file.c 24.4 KB
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/*
 *  linux/fs/affs/file.c
 *
 *  (c) 1996  Hans-Joachim Widmaier - Rewritten
 *
 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
 *
 *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 *
 *  affs regular file handling primitives
 */

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#include <linux/uio.h>
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#include "affs.h"

static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);

static int
affs_file_open(struct inode *inode, struct file *filp)
{
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	pr_debug("open(%lu,%d)\n",
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		 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
	atomic_inc(&AFFS_I(inode)->i_opencnt);
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	return 0;
}

static int
affs_file_release(struct inode *inode, struct file *filp)
{
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	pr_debug("release(%lu, %d)\n",
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		 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));

	if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
		mutex_lock(&inode->i_mutex);
		if (inode->i_size != AFFS_I(inode)->mmu_private)
			affs_truncate(inode);
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		affs_free_prealloc(inode);
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		mutex_unlock(&inode->i_mutex);
	}
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	return 0;
}

static int
affs_grow_extcache(struct inode *inode, u32 lc_idx)
{
	struct super_block	*sb = inode->i_sb;
	struct buffer_head	*bh;
	u32 lc_max;
	int i, j, key;

	if (!AFFS_I(inode)->i_lc) {
		char *ptr = (char *)get_zeroed_page(GFP_NOFS);
		if (!ptr)
			return -ENOMEM;
		AFFS_I(inode)->i_lc = (u32 *)ptr;
		AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
	}

	lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;

	if (AFFS_I(inode)->i_extcnt > lc_max) {
		u32 lc_shift, lc_mask, tmp, off;

		/* need to recalculate linear cache, start from old size */
		lc_shift = AFFS_I(inode)->i_lc_shift;
		tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
		for (; tmp; tmp >>= 1)
			lc_shift++;
		lc_mask = (1 << lc_shift) - 1;

		/* fix idx and old size to new shift */
		lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
		AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);

		/* first shrink old cache to make more space */
		off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
		for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
			AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];

		AFFS_I(inode)->i_lc_shift = lc_shift;
		AFFS_I(inode)->i_lc_mask = lc_mask;
	}

	/* fill cache to the needed index */
	i = AFFS_I(inode)->i_lc_size;
	AFFS_I(inode)->i_lc_size = lc_idx + 1;
	for (; i <= lc_idx; i++) {
		if (!i) {
			AFFS_I(inode)->i_lc[0] = inode->i_ino;
			continue;
		}
		key = AFFS_I(inode)->i_lc[i - 1];
		j = AFFS_I(inode)->i_lc_mask + 1;
		// unlock cache
		for (; j > 0; j--) {
			bh = affs_bread(sb, key);
			if (!bh)
				goto err;
			key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
			affs_brelse(bh);
		}
		// lock cache
		AFFS_I(inode)->i_lc[i] = key;
	}

	return 0;

err:
	// lock cache
	return -EIO;
}

static struct buffer_head *
affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
{
	struct super_block *sb = inode->i_sb;
	struct buffer_head *new_bh;
	u32 blocknr, tmp;

	blocknr = affs_alloc_block(inode, bh->b_blocknr);
	if (!blocknr)
		return ERR_PTR(-ENOSPC);

	new_bh = affs_getzeroblk(sb, blocknr);
	if (!new_bh) {
		affs_free_block(sb, blocknr);
		return ERR_PTR(-EIO);
	}

	AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
	AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
	AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
	AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
	affs_fix_checksum(sb, new_bh);

	mark_buffer_dirty_inode(new_bh, inode);

	tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
	if (tmp)
		affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
	AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
	affs_adjust_checksum(bh, blocknr - tmp);
	mark_buffer_dirty_inode(bh, inode);

	AFFS_I(inode)->i_extcnt++;
	mark_inode_dirty(inode);

	return new_bh;
}

static inline struct buffer_head *
affs_get_extblock(struct inode *inode, u32 ext)
{
	/* inline the simplest case: same extended block as last time */
	struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
	if (ext == AFFS_I(inode)->i_ext_last)
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		get_bh(bh);
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	else
		/* we have to do more (not inlined) */
		bh = affs_get_extblock_slow(inode, ext);

	return bh;
}

static struct buffer_head *
affs_get_extblock_slow(struct inode *inode, u32 ext)
{
	struct super_block *sb = inode->i_sb;
	struct buffer_head *bh;
	u32 ext_key;
	u32 lc_idx, lc_off, ac_idx;
	u32 tmp, idx;

	if (ext == AFFS_I(inode)->i_ext_last + 1) {
		/* read the next extended block from the current one */
		bh = AFFS_I(inode)->i_ext_bh;
		ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
		if (ext < AFFS_I(inode)->i_extcnt)
			goto read_ext;
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		BUG_ON(ext > AFFS_I(inode)->i_extcnt);
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		bh = affs_alloc_extblock(inode, bh, ext);
		if (IS_ERR(bh))
			return bh;
		goto store_ext;
	}

	if (ext == 0) {
		/* we seek back to the file header block */
		ext_key = inode->i_ino;
		goto read_ext;
	}

	if (ext >= AFFS_I(inode)->i_extcnt) {
		struct buffer_head *prev_bh;

		/* allocate a new extended block */
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		BUG_ON(ext > AFFS_I(inode)->i_extcnt);
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		/* get previous extended block */
		prev_bh = affs_get_extblock(inode, ext - 1);
		if (IS_ERR(prev_bh))
			return prev_bh;
		bh = affs_alloc_extblock(inode, prev_bh, ext);
		affs_brelse(prev_bh);
		if (IS_ERR(bh))
			return bh;
		goto store_ext;
	}

again:
	/* check if there is an extended cache and whether it's large enough */
	lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
	lc_off = ext & AFFS_I(inode)->i_lc_mask;

	if (lc_idx >= AFFS_I(inode)->i_lc_size) {
		int err;

		err = affs_grow_extcache(inode, lc_idx);
		if (err)
			return ERR_PTR(err);
		goto again;
	}

	/* every n'th key we find in the linear cache */
	if (!lc_off) {
		ext_key = AFFS_I(inode)->i_lc[lc_idx];
		goto read_ext;
	}

	/* maybe it's still in the associative cache */
	ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
	if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
		ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
		goto read_ext;
	}

	/* try to find one of the previous extended blocks */
	tmp = ext;
	idx = ac_idx;
	while (--tmp, --lc_off > 0) {
		idx = (idx - 1) & AFFS_AC_MASK;
		if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
			ext_key = AFFS_I(inode)->i_ac[idx].key;
			goto find_ext;
		}
	}

	/* fall back to the linear cache */
	ext_key = AFFS_I(inode)->i_lc[lc_idx];
find_ext:
	/* read all extended blocks until we find the one we need */
	//unlock cache
	do {
		bh = affs_bread(sb, ext_key);
		if (!bh)
			goto err_bread;
		ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
		affs_brelse(bh);
		tmp++;
	} while (tmp < ext);
	//lock cache

	/* store it in the associative cache */
	// recalculate ac_idx?
	AFFS_I(inode)->i_ac[ac_idx].ext = ext;
	AFFS_I(inode)->i_ac[ac_idx].key = ext_key;

read_ext:
	/* finally read the right extended block */
	//unlock cache
	bh = affs_bread(sb, ext_key);
	if (!bh)
		goto err_bread;
	//lock cache

store_ext:
	/* release old cached extended block and store the new one */
	affs_brelse(AFFS_I(inode)->i_ext_bh);
	AFFS_I(inode)->i_ext_last = ext;
	AFFS_I(inode)->i_ext_bh = bh;
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	get_bh(bh);
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	return bh;

err_bread:
	affs_brelse(bh);
	return ERR_PTR(-EIO);
}

static int
affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
{
	struct super_block	*sb = inode->i_sb;
	struct buffer_head	*ext_bh;
	u32			 ext;

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	pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
		 (unsigned long long)block);
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	BUG_ON(block > (sector_t)0x7fffffffUL);
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	if (block >= AFFS_I(inode)->i_blkcnt) {
		if (block > AFFS_I(inode)->i_blkcnt || !create)
			goto err_big;
	} else
		create = 0;

	//lock cache
	affs_lock_ext(inode);

	ext = (u32)block / AFFS_SB(sb)->s_hashsize;
	block -= ext * AFFS_SB(sb)->s_hashsize;
	ext_bh = affs_get_extblock(inode, ext);
	if (IS_ERR(ext_bh))
		goto err_ext;
	map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));

	if (create) {
		u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
		if (!blocknr)
			goto err_alloc;
		set_buffer_new(bh_result);
		AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
		AFFS_I(inode)->i_blkcnt++;

		/* store new block */
		if (bh_result->b_blocknr)
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			affs_warning(sb, "get_block",
				     "block already set (%llx)",
				     (unsigned long long)bh_result->b_blocknr);
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		AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
		AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
		affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
		bh_result->b_blocknr = blocknr;

		if (!block) {
			/* insert first block into header block */
			u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
			if (tmp)
				affs_warning(sb, "get_block", "first block already set (%d)", tmp);
			AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
			affs_adjust_checksum(ext_bh, blocknr - tmp);
		}
	}

	affs_brelse(ext_bh);
	//unlock cache
	affs_unlock_ext(inode);
	return 0;

err_big:
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	affs_error(inode->i_sb, "get_block", "strange block request %llu",
		   (unsigned long long)block);
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	return -EIO;
err_ext:
	// unlock cache
	affs_unlock_ext(inode);
	return PTR_ERR(ext_bh);
err_alloc:
	brelse(ext_bh);
	clear_buffer_mapped(bh_result);
	bh_result->b_bdev = NULL;
	// unlock cache
	affs_unlock_ext(inode);
	return -ENOSPC;
}

static int affs_writepage(struct page *page, struct writeback_control *wbc)
{
	return block_write_full_page(page, affs_get_block, wbc);
}
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static int affs_readpage(struct file *file, struct page *page)
{
	return block_read_full_page(page, affs_get_block);
}
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static void affs_write_failed(struct address_space *mapping, loff_t to)
{
	struct inode *inode = mapping->host;

	if (to > inode->i_size) {
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		truncate_pagecache(inode, inode->i_size);
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		affs_truncate(inode);
	}
}

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static ssize_t
affs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
	       loff_t offset)
{
	struct file *file = iocb->ki_filp;
	struct address_space *mapping = file->f_mapping;
	struct inode *inode = mapping->host;
	size_t count = iov_iter_count(iter);
	ssize_t ret;

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	if (iov_iter_rw(iter) == WRITE) {
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		loff_t size = offset + count;

		if (AFFS_I(inode)->mmu_private < size)
			return 0;
	}

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	ret = blockdev_direct_IO(iocb, inode, iter, offset, affs_get_block);
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	if (ret < 0 && iov_iter_rw(iter) == WRITE)
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		affs_write_failed(mapping, offset + count);
	return ret;
}

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static int affs_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
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{
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	int ret;

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	*pagep = NULL;
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	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
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				affs_get_block,
				&AFFS_I(mapping->host)->mmu_private);
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	if (unlikely(ret))
		affs_write_failed(mapping, pos + len);
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	return ret;
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}
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static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping,block,affs_get_block);
}
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const struct address_space_operations affs_aops = {
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	.readpage = affs_readpage,
	.writepage = affs_writepage,
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	.write_begin = affs_write_begin,
	.write_end = generic_write_end,
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	.direct_IO = affs_direct_IO,
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	.bmap = _affs_bmap
};

static inline struct buffer_head *
affs_bread_ino(struct inode *inode, int block, int create)
{
	struct buffer_head *bh, tmp_bh;
	int err;

	tmp_bh.b_state = 0;
	err = affs_get_block(inode, block, &tmp_bh, create);
	if (!err) {
		bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
		if (bh) {
			bh->b_state |= tmp_bh.b_state;
			return bh;
		}
		err = -EIO;
	}
	return ERR_PTR(err);
}

static inline struct buffer_head *
affs_getzeroblk_ino(struct inode *inode, int block)
{
	struct buffer_head *bh, tmp_bh;
	int err;

	tmp_bh.b_state = 0;
	err = affs_get_block(inode, block, &tmp_bh, 1);
	if (!err) {
		bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
		if (bh) {
			bh->b_state |= tmp_bh.b_state;
			return bh;
		}
		err = -EIO;
	}
	return ERR_PTR(err);
}

static inline struct buffer_head *
affs_getemptyblk_ino(struct inode *inode, int block)
{
	struct buffer_head *bh, tmp_bh;
	int err;

	tmp_bh.b_state = 0;
	err = affs_get_block(inode, block, &tmp_bh, 1);
	if (!err) {
		bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
		if (bh) {
			bh->b_state |= tmp_bh.b_state;
			return bh;
		}
		err = -EIO;
	}
	return ERR_PTR(err);
}

static int
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affs_do_readpage_ofs(struct page *page, unsigned to)
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{
	struct inode *inode = page->mapping->host;
	struct super_block *sb = inode->i_sb;
	struct buffer_head *bh;
	char *data;
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	unsigned pos = 0;
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	u32 bidx, boff, bsize;
	u32 tmp;

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	pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
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		 page->index, to);
	BUG_ON(to > PAGE_CACHE_SIZE);
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	kmap(page);
	data = page_address(page);
	bsize = AFFS_SB(sb)->s_data_blksize;
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	tmp = page->index << PAGE_CACHE_SHIFT;
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	bidx = tmp / bsize;
	boff = tmp % bsize;

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	while (pos < to) {
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		bh = affs_bread_ino(inode, bidx, 0);
		if (IS_ERR(bh))
			return PTR_ERR(bh);
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		tmp = min(bsize - boff, to - pos);
		BUG_ON(pos + tmp > to || tmp > bsize);
		memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
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		affs_brelse(bh);
		bidx++;
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		pos += tmp;
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		boff = 0;
	}
	flush_dcache_page(page);
	kunmap(page);
	return 0;
}

static int
affs_extent_file_ofs(struct inode *inode, u32 newsize)
{
	struct super_block *sb = inode->i_sb;
	struct buffer_head *bh, *prev_bh;
	u32 bidx, boff;
	u32 size, bsize;
	u32 tmp;

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	pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
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	bsize = AFFS_SB(sb)->s_data_blksize;
	bh = NULL;
	size = AFFS_I(inode)->mmu_private;
	bidx = size / bsize;
	boff = size % bsize;
	if (boff) {
		bh = affs_bread_ino(inode, bidx, 0);
		if (IS_ERR(bh))
			return PTR_ERR(bh);
		tmp = min(bsize - boff, newsize - size);
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		BUG_ON(boff + tmp > bsize || tmp > bsize);
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		memset(AFFS_DATA(bh) + boff, 0, tmp);
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		be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
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		affs_fix_checksum(sb, bh);
		mark_buffer_dirty_inode(bh, inode);
		size += tmp;
		bidx++;
	} else if (bidx) {
		bh = affs_bread_ino(inode, bidx - 1, 0);
		if (IS_ERR(bh))
			return PTR_ERR(bh);
	}

	while (size < newsize) {
		prev_bh = bh;
		bh = affs_getzeroblk_ino(inode, bidx);
		if (IS_ERR(bh))
			goto out;
		tmp = min(bsize, newsize - size);
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		BUG_ON(tmp > bsize);
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		AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
		AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
		AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
		AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
		affs_fix_checksum(sb, bh);
		bh->b_state &= ~(1UL << BH_New);
		mark_buffer_dirty_inode(bh, inode);
		if (prev_bh) {
587 588 589 590 591 592
			u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);

			if (tmp_next)
				affs_warning(sb, "extent_file_ofs",
					     "next block already set for %d (%d)",
					     bidx, tmp_next);
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593
			AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
594
			affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
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595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616
			mark_buffer_dirty_inode(prev_bh, inode);
			affs_brelse(prev_bh);
		}
		size += bsize;
		bidx++;
	}
	affs_brelse(bh);
	inode->i_size = AFFS_I(inode)->mmu_private = newsize;
	return 0;

out:
	inode->i_size = AFFS_I(inode)->mmu_private = newsize;
	return PTR_ERR(bh);
}

static int
affs_readpage_ofs(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	u32 to;
	int err;

617
	pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
L
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618 619 620 621 622 623
	to = PAGE_CACHE_SIZE;
	if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
		to = inode->i_size & ~PAGE_CACHE_MASK;
		memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
	}

624
	err = affs_do_readpage_ofs(page, to);
L
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	if (!err)
		SetPageUptodate(page);
	unlock_page(page);
	return err;
}

N
Nick Piggin 已提交
631 632 633
static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
				loff_t pos, unsigned len, unsigned flags,
				struct page **pagep, void **fsdata)
L
Linus Torvalds 已提交
634
{
N
Nick Piggin 已提交
635 636 637
	struct inode *inode = mapping->host;
	struct page *page;
	pgoff_t index;
L
Linus Torvalds 已提交
638 639
	int err = 0;

640 641
	pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
		 pos + len);
N
Nick Piggin 已提交
642 643 644 645 646
	if (pos > AFFS_I(inode)->mmu_private) {
		/* XXX: this probably leaves a too-big i_size in case of
		 * failure. Should really be updating i_size at write_end time
		 */
		err = affs_extent_file_ofs(inode, pos);
L
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		if (err)
			return err;
	}
N
Nick Piggin 已提交
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	index = pos >> PAGE_CACHE_SHIFT;
652
	page = grab_cache_page_write_begin(mapping, index, flags);
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Nick Piggin 已提交
653 654 655
	if (!page)
		return -ENOMEM;
	*pagep = page;
L
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656 657 658 659

	if (PageUptodate(page))
		return 0;

N
Nick Piggin 已提交
660
	/* XXX: inefficient but safe in the face of short writes */
661
	err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
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Nick Piggin 已提交
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	if (err) {
		unlock_page(page);
		page_cache_release(page);
L
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	}
	return err;
}

N
Nick Piggin 已提交
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static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
				loff_t pos, unsigned len, unsigned copied,
				struct page *page, void *fsdata)
L
Linus Torvalds 已提交
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{
N
Nick Piggin 已提交
673
	struct inode *inode = mapping->host;
L
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674 675 676 677
	struct super_block *sb = inode->i_sb;
	struct buffer_head *bh, *prev_bh;
	char *data;
	u32 bidx, boff, bsize;
N
Nick Piggin 已提交
678
	unsigned from, to;
L
Linus Torvalds 已提交
679 680 681
	u32 tmp;
	int written;

N
Nick Piggin 已提交
682 683 684 685 686 687 688 689
	from = pos & (PAGE_CACHE_SIZE - 1);
	to = pos + len;
	/*
	 * XXX: not sure if this can handle short copies (len < copied), but
	 * we don't have to, because the page should always be uptodate here,
	 * due to write_begin.
	 */

690 691
	pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
		 pos + len);
L
Linus Torvalds 已提交
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	bsize = AFFS_SB(sb)->s_data_blksize;
	data = page_address(page);

	bh = NULL;
	written = 0;
	tmp = (page->index << PAGE_CACHE_SHIFT) + from;
	bidx = tmp / bsize;
	boff = tmp % bsize;
	if (boff) {
		bh = affs_bread_ino(inode, bidx, 0);
702 703 704 705
		if (IS_ERR(bh)) {
			written = PTR_ERR(bh);
			goto err_first_bh;
		}
L
Linus Torvalds 已提交
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		tmp = min(bsize - boff, to - from);
J
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707
		BUG_ON(boff + tmp > bsize || tmp > bsize);
L
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		memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
M
Marcin Slusarz 已提交
709
		be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
L
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		affs_fix_checksum(sb, bh);
		mark_buffer_dirty_inode(bh, inode);
		written += tmp;
		from += tmp;
		bidx++;
	} else if (bidx) {
		bh = affs_bread_ino(inode, bidx - 1, 0);
717 718 719 720
		if (IS_ERR(bh)) {
			written = PTR_ERR(bh);
			goto err_first_bh;
		}
L
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721 722 723 724 725
	}
	while (from + bsize <= to) {
		prev_bh = bh;
		bh = affs_getemptyblk_ino(inode, bidx);
		if (IS_ERR(bh))
726
			goto err_bh;
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		memcpy(AFFS_DATA(bh), data + from, bsize);
		if (buffer_new(bh)) {
			AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
			AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
			AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
			AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
			AFFS_DATA_HEAD(bh)->next = 0;
			bh->b_state &= ~(1UL << BH_New);
			if (prev_bh) {
736 737 738 739 740 741
				u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);

				if (tmp_next)
					affs_warning(sb, "commit_write_ofs",
						     "next block already set for %d (%d)",
						     bidx, tmp_next);
L
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742
				AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
743
				affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
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				mark_buffer_dirty_inode(prev_bh, inode);
			}
		}
		affs_brelse(prev_bh);
		affs_fix_checksum(sb, bh);
		mark_buffer_dirty_inode(bh, inode);
		written += bsize;
		from += bsize;
		bidx++;
	}
	if (from < to) {
		prev_bh = bh;
		bh = affs_bread_ino(inode, bidx, 1);
		if (IS_ERR(bh))
758
			goto err_bh;
L
Linus Torvalds 已提交
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		tmp = min(bsize, to - from);
J
Julia Lawall 已提交
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		BUG_ON(tmp > bsize);
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		memcpy(AFFS_DATA(bh), data + from, tmp);
		if (buffer_new(bh)) {
			AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
			AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
			AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
			AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
			AFFS_DATA_HEAD(bh)->next = 0;
			bh->b_state &= ~(1UL << BH_New);
			if (prev_bh) {
770 771 772 773 774 775
				u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);

				if (tmp_next)
					affs_warning(sb, "commit_write_ofs",
						     "next block already set for %d (%d)",
						     bidx, tmp_next);
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				AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
777
				affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
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				mark_buffer_dirty_inode(prev_bh, inode);
			}
		} else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
			AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
		affs_brelse(prev_bh);
		affs_fix_checksum(sb, bh);
		mark_buffer_dirty_inode(bh, inode);
		written += tmp;
		from += tmp;
		bidx++;
	}
	SetPageUptodate(page);

done:
	affs_brelse(bh);
	tmp = (page->index << PAGE_CACHE_SHIFT) + from;
	if (tmp > inode->i_size)
		inode->i_size = AFFS_I(inode)->mmu_private = tmp;

797
err_first_bh:
N
Nick Piggin 已提交
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	unlock_page(page);
	page_cache_release(page);

L
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	return written;

803
err_bh:
L
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	bh = prev_bh;
	if (!written)
		written = PTR_ERR(bh);
	goto done;
}

810
const struct address_space_operations affs_aops_ofs = {
L
Linus Torvalds 已提交
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	.readpage = affs_readpage_ofs,
	//.writepage = affs_writepage_ofs,
N
Nick Piggin 已提交
813 814
	.write_begin = affs_write_begin_ofs,
	.write_end = affs_write_end_ofs
L
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};

/* Free any preallocated blocks. */

void
affs_free_prealloc(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;

F
Fabian Frederick 已提交
824
	pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
L
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	while (AFFS_I(inode)->i_pa_cnt) {
		AFFS_I(inode)->i_pa_cnt--;
		affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
	}
}

/* Truncate (or enlarge) a file to the requested size. */

void
affs_truncate(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	u32 ext, ext_key;
	u32 last_blk, blkcnt, blk;
	u32 size;
	struct buffer_head *ext_bh;
	int i;

844 845
	pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
		 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
L
Linus Torvalds 已提交
846 847 848 849 850 851 852 853 854 855 856

	last_blk = 0;
	ext = 0;
	if (inode->i_size) {
		last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
		ext = last_blk / AFFS_SB(sb)->s_hashsize;
	}

	if (inode->i_size > AFFS_I(inode)->mmu_private) {
		struct address_space *mapping = inode->i_mapping;
		struct page *page;
N
Nick Piggin 已提交
857
		void *fsdata;
858
		loff_t isize = inode->i_size;
L
Linus Torvalds 已提交
859 860
		int res;

861
		res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
L
Linus Torvalds 已提交
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		if (!res)
863
			res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
864 865
		else
			inode->i_size = AFFS_I(inode)->mmu_private;
L
Linus Torvalds 已提交
866 867 868 869 870 871 872 873
		mark_inode_dirty(inode);
		return;
	} else if (inode->i_size == AFFS_I(inode)->mmu_private)
		return;

	// lock cache
	ext_bh = affs_get_extblock(inode, ext);
	if (IS_ERR(ext_bh)) {
874 875
		affs_warning(sb, "truncate",
			     "unexpected read error for ext block %u (%ld)",
876
			     ext, PTR_ERR(ext_bh));
L
Linus Torvalds 已提交
877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
		return;
	}
	if (AFFS_I(inode)->i_lc) {
		/* clear linear cache */
		i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
		if (AFFS_I(inode)->i_lc_size > i) {
			AFFS_I(inode)->i_lc_size = i;
			for (; i < AFFS_LC_SIZE; i++)
				AFFS_I(inode)->i_lc[i] = 0;
		}
		/* clear associative cache */
		for (i = 0; i < AFFS_AC_SIZE; i++)
			if (AFFS_I(inode)->i_ac[i].ext >= ext)
				AFFS_I(inode)->i_ac[i].ext = 0;
	}
	ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);

	blkcnt = AFFS_I(inode)->i_blkcnt;
	i = 0;
	blk = last_blk;
	if (inode->i_size) {
		i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
		blk++;
	} else
		AFFS_HEAD(ext_bh)->first_data = 0;
902
	AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
L
Linus Torvalds 已提交
903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920
	size = AFFS_SB(sb)->s_hashsize;
	if (size > blkcnt - blk + i)
		size = blkcnt - blk + i;
	for (; i < size; i++, blk++) {
		affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
		AFFS_BLOCK(sb, ext_bh, i) = 0;
	}
	AFFS_TAIL(sb, ext_bh)->extension = 0;
	affs_fix_checksum(sb, ext_bh);
	mark_buffer_dirty_inode(ext_bh, inode);
	affs_brelse(ext_bh);

	if (inode->i_size) {
		AFFS_I(inode)->i_blkcnt = last_blk + 1;
		AFFS_I(inode)->i_extcnt = ext + 1;
		if (AFFS_SB(sb)->s_flags & SF_OFS) {
			struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
			u32 tmp;
D
Dan Carpenter 已提交
921
			if (IS_ERR(bh)) {
922 923
				affs_warning(sb, "truncate",
					     "unexpected read error for last block %u (%ld)",
924
					     ext, PTR_ERR(bh));
L
Linus Torvalds 已提交
925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951
				return;
			}
			tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
			AFFS_DATA_HEAD(bh)->next = 0;
			affs_adjust_checksum(bh, -tmp);
			affs_brelse(bh);
		}
	} else {
		AFFS_I(inode)->i_blkcnt = 0;
		AFFS_I(inode)->i_extcnt = 1;
	}
	AFFS_I(inode)->mmu_private = inode->i_size;
	// unlock cache

	while (ext_key) {
		ext_bh = affs_bread(sb, ext_key);
		size = AFFS_SB(sb)->s_hashsize;
		if (size > blkcnt - blk)
			size = blkcnt - blk;
		for (i = 0; i < size; i++, blk++)
			affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
		affs_free_block(sb, ext_key);
		ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
		affs_brelse(ext_bh);
	}
	affs_free_prealloc(inode);
}
A
Al Viro 已提交
952

953
int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
A
Al Viro 已提交
954
{
955
	struct inode *inode = filp->f_mapping->host;
A
Al Viro 已提交
956 957
	int ret, err;

958 959 960 961 962
	err = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (err)
		return err;

	mutex_lock(&inode->i_mutex);
A
Al Viro 已提交
963 964 965 966
	ret = write_inode_now(inode, 0);
	err = sync_blockdev(inode->i_sb->s_bdev);
	if (!ret)
		ret = err;
967
	mutex_unlock(&inode->i_mutex);
A
Al Viro 已提交
968 969
	return ret;
}
970 971 972 973 974 975 976 977 978 979 980 981 982 983
const struct file_operations affs_file_operations = {
	.llseek		= generic_file_llseek,
	.read_iter	= generic_file_read_iter,
	.write_iter	= generic_file_write_iter,
	.mmap		= generic_file_mmap,
	.open		= affs_file_open,
	.release	= affs_file_release,
	.fsync		= affs_file_fsync,
	.splice_read	= generic_file_splice_read,
};

const struct inode_operations affs_file_inode_operations = {
	.setattr	= affs_notify_change,
};