[PATCHSET] Sanitize queue flags

[PATCHSET] Sanitize queue flags

[Jens Axboe]

Small series to remove (now) unused functionality, and to clean
up the flags we have and do use.

-- 
Jens Axboe

[PATCH 1/2] block: kill QUEUE_FLAG_FLUSH_NQ

[Jens Axboe]

We have various helpers for setting/clearing this flag, and also
a helper to check if the queue supports queueable flushes or not.
But nobody uses them anymore, kill it with fire.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/blk-mq-debugfs.c        | 1 -
 block/blk-settings.c          | 9 ---------
 drivers/ata/libata-scsi.c     | 2 --
 drivers/block/null_blk_main.c | 1 -
 include/linux/blkdev.h        | 7 -------
 5 files changed, 20 deletions(-)

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index f8120832ca7b..c782e81db627 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -132,7 +132,6 @@ static const char *const blk_queue_flag_name[] = {
 	QUEUE_FLAG_NAME(POLL),
 	QUEUE_FLAG_NAME(WC),
 	QUEUE_FLAG_NAME(FUA),
-	QUEUE_FLAG_NAME(FLUSH_NQ),
 	QUEUE_FLAG_NAME(DAX),
 	QUEUE_FLAG_NAME(STATS),
 	QUEUE_FLAG_NAME(POLL_STATS),
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 3e7038e475ee..6375afaedcec 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -799,15 +799,6 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
 }
 EXPORT_SYMBOL(blk_queue_update_dma_alignment);
 
-void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
-{
-	if (queueable)
-		blk_queue_flag_clear(QUEUE_FLAG_FLUSH_NQ, q);
-	else
-		blk_queue_flag_set(QUEUE_FLAG_FLUSH_NQ, q);
-}
-EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
-
 /**
  * blk_set_queue_depth - tell the block layer about the device queue depth
  * @q:		the request queue for the device
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 3d4887d0e84a..dfe66d00dd5b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1318,8 +1318,6 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
 		scsi_change_queue_depth(sdev, depth);
 	}
 
-	blk_queue_flush_queueable(q, false);
-
 	if (dev->flags & ATA_DFLAG_TRUSTED)
 		sdev->security_supported = 1;
 
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 62c9654b9ce8..83c38a6217d7 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -1678,7 +1678,6 @@ static int null_add_dev(struct nullb_device *dev)
 	if (dev->cache_size > 0) {
 		set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags);
 		blk_queue_write_cache(nullb->q, true, true);
-		blk_queue_flush_queueable(nullb->q, true);
 	}
 
 	if (dev->zoned) {
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 338604dff7d0..24ccab51085f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -592,7 +592,6 @@ struct request_queue {
 #define QUEUE_FLAG_POLL	       19	/* IO polling enabled if set */
 #define QUEUE_FLAG_WC	       20	/* Write back caching */
 #define QUEUE_FLAG_FUA	       21	/* device supports FUA writes */
-#define QUEUE_FLAG_FLUSH_NQ    22	/* flush not queueuable */
 #define QUEUE_FLAG_DAX         23	/* device supports DAX */
 #define QUEUE_FLAG_STATS       24	/* track IO start and completion times */
 #define QUEUE_FLAG_POLL_STATS  25	/* collecting stats for hybrid polling */
@@ -1069,7 +1068,6 @@ extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
 extern void blk_queue_dma_alignment(struct request_queue *, int);
 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
-extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
 
 /*
@@ -1446,11 +1444,6 @@ static inline unsigned int block_size(struct block_device *bdev)
 	return bdev->bd_block_size;
 }
 
-static inline bool queue_flush_queueable(struct request_queue *q)
-{
-	return !test_bit(QUEUE_FLAG_FLUSH_NQ, &q->queue_flags);
-}
-
 typedef struct {struct page *v;} Sector;
 
 unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
-- 
2.17.1

[PATCH 2/2] block: queue flag cleanup

[Jens Axboe]

We have QUEUE_FLAG_DEFAULT defined, but it's not used anymore since
the legacy IO stack is gone. Kill it.

Sanitize the queue flags in general, they use spaces (for some
reason), and the space is pretty sparse. With the flags renumbered,
we can more clearly see how many we have available.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/blkdev.h | 58 ++++++++++++++++++++----------------------
 1 file changed, 27 insertions(+), 31 deletions(-)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 24ccab51085f..3603270cb82d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -572,37 +572,33 @@ struct request_queue {
 	u64			write_hints[BLK_MAX_WRITE_HINTS];
 };
 
-#define QUEUE_FLAG_STOPPED	1	/* queue is stopped */
-#define QUEUE_FLAG_DYING	2	/* queue being torn down */
-#define QUEUE_FLAG_BIDI		4	/* queue supports bidi requests */
-#define QUEUE_FLAG_NOMERGES     5	/* disable merge attempts */
-#define QUEUE_FLAG_SAME_COMP	6	/* complete on same CPU-group */
-#define QUEUE_FLAG_FAIL_IO	7	/* fake timeout */
-#define QUEUE_FLAG_NONROT	9	/* non-rotational device (SSD) */
-#define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
-#define QUEUE_FLAG_IO_STAT     10	/* do disk/partitions IO accounting */
-#define QUEUE_FLAG_DISCARD     11	/* supports DISCARD */
-#define QUEUE_FLAG_NOXMERGES   12	/* No extended merges */
-#define QUEUE_FLAG_ADD_RANDOM  13	/* Contributes to random pool */
-#define QUEUE_FLAG_SECERASE    14	/* supports secure erase */
-#define QUEUE_FLAG_SAME_FORCE  15	/* force complete on same CPU */
-#define QUEUE_FLAG_DEAD        16	/* queue tear-down finished */
-#define QUEUE_FLAG_INIT_DONE   17	/* queue is initialized */
-#define QUEUE_FLAG_NO_SG_MERGE 18	/* don't attempt to merge SG segments*/
-#define QUEUE_FLAG_POLL	       19	/* IO polling enabled if set */
-#define QUEUE_FLAG_WC	       20	/* Write back caching */
-#define QUEUE_FLAG_FUA	       21	/* device supports FUA writes */
-#define QUEUE_FLAG_DAX         23	/* device supports DAX */
-#define QUEUE_FLAG_STATS       24	/* track IO start and completion times */
-#define QUEUE_FLAG_POLL_STATS  25	/* collecting stats for hybrid polling */
-#define QUEUE_FLAG_REGISTERED  26	/* queue has been registered to a disk */
-#define QUEUE_FLAG_SCSI_PASSTHROUGH 27	/* queue supports SCSI commands */
-#define QUEUE_FLAG_QUIESCED    28	/* queue has been quiesced */
-#define QUEUE_FLAG_PCI_P2PDMA  29	/* device supports PCI p2p requests */
-
-#define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
-				 (1 << QUEUE_FLAG_SAME_COMP)	|	\
-				 (1 << QUEUE_FLAG_ADD_RANDOM))
+#define QUEUE_FLAG_STOPPED	0	/* queue is stopped */
+#define QUEUE_FLAG_DYING	1	/* queue being torn down */
+#define QUEUE_FLAG_BIDI		2	/* queue supports bidi requests */
+#define QUEUE_FLAG_NOMERGES     3	/* disable merge attempts */
+#define QUEUE_FLAG_SAME_COMP	4	/* complete on same CPU-group */
+#define QUEUE_FLAG_FAIL_IO	5	/* fake timeout */
+#define QUEUE_FLAG_NONROT	6	/* non-rotational device (SSD) */
+#define QUEUE_FLAG_VIRT		QUEUE_FLAG_NONROT /* paravirt device */
+#define QUEUE_FLAG_IO_STAT	7	/* do disk/partitions IO accounting */
+#define QUEUE_FLAG_DISCARD	8	/* supports DISCARD */
+#define QUEUE_FLAG_NOXMERGES	9	/* No extended merges */
+#define QUEUE_FLAG_ADD_RANDOM	10	/* Contributes to random pool */
+#define QUEUE_FLAG_SECERASE	11	/* supports secure erase */
+#define QUEUE_FLAG_SAME_FORCE	12	/* force complete on same CPU */
+#define QUEUE_FLAG_DEAD		13	/* queue tear-down finished */
+#define QUEUE_FLAG_INIT_DONE	14	/* queue is initialized */
+#define QUEUE_FLAG_NO_SG_MERGE	15	/* don't attempt to merge SG segments*/
+#define QUEUE_FLAG_POLL		16	/* IO polling enabled if set */
+#define QUEUE_FLAG_WC		17	/* Write back caching */
+#define QUEUE_FLAG_FUA		18	/* device supports FUA writes */
+#define QUEUE_FLAG_DAX		19	/* device supports DAX */
+#define QUEUE_FLAG_STATS	20	/* track IO start and completion times */
+#define QUEUE_FLAG_POLL_STATS	21	/* collecting stats for hybrid polling */
+#define QUEUE_FLAG_REGISTERED	22	/* queue has been registered to a disk */
+#define QUEUE_FLAG_SCSI_PASSTHROUGH 23	/* queue supports SCSI commands */
+#define QUEUE_FLAG_QUIESCED	24	/* queue has been quiesced */
+#define QUEUE_FLAG_PCI_P2PDMA	25	/* device supports PCI p2p requests */
 
 #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
 				 (1 << QUEUE_FLAG_SAME_COMP))
-- 
2.17.1

Re: [PATCH 1/2] block: kill QUEUE_FLAG_FLUSH_NQ

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 2/2] block: queue flag cleanup

[Christoph Hellwig]

On Sat, Feb 09, 2019 at 03:44:24PM -0700, Jens Axboe wrote:
> We have QUEUE_FLAG_DEFAULT defined, but it's not used anymore since
> the legacy IO stack is gone. Kill it.
> 
> Sanitize the queue flags in general, they use spaces (for some
> reason), and the space is pretty sparse. With the flags renumbered,
> we can more clearly see how many we have available.
> 
> Signed-off-by: Jens Axboe <axboe@kernel.dk>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Btw, I think we should kill off QUEUE_FLAG_MQ_DEFAULT as well and open
code it in blk_mq_init_allocated_queue instead.