[SCSI] scsi_debug: factor out copying PI from dif_storep to prot_sglist

If data integrity support is enabled, prot_verify_read() is called in
response to READ commands and it verifies protection info from dif_storep
by comparing against fake_storep, and copies protection info to
prot_sglist.

This factors out the portion of copying protection info into a separate
function.  It will also be reused in the next change after supporting
the opposite direction (copying prot_sglist to dif_storep).

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.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 f640b6b..99e74d7 100644 (file)
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1789,37 +1789,16 @@ static int dif_verify(struct sd_dif_tuple *sdt, const void *data,
        return 0;
 }
 
-static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
-                           unsigned int sectors, u32 ei_lba)
+static void dif_copy_prot(struct scsi_cmnd *SCpnt, sector_t sector,
+                         unsigned int sectors)
 {
        unsigned int i, resid;
        struct scatterlist *psgl;
-       struct sd_dif_tuple *sdt;
-       sector_t sector;
        void *paddr;
        const void *dif_store_end = dif_storep + sdebug_store_sectors;
 
-       for (i = 0; i < sectors; i++) {
-               int ret;
-
-               sector = start_sec + i;
-               sdt = dif_store(sector);
-
-               if (sdt->app_tag == 0xffff)
-                       continue;
-
-               ret = dif_verify(sdt, fake_store(sector), sector, ei_lba);
-               if (ret) {
-                       dif_errors++;
-                       return ret;
-               }
-
-               ei_lba++;
-       }
-
        /* 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);
@@ -1839,7 +1818,34 @@ static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
                resid -= len;
                kunmap_atomic(paddr);
        }
+}
+
+static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
+                           unsigned int sectors, u32 ei_lba)
+{
+       unsigned int i;
+       struct sd_dif_tuple *sdt;
+       sector_t sector;
+
+       for (i = 0; i < sectors; i++) {
+               int ret;
+
+               sector = start_sec + i;
+               sdt = dif_store(sector);
+
+               if (sdt->app_tag == 0xffff)
+                       continue;
+
+               ret = dif_verify(sdt, fake_store(sector), sector, ei_lba);
+               if (ret) {
+                       dif_errors++;
+                       return ret;
+               }
+
+               ei_lba++;
+       }
 
+       dif_copy_prot(SCpnt, start_sec, sectors);
        dix_reads++;
 
        return 0;