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Diffstat (limited to 'compat/fsmonitor/fsm-settings-win32.c')
| -rw-r--r-- | compat/fsmonitor/fsm-settings-win32.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/compat/fsmonitor/fsm-settings-win32.c b/compat/fsmonitor/fsm-settings-win32.c new file mode 100644 index 0000000..9076557 --- /dev/null +++ b/compat/fsmonitor/fsm-settings-win32.c @@ -0,0 +1,137 @@ +#include "cache.h" +#include "config.h" +#include "repository.h" +#include "fsmonitor-settings.h" +#include "fsmonitor.h" + +/* + * VFS for Git is incompatible with FSMonitor. + * + * Granted, core Git does not know anything about VFS for Git and we + * shouldn't make assumptions about a downstream feature, but users + * can install both versions. And this can lead to incorrect results + * from core Git commands. So, without bringing in any of the VFS for + * Git code, do a simple config test for a published config setting. + * (We do not look at the various *_TEST_* environment variables.) + */ +static enum fsmonitor_reason check_vfs4git(struct repository *r) +{ + const char *const_str; + + if (!repo_config_get_value(r, "core.virtualfilesystem", &const_str)) + return FSMONITOR_REASON_VFS4GIT; + + return FSMONITOR_REASON_OK; +} + +/* + * 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 check_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_ERROR; + + /* + * 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_ERROR; + + driveType = GetDriveTypeW(wfullpath); + trace_printf_key(&trace_fsmonitor, + "DriveType '%s' L'%ls' (%u)", + r->worktree, wfullpath, driveType); + + if (driveType == DRIVE_REMOTE) { + trace_printf_key(&trace_fsmonitor, + "check_remote('%s') true", + r->worktree); + return FSMONITOR_REASON_REMOTE; + } + + return FSMONITOR_REASON_OK; +} + +enum fsmonitor_reason fsm_os__incompatible(struct repository *r) +{ + enum fsmonitor_reason reason; + + reason = check_vfs4git(r); + if (reason != FSMONITOR_REASON_OK) + return reason; + + reason = check_remote(r); + if (reason != FSMONITOR_REASON_OK) + return reason; + + return FSMONITOR_REASON_OK; +} |