ENOENT:
case -EFSCORRUPTED:
error = -ESTALE;
break;
default:
break;
}
return ERR_PTR(error);
}
/*
* Reload the incore unlinked list to avoid failure in inodegc.
* Use an unlocked check here because unrecovered unlinked inodes
* should be somewhat rare.
*/
if (xfs_inode_unlinked_incomplete(ip)) {
error = xfs_inode_reload_unlinked(ip);
if (error) {
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
xfs_irele(ip);
return ERR_PTR(error);
}
}
if (VFS_I(ip)->i_generation != generation || IS_PRIVATE(VFS_I(ip))) {
xfs_irele(ip);
return ERR_PTR(-ESTALE);
}
return VFS_I(ip);
}
STATIC struct dentry *
xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
int fh_len, int fileid_type)
{
struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
struct inode *inode = NULL;
if (fh_len < xfs_fileid_length(fileid_type))
return NULL;
switch (fileid_type) {
case FILEID_INO32_GEN_PARENT:
case FILEID_INO32_GEN:
inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
break;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
break;
}
return d_obtain_alias(inode);
}
STATIC struct dentry *
xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
int fh_len, int fileid_type)
{
struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
struct inode *inode = NULL;
if (fh_len < xfs_fileid_length(fileid_type))
return NULL;
switch (fileid_type) {
case FILEID_INO32_GEN_PARENT:
inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
fid->i32.parent_gen);
break;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
fid64->parent_gen);
break;
}
return d_obtain_alias(inode);
}
STATIC struct dentry *
xfs_fs_get_parent(
struct dentry *child)
{
int error;
struct xfs_inode *cip;
error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
if (unlikely(error))
return ERR_PTR(error);
return d_obtain_alias(VFS_I(cip));
}
STATIC int
xfs_fs_nfs_commit_metadata(
struct inode *inode)
{
return xfs_log_force_inode(XFS_I(inode));
}
const struct export_operations xfs_export_operations = {
.encode_fh = xfs_fs_encode_fh,
.fh_to_dentry = xfs_fs_fh_to_dentry,
.fh_to_parent = xfs_fs_fh_to_parent,
.get_parent = xfs_fs_get_parent,
.commit_metadata = xfs_fs_nfs_commit_metadata,
#ifdef CONFIG_EXPORTFS_BLOCK_OPS
.get_uuid = xfs_fs_get_uuid,
.map_blocks = xfs_fs_map_blocks,
.commit_blocks = xfs_fs_commit_blocks,
#endif
};
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