diff mbox

[3.13.y-ckt,stable] Patch "target: Drop arbitrary maximum I/O size limit" has been added to staging queue

Message ID 1424305728-15469-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Feb. 19, 2015, 12:28 a.m. UTC
This is a note to let you know that I have just added a patch titled

    target: Drop arbitrary maximum I/O size limit

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt16.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From e13f9865e0977fd939758d4a680aa64321655117 Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Tue, 6 Jan 2015 16:10:37 -0800
Subject: target: Drop arbitrary maximum I/O size limit

commit 046ba64285a4389ae5e9a7dfa253c6bff3d7c341 upstream.

This patch drops the arbitrary maximum I/O size limit in sbc_parse_cdb(),
which currently for fabric_max_sectors is hardcoded to 8192 (4 MB for 512
byte sector devices), and for hw_max_sectors is a backend driver dependent
value.

This limit is problematic because Linux initiators have only recently
started to honor block limits MAXIMUM TRANSFER LENGTH, and other non-Linux
based initiators (eg: MSFT Fibre Channel) can also generate I/Os larger
than 4 MB in size.

Currently when this happens, the following message will appear on the
target resulting in I/Os being returned with non recoverable status:

  SCSI OP 28h with too big sectors 16384 exceeds fabric_max_sectors: 8192

Instead, drop both [fabric,hw]_max_sector checks in sbc_parse_cdb(),
and convert the existing hw_max_sectors into a purely informational
attribute used to represent the granuality that backend driver and/or
subsystem code is splitting I/Os upon.

Also, update FILEIO with an explicit FD_MAX_BYTES check in fd_execute_rw()
to deal with the one special iovec limitiation case.

v2 changes:
  - Drop hw_max_sectors check in sbc_parse_cdb()

Reported-by: Lance Gropper <lance.gropper@qosserver.com>
Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
[ kamal: backport to 3.13-stable: context ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/target/target_core_device.c |  8 ++++----
 drivers/target/target_core_file.c   | 11 ++++++++++-
 drivers/target/target_core_iblock.c |  2 +-
 drivers/target/target_core_sbc.c    | 15 ---------------
 drivers/target/target_core_spc.c    |  5 +----
 5 files changed, 16 insertions(+), 25 deletions(-)

--
1.9.1
diff mbox

Patch

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 27bee70..eb69b00 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1065,10 +1065,10 @@  int se_dev_set_optimal_sectors(struct se_device *dev, u32 optimal_sectors)
 				" changed for TCM/pSCSI\n", dev);
 		return -EINVAL;
 	}
-	if (optimal_sectors > dev->dev_attrib.fabric_max_sectors) {
+	if (optimal_sectors > dev->dev_attrib.hw_max_sectors) {
 		pr_err("dev[%p]: Passed optimal_sectors %u cannot be"
-			" greater than fabric_max_sectors: %u\n", dev,
-			optimal_sectors, dev->dev_attrib.fabric_max_sectors);
+			" greater than hw_max_sectors: %u\n", dev,
+			optimal_sectors, dev->dev_attrib.hw_max_sectors);
 		return -EINVAL;
 	}

@@ -1473,7 +1473,6 @@  struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
 				DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT;
 	dev->dev_attrib.max_write_same_len = DA_MAX_WRITE_SAME_LEN;
 	dev->dev_attrib.fabric_max_sectors = DA_FABRIC_MAX_SECTORS;
-	dev->dev_attrib.optimal_sectors = DA_FABRIC_MAX_SECTORS;

 	xcopy_lun = &dev->xcopy_lun;
 	xcopy_lun->lun_se_dev = dev;
@@ -1514,6 +1513,7 @@  int target_configure_device(struct se_device *dev)
 	dev->dev_attrib.hw_max_sectors =
 		se_dev_align_max_sectors(dev->dev_attrib.hw_max_sectors,
 					 dev->dev_attrib.hw_block_size);
+	dev->dev_attrib.optimal_sectors = dev->dev_attrib.hw_max_sectors;

 	dev->dev_index = scsi_get_new_index(SCSI_DEVICE_INDEX);
 	dev->creation_time = get_jiffies_64();
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 78241a5..f35b2de 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -552,7 +552,16 @@  fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 {
 	struct se_device *dev = cmd->se_dev;
 	int ret = 0;
-
+	/*
+	 * We are currently limited by the number of iovecs (2048) per
+	 * single vfs_[writev,readv] call.
+	 */
+	if (cmd->data_length > FD_MAX_BYTES) {
+		pr_err("FILEIO: Not able to process I/O of %u bytes due to"
+		       "FD_MAX_BYTES: %u iovec count limitiation\n",
+			cmd->data_length, FD_MAX_BYTES);
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
 	/*
 	 * Call vectorized fileio functions to map struct scatterlist
 	 * physical memory addresses to struct iovec virtual memory.
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index c87959f..6d070e5 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -122,7 +122,7 @@  static int iblock_configure_device(struct se_device *dev)
 	q = bdev_get_queue(bd);

 	dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
-	dev->dev_attrib.hw_max_sectors = UINT_MAX;
+	dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 	dev->dev_attrib.hw_queue_depth = q->nr_requests;

 	/*
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 45d0bc6..6aae89d 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -839,21 +839,6 @@  sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
 		unsigned long long end_lba;

-		if (sectors > dev->dev_attrib.fabric_max_sectors) {
-			printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
-				" big sectors %u exceeds fabric_max_sectors:"
-				" %u\n", cdb[0], sectors,
-				dev->dev_attrib.fabric_max_sectors);
-			return TCM_INVALID_CDB_FIELD;
-		}
-		if (sectors > dev->dev_attrib.hw_max_sectors) {
-			printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
-				" big sectors %u exceeds backend hw_max_sectors:"
-				" %u\n", cdb[0], sectors,
-				dev->dev_attrib.hw_max_sectors);
-			return TCM_INVALID_CDB_FIELD;
-		}
-
 		end_lba = dev->transport->get_blocks(dev) + 1;
 		if (cmd->t_task_lba + sectors > end_lba) {
 			pr_err("cmd exceeds last lba %llu "
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 143e75b..e5f4eac 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -450,7 +450,6 @@  static sense_reason_t
 spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf)
 {
 	struct se_device *dev = cmd->se_dev;
-	u32 max_sectors;
 	int have_tp = 0;
 	int opt, min;

@@ -484,9 +483,7 @@  spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf)
 	/*
 	 * Set MAXIMUM TRANSFER LENGTH
 	 */
-	max_sectors = min(dev->dev_attrib.fabric_max_sectors,
-			  dev->dev_attrib.hw_max_sectors);
-	put_unaligned_be32(max_sectors, &buf[8]);
+	put_unaligned_be32(dev->dev_attrib.hw_max_sectors, &buf[8]);

 	/*
 	 * Set OPTIMAL TRANSFER LENGTH