Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 299 insertions, 0 deletions

diff --git a/fsmonitor-settings.c b/fsmonitor-settings.c
new file mode 100644
index 0000000..ee63a97
--- /dev/null
+++ b/fsmonitor-settings.c
@@ -0,0 +1,299 @@
+#include "cache.h"
+#include "config.h"
+#include "repository.h"
+#include "fsmonitor-ipc.h"
+#include "fsmonitor-settings.h"
+#include "fsmonitor-path-utils.h"
+
+/*
+ * We keep this structure defintion private and have getters
+ * for all fields so that we can lazy load it as needed.
+ */
+struct fsmonitor_settings {
+	enum fsmonitor_mode mode;
+	enum fsmonitor_reason reason;
+	char *hook_path;
+};
+
+/*
+ * Remote working directories are problematic for FSMonitor.
+ *
+ * The underlying file system on the server machine and/or the remote
+ * mount type dictates whether notification events are available at
+ * all to remote client machines.
+ *
+ * Kernel differences between the server and client machines also
+ * dictate the how (buffering, frequency, de-dup) the events are
+ * delivered to client machine processes.
+ *
+ * A client machine (such as a laptop) may choose to suspend/resume
+ * and it is unclear (without lots of testing) whether the watcher can
+ * resync after a resume.  We might be able to treat this as a normal
+ * "events were dropped by the kernel" event and do our normal "flush
+ * and resync" --or-- we might need to close the existing (zombie?)
+ * notification fd and create a new one.
+ *
+ * In theory, the above issues need to be addressed whether we are
+ * using the Hook or IPC API.
+ *
+ * So (for now at least), mark remote working directories as
+ * incompatible unless 'fsmonitor.allowRemote' is true.
+ *
+ */
+#ifdef HAVE_FSMONITOR_OS_SETTINGS
+static enum fsmonitor_reason check_remote(struct repository *r)
+{
+	int allow_remote = -1; /* -1 unset, 0 not allowed, 1 allowed */
+	int is_remote = fsmonitor__is_fs_remote(r->worktree);
+
+	switch (is_remote) {
+		case 0:
+			return FSMONITOR_REASON_OK;
+		case 1:
+			repo_config_get_bool(r, "fsmonitor.allowremote", &allow_remote);
+			if (allow_remote < 1)
+				return FSMONITOR_REASON_REMOTE;
+			else
+				return FSMONITOR_REASON_OK;
+		default:
+			return FSMONITOR_REASON_ERROR;
+	}
+}
+#endif
+
+static enum fsmonitor_reason check_for_incompatible(struct repository *r, int ipc)
+{
+	if (!r->worktree) {
+		/*
+		 * Bare repositories don't have a working directory and
+		 * therefore have nothing to watch.
+		 */
+		return FSMONITOR_REASON_BARE;
+	}
+
+#ifdef HAVE_FSMONITOR_OS_SETTINGS
+	{
+		enum fsmonitor_reason reason;
+
+		reason = check_remote(r);
+		if (reason != FSMONITOR_REASON_OK)
+			return reason;
+		reason = fsm_os__incompatible(r, ipc);
+		if (reason != FSMONITOR_REASON_OK)
+			return reason;
+	}
+#endif
+
+	return FSMONITOR_REASON_OK;
+}
+
+static struct fsmonitor_settings *alloc_settings(void)
+{
+	struct fsmonitor_settings *s;
+
+	CALLOC_ARRAY(s, 1);
+	s->mode = FSMONITOR_MODE_DISABLED;
+	s->reason = FSMONITOR_REASON_UNTESTED;
+
+	return s;
+}
+
+static void lookup_fsmonitor_settings(struct repository *r)
+{
+	const char *const_str;
+	int bool_value;
+
+	if (r->settings.fsmonitor)
+		return;
+
+	/*
+	 * Overload the existing "core.fsmonitor" config setting (which
+	 * has historically been either unset or a hook pathname) to
+	 * now allow a boolean value to enable the builtin FSMonitor
+	 * or to turn everything off.  (This does imply that you can't
+	 * use a hook script named "true" or "false", but that's OK.)
+	 */
+	switch (repo_config_get_maybe_bool(r, "core.fsmonitor", &bool_value)) {
+
+	case 0: /* config value was set to <bool> */
+		if (bool_value)
+			fsm_settings__set_ipc(r);
+		else
+			fsm_settings__set_disabled(r);
+		return;
+
+	case 1: /* config value was unset */
+		const_str = getenv("GIT_TEST_FSMONITOR");
+		break;
+
+	case -1: /* config value set to an arbitrary string */
+		if (repo_config_get_pathname(r, "core.fsmonitor", &const_str))
+			return; /* should not happen */
+		break;
+
+	default: /* should not happen */
+		return;
+	}
+
+	if (const_str && *const_str)
+		fsm_settings__set_hook(r, const_str);
+	else
+		fsm_settings__set_disabled(r);
+}
+
+enum fsmonitor_mode fsm_settings__get_mode(struct repository *r)
+{
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		lookup_fsmonitor_settings(r);
+
+	return r->settings.fsmonitor->mode;
+}
+
+const char *fsm_settings__get_hook_path(struct repository *r)
+{
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		lookup_fsmonitor_settings(r);
+
+	return r->settings.fsmonitor->hook_path;
+}
+
+void fsm_settings__set_ipc(struct repository *r)
+{
+	enum fsmonitor_reason reason = check_for_incompatible(r, 1);
+
+	if (reason != FSMONITOR_REASON_OK) {
+		fsm_settings__set_incompatible(r, reason);
+		return;
+	}
+
+	/*
+	 * Caller requested IPC explicitly, so avoid (possibly
+	 * recursive) config lookup.
+	 */
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
+
+	r->settings.fsmonitor->mode = FSMONITOR_MODE_IPC;
+	r->settings.fsmonitor->reason = reason;
+	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
+}
+
+void fsm_settings__set_hook(struct repository *r, const char *path)
+{
+	enum fsmonitor_reason reason = check_for_incompatible(r, 0);
+
+	if (reason != FSMONITOR_REASON_OK) {
+		fsm_settings__set_incompatible(r, reason);
+		return;
+	}
+
+	/*
+	 * Caller requested hook explicitly, so avoid (possibly
+	 * recursive) config lookup.
+	 */
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
+
+	r->settings.fsmonitor->mode = FSMONITOR_MODE_HOOK;
+	r->settings.fsmonitor->reason = reason;
+	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
+	r->settings.fsmonitor->hook_path = strdup(path);
+}
+
+void fsm_settings__set_disabled(struct repository *r)
+{
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
+
+	r->settings.fsmonitor->mode = FSMONITOR_MODE_DISABLED;
+	r->settings.fsmonitor->reason = FSMONITOR_REASON_OK;
+	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
+}
+
+void fsm_settings__set_incompatible(struct repository *r,
+				    enum fsmonitor_reason reason)
+{
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		r->settings.fsmonitor = alloc_settings();
+
+	r->settings.fsmonitor->mode = FSMONITOR_MODE_INCOMPATIBLE;
+	r->settings.fsmonitor->reason = reason;
+	FREE_AND_NULL(r->settings.fsmonitor->hook_path);
+}
+
+enum fsmonitor_reason fsm_settings__get_reason(struct repository *r)
+{
+	if (!r)
+		r = the_repository;
+	if (!r->settings.fsmonitor)
+		lookup_fsmonitor_settings(r);
+
+	return r->settings.fsmonitor->reason;
+}
+
+char *fsm_settings__get_incompatible_msg(struct repository *r,
+					 enum fsmonitor_reason reason)
+{
+	struct strbuf msg = STRBUF_INIT;
+	const char *socket_dir;
+
+	switch (reason) {
+	case FSMONITOR_REASON_UNTESTED:
+	case FSMONITOR_REASON_OK:
+		goto done;
+
+	case FSMONITOR_REASON_BARE: {
+		char *cwd = xgetcwd();
+
+		strbuf_addf(&msg,
+			    _("bare repository '%s' is incompatible with fsmonitor"),
+			    cwd);
+		free(cwd);
+		goto done;
+	}
+
+	case FSMONITOR_REASON_ERROR:
+		strbuf_addf(&msg,
+			    _("repository '%s' is incompatible with fsmonitor due to errors"),
+			    r->worktree);
+		goto done;
+
+	case FSMONITOR_REASON_REMOTE:
+		strbuf_addf(&msg,
+			    _("remote repository '%s' is incompatible with fsmonitor"),
+			    r->worktree);
+		goto done;
+
+	case FSMONITOR_REASON_VFS4GIT:
+		strbuf_addf(&msg,
+			    _("virtual repository '%s' is incompatible with fsmonitor"),
+			    r->worktree);
+		goto done;
+
+	case FSMONITOR_REASON_NOSOCKETS:
+		socket_dir = dirname((char *)fsmonitor_ipc__get_path(r));
+		strbuf_addf(&msg,
+			    _("socket directory '%s' is incompatible with fsmonitor due"
+			      " to lack of Unix sockets support"),
+			    socket_dir);
+		goto done;
+	}
+
+	BUG("Unhandled case in fsm_settings__get_incompatible_msg: '%d'",
+	    reason);
+
+done:
+	return strbuf_detach(&msg, NULL);
+}