fs/f2fs/namei.c - kernel/msm-4.19 - Gitiles

 /*
  * fs/f2fs/namei.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/pagemap.h>
 #include <linux/sched.h>
 #include <linux/ctype.h>
 #include <linux/dcache.h>

 #include "f2fs.h"
 #include "node.h"
 #include "xattr.h"
 #include "acl.h"
 #include <trace/events/f2fs.h>

 static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	nid_t ino;
 	struct inode *inode;
 	bool nid_free = false;
 	int err;

 	inode = new_inode(dir->i_sb);
 	if (!inode)
 		return ERR_PTR(-ENOMEM);

 	f2fs_lock_op(sbi);
 	if (!alloc_nid(sbi, &ino)) {
 		f2fs_unlock_op(sbi);
 		err = -ENOSPC;
 		goto fail;
 	}
 	f2fs_unlock_op(sbi);

 	inode_init_owner(inode, dir, mode);

 	inode->i_ino = ino;
 	inode->i_blocks = 0;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 	inode->i_generation = sbi->s_next_generation++;

 	err = insert_inode_locked(inode);
 	if (err) {
 		err = -EINVAL;
 		nid_free = true;
 		goto out;
 	}

 	if (f2fs_may_inline(inode))
 		set_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
 	if (test_opt(sbi, INLINE_DENTRY) && S_ISDIR(inode->i_mode))
 		set_inode_flag(F2FS_I(inode), FI_INLINE_DENTRY);

 	trace_f2fs_new_inode(inode, 0);
 	mark_inode_dirty(inode);
 	return inode;

 out:
 	clear_nlink(inode);
 	unlock_new_inode(inode);
 fail:
 	trace_f2fs_new_inode(inode, err);
 	make_bad_inode(inode);
 	iput(inode);
 	if (nid_free)
 		alloc_nid_failed(sbi, ino);
 	return ERR_PTR(err);
 }

 static int is_multimedia_file(const unsigned char *s, const char *sub)
 {
 	size_t slen = strlen(s);
 	size_t sublen = strlen(sub);

 	if (sublen > slen)
 		return 0;

 	return !strncasecmp(s + slen - sublen, sub, sublen);
 }

 /*
  * Set multimedia files as cold files for hot/cold data separation
  */
 static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
 		const unsigned char *name)
 {
 	int i;
 	__u8 (*extlist)[8] = sbi->raw_super->extension_list;

 	int count = le32_to_cpu(sbi->raw_super->extension_count);
 	for (i = 0; i < count; i++) {
 		if (is_multimedia_file(name, extlist[i])) {
 			file_set_cold(inode);
 			break;
 		}
 	}
 }

 static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 						bool excl)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	nid_t ino = 0;
 	int err;

 	f2fs_balance_fs(sbi);

 	inode = f2fs_new_inode(dir, mode);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);

 	if (!test_opt(sbi, DISABLE_EXT_IDENTIFY))
 		set_cold_files(sbi, inode, dentry->d_name.name);

 	inode->i_op = &f2fs_file_inode_operations;
 	inode->i_fop = &f2fs_file_operations;
 	inode->i_mapping->a_ops = &f2fs_dblock_aops;
 	ino = inode->i_ino;

 	f2fs_lock_op(sbi);
 	err = f2fs_add_link(dentry, inode);
 	if (err)
 		goto out;
 	f2fs_unlock_op(sbi);

 	alloc_nid_done(sbi, ino);

 	stat_inc_inline_inode(inode);
 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
 	return 0;
 out:
 	handle_failed_inode(inode);
 	return err;
 }

 static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
 		struct dentry *dentry)
 {
 	struct inode *inode = old_dentry->d_inode;
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	int err;

 	f2fs_balance_fs(sbi);

 	inode->i_ctime = CURRENT_TIME;
 	ihold(inode);

 	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
 	f2fs_lock_op(sbi);
 	err = f2fs_add_link(dentry, inode);
 	if (err)
 		goto out;
 	f2fs_unlock_op(sbi);

 	d_instantiate(dentry, inode);
 	return 0;
 out:
 	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
 	iput(inode);
 	f2fs_unlock_op(sbi);
 	return err;
 }

 struct dentry *f2fs_get_parent(struct dentry *child)
 {
 	struct qstr dotdot = QSTR_INIT("..", 2);
 	unsigned long ino = f2fs_inode_by_name(child->d_inode, &dotdot);
 	if (!ino)
 		return ERR_PTR(-ENOENT);
 	return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
 }

 static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
 		unsigned int flags)
 {
 	struct inode *inode = NULL;
 	struct f2fs_dir_entry *de;
 	struct page *page;

 	if (dentry->d_name.len > F2FS_NAME_LEN)
 		return ERR_PTR(-ENAMETOOLONG);

 	de = f2fs_find_entry(dir, &dentry->d_name, &page);
 	if (de) {
 		nid_t ino = le32_to_cpu(de->ino);
 		if (!f2fs_has_inline_dentry(dir))
 			kunmap(page);
 		f2fs_put_page(page, 0);

 		inode = f2fs_iget(dir->i_sb, ino);
 		if (IS_ERR(inode))
 			return ERR_CAST(inode);
 	}

 	return d_splice_alias(inode, dentry);
 }

 static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode = dentry->d_inode;
 	struct f2fs_dir_entry *de;
 	struct page *page;
 	int err = -ENOENT;

 	trace_f2fs_unlink_enter(dir, dentry);
 	f2fs_balance_fs(sbi);

 	de = f2fs_find_entry(dir, &dentry->d_name, &page);
 	if (!de)
 		goto fail;

 	f2fs_lock_op(sbi);
 	err = acquire_orphan_inode(sbi);
 	if (err) {
 		f2fs_unlock_op(sbi);
 		if (!f2fs_has_inline_dentry(dir))
 			kunmap(page);
 		f2fs_put_page(page, 0);
 		goto fail;
 	}
 	f2fs_delete_entry(de, page, dir, inode);
 	f2fs_unlock_op(sbi);

 	/* In order to evict this inode, we set it dirty */
 	mark_inode_dirty(inode);
 fail:
 	trace_f2fs_unlink_exit(inode, err);
 	return err;
 }

 static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 					const char *symname)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	size_t symlen = strlen(symname) + 1;
 	int err;

 	f2fs_balance_fs(sbi);

 	inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);

 	inode->i_op = &f2fs_symlink_inode_operations;
 	inode->i_mapping->a_ops = &f2fs_dblock_aops;

 	f2fs_lock_op(sbi);
 	err = f2fs_add_link(dentry, inode);
 	if (err)
 		goto out;
 	f2fs_unlock_op(sbi);

 	err = page_symlink(inode, symname, symlen);
 	alloc_nid_done(sbi, inode->i_ino);

 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
 	return err;
 out:
 	handle_failed_inode(inode);
 	return err;
 }

 static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	int err;

 	f2fs_balance_fs(sbi);

 	inode = f2fs_new_inode(dir, S_IFDIR | mode);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);

 	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_ZERO);

 	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
 	f2fs_lock_op(sbi);
 	err = f2fs_add_link(dentry, inode);
 	if (err)
 		goto out_fail;
 	f2fs_unlock_op(sbi);

 	stat_inc_inline_dir(inode);
 	alloc_nid_done(sbi, inode->i_ino);

 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);

 	return 0;

 out_fail:
 	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
 	handle_failed_inode(inode);
 	return err;
 }

 static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	struct inode *inode = dentry->d_inode;
 	if (f2fs_empty_dir(inode))
 		return f2fs_unlink(dir, dentry);
 	return -ENOTEMPTY;
 }

 static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
 				umode_t mode, dev_t rdev)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	int err = 0;

 	if (!new_valid_dev(rdev))
 		return -EINVAL;

 	f2fs_balance_fs(sbi);

 	inode = f2fs_new_inode(dir, mode);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);

 	init_special_inode(inode, inode->i_mode, rdev);
 	inode->i_op = &f2fs_special_inode_operations;

 	f2fs_lock_op(sbi);
 	err = f2fs_add_link(dentry, inode);
 	if (err)
 		goto out;
 	f2fs_unlock_op(sbi);

 	alloc_nid_done(sbi, inode->i_ino);
 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
 	return 0;
 out:
 	handle_failed_inode(inode);
 	return err;
 }

 static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
 	struct inode *old_inode = old_dentry->d_inode;
 	struct inode *new_inode = new_dentry->d_inode;
 	struct page *old_dir_page;
 	struct page *old_page, *new_page;
 	struct f2fs_dir_entry *old_dir_entry = NULL;
 	struct f2fs_dir_entry *old_entry;
 	struct f2fs_dir_entry *new_entry;
 	int err = -ENOENT;

 	f2fs_balance_fs(sbi);

 	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 	if (!old_entry)
 		goto out;

 	if (S_ISDIR(old_inode->i_mode)) {
 		err = -EIO;
 		old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
 		if (!old_dir_entry)
 			goto out_old;
 	}

 	if (new_inode) {

 		err = -ENOTEMPTY;
 		if (old_dir_entry && !f2fs_empty_dir(new_inode))
 			goto out_dir;

 		err = -ENOENT;
 		new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
 						&new_page);
 		if (!new_entry)
 			goto out_dir;

 		f2fs_lock_op(sbi);

 		err = acquire_orphan_inode(sbi);
 		if (err)
 			goto put_out_dir;

 		if (update_dent_inode(old_inode, &new_dentry->d_name)) {
 			release_orphan_inode(sbi);
 			goto put_out_dir;
 		}

 		f2fs_set_link(new_dir, new_entry, new_page, old_inode);

 		new_inode->i_ctime = CURRENT_TIME;
 		down_write(&F2FS_I(new_inode)->i_sem);
 		if (old_dir_entry)
 			drop_nlink(new_inode);
 		drop_nlink(new_inode);
 		up_write(&F2FS_I(new_inode)->i_sem);

 		mark_inode_dirty(new_inode);

 		if (!new_inode->i_nlink)
 			add_orphan_inode(sbi, new_inode->i_ino);
 		else
 			release_orphan_inode(sbi);

 		update_inode_page(old_inode);
 		update_inode_page(new_inode);
 	} else {
 		f2fs_lock_op(sbi);

 		err = f2fs_add_link(new_dentry, old_inode);
 		if (err) {
 			f2fs_unlock_op(sbi);
 			goto out_dir;
 		}

 		if (old_dir_entry) {
 			inc_nlink(new_dir);
 			update_inode_page(new_dir);
 		}
 	}

 	down_write(&F2FS_I(old_inode)->i_sem);
 	file_lost_pino(old_inode);
 	up_write(&F2FS_I(old_inode)->i_sem);

 	old_inode->i_ctime = CURRENT_TIME;
 	mark_inode_dirty(old_inode);

 	f2fs_delete_entry(old_entry, old_page, old_dir, NULL);

 	if (old_dir_entry) {
 		if (old_dir != new_dir) {
 			f2fs_set_link(old_inode, old_dir_entry,
 						old_dir_page, new_dir);
 			update_inode_page(old_inode);
 		} else {
 			if (!f2fs_has_inline_dentry(old_inode))
 				kunmap(old_dir_page);
 			f2fs_put_page(old_dir_page, 0);
 		}
 		drop_nlink(old_dir);
 		mark_inode_dirty(old_dir);
 		update_inode_page(old_dir);
 	}

 	f2fs_unlock_op(sbi);
 	return 0;

 put_out_dir:
 	f2fs_unlock_op(sbi);
 	if (!f2fs_has_inline_dentry(new_dir))
 		kunmap(new_page);
 	f2fs_put_page(new_page, 0);
 out_dir:
 	if (old_dir_entry) {
 		if (!f2fs_has_inline_dentry(old_inode))
 			kunmap(old_dir_page);
 		f2fs_put_page(old_dir_page, 0);
 	}
 out_old:
 	if (!f2fs_has_inline_dentry(old_dir))
 		kunmap(old_page);
 	f2fs_put_page(old_page, 0);
 out:
 	return err;
 }

 static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 			     struct inode *new_dir, struct dentry *new_dentry)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
 	struct inode *old_inode = old_dentry->d_inode;
 	struct inode *new_inode = new_dentry->d_inode;
 	struct page *old_dir_page, *new_dir_page;
 	struct page *old_page, *new_page;
 	struct f2fs_dir_entry *old_dir_entry = NULL, *new_dir_entry = NULL;
 	struct f2fs_dir_entry *old_entry, *new_entry;
 	int old_nlink = 0, new_nlink = 0;
 	int err = -ENOENT;

 	f2fs_balance_fs(sbi);

 	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
 	if (!old_entry)
 		goto out;

 	new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 	if (!new_entry)
 		goto out_old;

 	/* prepare for updating ".." directory entry info later */
 	if (old_dir != new_dir) {
 		if (S_ISDIR(old_inode->i_mode)) {
 			err = -EIO;
 			old_dir_entry = f2fs_parent_dir(old_inode,
 							&old_dir_page);
 			if (!old_dir_entry)
 				goto out_new;
 		}

 		if (S_ISDIR(new_inode->i_mode)) {
 			err = -EIO;
 			new_dir_entry = f2fs_parent_dir(new_inode,
 							&new_dir_page);
 			if (!new_dir_entry)
 				goto out_old_dir;
 		}
 	}

 	/*
 	 * If cross rename between file and directory those are not
 	 * in the same directory, we will inc nlink of file's parent
 	 * later, so we should check upper boundary of its nlink.
 	 */
 	if ((!old_dir_entry || !new_dir_entry) &&
 				old_dir_entry != new_dir_entry) {
 		old_nlink = old_dir_entry ? -1 : 1;
 		new_nlink = -old_nlink;
 		err = -EMLINK;
 		if ((old_nlink > 0 && old_inode->i_nlink >= F2FS_LINK_MAX) ||
 			(new_nlink > 0 && new_inode->i_nlink >= F2FS_LINK_MAX))
 			goto out_new_dir;
 	}

 	f2fs_lock_op(sbi);

 	err = update_dent_inode(old_inode, &new_dentry->d_name);
 	if (err)
 		goto out_unlock;

 	err = update_dent_inode(new_inode, &old_dentry->d_name);
 	if (err)
 		goto out_undo;

 	/* update ".." directory entry info of old dentry */
 	if (old_dir_entry)
 		f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir);

 	/* update ".." directory entry info of new dentry */
 	if (new_dir_entry)
 		f2fs_set_link(new_inode, new_dir_entry, new_dir_page, old_dir);

 	/* update directory entry info of old dir inode */
 	f2fs_set_link(old_dir, old_entry, old_page, new_inode);

 	down_write(&F2FS_I(old_inode)->i_sem);
 	file_lost_pino(old_inode);
 	up_write(&F2FS_I(old_inode)->i_sem);

 	update_inode_page(old_inode);

 	old_dir->i_ctime = CURRENT_TIME;
 	if (old_nlink) {
 		down_write(&F2FS_I(old_dir)->i_sem);
 		if (old_nlink < 0)
 			drop_nlink(old_dir);
 		else
 			inc_nlink(old_dir);
 		up_write(&F2FS_I(old_dir)->i_sem);
 	}
 	mark_inode_dirty(old_dir);
 	update_inode_page(old_dir);

 	/* update directory entry info of new dir inode */
 	f2fs_set_link(new_dir, new_entry, new_page, old_inode);

 	down_write(&F2FS_I(new_inode)->i_sem);
 	file_lost_pino(new_inode);
 	up_write(&F2FS_I(new_inode)->i_sem);

 	update_inode_page(new_inode);

 	new_dir->i_ctime = CURRENT_TIME;
 	if (new_nlink) {
 		down_write(&F2FS_I(new_dir)->i_sem);
 		if (new_nlink < 0)
 			drop_nlink(new_dir);
 		else
 			inc_nlink(new_dir);
 		up_write(&F2FS_I(new_dir)->i_sem);
 	}
 	mark_inode_dirty(new_dir);
 	update_inode_page(new_dir);

 	f2fs_unlock_op(sbi);
 	return 0;
 out_undo:
 	/* Still we may fail to recover name info of f2fs_inode here */
 	update_dent_inode(old_inode, &old_dentry->d_name);
 out_unlock:
 	f2fs_unlock_op(sbi);
 out_new_dir:
 	if (new_dir_entry) {
 		if (!f2fs_has_inline_dentry(new_inode))
 			kunmap(new_dir_page);
 		f2fs_put_page(new_dir_page, 0);
 	}
 out_old_dir:
 	if (old_dir_entry) {
 		if (!f2fs_has_inline_dentry(old_inode))
 			kunmap(old_dir_page);
 		f2fs_put_page(old_dir_page, 0);
 	}
 out_new:
 	if (!f2fs_has_inline_dentry(new_dir))
 		kunmap(new_page);
 	f2fs_put_page(new_page, 0);
 out_old:
 	if (!f2fs_has_inline_dentry(old_dir))
 		kunmap(old_page);
 	f2fs_put_page(old_page, 0);
 out:
 	return err;
 }

 static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
 {
 	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
 		return -EINVAL;

 	if (flags & RENAME_EXCHANGE) {
 		return f2fs_cross_rename(old_dir, old_dentry,
 					 new_dir, new_dentry);
 	}
 	/*
 	 * VFS has already handled the new dentry existence case,
 	 * here, we just deal with "RENAME_NOREPLACE" as regular rename.
 	 */
 	return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry);
 }

 static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	int err;

 	inode = f2fs_new_inode(dir, mode);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);

 	inode->i_op = &f2fs_file_inode_operations;
 	inode->i_fop = &f2fs_file_operations;
 	inode->i_mapping->a_ops = &f2fs_dblock_aops;

 	f2fs_lock_op(sbi);
 	err = acquire_orphan_inode(sbi);
 	if (err)
 		goto out;

 	err = f2fs_do_tmpfile(inode, dir);
 	if (err)
 		goto release_out;

 	/*
 	 * add this non-linked tmpfile to orphan list, in this way we could
 	 * remove all unused data of tmpfile after abnormal power-off.
 	 */
 	add_orphan_inode(sbi, inode->i_ino);
 	f2fs_unlock_op(sbi);

 	alloc_nid_done(sbi, inode->i_ino);
 	d_tmpfile(dentry, inode);
 	unlock_new_inode(inode);
 	return 0;

 release_out:
 	release_orphan_inode(sbi);
 out:
 	handle_failed_inode(inode);
 	return err;
 }

 const struct inode_operations f2fs_dir_inode_operations = {
 	.create		= f2fs_create,
 	.lookup		= f2fs_lookup,
 	.link		= f2fs_link,
 	.unlink		= f2fs_unlink,
 	.symlink	= f2fs_symlink,
 	.mkdir		= f2fs_mkdir,
 	.rmdir		= f2fs_rmdir,
 	.mknod		= f2fs_mknod,
 	.rename2	= f2fs_rename2,
 	.tmpfile	= f2fs_tmpfile,
 	.getattr	= f2fs_getattr,
 	.setattr	= f2fs_setattr,
 	.get_acl	= f2fs_get_acl,
 	.set_acl	= f2fs_set_acl,
 #ifdef CONFIG_F2FS_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= f2fs_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
 };

 const struct inode_operations f2fs_symlink_inode_operations = {
 	.readlink       = generic_readlink,
 	.follow_link    = page_follow_link_light,
 	.put_link       = page_put_link,
 	.getattr	= f2fs_getattr,
 	.setattr	= f2fs_setattr,
 #ifdef CONFIG_F2FS_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= f2fs_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
 };

 const struct inode_operations f2fs_special_inode_operations = {
 	.getattr	= f2fs_getattr,
 	.setattr        = f2fs_setattr,
 	.get_acl	= f2fs_get_acl,
 	.set_acl	= f2fs_set_acl,
 #ifdef CONFIG_F2FS_FS_XATTR
 	.setxattr       = generic_setxattr,
 	.getxattr       = generic_getxattr,
 	.listxattr	= f2fs_listxattr,
 	.removexattr    = generic_removexattr,
 #endif
 };
	/*
	* fs/f2fs/namei.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/pagemap.h>
	#include <linux/sched.h>
	#include <linux/ctype.h>
	#include <linux/dcache.h>

	#include "f2fs.h"
	#include "node.h"
	#include "xattr.h"
	#include "acl.h"
	#include <trace/events/f2fs.h>

	static struct inode f2fs_new_inode(struct inode dir, umode_t mode)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	nid_t ino;
	struct inode *inode;
	bool nid_free = false;
	int err;

	inode = new_inode(dir->i_sb);
	if (!inode)
	return ERR_PTR(-ENOMEM);

	f2fs_lock_op(sbi);
	if (!alloc_nid(sbi, &ino)) {
	f2fs_unlock_op(sbi);
	err = -ENOSPC;
	goto fail;
	}
	f2fs_unlock_op(sbi);

	inode_init_owner(inode, dir, mode);

	inode->i_ino = ino;
	inode->i_blocks = 0;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_generation = sbi->s_next_generation++;

	err = insert_inode_locked(inode);
	if (err) {
	err = -EINVAL;
	nid_free = true;
	goto out;
	}

	if (f2fs_may_inline(inode))
	set_inode_flag(F2FS_I(inode), FI_INLINE_DATA);
	if (test_opt(sbi, INLINE_DENTRY) && S_ISDIR(inode->i_mode))
	set_inode_flag(F2FS_I(inode), FI_INLINE_DENTRY);

	trace_f2fs_new_inode(inode, 0);
	mark_inode_dirty(inode);
	return inode;

	out:
	clear_nlink(inode);
	unlock_new_inode(inode);
	fail:
	trace_f2fs_new_inode(inode, err);
	make_bad_inode(inode);
	iput(inode);
	if (nid_free)
	alloc_nid_failed(sbi, ino);
	return ERR_PTR(err);
	}

	static int is_multimedia_file(const unsigned char s, const char sub)
	{
	size_t slen = strlen(s);
	size_t sublen = strlen(sub);

	if (sublen > slen)
	return 0;

	return !strncasecmp(s + slen - sublen, sub, sublen);
	}

	/*
	* Set multimedia files as cold files for hot/cold data separation
	*/
	static inline void set_cold_files(struct f2fs_sb_info sbi, struct inode inode,
	const unsigned char *name)
	{
	int i;
	__u8 (*extlist)[8] = sbi->raw_super->extension_list;

	int count = le32_to_cpu(sbi->raw_super->extension_count);
	for (i = 0; i < count; i++) {
	if (is_multimedia_file(name, extlist[i])) {
	file_set_cold(inode);
	break;
	}
	}
	}

	static int f2fs_create(struct inode dir, struct dentry dentry, umode_t mode,
	bool excl)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	nid_t ino = 0;
	int err;

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, mode);
	if (IS_ERR(inode))
	return PTR_ERR(inode);

	if (!test_opt(sbi, DISABLE_EXT_IDENTIFY))
	set_cold_files(sbi, inode, dentry->d_name.name);

	inode->i_op = &f2fs_file_inode_operations;
	inode->i_fop = &f2fs_file_operations;
	inode->i_mapping->a_ops = &f2fs_dblock_aops;
	ino = inode->i_ino;

	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
	goto out;
	f2fs_unlock_op(sbi);

	alloc_nid_done(sbi, ino);

	stat_inc_inline_inode(inode);
	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	return 0;
	out:
	handle_failed_inode(inode);
	return err;
	}

	static int f2fs_link(struct dentry old_dentry, struct inode dir,
	struct dentry *dentry)
	{
	struct inode *inode = old_dentry->d_inode;
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	int err;

	f2fs_balance_fs(sbi);

	inode->i_ctime = CURRENT_TIME;
	ihold(inode);

	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
	goto out;
	f2fs_unlock_op(sbi);

	d_instantiate(dentry, inode);
	return 0;
	out:
	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
	iput(inode);
	f2fs_unlock_op(sbi);
	return err;
	}

	struct dentry f2fs_get_parent(struct dentry child)
	{
	struct qstr dotdot = QSTR_INIT("..", 2);
	unsigned long ino = f2fs_inode_by_name(child->d_inode, &dotdot);
	if (!ino)
	return ERR_PTR(-ENOENT);
	return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
	}

	static struct dentry f2fs_lookup(struct inode dir, struct dentry *dentry,
	unsigned int flags)
	{
	struct inode *inode = NULL;
	struct f2fs_dir_entry *de;
	struct page *page;

	if (dentry->d_name.len > F2FS_NAME_LEN)
	return ERR_PTR(-ENAMETOOLONG);

	de = f2fs_find_entry(dir, &dentry->d_name, &page);
	if (de) {
	nid_t ino = le32_to_cpu(de->ino);
	if (!f2fs_has_inline_dentry(dir))
	kunmap(page);
	f2fs_put_page(page, 0);

	inode = f2fs_iget(dir->i_sb, ino);
	if (IS_ERR(inode))
	return ERR_CAST(inode);
	}

	return d_splice_alias(inode, dentry);
	}

	static int f2fs_unlink(struct inode dir, struct dentry dentry)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode = dentry->d_inode;
	struct f2fs_dir_entry *de;
	struct page *page;
	int err = -ENOENT;

	trace_f2fs_unlink_enter(dir, dentry);
	f2fs_balance_fs(sbi);

	de = f2fs_find_entry(dir, &dentry->d_name, &page);
	if (!de)
	goto fail;

	f2fs_lock_op(sbi);
	err = acquire_orphan_inode(sbi);
	if (err) {
	f2fs_unlock_op(sbi);
	if (!f2fs_has_inline_dentry(dir))
	kunmap(page);
	f2fs_put_page(page, 0);
	goto fail;
	}
	f2fs_delete_entry(de, page, dir, inode);
	f2fs_unlock_op(sbi);

	/* In order to evict this inode, we set it dirty */
	mark_inode_dirty(inode);
	fail:
	trace_f2fs_unlink_exit(inode, err);
	return err;
	}

	static int f2fs_symlink(struct inode dir, struct dentry dentry,
	const char *symname)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	size_t symlen = strlen(symname) + 1;
	int err;

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, S_IFLNK \| S_IRWXUGO);
	if (IS_ERR(inode))
	return PTR_ERR(inode);

	inode->i_op = &f2fs_symlink_inode_operations;
	inode->i_mapping->a_ops = &f2fs_dblock_aops;

	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
	goto out;
	f2fs_unlock_op(sbi);

	err = page_symlink(inode, symname, symlen);
	alloc_nid_done(sbi, inode->i_ino);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	return err;
	out:
	handle_failed_inode(inode);
	return err;
	}

	static int f2fs_mkdir(struct inode dir, struct dentry dentry, umode_t mode)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	int err;

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, S_IFDIR \| mode);
	if (IS_ERR(inode))
	return PTR_ERR(inode);

	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_ZERO);

	set_inode_flag(F2FS_I(inode), FI_INC_LINK);
	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
	goto out_fail;
	f2fs_unlock_op(sbi);

	stat_inc_inline_dir(inode);
	alloc_nid_done(sbi, inode->i_ino);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

	return 0;

	out_fail:
	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
	handle_failed_inode(inode);
	return err;
	}

	static int f2fs_rmdir(struct inode dir, struct dentry dentry)
	{
	struct inode *inode = dentry->d_inode;
	if (f2fs_empty_dir(inode))
	return f2fs_unlink(dir, dentry);
	return -ENOTEMPTY;
	}

	static int f2fs_mknod(struct inode dir, struct dentry dentry,
	umode_t mode, dev_t rdev)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	int err = 0;

	if (!new_valid_dev(rdev))
	return -EINVAL;

	f2fs_balance_fs(sbi);

	inode = f2fs_new_inode(dir, mode);
	if (IS_ERR(inode))
	return PTR_ERR(inode);

	init_special_inode(inode, inode->i_mode, rdev);
	inode->i_op = &f2fs_special_inode_operations;

	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
	goto out;
	f2fs_unlock_op(sbi);

	alloc_nid_done(sbi, inode->i_ino);
	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	return 0;
	out:
	handle_failed_inode(inode);
	return err;
	}

	static int f2fs_rename(struct inode old_dir, struct dentry old_dentry,
	struct inode new_dir, struct dentry new_dentry)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
	struct inode *old_inode = old_dentry->d_inode;
	struct inode *new_inode = new_dentry->d_inode;
	struct page *old_dir_page;
	struct page old_page, new_page;
	struct f2fs_dir_entry *old_dir_entry = NULL;
	struct f2fs_dir_entry *old_entry;
	struct f2fs_dir_entry *new_entry;
	int err = -ENOENT;

	f2fs_balance_fs(sbi);

	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
	if (!old_entry)
	goto out;

	if (S_ISDIR(old_inode->i_mode)) {
	err = -EIO;
	old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
	if (!old_dir_entry)
	goto out_old;
	}

	if (new_inode) {

	err = -ENOTEMPTY;
	if (old_dir_entry && !f2fs_empty_dir(new_inode))
	goto out_dir;

	err = -ENOENT;
	new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
	&new_page);
	if (!new_entry)
	goto out_dir;

	f2fs_lock_op(sbi);

	err = acquire_orphan_inode(sbi);
	if (err)
	goto put_out_dir;

	if (update_dent_inode(old_inode, &new_dentry->d_name)) {
	release_orphan_inode(sbi);
	goto put_out_dir;
	}

	f2fs_set_link(new_dir, new_entry, new_page, old_inode);

	new_inode->i_ctime = CURRENT_TIME;
	down_write(&F2FS_I(new_inode)->i_sem);
	if (old_dir_entry)
	drop_nlink(new_inode);
	drop_nlink(new_inode);
	up_write(&F2FS_I(new_inode)->i_sem);

	mark_inode_dirty(new_inode);

	if (!new_inode->i_nlink)
	add_orphan_inode(sbi, new_inode->i_ino);
	else
	release_orphan_inode(sbi);

	update_inode_page(old_inode);
	update_inode_page(new_inode);
	} else {
	f2fs_lock_op(sbi);

	err = f2fs_add_link(new_dentry, old_inode);
	if (err) {
	f2fs_unlock_op(sbi);
	goto out_dir;
	}

	if (old_dir_entry) {
	inc_nlink(new_dir);
	update_inode_page(new_dir);
	}
	}

	down_write(&F2FS_I(old_inode)->i_sem);
	file_lost_pino(old_inode);
	up_write(&F2FS_I(old_inode)->i_sem);

	old_inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(old_inode);

	f2fs_delete_entry(old_entry, old_page, old_dir, NULL);

	if (old_dir_entry) {
	if (old_dir != new_dir) {
	f2fs_set_link(old_inode, old_dir_entry,
	old_dir_page, new_dir);
	update_inode_page(old_inode);
	} else {
	if (!f2fs_has_inline_dentry(old_inode))
	kunmap(old_dir_page);
	f2fs_put_page(old_dir_page, 0);
	}
	drop_nlink(old_dir);
	mark_inode_dirty(old_dir);
	update_inode_page(old_dir);
	}

	f2fs_unlock_op(sbi);
	return 0;

	put_out_dir:
	f2fs_unlock_op(sbi);
	if (!f2fs_has_inline_dentry(new_dir))
	kunmap(new_page);
	f2fs_put_page(new_page, 0);
	out_dir:
	if (old_dir_entry) {
	if (!f2fs_has_inline_dentry(old_inode))
	kunmap(old_dir_page);
	f2fs_put_page(old_dir_page, 0);
	}
	out_old:
	if (!f2fs_has_inline_dentry(old_dir))
	kunmap(old_page);
	f2fs_put_page(old_page, 0);
	out:
	return err;
	}

	static int f2fs_cross_rename(struct inode old_dir, struct dentry old_dentry,
	struct inode new_dir, struct dentry new_dentry)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
	struct inode *old_inode = old_dentry->d_inode;
	struct inode *new_inode = new_dentry->d_inode;
	struct page old_dir_page, new_dir_page;
	struct page old_page, new_page;
	struct f2fs_dir_entry old_dir_entry = NULL, new_dir_entry = NULL;
	struct f2fs_dir_entry old_entry, new_entry;
	int old_nlink = 0, new_nlink = 0;
	int err = -ENOENT;

	f2fs_balance_fs(sbi);

	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
	if (!old_entry)
	goto out;

	new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name, &new_page);
	if (!new_entry)
	goto out_old;

	/* prepare for updating ".." directory entry info later */
	if (old_dir != new_dir) {
	if (S_ISDIR(old_inode->i_mode)) {
	err = -EIO;
	old_dir_entry = f2fs_parent_dir(old_inode,
	&old_dir_page);
	if (!old_dir_entry)
	goto out_new;
	}

	if (S_ISDIR(new_inode->i_mode)) {
	err = -EIO;
	new_dir_entry = f2fs_parent_dir(new_inode,
	&new_dir_page);
	if (!new_dir_entry)
	goto out_old_dir;
	}
	}

	/*
	* If cross rename between file and directory those are not
	* in the same directory, we will inc nlink of file's parent
	* later, so we should check upper boundary of its nlink.
	*/
	if ((!old_dir_entry \|\| !new_dir_entry) &&
	old_dir_entry != new_dir_entry) {
	old_nlink = old_dir_entry ? -1 : 1;
	new_nlink = -old_nlink;
	err = -EMLINK;
	if ((old_nlink > 0 && old_inode->i_nlink >= F2FS_LINK_MAX) \|\|
	(new_nlink > 0 && new_inode->i_nlink >= F2FS_LINK_MAX))
	goto out_new_dir;
	}

	f2fs_lock_op(sbi);

	err = update_dent_inode(old_inode, &new_dentry->d_name);
	if (err)
	goto out_unlock;

	err = update_dent_inode(new_inode, &old_dentry->d_name);
	if (err)
	goto out_undo;

	/* update ".." directory entry info of old dentry */
	if (old_dir_entry)
	f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir);

	/* update ".." directory entry info of new dentry */
	if (new_dir_entry)
	f2fs_set_link(new_inode, new_dir_entry, new_dir_page, old_dir);

	/* update directory entry info of old dir inode */
	f2fs_set_link(old_dir, old_entry, old_page, new_inode);

	down_write(&F2FS_I(old_inode)->i_sem);
	file_lost_pino(old_inode);
	up_write(&F2FS_I(old_inode)->i_sem);

	update_inode_page(old_inode);

	old_dir->i_ctime = CURRENT_TIME;
	if (old_nlink) {
	down_write(&F2FS_I(old_dir)->i_sem);
	if (old_nlink < 0)
	drop_nlink(old_dir);
	else
	inc_nlink(old_dir);
	up_write(&F2FS_I(old_dir)->i_sem);
	}
	mark_inode_dirty(old_dir);
	update_inode_page(old_dir);

	/* update directory entry info of new dir inode */
	f2fs_set_link(new_dir, new_entry, new_page, old_inode);

	down_write(&F2FS_I(new_inode)->i_sem);
	file_lost_pino(new_inode);
	up_write(&F2FS_I(new_inode)->i_sem);

	update_inode_page(new_inode);

	new_dir->i_ctime = CURRENT_TIME;
	if (new_nlink) {
	down_write(&F2FS_I(new_dir)->i_sem);
	if (new_nlink < 0)
	drop_nlink(new_dir);
	else
	inc_nlink(new_dir);
	up_write(&F2FS_I(new_dir)->i_sem);
	}
	mark_inode_dirty(new_dir);
	update_inode_page(new_dir);

	f2fs_unlock_op(sbi);
	return 0;
	out_undo:
	/* Still we may fail to recover name info of f2fs_inode here */
	update_dent_inode(old_inode, &old_dentry->d_name);
	out_unlock:
	f2fs_unlock_op(sbi);
	out_new_dir:
	if (new_dir_entry) {
	if (!f2fs_has_inline_dentry(new_inode))
	kunmap(new_dir_page);
	f2fs_put_page(new_dir_page, 0);
	}
	out_old_dir:
	if (old_dir_entry) {
	if (!f2fs_has_inline_dentry(old_inode))
	kunmap(old_dir_page);
	f2fs_put_page(old_dir_page, 0);
	}
	out_new:
	if (!f2fs_has_inline_dentry(new_dir))
	kunmap(new_page);
	f2fs_put_page(new_page, 0);
	out_old:
	if (!f2fs_has_inline_dentry(old_dir))
	kunmap(old_page);
	f2fs_put_page(old_page, 0);
	out:
	return err;
	}

	static int f2fs_rename2(struct inode old_dir, struct dentry old_dentry,
	struct inode new_dir, struct dentry new_dentry,
	unsigned int flags)
	{
	if (flags & ~(RENAME_NOREPLACE \| RENAME_EXCHANGE))
	return -EINVAL;

	if (flags & RENAME_EXCHANGE) {
	return f2fs_cross_rename(old_dir, old_dentry,
	new_dir, new_dentry);
	}
	/*
	* VFS has already handled the new dentry existence case,
	* here, we just deal with "RENAME_NOREPLACE" as regular rename.
	*/
	return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry);
	}

	static int f2fs_tmpfile(struct inode dir, struct dentry dentry, umode_t mode)
	{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	int err;

	inode = f2fs_new_inode(dir, mode);
	if (IS_ERR(inode))
	return PTR_ERR(inode);

	inode->i_op = &f2fs_file_inode_operations;
	inode->i_fop = &f2fs_file_operations;
	inode->i_mapping->a_ops = &f2fs_dblock_aops;

	f2fs_lock_op(sbi);
	err = acquire_orphan_inode(sbi);
	if (err)
	goto out;

	err = f2fs_do_tmpfile(inode, dir);
	if (err)
	goto release_out;

	/*
	* add this non-linked tmpfile to orphan list, in this way we could
	* remove all unused data of tmpfile after abnormal power-off.
	*/
	add_orphan_inode(sbi, inode->i_ino);
	f2fs_unlock_op(sbi);

	alloc_nid_done(sbi, inode->i_ino);
	d_tmpfile(dentry, inode);
	unlock_new_inode(inode);
	return 0;

	release_out:
	release_orphan_inode(sbi);
	out:
	handle_failed_inode(inode);
	return err;
	}

	const struct inode_operations f2fs_dir_inode_operations = {
	.create = f2fs_create,
	.lookup = f2fs_lookup,
	.link = f2fs_link,
	.unlink = f2fs_unlink,
	.symlink = f2fs_symlink,
	.mkdir = f2fs_mkdir,
	.rmdir = f2fs_rmdir,
	.mknod = f2fs_mknod,
	.rename2 = f2fs_rename2,
	.tmpfile = f2fs_tmpfile,
	.getattr = f2fs_getattr,
	.setattr = f2fs_setattr,
	.get_acl = f2fs_get_acl,
	.set_acl = f2fs_set_acl,
	#ifdef CONFIG_F2FS_FS_XATTR
	.setxattr = generic_setxattr,
	.getxattr = generic_getxattr,
	.listxattr = f2fs_listxattr,
	.removexattr = generic_removexattr,
	#endif
	};

	const struct inode_operations f2fs_symlink_inode_operations = {
	.readlink = generic_readlink,
	.follow_link = page_follow_link_light,
	.put_link = page_put_link,
	.getattr = f2fs_getattr,
	.setattr = f2fs_setattr,
	#ifdef CONFIG_F2FS_FS_XATTR
	.setxattr = generic_setxattr,
	.getxattr = generic_getxattr,
	.listxattr = f2fs_listxattr,
	.removexattr = generic_removexattr,
	#endif
	};

	const struct inode_operations f2fs_special_inode_operations = {
	.getattr = f2fs_getattr,
	.setattr = f2fs_setattr,
	.get_acl = f2fs_get_acl,
	.set_acl = f2fs_set_acl,
	#ifdef CONFIG_F2FS_FS_XATTR
	.setxattr = generic_setxattr,
	.getxattr = generic_getxattr,
	.listxattr = f2fs_listxattr,
	.removexattr = generic_removexattr,
	#endif
	};