LXR linux/fs/xfs/scrub/symlink.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2017 Oracle.  All Rights Reserved.
   4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5 */
   6#include "xfs.h"
   7#include "xfs_fs.h"
   8#include "xfs_shared.h"
   9#include "xfs_format.h"
  10#include "xfs_trans_resv.h"
  11#include "xfs_mount.h"
  12#include "xfs_log_format.h"
  13#include "xfs_inode.h"
  14#include "xfs_symlink.h"
  15#include "scrub/scrub.h"
  16#include "scrub/common.h"
  17
  18/* Set us up to scrub a symbolic link. */
  19int
  20xchk_setup_symlink(
  21        struct xfs_scrub        *sc,
  22        struct xfs_inode        *ip)
  23{
  24        /* Allocate the buffer without the inode lock held. */
  25        sc->buf = kmem_zalloc_large(XFS_SYMLINK_MAXLEN + 1, KM_SLEEP);
  26        if (!sc->buf)
  27                return -ENOMEM;
  28
  29        return xchk_setup_inode_contents(sc, ip, 0);
  30}
  31
  32/* Symbolic links. */
  33
  34int
  35xchk_symlink(
  36        struct xfs_scrub        *sc)
  37{
  38        struct xfs_inode        *ip = sc->ip;
  39        struct xfs_ifork        *ifp;
  40        loff_t                  len;
  41        int                     error = 0;
  42
  43        if (!S_ISLNK(VFS_I(ip)->i_mode))
  44                return -ENOENT;
  45        ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
  46        len = ip->i_d.di_size;
  47
  48        /* Plausible size? */
  49        if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
  50                xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  51                goto out;
  52        }
  53
  54        /* Inline symlink? */
  55        if (ifp->if_flags & XFS_IFINLINE) {
  56                if (len > XFS_IFORK_DSIZE(ip) ||
  57                    len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
  58                        xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  59                goto out;
  60        }
  61
  62        /* Remote symlink; must read the contents. */
  63        error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
  64        if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
  65                goto out;
  66        if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
  67                xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
  68out:
  69        return error;
  70}
  71