decruft genhd.h v2

decruft genhd.h v2

[Christoph Hellwig]

Hi Jens,

this series tries to move as much out of genhd.h that doesn't really
belong there.

Changes since v1:
 - rebased to the latest block tree

[PATCH 1/9] block: mark block_depr static

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c         | 2 +-
 include/linux/genhd.h | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 792356e922a1..7dafd7504493 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -27,7 +27,7 @@
 #include "blk.h"
 
 static DEFINE_MUTEX(block_class_lock);
-struct kobject *block_depr;
+static struct kobject *block_depr;
 
 /* for extended dynamic devt allocation, currently only one major is used */
 #define NR_EXT_DEVT		(1 << MINORBITS)
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 790fdc3e0b3d..b322e805a916 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -27,7 +27,6 @@
 #define part_to_dev(part)	(&((part)->__dev))
 
 extern struct device_type part_type;
-extern struct kobject *block_depr;
 extern struct class block_class;
 
 #define DISK_MAX_PARTS			256
-- 
2.25.1

[PATCH 2/9] block: mark part_in_flight and part_in_flight_rw static

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c         | 7 ++++---
 include/linux/genhd.h | 3 ---
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 7dafd7504493..5f9df331822a 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -139,7 +139,8 @@ void part_dec_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
 		part_stat_local_dec(&part_to_disk(part)->part0, in_flight[rw]);
 }
 
-unsigned int part_in_flight(struct request_queue *q, struct hd_struct *part)
+static unsigned int part_in_flight(struct request_queue *q,
+		struct hd_struct *part)
 {
 	int cpu;
 	unsigned int inflight;
@@ -159,8 +160,8 @@ unsigned int part_in_flight(struct request_queue *q, struct hd_struct *part)
 	return inflight;
 }
 
-void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
-		       unsigned int inflight[2])
+static void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+		unsigned int inflight[2])
 {
 	int cpu;
 
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index b322e805a916..c0c5bb51fa56 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -409,9 +409,6 @@ static inline void free_part_stats(struct hd_struct *part)
 #define part_stat_local_read_cpu(gendiskp, field, cpu)			\
 	local_read(&(part_stat_get_cpu(gendiskp, field, cpu)))
 
-unsigned int part_in_flight(struct request_queue *q, struct hd_struct *part);
-void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
-		       unsigned int inflight[2]);
 void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
 			int rw);
 void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
-- 
2.25.1

[PATCH 3/9] block: unexport disk_get_part

[Christoph Hellwig]

disk_get_part is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/block/genhd.c b/block/genhd.c
index 5f9df331822a..0ee74b7e01f4 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -217,7 +217,6 @@ struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
 
 	return part;
 }
-EXPORT_SYMBOL_GPL(disk_get_part);
 
 /**
  * disk_part_iter_init - initialize partition iterator
-- 
2.25.1

[PATCH 4/9] block: unexport disk_map_sector_rcu

[Christoph Hellwig]

disk_map_sector_rcu is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/block/genhd.c b/block/genhd.c
index 0ee74b7e01f4..1e4855c8265a 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -372,7 +372,6 @@ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
 	}
 	return &disk->part0;
 }
-EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
 
 /*
  * Can be deleted altogether. Later.
-- 
2.25.1

[PATCH 5/9] block: unexport get_gendisk

[Christoph Hellwig]

get_gendisk is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/block/genhd.c b/block/genhd.c
index 1e4855c8265a..6323cc789efa 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -980,7 +980,6 @@ struct gendisk *get_gendisk(dev_t devt, int *partno)
 	}
 	return disk;
 }
-EXPORT_SYMBOL(get_gendisk);
 
 /**
  * bdget_disk - do bdget() by gendisk and partition number
-- 
2.25.1

[PATCH 6/9] block: move guard_bio_eod to bio.c

[Christoph Hellwig]

This is bio layer functionality and not related to buffer heads.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bio.c         | 43 +++++++++++++++++++++++++++++++++++++++++++
 fs/buffer.c         | 43 -------------------------------------------
 fs/internal.h       |  1 -
 include/linux/bio.h |  1 +
 4 files changed, 44 insertions(+), 44 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index bc9152977bf0..11e6aac35092 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -588,6 +588,49 @@ void bio_truncate(struct bio *bio, unsigned new_size)
 	bio->bi_iter.bi_size = new_size;
 }
 
+/**
+ * guard_bio_eod - truncate a BIO to fit the block device
+ * @bio:	bio to truncate
+ *
+ * This allows us to do IO even on the odd last sectors of a device, even if the
+ * block size is some multiple of the physical sector size.
+ *
+ * We'll just truncate the bio to the size of the device, and clear the end of
+ * the buffer head manually.  Truly out-of-range accesses will turn into actual
+ * I/O errors, this only handles the "we need to be able to do I/O at the final
+ * sector" case.
+ */
+void guard_bio_eod(struct bio *bio)
+{
+	sector_t maxsector;
+	struct hd_struct *part;
+
+	rcu_read_lock();
+	part = __disk_get_part(bio->bi_disk, bio->bi_partno);
+	if (part)
+		maxsector = part_nr_sects_read(part);
+	else
+		maxsector = get_capacity(bio->bi_disk);
+	rcu_read_unlock();
+
+	if (!maxsector)
+		return;
+
+	/*
+	 * If the *whole* IO is past the end of the device,
+	 * let it through, and the IO layer will turn it into
+	 * an EIO.
+	 */
+	if (unlikely(bio->bi_iter.bi_sector >= maxsector))
+		return;
+
+	maxsector -= bio->bi_iter.bi_sector;
+	if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
+		return;
+
+	bio_truncate(bio, maxsector << 9);
+}
+
 /**
  * bio_put - release a reference to a bio
  * @bio:   bio to release reference to
diff --git a/fs/buffer.c b/fs/buffer.c
index b8d28370cfd7..3f5758e01e40 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3019,49 +3019,6 @@ static void end_bio_bh_io_sync(struct bio *bio)
 	bio_put(bio);
 }
 
-/*
- * This allows us to do IO even on the odd last sectors
- * of a device, even if the block size is some multiple
- * of the physical sector size.
- *
- * We'll just truncate the bio to the size of the device,
- * and clear the end of the buffer head manually.
- *
- * Truly out-of-range accesses will turn into actual IO
- * errors, this only handles the "we need to be able to
- * do IO at the final sector" case.
- */
-void guard_bio_eod(struct bio *bio)
-{
-	sector_t maxsector;
-	struct hd_struct *part;
-
-	rcu_read_lock();
-	part = __disk_get_part(bio->bi_disk, bio->bi_partno);
-	if (part)
-		maxsector = part_nr_sects_read(part);
-	else
-		maxsector = get_capacity(bio->bi_disk);
-	rcu_read_unlock();
-
-	if (!maxsector)
-		return;
-
-	/*
-	 * If the *whole* IO is past the end of the device,
-	 * let it through, and the IO layer will turn it into
-	 * an EIO.
-	 */
-	if (unlikely(bio->bi_iter.bi_sector >= maxsector))
-		return;
-
-	maxsector -= bio->bi_iter.bi_sector;
-	if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
-		return;
-
-	bio_truncate(bio, maxsector << 9);
-}
-
 static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
 			 enum rw_hint write_hint, struct writeback_control *wbc)
 {
diff --git a/fs/internal.h b/fs/internal.h
index f3f280b952a3..4d37912a5587 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -38,7 +38,6 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait)
 /*
  * buffer.c
  */
-extern void guard_bio_eod(struct bio *bio);
 extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
 		get_block_t *get_block, struct iomap *iomap);
 
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 853d92ceee64..a430e9c1c2d2 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -471,6 +471,7 @@ extern struct bio *bio_copy_user_iov(struct request_queue *,
 extern int bio_uncopy_user(struct bio *);
 void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
 void bio_truncate(struct bio *bio, unsigned new_size);
+void guard_bio_eod(struct bio *bio);
 
 static inline void zero_fill_bio(struct bio *bio)
 {
-- 
2.25.1

[PATCH 7/9] block: move block layer internals out of include/linux/genhd.h

[Christoph Hellwig]

None of this needs to be exposed to drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk.h              | 116 +++++++++++++++++++++++++++++++++++++
 block/ioctl.c            |   1 +
 block/partitions/check.h |   1 +
 block/partitions/core.c  |   1 -
 include/linux/genhd.h    | 120 ---------------------------------------
 5 files changed, 118 insertions(+), 121 deletions(-)

diff --git a/block/blk.h b/block/blk.h
index 43df9dcb3d4e..ac20f972842e 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -149,6 +149,9 @@ static inline bool integrity_req_gap_front_merge(struct request *req,
 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
 				bip_next->bip_vec[0].bv_offset);
 }
+
+void blk_integrity_add(struct gendisk *);
+void blk_integrity_del(struct gendisk *);
 #else /* CONFIG_BLK_DEV_INTEGRITY */
 static inline bool integrity_req_gap_back_merge(struct request *req,
 		struct bio *next)
@@ -171,6 +174,12 @@ static inline bool bio_integrity_endio(struct bio *bio)
 static inline void bio_integrity_free(struct bio *bio)
 {
 }
+static inline void blk_integrity_add(struct gendisk *disk)
+{
+}
+static inline void blk_integrity_del(struct gendisk *disk)
+{
+}
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
 unsigned long blk_rq_timeout(unsigned long timeout);
@@ -365,4 +374,111 @@ void blk_queue_free_zone_bitmaps(struct request_queue *q);
 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
 #endif
 
+void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
+			int rw);
+void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
+			int rw);
+void update_io_ticks(struct hd_struct *part, unsigned long now, bool end);
+struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector);
+
+int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
+void blk_free_devt(dev_t devt);
+void blk_invalidate_devt(dev_t devt);
+char *disk_name(struct gendisk *hd, int partno, char *buf);
+#define ADDPART_FLAG_NONE	0
+#define ADDPART_FLAG_RAID	1
+#define ADDPART_FLAG_WHOLEDISK	2
+struct hd_struct *__must_check add_partition(struct gendisk *disk, int partno,
+		sector_t start, sector_t len, int flags,
+		struct partition_meta_info *info);
+void __delete_partition(struct percpu_ref *ref);
+void delete_partition(struct gendisk *disk, int partno);
+int disk_expand_part_tbl(struct gendisk *disk, int target);
+
+static inline int hd_ref_init(struct hd_struct *part)
+{
+	if (percpu_ref_init(&part->ref, __delete_partition, 0,
+				GFP_KERNEL))
+		return -ENOMEM;
+	return 0;
+}
+
+static inline void hd_struct_get(struct hd_struct *part)
+{
+	percpu_ref_get(&part->ref);
+}
+
+static inline int hd_struct_try_get(struct hd_struct *part)
+{
+	return percpu_ref_tryget_live(&part->ref);
+}
+
+static inline void hd_struct_put(struct hd_struct *part)
+{
+	percpu_ref_put(&part->ref);
+}
+
+static inline void hd_struct_kill(struct hd_struct *part)
+{
+	percpu_ref_kill(&part->ref);
+}
+
+static inline void hd_free_part(struct hd_struct *part)
+{
+	free_part_stats(part);
+	kfree(part->info);
+	percpu_ref_exit(&part->ref);
+}
+
+/*
+ * Any access of part->nr_sects which is not protected by partition
+ * bd_mutex or gendisk bdev bd_mutex, should be done using this
+ * accessor function.
+ *
+ * Code written along the lines of i_size_read() and i_size_write().
+ * CONFIG_PREEMPTION case optimizes the case of UP kernel with preemption
+ * on.
+ */
+static inline sector_t part_nr_sects_read(struct hd_struct *part)
+{
+#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+	sector_t nr_sects;
+	unsigned seq;
+	do {
+		seq = read_seqcount_begin(&part->nr_sects_seq);
+		nr_sects = part->nr_sects;
+	} while (read_seqcount_retry(&part->nr_sects_seq, seq));
+	return nr_sects;
+#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
+	sector_t nr_sects;
+
+	preempt_disable();
+	nr_sects = part->nr_sects;
+	preempt_enable();
+	return nr_sects;
+#else
+	return part->nr_sects;
+#endif
+}
+
+/*
+ * Should be called with mutex lock held (typically bd_mutex) of partition
+ * to provide mutual exlusion among writers otherwise seqcount might be
+ * left in wrong state leaving the readers spinning infinitely.
+ */
+static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
+{
+#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+	write_seqcount_begin(&part->nr_sects_seq);
+	part->nr_sects = size;
+	write_seqcount_end(&part->nr_sects_seq);
+#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
+	preempt_disable();
+	part->nr_sects = size;
+	preempt_enable();
+#else
+	part->nr_sects = size;
+#endif
+}
+
 #endif /* BLK_INTERNAL_H */
diff --git a/block/ioctl.c b/block/ioctl.c
index 127194b9f9bd..6e827de1a4c4 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -11,6 +11,7 @@
 #include <linux/blktrace_api.h>
 #include <linux/pr.h>
 #include <linux/uaccess.h>
+#include "blk.h"
 
 static int blkpg_do_ioctl(struct block_device *bdev,
 			  struct blkpg_partition __user *upart, int op)
diff --git a/block/partitions/check.h b/block/partitions/check.h
index f845355489ec..c577e9ee67f0 100644
--- a/block/partitions/check.h
+++ b/block/partitions/check.h
@@ -2,6 +2,7 @@
 #include <linux/pagemap.h>
 #include <linux/blkdev.h>
 #include <linux/genhd.h>
+#include "../blk.h"
 
 /*
  * add_gd_partition adds a partitions details to the devices partition
diff --git a/block/partitions/core.c b/block/partitions/core.c
index b442bc209b86..b79c4513629b 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -10,7 +10,6 @@
 #include <linux/vmalloc.h>
 #include <linux/blktrace_api.h>
 #include <linux/raid/detect.h>
-#include "../blk.h"
 #include "check.h"
 
 static int (*check_part[])(struct parsed_partitions *) = {
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index c0c5bb51fa56..14354a6e89c2 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -298,9 +298,6 @@ extern void disk_part_iter_init(struct disk_part_iter *piter,
 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 
-extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
-					     sector_t sector);
-
 /*
  * Macros to operate on percpu disk statistics:
  *
@@ -409,13 +406,6 @@ static inline void free_part_stats(struct hd_struct *part)
 #define part_stat_local_read_cpu(gendiskp, field, cpu)			\
 	local_read(&(part_stat_get_cpu(gendiskp, field, cpu)))
 
-void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
-			int rw);
-void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
-			int rw);
-
-void update_io_ticks(struct hd_struct *part, unsigned long now, bool end);
-
 /* block/genhd.c */
 extern void device_add_disk(struct device *parent, struct gendisk *disk,
 			    const struct attribute_group **groups);
@@ -465,27 +455,11 @@ static inline void set_capacity(struct gendisk *disk, sector_t size)
 	disk->part0.nr_sects = size;
 }
 
-#define ADDPART_FLAG_NONE	0
-#define ADDPART_FLAG_RAID	1
-#define ADDPART_FLAG_WHOLEDISK	2
-
-extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
-extern void blk_free_devt(dev_t devt);
-extern void blk_invalidate_devt(dev_t devt);
 extern dev_t blk_lookup_devt(const char *name, int partno);
-extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 
 int bdev_disk_changed(struct block_device *bdev, bool invalidate);
 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
 int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev);
-extern int disk_expand_part_tbl(struct gendisk *disk, int target);
-extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
-						     int partno, sector_t start,
-						     sector_t len, int flags,
-						     struct partition_meta_info
-						       *info);
-extern void __delete_partition(struct percpu_ref *);
-extern void delete_partition(struct gendisk *, int);
 extern void printk_all_partitions(void);
 
 extern struct gendisk *__alloc_disk_node(int minors, int node_id);
@@ -517,100 +491,6 @@ extern void blk_unregister_region(dev_t devt, unsigned long range);
 
 #define alloc_disk(minors) alloc_disk_node(minors, NUMA_NO_NODE)
 
-static inline int hd_ref_init(struct hd_struct *part)
-{
-	if (percpu_ref_init(&part->ref, __delete_partition, 0,
-				GFP_KERNEL))
-		return -ENOMEM;
-	return 0;
-}
-
-static inline void hd_struct_get(struct hd_struct *part)
-{
-	percpu_ref_get(&part->ref);
-}
-
-static inline int hd_struct_try_get(struct hd_struct *part)
-{
-	return percpu_ref_tryget_live(&part->ref);
-}
-
-static inline void hd_struct_put(struct hd_struct *part)
-{
-	percpu_ref_put(&part->ref);
-}
-
-static inline void hd_struct_kill(struct hd_struct *part)
-{
-	percpu_ref_kill(&part->ref);
-}
-
-static inline void hd_free_part(struct hd_struct *part)
-{
-	free_part_stats(part);
-	kfree(part->info);
-	percpu_ref_exit(&part->ref);
-}
-
-/*
- * Any access of part->nr_sects which is not protected by partition
- * bd_mutex or gendisk bdev bd_mutex, should be done using this
- * accessor function.
- *
- * Code written along the lines of i_size_read() and i_size_write().
- * CONFIG_PREEMPTION case optimizes the case of UP kernel with preemption
- * on.
- */
-static inline sector_t part_nr_sects_read(struct hd_struct *part)
-{
-#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
-	sector_t nr_sects;
-	unsigned seq;
-	do {
-		seq = read_seqcount_begin(&part->nr_sects_seq);
-		nr_sects = part->nr_sects;
-	} while (read_seqcount_retry(&part->nr_sects_seq, seq));
-	return nr_sects;
-#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
-	sector_t nr_sects;
-
-	preempt_disable();
-	nr_sects = part->nr_sects;
-	preempt_enable();
-	return nr_sects;
-#else
-	return part->nr_sects;
-#endif
-}
-
-/*
- * Should be called with mutex lock held (typically bd_mutex) of partition
- * to provide mutual exlusion among writers otherwise seqcount might be
- * left in wrong state leaving the readers spinning infinitely.
- */
-static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
-{
-#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
-	write_seqcount_begin(&part->nr_sects_seq);
-	part->nr_sects = size;
-	write_seqcount_end(&part->nr_sects_seq);
-#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
-	preempt_disable();
-	part->nr_sects = size;
-	preempt_enable();
-#else
-	part->nr_sects = size;
-#endif
-}
-
-#if defined(CONFIG_BLK_DEV_INTEGRITY)
-extern void blk_integrity_add(struct gendisk *);
-extern void blk_integrity_del(struct gendisk *);
-#else	/* CONFIG_BLK_DEV_INTEGRITY */
-static inline void blk_integrity_add(struct gendisk *disk) { }
-static inline void blk_integrity_del(struct gendisk *disk) { }
-#endif	/* CONFIG_BLK_DEV_INTEGRITY */
-
 #else /* CONFIG_BLOCK */
 
 static inline void printk_all_partitions(void) { }
-- 
2.25.1

[PATCH 8/9] block: move the part_stat* helpers from genhd.h to a new header

[Christoph Hellwig]

These macros are just used by a few files.  Move them out of genhd.h,
which is included everywhere into a new standalone header.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk.h                        |   1 +
 drivers/block/drbd/drbd_receiver.c |   1 +
 drivers/block/drbd/drbd_worker.c   |   1 +
 drivers/block/zram/zram_drv.c      |   1 +
 drivers/md/dm.c                    |   1 +
 drivers/md/md.c                    |   1 +
 drivers/nvme/target/admin-cmd.c    |   1 +
 fs/ext4/super.c                    |   2 +-
 fs/ext4/sysfs.c                    |   1 +
 fs/f2fs/f2fs.h                     |   1 +
 fs/f2fs/super.c                    |   1 +
 include/linux/genhd.h              | 108 ---------------------------
 include/linux/part_stat.h          | 115 +++++++++++++++++++++++++++++
 13 files changed, 126 insertions(+), 109 deletions(-)
 create mode 100644 include/linux/part_stat.h

diff --git a/block/blk.h b/block/blk.h
index ac20f972842e..d9673164a145 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -4,6 +4,7 @@
 
 #include <linux/idr.h>
 #include <linux/blk-mq.h>
+#include <linux/part_stat.h>
 #include <xen/xen.h>
 #include "blk-mq.h"
 #include "blk-mq-sched.h"
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 79e216446030..c15e7083b13a 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -33,6 +33,7 @@
 #include <linux/random.h>
 #include <linux/string.h>
 #include <linux/scatterlist.h>
+#include <linux/part_stat.h>
 #include "drbd_int.h"
 #include "drbd_protocol.h"
 #include "drbd_req.h"
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index b7f605c6e231..0dc019da1f8d 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -22,6 +22,7 @@
 #include <linux/random.h>
 #include <linux/string.h>
 #include <linux/scatterlist.h>
+#include <linux/part_stat.h>
 
 #include "drbd_int.h"
 #include "drbd_protocol.h"
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 1bdb5793842b..76e75097e9ab 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -33,6 +33,7 @@
 #include <linux/sysfs.h>
 #include <linux/debugfs.h>
 #include <linux/cpuhotplug.h>
+#include <linux/part_stat.h>
 
 #include "zram_drv.h"
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 0413018c8305..0d881cfa160b 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -25,6 +25,7 @@
 #include <linux/wait.h>
 #include <linux/pr.h>
 #include <linux/refcount.h>
+#include <linux/part_stat.h>
 
 #define DM_MSG_PREFIX "core"
 
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1c7193715f07..f6cf3b53f6c1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -61,6 +61,7 @@
 #include <linux/raid/detect.h>
 #include <linux/slab.h>
 #include <linux/percpu-refcount.h>
+#include <linux/part_stat.h>
 
 #include <trace/events/block.h>
 #include "md.h"
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 72a7e41f3018..cca759c918a4 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -6,6 +6,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #include <linux/module.h>
 #include <linux/rculist.h>
+#include <linux/part_stat.h>
 
 #include <generated/utsrelease.h>
 #include <asm/unaligned.h>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4cbd1cc34dfa..c8dff4c68141 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -43,7 +43,7 @@
 #include <linux/uaccess.h>
 #include <linux/iversion.h>
 #include <linux/unicode.h>
-
+#include <linux/part_stat.h>
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index d218ebdafa4a..04bfaf63752c 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -13,6 +13,7 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/proc_fs.h>
+#include <linux/part_stat.h>
 
 #include "ext4.h"
 #include "ext4_jbd2.h"
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5355be6b6755..088c3e7a1080 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -22,6 +22,7 @@
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/quotaops.h>
+#include <linux/part_stat.h>
 #include <crypto/hash.h>
 
 #include <linux/fscrypt.h>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 65a7a432dfee..d398b2d90c6c 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -24,6 +24,7 @@
 #include <linux/sysfs.h>
 #include <linux/quota.h>
 #include <linux/unicode.h>
+#include <linux/part_stat.h>
 
 #include "f2fs.h"
 #include "node.h"
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 14354a6e89c2..927eed0be179 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -298,114 +298,6 @@ extern void disk_part_iter_init(struct disk_part_iter *piter,
 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 
-/*
- * Macros to operate on percpu disk statistics:
- *
- * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
- * and should be called between disk_stat_lock() and
- * disk_stat_unlock().
- *
- * part_stat_read() can be called at any time.
- *
- * part_stat_{add|set_all}() and {init|free}_part_stats are for
- * internal use only.
- */
-#ifdef	CONFIG_SMP
-#define part_stat_lock()	({ rcu_read_lock(); get_cpu(); })
-#define part_stat_unlock()	do { put_cpu(); rcu_read_unlock(); } while (0)
-
-#define part_stat_get_cpu(part, field, cpu)					\
-	(per_cpu_ptr((part)->dkstats, (cpu))->field)
-
-#define part_stat_get(part, field)					\
-	part_stat_get_cpu(part, field, smp_processor_id())
-
-#define part_stat_read(part, field)					\
-({									\
-	typeof((part)->dkstats->field) res = 0;				\
-	unsigned int _cpu;						\
-	for_each_possible_cpu(_cpu)					\
-		res += per_cpu_ptr((part)->dkstats, _cpu)->field;	\
-	res;								\
-})
-
-static inline void part_stat_set_all(struct hd_struct *part, int value)
-{
-	int i;
-
-	for_each_possible_cpu(i)
-		memset(per_cpu_ptr(part->dkstats, i), value,
-				sizeof(struct disk_stats));
-}
-
-static inline int init_part_stats(struct hd_struct *part)
-{
-	part->dkstats = alloc_percpu(struct disk_stats);
-	if (!part->dkstats)
-		return 0;
-	return 1;
-}
-
-static inline void free_part_stats(struct hd_struct *part)
-{
-	free_percpu(part->dkstats);
-}
-
-#else /* !CONFIG_SMP */
-#define part_stat_lock()	({ rcu_read_lock(); 0; })
-#define part_stat_unlock()	rcu_read_unlock()
-
-#define part_stat_get(part, field)		((part)->dkstats.field)
-#define part_stat_get_cpu(part, field, cpu)	part_stat_get(part, field)
-#define part_stat_read(part, field)		part_stat_get(part, field)
-
-static inline void part_stat_set_all(struct hd_struct *part, int value)
-{
-	memset(&part->dkstats, value, sizeof(struct disk_stats));
-}
-
-static inline int init_part_stats(struct hd_struct *part)
-{
-	return 1;
-}
-
-static inline void free_part_stats(struct hd_struct *part)
-{
-}
-
-#endif /* CONFIG_SMP */
-
-#define part_stat_read_accum(part, field)				\
-	(part_stat_read(part, field[STAT_READ]) +			\
-	 part_stat_read(part, field[STAT_WRITE]) +			\
-	 part_stat_read(part, field[STAT_DISCARD]))
-
-#define __part_stat_add(part, field, addnd)				\
-	(part_stat_get(part, field) += (addnd))
-
-#define part_stat_add(part, field, addnd)	do {			\
-	__part_stat_add((part), field, addnd);				\
-	if ((part)->partno)						\
-		__part_stat_add(&part_to_disk((part))->part0,		\
-				field, addnd);				\
-} while (0)
-
-#define part_stat_dec(gendiskp, field)					\
-	part_stat_add(gendiskp, field, -1)
-#define part_stat_inc(gendiskp, field)					\
-	part_stat_add(gendiskp, field, 1)
-#define part_stat_sub(gendiskp, field, subnd)				\
-	part_stat_add(gendiskp, field, -subnd)
-
-#define part_stat_local_dec(gendiskp, field)				\
-	local_dec(&(part_stat_get(gendiskp, field)))
-#define part_stat_local_inc(gendiskp, field)				\
-	local_inc(&(part_stat_get(gendiskp, field)))
-#define part_stat_local_read(gendiskp, field)				\
-	local_read(&(part_stat_get(gendiskp, field)))
-#define part_stat_local_read_cpu(gendiskp, field, cpu)			\
-	local_read(&(part_stat_get_cpu(gendiskp, field, cpu)))
-
 /* block/genhd.c */
 extern void device_add_disk(struct device *parent, struct gendisk *disk,
 			    const struct attribute_group **groups);
diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h
new file mode 100644
index 000000000000..ece607607a86
--- /dev/null
+++ b/include/linux/part_stat.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_PART_STAT_H
+#define _LINUX_PART_STAT_H
+
+#include <linux/genhd.h>
+
+/*
+ * Macros to operate on percpu disk statistics:
+ *
+ * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
+ * and should be called between disk_stat_lock() and
+ * disk_stat_unlock().
+ *
+ * part_stat_read() can be called at any time.
+ *
+ * part_stat_{add|set_all}() and {init|free}_part_stats are for
+ * internal use only.
+ */
+#ifdef	CONFIG_SMP
+#define part_stat_lock()	({ rcu_read_lock(); get_cpu(); })
+#define part_stat_unlock()	do { put_cpu(); rcu_read_unlock(); } while (0)
+
+#define part_stat_get_cpu(part, field, cpu)				\
+	(per_cpu_ptr((part)->dkstats, (cpu))->field)
+
+#define part_stat_get(part, field)					\
+	part_stat_get_cpu(part, field, smp_processor_id())
+
+#define part_stat_read(part, field)					\
+({									\
+	typeof((part)->dkstats->field) res = 0;				\
+	unsigned int _cpu;						\
+	for_each_possible_cpu(_cpu)					\
+		res += per_cpu_ptr((part)->dkstats, _cpu)->field;	\
+	res;								\
+})
+
+static inline void part_stat_set_all(struct hd_struct *part, int value)
+{
+	int i;
+
+	for_each_possible_cpu(i)
+		memset(per_cpu_ptr(part->dkstats, i), value,
+				sizeof(struct disk_stats));
+}
+
+static inline int init_part_stats(struct hd_struct *part)
+{
+	part->dkstats = alloc_percpu(struct disk_stats);
+	if (!part->dkstats)
+		return 0;
+	return 1;
+}
+
+static inline void free_part_stats(struct hd_struct *part)
+{
+	free_percpu(part->dkstats);
+}
+
+#else /* !CONFIG_SMP */
+#define part_stat_lock()	({ rcu_read_lock(); 0; })
+#define part_stat_unlock()	rcu_read_unlock()
+
+#define part_stat_get(part, field)		((part)->dkstats.field)
+#define part_stat_get_cpu(part, field, cpu)	part_stat_get(part, field)
+#define part_stat_read(part, field)		part_stat_get(part, field)
+
+static inline void part_stat_set_all(struct hd_struct *part, int value)
+{
+	memset(&part->dkstats, value, sizeof(struct disk_stats));
+}
+
+static inline int init_part_stats(struct hd_struct *part)
+{
+	return 1;
+}
+
+static inline void free_part_stats(struct hd_struct *part)
+{
+}
+
+#endif /* CONFIG_SMP */
+
+#define part_stat_read_accum(part, field)				\
+	(part_stat_read(part, field[STAT_READ]) +			\
+	 part_stat_read(part, field[STAT_WRITE]) +			\
+	 part_stat_read(part, field[STAT_DISCARD]))
+
+#define __part_stat_add(part, field, addnd)				\
+	(part_stat_get(part, field) += (addnd))
+
+#define part_stat_add(part, field, addnd)	do {			\
+	__part_stat_add((part), field, addnd);				\
+	if ((part)->partno)						\
+		__part_stat_add(&part_to_disk((part))->part0,		\
+				field, addnd);				\
+} while (0)
+
+#define part_stat_dec(gendiskp, field)					\
+	part_stat_add(gendiskp, field, -1)
+#define part_stat_inc(gendiskp, field)					\
+	part_stat_add(gendiskp, field, 1)
+#define part_stat_sub(gendiskp, field, subnd)				\
+	part_stat_add(gendiskp, field, -subnd)
+
+#define part_stat_local_dec(gendiskp, field)				\
+	local_dec(&(part_stat_get(gendiskp, field)))
+#define part_stat_local_inc(gendiskp, field)				\
+	local_inc(&(part_stat_get(gendiskp, field)))
+#define part_stat_local_read(gendiskp, field)				\
+	local_read(&(part_stat_get(gendiskp, field)))
+#define part_stat_local_read_cpu(gendiskp, field, cpu)			\
+	local_read(&(part_stat_get_cpu(gendiskp, field, cpu)))
+
+#endif /* _LINUX_PART_STAT_H */
-- 
2.25.1

[PATCH 9/9] block: make the init_part_stats return value more logical

[Christoph Hellwig]

Return 0 / -ENOMEM instead of a boolean dressed up as int.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c             | 2 +-
 block/partitions/core.c   | 2 +-
 include/linux/part_stat.h | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 6323cc789efa..95aef19ca8ed 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1644,7 +1644,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
 
 	disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
 	if (disk) {
-		if (!init_part_stats(&disk->part0)) {
+		if (init_part_stats(&disk->part0)) {
 			kfree(disk);
 			return NULL;
 		}
diff --git a/block/partitions/core.c b/block/partitions/core.c
index b79c4513629b..6509351cb9d3 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -377,7 +377,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
 	if (!p)
 		return ERR_PTR(-EBUSY);
 
-	if (!init_part_stats(p)) {
+	if (init_part_stats(p)) {
 		err = -ENOMEM;
 		goto out_free;
 	}
diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h
index ece607607a86..521ad787b0ec 100644
--- a/include/linux/part_stat.h
+++ b/include/linux/part_stat.h
@@ -48,8 +48,8 @@ static inline int init_part_stats(struct hd_struct *part)
 {
 	part->dkstats = alloc_percpu(struct disk_stats);
 	if (!part->dkstats)
-		return 0;
-	return 1;
+		return -ENOMEM;
+	return 0;
 }
 
 static inline void free_part_stats(struct hd_struct *part)
@@ -72,7 +72,7 @@ static inline void part_stat_set_all(struct hd_struct *part, int value)
 
 static inline int init_part_stats(struct hd_struct *part)
 {
-	return 1;
+	return 0;
 }
 
 static inline void free_part_stats(struct hd_struct *part)
-- 
2.25.1

Re: decruft genhd.h v2

[Jens Axboe]

On 3/25/20 9:48 AM, Christoph Hellwig wrote:
> Hi Jens,
> 
> this series tries to move as much out of genhd.h that doesn't really
> belong there.
> 
> Changes since v1:
>  - rebased to the latest block tree

Applied, thanks.

-- 
Jens Axboe

Re: [PATCH 2/9] block: mark part_in_flight and part_in_flight_rw static

[Joe Perches]

On Wed, 2020-03-25 at 16:48 +0100, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Some people still ask for some commit description,
not just a sign-off line.

I do think that's unnecessary though when, as here,
the patch subject is descriptive and complete.

> diff --git a/block/genhd.c b/block/genhd.c
[]
> @@ -139,7 +139,8 @@ void part_dec_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
>  		part_stat_local_dec(&part_to_disk(part)->part0, in_flight[rw]);
>  }
>  
> -unsigned int part_in_flight(struct request_queue *q, struct hd_struct *part)
> +static unsigned int part_in_flight(struct request_queue *q,
> +		struct hd_struct *part)

genhd.c aligns multi-line arguments to open parenthesis,
it'd be nicer to maintain that style.

>  {
>  	int cpu;
>  	unsigned int inflight;
> @@ -159,8 +160,8 @@ unsigned int part_in_flight(struct request_queue *q, struct hd_struct *part)
>  	return inflight;
>  }
>  
> -void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
> -		       unsigned int inflight[2])
> +static void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
> +		unsigned int inflight[2])

etc.