releases/4.19.31/scsi-sd-optimal-i-o-size-should-be-a-multiple-of-physical-block-size.patch

   1 From a83da8a4509d3ebfe03bb7fffce022e4d5d4764f Mon Sep 17 00:00:00 2001
   2 From: "Martin K. Petersen" <martin.petersen@oracle.com>
   3 Date: Tue, 12 Feb 2019 16:21:05 -0500
   4 Subject: scsi: sd: Optimal I/O size should be a multiple of physical block size
   5
   6 From: Martin K. Petersen <martin.petersen@oracle.com>
   7
   8 commit a83da8a4509d3ebfe03bb7fffce022e4d5d4764f upstream.
   9
  10 It was reported that some devices report an OPTIMAL TRANSFER LENGTH of
  11 0xFFFF blocks. That looks bogus, especially for a device with a
  12 4096-byte physical block size.
  13
  14 Ignore OPTIMAL TRANSFER LENGTH if it is not a multiple of the device's
  15 reported physical block size.
  16
  17 To make the sanity checking conditionals more readable--and to
  18 facilitate printing warnings--relocate the checking to a helper
  19 function. No functional change aside from the printks.
  20
  21 Cc: <stable@vger.kernel.org>
  22 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199759
  23 Reported-by: Christoph Anton Mitterer <calestyo@scientia.net>
  24 Reviewed-by: Christoph Hellwig <hch@lst.de>
  25 Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27
  28 ---
  29  drivers/scsi/sd.c |   59 +++++++++++++++++++++++++++++++++++++++++++++---------
  30  1 file changed, 50 insertions(+), 9 deletions(-)
  31
  32 --- a/drivers/scsi/sd.c
  33 +++ b/drivers/scsi/sd.c
  34 @@ -3066,6 +3066,55 @@ static void sd_read_security(struct scsi
  35                 sdkp->security = 1;
  36  }
  37
  38 +/*
  39 + * Determine the device's preferred I/O size for reads and writes
  40 + * unless the reported value is unreasonably small, large, not a
  41 + * multiple of the physical block size, or simply garbage.
  42 + */
  43 +static bool sd_validate_opt_xfer_size(struct scsi_disk *sdkp,
  44 +                                     unsigned int dev_max)
  45 +{
  46 +       struct scsi_device *sdp = sdkp->device;
  47 +       unsigned int opt_xfer_bytes =
  48 +               logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
  49 +
  50 +       if (sdkp->opt_xfer_blocks > dev_max) {
  51 +               sd_first_printk(KERN_WARNING, sdkp,
  52 +                               "Optimal transfer size %u logical blocks " \
  53 +                               "> dev_max (%u logical blocks)\n",
  54 +                               sdkp->opt_xfer_blocks, dev_max);
  55 +               return false;
  56 +       }
  57 +
  58 +       if (sdkp->opt_xfer_blocks > SD_DEF_XFER_BLOCKS) {
  59 +               sd_first_printk(KERN_WARNING, sdkp,
  60 +                               "Optimal transfer size %u logical blocks " \
  61 +                               "> sd driver limit (%u logical blocks)\n",
  62 +                               sdkp->opt_xfer_blocks, SD_DEF_XFER_BLOCKS);
  63 +               return false;
  64 +       }
  65 +
  66 +       if (opt_xfer_bytes < PAGE_SIZE) {
  67 +               sd_first_printk(KERN_WARNING, sdkp,
  68 +                               "Optimal transfer size %u bytes < " \
  69 +                               "PAGE_SIZE (%u bytes)\n",
  70 +                               opt_xfer_bytes, (unsigned int)PAGE_SIZE);
  71 +               return false;
  72 +       }
  73 +
  74 +       if (opt_xfer_bytes & (sdkp->physical_block_size - 1)) {
  75 +               sd_first_printk(KERN_WARNING, sdkp,
  76 +                               "Optimal transfer size %u bytes not a " \
  77 +                               "multiple of physical block size (%u bytes)\n",
  78 +                               opt_xfer_bytes, sdkp->physical_block_size);
  79 +               return false;
  80 +       }
  81 +
  82 +       sd_first_printk(KERN_INFO, sdkp, "Optimal transfer size %u bytes\n",
  83 +                       opt_xfer_bytes);
  84 +       return true;
  85 +}
  86 +
  87  /**
  88   *     sd_revalidate_disk - called the first time a new disk is seen,
  89   *     performs disk spin up, read_capacity, etc.
  90 @@ -3144,15 +3193,7 @@ static int sd_revalidate_disk(struct gen
  91         dev_max = min_not_zero(dev_max, sdkp->max_xfer_blocks);
  92         q->limits.max_dev_sectors = logical_to_sectors(sdp, dev_max);
  93
  94 -       /*
  95 -        * Determine the device's preferred I/O size for reads and writes
  96 -        * unless the reported value is unreasonably small, large, or
  97 -        * garbage.
  98 -        */
  99 -       if (sdkp->opt_xfer_blocks &&
 100 -           sdkp->opt_xfer_blocks <= dev_max &&
 101 -           sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
 102 -           logical_to_bytes(sdp, sdkp->opt_xfer_blocks) >= PAGE_SIZE) {
 103 +       if (sd_validate_opt_xfer_size(sdkp, dev_max)) {
 104                 q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
 105                 rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
 106         } else