From a3938099758121b6cb8c3606108c8e479b1272ec Mon Sep 17 00:00:00 2001
From: fishsoupisgood <github@madingley.org>
Date: Mon, 14 May 2018 02:43:47 +0100
Subject: support non extents and fast symlinks

---
 src/clone_blocks.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 src/clone_blocks.c

diff --git a/src/clone_blocks.c b/src/clone_blocks.c
new file mode 100644
index 0000000..362cc55
--- /dev/null
+++ b/src/clone_blocks.c
@@ -0,0 +1,148 @@
+#include "project.h"
+
+
+typedef struct {
+  ext2_filsys fs;
+  ext2_ino_t i_num;
+  struct ext2_inode *dst_i;
+  ext2_extent_handle_t eh;
+
+  blk64_t l_start;
+  blk64_t l_len;
+
+  int ret;
+
+} context_t;
+
+static int make_extents (ext2_filsys fs, blk64_t *b_num,
+                         e2_blkcnt_t blockcnt,
+                         blk64_t ref_block,
+                         int ref_offset,
+                         void *_dst)
+{
+  context_t *dst = (context_t *)_dst;
+
+  if (dst->ret) return BLOCK_ABORT;
+
+  if (!dst->l_len)
+    dst->l_start = blockcnt;
+
+
+  if ((dst->l_start + dst->l_len) != blockcnt) {
+    dst->ret = allocate_extent (dst->fs, dst->i_num, dst->eh, dst->l_start, dst->l_len, EXT2_EXTENT_FLAGS_LEAF);
+
+    if (dst->ret) return BLOCK_ABORT;
+
+    dst->dst_i->i_blocks += dst->l_len * (dst->fs->blocksize / 512);
+
+    dst->l_len = 1;
+    dst->l_start = blockcnt;
+  } else
+    dst->l_len++;
+
+  return 0;
+}
+
+
+
+int clone_blocks (ext2_filsys src_fs, ext2_filsys dst_fs, ext2_ino_t i_num, struct ext2_inode *src_i, struct ext2_inode *dst_i)
+{
+  context_t dst;
+  struct ext2fs_extent e;
+  int ret;
+
+
+  dst.fs = dst_fs;
+  dst.i_num = i_num;
+  dst.dst_i = dst_i;
+  dst.eh = NULL;
+  dst.l_start = 0;
+  dst.l_len = 0;
+  dst.ret = 0;
+
+  do {
+
+    dst_i->i_flags  |= EXT4_EXTENTS_FL;
+
+    EXT2_MOAN_FAIL (ret, ext2fs_extent_open2 (dst_fs, i_num, dst_i, &dst.eh));
+
+    if (ret)
+      break;
+
+
+    EXT2_MOAN_FAIL (ret, ext2fs_block_iterate3 (src_fs, i_num, BLOCK_FLAG_DATA_ONLY | BLOCK_FLAG_READ_ONLY, 0, make_extents, &dst));
+
+    if (ret) break;
+
+    ret = dst.ret;
+
+    if (ret) break;
+
+    if (dst.l_len) {
+      ret = allocate_extent (dst_fs, i_num, dst.eh, dst.l_start, dst.l_len, EXT2_EXTENT_FLAGS_LEAF);
+      dst_i->i_blocks += dst.l_len * (dst_fs->blocksize / 512);
+
+      if (ret) break;
+    }
+
+    EXT2_MOAN_FAIL (ret, ext2fs_write_inode (dst_fs, i_num, dst_i));
+
+    if (ret)
+      break;
+
+    ret = ext2fs_extent_get (dst.eh, EXT2_EXTENT_ROOT, &e);
+
+    if (ret == EXT2_ET_EXTENT_NO_NEXT)  {
+      ret = 0;
+      break;
+    }
+
+    if (ret) {
+      EXT2_MOAN (ret, "ext2fs_extent_get (dst.eh, EXT2_EXTENT_ROOT, &e)");
+      break;
+    }
+
+
+    for (;;) {
+      uint64_t file_offset, file_len;
+
+
+      if ((e.e_flags & EXT2_EXTENT_FLAGS_LEAF) && ! (e.e_flags & EXT2_EXTENT_FLAGS_UNINIT)) {
+
+        file_offset = e.e_lblk;
+        file_len = e.e_len;
+
+        file_offset *= src_fs->blocksize;
+        file_len *= src_fs->blocksize;
+
+
+        if (clone_data (src_fs, dst_fs, i_num, src_i, dst_i, file_offset, file_len)) {
+          ret = 1;
+          break;
+        }
+      }
+
+      ret = ext2fs_extent_get (dst.eh, EXT2_EXTENT_NEXT_LEAF, &e);
+
+      if (ret == EXT2_ET_EXTENT_NO_NEXT)  {
+        ret = 0;
+        break;
+      }
+
+      if (ret) {
+        EXT2_MOAN (ret, "ext2fs_extent_get (dst.eh, EXT2_EXTENT_NEXT_LEAF, &e)");
+        break;
+      }
+    }
+
+  } while (0);
+
+  if (dst.eh)
+    ext2fs_extent_free (dst.eh);
+
+
+  return ret;
+}
+
+
+
-- 
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