ide-atapi: switch to blk_rq_bytes() on do_request() path

After the recent struct request cleanups, blk_rq_bytes() is guaranteed
to be valid and is the current total length of the rq's bio. Use that
instead of pc->req_xfer in the do_request() path after the command has
been queued

The remaining usage of pc->req_xfer now is only until we map the rq to a
bio.

While at it:

- remove local caching of rq completion length in ide_tape_issue_pc()

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>

3 files changed, 18 insertions, 16 deletions

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 8a894fa37b53..7129495b3e40 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -370,7 +370,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
                                                      ? "write" : "read");
                         pc->flags |= PC_FLAG_DMA_ERROR;
                 } else
-                        pc->xferred = pc->req_xfer;
+                        pc->xferred = blk_rq_bytes(rq);
                 debug_log("%s: DMA finished\n", drive->name);
         }
 
@@ -627,7 +627,7 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
         ide_hwif_t *hwif = drive->hwif;
         ide_expiry_t *expiry = NULL;
         struct request *rq = hwif->rq;
-        unsigned int timeout;
+        unsigned int timeout, bytes;
         u16 bcount;
         u8 valid_tf;
         u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
@@ -647,9 +647,11 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
                 pc->xferred = 0;
 
                 valid_tf = IDE_VALID_DEVICE;
-                bcount = ((drive->media == ide_tape) ?
-                                pc->req_xfer :
-                                min(pc->req_xfer, 63 * 1024));
+                bytes = blk_rq_bytes(rq);
+
+                bcount = ((drive->media == ide_tape) ? bytes
+                                                     : min_t(unsigned int,
+                                                             bytes, 63 * 1024));
 
                 if (pc->flags & PC_FLAG_DMA_ERROR) {
                         pc->flags &= ~PC_FLAG_DMA_ERROR;
diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index 650981758f15..a1c55985d4ae 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -210,7 +210,7 @@ static void idefloppy_create_rw_cmd(ide_drive_t *drive,
         if (rq->cmd_flags & REQ_RW)
                 pc->flags |= PC_FLAG_WRITING;
         pc->buf = NULL;
-        pc->req_xfer = pc->buf_size = blocks * floppy->block_size;
+        pc->buf_size = blk_rq_bytes(rq);
         pc->flags |= PC_FLAG_DMA_OK;
 }
 
@@ -227,7 +227,7 @@ static void idefloppy_blockpc_cmd(struct ide_disk_obj *floppy,
         }
         /* pio will be performed by ide_pio_bytes() which handles sg fine */
         pc->buf = NULL;
-        pc->req_xfer = pc->buf_size = blk_rq_bytes(rq);
+        pc->buf_size = blk_rq_bytes(rq);
 }
 
 static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
@@ -286,8 +286,8 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 
         cmd.rq = rq;
 
-        if (blk_fs_request(rq) || pc->req_xfer) {
-                ide_init_sg_cmd(&cmd, pc->req_xfer);
+        if (blk_fs_request(rq) || blk_rq_bytes(rq)) {
+                ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
                 ide_map_sg(drive, &cmd);
         }
 
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index fc79cf4812f3..aaeef12f80ad 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -292,6 +292,7 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
 {
         idetape_tape_t *tape = drive->driver_data;
         struct ide_atapi_pc *pc = drive->failed_pc;
+        struct request *rq = drive->hwif->rq;
 
         tape->sense_key = sense[2] & 0xF;
         tape->asc       = sense[12];
@@ -302,7 +303,7 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
 
         /* Correct pc->xferred by asking the tape.       */
         if (pc->flags & PC_FLAG_DMA_ERROR)
-                pc->xferred = pc->req_xfer -
+                pc->xferred = blk_rq_bytes(rq) -
                         tape->blk_size *
                         get_unaligned_be32(&sense[3]);
 
@@ -484,6 +485,7 @@ static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
                                          struct ide_atapi_pc *pc)
 {
         idetape_tape_t *tape = drive->driver_data;
+        struct request *rq = drive->hwif->rq;
 
         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
                 drive->failed_pc = pc;
@@ -493,7 +495,6 @@ static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 
         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
                 (pc->flags & PC_FLAG_ABORT)) {
-                unsigned int done = blk_rq_bytes(drive->hwif->rq);
 
                 /*
                  * We will "abort" retrying a packet command in case legitimate
@@ -517,7 +518,7 @@ static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
 
                 drive->failed_pc = NULL;
                 drive->pc_callback(drive, 0);
-                ide_complete_rq(drive, -EIO, done);
+                ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
                 return ide_stopped;
         }
         debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
@@ -592,9 +593,8 @@ static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
         pc->c[1] = 1;
         pc->buf = NULL;
-        pc->buf_size = length * tape->blk_size;
-        pc->req_xfer = pc->buf_size;
-        if (pc->req_xfer == tape->buffer_size)
+        pc->buf_size = blk_rq_bytes(rq);
+        if (pc->buf_size == tape->buffer_size)
                 pc->flags |= PC_FLAG_DMA_OK;
 
         if (opcode == READ_6)
@@ -718,7 +718,7 @@ out:
 
         cmd.rq = rq;
 
-        ide_init_sg_cmd(&cmd, pc->req_xfer);
+        ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
         ide_map_sg(drive, &cmd);
 
         return ide_tape_issue_pc(drive, &cmd, pc);