Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux

[mv-sheeva.git] / fs / btrfs / free-space-cache.c

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 850104f05178c0f6e7aa18ae6cfa11fb91267538..a0390657451b920dac20e17aa04bcc86a0b583e0 100644 (file)
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -987,11 +987,18 @@ tree_search_offset(struct btrfs_block_group_cache *block_group,
        return entry;
 }
 
-static void unlink_free_space(struct btrfs_block_group_cache *block_group,
-                             struct btrfs_free_space *info)
+static inline void
+__unlink_free_space(struct btrfs_block_group_cache *block_group,
+                   struct btrfs_free_space *info)
 {
        rb_erase(&info->offset_index, &block_group->free_space_offset);
        block_group->free_extents--;
+}
+
+static void unlink_free_space(struct btrfs_block_group_cache *block_group,
+                             struct btrfs_free_space *info)
+{
+       __unlink_free_space(block_group, info);
        block_group->free_space -= info->bytes;
 }
 
@@ -1209,6 +1216,7 @@ again:
         */
        search_start = *offset;
        search_bytes = *bytes;
+       search_bytes = min(search_bytes, end - search_start + 1);
        ret = search_bitmap(block_group, bitmap_info, &search_start,
                            &search_bytes);
        BUG_ON(ret < 0 || search_start != *offset);
@@ -1363,22 +1371,14 @@ out:
        return ret;
 }
 
-int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
-                        u64 offset, u64 bytes)
+bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
+                         struct btrfs_free_space *info, bool update_stat)
 {
-       struct btrfs_free_space *right_info = NULL;
-       struct btrfs_free_space *left_info = NULL;
-       struct btrfs_free_space *info = NULL;
-       int ret = 0;
-
-       info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
-       if (!info)
-               return -ENOMEM;
-
-       info->offset = offset;
-       info->bytes = bytes;
-
-       spin_lock(&block_group->tree_lock);
+       struct btrfs_free_space *left_info;
+       struct btrfs_free_space *right_info;
+       bool merged = false;
+       u64 offset = info->offset;
+       u64 bytes = info->bytes;
 
        /*
         * first we want to see if there is free space adjacent to the range we
@@ -1392,37 +1392,62 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
        else
                left_info = tree_search_offset(block_group, offset - 1, 0, 0);
 
-       /*
-        * If there was no extent directly to the left or right of this new
-        * extent then we know we're going to have to allocate a new extent, so
-        * before we do that see if we need to drop this into a bitmap
-        */
-       if ((!left_info || left_info->bitmap) &&
-           (!right_info || right_info->bitmap)) {
-               ret = insert_into_bitmap(block_group, info);
-
-               if (ret < 0) {
-                       goto out;
-               } else if (ret) {
-                       ret = 0;
-                       goto out;
-               }
-       }
-
        if (right_info && !right_info->bitmap) {
-               unlink_free_space(block_group, right_info);
+               if (update_stat)
+                       unlink_free_space(block_group, right_info);
+               else
+                       __unlink_free_space(block_group, right_info);
                info->bytes += right_info->bytes;
                kfree(right_info);
+               merged = true;
        }
 
        if (left_info && !left_info->bitmap &&
            left_info->offset + left_info->bytes == offset) {
-               unlink_free_space(block_group, left_info);
+               if (update_stat)
+                       unlink_free_space(block_group, left_info);
+               else
+                       __unlink_free_space(block_group, left_info);
                info->offset = left_info->offset;
                info->bytes += left_info->bytes;
                kfree(left_info);
+               merged = true;
        }
 
+       return merged;
+}
+
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+                        u64 offset, u64 bytes)
+{
+       struct btrfs_free_space *info;
+       int ret = 0;
+
+       info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
+       if (!info)
+               return -ENOMEM;
+
+       info->offset = offset;
+       info->bytes = bytes;
+
+       spin_lock(&block_group->tree_lock);
+
+       if (try_merge_free_space(block_group, info, true))
+               goto link;
+
+       /*
+        * There was no extent directly to the left or right of this new
+        * extent then we know we're going to have to allocate a new extent, so
+        * before we do that see if we need to drop this into a bitmap
+        */
+       ret = insert_into_bitmap(block_group, info);
+       if (ret < 0) {
+               goto out;
+       } else if (ret) {
+               ret = 0;
+               goto out;
+       }
+link:
        ret = link_free_space(block_group, info);
        if (ret)
                kfree(info);
@@ -1625,6 +1650,7 @@ __btrfs_return_cluster_to_free_space(
                node = rb_next(&entry->offset_index);
                rb_erase(&entry->offset_index, &cluster->root);
                BUG_ON(entry->bitmap);
+               try_merge_free_space(block_group, entry, false);
                tree_insert_offset(&block_group->free_space_offset,
                                   entry->offset, &entry->offset_index, 0);
        }
@@ -1788,6 +1814,8 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
 
        ret = search_start;
        bitmap_clear_bits(block_group, entry, ret, bytes);
+       if (entry->bytes == 0)
+               free_bitmap(block_group, entry);
 out:
        spin_unlock(&cluster->lock);
        spin_unlock(&block_group->tree_lock);
@@ -1841,15 +1869,26 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
                entry->offset += bytes;
                entry->bytes -= bytes;
 
-               if (entry->bytes == 0) {
+               if (entry->bytes == 0)
                        rb_erase(&entry->offset_index, &cluster->root);
-                       kfree(entry);
-               }
                break;
        }
 out:
        spin_unlock(&cluster->lock);
 
+       if (!ret)
+               return 0;
+
+       spin_lock(&block_group->tree_lock);
+
+       block_group->free_space -= bytes;
+       if (entry->bytes == 0) {
+               block_group->free_extents--;
+               kfree(entry);
+       }
+
+       spin_unlock(&block_group->tree_lock);
+
        return ret;
 }