scsi: sd: Optimal I/O size should be a multiple of physical block size
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>
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@ -3061,6 +3061,55 @@ static void sd_read_security(struct scsi_disk *sdkp, unsigned char *buffer)
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sdkp->security = 1;
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}
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/*
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* Determine the device's preferred I/O size for reads and writes
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* unless the reported value is unreasonably small, large, not a
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* multiple of the physical block size, or simply garbage.
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*/
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static bool sd_validate_opt_xfer_size(struct scsi_disk *sdkp,
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unsigned int dev_max)
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{
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struct scsi_device *sdp = sdkp->device;
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unsigned int opt_xfer_bytes =
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logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
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if (sdkp->opt_xfer_blocks > dev_max) {
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sd_first_printk(KERN_WARNING, sdkp,
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"Optimal transfer size %u logical blocks " \
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"> dev_max (%u logical blocks)\n",
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sdkp->opt_xfer_blocks, dev_max);
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return false;
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}
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if (sdkp->opt_xfer_blocks > SD_DEF_XFER_BLOCKS) {
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sd_first_printk(KERN_WARNING, sdkp,
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"Optimal transfer size %u logical blocks " \
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"> sd driver limit (%u logical blocks)\n",
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sdkp->opt_xfer_blocks, SD_DEF_XFER_BLOCKS);
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return false;
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}
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if (opt_xfer_bytes < PAGE_SIZE) {
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sd_first_printk(KERN_WARNING, sdkp,
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"Optimal transfer size %u bytes < " \
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"PAGE_SIZE (%u bytes)\n",
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opt_xfer_bytes, (unsigned int)PAGE_SIZE);
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return false;
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}
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if (opt_xfer_bytes & (sdkp->physical_block_size - 1)) {
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sd_first_printk(KERN_WARNING, sdkp,
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"Optimal transfer size %u bytes not a " \
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"multiple of physical block size (%u bytes)\n",
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opt_xfer_bytes, sdkp->physical_block_size);
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return false;
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}
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sd_first_printk(KERN_INFO, sdkp, "Optimal transfer size %u bytes\n",
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opt_xfer_bytes);
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return true;
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}
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/**
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* sd_revalidate_disk - called the first time a new disk is seen,
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* performs disk spin up, read_capacity, etc.
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@ -3130,15 +3179,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
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dev_max = min_not_zero(dev_max, sdkp->max_xfer_blocks);
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q->limits.max_dev_sectors = logical_to_sectors(sdp, dev_max);
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/*
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* Determine the device's preferred I/O size for reads and writes
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* unless the reported value is unreasonably small, large, or
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* garbage.
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*/
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if (sdkp->opt_xfer_blocks &&
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sdkp->opt_xfer_blocks <= dev_max &&
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sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
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logical_to_bytes(sdp, sdkp->opt_xfer_blocks) >= PAGE_SIZE) {
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if (sd_validate_opt_xfer_size(sdkp, dev_max)) {
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q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
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rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
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} else
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