![Eric Sandeen](/assets/img/avatar_default.png)
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
202 lines
4.7 KiB
C
202 lines
4.7 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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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_ag.h"
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#include "xfs_sb.h"
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#include "xfs_mount.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_inode.h"
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#include "xfs_error.h"
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#include "xfs_trace.h"
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#include "xfs_symlink.h"
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#include "xfs_cksum.h"
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#include "xfs_trans.h"
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#include "xfs_buf_item.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_sb_version_hascrc(&mp->m_sb))
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return 0;
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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_uuid);
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dsl->sl_owner = cpu_to_be64(ino);
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dsl->sl_blkno = cpu_to_be64(bp->b_bn);
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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 bool
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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_target->bt_mount;
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struct xfs_dsymlink_hdr *dsl = bp->b_addr;
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if (!xfs_sb_version_hascrc(&mp->m_sb))
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return false;
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if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
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return false;
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if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_uuid))
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return false;
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if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
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return false;
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if (be32_to_cpu(dsl->sl_offset) +
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be32_to_cpu(dsl->sl_bytes) >= MAXPATHLEN)
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return false;
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if (dsl->sl_owner == 0)
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return false;
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return true;
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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_target->bt_mount;
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/* no verification of non-crc buffers */
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if (!xfs_sb_version_hascrc(&mp->m_sb))
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return;
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if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
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xfs_buf_ioerror(bp, EFSBADCRC);
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else if (!xfs_symlink_verify(bp))
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xfs_buf_ioerror(bp, EFSCORRUPTED);
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if (bp->b_error)
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xfs_verifier_error(bp);
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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_target->bt_mount;
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struct xfs_buf_log_item *bip = bp->b_fspriv;
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/* no verification of non-crc buffers */
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if (!xfs_sb_version_hascrc(&mp->m_sb))
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return;
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if (!xfs_symlink_verify(bp)) {
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xfs_buf_ioerror(bp, EFSCORRUPTED);
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xfs_verifier_error(bp);
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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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.verify_read = xfs_symlink_read_verify,
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.verify_write = xfs_symlink_write_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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if (!xfs_sb_version_hascrc(&mp->m_sb)) {
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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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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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}
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