X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Freadahead-collect.c;h=50c1a0b6844b835d816a2d5f52da0ee69d16d48d;hp=937231ca4282d46355b01b738c51c6cbccf896ef;hb=858209c51f3c5eadd5489edc3154d84f24e1f00a;hpb=4030d7a923427a50745fc5786f4905aa703f0bcb diff --git a/src/readahead-collect.c b/src/readahead-collect.c index 937231ca4..50c1a0b68 100644 --- a/src/readahead-collect.c +++ b/src/readahead-collect.c @@ -40,6 +40,8 @@ #include #include #include +#include +#include #include "missing.h" #include "util.h" @@ -48,7 +50,19 @@ #include "ioprio.h" #include "readahead-common.h" -#define MINCORE_VEC_SIZE (READAHEAD_FILE_SIZE_MAX/PAGE_SIZE) +/* fixme: + * + * - detect ssd on btrfs/lvm... + * - read ahead directories + * - gzip? + * - remount rw? + * - handle files where nothing is in mincore + * - does ioprio_set work with fadvise()? + */ + +static unsigned arg_files_max = 16*1024; +static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX; +static usec_t arg_timeout = 2*USEC_PER_MINUTE; static int btrfs_defrag(int fd) { struct btrfs_ioctl_vol_args data; @@ -62,7 +76,7 @@ static int btrfs_defrag(int fd) { static int pack_file(FILE *pack, const char *fn, bool on_btrfs) { struct stat st; void *start = MAP_FAILED; - uint8_t vec[MINCORE_VEC_SIZE]; + uint8_t *vec; uint32_t b, c; size_t l, pages; bool mapped; @@ -77,7 +91,7 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) { goto finish; } - if ((k = file_verify(fd, fn, &st)) <= 0) { + if ((k = file_verify(fd, fn, arg_file_size_max, &st)) <= 0) { r = k; goto finish; } @@ -92,6 +106,9 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) { goto finish; } + pages = l / PAGE_SIZE; + + vec = alloca(pages); if (mincore(start, l, vec) < 0) { log_warning("mincore(%s) failed: %m", fn); r = -errno; @@ -101,10 +118,9 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) { fputs(fn, pack); fputc('\n', pack); - pages = l / PAGE_SIZE; mapped = false; for (c = 0; c < pages; c++) { - bool new_mapped = (vec[c] & 1); + bool new_mapped = !!(vec[c] & 1); if (!mapped && new_mapped) b = c; @@ -184,12 +200,13 @@ static int qsort_compare(const void *a, const void *b) { static int collect(const char *root) { enum { - FD_FANOTIFY, + FD_FANOTIFY, /* Get the actual fs events */ FD_SIGNAL, + FD_INOTIFY, /* We get notifications to quit early via this fd */ _FD_MAX }; struct pollfd pollfd[_FD_MAX]; - int fanotify_fd = -1, signal_fd = -1, r = 0; + int fanotify_fd = -1, signal_fd = -1, inotify_fd = -1, r = 0; pid_t my_pid; Hashmap *files = NULL; Iterator i; @@ -199,9 +216,12 @@ static int collect(const char *root) { char *pack_fn_new = NULL, *pack_fn = NULL; bool on_ssd, on_btrfs; struct statfs sfs; + usec_t not_after; assert(root); + write_one_line_file("/proc/self/oom_score_adj", "1000"); + if (ioprio_set(IOPRIO_WHO_PROCESS, getpid(), IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)) < 0) log_warning("Failed to set IDLE IO priority class: %m"); @@ -221,7 +241,7 @@ static int collect(const char *root) { goto finish; } - if ((fanotify_fd = fanotify_init(FAN_CLOEXEC, O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOATIME)) < 0) { + if ((fanotify_fd = fanotify_init(FAN_CLOEXEC|FAN_NONBLOCK, O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOATIME)) < 0) { log_error("Failed to create fanotify object: %m"); r = -errno; goto finish; @@ -233,6 +253,13 @@ static int collect(const char *root) { goto finish; } + if ((inotify_fd = open_inotify()) < 0) { + r = inotify_fd; + goto finish; + } + + not_after = now(CLOCK_MONOTONIC) + arg_timeout; + my_pid = getpid(); zero(pollfd); @@ -240,6 +267,8 @@ static int collect(const char *root) { pollfd[FD_FANOTIFY].events = POLLIN; pollfd[FD_SIGNAL].fd = signal_fd; pollfd[FD_SIGNAL].events = POLLIN; + pollfd[FD_INOTIFY].fd = inotify_fd; + pollfd[FD_INOTIFY].events = POLLIN; sd_notify(0, "READY=1\n" @@ -247,6 +276,17 @@ static int collect(const char *root) { log_debug("Collecting..."); + if (access("/dev/.systemd/readahead/cancel", F_OK) >= 0) { + log_debug("Collection canceled"); + r = -ECANCELED; + goto finish; + } + + if (access("/dev/.systemd/readahead/done", F_OK) >= 0) { + log_debug("Got termination request"); + goto done; + } + for (;;) { union { struct fanotify_event_metadata metadata; @@ -254,11 +294,21 @@ static int collect(const char *root) { } data; ssize_t n; struct fanotify_event_metadata *m; + usec_t t; + int h; + + if (hashmap_size(files) > arg_files_max) { + log_debug("Reached maximum number of read ahead files, ending collection."); + break; + } - if (hashmap_size(files) > READAHEAD_FILES_MAX) + t = now(CLOCK_MONOTONIC); + if (t >= not_after) { + log_debug("Reached maximum collection time, ending collection."); break; + } - if (poll(pollfd, _FD_MAX, -1) < 0) { + if ((h = poll(pollfd, _FD_MAX, (int) ((not_after - t) / USEC_PER_MSEC))) < 0) { if (errno == EINTR) continue; @@ -268,8 +318,51 @@ static int collect(const char *root) { goto finish; } - if (pollfd[FD_SIGNAL].revents != 0) + if (h == 0) { + log_debug("Reached maximum collection time, ending collection."); break; + } + + if (pollfd[FD_SIGNAL].revents) { + log_debug("Got signal."); + break; + } + + if (pollfd[FD_INOTIFY].revents) { + uint8_t inotify_buffer[sizeof(struct inotify_event) + FILENAME_MAX]; + struct inotify_event *e; + + if ((n = read(inotify_fd, &inotify_buffer, sizeof(inotify_buffer))) < 0) { + if (errno == EINTR || errno == EAGAIN) + continue; + + log_error("Failed to read inotify event: %m"); + r = -errno; + goto finish; + } + + e = (struct inotify_event*) inotify_buffer; + while (n > 0) { + size_t step; + + if ((e->mask & IN_CREATE) && streq(e->name, "cancel")) { + log_debug("Collection canceled"); + r = -ECANCELED; + goto finish; + } + + if ((e->mask & IN_CREATE) && streq(e->name, "done")) { + 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 ((n = read(fanotify_fd, &data, sizeof(data))) < 0) { @@ -281,8 +374,7 @@ static int collect(const char *root) { goto finish; } - m = &data.metadata; - while (FAN_EVENT_OK(m, n)) { + for (m = &data.metadata; FAN_EVENT_OK(m, n); m = FAN_EVENT_NEXT(m, n)) { if (m->pid != my_pid && m->fd >= 0) { char fn[PATH_MAX]; @@ -293,8 +385,10 @@ static int collect(const char *root) { if ((k = readlink_malloc(fn, &p)) >= 0) { - if (hashmap_get(files, p)) - /* Already read */ + if (startswith(p, "/tmp") || + hashmap_get(files, p)) + /* Not interesting, or + * already read */ free(p); else { unsigned long ul; @@ -302,10 +396,7 @@ static int collect(const char *root) { ul = fd_first_block(m->fd); if ((k = hashmap_put(files, p, ULONG_TO_PTR(ul))) < 0) { - - if (k != -EEXIST) - log_warning("set_put() failed: %s", strerror(-k)); - + log_warning("set_put() failed: %s", strerror(-k)); free(p); } } @@ -316,11 +407,10 @@ static int collect(const char *root) { if (m->fd) close_nointr_nofail(m->fd); - - m = FAN_EVENT_NEXT(m, n); } } +done: if (fanotify_fd >= 0) { close_nointr_nofail(fanotify_fd); fanotify_fd = -1; @@ -328,7 +418,7 @@ static int collect(const char *root) { log_debug("Writing Pack File..."); - on_ssd = fs_on_ssd(root); + on_ssd = fs_on_ssd(root) == 0; log_debug("On SSD: %s", yes_no(on_ssd)); on_btrfs = statfs(root, &sfs) >= 0 && sfs.f_type == BTRFS_SUPER_MAGIC; @@ -355,7 +445,7 @@ static int collect(const char *root) { if (on_ssd || on_btrfs) { /* On SSD or on btrfs, just write things out in the - * order the files where accessed. */ + * order the files were accessed. */ HASHMAP_FOREACH_KEY(q, p, files, i) pack_file(pack, p, on_btrfs); @@ -420,6 +510,9 @@ finish: if (signal_fd >= 0) close_nointr_nofail(signal_fd); + if (inotify_fd >= 0) + close_nointr_nofail(inotify_fd); + if (pack) { fclose(pack); unlink(pack_fn_new); @@ -429,20 +522,116 @@ finish: free(pack_fn); while ((p = hashmap_steal_first_key(files))) - free(q); + free(p); hashmap_free(files); return r; } +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; log_set_target(LOG_TARGET_SYSLOG_OR_KMSG); log_parse_environment(); log_open(); - if (collect(argc >= 2 ? argv[1] : "/") < 0) + if ((r = parse_argv(argc, argv)) <= 0) + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; + + if (!enough_ram()) { + log_info("Disabling readahead collector due to low memory."); + return 0; + } + + if (collect(optind < argc ? argv[optind] : "/") < 0) return 1; return 0;