2 * Various trivial helper wrappers around standard functions
12 static intmax_t count_fsync_writeout_only
;
13 static intmax_t count_fsync_hardware_flush
;
15 #ifdef HAVE_RTLGENRANDOM
16 /* This is required to get access to RtlGenRandom. */
17 #define SystemFunction036 NTAPI SystemFunction036
19 #undef SystemFunction036
22 static int memory_limit_check(size_t size
, int gentle
)
24 static size_t limit
= 0;
26 limit
= git_env_ulong("GIT_ALLOC_LIMIT", 0);
32 error("attempting to allocate %"PRIuMAX
" over limit %"PRIuMAX
,
33 (uintmax_t)size
, (uintmax_t)limit
);
36 die("attempting to allocate %"PRIuMAX
" over limit %"PRIuMAX
,
37 (uintmax_t)size
, (uintmax_t)limit
);
42 char *xstrdup(const char *str
)
44 char *ret
= strdup(str
);
46 die("Out of memory, strdup failed");
50 static void *do_xmalloc(size_t size
, int gentle
)
54 if (memory_limit_check(size
, gentle
))
61 die("Out of memory, malloc failed (tried to allocate %lu bytes)",
64 error("Out of memory, malloc failed (tried to allocate %lu bytes)",
70 memset(ret
, 0xA5, size
);
75 void *xmalloc(size_t size
)
77 return do_xmalloc(size
, 0);
80 static void *do_xmallocz(size_t size
, int gentle
)
83 if (unsigned_add_overflows(size
, 1)) {
85 error("Data too large to fit into virtual memory space.");
88 die("Data too large to fit into virtual memory space.");
90 ret
= do_xmalloc(size
+ 1, gentle
);
92 ((char*)ret
)[size
] = 0;
96 void *xmallocz(size_t size
)
98 return do_xmallocz(size
, 0);
101 void *xmallocz_gently(size_t size
)
103 return do_xmallocz(size
, 1);
107 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
108 * "data" to the allocated memory, zero terminates the allocated memory,
109 * and returns a pointer to the allocated memory. If the allocation fails,
112 void *xmemdupz(const void *data
, size_t len
)
114 return memcpy(xmallocz(len
), data
, len
);
117 char *xstrndup(const char *str
, size_t len
)
119 char *p
= memchr(str
, '\0', len
);
120 return xmemdupz(str
, p
? p
- str
: len
);
123 int xstrncmpz(const char *s
, const char *t
, size_t len
)
125 int res
= strncmp(s
, t
, len
);
128 return s
[len
] == '\0' ? 0 : 1;
131 void *xrealloc(void *ptr
, size_t size
)
140 memory_limit_check(size
, 0);
141 ret
= realloc(ptr
, size
);
143 die("Out of memory, realloc failed");
147 void *xcalloc(size_t nmemb
, size_t size
)
151 if (unsigned_mult_overflows(nmemb
, size
))
152 die("data too large to fit into virtual memory space");
154 memory_limit_check(size
* nmemb
, 0);
155 ret
= calloc(nmemb
, size
);
156 if (!ret
&& (!nmemb
|| !size
))
159 die("Out of memory, calloc failed");
163 void xsetenv(const char *name
, const char *value
, int overwrite
)
165 if (setenv(name
, value
, overwrite
))
166 die_errno(_("could not setenv '%s'"), name
? name
: "(null)");
170 * xopen() is the same as open(), but it die()s if the open() fails.
172 int xopen(const char *path
, int oflag
, ...)
178 * va_arg() will have undefined behavior if the specified type is not
179 * compatible with the argument type. Since integers are promoted to
180 * ints, we fetch the next argument as an int, and then cast it to a
181 * mode_t to avoid undefined behavior.
185 mode
= va_arg(ap
, int);
189 int fd
= open(path
, oflag
, mode
);
195 if ((oflag
& (O_CREAT
| O_EXCL
)) == (O_CREAT
| O_EXCL
))
196 die_errno(_("unable to create '%s'"), path
);
197 else if ((oflag
& O_RDWR
) == O_RDWR
)
198 die_errno(_("could not open '%s' for reading and writing"), path
);
199 else if ((oflag
& O_WRONLY
) == O_WRONLY
)
200 die_errno(_("could not open '%s' for writing"), path
);
202 die_errno(_("could not open '%s' for reading"), path
);
206 static int handle_nonblock(int fd
, short poll_events
, int err
)
210 if (err
!= EAGAIN
&& err
!= EWOULDBLOCK
)
214 pfd
.events
= poll_events
;
217 * no need to check for errors, here;
218 * a subsequent read/write will detect unrecoverable errors
225 * xread() is the same a read(), but it automatically restarts read()
226 * operations with a recoverable error (EAGAIN and EINTR). xread()
227 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
229 ssize_t
xread(int fd
, void *buf
, size_t len
)
232 if (len
> MAX_IO_SIZE
)
235 nr
= read(fd
, buf
, len
);
239 if (handle_nonblock(fd
, POLLIN
, errno
))
247 * xwrite() is the same a write(), but it automatically restarts write()
248 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
249 * GUARANTEE that "len" bytes is written even if the operation is successful.
251 ssize_t
xwrite(int fd
, const void *buf
, size_t len
)
254 if (len
> MAX_IO_SIZE
)
257 nr
= write(fd
, buf
, len
);
261 if (handle_nonblock(fd
, POLLOUT
, errno
))
270 * xpread() is the same as pread(), but it automatically restarts pread()
271 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
272 * NOT GUARANTEE that "len" bytes is read even if the data is available.
274 ssize_t
xpread(int fd
, void *buf
, size_t len
, off_t offset
)
277 if (len
> MAX_IO_SIZE
)
280 nr
= pread(fd
, buf
, len
, offset
);
281 if ((nr
< 0) && (errno
== EAGAIN
|| errno
== EINTR
))
287 ssize_t
read_in_full(int fd
, void *buf
, size_t count
)
293 ssize_t loaded
= xread(fd
, p
, count
);
306 ssize_t
write_in_full(int fd
, const void *buf
, size_t count
)
312 ssize_t written
= xwrite(fd
, p
, count
);
327 ssize_t
pread_in_full(int fd
, void *buf
, size_t count
, off_t offset
)
333 ssize_t loaded
= xpread(fd
, p
, count
, offset
);
351 die_errno("dup failed");
356 * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
358 FILE *xfopen(const char *path
, const char *mode
)
361 FILE *fp
= fopen(path
, mode
);
367 if (*mode
&& mode
[1] == '+')
368 die_errno(_("could not open '%s' for reading and writing"), path
);
369 else if (*mode
== 'w' || *mode
== 'a')
370 die_errno(_("could not open '%s' for writing"), path
);
372 die_errno(_("could not open '%s' for reading"), path
);
376 FILE *xfdopen(int fd
, const char *mode
)
378 FILE *stream
= fdopen(fd
, mode
);
380 die_errno("Out of memory? fdopen failed");
384 FILE *fopen_for_writing(const char *path
)
386 FILE *ret
= fopen(path
, "w");
388 if (!ret
&& errno
== EPERM
) {
390 ret
= fopen(path
, "w");
397 static void warn_on_inaccessible(const char *path
)
399 warning_errno(_("unable to access '%s'"), path
);
402 int warn_on_fopen_errors(const char *path
)
404 if (errno
!= ENOENT
&& errno
!= ENOTDIR
) {
405 warn_on_inaccessible(path
);
412 FILE *fopen_or_warn(const char *path
, const char *mode
)
414 FILE *fp
= fopen(path
, mode
);
419 warn_on_fopen_errors(path
);
423 int xmkstemp(char *filename_template
)
426 char origtemplate
[PATH_MAX
];
427 strlcpy(origtemplate
, filename_template
, sizeof(origtemplate
));
429 fd
= mkstemp(filename_template
);
431 int saved_errno
= errno
;
432 const char *nonrelative_template
;
434 if (strlen(filename_template
) != strlen(origtemplate
))
435 filename_template
= origtemplate
;
437 nonrelative_template
= absolute_path(filename_template
);
439 die_errno("Unable to create temporary file '%s'",
440 nonrelative_template
);
445 /* Adapted from libiberty's mkstemp.c. */
448 #define TMP_MAX 16384
450 int git_mkstemps_mode(char *pattern
, int suffix_len
, int mode
)
452 static const char letters
[] =
453 "abcdefghijklmnopqrstuvwxyz"
454 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
456 static const int num_letters
= ARRAY_SIZE(letters
) - 1;
457 static const char x_pattern
[] = "XXXXXX";
458 static const int num_x
= ARRAY_SIZE(x_pattern
) - 1;
459 char *filename_template
;
463 len
= strlen(pattern
);
465 if (len
< num_x
+ suffix_len
) {
470 if (strncmp(&pattern
[len
- num_x
- suffix_len
], x_pattern
, num_x
)) {
476 * Replace pattern's XXXXXX characters with randomness.
477 * Try TMP_MAX different filenames.
479 filename_template
= &pattern
[len
- num_x
- suffix_len
];
480 for (count
= 0; count
< TMP_MAX
; ++count
) {
483 if (csprng_bytes(&v
, sizeof(v
)) < 0)
484 return error_errno("unable to get random bytes for temporary file");
486 /* Fill in the random bits. */
487 for (i
= 0; i
< num_x
; i
++) {
488 filename_template
[i
] = letters
[v
% num_letters
];
492 fd
= open(pattern
, O_CREAT
| O_EXCL
| O_RDWR
, mode
);
496 * Fatal error (EPERM, ENOSPC etc).
497 * It doesn't make sense to loop.
502 /* We return the null string if we can't find a unique file name. */
507 int git_mkstemp_mode(char *pattern
, int mode
)
509 /* mkstemp is just mkstemps with no suffix */
510 return git_mkstemps_mode(pattern
, 0, mode
);
513 int xmkstemp_mode(char *filename_template
, int mode
)
516 char origtemplate
[PATH_MAX
];
517 strlcpy(origtemplate
, filename_template
, sizeof(origtemplate
));
519 fd
= git_mkstemp_mode(filename_template
, mode
);
521 int saved_errno
= errno
;
522 const char *nonrelative_template
;
524 if (!filename_template
[0])
525 filename_template
= origtemplate
;
527 nonrelative_template
= absolute_path(filename_template
);
529 die_errno("Unable to create temporary file '%s'",
530 nonrelative_template
);
536 * Some platforms return EINTR from fsync. Since fsync is invoked in some
537 * cases by a wrapper that dies on failure, do not expose EINTR to callers.
539 static int fsync_loop(int fd
)
545 } while (err
< 0 && errno
== EINTR
);
549 int git_fsync(int fd
, enum fsync_action action
)
552 case FSYNC_WRITEOUT_ONLY
:
553 count_fsync_writeout_only
+= 1;
557 * On macOS, fsync just causes filesystem cache writeback but
558 * does not flush hardware caches.
560 return fsync_loop(fd
);
563 #ifdef HAVE_SYNC_FILE_RANGE
565 * On linux 2.6.17 and above, sync_file_range is the way to
566 * issue a writeback without a hardware flush. An offset of
567 * 0 and size of 0 indicates writeout of the entire file and the
568 * wait flags ensure that all dirty data is written to the disk
569 * (potentially in a disk-side cache) before we continue.
572 return sync_file_range(fd
, 0, 0, SYNC_FILE_RANGE_WAIT_BEFORE
|
573 SYNC_FILE_RANGE_WRITE
|
574 SYNC_FILE_RANGE_WAIT_AFTER
);
577 #ifdef fsync_no_flush
578 return fsync_no_flush(fd
);
584 case FSYNC_HARDWARE_FLUSH
:
585 count_fsync_hardware_flush
+= 1;
588 * On macOS, a special fcntl is required to really flush the
589 * caches within the storage controller. As of this writing,
590 * this is a very expensive operation on Apple SSDs.
593 return fcntl(fd
, F_FULLFSYNC
);
595 return fsync_loop(fd
);
598 BUG("unexpected git_fsync(%d) call", action
);
602 static void log_trace_fsync_if(const char *key
, intmax_t value
)
605 trace2_data_intmax("fsync", the_repository
, key
, value
);
608 void trace_git_fsync_stats(void)
610 log_trace_fsync_if("fsync/writeout-only", count_fsync_writeout_only
);
611 log_trace_fsync_if("fsync/hardware-flush", count_fsync_hardware_flush
);
614 static int warn_if_unremovable(const char *op
, const char *file
, int rc
)
617 if (!rc
|| errno
== ENOENT
)
620 warning_errno("unable to %s '%s'", op
, file
);
625 int unlink_or_msg(const char *file
, struct strbuf
*err
)
627 int rc
= unlink(file
);
631 if (!rc
|| errno
== ENOENT
)
634 strbuf_addf(err
, "unable to unlink '%s': %s",
635 file
, strerror(errno
));
639 int unlink_or_warn(const char *file
)
641 return warn_if_unremovable("unlink", file
, unlink(file
));
644 int rmdir_or_warn(const char *file
)
646 return warn_if_unremovable("rmdir", file
, rmdir(file
));
649 int remove_or_warn(unsigned int mode
, const char *file
)
651 return S_ISGITLINK(mode
) ? rmdir_or_warn(file
) : unlink_or_warn(file
);
654 static int access_error_is_ok(int err
, unsigned flag
)
656 return (is_missing_file_error(err
) ||
657 ((flag
& ACCESS_EACCES_OK
) && err
== EACCES
));
660 int access_or_warn(const char *path
, int mode
, unsigned flag
)
662 int ret
= access(path
, mode
);
663 if (ret
&& !access_error_is_ok(errno
, flag
))
664 warn_on_inaccessible(path
);
668 int access_or_die(const char *path
, int mode
, unsigned flag
)
670 int ret
= access(path
, mode
);
671 if (ret
&& !access_error_is_ok(errno
, flag
))
672 die_errno(_("unable to access '%s'"), path
);
678 struct strbuf sb
= STRBUF_INIT
;
679 if (strbuf_getcwd(&sb
))
680 die_errno(_("unable to get current working directory"));
681 return strbuf_detach(&sb
, NULL
);
684 int xsnprintf(char *dst
, size_t max
, const char *fmt
, ...)
690 len
= vsnprintf(dst
, max
, fmt
, ap
);
694 BUG("your snprintf is broken");
696 BUG("attempt to snprintf into too-small buffer");
700 void write_file_buf(const char *path
, const char *buf
, size_t len
)
702 int fd
= xopen(path
, O_WRONLY
| O_CREAT
| O_TRUNC
, 0666);
703 if (write_in_full(fd
, buf
, len
) < 0)
704 die_errno(_("could not write to '%s'"), path
);
706 die_errno(_("could not close '%s'"), path
);
709 void write_file(const char *path
, const char *fmt
, ...)
712 struct strbuf sb
= STRBUF_INIT
;
714 va_start(params
, fmt
);
715 strbuf_vaddf(&sb
, fmt
, params
);
718 strbuf_complete_line(&sb
);
720 write_file_buf(path
, sb
.buf
, sb
.len
);
724 void sleep_millisec(int millisec
)
726 poll(NULL
, 0, millisec
);
729 int xgethostname(char *buf
, size_t len
)
732 * If the full hostname doesn't fit in buf, POSIX does not
733 * specify whether the buffer will be null-terminated, so to
734 * be safe, do it ourselves.
736 int ret
= gethostname(buf
, len
);
742 int is_empty_or_missing_file(const char *filename
)
746 if (stat(filename
, &st
) < 0) {
749 die_errno(_("could not stat %s"), filename
);
755 int open_nofollow(const char *path
, int flags
)
758 return open(path
, flags
| O_NOFOLLOW
);
761 if (lstat(path
, &st
) < 0)
763 if (S_ISLNK(st
.st_mode
)) {
767 return open(path
, flags
);
771 int csprng_bytes(void *buf
, size_t len
)
773 #if defined(HAVE_ARC4RANDOM) || defined(HAVE_ARC4RANDOM_LIBBSD)
774 /* This function never returns an error. */
775 arc4random_buf(buf
, len
);
777 #elif defined(HAVE_GETRANDOM)
781 res
= getrandom(p
, len
, 0);
788 #elif defined(HAVE_GETENTROPY)
792 /* getentropy has a maximum size of 256 bytes. */
793 size_t chunk
= len
< 256 ? len
: 256;
794 res
= getentropy(p
, chunk
);
801 #elif defined(HAVE_RTLGENRANDOM)
802 if (!RtlGenRandom(buf
, len
))
805 #elif defined(HAVE_OPENSSL_CSPRNG)
806 int res
= RAND_bytes(buf
, len
);
818 fd
= open("/dev/urandom", O_RDONLY
);
822 res
= xread(fd
, p
, len
);