freebsd-dev/lib/libc/gen/telldir.h

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* Copyright (c) 2000
* Daniel Eischen. All rights reserved.
*
* 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 University 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 REGENTS 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 REGENTS 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.
*
* $FreeBSD$
*/
#ifndef _TELLDIR_H_
#define _TELLDIR_H_
#include <sys/queue.h>
#include <stdbool.h>
/*
* telldir will malloc one of these to describe the current directory position,
* if it can't fit that information into the packed structure below. It
* records the current magic cookie returned by getdirentries and the offset
* within the buffer associated with that return value.
*/
struct ddloc_mem {
LIST_ENTRY(ddloc_mem) loc_lqe; /* entry in list */
long loc_index; /* key associated with structure */
Commit the 64-bit inode project. Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify struct dirent layout to add d_off, increase the size of d_fileno to 64-bits, increase the size of d_namlen to 16-bits, and change the required alignment. Increase struct statfs f_mntfromname[] and f_mntonname[] array length MNAMELEN to 1024. ABI breakage is mitigated by providing compatibility using versioned symbols, ingenious use of the existing padding in structures, and by employing other tricks. Unfortunately, not everything can be fixed, especially outside the base system. For instance, third-party APIs which pass struct stat around are broken in backward and forward incompatible ways. Kinfo sysctl MIBs ABI is changed in backward-compatible way, but there is no general mechanism to handle other sysctl MIBS which return structures where the layout has changed. It was considered that the breakage is either in the management interfaces, where we usually allow ABI slip, or is not important. Struct xvnode changed layout, no compat shims are provided. For struct xtty, dev_t tty device member was reduced to uint32_t. It was decided that keeping ABI compat in this case is more useful than reporting 64-bit dev_t, for the sake of pstat. Update note: strictly follow the instructions in UPDATING. Build and install the new kernel with COMPAT_FREEBSD11 option enabled, then reboot, and only then install new world. Credits: The 64-bit inode project, also known as ino64, started life many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick (mckusick) then picked up and updated the patch, and acted as a flag-waver. Feedback, suggestions, and discussions were carried by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles), and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial ports investigation followed by an exp-run by Antoine Brodin (antoine). Essential and all-embracing testing was done by Peter Holm (pho). The heavy lifting of coordinating all these efforts and bringing the project to completion were done by Konstantin Belousov (kib). Sponsored by: The FreeBSD Foundation (emaste, kib) Differential revision: https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
off_t loc_seek; /* magic cookie returned by getdirentries */
long loc_loc; /* offset of entry in buffer */
};
#ifdef __LP64__
#define DD_LOC_BITS 31
#define DD_SEEK_BITS 32
#define DD_INDEX_BITS 63
#else
#define DD_LOC_BITS 12
#define DD_SEEK_BITS 19
#define DD_INDEX_BITS 31
#endif
/*
* This is the real type returned by telldir. telldir will prefer to return
* the packed type, if possible, or the malloced type otherwise. For msdosfs,
* UFS, and NFS, directory positions usually fit within the packed type. For
* ZFS and tmpfs, they usually fit within the packed type on 64-bit
* architectures.
*/
union ddloc_packed {
long l; /* Opaque type returned by telldir(3) */
struct {
/* Identifies union type. Must be 0. */
unsigned long is_packed:1;
/* Index into directory's linked list of ddloc_mem */
unsigned long index:DD_INDEX_BITS;
} __packed i;
struct {
/* Identifies union type. Must be 1. */
unsigned long is_packed:1;
/* offset of entry in buffer*/
unsigned long loc:DD_LOC_BITS;
/* magic cookie returned by getdirentries */
unsigned long seek:DD_SEEK_BITS;
} __packed s;
};
_Static_assert(sizeof(long) == sizeof(union ddloc_packed),
"packed telldir size mismatch!");
/*
* One of these structures is malloced for each DIR to record telldir
* positions.
*/
struct _telldir {
LIST_HEAD(, ddloc_mem) td_locq; /* list of locations */
long td_loccnt; /* index of entry for sequential readdir's */
};
bool _filldir(DIR *, bool);
struct dirent *_readdir_unlocked(DIR *, int);
void _reclaim_telldir(DIR *);
void _seekdir(DIR *, long);
void _fixtelldir(DIR *dirp, long oldseek, long oldloc);
Commit the 64-bit inode project. Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify struct dirent layout to add d_off, increase the size of d_fileno to 64-bits, increase the size of d_namlen to 16-bits, and change the required alignment. Increase struct statfs f_mntfromname[] and f_mntonname[] array length MNAMELEN to 1024. ABI breakage is mitigated by providing compatibility using versioned symbols, ingenious use of the existing padding in structures, and by employing other tricks. Unfortunately, not everything can be fixed, especially outside the base system. For instance, third-party APIs which pass struct stat around are broken in backward and forward incompatible ways. Kinfo sysctl MIBs ABI is changed in backward-compatible way, but there is no general mechanism to handle other sysctl MIBS which return structures where the layout has changed. It was considered that the breakage is either in the management interfaces, where we usually allow ABI slip, or is not important. Struct xvnode changed layout, no compat shims are provided. For struct xtty, dev_t tty device member was reduced to uint32_t. It was decided that keeping ABI compat in this case is more useful than reporting 64-bit dev_t, for the sake of pstat. Update note: strictly follow the instructions in UPDATING. Build and install the new kernel with COMPAT_FREEBSD11 option enabled, then reboot, and only then install new world. Credits: The 64-bit inode project, also known as ino64, started life many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick (mckusick) then picked up and updated the patch, and acted as a flag-waver. Feedback, suggestions, and discussions were carried by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles), and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial ports investigation followed by an exp-run by Antoine Brodin (antoine). Essential and all-embracing testing was done by Peter Holm (pho). The heavy lifting of coordinating all these efforts and bringing the project to completion were done by Konstantin Belousov (kib). Sponsored by: The FreeBSD Foundation (emaste, kib) Differential revision: https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
#define RDU_SKIP 0x0001
#define RDU_SHORT 0x0002
#endif