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mirror of https://github.com/systemd/systemd.git synced 2024-11-08 11:27:32 +03:00
systemd/src/readahead-replay.c
2010-09-27 03:25:10 +02:00

346 lines
9.7 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
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 General Public License as published by
the Free Software Foundation; either version 2 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <inttypes.h>
#include <fcntl.h>
#include <linux/limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <getopt.h>
#include <sys/inotify.h>
#include "missing.h"
#include "util.h"
#include "set.h"
#include "sd-daemon.h"
#include "ioprio.h"
#include "readahead-common.h"
static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX;
static int unpack_file(FILE *pack) {
char fn[PATH_MAX];
int r = 0, fd = -1;
bool any = false;
struct stat st;
assert(pack);
if (!fgets(fn, sizeof(fn), pack))
return 0;
char_array_0(fn);
truncate_nl(fn);
if ((fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW)) < 0)
log_warning("open(%s) failed: %m", fn);
else if (file_verify(fd, fn, arg_file_size_max, &st) <= 0) {
close_nointr_nofail(fd);
fd = -1;
}
for (;;) {
uint32_t b, c;
if (fread(&b, sizeof(b), 1, pack) != 1 ||
fread(&c, sizeof(c), 1, pack) != 1) {
log_error("Premature end of pack file.");
r = -EIO;
goto finish;
}
if (b == 0 && c == 0)
break;
if (c <= b) {
log_error("Invalid pack file.");
r = -EIO;
goto finish;
}
log_debug("%s: page %u to %u", fn, b, c);
any = true;
if (fd >= 0)
if (posix_fadvise(fd, b * PAGE_SIZE, (c - b) * PAGE_SIZE, POSIX_FADV_WILLNEED) < 0) {
log_warning("posix_fadvise() failed: %m");
goto finish;
}
}
if (!any && fd >= 0) {
/* if no range is encoded in the pack file this is
* intended to mean that the whole file shall be
* read */
if (posix_fadvise(fd, 0, st.st_size, POSIX_FADV_WILLNEED) < 0) {
log_warning("posix_fadvise() failed: %m");
goto finish;
}
}
finish:
if (fd >= 0)
close_nointr_nofail(fd);
return r;
}
static int replay(const char *root) {
FILE *pack = NULL;
char line[LINE_MAX];
int r = 0;
char *pack_fn = NULL, c;
bool on_ssd, ready = false;
int prio;
int inotify_fd = -1;
assert(root);
write_one_line_file("/proc/self/oom_score_adj", "1000");
if (asprintf(&pack_fn, "%s/.readahead", root) < 0) {
log_error("Out of memory");
r = -ENOMEM;
goto finish;
}
if ((!(pack = fopen(pack_fn, "re")))) {
if (errno == -ENOENT)
log_debug("No pack file found.");
else {
log_error("Failed to open pack file: %m");
r = -errno;
}
goto finish;
}
if ((inotify_fd = open_inotify()) < 0) {
r = inotify_fd;
goto finish;
}
if (!(fgets(line, sizeof(line), pack))) {
log_error("Premature end of pack file.");
r = -EIO;
goto finish;
}
char_array_0(line);
if (!streq(line, CANONICAL_HOST "\n")) {
log_debug("Pack file host type mismatch.");
goto finish;
}
if ((c = getc(pack)) == EOF) {
log_debug("Premature end of pack file.");
r = -EIO;
goto finish;
}
/* We do not retest SSD here, so that we can start replaying
* before udev is up.*/
on_ssd = c == 'S';
log_debug("On SSD: %s", yes_no(on_ssd));
if (on_ssd)
prio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0);
else
prio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_RT, 7);
if (ioprio_set(IOPRIO_WHO_PROCESS, getpid(), prio) < 0)
log_warning("Failed to set IDLE IO priority class: %m");
sd_notify(0, "STATUS=Replaying readahead data");
log_debug("Replaying...");
if (access("/dev/.systemd/readahead/noreplay", F_OK) >= 0) {
log_debug("Got termination request");
goto done;
}
while (!feof(pack) && !ferror(pack)) {
uint8_t inotify_buffer[sizeof(struct inotify_event) + FILENAME_MAX];
int k;
ssize_t n;
if ((n = read(inotify_fd, &inotify_buffer, sizeof(inotify_buffer))) < 0) {
if (errno != EINTR && errno != EAGAIN) {
log_error("Failed to read inotify event: %m");
r = -errno;
goto finish;
}
} else {
struct inotify_event *e = (struct inotify_event*) inotify_buffer;
while (n > 0) {
size_t step;
if ((e->mask & IN_CREATE) && streq(e->name, "noreplay")) {
log_debug("Got termination request");
goto done;
}
step = sizeof(struct inotify_event) + e->len;
assert(step <= (size_t) n);
e = (struct inotify_event*) ((uint8_t*) e + step);
n -= step;
}
}
if ((k = unpack_file(pack)) < 0) {
r = k;
goto finish;
}
if (!ready) {
/* We delay the ready notification until we
* queued at least one read */
sd_notify(0, "READY=1");
ready = true;
}
}
done:
if (!ready)
sd_notify(0, "READY=1");
if (ferror(pack)) {
log_error("Failed to read pack file.");
r = -EIO;
goto finish;
}
log_debug("Done.");
finish:
if (pack)
fclose(pack);
if (inotify_fd >= 0)
close_nointr_nofail(inotify_fd);
free(pack_fn);
return r;
}
static int help(void) {
printf("%s [OPTIONS...] [DIRECTORY]\n\n"
"Replay collected read-ahead data on early boot.\n\n"
" -h --help Show this help\n"
" --max-file-size=BYTES Maximum size of files to read ahead\n",
program_invocation_short_name);
return 0;
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_FILE_SIZE_MAX
};
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "file-size-max", required_argument, NULL, ARG_FILE_SIZE_MAX },
{ NULL, 0, NULL, 0 }
};
int c;
assert(argc >= 0);
assert(argv);
while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
switch (c) {
case 'h':
help();
return 0;
case ARG_FILE_SIZE_MAX: {
unsigned long long ull;
if (safe_atollu(optarg, &ull) < 0 || ull <= 0) {
log_error("Failed to parse maximum file size %s.", optarg);
return -EINVAL;
}
arg_file_size_max = (off_t) ull;
break;
}
case '?':
return -EINVAL;
default:
log_error("Unknown option code %c", c);
return -EINVAL;
}
}
if (optind != argc &&
optind != argc-1) {
help();
return -EINVAL;
}
return 1;
}
int main(int argc, char*argv[]) {
int r;
log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
log_parse_environment();
log_open();
if ((r = parse_argv(argc, argv)) <= 0)
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
if (!enough_ram()) {
log_info("Disabling readahead replay due to low memory.");
return 0;
}
if (replay(optind < argc ? argv[optind] : "/") < 0)
return 1;
return 0;
}