[PATCH] sg driver for lk 2.5.70

This is a bug fix for a flawed patch I put in lk 2.4.19
(sg version 3.1.24) and has been carried through into
the 2.5 series. Thanks to Andy Polyakov
<appro@fy.chalmers.se> for pointing this out (more than once).

The sg.h header didn't get updated last time I submitted
an sg patch so this patch also addresses that.

drivers/scsi/sg.c

@@ -18,8 +18,8 @@
  *
  */
 #include <linux/config.h>
-static char *sg_version_str = "3.5.28 [20030308]";
-static int sg_version_num = 30528;	/* 2 digits for each component */
+static char *sg_version_str = "3.5.29 [20030529]";
+static int sg_version_num = 30529;	/* 2 digits for each component */
 /*
  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
@@ -1994,11 +1994,8 @@ sg_write_xfer(Sg_request * srp)
 			if (res)
 				return res;
 
-			for (; k < schp->k_use_sg; ++k, ++sclp) {
-				ksglen = (int) sclp->length;
-				p = sg_scatg2virt(sclp);
-				if (NULL == p)
-					break;
+			for (; p; ++sclp, ksglen = (int) sclp->length,
+				  p = sg_scatg2virt(sclp)) {
 				if (usglen <= 0)
 					break;
 				if (ksglen > usglen) {
@@ -2025,6 +2022,9 @@ sg_write_xfer(Sg_request * srp)
 					up += ksglen;
 					usglen -= ksglen;
 				}
+				++k;
+				if (k >= schp->k_use_sg)
+					return 0;
 			}
 		}
 	}
@@ -2151,11 +2151,8 @@ sg_read_xfer(Sg_request * srp)
 			if (res)
 				return res;
 
-			for (; k < schp->k_use_sg; ++k, ++sclp) {
-				ksglen = (int) sclp->length;
-				p = sg_scatg2virt(sclp);
-				if (NULL == p)
-					break;
+			for (; p; ++sclp, ksglen = (int) sclp->length,
+				  p = sg_scatg2virt(sclp)) {
 				if (usglen <= 0)
 					break;
 				if (ksglen > usglen) {
@@ -2182,6 +2179,9 @@ sg_read_xfer(Sg_request * srp)
 					up += ksglen;
 					usglen -= ksglen;
 				}
+				++k;
+				if (k >= schp->k_use_sg)
+					return 0;
 			}
 		}
 	}

include/scsi/sg.h

@@ -9,11 +9,18 @@
 Original driver (sg.h):
 *       Copyright (C) 1992 Lawrence Foard
 Version 2 and 3 extensions to driver:
-*       Copyright (C) 1998 - 2002 Douglas Gilbert
+*       Copyright (C) 1998 - 2003 Douglas Gilbert
 
-    Version: 3.5.27 (20020812)
+    Version: 3.5.29 (20030529)
     This version is for 2.5 series kernels.
 
+    Changes since 3.5.28 (20030308)
+	- fix bug introduced in version 3.1.24 (last segment of sgat list)
+    Changes since 3.5.27 (20020812)
+    	- remove procfs entries: hosts, host_hdr + host_strs (now in sysfs)
+	- add sysfs sg driver params: def_reserved_size, allow_dio, version
+	- new boot option: "sg_allow_dio" and module parameter: "allow_dio"
+        - multiple internal changes due to scsi subsystem rework	
     Changes since 3.5.26 (20020708)
 	- re-add direct IO using Kai Makisara's work
 	- re-tab to 8, start using C99-isms
@@ -237,7 +244,7 @@ typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
    read/written by a single scsi command. The user can find the value of
    PAGE_SIZE by calling getpagesize() defined in unistd.h . */
 
-#define SG_DEFAULT_RETRIES 1
+#define SG_DEFAULT_RETRIES 0
 
 /* Defaults, commented if they differ from original sg driver */
 #define SG_DEF_FORCE_LOW_DMA 0  /* was 1 -> memory below 16MB on i386 */