f2fs: enhance f2fs_is_checkpoint_ready()'s readability

This patch changes sematics of f2fs_is_checkpoint_ready()'s return
value as: return true when checkpoint is ready, other return false,
it can improve readability of below conditions.

f2fs_submit_page_write()
...
	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
				!f2fs_is_checkpoint_ready(sbi))
		__submit_merged_bio(io);

f2fs_balance_fs()
...
	if (!f2fs_is_checkpoint_ready(sbi))
		return;

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -634,7 +634,7 @@ skip:
 		goto next;
 out:
 	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
-				f2fs_is_checkpoint_ready(sbi))
+				!f2fs_is_checkpoint_ready(sbi))
 		__submit_merged_bio(io);
 	up_write(&io->io_rwsem);
 }
@@ -2570,9 +2570,10 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 
 	trace_f2fs_write_begin(inode, pos, len, flags);
 
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi)) {
-	if (err)
+		err = -ENOSPC;
 		goto fail;
+	}
 
 	if ((f2fs_is_atomic_file(inode) &&
 			!f2fs_available_free_memory(sbi, INMEM_PAGES)) ||

fs/f2fs/file.c

@@ -57,9 +57,11 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
 		err = -EIO;
 		goto err;
 	}
-	err = f2fs_is_checkpoint_ready(sbi);
+
-	if (err)
+	if (!f2fs_is_checkpoint_ready(sbi)) {
+		err = -ENOSPC;
 		goto err;
+	}
 
 	sb_start_pagefault(inode->i_sb);
 
@@ -1571,9 +1573,8 @@ static long f2fs_fallocate(struct file *file, int mode,
 
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
 		return -EIO;
-	ret = f2fs_is_checkpoint_ready(F2FS_I_SB(inode));
+	if (!f2fs_is_checkpoint_ready(F2FS_I_SB(inode)))
-	if (ret)
+		return -ENOSPC;
-		return ret;
 
 	/* f2fs only support ->fallocate for regular file */
 	if (!S_ISREG(inode->i_mode))
@@ -3146,13 +3147,10 @@ out:
 
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-	int ret;
-
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
 		return -EIO;
-	ret = f2fs_is_checkpoint_ready(F2FS_I_SB(file_inode(filp)));
+	if (!f2fs_is_checkpoint_ready(F2FS_I_SB(file_inode(filp))))
-	if (ret)
+		return -ENOSPC;
-		return ret;
 
 	switch (cmd) {
 	case F2FS_IOC_GETFLAGS:

fs/f2fs/inode.c

@@ -616,7 +616,7 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
 	if (!is_inode_flag_set(inode, FI_DIRTY_INODE))
 		return 0;
 
-	if (f2fs_is_checkpoint_ready(sbi))
+	if (!f2fs_is_checkpoint_ready(sbi))
 		return -ENOSPC;
 
 	/*

fs/f2fs/namei.c

@@ -272,9 +272,8 @@ static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (err)
+		return -ENOSPC;
-		return err;
 
 	err = dquot_initialize(dir);
 	if (err)
@@ -321,9 +320,8 @@ static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (err)
+		return -ENOSPC;
-		return err;
 
 	err = fscrypt_prepare_link(old_dentry, dir, dentry);
 	if (err)
@@ -592,9 +590,8 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (err)
+		return -ENOSPC;
-		return err;
 
 	err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
 				      &disk_link);
@@ -724,9 +721,8 @@ static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (err)
+		return -ENOSPC;
-		return err;
 
 	err = dquot_initialize(dir);
 	if (err)
@@ -822,13 +818,11 @@ out:
 static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
-	int ret;
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	ret = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (ret)
+		return -ENOSPC;
-		return ret;
 
 	if (IS_ENCRYPTED(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) {
 		int err = fscrypt_get_encryption_info(dir);
@@ -865,9 +859,8 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (err)
+		return -ENOSPC;
-		return err;
 
 	if (is_inode_flag_set(new_dir, FI_PROJ_INHERIT) &&
 			(!projid_eq(F2FS_I(new_dir)->i_projid,
@@ -1060,9 +1053,8 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (err)
+		return -ENOSPC;
-		return err;
 
 	if ((is_inode_flag_set(new_dir, FI_PROJ_INHERIT) &&
 			!projid_eq(F2FS_I(new_dir)->i_projid,

fs/f2fs/segment.c

@@ -501,7 +501,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
 	if (need && excess_cached_nats(sbi))
 		f2fs_balance_fs_bg(sbi);
 
-	if (f2fs_is_checkpoint_ready(sbi))
+	if (!f2fs_is_checkpoint_ready(sbi))
 		return;
 
 	/*

fs/f2fs/segment.h

@@ -586,13 +586,13 @@ static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi,
 		reserved_sections(sbi) + needed);
 }
 
-static inline int f2fs_is_checkpoint_ready(struct f2fs_sb_info *sbi)
+static inline bool f2fs_is_checkpoint_ready(struct f2fs_sb_info *sbi)
 {
 	if (likely(!is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
-		return 0;
+		return true;
 	if (likely(!has_not_enough_free_secs(sbi, 0, 0)))
-		return 0;
+		return true;
-	return -ENOSPC;
+	return false;
 }
 
 static inline bool excess_prefree_segs(struct f2fs_sb_info *sbi)

fs/f2fs/xattr.c

@@ -732,9 +732,8 @@ int f2fs_setxattr(struct inode *inode, int index, const char *name,
 
 	if (unlikely(f2fs_cp_error(sbi)))
 		return -EIO;
-	err = f2fs_is_checkpoint_ready(sbi);
+	if (!f2fs_is_checkpoint_ready(sbi))
-	if (err)
+		return -ENOSPC;
-		return err;
 
 	err = dquot_initialize(inode);
 	if (err)