[PATCH] Report Luns for scsi devices 2.5.10

Here's a patch for SCSI REPORT LUN scanning, including Douglas Gilbert's
recent changes to support a short INQUIRY followed by a longer INQUIRY.

Please apply, or let me know if you think it needs any modifications.

It's against linux-2.5.4. It does _not_ change the size of the linux lun.

A description of the 8 byte LUN layout can be found on page 35 of:

ftp://ftp.t10.org/t10/drafts/scc2/scc2r04.pdf

The above is a draft, but matches the layout seen on most disk arrays
(including EMC, IBM, LSI, and Hitachi). Later drafts (post SCSI-3) have
this information in the SCSI Architectural Model.

Patch description:

Adds REPORT LUN scanning.

Adds Douglas Gilbert's INQUIRY modification so broken devices that cannot handlean INQUIRY
of more than 36 bytes can be black-listed, plus saving the INQUIRY
result in Scsi_Device.

Adds scan_scsis_target function, replacing code in scan_scsis and parts
of scan_scsis_single. This cleans up the scanning code, and removes a
really ugly for loop. It would be difficult to add REPORT LUN scanning
without this change.

Adds missing scsi_release_commandblocks().

No longer sets max_dev_lun out of bounds for BLIST_FORCELUN devices.

Fixes scanning past LUN 7 for SCSI-3 devices (the patch in 2.4.17
for that fix will not cleanly apply against this code).

-- Patrick Mansfield

drivers/scsi/Config.help

@@ -145,6 +145,13 @@ CONFIG_SCSI_MULTI_LUN
   so most people can say N here and should in fact do so, because it
   is safer.
 
+CONFIG_SCSI_REPORT_LUNS
+  If you want to build with SCSI REPORT LUNS support in the kernel, say Y here.
+  The REPORT LUNS command is useful for devices (such as disk arrays) with
+  large numbers of LUNs where the LUN values are not contiguous (sparse LUN).
+  REPORT LUNS scanning is done only for SCSI-3 devices. Most users can safely
+  answer N here.
+
 CONFIG_SCSI_CONSTANTS
   The error messages regarding your SCSI hardware will be easier to
   understand if you say Y here; it will enlarge your kernel by about

drivers/scsi/Config.in

@@ -21,6 +21,7 @@ dep_tristate '  SCSI generic support' CONFIG_CHR_DEV_SG $CONFIG_SCSI
 comment 'Some SCSI devices (e.g. CD jukebox) support multiple LUNs'
 
 bool '  Probe all LUNs on each SCSI device' CONFIG_SCSI_MULTI_LUN
+bool '  Build with SCSI REPORT LUNS support' CONFIG_SCSI_REPORT_LUNS
   
 bool '  Verbose SCSI error reporting (kernel size +=12K)' CONFIG_SCSI_CONSTANTS
 bool '  SCSI logging facility' CONFIG_SCSI_LOGGING

drivers/scsi/scsi.c

@@ -158,6 +158,8 @@ const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE] =
 	"Enclosure        ",
 };
 
+static char * scsi_null_device_strs = "nullnullnullnull";
+
 /* 
  * Function prototypes.
  */
@@ -1831,6 +1833,8 @@ static int proc_scsi_gen_write(struct file * file, const char * buf,
 				HBA_ptr->host_queue = scd->next;
 			}
 			blk_cleanup_queue(&scd->request_queue);
+			if (scd->inquiry)
+				kfree(scd->inquiry);
 			kfree((char *) scd);
 		} else {
 			goto out;
@@ -2129,6 +2133,8 @@ int scsi_unregister_host(Scsi_Host_Template * tpnt)
 			blk_cleanup_queue(&SDpnt->request_queue);
 			/* Next free up the Scsi_Device structures for this host */
 			shpnt->host_queue = SDpnt->next;
+			if (SDpnt->inquiry)
+				kfree(SDpnt->inquiry);
 			kfree((char *) SDpnt);
 
 		}
@@ -2618,6 +2624,9 @@ Scsi_Device * scsi_get_host_dev(struct Scsi_Host * SHpnt)
         	return NULL;
         	
         memset(SDpnt, 0, sizeof(Scsi_Device));
+	SDpnt->vendor = scsi_null_device_strs;
+	SDpnt->model = scsi_null_device_strs;
+	SDpnt->rev = scsi_null_device_strs;
 
         SDpnt->host = SHpnt;
         SDpnt->id = SHpnt->this_id;
@@ -2664,6 +2673,8 @@ void scsi_free_host_dev(Scsi_Device * SDpnt)
          * it now.
          */
 	scsi_release_commandblocks(SDpnt);
+	if (SDpnt->inquiry)
+		kfree(SDpnt->inquiry);
         kfree(SDpnt);
 }
 

drivers/scsi/scsi.h

@@ -575,7 +575,11 @@ struct scsi_device {
 	devfs_handle_t de;      /* directory for the device      */
 	char type;
 	char scsi_level;
-	char vendor[8], model[16], rev[4];
+	unsigned char inquiry_len;	/* valid bytes in 'inquiry' */
+	unsigned char * inquiry;	/* INQUIRY response data */
+	char * vendor;		/* [back_compat] point into 'inquiry' ... */
+	char * model;		/* ... after scan; point to static string */
+	char * rev;		/* ... "nullnullnullnull" before scan */
 	unsigned char current_tag;	/* current tag */
 	unsigned char sync_min_period;	/* Not less than this period */
 	unsigned char sync_max_offset;	/* Not greater than this offset */

include/scsi/scsi.h

@@ -78,6 +78,7 @@
 #define MODE_SENSE_10         0x5a
 #define PERSISTENT_RESERVE_IN 0x5e
 #define PERSISTENT_RESERVE_OUT 0x5f
+#define REPORT_LUNS           0xa0
 #define MOVE_MEDIUM           0xa5
 #define READ_12               0xa8
 #define WRITE_12              0xaa
@@ -130,6 +131,7 @@
 
 #define TYPE_DISK           0x00
 #define TYPE_TAPE           0x01
+#define TYPE_PRINTER        0x02
 #define TYPE_PROCESSOR      0x03    /* HP scanners use this */
 #define TYPE_WORM           0x04    /* Treated as ROM by our system */
 #define TYPE_ROM            0x05
@@ -163,6 +165,13 @@ struct ccs_modesel_head
     u_char  block_length_lo;
 };
 
+/*
+ * ScsiLun: 8 byte LUN.
+ */
+typedef struct scsi_lun {
+	u8 scsi_lun[8];
+} ScsiLun;
+
 /*
  *  MESSAGE CODES
  */