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732436ef91
We're about to make this logic do a bit more, so convert the macro to a static inline function for better typechecking and fewer shouty macros. No functional changes here. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
234 lines
5.3 KiB
C
234 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2000-2006 Silicon Graphics, Inc.
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* Copyright (c) 2012-2013 Red Hat, Inc.
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* All rights reserved.
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*/
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#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
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#include "xfs_shared.h"
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#include "xfs_trans_resv.h"
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#include "xfs_mount.h"
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#include "xfs_inode.h"
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#include "xfs_error.h"
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#include "xfs_trans.h"
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#include "xfs_buf_item.h"
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#include "xfs_log.h"
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/*
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* Each contiguous block has a header, so it is not just a simple pathlen
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* to FSB conversion.
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*/
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int
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xfs_symlink_blocks(
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struct xfs_mount *mp,
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int pathlen)
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{
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int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
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return (pathlen + buflen - 1) / buflen;
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}
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int
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xfs_symlink_hdr_set(
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struct xfs_mount *mp,
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xfs_ino_t ino,
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uint32_t offset,
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uint32_t size,
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struct xfs_buf *bp)
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{
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struct xfs_dsymlink_hdr *dsl = bp->b_addr;
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if (!xfs_has_crc(mp))
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return 0;
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memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
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dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
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dsl->sl_offset = cpu_to_be32(offset);
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dsl->sl_bytes = cpu_to_be32(size);
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uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
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dsl->sl_owner = cpu_to_be64(ino);
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dsl->sl_blkno = cpu_to_be64(xfs_buf_daddr(bp));
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bp->b_ops = &xfs_symlink_buf_ops;
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return sizeof(struct xfs_dsymlink_hdr);
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}
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/*
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* Checking of the symlink header is split into two parts. the verifier does
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* CRC, location and bounds checking, the unpacking function checks the path
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* parameters and owner.
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*/
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bool
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xfs_symlink_hdr_ok(
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xfs_ino_t ino,
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uint32_t offset,
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uint32_t size,
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struct xfs_buf *bp)
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{
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struct xfs_dsymlink_hdr *dsl = bp->b_addr;
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if (offset != be32_to_cpu(dsl->sl_offset))
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return false;
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if (size != be32_to_cpu(dsl->sl_bytes))
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return false;
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if (ino != be64_to_cpu(dsl->sl_owner))
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return false;
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/* ok */
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return true;
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}
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static xfs_failaddr_t
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xfs_symlink_verify(
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struct xfs_buf *bp)
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{
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struct xfs_mount *mp = bp->b_mount;
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struct xfs_dsymlink_hdr *dsl = bp->b_addr;
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if (!xfs_has_crc(mp))
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return __this_address;
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if (!xfs_verify_magic(bp, dsl->sl_magic))
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return __this_address;
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if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
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return __this_address;
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if (xfs_buf_daddr(bp) != be64_to_cpu(dsl->sl_blkno))
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return __this_address;
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if (be32_to_cpu(dsl->sl_offset) +
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be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
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return __this_address;
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if (dsl->sl_owner == 0)
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return __this_address;
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if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
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return __this_address;
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return NULL;
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}
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static void
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xfs_symlink_read_verify(
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struct xfs_buf *bp)
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{
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struct xfs_mount *mp = bp->b_mount;
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xfs_failaddr_t fa;
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/* no verification of non-crc buffers */
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if (!xfs_has_crc(mp))
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return;
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if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
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xfs_verifier_error(bp, -EFSBADCRC, __this_address);
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else {
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fa = xfs_symlink_verify(bp);
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if (fa)
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xfs_verifier_error(bp, -EFSCORRUPTED, fa);
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}
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}
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static void
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xfs_symlink_write_verify(
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struct xfs_buf *bp)
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{
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struct xfs_mount *mp = bp->b_mount;
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struct xfs_buf_log_item *bip = bp->b_log_item;
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xfs_failaddr_t fa;
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/* no verification of non-crc buffers */
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if (!xfs_has_crc(mp))
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return;
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fa = xfs_symlink_verify(bp);
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if (fa) {
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xfs_verifier_error(bp, -EFSCORRUPTED, fa);
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return;
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}
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if (bip) {
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struct xfs_dsymlink_hdr *dsl = bp->b_addr;
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dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
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}
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xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
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}
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const struct xfs_buf_ops xfs_symlink_buf_ops = {
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.name = "xfs_symlink",
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.magic = { 0, cpu_to_be32(XFS_SYMLINK_MAGIC) },
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.verify_read = xfs_symlink_read_verify,
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.verify_write = xfs_symlink_write_verify,
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.verify_struct = xfs_symlink_verify,
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};
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void
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xfs_symlink_local_to_remote(
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struct xfs_trans *tp,
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struct xfs_buf *bp,
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struct xfs_inode *ip,
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struct xfs_ifork *ifp)
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{
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struct xfs_mount *mp = ip->i_mount;
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char *buf;
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xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
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if (!xfs_has_crc(mp)) {
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bp->b_ops = NULL;
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memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
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xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
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return;
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}
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/*
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* As this symlink fits in an inode literal area, it must also fit in
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* the smallest buffer the filesystem supports.
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*/
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ASSERT(BBTOB(bp->b_length) >=
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ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
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bp->b_ops = &xfs_symlink_buf_ops;
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buf = bp->b_addr;
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buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
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memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
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xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
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ifp->if_bytes - 1);
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}
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/*
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* Verify the in-memory consistency of an inline symlink data fork. This
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* does not do on-disk format checks.
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*/
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xfs_failaddr_t
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xfs_symlink_shortform_verify(
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struct xfs_inode *ip)
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{
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struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
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char *sfp = (char *)ifp->if_u1.if_data;
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int size = ifp->if_bytes;
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char *endp = sfp + size;
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ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
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/*
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* Zero length symlinks should never occur in memory as they are
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* never allowed to exist on disk.
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*/
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if (!size)
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return __this_address;
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/* No negative sizes or overly long symlink targets. */
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if (size < 0 || size > XFS_SYMLINK_MAXLEN)
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return __this_address;
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/* No NULLs in the target either. */
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if (memchr(sfp, 0, size - 1))
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return __this_address;
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/* We /did/ null-terminate the buffer, right? */
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if (*endp != 0)
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return __this_address;
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return NULL;
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}
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