679 lines
20 KiB
C
679 lines
20 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <errno.h>
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#include <inttypes.h>
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#include <fcntl.h>
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#include <linux/limits.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/select.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <linux/fanotify.h>
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#include <sys/signalfd.h>
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#include <sys/poll.h>
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#include <sys/mman.h>
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#include <linux/fs.h>
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#include <linux/fiemap.h>
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#include <sys/ioctl.h>
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#include <sys/vfs.h>
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#include <getopt.h>
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#include <sys/inotify.h>
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#include "missing.h"
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#include "util.h"
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#include "set.h"
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#include "sd-daemon.h"
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#include "ioprio.h"
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#include "readahead-common.h"
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/* fixme:
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*
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* - detect ssd on btrfs/lvm...
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* - read ahead directories
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* - gzip?
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* - remount rw?
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* - handle files where nothing is in mincore
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* - does ioprio_set work with fadvise()?
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*/
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static unsigned arg_files_max = 16*1024;
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static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX;
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static usec_t arg_timeout = 2*USEC_PER_MINUTE;
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static ReadaheadShared *shared = NULL;
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/* Avoid collisions with the NULL pointer */
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#define SECTOR_TO_PTR(s) ULONG_TO_PTR((s)+1)
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#define PTR_TO_SECTOR(p) (PTR_TO_ULONG(p)-1)
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static int btrfs_defrag(int fd) {
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struct btrfs_ioctl_vol_args data;
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zero(data);
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data.fd = fd;
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return ioctl(fd, BTRFS_IOC_DEFRAG, &data);
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}
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static int pack_file(FILE *pack, const char *fn, bool on_btrfs) {
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struct stat st;
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void *start = MAP_FAILED;
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uint8_t *vec;
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uint32_t b, c;
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size_t l, pages;
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bool mapped;
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int r = 0, fd = -1, k;
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assert(pack);
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assert(fn);
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if ((fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW)) < 0) {
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if (errno == ENOENT)
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return 0;
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if (errno == EPERM || errno == EACCES)
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return 0;
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log_warning("open(%s) failed: %m", fn);
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r = -errno;
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goto finish;
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}
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if ((k = file_verify(fd, fn, arg_file_size_max, &st)) <= 0) {
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r = k;
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goto finish;
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}
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if (on_btrfs)
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btrfs_defrag(fd);
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l = PAGE_ALIGN(st.st_size);
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if ((start = mmap(NULL, l, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
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log_warning("mmap(%s) failed: %m", fn);
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r = -errno;
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goto finish;
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}
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pages = l / PAGE_SIZE;
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vec = alloca(pages);
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if (mincore(start, l, vec) < 0) {
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log_warning("mincore(%s) failed: %m", fn);
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r = -errno;
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goto finish;
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}
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fputs(fn, pack);
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fputc('\n', pack);
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mapped = false;
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for (c = 0; c < pages; c++) {
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bool new_mapped = !!(vec[c] & 1);
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if (!mapped && new_mapped)
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b = c;
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else if (mapped && !new_mapped) {
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fwrite(&b, sizeof(b), 1, pack);
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fwrite(&c, sizeof(c), 1, pack);
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log_debug("%s: page %u to %u", fn, b, c);
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}
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mapped = new_mapped;
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}
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/* We don't write any range data if we should read the entire file */
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if (mapped && b > 0) {
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fwrite(&b, sizeof(b), 1, pack);
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fwrite(&c, sizeof(c), 1, pack);
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log_debug("%s: page %u to %u", fn, b, c);
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}
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/* End marker */
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b = 0;
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fwrite(&b, sizeof(b), 1, pack);
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fwrite(&b, sizeof(b), 1, pack);
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finish:
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if (start != MAP_FAILED)
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munmap(start, l);
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if (fd >= 0)
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close_nointr_nofail(fd);
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return r;
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}
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static unsigned long fd_first_block(int fd) {
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struct {
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struct fiemap fiemap;
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struct fiemap_extent extent;
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} data;
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zero(data);
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data.fiemap.fm_length = ~0ULL;
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data.fiemap.fm_extent_count = 1;
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if (ioctl(fd, FS_IOC_FIEMAP, &data) < 0)
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return 0;
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if (data.fiemap.fm_mapped_extents <= 0)
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return 0;
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if (data.fiemap.fm_extents[0].fe_flags & FIEMAP_EXTENT_UNKNOWN)
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return 0;
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return (unsigned long) data.fiemap.fm_extents[0].fe_physical;
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}
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struct item {
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const char *path;
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unsigned long block;
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};
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static int qsort_compare(const void *a, const void *b) {
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const struct item *i, *j;
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i = a;
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j = b;
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if (i->block < j->block)
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return -1;
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if (i->block > j->block)
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return 1;
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return strcmp(i->path, j->path);
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}
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static int collect(const char *root) {
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enum {
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FD_FANOTIFY, /* Get the actual fs events */
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FD_SIGNAL,
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FD_INOTIFY, /* We get notifications to quit early via this fd */
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_FD_MAX
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};
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struct pollfd pollfd[_FD_MAX];
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int fanotify_fd = -1, signal_fd = -1, inotify_fd = -1, r = 0;
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pid_t my_pid;
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Hashmap *files = NULL;
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Iterator i;
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char *p, *q;
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sigset_t mask;
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FILE *pack = NULL;
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char *pack_fn_new = NULL, *pack_fn = NULL;
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bool on_ssd, on_btrfs;
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struct statfs sfs;
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usec_t not_after;
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assert(root);
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write_one_line_file("/proc/self/oom_score_adj", "1000");
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if (ioprio_set(IOPRIO_WHO_PROCESS, getpid(), IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)) < 0)
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log_warning("Failed to set IDLE IO priority class: %m");
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assert_se(sigemptyset(&mask) == 0);
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sigset_add_many(&mask, SIGINT, SIGTERM, -1);
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assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
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if ((signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) {
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log_error("signalfd(): %m");
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r = -errno;
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goto finish;
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}
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if (!(files = hashmap_new(string_hash_func, string_compare_func))) {
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log_error("Failed to allocate set.");
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r = -ENOMEM;
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goto finish;
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}
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if ((fanotify_fd = fanotify_init(FAN_CLOEXEC|FAN_NONBLOCK, O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOATIME)) < 0) {
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log_error("Failed to create fanotify object: %m");
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r = -errno;
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goto finish;
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}
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if (fanotify_mark(fanotify_fd, FAN_MARK_ADD|FAN_MARK_MOUNT, FAN_OPEN, AT_FDCWD, root) < 0) {
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log_error("Failed to mark %s: %m", root);
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r = -errno;
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goto finish;
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}
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if ((inotify_fd = open_inotify()) < 0) {
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r = inotify_fd;
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goto finish;
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}
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not_after = now(CLOCK_MONOTONIC) + arg_timeout;
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my_pid = getpid();
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zero(pollfd);
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pollfd[FD_FANOTIFY].fd = fanotify_fd;
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pollfd[FD_FANOTIFY].events = POLLIN;
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pollfd[FD_SIGNAL].fd = signal_fd;
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pollfd[FD_SIGNAL].events = POLLIN;
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pollfd[FD_INOTIFY].fd = inotify_fd;
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pollfd[FD_INOTIFY].events = POLLIN;
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sd_notify(0,
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"READY=1\n"
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"STATUS=Collecting readahead data");
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log_debug("Collecting...");
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if (access("/dev/.run/systemd/readahead/cancel", F_OK) >= 0) {
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log_debug("Collection canceled");
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r = -ECANCELED;
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goto finish;
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}
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if (access("/dev/.run/systemd/readahead/done", F_OK) >= 0) {
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log_debug("Got termination request");
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goto done;
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}
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for (;;) {
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union {
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struct fanotify_event_metadata metadata;
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char buffer[4096];
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} data;
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ssize_t n;
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struct fanotify_event_metadata *m;
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usec_t t;
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int h;
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if (hashmap_size(files) > arg_files_max) {
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log_debug("Reached maximum number of read ahead files, ending collection.");
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break;
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}
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t = now(CLOCK_MONOTONIC);
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if (t >= not_after) {
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log_debug("Reached maximum collection time, ending collection.");
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break;
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}
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if ((h = poll(pollfd, _FD_MAX, (int) ((not_after - t) / USEC_PER_MSEC))) < 0) {
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if (errno == EINTR)
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continue;
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log_error("poll(): %m");
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r = -errno;
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goto finish;
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}
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if (h == 0) {
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log_debug("Reached maximum collection time, ending collection.");
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break;
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}
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if (pollfd[FD_SIGNAL].revents) {
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log_debug("Got signal.");
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break;
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}
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if (pollfd[FD_INOTIFY].revents) {
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uint8_t inotify_buffer[sizeof(struct inotify_event) + FILENAME_MAX];
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struct inotify_event *e;
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if ((n = read(inotify_fd, &inotify_buffer, sizeof(inotify_buffer))) < 0) {
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if (errno == EINTR || errno == EAGAIN)
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continue;
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log_error("Failed to read inotify event: %m");
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r = -errno;
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goto finish;
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}
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e = (struct inotify_event*) inotify_buffer;
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while (n > 0) {
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size_t step;
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if ((e->mask & IN_CREATE) && streq(e->name, "cancel")) {
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log_debug("Collection canceled");
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r = -ECANCELED;
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goto finish;
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}
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if ((e->mask & IN_CREATE) && streq(e->name, "done")) {
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log_debug("Got termination request");
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goto done;
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}
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step = sizeof(struct inotify_event) + e->len;
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assert(step <= (size_t) n);
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e = (struct inotify_event*) ((uint8_t*) e + step);
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n -= step;
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}
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}
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if ((n = read(fanotify_fd, &data, sizeof(data))) < 0) {
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if (errno == EINTR || errno == EAGAIN)
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continue;
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log_error("Failed to read event: %m");
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r = -errno;
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goto finish;
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}
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for (m = &data.metadata; FAN_EVENT_OK(m, n); m = FAN_EVENT_NEXT(m, n)) {
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char fn[PATH_MAX];
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int k;
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if (m->fd < 0)
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goto next_iteration;
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if (m->pid == my_pid)
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goto next_iteration;
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__sync_synchronize();
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if (m->pid == shared->replay)
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goto next_iteration;
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snprintf(fn, sizeof(fn), "/proc/self/fd/%i", m->fd);
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char_array_0(fn);
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if ((k = readlink_malloc(fn, &p)) >= 0) {
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if (startswith(p, "/tmp") ||
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endswith(p, " (deleted)") ||
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hashmap_get(files, p))
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/* Not interesting, or
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* already read */
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free(p);
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else {
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unsigned long ul;
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ul = fd_first_block(m->fd);
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if ((k = hashmap_put(files, p, SECTOR_TO_PTR(ul))) < 0) {
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log_warning("set_put() failed: %s", strerror(-k));
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free(p);
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}
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}
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} else
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log_warning("readlink(%s) failed: %s", fn, strerror(-k));
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next_iteration:
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if (m->fd)
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close_nointr_nofail(m->fd);
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}
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}
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done:
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if (fanotify_fd >= 0) {
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close_nointr_nofail(fanotify_fd);
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fanotify_fd = -1;
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}
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log_debug("Writing Pack File...");
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on_ssd = fs_on_ssd(root) > 0;
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log_debug("On SSD: %s", yes_no(on_ssd));
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on_btrfs = statfs(root, &sfs) >= 0 && (long) sfs.f_type == (long) BTRFS_SUPER_MAGIC;
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log_debug("On btrfs: %s", yes_no(on_btrfs));
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asprintf(&pack_fn, "%s/.readahead", root);
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asprintf(&pack_fn_new, "%s/.readahead.new", root);
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if (!pack_fn || !pack_fn_new) {
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log_error("Out of memory");
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r = -ENOMEM;
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goto finish;
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}
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if (!(pack = fopen(pack_fn_new, "we"))) {
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log_error("Failed to open pack file: %m");
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r = -errno;
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goto finish;
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}
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fputs(CANONICAL_HOST "\n", pack);
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putc(on_ssd ? 'S' : 'R', pack);
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if (on_ssd || on_btrfs) {
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/* On SSD or on btrfs, just write things out in the
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* order the files were accessed. */
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HASHMAP_FOREACH_KEY(q, p, files, i)
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pack_file(pack, p, on_btrfs);
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} else {
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struct item *ordered, *j;
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unsigned k, n;
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/* On rotating media, order things by the block
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* numbers */
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log_debug("Ordering...");
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n = hashmap_size(files);
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if (!(ordered = new(struct item, n))) {
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log_error("Out of memory");
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r = -ENOMEM;
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goto finish;
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}
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j = ordered;
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HASHMAP_FOREACH_KEY(q, p, files, i) {
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j->path = p;
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j->block = PTR_TO_SECTOR(q);
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j++;
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}
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assert(ordered + n == j);
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qsort(ordered, n, sizeof(struct item), qsort_compare);
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for (k = 0; k < n; k++)
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pack_file(pack, ordered[k].path, on_btrfs);
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free(ordered);
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}
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log_debug("Finalizing...");
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fflush(pack);
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if (ferror(pack)) {
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log_error("Failed to write pack file.");
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r = -EIO;
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goto finish;
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}
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if (rename(pack_fn_new, pack_fn) < 0) {
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log_error("Failed to rename readahead file: %m");
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r = -errno;
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goto finish;
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}
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fclose(pack);
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pack = NULL;
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log_debug("Done.");
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finish:
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if (fanotify_fd >= 0)
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close_nointr_nofail(fanotify_fd);
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if (signal_fd >= 0)
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close_nointr_nofail(signal_fd);
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if (inotify_fd >= 0)
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close_nointr_nofail(inotify_fd);
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if (pack) {
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fclose(pack);
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unlink(pack_fn_new);
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}
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free(pack_fn_new);
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free(pack_fn);
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while ((p = hashmap_steal_first_key(files)))
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free(p);
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hashmap_free(files);
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return r;
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|
}
|
|
|
|
static int help(void) {
|
|
|
|
printf("%s [OPTIONS...] [DIRECTORY]\n\n"
|
|
"Collect read-ahead data on early boot.\n\n"
|
|
" -h --help Show this help\n"
|
|
" --max-files=INT Maximum number of files to read ahead\n"
|
|
" --max-file-size=BYTES Maximum size of files to read ahead\n"
|
|
" --timeout=USEC Maximum time to spend collecting data\n",
|
|
program_invocation_short_name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int parse_argv(int argc, char *argv[]) {
|
|
|
|
enum {
|
|
ARG_FILES_MAX = 0x100,
|
|
ARG_FILE_SIZE_MAX,
|
|
ARG_TIMEOUT
|
|
};
|
|
|
|
static const struct option options[] = {
|
|
{ "help", no_argument, NULL, 'h' },
|
|
{ "files-max", required_argument, NULL, ARG_FILES_MAX },
|
|
{ "file-size-max", required_argument, NULL, ARG_FILE_SIZE_MAX },
|
|
{ "timeout", required_argument, NULL, ARG_TIMEOUT },
|
|
{ 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_FILES_MAX:
|
|
if (safe_atou(optarg, &arg_files_max) < 0 || arg_files_max <= 0) {
|
|
log_error("Failed to parse maximum number of files %s.", optarg);
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
|
|
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 ARG_TIMEOUT:
|
|
if (parse_usec(optarg, &arg_timeout) < 0 || arg_timeout <= 0) {
|
|
log_error("Failed to parse timeout %s.", optarg);
|
|
return -EINVAL;
|
|
}
|
|
|
|
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();
|
|
|
|
if ((r = parse_argv(argc, argv)) <= 0)
|
|
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
|
|
|
|
root = optind < argc ? argv[optind] : "/";
|
|
|
|
if (fs_on_read_only(root) > 0) {
|
|
log_info("Disabling readahead collector due to read-only media.");
|
|
return 0;
|
|
}
|
|
|
|
if (!enough_ram()) {
|
|
log_info("Disabling readahead collector due to low memory.");
|
|
return 0;
|
|
}
|
|
|
|
if (detect_virtualization(NULL) > 0) {
|
|
log_info("Disabling readahead collector due to execution in virtualized environment.");
|
|
return 0;
|
|
}
|
|
|
|
if (!(shared = shared_get()))
|
|
return 1;
|
|
|
|
shared->collect = getpid();
|
|
__sync_synchronize();
|
|
|
|
if (collect(root) < 0)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|