Btrfs: Optimizations for the extent_buffer code (479965d6) · Commits · github.com / kvm-riscv / linux

fs/btrfs/ctree.c

+24 −27

Original line number	Diff line number	Diff line
		@@ -464,22 +464,12 @@ static int check_block(struct btrfs_root root, struct btrfs_path path,
		int level)
		{
		struct extent_buffer *buf = path->nodes[level];
		char fsid[BTRFS_FSID_SIZE];

		read_extent_buffer(buf, fsid, (unsigned long)btrfs_header_fsid(buf),
		BTRFS_FSID_SIZE);

		if (memcmp(fsid, root->fs_info->fsid, BTRFS_FSID_SIZE)) {
		int i = 0;
		if (memcmp_extent_buffer(buf, root->fs_info->fsid,
		(unsigned long)btrfs_header_fsid(buf),
		BTRFS_FSID_SIZE)) {
		printk("warning bad block %Lu\n", buf->start);
		if (!btrfs_buffer_uptodate(buf)) {
		WARN_ON(1);
		}
		for (i = 0; i < BTRFS_FSID_SIZE; i++) {
		printk("%x:%x ", root->fs_info->fsid[i], fsid[i]);
		}
		printk("\n");
		// BUG();
		BUG();
		}
		if (level == 0)
		return check_leaf(root, path, level);
		@@ -504,13 +494,14 @@ static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
		int high = max;
		int mid;
		int ret;
		struct btrfs_disk_key *tmp;
		struct btrfs_disk_key *tmp = NULL;
		struct btrfs_disk_key unaligned;
		unsigned long offset;
		char *map_token = NULL;
		char *kaddr = NULL;
		unsigned long map_start = 0;
		unsigned long map_len = 0;
		int err;

		while(low < high) {
		mid = (low + high) / 2;
		@@ -519,19 +510,24 @@ static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
		if (!map_token \|\| offset < map_start \|\|
		(offset + sizeof(struct btrfs_disk_key)) >
		map_start + map_len) {
		if (map_token)
		if (map_token) {
		unmap_extent_buffer(eb, map_token, KM_USER0);
		map_extent_buffer(eb, offset, &map_token, &kaddr,
		map_token = NULL;
		}
		err = map_extent_buffer(eb, offset,
		sizeof(struct btrfs_disk_key),
		&map_token, &kaddr,
		&map_start, &map_len, KM_USER0);

		}
		if (offset + sizeof(struct btrfs_disk_key) >
		map_start + map_len) {
		unmap_extent_buffer(eb, map_token, KM_USER0);
		if (!err) {
		tmp = (struct btrfs_disk_key *)(kaddr + offset -
		map_start);
		} else {
		read_extent_buffer(eb, &unaligned,
		offset, sizeof(unaligned));
		map_token = NULL;
		tmp = &unaligned;
		}

		} else {
		tmp = (struct btrfs_disk_key *)(kaddr + offset -
		map_start);
		@@ -544,6 +540,7 @@ static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
		high = mid;
		else {
		*slot = mid;
		if (map_token)
		unmap_extent_buffer(eb, map_token, KM_USER0);
		return 0;
		}

fs/btrfs/ctree.h

+43 −5

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@
		#include <linux/fs.h>
		#include <linux/workqueue.h>
		#include <linux/completion.h>
		#include <asm/kmap_types.h>
		#include "bit-radix.h"
		#include "extent_map.h"

		@@ -431,15 +432,52 @@ struct btrfs_root {
		static inline u##bits btrfs_##name(struct extent_buffer *eb, \
		type *s) \
		{ \
		int err; \
		char *map_token; \
		char *kaddr; \
		unsigned long map_start; \
		unsigned long map_len; \
		unsigned long offset = (unsigned long)s + \
		offsetof(type, member); \
		err = map_extent_buffer(eb, offset, \
		sizeof(((type *)0)->member), \
		&map_token, &kaddr, \
		&map_start, &map_len, KM_USER0); \
		if (!err) { \
		__le##bits tmp = (__le##bits )(kaddr + offset - \
		map_start); \
		u##bits res = le##bits##_to_cpu(*tmp); \
		unmap_extent_buffer(eb, map_token, KM_USER0); \
		return res; \
		} else { \
		__le##bits res; \
		read_eb_member(eb, s, type, member, &res); \
		return le##bits##_to_cpu(res); \
		} \
		} \
		static inline void btrfs_set_##name(struct extent_buffer *eb, \
		type *s, u##bits val) \
		{ \
		int err; \
		char *map_token; \
		char *kaddr; \
		unsigned long map_start; \
		unsigned long map_len; \
		unsigned long offset = (unsigned long)s + \
		offsetof(type, member); \
		err = map_extent_buffer(eb, offset, \
		sizeof(((type *)0)->member), \
		&map_token, &kaddr, \
		&map_start, &map_len, KM_USER0); \
		if (!err) { \
		__le##bits tmp = (__le##bits )(kaddr + offset - \
		map_start); \
		*tmp = cpu_to_le##bits(val); \
		unmap_extent_buffer(eb, map_token, KM_USER0); \
		} else { \
		val = cpu_to_le##bits(val); \
		write_eb_member(eb, s, type, member, &val); \
		} \
		}

		#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits) \

fs/btrfs/extent_map.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -2140,14 +2140,20 @@ void read_extent_buffer(struct extent_buffer eb, void dstv,
		EXPORT_SYMBOL(read_extent_buffer);

		int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
		unsigned long min_len,
		char token, char map,
		unsigned long *map_start,
		unsigned long *map_len, int km)
		{
		size_t offset;
		size_t offset = start & (PAGE_CACHE_SIZE - 1);
		char *kaddr;
		size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
		unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
		unsigned long end_i = (start_offset + start + min_len) >>
		PAGE_CACHE_SHIFT;

		if (i != end_i)
		return -EINVAL;

		WARN_ON(start > eb->len);

		@@ -2155,8 +2161,7 @@ int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
		offset = start_offset;
		*map_start = 0;
		} else {
		offset = 0;
		*map_start = (i << PAGE_CACHE_SHIFT) - offset;
		*map_start = (i << PAGE_CACHE_SHIFT) - start_offset;
		}

		// kaddr = kmap_atomic(eb->pages[i], km);

fs/btrfs/extent_map.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -173,7 +173,7 @@ int set_extent_buffer_uptodate(struct extent_map_tree *tree,
		int extent_buffer_uptodate(struct extent_map_tree *tree,
		struct extent_buffer *eb);
		int map_extent_buffer(struct extent_buffer *eb, unsigned long offset,
		char token, char map,
		unsigned long min_len, char token, char map,
		unsigned long *map_start,
		unsigned long *map_len, int km);
		void unmap_extent_buffer(struct extent_buffer eb, char token, int km);