4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin K. Petersen martin.petersen@oracle.com
commit a83da8a4509d3ebfe03bb7fffce022e4d5d4764f upstream.
It was reported that some devices report an OPTIMAL TRANSFER LENGTH of 0xFFFF blocks. That looks bogus, especially for a device with a 4096-byte physical block size.
Ignore OPTIMAL TRANSFER LENGTH if it is not a multiple of the device's reported physical block size.
To make the sanity checking conditionals more readable--and to facilitate printing warnings--relocate the checking to a helper function. No functional change aside from the printks.
Cc: stable@vger.kernel.org Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199759 Reported-by: Christoph Anton Mitterer calestyo@scientia.net Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/scsi/sd.c | 59 +++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 50 insertions(+), 9 deletions(-)
--- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2834,6 +2834,55 @@ static void sd_read_write_same(struct sc sdkp->ws10 = 1; }
+/* + * Determine the device's preferred I/O size for reads and writes + * unless the reported value is unreasonably small, large, not a + * multiple of the physical block size, or simply garbage. + */ +static bool sd_validate_opt_xfer_size(struct scsi_disk *sdkp, + unsigned int dev_max) +{ + struct scsi_device *sdp = sdkp->device; + unsigned int opt_xfer_bytes = + logical_to_bytes(sdp, sdkp->opt_xfer_blocks); + + if (sdkp->opt_xfer_blocks > dev_max) { + sd_first_printk(KERN_WARNING, sdkp, + "Optimal transfer size %u logical blocks " \ + "> dev_max (%u logical blocks)\n", + sdkp->opt_xfer_blocks, dev_max); + return false; + } + + if (sdkp->opt_xfer_blocks > SD_DEF_XFER_BLOCKS) { + sd_first_printk(KERN_WARNING, sdkp, + "Optimal transfer size %u logical blocks " \ + "> sd driver limit (%u logical blocks)\n", + sdkp->opt_xfer_blocks, SD_DEF_XFER_BLOCKS); + return false; + } + + if (opt_xfer_bytes < PAGE_SIZE) { + sd_first_printk(KERN_WARNING, sdkp, + "Optimal transfer size %u bytes < " \ + "PAGE_SIZE (%u bytes)\n", + opt_xfer_bytes, (unsigned int)PAGE_SIZE); + return false; + } + + if (opt_xfer_bytes & (sdkp->physical_block_size - 1)) { + sd_first_printk(KERN_WARNING, sdkp, + "Optimal transfer size %u bytes not a " \ + "multiple of physical block size (%u bytes)\n", + opt_xfer_bytes, sdkp->physical_block_size); + return false; + } + + sd_first_printk(KERN_INFO, sdkp, "Optimal transfer size %u bytes\n", + opt_xfer_bytes); + return true; +} + /** * sd_revalidate_disk - called the first time a new disk is seen, * performs disk spin up, read_capacity, etc. @@ -2898,15 +2947,7 @@ static int sd_revalidate_disk(struct gen dev_max = min_not_zero(dev_max, sdkp->max_xfer_blocks); q->limits.max_dev_sectors = logical_to_sectors(sdp, dev_max);
- /* - * Determine the device's preferred I/O size for reads and writes - * 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 && - logical_to_bytes(sdp, sdkp->opt_xfer_blocks) >= PAGE_SIZE) { + if (sd_validate_opt_xfer_size(sdkp, dev_max)) { q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks); rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks); } else