Re: [PATCH v3 0/3] last batch of add_disk() error handling conversions

[Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>]

On 2021/10/22 1:38, Luis Chamberlain wrote:
> I rebased Tetsuo Handa's patch onto the latest linux-next as this
> series depends on it, and so I am sending it part of this series as
> without it, this won't apply. Tetsuo, does the rebase of your patch
> look OK?

OK, though I wanted my fix to be sent to upstream and stable before this series.

> 
> If it is not too much trouble, I'd like to ask for testing for the
> ataflop changes from Michael Schmitz, if possible, that is he'd just
> have to merge Tetsuo's rebased patch and the 2nd patch in this series.
> This is all rebased on linux-next tag 20211020.

Yes, please.

After this series, I guess we can remove "bool registered[NUM_DISK_MINORS];" like below
due to (unit[drive].disk[type] != NULL) == (unit[drive].registered[type] == true).
Regarding this series, setting unit[drive].registered[type] = true in ataflop_probe() is
pointless because atari_floppy_cleanup() checks unit[i].disk[type] != NULL for calling
del_gendisk(). And we need to fix __register_blkdev() in driver/block/floppy.c because
floppy_probe_lock is pointless.

 drivers/block/ataflop.c | 75 +++++++++++++++--------------------------
 1 file changed, 28 insertions(+), 47 deletions(-)

diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index c58750dcc685..7fedf8506335 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -299,7 +299,6 @@ static struct atari_floppy_struct {
 				   disk change detection) */
 	int flags;		/* flags */
 	struct gendisk *disk[NUM_DISK_MINORS];
-	bool registered[NUM_DISK_MINORS];
 	int ref;
 	int type;
 	struct blk_mq_tag_set tag_set;
@@ -1988,41 +1987,20 @@ static int ataflop_probe(dev_t dev)
 	if (drive >= FD_MAX_UNITS || type >= NUM_DISK_MINORS)
 		return -EINVAL;
 
-	if (!unit[drive].disk[type]) {
-		err = ataflop_alloc_disk(drive, type);
-		if (err == 0) {
-			err = add_disk(unit[drive].disk[type]);
-			if (err) {
-				blk_cleanup_disk(unit[drive].disk[type]);
-				unit[drive].disk[type] = NULL;
-			} else
-				unit[drive].registered[type] = true;
+	if (unit[drive].disk[type])
+		return 0;
+	err = ataflop_alloc_disk(drive, type);
+	if (err == 0) {
+		err = add_disk(unit[drive].disk[type]);
+		if (err) {
+			blk_cleanup_disk(unit[drive].disk[type]);
+			unit[drive].disk[type] = NULL;
 		}
 	}
 
 	return err;
 }
 
-static void atari_floppy_cleanup(void)
-{
-	int i;
-	int type;
-
-	for (i = 0; i < FD_MAX_UNITS; i++) {
-		for (type = 0; type < NUM_DISK_MINORS; type++) {
-			if (!unit[i].disk[type])
-				continue;
-			del_gendisk(unit[i].disk[type]);
-			blk_cleanup_queue(unit[i].disk[type]->queue);
-			put_disk(unit[i].disk[type]);
-		}
-		blk_mq_free_tag_set(&unit[i].tag_set);
-	}
-
-	del_timer_sync(&fd_timer);
-	atari_stram_free(DMABuffer);
-}
-
 static void atari_cleanup_floppy_disk(struct atari_floppy_struct *fs)
 {
 	int type;
@@ -2030,13 +2008,24 @@ static void atari_cleanup_floppy_disk(struct atari_floppy_struct *fs)
 	for (type = 0; type < NUM_DISK_MINORS; type++) {
 		if (!fs->disk[type])
 			continue;
-		if (fs->registered[type])
-			del_gendisk(fs->disk[type]);
+		del_gendisk(fs->disk[type]);
 		blk_cleanup_disk(fs->disk[type]);
 	}
 	blk_mq_free_tag_set(&fs->tag_set);
 }
 
+static void atari_floppy_cleanup(void)
+{
+	int i;
+
+	for (i = 0; i < FD_MAX_UNITS; i++)
+		atari_cleanup_floppy_disk(&unit[i]);
+
+	del_timer_sync(&fd_timer);
+	if (DMABuffer)
+		atari_stram_free(DMABuffer);
+}
+
 static int __init atari_floppy_init (void)
 {
 	int i;
@@ -2055,13 +2044,10 @@ static int __init atari_floppy_init (void)
 		unit[i].tag_set.numa_node = NUMA_NO_NODE;
 		unit[i].tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 		ret = blk_mq_alloc_tag_set(&unit[i].tag_set);
-		if (ret)
-			goto err;
-
-		ret = ataflop_alloc_disk(i, 0);
 		if (ret) {
-			blk_mq_free_tag_set(&unit[i].tag_set);
-			goto err;
+			while (--i >= 0)
+				blk_mq_free_tag_set(&unit[i].tag_set);
+			return ret;
 		}
 	}
 
@@ -2090,10 +2076,9 @@ static int __init atari_floppy_init (void)
 	for (i = 0; i < FD_MAX_UNITS; i++) {
 		unit[i].track = -1;
 		unit[i].flags = 0;
-		ret = add_disk(unit[i].disk[0]);
-		if (ret)
-			goto err_out_dma;
-		unit[i].registered[0] = true;
+		ret = ataflop_probe(MKDEV(0, 1 << 2));
+		if (err)
+			goto err;
 	}
 
 	printk(KERN_INFO "Atari floppy driver: max. %cD, %strack buffering\n",
@@ -2108,12 +2093,8 @@ static int __init atari_floppy_init (void)
 	}
 	return ret;
 
-err_out_dma:
-	atari_stram_free(DMABuffer);
 err:
-	while (--i >= 0)
-		atari_cleanup_floppy_disk(&unit[i]);
-
+	atari_floppy_cleanup();
 	return ret;
 }
 
-- 
2.18.4