From 0ba0416dbb373fb912d31cb945ea88b1d237c1fb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=AD=99=E5=8D=93=E8=AF=86?= Date: Sun, 16 Jan 2022 03:38:33 +0800 Subject: [PATCH] Add config option `windows.appendAtomically` MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Atomic append on windows is only supported on local disk files, and it may cause errors in other situations, e.g. network file system. If that is the case, this config option should be used to turn atomic append off. Co-Authored-By: Johannes Schindelin Signed-off-by: 孙卓识 Signed-off-by: Johannes Schindelin --- Documentation/config.txt | 2 ++ Documentation/config/windows.txt | 4 ++++ compat/mingw.c | 32 ++++++++++++++++++++++++++++++-- 3 files changed, 36 insertions(+), 2 deletions(-) create mode 100644 Documentation/config/windows.txt diff --git a/Documentation/config.txt b/Documentation/config.txt index 5b5b9765699933..d4aac2d58e88d2 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -539,4 +539,6 @@ include::config/versionsort.txt[] include::config/web.txt[] +include::config/windows.txt[] + include::config/worktree.txt[] diff --git a/Documentation/config/windows.txt b/Documentation/config/windows.txt new file mode 100644 index 00000000000000..fdaaf1c65504f3 --- /dev/null +++ b/Documentation/config/windows.txt @@ -0,0 +1,4 @@ +windows.appendAtomically:: + By default, append atomic API is used on windows. But it works only with + local disk files, if you're working on a network file system, you should + set it false to turn it off. diff --git a/compat/mingw.c b/compat/mingw.c index 901375d58415a3..a9a36e96f22fbf 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -535,6 +535,7 @@ static int is_local_named_pipe_path(const char *filename) int mingw_open (const char *filename, int oflags, ...) { + static int append_atomically = -1; typedef int (*open_fn_t)(wchar_t const *wfilename, int oflags, ...); va_list args; unsigned mode; @@ -551,7 +552,16 @@ int mingw_open (const char *filename, int oflags, ...) return -1; } - if ((oflags & O_APPEND) && !is_local_named_pipe_path(filename)) + /* + * Only set append_atomically to default value(1) when repo is initialized + * and fail to get config value + */ + if (append_atomically < 0 && the_repository && the_repository->commondir && + git_config_get_bool("windows.appendatomically", &append_atomically)) + append_atomically = 1; + + if (append_atomically && (oflags & O_APPEND) && + !is_local_named_pipe_path(filename)) open_fn = mingw_open_append; else open_fn = _wopen; @@ -700,8 +710,26 @@ ssize_t mingw_write(int fd, const void *buf, size_t len) HANDLE h = (HANDLE) _get_osfhandle(fd); if (GetFileType(h) == FILE_TYPE_PIPE) errno = EPIPE; - else + else { + wchar_t path[MAX_LONG_PATH]; + DWORD ret = GetFinalPathNameByHandleW(h, path, + ARRAY_SIZE(path), 0); + UINT drive_type = ret > 0 && ret < ARRAY_SIZE(path) ? + GetDriveTypeW(path) : DRIVE_UNKNOWN; + + /* + * The default atomic append causes such an error on + * network file systems, in such a case, it should be + * turned off via config. + * + * `drive_type` of UNC path: DRIVE_NO_ROOT_DIR + */ + if (DRIVE_NO_ROOT_DIR == drive_type || DRIVE_REMOTE == drive_type) + warning("invalid write operation detected; you may try:\n" + "\n\tgit config windows.appendAtomically false"); + errno = EINVAL; + } } return result;