Commit 810191ff authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: extent_map optimizations to cut down on CPU usage 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 3326d1b0

fs/btrfs/ctree.c

+1 −0
Original line number Diff line number Diff line
@@ -463,6 +463,7 @@ static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, 
static int check_block(struct btrfs_root *root, struct btrfs_path *path,

			int level)

{

	return 0;

#if 0

	struct extent_buffer *buf = path->nodes[level];

fs/btrfs/ctree.h

+14 −60
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 
#ifndef __BTRFS__

#define __BTRFS__



#include <linux/mm.h>

#include <linux/highmem.h>

#include <linux/fs.h>

#include <linux/workqueue.h>

#include <linux/completion.h>
@@ -499,70 +501,22 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ 
#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)		\

static inline u##bits btrfs_##name(struct extent_buffer *eb)		\

{									\

	int err;							\

	char *map_token;						\

	char *kaddr;							\

	unsigned long map_start;					\

	unsigned long map_len;						\

	char *kaddr = kmap_atomic(eb->first_page, KM_USER0);		\

	unsigned long offset = offsetof(type, member);			\

	int unmap_on_exit = (eb->map_token == NULL);			\

	if (eb->map_token && offset >= eb->map_start &&			\

	    offset + sizeof(((type *)0)->member) <= eb->map_start +	\

	    eb->map_len) {						\

	    kaddr = eb->kaddr;						\

	    map_start = eb->map_start;					\

	    err = 0;							\

	} else {							\

		err = map_extent_buffer(eb, offset,			\

			        sizeof(((type *)0)->member),		\

				&map_token, &kaddr,			\

				&map_start, &map_len, KM_USER1);	\

	}								\

	if (!err) {							\

		__le##bits *tmp = (__le##bits *)(kaddr + offset -	\

					       map_start);		\

		u##bits res = le##bits##_to_cpu(*tmp);			\

		if (unmap_on_exit)					\

			unmap_extent_buffer(eb, map_token, KM_USER1);	\

	u##bits res;							\

	__le##bits *tmp = (__le##bits *)(kaddr + offset);		\

	res = le##bits##_to_cpu(*tmp);					\

	kunmap_atomic(kaddr, KM_USER0);					\

	return res;							\

	} else {							\

		__le##bits res;						\

		read_eb_member(eb, NULL, type, member, &res);		\

		return le##bits##_to_cpu(res);				\

	}								\

}									\

static inline void btrfs_set_##name(struct extent_buffer *eb,		\

				    u##bits val)			\

{									\

	int err;							\

	char *map_token;						\

	char *kaddr;							\

	unsigned long map_start;					\

	unsigned long map_len;						\

	char *kaddr = kmap_atomic(eb->first_page, KM_USER0);		\

	unsigned long offset = offsetof(type, member);			\

	int unmap_on_exit = (eb->map_token == NULL);			\

	if (eb->map_token && offset >= eb->map_start &&			\

	    offset + sizeof(((type *)0)->member) <= eb->map_start +	\

	    eb->map_len) {						\

	    kaddr = eb->kaddr;						\

	    map_start = eb->map_start;					\

	    err = 0;							\

	} else {							\

		err = map_extent_buffer(eb, offset,			\

			        sizeof(((type *)0)->member),		\

				&map_token, &kaddr,			\

				&map_start, &map_len, KM_USER1);	\

	}								\

	if (!err) {							\

		__le##bits *tmp = (__le##bits *)(kaddr + offset -	\

					       map_start);		\

	__le##bits *tmp = (__le##bits *)(kaddr + offset);		\

	*tmp = cpu_to_le##bits(val);					\

		if (unmap_on_exit)					\

			unmap_extent_buffer(eb, map_token, KM_USER1);	\

	} else {							\

		val = cpu_to_le##bits(val);				\

		write_eb_member(eb, NULL, type, member, &val);		\

	}								\

	kunmap_atomic(kaddr, KM_USER0);					\

}



#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)		\
@@ -659,13 +613,13 @@ static inline void btrfs_set_node_blockptr(struct extent_buffer *eb, 
	btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);

}



static unsigned long btrfs_node_key_ptr_offset(int nr)

static inline unsigned long btrfs_node_key_ptr_offset(int nr)

{

	return offsetof(struct btrfs_node, ptrs) +

		sizeof(struct btrfs_key_ptr) * nr;

}



static void btrfs_node_key(struct extent_buffer *eb,

static inline void btrfs_node_key(struct extent_buffer *eb,

			   struct btrfs_disk_key *disk_key, int nr)

{

	unsigned long ptr;

fs/btrfs/disk-io.c

+10 −10
Original line number Diff line number Diff line
@@ -644,20 +644,20 @@ int close_ctree(struct btrfs_root *root) 


int btrfs_buffer_uptodate(struct extent_buffer *buf)

{

	struct inode *btree_inode = buf->last_page->mapping->host;

	struct inode *btree_inode = buf->first_page->mapping->host;

	return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);

}



int btrfs_set_buffer_uptodate(struct extent_buffer *buf)

{

	struct inode *btree_inode = buf->last_page->mapping->host;

	struct inode *btree_inode = buf->first_page->mapping->host;

	return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,

					  buf);

}



void btrfs_mark_buffer_dirty(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	u64 transid = btrfs_header_generation(buf);

	struct inode *btree_inode = root->fs_info->btree_inode;
@@ -678,7 +678,7 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr) 


void btrfs_set_buffer_defrag(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	struct inode *btree_inode = root->fs_info->btree_inode;

	set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,

			buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
@@ -686,7 +686,7 @@ void btrfs_set_buffer_defrag(struct extent_buffer *buf) 


void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	struct inode *btree_inode = root->fs_info->btree_inode;

	set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,

			buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
@@ -695,7 +695,7 @@ void btrfs_set_buffer_defrag_done(struct extent_buffer *buf) 


int btrfs_buffer_defrag(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	struct inode *btree_inode = root->fs_info->btree_inode;

	return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,

		     buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
@@ -703,7 +703,7 @@ int btrfs_buffer_defrag(struct extent_buffer *buf) 


int btrfs_buffer_defrag_done(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	struct inode *btree_inode = root->fs_info->btree_inode;

	return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,

		     buf->start, buf->start + buf->len - 1,
@@ -712,7 +712,7 @@ int btrfs_buffer_defrag_done(struct extent_buffer *buf) 


int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	struct inode *btree_inode = root->fs_info->btree_inode;

	return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,

		     buf->start, buf->start + buf->len - 1,
@@ -721,7 +721,7 @@ int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf) 


int btrfs_clear_buffer_defrag(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	struct inode *btree_inode = root->fs_info->btree_inode;

	return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,

		     buf->start, buf->start + buf->len - 1,
@@ -730,7 +730,7 @@ int btrfs_clear_buffer_defrag(struct extent_buffer *buf) 


int btrfs_read_buffer(struct extent_buffer *buf)

{

	struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;

	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;

	struct inode *btree_inode = root->fs_info->btree_inode;

	return read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,

					buf, 1);

fs/btrfs/extent_map.c

+14 −19
Original line number Diff line number Diff line
@@ -1963,9 +1963,9 @@ static inline struct page *extent_buffer_page(struct extent_buffer *eb, 
	struct page *p;



	if (i == 0)

		return eb->last_page;

		return eb->first_page;

	i += eb->start >> PAGE_CACHE_SHIFT;

	p = find_get_page(eb->last_page->mapping, i);

	p = find_get_page(eb->first_page->mapping, i);

	page_cache_release(p);

	return p;

}
@@ -2037,7 +2037,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree, 
		}

		set_page_extent_mapped(p);

		if (i == 0)

			eb->last_page = p;

			eb->first_page = p;

		if (!PageUptodate(p))

			uptodate = 0;

		unlock_page(p);
@@ -2083,7 +2083,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree, 
		}

		set_page_extent_mapped(p);

		if (i == 0)

			eb->last_page = p;

			eb->first_page = p;

		if (!PageUptodate(p))

			uptodate = 0;

		unlock_page(p);
@@ -2169,7 +2169,15 @@ EXPORT_SYMBOL(wait_on_extent_buffer_writeback); 
int set_extent_buffer_dirty(struct extent_map_tree *tree,

			     struct extent_buffer *eb)

{

	return set_range_dirty(tree, eb->start, eb->start + eb->len - 1);

	unsigned long i;

	unsigned long num_pages;



	num_pages = num_extent_pages(eb->start, eb->len);

	for (i = 0; i < num_pages; i++) {

		__set_page_dirty_nobuffers(extent_buffer_page(eb, i));

	}

	return set_extent_dirty(tree, eb->start,

				eb->start + eb->len - 1, GFP_NOFS);

}

EXPORT_SYMBOL(set_extent_buffer_dirty);
@@ -2322,11 +2330,6 @@ static int __map_extent_buffer(struct extent_buffer *eb, unsigned long start, 
	if (i != end_i)

		return -EINVAL;



	if (start >= eb->len) {

		printk("bad start in map eb start %Lu len %lu caller start %lu min %lu\n", eb->start, eb->len, start, min_len);

		WARN_ON(1);

	}



	if (i == 0) {

		offset = start_offset;

		*map_start = 0;
@@ -2353,14 +2356,6 @@ int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 
	int err;

	int save = 0;

	if (eb->map_token) {

		if (start >= eb->map_start &&

		    start + min_len <= eb->map_start + eb->map_len) {

			*token = eb->map_token;

			*map = eb->kaddr;

			*map_start = eb->map_start;

			*map_len = eb->map_len;

			return 0;

		}

		unmap_extent_buffer(eb, eb->map_token, km);

		eb->map_token = NULL;

		save = 1;

fs/btrfs/extent_map.h

+1 −1
Original line number Diff line number Diff line
@@ -75,7 +75,7 @@ struct extent_buffer { 
	char *kaddr;

	unsigned long map_start;

	unsigned long map_len;

	struct page *last_page;

	struct page *first_page;

	struct list_head lru;

	atomic_t refs;

	int flags;