Btrfs: extent_map optimizations to cut down on CPU usage
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 85b28a6..f8aaba8 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1963,9 +1963,9 @@
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 @@
}
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 @@
}
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 @@
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);
@@ -2317,16 +2325,11 @@
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;
+ PAGE_CACHE_SHIFT;
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 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;