mm/slab: move and refactor __kmem_cache_alias()

Move __kmem_cache_alias() to slab_common.c since it's called by
__kmem_cache_create_args() and calls find_mergeable() that both
are in this file. We can remove two slab.h declarations and make
them static. Instead declare sysfs_slab_alias() from slub.c so
that __kmem_cache_alias() can keep calling it.

Add args parameter to __kmem_cache_alias() and find_mergeable() instead
of align and ctor. With that we can also move the checks for usersize
and sheaf_capacity there from __kmem_cache_create_args() and make the
result more symmetric with slab_unmergeable().

No functional changes intended.

Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/mm/slab.h b/mm/slab.h
index e767aa7e91b098311055192f06c11515d16188e4..0993800fccedd649c41695a040e3813dafe97950 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -281,9 +281,12 @@ struct kmem_cache {
 #define SLAB_SUPPORTS_SYSFS 1
 void sysfs_slab_unlink(struct kmem_cache *s);
 void sysfs_slab_release(struct kmem_cache *s);
+int sysfs_slab_alias(struct kmem_cache *s, const char *name);
 #else
 static inline void sysfs_slab_unlink(struct kmem_cache *s) { }
 static inline void sysfs_slab_release(struct kmem_cache *s) { }
+static inline int sysfs_slab_alias(struct kmem_cache *s, const char *name)
+                                                       { return 0; }
 #endif
 
 void *fixup_red_left(struct kmem_cache *s, void *p);
@@ -400,11 +403,6 @@ extern void create_boot_cache(struct kmem_cache *, const char *name,
                        unsigned int useroffset, unsigned int usersize);
 
 int slab_unmergeable(struct kmem_cache *s);
-struct kmem_cache *find_mergeable(unsigned size, unsigned align,
-               slab_flags_t flags, const char *name, void (*ctor)(void *));
-struct kmem_cache *
-__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
-                  slab_flags_t flags, void (*ctor)(void *));
 
 slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name);
 

diff --git a/mm/slab_common.c b/mm/slab_common.c
index e691ede0e6a87ede8d8b98efc464a95ce0ba291f..ee245a8806032eb5fddaaa011fc46058b4e15028 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -174,15 +174,22 @@ int slab_unmergeable(struct kmem_cache *s)
        return 0;
 }
 
-struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
-               slab_flags_t flags, const char *name, void (*ctor)(void *))
+static struct kmem_cache *find_mergeable(unsigned int size, slab_flags_t flags,
+               const char *name, struct kmem_cache_args *args)
 {
        struct kmem_cache *s;
+       unsigned int align;
 
        if (slab_nomerge)
                return NULL;
 
-       if (ctor)
+       if (args->ctor)
+               return NULL;
+
+       if (IS_ENABLED(CONFIG_HARDENED_USERCOPY) && args->usersize)
+               return NULL;
+
+       if (args->sheaf_capacity)
                return NULL;
 
        flags = kmem_cache_flags(flags, name);
@@ -191,7 +198,7 @@ struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
                return NULL;
 
        size = ALIGN(size, sizeof(void *));
-       align = calculate_alignment(flags, align, size);
+       align = calculate_alignment(flags, args->align, size);
        size = ALIGN(size, align);
 
        list_for_each_entry_reverse(s, &slab_caches, list) {
@@ -252,6 +259,31 @@ out:
        return ERR_PTR(err);
 }
 
+static struct kmem_cache *
+__kmem_cache_alias(const char *name, unsigned int size, slab_flags_t flags,
+                  struct kmem_cache_args *args)
+{
+       struct kmem_cache *s;
+
+       s = find_mergeable(size, flags, name, args);
+       if (s) {
+               if (sysfs_slab_alias(s, name))
+                       pr_err("SLUB: Unable to add cache alias %s to sysfs\n",
+                              name);
+
+               s->refcount++;
+
+               /*
+                * Adjust the object sizes so that we clear
+                * the complete object on kzalloc.
+                */
+               s->object_size = max(s->object_size, size);
+               s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
+       }
+
+       return s;
+}
+
 /**
  * __kmem_cache_create_args - Create a kmem cache.
  * @name: A string which is used in /proc/slabinfo to identify this cache.
@@ -323,9 +355,7 @@ struct kmem_cache *__kmem_cache_create_args(const char *name,
                    object_size - args->usersize < args->useroffset))
                args->usersize = args->useroffset = 0;
 
-       if (!args->usersize && !args->sheaf_capacity)
-               s = __kmem_cache_alias(name, object_size, args->align, flags,
-                                      args->ctor);
+       s = __kmem_cache_alias(name, object_size, flags, args);
        if (s)
                goto out_unlock;
 

diff --git a/mm/slub.c b/mm/slub.c
index 49223795a7d64d63841b717dc5cff8cece22776a..afc3e511ff395993a082b754532ffcaa7257035e 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -350,11 +350,8 @@ enum track_item { TRACK_ALLOC, TRACK_FREE };
 
 #ifdef SLAB_SUPPORTS_SYSFS
 static int sysfs_slab_add(struct kmem_cache *);
-static int sysfs_slab_alias(struct kmem_cache *, const char *);
 #else
 static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
-static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
-                                                       { return 0; }
 #endif
 
 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
@@ -8580,31 +8577,6 @@ void __init kmem_cache_init_late(void)
        WARN_ON(!flushwq);
 }
 
-struct kmem_cache *
-__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
-                  slab_flags_t flags, void (*ctor)(void *))
-{
-       struct kmem_cache *s;
-
-       s = find_mergeable(size, align, flags, name, ctor);
-       if (s) {
-               if (sysfs_slab_alias(s, name))
-                       pr_err("SLUB: Unable to add cache alias %s to sysfs\n",
-                              name);
-
-               s->refcount++;
-
-               /*
-                * Adjust the object sizes so that we clear
-                * the complete object on kzalloc.
-                */
-               s->object_size = max(s->object_size, size);
-               s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
-       }
-
-       return s;
-}
-
 int do_kmem_cache_create(struct kmem_cache *s, const char *name,
                         unsigned int size, struct kmem_cache_args *args,
                         slab_flags_t flags)
@@ -9837,7 +9809,7 @@ struct saved_alias {
 
 static struct saved_alias *alias_list;
 
-static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
+int sysfs_slab_alias(struct kmem_cache *s, const char *name)
 {
        struct saved_alias *al;