1 files changed, 21 insertions, 4 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 53e12977bfd0..84e060eb0de8 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3452,7 +3452,7 @@ again:
                 num_pages = 1;
 
         num_pages *= 16;
-        num_pages *= PAGE_CACHE_SIZE;
+        num_pages *= PAGE_SIZE;
 
         ret = btrfs_check_data_free_space(inode, 0, num_pages);
         if (ret)
@@ -4639,7 +4639,7 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
         loops = 0;
         while (delalloc_bytes && loops < 3) {
                 max_reclaim = min(delalloc_bytes, to_reclaim);
-                nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
+                nr_pages = max_reclaim >> PAGE_SHIFT;
                 btrfs_writeback_inodes_sb_nr(root, nr_pages, items);
                 /*
                  * We need to wait for the async pages to actually start before
@@ -9386,15 +9386,23 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
         u64 dev_min = 1;
         u64 dev_nr = 0;
         u64 target;
+        int debug;
         int index;
         int full = 0;
         int ret = 0;
 
+        debug = btrfs_test_opt(root, ENOSPC_DEBUG);
+
         block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
 
         /* odd, couldn't find the block group, leave it alone */
-        if (!block_group)
+        if (!block_group) {
+                if (debug)
+                        btrfs_warn(root->fs_info,
+                                   "can't find block group for bytenr %llu",
+                                   bytenr);
                 return -1;
+        }
 
         min_free = btrfs_block_group_used(&block_group->item);
 
@@ -9448,8 +9456,13 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
                  * this is just a balance, so if we were marked as full
                  * we know there is no space for a new chunk
                  */
-                if (full)
+                if (full) {
+                        if (debug)
+                                btrfs_warn(root->fs_info,
+                                        "no space to alloc new chunk for block group %llu",
+                                        block_group->key.objectid);
                         goto out;
+                }
 
                 index = get_block_group_index(block_group);
         }
@@ -9496,6 +9509,10 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
                         ret = -1;
                 }
         }
+        if (debug && ret == -1)
+                btrfs_warn(root->fs_info,
+                        "no space to allocate a new chunk for block group %llu",
+                        block_group->key.objectid);
         mutex_unlock(&root->fs_info->chunk_mutex);
         btrfs_end_transaction(trans, root);
 out: