@@ -2885,10 +2885,13 @@ static int sd_revalidate_disk(struct gendisk *disk)
/*
* 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
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. The patch is available here: git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes The short changelog is: Martin K. Petersen (1): sd: Reject optimal transfer length smaller than page size And the diffstat: drivers/scsi/sd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) With full diff below. James --- -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html