libata: add ATA_HORKAGE_MAX_SEC_1024 to revert back to previous max_s…

…ectors limit

Since no longer limiting max_sectors to BLK_DEF_MAX_SECTORS (commit 34b48db),
data corruption may occur on ST380013AS drive configured on 82801JI (ICH10 Family)
SATA controller. This patch will allow the driver to limit max_sectors as before

 # cat /sys/block/sdb/queue/max_sectors_kb
 512

I was able to double the max_sectors_kb value up to 16384 on linux-4.2.0-rc2
before seeing corruption, but seems safer to use previous limit. Without this
patch max_sectors_kb will be 32767.

tj: Minor comment update.

Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v3.19 and later
Fixes: 34b48db ("block: remove artifical max_hw_sectors cap")

drivers/ata/libata-core.c

@@ -2478,6 +2478,10 @@ int ata_dev_configure(struct ata_device *dev)
 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
 					 dev->max_sectors);
 
+	if (dev->horkage & ATA_HORKAGE_MAX_SEC_1024)
+		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_1024,
+					 dev->max_sectors);
+
 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_LBA48)
 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
 
@@ -4146,6 +4150,12 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	{ "Slimtype DVD A  DS8A8SH", NULL,	ATA_HORKAGE_MAX_SEC_LBA48 },
 	{ "Slimtype DVD A  DS8A9SH", NULL,	ATA_HORKAGE_MAX_SEC_LBA48 },
 
+	/*
+	 * Causes silent data corruption with higher max sects.
+	 * http://lkml.kernel.org/g/x49wpy40ysk.fsf@segfault.boston.devel.redhat.com
+	 */
+	{ "ST380013AS",		"3.20",		ATA_HORKAGE_MAX_SEC_1024 },
+
 	/* Devices we expect to fail diagnostics */
 
 	/* Devices where NCQ should be avoided */

include/linux/ata.h

@@ -45,6 +45,7 @@ enum {
 	ATA_SECT_SIZE		= 512,
 	ATA_MAX_SECTORS_128	= 128,
 	ATA_MAX_SECTORS		= 256,
+	ATA_MAX_SECTORS_1024    = 1024,
 	ATA_MAX_SECTORS_LBA48	= 65535,/* TODO: 65536? */
 	ATA_MAX_SECTORS_TAPE	= 65535,
 

include/linux/libata.h

@@ -432,7 +432,7 @@ enum {
 	ATA_HORKAGE_ZERO_AFTER_TRIM = (1 << 22),/* guarantees zero after trim */
 	ATA_HORKAGE_NO_NCQ_LOG	= (1 << 23),	/* don't use NCQ for log read */
 	ATA_HORKAGE_NOTRIM	= (1 << 24),	/* don't use TRIM */
-
+	ATA_HORKAGE_MAX_SEC_1024 = (1 << 25),	/* Limit max sects to 1024 */
 
 	 /* DMA mask for user DMA control: User visible values; DO NOT
 	    renumber */