Author eryksun
Recipients eryksun, paul.moore, steve.dower, tim.golden, zach.ware
Date 2019-09-04.20:26:31
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <1567628792.17.0.732081344869.issue38030@roundup.psfhosted.org>
In-reply-to
Content
In issue 37834, I posted a suggest implementation of win32_xstat_impl that included the following snippet of code:

        if (!GetFileInformationByHandle(hFile, &fileInfo)) {
            error = GetLastError();
            if (error != ERROR_INVALID_PARAMETER &&
                error != ERROR_INVALID_FUNCTION &&
                error != ERROR_NOT_SUPPORTED) {
                retval = -1;
                goto cleanup;
            }
            /* Volumes and physical disks are block devices, e.g.
               \\.\C: and \\.\PhysicalDrive0. */
            memset(result, 0, sizeof(*result));
            result->st_mode = 0x6000; /* S_IFBLK */
            goto cleanup;
        }

This is meant to handle the above errors. We know we have FILE_TYPE_DISK. If GetFileInformationByHandle fails with one of the above error codes, then we must have a disk or volume device without a mounted file-system device. This should be reported as a block device.

However it was changed in the final version as follows:

        if (!GetFileInformationByHandle(hFile, &fileInfo)) {
            switch (GetLastError()) {
            case ERROR_INVALID_PARAMETER:
            case ERROR_INVALID_FUNCTION:
            case ERROR_NOT_SUPPORTED:
                retval = -1;
                goto cleanup;
            }
            /* Volumes and physical disks are block devices, e.g.
               \\.\C: and \\.\PhysicalDrive0. */
            memset(result, 0, sizeof(*result));
            result->st_mode = 0x6000; /* S_IFBLK */
            goto cleanup;
        }

Now it's failing on the errors that should be handled, and succeeding on all other errors that should fail. If we want to use a switch statement here, I suggest the following:

        if (!GetFileInformationByHandle(hFile, &fileInfo)) {
            switch (GetLastError()) {
            case ERROR_INVALID_PARAMETER:
            case ERROR_INVALID_FUNCTION:
            case ERROR_NOT_SUPPORTED:
                /* Volumes and physical disks are block devices, e.g.
                   \\.\C: and \\.\PhysicalDrive0. */
                memset(result, 0, sizeof(*result));
                result->st_mode = 0x6000; /* S_IFBLK */
                goto cleanup;
            }
            retval = -1;
            goto cleanup;
        }
History
Date User Action Args
2019-09-04 20:26:32eryksunsetrecipients: + eryksun, paul.moore, tim.golden, zach.ware, steve.dower
2019-09-04 20:26:32eryksunsetmessageid: <1567628792.17.0.732081344869.issue38030@roundup.psfhosted.org>
2019-09-04 20:26:32eryksunlinkissue38030 messages
2019-09-04 20:26:31eryksuncreate