fs/f2fs/file.c - kernel/msm-4.9 - Gitiles

 /*
  * fs/f2fs/file.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/stat.h>
 #include <linux/buffer_head.h>
 #include <linux/writeback.h>
 #include <linux/falloc.h>
 #include <linux/types.h>
 #include <linux/compat.h>
 #include <linux/uaccess.h>
 #include <linux/mount.h>

 #include "f2fs.h"
 #include "node.h"
 #include "segment.h"
 #include "xattr.h"
 #include "acl.h"

 static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
 						struct vm_fault *vmf)
 {
 	struct page *page = vmf->page;
 	struct inode *inode = file_inode(vma->vm_file);
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	block_t old_blk_addr;
 	struct dnode_of_data dn;
 	int err;

 	f2fs_balance_fs(sbi);

 	sb_start_pagefault(inode->i_sb);

 	mutex_lock_op(sbi, DATA_NEW);

 	/* block allocation */
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 	err = get_dnode_of_data(&dn, page->index, 0);
 	if (err) {
 		mutex_unlock_op(sbi, DATA_NEW);
 		goto out;
 	}

 	old_blk_addr = dn.data_blkaddr;

 	if (old_blk_addr == NULL_ADDR) {
 		err = reserve_new_block(&dn);
 		if (err) {
 			f2fs_put_dnode(&dn);
 			mutex_unlock_op(sbi, DATA_NEW);
 			goto out;
 		}
 	}
 	f2fs_put_dnode(&dn);

 	mutex_unlock_op(sbi, DATA_NEW);

 	lock_page(page);
 	if (page->mapping != inode->i_mapping ||
 			page_offset(page) >= i_size_read(inode) ||
 			!PageUptodate(page)) {
 		unlock_page(page);
 		err = -EFAULT;
 		goto out;
 	}

 	/*
 	 * check to see if the page is mapped already (no holes)
 	 */
 	if (PageMappedToDisk(page))
 		goto out;

 	/* fill the page */
 	wait_on_page_writeback(page);

 	/* page is wholly or partially inside EOF */
 	if (((page->index + 1) << PAGE_CACHE_SHIFT) > i_size_read(inode)) {
 		unsigned offset;
 		offset = i_size_read(inode) & ~PAGE_CACHE_MASK;
 		zero_user_segment(page, offset, PAGE_CACHE_SIZE);
 	}
 	set_page_dirty(page);
 	SetPageUptodate(page);

 	file_update_time(vma->vm_file);
 out:
 	sb_end_pagefault(inode->i_sb);
 	return block_page_mkwrite_return(err);
 }

 static const struct vm_operations_struct f2fs_file_vm_ops = {
 	.fault		= filemap_fault,
 	.page_mkwrite	= f2fs_vm_page_mkwrite,
 	.remap_pages	= generic_file_remap_pages,
 };

 static int need_to_sync_dir(struct f2fs_sb_info *sbi, struct inode *inode)
 {
 	struct dentry *dentry;
 	nid_t pino;

 	inode = igrab(inode);
 	dentry = d_find_any_alias(inode);
 	if (!dentry) {
 		iput(inode);
 		return 0;
 	}
 	pino = dentry->d_parent->d_inode->i_ino;
 	dput(dentry);
 	iput(inode);
 	return !is_checkpointed_node(sbi, pino);
 }

 int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 {
 	struct inode *inode = file->f_mapping->host;
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	unsigned long long cur_version;
 	int ret = 0;
 	bool need_cp = false;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_ALL,
 		.nr_to_write = LONG_MAX,
 		.for_reclaim = 0,
 	};

 	if (inode->i_sb->s_flags & MS_RDONLY)
 		return 0;

 	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 	if (ret)
 		return ret;

 	/* guarantee free sections for fsync */
 	f2fs_balance_fs(sbi);

 	mutex_lock(&inode->i_mutex);

 	if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
 		goto out;

 	mutex_lock(&sbi->cp_mutex);
 	cur_version = le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver);
 	mutex_unlock(&sbi->cp_mutex);

 	if (F2FS_I(inode)->data_version != cur_version &&
 					!(inode->i_state & I_DIRTY))
 		goto out;
 	F2FS_I(inode)->data_version--;

 	if (!S_ISREG(inode->i_mode) || inode->i_nlink != 1)
 		need_cp = true;
 	else if (is_inode_flag_set(F2FS_I(inode), FI_NEED_CP))
 		need_cp = true;
 	else if (!space_for_roll_forward(sbi))
 		need_cp = true;
 	else if (need_to_sync_dir(sbi, inode))
 		need_cp = true;

 	if (need_cp) {
 		/* all the dirty node pages should be flushed for POR */
 		ret = f2fs_sync_fs(inode->i_sb, 1);
 		clear_inode_flag(F2FS_I(inode), FI_NEED_CP);
 	} else {
 		/* if there is no written node page, write its inode page */
 		while (!sync_node_pages(sbi, inode->i_ino, &wbc)) {
 			ret = f2fs_write_inode(inode, NULL);
 			if (ret)
 				goto out;
 		}
 		filemap_fdatawait_range(sbi->node_inode->i_mapping,
 							0, LONG_MAX);
 	}
 out:
 	mutex_unlock(&inode->i_mutex);
 	return ret;
 }

 static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	file_accessed(file);
 	vma->vm_ops = &f2fs_file_vm_ops;
 	return 0;
 }

 static int truncate_data_blocks_range(struct dnode_of_data *dn, int count)
 {
 	int nr_free = 0, ofs = dn->ofs_in_node;
 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 	struct f2fs_node *raw_node;
 	__le32 *addr;

 	raw_node = page_address(dn->node_page);
 	addr = blkaddr_in_node(raw_node) + ofs;

 	for ( ; count > 0; count--, addr++, dn->ofs_in_node++) {
 		block_t blkaddr = le32_to_cpu(*addr);
 		if (blkaddr == NULL_ADDR)
 			continue;

 		update_extent_cache(NULL_ADDR, dn);
 		invalidate_blocks(sbi, blkaddr);
 		dec_valid_block_count(sbi, dn->inode, 1);
 		nr_free++;
 	}
 	if (nr_free) {
 		set_page_dirty(dn->node_page);
 		sync_inode_page(dn);
 	}
 	dn->ofs_in_node = ofs;
 	return nr_free;
 }

 void truncate_data_blocks(struct dnode_of_data *dn)
 {
 	truncate_data_blocks_range(dn, ADDRS_PER_BLOCK);
 }

 static void truncate_partial_data_page(struct inode *inode, u64 from)
 {
 	unsigned offset = from & (PAGE_CACHE_SIZE - 1);
 	struct page *page;

 	if (!offset)
 		return;

 	page = find_data_page(inode, from >> PAGE_CACHE_SHIFT);
 	if (IS_ERR(page))
 		return;

 	lock_page(page);
 	wait_on_page_writeback(page);
 	zero_user(page, offset, PAGE_CACHE_SIZE - offset);
 	set_page_dirty(page);
 	f2fs_put_page(page, 1);
 }

 static int truncate_blocks(struct inode *inode, u64 from)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	unsigned int blocksize = inode->i_sb->s_blocksize;
 	struct dnode_of_data dn;
 	pgoff_t free_from;
 	int count = 0;
 	int err;

 	free_from = (pgoff_t)
 			((from + blocksize - 1) >> (sbi->log_blocksize));

 	mutex_lock_op(sbi, DATA_TRUNC);

 	set_new_dnode(&dn, inode, NULL, NULL, 0);
 	err = get_dnode_of_data(&dn, free_from, RDONLY_NODE);
 	if (err) {
 		if (err == -ENOENT)
 			goto free_next;
 		mutex_unlock_op(sbi, DATA_TRUNC);
 		return err;
 	}

 	if (IS_INODE(dn.node_page))
 		count = ADDRS_PER_INODE;
 	else
 		count = ADDRS_PER_BLOCK;

 	count -= dn.ofs_in_node;
 	BUG_ON(count < 0);
 	if (dn.ofs_in_node || IS_INODE(dn.node_page)) {
 		truncate_data_blocks_range(&dn, count);
 		free_from += count;
 	}

 	f2fs_put_dnode(&dn);
 free_next:
 	err = truncate_inode_blocks(inode, free_from);
 	mutex_unlock_op(sbi, DATA_TRUNC);

 	/* lastly zero out the first data page */
 	truncate_partial_data_page(inode, from);

 	return err;
 }

 void f2fs_truncate(struct inode *inode)
 {
 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 				S_ISLNK(inode->i_mode)))
 		return;

 	if (!truncate_blocks(inode, i_size_read(inode))) {
 		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 		mark_inode_dirty(inode);
 	}
 }

 static int f2fs_getattr(struct vfsmount *mnt,
 			 struct dentry *dentry, struct kstat *stat)
 {
 	struct inode *inode = dentry->d_inode;
 	generic_fillattr(inode, stat);
 	stat->blocks <<= 3;
 	return 0;
 }

 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 static void __setattr_copy(struct inode *inode, const struct iattr *attr)
 {
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	unsigned int ia_valid = attr->ia_valid;

 	if (ia_valid & ATTR_UID)
 		inode->i_uid = attr->ia_uid;
 	if (ia_valid & ATTR_GID)
 		inode->i_gid = attr->ia_gid;
 	if (ia_valid & ATTR_ATIME)
 		inode->i_atime = timespec_trunc(attr->ia_atime,
 						inode->i_sb->s_time_gran);
 	if (ia_valid & ATTR_MTIME)
 		inode->i_mtime = timespec_trunc(attr->ia_mtime,
 						inode->i_sb->s_time_gran);
 	if (ia_valid & ATTR_CTIME)
 		inode->i_ctime = timespec_trunc(attr->ia_ctime,
 						inode->i_sb->s_time_gran);
 	if (ia_valid & ATTR_MODE) {
 		umode_t mode = attr->ia_mode;

 		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
 			mode &= ~S_ISGID;
 		set_acl_inode(fi, mode);
 	}
 }
 #else
 #define __setattr_copy setattr_copy
 #endif

 int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = dentry->d_inode;
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	int err;

 	err = inode_change_ok(inode, attr);
 	if (err)
 		return err;

 	if ((attr->ia_valid & ATTR_SIZE) &&
 			attr->ia_size != i_size_read(inode)) {
 		truncate_setsize(inode, attr->ia_size);
 		f2fs_truncate(inode);
 		f2fs_balance_fs(F2FS_SB(inode->i_sb));
 	}

 	__setattr_copy(inode, attr);

 	if (attr->ia_valid & ATTR_MODE) {
 		err = f2fs_acl_chmod(inode);
 		if (err || is_inode_flag_set(fi, FI_ACL_MODE)) {
 			inode->i_mode = fi->i_acl_mode;
 			clear_inode_flag(fi, FI_ACL_MODE);
 		}
 	}

 	mark_inode_dirty(inode);
 	return err;
 }

 const struct inode_operations f2fs_file_inode_operations = {
 	.getattr	= f2fs_getattr,
 	.setattr	= f2fs_setattr,
 	.get_acl	= f2fs_get_acl,
 #ifdef CONFIG_F2FS_FS_XATTR
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,
 	.listxattr	= f2fs_listxattr,
 	.removexattr	= generic_removexattr,
 #endif
 };

 static void fill_zero(struct inode *inode, pgoff_t index,
 					loff_t start, loff_t len)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct page *page;

 	if (!len)
 		return;

 	f2fs_balance_fs(sbi);

 	mutex_lock_op(sbi, DATA_NEW);
 	page = get_new_data_page(inode, index, false);
 	mutex_unlock_op(sbi, DATA_NEW);

 	if (!IS_ERR(page)) {
 		wait_on_page_writeback(page);
 		zero_user(page, start, len);
 		set_page_dirty(page);
 		f2fs_put_page(page, 1);
 	}
 }

 int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end)
 {
 	pgoff_t index;
 	int err;

 	for (index = pg_start; index < pg_end; index++) {
 		struct dnode_of_data dn;
 		struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

 		f2fs_balance_fs(sbi);

 		mutex_lock_op(sbi, DATA_TRUNC);
 		set_new_dnode(&dn, inode, NULL, NULL, 0);
 		err = get_dnode_of_data(&dn, index, RDONLY_NODE);
 		if (err) {
 			mutex_unlock_op(sbi, DATA_TRUNC);
 			if (err == -ENOENT)
 				continue;
 			return err;
 		}

 		if (dn.data_blkaddr != NULL_ADDR)
 			truncate_data_blocks_range(&dn, 1);
 		f2fs_put_dnode(&dn);
 		mutex_unlock_op(sbi, DATA_TRUNC);
 	}
 	return 0;
 }

 static int punch_hole(struct inode *inode, loff_t offset, loff_t len, int mode)
 {
 	pgoff_t pg_start, pg_end;
 	loff_t off_start, off_end;
 	int ret = 0;

 	pg_start = ((unsigned long long) offset) >> PAGE_CACHE_SHIFT;
 	pg_end = ((unsigned long long) offset + len) >> PAGE_CACHE_SHIFT;

 	off_start = offset & (PAGE_CACHE_SIZE - 1);
 	off_end = (offset + len) & (PAGE_CACHE_SIZE - 1);

 	if (pg_start == pg_end) {
 		fill_zero(inode, pg_start, off_start,
 						off_end - off_start);
 	} else {
 		if (off_start)
 			fill_zero(inode, pg_start++, off_start,
 					PAGE_CACHE_SIZE - off_start);
 		if (off_end)
 			fill_zero(inode, pg_end, 0, off_end);

 		if (pg_start < pg_end) {
 			struct address_space *mapping = inode->i_mapping;
 			loff_t blk_start, blk_end;

 			blk_start = pg_start << PAGE_CACHE_SHIFT;
 			blk_end = pg_end << PAGE_CACHE_SHIFT;
 			truncate_inode_pages_range(mapping, blk_start,
 					blk_end - 1);
 			ret = truncate_hole(inode, pg_start, pg_end);
 		}
 	}

 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
 		i_size_read(inode) <= (offset + len)) {
 		i_size_write(inode, offset);
 		mark_inode_dirty(inode);
 	}

 	return ret;
 }

 static int expand_inode_data(struct inode *inode, loff_t offset,
 					loff_t len, int mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	pgoff_t index, pg_start, pg_end;
 	loff_t new_size = i_size_read(inode);
 	loff_t off_start, off_end;
 	int ret = 0;

 	ret = inode_newsize_ok(inode, (len + offset));
 	if (ret)
 		return ret;

 	pg_start = ((unsigned long long) offset) >> PAGE_CACHE_SHIFT;
 	pg_end = ((unsigned long long) offset + len) >> PAGE_CACHE_SHIFT;

 	off_start = offset & (PAGE_CACHE_SIZE - 1);
 	off_end = (offset + len) & (PAGE_CACHE_SIZE - 1);

 	for (index = pg_start; index <= pg_end; index++) {
 		struct dnode_of_data dn;

 		mutex_lock_op(sbi, DATA_NEW);

 		set_new_dnode(&dn, inode, NULL, NULL, 0);
 		ret = get_dnode_of_data(&dn, index, 0);
 		if (ret) {
 			mutex_unlock_op(sbi, DATA_NEW);
 			break;
 		}

 		if (dn.data_blkaddr == NULL_ADDR) {
 			ret = reserve_new_block(&dn);
 			if (ret) {
 				f2fs_put_dnode(&dn);
 				mutex_unlock_op(sbi, DATA_NEW);
 				break;
 			}
 		}
 		f2fs_put_dnode(&dn);

 		mutex_unlock_op(sbi, DATA_NEW);

 		if (pg_start == pg_end)
 			new_size = offset + len;
 		else if (index == pg_start && off_start)
 			new_size = (index + 1) << PAGE_CACHE_SHIFT;
 		else if (index == pg_end)
 			new_size = (index << PAGE_CACHE_SHIFT) + off_end;
 		else
 			new_size += PAGE_CACHE_SIZE;
 	}

 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
 		i_size_read(inode) < new_size) {
 		i_size_write(inode, new_size);
 		mark_inode_dirty(inode);
 	}

 	return ret;
 }

 static long f2fs_fallocate(struct file *file, int mode,
 				loff_t offset, loff_t len)
 {
 	struct inode *inode = file_inode(file);
 	long ret;

 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
 		return -EOPNOTSUPP;

 	if (mode & FALLOC_FL_PUNCH_HOLE)
 		ret = punch_hole(inode, offset, len, mode);
 	else
 		ret = expand_inode_data(inode, offset, len, mode);

 	if (!ret) {
 		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 		mark_inode_dirty(inode);
 	}
 	return ret;
 }

 #define F2FS_REG_FLMASK		(~(FS_DIRSYNC_FL | FS_TOPDIR_FL))
 #define F2FS_OTHER_FLMASK	(FS_NODUMP_FL | FS_NOATIME_FL)

 static inline __u32 f2fs_mask_flags(umode_t mode, __u32 flags)
 {
 	if (S_ISDIR(mode))
 		return flags;
 	else if (S_ISREG(mode))
 		return flags & F2FS_REG_FLMASK;
 	else
 		return flags & F2FS_OTHER_FLMASK;
 }

 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	unsigned int flags;
 	int ret;

 	switch (cmd) {
 	case FS_IOC_GETFLAGS:
 		flags = fi->i_flags & FS_FL_USER_VISIBLE;
 		return put_user(flags, (int __user *) arg);
 	case FS_IOC_SETFLAGS:
 	{
 		unsigned int oldflags;

 		ret = mnt_want_write_file(filp);
 		if (ret)
 			return ret;

 		if (!inode_owner_or_capable(inode)) {
 			ret = -EACCES;
 			goto out;
 		}

 		if (get_user(flags, (int __user *) arg)) {
 			ret = -EFAULT;
 			goto out;
 		}

 		flags = f2fs_mask_flags(inode->i_mode, flags);

 		mutex_lock(&inode->i_mutex);

 		oldflags = fi->i_flags;

 		if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 			if (!capable(CAP_LINUX_IMMUTABLE)) {
 				mutex_unlock(&inode->i_mutex);
 				ret = -EPERM;
 				goto out;
 			}
 		}

 		flags = flags & FS_FL_USER_MODIFIABLE;
 		flags |= oldflags & ~FS_FL_USER_MODIFIABLE;
 		fi->i_flags = flags;
 		mutex_unlock(&inode->i_mutex);

 		f2fs_set_inode_flags(inode);
 		inode->i_ctime = CURRENT_TIME;
 		mark_inode_dirty(inode);
 out:
 		mnt_drop_write_file(filp);
 		return ret;
 	}
 	default:
 		return -ENOTTY;
 	}
 }

 #ifdef CONFIG_COMPAT
 long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	switch (cmd) {
 	case F2FS_IOC32_GETFLAGS:
 		cmd = F2FS_IOC_GETFLAGS;
 		break;
 	case F2FS_IOC32_SETFLAGS:
 		cmd = F2FS_IOC_SETFLAGS;
 		break;
 	default:
 		return -ENOIOCTLCMD;
 	}
 	return f2fs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 }
 #endif

 const struct file_operations f2fs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
 	.open		= generic_file_open,
 	.mmap		= f2fs_file_mmap,
 	.fsync		= f2fs_sync_file,
 	.fallocate	= f2fs_fallocate,
 	.unlocked_ioctl	= f2fs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= f2fs_compat_ioctl,
 #endif
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= generic_file_splice_write,
 };
	/*
	* fs/f2fs/file.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/stat.h>
	#include <linux/buffer_head.h>
	#include <linux/writeback.h>
	#include <linux/falloc.h>
	#include <linux/types.h>
	#include <linux/compat.h>
	#include <linux/uaccess.h>
	#include <linux/mount.h>

	#include "f2fs.h"
	#include "node.h"
	#include "segment.h"
	#include "xattr.h"
	#include "acl.h"

	static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
	struct vm_fault *vmf)
	{
	struct page *page = vmf->page;
	struct inode *inode = file_inode(vma->vm_file);
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	block_t old_blk_addr;
	struct dnode_of_data dn;
	int err;

	f2fs_balance_fs(sbi);

	sb_start_pagefault(inode->i_sb);

	mutex_lock_op(sbi, DATA_NEW);

	/* block allocation */
	set_new_dnode(&dn, inode, NULL, NULL, 0);
	err = get_dnode_of_data(&dn, page->index, 0);
	if (err) {
	mutex_unlock_op(sbi, DATA_NEW);
	goto out;
	}

	old_blk_addr = dn.data_blkaddr;

	if (old_blk_addr == NULL_ADDR) {
	err = reserve_new_block(&dn);
	if (err) {
	f2fs_put_dnode(&dn);
	mutex_unlock_op(sbi, DATA_NEW);
	goto out;
	}
	}
	f2fs_put_dnode(&dn);

	mutex_unlock_op(sbi, DATA_NEW);

	lock_page(page);
	if (page->mapping != inode->i_mapping \|\|
	page_offset(page) >= i_size_read(inode) \|\|
	!PageUptodate(page)) {
	unlock_page(page);
	err = -EFAULT;
	goto out;
	}

	/*
	* check to see if the page is mapped already (no holes)
	*/
	if (PageMappedToDisk(page))
	goto out;

	/* fill the page */
	wait_on_page_writeback(page);

	/* page is wholly or partially inside EOF */
	if (((page->index + 1) << PAGE_CACHE_SHIFT) > i_size_read(inode)) {
	unsigned offset;
	offset = i_size_read(inode) & ~PAGE_CACHE_MASK;
	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
	}
	set_page_dirty(page);
	SetPageUptodate(page);

	file_update_time(vma->vm_file);
	out:
	sb_end_pagefault(inode->i_sb);
	return block_page_mkwrite_return(err);
	}

	static const struct vm_operations_struct f2fs_file_vm_ops = {
	.fault = filemap_fault,
	.page_mkwrite = f2fs_vm_page_mkwrite,
	.remap_pages = generic_file_remap_pages,
	};

	static int need_to_sync_dir(struct f2fs_sb_info sbi, struct inode inode)
	{
	struct dentry *dentry;
	nid_t pino;

	inode = igrab(inode);
	dentry = d_find_any_alias(inode);
	if (!dentry) {
	iput(inode);
	return 0;
	}
	pino = dentry->d_parent->d_inode->i_ino;
	dput(dentry);
	iput(inode);
	return !is_checkpointed_node(sbi, pino);
	}

	int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
	{
	struct inode *inode = file->f_mapping->host;
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	unsigned long long cur_version;
	int ret = 0;
	bool need_cp = false;
	struct writeback_control wbc = {
	.sync_mode = WB_SYNC_ALL,
	.nr_to_write = LONG_MAX,
	.for_reclaim = 0,
	};

	if (inode->i_sb->s_flags & MS_RDONLY)
	return 0;

	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (ret)
	return ret;

	/* guarantee free sections for fsync */
	f2fs_balance_fs(sbi);

	mutex_lock(&inode->i_mutex);

	if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
	goto out;

	mutex_lock(&sbi->cp_mutex);
	cur_version = le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver);
	mutex_unlock(&sbi->cp_mutex);

	if (F2FS_I(inode)->data_version != cur_version &&
	!(inode->i_state & I_DIRTY))
	goto out;
	F2FS_I(inode)->data_version--;

	if (!S_ISREG(inode->i_mode) \|\| inode->i_nlink != 1)
	need_cp = true;
	else if (is_inode_flag_set(F2FS_I(inode), FI_NEED_CP))
	need_cp = true;
	else if (!space_for_roll_forward(sbi))
	need_cp = true;
	else if (need_to_sync_dir(sbi, inode))
	need_cp = true;

	if (need_cp) {
	/* all the dirty node pages should be flushed for POR */
	ret = f2fs_sync_fs(inode->i_sb, 1);
	clear_inode_flag(F2FS_I(inode), FI_NEED_CP);
	} else {
	/* if there is no written node page, write its inode page */
	while (!sync_node_pages(sbi, inode->i_ino, &wbc)) {
	ret = f2fs_write_inode(inode, NULL);
	if (ret)
	goto out;
	}
	filemap_fdatawait_range(sbi->node_inode->i_mapping,
	0, LONG_MAX);
	}
	out:
	mutex_unlock(&inode->i_mutex);
	return ret;
	}

	static int f2fs_file_mmap(struct file file, struct vm_area_struct vma)
	{
	file_accessed(file);
	vma->vm_ops = &f2fs_file_vm_ops;
	return 0;
	}

	static int truncate_data_blocks_range(struct dnode_of_data *dn, int count)
	{
	int nr_free = 0, ofs = dn->ofs_in_node;
	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
	struct f2fs_node *raw_node;
	__le32 *addr;

	raw_node = page_address(dn->node_page);
	addr = blkaddr_in_node(raw_node) + ofs;

	for ( ; count > 0; count--, addr++, dn->ofs_in_node++) {
	block_t blkaddr = le32_to_cpu(*addr);
	if (blkaddr == NULL_ADDR)
	continue;

	update_extent_cache(NULL_ADDR, dn);
	invalidate_blocks(sbi, blkaddr);
	dec_valid_block_count(sbi, dn->inode, 1);
	nr_free++;
	}
	if (nr_free) {
	set_page_dirty(dn->node_page);
	sync_inode_page(dn);
	}
	dn->ofs_in_node = ofs;
	return nr_free;
	}

	void truncate_data_blocks(struct dnode_of_data *dn)
	{
	truncate_data_blocks_range(dn, ADDRS_PER_BLOCK);
	}

	static void truncate_partial_data_page(struct inode *inode, u64 from)
	{
	unsigned offset = from & (PAGE_CACHE_SIZE - 1);
	struct page *page;

	if (!offset)
	return;

	page = find_data_page(inode, from >> PAGE_CACHE_SHIFT);
	if (IS_ERR(page))
	return;

	lock_page(page);
	wait_on_page_writeback(page);
	zero_user(page, offset, PAGE_CACHE_SIZE - offset);
	set_page_dirty(page);
	f2fs_put_page(page, 1);
	}

	static int truncate_blocks(struct inode *inode, u64 from)
	{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	unsigned int blocksize = inode->i_sb->s_blocksize;
	struct dnode_of_data dn;
	pgoff_t free_from;
	int count = 0;
	int err;

	free_from = (pgoff_t)
	((from + blocksize - 1) >> (sbi->log_blocksize));

	mutex_lock_op(sbi, DATA_TRUNC);

	set_new_dnode(&dn, inode, NULL, NULL, 0);
	err = get_dnode_of_data(&dn, free_from, RDONLY_NODE);
	if (err) {
	if (err == -ENOENT)
	goto free_next;
	mutex_unlock_op(sbi, DATA_TRUNC);
	return err;
	}

	if (IS_INODE(dn.node_page))
	count = ADDRS_PER_INODE;
	else
	count = ADDRS_PER_BLOCK;

	count -= dn.ofs_in_node;
	BUG_ON(count < 0);
	if (dn.ofs_in_node \|\| IS_INODE(dn.node_page)) {
	truncate_data_blocks_range(&dn, count);
	free_from += count;
	}

	f2fs_put_dnode(&dn);
	free_next:
	err = truncate_inode_blocks(inode, free_from);
	mutex_unlock_op(sbi, DATA_TRUNC);

	/* lastly zero out the first data page */
	truncate_partial_data_page(inode, from);

	return err;
	}

	void f2fs_truncate(struct inode *inode)
	{
	if (!(S_ISREG(inode->i_mode) \|\| S_ISDIR(inode->i_mode) \|\|
	S_ISLNK(inode->i_mode)))
	return;

	if (!truncate_blocks(inode, i_size_read(inode))) {
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(inode);
	}
	}

	static int f2fs_getattr(struct vfsmount *mnt,
	struct dentry dentry, struct kstat stat)
	{
	struct inode *inode = dentry->d_inode;
	generic_fillattr(inode, stat);
	stat->blocks <<= 3;
	return 0;
	}

	#ifdef CONFIG_F2FS_FS_POSIX_ACL
	static void __setattr_copy(struct inode inode, const struct iattr attr)
	{
	struct f2fs_inode_info *fi = F2FS_I(inode);
	unsigned int ia_valid = attr->ia_valid;

	if (ia_valid & ATTR_UID)
	inode->i_uid = attr->ia_uid;
	if (ia_valid & ATTR_GID)
	inode->i_gid = attr->ia_gid;
	if (ia_valid & ATTR_ATIME)
	inode->i_atime = timespec_trunc(attr->ia_atime,
	inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_MTIME)
	inode->i_mtime = timespec_trunc(attr->ia_mtime,
	inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_CTIME)
	inode->i_ctime = timespec_trunc(attr->ia_ctime,
	inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_MODE) {
	umode_t mode = attr->ia_mode;

	if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
	mode &= ~S_ISGID;
	set_acl_inode(fi, mode);
	}
	}
	#else
	#define __setattr_copy setattr_copy
	#endif

	int f2fs_setattr(struct dentry dentry, struct iattr attr)
	{
	struct inode *inode = dentry->d_inode;
	struct f2fs_inode_info *fi = F2FS_I(inode);
	int err;

	err = inode_change_ok(inode, attr);
	if (err)
	return err;

	if ((attr->ia_valid & ATTR_SIZE) &&
	attr->ia_size != i_size_read(inode)) {
	truncate_setsize(inode, attr->ia_size);
	f2fs_truncate(inode);
	f2fs_balance_fs(F2FS_SB(inode->i_sb));
	}

	__setattr_copy(inode, attr);

	if (attr->ia_valid & ATTR_MODE) {
	err = f2fs_acl_chmod(inode);
	if (err \|\| is_inode_flag_set(fi, FI_ACL_MODE)) {
	inode->i_mode = fi->i_acl_mode;
	clear_inode_flag(fi, FI_ACL_MODE);
	}
	}

	mark_inode_dirty(inode);
	return err;
	}

	const struct inode_operations f2fs_file_inode_operations = {
	.getattr = f2fs_getattr,
	.setattr = f2fs_setattr,
	.get_acl = f2fs_get_acl,
	#ifdef CONFIG_F2FS_FS_XATTR
	.setxattr = generic_setxattr,
	.getxattr = generic_getxattr,
	.listxattr = f2fs_listxattr,
	.removexattr = generic_removexattr,
	#endif
	};

	static void fill_zero(struct inode *inode, pgoff_t index,
	loff_t start, loff_t len)
	{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	struct page *page;

	if (!len)
	return;

	f2fs_balance_fs(sbi);

	mutex_lock_op(sbi, DATA_NEW);
	page = get_new_data_page(inode, index, false);
	mutex_unlock_op(sbi, DATA_NEW);

	if (!IS_ERR(page)) {
	wait_on_page_writeback(page);
	zero_user(page, start, len);
	set_page_dirty(page);
	f2fs_put_page(page, 1);
	}
	}

	int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end)
	{
	pgoff_t index;
	int err;

	for (index = pg_start; index < pg_end; index++) {
	struct dnode_of_data dn;
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

	f2fs_balance_fs(sbi);

	mutex_lock_op(sbi, DATA_TRUNC);
	set_new_dnode(&dn, inode, NULL, NULL, 0);
	err = get_dnode_of_data(&dn, index, RDONLY_NODE);
	if (err) {
	mutex_unlock_op(sbi, DATA_TRUNC);
	if (err == -ENOENT)
	continue;
	return err;
	}

	if (dn.data_blkaddr != NULL_ADDR)
	truncate_data_blocks_range(&dn, 1);
	f2fs_put_dnode(&dn);
	mutex_unlock_op(sbi, DATA_TRUNC);
	}
	return 0;
	}

	static int punch_hole(struct inode *inode, loff_t offset, loff_t len, int mode)
	{
	pgoff_t pg_start, pg_end;
	loff_t off_start, off_end;
	int ret = 0;

	pg_start = ((unsigned long long) offset) >> PAGE_CACHE_SHIFT;
	pg_end = ((unsigned long long) offset + len) >> PAGE_CACHE_SHIFT;

	off_start = offset & (PAGE_CACHE_SIZE - 1);
	off_end = (offset + len) & (PAGE_CACHE_SIZE - 1);

	if (pg_start == pg_end) {
	fill_zero(inode, pg_start, off_start,
	off_end - off_start);
	} else {
	if (off_start)
	fill_zero(inode, pg_start++, off_start,
	PAGE_CACHE_SIZE - off_start);
	if (off_end)
	fill_zero(inode, pg_end, 0, off_end);

	if (pg_start < pg_end) {
	struct address_space *mapping = inode->i_mapping;
	loff_t blk_start, blk_end;

	blk_start = pg_start << PAGE_CACHE_SHIFT;
	blk_end = pg_end << PAGE_CACHE_SHIFT;
	truncate_inode_pages_range(mapping, blk_start,
	blk_end - 1);
	ret = truncate_hole(inode, pg_start, pg_end);
	}
	}

	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
	i_size_read(inode) <= (offset + len)) {
	i_size_write(inode, offset);
	mark_inode_dirty(inode);
	}

	return ret;
	}

	static int expand_inode_data(struct inode *inode, loff_t offset,
	loff_t len, int mode)
	{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
	pgoff_t index, pg_start, pg_end;
	loff_t new_size = i_size_read(inode);
	loff_t off_start, off_end;
	int ret = 0;

	ret = inode_newsize_ok(inode, (len + offset));
	if (ret)
	return ret;

	pg_start = ((unsigned long long) offset) >> PAGE_CACHE_SHIFT;
	pg_end = ((unsigned long long) offset + len) >> PAGE_CACHE_SHIFT;

	off_start = offset & (PAGE_CACHE_SIZE - 1);
	off_end = (offset + len) & (PAGE_CACHE_SIZE - 1);

	for (index = pg_start; index <= pg_end; index++) {
	struct dnode_of_data dn;

	mutex_lock_op(sbi, DATA_NEW);

	set_new_dnode(&dn, inode, NULL, NULL, 0);
	ret = get_dnode_of_data(&dn, index, 0);
	if (ret) {
	mutex_unlock_op(sbi, DATA_NEW);
	break;
	}

	if (dn.data_blkaddr == NULL_ADDR) {
	ret = reserve_new_block(&dn);
	if (ret) {
	f2fs_put_dnode(&dn);
	mutex_unlock_op(sbi, DATA_NEW);
	break;
	}
	}
	f2fs_put_dnode(&dn);

	mutex_unlock_op(sbi, DATA_NEW);

	if (pg_start == pg_end)
	new_size = offset + len;
	else if (index == pg_start && off_start)
	new_size = (index + 1) << PAGE_CACHE_SHIFT;
	else if (index == pg_end)
	new_size = (index << PAGE_CACHE_SHIFT) + off_end;
	else
	new_size += PAGE_CACHE_SIZE;
	}

	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
	i_size_read(inode) < new_size) {
	i_size_write(inode, new_size);
	mark_inode_dirty(inode);
	}

	return ret;
	}

	static long f2fs_fallocate(struct file *file, int mode,
	loff_t offset, loff_t len)
	{
	struct inode *inode = file_inode(file);
	long ret;

	if (mode & ~(FALLOC_FL_KEEP_SIZE \| FALLOC_FL_PUNCH_HOLE))
	return -EOPNOTSUPP;

	if (mode & FALLOC_FL_PUNCH_HOLE)
	ret = punch_hole(inode, offset, len, mode);
	else
	ret = expand_inode_data(inode, offset, len, mode);

	if (!ret) {
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(inode);
	}
	return ret;
	}

	#define F2FS_REG_FLMASK (~(FS_DIRSYNC_FL \| FS_TOPDIR_FL))
	#define F2FS_OTHER_FLMASK (FS_NODUMP_FL \| FS_NOATIME_FL)

	static inline __u32 f2fs_mask_flags(umode_t mode, __u32 flags)
	{
	if (S_ISDIR(mode))
	return flags;
	else if (S_ISREG(mode))
	return flags & F2FS_REG_FLMASK;
	else
	return flags & F2FS_OTHER_FLMASK;
	}

	long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	struct inode *inode = file_inode(filp);
	struct f2fs_inode_info *fi = F2FS_I(inode);
	unsigned int flags;
	int ret;

	switch (cmd) {
	case FS_IOC_GETFLAGS:
	flags = fi->i_flags & FS_FL_USER_VISIBLE;
	return put_user(flags, (int __user *) arg);
	case FS_IOC_SETFLAGS:
	{
	unsigned int oldflags;

	ret = mnt_want_write_file(filp);
	if (ret)
	return ret;

	if (!inode_owner_or_capable(inode)) {
	ret = -EACCES;
	goto out;
	}

	if (get_user(flags, (int __user *) arg)) {
	ret = -EFAULT;
	goto out;
	}

	flags = f2fs_mask_flags(inode->i_mode, flags);

	mutex_lock(&inode->i_mutex);

	oldflags = fi->i_flags;

	if ((flags ^ oldflags) & (FS_APPEND_FL \| FS_IMMUTABLE_FL)) {
	if (!capable(CAP_LINUX_IMMUTABLE)) {
	mutex_unlock(&inode->i_mutex);
	ret = -EPERM;
	goto out;
	}
	}

	flags = flags & FS_FL_USER_MODIFIABLE;
	flags \|= oldflags & ~FS_FL_USER_MODIFIABLE;
	fi->i_flags = flags;
	mutex_unlock(&inode->i_mutex);

	f2fs_set_inode_flags(inode);
	inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(inode);
	out:
	mnt_drop_write_file(filp);
	return ret;
	}
	default:
	return -ENOTTY;
	}
	}

	#ifdef CONFIG_COMPAT
	long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	switch (cmd) {
	case F2FS_IOC32_GETFLAGS:
	cmd = F2FS_IOC_GETFLAGS;
	break;
	case F2FS_IOC32_SETFLAGS:
	cmd = F2FS_IOC_SETFLAGS;
	break;
	default:
	return -ENOIOCTLCMD;
	}
	return f2fs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
	}
	#endif

	const struct file_operations f2fs_file_operations = {
	.llseek = generic_file_llseek,
	.read = do_sync_read,
	.write = do_sync_write,
	.aio_read = generic_file_aio_read,
	.aio_write = generic_file_aio_write,
	.open = generic_file_open,
	.mmap = f2fs_file_mmap,
	.fsync = f2fs_sync_file,
	.fallocate = f2fs_fallocate,
	.unlocked_ioctl = f2fs_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = f2fs_compat_ioctl,
	#endif
	.splice_read = generic_file_splice_read,
	.splice_write = generic_file_splice_write,
	};