Btrfs: Fix extent bit range testing

It could return the bit as set when there was actually a hole at the
very end of the range.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 0077c6c..b3ff63c 100644 (file)
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -96,7 +96,7 @@ void extent_map_tree_empty_lru(struct extent_map_tree *tree)
        while(!list_empty(&tree->buffer_lru)) {
                eb = list_entry(tree->buffer_lru.next, struct extent_buffer,
                                lru);
-               list_del(&eb->lru);
+               list_del_init(&eb->lru);
                free_extent_buffer(eb);
        }
 }
@@ -1212,13 +1212,15 @@ int test_range_bit(struct extent_map_tree *tree, u64 start, u64 end,
        node = tree_search(&tree->state, start);
        while (node && start <= end) {
                state = rb_entry(node, struct extent_state, rb_node);
-               if (state->start > end)
-                       break;
 
                if (filled && state->start > start) {
                        bitset = 0;
                        break;
                }
+
+               if (state->start > end)
+                       break;
+
                if (state->state & bits) {
                        bitset = 1;
                        if (!filled)
@@ -2208,6 +2210,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
                page_cache_get(page0);
                mark_page_accessed(page0);
                set_page_extent_mapped(page0);
+               WARN_ON(!PageUptodate(page0));
                set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE |
                                 len << 2);
        } else {
@@ -2248,9 +2251,11 @@ fail:
        spin_unlock(&tree->lru_lock);
        if (!atomic_dec_and_test(&eb->refs))
                return NULL;
-       for (index = 0; index < i; index++) {
+       for (index = 1; index < i; index++) {
                page_cache_release(extent_buffer_page(eb, index));
        }
+       if (i > 0)
+               page_cache_release(extent_buffer_page(eb, 0));
        __free_extent_buffer(eb);
        return NULL;
 }
@@ -2310,9 +2315,11 @@ fail:
        spin_unlock(&tree->lru_lock);
        if (!atomic_dec_and_test(&eb->refs))
                return NULL;
-       for (index = 0; index < i; index++) {
+       for (index = 1; index < i; index++) {
                page_cache_release(extent_buffer_page(eb, index));
        }
+       if (i > 0)
+               page_cache_release(extent_buffer_page(eb, 0));
        __free_extent_buffer(eb);
        return NULL;
 }
@@ -2329,11 +2336,13 @@ void free_extent_buffer(struct extent_buffer *eb)
        if (!atomic_dec_and_test(&eb->refs))
                return;
 
+       WARN_ON(!list_empty(&eb->lru));
        num_pages = num_extent_pages(eb->start, eb->len);
 
-       for (i = 0; i < num_pages; i++) {
+       for (i = 1; i < num_pages; i++) {
                page_cache_release(extent_buffer_page(eb, i));
        }
+       page_cache_release(extent_buffer_page(eb, 0));
        __free_extent_buffer(eb);
 }
 EXPORT_SYMBOL(free_extent_buffer);
@@ -2469,6 +2478,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree,
                           EXTENT_UPTODATE, 1)) {
                return 0;
        }
+
        if (start) {
                WARN_ON(start < eb->start);
                start_i = (start >> PAGE_CACHE_SHIFT) -
@@ -2577,7 +2587,7 @@ int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
                *map_start = 0;
        } else {
                offset = 0;
-               *map_start = (i << PAGE_CACHE_SHIFT) - start_offset;
+               *map_start = ((u64)i << PAGE_CACHE_SHIFT) - start_offset;
        }
        if (start + min_len > eb->len) {
 printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);