/*
* Create an fsentry-based directory listing (similar to opendir / readdir).
* Dir should not contain trailing '/'. Use an empty string for the current
* directory (not "."!).
*/
static struct fsentry *fsentry_create_list(const struct fsentry *dir)
{
wchar_t pattern[MAX_LONG_PATH + 2]; /* + 2 for "\*" */
WIN32_FIND_DATAW fdata;
HANDLE h;
int wlen;
struct fsentry *list, **phead;
DWORD err;
/* convert name to UTF-16 and check length */
if ((wlen = xutftowcs_path_ex(pattern, dir->name, MAX_LONG_PATH,
dir->len, MAX_PATH - 2, core_long_paths)) < 0)
return NULL;
/*
* append optional '\' and wildcard '*'. Note: we need to use '\' as
* Windows doesn't translate '/' to '\' for "\\?\"-prefixed paths.
*/
if (wlen)
pattern[wlen++] = '\\';
pattern[wlen++] = '*';
pattern[wlen] = 0;
/* open find handle */
h = FindFirstFileW(pattern, &fdata);
if (h == INVALID_HANDLE_VALUE) {
err = GetLastError();
errno = (err == ERROR_DIRECTORY) ? ENOTDIR : err_win_to_posix(err);
return NULL;
}
/* allocate object to hold directory listing */
list = fsentry_alloc(NULL, dir->name, dir->len);
/* walk directory and build linked list of fsentry structures */
phead = &list->next;
do {
*phead = fseentry_create_entry(list, &fdata);
phead = &(*phead)->next;
} while (FindNextFileW(h, &fdata));
/* remember result of last FindNextFile, then close find handle */
err = GetLastError();
FindClose(h);
/* return the list if we've got all the files */
if (err == ERROR_NO_MORE_FILES)
return list;
/* otherwise free the list and return error */
fsentry_release(list);
errno = err_win_to_posix(err);
return NULL;
}
/*
* Allocate and initialize an fsentry from a FILE_FULL_DIR_INFORMATION structure.
*/
static struct fsentry *fseentry_create_entry(struct fscache *cache, struct fsentry *list,
PFILE_FULL_DIR_INFORMATION fdata)
{
char buf[MAX_PATH * 3];
int len;
struct fsentry *fse;
len = xwcstoutfn(buf, ARRAY_SIZE(buf), fdata->FileName, fdata->FileNameLength / sizeof(wchar_t));
fse = fsentry_alloc(cache, list, buf, len);
/*
* 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 (fdata->FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT &&
fdata->EaSize == IO_REPARSE_TAG_SYMLINK &&
sizeof(buf) > (list ? list->len + 1 : 0) + fse->len + 1 &&
is_inside_windows_container()) {
size_t off = 0;
if (list) {
memcpy(buf, list->name, list->len);
buf[list->len] = '/';
off = list->len + 1;
}
memcpy(buf + off, fse->name, fse->len);
buf[off + fse->len] = '\0';
}
fse->st_mode = file_attr_to_st_mode(fdata->FileAttributes,
fdata->EaSize, buf);
fse->st_size = S_ISLNK(fse->st_mode) ? MAX_LONG_PATH :
fdata->EndOfFile.LowPart | (((off_t)fdata->EndOfFile.HighPart) << 32);
filetime_to_timespec((FILETIME *)&(fdata->LastAccessTime), &(fse->st_atim));
filetime_to_timespec((FILETIME *)&(fdata->LastWriteTime), &(fse->st_mtim));
filetime_to_timespec((FILETIME *)&(fdata->CreationTime), &(fse->st_ctim));
return fse;
}
/*
* Allocate and initialize an fsentry from a WIN32_FIND_DATA structure.
*/
static struct fsentry *fseentry_create_entry(struct fsentry *list,
const WIN32_FIND_DATAW *fdata)
{
char buf[MAX_PATH * 3];
int len;
struct fsentry *fse;
len = xwcstoutf(buf, fdata->cFileName, ARRAY_SIZE(buf));
fse = fsentry_alloc(list, buf, len);
fse->st_mode = file_attr_to_st_mode(fdata->dwFileAttributes,
fdata->dwReserved0);
fse->st_size = S_ISLNK(fse->st_mode) ? MAX_LONG_PATH :
fdata->nFileSizeLow | (((off_t) fdata->nFileSizeHigh) << 32);
filetime_to_timespec(&(fdata->ftLastAccessTime), &(fse->st_atim));
filetime_to_timespec(&(fdata->ftLastWriteTime), &(fse->st_mtim));
filetime_to_timespec(&(fdata->ftCreationTime), &(fse->st_ctim));
return fse;
}
/*
* Looks up or creates a cache entry for the specified key.
*/
static struct fsentry *fscache_get(struct fscache *cache, struct fsentry *key)
{
struct fsentry *fse;
int dir_not_found;
cache->fscache_requests++;
/* check if entry is in cache */
fse = hashmap_get(&cache->map, key, NULL);
if (fse) {
if (fse->st_mode)
fsentry_addref(fse);
else
fse = NULL; /* non-existing directory */
return fse;
}
/* if looking for a file, check if directory listing is in cache */
if (!fse && key->list) {
fse = hashmap_get(&cache->map, key->list, NULL);
if (fse) {
/*
* dir entry without file entry, or dir does not
* exist -> file doesn't exist
*/
errno = ENOENT;
return NULL;
}
}
/* create the directory listing */
fse = fsentry_create_list(cache, key->list ? key->list : key, &dir_not_found);
/* leave on error (errno set by fsentry_create_list) */
if (!fse) {
if (dir_not_found && key->list) {
/*
* Record that the directory does not exist (or is
* empty, which for all practical matters is the same
* thing as far as fscache is concerned).
*/
fse = fsentry_alloc(cache, key->list->list,
key->list->name, key->list->len);
fse->st_mode = 0;
hashmap_add(&cache->map, fse);
}
return NULL;
}
/* add directory listing to the cache */
cache->fscache_misses++;
fscache_add(cache, fse);
/* lookup file entry if requested (fse already points to directory) */
if (key->list)
fse = hashmap_get(&cache->map, key, NULL);
if (fse && !fse->st_mode)
fse = NULL; /* non-existing directory */
/* return entry or ENOENT */
if (fse)
fsentry_addref(fse);
else
errno = ENOENT;
return fse;
}
/*
* Create an fsentry-based directory listing (similar to opendir / readdir).
* Dir should not contain trailing '/'. Use an empty string for the current
* directory (not "."!).
*/
static struct fsentry *fsentry_create_list(struct fscache *cache, const struct fsentry *dir,
int *dir_not_found)
{
wchar_t pattern[MAX_LONG_PATH];
NTSTATUS status;
IO_STATUS_BLOCK iosb;
PFILE_FULL_DIR_INFORMATION di;
HANDLE h;
int wlen;
struct fsentry *list, **phead;
DWORD err;
*dir_not_found = 0;
/* convert name to UTF-16 and check length */
if ((wlen = xutftowcs_path_ex(pattern, dir->name, MAX_LONG_PATH,
dir->len, MAX_PATH - 2, core_long_paths)) < 0)
return NULL;
/* handle CWD */
if (!wlen) {
wlen = GetCurrentDirectoryW(ARRAY_SIZE(pattern), pattern);
if (!wlen || wlen >= ARRAY_SIZE(pattern)) {
errno = wlen ? ENAMETOOLONG : err_win_to_posix(GetLastError());
return NULL;
}
}
h = CreateFileW(pattern, FILE_LIST_DIRECTORY,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
if (h == INVALID_HANDLE_VALUE) {
err = GetLastError();
*dir_not_found = 1; /* or empty directory */
errno = (err == ERROR_DIRECTORY) ? ENOTDIR : err_win_to_posix(err);
trace_printf_key(&trace_fscache, "fscache: error(%d) '%.*s'\n",
errno, dir->len, dir->name);
return NULL;
}
/* allocate object to hold directory listing */
list = fsentry_alloc(cache, NULL, dir->name, dir->len);
list->st_mode = S_IFDIR;
/* walk directory and build linked list of fsentry structures */
phead = &list->next;
status = NtQueryDirectoryFile(h, NULL, 0, 0, &iosb, cache->buffer,
sizeof(cache->buffer), FileFullDirectoryInformation, FALSE, NULL, FALSE);
if (!NT_SUCCESS(status)) {
/*
* NtQueryDirectoryFile returns STATUS_INVALID_PARAMETER when
* asked to enumerate an invalid directory (ie it is a file
* instead of a directory). Verify that is the actual cause
* of the error.
*/
if (status == STATUS_INVALID_PARAMETER) {
DWORD attributes = GetFileAttributesW(pattern);
if (!(attributes & FILE_ATTRIBUTE_DIRECTORY))
status = ERROR_DIRECTORY;
}
goto Error;
}
di = (PFILE_FULL_DIR_INFORMATION)(cache->buffer);
for (;;) {
*phead = fseentry_create_entry(cache, list, di);
phead = &(*phead)->next;
/* If there is no offset in the entry, the buffer has been exhausted. */
if (di->NextEntryOffset == 0) {
status = NtQueryDirectoryFile(h, NULL, 0, 0, &iosb, cache->buffer,
sizeof(cache->buffer), FileFullDirectoryInformation, FALSE, NULL, FALSE);
if (!NT_SUCCESS(status)) {
if (status == STATUS_NO_MORE_FILES)
break;
goto Error;
}
di = (PFILE_FULL_DIR_INFORMATION)(cache->buffer);
continue;
}
/* Advance to the next entry. */
di = (PFILE_FULL_DIR_INFORMATION)(((PUCHAR)di) + di->NextEntryOffset);
}
CloseHandle(h);
return list;
Error:
errno = (status == ERROR_DIRECTORY) ? ENOTDIR : err_win_to_posix(status);
trace_printf_key(&trace_fscache, "fscache: error(%d) unable to query directory contents '%.*s'\n",
errno, dir->len, dir->name);
CloseHandle(h);
fsentry_release(list);
return NULL;
}
/*
* Looks up or creates a cache entry for the specified key.
*/
static struct fsentry *fscache_get(struct fsentry *key)
{
struct fsentry *fse, *future, *waiter;
int dir_not_found;
EnterCriticalSection(&mutex);
/* check if entry is in cache */
fse = fscache_get_wait(key);
if (fse) {
if (fse->st_mode)
fsentry_addref(fse);
else
fse = NULL; /* non-existing directory */
LeaveCriticalSection(&mutex);
return fse;
}
/* if looking for a file, check if directory listing is in cache */
if (!fse && key->list) {
fse = fscache_get_wait(key->list);
if (fse) {
LeaveCriticalSection(&mutex);
/*
* dir entry without file entry, or dir does not
* exist -> file doesn't exist
*/
errno = ENOENT;
return NULL;
}
}
/* add future entry to indicate that we're loading it */
future = key->list ? key->list : key;
future->next = NULL;
future->refcnt = 0;
hashmap_add(&map, future);
/* create the directory listing (outside mutex!) */
LeaveCriticalSection(&mutex);
fse = fsentry_create_list(future, &dir_not_found);
EnterCriticalSection(&mutex);
/* remove future entry and signal waiting threads */
hashmap_remove(&map, future, NULL);
waiter = future->next;
while (waiter) {
HANDLE h = waiter->hwait;
waiter = waiter->next;
SetEvent(h);
}
/* leave on error (errno set by fsentry_create_list) */
if (!fse) {
if (dir_not_found && key->list) {
/*
* Record that the directory does not exist (or is
* empty, which for all practical matters is the same
* thing as far as fscache is concerned).
*/
fse = fsentry_alloc(key->list->list,
key->list->name, key->list->len);
fse->st_mode = 0;
hashmap_add(&map, fse);
}
LeaveCriticalSection(&mutex);
return NULL;
}
/* add directory listing to the cache */
fscache_add(fse);
/* lookup file entry if requested (fse already points to directory) */
if (key->list)
fse = hashmap_get(&map, key, NULL);
if (fse && !fse->st_mode)
fse = NULL; /* non-existing directory */
/* return entry or ENOENT */
if (fse)
fsentry_addref(fse);
else
errno = ENOENT;
LeaveCriticalSection(&mutex);
return fse;
}
