f2fs: detect idle time depending on user behavior

This patch adds last time that user requested filesystem operations.
This information is used to detect whether system is idle or not later.

Signed-off-by: Jaegeuk Kim <[e-mail]>

Documentation/ABI/testing/sysfs-fs-f2fs

···
 Description:
 		 Controls the checkpoint timing.
 
+What:		/sys/fs/f2fs/<disk>/idle_interval
+Date:		January 2016
+Contact:	"Jaegeuk Kim" <[e-mail]>
+Description:
+		 Controls the idle timing.
+
 What:		/sys/fs/f2fs/<disk>/ra_nid_pages
 Date:		October 2015
 Contact:	"Chao Yu" <[e-mail]>

fs/f2fs/data.c

···
 	}
 
 	f2fs_put_page(page, 1);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return copied;
 }
 

fs/f2fs/dir.c

···
 	f2fs_put_page(dentry_page, 1);
 out:
 	f2fs_fname_free_filename(&fname);
+	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
 	return err;
 }
 
···
 	clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
 fail:
 	up_write(&F2FS_I(inode)->i_sem);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return err;
 }
 
···
 	unsigned int bit_pos;
 	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
 	int i;
+
+	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
 
 	if (f2fs_has_inline_dentry(dir))
 		return f2fs_delete_inline_entry(dentry, page, dir, inode);

fs/f2fs/f2fs.h

···
 #include <linux/sched.h>
 #include <linux/vmalloc.h>
 #include <linux/bio.h>
+#include <linux/blkdev.h>
 
 #ifdef CONFIG_F2FS_CHECK_FS
 #define f2fs_bug_on(sbi, condition)	BUG_ON(condition)
···
 #define BATCHED_TRIM_BLOCKS(sbi)	\
 		(BATCHED_TRIM_SEGMENTS(sbi) << (sbi)->log_blocks_per_seg)
 #define DEF_CP_INTERVAL			60	/* 60 secs */
+#define DEF_IDLE_INTERVAL		120	/* 2 mins */
 
 struct cp_control {
 	int reason;
···
 
 enum {
 	CP_TIME,
+	REQ_TIME,
 	MAX_TIME,
 };
 
···
 	unsigned long interval = timespec_to_jiffies(&ts);
 
 	return time_after(jiffies, sbi->last_time[type] + interval);
+}
+
+static inline bool is_idle(struct f2fs_sb_info *sbi)
+{
+	struct block_device *bdev = sbi->sb->s_bdev;
+	struct request_queue *q = bdev_get_queue(bdev);
+	struct request_list *rl = &q->root_rl;
+
+	if (rl->count[BLK_RW_SYNC] || rl->count[BLK_RW_ASYNC])
+		return 0;
+
+	return f2fs_time_over(sbi, REQ_TIME);
 }
 
 /*

fs/f2fs/file.c

···
 	clear_cold_data(page);
 out:
 	sb_end_pagefault(inode->i_sb);
+	f2fs_update_time(sbi, REQ_TIME);
 	return block_page_mkwrite_return(err);
 }
 
···
 	remove_ino_entry(sbi, ino, UPDATE_INO);
 	clear_inode_flag(fi, FI_UPDATE_WRITE);
 	ret = f2fs_issue_flush(sbi);
+	f2fs_update_time(sbi, REQ_TIME);
 out:
 	trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
 	f2fs_trace_ios(NULL, 1);
···
 	}
 	dn->ofs_in_node = ofs;
 
+	f2fs_update_time(sbi, REQ_TIME);
 	trace_f2fs_truncate_data_blocks_range(dn->inode, dn->nid,
 					 dn->ofs_in_node, nr_free);
 	return nr_free;
···
 	if (!ret) {
 		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 		mark_inode_dirty(inode);
+		f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	}
 
 out:
···
 		return ret;
 
 	set_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+
 	return 0;
 }
 
···
 		return ret;
 
 	set_inode_flag(F2FS_I(inode), FI_VOLATILE_FILE);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return 0;
 }
 
···
 	}
 
 	mnt_drop_write_file(filp);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return ret;
 }
 
···
 	default:
 		return -EINVAL;
 	}
+	f2fs_update_time(sbi, REQ_TIME);
 	return 0;
 }
 
···
 	if (copy_to_user((struct fstrim_range __user *)arg, &range,
 				sizeof(range)))
 		return -EFAULT;
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return 0;
 }
 
···
 				sizeof(policy)))
 		return -EFAULT;
 
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return f2fs_process_policy(&policy, inode);
 #else
 	return -EOPNOTSUPP;
···
 	}
 
 	err = f2fs_defragment_range(sbi, filp, &range);
+	f2fs_update_time(sbi, REQ_TIME);
 	if (err < 0)
 		goto out;
 

fs/f2fs/gc.c

···
 #include <linux/kthread.h>
 #include <linux/delay.h>
 #include <linux/freezer.h>
-#include <linux/blkdev.h>
 
 #include "f2fs.h"
 #include "node.h"

fs/f2fs/gc.h

···
 		return true;
 	return false;
 }
-
-static inline int is_idle(struct f2fs_sb_info *sbi)
-{
-	struct block_device *bdev = sbi->sb->s_bdev;
-	struct request_queue *q = bdev_get_queue(bdev);
-	struct request_list *rl = &q->root_rl;
-	return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
-}

fs/f2fs/segment.c

···
 	if (!available_free_memory(sbi, NAT_ENTRIES) ||
 			excess_prefree_segs(sbi) ||
 			!available_free_memory(sbi, INO_ENTRIES) ||
-			f2fs_time_over(sbi, CP_TIME)) {
+			(is_idle(sbi) && f2fs_time_over(sbi, CP_TIME))) {
 		if (test_opt(sbi, DATA_FLUSH))
 			sync_dirty_inodes(sbi, FILE_INODE);
 		f2fs_sync_fs(sbi->sb, true);

fs/f2fs/super.c

···
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
 
 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
 static struct attribute *f2fs_attrs[] = {
···
 	ATTR_LIST(ram_thresh),
 	ATTR_LIST(ra_nid_pages),
 	ATTR_LIST(cp_interval),
+	ATTR_LIST(idle_interval),
 	NULL,
 };
 
···
 
 	sbi->dir_level = DEF_DIR_LEVEL;
 	sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL;
+	sbi->interval_time[REQ_TIME] = DEF_IDLE_INTERVAL;
 	clear_sbi_flag(sbi, SBI_NEED_FSCK);
 
 	INIT_LIST_HEAD(&sbi->s_list);
···
 	}
 
 	f2fs_update_time(sbi, CP_TIME);
+	f2fs_update_time(sbi, REQ_TIME);
 	return 0;
 
 free_kobj:

fs/f2fs/xattr.c

···
 	up_write(&F2FS_I(inode)->i_sem);
 	f2fs_unlock_op(sbi);
 
+	f2fs_update_time(sbi, REQ_TIME);
 	return err;
 }