From 0043f510cbd84cd0fa776f0169e2e980daaa1e86 Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Thu, 4 Jul 2013 04:26:21 +0000
Subject: [PATCH] block shift cleanups and fixes

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@4912 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/dev_handlers/scst_tape.c |  6 +++---
 scst/src/dev_handlers/scst_user.c | 13 +++++++++++--
 scst/src/scst_lib.c               |  2 ++
 scst/src/scst_targ.c              |  3 ++-
 4 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/scst/src/dev_handlers/scst_tape.c b/scst/src/dev_handlers/scst_tape.c
index 3553b4d07..e30812699 100644
--- a/scst/src/dev_handlers/scst_tape.c
+++ b/scst/src/dev_handlers/scst_tape.c
@@ -166,7 +166,7 @@ static int tape_attach(struct scst_device *dev)
 	}
 
 	dev->block_size = TAPE_DEF_BLOCK_SIZE;
-	dev->block_shift = scst_calc_block_shift(dev->block_size);
+	dev->block_shift = -1; /* not used */
 
 	buffer = kmalloc(buffer_size, GFP_KERNEL);
 	if (!buffer) {
@@ -223,7 +223,7 @@ static int tape_attach(struct scst_device *dev)
 		res = -ENODEV;
 		goto out_free_buf;
 	}
-	dev->block_shift = scst_calc_block_shift(dev->block_size);
+	dev->block_shift = -1; /* not used */
 
 obtain:
 	res = scst_obtain_device_parameters(dev, NULL);
@@ -270,7 +270,7 @@ static void tape_set_block_size(struct scst_cmd *cmd, int block_size)
 	 * there are existing commands.
 	 */
 	dev->block_size = block_size;
-	dev->block_shift = scst_calc_block_shift(dev->block_size);
+	dev->block_shift = -1; /* not used */
 	return;
 }
 
diff --git a/scst/src/dev_handlers/scst_user.c b/scst/src/dev_handlers/scst_user.c
index 49577a536..eb3c36f20 100644
--- a/scst/src/dev_handlers/scst_user.c
+++ b/scst/src/dev_handlers/scst_user.c
@@ -1053,7 +1053,7 @@ static void dev_user_set_block_size(struct scst_cmd *cmd, int block_size)
 		struct scst_user_dev *udev = cmd->dev->dh_priv;
 		dev->block_size = udev->def_block_size;
 	}
-	dev->block_shift = scst_calc_block_shift(dev->block_size);
+	dev->block_shift = -1; /* not used */
 
 	TRACE_EXIT();
 	return;
@@ -2591,7 +2591,16 @@ static int dev_user_attach(struct scst_device *sdev)
 	}
 
 	sdev->block_size = dev->def_block_size;
-	sdev->block_shift = scst_calc_block_shift(sdev->block_size);
+	switch (sdev->type) {
+	case TYPE_DISK:
+	case TYPE_ROM:
+	case TYPE_MOD:
+		sdev->block_shift = scst_calc_block_shift(sdev->block_size);
+		break;
+	default:
+		sdev->block_shift = -1; /* not used */
+		break;
+	}
 
 	sdev->dh_priv = dev;
 	sdev->tst = dev->tst;
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 2e6d755e8..c6dbf9c07 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -6995,6 +6995,8 @@ static inline int scst_generic_parse(struct scst_cmd *cmd, const int timeout[3])
 
 	TRACE_ENTRY();
 
+	EXTRACHECKS_BUG_ON(block_shift < 0);
+
 	/*
 	 * SCST sets good defaults for cmd->data_direction and cmd->bufflen,
 	 * therefore change them only if necessary
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 7627c2579..0cf894974 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -1596,7 +1596,8 @@ static int scst_tgt_pre_exec(struct scst_cmd *cmd)
 					do_zero = true;
 			}
 			if (do_zero) {
-				if ((cmd->write_len & ((1 << cmd->dev->block_shift) - 1)) == 0) {
+				if (!(cmd->op_flags & SCST_TRANSFER_LEN_TYPE_FIXED) ||
+				    (cmd->write_len & ((1 << cmd->dev->block_shift) - 1)) == 0) {
 					scst_check_restore_sg_buff(cmd);
 					scst_zero_write_rest(cmd);
 				} else {