Release 4.10 fs/affs/file.c

/*
 *  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
 */

#include <linux/uio.h>
#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)
{
	pr_debug("open(%lu,%d)\n",
		 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
	atomic_inc(&AFFS_I(inode)->i_opencnt);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
28
56.00%
2
33.33%
roman zippel
roman zippel
12
24.00%
1
16.67%
pre-git
pre-git
9
18.00%
2
33.33%
fabian frederick
fabian frederick
1
2.00%
1
16.67%
Total
50
100.00%
6
100.00%


static int

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

	if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
		inode_lock(inode);
		if (inode->i_size != AFFS_I(inode)->mmu_private)
			affs_truncate(inode);
		affs_free_prealloc(inode);
		inode_unlock(inode);
	}

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
43
49.43%
2
25.00%
roman zippel
roman zippel
34
39.08%
1
12.50%
pre-git
pre-git
7
8.05%
3
37.50%
al viro
al viro
2
2.30%
1
12.50%
fabian frederick
fabian frederick
1
1.15%
1
12.50%
Total
87
100.00%
8
100.00%


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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
364
81.98%
3
50.00%
pre-git
pre-git
80
18.02%
3
50.00%
Total
444
100.00%
6
100.00%


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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
145
61.44%
3
37.50%
pre-git
pre-git
91
38.56%
5
62.50%
Total
236
100.00%
8
100.00%


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)
		get_bh(bh);
	else
		/* we have to do more (not inlined) */
		bh = affs_get_extblock_slow(inode, ext);

	return bh;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
47
78.33%
2
40.00%
pre-git
pre-git
12
20.00%
2
40.00%
roman zippel
roman zippel
1
1.67%
1
20.00%
Total
60
100.00%
5
100.00%


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;
		BUG_ON(ext > AFFS_I(inode)->i_extcnt);
		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 */
		BUG_ON(ext > AFFS_I(inode)->i_extcnt);

		/* 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;
	get_bh(bh);

	return bh;

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

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
484
79.87%
2
22.22%
pre-git
pre-git
115
18.98%
5
55.56%
fabian frederick
fabian frederick
6
0.99%
1
11.11%
roman zippel
roman zippel
1
0.17%
1
11.11%
Total
606
100.00%
9
100.00%


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;

	pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
		 (unsigned long long)block);

	BUG_ON(block > (sector_t)0x7fffffffUL);

	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)
			affs_warning(sb, "get_block",
				     "block already set (%llx)",
				     (unsigned long long)bh_result->b_blocknr);
		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:
	affs_error(inode->i_sb, "get_block", "strange block request %llu",
		   (unsigned long long)block);
	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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
367
84.17%
6
40.00%
andrew morton
andrew morton
22
5.05%
2
13.33%
pre-git
pre-git
19
4.36%
2
13.33%
brian gerst
brian gerst
9
2.06%
1
6.67%
geert uytterhoeven
geert uytterhoeven
8
1.83%
1
6.67%
fabian frederick
fabian frederick
8
1.83%
2
13.33%
julia lawall
julia lawall
3
0.69%
1
6.67%
Total
436
100.00%
15
100.00%



static int affs_writepage(struct page *page, struct writeback_control *wbc)
{
	return block_write_full_page(page, affs_get_block, wbc);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
19
73.08%
1
50.00%
andrew morton
andrew morton
7
26.92%
1
50.00%
Total
26
100.00%
2
100.00%



static int affs_readpage(struct file *file, struct page *page)
{
	return block_read_full_page(page, affs_get_block);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
24
100.00%
1
100.00%
Total
24
100.00%
1
100.00%



static void affs_write_failed(struct address_space *mapping, loff_t to)
{
	struct inode *inode = mapping->host;

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

Contributors
Person
Tokens
Prop
Commits
CommitProp
marco stornelli
marco stornelli
47
100.00%
1
100.00%
Total
47
100.00%
1
100.00%


static ssize_t

affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
	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);
	loff_t offset = iocb->ki_pos;
	ssize_t ret;

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

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

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

Contributors
Person
Tokens
Prop
Commits
CommitProp
fabian frederick
fabian frederick
115
87.79%
2
50.00%
omar sandoval
omar sandoval
9
6.87%
1
25.00%
christoph hellwig
christoph hellwig
7
5.34%
1
25.00%
Total
131
100.00%
4
100.00%



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

	*pagep = NULL;
	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
				affs_get_block,
				&AFFS_I(mapping->host)->mmu_private);
	if (unlikely(ret))
		affs_write_failed(mapping, pos + len);

	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
nick piggin
nick piggin
36
38.30%
1
20.00%
linus torvalds
linus torvalds
34
36.17%
2
40.00%
christoph hellwig
christoph hellwig
21
22.34%
1
20.00%
marco stornelli
marco stornelli
3
3.19%
1
20.00%
Total
94
100.00%
5
100.00%



static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping,block,affs_get_block);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
22
91.67%
1
50.00%
andrew morton
andrew morton
2
8.33%
1
50.00%
Total
24
100.00%
2
100.00%


const struct address_space_operations affs_aops = {
	.readpage = affs_readpage,
	.writepage = affs_writepage,
	.write_begin = affs_write_begin,
	.write_end = generic_write_end,
	.direct_IO = affs_direct_IO,
	.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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
98
100.00%
1
100.00%
Total
98
100.00%
1
100.00%


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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
95
100.00%
1
100.00%
Total
95
100.00%
1
100.00%


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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
95
100.00%
1
100.00%
Total
95
100.00%
1
100.00%


static int

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

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

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

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
164
74.21%
2
18.18%
roman zippel
roman zippel
16
7.24%
1
9.09%
al viro
al viro
12
5.43%
1
9.09%
fabian frederick
fabian frederick
12
5.43%
2
18.18%
julia lawall
julia lawall
6
2.71%
1
9.09%
andrew morton
andrew morton
5
2.26%
1
9.09%
brian gerst
brian gerst
3
1.36%
1
9.09%
kirill a. shutemov
kirill a. shutemov
2
0.90%
1
9.09%
geert uytterhoeven
geert uytterhoeven
1
0.45%
1
9.09%
Total
221
100.00%
11
100.00%


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;

	pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
	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);
		BUG_ON(boff + tmp > bsize || tmp > bsize);
		memset(AFFS_DATA(bh) + boff, 0, tmp);
		be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
		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);
		BUG_ON(tmp > bsize);
		AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
		AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino