From 01c1251f72982482a73043f1f8c4019b43851d28 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Mon, 23 Apr 2018 23:20:00 +0200 Subject: [PATCH] mingw: Windows Docker volumes are *not* symbolic links ... even if they may look like them. As looking up the target of the "symbolic link" (just to see whether it starts with `/ContainerMappedDirectories/`) is pretty expensive, we do it when we can be *really* sure that there is a possibility that this might be the case. Signed-off-by: Johannes Schindelin Signed-off-by: JiSeop Moon --- compat/mingw.c | 25 +++++++++++++++++++------ compat/win32.h | 2 +- compat/win32/fscache.c | 24 +++++++++++++++++++++++- 3 files changed, 43 insertions(+), 8 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index b9a6f854927112..74203f0ac73296 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -1122,7 +1122,7 @@ int mingw_lstat(const char *file_name, struct stat *buf) buf->st_uid = 0; buf->st_nlink = 1; buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, - reparse_tag); + reparse_tag, file_name); buf->st_size = S_ISLNK(buf->st_mode) ? link_len : fdata.nFileSizeLow | (((off_t) fdata.nFileSizeHigh) << 32); buf->st_dev = buf->st_rdev = 0; /* not used by Git */ @@ -1173,7 +1173,7 @@ static int get_file_info_by_handle(HANDLE hnd, struct stat *buf) buf->st_gid = 0; buf->st_uid = 0; buf->st_nlink = 1; - buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, 0); + buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes, 0, NULL); buf->st_size = fdata.nFileSizeLow | (((off_t)fdata.nFileSizeHigh)<<32); buf->st_dev = buf->st_rdev = 0; /* not used by Git */ @@ -4186,12 +4186,25 @@ int is_inside_windows_container(void) return inside_container; } -int file_attr_to_st_mode (DWORD attr, DWORD tag) +int file_attr_to_st_mode (DWORD attr, DWORD tag, const char *path) { int fMode = S_IREAD; - if ((attr & FILE_ATTRIBUTE_REPARSE_POINT) && tag == IO_REPARSE_TAG_SYMLINK) - fMode |= S_IFLNK; - else if (attr & FILE_ATTRIBUTE_DIRECTORY) + if ((attr & FILE_ATTRIBUTE_REPARSE_POINT) && + tag == IO_REPARSE_TAG_SYMLINK) { + int flag = S_IFLNK; + char buf[MAX_LONG_PATH]; + + /* + * Windows containers' mapped volumes are marked as reparse + * points and look like symbolic links, but they are not. + */ + if (path && is_inside_windows_container() && + readlink(path, buf, sizeof(buf)) > 27 && + starts_with(buf, "/ContainerMappedDirectories/")) + flag = S_IFDIR; + + fMode |= flag; + } else if (attr & FILE_ATTRIBUTE_DIRECTORY) fMode |= S_IFDIR; else fMode |= S_IFREG; diff --git a/compat/win32.h b/compat/win32.h index 52169ae19f4371..299f01bdf0f5a4 100644 --- a/compat/win32.h +++ b/compat/win32.h @@ -6,7 +6,7 @@ #include #endif -extern int file_attr_to_st_mode (DWORD attr, DWORD tag); +extern int file_attr_to_st_mode (DWORD attr, DWORD tag, const char *path); static inline int get_file_attr(const char *fname, WIN32_FILE_ATTRIBUTE_DATA *fdata) { diff --git a/compat/win32/fscache.c b/compat/win32/fscache.c index f1c124160dfd5e..724198e5e1228d 100644 --- a/compat/win32/fscache.c +++ b/compat/win32/fscache.c @@ -202,8 +202,30 @@ static struct fsentry *fseentry_create_entry(struct fscache *cache, fdata->FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT ? fdata->EaSize : 0; + /* + * On certain Windows versions, host directories mapped into + * Windows Containers ("Volumes", see https://docs.docker.com/storage/volumes/) + * look like symbolic links, but their targets are paths that + * are valid only in kernel mode. + * + * Let's work around this by detecting that situation and + * telling Git that these are *not* symbolic links. + */ + if (fse->reparse_tag == IO_REPARSE_TAG_SYMLINK && + sizeof(buf) > (size_t)(list ? list->len + 1 : 0) + fse->len + 1 && + is_inside_windows_container()) { + size_t off = 0; + if (list) { + memcpy(buf, list->dirent.d_name, list->len); + buf[list->len] = '/'; + off = list->len + 1; + } + memcpy(buf + off, fse->dirent.d_name, fse->len); + buf[off + fse->len] = '\0'; + } + fse->st_mode = file_attr_to_st_mode(fdata->FileAttributes, - fdata->EaSize); + fdata->EaSize, buf); fse->dirent.d_type = S_ISREG(fse->st_mode) ? DT_REG : S_ISDIR(fse->st_mode) ? DT_DIR : DT_LNK; fse->u.s.st_size = S_ISLNK(fse->st_mode) ? MAX_LONG_PATH :