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scsi: core: Introduce enum scsi_disposition

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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: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bart Van Assche 2021-04-15 15:08:11 -07:00 committed by Martin K. Petersen
parent 280e91b026
commit b8e162f9e7
10 changed files with 57 additions and 51 deletions
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2
drivers/ata/libata-eh.c
View File

@ -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

4
drivers/scsi/device_handler/scsi_dh_alua.c
View File

@ -405,8 +405,8 @@ static char print_alua_state(unsigned char state)
}
}
static int alua_check_sense(struct scsi_device *sdev,
struct scsi_sense_hdr *sense_hdr)
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;
struct alua_port_group *pg;

4
drivers/scsi/device_handler/scsi_dh_emc.c
View File

@ -280,8 +280,8 @@ static int send_trespass_cmd(struct scsi_device *sdev,
return res;
}
static int clariion_check_sense(struct scsi_device *sdev,
struct scsi_sense_hdr *sense_hdr)
static enum scsi_disposition clariion_check_sense(struct scsi_device *sdev,
struct scsi_sense_hdr *sense_hdr)
{
switch (sense_hdr->sense_key) {
case NOT_READY:

4
drivers/scsi/device_handler/scsi_dh_rdac.c
View File

@ -656,8 +656,8 @@ 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,
struct scsi_sense_hdr *sense_hdr)
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;

64
drivers/scsi/scsi_error.c
View File

@ -60,8 +60,8 @@ 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 *,
struct scsi_cmnd *);
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 @@ retry:
* 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 @@ check_type:
* 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;

2
drivers/scsi/scsi_lib.c
View File

@ -1441,7 +1441,7 @@ static bool scsi_mq_lld_busy(struct request_queue *q)
static void scsi_complete(struct request *rq)
{
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
int disposition;
enum scsi_disposition disposition;
INIT_LIST_HEAD(&cmd->eh_entry);

2
drivers/scsi/scsi_priv.h
View File

@ -74,7 +74,7 @@ extern void scsi_exit_devinfo(void);
extern void scmd_eh_abort_handler(struct work_struct *work);
extern enum blk_eh_timer_return scsi_times_out(struct request *req);
extern int scsi_error_handler(void *host);
extern int scsi_decide_disposition(struct scsi_cmnd *cmd);
extern enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *cmd);
extern void scsi_eh_wakeup(struct Scsi_Host *shost);
extern void scsi_eh_scmd_add(struct scsi_cmnd *);
void scsi_eh_ready_devs(struct Scsi_Host *shost,

21
include/scsi/scsi.h
View File

@ -180,16 +180,17 @@ static inline int scsi_is_wlun(u64 lun)
/*
* Internal return values.
*/
#define NEEDS_RETRY 0x2001
#define SUCCESS 0x2002
#define FAILED 0x2003
#define QUEUED 0x2004
#define SOFT_ERROR 0x2005
#define ADD_TO_MLQUEUE 0x2006
#define TIMEOUT_ERROR 0x2007
#define SCSI_RETURN_NOT_HANDLED 0x2008
#define FAST_IO_FAIL 0x2009
enum scsi_disposition {
NEEDS_RETRY = 0x2001,
SUCCESS = 0x2002,
FAILED = 0x2003,
QUEUED = 0x2004,
SOFT_ERROR = 0x2005,
ADD_TO_MLQUEUE = 0x2006,
TIMEOUT_ERROR = 0x2007,
SCSI_RETURN_NOT_HANDLED = 0x2008,
FAST_IO_FAIL = 0x2009,
};
/*
* Midlevel queue return values.

3
include/scsi/scsi_dh.h
View File

@ -52,7 +52,8 @@ struct scsi_device_handler {
/* Filled by the hardware handler */
struct module *module;
const char *name;
int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr *);
enum scsi_disposition (*check_sense)(struct scsi_device *,
struct scsi_sense_hdr *);
int (*attach)(struct scsi_device *);
void (*detach)(struct scsi_device *);
int (*activate)(struct scsi_device *, activate_complete, void *);

2
include/scsi/scsi_eh.h
View File

@ -17,7 +17,7 @@ extern void scsi_report_device_reset(struct Scsi_Host *, int, int);
extern int scsi_block_when_processing_errors(struct scsi_device *);
extern bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
struct scsi_sense_hdr *sshdr);
extern int scsi_check_sense(struct scsi_cmnd *);
extern enum scsi_disposition scsi_check_sense(struct scsi_cmnd *);
static inline bool scsi_sense_is_deferred(const struct scsi_sense_hdr *sshdr)
{