Miao Xie
2010-Oct-12 09:43 UTC
[PATCH RESEND 1/2] btrfs: restructure try_release_extent_buffer()
restructure try_release_extent_buffer() and write a function to release the
extent buffer. It will be used later.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
fs/btrfs/extent_io.c | 48 +++++++++++++++++++++++++++++++++++++-----------
1 files changed, 37 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 41277d6..70b7cc5 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3097,6 +3097,39 @@ static void __free_extent_buffer(struct extent_buffer
*eb)
kmem_cache_free(extent_buffer_cache, eb);
}
+/*
+ * Helper for releasing extent buffer page.
+ */
+static void btrfs_release_extent_buffer_page(struct extent_buffer *eb,
+ unsigned long start_idx)
+{
+ unsigned long index;
+ struct page *page;
+
+ if (!eb->first_page)
+ return;
+
+ index = num_extent_pages(eb->start, eb->len);
+ if (start_idx >= index)
+ return;
+
+ do {
+ index--;
+ page = extent_buffer_page(eb, index);
+ if (page)
+ page_cache_release(page);
+ } while (index != start_idx);
+}
+
+/*
+ * Helper for releasing the extent buffer.
+ */
+static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
+{
+ btrfs_release_extent_buffer_page(eb, 0);
+ __free_extent_buffer(eb);
+}
+
struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
u64 start, unsigned long len,
struct page *page0,
@@ -3174,10 +3207,7 @@ struct extent_buffer *alloc_extent_buffer(struct
extent_io_tree *tree,
free_eb:
if (!atomic_dec_and_test(&eb->refs))
return exists;
- for (index = 1; index < i; index++)
- page_cache_release(extent_buffer_page(eb, index));
- page_cache_release(extent_buffer_page(eb, 0));
- __free_extent_buffer(eb);
+ btrfs_release_extent_buffer(eb);
return exists;
}
@@ -3831,8 +3861,6 @@ int try_release_extent_buffer(struct extent_io_tree *tree,
struct page *page)
u64 start = page_offset(page);
struct extent_buffer *eb;
int ret = 1;
- unsigned long i;
- unsigned long num_pages;
spin_lock(&tree->buffer_lock);
eb = buffer_search(tree, start);
@@ -3847,12 +3875,10 @@ int try_release_extent_buffer(struct extent_io_tree
*tree, struct page *page)
ret = 0;
goto out;
}
- /* at this point we can safely release the extent buffer */
- num_pages = num_extent_pages(eb->start, eb->len);
- for (i = 0; i < num_pages; i++)
- page_cache_release(extent_buffer_page(eb, i));
+
rb_erase(&eb->rb_node, &tree->buffer);
- __free_extent_buffer(eb);
+ /* at this point we can safely release the extent buffer */
+ btrfs_release_extent_buffer(eb);
out:
spin_unlock(&tree->buffer_lock);
return ret;
--
1.7.0.1
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