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Diffstat (limited to 'builtin/gc.c')
-rw-r--r--builtin/gc.c95
1 files changed, 93 insertions, 2 deletions
diff --git a/builtin/gc.c b/builtin/gc.c
index 6be6c8d..c14190f 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -14,6 +14,7 @@
#include "cache.h"
#include "parse-options.h"
#include "run-command.h"
+#include "sigchain.h"
#include "argv-array.h"
#define FAILED_RUN "failed to run %s"
@@ -35,6 +36,21 @@ static struct argv_array repack = ARGV_ARRAY_INIT;
static struct argv_array prune = ARGV_ARRAY_INIT;
static struct argv_array rerere = ARGV_ARRAY_INIT;
+static char *pidfile;
+
+static void remove_pidfile(void)
+{
+ if (pidfile)
+ unlink(pidfile);
+}
+
+static void remove_pidfile_on_signal(int signo)
+{
+ remove_pidfile();
+ sigchain_pop(signo);
+ raise(signo);
+}
+
static int gc_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, "gc.packrefs")) {
@@ -167,19 +183,86 @@ static int need_to_gc(void)
return 1;
}
+/* return NULL on success, else hostname running the gc */
+static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
+{
+ static struct lock_file lock;
+ static char locking_host[128];
+ char my_host[128];
+ struct strbuf sb = STRBUF_INIT;
+ struct stat st;
+ uintmax_t pid;
+ FILE *fp;
+ int fd, should_exit;
+
+ if (pidfile)
+ /* already locked */
+ return NULL;
+
+ if (gethostname(my_host, sizeof(my_host)))
+ strcpy(my_host, "unknown");
+
+ fd = hold_lock_file_for_update(&lock, git_path("gc.pid"),
+ LOCK_DIE_ON_ERROR);
+ if (!force) {
+ fp = fopen(git_path("gc.pid"), "r");
+ memset(locking_host, 0, sizeof(locking_host));
+ should_exit =
+ fp != NULL &&
+ !fstat(fileno(fp), &st) &&
+ /*
+ * 12 hour limit is very generous as gc should
+ * never take that long. On the other hand we
+ * don't really need a strict limit here,
+ * running gc --auto one day late is not a big
+ * problem. --force can be used in manual gc
+ * after the user verifies that no gc is
+ * running.
+ */
+ time(NULL) - st.st_mtime <= 12 * 3600 &&
+ fscanf(fp, "%"PRIuMAX" %127c", &pid, locking_host) == 2 &&
+ /* be gentle to concurrent "gc" on remote hosts */
+ (strcmp(locking_host, my_host) || !kill(pid, 0));
+ if (fp != NULL)
+ fclose(fp);
+ if (should_exit) {
+ if (fd >= 0)
+ rollback_lock_file(&lock);
+ *ret_pid = pid;
+ return locking_host;
+ }
+ }
+
+ strbuf_addf(&sb, "%"PRIuMAX" %s",
+ (uintmax_t) getpid(), my_host);
+ write_in_full(fd, sb.buf, sb.len);
+ strbuf_release(&sb);
+ commit_lock_file(&lock);
+
+ pidfile = git_pathdup("gc.pid");
+ sigchain_push_common(remove_pidfile_on_signal);
+ atexit(remove_pidfile);
+
+ return NULL;
+}
+
int cmd_gc(int argc, const char **argv, const char *prefix)
{
int aggressive = 0;
int auto_gc = 0;
int quiet = 0;
+ int force = 0;
+ const char *name;
+ pid_t pid;
struct option builtin_gc_options[] = {
OPT__QUIET(&quiet, N_("suppress progress reporting")),
{ OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
N_("prune unreferenced objects"),
PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
- OPT_BOOLEAN(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
- OPT_BOOLEAN(0, "auto", &auto_gc, N_("enable auto-gc mode")),
+ OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
+ OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
+ OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
OPT_END()
};
@@ -225,6 +308,14 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
} else
add_repack_all_option();
+ name = lock_repo_for_gc(force, &pid);
+ if (name) {
+ if (auto_gc)
+ return 0; /* be quiet on --auto */
+ die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
+ name, (uintmax_t)pid);
+ }
+
if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
return error(FAILED_RUN, pack_refs_cmd.argv[0]);