ide-atapi: convert ide-{floppy,tape} to using preallocated sense buffer

Since we're issuing REQ_TYPE_SENSE now we need to allow those types of
rqs in the ->do_request callbacks. As a future improvement, sense_len
assignment might be unified across all ATAPI devices. Borislav to
check with specs and test.

As a result, get rid of ide_queue_pc_head() and
drive->request_sense_rq.

tj: * Init request sense ide_atapi_pc from sense request.  In the
      longer timer, it would probably better to fold
      ide_create_request_sense_cmd() into its only current user -
      ide_floppy_get_format_progress().

    * ide_retry_pc() no longer takes @disk.

CC: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

4 files changed, 23 insertions, 39 deletions

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index c6e03485a63a..972c522516f8 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -80,34 +80,6 @@ void ide_init_pc(struct ide_atapi_pc *pc)
 EXPORT_SYMBOL_GPL(ide_init_pc);
 
 /*
- * Generate a new packet command request in front of the request queue, before
- * the current request, so that it will be processed immediately, on the next
- * pass through the driver.
- */
-static void ide_queue_pc_head(ide_drive_t *drive, struct gendisk *disk,
-                              struct ide_atapi_pc *pc, struct request *rq)
-{
-        blk_rq_init(NULL, rq);
-        rq->cmd_type = REQ_TYPE_SPECIAL;
-        rq->cmd_flags |= REQ_PREEMPT;
-        rq->special = (char *)pc;
-        rq->rq_disk = disk;
-
-        if (pc->req_xfer) {
-                rq->data = pc->buf;
-                rq->data_len = pc->req_xfer;
-        }
-
-        memcpy(rq->cmd, pc->c, 12);
-        if (drive->media == ide_tape)
-                rq->cmd[13] = REQ_IDETAPE_PC1;
-
-        drive->hwif->rq = NULL;
-
-        elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 0);
-}
-
-/*
  * Add a special packet command request to the tail of the request queue,
  * and wait for it to be serviced.
  */
@@ -254,18 +226,26 @@ EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
 
 /*
  * Called when an error was detected during the last packet command.
- * We queue a request sense packet command in the head of the request list.
+ * We queue a request sense packet command at the head of the request
+ * queue.
  */
-void ide_retry_pc(ide_drive_t *drive, struct gendisk *disk)
+void ide_retry_pc(ide_drive_t *drive)
 {
-        struct request *rq = &drive->request_sense_rq;
+        struct request *sense_rq = &drive->sense_rq;
         struct ide_atapi_pc *pc = &drive->request_sense_pc;
 
         (void)ide_read_error(drive);
-        ide_create_request_sense_cmd(drive, pc);
+
+        /* init pc from sense_rq */
+        ide_init_pc(pc);
+        memcpy(pc->c, sense_rq->cmd, 12);
+        pc->buf = sense_rq->data;
+        pc->req_xfer = sense_rq->data_len;
+
         if (drive->media == ide_tape)
                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
-        ide_queue_pc_head(drive, disk, pc, rq);
+
+        ide_queue_sense_rq(drive, pc);
 }
 EXPORT_SYMBOL_GPL(ide_retry_pc);
 
@@ -404,7 +384,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
                         debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
 
                         /* Retry operation */
-                        ide_retry_pc(drive, rq->rq_disk);
+                        ide_retry_pc(drive);
 
                         /* queued, but not started */
                         return ide_stopped;
diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index 94600331a271..d3302cc891e4 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -263,7 +263,7 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
                 }
                 pc = &floppy->queued_pc;
                 idefloppy_create_rw_cmd(drive, pc, rq, (unsigned long)block);
-        } else if (blk_special_request(rq)) {
+        } else if (blk_special_request(rq) || blk_sense_request(rq)) {
                 pc = (struct ide_atapi_pc *)rq->special;
         } else if (blk_pc_request(rq)) {
                 pc = &floppy->queued_pc;
@@ -273,6 +273,8 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
                 goto out_end;
         }
 
+        ide_prep_sense(drive, rq);
+
         memset(&cmd, 0, sizeof(cmd));
 
         if (rq_data_dir(rq))
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index aadf53cfac6f..8324dfa78a3f 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -695,7 +695,7 @@ static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
                                                 tape->name);
                         /* Retry operation */
-                        ide_retry_pc(drive, tape->disk);
+                        ide_retry_pc(drive);
                         return ide_stopped;
                 }
                 pc->error = 0;
@@ -752,7 +752,7 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                         (unsigned long long)rq->sector, rq->nr_sectors,
                         rq->current_nr_sectors);
 
-        if (!blk_special_request(rq)) {
+        if (!(blk_special_request(rq) || blk_sense_request(rq))) {
                 /* We do not support buffer cache originated requests. */
                 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
                         "request queue (%d)\n", drive->name, rq->cmd_type);
@@ -840,6 +840,9 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
         BUG();
 
 out:
+        /* prepare sense request for this command */
+        ide_prep_sense(drive, rq);
+
         memset(&cmd, 0, sizeof(cmd));
 
         if (rq_data_dir(rq))
diff --git a/include/linux/ide.h b/include/linux/ide.h
index a69ccac56411..9e67ccac3c1f 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -604,7 +604,6 @@ struct ide_drive_s {
         unsigned long atapi_flags;
 
         struct ide_atapi_pc request_sense_pc;
-        struct request request_sense_rq;
 
         /* current sense rq and buffer */
         bool sense_rq_armed;
@@ -1181,7 +1180,7 @@ int ide_do_test_unit_ready(ide_drive_t *, struct gendisk *);
 int ide_do_start_stop(ide_drive_t *, struct gendisk *, int);
 int ide_set_media_lock(ide_drive_t *, struct gendisk *, int);
 void ide_create_request_sense_cmd(ide_drive_t *, struct ide_atapi_pc *);
-void ide_retry_pc(ide_drive_t *, struct gendisk *);
+void ide_retry_pc(ide_drive_t *drive);
 
 void ide_prep_sense(ide_drive_t *drive, struct request *rq);
 void ide_queue_sense_rq(ide_drive_t *drive, void *special);