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 <jaegeuk@kernel.org>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ff06827..3d43857 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -96,6 +96,7 @@
 	clear_cold_data(page);
 out:
 	sb_end_pagefault(inode->i_sb);
+	f2fs_update_time(sbi, REQ_TIME);
 	return block_page_mkwrite_return(err);
 }
 
@@ -280,6 +281,7 @@
 	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);
@@ -485,6 +487,7 @@
 	}
 	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;
@@ -1236,6 +1239,7 @@
 	if (!ret) {
 		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 		mark_inode_dirty(inode);
+		f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	}
 
 out:
@@ -1351,6 +1355,8 @@
 		return ret;
 
 	set_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+
 	return 0;
 }
 
@@ -1398,6 +1404,7 @@
 		return ret;
 
 	set_inode_flag(F2FS_I(inode), FI_VOLATILE_FILE);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return 0;
 }
 
@@ -1439,6 +1446,7 @@
 	}
 
 	mnt_drop_write_file(filp);
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return ret;
 }
 
@@ -1478,6 +1486,7 @@
 	default:
 		return -EINVAL;
 	}
+	f2fs_update_time(sbi, REQ_TIME);
 	return 0;
 }
 
@@ -1508,6 +1517,7 @@
 	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;
 }
 
@@ -1531,6 +1541,7 @@
 				sizeof(policy)))
 		return -EFAULT;
 
+	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 	return f2fs_process_policy(&policy, inode);
 #else
 	return -EOPNOTSUPP;
@@ -1807,6 +1818,7 @@
 	}
 
 	err = f2fs_defragment_range(sbi, filp, &range);
+	f2fs_update_time(sbi, REQ_TIME);
 	if (err < 0)
 		goto out;