Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin

* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...

6 files changed, 9 insertions, 101 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 6b9aee20f242..ca389394fa2a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -102,9 +102,6 @@
  *    ->inode_lock		(zap_pte_range->set_page_dirty)
  *    ->private_lock		(zap_pte_range->__set_page_dirty_buffers)
  *
- *  ->task->proc_lock
- *    ->dcache_lock		(proc_pid_lookup)
- *
  *  (code doesn't rely on that order, so you could switch it around)
  *  ->tasklist_lock             (memory_failure, collect_procs_ao)
  *    ->i_mmap_lock
diff --git a/mm/shmem.c b/mm/shmem.c
index 47fdeeb9d636..5ee67c990602 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2415,13 +2415,20 @@ static struct inode *shmem_alloc_inode(struct super_block *sb)
 	return &p->vfs_inode;
 }
 
+static void shmem_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
+}
+
 static void shmem_destroy_inode(struct inode *inode)
 {
 	if ((inode->i_mode & S_IFMT) == S_IFREG) {
 		/* only struct inode is valid if it's an inline symlink */
 		mpol_free_shared_policy(&SHMEM_I(inode)->policy);
 	}
-	kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
+	call_rcu(&inode->i_rcu, shmem_i_callback);
 }
 
 static void init_once(void *foo)
diff --git a/mm/slab.c b/mm/slab.c
index b1e40dafbab3..6107f2380e08 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2781,7 +2781,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 /*
  * Map pages beginning at addr to the given cache and slab. This is required
  * for the slab allocator to be able to lookup the cache and slab of a
- * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
+ * virtual address for kfree, ksize, and slab debugging.
  */
 static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
 			   void *addr)
@@ -3660,36 +3660,6 @@ void *kmem_cache_alloc_notrace(struct kmem_cache *cachep, gfp_t flags)
 EXPORT_SYMBOL(kmem_cache_alloc_notrace);
 #endif
 
-/**
- * kmem_ptr_validate - check if an untrusted pointer might be a slab entry.
- * @cachep: the cache we're checking against
- * @ptr: pointer to validate
- *
- * This verifies that the untrusted pointer looks sane;
- * it is _not_ a guarantee that the pointer is actually
- * part of the slab cache in question, but it at least
- * validates that the pointer can be dereferenced and
- * looks half-way sane.
- *
- * Currently only used for dentry validation.
- */
-int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
-{
-	unsigned long size = cachep->buffer_size;
-	struct page *page;
-
-	if (unlikely(!kern_ptr_validate(ptr, size)))
-		goto out;
-	page = virt_to_page(ptr);
-	if (unlikely(!PageSlab(page)))
-		goto out;
-	if (unlikely(page_get_cache(page) != cachep))
-		goto out;
-	return 1;
-out:
-	return 0;
-}
-
 #ifdef CONFIG_NUMA
 void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 {
diff --git a/mm/slob.c b/mm/slob.c
index 617b6d6c42c7..3588eaaef726 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -678,11 +678,6 @@ int kmem_cache_shrink(struct kmem_cache *d)
 }
 EXPORT_SYMBOL(kmem_cache_shrink);
 
-int kmem_ptr_validate(struct kmem_cache *a, const void *b)
-{
-	return 0;
-}
-
 static unsigned int slob_ready __read_mostly;
 
 int slab_is_available(void)
diff --git a/mm/slub.c b/mm/slub.c
index bec0e355fbad..a2fe1727ed85 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1917,17 +1917,6 @@ void kmem_cache_free(struct kmem_cache *s, void *x)
 }
 EXPORT_SYMBOL(kmem_cache_free);
 
-/* Figure out on which slab page the object resides */
-static struct page *get_object_page(const void *x)
-{
-	struct page *page = virt_to_head_page(x);
-
-	if (!PageSlab(page))
-		return NULL;
-
-	return page;
-}
-
 /*
  * Object placement in a slab is made very easy because we always start at
  * offset 0. If we tune the size of the object to the alignment then we can
@@ -2386,35 +2375,6 @@ error:
 }
 
 /*
- * Check if a given pointer is valid
- */
-int kmem_ptr_validate(struct kmem_cache *s, const void *object)
-{
-	struct page *page;
-
-	if (!kern_ptr_validate(object, s->size))
-		return 0;
-
-	page = get_object_page(object);
-
-	if (!page || s != page->slab)
-		/* No slab or wrong slab */
-		return 0;
-
-	if (!check_valid_pointer(s, page, object))
-		return 0;
-
-	/*
-	 * We could also check if the object is on the slabs freelist.
-	 * But this would be too expensive and it seems that the main
-	 * purpose of kmem_ptr_valid() is to check if the object belongs
-	 * to a certain slab.
-	 */
-	return 1;
-}
-EXPORT_SYMBOL(kmem_ptr_validate);
-
-/*
  * Determine the size of a slab object
  */
 unsigned int kmem_cache_size(struct kmem_cache *s)
diff --git a/mm/util.c b/mm/util.c
index 73dac81e9f78..f126975ef23e 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -186,27 +186,6 @@ void kzfree(const void *p)
 }
 EXPORT_SYMBOL(kzfree);
 
-int kern_ptr_validate(const void *ptr, unsigned long size)
-{
-	unsigned long addr = (unsigned long)ptr;
-	unsigned long min_addr = PAGE_OFFSET;
-	unsigned long align_mask = sizeof(void *) - 1;
-
-	if (unlikely(addr < min_addr))
-		goto out;
-	if (unlikely(addr > (unsigned long)high_memory - size))
-		goto out;
-	if (unlikely(addr & align_mask))
-		goto out;
-	if (unlikely(!kern_addr_valid(addr)))
-		goto out;
-	if (unlikely(!kern_addr_valid(addr + size - 1)))
-		goto out;
-	return 1;
-out:
-	return 0;
-}
-
 /*
  * strndup_user - duplicate an existing string from user space
  * @s: The string to duplicate