struct address_space *mapping, gfp_t mask)
{
tree->state = RB_ROOT;
- tree->buffer = RB_ROOT;
+ INIT_RADIX_TREE(&tree->buffer, GFP_ATOMIC);
tree->ops = NULL;
tree->dirty_bytes = 0;
spin_lock_init(&tree->lock);
return ret;
}
-static struct extent_buffer *buffer_tree_insert(struct extent_io_tree *tree,
- u64 offset, struct rb_node *node)
-{
- struct rb_root *root = &tree->buffer;
- struct rb_node **p = &root->rb_node;
- struct rb_node *parent = NULL;
- struct extent_buffer *eb;
-
- while (*p) {
- parent = *p;
- eb = rb_entry(parent, struct extent_buffer, rb_node);
-
- if (offset < eb->start)
- p = &(*p)->rb_left;
- else if (offset > eb->start)
- p = &(*p)->rb_right;
- else
- return eb;
- }
-
- rb_link_node(node, parent, p);
- rb_insert_color(node, root);
- return NULL;
-}
-
-static struct extent_buffer *buffer_search(struct extent_io_tree *tree,
- u64 offset)
-{
- struct rb_root *root = &tree->buffer;
- struct rb_node *n = root->rb_node;
- struct extent_buffer *eb;
-
- while (n) {
- eb = rb_entry(n, struct extent_buffer, rb_node);
- if (offset < eb->start)
- n = n->rb_left;
- else if (offset > eb->start)
- n = n->rb_right;
- else
- return eb;
- }
- return NULL;
-}
-
static void merge_cb(struct extent_io_tree *tree, struct extent_state *new,
struct extent_state *other)
{
struct page *page = bvec->bv_page;
struct extent_io_tree *tree = bio->bi_private;
u64 start;
- u64 end;
start = ((u64)page->index << PAGE_CACHE_SHIFT) + bvec->bv_offset;
- end = start + bvec->bv_len - 1;
bio->bi_private = NULL;
u64 last_byte = i_size_read(inode);
u64 block_start;
u64 iosize;
- u64 unlock_start;
sector_t sector;
struct extent_state *cached_state = NULL;
struct extent_map *em;
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, start,
page_end, NULL, 1);
- unlock_start = page_end + 1;
goto done;
}
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, cur,
page_end, NULL, 1);
- unlock_start = page_end + 1;
break;
}
em = epd->get_extent(inode, page, pg_offset, cur,
cur += iosize;
pg_offset += iosize;
- unlock_start = cur;
continue;
}
/* leave this out until we have a page_mkwrite call */
pgoff_t index;
pgoff_t end; /* Inclusive */
int scanned = 0;
- int range_whole = 0;
pagevec_init(&pvec, 0);
if (wbc->range_cyclic) {
} else {
index = wbc->range_start >> PAGE_CACHE_SHIFT;
end = wbc->range_end >> PAGE_CACHE_SHIFT;
- if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
- range_whole = 1;
scanned = 1;
}
retry:
NULL, 1,
end_bio_extent_preparewrite, 0,
0, 0);
+ if (ret && !err)
+ err = ret;
iocount++;
block_start = block_start + iosize;
} else {
kmem_cache_free(extent_buffer_cache, eb);
}
+/*
+ * Helper for releasing extent buffer page.
+ */
+static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
+ unsigned long start_idx)
+{
+ unsigned long index;
+ struct page *page;
+
+ if (!eb->first_page)
+ return;
+
+ index = num_extent_pages(eb->start, eb->len);
+ if (start_idx >= index)
+ return;
+
+ do {
+ index--;
+ page = extent_buffer_page(eb, index);
+ if (page)
+ page_cache_release(page);
+ } while (index != start_idx);
+}
+
+/*
+ * Helper for releasing the extent buffer.
+ */
+static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
+{
+ btrfs_release_extent_buffer_page(eb, 0);
+ __free_extent_buffer(eb);
+}
+
struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
u64 start, unsigned long len,
struct page *page0,
struct page *p;
struct address_space *mapping = tree->mapping;
int uptodate = 1;
+ int ret;
- spin_lock(&tree->buffer_lock);
- eb = buffer_search(tree, start);
- if (eb) {
- atomic_inc(&eb->refs);
- spin_unlock(&tree->buffer_lock);
+ rcu_read_lock();
+ eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
+ if (eb && atomic_inc_not_zero(&eb->refs)) {
+ rcu_read_unlock();
mark_page_accessed(eb->first_page);
return eb;
}
- spin_unlock(&tree->buffer_lock);
+ rcu_read_unlock();
eb = __alloc_extent_buffer(tree, start, len, mask);
if (!eb)
if (uptodate)
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
+ ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
+ if (ret)
+ goto free_eb;
+
spin_lock(&tree->buffer_lock);
- exists = buffer_tree_insert(tree, start, &eb->rb_node);
- if (exists) {
+ ret = radix_tree_insert(&tree->buffer, start >> PAGE_CACHE_SHIFT, eb);
+ if (ret == -EEXIST) {
+ exists = radix_tree_lookup(&tree->buffer,
+ start >> PAGE_CACHE_SHIFT);
/* add one reference for the caller */
atomic_inc(&exists->refs);
spin_unlock(&tree->buffer_lock);
+ radix_tree_preload_end();
goto free_eb;
}
/* add one reference for the tree */
atomic_inc(&eb->refs);
spin_unlock(&tree->buffer_lock);
+ radix_tree_preload_end();
return eb;
free_eb:
if (!atomic_dec_and_test(&eb->refs))
return exists;
- for (index = 1; index < i; index++)
- page_cache_release(extent_buffer_page(eb, index));
- page_cache_release(extent_buffer_page(eb, 0));
- __free_extent_buffer(eb);
+ btrfs_release_extent_buffer(eb);
return exists;
}
{
struct extent_buffer *eb;
- spin_lock(&tree->buffer_lock);
- eb = buffer_search(tree, start);
- if (eb)
- atomic_inc(&eb->refs);
- spin_unlock(&tree->buffer_lock);
-
- if (eb)
+ rcu_read_lock();
+ eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
+ if (eb && atomic_inc_not_zero(&eb->refs)) {
+ rcu_read_unlock();
mark_page_accessed(eb->first_page);
+ return eb;
+ }
+ rcu_read_unlock();
- return eb;
+ return NULL;
}
void free_extent_buffer(struct extent_buffer *eb)
}
}
+static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
+{
+ struct extent_buffer *eb =
+ container_of(head, struct extent_buffer, rcu_head);
+
+ btrfs_release_extent_buffer(eb);
+}
+
int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page)
{
u64 start = page_offset(page);
struct extent_buffer *eb;
int ret = 1;
- unsigned long i;
- unsigned long num_pages;
spin_lock(&tree->buffer_lock);
- eb = buffer_search(tree, start);
+ eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT);
if (!eb)
goto out;
- if (atomic_read(&eb->refs) > 1) {
+ if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
ret = 0;
goto out;
}
- if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
+
+ /*
+ * set @eb->refs to 0 if it is already 1, and then release the @eb.
+ * Or go back.
+ */
+ if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) {
ret = 0;
goto out;
}
- /* at this point we can safely release the extent buffer */
- num_pages = num_extent_pages(eb->start, eb->len);
- for (i = 0; i < num_pages; i++)
- page_cache_release(extent_buffer_page(eb, i));
- rb_erase(&eb->rb_node, &tree->buffer);
- __free_extent_buffer(eb);
+
+ radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT);
out:
spin_unlock(&tree->buffer_lock);
+
+ /* at this point we can safely release the extent buffer */
+ if (atomic_read(&eb->refs) == 0)
+ call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
return ret;
}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff