drive_encryption: Fix ata passthrough12 verify

Based on documentation SCSI Primary Commands - 4 (SPC-4) only first 7 bits
of first byte in sense data are used to store response code. The current
verification uses all 8 bits for comparison of response code.

Incorrect verification may make impossible to use SATA disks with IMSM,
because IMSM requires verification of the encryption state before use.

There was issue in kernel libata [1]. This issue hides bug in mdadm because
last bit was not set.

Example output with affected mdadm:

          Port3 : /dev/sde (BTPR212503EK120LGN)
mdadm: Failed ata passthrough12 ioctl. Device: /dev/sde.
mdadm: Failed to get drive encryption information

The fix is use the first 7 bits of Byte 0, to compare with the expected
values.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/libata/linux.git/commit/?id=38dab832c3f4

Fixes: df38df3052c3 ("Add reading SATA encryption information")
Signed-off-by: Blazej Kucman <blazej.kucman@intel.com>

diff --git a/drive_encryption.c b/drive_encryption.c
index a4ad799f698cb682071372ba4a21de5dfb60b589..63bdab1a5743ab9af7b6d12e832bef85252c91ac 100644 (file)
--- a/drive_encryption.c
+++ b/drive_encryption.c
@@ -65,6 +65,7 @@
 #define SENSE_DATA_CURRENT_FIXED (0x70)
 #define SENSE_DATA_CURRENT_DESC (0x72)
 #define SENSE_CURRENT_RES_DESC_POS (8)
+#define SENSE_RESPONSE_CODE_MASK (0x7f)
 #define SG_DRIVER_SENSE        (0x08)
 
 typedef enum drive_feature_support_status {
@@ -473,6 +474,7 @@ ata_pass_through12_ioctl(int disk_fd, __u8 ata_command,  __u8 sec_protocol, __u1
 {
        __u8 cdb[ATA_INQUIRY_LENGTH] = {0};
        __u8 sense[SG_SENSE_SIZE] = {0};
+       __u8 sense_response_code;
        __u8 *sense_desc = NULL;
        sg_io_hdr_t sg = {0};
 
@@ -517,15 +519,17 @@ ata_pass_through12_ioctl(int disk_fd, __u8 ata_command,  __u8 sec_protocol, __u1
                return MDADM_STATUS_ERROR;
        }
 
+       sense_response_code = sense[0] & SENSE_RESPONSE_CODE_MASK;
        /* verify expected sense response code */
-       if (!(sense[0] == SENSE_DATA_CURRENT_DESC || sense[0] == SENSE_DATA_CURRENT_FIXED)) {
+       if (!(sense_response_code == SENSE_DATA_CURRENT_DESC ||
+             sense_response_code == SENSE_DATA_CURRENT_FIXED)) {
                pr_vrb("Failed ata passthrough12 ioctl. Device: /dev/%s.\n", fd2kname(disk_fd));
                return MDADM_STATUS_ERROR;
        }
 
        sense_desc = sense + SENSE_CURRENT_RES_DESC_POS;
        /* verify sense data current response with descriptor format */
-       if (sense[0] == SENSE_DATA_CURRENT_DESC &&
+       if (sense_response_code == SENSE_DATA_CURRENT_DESC &&
            !(sense_desc[0] == ATA_STATUS_RETURN_DESCRIPTOR &&
            sense_desc[1] == ATA_INQUIRY_LENGTH)) {
                pr_vrb("Failed ata passthrough12 ioctl. Device: /dev/%s. Sense data ASC: %d, ASCQ: %d.\n",
@@ -534,7 +538,7 @@ ata_pass_through12_ioctl(int disk_fd, __u8 ata_command,  __u8 sec_protocol, __u1
        }
 
        /* verify sense data current response with fixed format */
-       if (sense[0] == SENSE_DATA_CURRENT_FIXED &&
+       if (sense_response_code == SENSE_DATA_CURRENT_FIXED &&
            !(sense[12] == ATA_PT_INFORMATION_AVAILABLE_ASC &&
            sense[13] == ATA_PT_INFORMATION_AVAILABLE_ASCQ)) {
                pr_vrb("Failed ata passthrough12 ioctl. Device: /dev/%s. Sense data ASC: %d, ASCQ: %d.\n",