f2fs: enable inline data by default

Enable inline_data feature by default since it brings us better
performance and space utilization and now has already stable.
Add another option noinline_data to disable it during mount.

Suggested-by: Jaegeuk Kim <[e-mail]>
Suggested-by: Chao Yu <[e-mail]>
Signed-off-by: Wanpeng Li <[e-mail]>
Signed-off-by: Jaegeuk Kim <[e-mail]>

Documentation/filesystems/f2fs.txt

···
                        as many as extent which map between contiguous logical
                        address and physical address per inode, resulting in
                        increasing the cache hit ratio.
+noinline_data          Disable the inline data feature, inline data feature is
+                       enabled by default.
 
 ================================================================================
 DEBUGFS ENTRIES

fs/f2fs/super.c

···
 	Opt_nobarrier,
 	Opt_fastboot,
 	Opt_extent_cache,
+	Opt_noinline_data,
 	Opt_err,
 };
 
···
 	{Opt_nobarrier, "nobarrier"},
 	{Opt_fastboot, "fastboot"},
 	{Opt_extent_cache, "extent_cache"},
+	{Opt_noinline_data, "noinline_data"},
 	{Opt_err, NULL},
 };
 
···
 		case Opt_extent_cache:
 			set_opt(sbi, EXTENT_CACHE);
 			break;
+		case Opt_noinline_data:
+			clear_opt(sbi, INLINE_DATA);
+			break;
 		default:
 			f2fs_msg(sb, KERN_ERR,
 				"Unrecognized mount option \"%s\" or missing value",
···
 		seq_puts(seq, ",disable_ext_identify");
 	if (test_opt(sbi, INLINE_DATA))
 		seq_puts(seq, ",inline_data");
+	else
+		seq_puts(seq, ",noinline_data");
 	if (test_opt(sbi, INLINE_DENTRY))
 		seq_puts(seq, ",inline_dentry");
 	if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
···
 	sbi->active_logs = NR_CURSEG_TYPE;
 
 	set_opt(sbi, BG_GC);
+	set_opt(sbi, INLINE_DATA);
 
 #ifdef CONFIG_F2FS_FS_XATTR
 	set_opt(sbi, XATTR_USER);