We have come across a couple of devices that report crackpot values in
the optimal I/O size in the Block Limits VPD page. Since this is a
32-bit entity that gets multiplied by the logical block size we can get
disproportionately large values reported to the block layer.
Cap io_opt at 256 MB.
Reported-by: Chris Friesen <chris.friesen@xxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/scsi/sd.c | 3 ++-
drivers/scsi/sd.h | 9 +++++----
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index ebf35cb64216..faf3725492ce 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2593,7 +2593,8 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
blk_queue_io_min(sdkp->disk->queue,
get_unaligned_be16(&buffer[6]) * sector_sz);
blk_queue_io_opt(sdkp->disk->queue,
- get_unaligned_be32(&buffer[12]) * sector_sz);
+ min_t(unsigned int, SD_MAX_IO_OPT_BYTES,
+ get_unaligned_be32(&buffer[12]) * sector_sz));
if (buffer[3] == 0x3c) {
unsigned int lba_count, desc_count;
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 63ba5ca7f9a1..f175a3f2944a 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -44,10 +44,11 @@ enum {
};
enum {
- SD_DEF_XFER_BLOCKS = 0xffff,
- SD_MAX_XFER_BLOCKS = 0xffffffff,
- SD_MAX_WS10_BLOCKS = 0xffff,
- SD_MAX_WS16_BLOCKS = 0x7fffff,
+ SD_DEF_XFER_BLOCKS = 0xffff,
+ SD_MAX_XFER_BLOCKS = 0xffffffff,
+ SD_MAX_WS10_BLOCKS = 0xffff,
+ SD_MAX_WS16_BLOCKS = 0x7fffff,
+ SD_MAX_IO_OPT_BYTES = 256 * 1024 * 1024,
};
enum {
--
1.9.3
--
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