4 files changed, 114 insertions, 46 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5be778e62a29..f52a60b9eba5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3772,7 +3772,10 @@ extern const struct file_operations btrfs_file_operations;
 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root, struct inode *inode,
                          struct btrfs_path *path, u64 start, u64 end,
-                         u64 *drop_end, int drop_cache);
+                         u64 *drop_end, int drop_cache,
+                         int replace_extent,
+                         u32 extent_item_size,
+                         int *key_inserted);
 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root, struct inode *inode, u64 start,
                        u64 end, int drop_cache);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 35bf83876f3f..030012e1710c 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -692,7 +692,10 @@ next:
 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root, struct inode *inode,
                          struct btrfs_path *path, u64 start, u64 end,
-                         u64 *drop_end, int drop_cache)
+                         u64 *drop_end, int drop_cache,
+                         int replace_extent,
+                         u32 extent_item_size,
+                         int *key_inserted)
 {
         struct extent_buffer *leaf;
         struct btrfs_file_extent_item *fi;
@@ -712,6 +715,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
         int modify_tree = -1;
         int update_refs = (root->ref_cows || root == root->fs_info->tree_root);
         int found = 0;
+        int leafs_visited = 0;
 
         if (drop_cache)
                 btrfs_drop_extent_cache(inode, start, end - 1, 0);
@@ -733,6 +737,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
                                 path->slots[0]--;
                 }
                 ret = 0;
+                leafs_visited++;
 next_slot:
                 leaf = path->nodes[0];
                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
@@ -744,6 +749,7 @@ next_slot:
                                 ret = 0;
                                 break;
                         }
+                        leafs_visited++;
                         leaf = path->nodes[0];
                         recow = 1;
                 }
@@ -927,14 +933,44 @@ next_slot:
         }
 
         if (!ret && del_nr > 0) {
+                /*
+                 * Set path->slots[0] to first slot, so that after the delete
+                 * if items are move off from our leaf to its immediate left or
+                 * right neighbor leafs, we end up with a correct and adjusted
+                 * path->slots[0] for our insertion.
+                 */
+                path->slots[0] = del_slot;
                 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
                 if (ret)
                         btrfs_abort_transaction(trans, root, ret);
+
+                leaf = path->nodes[0];
+                /*
+                 * leaf eb has flag EXTENT_BUFFER_STALE if it was deleted (that
+                 * is, its contents got pushed to its neighbors), in which case
+                 * it means path->locks[0] == 0
+                 */
+                if (!ret && replace_extent && leafs_visited == 1 &&
+                    path->locks[0] &&
+                    btrfs_leaf_free_space(root, leaf) >=
+                    sizeof(struct btrfs_item) + extent_item_size) {
+
+                        key.objectid = ino;
+                        key.type = BTRFS_EXTENT_DATA_KEY;
+                        key.offset = start;
+                        setup_items_for_insert(root, path, &key,
+                                               &extent_item_size,
+                                               extent_item_size,
+                                               sizeof(struct btrfs_item) +
+                                               extent_item_size, 1);
+                        *key_inserted = 1;
+                }
         }
 
+        if (!replace_extent || !(*key_inserted))
+                btrfs_release_path(path);
         if (drop_end)
                 *drop_end = found ? min(end, extent_end) : end;
-        btrfs_release_path(path);
         return ret;
 }
 
@@ -949,7 +985,7 @@ int btrfs_drop_extents(struct btrfs_trans_handle *trans,
         if (!path)
                 return -ENOMEM;
         ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
-                                   drop_cache);
+                                   drop_cache, 0, 0, NULL);
         btrfs_free_path(path);
         return ret;
 }
@@ -2219,7 +2255,7 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
         while (cur_offset < lockend) {
                 ret = __btrfs_drop_extents(trans, root, inode, path,
                                            cur_offset, lockend + 1,
-                                           &drop_end, 1);
+                                           &drop_end, 1, 0, 0, NULL);
                 if (ret != -ENOSPC)
                         break;
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ffb23e506762..23f18eb5fb55 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -125,13 +125,12 @@ static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
  * no overlapping inline items exist in the btree
  */
 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
+                                struct btrfs_path *path, int extent_inserted,
                                 struct btrfs_root *root, struct inode *inode,
                                 u64 start, size_t size, size_t compressed_size,
                                 int compress_type,
                                 struct page **compressed_pages)
 {
-        struct btrfs_key key;
-        struct btrfs_path *path;
         struct extent_buffer *leaf;
         struct page *page = NULL;
         char *kaddr;
@@ -140,29 +139,29 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
         int err = 0;
         int ret;
         size_t cur_size = size;
-        size_t datasize;
         unsigned long offset;
 
         if (compressed_size && compressed_pages)
                 cur_size = compressed_size;
 
-        path = btrfs_alloc_path();
-        if (!path)
-                return -ENOMEM;
+        inode_add_bytes(inode, size);
 
-        path->leave_spinning = 1;
+        if (!extent_inserted) {
+                struct btrfs_key key;
+                size_t datasize;
 
-        key.objectid = btrfs_ino(inode);
-        key.offset = start;
-        btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
-        datasize = btrfs_file_extent_calc_inline_size(cur_size);
+                key.objectid = btrfs_ino(inode);
+                key.offset = start;
+                btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
 
-        inode_add_bytes(inode, size);
-        ret = btrfs_insert_empty_item(trans, root, path, &key,
-                                      datasize);
-        if (ret) {
-                err = ret;
-                goto fail;
+                datasize = btrfs_file_extent_calc_inline_size(cur_size);
+                path->leave_spinning = 1;
+                ret = btrfs_insert_empty_item(trans, root, path, &key,
+                                              datasize);
+                if (ret) {
+                        err = ret;
+                        goto fail;
+                }
         }
         leaf = path->nodes[0];
         ei = btrfs_item_ptr(leaf, path->slots[0],
@@ -203,7 +202,7 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
                 page_cache_release(page);
         }
         btrfs_mark_buffer_dirty(leaf);
-        btrfs_free_path(path);
+        btrfs_release_path(path);
 
         /*
          * we're an inline extent, so nobody can
@@ -219,7 +218,6 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
 
         return ret;
 fail:
-        btrfs_free_path(path);
         return err;
 }
 
@@ -242,6 +240,9 @@ static noinline int cow_file_range_inline(struct btrfs_root *root,
         u64 aligned_end = ALIGN(end, root->sectorsize);
         u64 data_len = inline_len;
         int ret;
+        struct btrfs_path *path;
+        int extent_inserted = 0;
+        u32 extent_item_size;
 
         if (compressed_size)
                 data_len = compressed_size;
@@ -256,12 +257,27 @@ static noinline int cow_file_range_inline(struct btrfs_root *root,
                 return 1;
         }
 
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
         trans = btrfs_join_transaction(root);
-        if (IS_ERR(trans))
+        if (IS_ERR(trans)) {
+                btrfs_free_path(path);
                 return PTR_ERR(trans);
+        }
         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 
-        ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
+        if (compressed_size && compressed_pages)
+                extent_item_size = btrfs_file_extent_calc_inline_size(
+                   compressed_size);
+        else
+                extent_item_size = btrfs_file_extent_calc_inline_size(
+                    inline_len);
+
+        ret = __btrfs_drop_extents(trans, root, inode, path,
+                                   start, aligned_end, NULL,
+                                   1, 1, extent_item_size, &extent_inserted);
         if (ret) {
                 btrfs_abort_transaction(trans, root, ret);
                 goto out;
@@ -269,7 +285,8 @@ static noinline int cow_file_range_inline(struct btrfs_root *root,
 
         if (isize > actual_end)
                 inline_len = min_t(u64, isize, actual_end);
-        ret = insert_inline_extent(trans, root, inode, start,
+        ret = insert_inline_extent(trans, path, extent_inserted,
+                                   root, inode, start,
                                    inline_len, compressed_size,
                                    compress_type, compressed_pages);
         if (ret && ret != -ENOSPC) {
@@ -284,6 +301,7 @@ static noinline int cow_file_range_inline(struct btrfs_root *root,
         btrfs_delalloc_release_metadata(inode, end + 1 - start);
         btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
 out:
+        btrfs_free_path(path);
         btrfs_end_transaction(trans, root);
         return ret;
 }
@@ -1841,14 +1859,13 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
         struct btrfs_path *path;
         struct extent_buffer *leaf;
         struct btrfs_key ins;
+        int extent_inserted = 0;
         int ret;
 
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
 
-        path->leave_spinning = 1;
-
         /*
          * we may be replacing one extent in the tree with another.
          * The new extent is pinned in the extent map, and we don't want
@@ -1858,17 +1875,23 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
          * the caller is expected to unpin it and allow it to be merged
          * with the others.
          */
-        ret = btrfs_drop_extents(trans, root, inode, file_pos,
-                                 file_pos + num_bytes, 0);
+        ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
+                                   file_pos + num_bytes, NULL, 0,
+                                   1, sizeof(*fi), &extent_inserted);
         if (ret)
                 goto out;
 
-        ins.objectid = btrfs_ino(inode);
-        ins.offset = file_pos;
-        ins.type = BTRFS_EXTENT_DATA_KEY;
-        ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
-        if (ret)
-                goto out;
+        if (!extent_inserted) {
+                ins.objectid = btrfs_ino(inode);
+                ins.offset = file_pos;
+                ins.type = BTRFS_EXTENT_DATA_KEY;
+
+                path->leave_spinning = 1;
+                ret = btrfs_insert_empty_item(trans, root, path, &ins,
+                                              sizeof(*fi));
+                if (ret)
+                        goto out;
+        }
         leaf = path->nodes[0];
         fi = btrfs_item_ptr(leaf, path->slots[0],
                             struct btrfs_file_extent_item);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index ba2f15109dac..b561e7a4007d 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3495,21 +3495,27 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
         int ret;
         int index = log->log_transid % 2;
         bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
-
-        ret = __btrfs_drop_extents(trans, log, inode, path, em->start,
-                                   em->start + em->len, NULL, 0);
-        if (ret)
-                return ret;
+        int extent_inserted = 0;
 
         INIT_LIST_HEAD(&ordered_sums);
         btrfs_init_map_token(&token);
-        key.objectid = btrfs_ino(inode);
-        key.type = BTRFS_EXTENT_DATA_KEY;
-        key.offset = em->start;
 
-        ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*fi));
+        ret = __btrfs_drop_extents(trans, log, inode, path, em->start,
+                                   em->start + em->len, NULL, 0, 1,
+                                   sizeof(*fi), &extent_inserted);
         if (ret)
                 return ret;
+
+        if (!extent_inserted) {
+                key.objectid = btrfs_ino(inode);
+                key.type = BTRFS_EXTENT_DATA_KEY;
+                key.offset = em->start;
+
+                ret = btrfs_insert_empty_item(trans, log, path, &key,
+                                              sizeof(*fi));
+                if (ret)
+                        return ret;
+        }
         leaf = path->nodes[0];
         fi = btrfs_item_ptr(leaf, path->slots[0],
                             struct btrfs_file_extent_item);