1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* AFS fileserver XDR types 3 * 4 * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #ifndef XDR_FS_H 9 #define XDR_FS_H 10 11 struct afs_xdr_AFSFetchStatus { 12 __be32 if_version; 13 #define AFS_FSTATUS_VERSION 1 14 __be32 type; 15 __be32 nlink; 16 __be32 size_lo; 17 __be32 data_version_lo; 18 __be32 author; 19 __be32 owner; 20 __be32 caller_access; 21 __be32 anon_access; 22 __be32 mode; 23 __be32 parent_vnode; 24 __be32 parent_unique; 25 __be32 seg_size; 26 __be32 mtime_client; 27 __be32 mtime_server; 28 __be32 group; 29 __be32 sync_counter; 30 __be32 data_version_hi; 31 __be32 lock_count; 32 __be32 size_hi; 33 __be32 abort_code; 34 } __packed; 35 36 #define AFS_DIR_HASHTBL_SIZE 128 37 #define AFS_DIR_DIRENT_SIZE 32 38 #define AFS_DIR_SLOTS_PER_BLOCK 64 39 #define AFS_DIR_BLOCK_SIZE 2048 40 #define AFS_DIR_BLOCKS_PER_PAGE (PAGE_SIZE / AFS_DIR_BLOCK_SIZE) 41 #define AFS_DIR_MAX_SLOTS 65536 42 #define AFS_DIR_BLOCKS_WITH_CTR 128 43 #define AFS_DIR_MAX_BLOCKS 1023 44 #define AFS_DIR_RESV_BLOCKS 1 45 #define AFS_DIR_RESV_BLOCKS0 13 46 47 /* 48 * Directory entry structure. 49 */ 50 union afs_xdr_dirent { 51 struct { 52 u8 valid; 53 u8 unused[1]; 54 __be16 hash_next; 55 __be32 vnode; 56 __be32 unique; 57 u8 name[]; 58 /* When determining the number of dirent slots needed to 59 * represent a directory entry, name should be assumed to be 16 60 * bytes, due to a now-standardised (mis)calculation, but it is 61 * in fact 20 bytes in size. afs_dir_calc_slots() should be 62 * used for this. 63 * 64 * For names longer than (16 or) 20 bytes, extra slots should 65 * be annexed to this one using the extended_name format. 66 */ 67 } u; 68 u8 extended_name[32]; 69 } __packed; 70 71 /* 72 * Directory block header (one at the beginning of every 2048-byte block). 73 */ 74 struct afs_xdr_dir_hdr { 75 __be16 npages; 76 __be16 magic; 77 #define AFS_DIR_MAGIC htons(1234) 78 u8 reserved; 79 u8 bitmap[8]; 80 u8 pad[19]; 81 } __packed; 82 83 /* 84 * Directory block layout 85 */ 86 union afs_xdr_dir_block { 87 struct afs_xdr_dir_hdr hdr; 88 89 struct { 90 struct afs_xdr_dir_hdr hdr; 91 u8 alloc_ctrs[AFS_DIR_MAX_BLOCKS]; 92 __be16 hashtable[AFS_DIR_HASHTBL_SIZE]; 93 } meta; 94 95 union afs_xdr_dirent dirents[AFS_DIR_SLOTS_PER_BLOCK]; 96 } __packed; 97 98 /* 99 * Directory layout on a linux VM page. 100 */ 101 struct afs_xdr_dir_page { 102 union afs_xdr_dir_block blocks[AFS_DIR_BLOCKS_PER_PAGE]; 103 }; 104 105 /* 106 * Calculate the number of dirent slots required for any given name length. 107 * The calculation is made assuming the part of the name in the first slot is 108 * 16 bytes, rather than 20, but this miscalculation is now standardised. 109 */ afs_dir_calc_slots(size_t name_len)110static inline unsigned int afs_dir_calc_slots(size_t name_len) 111 { 112 name_len++; /* NUL-terminated */ 113 return 1 + ((name_len + 15) / AFS_DIR_DIRENT_SIZE); 114 } 115 116 #endif /* XDR_FS_H */ 117