Re: [PATCH v9 11/61] xarray: Add definition of struct xarray

[Josef Bacik]

On Tue, Mar 13, 2018 at 06:25:49AM -0700, Matthew Wilcox wrote:
> From: Matthew Wilcox 
> 
> This is a direct replacement for struct radix_tree_root.  Some of the
> struct members have changed name; convert those, and use a #define so
> that radix_tree users continue to work without change.
> 
> Signed-off-by: Matthew Wilcox 

Reviewed-by: Josef Bacik 

Thanks,

Josef

Re: [PATCH v9 11/61] xarray: Add definition of struct xarray

[Josef Bacik]

On Tue, Mar 13, 2018 at 06:25:49AM -0700, Matthew Wilcox wrote:
> From: Matthew Wilcox 
> 
> This is a direct replacement for struct radix_tree_root.  Some of the
> struct members have changed name; convert those, and use a #define so
> that radix_tree users continue to work without change.
> 
> Signed-off-by: Matthew Wilcox 

Reviewed-by: Josef Bacik 

Thanks,

Josef

[PATCH v9 11/61] xarray: Add definition of struct xarray

[Matthew Wilcox]

From: Matthew Wilcox 

This is a direct replacement for struct radix_tree_root.  Some of the
struct members have changed name; convert those, and use a #define so
that radix_tree users continue to work without change.

Signed-off-by: Matthew Wilcox 
---
 include/linux/radix-tree.h   | 33 --
 include/linux/xarray.h   | 61 ++
 lib/Makefile |  2 +-
 lib/idr.c|  4 +-
 lib/radix-tree.c | 75 
 lib/xarray.c | 44 +++
 tools/include/linux/spinlock.h   |  3 +-
 tools/testing/radix-tree/.gitignore  |  1 +
 tools/testing/radix-tree/Makefile|  8 +++-
 tools/testing/radix-tree/linux/bug.h |  1 +
 tools/testing/radix-tree/linux/kconfig.h |  1 +
 tools/testing/radix-tree/linux/xarray.h  |  2 +
 tools/testing/radix-tree/multiorder.c|  6 +--
 tools/testing/radix-tree/test.c  |  6 +--
 14 files changed, 173 insertions(+), 74 deletions(-)
 create mode 100644 lib/xarray.c
 create mode 100644 tools/testing/radix-tree/linux/kconfig.h
 create mode 100644 tools/testing/radix-tree/linux/xarray.h

diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 87f35fe00e55..c8a33e9e9a3c 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -30,6 +30,9 @@
 #include 
 #include 
 
+/* Keep unconverted code working */
+#define radix_tree_rootxarray
+
 /*
  * The bottom two bits of the slot determine how the remaining bits in the
  * slot are interpreted:
@@ -59,10 +62,7 @@ static inline bool radix_tree_is_internal_node(void *ptr)
 
 #define RADIX_TREE_MAX_TAGS 3
 
-#ifndef RADIX_TREE_MAP_SHIFT
-#define RADIX_TREE_MAP_SHIFT   (CONFIG_BASE_SMALL ? 4 : 6)
-#endif
-
+#define RADIX_TREE_MAP_SHIFT   XA_CHUNK_SHIFT
 #define RADIX_TREE_MAP_SIZE(1UL << RADIX_TREE_MAP_SHIFT)
 #define RADIX_TREE_MAP_MASK(RADIX_TREE_MAP_SIZE-1)
 
@@ -95,36 +95,21 @@ struct radix_tree_node {
unsigned long   tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
 };
 
-/* The IDR tag is stored in the low bits of the GFP flags */
+/* The IDR tag is stored in the low bits of xa_flags */
 #define ROOT_IS_IDR((__force gfp_t)4)
-/* The top bits of gfp_mask are used to store the root tags */
+/* The top bits of xa_flags are used to store the root tags */
 #define ROOT_TAG_SHIFT (__GFP_BITS_SHIFT)
 
-struct radix_tree_root {
-   spinlock_t  xa_lock;
-   gfp_t   gfp_mask;
-   struct radix_tree_node  __rcu *rnode;
-};
-
-#define RADIX_TREE_INIT(name, mask){   \
-   .xa_lock = __SPIN_LOCK_UNLOCKED(name.xa_lock),  \
-   .gfp_mask = (mask), \
-   .rnode = NULL,  \
-}
+#define RADIX_TREE_INIT(name, mask)XARRAY_INIT_FLAGS(name, mask)
 
 #define RADIX_TREE(name, mask) \
struct radix_tree_root name = RADIX_TREE_INIT(name, mask)
 
-#define INIT_RADIX_TREE(root, mask)\
-do {   \
-   spin_lock_init(&(root)->xa_lock);   \
-   (root)->gfp_mask = (mask);  \
-   (root)->rnode = NULL;   \
-} while (0)
+#define INIT_RADIX_TREE(root, mask) xa_init_flags(root, mask)
 
 static inline bool radix_tree_empty(const struct radix_tree_root *root)
 {
-   return root->rnode == NULL;
+   return root->xa_head == NULL;
 }
 
 /**
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index 283beb5aac58..9b05b907062b 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -10,6 +10,8 @@
  */
 
 #include 
+#include 
+#include 
 #include 
 #include 
 
@@ -105,6 +107,65 @@ static inline bool xa_is_internal(const void *entry)
return ((unsigned long)entry & 3) == 2;
 }
 
+/**
+ * struct xarray - The anchor of the XArray.
+ * @xa_lock: Lock that protects the contents of the XArray.
+ *
+ * To use the xarray, define it statically or embed it in your data structure.
+ * It is a very small data structure, so it does not usually make sense to
+ * allocate it separately and keep a pointer to it in your data structure.
+ *
+ * You may use the xa_lock to protect your own data structures as well.
+ */
+/*
+ * If all of the entries in the array are NULL, @xa_head is a NULL pointer.
+ * If the only non-NULL entry in the array is at index 0, @xa_head is that
+ * entry.  If any other entry in the array is non-NULL, @xa_head points
+ * to an @xa_node.
+ */
+struct xarray {
+   spinlock_t  xa_lock;
+/* private: The rest of the data structure is not to be used directly. */
+   gfp_t   xa_flags;
+   

[PATCH v9 11/61] xarray: Add definition of struct xarray

[Matthew Wilcox]

From: Matthew Wilcox 

This is a direct replacement for struct radix_tree_root.  Some of the
struct members have changed name; convert those, and use a #define so
that radix_tree users continue to work without change.

Signed-off-by: Matthew Wilcox 
---
 include/linux/radix-tree.h   | 33 --
 include/linux/xarray.h   | 61 ++
 lib/Makefile |  2 +-
 lib/idr.c|  4 +-
 lib/radix-tree.c | 75 
 lib/xarray.c | 44 +++
 tools/include/linux/spinlock.h   |  3 +-
 tools/testing/radix-tree/.gitignore  |  1 +
 tools/testing/radix-tree/Makefile|  8 +++-
 tools/testing/radix-tree/linux/bug.h |  1 +
 tools/testing/radix-tree/linux/kconfig.h |  1 +
 tools/testing/radix-tree/linux/xarray.h  |  2 +
 tools/testing/radix-tree/multiorder.c|  6 +--
 tools/testing/radix-tree/test.c  |  6 +--
 14 files changed, 173 insertions(+), 74 deletions(-)
 create mode 100644 lib/xarray.c
 create mode 100644 tools/testing/radix-tree/linux/kconfig.h
 create mode 100644 tools/testing/radix-tree/linux/xarray.h

diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 87f35fe00e55..c8a33e9e9a3c 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -30,6 +30,9 @@
 #include 
 #include 
 
+/* Keep unconverted code working */
+#define radix_tree_rootxarray
+
 /*
  * The bottom two bits of the slot determine how the remaining bits in the
  * slot are interpreted:
@@ -59,10 +62,7 @@ static inline bool radix_tree_is_internal_node(void *ptr)
 
 #define RADIX_TREE_MAX_TAGS 3
 
-#ifndef RADIX_TREE_MAP_SHIFT
-#define RADIX_TREE_MAP_SHIFT   (CONFIG_BASE_SMALL ? 4 : 6)
-#endif
-
+#define RADIX_TREE_MAP_SHIFT   XA_CHUNK_SHIFT
 #define RADIX_TREE_MAP_SIZE(1UL << RADIX_TREE_MAP_SHIFT)
 #define RADIX_TREE_MAP_MASK(RADIX_TREE_MAP_SIZE-1)
 
@@ -95,36 +95,21 @@ struct radix_tree_node {
unsigned long   tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
 };
 
-/* The IDR tag is stored in the low bits of the GFP flags */
+/* The IDR tag is stored in the low bits of xa_flags */
 #define ROOT_IS_IDR((__force gfp_t)4)
-/* The top bits of gfp_mask are used to store the root tags */
+/* The top bits of xa_flags are used to store the root tags */
 #define ROOT_TAG_SHIFT (__GFP_BITS_SHIFT)
 
-struct radix_tree_root {
-   spinlock_t  xa_lock;
-   gfp_t   gfp_mask;
-   struct radix_tree_node  __rcu *rnode;
-};
-
-#define RADIX_TREE_INIT(name, mask){   \
-   .xa_lock = __SPIN_LOCK_UNLOCKED(name.xa_lock),  \
-   .gfp_mask = (mask), \
-   .rnode = NULL,  \
-}
+#define RADIX_TREE_INIT(name, mask)XARRAY_INIT_FLAGS(name, mask)
 
 #define RADIX_TREE(name, mask) \
struct radix_tree_root name = RADIX_TREE_INIT(name, mask)
 
-#define INIT_RADIX_TREE(root, mask)\
-do {   \
-   spin_lock_init(&(root)->xa_lock);   \
-   (root)->gfp_mask = (mask);  \
-   (root)->rnode = NULL;   \
-} while (0)
+#define INIT_RADIX_TREE(root, mask) xa_init_flags(root, mask)
 
 static inline bool radix_tree_empty(const struct radix_tree_root *root)
 {
-   return root->rnode == NULL;
+   return root->xa_head == NULL;
 }
 
 /**
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index 283beb5aac58..9b05b907062b 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -10,6 +10,8 @@
  */
 
 #include 
+#include 
+#include 
 #include 
 #include 
 
@@ -105,6 +107,65 @@ static inline bool xa_is_internal(const void *entry)
return ((unsigned long)entry & 3) == 2;
 }
 
+/**
+ * struct xarray - The anchor of the XArray.
+ * @xa_lock: Lock that protects the contents of the XArray.
+ *
+ * To use the xarray, define it statically or embed it in your data structure.
+ * It is a very small data structure, so it does not usually make sense to
+ * allocate it separately and keep a pointer to it in your data structure.
+ *
+ * You may use the xa_lock to protect your own data structures as well.
+ */
+/*
+ * If all of the entries in the array are NULL, @xa_head is a NULL pointer.
+ * If the only non-NULL entry in the array is at index 0, @xa_head is that
+ * entry.  If any other entry in the array is non-NULL, @xa_head points
+ * to an @xa_node.
+ */
+struct xarray {
+   spinlock_t  xa_lock;
+/* private: The rest of the data structure is not to be used directly. */
+   gfp_t   xa_flags;
+   void __rcu *xa_head;
+};
+
+#define