/* $NetBSD: wapbl_replay.h,v 1.3 2026/02/17 22:26:52 andvar Exp $ */ /*- * Copyright (c) 2003,2008 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Wasabi Systems, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #ifndef _SYS_WAPBL_REPLAY_H #define _SYS_WAPBL_REPLAY_H #include <sys/types.h> /* The WAPBL journal layout. * * The journal consists of a header followed by a circular buffer * region. The circular data area is described by the header * wc_circ_off, wc_circ_size, wc_head and wc_tail fields as bytes * from the start of the journal header. New records are inserted * at wc_head and the oldest valid record can be found at wc_tail. * When ((wc_head == wc_tail) && (wc_head == 0)), the journal is empty. * The condition of ((wc_head == wc_tail) && (wc_head != 0)) * indicates a full journal, although this condition is rare. * * The journal header as well as its records are marked by a 32bit * type tag and length for ease of parsing. Journal records are * padded so as to fall on journal device block boundaries. */ /* * The following are the 4 record types used by the journal: * Each tag indicates journal data organized by one of the * structures used below. */ enum { WAPBL_WC_HEADER = 0x5741424c, /* "WABL", struct wapbl_wc_header */ WAPBL_WC_INODES, /* struct wapbl_wc_inodelist */ WAPBL_WC_REVOCATIONS, /* struct wapbl_wc_blocklist */ WAPBL_WC_BLOCKS, /* struct wapbl_wc_blocklist */ }; /* null entry (on disk) */ /* This structure isn't used directly, but shares its header * layout with all the other log structures for the purpose * of reading a log structure and determining its type */ struct wapbl_wc_null { uint32_t wc_type; /* WAPBL_WC_* */ int32_t wc_len; uint8_t wc_spare[0]; /* actually longer */ }; /* journal header (on-disk) * This record is found at the start of the * journal, but not within the circular buffer region. As well as * describing the journal parameters and matching filesystem, it * additionally serves as the atomic update record for journal * updates. */ struct wapbl_wc_header { uint32_t wc_type; /* WAPBL_WC_HEADER log magic number */ int32_t wc_len; /* length of this journal entry */ uint32_t wc_checksum; uint32_t wc_generation; int32_t wc_fsid[2]; uint64_t wc_time; uint32_t wc_timensec; uint32_t wc_version; uint32_t wc_log_dev_bshift; uint32_t wc_fs_dev_bshift; int64_t wc_head; int64_t wc_tail; int64_t wc_circ_off; /* offset of circ buffer region */ int64_t wc_circ_size; /* size of circular buffer region */ uint8_t wc_spare[0]; /* actually longer */ }; /* list of blocks (on disk) * This record is used to describe a set of filesystem blocks, * and is used with two type tags, WAPBL_WC_BLOCKS and * WAPBL_WC_REVOCATIONS. * * For WAPBL_WC_BLOCKS, a copy of each listed block can be found * starting at the next log device blocksize boundary. starting at * one log device block since the start of the record. This contains * the bulk of the filesystem journal data which is written using * these records before being written into the filesystem. * * The WAPBL_WC_REVOCATIONS record is used to indicate that any * previously listed blocks should not be written into the filesystem. * This is important so that deallocated and reallocated data blocks * do not get overwritten with stale data from the journal. The * revocation records do not contain a copy of any actual block data. */ struct wapbl_wc_blocklist { uint32_t wc_type; /* WAPBL_WC_{REVOCATIONS,BLOCKS} */ int32_t wc_len; int32_t wc_blkcount; int32_t wc_unused; struct { int64_t wc_daddr; int32_t wc_unused; int32_t wc_dlen; } wc_blocks[0]; /* actually longer */ }; /* list of inodes (on disk) * This record is used to describe the set of inodes which * may be allocated but are unlinked. Inodes end up listed here * while they are in the process of being initialized and * deinitialized. Inodes unlinked while in use by a process * will be listed here and the actual deletion must be completed * on journal replay. */ struct wapbl_wc_inodelist { uint32_t wc_type; /* WAPBL_WC_INODES */ int32_t wc_len; int32_t wc_inocnt; int32_t wc_clear; /* set if previously listed inodes should be ignored */ struct { uint32_t wc_inumber; uint32_t wc_imode; } wc_inodes[0]; /* actually longer */ }; #endif /* _SYS_WAPBL_REPLAY_H */
