2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1983, 1993
5 * The Regents of the University of California. All rights reserved.
8 * Daniel Eischen. All rights reserved.
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11 * modification, are permitted provided that the following conditions
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14 * notice, this list of conditions and the following disclaimer.
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22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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40 #include <sys/queue.h>
44 * telldir will malloc one of these to describe the current directory position,
45 * if it can't fit that information into the packed structure below. It
46 * records the current magic cookie returned by getdirentries and the offset
47 * within the buffer associated with that return value.
50 LIST_ENTRY(ddloc_mem) loc_lqe; /* entry in list */
51 long loc_index; /* key associated with structure */
52 off_t loc_seek; /* magic cookie returned by getdirentries */
53 long loc_loc; /* offset of entry in buffer */
57 #define DD_LOC_BITS 31
58 #define DD_SEEK_BITS 32
59 #define DD_INDEX_BITS 63
61 #define DD_LOC_BITS 12
62 #define DD_SEEK_BITS 19
63 #define DD_INDEX_BITS 31
67 * This is the real type returned by telldir. telldir will prefer to return
68 * the packed type, if possible, or the malloced type otherwise. For msdosfs,
69 * UFS, and NFS, directory positions usually fit within the packed type. For
70 * ZFS and tmpfs, they usually fit within the packed type on 64-bit
74 long l; /* Opaque type returned by telldir(3) */
76 /* Identifies union type. Must be 0. */
77 unsigned long is_packed:1;
78 /* Index into directory's linked list of ddloc_mem */
79 unsigned long index:DD_INDEX_BITS;
82 /* Identifies union type. Must be 1. */
83 unsigned long is_packed:1;
84 /* offset of entry in buffer*/
85 unsigned long loc:DD_LOC_BITS;
86 /* magic cookie returned by getdirentries */
87 unsigned long seek:DD_SEEK_BITS;
91 _Static_assert(sizeof(long) == sizeof(union ddloc_packed),
92 "packed telldir size mismatch!");
95 * One of these structures is malloced for each DIR to record telldir
99 LIST_HEAD(, ddloc_mem) td_locq; /* list of locations */
100 long td_loccnt; /* index of entry for sequential readdir's */
103 bool _filldir(DIR *, bool);
104 struct dirent *_readdir_unlocked(DIR *, int);
105 void _reclaim_telldir(DIR *);
106 void _seekdir(DIR *, long);
107 void _fixtelldir(DIR *dirp, long oldseek, long oldloc);
109 #define RDU_SKIP 0x0001
110 #define RDU_SHORT 0x0002