btrfs: use only inline_pages from extent buffer

The nodesize is capped at 64k and there are enough pages preallocated in
extent_buffer::inline_pages. The fallback to kmalloc never happened
because even on the smallest page size considered (4k) inline_pages
covered the needs.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 597ab8966c80fc90efd25e66834c23f30e103b0f..0306665cb1d70174ffd6b050b260c65d8db4a674 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3981,8 +3981,6 @@ static void __free_extent_buffer(struct extent_buffer *eb)
        list_del(&eb->leak_list);
        spin_unlock_irqrestore(&leak_lock, flags);
 #endif
-       if (eb->pages && eb->pages != eb->inline_pages)
-               kfree(eb->pages);
        kmem_cache_free(extent_buffer_cache, eb);
 }
 
@@ -4023,19 +4021,12 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
        atomic_set(&eb->refs, 1);
        atomic_set(&eb->io_pages, 0);
 
-       if (len > MAX_INLINE_EXTENT_BUFFER_SIZE) {
-               struct page **pages;
-               int num_pages = (len + PAGE_CACHE_SIZE - 1) >>
-                       PAGE_CACHE_SHIFT;
-               pages = kzalloc(num_pages, mask);
-               if (!pages) {
-                       __free_extent_buffer(eb);
-                       return NULL;
-               }
-               eb->pages = pages;
-       } else {
-               eb->pages = eb->inline_pages;
-       }
+       /*
+        * Sanity checks, currently the maximum is 64k covered by 16x 4k pages
+        */
+       BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE
+               > MAX_INLINE_EXTENT_BUFFER_SIZE);
+       BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
 
        return eb;
 }

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index dc81868d975a9f0cfb8604f6c1b79ef904dc4f73..6068a1985560eed72a8df42fa528377c3584c93a 100644 (file)
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -158,8 +158,7 @@ struct extent_buffer {
         */
        wait_queue_head_t read_lock_wq;
        wait_queue_head_t lock_wq;
-       struct page *inline_pages[INLINE_EXTENT_BUFFER_PAGES];
-       struct page **pages;
+       struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 };
 
 static inline void extent_set_compress_type(unsigned long *bio_flags,