// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <djwong@kernel.org>
 */
#include "xfs_platform.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_inode.h"
#include "xfs_symlink.h"
#include "xfs_health.h"
#include "xfs_symlink_remote.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/health.h"
#include "scrub/repair.h"

/* Set us up to scrub a symbolic link. */
int
xchk_setup_symlink(
        struct xfs_scrub        *sc)
{
        unsigned int            resblks = 0;
        int                     error;

        /* Allocate the buffer without the inode lock held. */
        sc->buf = kvzalloc(XFS_SYMLINK_MAXLEN + 1, XCHK_GFP_FLAGS);
        if (!sc->buf)
                return -ENOMEM;

        if (xchk_could_repair(sc)) {
                error = xrep_setup_symlink(sc, &resblks);
                if (error)
                        return error;
        }

        return xchk_setup_inode_contents(sc, resblks);
}

/* Symbolic links. */

int
xchk_symlink(
        struct xfs_scrub        *sc)
{
        struct xfs_inode        *ip = sc->ip;
        struct xfs_ifork        *ifp;
        loff_t                  len;
        int                     error = 0;

        if (!S_ISLNK(VFS_I(ip)->i_mode))
                return -ENOENT;

        if (xchk_file_looks_zapped(sc, XFS_SICK_INO_SYMLINK_ZAPPED)) {
                xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
                return 0;
        }

        ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
        len = ip->i_disk_size;

        /* Plausible size? */
        if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
                xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
                return 0;
        }

        /* Inline symlink? */
        if (ifp->if_format == XFS_DINODE_FMT_LOCAL) {
                if (len > xfs_inode_data_fork_size(ip) ||
                    len > strnlen(ifp->if_data, xfs_inode_data_fork_size(ip)))
                        xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
                return 0;
        }

        /* Remote symlink; must read the contents. */
        error = xfs_symlink_remote_read(sc->ip, sc->buf);
        if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
                return error;
        if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
                xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);

        /* If a remote symlink is clean, it is clearly not zapped. */
        xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_SYMLINK_ZAPPED);
        return 0;
}