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Btrfs: Optimizations for the extent_buffer code
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Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Chris Mason committed Sep 25, 2008
1 parent 5f39d39 commit 479965d
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Showing 4 changed files with 76 additions and 36 deletions.
51 changes: 24 additions & 27 deletions fs/btrfs/ctree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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;
Expand All @@ -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_start, &map_len, KM_USER0);
map_token = NULL;
}
err = map_extent_buffer(eb, offset,
sizeof(struct btrfs_disk_key),
&map_token, &kaddr,
&map_start, &map_len, KM_USER0);

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

}
if (offset + sizeof(struct btrfs_disk_key) >
map_start + map_len) {
unmap_extent_buffer(eb, map_token, KM_USER0);
read_extent_buffer(eb, &unaligned,
offset, sizeof(unaligned));
map_token = NULL;
tmp = &unaligned;
} else {
tmp = (struct btrfs_disk_key *)(kaddr + offset -
map_start);
Expand All @@ -544,7 +540,8 @@ static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
high = mid;
else {
*slot = mid;
unmap_extent_buffer(eb, map_token, KM_USER0);
if (map_token)
unmap_extent_buffer(eb, map_token, KM_USER0);
return 0;
}
}
Expand Down
48 changes: 43 additions & 5 deletions fs/btrfs/ctree.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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"

Expand Down Expand Up @@ -431,15 +432,52 @@ struct btrfs_root {
static inline u##bits btrfs_##name(struct extent_buffer *eb, \
type *s) \
{ \
__le##bits res; \
read_eb_member(eb, s, type, member, &res); \
return le##bits##_to_cpu(res); \
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) \
{ \
val = cpu_to_le##bits(val); \
write_eb_member(eb, s, type, member, &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) \
Expand Down
11 changes: 8 additions & 3 deletions fs/btrfs/extent_map.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2140,23 +2140,28 @@ 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);

if (i == 0) {
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);
Expand Down
2 changes: 1 addition & 1 deletion fs/btrfs/extent_map.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down

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