[SCSI] st: integrate st_scsi_kern_execute and st_do_scsi

This integrates st_scsi_kern_execute and st_do_scsi. IOW, it removes
st_scsi_kern_execute. Then st has a single function, st_do_scsi, to
perform SCSI commands.

Signed-off-by: Kai Makisara <Kai.Makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 66 insertions, 136 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index fe4c20259bca..ddf2630b3479 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -17,7 +17,7 @@
    Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  */
 
-static const char *verstr = "20080504";
+static const char *verstr = "20081215";
 
 #include <linux/module.h>
 
@@ -491,10 +491,13 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 
         mdata->null_mapped = 1;
 
-        err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen, GFP_KERNEL);
-        if (err) {
-                blk_put_request(req);
-                return DRIVER_ERROR << 24;
+        if (bufflen) {
+                err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
+                                      GFP_KERNEL);
+                if (err) {
+                        blk_put_request(req);
+                        return DRIVER_ERROR << 24;
+                }
         }
 
         SRpnt->bio = req->bio;
@@ -577,28 +580,6 @@ st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd
         return SRpnt;
 }
 
-static int st_scsi_kern_execute(struct st_request *streq,
-                                const unsigned char *cmd, int data_direction,
-                                void *buffer, unsigned bufflen, int timeout,
-                                int retries)
-{
-        struct scsi_tape *stp = streq->stp;
-        int ret, resid;
-
-        stp->buffer->cmdstat.have_sense = 0;
-        memcpy(streq->cmd, cmd, sizeof(streq->cmd));
-
-        ret = scsi_execute(stp->device, cmd, data_direction, buffer, bufflen,
-                           streq->sense, timeout, retries, 0, &resid);
-        if (driver_byte(ret) & DRIVER_ERROR)
-                return -EBUSY;
-
-        stp->buffer->cmdstat.midlevel_result = streq->result = ret;
-        stp->buffer->cmdstat.residual = resid;
-        stp->buffer->syscall_result = st_chk_result(stp, streq);
-
-        return 0;
-}
 
 /* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
    write has been correct but EOM early warning reached, -EIO if write ended in
@@ -671,7 +652,6 @@ static int cross_eof(struct scsi_tape * STp, int forward)
 {
         struct st_request *SRpnt;
         unsigned char cmd[MAX_COMMAND_SIZE];
-        int ret;
 
         cmd[0] = SPACE;
         cmd[1] = 0x01;          /* Space FileMarks */
@@ -685,26 +665,20 @@ static int cross_eof(struct scsi_tape * STp, int forward)
         DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n",
                    tape_name(STp), forward ? "forward" : "backward"));
 
-        SRpnt = st_allocate_request(STp);
+        SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
+                           STp->device->request_queue->rq_timeout,
+                           MAX_RETRIES, 1);
         if (!SRpnt)
-                return STp->buffer->syscall_result;
-
-        ret = st_scsi_kern_execute(SRpnt, cmd, DMA_NONE, NULL, 0,
-                                   STp->device->request_queue->rq_timeout,
-                                   MAX_RETRIES);
-        if (ret)
-                goto out;
+                return (STp->buffer)->syscall_result;
 
-        ret = STp->buffer->syscall_result;
+        st_release_request(SRpnt);
+        SRpnt = NULL;
 
         if ((STp->buffer)->cmdstat.midlevel_result != 0)
                 printk(KERN_ERR "%s: Stepping over filemark %s failed.\n",
                    tape_name(STp), forward ? "forward" : "backward");
 
-out:
-        st_release_request(SRpnt);
-
-        return ret;
+        return (STp->buffer)->syscall_result;
 }
 
 
@@ -925,24 +899,21 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
         int attentions, waits, max_wait, scode;
         int retval = CHKRES_READY, new_session = 0;
         unsigned char cmd[MAX_COMMAND_SIZE];
-        struct st_request *SRpnt;
+        struct st_request *SRpnt = NULL;
         struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 
-        SRpnt = st_allocate_request(STp);
-        if (!SRpnt)
-                return STp->buffer->syscall_result;
-
         max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 
         for (attentions=waits=0; ; ) {
                 memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
                 cmd[0] = TEST_UNIT_READY;
+                SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
+                                   STp->long_timeout, MAX_READY_RETRIES, 1);
 
-                retval = st_scsi_kern_execute(SRpnt, cmd, DMA_NONE, NULL, 0,
-                                              STp->long_timeout,
-                                              MAX_READY_RETRIES);
-                if (retval)
+                if (!SRpnt) {
+                        retval = (STp->buffer)->syscall_result;
                         break;
+                }
 
                 if (cmdstatp->have_sense) {
 
@@ -986,8 +957,8 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
                 break;
         }
 
-        st_release_request(SRpnt);
-
+        if (SRpnt != NULL)
+                st_release_request(SRpnt);
         return retval;
 }
 
@@ -1064,24 +1035,17 @@ static int check_tape(struct scsi_tape *STp, struct file *filp)
                 }
         }
 
-        SRpnt = st_allocate_request(STp);
-        if (!SRpnt) {
-                retval = STp->buffer->syscall_result;
-                goto err_out;
-        }
-
         if (STp->omit_blklims)
                 STp->min_block = STp->max_block = (-1);
         else {
                 memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
                 cmd[0] = READ_BLOCK_LIMITS;
 
-                retval = st_scsi_kern_execute(SRpnt, cmd, DMA_FROM_DEVICE,
-                                              STp->buffer->b_data, 6,
-                                              STp->device->request_queue->rq_timeout,
-                                              MAX_READY_RETRIES);
-                if (retval) {
-                        st_release_request(SRpnt);
+                SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
+                                   STp->device->request_queue->rq_timeout,
+                                   MAX_READY_RETRIES, 1);
+                if (!SRpnt) {
+                        retval = (STp->buffer)->syscall_result;
                         goto err_out;
                 }
 
@@ -1105,12 +1069,11 @@ static int check_tape(struct scsi_tape *STp, struct file *filp)
         cmd[0] = MODE_SENSE;
         cmd[4] = 12;
 
-        retval = st_scsi_kern_execute(SRpnt, cmd, DMA_FROM_DEVICE,
-                                      STp->buffer->b_data, 12,
-                                      STp->device->request_queue->rq_timeout,
-                                      MAX_READY_RETRIES);
-        if (retval) {
-                st_release_request(SRpnt);
+        SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
+                           STp->device->request_queue->rq_timeout,
+                           MAX_READY_RETRIES, 1);
+        if (!SRpnt) {
+                retval = (STp->buffer)->syscall_result;
                 goto err_out;
         }
 
@@ -1340,17 +1303,11 @@ static int st_flush(struct file *filp, fl_owner_t id)
                 cmd[0] = WRITE_FILEMARKS;
                 cmd[4] = 1 + STp->two_fm;
 
-                SRpnt = st_allocate_request(STp);
+                SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
+                                   STp->device->request_queue->rq_timeout,
+                                   MAX_WRITE_RETRIES, 1);
                 if (!SRpnt) {
-                        result = STp->buffer->syscall_result;
-                        goto out;
-                }
-
-                result = st_scsi_kern_execute(SRpnt, cmd, DMA_NONE, NULL, 0,
-                                              STp->device->request_queue->rq_timeout,
-                                              MAX_WRITE_RETRIES);
-                if (result) {
-                        st_release_request(SRpnt);
+                        result = (STp->buffer)->syscall_result;
                         goto out;
                 }
 
@@ -2415,7 +2372,6 @@ static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
 {
         unsigned char cmd[MAX_COMMAND_SIZE];
         struct st_request *SRpnt;
-        int ret;
 
         memset(cmd, 0, MAX_COMMAND_SIZE);
         cmd[0] = MODE_SENSE;
@@ -2424,17 +2380,14 @@ static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
         cmd[2] = page;
         cmd[4] = 255;
 
-        SRpnt = st_allocate_request(STp);
-        if (!SRpnt)
-                return STp->buffer->syscall_result;
+        SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
+                           STp->device->request_queue->rq_timeout, 0, 1);
+        if (SRpnt == NULL)
+                return (STp->buffer)->syscall_result;
 
-        ret = st_scsi_kern_execute(SRpnt, cmd, DMA_FROM_DEVICE,
-                                   STp->buffer->b_data, cmd[4],
-                                   STp->device->request_queue->rq_timeout,
-                                   MAX_RETRIES);
         st_release_request(SRpnt);
 
-        return ret ? : STp->buffer->syscall_result;
+        return STp->buffer->syscall_result;
 }
 
 
@@ -2442,9 +2395,10 @@ static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
    in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
 static int write_mode_page(struct scsi_tape *STp, int page, int slow)
 {
-        int pgo, timeout, ret = 0;
+        int pgo;
         unsigned char cmd[MAX_COMMAND_SIZE];
         struct st_request *SRpnt;
+        int timeout;
 
         memset(cmd, 0, MAX_COMMAND_SIZE);
         cmd[0] = MODE_SELECT;
@@ -2458,21 +2412,16 @@ static int write_mode_page(struct scsi_tape *STp, int page, int slow)
         (STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
         (STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
 
-        SRpnt = st_allocate_request(STp);
-        if (!SRpnt)
-                return ret;
-
-        timeout = slow ? STp->long_timeout :
-                STp->device->request_queue->rq_timeout;
-
-        ret = st_scsi_kern_execute(SRpnt, cmd, DMA_TO_DEVICE,
-                                   STp->buffer->b_data, cmd[4], timeout, 0);
-        if (!ret)
-                ret = STp->buffer->syscall_result;
+        timeout = slow ?
+                STp->long_timeout : STp->device->request_queue->rq_timeout;
+        SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
+                           timeout, 0, 1);
+        if (SRpnt == NULL)
+                return (STp->buffer)->syscall_result;
 
         st_release_request(SRpnt);
 
-        return ret;
+        return STp->buffer->syscall_result;
 }
 
 
@@ -2590,16 +2539,13 @@ static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_cod
                 printk(ST_DEB_MSG "%s: Loading tape.\n", name);
                 );
 
-        SRpnt = st_allocate_request(STp);
+        SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
+                           timeout, MAX_RETRIES, 1);
         if (!SRpnt)
-                return STp->buffer->syscall_result;
-
-        retval = st_scsi_kern_execute(SRpnt, cmd, DMA_NONE, NULL, 0, timeout,
-                                      MAX_RETRIES);
-        if (retval)
-                goto out;
+                return (STp->buffer)->syscall_result;
 
         retval = (STp->buffer)->syscall_result;
+        st_release_request(SRpnt);
 
         if (!retval) {  /* SCSI command successful */
 
@@ -2618,8 +2564,6 @@ static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_cod
                 STps = &(STp->ps[STp->partition]);
                 STps->drv_file = STps->drv_block = (-1);
         }
-out:
-        st_release_request(SRpnt);
 
         return retval;
 }
@@ -2895,15 +2839,12 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon
                 return (-ENOSYS);
         }
 
-        SRpnt = st_allocate_request(STp);
+        SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
+                           timeout, MAX_RETRIES, 1);
         if (!SRpnt)
                 return (STp->buffer)->syscall_result;
 
-        ioctl_result = st_scsi_kern_execute(SRpnt, cmd, direction,
-                                            STp->buffer->b_data, datalen,
-                                            timeout, MAX_RETRIES);
-        if (!ioctl_result)
-                ioctl_result = (STp->buffer)->syscall_result;
+        ioctl_result = (STp->buffer)->syscall_result;
 
         if (!ioctl_result) {    /* SCSI command successful */
                 st_release_request(SRpnt);
@@ -3065,17 +3006,11 @@ static int get_location(struct scsi_tape *STp, unsigned int *block, int *partiti
                 if (!logical && !STp->scsi2_logical)
                         scmd[1] = 1;
         }
-
-        SRpnt = st_allocate_request(STp);
+        SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
+                           STp->device->request_queue->rq_timeout,
+                           MAX_READY_RETRIES, 1);
         if (!SRpnt)
-                return STp->buffer->syscall_result;
-
-        result = st_scsi_kern_execute(SRpnt, scmd, DMA_FROM_DEVICE,
-                                      STp->buffer->b_data, 20,
-                                      STp->device->request_queue->rq_timeout,
-                                      MAX_READY_RETRIES);
-        if (result)
-                goto out;
+                return (STp->buffer)->syscall_result;
 
         if ((STp->buffer)->syscall_result != 0 ||
             (STp->device->scsi_level >= SCSI_2 &&
@@ -3103,7 +3038,6 @@ static int get_location(struct scsi_tape *STp, unsigned int *block, int *partiti
                 DEBC(printk(ST_DEB_MSG "%s: Got tape pos. blk %d part %d.\n", name,
                             *block, *partition));
         }
-out:
         st_release_request(SRpnt);
         SRpnt = NULL;
 
@@ -3178,14 +3112,10 @@ static int set_location(struct scsi_tape *STp, unsigned int block, int partition
                 timeout = STp->device->request_queue->rq_timeout;
         }
 
-        SRpnt = st_allocate_request(STp);
+        SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
+                           timeout, MAX_READY_RETRIES, 1);
         if (!SRpnt)
-                return STp->buffer->syscall_result;
-
-        result = st_scsi_kern_execute(SRpnt, scmd, DMA_NONE, NULL, 0,
-                                      timeout, MAX_READY_RETRIES);
-        if (result)
-                goto out;
+                return (STp->buffer)->syscall_result;
 
         STps->drv_block = STps->drv_file = (-1);
         STps->eof = ST_NOEOF;
@@ -3210,7 +3140,7 @@ static int set_location(struct scsi_tape *STp, unsigned int block, int partition
                         STps->drv_block = STps->drv_file = 0;
                 result = 0;
         }
-out:
+
         st_release_request(SRpnt);
         SRpnt = NULL;