readahead: wipe out readahead

1 files changed, 0 insertions, 650 deletions

diff --git a/src/readahead/readahead-collect.c b/src/readahead/readahead-collect.c
deleted file mode 100644
index 822a803a41..0000000000
--- a/src/readahead/readahead-collect.c
+++ /dev/null
@@ -1,650 +0,0 @@
-/*-*- 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>
-#include <math.h>
-
-#ifdef HAVE_LINUX_BTRFS_H
-#include <linux/btrfs.h>
-#endif
-
-#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;
-static usec_t starttime;
-
-/* 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 = { .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 = alloca0(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);
-
-        safe_close(fd);
-
-        return r;
-}
-
-static unsigned long fd_first_block(int fd) {
-        struct {
-                struct fiemap fiemap;
-                struct fiemap_extent extent;
-        } data = {
-                .fiemap.fm_length = ~0ULL,
-                .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;
-        unsigned long bin;
-};
-
-static int qsort_compare(const void *a, const void *b) {
-        const struct item *i, *j;
-
-        i = a;
-        j = b;
-
-        /* sort by bin first */
-        if (i->bin < j->bin)
-                return -1;
-        if (i->bin > j->bin)
-                return 1;
-
-        /* then sort by sector */
-        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;
-        }
-
-        starttime = now(CLOCK_MONOTONIC);
-
-        /* 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;
-        }
-
-        files = hashmap_new(&string_hash_ops);
-        if (!files) {
-                log_error("Failed to allocate set.");
-                r = -ENOMEM;
-                goto finish;
-        }
-
-        fanotify_fd = fanotify_init(FAN_CLOEXEC|FAN_NONBLOCK, O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOATIME);
-        if (fanotify_fd < 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;
-        }
-
-        inotify_fd = open_inotify();
-        if (inotify_fd < 0) {
-                r = inotify_fd;
-                goto finish;
-        }
-
-        not_after = now(CLOCK_MONOTONIC) + arg_timeout;
-
-        my_pid = getpid();
-
-        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;
-                        }
-                }
-
-                n = read(fanotify_fd, &data, sizeof(data));
-                if (n < 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[sizeof("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
-                        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);
-                        k = readlink_malloc(fn, &p);
-                        if (k >= 0) {
-                                if (startswith(p, "/tmp") ||
-                                    endswith(p, " (deleted)") ||
-                                    hashmap_get(files, p))
-                                        /* Not interesting, or
-                                         * already read */
-                                        free(p);
-                                else {
-                                        unsigned long ul;
-                                        usec_t entrytime;
-                                        struct item *entry;
-
-                                        entry = new0(struct item, 1);
-                                        if (!entry) {
-                                                r = log_oom();
-                                                goto finish;
-                                        }
-
-                                        ul = fd_first_block(m->fd);
-
-                                        entrytime = now(CLOCK_MONOTONIC);
-
-                                        entry->block = ul;
-                                        entry->path = strdup(p);
-                                        if (!entry->path) {
-                                                free(entry);
-                                                r = log_oom();
-                                                goto finish;
-                                        }
-                                        entry->bin = (entrytime - starttime) / 2000000;
-
-                                        k = hashmap_put(files, p, entry);
-                                        if (k < 0) {
-                                                log_warning("hashmap_put() failed: %s", strerror(-k));
-                                                free(p);
-                                        }
-                                }
-
-                        } else
-                                log_warning("readlink(%s) failed: %s", fn, strerror(-k));
-
-                next_iteration:
-                        safe_close(m->fd);
-                }
-        }
-
-done:
-        fanotify_fd = safe_close(fanotify_fd);
-
-        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 && F_TYPE_EQUAL(sfs.f_type, 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 {
-                unsigned n;
-
-                /* On rotating media, order things by the block
-                 * numbers */
-
-                log_debug("Ordering...");
-
-                n = hashmap_size(files);
-                if (n) {
-                        _cleanup_free_ struct item *ordered;
-                        struct item *j;
-                        unsigned k;
-
-                        ordered = new(struct item, n);
-                        if (!ordered) {
-                                r = log_oom();
-                                goto finish;
-                        }
-
-                        j = ordered;
-                        HASHMAP_FOREACH_KEY(q, p, files, i) {
-                                memcpy(j, q, sizeof(struct item));
-                                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);
-                } else
-                        log_warning("No pack files");
-        }
-
-        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:
-        safe_close(fanotify_fd);
-        safe_close(signal_fd);
-        safe_close(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;
-}