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ataflop: dequeue and track in-flight request
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ataflop has single request in flight.  Till now, whenever it needs to
access the in-flight request it called elv_next_request().  This patch
makes ataflop track the in-flight request directly and dequeue it when
processing starts.  The added complexity is minimal and this will help
future block layer changes.

[ Impact: dequeue in-flight request, one elv_next_request() per request ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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Tejun Heo authored and Jens Axboe committed May 11, 2009
1 parent 8a12c4a commit a336ca6
Showing 1 changed file with 35 additions and 28 deletions.
63 changes: 35 additions & 28 deletions drivers/block/ataflop.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -79,9 +79,7 @@
#undef DEBUG

static struct request_queue *floppy_queue;

#define QUEUE (floppy_queue)
#define CURRENT elv_next_request(floppy_queue)
static struct request *fd_request;

/* Disk types: DD, HD, ED */
static struct atari_disk_type {
Expand Down Expand Up @@ -376,6 +374,12 @@ static DEFINE_TIMER(readtrack_timer, fd_readtrack_check, 0, 0);
static DEFINE_TIMER(timeout_timer, fd_times_out, 0, 0);
static DEFINE_TIMER(fd_timer, check_change, 0, 0);

static void fd_end_request_cur(int err)
{
if (!__blk_end_request_cur(fd_request, err))
fd_request = NULL;
}

static inline void start_motor_off_timer(void)
{
mod_timer(&motor_off_timer, jiffies + FD_MOTOR_OFF_DELAY);
Expand Down Expand Up @@ -606,15 +610,15 @@ static void fd_error( void )
return;
}

if (!CURRENT)
if (!fd_request)
return;

CURRENT->errors++;
if (CURRENT->errors >= MAX_ERRORS) {
fd_request->errors++;
if (fd_request->errors >= MAX_ERRORS) {
printk(KERN_ERR "fd%d: too many errors.\n", SelectedDrive );
__blk_end_request_cur(CURRENT, -EIO);
fd_end_request_cur(-EIO);
}
else if (CURRENT->errors == RECALIBRATE_ERRORS) {
else if (fd_request->errors == RECALIBRATE_ERRORS) {
printk(KERN_WARNING "fd%d: recalibrating\n", SelectedDrive );
if (SelectedDrive != -1)
SUD.track = -1;
Expand Down Expand Up @@ -725,14 +729,14 @@ static void do_fd_action( int drive )
if (IS_BUFFERED( drive, ReqSide, ReqTrack )) {
if (ReqCmd == READ) {
copy_buffer( SECTOR_BUFFER(ReqSector), ReqData );
if (++ReqCnt < blk_rq_cur_sectors(CURRENT)) {
if (++ReqCnt < blk_rq_cur_sectors(fd_request)) {
/* read next sector */
setup_req_params( drive );
goto repeat;
}
else {
/* all sectors finished */
__blk_end_request_cur(CURRENT, 0);
fd_end_request_cur(0);
redo_fd_request();
return;
}
Expand Down Expand Up @@ -1130,14 +1134,14 @@ static void fd_rwsec_done1(int status)
}
}

if (++ReqCnt < blk_rq_cur_sectors(CURRENT)) {
if (++ReqCnt < blk_rq_cur_sectors(fd_request)) {
/* read next sector */
setup_req_params( SelectedDrive );
do_fd_action( SelectedDrive );
}
else {
/* all sectors finished */
__blk_end_request_cur(CURRENT, 0);
fd_end_request_cur(0);
redo_fd_request();
}
return;
Expand Down Expand Up @@ -1378,7 +1382,7 @@ static void setup_req_params( int drive )
ReqData = ReqBuffer + 512 * ReqCnt;

if (UseTrackbuffer)
read_track = (ReqCmd == READ && CURRENT->errors == 0);
read_track = (ReqCmd == READ && fd_request->errors == 0);
else
read_track = 0;

Expand All @@ -1392,25 +1396,28 @@ static void redo_fd_request(void)
int drive, type;
struct atari_floppy_struct *floppy;

DPRINT(("redo_fd_request: CURRENT=%p dev=%s CURRENT->sector=%ld\n",
CURRENT, CURRENT ? CURRENT->rq_disk->disk_name : "",
CURRENT ? blk_rq_pos(CURRENT) : 0 ));
DPRINT(("redo_fd_request: fd_request=%p dev=%s fd_request->sector=%ld\n",
fd_request, fd_request ? fd_request->rq_disk->disk_name : "",
fd_request ? blk_rq_pos(fd_request) : 0 ));

IsFormatting = 0;

repeat:
if (!fd_request) {
fd_request = elv_next_request(floppy_queue);
if (!fd_request)
goto the_end;
blkdev_dequeue_request(fd_request);
}

if (!CURRENT)
goto the_end;

floppy = CURRENT->rq_disk->private_data;
floppy = fd_request->rq_disk->private_data;
drive = floppy - unit;
type = floppy->type;

if (!UD.connected) {
/* drive not connected */
printk(KERN_ERR "Unknown Device: fd%d\n", drive );
__blk_end_request_cur(CURRENT, -EIO);
fd_end_request_cur(-EIO);
goto repeat;
}

Expand All @@ -1426,12 +1433,12 @@ static void redo_fd_request(void)
/* user supplied disk type */
if (--type >= NUM_DISK_MINORS) {
printk(KERN_WARNING "fd%d: invalid disk format", drive );
__blk_end_request_cur(CURRENT, -EIO);
fd_end_request_cur(-EIO);
goto repeat;
}
if (minor2disktype[type].drive_types > DriveType) {
printk(KERN_WARNING "fd%d: unsupported disk format", drive );
__blk_end_request_cur(CURRENT, -EIO);
fd_end_request_cur(-EIO);
goto repeat;
}
type = minor2disktype[type].index;
Expand All @@ -1440,18 +1447,18 @@ static void redo_fd_request(void)
UD.autoprobe = 0;
}

if (blk_rq_pos(CURRENT) + 1 > UDT->blocks) {
__blk_end_request_cur(CURRENT, -EIO);
if (blk_rq_pos(fd_request) + 1 > UDT->blocks) {
fd_end_request_cur(-EIO);
goto repeat;
}

/* stop deselect timer */
del_timer( &motor_off_timer );

ReqCnt = 0;
ReqCmd = rq_data_dir(CURRENT);
ReqBlock = blk_rq_pos(CURRENT);
ReqBuffer = CURRENT->buffer;
ReqCmd = rq_data_dir(fd_request);
ReqBlock = blk_rq_pos(fd_request);
ReqBuffer = fd_request->buffer;
setup_req_params( drive );
do_fd_action( drive );

Expand Down

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