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-rw-r--r--src/readahead/readahead-replay.c371
1 files changed, 371 insertions, 0 deletions
diff --git a/src/readahead/readahead-replay.c b/src/readahead/readahead-replay.c
new file mode 100644
index 000000000..65011ac4b
--- /dev/null
+++ b/src/readahead/readahead-replay.c
@@ -0,0 +1,371 @@
+/*-*- 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"
+#include "virt.h"
+
+static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX;
+
+static ReadaheadShared *shared = NULL;
+
+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) {
+
+ if (errno != ENOENT && errno != EPERM && errno != EACCES)
+ 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;
+ int c;
+ bool on_ssd, ready = false;
+ int prio;
+ int inotify_fd = -1;
+
+ assert(root);
+
+ write_one_line_file("/proc/self/oom_score_adj", "1000");
+ bump_request_nr(root);
+
+ 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;
+ }
+
+ posix_fadvise(fileno(pack), 0, 0, POSIX_FADV_WILLNEED);
+
+ 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("/run/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;
+ const char *root;
+
+ log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
+ log_parse_environment();
+ log_open();
+
+ umask(0022);
+
+ if ((r = parse_argv(argc, argv)) <= 0)
+ return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+
+ root = optind < argc ? argv[optind] : "/";
+
+ if (!enough_ram()) {
+ log_info("Disabling readahead replay due to low memory.");
+ return 0;
+ }
+
+ if (detect_virtualization(NULL) > 0) {
+ log_info("Disabling readahead replay due to execution in virtualized environment.");
+ return 0;
+ }
+
+ if (!(shared = shared_get()))
+ return 1;
+
+ shared->replay = getpid();
+ __sync_synchronize();
+
+ if (replay(root) < 0)
+ return 1;
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-06 18:49:52 +0000