btrfs: add wrapper for counting BTRFS_MAX_EXTENT_SIZE

The expression is open-coded in several places, this asks for a wrapper. As we know the MAX_EXTENT fits to u32, we can use the appropirate division helper. This cascades to the result type updates. Compiler is clever enough to use shift instead of integer division, so there's no change in the generated assembly.

David Sterba committed 9 years ago

Commit 823bb201 parent 95995db3 files · +23 −31Browse files

Unified · Split

3 files

fs/btrfs/ctree.h +8 −0
fs/btrfs/extent-tree.c +4 −8
fs/btrfs/inode.c +11 −23

fs/btrfs/ctree.h+8−0

@@ -97,6 +97,14 @@ static const int btrfs_csum_sizes[] = { 4 }; · 96 unmodified lines
97	97
98	98	#define BTRFS_MAX_EXTENT_SIZE SZ_128M
99	99
	100	+/*
	101	+ * Count how many BTRFS_MAX_EXTENT_SIZE cover the @size
	102	+ */
	103	+static inline u32 count_max_extents(u64 size)
	104	+{
	105	+ return div_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE);
	106	+}
	107	+
100	108	struct btrfs_mapping_tree {
101	109	struct extent_map_tree map_tree;
102	110	};

fs/btrfs/extent-tree.c+4−8

@@ -5844,11 +5844,9 @@ static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes) · 5843 unmodified lines
5844	5844	{
5845	5845	unsigned drop_inode_space = 0;
5846	5846	unsigned dropped_extents = 0;
5847		− unsigned num_extents = 0;
	5847	+ unsigned num_extents;
5848	5848
5849		− num_extents = (unsigned)div64_u64(num_bytes +
5850		− BTRFS_MAX_EXTENT_SIZE - 1,
5851		− BTRFS_MAX_EXTENT_SIZE);
	5849	+ num_extents = count_max_extents(num_bytes);
5852	5850	ASSERT(num_extents);
5853	5851	ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents);
5854	5852	BTRFS_I(inode)->outstanding_extents -= num_extents;
@@ -5927,7 +5925,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) · 72 unmodified lines
5927	5925	struct btrfs_block_rsv *block_rsv = &fs_info->delalloc_block_rsv;
5928	5926	u64 to_reserve = 0;
5929	5927	u64 csum_bytes;
5930		− unsigned nr_extents = 0;
	5928	+ unsigned nr_extents;
5931	5929	enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
5932	5930	int ret = 0;
5933	5931	bool delalloc_lock = true;
@@ -5960,9 +5958,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) · 26 unmodified lines
5960	5958	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
5961	5959
5962	5960	spin_lock(&BTRFS_I(inode)->lock);
5963		− nr_extents = (unsigned)div64_u64(num_bytes +
5964		− BTRFS_MAX_EXTENT_SIZE - 1,
5965		− BTRFS_MAX_EXTENT_SIZE);
	5961	+ nr_extents = count_max_extents(num_bytes);
5966	5962	BTRFS_I(inode)->outstanding_extents += nr_extents;
5967	5963
5968	5964	nr_extents = 0;

fs/btrfs/inode.c+11−23

@@ -1605,7 +1605,7 @@ static void btrfs_split_extent_hook(struct inode *inode, · 1604 unmodified lines
1605	1605
1606	1606	size = orig->end - orig->start + 1;
1607	1607	if (size > BTRFS_MAX_EXTENT_SIZE) {
1608		− u64 num_extents;
	1608	+ u32 num_extents;
1609	1609	u64 new_size;
1610	1610
1611	1611	/*
@@ -1613,13 +1613,10 @@ static void btrfs_split_extent_hook(struct inode *inode, · 1 unmodified line
1613	1613	* applies here, just in reverse.
1614	1614	*/
1615	1615	new_size = orig->end - split + 1;
1616		− num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1617		− BTRFS_MAX_EXTENT_SIZE);
	1616	+ num_extents = count_max_extents(new_size);
1618	1617	new_size = split - orig->start;
1619		− num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1620		− BTRFS_MAX_EXTENT_SIZE);
1621		− if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1622		− BTRFS_MAX_EXTENT_SIZE) >= num_extents)
	1618	+ num_extents += count_max_extents(new_size);
	1619	+ if (count_max_extents(size) >= num_extents)
1623	1620	return;
1624	1621	}
1625	1622
@@ -1639,7 +1636,7 @@ static void btrfs_merge_extent_hook(struct inode *inode, · 13 unmodified lines
1639	1636	struct extent_state *other)
1640	1637	{
1641	1638	u64 new_size, old_size;
1642		− u64 num_extents;
	1639	+ u32 num_extents;
1643	1640
1644	1641	/* not delalloc, ignore it */
1645	1642	if (!(other->state & EXTENT_DELALLOC))
@@ -1677,14 +1674,10 @@ static void btrfs_merge_extent_hook(struct inode *inode, · 31 unmodified lines
1677	1674	* this case.
1678	1675	*/
1679	1676	old_size = other->end - other->start + 1;
1680		− num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1681		− BTRFS_MAX_EXTENT_SIZE);
	1677	+ num_extents = count_max_extents(old_size);
1682	1678	old_size = new->end - new->start + 1;
1683		− num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1684		− BTRFS_MAX_EXTENT_SIZE);
1685		−
1686		− if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1687		− BTRFS_MAX_EXTENT_SIZE) >= num_extents)
	1679	+ num_extents += count_max_extents(old_size);
	1680	+ if (count_max_extents(new_size) >= num_extents)
1688	1681	return;
1689	1682
1690	1683	spin_lock(&BTRFS_I(inode)->lock);
@@ -1793,8 +1786,7 @@ static void btrfs_clear_bit_hook(struct inode *inode, · 102 unmodified lines
1793	1786	{
1794	1787	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1795	1788	u64 len = state->end + 1 - state->start;
1796		− u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1797		− BTRFS_MAX_EXTENT_SIZE);
	1789	+ u32 num_extents = count_max_extents(len);
1798	1790
1799	1791	spin_lock(&BTRFS_I(inode)->lock);
1800	1792	if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
@@ -7617,10 +7609,8 @@ static void adjust_dio_outstanding_extents(struct inode *inode, · 5816 unmodified lines
7617	7609	struct btrfs_dio_data *dio_data,
7618	7610	const u64 len)
7619	7611	{
7620		− unsigned num_extents;
	7612	+ unsigned num_extents = count_max_extents(len);
7621	7613
7622		− num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7623		− BTRFS_MAX_EXTENT_SIZE);
7624	7614	/*
7625	7615	* If we have an outstanding_extents count still set then we're
7626	7616	* within our reservation, otherwise we need to adjust our inode
@@ -8681,9 +8671,7 @@ static ssize_t btrfs_direct_IO(struct kiocb iocb, struct iov_iter iter) · 1054 unmodified lines
8681	8671	ret = btrfs_delalloc_reserve_space(inode, offset, count);
8682	8672	if (ret)
8683	8673	goto out;
8684		− dio_data.outstanding_extents = div64_u64(count +
8685		− BTRFS_MAX_EXTENT_SIZE - 1,
8686		− BTRFS_MAX_EXTENT_SIZE);
	8674	+ dio_data.outstanding_extents = count_max_extents(count);
8687	8675
8688	8676	/*
8689	8677	* We need to know how many extents we reserved so that we can

btrfs: add wrapper for counting BTRFS_MAX_EXTENT_SIZE

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