/*
   * fs/f2fs/inode.c
   *
   * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   *             http://www.samsung.com/
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #include <linux/fs.h>
  #include <linux/f2fs_fs.h>
  #include <linux/buffer_head.h>
  #include <linux/writeback.h>
  
  #include "f2fs.h"
  #include "node.h"
  
  #include <trace/events/f2fs.h>
  
  void f2fs_set_inode_flags(struct inode *inode)
  {
  	unsigned int flags = F2FS_I(inode)->i_flags;
  	unsigned int new_fl = 0;
  
  	if (flags & FS_SYNC_FL)
  		new_fl |= S_SYNC;
  	if (flags & FS_APPEND_FL)
  		new_fl |= S_APPEND;
  	if (flags & FS_IMMUTABLE_FL)
  		new_fl |= S_IMMUTABLE;
  	if (flags & FS_NOATIME_FL)
  		new_fl |= S_NOATIME;
  	if (flags & FS_DIRSYNC_FL)
  		new_fl |= S_DIRSYNC;
  	inode_set_flags(inode, new_fl,
  			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
  }
  
  static void __get_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
  {
  	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
  			S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
  		if (ri->i_addr[0])
  			inode->i_rdev =
  				old_decode_dev(le32_to_cpu(ri->i_addr[0]));
  		else
  			inode->i_rdev =
  				new_decode_dev(le32_to_cpu(ri->i_addr[1]));
  	}
  }
  
  static bool __written_first_block(struct f2fs_inode *ri)
  {
  	block_t addr = le32_to_cpu(ri->i_addr[0]);
  
  	if (addr != NEW_ADDR && addr != NULL_ADDR)
  		return true;
  	return false;
  }
  
  static void __set_inode_rdev(struct inode *inode, struct f2fs_inode *ri)
  {
  	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
  		if (old_valid_dev(inode->i_rdev)) {
  			ri->i_addr[0] =
  				cpu_to_le32(old_encode_dev(inode->i_rdev));
  			ri->i_addr[1] = 0;
  		} else {
  			ri->i_addr[0] = 0;
  			ri->i_addr[1] =
  				cpu_to_le32(new_encode_dev(inode->i_rdev));
  			ri->i_addr[2] = 0;
  		}
  	}
  }
  
  static void __recover_inline_status(struct inode *inode, struct page *ipage)
  {
  	void *inline_data = inline_data_addr(ipage);
  	__le32 *start = inline_data;
  	__le32 *end = start + MAX_INLINE_DATA / sizeof(__le32);
  
  	while (start < end) {
  		if (*start++) {
  			f2fs_wait_on_page_writeback(ipage, NODE);
  
  			set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
  			set_raw_inline(F2FS_I(inode), F2FS_INODE(ipage));
  			set_page_dirty(ipage);
  			return;
  		}
  	}
  	return;
  }
  
  static int do_read_inode(struct inode *inode)
  {
  	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
  	struct f2fs_inode_info *fi = F2FS_I(inode);
  	struct page *node_page;
  	struct f2fs_inode *ri;
  
  	/* Check if ino is within scope */
  	if (check_nid_range(sbi, inode->i_ino)) {
  		f2fs_msg(inode->i_sb, KERN_ERR, "bad inode number: %lu",
  			 (unsigned long) inode->i_ino);
  		WARN_ON(1);
  		return -EINVAL;
  	}
  
  	node_page = get_node_page(sbi, inode->i_ino);
  	if (IS_ERR(node_page))
  		return PTR_ERR(node_page);
  
  	ri = F2FS_INODE(node_page);
  
  	inode->i_mode = le16_to_cpu(ri->i_mode);
  	i_uid_write(inode, le32_to_cpu(ri->i_uid));
  	i_gid_write(inode, le32_to_cpu(ri->i_gid));
  	set_nlink(inode, le32_to_cpu(ri->i_links));
  	inode->i_size = le64_to_cpu(ri->i_size);
  	inode->i_blocks = le64_to_cpu(ri->i_blocks);
  
  	inode->i_atime.tv_sec = le64_to_cpu(ri->i_atime);
  	inode->i_ctime.tv_sec = le64_to_cpu(ri->i_ctime);
  	inode->i_mtime.tv_sec = le64_to_cpu(ri->i_mtime);
  	inode->i_atime.tv_nsec = le32_to_cpu(ri->i_atime_nsec);
  	inode->i_ctime.tv_nsec = le32_to_cpu(ri->i_ctime_nsec);
  	inode->i_mtime.tv_nsec = le32_to_cpu(ri->i_mtime_nsec);
  	inode->i_generation = le32_to_cpu(ri->i_generation);
  
  	fi->i_current_depth = le32_to_cpu(ri->i_current_depth);
  	fi->i_xattr_nid = le32_to_cpu(ri->i_xattr_nid);
  	fi->i_flags = le32_to_cpu(ri->i_flags);
  	fi->flags = 0;
  	fi->i_advise = ri->i_advise;
  	fi->i_pino = le32_to_cpu(ri->i_pino);
  	fi->i_dir_level = ri->i_dir_level;
  
  	f2fs_init_extent_tree(inode, &ri->i_ext);
  
  	get_inline_info(fi, ri);
  
  	/* check data exist */
  	if (f2fs_has_inline_data(inode) && !f2fs_exist_data(inode))
  		__recover_inline_status(inode, node_page);
  
  	/* get rdev by using inline_info */
  	__get_inode_rdev(inode, ri);
  
  	if (__written_first_block(ri))
  		set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
  
  	f2fs_put_page(node_page, 1);
  
  	stat_inc_inline_xattr(inode);
  	stat_inc_inline_inode(inode);
  	stat_inc_inline_dir(inode);
  
  	return 0;
  }
  
  struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
  {
  	struct f2fs_sb_info *sbi = F2FS_SB(sb);
  	struct inode *inode;
  	int ret = 0;
  
  	inode = iget_locked(sb, ino);
  	if (!inode)
  		return ERR_PTR(-ENOMEM);
  
  	if (!(inode->i_state & I_NEW)) {
  		trace_f2fs_iget(inode);
  		return inode;
  	}
  	if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi))
  		goto make_now;
  
  	ret = do_read_inode(inode);
  	if (ret)
  		goto bad_inode;
  make_now:
  	if (ino == F2FS_NODE_INO(sbi)) {
  		inode->i_mapping->a_ops = &f2fs_node_aops;
  		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
  	} else if (ino == F2FS_META_INO(sbi)) {
  		inode->i_mapping->a_ops = &f2fs_meta_aops;
  		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
  	} else if (S_ISREG(inode->i_mode)) {
  		inode->i_op = &f2fs_file_inode_operations;
  		inode->i_fop = &f2fs_file_operations;
  		inode->i_mapping->a_ops = &f2fs_dblock_aops;
  	} else if (S_ISDIR(inode->i_mode)) {
  		inode->i_op = &f2fs_dir_inode_operations;
  		inode->i_fop = &f2fs_dir_operations;
  		inode->i_mapping->a_ops = &f2fs_dblock_aops;
  		mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_HIGH_ZERO);
  	} else if (S_ISLNK(inode->i_mode)) {
  		if (f2fs_encrypted_inode(inode))
  			inode->i_op = &f2fs_encrypted_symlink_inode_operations;
  		else
  			inode->i_op = &f2fs_symlink_inode_operations;
  		inode->i_mapping->a_ops = &f2fs_dblock_aops;
  	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
  			S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
  		inode->i_op = &f2fs_special_inode_operations;
  		init_special_inode(inode, inode->i_mode, inode->i_rdev);
  	} else {
  		ret = -EIO;
  		goto bad_inode;
  	}
  	unlock_new_inode(inode);
  	trace_f2fs_iget(inode);
  	return inode;
  
  bad_inode:
  	iget_failed(inode);
  	trace_f2fs_iget_exit(inode, ret);
  	return ERR_PTR(ret);
  }
  
  void update_inode(struct inode *inode, struct page *node_page)
  {
  	struct f2fs_inode *ri;
  
  	f2fs_wait_on_page_writeback(node_page, NODE);
  
  	ri = F2FS_INODE(node_page);
  
  	ri->i_mode = cpu_to_le16(inode->i_mode);
  	ri->i_advise = F2FS_I(inode)->i_advise;
  	ri->i_uid = cpu_to_le32(i_uid_read(inode));
  	ri->i_gid = cpu_to_le32(i_gid_read(inode));
  	ri->i_links = cpu_to_le32(inode->i_nlink);
  	ri->i_size = cpu_to_le64(i_size_read(inode));
  	ri->i_blocks = cpu_to_le64(inode->i_blocks);
  
  	if (F2FS_I(inode)->extent_tree)
  		set_raw_extent(&F2FS_I(inode)->extent_tree->largest,
  							&ri->i_ext);
  	else
  		memset(&ri->i_ext, 0, sizeof(ri->i_ext));
  	set_raw_inline(F2FS_I(inode), ri);
  
  	ri->i_atime = cpu_to_le64(inode->i_atime.tv_sec);
  	ri->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
  	ri->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
  	ri->i_atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec);
  	ri->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
  	ri->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
  	ri->i_current_depth = cpu_to_le32(F2FS_I(inode)->i_current_depth);
  	ri->i_xattr_nid = cpu_to_le32(F2FS_I(inode)->i_xattr_nid);
  	ri->i_flags = cpu_to_le32(F2FS_I(inode)->i_flags);
  	ri->i_pino = cpu_to_le32(F2FS_I(inode)->i_pino);
  	ri->i_generation = cpu_to_le32(inode->i_generation);
  	ri->i_dir_level = F2FS_I(inode)->i_dir_level;
  
  	__set_inode_rdev(inode, ri);
  	set_cold_node(inode, node_page);
  	set_page_dirty(node_page);
  
  	clear_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
  }
  
  void update_inode_page(struct inode *inode)
  {
  	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
  	struct page *node_page;
  retry:
  	node_page = get_node_page(sbi, inode->i_ino);
  	if (IS_ERR(node_page)) {
  		int err = PTR_ERR(node_page);
  		if (err == -ENOMEM) {
  			cond_resched();
  			goto retry;
  		} else if (err != -ENOENT) {
  			f2fs_stop_checkpoint(sbi);
  		}
  		return;
  	}
  	update_inode(inode, node_page);
  	f2fs_put_page(node_page, 1);
  }
  
  int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
  {
  	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
  
  	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
  			inode->i_ino == F2FS_META_INO(sbi))
  		return 0;
  
  	if (!is_inode_flag_set(F2FS_I(inode), FI_DIRTY_INODE))
  		return 0;
  
  	/*
  	 * We need to balance fs here to prevent from producing dirty node pages
  	 * during the urgent cleaning time when runing out of free sections.
  	 */
  	update_inode_page(inode);
  
  	f2fs_balance_fs(sbi);
  	return 0;
  }
  
  /*
   * Called at the last iput() if i_nlink is zero
   */
  void f2fs_evict_inode(struct inode *inode)
  {
  	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
  	struct f2fs_inode_info *fi = F2FS_I(inode);
  	nid_t xnid = fi->i_xattr_nid;
  	int err = 0;
  
  	/* some remained atomic pages should discarded */
  	if (f2fs_is_atomic_file(inode))
  		commit_inmem_pages(inode, true);
  
  	trace_f2fs_evict_inode(inode);
  	truncate_inode_pages_final(&inode->i_data);
  
  	if (inode->i_ino == F2FS_NODE_INO(sbi) ||
  			inode->i_ino == F2FS_META_INO(sbi))
  		goto out_clear;
  
  	f2fs_bug_on(sbi, get_dirty_pages(inode));
  	remove_dirty_dir_inode(inode);
  
  	f2fs_destroy_extent_tree(inode);
  
  	if (inode->i_nlink || is_bad_inode(inode))
  		goto no_delete;
  
  	sb_start_intwrite(inode->i_sb);
  	set_inode_flag(fi, FI_NO_ALLOC);
  	i_size_write(inode, 0);
  
  	if (F2FS_HAS_BLOCKS(inode))
  		err = f2fs_truncate(inode, true);
  
  	if (!err) {
  		f2fs_lock_op(sbi);
  		err = remove_inode_page(inode);
  		f2fs_unlock_op(sbi);
  	}
  
  	sb_end_intwrite(inode->i_sb);
  no_delete:
  	stat_dec_inline_xattr(inode);
  	stat_dec_inline_dir(inode);
  	stat_dec_inline_inode(inode);
  
  	invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino, inode->i_ino);
  	if (xnid)
  		invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid);
  	if (is_inode_flag_set(fi, FI_APPEND_WRITE))
  		add_dirty_inode(sbi, inode->i_ino, APPEND_INO);
  	if (is_inode_flag_set(fi, FI_UPDATE_WRITE))
  		add_dirty_inode(sbi, inode->i_ino, UPDATE_INO);
  	if (is_inode_flag_set(fi, FI_FREE_NID)) {
  		if (err && err != -ENOENT)
  			alloc_nid_done(sbi, inode->i_ino);
  		else
  			alloc_nid_failed(sbi, inode->i_ino);
  		clear_inode_flag(fi, FI_FREE_NID);
  	}
  
  	if (err && err != -ENOENT) {
  		if (!exist_written_data(sbi, inode->i_ino, ORPHAN_INO)) {
  			/*
  			 * get here because we failed to release resource
  			 * of inode previously, reminder our user to run fsck
  			 * for fixing.
  			 */
  			set_sbi_flag(sbi, SBI_NEED_FSCK);
  			f2fs_msg(sbi->sb, KERN_WARNING,
  				"inode (ino:%lu) resource leak, run fsck "
  				"to fix this issue!", inode->i_ino);
  		}
  	}
  out_clear:
  #ifdef CONFIG_F2FS_FS_ENCRYPTION
  	if (fi->i_crypt_info)
  		f2fs_free_encryption_info(inode, fi->i_crypt_info);
  #endif
  	clear_inode(inode);
  }
  
  /* caller should call f2fs_lock_op() */
  void handle_failed_inode(struct inode *inode)
  {
  	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
  	int err = 0;
  
  	clear_nlink(inode);
  	make_bad_inode(inode);
  	unlock_new_inode(inode);
  
  	i_size_write(inode, 0);
  	if (F2FS_HAS_BLOCKS(inode))
  		err = f2fs_truncate(inode, false);
  
  	if (!err)
  		err = remove_inode_page(inode);
  
  	/*
  	 * if we skip truncate_node in remove_inode_page bacause we failed
  	 * before, it's better to find another way to release resource of
  	 * this inode (e.g. valid block count, node block or nid). Here we
  	 * choose to add this inode to orphan list, so that we can call iput
  	 * for releasing in orphan recovery flow.
  	 *
  	 * Note: we should add inode to orphan list before f2fs_unlock_op()
  	 * so we can prevent losing this orphan when encoutering checkpoint
  	 * and following suddenly power-off.
  	 */
  	if (err && err != -ENOENT) {
  		err = acquire_orphan_inode(sbi);
  		if (!err)
  			add_orphan_inode(sbi, inode->i_ino);
  	}
  
  	set_inode_flag(F2FS_I(inode), FI_FREE_NID);
  	f2fs_unlock_op(sbi);
  
  	/* iput will drop the inode object */
  	iput(inode);
  }