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fs.c
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fs.c
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/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/* Caveat emptor: this file deviates from the libuv convention of returning
* negated errno codes. Most uv_fs_*() functions map directly to the system
* call of the same name. For more complex wrappers, it's easier to just
* return -1 with errno set. The dispatcher in uv__fs_work() takes care of
* getting the errno to the right place (req->result or as the return value.)
*/
#include "uv.h"
#include "internal.h"
#include <errno.h>
#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h> /* PATH_MAX */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <pthread.h>
#include <unistd.h>
#include <fcntl.h>
#include <poll.h>
#if defined(__DragonFly__) || \
defined(__FreeBSD__) || \
defined(__FreeBSD_kernel__) || \
defined(__OpenBSD__) || \
defined(__NetBSD__)
# define HAVE_PREADV 1
#else
# define HAVE_PREADV 0
#endif
#if defined(__linux__) || defined(__sun)
# include <sys/sendfile.h>
#endif
#if defined(__APPLE__)
# include <sys/sysctl.h>
#elif defined(__linux__) && !defined(FICLONE)
# include <sys/ioctl.h>
# define FICLONE _IOW(0x94, 9, int)
#endif
#if defined(_AIX) && !defined(_AIX71)
# include <utime.h>
#endif
#if defined(__APPLE__) || \
defined(__DragonFly__) || \
defined(__FreeBSD__) || \
defined(__FreeBSD_kernel__) || \
defined(__OpenBSD__) || \
defined(__NetBSD__)
# include <sys/param.h>
# include <sys/mount.h>
#elif defined(__sun) || \
defined(__MVS__) || \
defined(__NetBSD__) || \
defined(__HAIKU__) || \
defined(__QNX__)
# include <sys/statvfs.h>
#else
# include <sys/statfs.h>
#endif
#if defined(_AIX) && _XOPEN_SOURCE <= 600
extern char *mkdtemp(char *template); /* See issue #740 on AIX < 7 */
#endif
#define INIT(subtype) \
do { \
if (req == NULL) \
return UV_EINVAL; \
UV_REQ_INIT(req, UV_FS); \
req->fs_type = UV_FS_ ## subtype; \
req->result = 0; \
req->ptr = NULL; \
req->loop = loop; \
req->path = NULL; \
req->new_path = NULL; \
req->bufs = NULL; \
req->cb = cb; \
} \
while (0)
#define PATH \
do { \
assert(path != NULL); \
if (cb == NULL) { \
req->path = path; \
} else { \
req->path = uv__strdup(path); \
if (req->path == NULL) \
return UV_ENOMEM; \
} \
} \
while (0)
#define PATH2 \
do { \
if (cb == NULL) { \
req->path = path; \
req->new_path = new_path; \
} else { \
size_t path_len; \
size_t new_path_len; \
path_len = strlen(path) + 1; \
new_path_len = strlen(new_path) + 1; \
req->path = uv__malloc(path_len + new_path_len); \
if (req->path == NULL) \
return UV_ENOMEM; \
req->new_path = req->path + path_len; \
memcpy((void*) req->path, path, path_len); \
memcpy((void*) req->new_path, new_path, new_path_len); \
} \
} \
while (0)
#define POST \
do { \
if (cb != NULL) { \
uv__req_register(loop, req); \
uv__work_submit(loop, \
&req->work_req, \
UV__WORK_FAST_IO, \
uv__fs_work, \
uv__fs_done); \
return 0; \
} \
else { \
uv__fs_work(&req->work_req); \
return req->result; \
} \
} \
while (0)
static int uv__fs_close(int fd) {
int rc;
rc = uv__close_nocancel(fd);
if (rc == -1)
if (errno == EINTR || errno == EINPROGRESS)
rc = 0; /* The close is in progress, not an error. */
return rc;
}
static ssize_t uv__fs_fsync(uv_fs_t* req) {
#if defined(__APPLE__)
/* Apple's fdatasync and fsync explicitly do NOT flush the drive write cache
* to the drive platters. This is in contrast to Linux's fdatasync and fsync
* which do, according to recent man pages. F_FULLFSYNC is Apple's equivalent
* for flushing buffered data to permanent storage. If F_FULLFSYNC is not
* supported by the file system we fall back to F_BARRIERFSYNC or fsync().
* This is the same approach taken by sqlite, except sqlite does not issue
* an F_BARRIERFSYNC call.
*/
int r;
r = fcntl(req->file, F_FULLFSYNC);
if (r != 0)
r = fcntl(req->file, 85 /* F_BARRIERFSYNC */); /* fsync + barrier */
if (r != 0)
r = fsync(req->file);
return r;
#else
return fsync(req->file);
#endif
}
static ssize_t uv__fs_fdatasync(uv_fs_t* req) {
#if defined(__linux__) || defined(__sun) || defined(__NetBSD__)
return fdatasync(req->file);
#elif defined(__APPLE__)
/* See the comment in uv__fs_fsync. */
return uv__fs_fsync(req);
#else
return fsync(req->file);
#endif
}
UV_UNUSED(static struct timespec uv__fs_to_timespec(double time)) {
struct timespec ts;
ts.tv_sec = time;
ts.tv_nsec = (uint64_t)(time * 1000000) % 1000000 * 1000;
return ts;
}
UV_UNUSED(static struct timeval uv__fs_to_timeval(double time)) {
struct timeval tv;
tv.tv_sec = time;
tv.tv_usec = (uint64_t)(time * 1000000) % 1000000;
return tv;
}
static ssize_t uv__fs_futime(uv_fs_t* req) {
#if defined(__linux__) \
|| defined(_AIX71) \
|| defined(__HAIKU__)
/* utimesat() has nanosecond resolution but we stick to microseconds
* for the sake of consistency with other platforms.
*/
struct timespec ts[2];
ts[0] = uv__fs_to_timespec(req->atime);
ts[1] = uv__fs_to_timespec(req->mtime);
return futimens(req->file, ts);
#elif defined(__APPLE__) \
|| defined(__DragonFly__) \
|| defined(__FreeBSD__) \
|| defined(__FreeBSD_kernel__) \
|| defined(__NetBSD__) \
|| defined(__OpenBSD__) \
|| defined(__sun)
struct timeval tv[2];
tv[0] = uv__fs_to_timeval(req->atime);
tv[1] = uv__fs_to_timeval(req->mtime);
# if defined(__sun)
return futimesat(req->file, NULL, tv);
# else
return futimes(req->file, tv);
# endif
#elif defined(__MVS__)
attrib_t atr;
memset(&atr, 0, sizeof(atr));
atr.att_mtimechg = 1;
atr.att_atimechg = 1;
atr.att_mtime = req->mtime;
atr.att_atime = req->atime;
return __fchattr(req->file, &atr, sizeof(atr));
#else
errno = ENOSYS;
return -1;
#endif
}
static ssize_t uv__fs_mkdtemp(uv_fs_t* req) {
return mkdtemp((char*) req->path) ? 0 : -1;
}
static int (*uv__mkostemp)(char*, int);
static void uv__mkostemp_initonce(void) {
/* z/os doesn't have RTLD_DEFAULT but that's okay
* because it doesn't have mkostemp(O_CLOEXEC) either.
*/
#ifdef RTLD_DEFAULT
uv__mkostemp = (int (*)(char*, int)) dlsym(RTLD_DEFAULT, "mkostemp");
/* We don't care about errors, but we do want to clean them up.
* If there has been no error, then dlerror() will just return
* NULL.
*/
dlerror();
#endif /* RTLD_DEFAULT */
}
static int uv__fs_mkstemp(uv_fs_t* req) {
static uv_once_t once = UV_ONCE_INIT;
int r;
#ifdef O_CLOEXEC
static int no_cloexec_support;
#endif
static const char pattern[] = "XXXXXX";
static const size_t pattern_size = sizeof(pattern) - 1;
char* path;
size_t path_length;
path = (char*) req->path;
path_length = strlen(path);
/* EINVAL can be returned for 2 reasons:
1. The template's last 6 characters were not XXXXXX
2. open() didn't support O_CLOEXEC
We want to avoid going to the fallback path in case
of 1, so it's manually checked before. */
if (path_length < pattern_size ||
strcmp(path + path_length - pattern_size, pattern)) {
errno = EINVAL;
r = -1;
goto clobber;
}
uv_once(&once, uv__mkostemp_initonce);
#ifdef O_CLOEXEC
if (uv__load_relaxed(&no_cloexec_support) == 0 && uv__mkostemp != NULL) {
r = uv__mkostemp(path, O_CLOEXEC);
if (r >= 0)
return r;
/* If mkostemp() returns EINVAL, it means the kernel doesn't
support O_CLOEXEC, so we just fallback to mkstemp() below. */
if (errno != EINVAL)
goto clobber;
/* We set the static variable so that next calls don't even
try to use mkostemp. */
uv__store_relaxed(&no_cloexec_support, 1);
}
#endif /* O_CLOEXEC */
if (req->cb != NULL)
uv_rwlock_rdlock(&req->loop->cloexec_lock);
r = mkstemp(path);
/* In case of failure `uv__cloexec` will leave error in `errno`,
* so it is enough to just set `r` to `-1`.
*/
if (r >= 0 && uv__cloexec(r, 1) != 0) {
r = uv__close(r);
if (r != 0)
abort();
r = -1;
}
if (req->cb != NULL)
uv_rwlock_rdunlock(&req->loop->cloexec_lock);
clobber:
if (r < 0)
path[0] = '\0';
return r;
}
static ssize_t uv__fs_open(uv_fs_t* req) {
#ifdef O_CLOEXEC
return open(req->path, req->flags | O_CLOEXEC, req->mode);
#else /* O_CLOEXEC */
int r;
if (req->cb != NULL)
uv_rwlock_rdlock(&req->loop->cloexec_lock);
r = open(req->path, req->flags, req->mode);
/* In case of failure `uv__cloexec` will leave error in `errno`,
* so it is enough to just set `r` to `-1`.
*/
if (r >= 0 && uv__cloexec(r, 1) != 0) {
r = uv__close(r);
if (r != 0)
abort();
r = -1;
}
if (req->cb != NULL)
uv_rwlock_rdunlock(&req->loop->cloexec_lock);
return r;
#endif /* O_CLOEXEC */
}
#if !HAVE_PREADV
static ssize_t uv__fs_preadv(uv_file fd,
uv_buf_t* bufs,
unsigned int nbufs,
off_t off) {
uv_buf_t* buf;
uv_buf_t* end;
ssize_t result;
ssize_t rc;
size_t pos;
assert(nbufs > 0);
result = 0;
pos = 0;
buf = bufs + 0;
end = bufs + nbufs;
for (;;) {
do
rc = pread(fd, buf->base + pos, buf->len - pos, off + result);
while (rc == -1 && errno == EINTR);
if (rc == 0)
break;
if (rc == -1 && result == 0)
return UV__ERR(errno);
if (rc == -1)
break; /* We read some data so return that, ignore the error. */
pos += rc;
result += rc;
if (pos < buf->len)
continue;
pos = 0;
buf += 1;
if (buf == end)
break;
}
return result;
}
#endif
static ssize_t uv__fs_read(uv_fs_t* req) {
#if defined(__linux__)
static int no_preadv;
#endif
unsigned int iovmax;
ssize_t result;
iovmax = uv__getiovmax();
if (req->nbufs > iovmax)
req->nbufs = iovmax;
if (req->off < 0) {
if (req->nbufs == 1)
result = read(req->file, req->bufs[0].base, req->bufs[0].len);
else
result = readv(req->file, (struct iovec*) req->bufs, req->nbufs);
} else {
if (req->nbufs == 1) {
result = pread(req->file, req->bufs[0].base, req->bufs[0].len, req->off);
goto done;
}
#if HAVE_PREADV
result = preadv(req->file, (struct iovec*) req->bufs, req->nbufs, req->off);
#else
# if defined(__linux__)
if (uv__load_relaxed(&no_preadv)) retry:
# endif
{
result = uv__fs_preadv(req->file, req->bufs, req->nbufs, req->off);
}
# if defined(__linux__)
else {
result = uv__preadv(req->file,
(struct iovec*)req->bufs,
req->nbufs,
req->off);
if (result == -1 && errno == ENOSYS) {
uv__store_relaxed(&no_preadv, 1);
goto retry;
}
}
# endif
#endif
}
done:
/* Early cleanup of bufs allocation, since we're done with it. */
if (req->bufs != req->bufsml)
uv__free(req->bufs);
req->bufs = NULL;
req->nbufs = 0;
#ifdef __PASE__
/* PASE returns EOPNOTSUPP when reading a directory, convert to EISDIR */
if (result == -1 && errno == EOPNOTSUPP) {
struct stat buf;
ssize_t rc;
rc = fstat(req->file, &buf);
if (rc == 0 && S_ISDIR(buf.st_mode)) {
errno = EISDIR;
}
}
#endif
return result;
}
#if defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_8)
#define UV_CONST_DIRENT uv__dirent_t
#else
#define UV_CONST_DIRENT const uv__dirent_t
#endif
static int uv__fs_scandir_filter(UV_CONST_DIRENT* dent) {
return strcmp(dent->d_name, ".") != 0 && strcmp(dent->d_name, "..") != 0;
}
static int uv__fs_scandir_sort(UV_CONST_DIRENT** a, UV_CONST_DIRENT** b) {
return strcmp((*a)->d_name, (*b)->d_name);
}
static ssize_t uv__fs_scandir(uv_fs_t* req) {
uv__dirent_t** dents;
int n;
dents = NULL;
n = scandir(req->path, &dents, uv__fs_scandir_filter, uv__fs_scandir_sort);
/* NOTE: We will use nbufs as an index field */
req->nbufs = 0;
if (n == 0) {
/* OS X still needs to deallocate some memory.
* Memory was allocated using the system allocator, so use free() here.
*/
free(dents);
dents = NULL;
} else if (n == -1) {
return n;
}
req->ptr = dents;
return n;
}
static int uv__fs_opendir(uv_fs_t* req) {
uv_dir_t* dir;
dir = uv__malloc(sizeof(*dir));
if (dir == NULL)
goto error;
dir->dir = opendir(req->path);
if (dir->dir == NULL)
goto error;
req->ptr = dir;
return 0;
error:
uv__free(dir);
req->ptr = NULL;
return -1;
}
static int uv__fs_readdir(uv_fs_t* req) {
uv_dir_t* dir;
uv_dirent_t* dirent;
struct dirent* res;
unsigned int dirent_idx;
unsigned int i;
dir = req->ptr;
dirent_idx = 0;
while (dirent_idx < dir->nentries) {
/* readdir() returns NULL on end of directory, as well as on error. errno
is used to differentiate between the two conditions. */
errno = 0;
res = readdir(dir->dir);
if (res == NULL) {
if (errno != 0)
goto error;
break;
}
if (strcmp(res->d_name, ".") == 0 || strcmp(res->d_name, "..") == 0)
continue;
dirent = &dir->dirents[dirent_idx];
dirent->name = uv__strdup(res->d_name);
if (dirent->name == NULL)
goto error;
dirent->type = uv__fs_get_dirent_type(res);
++dirent_idx;
}
return dirent_idx;
error:
for (i = 0; i < dirent_idx; ++i) {
uv__free((char*) dir->dirents[i].name);
dir->dirents[i].name = NULL;
}
return -1;
}
static int uv__fs_closedir(uv_fs_t* req) {
uv_dir_t* dir;
dir = req->ptr;
if (dir->dir != NULL) {
closedir(dir->dir);
dir->dir = NULL;
}
uv__free(req->ptr);
req->ptr = NULL;
return 0;
}
static int uv__fs_statfs(uv_fs_t* req) {
uv_statfs_t* stat_fs;
#if defined(__sun) || \
defined(__MVS__) || \
defined(__NetBSD__) || \
defined(__HAIKU__) || \
defined(__QNX__)
struct statvfs buf;
if (0 != statvfs(req->path, &buf))
#else
struct statfs buf;
if (0 != statfs(req->path, &buf))
#endif /* defined(__sun) */
return -1;
stat_fs = uv__malloc(sizeof(*stat_fs));
if (stat_fs == NULL) {
errno = ENOMEM;
return -1;
}
#if defined(__sun) || \
defined(__MVS__) || \
defined(__OpenBSD__) || \
defined(__NetBSD__) || \
defined(__HAIKU__) || \
defined(__QNX__)
stat_fs->f_type = 0; /* f_type is not supported. */
#else
stat_fs->f_type = buf.f_type;
#endif
stat_fs->f_bsize = buf.f_bsize;
stat_fs->f_blocks = buf.f_blocks;
stat_fs->f_bfree = buf.f_bfree;
stat_fs->f_bavail = buf.f_bavail;
stat_fs->f_files = buf.f_files;
stat_fs->f_ffree = buf.f_ffree;
req->ptr = stat_fs;
return 0;
}
static ssize_t uv__fs_pathmax_size(const char* path) {
ssize_t pathmax;
pathmax = pathconf(path, _PC_PATH_MAX);
if (pathmax == -1)
pathmax = UV__PATH_MAX;
return pathmax;
}
static ssize_t uv__fs_readlink(uv_fs_t* req) {
ssize_t maxlen;
ssize_t len;
char* buf;
#if defined(_POSIX_PATH_MAX) || defined(PATH_MAX)
maxlen = uv__fs_pathmax_size(req->path);
#else
/* We may not have a real PATH_MAX. Read size of link. */
struct stat st;
int ret;
ret = lstat(req->path, &st);
if (ret != 0)
return -1;
if (!S_ISLNK(st.st_mode)) {
errno = EINVAL;
return -1;
}
maxlen = st.st_size;
/* According to readlink(2) lstat can report st_size == 0
for some symlinks, such as those in /proc or /sys. */
if (maxlen == 0)
maxlen = uv__fs_pathmax_size(req->path);
#endif
buf = uv__malloc(maxlen);
if (buf == NULL) {
errno = ENOMEM;
return -1;
}
#if defined(__MVS__)
len = os390_readlink(req->path, buf, maxlen);
#else
len = readlink(req->path, buf, maxlen);
#endif
if (len == -1) {
uv__free(buf);
return -1;
}
/* Uncommon case: resize to make room for the trailing nul byte. */
if (len == maxlen) {
buf = uv__reallocf(buf, len + 1);
if (buf == NULL)
return -1;
}
buf[len] = '\0';
req->ptr = buf;
return 0;
}
static ssize_t uv__fs_realpath(uv_fs_t* req) {
char* buf;
#if defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L
buf = realpath(req->path, NULL);
if (buf == NULL)
return -1;
#else
ssize_t len;
len = uv__fs_pathmax_size(req->path);
buf = uv__malloc(len + 1);
if (buf == NULL) {
errno = ENOMEM;
return -1;
}
if (realpath(req->path, buf) == NULL) {
uv__free(buf);
return -1;
}
#endif
req->ptr = buf;
return 0;
}
static ssize_t uv__fs_sendfile_emul(uv_fs_t* req) {
struct pollfd pfd;
int use_pread;
off_t offset;
ssize_t nsent;
ssize_t nread;
ssize_t nwritten;
size_t buflen;
size_t len;
ssize_t n;
int in_fd;
int out_fd;
char buf[8192];
len = req->bufsml[0].len;
in_fd = req->flags;
out_fd = req->file;
offset = req->off;
use_pread = 1;
/* Here are the rules regarding errors:
*
* 1. Read errors are reported only if nsent==0, otherwise we return nsent.
* The user needs to know that some data has already been sent, to stop
* them from sending it twice.
*
* 2. Write errors are always reported. Write errors are bad because they
* mean data loss: we've read data but now we can't write it out.
*
* We try to use pread() and fall back to regular read() if the source fd
* doesn't support positional reads, for example when it's a pipe fd.
*
* If we get EAGAIN when writing to the target fd, we poll() on it until
* it becomes writable again.
*
* FIXME: If we get a write error when use_pread==1, it should be safe to
* return the number of sent bytes instead of an error because pread()
* is, in theory, idempotent. However, special files in /dev or /proc
* may support pread() but not necessarily return the same data on
* successive reads.
*
* FIXME: There is no way now to signal that we managed to send *some* data
* before a write error.
*/
for (nsent = 0; (size_t) nsent < len; ) {
buflen = len - nsent;
if (buflen > sizeof(buf))
buflen = sizeof(buf);
do
if (use_pread)
nread = pread(in_fd, buf, buflen, offset);
else
nread = read(in_fd, buf, buflen);
while (nread == -1 && errno == EINTR);
if (nread == 0)
goto out;
if (nread == -1) {
if (use_pread && nsent == 0 && (errno == EIO || errno == ESPIPE)) {
use_pread = 0;
continue;
}
if (nsent == 0)
nsent = -1;
goto out;
}
for (nwritten = 0; nwritten < nread; ) {
do
n = write(out_fd, buf + nwritten, nread - nwritten);
while (n == -1 && errno == EINTR);
if (n != -1) {
nwritten += n;
continue;
}
if (errno != EAGAIN && errno != EWOULDBLOCK) {
nsent = -1;
goto out;
}
pfd.fd = out_fd;
pfd.events = POLLOUT;
pfd.revents = 0;
do
n = poll(&pfd, 1, -1);
while (n == -1 && errno == EINTR);
if (n == -1 || (pfd.revents & ~POLLOUT) != 0) {
errno = EIO;
nsent = -1;
goto out;
}
}
offset += nread;
nsent += nread;
}
out:
if (nsent != -1)
req->off = offset;
return nsent;
}
static ssize_t uv__fs_sendfile(uv_fs_t* req) {
int in_fd;
int out_fd;
in_fd = req->flags;
out_fd = req->file;
#if defined(__linux__) || defined(__sun)
{
off_t off;
ssize_t r;
off = req->off;
#ifdef __linux__
{
static int copy_file_range_support = 1;
if (copy_file_range_support) {
r = uv__fs_copy_file_range(in_fd, NULL, out_fd, &off, req->bufsml[0].len, 0);
if (r == -1 && errno == ENOSYS) {
errno = 0;
copy_file_range_support = 0;
} else {
goto ok;
}
}
}
#endif
r = sendfile(out_fd, in_fd, &off, req->bufsml[0].len);
ok:
/* sendfile() on SunOS returns EINVAL if the target fd is not a socket but
* it still writes out data. Fortunately, we can detect it by checking if
* the offset has been updated.
*/
if (r != -1 || off > req->off) {
r = off - req->off;
req->off = off;
return r;
}
if (errno == EINVAL ||
errno == EIO ||
errno == ENOTSOCK ||
errno == EXDEV) {
errno = 0;
return uv__fs_sendfile_emul(req);
}
return -1;
}
#elif defined(__APPLE__) || \
defined(__DragonFly__) || \
defined(__FreeBSD__) || \
defined(__FreeBSD_kernel__)
{
off_t len;
ssize_t r;
/* sendfile() on FreeBSD and Darwin returns EAGAIN if the target fd is in
* non-blocking mode and not all data could be written. If a non-zero
* number of bytes have been sent, we don't consider it an error.
*/
#if defined(__FreeBSD__) || defined(__DragonFly__)
len = 0;
r = sendfile(in_fd, out_fd, req->off, req->bufsml[0].len, NULL, &len, 0);
#elif defined(__FreeBSD_kernel__)
len = 0;
r = bsd_sendfile(in_fd,
out_fd,
req->off,
req->bufsml[0].len,
NULL,
&len,
0);
#else
/* The darwin sendfile takes len as an input for the length to send,
* so make sure to initialize it with the caller's value. */
len = req->bufsml[0].len;
r = sendfile(in_fd, out_fd, req->off, &len, NULL, 0);
#endif
/*
* The man page for sendfile(2) on DragonFly states that `len` contains
* a meaningful value ONLY in case of EAGAIN and EINTR.
* Nothing is said about it's value in case of other errors, so better
* not depend on the potential wrong assumption that is was not modified
* by the syscall.
*/
if (r == 0 || ((errno == EAGAIN || errno == EINTR) && len != 0)) {
req->off += len;
return (ssize_t) len;
}
if (errno == EINVAL ||
errno == EIO ||
errno == ENOTSOCK ||
errno == EXDEV) {
errno = 0;
return uv__fs_sendfile_emul(req);
}
return -1;
}
#else
/* Squelch compiler warnings. */
(void) &in_fd;