[v11,0/6] fsmonitor: option to allow fsmonitor to run against network-mounted repos

Message

Philippe Blain via GitGitGadget Sept. 21, 2022, 10:18 p.m. UTC

Follow-on to the work done to allow Windows to work against network-mounted
repos for macOS.

Have macOS take advantage of the same configuration option,
'fsmonitor.allowRemote' that was introduced for Windows. Setting this option
to true will override the default behavior (erroring-out) when a
network-mounted repo is detected by fsmonitor.

The added wrinkle being that the Unix domain socket (UDS) file used for IPC
cannot be created in a network location; instead $HOME is used if the
default location is on the network. The user may, optionally, set the
'fsmonitor.socketDir' configuration option to a valid, local directory if
$HOME itself is on the network or is simply not the desired location for the
UDS file.

An additional issue is that for mount points in the root directory, FSEvents
does not report a path that matches the worktree directory due to the
introduction of 'synthetic firmlinks'. fsmonitor must map the FSEvents paths
to the worktree directory by interrogating the root filesystem for synthetic
firmlinks and using that information to translate the path.

v11 differs from v10:

 * incorporates code review feedback
 * fix memory leak in fsm-listen-darwin.c

v10 differs from v9:

 * incorporates code review feedback
 * improves error messaging for incompatible socket directory

v9 differs from v8:

 * incorporates code review feedback
 * check for incompatibility before communicating with fsmonitor

v8 differs from v7:

 * incorporates code review feedback
 * gets the rebase right

v7 differs from v6:

 * incorporates code review feedback

v6 differs from v5:

 * incorporates earlier, Windows-specific changes that have not made it back
   yet to the master branch
 * incorporates code review feedback
 * adds documentation for 'fsmonitor.allowRemote' and 'fsmonitor.socketDir'

v5 differs significantly from earlier versions:

 * redesign of handling 'fsmonitor.allowRemote' and 'fsmonitor.socketDir'
   such that these options are no longer added to the settings data
   structure but are rather read from config at point of use
 * refactoring of code for handling platform-specific file system checks via
   a common interface to avoid platform #ifdef in IPC code and be in-model
   with other platform-specific fsmonitor code
 * dealing with 'synthetic firmlinks' on macOS

Eric DeCosta (6):
  fsmonitor: refactor filesystem checks to common interface
  fsmonitor: relocate socket file if .git directory is remote
  fsmonitor: avoid socket location check if using hook
  fsmonitor: deal with synthetic firmlinks on macOS
  fsmonitor: check for compatability before communicating with fsmonitor
  fsmonitor: add documentation for allowRemote and socketDir options

 Documentation/git-fsmonitor--daemon.txt  |  48 ++++++-
 Makefile                                 |   2 +
 builtin/fsmonitor--daemon.c              |  11 +-
 compat/fsmonitor/fsm-ipc-darwin.c        |  51 +++++++
 compat/fsmonitor/fsm-ipc-win32.c         |   9 ++
 compat/fsmonitor/fsm-listen-darwin.c     |  14 +-
 compat/fsmonitor/fsm-path-utils-darwin.c | 132 +++++++++++++++++
 compat/fsmonitor/fsm-path-utils-win32.c  | 145 +++++++++++++++++++
 compat/fsmonitor/fsm-settings-darwin.c   |  72 +++-------
 compat/fsmonitor/fsm-settings-win32.c    | 174 +----------------------
 contrib/buildsystems/CMakeLists.txt      |   4 +
 fsmonitor--daemon.h                      |   3 +
 fsmonitor-ipc.c                          |  18 ++-
 fsmonitor-ipc.h                          |   4 +-
 fsmonitor-path-utils.h                   |  59 ++++++++
 fsmonitor-settings.c                     |  68 ++++++++-
 fsmonitor-settings.h                     |   4 +-
 fsmonitor.c                              |   4 +
 18 files changed, 576 insertions(+), 246 deletions(-)
 create mode 100644 compat/fsmonitor/fsm-ipc-darwin.c
 create mode 100644 compat/fsmonitor/fsm-ipc-win32.c
 create mode 100644 compat/fsmonitor/fsm-path-utils-darwin.c
 create mode 100644 compat/fsmonitor/fsm-path-utils-win32.c
 create mode 100644 fsmonitor-path-utils.h


base-commit: d3fa443f97e3a8d75b51341e2d5bac380b7422df
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1326%2Fedecosta-mw%2Ffsmonitor_macos-v11
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1326/edecosta-mw/fsmonitor_macos-v11
Pull-Request: https://github.com/gitgitgadget/git/pull/1326

Range-diff vs v10:

 1:  155a6890806 = 1:  155a6890806 fsmonitor: refactor filesystem checks to common interface
 2:  dbe113abb87 = 2:  dbe113abb87 fsmonitor: relocate socket file if .git directory is remote
 3:  86c15299ae8 = 3:  86c15299ae8 fsmonitor: avoid socket location check if using hook
 4:  4f6c98cf834 ! 4:  1a516fd9214 fsmonitor: deal with synthetic firmlinks on macOS
     @@ compat/fsmonitor/fsm-listen-darwin.c
       
       struct fsm_listen_data
       {
     +@@ compat/fsmonitor/fsm-listen-darwin.c: static void fsevent_callback(ConstFSEventStreamRef streamRef,
     + 	struct string_list cookie_list = STRING_LIST_INIT_DUP;
     + 	const char *path_k;
     + 	const char *slash;
     +-	int k;
     ++	char *resolved = NULL;
     + 	struct strbuf tmp = STRBUF_INIT;
     ++	int k;
     + 
     + 	/*
     + 	 * Build a list of all filesystem changes into a private/local
      @@ compat/fsmonitor/fsm-listen-darwin.c: static void fsevent_callback(ConstFSEventStreamRef streamRef,
       		/*
       		 * On Mac, we receive an array of absolute paths.
       		 */
      -		path_k = paths[k];
     -+		path_k = fsmonitor__resolve_alias(paths[k], &state->alias);
     -+		if (!path_k)
     ++		free(resolved);
     ++		resolved = fsmonitor__resolve_alias(paths[k], &state->alias);
     ++		if (resolved)
     ++			path_k = resolved;
     ++		else
      +			path_k = paths[k];
       
       		/*
     @@ compat/fsmonitor/fsm-listen-darwin.c: static void fsevent_callback(ConstFSEventS
       
       			/*
       			 * We assume that any events that we received
     +@@ compat/fsmonitor/fsm-listen-darwin.c: static void fsevent_callback(ConstFSEventStreamRef streamRef,
     + 		}
     + 	}
     + 
     ++	free(resolved);
     + 	fsmonitor_publish(state, batch, &cookie_list);
     + 	string_list_clear(&cookie_list, 0);
     + 	strbuf_release(&tmp);
     + 	return;
     + 
     + force_shutdown:
     ++	free(resolved);
     + 	fsmonitor_batch__free_list(batch);
     + 	string_list_clear(&cookie_list, 0);
     + 
      
       ## compat/fsmonitor/fsm-path-utils-darwin.c ##
      @@
 5:  8f6c1fbacbf ! 5:  e0fe05dabef fsmonitor: check for compatability before communicating with fsmonitor
     @@ fsmonitor-settings.c: char *fsm_settings__get_incompatible_msg(const struct repo
       		strbuf_addf(&msg,
      -			    _("repository '%s' is incompatible with fsmonitor due to lack of Unix sockets"),
      -			    r->worktree);
     -+			    _("socket directory '%s' is incompatible with fsmonitor due"),
     ++			    _("socket directory '%s' is incompatible with fsmonitor due"
     ++				  " to lack of Unix sockets support"),
      +			    socket_dir);
     -+		strbuf_add(&msg, _(" to lack of Unix sockets support"), 32);
       		goto done;
       	}
       
     @@ fsmonitor.c: void refresh_fsmonitor(struct index_state *istate)
      +	enum fsmonitor_reason reason = fsm_settings__get_reason(r);
      +
      +	if (reason > FSMONITOR_REASON_OK)
     -+		die("%s", fsm_settings__get_incompatible_msg(r, reason));
     ++		warning("%s", fsm_settings__get_incompatible_msg(r, reason));
       
       	if (fsm_mode <= FSMONITOR_MODE_DISABLED ||
       	    istate->fsmonitor_has_run_once)
 6:  d7c25bf96c6 = 6:  3200b505988 fsmonitor: add documentation for allowRemote and socketDir options