[btrfs-devel][patch]Fix typo and off by one error in extent buffer
codes
Yan Zheng
yanzheng at 21cn.com
Mon Oct 22 01:27:49 PDT 2007
Hello
In alloc_extent_buffer, variable 'uptodate' should be 1 at first,
otherwise test for page update in subsequent codes is nonsense. The
off by one errors are obvious, I think no description is needed.
Regards
YZ
--
diff -r 9bf00d0c038f extent_map.c
--- a/extent_map.c Fri Oct 19 14:01:21 2007 -0400
+++ b/extent_map.c Mon Oct 22 12:37:35 2007 +0800
@@ -2045,7 +2045,7 @@ struct extent_buffer *alloc_extent_buffe
struct extent_buffer *eb;
struct page *p;
struct address_space *mapping = tree->mapping;
- int uptodate = 0;
+ int uptodate = 1;
eb = __alloc_extent_buffer(tree, start, len, mask);
if (!eb || IS_ERR(eb))
@@ -2197,7 +2197,7 @@ int clear_extent_buffer_dirty(struct ext
*/
if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
((i == num_pages - 1) &&
- ((eb->start + eb->len - 1) & (PAGE_CACHE_SIZE - 1)))) {
+ ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
start = page->index << PAGE_CACHE_SHIFT;
end = start + PAGE_CACHE_SIZE - 1;
if (test_range_bit(tree, start, end,
@@ -2265,7 +2265,7 @@ int set_extent_buffer_uptodate(struct ex
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)))) {
+ ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) {
check_page_uptodate(tree, page);
continue;
}
@@ -2401,7 +2401,7 @@ int map_private_extent_buffer(struct ext
struct page *p;
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) >>
+ unsigned long end_i = (start_offset + start + min_len - 1) >>
PAGE_CACHE_SHIFT;
if (i != end_i)
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