linux_dsm_epyc7002/fs/xfs/libxfs/xfs_symlink_remote.c
Darrick J. Wong 6eb0b8df9f xfs: rename MAXPATHLEN to XFS_SYMLINK_MAXLEN
XFS has a maximum symlink target length of 1024 bytes; this is a
holdover from the Irix days.  Unfortunately, the constant establishing
this is 'MAXPATHLEN' and is /not/ the same as the Linux MAXPATHLEN,
which is 4096.

The kernel enforces its 1024 byte MAXPATHLEN on symlink targets, but
xfsprogs picks up the (Linux) system 4096 byte MAXPATHLEN, which means
that xfs_repair doesn't complain about oversized symlinks.

Since this is an on-disk format constraint, put the define in the XFS
namespace and move everything over to use the new name.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-07 08:37:26 -07:00

210 lines
5.1 KiB
C

/*
* Copyright (c) 2000-2006 Silicon Graphics, Inc.
* Copyright (c) 2012-2013 Red Hat, Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_shared.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_symlink.h"
#include "xfs_cksum.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_log.h"
/*
* Each contiguous block has a header, so it is not just a simple pathlen
* to FSB conversion.
*/
int
xfs_symlink_blocks(
struct xfs_mount *mp,
int pathlen)
{
int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
return (pathlen + buflen - 1) / buflen;
}
int
xfs_symlink_hdr_set(
struct xfs_mount *mp,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
struct xfs_buf *bp)
{
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return 0;
memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
dsl->sl_offset = cpu_to_be32(offset);
dsl->sl_bytes = cpu_to_be32(size);
uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
dsl->sl_owner = cpu_to_be64(ino);
dsl->sl_blkno = cpu_to_be64(bp->b_bn);
bp->b_ops = &xfs_symlink_buf_ops;
return sizeof(struct xfs_dsymlink_hdr);
}
/*
* Checking of the symlink header is split into two parts. the verifier does
* CRC, location and bounds checking, the unpacking function checks the path
* parameters and owner.
*/
bool
xfs_symlink_hdr_ok(
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
struct xfs_buf *bp)
{
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
if (offset != be32_to_cpu(dsl->sl_offset))
return false;
if (size != be32_to_cpu(dsl->sl_bytes))
return false;
if (ino != be64_to_cpu(dsl->sl_owner))
return false;
/* ok */
return true;
}
static bool
xfs_symlink_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return false;
if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
return false;
if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
return false;
if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
return false;
if (be32_to_cpu(dsl->sl_offset) +
be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
return false;
if (dsl->sl_owner == 0)
return false;
if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
return false;
return true;
}
static void
xfs_symlink_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
xfs_buf_ioerror(bp, -EFSBADCRC);
else if (!xfs_symlink_verify(bp))
xfs_buf_ioerror(bp, -EFSCORRUPTED);
if (bp->b_error)
xfs_verifier_error(bp);
}
static void
xfs_symlink_write_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_buf_log_item *bip = bp->b_fspriv;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
if (!xfs_symlink_verify(bp)) {
xfs_buf_ioerror(bp, -EFSCORRUPTED);
xfs_verifier_error(bp);
return;
}
if (bip) {
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
}
xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
}
const struct xfs_buf_ops xfs_symlink_buf_ops = {
.name = "xfs_symlink",
.verify_read = xfs_symlink_read_verify,
.verify_write = xfs_symlink_write_verify,
};
void
xfs_symlink_local_to_remote(
struct xfs_trans *tp,
struct xfs_buf *bp,
struct xfs_inode *ip,
struct xfs_ifork *ifp)
{
struct xfs_mount *mp = ip->i_mount;
char *buf;
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
if (!xfs_sb_version_hascrc(&mp->m_sb)) {
bp->b_ops = NULL;
memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
return;
}
/*
* As this symlink fits in an inode literal area, it must also fit in
* the smallest buffer the filesystem supports.
*/
ASSERT(BBTOB(bp->b_length) >=
ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
bp->b_ops = &xfs_symlink_buf_ops;
buf = bp->b_addr;
buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
ifp->if_bytes - 1);
}