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| author | Martin K. Petersen <martin.petersen@oracle.com> | 2015-12-16 23:53:52 +0100 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2015-12-22 03:37:18 +0100 |
| commit | 9c1d9c207bb800498347a2716da298043ee280c5 (patch) | |
| tree | e05d8f3b152b028d81d5b2694dfd533023bf54db | |
| parent | Revert "SCSI: Fix NULL pointer dereference in runtime PM" (diff) | |
| download | linux-9c1d9c207bb800498347a2716da298043ee280c5.tar.xz linux-9c1d9c207bb800498347a2716da298043ee280c5.zip | |
sd: Reject optimal transfer length smaller than page size
Eryu Guan reported that loading scsi_debug would fail. This turned out
to be caused by scsi_debug reporting an optimal I/O size of 32KB which
is smaller than the 64KB page size on the PowerPC system in question.
Add a check to ensure that we only use the device-reported OPTIMAL
TRANSFER LENGTH if it is bigger than or equal to the page cache size.
Reported-by: Eryu Guan <guaneryu@gmail.com>
Reported-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
| -rw-r--r-- | drivers/scsi/sd.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3d22fc3e3c1a..4e08d1cd704d 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -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 |