/* * Copyright (c) 2011-2019 The DragonFly Project. All rights reserved. * * This code is derived from software contributed to The DragonFly Project * by Matthew Dillon * by Venkatesh Srinivas * * 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. * 3. Neither the name of The DragonFly Project nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific, prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 * COPYRIGHT HOLDERS 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 _VFS_HAMMER2_DISK_H_ #define _VFS_HAMMER2_DISK_H_ #ifndef _SYS_UUID_H_ #include #endif #ifndef _SYS_DMSG_H_ #include #endif /* * The structures below represent the on-disk media structures for the HAMMER2 * filesystem. Note that all fields for on-disk structures are naturally * aligned. The host endian format is typically used - compatibility is * possible if the implementation detects reversed endian and adjusts accesses * accordingly. * * HAMMER2 primarily revolves around the directory topology: inodes, * directory entries, and block tables. Block device buffer cache buffers * are always 64KB. Logical file buffers are typically 16KB. All data * references utilize 64-bit byte offsets. * * Free block management is handled independently using blocks reserved by * the media topology. */ /* * The data at the end of a file or directory may be a fragment in order * to optimize storage efficiency. The minimum fragment size is 1KB. * Since allocations are in powers of 2 fragments must also be sized in * powers of 2 (1024, 2048, ... 65536). * * For the moment the maximum allocation size is HAMMER2_PBUFSIZE (64K), * which is 2^16. Larger extents may be supported in the future. Smaller * fragments might be supported in the future (down to 64 bytes is possible), * but probably will not be. * * A full indirect block use supports 512 x 128-byte blockrefs in a 64KB * buffer. Indirect blocks down to 1KB are supported to keep small * directories small. * * A maximally sized file (2^64-1 bytes) requires ~6 indirect block levels * using 64KB indirect blocks (128 byte refs, 512 or radix 9 per indblk). * * 16(datablk) + 9 + 9 + 9 + 9 + 9 + 9 = ~70. * 16(datablk) + 7 + 9 + 9 + 9 + 9 + 9 = ~68. (smaller top level indblk) * * The actual depth depends on copies redundancy and whether the filesystem * has chosen to use a smaller indirect block size at the top level or not. */ #define HAMMER2_ALLOC_MIN 1024 /* minimum allocation size */ #define HAMMER2_RADIX_MIN 10 /* minimum allocation size 2^N */ #define HAMMER2_ALLOC_MAX 65536 /* maximum allocation size */ #define HAMMER2_RADIX_MAX 16 /* maximum allocation size 2^N */ #define HAMMER2_RADIX_KEY 64 /* number of bits in key */ /* * HAMMER2_LBUFSIZE - Nominal buffer size for I/O rollups. * * HAMMER2_PBUFSIZE - Topological block size used by files for all * blocks except the block straddling EOF. * * HAMMER2_SEGSIZE - Allocation map segment size, typically 4MB * (space represented by a level0 bitmap). */ #define HAMMER2_SEGSIZE (1 << HAMMER2_FREEMAP_LEVEL0_RADIX) #define HAMMER2_SEGRADIX HAMMER2_FREEMAP_LEVEL0_RADIX #define HAMMER2_PBUFRADIX 16 /* physical buf (1<<16) bytes */ #define HAMMER2_PBUFSIZE 65536 #define HAMMER2_LBUFRADIX 14 /* logical buf (1<<14) bytes */ #define HAMMER2_LBUFSIZE 16384 #define HAMMER2_IND_BYTES_MIN 4096 #define HAMMER2_IND_BYTES_NOM HAMMER2_LBUFSIZE #define HAMMER2_IND_BYTES_MAX HAMMER2_PBUFSIZE #define HAMMER2_IND_RADIX_MIN 12 #define HAMMER2_IND_RADIX_NOM HAMMER2_LBUFRADIX #define HAMMER2_IND_RADIX_MAX HAMMER2_PBUFRADIX #define HAMMER2_IND_COUNT_MIN (HAMMER2_IND_BYTES_MIN / \ sizeof(hammer2_blockref_t)) #define HAMMER2_IND_COUNT_NOM (HAMMER2_IND_BYTES_NOM / \ sizeof(hammer2_blockref_t)) #define HAMMER2_IND_COUNT_MAX (HAMMER2_IND_BYTES_MAX / \ sizeof(hammer2_blockref_t)) /* * In HAMMER2, arrays of blockrefs are fully set-associative, meaning that * any element can occur at any index and holes can be anywhere. * * Inodes embed either 512 bytes of direct data or an array of 4 blockrefs, * resulting in highly efficient storage for files <= 512 bytes and for files * <= 512KB. Up to 4 directory entries can be referenced from a directory * without requiring an indirect block. */ #define HAMMER2_SET_RADIX 2 /* radix 2 = 4 entries */ #define HAMMER2_SET_COUNT (1 << HAMMER2_SET_RADIX) #define HAMMER2_EMBEDDED_BYTES 512 /* inode blockset/dd size */ #define HAMMER2_EMBEDDED_RADIX 9 #define HAMMER2_PBUFMASK (HAMMER2_PBUFSIZE - 1) #define HAMMER2_LBUFMASK (HAMMER2_LBUFSIZE - 1) #define HAMMER2_SEGMASK (HAMMER2_SEGSIZE - 1) #define HAMMER2_LBUFMASK64 ((hammer2_off_t)HAMMER2_LBUFMASK) #define HAMMER2_PBUFSIZE64 ((hammer2_off_t)HAMMER2_PBUFSIZE) #define HAMMER2_PBUFMASK64 ((hammer2_off_t)HAMMER2_PBUFMASK) #define HAMMER2_SEGSIZE64 ((hammer2_off_t)HAMMER2_SEGSIZE) #define HAMMER2_SEGMASK64 ((hammer2_off_t)HAMMER2_SEGMASK) #define HAMMER2_UUID_STRING "5cbb9ad1-862d-11dc-a94d-01301bb8a9f5" /* * A 4MB segment is reserved at the beginning of each 1GB. This segment * contains the volume header (or backup volume header), the free block * table, and possibly other information in the future. * * 4MB = 64 x 64K blocks. Each 4MB segment is broken down as follows: * * ========== * 0 volume header (for the first four 2GB zones) * 1 freemap00 level1 FREEMAP_LEAF (256 x 128B bitmap data per 1GB) * 2 level2 FREEMAP_NODE (256 x 128B indirect block per 256GB) * 3 level3 FREEMAP_NODE (256 x 128B indirect block per 64TB) * 4 level4 FREEMAP_NODE (256 x 128B indirect block per 16PB) * 5 level5 FREEMAP_NODE (256 x 128B indirect block per 4EB) * 6 freemap01 level1 (rotation) * 7 level2 * 8 level3 * 9 level4 * 10 level5 * 11 freemap02 level1 (rotation) * 12 level2 * 13 level3 * 14 level4 * 15 level5 * 16 freemap03 level1 (rotation) * 17 level2 * 18 level3 * 19 level4 * 20 level5 * 21 freemap04 level1 (rotation) * 22 level2 * 23 level3 * 24 level4 * 25 level5 * 26 freemap05 level1 (rotation) * 27 level2 * 28 level3 * 29 level4 * 30 level5 * 31 freemap06 level1 (rotation) * 32 level2 * 33 level3 * 34 level4 * 35 level5 * 36 freemap07 level1 (rotation) * 37 level2 * 38 level3 * 39 level4 * 40 level5 * 41 unused * .. unused * 63 unused * ========== * * The first four 2GB zones contain volume headers and volume header backups. * After that the volume header block# is reserved for future use. Similarly, * there are many blocks related to various Freemap levels which are not * used in every segment and those are also reserved for future use. * Note that each FREEMAP_LEAF or FREEMAP_NODE uses 32KB out of 64KB slot. * * Freemap (see the FREEMAP document) * * The freemap utilizes blocks #1-40 in 8 sets of 5 blocks. Each block in * a set represents a level of depth in the freemap topology. Eight sets * exist to prevent live updates from disturbing the state of the freemap * were a crash/reboot to occur. That is, a live update is not committed * until the update's flush reaches the volume root. There are FOUR volume * roots representing the last four synchronization points, so the freemap * must be consistent no matter which volume root is chosen by the mount * code. * * Each freemap set is 5 x 64K blocks and represents the 1GB, 256GB, 64TB, * 16PB and 4EB indirect map. The volume header itself has a set of 4 freemap * blockrefs representing another 2 bits, giving us a total 64 bits of * representable address space. * * The Level 0 64KB block represents 1GB of storage represented by 32KB * (256 x struct hammer2_bmap_data). Each structure represents 4MB of storage * and has a 512 bit bitmap, using 2 bits to represent a 16KB chunk of * storage. These 2 bits represent the following states: * * 00 Free * 01 (reserved) (Possibly partially allocated) * 10 Possibly free * 11 Allocated * * One important thing to note here is that the freemap resolution is 16KB, * but the minimum storage allocation size is 1KB. The hammer2 vfs keeps * track of sub-allocations in memory, which means that on a unmount or reboot * the entire 16KB of a partially allocated block will be considered fully * allocated. It is possible for fragmentation to build up over time, but * defragmentation is fairly easy to accomplish since all modifications * allocate a new block. * * The Second thing to note is that due to the way snapshots and inode * replication works, deleting a file cannot immediately free the related * space. Furthermore, deletions often do not bother to traverse the * block subhierarchy being deleted. And to go even further, whole * sub-directory trees can be deleted simply by deleting the directory inode * at the top. So even though we have a symbol to represent a 'possibly free' * block (binary 10), only the bulk free scanning code can actually use it. * Normal 'rm's or other deletions do not. * * WARNING! ZONE_SEG and VOLUME_ALIGN must be a multiple of 1<= ZONE_SEG. * * In Summary: * * (1) Modifications to freemap blocks 'allocate' a new copy (aka use a block * from the next set). The new copy is reused until a flush occurs at * which point the next modification will then rotate to the next set. */ #define HAMMER2_VOLUME_ALIGN (8 * 1024 * 1024) #define HAMMER2_VOLUME_ALIGN64 ((hammer2_off_t)HAMMER2_VOLUME_ALIGN) #define HAMMER2_VOLUME_ALIGNMASK (HAMMER2_VOLUME_ALIGN - 1) #define HAMMER2_VOLUME_ALIGNMASK64 ((hammer2_off_t)HAMMER2_VOLUME_ALIGNMASK) #define HAMMER2_NEWFS_ALIGN (HAMMER2_VOLUME_ALIGN) #define HAMMER2_NEWFS_ALIGN64 ((hammer2_off_t)HAMMER2_VOLUME_ALIGN) #define HAMMER2_NEWFS_ALIGNMASK (HAMMER2_VOLUME_ALIGN - 1) #define HAMMER2_NEWFS_ALIGNMASK64 ((hammer2_off_t)HAMMER2_NEWFS_ALIGNMASK) #define HAMMER2_ZONE_BYTES64 (2LLU * 1024 * 1024 * 1024) #define HAMMER2_ZONE_MASK64 (HAMMER2_ZONE_BYTES64 - 1) #define HAMMER2_ZONE_SEG (4 * 1024 * 1024) #define HAMMER2_ZONE_SEG64 ((hammer2_off_t)HAMMER2_ZONE_SEG) #define HAMMER2_ZONE_BLOCKS_SEG (HAMMER2_ZONE_SEG / HAMMER2_PBUFSIZE) #define HAMMER2_ZONE_FREEMAP_INC 5 /* 5 deep */ #define HAMMER2_ZONE_VOLHDR 0 /* volume header or backup */ #define HAMMER2_ZONE_FREEMAP_00 1 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_01 6 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_02 11 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_03 16 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_04 21 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_05 26 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_06 31 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_07 36 /* normal freemap rotation */ #define HAMMER2_ZONE_FREEMAP_END 41 /* (non-inclusive) */ #define HAMMER2_ZONE_UNUSED41 41 #define HAMMER2_ZONE_UNUSED42 42 #define HAMMER2_ZONE_UNUSED43 43 #define HAMMER2_ZONE_UNUSED44 44 #define HAMMER2_ZONE_UNUSED45 45 #define HAMMER2_ZONE_UNUSED46 46 #define HAMMER2_ZONE_UNUSED47 47 #define HAMMER2_ZONE_UNUSED48 48 #define HAMMER2_ZONE_UNUSED49 49 #define HAMMER2_ZONE_UNUSED50 50 #define HAMMER2_ZONE_UNUSED51 51 #define HAMMER2_ZONE_UNUSED52 52 #define HAMMER2_ZONE_UNUSED53 53 #define HAMMER2_ZONE_UNUSED54 54 #define HAMMER2_ZONE_UNUSED55 55 #define HAMMER2_ZONE_UNUSED56 56 #define HAMMER2_ZONE_UNUSED57 57 #define HAMMER2_ZONE_UNUSED58 58 #define HAMMER2_ZONE_UNUSED59 59 #define HAMMER2_ZONE_UNUSED60 60 #define HAMMER2_ZONE_UNUSED61 61 #define HAMMER2_ZONE_UNUSED62 62 #define HAMMER2_ZONE_UNUSED63 63 #define HAMMER2_ZONE_END 64 /* non-inclusive */ #define HAMMER2_NFREEMAPS 8 /* FREEMAP_00 - FREEMAP_07 */ /* relative to FREEMAP_x */ #define HAMMER2_ZONEFM_LEVEL1 0 /* 1GB leafmap */ #define HAMMER2_ZONEFM_LEVEL2 1 /* 256GB indmap */ #define HAMMER2_ZONEFM_LEVEL3 2 /* 64TB indmap */ #define HAMMER2_ZONEFM_LEVEL4 3 /* 16PB indmap */ #define HAMMER2_ZONEFM_LEVEL5 4 /* 4EB indmap */ /* LEVEL6 is a set of 4 blockrefs in the volume header 16EB */ /* * Freemap radix. Assumes a set-count of 4, 128-byte blockrefs, * 32KB indirect block for freemap (LEVELN_PSIZE below). * * Leaf entry represents 4MB of storage broken down into a 512-bit * bitmap, 2-bits per entry. So course bitmap item represents 16KB. */ #if HAMMER2_SET_COUNT != 4 #error "hammer2_disk.h - freemap assumes SET_COUNT is 4" #endif #define HAMMER2_FREEMAP_LEVEL6_RADIX 64 /* 16EB (end) */ #define HAMMER2_FREEMAP_LEVEL5_RADIX 62 /* 4EB */ #define HAMMER2_FREEMAP_LEVEL4_RADIX 54 /* 16PB */ #define HAMMER2_FREEMAP_LEVEL3_RADIX 46 /* 64TB */ #define HAMMER2_FREEMAP_LEVEL2_RADIX 38 /* 256GB */ #define HAMMER2_FREEMAP_LEVEL1_RADIX 30 /* 1GB */ #define HAMMER2_FREEMAP_LEVEL0_RADIX 22 /* 4MB (x 256 in l-1 leaf) */ #define HAMMER2_FREEMAP_LEVELN_PSIZE 32768 /* physical bytes */ #define HAMMER2_FREEMAP_LEVEL5_SIZE ((hammer2_off_t)1 << \ HAMMER2_FREEMAP_LEVEL5_RADIX) #define HAMMER2_FREEMAP_LEVEL4_SIZE ((hammer2_off_t)1 << \ HAMMER2_FREEMAP_LEVEL4_RADIX) #define HAMMER2_FREEMAP_LEVEL3_SIZE ((hammer2_off_t)1 << \ HAMMER2_FREEMAP_LEVEL3_RADIX) #define HAMMER2_FREEMAP_LEVEL2_SIZE ((hammer2_off_t)1 << \ HAMMER2_FREEMAP_LEVEL2_RADIX) #define HAMMER2_FREEMAP_LEVEL1_SIZE ((hammer2_off_t)1 << \ HAMMER2_FREEMAP_LEVEL1_RADIX) #define HAMMER2_FREEMAP_LEVEL0_SIZE ((hammer2_off_t)1 << \ HAMMER2_FREEMAP_LEVEL0_RADIX) #define HAMMER2_FREEMAP_LEVEL5_MASK (HAMMER2_FREEMAP_LEVEL5_SIZE - 1) #define HAMMER2_FREEMAP_LEVEL4_MASK (HAMMER2_FREEMAP_LEVEL4_SIZE - 1) #define HAMMER2_FREEMAP_LEVEL3_MASK (HAMMER2_FREEMAP_LEVEL3_SIZE - 1) #define HAMMER2_FREEMAP_LEVEL2_MASK (HAMMER2_FREEMAP_LEVEL2_SIZE - 1) #define HAMMER2_FREEMAP_LEVEL1_MASK (HAMMER2_FREEMAP_LEVEL1_SIZE - 1) #define HAMMER2_FREEMAP_LEVEL0_MASK (HAMMER2_FREEMAP_LEVEL0_SIZE - 1) #define HAMMER2_FREEMAP_COUNT (int)(HAMMER2_FREEMAP_LEVELN_PSIZE / \ sizeof(hammer2_bmap_data_t)) /* * XXX I made a mistake and made the reserved area begin at each LEVEL1 zone, * which is on a 1GB demark. This will eat a little more space but for * now we retain compatibility and make FMZONEBASE every 1GB */ #define H2FMZONEBASE(key) ((key) & ~HAMMER2_FREEMAP_LEVEL1_MASK) #define H2FMBASE(key, radix) rounddown2(key, (hammer2_off_t)1 << (radix)) /* * 16KB bitmap granularity (x2 bits per entry). */ #define HAMMER2_FREEMAP_BLOCK_RADIX 14 #define HAMMER2_FREEMAP_BLOCK_SIZE (1 << HAMMER2_FREEMAP_BLOCK_RADIX) #define HAMMER2_FREEMAP_BLOCK_MASK (HAMMER2_FREEMAP_BLOCK_SIZE - 1) /* * bitmap[] structure. 2 bits per HAMMER2_FREEMAP_BLOCK_SIZE. * * 8 x 64-bit elements, 2 bits per block. * 32 blocks (radix 5) per element. * representing INDEX_SIZE bytes worth of storage per element. */ typedef uint64_t hammer2_bitmap_t; #define HAMMER2_BMAP_ALLONES ((hammer2_bitmap_t)-1) #define HAMMER2_BMAP_ELEMENTS 8 #define HAMMER2_BMAP_BITS_PER_ELEMENT 64 #define HAMMER2_BMAP_INDEX_RADIX 5 /* 32 blocks per element */ #define HAMMER2_BMAP_BLOCKS_PER_ELEMENT (1 << HAMMER2_BMAP_INDEX_RADIX) #define HAMMER2_BMAP_INDEX_SIZE (HAMMER2_FREEMAP_BLOCK_SIZE * \ HAMMER2_BMAP_BLOCKS_PER_ELEMENT) #define HAMMER2_BMAP_INDEX_MASK (HAMMER2_BMAP_INDEX_SIZE - 1) #define HAMMER2_BMAP_SIZE (HAMMER2_BMAP_INDEX_SIZE * \ HAMMER2_BMAP_ELEMENTS) #define HAMMER2_BMAP_MASK (HAMMER2_BMAP_SIZE - 1) /* * Two linear areas can be reserved after the initial 4MB segment in the base * zone (the one starting at offset 0). These areas are NOT managed by the * block allocator and do not fall under HAMMER2 crc checking rules based * at the volume header (but can be self-CRCd internally, depending). */ #define HAMMER2_BOOT_MIN_BYTES HAMMER2_VOLUME_ALIGN #define HAMMER2_BOOT_NOM_BYTES (64*1024*1024) #define HAMMER2_BOOT_MAX_BYTES (256*1024*1024) #define HAMMER2_AUX_MIN_BYTES HAMMER2_VOLUME_ALIGN #define HAMMER2_AUX_NOM_BYTES (256*1024*1024) #define HAMMER2_AUX_MAX_BYTES (1024*1024*1024) /* * Most HAMMER2 types are implemented as unsigned 64-bit integers. * Transaction ids are monotonic. * * We utilize 32-bit iSCSI CRCs. */ typedef uint64_t hammer2_tid_t; typedef uint64_t hammer2_off_t; typedef uint64_t hammer2_key_t; typedef uint32_t hammer2_crc32_t; /* * Miscellaneous ranges (all are unsigned). */ #define HAMMER2_TID_MIN 1ULL #define HAMMER2_TID_MAX 0xFFFFFFFFFFFFFFFFULL #define HAMMER2_KEY_MIN 0ULL #define HAMMER2_KEY_MAX 0xFFFFFFFFFFFFFFFFULL /* * HAMMER2 data offset special cases and masking. * * All HAMMER2 data offsets have to be broken down into a 64K buffer base * offset (HAMMER2_OFF_MASK_HI) and a 64K buffer index (HAMMER2_OFF_MASK_LO). * * Indexes into physical buffers are always 64-byte aligned. The low 6 bits * of the data offset field specifies how large the data chunk being pointed * to as a power of 2. The theoretical minimum radix is thus 6 (The space * needed in the low bits of the data offset field). However, the practical * minimum allocation chunk size is 1KB (a radix of 10), so HAMMER2 sets * HAMMER2_RADIX_MIN to 10. The maximum radix is currently 16 (64KB), but * we fully intend to support larger extents in the future. * * WARNING! A radix of 0 (such as when data_off is all 0's) is a special * case which means no data associated with the blockref, and * not the '1 byte' it would otherwise calculate to. */ #define HAMMER2_OFF_MASK 0xFFFFFFFFFFFFFFC0ULL #define HAMMER2_OFF_MASK_LO (HAMMER2_OFF_MASK & HAMMER2_PBUFMASK64) #define HAMMER2_OFF_MASK_HI (~HAMMER2_PBUFMASK64) #define HAMMER2_OFF_MASK_RADIX 0x000000000000003FULL /* * HAMMER2 directory support and pre-defined keys */ #define HAMMER2_DIRHASH_VISIBLE 0x8000000000000000ULL #define HAMMER2_DIRHASH_USERMSK 0x7FFFFFFFFFFFFFFFULL #define HAMMER2_DIRHASH_LOMASK 0x0000000000007FFFULL #if 0 #define HAMMER2_DIRHASH_HIMASK 0xFFFFFFFFFFFF0000ULL #define HAMMER2_DIRHASH_FORCED 0x0000000000008000ULL /* bit forced on */ #endif #define HAMMER2_SROOT_KEY 0x0000000000000000ULL /* volume to sroot */ #define HAMMER2_BOOT_KEY 0xd9b36ce135528000ULL /* sroot to BOOT PFS */ /************************************************************************ * DMSG SUPPORT * ************************************************************************ * LNK_VOLCONF * * All HAMMER2 directories directly under the super-root on your local * media can be mounted separately, even if they share the same physical * device. * * When you do a HAMMER2 mount you are effectively tying into a HAMMER2 * cluster via local media. The local media does not have to participate * in the cluster, other than to provide the hammer2_volconf[] array and * root inode for the mount. * * This is important: The mount device path you specify serves to bootstrap * your entry into the cluster, but your mount will make active connections * to ALL copy elements in the hammer2_volconf[] array which match the * PFSID of the directory in the super-root that you specified. The local * media path does not have to be mentioned in this array but becomes part * of the cluster based on its type and access rights. ALL ELEMENTS ARE * TREATED ACCORDING TO TYPE NO MATTER WHICH ONE YOU MOUNT FROM. * * The actual cluster may be far larger than the elements you list in the * hammer2_volconf[] array. You list only the elements you wish to * directly connect to and you are able to access the rest of the cluster * indirectly through those connections. * * WARNING! This structure must be exactly 128 bytes long for its config * array to fit in the volume header. */ struct hammer2_volconf { uint8_t copyid; /* 00 copyid 0-255 (must match slot) */ uint8_t inprog; /* 01 operation in progress, or 0 */ uint8_t chain_to; /* 02 operation chaining to, or 0 */ uint8_t chain_from; /* 03 operation chaining from, or 0 */ uint16_t flags; /* 04-05 flags field */ uint8_t error; /* 06 last operational error */ uint8_t priority; /* 07 priority and round-robin flag */ uint8_t remote_pfs_type;/* 08 probed direct remote PFS type */ uint8_t reserved08[23]; /* 09-1F */ uuid_t pfs_clid; /* 20-2F copy target must match this uuid */ uint8_t label[16]; /* 30-3F import/export label */ uint8_t path[64]; /* 40-7F target specification string or key */ } __packed; typedef struct hammer2_volconf hammer2_volconf_t; #define DMSG_VOLF_ENABLED 0x0001 #define DMSG_VOLF_INPROG 0x0002 #define DMSG_VOLF_CONN_RR 0x80 /* round-robin at same priority */ #define DMSG_VOLF_CONN_EF 0x40 /* media errors flagged */ #define DMSG_VOLF_CONN_PRI 0x0F /* select priority 0-15 (15=best) */ struct dmsg_lnk_hammer2_volconf { dmsg_hdr_t head; hammer2_volconf_t copy; /* copy spec */ int32_t index; int32_t unused01; uuid_t mediaid; int64_t reserved02[32]; } __packed; typedef struct dmsg_lnk_hammer2_volconf dmsg_lnk_hammer2_volconf_t; #define DMSG_LNK_HAMMER2_VOLCONF DMSG_LNK(DMSG_LNK_CMD_HAMMER2_VOLCONF, \ dmsg_lnk_hammer2_volconf) #define H2_LNK_VOLCONF(msg) ((dmsg_lnk_hammer2_volconf_t *)(msg)->any.buf) /* * HAMMER2 directory entry header (embedded in blockref) exactly 16 bytes */ struct hammer2_dirent_head { hammer2_tid_t inum; /* inode number */ uint16_t namlen; /* name length */ uint8_t type; /* OBJTYPE_* */ uint8_t unused0B; uint8_t unused0C[4]; } __packed; typedef struct hammer2_dirent_head hammer2_dirent_head_t; /* * The media block reference structure. This forms the core of the HAMMER2 * media topology recursion. This 128-byte data structure is embedded in the * volume header, in inodes (which are also directory entries), and in * indirect blocks. * * A blockref references a single media item, which typically can be a * directory entry (aka inode), indirect block, or data block. * * The primary feature a blockref represents is the ability to validate * the entire tree underneath it via its check code. Any modification to * anything propagates up the blockref tree all the way to the root, replacing * the related blocks and compounding the generated check code. * * The check code can be a simple 32-bit iscsi code, a 64-bit crc, or as * complex as a 512 bit cryptographic hash. I originally used a 64-byte * blockref but later expanded it to 128 bytes to be able to support the * larger check code as well as to embed statistics for quota operation. * * Simple check codes are not sufficient for unverified dedup. Even with * a maximally-sized check code unverified dedup should only be used in * subdirectory trees where you do not need 100% data integrity. * * Unverified dedup is deduping based on meta-data only without verifying * that the data blocks are actually identical. Verified dedup guarantees * integrity but is a far more I/O-expensive operation. * * -- * * mirror_tid - per cluster node modified (propagated upward by flush) * modify_tid - clc record modified (not propagated). * update_tid - clc record updated (propagated upward on verification) * * CLC - Stands for 'Cluster Level Change', identifiers which are identical * within the topology across all cluster nodes (when fully * synchronized). * * NOTE: The range of keys represented by the blockref is (key) to * ((key) + (1LL << keybits) - 1). HAMMER2 usually populates * blocks bottom-up, inserting a new root when radix expansion * is required. * * leaf_count - Helps manage leaf collapse calculations when indirect * blocks become mostly empty. This value caps out at * HAMMER2_BLOCKREF_LEAF_MAX (65535). * * Used by the chain code to determine when to pull leafs up * from nearly empty indirect blocks. For the purposes of this * calculation, BREF_TYPE_INODE is considered a leaf, along * with DIRENT and DATA. * * RESERVED FIELDS * * A number of blockref fields are reserved and should generally be set to * 0 for future compatibility. * * FUTURE BLOCKREF EXPANSION * * CONTENT ADDRESSABLE INDEXING (future) - Using a 256 or 512-bit check code. */ struct hammer2_blockref { /* MUST BE EXACTLY 128 BYTES */ uint8_t type; /* type of underlying item */ uint8_t methods; /* check method & compression method */ uint8_t copyid; /* specify which copy this is */ uint8_t keybits; /* #of keybits masked off 0=leaf */ uint8_t vradix; /* virtual data/meta-data size */ uint8_t flags; /* blockref flags */ uint16_t leaf_count; /* leaf aggregation count */ hammer2_key_t key; /* key specification */ hammer2_tid_t mirror_tid; /* media flush topology & freemap */ hammer2_tid_t modify_tid; /* clc modify (not propagated) */ hammer2_off_t data_off; /* low 6 bits is phys size (radix)*/ hammer2_tid_t update_tid; /* clc modify (propagated upward) */ union { char buf[16]; /* * Directory entry header (BREF_TYPE_DIRENT) * * NOTE: check.buf contains filename if <= 64 bytes. Longer * filenames are stored in a data reference of size * HAMMER2_ALLOC_MIN (at least 256, typically 1024). * * NOTE: inode structure may contain a copy of a recently * associated filename, for recovery purposes. * * NOTE: Superroot entries are INODEs, not DIRENTs. Code * allows both cases. */ hammer2_dirent_head_t dirent; /* * Statistics aggregation (BREF_TYPE_INODE, BREF_TYPE_INDIRECT) */ struct { hammer2_key_t data_count; hammer2_key_t inode_count; } stats; } embed; union { /* check info */ char buf[64]; struct { uint32_t value; uint32_t reserved[15]; } iscsi32; struct { uint64_t value; uint64_t reserved[7]; } xxhash64; struct { char data[24]; char reserved[40]; } sha192; struct { char data[32]; char reserved[32]; } sha256; struct { char data[64]; } sha512; /* * Freemap hints are embedded in addition to the icrc32. * * bigmask - Radixes available for allocation (0-31). * Heuristical (may be permissive but not * restrictive). Typically only radix values * 10-16 are used (i.e. (1<<10) through (1<<16)). * * avail - Total available space remaining, in bytes */ struct { uint32_t icrc32; uint32_t bigmask; /* available radixes */ uint64_t avail; /* total available bytes */ char reserved[48]; } freemap; } check; } __packed; typedef struct hammer2_blockref hammer2_blockref_t; #define HAMMER2_BLOCKREF_BYTES 128 /* blockref struct in bytes */ #define HAMMER2_BLOCKREF_RADIX 7 #define HAMMER2_BLOCKREF_LEAF_MAX 65535 /* * On-media and off-media blockref types. * * types >= 128 are pseudo values that should never be present on-media. */ #define HAMMER2_BREF_TYPE_EMPTY 0 #define HAMMER2_BREF_TYPE_INODE 1 #define HAMMER2_BREF_TYPE_INDIRECT 2 #define HAMMER2_BREF_TYPE_DATA 3 #define HAMMER2_BREF_TYPE_DIRENT 4 #define HAMMER2_BREF_TYPE_FREEMAP_NODE 5 #define HAMMER2_BREF_TYPE_FREEMAP_LEAF 6 #define HAMMER2_BREF_TYPE_INVALID 7 #define HAMMER2_BREF_TYPE_FREEMAP 254 /* pseudo-type */ #define HAMMER2_BREF_TYPE_VOLUME 255 /* pseudo-type */ #define HAMMER2_BREF_FLAG_PFSROOT 0x01 /* see also related opflag */ #define HAMMER2_BREF_FLAG_UNUSED 0x02 #define HAMMER2_BREF_FLAG_EMERG_MIP 0x04 /* emerg modified-in-place */ /* * Check mode defaults to xxhash64. */ #define HAMMER2_CHECK_NONE 0 #define HAMMER2_CHECK_DISABLED 1 #define HAMMER2_CHECK_ISCSI32 2 #define HAMMER2_CHECK_XXHASH64 3 #define HAMMER2_CHECK_SHA192 4 #define HAMMER2_CHECK_FREEMAP 5 #define HAMMER2_CHECK_DEFAULT HAMMER2_CHECK_XXHASH64 /* * Compression mode defaults to LZ4. */ #define HAMMER2_COMP_NONE 0 #define HAMMER2_COMP_AUTOZERO 1 #define HAMMER2_COMP_LZ4 2 #define HAMMER2_COMP_ZLIB 3 #define HAMMER2_COMP_DEFAULT HAMMER2_COMP_LZ4 /* * Encode/decode check mode and compression mode for bref.methods. * The compression level is not encoded in bref.methods. */ #define HAMMER2_ENC_CHECK(n) (((n) & 15) << 4) #define HAMMER2_DEC_CHECK(n) (((n) >> 4) & 15) #define HAMMER2_ENC_COMP(n) ((n) & 15) #define HAMMER2_DEC_COMP(n) ((n) & 15) /* * Encode/decode check or compression algorithm request in * ipdata->meta.check_algo and ipdata->meta.comp_algo. */ #define HAMMER2_ENC_ALGO(n) (n) #define HAMMER2_DEC_ALGO(n) ((n) & 15) #define HAMMER2_ENC_LEVEL(n) ((n) << 4) #define HAMMER2_DEC_LEVEL(n) (((n) >> 4) & 15) /* * HAMMER2 block references are collected into sets of 4 blockrefs. These * sets are fully associative, meaning the elements making up a set may * contain duplicate entries, holes, but valid elements are always sorted. * * When redundancy is desired a set may contain several duplicate * entries pointing to different copies of the same data. Up to 4 copies * are supported. Not implemented. * * When a set fills up another level of indirection is inserted, moving * some or all of the set's contents into indirect blocks placed under the * set. This is a top-down approach in that indirect blocks are not created * until the set actually becomes full (that is, the entries in the set can * shortcut the indirect blocks when the set is not full). Depending on how * things are filled multiple indirect blocks will eventually be created. */ struct hammer2_blockset { hammer2_blockref_t blockref[HAMMER2_SET_COUNT]; }; typedef struct hammer2_blockset hammer2_blockset_t; /* * Catch programmer snafus */ #if (1 << HAMMER2_SET_RADIX) != HAMMER2_SET_COUNT #error "hammer2 direct radix is incorrect" #endif #if (1 << HAMMER2_PBUFRADIX) != HAMMER2_PBUFSIZE #error "HAMMER2_PBUFRADIX and HAMMER2_PBUFSIZE are inconsistent" #endif #if (1 << HAMMER2_RADIX_MIN) != HAMMER2_ALLOC_MIN #error "HAMMER2_RADIX_MIN and HAMMER2_ALLOC_MIN are inconsistent" #endif /* * hammer2_bmap_data - A freemap entry in the LEVEL1 block. * * Each 128-byte entry contains the bitmap and meta-data required to manage * a LEVEL0 (4MB) block of storage. The storage is managed in 256 x 16KB * chunks. * * A smaller allocation granularity is supported via a linear iterator and/or * must otherwise be tracked in ram. * * (data structure must be 128 bytes exactly) * * linear - A BYTE linear allocation offset used for sub-16KB allocations * only. May contain values between 0 and 4MB. Must be ignored * if 16KB-aligned (i.e. force bitmap scan), otherwise may be * used to sub-allocate within the 16KB block (which is already * marked as allocated in the bitmap). * * Sub-allocations need only be 1KB-aligned and do not have to be * size-aligned, and 16KB or larger allocations do not update this * field, resulting in pretty good packing. * * Please note that file data granularity may be limited by * other issues such as buffer cache direct-mapping and the * desire to support sector sizes up to 16KB (so H2 only issues * I/O's in multiples of 16KB anyway). * * class - Clustering class. Cleared to 0 only if the entire leaf becomes * free. Used to cluster device buffers so all elements must have * the same device block size, but may mix logical sizes. * * Typically integrated with the blockref type in the upper 8 bits * to localize inodes and indrect blocks, improving bulk free scans * and directory scans. * * bitmap - Two bits per 16KB allocation block arranged in arrays of * 64-bit elements, 256x2 bits representing ~4MB worth of media * storage. Bit patterns are as follows: * * 00 Unallocated * 01 (reserved) * 10 Possibly free * 11 Allocated * * ========== * level6 freemap * blockref[0] : 4EB * blockref[1] : 4EB * blockref[2] : 4EB * blockref[3] : 4EB * ----------------------------------------------------------------------- * 4 x 128B = 512B : 4 x 4EB = 16EB * * level2-5 FREEMAP_NODE * blockref[0] : 1GB,256GB,64TB,16PB * blockref[1] : 1GB,256GB,64TB,16PB * ... * blockref[255] : 1GB,256GB,64TB,16PB * ----------------------------------------------------------------------- * 256 x 128B = 32KB : 256 x 1GB,256GB,64TB,16PB = 256GB,64TB,16PB,4EB * * level1 FREEMAP_LEAF * bmap_data[0] : 8 x 8B = 512bits = 256 x 2bits -> 256 x 16KB = 4MB * bmap_data[1] : 8 x 8B = 512bits = 256 x 2bits -> 256 x 16KB = 4MB * ... * bmap_data[255] : 8 x 8B = 512bits = 256 x 2bits -> 256 x 16KB = 4MB * ----------------------------------------------------------------------- * 256 x 128B = 32KB : 256 x 4MB = 1GB * ========== */ struct hammer2_bmap_data { int32_t linear; /* 00 linear sub-granular allocation offset */ uint16_t class; /* 04-05 clustering class ((type<<8)|radix) */ uint8_t reserved06; /* 06 */ uint8_t reserved07; /* 07 */ uint32_t reserved08; /* 08 */ uint32_t reserved0C; /* 0C */ uint32_t reserved10; /* 10 */ uint32_t reserved14; /* 14 */ uint32_t reserved18; /* 18 */ uint32_t avail; /* 1C */ uint32_t reserved20[8]; /* 20-3F */ /* 40-7F 512 bits manages 4MB of storage */ hammer2_bitmap_t bitmapq[HAMMER2_BMAP_ELEMENTS]; } __packed; typedef struct hammer2_bmap_data hammer2_bmap_data_t; /* * The inode number is stored in the inode rather than being * based on the location of the inode (since the location moves every time * the inode or anything underneath the inode is modified). * * The inode is 1024 bytes, made up of 256 bytes of meta-data, 256 bytes * for the filename, and 512 bytes worth of direct file data OR an embedded * blockset. The in-memory hammer2_inode structure contains only the mostly- * node-independent meta-data portion (some flags are node-specific and will * not be synchronized). The rest of the inode is node-specific and chain I/O * is required to obtain it. * * Directories represent one inode per blockref. Inodes are not laid out * as a file but instead are represented by the related blockrefs. The * blockrefs, in turn, are indexed by the 64-bit directory hash key. Remember * that blocksets are fully associative, so a certain degree efficiency is * achieved just from that. * * Up to 512 bytes of direct data can be embedded in an inode, and since * inodes are essentially directory entries this also means that small data * files end up simply being laid out linearly in the directory, resulting * in fewer seeks and highly optimal access. * * The compression mode can be changed at any time in the inode and is * recorded on a blockref-by-blockref basis. */ #define HAMMER2_INODE_BYTES 1024 /* (asserted by code) */ #define HAMMER2_INODE_MAXNAME 256 /* maximum name in bytes */ #define HAMMER2_INODE_VERSION_ONE 1 #define HAMMER2_INODE_START 1024 /* dynamically allocated */ struct hammer2_inode_meta { uint16_t version; /* 0000 inode data version */ uint8_t reserved02; /* 0002 */ uint8_t pfs_subtype; /* 0003 pfs sub-type */ /* * core inode attributes, inode type, misc flags */ uint32_t uflags; /* 0004 chflags */ uint32_t rmajor; /* 0008 available for device nodes */ uint32_t rminor; /* 000C available for device nodes */ uint64_t ctime; /* 0010 inode change time */ uint64_t mtime; /* 0018 modified time */ uint64_t atime; /* 0020 access time (unsupported) */ uint64_t btime; /* 0028 birth time */ uuid_t uid; /* 0030 uid / degenerate unix uid */ uuid_t gid; /* 0040 gid / degenerate unix gid */ uint8_t type; /* 0050 object type */ uint8_t op_flags; /* 0051 operational flags */ uint16_t cap_flags; /* 0052 capability flags */ uint32_t mode; /* 0054 unix modes (typ low 16 bits) */ /* * inode size, identification, localized recursive configuration * for compression and backup copies. * * NOTE: Nominal parent inode number (iparent) is only applicable * for directories but can also help for files during * catastrophic recovery. */ hammer2_tid_t inum; /* 0058 inode number */ hammer2_off_t size; /* 0060 size of file */ uint64_t nlinks; /* 0068 hard links (typ only dirs) */ hammer2_tid_t iparent; /* 0070 nominal parent inum */ hammer2_key_t name_key; /* 0078 full filename key */ uint16_t name_len; /* 0080 filename length */ uint8_t ncopies; /* 0082 ncopies to local media */ uint8_t comp_algo; /* 0083 compression request & algo */ uint8_t unused84; /* 0084 */ uint8_t check_algo; /* 0085 check code request & algo */ /* * These fields are currently only applicable to PFSROOTs. * * NOTE: We can't use {volume_data->fsid, pfs_clid} to uniquely * identify an instance of a PFS in the cluster because * a mount may contain more than one copy of the PFS as * a separate node. {pfs_clid, pfs_fsid} must be used for * registration in the cluster. */ uint8_t pfs_nmasters; /* 0086 (if PFSROOT) if multi-master */ uint8_t pfs_type; /* 0087 (if PFSROOT) node type */ hammer2_tid_t pfs_inum; /* 0088 (if PFSROOT) inum allocator */ uuid_t pfs_clid; /* 0090 (if PFSROOT) cluster uuid */ uuid_t pfs_fsid; /* 00A0 (if PFSROOT) unique uuid */ /* * Quotas and aggregate sub-tree inode and data counters. Note that * quotas are not replicated downward, they are explicitly set by * the sysop and in-memory structures keep track of inheritance. */ hammer2_key_t data_quota; /* 00B0 subtree quota in bytes */ hammer2_key_t unusedB8; /* 00B8 */ hammer2_key_t inode_quota; /* 00C0 subtree quota inode count */ hammer2_key_t unusedC8; /* 00C8 */ /* * The last snapshot tid is tested against modify_tid to determine * when a copy must be made of a data block whos check mode has been * disabled (a disabled check mode allows data blocks to be updated * in place instead of copy-on-write). */ hammer2_tid_t pfs_lsnap_tid; /* 00D0 last snapshot tid */ hammer2_tid_t reservedD8; /* 00D8 (avail) */ /* * Tracks (possibly degenerate) free areas covering all sub-tree * allocations under inode, not counting the inode itself. * 0/0 indicates empty entry. fully set-associative. * * (not yet implemented) */ uint64_t decrypt_check; /* 00E0 decryption validator */ hammer2_off_t reservedE8[3]; /* 00E8/F0/F8 */ } __packed; typedef struct hammer2_inode_meta hammer2_inode_meta_t; struct hammer2_inode_data { hammer2_inode_meta_t meta; /* 0000-00FF */ unsigned char filename[HAMMER2_INODE_MAXNAME]; /* 0100-01FF (256 char, unterminated) */ union { /* 0200-03FF (64x8 = 512 bytes) */ hammer2_blockset_t blockset; char data[HAMMER2_EMBEDDED_BYTES]; } u; } __packed; typedef struct hammer2_inode_data hammer2_inode_data_t; #define HAMMER2_OPFLAG_DIRECTDATA 0x01 #define HAMMER2_OPFLAG_PFSROOT 0x02 /* (see also bref flag) */ #define HAMMER2_OPFLAG_COPYIDS 0x04 /* copyids override parent */ #define HAMMER2_OBJTYPE_UNKNOWN 0 #define HAMMER2_OBJTYPE_DIRECTORY 1 #define HAMMER2_OBJTYPE_REGFILE 2 #define HAMMER2_OBJTYPE_FIFO 4 #define HAMMER2_OBJTYPE_CDEV 5 #define HAMMER2_OBJTYPE_BDEV 6 #define HAMMER2_OBJTYPE_SOFTLINK 7 #define HAMMER2_OBJTYPE_UNUSED08 8 #define HAMMER2_OBJTYPE_SOCKET 9 #define HAMMER2_OBJTYPE_WHITEOUT 10 #define HAMMER2_COPYID_NONE 0 #define HAMMER2_COPYID_LOCAL ((uint8_t)-1) #define HAMMER2_COPYID_COUNT 256 /* * PFS types identify the role of a PFS within a cluster. The PFS types * is stored on media and in LNK_SPAN messages and used in other places. * * The low 4 bits specify the current active type while the high 4 bits * specify the transition target if the PFS is being upgraded or downgraded, * If the upper 4 bits are not zero it may effect how a PFS is used during * the transition. * * Generally speaking, downgrading a MASTER to a SLAVE cannot complete until * at least all MASTERs have updated their pfs_nmasters field. And upgrading * a SLAVE to a MASTER cannot complete until the new prospective master has * been fully synchronized (though theoretically full synchronization is * not required if a (new) quorum of other masters are fully synchronized). * * It generally does not matter which PFS element you actually mount, you * are mounting 'the cluster'. So, for example, a network mount will mount * a DUMMY PFS type on a memory filesystem. However, there are two exceptions. * In order to gain the benefits of a SOFT_MASTER or SOFT_SLAVE, those PFSs * must be directly mounted. */ #define HAMMER2_PFSTYPE_NONE 0x00 #define HAMMER2_PFSTYPE_CACHE 0x01 #define HAMMER2_PFSTYPE_UNUSED02 0x02 #define HAMMER2_PFSTYPE_SLAVE 0x03 #define HAMMER2_PFSTYPE_SOFT_SLAVE 0x04 #define HAMMER2_PFSTYPE_SOFT_MASTER 0x05 #define HAMMER2_PFSTYPE_MASTER 0x06 #define HAMMER2_PFSTYPE_UNUSED07 0x07 #define HAMMER2_PFSTYPE_SUPROOT 0x08 #define HAMMER2_PFSTYPE_DUMMY 0x09 #define HAMMER2_PFSTYPE_MAX 16 #define HAMMER2_PFSTRAN_NONE 0x00 /* no transition in progress */ #define HAMMER2_PFSTRAN_CACHE 0x10 #define HAMMER2_PFSTRAN_UNUSED20 0x20 #define HAMMER2_PFSTRAN_SLAVE 0x30 #define HAMMER2_PFSTRAN_SOFT_SLAVE 0x40 #define HAMMER2_PFSTRAN_SOFT_MASTER 0x50 #define HAMMER2_PFSTRAN_MASTER 0x60 #define HAMMER2_PFSTRAN_UNUSED70 0x70 #define HAMMER2_PFSTRAN_SUPROOT 0x80 #define HAMMER2_PFSTRAN_DUMMY 0x90 #define HAMMER2_PFS_DEC(n) ((n) & 0x0F) #define HAMMER2_PFS_DEC_TRANSITION(n) (((n) >> 4) & 0x0F) #define HAMMER2_PFS_ENC_TRANSITION(n) (((n) & 0x0F) << 4) #define HAMMER2_PFSSUBTYPE_NONE 0 #define HAMMER2_PFSSUBTYPE_SNAPSHOT 1 /* manual/managed snapshot */ #define HAMMER2_PFSSUBTYPE_AUTOSNAP 2 /* automatic snapshot */ /* * PFS mode of operation is a bitmask. This is typically not stored * on-media, but defined here because the field may be used in dmsgs. */ #define HAMMER2_PFSMODE_QUORUM 0x01 #define HAMMER2_PFSMODE_RW 0x02 /* * The volume header eats a 64K block at the beginning of each 2GB zone * up to four copies. * * All information is stored in host byte order. The volume header's magic * number may be checked to determine the byte order. If you wish to mount * between machines w/ different endian modes you'll need filesystem code * which acts on the media data consistently (either all one way or all the * other). Our code currently does not do that. * * A read-write mount may have to recover missing allocations by doing an * incremental mirror scan looking for modifications made after alloc_tid. * If alloc_tid == last_tid then no recovery operation is needed. Recovery * operations are usually very, very fast. * * Read-only mounts do not need to do any recovery, access to the filesystem * topology is always consistent after a crash (is always consistent, period). * However, there may be shortcutted blockref updates present from deep in * the tree which are stored in the volumeh eader and must be tracked on * the fly. * * NOTE: The copyinfo[] array contains the configuration for both the * cluster connections and any local media copies. The volume * header will be replicated for each local media copy. * * The mount command may specify multiple medias or just one and * allow HAMMER2 to pick up the others when it checks the copyinfo[] * array on mount. * * NOTE: sroot_blockset points to the super-root directory, not the root * directory. The root directory will be a subdirectory under the * super-root. * * The super-root directory contains all root directories and all * snapshots (readonly or writable). It is possible to do a * null-mount of the super-root using special path constructions * relative to your mounted root. */ #define HAMMER2_VOLUME_ID_HBO 0x48414d3205172011LLU #define HAMMER2_VOLUME_ID_ABO 0x11201705324d4148LLU /* * If volume version is HAMMER2_VOL_VERSION_MULTI_VOLUMES or above, max * HAMMER2_MAX_VOLUMES volumes are supported. There must be 1 (and only 1) * volume with volume id HAMMER2_ROOT_VOLUME. * Otherwise filesystem only supports 1 volume, and that volume must have * volume id HAMMER2_ROOT_VOLUME(0) which was a reserved field then. */ #define HAMMER2_MAX_VOLUMES 64 #define HAMMER2_ROOT_VOLUME 0 struct hammer2_volume_data { /* * sector #0 - 512 bytes */ uint64_t magic; /* 0000 Signature */ hammer2_off_t boot_beg; /* 0008 Boot area (future) */ hammer2_off_t boot_end; /* 0010 (size = end - beg) */ hammer2_off_t aux_beg; /* 0018 Aux area (future) */ hammer2_off_t aux_end; /* 0020 (size = end - beg) */ hammer2_off_t volu_size; /* 0028 Volume size, bytes */ uint32_t version; /* 0030 */ uint32_t flags; /* 0034 */ uint8_t copyid; /* 0038 copyid of phys vol */ uint8_t freemap_version; /* 0039 freemap algorithm */ uint8_t peer_type; /* 003A HAMMER2_PEER_xxx */ uint8_t volu_id; /* 003B */ uint8_t nvolumes; /* 003C */ uint8_t reserved003D; /* 003D */ uint16_t reserved003E; /* 003E */ uuid_t fsid; /* 0040 */ uuid_t fstype; /* 0050 */ /* * allocator_size is precalculated at newfs time and does not include * reserved blocks, boot, or aux areas. * * Initial non-reserved-area allocations do not use the freemap * but instead adjust alloc_iterator. Dynamic allocations take * over starting at (allocator_beg). This makes newfs_hammer2's * job a lot easier and can also serve as a testing jig. */ hammer2_off_t allocator_size; /* 0060 Total data space */ hammer2_off_t allocator_free; /* 0068 Free space */ hammer2_off_t allocator_beg; /* 0070 Initial allocations */ /* * mirror_tid reflects the highest committed change for this * block device regardless of whether it is to the super-root * or to a PFS or whatever. * * freemap_tid reflects the highest committed freemap change for * this block device. */ hammer2_tid_t mirror_tid; /* 0078 committed tid (vol) */ hammer2_tid_t reserved0080; /* 0080 */ hammer2_tid_t reserved0088; /* 0088 */ hammer2_tid_t freemap_tid; /* 0090 committed tid (fmap) */ hammer2_tid_t bulkfree_tid; /* 0098 bulkfree incremental */ hammer2_tid_t reserved00A0[4]; /* 00A0-00BF */ hammer2_off_t total_size; /* 00C0 Total volume size, bytes */ /* * Copyids are allocated dynamically from the copyexists bitmap. * An id from the active copies set (up to 8, see copyinfo later on) * may still exist after the copy set has been removed from the * volume header and its bit will remain active in the bitmap and * cannot be reused until it is 100% removed from the hierarchy. */ uint32_t copyexists[8]; /* 00C8-00E7 copy exists bmap */ char reserved00E8[248]; /* 00E8-01DF */ /* * 32 bit CRC array at the end of the first 512 byte sector. * * icrc_sects[7] - First 512-4 bytes of volume header (including all * the other icrc's except this one). * * icrc_sects[6] - Sector 1 (512 bytes) of volume header, which is * the blockset for the root. * * icrc_sects[5] - Sector 2 * icrc_sects[4] - Sector 3 * icrc_sects[3] - Sector 4 (the freemap blockset) */ hammer2_crc32_t icrc_sects[8]; /* 01E0-01FF */ /* * sector #1 - 512 bytes * * The entire sector is used by a blockset, but currently only first * blockref is used. */ hammer2_blockset_t sroot_blockset; /* 0200-03FF Superroot dir */ /* * sector #2-6 */ char sector2[512]; /* 0400-05FF reserved */ char sector3[512]; /* 0600-07FF reserved */ hammer2_blockset_t freemap_blockset; /* 0800-09FF freemap */ char sector5[512]; /* 0A00-0BFF reserved */ char sector6[512]; /* 0C00-0DFF reserved */ /* * sector #7 - 512 bytes * Maximum 64 volume offsets within logical offset. */ hammer2_off_t volu_loff[HAMMER2_MAX_VOLUMES]; /* * sector #8-71 - 32768 bytes * * Contains the configuration for up to 256 copyinfo targets. These * specify local and remote copies operating as masters or slaves. * copyid's 0 and 255 are reserved (0 indicates an empty slot and 255 * indicates the local media). */ /* 1000-8FFF copyinfo config */ hammer2_volconf_t copyinfo[HAMMER2_COPYID_COUNT]; /* * Remaining sections are reserved for future use. */ char reserved9000[0x6FFC]; /* 9000-FFFB reserved */ /* * icrc on entire volume header */ hammer2_crc32_t icrc_volheader; /* FFFC-FFFF full volume icrc*/ } __packed; typedef struct hammer2_volume_data hammer2_volume_data_t; /* * Various parts of the volume header have their own iCRCs. * * The first 512 bytes has its own iCRC stored at the end of the 512 bytes * and not included the icrc calculation. * * The second 512 bytes also has its own iCRC but it is stored in the first * 512 bytes so it covers the entire second 512 bytes. * * The whole volume block (64KB) has an iCRC covering all but the last 4 bytes, * which is where the iCRC for the whole volume is stored. This is currently * a catch-all for anything not individually iCRCd. */ #define HAMMER2_VOL_ICRC_SECT0 7 #define HAMMER2_VOL_ICRC_SECT1 6 #define HAMMER2_VOLUME_BYTES 65536 #define HAMMER2_VOLUME_ICRC0_OFF 0 #define HAMMER2_VOLUME_ICRC1_OFF 512 #define HAMMER2_VOLUME_ICRCVH_OFF 0 #define HAMMER2_VOLUME_ICRC0_SIZE (512 - 4) #define HAMMER2_VOLUME_ICRC1_SIZE (512) #define HAMMER2_VOLUME_ICRCVH_SIZE (65536 - 4) #define HAMMER2_VOL_VERSION_MULTI_VOLUMES 2 #define HAMMER2_VOL_VERSION_MIN 1 #define HAMMER2_VOL_VERSION_DEFAULT HAMMER2_VOL_VERSION_MULTI_VOLUMES #define HAMMER2_VOL_VERSION_WIP (HAMMER2_VOL_VERSION_MULTI_VOLUMES + 1) #define HAMMER2_NUM_VOLHDRS 4 union hammer2_media_data { hammer2_volume_data_t voldata; hammer2_inode_data_t ipdata; hammer2_blockset_t blkset; hammer2_blockref_t npdata[HAMMER2_IND_COUNT_MAX]; hammer2_bmap_data_t bmdata[HAMMER2_FREEMAP_COUNT]; char buf[HAMMER2_PBUFSIZE]; } __packed; typedef union hammer2_media_data hammer2_media_data_t; #endif /* !_VFS_HAMMER2_DISK_H_ */