- Drivers/transports that want to send a synchronous REQUEST_SENSE command
as part of their .queuecommand sequence, have 2 new API's that facilitate
in doing so and abstract them from scsi-ml internals.
void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
struct scsi_eh_save *sesci, unsigned char *cmnd,
int cmnd_size, int sense_bytes)
Will hijack a command and prepare it for request sense if needed.
And will save any later needed info into a scsi_eh_save structure.
void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
struct scsi_eh_save *sesci);
Will undo any changes done to a command by above function. Making
it ready for completion.
- Re-factor scsi_send_eh_cmnd() to use above APIs
Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
---
drivers/scsi/scsi_error.c | 126 ++++++++++++++++++++++++++------------------
include/scsi/scsi_eh.h | 23 ++++++++-
2 files changed, 96 insertions(+), 53 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 46d57f1..cd9fb34 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -590,42 +590,23 @@ static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
}
/**
- * scsi_send_eh_cmnd - submit a scsi command as part of error recory
+ * scsi_eh_prep_cmnd - Save a scsi command info as part of error recory
* @scmd: SCSI command structure to hijack
- * @cmnd: CDB to send
+ * @ses: structure to save restore information
+ * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
* @cmnd_size: size in bytes of @cmnd
- * @timeout: timeout for this request
- * @copy_sense: request sense data if set to 1
+ * @sense_bytes: size of sense data to copy. or 0
*
- * This function is used to send a scsi command down to a target device
- * as part of the error recovery process. If @copy_sense is 0 the command
- * sent must be one that does not transfer any data. If @copy_sense is 1
- * the command must be REQUEST_SENSE and this functions copies out the
- * sense buffer it got into @scmd->sense_buffer.
- *
- * Return value:
- * SUCCESS or FAILED or NEEDS_RETRY
+ * This function is used to save a scsi command information before re-execution
+ * as part of an error recovery process. If @sense_bytes is 0 the command
+ * given must be one that does not transfer any data. If @sense_bytes != 0
+ * the command should be NULL and this functions sets up the cmnd and
+ * command buffers to read @sense_bytes into @scmd->sense_buffer.
**/
-static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
- int cmnd_size, int timeout, unsigned sense_bytes)
+void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
+ unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
{
struct scsi_device *sdev = scmd->device;
- struct Scsi_Host *shost = sdev->host;
- DECLARE_COMPLETION_ONSTACK(done);
- unsigned long timeleft;
- unsigned long flags;
-
- unsigned char old_cmd_len;
- unsigned char old_cmnd[MAX_COMMAND_SIZE];
- enum dma_data_direction old_data_direction;
- unsigned old_bufflen;
- void *old_buffer;
- unsigned short old_use_sg;
- int old_resid;
- int old_result;
-
- struct scatterlist sgl;
- int rtn;
/*
* We need saved copies of a number of fields - this is because
@@ -634,14 +615,14 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
* we will need to restore these values prior to running the actual
* command.
*/
- old_cmd_len = scmd->cmd_len;
- memcpy(old_cmnd, scmd->cmnd, sizeof(scmd->cmnd));
- old_data_direction = scmd->sc_data_direction;
- old_bufflen = scmd->request_bufflen;
- old_buffer = scmd->request_buffer;
- old_use_sg = scmd->use_sg;
- old_resid = scmd->resid;
- old_result = scmd->result;
+ ses->cmd_len = scmd->cmd_len;
+ memcpy(ses->cmnd, scmd->cmnd, sizeof(scmd->cmnd));
+ ses->data_direction = scmd->sc_data_direction;
+ ses->bufflen = scmd->request_bufflen;
+ ses->buffer = scmd->request_buffer;
+ ses->use_sg = scmd->use_sg;
+ ses->resid = scmd->resid;
+ ses->result = scmd->result;
if (cmnd) {
memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
@@ -652,8 +633,9 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
if (sense_bytes) {
scmd->request_bufflen = min_t(unsigned,
sizeof(scmd->sense_buffer), sense_bytes);
- sg_init_one(&sgl, scmd->sense_buffer, scmd->request_bufflen);
- scmd->request_buffer = &sgl;
+ sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
+ scmd->request_bufflen);
+ scmd->request_buffer = &ses->sense_sgl;
scmd->sc_data_direction = DMA_FROM_DEVICE;
scmd->use_sg = 1;
memset(scmd->cmnd, 0, 6);
@@ -676,7 +658,58 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
(sdev->lun << 5 & 0xe0);
+}
+EXPORT_SYMBOL(scsi_eh_prep_cmnd);
+
+/**
+ * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recory
+ * @scmd: SCSI command structure to restore
+ * @ses: saved information from a coresponding call to scsi_prep_eh_cmnd
+ *
+ * Undo any damage done by above scsi_prep_eh_cmnd().
+ **/
+void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
+{
+ /*
+ * Restore original data
+ */
+ scmd->cmd_len = ses->cmd_len;
+ memcpy(scmd->cmnd, ses->cmnd, sizeof(scmd->cmnd));
+ scmd->sc_data_direction = ses->data_direction;
+ scmd->request_bufflen = ses->bufflen;
+ scmd->request_buffer = ses->buffer;
+ scmd->use_sg = ses->use_sg;
+ scmd->resid = ses->resid;
+ scmd->result = ses->result;
+}
+EXPORT_SYMBOL(scsi_eh_restore_cmnd);
+/**
+ * scsi_send_eh_cmnd - submit a scsi command as part of error recory
+ * @scmd: SCSI command structure to hijack
+ * @cmnd: CDB to send
+ * @cmnd_size: size in bytes of @cmnd
+ * @timeout: timeout for this request
+ * @sense_bytes: size of sense data to copy or 0
+ *
+ * This function is used to send a scsi command down to a target device
+ * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
+ *
+ * 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)
+{
+ struct scsi_device *sdev = scmd->device;
+ struct Scsi_Host *shost = sdev->host;
+ DECLARE_COMPLETION_ONSTACK(done);
+ unsigned long timeleft;
+ unsigned long flags;
+ struct scsi_eh_save ses;
+ int rtn;
+
+ scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
shost->eh_action = &done;
spin_lock_irqsave(shost->host_lock, flags);
@@ -720,18 +753,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
rtn = FAILED;
}
-
- /*
- * Restore original data
- */
- scmd->cmd_len = old_cmd_len;
- memcpy(scmd->cmnd, old_cmnd, sizeof(scmd->cmnd));
- scmd->sc_data_direction = old_data_direction;
- scmd->request_bufflen = old_bufflen;
- scmd->request_buffer = old_buffer;
- scmd->use_sg = old_use_sg;
- scmd->resid = old_resid;
- scmd->result = old_result;
+ scsi_eh_restore_cmnd(scmd, &ses);
return rtn;
}
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index c5c0f67..44224ba 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -1,7 +1,7 @@
#ifndef _SCSI_SCSI_EH_H
#define _SCSI_SCSI_EH_H
-struct scsi_cmnd;
+#include <scsi/scsi_cmnd.h>
struct scsi_device;
struct Scsi_Host;
@@ -65,4 +65,25 @@ extern int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
extern int scsi_reset_provider(struct scsi_device *, int);
+struct scsi_eh_save {
+ int result;
+ enum dma_data_direction data_direction;
+ unsigned char cmd_len;
+ unsigned char cmnd[MAX_COMMAND_SIZE];
+
+ void *buffer;
+ unsigned bufflen;
+ unsigned short use_sg;
+ int resid;
+
+ struct scatterlist sense_sgl;
+};
+
+extern void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
+ struct scsi_eh_save *ses, unsigned char *cmnd,
+ int cmnd_size, unsigned sense_bytes);
+
+extern void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
+ struct scsi_eh_save *ses);
+
#endif /* _SCSI_SCSI_EH_H */
--
1.5.3.1
-
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