diff --git a/compat/fsmonitor/fsm-settings-win32.c b/compat/fsmonitor/fsm-settings-win32.c index 7caa79570afa92..39e907046f14d7 100644 --- a/compat/fsmonitor/fsm-settings-win32.c +++ b/compat/fsmonitor/fsm-settings-win32.c @@ -2,6 +2,7 @@ #include "config.h" #include "repository.h" #include "fsmonitor-settings.h" +#include "fsmonitor.h" /* * GVFS (aka VFS for Git) is incompatible with FSMonitor. @@ -23,6 +24,103 @@ static enum fsmonitor_reason is_virtual(struct repository *r) return FSMONITOR_REASON_ZERO; } +/* + * 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. + * + * Notes for testing: + * + * (a) Windows allows a network share to be mapped to a drive letter. + * (This is the normal method to access it.) + * + * $ NET USE Z: \\server\share + * $ git -C Z:/repo status + * + * (b) Windows allows a network share to be referenced WITHOUT mapping + * it to drive letter. + * + * $ NET USE \\server\share\dir + * $ git -C //server/share/repo status + * + * (c) Windows allows "SUBST" to create a fake drive mapping to an + * arbitrary path (which may be remote) + * + * $ SUBST Q: Z:\repo + * $ git -C Q:/ status + * + * (d) Windows allows a directory symlink to be created on a local + * file system that points to a remote repo. + * + * $ mklink /d ./link //server/share/repo + * $ git -C ./link status + */ +static enum fsmonitor_reason is_remote(struct repository *r) +{ + wchar_t wpath[MAX_PATH]; + wchar_t wfullpath[MAX_PATH]; + size_t wlen; + UINT driveType; + + /* + * Do everything in wide chars because the drive letter might be + * a multi-byte sequence. See win32_has_dos_drive_prefix(). + */ + if (xutftowcs_path(wpath, r->worktree) < 0) + return FSMONITOR_REASON_ZERO; + + /* + * GetDriveTypeW() requires a final slash. We assume that the + * worktree pathname points to an actual directory. + */ + wlen = wcslen(wpath); + if (wpath[wlen - 1] != L'\\' && wpath[wlen - 1] != L'/') { + wpath[wlen++] = L'\\'; + wpath[wlen] = 0; + } + + /* + * Normalize the path. If nothing else, this converts forward + * slashes to backslashes. This is essential to get GetDriveTypeW() + * correctly handle some UNC "\\server\share\..." paths. + */ + if (!GetFullPathNameW(wpath, MAX_PATH, wfullpath, NULL)) + return FSMONITOR_REASON_ZERO; + + driveType = GetDriveTypeW(wfullpath); + trace_printf_key(&trace_fsmonitor, + "DriveType '%s' L'%S' (%u)", + r->worktree, wfullpath, driveType); + + if (driveType == DRIVE_REMOTE) { + trace_printf_key(&trace_fsmonitor, + "is_remote('%s') true", + r->worktree); + return FSMONITOR_REASON_REMOTE; + } + + return FSMONITOR_REASON_ZERO; +} + enum fsmonitor_reason fsm_os__incompatible(struct repository *r) { enum fsmonitor_reason reason; @@ -31,5 +129,9 @@ enum fsmonitor_reason fsm_os__incompatible(struct repository *r) if (reason) return reason; + reason = is_remote(r); + if (reason) + return reason; + return FSMONITOR_REASON_ZERO; }