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 */
110 static 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
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