Nixyri/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2024-11-15 00:26:57 +00:00
Code Issues Packages Projects Releases Wiki Activity

fs: handle OBJECT_NAME_COLLISION in makeOpenPath

Browse Source 
This fixes a race condition when two threads/processes try to
`makeOpenPath` the same path simultaneously.
This commit is contained in:
Jacob Young 2024-05-06 19:46:29 -04:00
parent db890dbae7
commit 67455c5e70
1 changed files with 37 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
lib/std/fs/Dir.zig
View File

@ -1104,27 +1104,29 @@ pub fn createFileW(self: Dir, sub_path_w: []const u16, flags: File.CreateFlags)
return file;
}
pub const MakeError = posix.MakeDirError;
/// Creates a single directory with a relative or absolute path.
/// To create multiple directories to make an entire path, see `makePath`.
/// To operate on only absolute paths, see `makeDirAbsolute`.
/// On Windows, `sub_path` should be encoded as [WTF-8](https://simonsapin.github.io/wtf-8/).
/// On WASI, `sub_path` should be encoded as valid UTF-8.
/// On other platforms, `sub_path` is an opaque sequence of bytes with no particular encoding.
pub fn makeDir(self: Dir, sub_path: []const u8) !void {
pub fn makeDir(self: Dir, sub_path: []const u8) MakeError!void {
try posix.mkdirat(self.fd, sub_path, default_mode);
}
/// Same as `makeDir`, but `sub_path` is null-terminated.
/// To create multiple directories to make an entire path, see `makePath`.
/// To operate on only absolute paths, see `makeDirAbsoluteZ`.
pub fn makeDirZ(self: Dir, sub_path: [*:0]const u8) !void {
pub fn makeDirZ(self: Dir, sub_path: [*:0]const u8) MakeError!void {
try posix.mkdiratZ(self.fd, sub_path, default_mode);
}
/// Creates a single directory with a relative or absolute null-terminated WTF-16 LE-encoded path.
/// To create multiple directories to make an entire path, see `makePath`.
/// To operate on only absolute paths, see `makeDirAbsoluteW`.
pub fn makeDirW(self: Dir, sub_path: [*:0]const u16) !void {
pub fn makeDirW(self: Dir, sub_path: [*:0]const u16) MakeError!void {
try posix.mkdiratW(self.fd, sub_path, default_mode);
}
@ -1144,7 +1146,7 @@ pub fn makeDirW(self: Dir, sub_path: [*:0]const u16) !void {
/// - On other platforms, `..` are not resolved before the path is passed to `mkdirat`,
/// meaning a `sub_path` like "first/../second" will create both a `./first`
/// and a `./second` directory.
pub fn makePath(self: Dir, sub_path: []const u8) !void {
pub fn makePath(self: Dir, sub_path: []const u8) (MakeError || StatFileError)!void {
var it = try fs.path.componentIterator(sub_path);
var component = it.last() orelse return;
while (true) {
@ -1178,7 +1180,7 @@ pub fn makePath(self: Dir, sub_path: []const u8) !void {
/// This function is not atomic, and if it returns an error, the file system may
/// have been modified regardless.
/// `sub_path` should be encoded as [WTF-8](https://simonsapin.github.io/wtf-8/).
fn makeOpenPathAccessMaskW(self: Dir, sub_path: []const u8, access_mask: u32, no_follow: bool) OpenError!Dir {
fn makeOpenPathAccessMaskW(self: Dir, sub_path: []const u8, access_mask: u32, no_follow: bool) (MakeError || OpenError || StatFileError)!Dir {
const w = windows;
var it = try fs.path.componentIterator(sub_path);
// If there are no components in the path, then create a dummy component with the full path.
@ -1198,12 +1200,27 @@ fn makeOpenPathAccessMaskW(self: Dir, sub_path: []const u8, access_mask: u32, no
component = it.previous() orelse return e;
continue;
},
error.PathAlreadyExists => result: {
assert(!is_last);
// stat the file and return an error if it's not a directory
// this is important because otherwise a dangling symlink
// could cause an infinite loop
check_dir: {
// workaround for windows, see https://github.com/ziglang/zig/issues/16738
const fstat = self.statFile(component.path) catch |stat_err| switch (stat_err) {
error.IsDir => break :check_dir,
else => |e| return e,
};
if (fstat.kind != .directory) return error.NotDir;
}
break :result null;
},
else => |e| return e,
};
component = it.next() orelse return result;
// Don't leak the intermediate file handles
result.close();
errdefer if (result) |*dir| dir.close();
component = it.next() orelse return result.?;
}
}
@ -1213,7 +1230,7 @@ fn makeOpenPathAccessMaskW(self: Dir, sub_path: []const u8, access_mask: u32, no
/// On Windows, `sub_path` should be encoded as [WTF-8](https://simonsapin.github.io/wtf-8/).
/// On WASI, `sub_path` should be encoded as valid UTF-8.
/// On other platforms, `sub_path` is an opaque sequence of bytes with no particular encoding.
pub fn makeOpenPath(self: Dir, sub_path: []const u8, open_dir_options: OpenDirOptions) !Dir {
pub fn makeOpenPath(self: Dir, sub_path: []const u8, open_dir_options: OpenDirOptions) (MakeError || OpenError || StatFileError)!Dir {
return switch (native_os) {
.windows => {
const w = windows;
@ -1516,10 +1533,17 @@ pub fn openDirW(self: Dir, sub_path_w: [*:0]const u16, args: OpenDirOptions) Ope
const base_flags = w.STANDARD_RIGHTS_READ | w.FILE_READ_ATTRIBUTES | w.FILE_READ_EA |
w.SYNCHRONIZE | w.FILE_TRAVERSE;
const flags: u32 = if (args.iterate) base_flags | w.FILE_LIST_DIRECTORY else base_flags;
const dir = try self.makeOpenDirAccessMaskW(sub_path_w, flags, .{
const dir = self.makeOpenDirAccessMaskW(sub_path_w, flags, .{
.no_follow = args.no_follow,
.create_disposition = w.FILE_OPEN,
});
}) catch |err| switch (err) {
error.ReadOnlyFileSystem => unreachable,
error.DiskQuota => unreachable,
error.NoSpaceLeft => unreachable,
error.PathAlreadyExists => unreachable,
error.LinkQuotaExceeded => unreachable,
else => |e| return e,
};
return dir;
}
@ -1544,7 +1568,7 @@ const MakeOpenDirAccessMaskWOptions = struct {
create_disposition: u32,
};
fn makeOpenDirAccessMaskW(self: Dir, sub_path_w: [*:0]const u16, access_mask: u32, flags: MakeOpenDirAccessMaskWOptions) OpenError!Dir {
fn makeOpenDirAccessMaskW(self: Dir, sub_path_w: [*:0]const u16, access_mask: u32, flags: MakeOpenDirAccessMaskWOptions) (MakeError || OpenError)!Dir {
const w = windows;
var result = Dir{
@ -1585,6 +1609,7 @@ fn makeOpenDirAccessMaskW(self: Dir, sub_path_w: [*:0]const u16, access_mask: u3
.SUCCESS => return result,
.OBJECT_NAME_INVALID => return error.BadPathName,
.OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
.OBJECT_NAME_COLLISION => return error.PathAlreadyExists,
.OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
.NOT_A_DIRECTORY => return error.NotDir,
// This can happen if the directory has 'List folder contents' permission set to 'Deny'