Systemd/src/shared/macro.h
Zbigniew Jędrzejewski-Szmek 348ced9097 journald: do not free space when disk space runs low
Before, journald would remove journal files until both MaxUse= and
KeepFree= settings would be satisfied. The first one depends (if set
automatically) on the size of the file system and is constant.  But
the second one depends on current use of the file system, and a spike
in disk usage would cause journald to delete journal files, trying to
reach usage which would leave 15% of the disk free. This behaviour is
surprising for the user who doesn't expect his logs to be purged when
disk usage goes above 85%, which on a large disk could be some
gigabytes from being full. In addition attempting to keep 15% free
provides an attack vector where filling the disk sufficiently disposes
of almost all logs.

Instead, obey KeepFree= only as a limit on adding additional files.
When replacing old files with new, ignore KeepFree=. This means that
if journal disk usage reached some high point that at some later point
start to violate the KeepFree= constraint, journald will not add files
to go above this point, but it will stay (slightly) below it. When
journald is restarted, it forgets the previous maximum usage value,
and sets the limit based on the current usage, so if disk remains to
be filled, journald might use one journal-file-size less on each
restart, if restarts happen just after rotation. This seems like a
reasonable compromise between implementation complexity and robustness.
2014-01-11 16:54:59 -05:00

334 lines
14 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#pragma once
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <assert.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <inttypes.h>
#define _printf_(a,b) __attribute__ ((format (printf, a, b)))
#define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
#define _sentinel_ __attribute__ ((sentinel))
#define _unused_ __attribute__ ((unused))
#define _destructor_ __attribute__ ((destructor))
#define _pure_ __attribute__ ((pure))
#define _const_ __attribute__ ((const))
#define _deprecated_ __attribute__ ((deprecated))
#define _packed_ __attribute__ ((packed))
#define _malloc_ __attribute__ ((malloc))
#define _weak_ __attribute__ ((weak))
#define _likely_(x) (__builtin_expect(!!(x),1))
#define _unlikely_(x) (__builtin_expect(!!(x),0))
#define _public_ __attribute__ ((visibility("default")))
#define _hidden_ __attribute__ ((visibility("hidden")))
#define _weakref_(x) __attribute__((weakref(#x)))
#define _alignas_(x) __attribute__((aligned(__alignof(x))))
#define _cleanup_(x) __attribute__((cleanup(x)))
/* automake test harness */
#define EXIT_TEST_SKIP 77
#define XSTRINGIFY(x) #x
#define STRINGIFY(x) XSTRINGIFY(x)
#define XCONCATENATE(x, y) x ## y
#define CONCATENATE(x, y) XCONCATENATE(x, y)
#define UNIQUE(prefix) CONCATENATE(prefix, __LINE__)
/* Rounds up */
#define ALIGN4(l) (((l) + 3) & ~3)
#define ALIGN8(l) (((l) + 7) & ~7)
#if __SIZEOF_POINTER__ == 8
#define ALIGN(l) ALIGN8(l)
#elif __SIZEOF_POINTER__ == 4
#define ALIGN(l) ALIGN4(l)
#else
#error "Wut? Pointers are neither 4 nor 8 bytes long?"
#endif
#define ALIGN_PTR(p) ((void*) ALIGN((unsigned long) p))
#define ALIGN4_PTR(p) ((void*) ALIGN4((unsigned long) p))
#define ALIGN8_PTR(p) ((void*) ALIGN8((unsigned long) p))
static inline size_t ALIGN_TO(size_t l, size_t ali) {
return ((l + ali - 1) & ~(ali - 1));
}
#define ALIGN_TO_PTR(p, ali) ((void*) ALIGN_TO((unsigned long) p))
#define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
/*
* container_of - cast a member of a structure out to the containing structure
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
*/
#define container_of(ptr, type, member) \
__extension__ ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) ); \
})
#undef MAX
#define MAX(a,b) \
__extension__ ({ \
typeof(a) _a = (a); \
typeof(b) _b = (b); \
_a > _b ? _a : _b; \
})
#define MAX3(x,y,z) \
__extension__ ({ \
typeof(x) _c = MAX(x,y); \
MAX(_c, z); \
})
#undef MIN
#define MIN(a,b) \
__extension__ ({ \
typeof(a) _a = (a); \
typeof(b) _b = (b); \
_a < _b ? _a : _b; \
})
#define LESS_BY(A,B) \
__extension__ ({ \
typeof(A) _A = (A); \
typeof(B) _B = (B); \
_A > _B ? _A - _B : 0; \
})
#ifndef CLAMP
#define CLAMP(x, low, high) \
__extension__ ({ \
typeof(x) _x = (x); \
typeof(low) _low = (low); \
typeof(high) _high = (high); \
((_x > _high) ? _high : ((_x < _low) ? _low : _x)); \
})
#endif
#define assert_se(expr) \
do { \
if (_unlikely_(!(expr))) \
log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
} while (false) \
/* We override the glibc assert() here. */
#undef assert
#ifdef NDEBUG
#define assert(expr) do {} while(false)
#else
#define assert(expr) assert_se(expr)
#endif
#define assert_not_reached(t) \
do { \
log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
} while (false)
#if defined(static_assert)
#define assert_cc(expr) static_assert(expr, #expr)
#else
#define assert_cc(expr) struct UNIQUE(_assert_struct_) { char x[(expr) ? 0 : -1]; };
#endif
#define assert_return(expr, r) \
do { \
if (_unlikely_(!(expr))) { \
log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
return (r); \
} \
} while (false)
#define PTR_TO_INT(p) ((int) ((intptr_t) (p)))
#define INT_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_UINT(p) ((unsigned int) ((uintptr_t) (p)))
#define UINT_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define PTR_TO_LONG(p) ((long) ((intptr_t) (p)))
#define LONG_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_ULONG(p) ((unsigned long) ((uintptr_t) (p)))
#define ULONG_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define PTR_TO_INT32(p) ((int32_t) ((intptr_t) (p)))
#define INT32_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_UINT32(p) ((uint32_t) ((uintptr_t) (p)))
#define UINT32_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define PTR_TO_INT64(p) ((int64_t) ((intptr_t) (p)))
#define INT64_TO_PTR(u) ((void *) ((intptr_t) (u)))
#define PTR_TO_UINT64(p) ((uint64_t) ((uintptr_t) (p)))
#define UINT64_TO_PTR(u) ((void *) ((uintptr_t) (u)))
#define memzero(x,l) (memset((x), 0, (l)))
#define zero(x) (memzero(&(x), sizeof(x)))
#define CHAR_TO_STR(x) ((char[2]) { x, 0 })
#define char_array_0(x) x[sizeof(x)-1] = 0;
#define IOVEC_SET_STRING(i, s) \
do { \
struct iovec *_i = &(i); \
char *_s = (char *)(s); \
_i->iov_base = _s; \
_i->iov_len = strlen(_s); \
} while(false)
static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, unsigned n) {
unsigned j;
size_t r = 0;
for (j = 0; j < n; j++)
r += i[j].iov_len;
return r;
}
static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
unsigned j;
for (j = 0; j < n; j++) {
size_t sub;
if (_unlikely_(k <= 0))
break;
sub = MIN(i[j].iov_len, k);
i[j].iov_len -= sub;
i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
k -= sub;
}
return k;
}
#define VA_FORMAT_ADVANCE(format, ap) \
do { \
int _argtypes[128]; \
size_t _i, _k; \
_k = parse_printf_format((format), ELEMENTSOF(_argtypes), _argtypes); \
assert(_k < ELEMENTSOF(_argtypes)); \
for (_i = 0; _i < _k; _i++) { \
if (_argtypes[_i] & PA_FLAG_PTR) { \
(void) va_arg(ap, void*); \
continue; \
} \
\
switch (_argtypes[_i]) { \
case PA_INT: \
case PA_INT|PA_FLAG_SHORT: \
case PA_CHAR: \
(void) va_arg(ap, int); \
break; \
case PA_INT|PA_FLAG_LONG: \
(void) va_arg(ap, long int); \
break; \
case PA_INT|PA_FLAG_LONG_LONG: \
(void) va_arg(ap, long long int); \
break; \
case PA_WCHAR: \
(void) va_arg(ap, wchar_t); \
break; \
case PA_WSTRING: \
case PA_STRING: \
case PA_POINTER: \
(void) va_arg(ap, void*); \
break; \
case PA_FLOAT: \
case PA_DOUBLE: \
(void) va_arg(ap, double); \
break; \
case PA_DOUBLE|PA_FLAG_LONG_DOUBLE: \
(void) va_arg(ap, long double); \
break; \
default: \
assert_not_reached("Unknown format string argument."); \
} \
} \
} while(false)
/* Because statfs.t_type can be int on some architectures, we have to cast
* the const magic to the type, otherwise the compiler warns about
* signed/unsigned comparison, because the magic can be 32 bit unsigned.
*/
#define F_TYPE_EQUAL(a, b) (a == (typeof(a)) b)
/* Returns the number of chars needed to format variables of the
* specified type as a decimal string. Adds in extra space for a
* negative '-' prefix. */
#define DECIMAL_STR_MAX(type) \
(2+(sizeof(type) <= 1 ? 3 : \
sizeof(type) <= 2 ? 5 : \
sizeof(type) <= 4 ? 10 : \
sizeof(type) <= 8 ? 20 : sizeof(int[-2*(sizeof(type) > 8)])))
#define SET_FLAG(v, flag, b) \
(v) = (b) ? ((v) | (flag)) : ((v) & ~(flag))
#define IN_SET(x, ...) \
({ \
const typeof(x) _x = (x); \
unsigned _i; \
bool _found = false; \
for (_i = 0; _i < sizeof((const typeof(_x)[]) { __VA_ARGS__ })/sizeof(const typeof(_x)); _i++) \
if (((const typeof(_x)[]) { __VA_ARGS__ })[_i] == _x) { \
_found = true; \
break; \
} \
_found; \
})
/* Define C11 thread_local attribute even on older gcc compiler
* version */
#ifndef thread_local
/*
* Don't break on glibc < 2.16 that doesn't define __STDC_NO_THREADS__
* see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
*/
#if __STDC_VERSION__ >= 201112L && !(defined(__STDC_NO_THREADS__) || (defined(__GNU_LIBRARY__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16))
#define thread_local _Thread_local
#else
#define thread_local __thread
#endif
#endif
/* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
* compiler versions */
#ifndef noreturn
#if __STDC_VERSION__ >= 201112L
#define noreturn _Noreturn
#else
#define noreturn __attribute__((noreturn))
#endif
#endif
#include "log.h"