ext4: isolate ext4_extents.h file

After applied the commit (4a092d73), we have reduced the number of
source files that need to #include ext4_extents.h.  But we can do
better.

This commit defines ext4_zeroout_es() in extents.c and move
EXT_MAX_BLOCKS into ext4.h in order not to include ext4_extents.h in
indirect.c and ioctl.c.  Meanwhile we just need to include this file in
extent_status.c when ES_AGGRESSIVE_TEST is defined.  Otherwise, this
commit removes a duplicated declaration in trace/events/ext4.h.

After applied this patch, we just need to include ext4_extents.h file
in {super,migrate,move_extents,extents}.c, and it is easy for us to
define a new extent disk layout.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/ext4.h

@@ -2686,6 +2686,12 @@ extern int ext4_check_blockref(const char *, unsigned int,
 struct ext4_ext_path;
 struct ext4_extent;
 
+/*
+ * Maximum number of logical blocks in a file; ext4_extent's ee_block is
+ * __le32.
+ */
+#define EXT_MAX_BLOCKS	0xffffffff
+
 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);

fs/ext4/ext4_extents.h

@@ -133,12 +133,6 @@ struct ext4_ext_path {
  * structure for external API
  */
 
-/*
- * Maximum number of logical blocks in a file; ext4_extent's ee_block is
- * __le32.
- */
-#define EXT_MAX_BLOCKS	0xffffffff
-
 /*
  * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
  * initialized extent. This is 2^15 and not (2^16 - 1), since we use the

fs/ext4/extents.c

@@ -3048,6 +3048,23 @@ void ext4_ext_release(struct super_block *sb)
 #endif
 }
 
+static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
+{
+	ext4_lblk_t  ee_block;
+	ext4_fsblk_t ee_pblock;
+	unsigned int ee_len;
+
+	ee_block  = le32_to_cpu(ex->ee_block);
+	ee_len    = ext4_ext_get_actual_len(ex);
+	ee_pblock = ext4_ext_pblock(ex);
+
+	if (ee_len == 0)
+		return 0;
+
+	return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
+				     EXTENT_STATUS_WRITTEN);
+}
+
 /* FIXME!! we need to try to merge to left or right after zero-out  */
 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
 {
@@ -3200,7 +3217,7 @@ static int ext4_split_extent_at(handle_t *handle,
 			goto fix_extent_len;
 
 		/* update extent status tree */
-		err = ext4_es_zeroout(inode, &zero_ex);
+		err = ext4_zeroout_es(inode, &zero_ex);
 
 		goto out;
 	} else if (err)
@@ -3551,7 +3568,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
 out:
 	/* If we have gotten a failure, don't zero out status tree */
 	if (!err)
-		err = ext4_es_zeroout(inode, &zero_ex);
+		err = ext4_zeroout_es(inode, &zero_ex);
 	return err ? err : allocated;
 }
 

fs/ext4/extents_status.c

@@ -13,7 +13,6 @@
 #include <linux/list_sort.h>
 #include "ext4.h"
 #include "extents_status.h"
-#include "ext4_extents.h"
 
 #include <trace/events/ext4.h>
 
@@ -409,6 +408,8 @@ ext4_es_try_to_merge_right(struct inode *inode, struct extent_status *es)
 }
 
 #ifdef ES_AGGRESSIVE_TEST
+#include "ext4_extents.h"	/* Needed when ES_AGGRESSIVE_TEST is defined */
+
 static void ext4_es_insert_extent_ext_check(struct inode *inode,
 					    struct extent_status *es)
 {
@@ -903,23 +904,6 @@ int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	return err;
 }
 
-int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex)
-{
-	ext4_lblk_t  ee_block;
-	ext4_fsblk_t ee_pblock;
-	unsigned int ee_len;
-
-	ee_block  = le32_to_cpu(ex->ee_block);
-	ee_len    = ext4_ext_get_actual_len(ex);
-	ee_pblock = ext4_ext_pblock(ex);
-
-	if (ee_len == 0)
-		return 0;
-
-	return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
-				     EXTENT_STATUS_WRITTEN);
-}
-
 static int ext4_inode_touch_time_cmp(void *priv, struct list_head *a,
 				     struct list_head *b)
 {

fs/ext4/extents_status.h

@@ -81,7 +81,6 @@ extern void ext4_es_find_delayed_extent_range(struct inode *inode,
 					struct extent_status *es);
 extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
 				 struct extent_status *es);
-extern int ext4_es_zeroout(struct inode *inode, struct ext4_extent *ex);
 
 static inline int ext4_es_is_written(struct extent_status *es)
 {

fs/ext4/indirect.c

@@ -23,7 +23,6 @@
 #include <linux/aio.h>
 #include "ext4_jbd2.h"
 #include "truncate.h"
-#include "ext4_extents.h"	/* Needed for EXT_MAX_BLOCKS */
 
 #include <trace/events/ext4.h>
 

fs/ext4/ioctl.c

@@ -17,7 +17,6 @@
 #include <asm/uaccess.h>
 #include "ext4_jbd2.h"
 #include "ext4.h"
-#include "ext4_extents.h"
 
 #define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)
 

include/trace/events/ext4.h

@@ -14,7 +14,6 @@ struct ext4_prealloc_space;
 struct ext4_inode_info;
 struct mpage_da_data;
 struct ext4_map_blocks;
-struct ext4_extent;
 struct extent_status;
 
 #define EXT4_I(inode) (container_of(inode, struct ext4_inode_info, vfs_inode))