Re: [PATCH 3/4] bitmap: Introduce bitmap_size()

Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> · Sun, 3 Jul 2022 08:50:19 +0200

Le 02/07/2022 à 23:09, Yury Norov a écrit :
On Sat, Jul 02, 2022 at 08:29:36PM +0200, Christophe JAILLET wrote:
The new bitmap_size() function returns the size, in bytes, of a bitmap.

Remove the already existing bitmap_size() functions and macro in some
files.
These files already use the bitmap API and will use the new function
in bitmap.h automatically.

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
  drivers/md/dm-clone-metadata.c | 5 -----
  include/linux/bitmap.h         | 6 ++++++
  lib/math/prime_numbers.c       | 2 --
  3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/md/dm-clone-metadata.c b/drivers/md/dm-clone-metadata.c
index c43d55672bce..47c1fa7aad8b 100644
--- a/drivers/md/dm-clone-metadata.c
+++ b/drivers/md/dm-clone-metadata.c
@@ -465,11 +465,6 @@ static void __destroy_persistent_data_structures(struct dm_clone_metadata *cmd)
  
  /*---------------------------------------------------------------------------*/
  
-static size_t bitmap_size(unsigned long nr_bits)
-{
-	return BITS_TO_LONGS(nr_bits) * sizeof(long);
-}
-
  static int __dirty_map_init(struct dirty_map *dmap, unsigned long nr_words,
  			    unsigned long nr_regions)
  {
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index f091a1664bf1..f66fb98a4126 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -48,6 +48,7 @@ struct device;
   *  bitmap_equal(src1, src2, nbits)             Are *src1 and *src2 equal?
   *  bitmap_intersects(src1, src2, nbits)        Do *src1 and *src2 overlap?
   *  bitmap_subset(src1, src2, nbits)            Is *src1 a subset of *src2?
+ *  bitmap_size(nbits)                          Size, in bytes, of a bitmap
   *  bitmap_empty(src, nbits)                    Are all bits zero in *src?
   *  bitmap_full(src, nbits)                     Are all bits set in *src?
   *  bitmap_weight(src, nbits)                   Hamming Weight: number set bits
@@ -124,6 +125,11 @@ unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
  unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
  void bitmap_free(const unsigned long *bitmap);
  
+static __always_inline size_t bitmap_size(unsigned long nbits)
+{
+	return BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+}
+
  /* Managed variants of the above. */
  unsigned long *devm_bitmap_alloc(struct device *dev,
  				 unsigned int nbits, gfp_t flags);
diff --git a/lib/math/prime_numbers.c b/lib/math/prime_numbers.c
index d42cebf7407f..d3b64b10da1c 100644
--- a/lib/math/prime_numbers.c
+++ b/lib/math/prime_numbers.c
@@ -6,8 +6,6 @@
  #include <linux/prime_numbers.h>
  #include <linux/slab.h>
  
-#define bitmap_size(nbits) (BITS_TO_LONGS(nbits) * sizeof(unsigned long))
-

This should be dropped, for sure, and kmalloc() at line 128 should be
replaced with bitmap_alloc().

This kmalloc() is for a structure and a flexible array.

You mean re-arranging the code to allocate the structure alone at first, 
then the bitmap?

CJ


For the driver, we need to introduce bitmap_kvmalloc/bitmap_kvfree etc.

  struct primes {
  	struct rcu_head rcu;
  	unsigned long last, sz;
--
2.34.1









