f2fs: introduce get_available_block_count() for cleanup

There are very similar codes in inc_valid_block_count() and
inc_valid_node_count() which is used for available user block
count calculation.

This patch introduces a new helper get_available_block_count()
to include those common codes, and used it to clean up codes.
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -2280,6 +2280,27 @@ static inline bool __allow_reserved_blocks(struct f2fs_sb_info *sbi,
 	return false;
 }
 
+static inline unsigned int get_available_block_count(struct f2fs_sb_info *sbi,
+						struct inode *inode, bool cap)
+{
+	block_t avail_user_block_count;
+
+	avail_user_block_count = sbi->user_block_count -
+					sbi->current_reserved_blocks;
+
+	if (!__allow_reserved_blocks(sbi, inode, cap))
+		avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks;
+
+	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
+		if (avail_user_block_count > sbi->unusable_block_count)
+			avail_user_block_count -= sbi->unusable_block_count;
+		else
+			avail_user_block_count = 0;
+	}
+
+	return avail_user_block_count;
+}
+
 static inline void f2fs_i_blocks_write(struct inode *, block_t, bool, bool);
 static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
 				 struct inode *inode, blkcnt_t *count, bool partial)
@@ -2305,18 +2326,8 @@ static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
 
 	spin_lock(&sbi->stat_lock);
 	sbi->total_valid_block_count += (block_t)(*count);
-	avail_user_block_count = sbi->user_block_count -
-					sbi->current_reserved_blocks;
+	avail_user_block_count = get_available_block_count(sbi, inode, true);
 
-	if (!__allow_reserved_blocks(sbi, inode, true))
-		avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks;
-
-	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
-		if (avail_user_block_count > sbi->unusable_block_count)
-			avail_user_block_count -= sbi->unusable_block_count;
-		else
-			avail_user_block_count = 0;
-	}
 	if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
 		if (!partial) {
 			spin_unlock(&sbi->stat_lock);
@@ -2612,7 +2623,8 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
 					struct inode *inode, bool is_inode)
 {
 	block_t	valid_block_count;
-	unsigned int valid_node_count, user_block_count;
+	unsigned int valid_node_count;
+	unsigned int avail_user_block_count;
 	int err;
 
 	if (is_inode) {
@@ -2632,17 +2644,10 @@ static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
 
 	spin_lock(&sbi->stat_lock);
 
-	valid_block_count = sbi->total_valid_block_count +
-					sbi->current_reserved_blocks + 1;
-
-	if (!__allow_reserved_blocks(sbi, inode, false))
-		valid_block_count += F2FS_OPTION(sbi).root_reserved_blocks;
-
-	user_block_count = sbi->user_block_count;
-	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
-		user_block_count -= sbi->unusable_block_count;
+	valid_block_count = sbi->total_valid_block_count + 1;
+	avail_user_block_count = get_available_block_count(sbi, inode, false);
 
-	if (unlikely(valid_block_count > user_block_count)) {
+	if (unlikely(valid_block_count > avail_user_block_count)) {
 		spin_unlock(&sbi->stat_lock);
 		goto enospc;
 	}