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authorBoaz Harrosh <bharrosh@panasas.com>2007-10-08 16:36:45 +0200
committerJames Bottomley <jejb@mulgrave.localdomain>2007-10-12 14:54:58 -0400
commite1c234685c50807e10a3e7873e6e006976a4d8e8 (patch)
tree4be0f09620503f6669a40dacd49326443c9c07dc /drivers/scsi
parent55db6c1b8ed52bfc876e87971de8c67c42f36909 (diff)
[SCSI] scsi_error: Refactoring scsi_error to facilitate in synchronous REQUEST_SENSE
- 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@panasas.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/scsi_error.c114
1 files changed, 68 insertions, 46 deletions
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 4d535019e04..d29f8464b74 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
+ * @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
* @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
*
- * This function is used to send a scsi command down to a target device
+ * This function is used to save a scsi command information before re-execution
* as part of the error recovery process. If @sense_bytes is 0 the command
* sent must be one that does not transfer any data. If @sense_bytes != 0
* @cmnd is ignored and this functions sets up a REQUEST_SENSE command
* and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
- *
- * 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)
+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
@@ -634,20 +615,21 @@ 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 (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, sizeof(scmd->cmnd));
@@ -677,7 +659,58 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
* untransferred sense data should be interpreted as being zero.
*/
memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
+}
+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);
@@ -721,18 +754,7 @@ 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;
}