Added v1->v2 migration into CI

Also fixed issue where migration would not handle large dirs due to v1
iteration changing the pair of the directory.

.travis.yml

@@ -130,7 +130,58 @@ jobs:
         - ls -flh
         - make -B test_dirs test_files QUIET=1
 
-      # Automatically update releases
+    # self-host with littlefs-fuse for fuzz test
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-migration
+      install:
+        - sudo apt-get install libfuse-dev
+        - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2-alpha v2
+        - git clone --depth 1 https://github.com/geky/littlefs-fuse v1
+        - fusermount -V
+        - gcc --version
+      before_script:
+        # setup disk for littlefs-fuse
+        - rm -rf v2/littlefs/*
+        - cp -r $(git ls-tree --name-only HEAD) v2/littlefs
+
+        - mkdir mount
+        - sudo chmod a+rw /dev/loop0
+        - dd if=/dev/zero bs=512 count=4096 of=disk
+        - losetup /dev/loop0 disk
+      script:
+        # compile v1 and v2
+        - make -C v1
+        - make -C v2
+
+        # run self-host test with v1
+        - v1/lfs --format /dev/loop0
+        - v1/lfs /dev/loop0 mount
+
+        - ls mount
+        - mkdir mount/littlefs
+        - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
+        - cd mount/littlefs
+        - stat .
+        - ls -flh
+        - make -B test_dirs test_files QUIET=1
+
+        # attempt to migrate
+        - cd ../..
+        - fusermount -u mount
+
+        - v2/lfs --migrate /dev/loop0
+        - v2/lfs /dev/loop0 mount
+
+        # run self-host test with v2 right where we left off
+        - ls mount
+        - cd mount/littlefs
+        - stat .
+        - ls -flh
+        - make -B test_dirs test_files QUIET=1
+
+    # Automatically create releases
     - stage: deploy
       env:
         - STAGE=deploy

lfs.c

@@ -4268,6 +4268,8 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
             }
 
             dir2.rev = dir1.d.rev;
+            dir1.head[0] = dir1.pair[0];
+            dir1.head[1] = dir1.pair[1];
             lfs->root[0] = dir2.pair[0];
             lfs->root[1] = dir2.pair[1];
 
@@ -4368,7 +4370,10 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
 
             // Copy over first block to thread into fs. Unfortunately
             // if this fails there is not much we can do.
-            err = lfs_bd_erase(lfs, dir1.pair[1]);
+            LFS_DEBUG("Migrating %"PRIu32" %"PRIu32" -> %"PRIu32" %"PRIu32,
+                    lfs->root[0], lfs->root[1], dir1.head[0], dir1.head[1]);
+
+            err = lfs_bd_erase(lfs, dir1.head[1]);
             if (err) {
                 goto cleanup;
             }
@@ -4389,7 +4394,7 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
 
                 err = lfs_bd_prog(lfs,
                         &lfs->pcache, &lfs->rcache, true,
-                        dir1.pair[1], i, &dat, 1);
+                        dir1.head[1], i, &dat, 1);
                 if (err) {
                     goto cleanup;
                 }