If data integrity support is enabled, prot_verify_write() is called in
response to WRITE commands and it verifies protection info from
prot_sglist by comparing against data sglist, and copies protection info
to dif_storep.
When multiple blocks are transfered by a WRITE command, it verifies and
copies these blocks one by one. So if it fails to verify protection
info in the middle of blocks, the actual data transfer to fake_storep
isn't proceeded at all although protection info for some blocks are
already copied to dif_storep. Therefore, it breaks the data integrity
between fake_storep and dif_storep.
This fixes it by ensuring that copying protection info to dif_storep is
done after all blocks are successfully verified. Reusing dif_copy_prot()
with supporting the opposite direction simplifies this fix.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: "James E.J. Bottomley" <JBottomley@xxxxxxxxxxxxx>
Cc: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Cc: linux-scsi@xxxxxxxxxxxxxxx
---
drivers/scsi/scsi_debug.c | 40 +++++++++++++++++-----------------------
1 file changed, 17 insertions(+), 23 deletions(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 99e74d7..43369e9 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1790,7 +1790,7 @@ static int dif_verify(struct sd_dif_tuple *sdt, const void *data,
}
static void dif_copy_prot(struct scsi_cmnd *SCpnt, sector_t sector,
- unsigned int sectors)
+ unsigned int sectors, bool read)
{
unsigned int i, resid;
struct scatterlist *psgl;
@@ -1809,10 +1809,18 @@ static void dif_copy_prot(struct scsi_cmnd *SCpnt, sector_t sector,
rest = start + len - dif_store_end;
paddr = kmap_atomic(sg_page(psgl)) + psgl->offset;
- memcpy(paddr, start, len - rest);
- if (rest)
- memcpy(paddr + len - rest, dif_storep, rest);
+ if (read)
+ memcpy(paddr, start, len - rest);
+ else
+ memcpy(start, paddr, len - rest);
+
+ if (rest) {
+ if (read)
+ memcpy(paddr + len - rest, dif_storep, rest);
+ else
+ memcpy(dif_storep, paddr + len - rest, rest);
+ }
sector += len / sizeof(*dif_storep);
resid -= len;
@@ -1845,7 +1853,7 @@ static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
ei_lba++;
}
- dif_copy_prot(SCpnt, start_sec, sectors);
+ dif_copy_prot(SCpnt, start_sec, sectors, true);
dix_reads++;
return 0;
@@ -1928,15 +1936,12 @@ static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
{
int i, j, ret;
struct sd_dif_tuple *sdt;
- struct scatterlist *dsgl = scsi_sglist(SCpnt);
+ struct scatterlist *dsgl;
struct scatterlist *psgl = scsi_prot_sglist(SCpnt);
void *daddr, *paddr;
- sector_t tmp_sec = start_sec;
- sector_t sector;
+ sector_t sector = start_sec;
int ppage_offset;
- sector = do_div(tmp_sec, sdebug_store_sectors);
-
BUG_ON(scsi_sg_count(SCpnt) == 0);
BUG_ON(scsi_prot_sg_count(SCpnt) == 0);
@@ -1964,25 +1969,13 @@ static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
sdt = paddr + ppage_offset;
- ret = dif_verify(sdt, daddr + j, start_sec, ei_lba);
+ ret = dif_verify(sdt, daddr + j, sector, ei_lba);
if (ret) {
dump_sector(daddr + j, scsi_debug_sector_size);
goto out;
}
- /* Would be great to copy this in bigger
- * chunks. However, for the sake of
- * correctness we need to verify each sector
- * before writing it to "stable" storage
- */
- memcpy(dif_storep + sector, sdt, sizeof(*sdt));
-
sector++;
-
- if (sector == sdebug_store_sectors)
- sector = 0; /* Force wrap */
-
- start_sec++;
ei_lba++;
ppage_offset += sizeof(struct sd_dif_tuple);
}
@@ -1991,6 +1984,7 @@ static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
kunmap_atomic(daddr);
}
+ dif_copy_prot(SCpnt, start_sec, sectors, false);
dix_writes++;
return 0;
--
1.8.3.1
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