Merge branch 'slab/for-6.19/mempool_alloc_bulk' into slab/for-next

Merges series "mempool_alloc_bulk and various mempool improvements v3"
from Christoph Hellwig.

From the cover letter [1]:

This series adds a bulk version of mempool_alloc that makes allocating
multiple objects deadlock safe.

The initial users is the blk-crypto-fallback code:

  https://lore.kernel.org/linux-block/20251031093517.1603379-1-hch@lst.de/

with which v1 was posted, but I also have a few other users in mind.

Link: https://lore.kernel.org/all/20251113084022.1255121-1-hch@lst.de/ [1]

Author: tehcaster

include/linux/fault-inject.h

@@ -8,6 +8,10 @@
 struct dentry;
 struct kmem_cache;
 
+enum fault_flags {
+	FAULT_NOWARN =	1 << 0,
+};
+
 #ifdef CONFIG_FAULT_INJECTION
 
 #include <linux/atomic.h>
@@ -36,10 +40,6 @@ struct fault_attr {
 	struct dentry *dname;
 };
 
-enum fault_flags {
-	FAULT_NOWARN =	1 << 0,
-};
-
 #define FAULT_ATTR_INITIALIZER {					\
 		.interval = 1,						\
 		.times = ATOMIC_INIT(1),				\

include/linux/mempool.h

@@ -27,48 +27,53 @@ typedef struct mempool {
 	wait_queue_head_t wait;
 } mempool_t;
 
-static inline bool mempool_initialized(mempool_t *pool)
+static inline bool mempool_initialized(struct mempool *pool)
 {
 	return pool->elements != NULL;
 }
 
-static inline bool mempool_is_saturated(mempool_t *pool)
+static inline bool mempool_is_saturated(struct mempool *pool)
 {
 	return READ_ONCE(pool->curr_nr) >= pool->min_nr;
 }
 
-void mempool_exit(mempool_t *pool);
-int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
-		      mempool_free_t *free_fn, void *pool_data,
-		      gfp_t gfp_mask, int node_id);
-
-int mempool_init_noprof(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
-		 mempool_free_t *free_fn, void *pool_data);
+void mempool_exit(struct mempool *pool);
+int mempool_init_node(struct mempool *pool, int min_nr,
+		mempool_alloc_t *alloc_fn, mempool_free_t *free_fn,
+		void *pool_data, gfp_t gfp_mask, int node_id);
+int mempool_init_noprof(struct mempool *pool, int min_nr,
+		mempool_alloc_t *alloc_fn, mempool_free_t *free_fn,
+		void *pool_data);
 #define mempool_init(...)						\
 	alloc_hooks(mempool_init_noprof(__VA_ARGS__))
 
-extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
-			mempool_free_t *free_fn, void *pool_data);
-
-extern mempool_t *mempool_create_node_noprof(int min_nr, mempool_alloc_t *alloc_fn,
-			mempool_free_t *free_fn, void *pool_data,
-			gfp_t gfp_mask, int nid);
+struct mempool *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
+		mempool_free_t *free_fn, void *pool_data);
+struct mempool *mempool_create_node_noprof(int min_nr,
+		mempool_alloc_t *alloc_fn, mempool_free_t *free_fn,
+		void *pool_data, gfp_t gfp_mask, int nid);
 #define mempool_create_node(...)					\
 	alloc_hooks(mempool_create_node_noprof(__VA_ARGS__))
 
 #define mempool_create(_min_nr, _alloc_fn, _free_fn, _pool_data)	\
 	mempool_create_node(_min_nr, _alloc_fn, _free_fn, _pool_data,	\
 			    GFP_KERNEL, NUMA_NO_NODE)
 
-extern int mempool_resize(mempool_t *pool, int new_min_nr);
-extern void mempool_destroy(mempool_t *pool);
+int mempool_resize(struct mempool *pool, int new_min_nr);
+void mempool_destroy(struct mempool *pool);
 
-extern void *mempool_alloc_noprof(mempool_t *pool, gfp_t gfp_mask) __malloc;
+void *mempool_alloc_noprof(struct mempool *pool, gfp_t gfp_mask) __malloc;
 #define mempool_alloc(...)						\
 	alloc_hooks(mempool_alloc_noprof(__VA_ARGS__))
+int mempool_alloc_bulk_noprof(struct mempool *pool, void **elem,
+		unsigned int count, unsigned int allocated);
+#define mempool_alloc_bulk(...)						\
+	alloc_hooks(mempool_alloc_bulk_noprof(__VA_ARGS__))
 
-extern void *mempool_alloc_preallocated(mempool_t *pool) __malloc;
-extern void mempool_free(void *element, mempool_t *pool);
+void *mempool_alloc_preallocated(struct mempool *pool) __malloc;
+void mempool_free(void *element, struct mempool *pool);
+unsigned int mempool_free_bulk(struct mempool *pool, void **elem,
+		unsigned int count);
 
 /*
  * A mempool_alloc_t and mempool_free_t that get the memory from
@@ -97,19 +102,6 @@ void mempool_kfree(void *element, void *pool_data);
 	mempool_create((_min_nr), mempool_kmalloc, mempool_kfree,	\
 		       (void *)(unsigned long)(_size))
 
-void *mempool_kvmalloc(gfp_t gfp_mask, void *pool_data);
-void mempool_kvfree(void *element, void *pool_data);
-
-static inline int mempool_init_kvmalloc_pool(mempool_t *pool, int min_nr, size_t size)
-{
-	return mempool_init(pool, min_nr, mempool_kvmalloc, mempool_kvfree, (void *) size);
-}
-
-static inline mempool_t *mempool_create_kvmalloc_pool(int min_nr, size_t size)
-{
-	return mempool_create(min_nr, mempool_kvmalloc, mempool_kvfree, (void *) size);
-}
-
 /*
  * A mempool_alloc_t and mempool_free_t for a simple page allocator that
  * allocates pages of the order specified by pool_data