diff options
Diffstat (limited to 'fs/xfs/xfs_symlink_remote.c')
| -rw-r--r-- | fs/xfs/xfs_symlink_remote.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/fs/xfs/xfs_symlink_remote.c b/fs/xfs/xfs_symlink_remote.c new file mode 100644 index 000000000000..01c85e3f6470 --- /dev/null +++ b/fs/xfs/xfs_symlink_remote.c @@ -0,0 +1,200 @@ +/* + * 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.h" +#include "xfs_trans.h" +#include "xfs_ag.h" +#include "xfs_sb.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_buf_item.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; + + 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_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( + 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 (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_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) >= MAXPATHLEN) + return false; + if (dsl->sl_owner == 0) + 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_verify_cksum(bp->b_addr, BBTOB(bp->b_length), + offsetof(struct xfs_dsymlink_hdr, sl_crc)) || + !xfs_symlink_verify(bp)) { + XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr); + xfs_buf_ioerror(bp, EFSCORRUPTED); + } +} + +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_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr); + xfs_buf_ioerror(bp, EFSCORRUPTED); + return; + } + + if (bip) { + struct xfs_dsymlink_hdr *dsl = bp->b_addr; + dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn); + } + xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), + offsetof(struct xfs_dsymlink_hdr, sl_crc)); +} + +const struct xfs_buf_ops xfs_symlink_buf_ops = { + .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; + + if (!xfs_sb_version_hascrc(&mp->m_sb)) { + bp->b_ops = NULL; + memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes); + 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); +} |