Starting with go1.22 the standard os.MkdirAll has improved its handling of volume names,
and as part of that it now stops recursing into parent directory if it is a volume name
(see: cd589c8a73).
This is similar to what was our main change and reason for creating a custom version. When
building with go1.22 or newer we can therefore stop using our custom version, with the
advantage that we automatically get current and future relevant improvements from golang.
To support building with go1.21 the existing custom version is still kept, and therefore
also our wrapper function file.MkdirAll - but it now just calls os.MkdirAll with go1.22
or newer on Windows.
See #5401, #6420 and acf1e2df84 for details about the
creation of our custom version of MkdirAll.
On Windows, this change includes the `FILE_FLAG_BACKUP_SEMANTICS` in
all calls to `CreateFile`.
Adding this flag allows is useful when rclone is running within a
security context that has `SeBackupPrivilege` and/or `SeRestorePrivilege`
token privileges enabled.
Without this flag, rclone cannot properly leverage special security
groups such as Backup Operators who possess the these privileges.
See: https://forum.rclone.org/t/rclone-sebackupprivilege-file-flag-backup-semantics/45339
See: https://github.com/rclone/rclone/pull/7877.
In ths security related issue the go1.21.4 stdlib changed the parsing
of volume names on Windows.
https://github.com/golang/go/issues/63713
This had the consequences of breaking the MkdirAll tests which were
looking for specific error messages which changed and using invalid
paths.
In particular under go1.21.3:
filepath.VolumeName(`\\?\C:`) == `\\?\C:`
But under go1.21.4 it is:
filepath.VolumeName(`\\?\C:`) == `\\?`
The path `\\?\C:` isn't actually a valid Windows path. I reported this
as a FYI bug upstream - I'm not expecting it to be fixed.
See: https://github.com/golang/go/issues/64101
The directory created by `T.TempDir` is automatically removed when the
test and all its subtests complete.
Reference: https://pkg.go.dev/testing#T.TempDir
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
This is possible now that we no longer support go1.12 and brings
rclone into line with standard practices in the Go world.
This also removes errors.New and errors.Errorf from lib/errors and
prefers the stdlib errors package over lib/errors.
This replaces built-in os.MkdirAll with a patched version that stops the recursion
when reaching the volume part of the path. The original version would continue recursion,
and for extended length paths end up with \\? as the top-level directory, and the error
message would then be something like:
mkdir \\?: The filename, directory name, or volume label syntax is incorrect.
Before this change, sometimes preallocate failed with EINTR which
rclone ignored.
Retrying the syscall is the correct thing to do and seems to make
preallocate 100% reliable.
Add --network-mode option to activate mounting as network drive without having to set volume prefix.
Add support for automatic drive letter assignment (not specific to network drive mounting).
Allow full network share unc path in --volname, which will also implicitely activate network drive mounting.
Allow full network share unc path as mountpoint, which will also implicitely activate network drive mounting, and the specified path will be used as volume prefix and the remote will be mounted on an automatically assigned drive letter instead.
Before this change we passed both lpOverlapped and lpBytesReturned as NULL.
> If lpOverlapped is NULL, lpBytesReturned cannot be NULL. Even when
> an operation produces no output data, and lpOutBuffer can be NULL,
> the DeviceIoControl function makes use of the variable pointed to by
> lpBytesReturned. After such an operation, the value of the variable
> is without meaning.
After this change we set lpBytesReturned to a valid pointer.
See: https://forum.rclone.org/t/errors-when-downloading-any-file-over-250mb-from-google-drive-windows-sparse-files/16889
Normally os.OpenFile under Windows does not allow renaming or deleting
open file handles. This package provides equivelents for os.OpenFile,
os.Open and os.Create which do allow that.
