[PATCH 4/8] block: convert features and flags to __bitwise types

[Christoph Hellwig <hch@lst.de>]

... and let sparse help us catch mismatches or abuses.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-sysfs.c      |  6 +--
 include/linux/blkdev.h | 85 +++++++++++++++++++++---------------------
 2 files changed, 46 insertions(+), 45 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 6db65886e7ed5a..2d033275da6ea4 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -288,7 +288,7 @@ static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page)
 }
 
 static ssize_t queue_feature_store(struct request_queue *q, const char *page,
-		size_t count, unsigned int feature)
+		size_t count, blk_features_t feature)
 {
 	struct queue_limits lim;
 	unsigned long val;
@@ -418,7 +418,7 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
 
 static ssize_t queue_poll_show(struct request_queue *q, char *page)
 {
-	return queue_var_show(q->limits.features & BLK_FEAT_POLL, page);
+	return queue_var_show(!!(q->limits.features & BLK_FEAT_POLL), page);
 }
 
 static ssize_t queue_poll_store(struct request_queue *q, const char *page,
@@ -493,7 +493,7 @@ static ssize_t queue_fua_show(struct request_queue *q, char *page)
 
 static ssize_t queue_dax_show(struct request_queue *q, char *page)
 {
-	return queue_var_show(blk_queue_dax(q), page);
+	return queue_var_show(!!blk_queue_dax(q), page);
 }
 
 #define QUEUE_RO_ENTRY(_prefix, _name)			\
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1a7e9d9c16d78b..b37826b350a2e3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -283,55 +283,56 @@ static inline bool blk_op_is_passthrough(blk_opf_t op)
 }
 
 /* flags set by the driver in queue_limits.features */
-enum {
-	/* supports a volatile write cache */
-	BLK_FEAT_WRITE_CACHE			= (1u << 0),
+typedef unsigned int __bitwise blk_features_t;
 
-	/* supports passing on the FUA bit */
-	BLK_FEAT_FUA				= (1u << 1),
+/* supports a volatile write cache */
+#define BLK_FEAT_WRITE_CACHE		((__force blk_features_t)(1u << 0))
 
-	/* rotational device (hard drive or floppy) */
-	BLK_FEAT_ROTATIONAL			= (1u << 2),
+/* supports passing on the FUA bit */
+#define BLK_FEAT_FUA			((__force blk_features_t)(1u << 1))
 
-	/* contributes to the random number pool */
-	BLK_FEAT_ADD_RANDOM			= (1u << 3),
+/* rotational device (hard drive or floppy) */
+#define BLK_FEAT_ROTATIONAL		((__force blk_features_t)(1u << 2))
 
-	/* do disk/partitions IO accounting */
-	BLK_FEAT_IO_STAT			= (1u << 4),
+/* contributes to the random number pool */
+#define BLK_FEAT_ADD_RANDOM		((__force blk_features_t)(1u << 3))
 
-	/* don't modify data until writeback is done */
-	BLK_FEAT_STABLE_WRITES			= (1u << 5),
+/* do disk/partitions IO accounting */
+#define BLK_FEAT_IO_STAT		((__force blk_features_t)(1u << 4))
 
-	/* always completes in submit context */
-	BLK_FEAT_SYNCHRONOUS			= (1u << 6),
+/* don't modify data until writeback is done */
+#define BLK_FEAT_STABLE_WRITES		((__force blk_features_t)(1u << 5))
 
-	/* supports REQ_NOWAIT */
-	BLK_FEAT_NOWAIT				= (1u << 7),
+/* always completes in submit context */
+#define BLK_FEAT_SYNCHRONOUS		((__force blk_features_t)(1u << 6))
 
-	/* supports DAX */
-	BLK_FEAT_DAX				= (1u << 8),
+/* supports REQ_NOWAIT */
+#define BLK_FEAT_NOWAIT			((__force blk_features_t)(1u << 7))
 
-	/* supports I/O polling */
-	BLK_FEAT_POLL				= (1u << 9),
+/* supports DAX */
+#define BLK_FEAT_DAX			((__force blk_features_t)(1u << 8))
 
-	/* is a zoned device */
-	BLK_FEAT_ZONED				= (1u << 10),
+/* supports I/O polling */
+#define BLK_FEAT_POLL			((__force blk_features_t)(1u << 9))
 
-	/* supports Zone Reset All */
-	BLK_FEAT_ZONE_RESETALL			= (1u << 11),
+/* is a zoned device */
+#define BLK_FEAT_ZONED			((__force blk_features_t)(1u << 10))
 
-	/* supports PCI(e) p2p requests */
-	BLK_FEAT_PCI_P2PDMA			= (1u << 12),
+/* supports Zone Reset All */
+#define BLK_FEAT_ZONE_RESETALL		((__force blk_features_t)(1u << 11))
 
-	/* skip this queue in blk_mq_(un)quiesce_tagset */
-	BLK_FEAT_SKIP_TAGSET_QUIESCE		= (1u << 13),
+/* supports PCI(e) p2p requests */
+#define BLK_FEAT_PCI_P2PDMA		((__force blk_features_t)(1u << 12))
 
-	/* bounce all highmem pages */
-	BLK_FEAT_BOUNCE_HIGH			= (1u << 14),
+/* skip this queue in blk_mq_(un)quiesce_tagset */
+#define BLK_FEAT_SKIP_TAGSET_QUIESCE	((__force blk_features_t)(1u << 13))
 
-	/* undocumented magic for bcache */
-	BLK_FEAT_RAID_PARTIAL_STRIPES_EXPENSIVE	= (1u << 15),
-};
+/* bounce all highmem pages */
+#define BLK_FEAT_BOUNCE_HIGH		((__force blk_features_t)(1u << 14))
+
+/* undocumented magic for bcache */
+#define BLK_FEAT_RAID_PARTIAL_STRIPES_EXPENSIVE \
+	((__force blk_features_t)(1u << 15))
 
 /*
  * Flags automatically inherited when stacking limits.
@@ -342,17 +343,17 @@ enum {
 	 BLK_FEAT_RAID_PARTIAL_STRIPES_EXPENSIVE)
 
 /* internal flags in queue_limits.flags */
-enum {
-	/* do not send FLUSH/FUA commands despite advertising a write cache */
-	BLK_FLAG_WRITE_CACHE_DISABLED		= (1u << 0),
+typedef unsigned int __bitwise blk_flags_t;
 
-	/* I/O topology is misaligned */
-	BLK_FLAG_MISALIGNED			= (1u << 1),
-};
+/* do not send FLUSH/FUA commands despite advertising a write cache */
+#define BLK_FLAG_WRITE_CACHE_DISABLED	((__force blk_flags_t)(1u << 0))
+
+/* I/O topology is misaligned */
+#define BLK_FLAG_MISALIGNED		((__force blk_flags_t)(1u << 1))
 
 struct queue_limits {
-	unsigned int		features;
-	unsigned int		flags;
+	blk_features_t		features;
+	blk_flags_t		flags;
 	unsigned long		seg_boundary_mask;
 	unsigned long		virt_boundary_mask;
 
-- 
2.43.0