1 files changed, 278 insertions, 180 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index bebc9fd16665..3764248bdc05 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2266,66 +2266,27 @@ noinline int btrfs_leaf_free_space(struct btrfs_root *root,
         return ret;
 }
 
-/*
- * push some data in the path leaf to the right, trying to free up at
- * least data_size bytes.  returns zero if the push worked, nonzero otherwise
- *
- * returns 1 if the push failed because the other node didn't have enough
- * room, 0 if everything worked out and < 0 if there were major errors.
- */
-static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
-                           *root, struct btrfs_path *path, int data_size,
-                           int empty)
+static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
+                                      struct btrfs_root *root,
+                                      struct btrfs_path *path,
+                                      int data_size, int empty,
+                                      struct extent_buffer *right,
+                                      int free_space, u32 left_nritems)
 {
         struct extent_buffer *left = path->nodes[0];
-        struct extent_buffer *right;
-        struct extent_buffer *upper;
+        struct extent_buffer *upper = path->nodes[1];
         struct btrfs_disk_key disk_key;
         int slot;
         u32 i;
-        int free_space;
         int push_space = 0;
         int push_items = 0;
         struct btrfs_item *item;
-        u32 left_nritems;
         u32 nr;
         u32 right_nritems;
         u32 data_end;
         u32 this_item_size;
         int ret;
 
-        slot = path->slots[1];
-        if (!path->nodes[1])
-                return 1;
-
-        upper = path->nodes[1];
-        if (slot >= btrfs_header_nritems(upper) - 1)
-                return 1;
-
-        btrfs_assert_tree_locked(path->nodes[1]);
-
-        right = read_node_slot(root, upper, slot + 1);
-        btrfs_tree_lock(right);
-        btrfs_set_lock_blocking(right);
-
-        free_space = btrfs_leaf_free_space(root, right);
-        if (free_space < data_size)
-                goto out_unlock;
-
-        /* cow and double check */
-        ret = btrfs_cow_block(trans, root, right, upper,
-                              slot + 1, &right);
-        if (ret)
-                goto out_unlock;
-
-        free_space = btrfs_leaf_free_space(root, right);
-        if (free_space < data_size)
-                goto out_unlock;
-
-        left_nritems = btrfs_header_nritems(left);
-        if (left_nritems == 0)
-                goto out_unlock;
-
         if (empty)
                 nr = 0;
         else
@@ -2334,6 +2295,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
         if (path->slots[0] >= left_nritems)
                 push_space += data_size;
 
+        slot = path->slots[1];
         i = left_nritems - 1;
         while (i >= nr) {
                 item = btrfs_item_nr(left, i);
@@ -2465,24 +2427,82 @@ out_unlock:
 }
 
 /*
+ * push some data in the path leaf to the right, trying to free up at
+ * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ *
+ * returns 1 if the push failed because the other node didn't have enough
+ * room, 0 if everything worked out and < 0 if there were major errors.
+ */
+static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
+                           *root, struct btrfs_path *path, int data_size,
+                           int empty)
+{
+        struct extent_buffer *left = path->nodes[0];
+        struct extent_buffer *right;
+        struct extent_buffer *upper;
+        int slot;
+        int free_space;
+        u32 left_nritems;
+        int ret;
+
+        if (!path->nodes[1])
+                return 1;
+
+        slot = path->slots[1];
+        upper = path->nodes[1];
+        if (slot >= btrfs_header_nritems(upper) - 1)
+                return 1;
+
+        btrfs_assert_tree_locked(path->nodes[1]);
+
+        right = read_node_slot(root, upper, slot + 1);
+        btrfs_tree_lock(right);
+        btrfs_set_lock_blocking(right);
+
+        free_space = btrfs_leaf_free_space(root, right);
+        if (free_space < data_size)
+                goto out_unlock;
+
+        /* cow and double check */
+        ret = btrfs_cow_block(trans, root, right, upper,
+                              slot + 1, &right);
+        if (ret)
+                goto out_unlock;
+
+        free_space = btrfs_leaf_free_space(root, right);
+        if (free_space < data_size)
+                goto out_unlock;
+
+        left_nritems = btrfs_header_nritems(left);
+        if (left_nritems == 0)
+                goto out_unlock;
+
+        return __push_leaf_right(trans, root, path, data_size, empty,
+                                right, free_space, left_nritems);
+out_unlock:
+        btrfs_tree_unlock(right);
+        free_extent_buffer(right);
+        return 1;
+}
+
+/*
  * push some data in the path leaf to the left, trying to free up at
  * least data_size bytes.  returns zero if the push worked, nonzero otherwise
  */
-static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
-                          *root, struct btrfs_path *path, int data_size,
-                          int empty)
+static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
+                                     struct btrfs_root *root,
+                                     struct btrfs_path *path, int data_size,
+                                     int empty, struct extent_buffer *left,
+                                     int free_space, int right_nritems)
 {
         struct btrfs_disk_key disk_key;
         struct extent_buffer *right = path->nodes[0];
-        struct extent_buffer *left;
         int slot;
         int i;
-        int free_space;
         int push_space = 0;
         int push_items = 0;
         struct btrfs_item *item;
         u32 old_left_nritems;
-        u32 right_nritems;
         u32 nr;
         int ret = 0;
         int wret;
@@ -2490,41 +2510,6 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
         u32 old_left_item_size;
 
         slot = path->slots[1];
-        if (slot == 0)
-                return 1;
-        if (!path->nodes[1])
-                return 1;
-
-        right_nritems = btrfs_header_nritems(right);
-        if (right_nritems == 0)
-                return 1;
-
-        btrfs_assert_tree_locked(path->nodes[1]);
-
-        left = read_node_slot(root, path->nodes[1], slot - 1);
-        btrfs_tree_lock(left);
-        btrfs_set_lock_blocking(left);
-
-        free_space = btrfs_leaf_free_space(root, left);
-        if (free_space < data_size) {
-                ret = 1;
-                goto out;
-        }
-
-        /* cow and double check */
-        ret = btrfs_cow_block(trans, root, left,
-                              path->nodes[1], slot - 1, &left);
-        if (ret) {
-                /* we hit -ENOSPC, but it isn't fatal here */
-                ret = 1;
-                goto out;
-        }
-
-        free_space = btrfs_leaf_free_space(root, left);
-        if (free_space < data_size) {
-                ret = 1;
-                goto out;
-        }
 
         if (empty)
                 nr = right_nritems;
@@ -2692,6 +2677,154 @@ out:
 }
 
 /*
+ * push some data in the path leaf to the left, trying to free up at
+ * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ */
+static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
+                          *root, struct btrfs_path *path, int data_size,
+                          int empty)
+{
+        struct extent_buffer *right = path->nodes[0];
+        struct extent_buffer *left;
+        int slot;
+        int free_space;
+        u32 right_nritems;
+        int ret = 0;
+
+        slot = path->slots[1];
+        if (slot == 0)
+                return 1;
+        if (!path->nodes[1])
+                return 1;
+
+        right_nritems = btrfs_header_nritems(right);
+        if (right_nritems == 0)
+                return 1;
+
+        btrfs_assert_tree_locked(path->nodes[1]);
+
+        left = read_node_slot(root, path->nodes[1], slot - 1);
+        btrfs_tree_lock(left);
+        btrfs_set_lock_blocking(left);
+
+        free_space = btrfs_leaf_free_space(root, left);
+        if (free_space < data_size) {
+                ret = 1;
+                goto out;
+        }
+
+        /* cow and double check */
+        ret = btrfs_cow_block(trans, root, left,
+                              path->nodes[1], slot - 1, &left);
+        if (ret) {
+                /* we hit -ENOSPC, but it isn't fatal here */
+                ret = 1;
+                goto out;
+        }
+
+        free_space = btrfs_leaf_free_space(root, left);
+        if (free_space < data_size) {
+                ret = 1;
+                goto out;
+        }
+
+        return __push_leaf_left(trans, root, path, data_size,
+                               empty, left, free_space, right_nritems);
+out:
+        btrfs_tree_unlock(left);
+        free_extent_buffer(left);
+        return ret;
+}
+
+/*
+ * split the path's leaf in two, making sure there is at least data_size
+ * available for the resulting leaf level of the path.
+ *
+ * returns 0 if all went well and < 0 on failure.
+ */
+static noinline int copy_for_split(struct btrfs_trans_handle *trans,
+                               struct btrfs_root *root,
+                               struct btrfs_path *path,
+                               struct extent_buffer *l,
+                               struct extent_buffer *right,
+                               int slot, int mid, int nritems)
+{
+        int data_copy_size;
+        int rt_data_off;
+        int i;
+        int ret = 0;
+        int wret;
+        struct btrfs_disk_key disk_key;
+
+        nritems = nritems - mid;
+        btrfs_set_header_nritems(right, nritems);
+        data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
+
+        copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
+                           btrfs_item_nr_offset(mid),
+                           nritems * sizeof(struct btrfs_item));
+
+        copy_extent_buffer(right, l,
+                     btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
+                     data_copy_size, btrfs_leaf_data(l) +
+                     leaf_data_end(root, l), data_copy_size);
+
+        rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
+                      btrfs_item_end_nr(l, mid);
+
+        for (i = 0; i < nritems; i++) {
+                struct btrfs_item *item = btrfs_item_nr(right, i);
+                u32 ioff;
+
+                if (!right->map_token) {
+                        map_extent_buffer(right, (unsigned long)item,
+                                        sizeof(struct btrfs_item),
+                                        &right->map_token, &right->kaddr,
+                                        &right->map_start, &right->map_len,
+                                        KM_USER1);
+                }
+
+                ioff = btrfs_item_offset(right, item);
+                btrfs_set_item_offset(right, item, ioff + rt_data_off);
+        }
+
+        if (right->map_token) {
+                unmap_extent_buffer(right, right->map_token, KM_USER1);
+                right->map_token = NULL;
+        }
+
+        btrfs_set_header_nritems(l, mid);
+        ret = 0;
+        btrfs_item_key(right, &disk_key, 0);
+        wret = insert_ptr(trans, root, path, &disk_key, right->start,
+                          path->slots[1] + 1, 1);
+        if (wret)
+                ret = wret;
+
+        btrfs_mark_buffer_dirty(right);
+        btrfs_mark_buffer_dirty(l);
+        BUG_ON(path->slots[0] != slot);
+
+        ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
+        BUG_ON(ret);
+
+        if (mid <= slot) {
+                btrfs_tree_unlock(path->nodes[0]);
+                free_extent_buffer(path->nodes[0]);
+                path->nodes[0] = right;
+                path->slots[0] -= mid;
+                path->slots[1] += 1;
+        } else {
+                btrfs_tree_unlock(right);
+                free_extent_buffer(right);
+        }
+
+        BUG_ON(path->slots[0] < 0);
+
+        return ret;
+}
+
+/*
  * split the path's leaf in two, making sure there is at least data_size
  * available for the resulting leaf level of the path.
  *
@@ -2708,14 +2841,10 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
         int mid;
         int slot;
         struct extent_buffer *right;
-        int data_copy_size;
-        int rt_data_off;
-        int i;
         int ret = 0;
         int wret;
         int double_split;
         int num_doubles = 0;
-        struct btrfs_disk_key disk_key;
 
         /* first try to make some room by pushing left and right */
         if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
@@ -2767,11 +2896,14 @@ again:
         write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
                             (unsigned long)btrfs_header_chunk_tree_uuid(right),
                             BTRFS_UUID_SIZE);
+
         if (mid <= slot) {
                 if (nritems == 1 ||
                     leaf_space_used(l, mid, nritems - mid) + data_size >
                         BTRFS_LEAF_DATA_SIZE(root)) {
                         if (slot >= nritems) {
+                                struct btrfs_disk_key disk_key;
+
                                 btrfs_cpu_key_to_disk(&disk_key, ins_key);
                                 btrfs_set_header_nritems(right, 0);
                                 wret = insert_ptr(trans, root, path,
@@ -2799,6 +2931,8 @@ again:
                 if (leaf_space_used(l, 0, mid) + data_size >
                         BTRFS_LEAF_DATA_SIZE(root)) {
                         if (!extend && data_size && slot == 0) {
+                                struct btrfs_disk_key disk_key;
+
                                 btrfs_cpu_key_to_disk(&disk_key, ins_key);
                                 btrfs_set_header_nritems(right, 0);
                                 wret = insert_ptr(trans, root, path,
@@ -2831,76 +2965,16 @@ again:
                         }
                 }
         }
-        nritems = nritems - mid;
-        btrfs_set_header_nritems(right, nritems);
-        data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
-
-        copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
-                           btrfs_item_nr_offset(mid),
-                           nritems * sizeof(struct btrfs_item));
-
-        copy_extent_buffer(right, l,
-                     btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
-                     data_copy_size, btrfs_leaf_data(l) +
-                     leaf_data_end(root, l), data_copy_size);
-
-        rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
-                      btrfs_item_end_nr(l, mid);
 
-        for (i = 0; i < nritems; i++) {
-                struct btrfs_item *item = btrfs_item_nr(right, i);
-                u32 ioff;
-
-                if (!right->map_token) {
-                        map_extent_buffer(right, (unsigned long)item,
-                                        sizeof(struct btrfs_item),
-                                        &right->map_token, &right->kaddr,
-                                        &right->map_start, &right->map_len,
-                                        KM_USER1);
-                }
-
-                ioff = btrfs_item_offset(right, item);
-                btrfs_set_item_offset(right, item, ioff + rt_data_off);
-        }
-
-        if (right->map_token) {
-                unmap_extent_buffer(right, right->map_token, KM_USER1);
-                right->map_token = NULL;
-        }
-
-        btrfs_set_header_nritems(l, mid);
-        ret = 0;
-        btrfs_item_key(right, &disk_key, 0);
-        wret = insert_ptr(trans, root, path, &disk_key, right->start,
-                          path->slots[1] + 1, 1);
-        if (wret)
-                ret = wret;
-
-        btrfs_mark_buffer_dirty(right);
-        btrfs_mark_buffer_dirty(l);
-        BUG_ON(path->slots[0] != slot);
-
-        ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
+        ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
         BUG_ON(ret);
 
-        if (mid <= slot) {
-                btrfs_tree_unlock(path->nodes[0]);
-                free_extent_buffer(path->nodes[0]);
-                path->nodes[0] = right;
-                path->slots[0] -= mid;
-                path->slots[1] += 1;
-        } else {
-                btrfs_tree_unlock(right);
-                free_extent_buffer(right);
-        }
-
-        BUG_ON(path->slots[0] < 0);
-
         if (double_split) {
                 BUG_ON(num_doubles != 0);
                 num_doubles++;
                 goto again;
         }
+
         return ret;
 }
 
@@ -3382,39 +3456,27 @@ out:
 }
 
 /*
- * Given a key and some data, insert items into the tree.
- * This does all the path init required, making room in the tree if needed.
+ * this is a helper for btrfs_insert_empty_items, the main goal here is
+ * to save stack depth by doing the bulk of the work in a function
+ * that doesn't call btrfs_search_slot
  */
-int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
-                            struct btrfs_root *root,
-                            struct btrfs_path *path,
-                            struct btrfs_key *cpu_key, u32 *data_size,
-                            int nr)
+static noinline_for_stack int
+setup_items_for_insert(struct btrfs_trans_handle *trans,
+                      struct btrfs_root *root, struct btrfs_path *path,
+                      struct btrfs_key *cpu_key, u32 *data_size,
+                      u32 total_data, u32 total_size, int nr)
 {
-        struct extent_buffer *leaf;
         struct btrfs_item *item;
-        int ret = 0;
-        int slot;
-        int slot_orig;
         int i;
         u32 nritems;
-        u32 total_size = 0;
-        u32 total_data = 0;
         unsigned int data_end;
         struct btrfs_disk_key disk_key;
+        int ret;
+        struct extent_buffer *leaf;
+        int slot;
 
-        for (i = 0; i < nr; i++)
-                total_data += data_size[i];
-
-        total_size = total_data + (nr * sizeof(struct btrfs_item));
-        ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
-        if (ret == 0)
-                return -EEXIST;
-        if (ret < 0)
-                goto out;
-
-        slot_orig = path->slots[0];
         leaf = path->nodes[0];
+        slot = path->slots[0];
 
         nritems = btrfs_header_nritems(leaf);
         data_end = leaf_data_end(root, leaf);
@@ -3426,9 +3488,6 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                 BUG();
         }
 
-        slot = path->slots[0];
-        BUG_ON(slot < 0);
-
         if (slot != nritems) {
                 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
 
@@ -3484,11 +3543,13 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                 data_end -= data_size[i];
                 btrfs_set_item_size(leaf, item, data_size[i]);
         }
+
         btrfs_set_header_nritems(leaf, nritems + nr);
         btrfs_mark_buffer_dirty(leaf);
 
         ret = 0;
         if (slot == 0) {
+                struct btrfs_disk_key disk_key;
                 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
                 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
         }
@@ -3497,6 +3558,43 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                 btrfs_print_leaf(root, leaf);
                 BUG();
         }
+        return ret;
+}
+
+/*
+ * Given a key and some data, insert items into the tree.
+ * This does all the path init required, making room in the tree if needed.
+ */
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root,
+                            struct btrfs_path *path,
+                            struct btrfs_key *cpu_key, u32 *data_size,
+                            int nr)
+{
+        struct extent_buffer *leaf;
+        int ret = 0;
+        int slot;
+        int i;
+        u32 total_size = 0;
+        u32 total_data = 0;
+
+        for (i = 0; i < nr; i++)
+                total_data += data_size[i];
+
+        total_size = total_data + (nr * sizeof(struct btrfs_item));
+        ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
+        if (ret == 0)
+                return -EEXIST;
+        if (ret < 0)
+                goto out;
+
+        leaf = path->nodes[0];
+        slot = path->slots[0];
+        BUG_ON(slot < 0);
+
+        ret = setup_items_for_insert(trans, root, path, cpu_key, data_size,
+                               total_data, total_size, nr);
+
 out:
         btrfs_unlock_up_safe(path, 1);
         return ret;