diff options
Diffstat (limited to 'src/readahead')
l--------- | src/readahead/Makefile | 1 | ||||
-rw-r--r-- | src/readahead/readahead-analyze.c | 150 | ||||
-rw-r--r-- | src/readahead/readahead-collect.c | 623 | ||||
-rw-r--r-- | src/readahead/readahead-common.c | 359 | ||||
-rw-r--r-- | src/readahead/readahead-common.h | 61 | ||||
-rw-r--r-- | src/readahead/readahead-replay.c | 311 | ||||
-rw-r--r-- | src/readahead/readahead.c | 158 | ||||
-rw-r--r-- | src/readahead/sd-readahead.c | 89 |
8 files changed, 1752 insertions, 0 deletions
diff --git a/src/readahead/Makefile b/src/readahead/Makefile new file mode 120000 index 0000000000..d0b0e8e008 --- /dev/null +++ b/src/readahead/Makefile @@ -0,0 +1 @@ +../Makefile
\ No newline at end of file diff --git a/src/readahead/readahead-analyze.c b/src/readahead/readahead-analyze.c new file mode 100644 index 0000000000..9a929c0937 --- /dev/null +++ b/src/readahead/readahead-analyze.c @@ -0,0 +1,150 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2012 Auke Kok <auke-jan.h.kok@intel.com> + + 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 <stdio.h> +#include <stdlib.h> +#include <stdbool.h> +#include <unistd.h> +#include <inttypes.h> +#include <linux/limits.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <string.h> + +#include "readahead-common.h" + +int main_analyze(const char *pack_path) { + char line[LINE_MAX]; + FILE *pack; + int a; + int missing = 0; + off_t tsize = 0; + + if (!pack_path) + pack_path = "/.readahead"; + + pack = fopen(pack_path, "re"); + if (!pack) { + log_error("Pack file missing."); + goto fail; + } + + if (!fgets(line, sizeof(line), pack)) { + log_error("Pack file corrupt."); + goto fail; + } + + char_array_0(line); + + if (!endswith(line, READAHEAD_PACK_FILE_VERSION)) { + log_error("Pack file version incompatible with this parser."); + goto fail; + } + + if ((a = getc(pack)) == EOF) { + log_error("Pack file corrupt."); + goto fail; + } + + fputs(" pct sections size: path\n" + " === ======== ====: ====\n", stdout); + + for (;;) { + char path[PATH_MAX]; + struct stat st; + uint64_t inode; + int pages = 0; + int sections = 0; + + if (!fgets(path, sizeof(path), pack)) + break; /* done */ + + path[strlen(path)-1] = 0; + + if (fread(&inode, sizeof(inode), 1, pack) != 1) { + log_error("Pack file corrupt."); + goto fail; + } + + for (;;) { + uint32_t b, c; + + if (fread(&b, sizeof(b), 1, pack) != 1 || + fread(&c, sizeof(c), 1, pack) != 1) { + log_error("Pack file corrupt."); + goto fail; + } + if ((b == 0) && (c == 0)) + break; + + /* Uncomment this to get all the chunks separately + printf(" %d: %d %d\n", sections, b, c); + */ + + pages += (c - b); + sections++; + } + + if (stat(path, &st) == 0) { + off_t size; + + if (sections == 0) + size = st.st_size; + else + size = pages * page_size(); + + tsize += size; + + printf(" %4d%% (%2d) %12ld: %s\n", + sections ? (int) (size * 100 / st.st_size) : 100, + sections ? sections : 1, + (unsigned long)size, + path); + } else { + printf(" %4dp (%2d) %12s: %s (MISSING)\n", + sections ? pages : -1, + sections ? sections : 1, + "???", + path); + missing++; + } + + } + + fclose(pack); + + printf("\nHOST: %s" + "TYPE: %c\n" + "MISSING: %d\n" + "TOTAL: %llu\n", + line, + a, + missing, + (unsigned long long) tsize); + + return EXIT_SUCCESS; + +fail: + if(pack) + fclose(pack); + return EXIT_FAILURE; +} diff --git a/src/readahead/readahead-collect.c b/src/readahead/readahead-collect.c new file mode 100644 index 0000000000..5d07f4704a --- /dev/null +++ b/src/readahead/readahead-collect.c @@ -0,0 +1,623 @@ +/*-*- 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 <linux/fanotify.h> +#include <sys/signalfd.h> +#include <sys/poll.h> +#include <sys/mman.h> +#include <linux/fs.h> +#include <linux/fiemap.h> +#include <sys/ioctl.h> +#include <sys/vfs.h> +#include <getopt.h> +#include <sys/inotify.h> + +#ifdef HAVE_FANOTIFY_INIT +#include <sys/fanotify.h> +#endif + +#include <systemd/sd-daemon.h> + +#include "missing.h" +#include "util.h" +#include "set.h" +#include "ioprio.h" +#include "readahead-common.h" +#include "virt.h" + +/* 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 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; + + zero(data); + data.fd = fd; + + return ioctl(fd, BTRFS_IOC_DEFRAG, &data); +} + +static int pack_file(FILE *pack, const char *fn, bool on_btrfs) { + struct stat st; + void *start = MAP_FAILED; + uint8_t *vec; + uint32_t b, c; + uint64_t inode; + size_t l, pages; + bool mapped; + int r = 0, fd = -1, k; + + assert(pack); + assert(fn); + + fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW); + if (fd < 0) { + + if (errno == ENOENT) + return 0; + + if (errno == EPERM || errno == EACCES) + return 0; + + log_warning("open(%s) failed: %m", fn); + r = -errno; + goto finish; + } + + k = file_verify(fd, fn, arg_file_size_max, &st); + if (k <= 0) { + r = k; + goto finish; + } + + if (on_btrfs) + btrfs_defrag(fd); + + l = PAGE_ALIGN(st.st_size); + start = mmap(NULL, l, PROT_READ, MAP_SHARED, fd, 0); + if (start == MAP_FAILED) { + log_warning("mmap(%s) failed: %m", fn); + r = -errno; + goto finish; + } + + pages = l / page_size(); + vec = alloca(pages); + memset(vec, 0, pages); + if (mincore(start, l, vec) < 0) { + log_warning("mincore(%s) failed: %m", fn); + r = -errno; + goto finish; + } + + fputs(fn, pack); + fputc('\n', pack); + + /* Store the inode, so that we notice when the file is deleted */ + inode = (uint64_t) st.st_ino; + fwrite(&inode, sizeof(inode), 1, pack); + + mapped = false; + for (c = 0; c < pages; c++) { + bool new_mapped = !!(vec[c] & 1); + + if (!mapped && new_mapped) + b = c; + else if (mapped && !new_mapped) { + fwrite(&b, sizeof(b), 1, pack); + fwrite(&c, sizeof(c), 1, pack); + + log_debug("%s: page %u to %u", fn, b, c); + } + + mapped = new_mapped; + } + + /* We don't write any range data if we should read the entire file */ + if (mapped && b > 0) { + fwrite(&b, sizeof(b), 1, pack); + fwrite(&c, sizeof(c), 1, pack); + + log_debug("%s: page %u to %u", fn, b, c); + } + + /* End marker */ + b = 0; + fwrite(&b, sizeof(b), 1, pack); + fwrite(&b, sizeof(b), 1, pack); + +finish: + if (start != MAP_FAILED) + munmap(start, l); + + if (fd >= 0) + close_nointr_nofail(fd); + + return r; +} + +static unsigned long fd_first_block(int fd) { + struct { + struct fiemap fiemap; + struct fiemap_extent extent; + } data; + + zero(data); + data.fiemap.fm_length = ~0ULL; + data.fiemap.fm_extent_count = 1; + + if (ioctl(fd, FS_IOC_FIEMAP, &data) < 0) + return 0; + + if (data.fiemap.fm_mapped_extents <= 0) + return 0; + + if (data.fiemap.fm_extents[0].fe_flags & FIEMAP_EXTENT_UNKNOWN) + return 0; + + return (unsigned long) data.fiemap.fm_extents[0].fe_physical; +} + +struct item { + const char *path; + unsigned long block; +}; + +static int qsort_compare(const void *a, const void *b) { + const struct item *i, *j; + + i = a; + j = b; + + if (i->block < j->block) + return -1; + if (i->block > j->block) + return 1; + + return strcmp(i->path, j->path); +} + +static int collect(const char *root) { + enum { + 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, inotify_fd = -1, r = 0; + pid_t my_pid; + Hashmap *files = NULL; + Iterator i; + char *p, *q; + sigset_t mask; + FILE *pack = NULL; + char *pack_fn_new = NULL, *pack_fn = NULL; + bool on_ssd, on_btrfs; + struct statfs sfs; + usec_t not_after; + uint64_t previous_block_readahead; + bool previous_block_readahead_set = false; + + assert(root); + + if (asprintf(&pack_fn, "%s/.readahead", root) < 0) { + r = log_oom(); + goto finish; + } + + /* If there's no pack file yet we lower the kernel readahead + * so that mincore() is accurate. If there is a pack file + * already we assume it is accurate enough so that kernel + * readahead is never triggered. */ + previous_block_readahead_set = + access(pack_fn, F_OK) < 0 && + block_get_readahead(root, &previous_block_readahead) >= 0 && + block_set_readahead(root, 8*1024) >= 0; + + 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"); + + assert_se(sigemptyset(&mask) == 0); + sigset_add_many(&mask, SIGINT, SIGTERM, -1); + assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); + + if ((signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) { + log_error("signalfd(): %m"); + r = -errno; + goto finish; + } + + if (!(files = hashmap_new(string_hash_func, string_compare_func))) { + log_error("Failed to allocate set."); + r = -ENOMEM; + goto finish; + } + + 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; + } + + if (fanotify_mark(fanotify_fd, FAN_MARK_ADD|FAN_MARK_MOUNT, FAN_OPEN, AT_FDCWD, root) < 0) { + log_error("Failed to mark %s: %m", root); + r = -errno; + 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); + pollfd[FD_FANOTIFY].fd = fanotify_fd; + 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" + "STATUS=Collecting readahead data"); + + log_debug("Collecting..."); + + if (access("/run/systemd/readahead/cancel", F_OK) >= 0) { + log_debug("Collection canceled"); + r = -ECANCELED; + goto finish; + } + + if (access("/run/systemd/readahead/done", F_OK) >= 0) { + log_debug("Got termination request"); + goto done; + } + + for (;;) { + union { + struct fanotify_event_metadata metadata; + char buffer[4096]; + } 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; + } + + t = now(CLOCK_MONOTONIC); + if (t >= not_after) { + log_debug("Reached maximum collection time, ending collection."); + break; + } + + if ((h = poll(pollfd, _FD_MAX, (int) ((not_after - t) / USEC_PER_MSEC))) < 0) { + + if (errno == EINTR) + continue; + + log_error("poll(): %m"); + r = -errno; + goto finish; + } + + 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) { + + if (errno == EINTR || errno == EAGAIN) + continue; + + /* fanotify sometimes returns EACCES on read() + * where it shouldn't. For now let's just + * ignore it here (which is safe), but + * eventually this should be + * dropped when the kernel is fixed. + * + * https://bugzilla.redhat.com/show_bug.cgi?id=707577 */ + if (errno == EACCES) + continue; + + log_error("Failed to read event: %m"); + r = -errno; + goto finish; + } + + for (m = &data.metadata; FAN_EVENT_OK(m, n); m = FAN_EVENT_NEXT(m, n)) { + char fn[PATH_MAX]; + int k; + + if (m->fd < 0) + goto next_iteration; + + if (m->pid == my_pid) + goto next_iteration; + + __sync_synchronize(); + if (m->pid == shared->replay) + goto next_iteration; + + snprintf(fn, sizeof(fn), "/proc/self/fd/%i", m->fd); + char_array_0(fn); + + 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; + + 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)); + + next_iteration: + if (m->fd >= 0) + close_nointr_nofail(m->fd); + } + } + +done: + if (fanotify_fd >= 0) { + close_nointr_nofail(fanotify_fd); + fanotify_fd = -1; + } + + log_debug("Writing Pack File..."); + + on_ssd = fs_on_ssd(root) > 0; + log_debug("On SSD: %s", yes_no(on_ssd)); + + on_btrfs = statfs(root, &sfs) >= 0 && (long) sfs.f_type == (long) BTRFS_SUPER_MAGIC; + log_debug("On btrfs: %s", yes_no(on_btrfs)); + + if (asprintf(&pack_fn_new, "%s/.readahead.new", root) < 0) { + r = log_oom(); + goto finish; + } + + pack = fopen(pack_fn_new, "we"); + if (!pack) { + log_error("Failed to open pack file: %m"); + r = -errno; + goto finish; + } + + fputs(CANONICAL_HOST READAHEAD_PACK_FILE_VERSION, pack); + putc(on_ssd ? 'S' : 'R', pack); + + if (on_ssd || on_btrfs) { + + /* On SSD or on btrfs, just write things out in the + * order the files were accessed. */ + + HASHMAP_FOREACH_KEY(q, p, files, i) + pack_file(pack, p, on_btrfs); + } else { + struct item *ordered, *j; + unsigned k, n; + + /* On rotating media, order things by the block + * numbers */ + + log_debug("Ordering..."); + + n = hashmap_size(files); + if (!(ordered = new(struct item, n))) { + r = log_oom(); + goto finish; + } + + j = ordered; + HASHMAP_FOREACH_KEY(q, p, files, i) { + j->path = p; + j->block = PTR_TO_SECTOR(q); + j++; + } + + assert(ordered + n == j); + + qsort(ordered, n, sizeof(struct item), qsort_compare); + + for (k = 0; k < n; k++) + pack_file(pack, ordered[k].path, on_btrfs); + + free(ordered); + } + + log_debug("Finalizing..."); + + fflush(pack); + + if (ferror(pack)) { + log_error("Failed to write pack file."); + r = -EIO; + goto finish; + } + + if (rename(pack_fn_new, pack_fn) < 0) { + log_error("Failed to rename readahead file: %m"); + r = -errno; + goto finish; + } + + fclose(pack); + pack = NULL; + + log_debug("Done."); + +finish: + if (fanotify_fd >= 0) + close_nointr_nofail(fanotify_fd); + + 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); + } + free(pack_fn_new); + free(pack_fn); + + while ((p = hashmap_steal_first_key(files))) + free(p); + + hashmap_free(files); + + if (previous_block_readahead_set) { + uint64_t bytes; + + /* Restore the original kernel readahead setting if we + * changed it, and nobody has overwritten it since + * yet. */ + if (block_get_readahead(root, &bytes) >= 0 && bytes == 8*1024) + block_set_readahead(root, previous_block_readahead); + } + + return r; +} + +int main_collect(const char *root) { + + if (!root) + root = "/"; + + /* Skip this step on read-only media. Note that we check the + * underlying block device here, not he read-only flag of the + * file system on top, since that one is most likely mounted + * read-only anyway at boot, even if the underlying block + * device is theoretically writable. */ + if (fs_on_read_only(root) > 0) { + log_info("Disabling readahead collector due to read-only media."); + return EXIT_SUCCESS; + } + + if (!enough_ram()) { + log_info("Disabling readahead collector due to low memory."); + return EXIT_SUCCESS; + } + + shared = shared_get(); + if (!shared) + return EXIT_FAILURE; + + shared->collect = getpid(); + __sync_synchronize(); + + if (collect(root) < 0) + return EXIT_FAILURE; + + return EXIT_SUCCESS; +} diff --git a/src/readahead/readahead-common.c b/src/readahead/readahead-common.c new file mode 100644 index 0000000000..10b0ccc548 --- /dev/null +++ b/src/readahead/readahead-common.c @@ -0,0 +1,359 @@ +/*-*- 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 <stdlib.h> +#include <string.h> +#include <sys/sysinfo.h> +#include <sys/inotify.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <unistd.h> +#include <libudev.h> + +#include "log.h" +#include "readahead-common.h" +#include "util.h" + +int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st) { + assert(fd >= 0); + assert(fn); + assert(st); + + if (fstat(fd, st) < 0) { + log_warning("fstat(%s) failed: %m", fn); + return -errno; + } + + if (!S_ISREG(st->st_mode)) { + log_debug("Not preloading special file %s", fn); + return 0; + } + + if (st->st_size <= 0 || st->st_size > file_size_max) { + log_debug("Not preloading file %s with size out of bounds %llu", fn, (unsigned long long) st->st_size); + return 0; + } + + return 1; +} + +int fs_on_ssd(const char *p) { + struct stat st; + struct udev *udev = NULL; + struct udev_device *udev_device = NULL, *look_at = NULL; + bool b = false; + const char *devtype, *rotational, *model, *id; + + assert(p); + + if (stat(p, &st) < 0) + return -errno; + + if (major(st.st_dev) == 0) + return false; + + udev = udev_new(); + if (!udev) + return -ENOMEM; + + udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev); + if (!udev_device) + goto finish; + + devtype = udev_device_get_property_value(udev_device, "DEVTYPE"); + if (devtype && streq(devtype, "partition")) + look_at = udev_device_get_parent(udev_device); + else + look_at = udev_device; + + if (!look_at) + goto finish; + + /* First, try high-level property */ + id = udev_device_get_property_value(look_at, "ID_SSD"); + if (id) { + b = streq(id, "1"); + goto finish; + } + + /* Second, try kernel attribute */ + rotational = udev_device_get_sysattr_value(look_at, "queue/rotational"); + if (rotational) + if ((b = streq(rotational, "0"))) + goto finish; + + /* Finally, fallback to heuristics */ + look_at = udev_device_get_parent(look_at); + if (!look_at) + goto finish; + + model = udev_device_get_sysattr_value(look_at, "model"); + if (model) + b = !!strstr(model, "SSD"); + +finish: + if (udev_device) + udev_device_unref(udev_device); + + if (udev) + udev_unref(udev); + + return b; +} + +int fs_on_read_only(const char *p) { + struct stat st; + struct udev *udev = NULL; + struct udev_device *udev_device = NULL; + bool b = false; + const char *read_only; + + assert(p); + + if (stat(p, &st) < 0) + return -errno; + + if (major(st.st_dev) == 0) + return false; + + if (!(udev = udev_new())) + return -ENOMEM; + + if (!(udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev))) + goto finish; + + if ((read_only = udev_device_get_sysattr_value(udev_device, "ro"))) + if ((b = streq(read_only, "1"))) + goto finish; + +finish: + if (udev_device) + udev_device_unref(udev_device); + + if (udev) + udev_unref(udev); + + return b; +} + +bool enough_ram(void) { + struct sysinfo si; + + assert_se(sysinfo(&si) >= 0); + + /* Enable readahead only with at least 128MB memory */ + return si.totalram > 127 * 1024*1024 / si.mem_unit; +} + +int open_inotify(void) { + int fd; + + if ((fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) { + log_error("Failed to create inotify handle: %m"); + return -errno; + } + + mkdir("/run/systemd", 0755); + mkdir("/run/systemd/readahead", 0755); + + if (inotify_add_watch(fd, "/run/systemd/readahead", IN_CREATE) < 0) { + log_error("Failed to watch /run/systemd/readahead: %m"); + close_nointr_nofail(fd); + return -errno; + } + + return fd; +} + +ReadaheadShared *shared_get(void) { + int fd; + ReadaheadShared *m = NULL; + + mkdir("/run/systemd", 0755); + mkdir("/run/systemd/readahead", 0755); + + if ((fd = open("/run/systemd/readahead/shared", O_CREAT|O_RDWR|O_CLOEXEC, 0644)) < 0) { + log_error("Failed to create shared memory segment: %m"); + goto finish; + } + + if (ftruncate(fd, sizeof(ReadaheadShared)) < 0) { + log_error("Failed to truncate shared memory segment: %m"); + goto finish; + } + + if ((m = mmap(NULL, sizeof(ReadaheadShared), PROT_WRITE|PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) { + log_error("Failed to mmap shared memory segment: %m"); + m = NULL; + goto finish; + } + +finish: + if (fd >= 0) + close_nointr_nofail(fd); + + return m; +} + +/* We use 20K instead of the more human digestable 16K here. Why? + Simply so that it is more unlikely that users end up picking this + value too so that we can recognize better whether the user changed + the value while we had it temporarily bumped. */ +#define BUMP_REQUEST_NR (20*1024) + +int block_bump_request_nr(const char *p) { + struct stat st; + uint64_t u; + char *ap = NULL, *line = NULL; + int r; + dev_t d; + + assert(p); + + if (stat(p, &st) < 0) + return -errno; + + if (major(st.st_dev) == 0) + return 0; + + d = st.st_dev; + block_get_whole_disk(d, &d); + + if (asprintf(&ap, "/sys/dev/block/%u:%u/queue/nr_requests", major(d), minor(d)) < 0) { + r= -ENOMEM; + goto finish; + } + + r = read_one_line_file(ap, &line); + if (r < 0) { + if (r == -ENOENT) + r = 0; + goto finish; + } + + r = safe_atou64(line, &u); + if (r >= 0 && u >= BUMP_REQUEST_NR) { + r = 0; + goto finish; + } + + free(line); + line = NULL; + + if (asprintf(&line, "%lu", (unsigned long) BUMP_REQUEST_NR) < 0) { + r = -ENOMEM; + goto finish; + } + + r = write_one_line_file(ap, line); + if (r < 0) + goto finish; + + log_info("Bumped block_nr parameter of %u:%u to %lu. This is a temporary hack and should be removed one day.", major(d), minor(d), (unsigned long) BUMP_REQUEST_NR); + r = 1; + +finish: + free(ap); + free(line); + + return r; +} + +int block_get_readahead(const char *p, uint64_t *bytes) { + struct stat st; + char *ap = NULL, *line = NULL; + int r; + dev_t d; + uint64_t u; + + assert(p); + assert(bytes); + + if (stat(p, &st) < 0) + return -errno; + + if (major(st.st_dev) == 0) + return 0; + + d = st.st_dev; + block_get_whole_disk(d, &d); + + if (asprintf(&ap, "/sys/dev/block/%u:%u/bdi/read_ahead_kb", major(d), minor(d)) < 0) { + r = -ENOMEM; + goto finish; + } + + r = read_one_line_file(ap, &line); + if (r < 0) + goto finish; + + r = safe_atou64(line, &u); + if (r < 0) + goto finish; + + *bytes = u * 1024ULL; + +finish: + free(ap); + free(line); + + return r; +} + +int block_set_readahead(const char *p, uint64_t bytes) { + struct stat st; + char *ap = NULL, *line = NULL; + int r; + dev_t d; + + assert(p); + assert(bytes); + + if (stat(p, &st) < 0) + return -errno; + + if (major(st.st_dev) == 0) + return 0; + + d = st.st_dev; + block_get_whole_disk(d, &d); + + if (asprintf(&ap, "/sys/dev/block/%u:%u/bdi/read_ahead_kb", major(d), minor(d)) < 0) { + r = -ENOMEM; + goto finish; + } + + if (asprintf(&line, "%llu", (unsigned long long) bytes / 1024ULL) < 0) { + r = -ENOMEM; + goto finish; + } + + r = write_one_line_file(ap, line); + if (r < 0) + goto finish; + +finish: + free(ap); + free(line); + + return r; +} diff --git a/src/readahead/readahead-common.h b/src/readahead/readahead-common.h new file mode 100644 index 0000000000..b34f3aadd7 --- /dev/null +++ b/src/readahead/readahead-common.h @@ -0,0 +1,61 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + 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 <sys/stat.h> +#include <sys/types.h> + +#include "macro.h" +#include "util.h" + +#define READAHEAD_FILE_SIZE_MAX (10*1024*1024) + +#define READAHEAD_PACK_FILE_VERSION ";VERSION=2\n" + +extern unsigned arg_files_max; +extern off_t arg_file_size_max; +extern usec_t arg_timeout; + +int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st); + +int fs_on_ssd(const char *p); +int fs_on_read_only(const char *p); + +bool enough_ram(void); + +int open_inotify(void); + +typedef struct ReadaheadShared { + pid_t collect; + pid_t replay; +} _packed_ ReadaheadShared; + +ReadaheadShared *shared_get(void); + +int block_bump_request_nr(const char *p); + +int block_get_readahead(const char *p, uint64_t *bytes); +int block_set_readahead(const char *p, uint64_t bytes); + +int main_collect(const char *root); +int main_replay(const char *root); +int main_analyze(const char *pack_path); diff --git a/src/readahead/readahead-replay.c b/src/readahead/readahead-replay.c new file mode 100644 index 0000000000..a1ac6b0c91 --- /dev/null +++ b/src/readahead/readahead-replay.c @@ -0,0 +1,311 @@ +/*-*- 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) { + r = log_oom(); + 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; +} diff --git a/src/readahead/readahead.c b/src/readahead/readahead.c new file mode 100644 index 0000000000..abeecc7634 --- /dev/null +++ b/src/readahead/readahead.c @@ -0,0 +1,158 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2012 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 <stdio.h> +#include <getopt.h> +#include <stddef.h> +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> + +#include "util.h" +#include "def.h" +#include "readahead-common.h" + +unsigned arg_files_max = 16*1024; +off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX; +usec_t arg_timeout = 2*USEC_PER_MINUTE; + +static int help(void) { + + printf("%s [OPTIONS...] collect [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" + " --file-size-max=BYTES Maximum size of files to read ahead\n" + " --timeout=USEC Maximum time to spend collecting data\n\n\n", + program_invocation_short_name); + + printf("%s [OPTIONS...] replay [DIRECTORY]\n\n" + "Replay collected read-ahead data on early boot.\n\n" + " -h --help Show this help\n" + " --file-size-max=BYTES Maximum size of files to read ahead\n\n\n", + program_invocation_short_name); + + printf("%s [OPTIONS...] analyze [PACK FILE]\n\n" + "Analyze collected read-ahead data.\n\n" + " -h --help Show this help\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-1 && + optind != argc-2) { + help(); + return -EINVAL; + } + + return 1; +} + +int main(int argc, char *argv[]) { + int r; + + log_set_target(LOG_TARGET_SAFE); + log_parse_environment(); + log_open(); + + umask(0022); + + r = parse_argv(argc, argv); + if (r <= 0) + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; + + if (streq(argv[optind], "collect")) + return main_collect(argv[optind+1]); + else if (streq(argv[optind], "replay")) + return main_replay(argv[optind+1]); + else if (streq(argv[optind], "analyze")) + return main_analyze(argv[optind+1]); + + log_error("Unknown verb %s.", argv[optind]); + return EXIT_FAILURE; +} diff --git a/src/readahead/sd-readahead.c b/src/readahead/sd-readahead.c new file mode 100644 index 0000000000..d48cd76807 --- /dev/null +++ b/src/readahead/sd-readahead.c @@ -0,0 +1,89 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + Copyright 2010 Lennart Poettering + + Permission is hereby granted, free of charge, to any person + obtaining a copy of this software and associated documentation files + (the "Software"), to deal in the Software without restriction, + including without limitation the rights to use, copy, modify, merge, + publish, distribute, sublicense, and/or sell copies of the Software, + and to permit persons to whom the Software is furnished to do so, + subject to the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +***/ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include <unistd.h> +#include <errno.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <fcntl.h> +#include <string.h> + +#include "sd-readahead.h" + +#if (__GNUC__ >= 4) +#ifdef SD_EXPORT_SYMBOLS +/* Export symbols */ +#define _sd_export_ __attribute__ ((visibility("default"))) +#else +/* Don't export the symbols */ +#define _sd_export_ __attribute__ ((visibility("hidden"))) +#endif +#else +#define _sd_export_ +#endif + +static int touch(const char *path) { + +#if !defined(DISABLE_SYSTEMD) && defined(__linux__) + int fd; + + mkdir("/run/systemd", 0755); + mkdir("/run/systemd/readahead", 0755); + + fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0666); + if (fd < 0) + return -errno; + + for (;;) { + if (close(fd) >= 0) + break; + + if (errno != -EINTR) + return -errno; + } + +#endif + return 0; +} + +_sd_export_ int sd_readahead(const char *action) { + + if (!action) + return -EINVAL; + + if (strcmp(action, "cancel") == 0) + return touch("/run/systemd/readahead/cancel"); + else if (strcmp(action, "done") == 0) + return touch("/run/systemd/readahead/done"); + else if (strcmp(action, "noreplay") == 0) + return touch("/run/systemd/readahead/noreplay"); + + return -EINVAL; +} |