| /*-*- 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 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 <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 <systemd/sd-daemon.h> |
| |
| #include "missing.h" |
| #include "util.h" |
| #include "set.h" |
| #include "ioprio.h" |
| #include "readahead-common.h" |
| #include "virt.h" |
| |
| 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; |
| uint64_t inode; |
| |
| assert(pack); |
| |
| if (!fgets(fn, sizeof(fn), pack)) |
| return 0; |
| |
| char_array_0(fn); |
| truncate_nl(fn); |
| |
| fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW); |
| if (fd < 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; |
| } |
| |
| if (fread(&inode, sizeof(inode), 1, pack) != 1) { |
| log_error("Premature end of pack file."); |
| r = -EIO; |
| goto finish; |
| } |
| |
| if (fd >= 0) { |
| /* If the inode changed the file got deleted, so just |
| * ignore this entry */ |
| if (st.st_ino != (uint64_t) inode) { |
| 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); |
| |
| block_bump_request_nr(root); |
| |
| if (asprintf(&pack_fn, "%s/.readahead", root) < 0) { |
| log_error("Out of memory"); |
| r = -ENOMEM; |
| goto finish; |
| } |
| |
| pack = fopen(pack_fn, "re"); |
| if (!pack) { |
| 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 READAHEAD_PACK_FILE_VERSION)) { |
| log_debug("Pack file host or version 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 |
| /* We are not using RT here, since we'd starve IO that |
| we didn't record (which is for example blkid, since |
| its disk accesses go directly to the block device and |
| are thus not visible in fallocate) to death. However, |
| we do ask for an IO prio that is slightly higher than |
| the default (which is BE. 4) */ |
| prio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 2); |
| |
| 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; |
| } |
| |
| int main_replay(const char *root) { |
| |
| if (!root) |
| root = "/"; |
| |
| if (!enough_ram()) { |
| log_info("Disabling readahead replay due to low memory."); |
| return EXIT_SUCCESS; |
| } |
| |
| shared = shared_get(); |
| if (!shared) |
| return EXIT_FAILURE; |
| |
| shared->replay = getpid(); |
| __sync_synchronize(); |
| |
| if (replay(root) < 0) |
| return EXIT_FAILURE; |
| |
| return EXIT_SUCCESS; |
| } |