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Btrfs: Avoid memcpy where possible in extent_buffers 

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-10-15 16:14:37 -04:00
parent 479965d66e
commit 6d36dcd48f
4 changed files with 147 additions and 41 deletions
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45
fs/btrfs/ctree.h
View File

@ -483,15 +483,50 @@ 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) \
{ \
__le##bits res; \
read_eb_member(eb, NULL, 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 = 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, NULL, type, member, &res); \
return le##bits##_to_cpu(res); \
} \
} \
static inline void btrfs_set_##name(struct extent_buffer *eb, \
u##bits val) \
{ \
val = cpu_to_le##bits(val); \
write_eb_member(eb, NULL, type, member, &val); \
int err; \
char *map_token; \
char *kaddr; \
unsigned long map_start; \
unsigned long map_len; \
unsigned long offset = 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, NULL, type, member, &val); \
} \
}
#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits) \

6
fs/btrfs/disk-io.c
View File

@ -609,20 +609,20 @@ int close_ctree(struct btrfs_root *root)
int btrfs_buffer_uptodate(struct extent_buffer *buf)
{
struct inode *btree_inode = buf->pages[0]->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->pages[0]->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->pages[0]->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;

132
fs/btrfs/extent_map.c
View File

@ -18,6 +18,11 @@ struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
static struct kmem_cache *extent_map_cache;
static struct kmem_cache *extent_state_cache;
static struct kmem_cache *extent_buffer_cache;
static LIST_HEAD(extent_buffers);
static spinlock_t extent_buffers_lock;
static int nr_extent_buffers;
#define MAX_EXTENT_BUFFER_CACHE 128
struct tree_entry {
u64 start;
@ -29,21 +34,33 @@ struct tree_entry {
void __init extent_map_init(void)
{
extent_map_cache = btrfs_cache_create("extent_map",
sizeof(struct extent_map),
SLAB_DESTROY_BY_RCU,
sizeof(struct extent_map), 0,
NULL);
extent_state_cache = btrfs_cache_create("extent_state",
sizeof(struct extent_state),
SLAB_DESTROY_BY_RCU,
sizeof(struct extent_state), 0,
NULL);
extent_buffer_cache = btrfs_cache_create("extent_buffers",
sizeof(struct extent_buffer), 0,
NULL);
spin_lock_init(&extent_buffers_lock);
}
void __exit extent_map_exit(void)
{
struct extent_buffer *eb;
while (!list_empty(&extent_buffers)) {
eb = list_entry(extent_buffers.next,
struct extent_buffer, list);
list_del(&eb->list);
kmem_cache_free(extent_buffer_cache, eb);
}
if (extent_map_cache)
kmem_cache_destroy(extent_map_cache);
if (extent_state_cache)
kmem_cache_destroy(extent_state_cache);
if (extent_buffer_cache)
kmem_cache_destroy(extent_buffer_cache);
}
void extent_map_tree_init(struct extent_map_tree *tree,
@ -1858,6 +1875,48 @@ sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
return (em->block_start + start - em->start) >> inode->i_blkbits;
}
static struct extent_buffer *__alloc_extent_buffer(gfp_t mask)
{
struct extent_buffer *eb = NULL;
spin_lock(&extent_buffers_lock);
if (!list_empty(&extent_buffers)) {
eb = list_entry(extent_buffers.next, struct extent_buffer,
list);
list_del(&eb->list);
WARN_ON(nr_extent_buffers == 0);
nr_extent_buffers--;
}
spin_unlock(&extent_buffers_lock);
if (eb) {
memset(eb, 0, sizeof(*eb));
return eb;
}
return kmem_cache_zalloc(extent_buffer_cache, mask);
}
static void __free_extent_buffer(struct extent_buffer *eb)
{
if (nr_extent_buffers >= MAX_EXTENT_BUFFER_CACHE) {
kmem_cache_free(extent_buffer_cache, eb);
} else {
spin_lock(&extent_buffers_lock);
list_add(&eb->list, &extent_buffers);
nr_extent_buffers++;
spin_unlock(&extent_buffers_lock);
}
}
static inline struct page *extent_buffer_page(struct extent_buffer *eb, int i)
{
struct page *p;
if (i == 0)
return eb->first_page;
i += eb->start >> PAGE_CACHE_SHIFT;
p = find_get_page(eb->first_page->mapping, i);
page_cache_release(p);
return p;
}
struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
u64 start, unsigned long len,
gfp_t mask)
@ -1871,7 +1930,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
struct address_space *mapping = tree->mapping;
int uptodate = 0;
eb = kzalloc(EXTENT_BUFFER_SIZE(num_pages), mask);
eb = __alloc_extent_buffer(mask);
if (!eb || IS_ERR(eb))
return NULL;
@ -1881,9 +1940,16 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
for (i = 0; i < num_pages; i++, index++) {
p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
if (!p)
if (!p) {
/* make sure the free only frees the pages we've
* grabbed a reference on
*/
eb->len = i << PAGE_CACHE_SHIFT;
eb->start &= ~((u64)PAGE_CACHE_SIZE - 1);
goto fail;
eb->pages[i] = p;
}
if (i == 0)
eb->first_page = p;
if (!PageUptodate(p))
uptodate = 0;
unlock_page(p);
@ -1909,7 +1975,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
struct page *p;
struct address_space *mapping = tree->mapping;
eb = kzalloc(EXTENT_BUFFER_SIZE(num_pages), mask);
eb = __alloc_extent_buffer(mask);
if (!eb || IS_ERR(eb))
return NULL;
@ -1919,9 +1985,16 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
for (i = 0; i < num_pages; i++, index++) {
p = find_get_page(mapping, index);
if (!p)
if (!p) {
/* make sure the free only frees the pages we've
* grabbed a reference on
*/
eb->len = i << PAGE_CACHE_SHIFT;
eb->start &= ~((u64)PAGE_CACHE_SIZE - 1);
goto fail;
eb->pages[i] = p;
}
if (i == 0)
eb->first_page = p;
}
return eb;
fail:
@ -1944,11 +2017,12 @@ void free_extent_buffer(struct extent_buffer *eb)
num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
(eb->start >> PAGE_CACHE_SHIFT) + 1;
for (i = 0; i < num_pages; i++) {
if (eb->pages[i])
page_cache_release(eb->pages[i]);
if (eb->first_page)
page_cache_release(eb->first_page);
for (i = 1; i < num_pages; i++) {
page_cache_release(extent_buffer_page(eb, i));
}
kfree(eb);
__free_extent_buffer(eb);
}
EXPORT_SYMBOL(free_extent_buffer);
@ -1968,7 +2042,7 @@ int clear_extent_buffer_dirty(struct extent_map_tree *tree,
(eb->start >> PAGE_CACHE_SHIFT) + 1;
for (i = 0; i < num_pages; i++) {
page = eb->pages[i];
page = extent_buffer_page(eb, i);
lock_page(page);
/*
* if we're on the last page or the first page and the
@ -2021,7 +2095,7 @@ int set_extent_buffer_uptodate(struct extent_map_tree *tree,
set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
GFP_NOFS);
for (i = 0; i < num_pages; i++) {
page = eb->pages[i];
page = extent_buffer_page(eb, i);
if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
((i == num_pages - 1) &&
((eb->start + eb->len - 1) & (PAGE_CACHE_SIZE - 1)))) {
@ -2064,7 +2138,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree,
num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
(eb->start >> PAGE_CACHE_SHIFT) + 1;
for (i = 0; i < num_pages; i++) {
page = eb->pages[i];
page = extent_buffer_page(eb, i);
if (PageUptodate(page)) {
continue;
}
@ -2090,7 +2164,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree,
}
for (i = 0; i < num_pages; i++) {
page = eb->pages[i];
page = extent_buffer_page(eb, i);
wait_on_page_locked(page);
if (!PageUptodate(page)) {
ret = -EIO;
@ -2116,12 +2190,12 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
page = eb->pages[i];
offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
while(len > 0) {
page = extent_buffer_page(eb, i);
WARN_ON(!PageUptodate(page));
cur = min(len, (PAGE_CACHE_SIZE - offset));
@ -2134,7 +2208,6 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
len -= cur;
offset = 0;
i++;
page = eb->pages[i];
}
}
EXPORT_SYMBOL(read_extent_buffer);
@ -2165,7 +2238,7 @@ int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
}
// kaddr = kmap_atomic(eb->pages[i], km);
kaddr = page_address(eb->pages[i]);
kaddr = page_address(extent_buffer_page(eb, i));
*token = kaddr;
*map = kaddr + offset;
*map_len = PAGE_CACHE_SIZE - offset;
@ -2195,12 +2268,12 @@ int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
page = eb->pages[i];
offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
while(len > 0) {
page = extent_buffer_page(eb, i);
WARN_ON(!PageUptodate(page));
cur = min(len, (PAGE_CACHE_SIZE - offset));
@ -2216,7 +2289,6 @@ int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
len -= cur;
offset = 0;
i++;
page = eb->pages[i];
}
return ret;
}
@ -2236,12 +2308,12 @@ void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
page = eb->pages[i];
offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
while(len > 0) {
page = extent_buffer_page(eb, i);
WARN_ON(!PageUptodate(page));
cur = min(len, PAGE_CACHE_SIZE - offset);
@ -2254,7 +2326,6 @@ void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
len -= cur;
offset = 0;
i++;
page = eb->pages[i];
}
}
EXPORT_SYMBOL(write_extent_buffer);
@ -2272,12 +2343,12 @@ void memset_extent_buffer(struct extent_buffer *eb, char c,
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
page = eb->pages[i];
offset = start & ((unsigned long)PAGE_CACHE_SIZE - 1);
if (i == 0)
offset += start_offset;
while(len > 0) {
page = extent_buffer_page(eb, i);
WARN_ON(!PageUptodate(page));
cur = min(len, PAGE_CACHE_SIZE - offset);
@ -2289,7 +2360,6 @@ void memset_extent_buffer(struct extent_buffer *eb, char c,
len -= cur;
offset = 0;
i++;
page = eb->pages[i];
}
}
EXPORT_SYMBOL(memset_extent_buffer);
@ -2313,7 +2383,7 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
offset += start_offset;
while(len > 0) {
page = dst->pages[i];
page = extent_buffer_page(dst, i);
WARN_ON(!PageUptodate(page));
cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));
@ -2414,7 +2484,8 @@ void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
cur = min(cur, (unsigned long)(PAGE_CACHE_SIZE -
dst_off_in_page));
copy_pages(dst->pages[dst_i], dst->pages[src_i],
copy_pages(extent_buffer_page(dst, dst_i),
extent_buffer_page(dst, src_i),
dst_off_in_page, src_off_in_page, cur);
src_offset += cur;
@ -2467,7 +2538,8 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
cur = min(len, src_off_in_page + 1);
cur = min(cur, dst_off_in_page + 1);
// printk("move pages orig dst %lu src %lu len %lu, this %lu %lu %lu\n", dst_offset, src_offset, len, dst_off_in_page - cur + 1, src_off_in_page - cur + 1, cur);
move_pages(dst->pages[dst_i], dst->pages[src_i],
move_pages(extent_buffer_page(dst, dst_i),
extent_buffer_page(dst, src_i),
dst_off_in_page - cur + 1,
src_off_in_page - cur + 1, cur);

5
fs/btrfs/extent_map.h
View File

@ -62,14 +62,13 @@ struct extent_state {
struct list_head list;
};
#define EXTENT_BUFFER_SIZE(nr) (sizeof(struct extent_buffer) + \
(nr - 1) * sizeof(struct page *))
struct extent_buffer {
u64 start;
unsigned long len;
atomic_t refs;
int flags;
struct page *pages[];
struct list_head list;
struct page *first_page;
};
typedef struct extent_map *(get_extent_t)(struct inode *inode,