btrfs: switch extent_state state to unsigned

Currently there's a 4B hole in the structure between refs and state and there
are only 16 bits used so we can make it unsigned. This will get a better
packing and may save some stack space for local variables.

The size of extent_state gets reduced by 8B and there are usually a lot
of slab objects.

struct extent_state {
	u64                        start;                /*     0     8 */
	u64                        end;                  /*     8     8 */
	struct rb_node             rb_node;              /*    16    24 */
	wait_queue_head_t          wq;                   /*    40    24 */
	/* --- cacheline 1 boundary (64 bytes) --- */
	atomic_t                   refs;                 /*    64     4 */

	/* XXX 4 bytes hole, try to pack */

	long unsigned int          state;                /*    72     8 */
	u64                        private;              /*    80     8 */

	/* size: 88, cachelines: 2, members: 7 */
	/* sum members: 84, holes: 1, sum holes: 4 */
	/* last cacheline: 24 bytes */
};
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/extent_io.c

@@ -64,7 +64,7 @@ void btrfs_leak_debug_check(void)
 
 	while (!list_empty(&states)) {
 		state = list_entry(states.next, struct extent_state, leak_list);
-		pr_err("BTRFS: state leak: start %llu end %llu state %lu in tree %d refs %d\n",
+		pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n",
 		       state->start, state->end, state->state,
 		       extent_state_in_tree(state),
 		       atomic_read(&state->refs));
@@ -396,21 +396,21 @@ static void merge_state(struct extent_io_tree *tree,
 }
 
 static void set_state_cb(struct extent_io_tree *tree,
-			 struct extent_state *state, unsigned long *bits)
+			 struct extent_state *state, unsigned *bits)
 {
 	if (tree->ops && tree->ops->set_bit_hook)
 		tree->ops->set_bit_hook(tree->mapping->host, state, bits);
 }
 
 static void clear_state_cb(struct extent_io_tree *tree,
-			   struct extent_state *state, unsigned long *bits)
+			   struct extent_state *state, unsigned *bits)
 {
 	if (tree->ops && tree->ops->clear_bit_hook)
 		tree->ops->clear_bit_hook(tree->mapping->host, state, bits);
 }
 
 static void set_state_bits(struct extent_io_tree *tree,
-			   struct extent_state *state, unsigned long *bits);
+			   struct extent_state *state, unsigned *bits);
 
 /*
  * insert an extent_state struct into the tree.  'bits' are set on the
@@ -426,7 +426,7 @@ static int insert_state(struct extent_io_tree *tree,
 			struct extent_state *state, u64 start, u64 end,
 			struct rb_node ***p,
 			struct rb_node **parent,
-			unsigned long *bits)
+			unsigned *bits)
 {
 	struct rb_node *node;
 
@@ -511,10 +511,10 @@ static struct extent_state *next_state(struct extent_state *state)
  */
 static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
 					    struct extent_state *state,
-					    unsigned long *bits, int wake)
+					    unsigned *bits, int wake)
 {
 	struct extent_state *next;
-	unsigned long bits_to_clear = *bits & ~EXTENT_CTLBITS;
+	unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS;
 
 	if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
 		u64 range = state->end - state->start + 1;
@@ -570,7 +570,7 @@ static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
  * This takes the tree lock, and returns 0 on success and < 0 on error.
  */
 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		     unsigned long bits, int wake, int delete,
+		     unsigned bits, int wake, int delete,
 		     struct extent_state **cached_state,
 		     gfp_t mask)
 {
@@ -789,9 +789,9 @@ static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 
 static void set_state_bits(struct extent_io_tree *tree,
 			   struct extent_state *state,
-			   unsigned long *bits)
+			   unsigned *bits)
 {
-	unsigned long bits_to_set = *bits & ~EXTENT_CTLBITS;
+	unsigned bits_to_set = *bits & ~EXTENT_CTLBITS;
 
 	set_state_cb(tree, state, bits);
 	if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
@@ -803,7 +803,7 @@ static void set_state_bits(struct extent_io_tree *tree,
 
 static void cache_state_if_flags(struct extent_state *state,
 				 struct extent_state **cached_ptr,
-				 const u64 flags)
+				 unsigned flags)
 {
 	if (cached_ptr && !(*cached_ptr)) {
 		if (!flags || (state->state & flags)) {
@@ -833,7 +833,7 @@ static void cache_state(struct extent_state *state,
 
 static int __must_check
 __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		 unsigned long bits, unsigned long exclusive_bits,
+		 unsigned bits, unsigned exclusive_bits,
 		 u64 *failed_start, struct extent_state **cached_state,
 		 gfp_t mask)
 {
@@ -1034,7 +1034,7 @@ __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 }
 
 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		   unsigned long bits, u64 * failed_start,
+		   unsigned bits, u64 * failed_start,
 		   struct extent_state **cached_state, gfp_t mask)
 {
 	return __set_extent_bit(tree, start, end, bits, 0, failed_start,
@@ -1060,7 +1060,7 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
  * boundary bits like LOCK.
  */
 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		       unsigned long bits, unsigned long clear_bits,
+		       unsigned bits, unsigned clear_bits,
 		       struct extent_state **cached_state, gfp_t mask)
 {
 	struct extent_state *state;
@@ -1268,14 +1268,14 @@ int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
 }
 
 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
-		    unsigned long bits, gfp_t mask)
+		    unsigned bits, gfp_t mask)
 {
 	return set_extent_bit(tree, start, end, bits, NULL,
 			      NULL, mask);
 }
 
 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
-		      unsigned long bits, gfp_t mask)
+		      unsigned bits, gfp_t mask)
 {
 	return clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask);
 }
@@ -1330,10 +1330,11 @@ int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
  * us if waiting is desired.
  */
 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
-		     unsigned long bits, struct extent_state **cached_state)
+		     unsigned bits, struct extent_state **cached_state)
 {
 	int err;
 	u64 failed_start;
+
 	while (1) {
 		err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
 				       EXTENT_LOCKED, &failed_start,
@@ -1440,7 +1441,7 @@ static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
  */
 static struct extent_state *
 find_first_extent_bit_state(struct extent_io_tree *tree,
-			    u64 start, unsigned long bits)
+			    u64 start, unsigned bits)
 {
 	struct rb_node *node;
 	struct extent_state *state;
@@ -1474,7 +1475,7 @@ find_first_extent_bit_state(struct extent_io_tree *tree,
  * If nothing was found, 1 is returned. If found something, return 0.
  */
 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
-			  u64 *start_ret, u64 *end_ret, unsigned long bits,
+			  u64 *start_ret, u64 *end_ret, unsigned bits,
 			  struct extent_state **cached_state)
 {
 	struct extent_state *state;
@@ -1753,7 +1754,7 @@ STATIC u64 find_lock_delalloc_range(struct inode *inode,
 
 int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
 				 struct page *locked_page,
-				 unsigned long clear_bits,
+				 unsigned clear_bits,
 				 unsigned long page_ops)
 {
 	struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
@@ -1810,7 +1811,7 @@ int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
  */
 u64 count_range_bits(struct extent_io_tree *tree,
 		     u64 *start, u64 search_end, u64 max_bytes,
-		     unsigned long bits, int contig)
+		     unsigned bits, int contig)
 {
 	struct rb_node *node;
 	struct extent_state *state;
@@ -1928,7 +1929,7 @@ int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
  * range is found set.
  */
 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		   unsigned long bits, int filled, struct extent_state *cached)
+		   unsigned bits, int filled, struct extent_state *cached)
 {
 	struct extent_state *state = NULL;
 	struct rb_node *node;

fs/btrfs/extent_io.h

@@ -4,20 +4,20 @@
 #include <linux/rbtree.h>
 
 /* bits for the extent state */
-#define EXTENT_DIRTY 1
-#define EXTENT_WRITEBACK (1 << 1)
-#define EXTENT_UPTODATE (1 << 2)
-#define EXTENT_LOCKED (1 << 3)
-#define EXTENT_NEW (1 << 4)
-#define EXTENT_DELALLOC (1 << 5)
-#define EXTENT_DEFRAG (1 << 6)
-#define EXTENT_BOUNDARY (1 << 9)
-#define EXTENT_NODATASUM (1 << 10)
-#define EXTENT_DO_ACCOUNTING (1 << 11)
-#define EXTENT_FIRST_DELALLOC (1 << 12)
-#define EXTENT_NEED_WAIT (1 << 13)
-#define EXTENT_DAMAGED (1 << 14)
-#define EXTENT_NORESERVE (1 << 15)
+#define EXTENT_DIRTY		(1U << 0)
+#define EXTENT_WRITEBACK	(1U << 1)
+#define EXTENT_UPTODATE		(1U << 2)
+#define EXTENT_LOCKED		(1U << 3)
+#define EXTENT_NEW		(1U << 4)
+#define EXTENT_DELALLOC		(1U << 5)
+#define EXTENT_DEFRAG		(1U << 6)
+#define EXTENT_BOUNDARY		(1U << 9)
+#define EXTENT_NODATASUM	(1U << 10)
+#define EXTENT_DO_ACCOUNTING	(1U << 11)
+#define EXTENT_FIRST_DELALLOC	(1U << 12)
+#define EXTENT_NEED_WAIT	(1U << 13)
+#define EXTENT_DAMAGED		(1U << 14)
+#define EXTENT_NORESERVE	(1U << 15)
 #define EXTENT_IOBITS		(EXTENT_LOCKED | EXTENT_WRITEBACK)
 #define EXTENT_CTLBITS		(EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
 
@@ -81,9 +81,9 @@ struct extent_io_ops {
 	int (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
 				      struct extent_state *state, int uptodate);
 	void (*set_bit_hook)(struct inode *inode, struct extent_state *state,
-			     unsigned long *bits);
+			     unsigned *bits);
 	void (*clear_bit_hook)(struct inode *inode, struct extent_state *state,
-			       unsigned long *bits);
+			       unsigned *bits);
 	void (*merge_extent_hook)(struct inode *inode,
 				  struct extent_state *new,
 				  struct extent_state *other);
@@ -108,7 +108,7 @@ struct extent_state {
 	/* ADD NEW ELEMENTS AFTER THIS */
 	wait_queue_head_t wq;
 	atomic_t refs;
-	unsigned long state;
+	unsigned state;
 
 	/* for use by the FS */
 	u64 private;
@@ -188,7 +188,7 @@ int try_release_extent_mapping(struct extent_map_tree *map,
 int try_release_extent_buffer(struct page *page);
 int lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
-		     unsigned long bits, struct extent_state **cached);
+		     unsigned bits, struct extent_state **cached);
 int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end);
 int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end,
 			 struct extent_state **cached, gfp_t mask);
@@ -202,21 +202,21 @@ void extent_io_exit(void);
 
 u64 count_range_bits(struct extent_io_tree *tree,
 		     u64 *start, u64 search_end,
-		     u64 max_bytes, unsigned long bits, int contig);
+		     u64 max_bytes, unsigned bits, int contig);
 
 void free_extent_state(struct extent_state *state);
 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		   unsigned long bits, int filled,
+		   unsigned bits, int filled,
 		   struct extent_state *cached_state);
 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
-		      unsigned long bits, gfp_t mask);
+		      unsigned bits, gfp_t mask);
 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		     unsigned long bits, int wake, int delete,
+		     unsigned bits, int wake, int delete,
 		     struct extent_state **cached, gfp_t mask);
 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
-		    unsigned long bits, gfp_t mask);
+		    unsigned bits, gfp_t mask);
 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		   unsigned long bits, u64 *failed_start,
+		   unsigned bits, u64 *failed_start,
 		   struct extent_state **cached_state, gfp_t mask);
 int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
 			struct extent_state **cached_state, gfp_t mask);
@@ -229,14 +229,14 @@ int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
 		       gfp_t mask);
 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
-		       unsigned long bits, unsigned long clear_bits,
+		       unsigned bits, unsigned clear_bits,
 		       struct extent_state **cached_state, gfp_t mask);
 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
 			struct extent_state **cached_state, gfp_t mask);
 int set_extent_defrag(struct extent_io_tree *tree, u64 start, u64 end,
 		      struct extent_state **cached_state, gfp_t mask);
 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
-			  u64 *start_ret, u64 *end_ret, unsigned long bits,
+			  u64 *start_ret, u64 *end_ret, unsigned bits,
 			  struct extent_state **cached_state);
 int extent_invalidatepage(struct extent_io_tree *tree,
 			  struct page *page, unsigned long offset);
@@ -323,7 +323,7 @@ int extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
 int extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
 int extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
 				 struct page *locked_page,
-				 unsigned long bits_to_clear,
+				 unsigned bits_to_clear,
 				 unsigned long page_ops);
 struct bio *
 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,

fs/btrfs/inode.c

@@ -1604,7 +1604,7 @@ static void btrfs_del_delalloc_inode(struct btrfs_root *root,
  * have pending delalloc work to be done.
  */
 static void btrfs_set_bit_hook(struct inode *inode,
-			       struct extent_state *state, unsigned long *bits)
+			       struct extent_state *state, unsigned *bits)
 {
 
 	if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
@@ -1645,7 +1645,7 @@ static void btrfs_set_bit_hook(struct inode *inode,
  */
 static void btrfs_clear_bit_hook(struct inode *inode,
 				 struct extent_state *state,
-				 unsigned long *bits)
+				 unsigned *bits)
 {
 	u64 len = state->end + 1 - state->start;
 

fs/btrfs/tests/extent-io-tests.c

@@ -258,8 +258,7 @@ static int test_find_delalloc(void)
 	}
 	ret = 0;
 out_bits:
-	clear_extent_bits(&tmp, 0, total_dirty - 1,
-			  (unsigned long)-1, GFP_NOFS);
+	clear_extent_bits(&tmp, 0, total_dirty - 1, (unsigned)-1, GFP_NOFS);
 out:
 	if (locked_page)
 		page_cache_release(locked_page);