diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_symlink_remote.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_symlink_remote.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_symlink_remote.c b/fs/xfs/libxfs/xfs_symlink_remote.c new file mode 100644 index 000000000..594bc447a --- /dev/null +++ b/fs/xfs/libxfs/xfs_symlink_remote.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2006 Silicon Graphics, Inc. + * Copyright (c) 2012-2013 Red Hat, Inc. + * All rights reserved. + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_shared.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_inode.h" +#include "xfs_error.h" +#include "xfs_trans.h" +#include "xfs_buf_item.h" +#include "xfs_log.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; + + memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr)); + 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_meta_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( + 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 xfs_failaddr_t +xfs_symlink_verify( + struct xfs_buf *bp) +{ + struct xfs_mount *mp = bp->b_mount; + struct xfs_dsymlink_hdr *dsl = bp->b_addr; + + if (!xfs_sb_version_hascrc(&mp->m_sb)) + return __this_address; + if (!xfs_verify_magic(bp, dsl->sl_magic)) + return __this_address; + if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid)) + return __this_address; + if (bp->b_bn != be64_to_cpu(dsl->sl_blkno)) + return __this_address; + if (be32_to_cpu(dsl->sl_offset) + + be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN) + return __this_address; + if (dsl->sl_owner == 0) + return __this_address; + if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn))) + return __this_address; + + return NULL; +} + +static void +xfs_symlink_read_verify( + struct xfs_buf *bp) +{ + struct xfs_mount *mp = bp->b_mount; + xfs_failaddr_t fa; + + /* no verification of non-crc buffers */ + if (!xfs_sb_version_hascrc(&mp->m_sb)) + return; + + if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF)) + xfs_verifier_error(bp, -EFSBADCRC, __this_address); + else { + fa = xfs_symlink_verify(bp); + if (fa) + xfs_verifier_error(bp, -EFSCORRUPTED, fa); + } +} + +static void +xfs_symlink_write_verify( + struct xfs_buf *bp) +{ + struct xfs_mount *mp = bp->b_mount; + struct xfs_buf_log_item *bip = bp->b_log_item; + xfs_failaddr_t fa; + + /* no verification of non-crc buffers */ + if (!xfs_sb_version_hascrc(&mp->m_sb)) + return; + + fa = xfs_symlink_verify(bp); + if (fa) { + xfs_verifier_error(bp, -EFSCORRUPTED, fa); + return; + } + + if (bip) { + struct xfs_dsymlink_hdr *dsl = bp->b_addr; + dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn); + } + xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF); +} + +const struct xfs_buf_ops xfs_symlink_buf_ops = { + .name = "xfs_symlink", + .magic = { 0, cpu_to_be32(XFS_SYMLINK_MAGIC) }, + .verify_read = xfs_symlink_read_verify, + .verify_write = xfs_symlink_write_verify, + .verify_struct = xfs_symlink_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; + + xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_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); + xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1); + 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); + xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) + + ifp->if_bytes - 1); +} + +/* + * Verify the in-memory consistency of an inline symlink data fork. This + * does not do on-disk format checks. + */ +xfs_failaddr_t +xfs_symlink_shortform_verify( + struct xfs_inode *ip) +{ + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK); + char *sfp = (char *)ifp->if_u1.if_data; + int size = ifp->if_bytes; + char *endp = sfp + size; + + ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL); + + /* + * Zero length symlinks should never occur in memory as they are + * never alllowed to exist on disk. + */ + if (!size) + return __this_address; + + /* No negative sizes or overly long symlink targets. */ + if (size < 0 || size > XFS_SYMLINK_MAXLEN) + return __this_address; + + /* No NULLs in the target either. */ + if (memchr(sfp, 0, size - 1)) + return __this_address; + + /* We /did/ null-terminate the buffer, right? */ + if (*endp != 0) + return __this_address; + return NULL; +} |