Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fix from James Bottomley:
"A single fix for machines with pages > 4k (PPC mostly).
There's a bug in our optimal transfer size code where we don't account
for pages > 4k and can set the transfer size to be less than the page
size causing nasty failures"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
sd: Reject optimal transfer length smaller than page size
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3d22fc3..4e08d1cd 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2885,10 +2885,13 @@
/*
* Use the device's preferred I/O size for reads and writes
- * unless the reported value is unreasonably large (or garbage).
+ * unless the reported value is unreasonably small, large, or
+ * garbage.
*/
- if (sdkp->opt_xfer_blocks && sdkp->opt_xfer_blocks <= dev_max &&
- sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS)
+ if (sdkp->opt_xfer_blocks &&
+ sdkp->opt_xfer_blocks <= dev_max &&
+ sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
+ sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_CACHE_SIZE)
rw_max = q->limits.io_opt =
logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
else
