chiark / gitweb /
readahead: modernizations
[elogind.git] / src / readahead / readahead-replay.c
index 65011ac4be3996d0ff41f92f44e889fdf3cb289a..f46dc3baeb9f37e302fdc9341eb445e5fbc722bc 100644 (file)
@@ -6,16 +6,16 @@
   Copyright 2010 Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
+  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
-  General Public License for more details.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  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 <getopt.h>
 #include <sys/inotify.h>
 
+#include <systemd/sd-daemon.h>
+
 #include "missing.h"
 #include "util.h"
 #include "set.h"
-#include "sd-daemon.h"
 #include "ioprio.h"
 #include "readahead-common.h"
 #include "virt.h"
 
-static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX;
-
 static ReadaheadShared *shared = NULL;
 
 static int unpack_file(FILE *pack) {
+        _cleanup_close_ int fd = -1;
         char fn[PATH_MAX];
-        int r = 0, fd = -1;
         bool any = false;
         struct stat st;
+        uint64_t inode;
 
         assert(pack);
 
@@ -61,14 +61,24 @@ static int unpack_file(FILE *pack) {
         char_array_0(fn);
         truncate_nl(fn);
 
-        if ((fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW)) < 0) {
-
-                if (errno != ENOENT && errno != EPERM && errno != EACCES)
+        fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0) {
+                if (errno != ENOENT && errno != EPERM && errno != EACCES && errno != ELOOP)
                         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;
+        } else if (file_verify(fd, fn, arg_file_size_max, &st) <= 0)
+                fd = safe_close(fd);
+
+        if (fread(&inode, sizeof(inode), 1, pack) != 1) {
+                log_error("Premature end of pack file.");
+                return -EIO;
+        }
+
+        if (fd >= 0) {
+                /* If the inode changed the file got deleted, so just
+                 * ignore this entry */
+                if (st.st_ino != (uint64_t) inode)
+                        fd = safe_close(fd);
         }
 
         for (;;) {
@@ -77,8 +87,7 @@ static int unpack_file(FILE *pack) {
                 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;
+                        return -EIO;
                 }
 
                 if (b == 0 && c == 0)
@@ -86,19 +95,19 @@ static int unpack_file(FILE *pack) {
 
                 if (c <= b) {
                         log_error("Invalid pack file.");
-                        r = -EIO;
-                        goto finish;
+                        return -EIO;
                 }
 
                 log_debug("%s: page %u to %u", fn, b, c);
 
                 any = true;
 
-                if (fd >= 0)
+                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;
+                                return -errno;
                         }
+                }
         }
 
         if (!any && fd >= 0) {
@@ -108,73 +117,61 @@ static int unpack_file(FILE *pack) {
 
                 if (posix_fadvise(fd, 0, st.st_size, POSIX_FADV_WILLNEED) < 0) {
                         log_warning("posix_fadvise() failed: %m");
-                        goto finish;
+                        return -errno;
                 }
         }
 
-finish:
-        if (fd >= 0)
-                close_nointr_nofail(fd);
-
-        return r;
+        return 0;
 }
 
 static int replay(const char *root) {
-        FILE *pack = NULL;
-        char line[LINE_MAX];
-        int r = 0;
-        char *pack_fn = NULL;
-        int c;
+        _cleanup_close_ int inotify_fd = -1;
+        _cleanup_free_ char *pack_fn = NULL;
+        _cleanup_fclose_ FILE *pack = NULL;
         bool on_ssd, ready = false;
-        int prio;
-        int inotify_fd = -1;
+        char line[LINE_MAX];
+        int prio, c;
 
         assert(root);
 
-        write_one_line_file("/proc/self/oom_score_adj", "1000");
-        bump_request_nr(root);
+        block_bump_request_nr(root);
 
-        if (asprintf(&pack_fn, "%s/.readahead", root) < 0) {
-                log_error("Out of memory");
-                r = -ENOMEM;
-                goto finish;
-        }
+        if (asprintf(&pack_fn, "%s/.readahead", root) < 0)
+                return log_oom();
 
-        if ((!(pack = fopen(pack_fn, "re")))) {
-                if (errno == ENOENT)
+        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;
+                        return 0;
                 }
 
-                goto finish;
+                log_error("Failed to open pack file: %m");
+                return -errno;
         }
 
         posix_fadvise(fileno(pack), 0, 0, POSIX_FADV_WILLNEED);
 
-        if ((inotify_fd = open_inotify()) < 0) {
-                r = inotify_fd;
-                goto finish;
-        }
+        inotify_fd = open_inotify();
+        if (inotify_fd < 0)
+                return inotify_fd;
 
-        if (!(fgets(line, sizeof(line), pack))) {
+        if (!fgets(line, sizeof(line), pack)) {
                 log_error("Premature end of pack file.");
-                r = -EIO;
-                goto finish;
+                return -EIO;
         }
 
         char_array_0(line);
 
-        if (!streq(line, CANONICAL_HOST "\n")) {
-                log_debug("Pack file host type mismatch.");
-                goto finish;
+        if (!streq(line, CANONICAL_HOST READAHEAD_PACK_FILE_VERSION)) {
+                log_debug("Pack file host or version type mismatch.");
+                goto done;
         }
 
-        if ((c = getc(pack)) == EOF) {
+        c = getc(pack);
+        if (c == EOF) {
                 log_debug("Premature end of pack file.");
-                r = -EIO;
-                goto finish;
+                return -EIO;
         }
 
         /* We do not retest SSD here, so that we can start replaying
@@ -185,7 +182,13 @@ static int replay(const char *root) {
         if (on_ssd)
                 prio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0);
         else
-                prio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_RT, 7);
+                /* 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");
@@ -204,11 +207,11 @@ static int replay(const char *root) {
                 int k;
                 ssize_t n;
 
-                if ((n = read(inotify_fd, &inotify_buffer, sizeof(inotify_buffer))) < 0) {
+                n = read(inotify_fd, &inotify_buffer, sizeof(inotify_buffer));
+                if (n < 0) {
                         if (errno != EINTR && errno != EAGAIN) {
                                 log_error("Failed to read inotify event: %m");
-                                r = -errno;
-                                goto finish;
+                                return -errno;
                         }
                 } else {
                         struct inotify_event *e = (struct inotify_event*) inotify_buffer;
@@ -229,10 +232,9 @@ static int replay(const char *root) {
                         }
                 }
 
-                if ((k = unpack_file(pack)) < 0) {
-                        r = k;
-                        goto finish;
-                }
+                k = unpack_file(pack);
+                if (k < 0)
+                        return k;
 
                 if (!ready) {
                         /* We delay the ready notification until we
@@ -243,129 +245,37 @@ static int replay(const char *root) {
         }
 
 done:
-        if (!ready)
-                sd_notify(0, "READY=1");
-
         if (ferror(pack)) {
                 log_error("Failed to read pack file.");
-                r = -EIO;
-                goto finish;
+                return -EIO;
         }
 
-        log_debug("Done.");
-
-finish:
-        if (pack)
-                fclose(pack);
-
-        if (inotify_fd >= 0)
-                close_nointr_nofail(inotify_fd);
-
-        free(pack_fn);
-
-        return r;
-}
-
-
-static int help(void) {
-
-        printf("%s [OPTIONS...] [DIRECTORY]\n\n"
-               "Replay collected read-ahead data on early boot.\n\n"
-               "  -h --help                 Show this help\n"
-               "     --max-file-size=BYTES  Maximum size of files to read ahead\n",
-               program_invocation_short_name);
+        if (!ready)
+                sd_notify(0, "READY=1");
 
+        log_debug("Done.");
         return 0;
 }
 
-static int parse_argv(int argc, char *argv[]) {
+int main_replay(const char *root) {
 
-        enum {
-                ARG_FILE_SIZE_MAX
-        };
-
-        static const struct option options[] = {
-                { "help",          no_argument,       NULL, 'h'                },
-                { "file-size-max", required_argument, NULL, ARG_FILE_SIZE_MAX  },
-                { 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_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 '?':
-                        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();
-
-        umask(0022);
-
-        if ((r = parse_argv(argc, argv)) <= 0)
-                return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
-
-        root = optind < argc ? argv[optind] : "/";
+        if (!root)
+                root = "/";
 
         if (!enough_ram()) {
                 log_info("Disabling readahead replay due to low memory.");
-                return 0;
+                return EXIT_SUCCESS;
         }
 
-        if (detect_virtualization(NULL) > 0) {
-                log_info("Disabling readahead replay due to execution in virtualized environment.");
-                return 0;
-        }
-
-        if (!(shared = shared_get()))
-                return 1;
+        shared = shared_get();
+        if (!shared)
+                return EXIT_FAILURE;
 
         shared->replay = getpid();
         __sync_synchronize();
 
         if (replay(root) < 0)
-                return 1;
+                return EXIT_FAILURE;
 
-        return 0;
+        return EXIT_SUCCESS;
 }