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ataflop: convert to blk-mq 

This driver is already pretty broken, in that it has two wait_events()
(one in stdma_lock()) in request_fn. Get rid of the first one by
freezing/quiescing the queue on format, and the second one by replacing
it with stdma_try_lock(). The rest is straightforward. Compile-tested
only and probably incorrect.

Cc: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>

Converted to blk_mq_init_sq_queue()

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Omar Sandoval 2018-10-15 09:18:24 -06:00 committed by Jens Axboe
parent 71327f547e
commit 6ec3938cff
1 changed files with 71 additions and 102 deletions
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173
drivers/block/ataflop.c
View File

@ -66,7 +66,7 @@
#include <linux/fd.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/mutex.h>
#include <linux/completion.h>
#include <linux/wait.h>
@ -81,7 +81,6 @@
static DEFINE_MUTEX(ataflop_mutex);
static struct request *fd_request;
static int fdc_queue;
/*
* WD1772 stuff
@ -300,6 +299,7 @@ static struct atari_floppy_struct {
struct gendisk *disk;
int ref;
int type;
struct blk_mq_tag_set tag_set;
} unit[FD_MAX_UNITS];
#define UD unit[drive]
@ -379,9 +379,6 @@ static int IsFormatting = 0, FormatError;
static int UserSteprate[FD_MAX_UNITS] = { -1, -1 };
module_param_array(UserSteprate, int, NULL, 0);
/* Synchronization of FDC access. */
static volatile int fdc_busy = 0;
static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
static DECLARE_COMPLETION(format_wait);
static unsigned long changed_floppies = 0xff, fake_change = 0;
@ -441,7 +438,6 @@ static void fd_times_out(struct timer_list *unused);
static void finish_fdc( void );
static void finish_fdc_done( int dummy );
static void setup_req_params( int drive );
static void redo_fd_request( void);
static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int
cmd, unsigned long param);
static void fd_probe( int drive );
@ -459,8 +455,11 @@ static DEFINE_TIMER(fd_timer, check_change);
static void fd_end_request_cur(blk_status_t err)
{
if (!__blk_end_request_cur(fd_request, err))
if (!blk_update_request(fd_request, err,
blk_rq_cur_bytes(fd_request))) {
__blk_mq_end_request(fd_request, err);
fd_request = NULL;
}
}
static inline void start_motor_off_timer(void)
@ -706,7 +705,6 @@ static void fd_error( void )
if (SelectedDrive != -1)
SUD.track = -1;
}
redo_fd_request();
}
@ -724,14 +722,15 @@ static void fd_error( void )
static int do_format(int drive, int type, struct atari_format_descr *desc)
{
struct request_queue *q = unit[drive].disk->queue;
unsigned char *p;
int sect, nsect;
unsigned long flags;
int ret;
DPRINT(("do_format( dr=%d tr=%d he=%d offs=%d )\n",
drive, desc->track, desc->head, desc->sect_offset ));
blk_mq_freeze_queue(q);
blk_mq_quiesce_queue(q);
wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0);
local_irq_save(flags);
stdma_lock(floppy_irq, NULL);
atari_turnon_irq( IRQ_MFP_FDC ); /* should be already, just to be sure */
@ -740,16 +739,16 @@ static int do_format(int drive, int type, struct atari_format_descr *desc)
if (type) {
if (--type >= NUM_DISK_MINORS ||
minor2disktype[type].drive_types > DriveType) {
redo_fd_request();
return -EINVAL;
ret = -EINVAL;
goto out;
}
type = minor2disktype[type].index;
UDT = &atari_disk_type[type];
}
if (!UDT || desc->track >= UDT->blocks/UDT->spt/2 || desc->head >= 2) {
redo_fd_request();
return -EINVAL;
ret = -EINVAL;
goto out;
}
nsect = UDT->spt;
@ -788,8 +787,11 @@ static int do_format(int drive, int type, struct atari_format_descr *desc)
wait_for_completion(&format_wait);
redo_fd_request();
return( FormatError ? -EIO : 0 );
ret = FormatError ? -EIO : 0;
out:
blk_mq_unquiesce_queue(q);
blk_mq_unfreeze_queue(q);
return ret;
}
@ -819,7 +821,6 @@ static void do_fd_action( int drive )
else {
/* all sectors finished */
fd_end_request_cur(BLK_STS_OK);
redo_fd_request();
return;
}
}
@ -1224,7 +1225,6 @@ static void fd_rwsec_done1(int status)
else {
/* all sectors finished */
fd_end_request_cur(BLK_STS_OK);
redo_fd_request();
}
return;
@ -1382,8 +1382,6 @@ static void finish_fdc_done( int dummy )
local_irq_save(flags);
stdma_release();
fdc_busy = 0;
wake_up( &fdc_wait );
local_irq_restore(flags);
DPRINT(("finish_fdc() finished\n"));
@ -1473,59 +1471,34 @@ static void setup_req_params( int drive )
ReqTrack, ReqSector, (unsigned long)ReqData ));
}
/*
* Round-robin between our available drives, doing one request from each
*/
static struct request *set_next_request(void)
static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *bd)
{
struct request_queue *q;
int old_pos = fdc_queue;
struct request *rq = NULL;
struct atari_floppy_struct *floppy = bd->rq->rq_disk->private_data;
int drive = floppy - unit;
int type = floppy->type;
do {
q = unit[fdc_queue].disk->queue;
if (++fdc_queue == FD_MAX_UNITS)
fdc_queue = 0;
if (q) {
rq = blk_fetch_request(q);
if (rq) {
rq->error_count = 0;
break;
}
}
} while (fdc_queue != old_pos);
spin_lock_irq(&ataflop_lock);
if (fd_request) {
spin_unlock_irq(&ataflop_lock);
return BLK_STS_DEV_RESOURCE;
}
if (!stdma_try_lock(floppy_irq, NULL)) {
spin_unlock_irq(&ataflop_lock);
return BLK_STS_RESOURCE;
}
fd_request = bd->rq;
blk_mq_start_request(fd_request);
return rq;
}
static void redo_fd_request(void)
{
int drive, type;
struct atari_floppy_struct *floppy;
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 ));
atari_disable_irq( IRQ_MFP_FDC );
IsFormatting = 0;
repeat:
if (!fd_request) {
fd_request = set_next_request();
if (!fd_request)
goto the_end;
}
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 );
fd_end_request_cur(BLK_STS_IOERR);
goto repeat;
goto out;
}
if (type == 0) {
@ -1541,23 +1514,18 @@ static void redo_fd_request(void)
if (--type >= NUM_DISK_MINORS) {
printk(KERN_WARNING "fd%d: invalid disk format", drive );
fd_end_request_cur(BLK_STS_IOERR);
goto repeat;
goto out;
}
if (minor2disktype[type].drive_types > DriveType) {
printk(KERN_WARNING "fd%d: unsupported disk format", drive );
fd_end_request_cur(BLK_STS_IOERR);
goto repeat;
goto out;
}
type = minor2disktype[type].index;
UDT = &atari_disk_type[type];
set_capacity(floppy->disk, UDT->blocks);
UD.autoprobe = 0;
}
if (blk_rq_pos(fd_request) + 1 > UDT->blocks) {
fd_end_request_cur(BLK_STS_IOERR);
goto repeat;
}
/* stop deselect timer */
del_timer( &motor_off_timer );
@ -1569,22 +1537,13 @@ static void redo_fd_request(void)
setup_req_params( drive );
do_fd_action( drive );
return;
the_end:
finish_fdc();
}
void do_fd_request(struct request_queue * q)
{
DPRINT(("do_fd_request for pid %d\n",current->pid));
wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0);
stdma_lock(floppy_irq, NULL);
atari_disable_irq( IRQ_MFP_FDC );
redo_fd_request();
if (bd->last)
finish_fdc();
atari_enable_irq( IRQ_MFP_FDC );
out:
spin_unlock_irq(&ataflop_lock);
return BLK_STS_OK;
}
static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
@ -1662,7 +1621,6 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
/* what if type > 0 here? Overwrite specified entry ? */
if (type) {
/* refuse to re-set a predefined type for now */
redo_fd_request();
return -EINVAL;
}
@ -1730,10 +1688,8 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
/* sanity check */
if (setprm.track != dtp->blocks/dtp->spt/2 ||
setprm.head != 2) {
redo_fd_request();
setprm.head != 2)
return -EINVAL;
}
UDT = dtp;
set_capacity(floppy->disk, UDT->blocks);
@ -1989,6 +1945,10 @@ static const struct block_device_operations floppy_fops = {
.revalidate_disk= floppy_revalidate,
};
static const struct blk_mq_ops ataflop_mq_ops = {
.queue_rq = ataflop_queue_rq,
};
static struct kobject *floppy_find(dev_t dev, int *part, void *data)
{
int drive = *part & 3;
@ -2002,6 +1962,7 @@ static struct kobject *floppy_find(dev_t dev, int *part, void *data)
static int __init atari_floppy_init (void)
{
int i;
int ret;
if (!MACH_IS_ATARI)
/* Amiga, Mac, ... don't have Atari-compatible floppy :-) */
@ -2012,13 +1973,19 @@ static int __init atari_floppy_init (void)
for (i = 0; i < FD_MAX_UNITS; i++) {
unit[i].disk = alloc_disk(1);
if (!unit[i].disk)
goto Enomem;
if (!unit[i].disk) {
ret = -ENOMEM;
goto err;
}
unit[i].disk->queue = blk_init_queue(do_fd_request,
&ataflop_lock);
if (!unit[i].disk->queue)
goto Enomem;
unit[i].disk->queue = blk_mq_init_sq_queue(&unit[i].tag_set,
&ataflop_mq_ops, 2,
BLK_MQ_F_SHOULD_MERGE);
if (IS_ERR(unit[i].disk->queue)) {
ret = PTR_ERR(unit[i].disk->queue);
unit[i].disk->queue = NULL;
goto err;
}
}
if (UseTrackbuffer < 0)
@ -2035,7 +2002,8 @@ static int __init atari_floppy_init (void)
DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");
if (!DMABuffer) {
printk(KERN_ERR "atari_floppy_init: cannot get dma buffer\n");
goto Enomem;
ret = -ENOMEM;
goto err;
}
TrackBuffer = DMABuffer + 512;
PhysDMABuffer = atari_stram_to_phys(DMABuffer);
@ -2063,7 +2031,8 @@ static int __init atari_floppy_init (void)
config_types();
return 0;
Enomem:
err:
do {
struct gendisk *disk = unit[i].disk;
@ -2072,12 +2041,13 @@ static int __init atari_floppy_init (void)
blk_cleanup_queue(disk->queue);
disk->queue = NULL;
}
blk_mq_free_tag_set(&unit[i].tag_set);
put_disk(unit[i].disk);
}
} while (i--);
unregister_blkdev(FLOPPY_MAJOR, "fd");
return -ENOMEM;
return ret;
}
#ifndef MODULE
@ -2124,11 +2094,10 @@ static void __exit atari_floppy_exit(void)
int i;
blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
for (i = 0; i < FD_MAX_UNITS; i++) {
struct request_queue *q = unit[i].disk->queue;
del_gendisk(unit[i].disk);
blk_cleanup_queue(unit[i].disk->queue);
blk_mq_free_tag_set(&unit[i].tag_set);
put_disk(unit[i].disk);
blk_cleanup_queue(q);
}
unregister_blkdev(FLOPPY_MAJOR, "fd");