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authorMartin K. Petersen <martin.petersen@oracle.com>2019-02-12 16:21:05 -0500
committerMartin K. Petersen <martin.petersen@oracle.com>2019-02-26 10:08:36 -0500
commita83da8a4509d3ebfe03bb7fffce022e4d5d4764f (patch)
tree83b3e9c1ee9892d95bb0b5ecf9c9c0837a9c72a1 /drivers/scsi/sd.c
parentd1420f2c0fdf41abfb7ba3b9fd7b4157823bc2a7 (diff)
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>
Diffstat (limited to 'drivers/scsi/sd.c')
-rw-r--r--drivers/scsi/sd.c59
1 files changed, 50 insertions, 9 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index cc175b78b366..f3e5e6b6404c 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3061,6 +3061,55 @@ static void sd_read_security(struct scsi_disk *sdkp, unsigned char *buffer)
sdkp->security = 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.
@@ -3130,15 +3179,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
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