From c63c44e4f090bd7d0dd24cdd2f702ba4e8bcb2bc Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 12 Feb 2019 03:07:02 +0000
Subject: [PATCH 1/5] vdisk_fileio: Add additioinal consistency check for
 asynchronous I/O

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7918 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/dev_handlers/scst_vdisk.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 9ec6e4af6..884f6d827 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -3269,6 +3269,8 @@ static void fileio_async_complete(struct kiocb *iocb, long ret, long ret2)
 	struct vdisk_cmd_params *p = container_of(iocb, typeof(*p), async.iocb);
 	struct scst_cmd *cmd = p->cmd;
 
+	WARN_ON_ONCE(ret >= 0 && ret != cmd->bufflen);
+
 	if (ret < 0 &&
 	    scst_cmd_get_data_direction(cmd) & SCST_DATA_WRITE)
 		scst_set_cmd_error(cmd,

From 70150cb9129db9f5938c590a3629259adb17a2e0 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 12 Feb 2019 03:07:54 +0000
Subject: [PATCH 2/5] scst: Remove the exec_sync flag

Since all device handlers have at least one asynchronous mode, remove
the exec_sync flag.


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7919 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 doc/scst_pg.sgml                   | 10 ++--------
 scst/include/scst.h                | 11 ++---------
 scst/src/dev_handlers/scst_vdisk.c |  2 --
 scst/src/scst_targ.c               |  2 +-
 4 files changed, 5 insertions(+), 20 deletions(-)

diff --git a/doc/scst_pg.sgml b/doc/scst_pg.sgml
index eb2475b12..c75dddf82 100644
--- a/doc/scst_pg.sgml
+++ b/doc/scst_pg.sgml
@@ -563,8 +563,6 @@ struct scst_dev_type
 
 	unsigned no_proc:1;
 
-	unsigned exec_sync:1;
-
 	unsigned pr_cmds_notifications:1;
 
 	int threads_num;
@@ -607,9 +605,6 @@ execution in the atomic (non-sleeping) context.
 <item> <bf/no_proc/ - true, if no /proc files should be automatically
 created by SCST for this dev handler
 
-<item> <bf/exec_sync/ - should be true, if exec() is synchronous. This
-is a hint to SCST core to optimize commands order management.
-
 <item> <bf/pr_cmds_notifications/ - should be set if the device wants to
 receive notification of Persistent Reservation commands (PR OUT only)
 Note: The notifications will not be sent if the command failed.
@@ -682,9 +677,8 @@ Returns:
 	mid-level.
 </itemize>
 
-If this function provides sync execution, you should set
-exec_sync flag and consider to setup dedicated threads by
-setting <it/threads_num/ > 0.
+If this function provides sync execution, you should consider to setup
+dedicated threads by setting <it/threads_num/ > 0.
 
 Optional, if not set, the commands will be sent directly to SCSI
 device.
diff --git a/scst/include/scst.h b/scst/include/scst.h
index 78c0d1973..b96a778ee 100644
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -1381,12 +1381,6 @@ struct scst_dev_type {
 	unsigned no_proc:1;
 #endif
 
-	/*
-	 * Should be true, if exec() is synchronous. This is a hint to SCST core
-	 * to optimize commands order management.
-	 */
-	unsigned exec_sync:1;
-
 	/*
 	 * Should be set if the device wants to receive notification of
 	 * Persistent Reservation commands (PR OUT only)
@@ -1454,9 +1448,8 @@ struct scst_dev_type {
 	 *  - SCST_EXEC_NOT_COMPLETED - the cmd should be sent to SCSI
 	 *	mid-level.
 	 *
-	 * If this function provides sync execution, you should set
-	 * exec_sync flag and consider to setup dedicated threads by
-	 * setting threads_num > 0.
+	 * If this function provides sync execution, you should to set up
+	 * dedicated threads by setting threads_num > 0.
 	 *
 	 * Dev handlers implementing internal queuing in their exec() callback
 	 * should call scst_check_local_events() just before the actual
diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 884f6d827..8899bddeb 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -760,7 +760,6 @@ static vdisk_op_fn nullio_ops[256];
 static struct scst_dev_type vdisk_file_devtype = {
 	.name =			"vdisk_fileio",
 	.type =			TYPE_DISK,
-	.exec_sync =		1,
 	.threads_num =		-1,
 	.parse_atomic =		1,
 	.dev_done_atomic =	1,
@@ -922,7 +921,6 @@ static struct scst_dev_type vdisk_null_devtype = {
 static struct scst_dev_type vcdrom_devtype = {
 	.name =			"vcdrom",
 	.type =			TYPE_ROM,
-	.exec_sync =		1,
 	.threads_num =		-1,
 	.parse_atomic =		1,
 	.dev_done_atomic =	1,
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 0c23accc9..651b45de4 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -953,7 +953,7 @@ int scst_pre_parse(struct scst_cmd *cmd)
 #ifdef CONFIG_SCST_STRICT_SERIALIZING
 	cmd->inc_expected_sn_on_done = 1;
 #else
-	cmd->inc_expected_sn_on_done = devt->exec_sync || cmd->cmd_naca ||
+	cmd->inc_expected_sn_on_done = cmd->cmd_naca ||
 		(!dev->has_own_order_mgmt &&
 		 (dev->queue_alg == SCST_QUEUE_ALG_0_RESTRICTED_REORDER ||
 		  cmd->queue_type == SCST_CMD_QUEUE_ORDERED));

From 6dc08eb5b6b27f9401d289631369ebf53b4d766b Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 12 Feb 2019 03:08:39 +0000
Subject: [PATCH 3/5] scst_vdisk: Avoid that fileio_alloc_and_parse() locks up
 in tasklet context if low on memory

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7920 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/dev_handlers/scst_vdisk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 8899bddeb..229f6a58d 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -3092,7 +3092,8 @@ static int fileio_alloc_and_parse(struct scst_cmd *cmd)
 
 	TRACE_ENTRY();
 
-	p = kmem_cache_zalloc(vdisk_cmd_param_cachep, cmd->cmd_gfp_mask);
+	p = kmem_cache_zalloc(vdisk_cmd_param_cachep,
+			      in_interrupt() ? GFP_ATOMIC : cmd->cmd_gfp_mask);
 	if (!p) {
 		scst_set_busy(cmd);
 		goto out_err;

From aa6c9558e821aade778838bd672fad2c0d7d1fbd Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 12 Feb 2019 03:10:12 +0000
Subject: [PATCH 4/5] scst: Introduce enum scst_exec_res

This patch does not change any functionality.


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7921 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/include/scst.h                 | 21 +++++++--------
 scst/src/dev_handlers/scst_disk.c   | 13 ++++-----
 scst/src/dev_handlers/scst_modisk.c |  6 ++---
 scst/src/dev_handlers/scst_tape.c   |  6 ++---
 scst/src/dev_handlers/scst_user.c   |  4 +--
 scst/src/dev_handlers/scst_vdisk.c  | 27 ++++++++++---------
 scst/src/scst_copy_mgr.c            | 10 ++++---
 scst/src/scst_lib.c                 |  4 +--
 scst/src/scst_priv.h                | 11 ++++----
 scst/src/scst_targ.c                | 42 +++++++++++++++--------------
 10 files changed, 75 insertions(+), 69 deletions(-)

diff --git a/scst/include/scst.h b/scst/include/scst.h
index b96a778ee..68027ec4b 100644
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -448,17 +448,16 @@ enum scst_exec_context {
  ** Return codes for dev handler's exec()
  *************************************************************/
 
-/*
- * The cmd is completed, go to other ones. It doesn't necessary to be really
- * completed, it can still be being processed. This code means that SCST
- * core should start performing post processing actions for this cmd, like
- * increase SN and reactivate deferred commands, if allowed, and start
- * processing other commands.
- */
-#define SCST_EXEC_COMPLETED          0
+enum scst_exec_res {
+	/*
+	 * The device handler has finished executing the command or has
+	 * started executing the command asynchronously.
+	 */
+	SCST_EXEC_COMPLETED	= 0,
 
-/* The cmd should continue staying on the EXEC phase */
-#define SCST_EXEC_NOT_COMPLETED      1
+	/* Pass through the command to the SCSI mid-level. */
+	SCST_EXEC_NOT_COMPLETED	= 1,
+};
 
 /*************************************************************
  ** Session initialization phases
@@ -1458,7 +1457,7 @@ struct scst_dev_type {
 	 * OPTIONAL, if not set, the commands will be sent directly to SCSI
 	 * device.
 	 */
-	int (*exec)(struct scst_cmd *cmd);
+	enum scst_exec_res (*exec)(struct scst_cmd *cmd);
 
 	/*
 	 * Called to notify dev handler about the result of cmd execution
diff --git a/scst/src/dev_handlers/scst_disk.c b/scst/src/dev_handlers/scst_disk.c
index 01120b90b..e5ede7d66 100644
--- a/scst/src/dev_handlers/scst_disk.c
+++ b/scst/src/dev_handlers/scst_disk.c
@@ -45,10 +45,10 @@
 static int disk_attach(struct scst_device *dev);
 static void disk_detach(struct scst_device *dev);
 static int disk_parse(struct scst_cmd *cmd);
-static int disk_perf_exec(struct scst_cmd *cmd);
+static enum scst_exec_res disk_perf_exec(struct scst_cmd *cmd);
 static int disk_done(struct scst_cmd *cmd);
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 30)
-static int disk_exec(struct scst_cmd *cmd);
+static enum scst_exec_res disk_exec(struct scst_cmd *cmd);
 static bool disk_on_sg_tablesize_low(struct scst_cmd *cmd);
 #endif
 
@@ -396,9 +396,10 @@ out_complete:
 }
 
 /* Executes command and split CDB, if necessary */
-static int disk_exec(struct scst_cmd *cmd)
+static enum scst_exec_res disk_exec(struct scst_cmd *cmd)
 {
-	int res, rc;
+	enum scst_exec_res res;
+	int rc;
 	struct disk_work work;
 	struct scst_device *dev = cmd->dev;
 	unsigned int offset, cur_len; /* in blocks */
@@ -583,9 +584,9 @@ out_error:
 
 #endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 30) */
 
-static int disk_perf_exec(struct scst_cmd *cmd)
+static enum scst_exec_res disk_perf_exec(struct scst_cmd *cmd)
 {
-	int res;
+	enum scst_exec_res res;
 	int opcode = cmd->cdb[0];
 
 	TRACE_ENTRY();
diff --git a/scst/src/dev_handlers/scst_modisk.c b/scst/src/dev_handlers/scst_modisk.c
index 61cb17f3f..a63529e28 100644
--- a/scst/src/dev_handlers/scst_modisk.c
+++ b/scst/src/dev_handlers/scst_modisk.c
@@ -45,7 +45,7 @@ static int modisk_attach(struct scst_device *);
 static void modisk_detach(struct scst_device *);
 static int modisk_parse(struct scst_cmd *);
 static int modisk_done(struct scst_cmd *);
-static int modisk_perf_exec(struct scst_cmd *);
+static enum scst_exec_res modisk_perf_exec(struct scst_cmd *);
 
 static struct scst_dev_type modisk_devtype = {
 	.name =			MODISK_NAME,
@@ -308,9 +308,9 @@ static int modisk_done(struct scst_cmd *cmd)
 	return res;
 }
 
-static int modisk_perf_exec(struct scst_cmd *cmd)
+static enum scst_exec_res modisk_perf_exec(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_NOT_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_NOT_COMPLETED;
 	int opcode = cmd->cdb[0];
 
 	TRACE_ENTRY();
diff --git a/scst/src/dev_handlers/scst_tape.c b/scst/src/dev_handlers/scst_tape.c
index c8224b7ee..fa240094d 100644
--- a/scst/src/dev_handlers/scst_tape.c
+++ b/scst/src/dev_handlers/scst_tape.c
@@ -50,7 +50,7 @@ static int tape_attach(struct scst_device *);
 static void tape_detach(struct scst_device *);
 static int tape_parse(struct scst_cmd *);
 static int tape_done(struct scst_cmd *);
-static int tape_perf_exec(struct scst_cmd *);
+static enum scst_exec_res tape_perf_exec(struct scst_cmd *);
 
 static struct scst_dev_type tape_devtype = {
 	.name =			TAPE_NAME,
@@ -336,9 +336,9 @@ out:
 	return res;
 }
 
-static int tape_perf_exec(struct scst_cmd *cmd)
+static enum scst_exec_res tape_perf_exec(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_NOT_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_NOT_COMPLETED;
 	int opcode = cmd->cdb[0];
 
 	TRACE_ENTRY();
diff --git a/scst/src/dev_handlers/scst_user.c b/scst/src/dev_handlers/scst_user.c
index 8fb443814..d7ddca08b 100644
--- a/scst/src/dev_handlers/scst_user.c
+++ b/scst/src/dev_handlers/scst_user.c
@@ -913,10 +913,10 @@ out:
 	return;
 }
 
-static int dev_user_exec(struct scst_cmd *cmd)
+static enum scst_exec_res dev_user_exec(struct scst_cmd *cmd)
 {
 	struct scst_user_cmd *ucmd = cmd->dh_priv;
-	int res = SCST_EXEC_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
 
 	TRACE_ENTRY();
 
diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 229f6a58d..04e5201a3 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -331,10 +331,10 @@ static int vcdrom_get_supported_opcodes(struct scst_cmd *cmd,
 static int vdisk_parse(struct scst_cmd *);
 static int vcdrom_parse(struct scst_cmd *);
 static int non_fileio_parse(struct scst_cmd *);
-static int fileio_exec(struct scst_cmd *cmd);
-static int vcdrom_exec(struct scst_cmd *cmd);
-static int blockio_exec(struct scst_cmd *cmd);
-static int nullio_exec(struct scst_cmd *cmd);
+static enum scst_exec_res fileio_exec(struct scst_cmd *cmd);
+static enum scst_exec_res vcdrom_exec(struct scst_cmd *cmd);
+static enum scst_exec_res blockio_exec(struct scst_cmd *cmd);
+static enum scst_exec_res nullio_exec(struct scst_cmd *cmd);
 static void blockio_on_alua_state_change_start(struct scst_device *dev,
 	enum scst_tg_state old_state, enum scst_tg_state new_state);
 static void blockio_on_alua_state_change_finish(struct scst_device *dev,
@@ -3160,9 +3160,10 @@ out:
 	return res;
 }
 
-static int vdev_do_job(struct scst_cmd *cmd, const vdisk_op_fn *ops)
+static enum scst_exec_res vdev_do_job(struct scst_cmd *cmd,
+				      const vdisk_op_fn *ops)
 {
-	int res;
+	enum scst_exec_res res;
 	uint8_t *cdb = cmd->cdb;
 	int opcode = cdb[0];
 	struct vdisk_cmd_params *p = cmd->dh_priv;
@@ -3224,7 +3225,7 @@ out_invalid_opcode:
 	goto out_compl;
 }
 
-static int fileio_exec(struct scst_cmd *cmd)
+static enum scst_exec_res fileio_exec(struct scst_cmd *cmd)
 {
 	struct scst_vdisk_dev *virt_dev = cmd->dev->dh_priv;
 	const vdisk_op_fn *ops = virt_dev->vdev_devt->devt_priv;
@@ -3459,12 +3460,12 @@ out:
 	return res;
 }
 
-static int blockio_exec(struct scst_cmd *cmd)
+static enum scst_exec_res blockio_exec(struct scst_cmd *cmd)
 {
 	struct scst_vdisk_dev *virt_dev = cmd->dev->dh_priv;
 	const vdisk_op_fn *ops = virt_dev->vdev_devt->devt_priv;
 	struct vdisk_cmd_params p;
-	int res;
+	enum scst_exec_res res;
 
 	EXTRACHECKS_BUG_ON(!ops);
 
@@ -3505,12 +3506,12 @@ err:
 	goto out;
 }
 
-static int nullio_exec(struct scst_cmd *cmd)
+static enum scst_exec_res nullio_exec(struct scst_cmd *cmd)
 {
 	struct scst_vdisk_dev *virt_dev = cmd->dev->dh_priv;
 	const vdisk_op_fn *ops = virt_dev->vdev_devt->devt_priv;
 	struct vdisk_cmd_params p;
-	int res;
+	enum scst_exec_res res;
 
 	EXTRACHECKS_BUG_ON(!ops);
 
@@ -3533,9 +3534,9 @@ err:
 	goto out;
 }
 
-static int vcdrom_exec(struct scst_cmd *cmd)
+static enum scst_exec_res vcdrom_exec(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
 	int opcode = cmd->cdb[0];
 	struct scst_vdisk_dev *virt_dev = cmd->dev->dh_priv;
 
diff --git a/scst/src/scst_copy_mgr.c b/scst/src/scst_copy_mgr.c
index d57bc4a36..4f4136274 100644
--- a/scst/src/scst_copy_mgr.c
+++ b/scst/src/scst_copy_mgr.c
@@ -1616,9 +1616,10 @@ out:
 	return;
 }
 
-int scst_cm_ext_copy_exec(struct scst_cmd *ec_cmd)
+enum scst_exec_res scst_cm_ext_copy_exec(struct scst_cmd *ec_cmd)
 {
-	int res = SCST_EXEC_COMPLETED, rc;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
+	int rc;
 	struct scst_cm_ec_cmd_priv *priv = ec_cmd->cmd_data_descriptors;
 
 	TRACE_ENTRY();
@@ -2273,9 +2274,10 @@ out:
 	return;
 }
 
-int scst_cm_rcv_copy_res_exec(struct scst_cmd *cmd)
+enum scst_exec_res scst_cm_rcv_copy_res_exec(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_COMPLETED, action;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
+	int action;
 
 	TRACE_ENTRY();
 
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 4952ca481..d34c54481 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -6859,9 +6859,9 @@ out_finish:
 	goto out;
 }
 
-int scst_cmp_wr_local(struct scst_cmd *cmd)
+enum scst_exec_res scst_cmp_wr_local(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
 	struct scst_cwr_priv *cwrp;
 	uint8_t read16_cdb[16];
 	struct scst_cmd *rcmd;
diff --git a/scst/src/scst_priv.h b/scst/src/scst_priv.h
index 063a7f083..a5bab7e9e 100644
--- a/scst/src/scst_priv.h
+++ b/scst/src/scst_priv.h
@@ -862,7 +862,7 @@ void scst_unthrottle_cmd(struct scst_cmd *cmd);
 int scst_do_internal_parsing(struct scst_cmd *cmd);
 int scst_parse_descriptors(struct scst_cmd *cmd);
 
-int scst_cmp_wr_local(struct scst_cmd *cmd);
+enum scst_exec_res scst_cmp_wr_local(struct scst_cmd *cmd);
 
 int scst_pr_init(struct scst_device *dev);
 void scst_pr_cleanup(struct scst_device *dev);
@@ -912,8 +912,8 @@ bool scst_cm_on_del_lun(struct scst_acg_dev *acg_dev,
 int scst_cm_parse_descriptors(struct scst_cmd *cmd);
 void scst_cm_free_descriptors(struct scst_cmd *cmd);
 
-int scst_cm_ext_copy_exec(struct scst_cmd *cmd);
-int scst_cm_rcv_copy_res_exec(struct scst_cmd *cmd);
+enum scst_exec_res scst_cm_ext_copy_exec(struct scst_cmd *cmd);
+enum scst_exec_res scst_cm_rcv_copy_res_exec(struct scst_cmd *cmd);
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
 void sess_cm_list_id_cleanup_work_fn(void *p);
@@ -965,11 +965,12 @@ static inline int scst_cm_parse_descriptors(struct scst_cmd *cmd)
 }
 static inline void scst_cm_free_descriptors(struct scst_cmd *cmd) {}
 
-static inline int scst_cm_ext_copy_exec(struct scst_cmd *cmd)
+static inline enum scst_exec_res scst_cm_ext_copy_exec(struct scst_cmd *cmd)
 {
 	return SCST_EXEC_NOT_COMPLETED;
 }
-static inline int scst_cm_rcv_copy_res_exec(struct scst_cmd *cmd)
+
+static inline enum scst_exec_res scst_cm_rcv_copy_res_exec(struct scst_cmd *cmd)
 {
 	return SCST_EXEC_NOT_COMPLETED;
 }
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 651b45de4..628239d98 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -2247,9 +2247,9 @@ static void scst_cmd_done_local(struct scst_cmd *cmd, int next_state,
 	return;
 }
 
-static int scst_report_luns_local(struct scst_cmd *cmd)
+static enum scst_exec_res scst_report_luns_local(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
 	int dev_cnt = 0;
 	int buffer_size;
 	int i;
@@ -2348,9 +2348,9 @@ out_put_err:
 	goto out_compl;
 }
 
-static int scst_request_sense_local(struct scst_cmd *cmd)
+static enum scst_exec_res scst_request_sense_local(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
 	struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
 	uint8_t *buffer;
 	int buffer_size = 0, sl = 0;
@@ -2720,9 +2720,9 @@ out_err_put:
 	goto out_compl;
 }
 
-static int scst_maintenance_in(struct scst_cmd *cmd)
+static enum scst_exec_res scst_maintenance_in(struct scst_cmd *cmd)
 {
-	int res;
+	enum scst_exec_res res;
 
 	TRACE_ENTRY();
 
@@ -2742,9 +2742,9 @@ static int scst_maintenance_in(struct scst_cmd *cmd)
 	return res;
 }
 
-static int scst_reserve_local(struct scst_cmd *cmd)
+static enum scst_exec_res scst_reserve_local(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_NOT_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_NOT_COMPLETED;
 	struct scst_device *dev;
 	struct scst_lksb pr_lksb;
 
@@ -2818,9 +2818,9 @@ out_done:
 	goto out;
 }
 
-static int scst_release_local(struct scst_cmd *cmd)
+static enum scst_exec_res scst_release_local(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_NOT_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_NOT_COMPLETED;
 	struct scst_device *dev;
 	struct scst_lksb pr_lksb;
 
@@ -2894,7 +2894,7 @@ out_done:
 }
 
 /* No locks, no IRQ or IRQ-disabled context allowed */
-static int scst_persistent_reserve_in_local(struct scst_cmd *cmd)
+static enum scst_exec_res scst_persistent_reserve_in_local(struct scst_cmd *cmd)
 {
 	struct scst_device *dev;
 	struct scst_tgt_dev *tgt_dev;
@@ -3002,9 +3002,10 @@ out_unsup_act:
 }
 
 /* No locks, no IRQ or IRQ-disabled context allowed */
-static int scst_persistent_reserve_out_local(struct scst_cmd *cmd)
+static enum scst_exec_res
+scst_persistent_reserve_out_local(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_COMPLETED;
 	struct scst_device *dev;
 	struct scst_tgt_dev *tgt_dev;
 	struct scst_session *session;
@@ -3401,9 +3402,9 @@ out:
 }
 
 /* cmd must be additionally referenced to not die inside */
-static int scst_do_real_exec(struct scst_cmd *cmd)
+static enum scst_exec_res scst_do_real_exec(struct scst_cmd *cmd)
 {
-	int res = SCST_EXEC_NOT_COMPLETED;
+	enum scst_exec_res res = SCST_EXEC_NOT_COMPLETED;
 	int rc;
 	struct scst_device *dev = cmd->dev;
 	struct scst_dev_type *devt = cmd->devt;
@@ -3523,7 +3524,7 @@ out_done:
 	goto out;
 }
 
-typedef int (*scst_local_exec_fn)(struct scst_cmd *cmd);
+typedef enum scst_exec_res (*scst_local_exec_fn)(struct scst_cmd *cmd);
 
 static scst_local_exec_fn scst_local_fns[256] = {
 	[RESERVE] = scst_reserve_local,
@@ -3540,9 +3541,9 @@ static scst_local_exec_fn scst_local_fns[256] = {
 	[MAINTENANCE_IN] = scst_maintenance_in,
 };
 
-static int scst_do_local_exec(struct scst_cmd *cmd)
+static enum scst_exec_res scst_do_local_exec(struct scst_cmd *cmd)
 {
-	int res;
+	enum scst_exec_res res;
 	struct scst_tgt_dev *tgt_dev = cmd->tgt_dev;
 
 	TRACE_ENTRY();
@@ -3577,9 +3578,10 @@ out_done:
 	goto out;
 }
 
-static int scst_local_exec(struct scst_cmd *cmd)
+static enum scst_exec_res scst_local_exec(struct scst_cmd *cmd)
 {
-	int res, rc;
+	enum scst_exec_res res;
+	int rc;
 
 	TRACE_ENTRY();
 

From 34f9b158e236c63e7748477608d7581554b510a7 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 12 Feb 2019 03:16:12 +0000
Subject: [PATCH 5/5] scst: Only switch to thread context if no Data-Out buffer
 and no failure

This patch avoids that the following is reported:

[0]: scst_pre_parse:949:Failed CDB:
 (h)___0__1__2__3__4__5__6__7__8__9__A__B__C__D__E__F
   0: 8b 00 00 00 00 00 00 00 00 00 00 00 00 01 00 00   ................
[0]: dev_vdisk: vdisk_parse_offset:2999:Unknown opcode 0x8b
[0]: scst_parse_cmd:1333:Atomic context and non-WRITE data direction, rescheduling (cmd 00000000cd981f2b)
[0]: scst: scst_process_active_cmd:5571:***CRITICAL ERROR***: cmd 00000000cd981f2b is in invalid state 10)
BUG at /home/bart/software/scst.git/scst/src/scst_targ.c:5572
 ------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(val > preempt_count())
WARNING: CPU: 1 PID: 0 at kernel/sched/core.c:3230 preempt_count_sub+0x7f/0xd0
Modules linked in: qla2x00tgt(O) scst_vdisk(O) isert_scst(O) iscsi_scst(O) scst(O) sd_mod sg brd dlm af_packet crct10dif_pclmul hid_generic aesni_intel aes_x86_64 crypto_simd cryptd usbhid glue_helper hid qla2xxx_scst(O) virtio_balloon l
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G        W  O      5.0.0-rc6-dbg+ #2
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
 <IRQ>
 __local_bh_enable_ip+0x7e/0x140
 local_bh_enable+0x15/0x20 [scst]
 scst_process_active_cmd+0x555/0x570 [scst]
 scst_do_job_active.constprop.23+0x57/0xe0 [scst]
 scst_cmd_tasklet+0x42/0x70 [scst]
 tasklet_action_common.isra.14+0xc3/0x280
 tasklet_action+0x3d/0x50
 __do_softirq+0x12d/0x5b7
 irq_exit+0xdd/0x100
 do_IRQ+0xc3/0x160
 common_interrupt+0xf/0xf
 </IRQ>



git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7922 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/scst_targ.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 628239d98..617cc3cbb 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -1327,7 +1327,7 @@ set_res:
 	 * be because of the SCST_TGT_DEV_AFTER_* optimization, but during
 	 * parsing data_direction can change, so we need to recheck.
 	 */
-	if (unlikely(scst_cmd_atomic(cmd) &&
+	if (unlikely(scst_cmd_atomic(cmd) && cmd->status == 0 &&
 		     !(cmd->data_direction & SCST_DATA_WRITE))) {
 		TRACE_DBG_FLAG(TRACE_DEBUG|TRACE_MINOR, "Atomic context and "
 			"non-WRITE data direction, rescheduling (cmd %p)", cmd);