Commit b8e162f9 authored by Bart Van Assche's avatar Bart Van Assche Committed by Martin K. Petersen
Browse files

scsi: core: Introduce enum scsi_disposition 

Improve readability of the code in the SCSI core by introducing an
enumeration type for the values used internally that decide how to continue
processing a SCSI command. The eh_*_handler return values have not been
changed because that would involve modifying all SCSI drivers.

The output of the following command has been inspected to verify that no
out-of-range values are assigned to a variable of type enum
scsi_disposition:

KCFLAGS=-Wassign-enum make CC=clang W=1 drivers/scsi/

Link: https://lore.kernel.org/r/20210415220826.29438-6-bvanassche@acm.org


Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 280e91b0

drivers/ata/libata-eh.c

+1 −1
Original line number Diff line number Diff line
@@ -1599,7 +1599,7 @@ static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc, 
	}



	if (qc->flags & ATA_QCFLAG_SENSE_VALID) {

		int ret = scsi_check_sense(qc->scsicmd);

		enum scsi_disposition ret = scsi_check_sense(qc->scsicmd);

		/*

		 * SUCCESS here means that the sense code could be

		 * evaluated and should be passed to the upper layers

drivers/scsi/device_handler/scsi_dh_alua.c

+2 −2
Original line number Diff line number Diff line
@@ -405,7 +405,7 @@ static char print_alua_state(unsigned char state) 
	}

}



static int alua_check_sense(struct scsi_device *sdev,

static enum scsi_disposition alua_check_sense(struct scsi_device *sdev,

					      struct scsi_sense_hdr *sense_hdr)

{

	struct alua_dh_data *h = sdev->handler_data;

drivers/scsi/device_handler/scsi_dh_emc.c

+2 −2
Original line number Diff line number Diff line
@@ -280,7 +280,7 @@ static int send_trespass_cmd(struct scsi_device *sdev, 
	return res;

}



static int clariion_check_sense(struct scsi_device *sdev,

static enum scsi_disposition clariion_check_sense(struct scsi_device *sdev,

					struct scsi_sense_hdr *sense_hdr)

{

	switch (sense_hdr->sense_key) {

drivers/scsi/device_handler/scsi_dh_rdac.c

+2 −2
Original line number Diff line number Diff line
@@ -656,7 +656,7 @@ static blk_status_t rdac_prep_fn(struct scsi_device *sdev, struct request *req) 
	return BLK_STS_OK;

}



static int rdac_check_sense(struct scsi_device *sdev,

static enum scsi_disposition rdac_check_sense(struct scsi_device *sdev,

					      struct scsi_sense_hdr *sense_hdr)

{

	struct rdac_dh_data *h = sdev->handler_data;

drivers/scsi/scsi_error.c

+34 −30
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ static void scsi_eh_done(struct scsi_cmnd *scmd); 
#define HOST_RESET_SETTLE_TIME  (10)



static int scsi_eh_try_stu(struct scsi_cmnd *scmd);

static int scsi_try_to_abort_cmd(struct scsi_host_template *,

static enum scsi_disposition scsi_try_to_abort_cmd(struct scsi_host_template *,

						   struct scsi_cmnd *);



void scsi_eh_wakeup(struct Scsi_Host *shost)
@@ -151,7 +151,7 @@ scmd_eh_abort_handler(struct work_struct *work) 
	struct scsi_cmnd *scmd =

		container_of(work, struct scsi_cmnd, abort_work.work);

	struct scsi_device *sdev = scmd->device;

	int rtn;

	enum scsi_disposition rtn;



	if (scsi_host_eh_past_deadline(sdev->host)) {

		SCSI_LOG_ERROR_RECOVERY(3,
@@ -498,7 +498,7 @@ static void scsi_report_sense(struct scsi_device *sdev, 
 *	When a deferred error is detected the current command has

 *	not been executed and needs retrying.

 */

int scsi_check_sense(struct scsi_cmnd *scmd)

enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)

{

	struct scsi_device *sdev = scmd->device;

	struct scsi_sense_hdr sshdr;
@@ -512,7 +512,7 @@ int scsi_check_sense(struct scsi_cmnd *scmd) 
		return NEEDS_RETRY;



	if (sdev->handler && sdev->handler->check_sense) {

		int rc;

		enum scsi_disposition rc;



		rc = sdev->handler->check_sense(sdev, &sshdr);

		if (rc != SCSI_RETURN_NOT_HANDLED)
@@ -723,7 +723,7 @@ static void scsi_handle_queue_full(struct scsi_device *sdev) 
 *    don't allow for the possibility of retries here, and we are a lot

 *    more restrictive about what we consider acceptable.

 */

static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)

static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd)

{

	/*

	 * first check the host byte, to see if there is anything in there
@@ -804,10 +804,10 @@ static void scsi_eh_done(struct scsi_cmnd *scmd) 
 * scsi_try_host_reset - ask host adapter to reset itself

 * @scmd:	SCSI cmd to send host reset.

 */

static int scsi_try_host_reset(struct scsi_cmnd *scmd)

static enum scsi_disposition scsi_try_host_reset(struct scsi_cmnd *scmd)

{

	unsigned long flags;

	int rtn;

	enum scsi_disposition rtn;

	struct Scsi_Host *host = scmd->device->host;

	struct scsi_host_template *hostt = host->hostt;
@@ -834,10 +834,10 @@ static int scsi_try_host_reset(struct scsi_cmnd *scmd) 
 * scsi_try_bus_reset - ask host to perform a bus reset

 * @scmd:	SCSI cmd to send bus reset.

 */

static int scsi_try_bus_reset(struct scsi_cmnd *scmd)

static enum scsi_disposition scsi_try_bus_reset(struct scsi_cmnd *scmd)

{

	unsigned long flags;

	int rtn;

	enum scsi_disposition rtn;

	struct Scsi_Host *host = scmd->device->host;

	struct scsi_host_template *hostt = host->hostt;
@@ -876,10 +876,10 @@ static void __scsi_report_device_reset(struct scsi_device *sdev, void *data) 
 *    timer on it, and set the host back to a consistent state prior to

 *    returning.

 */

static int scsi_try_target_reset(struct scsi_cmnd *scmd)

static enum scsi_disposition scsi_try_target_reset(struct scsi_cmnd *scmd)

{

	unsigned long flags;

	int rtn;

	enum scsi_disposition rtn;

	struct Scsi_Host *host = scmd->device->host;

	struct scsi_host_template *hostt = host->hostt;
@@ -907,9 +907,9 @@ static int scsi_try_target_reset(struct scsi_cmnd *scmd) 
 *    timer on it, and set the host back to a consistent state prior to

 *    returning.

 */

static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)

static enum scsi_disposition scsi_try_bus_device_reset(struct scsi_cmnd *scmd)

{

	int rtn;

	enum scsi_disposition rtn;

	struct scsi_host_template *hostt = scmd->device->host->hostt;



	if (!hostt->eh_device_reset_handler)
@@ -938,8 +938,8 @@ static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd) 
 *    if the device is temporarily unavailable (eg due to a

 *    link down on FibreChannel)

 */

static int scsi_try_to_abort_cmd(struct scsi_host_template *hostt,

				 struct scsi_cmnd *scmd)

static enum scsi_disposition

scsi_try_to_abort_cmd(struct scsi_host_template *hostt, struct scsi_cmnd *scmd)

{

	if (!hostt->eh_abort_handler)

		return FAILED;
@@ -1072,8 +1072,8 @@ EXPORT_SYMBOL(scsi_eh_restore_cmnd); 
 * Return value:

 *    SUCCESS or FAILED or NEEDS_RETRY

 */

static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,

			     int cmnd_size, int timeout, unsigned sense_bytes)

static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd,

	unsigned char *cmnd, int cmnd_size, int timeout, unsigned sense_bytes)

{

	struct scsi_device *sdev = scmd->device;

	struct Scsi_Host *shost = sdev->host;
@@ -1180,12 +1180,13 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd, 
 *    that we obtain it on our own. This function will *not* return until

 *    the command either times out, or it completes.

 */

static int scsi_request_sense(struct scsi_cmnd *scmd)

static enum scsi_disposition scsi_request_sense(struct scsi_cmnd *scmd)

{

	return scsi_send_eh_cmnd(scmd, NULL, 0, scmd->device->eh_timeout, ~0);

}



static int scsi_eh_action(struct scsi_cmnd *scmd, int rtn)

static enum scsi_disposition

scsi_eh_action(struct scsi_cmnd *scmd, enum scsi_disposition rtn)

{

	if (!blk_rq_is_passthrough(scmd->request)) {

		struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
@@ -1238,7 +1239,7 @@ int scsi_eh_get_sense(struct list_head *work_q, 
{

	struct scsi_cmnd *scmd, *next;

	struct Scsi_Host *shost;

	int rtn;

	enum scsi_disposition rtn;



	/*

	 * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO,
@@ -1316,7 +1317,8 @@ EXPORT_SYMBOL_GPL(scsi_eh_get_sense); 
static int scsi_eh_tur(struct scsi_cmnd *scmd)

{

	static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};

	int retry_cnt = 1, rtn;

	int retry_cnt = 1;

	enum scsi_disposition rtn;



retry_tur:

	rtn = scsi_send_eh_cmnd(scmd, tur_command, 6,
@@ -1404,7 +1406,8 @@ static int scsi_eh_try_stu(struct scsi_cmnd *scmd) 
	static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};



	if (scmd->device->allow_restart) {

		int i, rtn = NEEDS_RETRY;

		int i;

		enum scsi_disposition rtn = NEEDS_RETRY;



		for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)

			rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->request_queue->rq_timeout, 0);
@@ -1498,7 +1501,7 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost, 
{

	struct scsi_cmnd *scmd, *bdr_scmd, *next;

	struct scsi_device *sdev;

	int rtn;

	enum scsi_disposition rtn;



	shost_for_each_device(sdev, shost) {

		if (scsi_host_eh_past_deadline(shost)) {
@@ -1565,7 +1568,7 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost, 


	while (!list_empty(&tmp_list)) {

		struct scsi_cmnd *next, *scmd;

		int rtn;

		enum scsi_disposition rtn;

		unsigned int id;



		if (scsi_host_eh_past_deadline(shost)) {
@@ -1623,7 +1626,7 @@ static int scsi_eh_bus_reset(struct Scsi_Host *shost, 
	struct scsi_cmnd *scmd, *chan_scmd, *next;

	LIST_HEAD(check_list);

	unsigned int channel;

	int rtn;

	enum scsi_disposition rtn;



	/*

	 * we really want to loop over the various channels, and do this on
@@ -1694,7 +1697,7 @@ static int scsi_eh_host_reset(struct Scsi_Host *shost, 
{

	struct scsi_cmnd *scmd, *next;

	LIST_HEAD(check_list);

	int rtn;

	enum scsi_disposition rtn;



	if (!list_empty(work_q)) {

		scmd = list_entry(work_q->next,
@@ -1800,9 +1803,9 @@ int scsi_noretry_cmd(struct scsi_cmnd *scmd) 
 *    doesn't require the error handler read (i.e. we don't need to

 *    abort/reset), this function should return SUCCESS.

 */

int scsi_decide_disposition(struct scsi_cmnd *scmd)

enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)

{

	int rtn;

	enum scsi_disposition rtn;



	/*

	 * if the device is offline, then we clearly just pass the result back
@@ -2365,7 +2368,8 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) 
	struct Scsi_Host *shost = dev->host;

	struct request *rq;

	unsigned long flags;

	int error = 0, rtn, val;

	int error = 0, val;

	enum scsi_disposition rtn;



	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))

		return -EACCES;