From e1c234685c50807e10a3e7873e6e006976a4d8e8 Mon Sep 17 00:00:00 2001 From: Boaz Harrosh Date: Mon, 8 Oct 2007 16:36:45 +0200 Subject: [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 Signed-off-by: James Bottomley --- drivers/scsi/scsi_error.c | 114 +++++++++++++++++++++++++++------------------- include/scsi/scsi_eh.h | 23 +++++++++- 2 files changed, 90 insertions(+), 47 deletions(-) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 4d535019e04b..d29f8464b74f 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; } diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h index c5c0f6762a01..44224ba4dd90 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 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 */ -- cgit v1.2.3-59-g8ed1b