f2fs: introduce max_file_blocks in sbi

Introduce max_file_blocks in sbi to store max block index of file in f2fs,
it could be used to avoid unneeded calculation of max block index in
runtime.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix overflow of sbi->max_file_blocks]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -762,7 +762,7 @@ static int get_data_block_bmap(struct inode *inode, sector_t iblock,
 			struct buffer_head *bh_result, int create)
 {
 	/* Block number less than F2FS MAX BLOCKS */
-	if (unlikely(iblock >= max_file_size(0)))
+	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
 		return -EFBIG;
 
 	return __get_data_block(inode, iblock, bh_result, create,

fs/f2fs/f2fs.h

@@ -783,6 +783,7 @@ struct f2fs_sb_info {
 	unsigned int total_node_count;		/* total node block count */
 	unsigned int total_valid_node_count;	/* valid node block count */
 	unsigned int total_valid_inode_count;	/* valid inode count */
+	loff_t max_file_blocks;			/* max block index of file */
 	int active_logs;			/* # of active logs */
 	int dir_level;				/* directory level */
 
@@ -1727,7 +1728,6 @@ static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
  * super.c
  */
 int f2fs_commit_super(struct f2fs_sb_info *, bool);
-loff_t max_file_size(unsigned bits);
 int f2fs_sync_fs(struct super_block *, int);
 extern __printf(3, 4)
 void f2fs_msg(struct super_block *, const char *, const char *, ...);

fs/f2fs/super.c

@@ -907,7 +907,7 @@ static const struct export_operations f2fs_export_ops = {
 	.get_parent = f2fs_get_parent,
 };
 
-loff_t max_file_size(unsigned bits)
+static loff_t max_file_blocks(void)
 {
 	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
 	loff_t leaf_count = ADDRS_PER_BLOCK;
@@ -923,7 +923,6 @@ loff_t max_file_size(unsigned bits)
 	leaf_count *= NIDS_PER_BLOCK;
 	result += leaf_count;
 
-	result <<= bits;
 	return result;
 }
 
@@ -1278,7 +1277,9 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		goto free_options;
 
-	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
+	sbi->max_file_blocks = max_file_blocks();
+	sb->s_maxbytes = sbi->max_file_blocks <<
+				le32_to_cpu(raw_super->log_blocksize);
 	sb->s_max_links = F2FS_LINK_MAX;
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));