From: Jan Janssen Date: Fri, 28 Jun 2013 15:26:30 +0000 (+0200) Subject: journalctl: Add support for showing messages from a previous boot X-Git-Tag: v206~79 X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=a331b5e6d4724365bad9edeb9420c7e26e7f50da;ds=sidebyside journalctl: Add support for showing messages from a previous boot Hi, I redid the boot ID look up to use enumerate_unique. This is quite fast if the cache is warm but painfully slow if it isn't. It has a slight chance of returning the wrong order if realtime clock jumps around. This one has to do n searches for every boot ID there is plus a sort, so it depends heavily on cache hotness. This is in contrast to the other way of look-up through filtering by a MESSAGE_ID, which only needs about 1 seek + whatever amount of relative IDs you want to walk. I also have a linked-list + (in-place) mergesort version of this patch, which has pretty much the same runtime. But since this one is using libc sorting and armortized allocation, I prefer this one. To summarize: The MESSAGE_ID way is a *lot* faster but can be incomplete due to rotation, while the enumerate+sort will find every boot ID out there but will be painfully slow for large journals and cold caches. You choose :P Jan --- diff --git a/TODO b/TODO index 10f2b74df..f5da81f52 100644 --- a/TODO +++ b/TODO @@ -356,7 +356,6 @@ Features: - journal-send.c, log.c: when the log socket is clogged, and we drop, count this and write a message about this when it gets unclogged again. - journal: find a way to allow dropping history early, based on priority, other rules - journal: When used on NFS, check payload hashes - - Introduce journalctl -b to show journal messages of a previous boot - journald: check whether it is OK if the client can still modify delivered journal entries - journal live copy, based on libneon (client) and libmicrohttpd (server) - journald: add kernel cmdline option to disable ratelimiting for debug purposes diff --git a/man/journalctl.xml b/man/journalctl.xml index b8b29b4cb..0e779b952 100644 --- a/man/journalctl.xml +++ b/man/journalctl.xml @@ -327,23 +327,51 @@ - - - - Show data only from - current boot. This will add a match - for _BOOT_ID= for - the current boot ID of the - kernel. + + + + Show messages from the specified + boot ID or from + current boot if no ID + is given. This will add a match for + _BOOT_ID=. + + The argument is a 128 bit ID given in + short or UUID form and optionally followed by + :n which identifies the nth + boot relative to the boot ID given to the left + of :. Supplying a negative + value for n will look for a past boot and a + positive value for a future boot. The boot IDs + are searched for in chronological order. If no + number is provided after :, + -1 is assumed. A value of 0 + is valid and equivalent to omitting + :0. + + Alternatively, the argument may constist + only of :n. In this case, a + positive value will look up the nth boot + starting from the beginning of the jouranl, a + negative value will look up a previous boot + relative to the current boot. :0 + will look for the current boot ID. Thus, + :1 is the first boot found in + the journal, :2 the second + and so on; while :-1 is the + previous boot, :-2 the boot + before that and so on. Omitting a value after + : will look for the previous + boot. - Show kernel messages from - current boot. This implies - and adds the match _TRANSPORT=kernel. + Show only kernel messages. This + implies and adds the match + _TRANSPORT=kernel. @@ -721,6 +749,10 @@ journalctl /dev/sda + Show all kernel logs from last boot: + + journalctl -k -b : + diff --git a/shell-completion/bash/journalctl b/shell-completion/bash/journalctl index 5ab59c994..29bf6bca3 100644 --- a/shell-completion/bash/journalctl +++ b/shell-completion/bash/journalctl @@ -37,19 +37,22 @@ __journal_fields=(MESSAGE{,_ID} PRIORITY CODE_{FILE,LINE,FUNC} _journalctl() { local field_vals= cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]} local -A OPTS=( - [STANDALONE]='-a --all --full - --system --user - -b --this-boot --disk-usage -f --follow --header + [STANDALONE]='-a --all --full --system --user + --disk-usage -f --follow --header -h --help -l --local --new-id128 -m --merge --no-pager --no-tail -q --quiet --setup-keys --this-boot --verify --version --list-catalog --update-catalog' - [ARG]='-D --directory -F --field -o --output -u --unit --user-unit' + [ARG]='-b --boot --this-boot -D --directory -F --field + -o --output -u --unit --user-unit' [ARGUNKNOWN]='-c --cursor --interval -n --lines -p --priority --since --until --verify-key' ) if __contains_word "$prev" ${OPTS[ARG]} ${OPTS[ARGUNKNOWN]}; then case $prev in + --boot|--this-boot|-b) + comps=$(journalctl -F '_BOOT_ID' 2>/dev/null) + ;; --directory|-D) comps=$(compgen -d -- "$cur") compopt -o filenames diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c index 5f44fce08..38b2cdd57 100644 --- a/src/journal/journalctl.c +++ b/src/journal/journalctl.c @@ -70,7 +70,8 @@ static int arg_lines = -1; static bool arg_no_tail = false; static bool arg_quiet = false; static bool arg_merge = false; -static bool arg_this_boot = false; +static bool arg_boot_id = false; +static char *arg_boot_id_descriptor = NULL; static bool arg_dmesg = false; static const char *arg_cursor = NULL; static const char *arg_directory = NULL; @@ -103,6 +104,11 @@ static enum { ACTION_UPDATE_CATALOG } arg_action = ACTION_SHOW; +typedef struct boot_id_t { + sd_id128_t id; + uint64_t timestamp; +} boot_id_t; + static int help(void) { printf("%s [OPTIONS...] [MATCHES...]\n\n" @@ -113,8 +119,8 @@ static int help(void) { " --since=DATE Start showing entries newer or of the specified date\n" " --until=DATE Stop showing entries older or of the specified date\n" " -c --cursor=CURSOR Start showing entries from specified cursor\n" - " -b --this-boot Show data only from current boot\n" - " -k --dmesg Show kmsg log from current boot\n" + " -b --boot[=ID] Show data only from ID or current boot if unspecified\n" + " -k --dmesg Show kernel message log from current boot\n" " -u --unit=UNIT Show data only from the specified unit\n" " --user-unit=UNIT Show data only from the specified user session unit\n" " -p --priority=RANGE Show only messages within the specified priority range\n" @@ -199,7 +205,8 @@ static int parse_argv(int argc, char *argv[]) { { "new-id128", no_argument, NULL, ARG_NEW_ID128 }, { "quiet", no_argument, NULL, 'q' }, { "merge", no_argument, NULL, 'm' }, - { "this-boot", no_argument, NULL, 'b' }, + { "boot", optional_argument, NULL, 'b' }, + { "this-boot", optional_argument, NULL, 'b' }, /* deprecated */ { "dmesg", no_argument, NULL, 'k' }, { "system", no_argument, NULL, ARG_SYSTEM }, { "user", no_argument, NULL, ARG_USER }, @@ -232,7 +239,7 @@ static int parse_argv(int argc, char *argv[]) { assert(argc >= 0); assert(argv); - while ((c = getopt_long(argc, argv, "hefo:aln::qmbkD:p:c:u:F:xr", options, NULL)) >= 0) { + while ((c = getopt_long(argc, argv, "hefo:aln::qmb::kD:p:c:u:F:xr", options, NULL)) >= 0) { switch (c) { @@ -331,11 +338,17 @@ static int parse_argv(int argc, char *argv[]) { break; case 'b': - arg_this_boot = true; + if (optarg) + arg_boot_id_descriptor = optarg; + else if (optind < argc && argv[optind][0] != '-') { + arg_boot_id_descriptor = argv[optind]; + optind++; + } + arg_boot_id = true; break; case 'k': - arg_this_boot = arg_dmesg = true; + arg_boot_id = arg_dmesg = true; break; case ARG_SYSTEM: @@ -630,11 +643,170 @@ static int add_matches(sd_journal *j, char **args) { return 0; } -static int add_this_boot(sd_journal *j) { - if (!arg_this_boot) +static int boot_id_cmp(const void *a, const void *b) { + uint64_t _a, _b; + + _a = ((const boot_id_t *)a)->timestamp; + _b = ((const boot_id_t *)b)->timestamp; + + return _a < _b ? -1 : (_a > _b ? 1 : 0); +} + +static int get_relative_boot_id(sd_journal *j, sd_id128_t *boot_id, int relative) { + int r; + const void *data; + unsigned int id_count = 0; + size_t length, allocated = 0; + boot_id_t ref_boot_id, *id; + _cleanup_free_ boot_id_t *all_ids = NULL; + bool find_first_boot = false, ref_boot_found = false; + + assert(j); + assert(boot_id); + + if (relative == 0) + return 0; + + if (sd_id128_equal(*boot_id, SD_ID128_NULL) && relative > 0) { + find_first_boot = true; + relative--; + } + + r = sd_journal_query_unique(j, "_BOOT_ID"); + if (r < 0) + return r; + + SD_JOURNAL_FOREACH_UNIQUE(j, data, length) { + if (length < strlen("_BOOT_ID=")) + continue; + + if (!GREEDY_REALLOC(all_ids, allocated, id_count + 1)) + return log_oom(); + + id = &all_ids[id_count]; + + r = sd_id128_from_string(((const char *)data) + strlen("_BOOT_ID="), &id->id); + if (r < 0) { + continue; + } + + sd_journal_flush_matches(j); + r = sd_journal_add_match(j, data, length); + if (r < 0) + continue; + + r = sd_journal_seek_head(j); + if (r < 0) + continue; + + r = sd_journal_next(j); + if (r <= 0) + continue; + + r = sd_journal_get_realtime_usec(j, &id->timestamp); + if (r < 0) + continue; + + if (!find_first_boot && sd_id128_equal(id->id, *boot_id)) { + ref_boot_id = *id; + ref_boot_found = true; + } + + id_count++; + } + + *boot_id = SD_ID128_NULL; + sd_journal_flush_matches(j); + + if (id_count == 0 || (!find_first_boot && !ref_boot_found)) + return 0; + + qsort(all_ids, id_count, sizeof(boot_id_t), boot_id_cmp); + if (find_first_boot) + id = all_ids; + else + id = bsearch(&ref_boot_id, all_ids, id_count, sizeof(boot_id_t), boot_id_cmp); + + if (!id || (relative < 0 && ((id - all_ids) + relative) < 0) || + (relative >= 0 && (unsigned long)((id - all_ids) + relative) >= id_count)) return 0; - return add_match_this_boot(j); + id += relative; + *boot_id = id->id; + return 0; +} + +static int add_boot(sd_journal *j) { + char match[9+32+1] = "_BOOT_ID="; + char *marker; + sd_id128_t boot_id; + int r, relative = 0; + + assert(j); + + if (!arg_boot_id) + return 0; + + if (arg_boot_id_descriptor) { + marker = strchr(arg_boot_id_descriptor, ':'); + if (marker) { + *marker = '\0'; + marker++; + + if (*marker == '\0') + relative = -1; + else { + r = safe_atoi(marker, &relative); + if (r < 0) { + log_error("Failed to parse relative boot ID number '%s'", marker); + return -EINVAL; + } + } + } + } + + if (isempty(arg_boot_id_descriptor)) { + if (relative > 0) { + /* We cannot look into the future. Instead, we look + * into the past (starting from first boot). The ID + * will be looked up later */ + boot_id = SD_ID128_NULL; + } else { + r = sd_id128_get_boot(&boot_id); + if (r < 0) { + log_error("Failed to get boot ID: %s", strerror(-r)); + return r; + } + } + } else { + r = sd_id128_from_string(arg_boot_id_descriptor, &boot_id); + if (r < 0) { + log_error("Failed to parse boot ID: %s", strerror(-r)); + return r; + } + } + + r = get_relative_boot_id(j, &boot_id, relative); + if (r < 0) { + log_error("Failed to look up boot ID: %s", strerror(-r)); + return r; + } else if (sd_id128_equal(boot_id, SD_ID128_NULL)) { + log_error("Failed to find boot ID"); + return -1; + } + + sd_id128_to_string(boot_id, match + 9); + r = sd_journal_add_match(j, match, strlen(match)); + if (r < 0) { + log_error("Failed to add match: %s", strerror(-r)); + return r; + } + + r = sd_journal_add_conjunction(j); + if (r < 0) + return r; + + return 0; } static int add_dmesg(sd_journal *j) { @@ -1195,7 +1367,9 @@ int main(int argc, char *argv[]) { return EXIT_SUCCESS; } - r = add_this_boot(j); + /* add_boot() must be called first! + * It may need to seek the journal to find parent boot IDs. */ + r = add_boot(j); if (r < 0) return EXIT_FAILURE;