In the function prot_verify_write(), kmap_atomic()/kunmap_atomic() for
data page and kmap_atomic()/kunmap_atomic() for protection information
page are not nested each other.
It worked perfectly before commit 3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73
("mm: stack based kmap_atomic()"). Because the kmap_atomic slot KM_IRQ0
was used for data page and the slot KM_IRQ1 was used for protection page.
But KM_types are gone and kmap_atomic() is using stack based implementation.
So two different kmap_atomic() usages must be strictly nested now.
This change ensures kmap_atomic() usage is strictly nested.
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
Acked-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
* New patch from v2
- Splitted from the patch "fix data integrity support on highmem machine" in v1
drivers/scsi/scsi_debug.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index caf6a94..0a428b6 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1891,12 +1891,12 @@ static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
BUG_ON(scsi_sg_count(SCpnt) == 0);
BUG_ON(scsi_prot_sg_count(SCpnt) == 0);
- paddr = kmap_atomic(sg_page(psgl)) + psgl->offset;
ppage_offset = 0;
/* For each data page */
scsi_for_each_sg(SCpnt, dsgl, scsi_sg_count(SCpnt), i) {
daddr = kmap_atomic(sg_page(dsgl)) + dsgl->offset;
+ paddr = kmap_atomic(sg_page(psgl)) + psgl->offset;
/* For each sector-sized chunk in data page */
for (j = 0 ; j < dsgl->length ; j += scsi_debug_sector_size) {
@@ -1981,19 +1981,18 @@ static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
ppage_offset += sizeof(struct sd_dif_tuple);
}
+ kunmap_atomic(paddr);
kunmap_atomic(daddr - dsgl->length);
}
- kunmap_atomic(paddr);
-
dix_writes++;
return 0;
out:
dif_errors++;
- kunmap_atomic(daddr);
kunmap_atomic(paddr);
+ kunmap_atomic(daddr);
return ret;
}
--
1.8.1.4
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