journal: rework vacuuming logic

Implement a maximum limit on number of journal files to keep around.
Enforcing a limit is useful on this since our performance when viewing
pays a heavy penalty for each journal file to interleve. This setting is
turned on now by default, and set to 100.

Also, actully implement what 348ced909724a1331b85d57aede80a102a00e428
promised: use whatever we find on disk at startup as lower bound on how
much disk space we can use. That commit introduced some provisions to
implement this, but actually never did.

This also adds "journalctl --vacuum-files=" to vacuum files on disk by
their number explicitly.

1 files changed, 19 insertions, 5 deletions

diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c
index 28ccb80661..d9851db36c 100644
--- a/src/journal/journalctl.c
+++ b/src/journal/journalctl.c
@@ -106,8 +106,9 @@ static bool arg_reverse = false;
 static int arg_journal_type = 0;
 static const char *arg_root = NULL;
 static const char *arg_machine = NULL;
-static uint64_t arg_vacuum_size = (uint64_t) -1;
-static usec_t arg_vacuum_time = USEC_INFINITY;
+static uint64_t arg_vacuum_size = 0;
+static uint64_t arg_vacuum_n_files = 0;
+static usec_t arg_vacuum_time = 0;
 
 static enum {
         ACTION_SHOW,
@@ -235,7 +236,8 @@ static void help(void) {
                "     --new-id128           Generate a new 128-bit ID\n"
                "     --disk-usage          Show total disk usage of all journal files\n"
                "     --vacuum-size=BYTES   Reduce disk usage below specified size\n"
-               "     --vacuum-time=TIME    Remove journal files older than specified date\n"
+               "     --vacuum-files=INT    Leave only the specified number of journal files\n"
+               "     --vacuum-time=TIME    Remove journal files older than specified time\n"
                "     --flush               Flush all journal data from /run into /var\n"
                "     --rotate              Request immediate rotation of the journal files\n"
                "     --header              Show journal header information\n"
@@ -281,6 +283,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_FLUSH,
                 ARG_ROTATE,
                 ARG_VACUUM_SIZE,
+                ARG_VACUUM_FILES,
                 ARG_VACUUM_TIME,
         };
 
@@ -335,6 +338,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "flush",          no_argument,       NULL, ARG_FLUSH          },
                 { "rotate",         no_argument,       NULL, ARG_ROTATE         },
                 { "vacuum-size",    required_argument, NULL, ARG_VACUUM_SIZE    },
+                { "vacuum-files",   required_argument, NULL, ARG_VACUUM_FILES   },
                 { "vacuum-time",    required_argument, NULL, ARG_VACUUM_TIME    },
                 {}
         };
@@ -540,6 +544,16 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_action = ACTION_VACUUM;
                         break;
 
+                case ARG_VACUUM_FILES:
+                        r = safe_atou64(optarg, &arg_vacuum_n_files);
+                        if (r < 0) {
+                                log_error("Failed to parse vacuum files: %s", optarg);
+                                return r;
+                        }
+
+                        arg_action = ACTION_VACUUM;
+                        break;
+
                 case ARG_VACUUM_TIME:
                         r = parse_sec(optarg, &arg_vacuum_time);
                         if (r < 0) {
@@ -1929,9 +1943,9 @@ int main(int argc, char *argv[]) {
                         if (d->is_root)
                                 continue;
 
-                        q = journal_directory_vacuum(d->path, arg_vacuum_size, arg_vacuum_time, NULL, true);
+                        q = journal_directory_vacuum(d->path, arg_vacuum_size, arg_vacuum_n_files, arg_vacuum_time, NULL, true);
                         if (q < 0) {
-                                log_error_errno(q, "Failed to vacuum: %m");
+                                log_error_errno(q, "Failed to vacuum %s: %m", d->path);
                                 r = q;
                         }
                 }