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>

1 files changed, 17 insertions, 7 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 0077c6c1d9f9..b3ff63c4bf2a 100644
--- 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);