X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Freadahead-collect.c;h=a9f544dd3ac4a29e30df58b139642a3ef88daa9b;hp=6b9fb4650b78e2fe60499c7fe0d7f183966b2ada;hb=a55c7d2ea0033487a3a5b784035689e3bebf6e94;hpb=902a339c93f44bc7290bede2f91f3a5c7cb16402 diff --git a/src/readahead-collect.c b/src/readahead-collect.c index 6b9fb4650..a9f544dd3 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" @@ -48,15 +50,26 @@ #include "ioprio.h" #include "readahead-common.h" -#define MINCORE_VEC_SIZE (READAHEAD_FILE_SIZE_MAX/PAGE_SIZE) - /* fixme: * - * - detect ssd/lvm/... on btrfs + * - detect ssd on btrfs/lvm... * - read ahead directories - * - sd_readahead_cancel + * - 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 ReadaheadShared *shared = NULL; + +/* Avoid collisions with the NULL pointer */ +#define SECTOR_TO_PTR(s) ULONG_TO_PTR((s)+1) +#define PTR_TO_SECTOR(p) (PTR_TO_ULONG(p)-1) + static int btrfs_defrag(int fd) { struct btrfs_ioctl_vol_args data; @@ -69,7 +82,7 @@ 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; @@ -84,7 +97,7 @@ 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; } @@ -99,6 +112,9 @@ 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; @@ -108,10 +124,9 @@ 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; @@ -191,12 +206,13 @@ 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; @@ -206,9 +222,12 @@ 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"); @@ -228,7 +247,7 @@ 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; @@ -240,6 +259,13 @@ 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); @@ -247,6 +273,8 @@ 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" @@ -254,6 +282,17 @@ 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; @@ -261,11 +300,21 @@ static int collect(const char *root) { } data; ssize_t n; struct fanotify_event_metadata *m; + usec_t t; + int h; - if (hashmap_size(files) > READAHEAD_FILES_MAX) + if (hashmap_size(files) > arg_files_max) { + log_debug("Reached maximum number of read ahead files, ending collection."); break; + } + + 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; @@ -275,8 +324,51 @@ 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) { @@ -288,43 +380,51 @@ 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)) { + char fn[PATH_MAX]; + int k; - if (m->pid != my_pid && m->fd >= 0) { - char fn[PATH_MAX]; - int k; + if (m->fd < 0) + goto next_iteration; - snprintf(fn, sizeof(fn), "/proc/self/fd/%i", m->fd); - char_array_0(fn); + if (m->pid == my_pid) + goto next_iteration; - if ((k = readlink_malloc(fn, &p)) >= 0) { + __sync_synchronize(); + if (m->pid == shared->replay) + goto next_iteration; - if (hashmap_get(files, p)) - /* Already read */ - free(p); - else { - unsigned long ul; + snprintf(fn, sizeof(fn), "/proc/self/fd/%i", m->fd); + char_array_0(fn); - ul = fd_first_block(m->fd); + if ((k = readlink_malloc(fn, &p)) >= 0) { + if (startswith(p, "/tmp") || + endswith(p, " (deleted)") || + hashmap_get(files, p)) + /* Not interesting, or + * already read */ + free(p); + else { + unsigned long ul; - if ((k = hashmap_put(files, p, ULONG_TO_PTR(ul))) < 0) { - log_warning("set_put() failed: %s", strerror(-k)); - free(p); - } + ul = fd_first_block(m->fd); + + if ((k = hashmap_put(files, p, SECTOR_TO_PTR(ul))) < 0) { + log_warning("set_put() failed: %s", strerror(-k)); + free(p); } + } - } else - log_warning("readlink(%s) failed: %s", fn, strerror(-k)); - } + } else + log_warning("readlink(%s) failed: %s", fn, strerror(-k)); + next_iteration: 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; @@ -332,10 +432,10 @@ 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; + on_btrfs = statfs(root, &sfs) >= 0 && (long) sfs.f_type == (long) BTRFS_SUPER_MAGIC; log_debug("On btrfs: %s", yes_no(on_btrfs)); asprintf(&pack_fn, "%s/.readahead", root); @@ -382,7 +482,7 @@ static int collect(const char *root) { j = ordered; HASHMAP_FOREACH_KEY(q, p, files, i) { j->path = p; - j->block = PTR_TO_ULONG(q); + j->block = PTR_TO_SECTOR(q); j++; } @@ -424,6 +524,9 @@ 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); @@ -433,25 +536,122 @@ 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 ((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(argc >= 2 ? argv[1] : "/") < 0) + if (!(shared = shared_get())) + return 1; + + shared->collect = getpid(); + __sync_synchronize(); + + if (collect(optind < argc ? argv[optind] : "/") < 0) return 1; return 0;