Patch "libata: add ATA_HORKAGE_MAX_SEC_1024 to revert back to previous max_sectors limit" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

libata: add ATA_HORKAGE_MAX_SEC_1024 to revert back to previous max_sectors limit

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
libata-add-ata_horkage_max_sec_1024-to-revert-back-to-previous-max_sectors-limit.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: David Milburn <[email protected]>
Date: Mon, 13 Jul 2015 11:48:23 -0500
Subject: libata: add ATA_HORKAGE_MAX_SEC_1024 to revert back to previous max_sectors limit

From: David Milburn <[email protected]>

commit af34d637637eabaf49406eb35c948cd51ba262a6 upstream.

Since no longer limiting max_sectors to BLK_DEF_MAX_SECTORS (commit 34b48db66e08), 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.

---
 drivers/ata/libata-core.c |   10 ++++++++++
 include/linux/ata.h       |    1 +
 include/linux/libata.h    |    2 +-
 3 files changed, 12 insertions(+), 1 deletion(-)

@@ -2478,6 +2478,10 @@ int ata_dev_configure(struct ata_device
 		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
 	{ "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/[email protected]
+	 */
+	{ "ST380013AS",		"3.20",		ATA_HORKAGE_MAX_SEC_1024 },
+
 	/* Devices we expect to fail diagnostics */
 
 	/* Devices where NCQ should be avoided */

@@ -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,
 

@@ -433,7 +433,7 @@ 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 */

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/libata-add-ata_horkage_max_sec_1024-to-revert-back-to-previous-max_sectors-limit.patch