git/fsmonitor-settings.c
Patrick Steinhardt 6073b3b5c3 config: clarify memory ownership in git_config_pathname()
The out parameter of `git_config_pathname()` is a `const char **` even
though we transfer ownership of memory to the caller. This is quite
misleading and has led to many memory leaks all over the place. Adapt
the parameter to instead be `char **`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:19:59 -07:00

291 lines
7.3 KiB
C

#include "git-compat-util.h"
#include "config.h"
#include "gettext.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 MAYBE_UNUSED)
{
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;
char *to_free = NULL;
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", &to_free))
return; /* should not happen */
const_str = to_free;
break;
default: /* should not happen */
return;
}
if (const_str && *const_str)
fsm_settings__set_hook(r, const_str);
else
fsm_settings__set_disabled(r);
free(to_free);
}
enum fsmonitor_mode fsm_settings__get_mode(struct repository *r)
{
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->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->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->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->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->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->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);
}