From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
This patch (as1203) increases the max_sector limit for USB tape
drives. By default usb-storage sets max_sectors to 240 (i.e., 120 KB)
for all devices. But tape drives need a higher limit, since tapes can
and do have very large block sizes. Without the ability to transfer
an entire large block in a single command, such tapes can't be used.
This fixes Bugzilla #12207.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-and-tested-by: Phil Mitchell <philipm@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/storage/scsiglue.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 727c506..ed710bc 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -135,6 +135,12 @@ static int slave_configure(struct scsi_device *sdev)
if (sdev->request_queue->max_sectors > max_sectors)
blk_queue_max_sectors(sdev->request_queue,
max_sectors);
+ } else if (sdev->type == TYPE_TAPE) {
+ /* Tapes need much higher max_sector limits, so just
+ * raise it to the maximum possible (4 GB / 512) and
+ * let the queue segment size sort out the real limit.
+ */
+ blk_queue_max_sectors(sdev->request_queue, 0x7FFFFF);
}
/* Some USB host controllers can't do DMA; they have to use PIO.
--
1.6.2
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