[SCSI] scsi_debug: simplify offset calculation for dif_storep

dif_storep is declared as pointer to unsigned char type.  But it is
actually used to store vmalloced array of struct sd_dif_tuple.

This changes the type of dif_storep to the pointer to struct sd_dif_tuple.
It simplifies offset calculation for dif_storep and enables to remove
hardcoded size of struct sd_dif_tuple.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Acked-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 83efec2919b13115ba06cfaabbcbefee5a9841d3..fc8b3aa083d4cc9b13a9ce84380fc1e830a55216 100644 (file)
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -258,7 +258,7 @@ struct sdebug_queued_cmd {
 static struct sdebug_queued_cmd queued_arr[SCSI_DEBUG_CANQUEUE];
 
 static unsigned char * fake_storep;    /* ramdisk storage */
-static unsigned char *dif_storep;      /* protection info */
+static struct sd_dif_tuple *dif_storep;        /* protection info */
 static void *map_storep;               /* provisioning map */
 
 static unsigned long map_size;
@@ -277,11 +277,6 @@ static char sdebug_proc_name[] = "scsi_debug";
 
 static struct bus_type pseudo_lld_bus;
 
-static inline sector_t dif_offset(sector_t sector)
-{
-       return sector << 3;
-}
-
 static struct device_driver sdebug_driverfs_driver = {
        .name           = sdebug_proc_name,
        .bus            = &pseudo_lld_bus,
@@ -1727,7 +1722,7 @@ static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
 
        start_sec = do_div(tmp_sec, sdebug_store_sectors);
 
-       sdt = (struct sd_dif_tuple *)(dif_storep + dif_offset(start_sec));
+       sdt = dif_storep + start_sec;
 
        for (i = 0 ; i < sectors ; i++) {
                u16 csum;
@@ -1782,16 +1777,17 @@ static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
                ei_lba++;
        }
 
-       resid = sectors * 8; /* Bytes of protection data to copy into sgl */
+       /* Bytes of protection data to copy into sgl */
+       resid = sectors * sizeof(*dif_storep);
        sector = start_sec;
 
        scsi_for_each_prot_sg(SCpnt, psgl, scsi_prot_sg_count(SCpnt), i) {
                int len = min(psgl->length, resid);
 
                paddr = kmap_atomic(sg_page(psgl)) + psgl->offset;
-               memcpy(paddr, dif_storep + dif_offset(sector), len);
+               memcpy(paddr, dif_storep + sector, len);
 
-               sector += len >> 3;
+               sector += len / sizeof(*dif_storep);
                if (sector >= sdebug_store_sectors) {
                        /* Force wrap */
                        tmp_sec = sector;
@@ -1968,7 +1964,7 @@ static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
                         * correctness we need to verify each sector
                         * before writing it to "stable" storage
                         */
-                       memcpy(dif_storep + dif_offset(sector), sdt, 8);
+                       memcpy(dif_storep + sector, sdt, sizeof(*sdt));
 
                        sector++;