From 11dd7dc766b7184167a60255a2213427ddad8253 Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Thu, 7 Jun 2012 23:26:07 +0000
Subject: [PATCH] wt_flag handling fixes and improvements

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@4337 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/dev_handlers/scst_vdisk.c | 32 +++++++++++++++++++++++++-----
 usr/fileio/common.c                |  6 +++---
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 7eff0bea4..ebeeb228f 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -620,7 +620,7 @@ static struct file *vdev_open_fd(const struct scst_vdisk_dev *virt_dev)
 	if (virt_dev->o_direct_flag)
 		open_flags |= O_DIRECT;
 	if (virt_dev->wt_flag && !virt_dev->nv_cache)
-		open_flags |= O_SYNC;
+		open_flags |= O_DSYNC;
 	TRACE_DBG("Opening file %s, flags 0x%x",
 		  virt_dev->filename, open_flags);
 	fd = filp_open(virt_dev->filename, O_LARGEFILE | open_flags, 0600);
@@ -2771,6 +2771,8 @@ out:
 static int vdisk_set_wt(struct scst_vdisk_dev *virt_dev, int wt)
 {
 	int res = 0;
+	struct file *fd;
+	bool old_wt = virt_dev->wt_flag;
 
 	TRACE_ENTRY();
 
@@ -2781,6 +2783,27 @@ static int vdisk_set_wt(struct scst_vdisk_dev *virt_dev, int wt)
 	virt_dev->wt_flag = wt;
 	spin_unlock(&virt_dev->flags_lock);
 
+	/*
+	 * MODE SELECT is strictly serialized command, so it's safe here
+	 * to reopen fd.
+	 */
+
+	fd = vdev_open_fd(virt_dev);
+	if (IS_ERR(fd)) {
+		PRINT_ERROR("filp_open(%s) returned an error %ld",
+			    virt_dev->filename, PTR_ERR(fd));
+		spin_lock(&virt_dev->flags_lock);
+		virt_dev->wt_flag = old_wt;
+		spin_unlock(&virt_dev->flags_lock);
+		res = PTR_ERR(fd);
+		goto out;
+	}
+
+	if (virt_dev->fd)
+		filp_close(virt_dev->fd, NULL);
+
+	virt_dev->fd = fd;
+
 out:
 	TRACE_EXIT_RES(res);
 	return res;
@@ -2880,8 +2903,7 @@ static enum compl_status_e vdisk_exec_mode_select(struct vdisk_cmd_params *p)
 			}
 			if (vdisk_set_wt(virt_dev,
 			      (address[offset + 2] & WCE) ? 0 : 1) != 0) {
-				scst_set_cmd_error(cmd,
-				    SCST_LOAD_SENSE(scst_sense_hardw_error));
+				scst_set_busy(cmd);
 				goto out_put;
 			}
 			break;
@@ -3570,7 +3592,7 @@ restart:
 	set_fs(old_fs);
 
 out_sync:
-	/* O_SYNC flag is used for WT devices */
+	/* O_DSYNC flag is used for WT devices */
 	if (p->fua)
 		vdisk_fsync(p, loff, scst_cmd_get_data_len(cmd), cmd->dev,
 			    scst_cmd_get_gfp_flags(cmd), cmd);
@@ -3978,7 +4000,7 @@ static enum compl_status_e blockio_exec_write_verify(struct vdisk_cmd_params *p)
 static enum compl_status_e fileio_exec_write_verify(struct vdisk_cmd_params *p)
 {
 	fileio_exec_write(p);
-	/* O_SYNC flag is used for WT devices */
+	/* O_DSYNC flag is used for WT devices */
 	if (scsi_status_is_good(p->cmd->status))
 		fileio_exec_verify(p);
 	return CMD_SUCCEEDED;
diff --git a/usr/fileio/common.c b/usr/fileio/common.c
index 50855ceaa..0f7374588 100644
--- a/usr/fileio/common.c
+++ b/usr/fileio/common.c
@@ -292,7 +292,7 @@ static int do_exec(struct vdisk_cmd *vcmd)
 			}
 
 			exec_write(vcmd, loff);
-			/* O_SYNC flag is used for WT devices */
+			/* O_DSYNC flag is used for WT devices */
 			if (fua)
 				exec_fsync(vcmd);
 		} else {
@@ -318,7 +318,7 @@ static int do_exec(struct vdisk_cmd *vcmd)
 			}
 
 			exec_write(vcmd, loff);
-			/* O_SYNC flag is used for WT devices */
+			/* O_DSYNC flag is used for WT devices */
 			if (reply->status == 0)
 				exec_verify(vcmd, loff);
 			else if (fua)
@@ -607,7 +607,7 @@ static int open_dev_fd(struct vdisk_dev *dev)
 	if (dev->o_direct_flag)
 		open_flags |= O_DIRECT;
 	if (dev->wt_flag)
-		open_flags |= O_SYNC;
+		open_flags |= O_DSYNC;
 
 	TRACE_DBG("Opening file %s, flags 0x%x", dev->file_name, open_flags);
 	res = open(dev->file_name, open_flags);