1 files changed, 78 insertions, 4 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 13575de85543..f561c953205b 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -24,6 +24,7 @@
 #include "free-space-cache.h"
 #include "transaction.h"
 #include "disk-io.h"
+#include "extent_io.h"
 
 #define BITS_PER_BITMAP         (PAGE_CACHE_SIZE * 8)
 #define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
@@ -224,6 +225,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
         u64 num_entries;
         u64 num_bitmaps;
         u64 generation;
+        u64 used = btrfs_block_group_used(&block_group->item);
         u32 cur_crc = ~(u32)0;
         pgoff_t index = 0;
         unsigned long first_page_offset;
@@ -469,6 +471,17 @@ next:
                 index++;
         }
 
+        spin_lock(&block_group->tree_lock);
+        if (block_group->free_space != (block_group->key.offset - used -
+                                        block_group->bytes_super)) {
+                spin_unlock(&block_group->tree_lock);
+                printk(KERN_ERR "block group %llu has an wrong amount of free "
+                       "space\n", block_group->key.objectid);
+                ret = 0;
+                goto free_cache;
+        }
+        spin_unlock(&block_group->tree_lock);
+
         ret = 1;
 out:
         kfree(checksums);
@@ -497,8 +510,11 @@ int btrfs_write_out_cache(struct btrfs_root *root,
         struct list_head *pos, *n;
         struct page *page;
         struct extent_state *cached_state = NULL;
+        struct btrfs_free_cluster *cluster = NULL;
+        struct extent_io_tree *unpin = NULL;
         struct list_head bitmap_list;
         struct btrfs_key key;
+        u64 start, end, len;
         u64 bytes = 0;
         u32 *crc, *checksums;
         pgoff_t index = 0, last_index = 0;
@@ -507,6 +523,7 @@ int btrfs_write_out_cache(struct btrfs_root *root,
         int entries = 0;
         int bitmaps = 0;
         int ret = 0;
+        bool next_page = false;
 
         root = root->fs_info->tree_root;
 
@@ -553,6 +570,18 @@ int btrfs_write_out_cache(struct btrfs_root *root,
          */
         first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64);
 
+        /* Get the cluster for this block_group if it exists */
+        if (!list_empty(&block_group->cluster_list))
+                cluster = list_entry(block_group->cluster_list.next,
+                                     struct btrfs_free_cluster,
+                                     block_group_list);
+
+        /*
+         * We shouldn't have switched the pinned extents yet so this is the
+         * right one
+         */
+        unpin = root->fs_info->pinned_extents;
+
         /*
          * Lock all pages first so we can lock the extent safely.
          *
@@ -582,6 +611,12 @@ int btrfs_write_out_cache(struct btrfs_root *root,
         lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
                          0, &cached_state, GFP_NOFS);
 
+        /*
+         * When searching for pinned extents, we need to start at our start
+         * offset.
+         */
+        start = block_group->key.objectid;
+
         /* Write out the extent entries */
         do {
                 struct btrfs_free_space_entry *entry;
@@ -589,6 +624,8 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                 unsigned long offset = 0;
                 unsigned long start_offset = 0;
 
+                next_page = false;
+
                 if (index == 0) {
                         start_offset = first_page_offset;
                         offset = start_offset;
@@ -600,7 +637,7 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                 entry = addr + start_offset;
 
                 memset(addr, 0, PAGE_CACHE_SIZE);
-                while (1) {
+                while (node && !next_page) {
                         struct btrfs_free_space *e;
 
                         e = rb_entry(node, struct btrfs_free_space, offset_index);
@@ -616,12 +653,49 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                                 entry->type = BTRFS_FREE_SPACE_EXTENT;
                         }
                         node = rb_next(node);
-                        if (!node)
-                                break;
+                        if (!node && cluster) {
+                                node = rb_first(&cluster->root);
+                                cluster = NULL;
+                        }
                         offset += sizeof(struct btrfs_free_space_entry);
                         if (offset + sizeof(struct btrfs_free_space_entry) >=
                             PAGE_CACHE_SIZE)
+                                next_page = true;
+                        entry++;
+                }
+
+                /*
+                 * We want to add any pinned extents to our free space cache
+                 * so we don't leak the space
+                 */
+                while (!next_page && (start < block_group->key.objectid +
+                                      block_group->key.offset)) {
+                        ret = find_first_extent_bit(unpin, start, &start, &end,
+                                                    EXTENT_DIRTY);
+                        if (ret) {
+                                ret = 0;
+                                break;
+                        }
+
+                        /* This pinned extent is out of our range */
+                        if (start >= block_group->key.objectid +
+                            block_group->key.offset)
                                 break;
+
+                        len = block_group->key.objectid +
+                                block_group->key.offset - start;
+                        len = min(len, end + 1 - start);
+
+                        entries++;
+                        entry->offset = cpu_to_le64(start);
+                        entry->bytes = cpu_to_le64(len);
+                        entry->type = BTRFS_FREE_SPACE_EXTENT;
+
+                        start = end + 1;
+                        offset += sizeof(struct btrfs_free_space_entry);
+                        if (offset + sizeof(struct btrfs_free_space_entry) >=
+                            PAGE_CACHE_SIZE)
+                                next_page = true;
                         entry++;
                 }
                 *crc = ~(u32)0;
@@ -652,7 +726,7 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                 page_cache_release(page);
 
                 index++;
-        } while (node);
+        } while (node || next_page);
 
         /* Write out the bitmaps */
         list_for_each_safe(pos, n, &bitmap_list) {