fetch real disk serial for ata smart shim (#12)

Makefile

@@ -20,7 +20,7 @@ SRCS-y  += compat/string_compat.c \
 		   shim/boot_dev/boot_shim_base.c shim/boot_dev/usb_boot_shim.c shim/boot_dev/fake_sata_boot_shim.c \
 		   shim/boot_dev/native_sata_boot_shim.c shim/boot_device_shim.c \
 		   \
-		   shim/storage/smart_shim.c shim/storage/sata_port_shim.c \
+		   shim/storage/smart_shim.c shim/storage/sata_port_shim.c shim/storage/scsi_disk_serial.c \
 		   shim/bios/bios_hwcap_shim.c shim/bios/bios_hwmon_shim.c shim/bios/rtc_proxy.c \
 		   shim/bios/bios_shims_collection.c shim/bios/bios_psu_status_shim.c shim/bios_shim.c \
 		   shim/block_fw_update_shim.c shim/disable_exectutables.c shim/pci_shim.c shim/pmu_shim.c shim/uart_fixer.c \

shim/storage/scsi_disk_serial.c

@@ -0,0 +1,71 @@
+#include<scsi/scsi_cmnd.h>
+#include<scsi/scsi_device.h>
+#include<scsi/scsi_host.h>
+
+#include "../../common.h"
+
+int rp_scsi_device_disk_name_match(struct device *dev, const void *data)
+{
+    struct Scsi_Host *shost;
+    struct scsi_device *sdev;
+    int found = 0;
+    char * blk_name = *(char **)data;
+
+    shost = class_to_shost(dev);
+    shost_for_each_device(sdev, shost){
+        if (strcmp(blk_name, sdev->syno_disk_name) == 0) {
+            pr_loc_dbg("scsi host no: %d, device id: %d, name: %s, serial: %s",
+                shost->host_no, sdev->id, sdev->syno_disk_name, sdev->syno_disk_serial);
+            found = 1;
+        }
+    }
+
+    return found == 1;
+}
+
+// refer from scsi_host_lookup
+struct Scsi_Host * rp_search_scsi_host_by_blk_name(struct class * shost_class, char * blk_name)
+{
+    struct device *cdev;
+    struct Scsi_Host *shost = NULL;
+
+    cdev = class_find_device(shost_class, NULL, &blk_name, rp_scsi_device_disk_name_match);
+    if (cdev) {
+        shost = scsi_host_get(class_to_shost(cdev));
+        put_device(cdev);
+    }
+    return shost;
+}
+
+char * rp_fetch_block_serial(char * blk_name) {
+    struct Scsi_Host * shost;
+    struct scsi_device * sdev;
+    struct class * shost_class;
+
+    char * serial = NULL;
+
+    // find the first scsi host to get shost class
+    shost = scsi_host_lookup(0);
+    if (shost == NULL) {
+        printk(KERN_ALERT "shost 0 not found\n");
+        return serial;
+    }
+
+    shost_class = shost->shost_dev.class;
+    scsi_host_put(shost);
+
+    shost = rp_search_scsi_host_by_blk_name(shost_class, blk_name);
+    if (shost == NULL) {
+        printk(KERN_ALERT "shost not found by block name %s\n", blk_name);
+        return serial;
+    }
+
+    shost_for_each_device(sdev, shost){
+        if (strcmp(blk_name, sdev->syno_disk_name) == 0) {
+            serial = sdev->syno_disk_serial;
+        }
+    }
+
+    scsi_host_put(shost);
+    return serial;
+}

shim/storage/scsi_disk_serial.h

@@ -0,0 +1,6 @@
+#ifndef REDPILL_SCSI_DISK_SERIAL_H
+#define REDPILL_SCSI_DISK_SERIAL_H
+
+char * rp_fetch_block_serial(char * blk_name);
+
+#endif // REDPILL_SCSI_DISK_SERIAL_H

shim/storage/smart_shim.c

@@ -86,6 +86,7 @@
 #include "../../internal/scsi/hdparam.h" //a ton of ATA constants
 #include "../../internal/scsi/scsi_toolbox.h" //checking for "sd" driver load state
 #include "../../internal/override/override_symbol.h" //installing sd_ioctl_canary()
+#include "scsi_disk_serial.h" // rp_fetch_block_serial()
 #include <linux/fs.h> //struct block_device
 #include <linux/genhd.h> //struct gendisk
 #include <linux/blkdev.h> //struct block_device_operations
@@ -694,7 +695,19 @@ static int handle_hdio_drive_cmd_ioctl(struct block_device *bdev, fmode_t mode,
         // we need to modify it to indicate SMART support
         case ATA_CMD_ID_ATA:
             pr_loc_dbg_ioctl(cmd, "ATA_CMD_ID_ATA", bdev);
-            return handle_ata_cmd_identify(ioctl_out, req_header, buff_ptr, bdev->bd_disk->disk_name);
+
+            // TODO for some disks from HBA, we can get smart info from SG_IO,
+            // but for SA6400, DSM only fetch ATA smart info,
+            // we need convert SG_IO smart info into ATA format instead of fake it.
+
+            // use the real serial if it's not empty, other wise use the disk name
+            char * disk_serial;
+            disk_serial = rp_fetch_block_serial(bdev->bd_disk->disk_name);
+            if (strlen(disk_serial) < 3) {
+                disk_serial = bdev->bd_disk->disk_name;
+            }
+
+            return handle_ata_cmd_identify(ioctl_out, req_header, buff_ptr, disk_serial);
 
         //this command asks directly for the SMART data of the drive and will fail on drives with no real SMART support
         case ATA_CMD_SMART: //if the drive supports SMART it will just return the data as-is, no need to proxy