scsi: scsi_debug: fix write_same with virtual_gb problem

The WRITE SAME(10) and (16) implementations didn't take account of the
buffer wrap required when the virtual_gb parameter is greater than 0.

Fix that and rename the fake_store() function to lba2fake_store() to lessen
confusion with the global fake_storep pointer. Bump version date.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reported-by: Bart Van Assche <bvanassche@acm.org>
Tested by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 661512b..e27f4df 100644 (file)
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -62,7 +62,7 @@
 
 /* make sure inq_product_rev string corresponds to this version */
 #define SDEBUG_VERSION "0188"  /* format to fit INQUIRY revision field */
-static const char *sdebug_version_date = "20180128";
+static const char *sdebug_version_date = "20190125";
 
 #define MY_NAME "scsi_debug"
 
@@ -735,7 +735,7 @@ static inline bool scsi_debug_lbp(void)
                (sdebug_lbpu || sdebug_lbpws || sdebug_lbpws10);
 }
 
-static void *fake_store(unsigned long long lba)
+static void *lba2fake_store(unsigned long long lba)
 {
        lba = do_div(lba, sdebug_store_sectors);
 
@@ -2514,8 +2514,8 @@ static int do_device_access(struct scsi_cmnd *scmd, u32 sg_skip, u64 lba,
        return ret;
 }
 
-/* If fake_store(lba,num) compares equal to arr(num), then copy top half of
- * arr into fake_store(lba,num) and return true. If comparison fails then
+/* If lba2fake_store(lba,num) compares equal to arr(num), then copy top half of
+ * arr into lba2fake_store(lba,num) and return true. If comparison fails then
  * return false. */
 static bool comp_write_worker(u64 lba, u32 num, const u8 *arr)
 {
@@ -2643,7 +2643,7 @@ static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
                if (sdt->app_tag == cpu_to_be16(0xffff))
                        continue;
 
-               ret = dif_verify(sdt, fake_store(sector), sector, ei_lba);
+               ret = dif_verify(sdt, lba2fake_store(sector), sector, ei_lba);
                if (ret) {
                        dif_errors++;
                        return ret;
@@ -3261,10 +3261,12 @@ err_out:
 static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num,
                           u32 ei_lba, bool unmap, bool ndob)
 {
+       int ret;
        unsigned long iflags;
        unsigned long long i;
-       int ret;
-       u64 lba_off;
+       u32 lb_size = sdebug_sector_size;
+       u64 block, lbaa;
+       u8 *fs1p;
 
        ret = check_device_access_params(scp, lba, num);
        if (ret)
@@ -3276,31 +3278,30 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num,
                unmap_region(lba, num);
                goto out;
        }
-
-       lba_off = lba * sdebug_sector_size;
+       lbaa = lba;
+       block = do_div(lbaa, sdebug_store_sectors);
        /* if ndob then zero 1 logical block, else fetch 1 logical block */
+       fs1p = fake_storep + (block * lb_size);
        if (ndob) {
-               memset(fake_storep + lba_off, 0, sdebug_sector_size);
+               memset(fs1p, 0, lb_size);
                ret = 0;
        } else
-               ret = fetch_to_dev_buffer(scp, fake_storep + lba_off,
-                                         sdebug_sector_size);
+               ret = fetch_to_dev_buffer(scp, fs1p, lb_size);
 
        if (-1 == ret) {
                write_unlock_irqrestore(&atomic_rw, iflags);
                return DID_ERROR << 16;
-       } else if (sdebug_verbose && !ndob && (ret < sdebug_sector_size))
+       } else if (sdebug_verbose && !ndob && (ret < lb_size))
                sdev_printk(KERN_INFO, scp->device,
                            "%s: %s: lb size=%u, IO sent=%d bytes\n",
-                           my_name, "write same",
-                           sdebug_sector_size, ret);
+                           my_name, "write same", lb_size, ret);
 
        /* Copy first sector to remaining blocks */
-       for (i = 1 ; i < num ; i++)
-               memcpy(fake_storep + ((lba + i) * sdebug_sector_size),
-                      fake_storep + lba_off,
-                      sdebug_sector_size);
-
+       for (i = 1 ; i < num ; i++) {
+               lbaa = lba + i;
+               block = do_div(lbaa, sdebug_store_sectors);
+               memmove(fake_storep + (block * lb_size), fs1p, lb_size);
+       }
        if (scsi_debug_lbp())
                map_region(lba, num);
 out: