Btrfs: Cache extent buffer mappings

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

1 files changed, 13 insertions, 2 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index f658703c42e6..ea6ee68ef53c 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -2037,6 +2037,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
         struct extent_buffer *eb;
         struct page *p;
         struct address_space *mapping = tree->mapping;
+        int uptodate = 1;
 
         eb = __alloc_extent_buffer(mask);
         if (!eb || IS_ERR(eb))
@@ -2048,7 +2049,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
         atomic_set(&eb->refs, 1);
 
         for (i = 0; i < num_pages; i++, index++) {
-                p = find_get_page(mapping, index);
+                p = find_lock_page(mapping, index);
                 if (!p) {
                         /* make sure the free only frees the pages we've
                          * grabbed a reference on
@@ -2060,7 +2061,12 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
                 set_page_extent_mapped(p);
                 if (i == 0)
                         eb->first_page = p;
+                if (!PageUptodate(p))
+                        uptodate = 0;
+                unlock_page(p);
         }
+        if (uptodate)
+                eb->flags |= EXTENT_UPTODATE;
         return eb;
 fail:
         free_extent_buffer(eb);
@@ -2192,7 +2198,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree,
         if (eb->flags & EXTENT_UPTODATE)
                 return 0;
 
-        if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
+        if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1,
                            EXTENT_UPTODATE, 1)) {
                 return 0;
         }
@@ -2247,6 +2253,7 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
         char *dst = (char *)dstv;
         size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
         unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
+        unsigned long num_pages = num_extent_pages(eb->start, eb->len);
 
         WARN_ON(start > eb->len);
         WARN_ON(start + len > eb->start + eb->len);
@@ -2257,6 +2264,10 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
 
         while(len > 0) {
                 page = extent_buffer_page(eb, i);
+                if (!PageUptodate(page)) {
+                        printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len);
+                        WARN_ON(1);
+                }
                 WARN_ON(!PageUptodate(page));
 
                 cur = min(len, (PAGE_CACHE_SIZE - offset));