Extended lfsr_format with some gc flags

These fall out quite naturally when you consider that we call
lfsr_mountinited internally to check that our format was successful.

That being said... they don't really do anything right now since we only
write a single mdir:

- LFS_F_COMPACT - The only gc operation that _might_ actually do
  something is LFS_F_COMPACT, but only if our fs config exceeds >1/2 the
  block size. But I'm not sure littlefs will even be able to write file
  metadata if this happens...

- LFS_F_CKMETA - We already check the only mdir by calling
  lfsr_mountinited, which implicitly fetches the mrootanchor.

- LFS_F_CKDATA - We uh, don't have any data immediately after
  lfsr_format. But I guess it doesn't hurt to keep this around for
  consistency, it at least implies CKMETA.

Hopefully these flags will be more interesting if/when we start adding
auxiliary trees to the filesystem, otherwise they may be worth reverting
in the future...

Until then, they at least provide some consistency, and I guess a way to
triply check that format was successful.

---

This could probably be better deduplicated, but calling lfsr_fs_gc from
both lfsr_mount and lfsr_format provides a bit better code organization:

           code          stack
  before: 36448           2680
  after:  36480 (+0.1%)   2680 (+0.0%)

lfs.c

@@ -13373,21 +13373,6 @@ int lfsr_mount(lfs_t *lfs, uint32_t flags,
         goto failed;
     }
 
-    // TODO this should use any configured values
-    LFS_DEBUG("Mounted littlefs v%"PRId32".%"PRId32" "
-            "%"PRId32"x%"PRId32" "
-            "0x{%"PRIx32",%"PRIx32"}.%"PRIx32" "
-            "w%"PRId32".%"PRId32,
-            LFS_DISK_VERSION_MAJOR,
-            LFS_DISK_VERSION_MINOR,
-            lfs->cfg->block_size,
-            lfs->block_count,
-            lfs->mroot.rbyd.blocks[0],
-            lfs->mroot.rbyd.blocks[1],
-            lfsr_rbyd_trunk(&lfs->mroot.rbyd),
-            lfsr_mtree_weight_(&lfs->mtree) >> lfs->mdir_bits,
-            1 << lfs->mdir_bits);
-
     // run gc if requested
     if (flags & (
             LFS_M_MTREEONLY
@@ -13409,6 +13394,21 @@ int lfsr_mount(lfs_t *lfs, uint32_t flags,
         }
     }
 
+    // TODO this should use any configured values
+    LFS_DEBUG("Mounted littlefs v%"PRId32".%"PRId32" "
+            "%"PRId32"x%"PRId32" "
+            "0x{%"PRIx32",%"PRIx32"}.%"PRIx32" "
+            "w%"PRId32".%"PRId32,
+            LFS_DISK_VERSION_MAJOR,
+            LFS_DISK_VERSION_MINOR,
+            lfs->cfg->block_size,
+            lfs->block_count,
+            lfs->mroot.rbyd.blocks[0],
+            lfs->mroot.rbyd.blocks[1],
+            lfsr_rbyd_trunk(&lfs->mroot.rbyd),
+            lfsr_mtree_weight_(&lfs->mtree) >> lfs->mdir_bits,
+            1 << lfs->mdir_bits);
+
     return 0;
 
 failed:;
@@ -13493,12 +13493,6 @@ static int lfsr_formatinited(lfs_t *lfs) {
         return err;
     }
 
-    // test that mount works with our formatted disk
-    err = lfsr_mountinited(lfs);
-    if (err) {
-        return err;
-    }
-
     return 0;
 }
 
@@ -13508,7 +13502,11 @@ int lfsr_format(lfs_t *lfs, uint32_t flags,
     LFS_ASSERT((flags & ~(
             LFS_F_RDWR
                 | LFS_F_CKPROGS
-                | LFS_IFDEF_CKREADS(LFS_F_CKREADS, 0))) == 0);
+                | LFS_IFDEF_CKREADS(LFS_F_CKREADS, 0)
+                | LFS_F_MTREEONLY
+                | LFS_F_COMPACT
+                | LFS_F_CKMETA
+                | LFS_F_CKDATA)) == 0);
     // some flags don't make sense when only traversing the mtree
     LFS_ASSERT(!lfsr_t_ismtreeonly(flags) || !lfsr_t_isckdata(flags));
 
@@ -13526,12 +13524,38 @@ int lfsr_format(lfs_t *lfs, uint32_t flags,
 
     err = lfsr_formatinited(lfs);
     if (err) {
-        // make sure we clean up on error
+        goto failed;
-        lfs_deinit(lfs);
+    }
-        return err;
+
+    // test that mount works with our formatted disk
+    err = lfsr_mountinited(lfs);
+    if (err) {
+        goto failed;
+    }
+
+    // run gc if requested
+    if (flags & (
+            LFS_F_MTREEONLY
+                | LFS_F_COMPACT
+                | LFS_F_CKMETA
+                | LFS_F_CKDATA)) {
+        err = lfsr_fs_gc(lfs, -1,
+                flags & (
+                    LFS_F_MTREEONLY
+                        | LFS_F_COMPACT
+                        | LFS_F_CKMETA
+                        | LFS_F_CKDATA));
+        if (err) {
+            goto failed;
+        }
     }
 
     return lfs_deinit(lfs);
+
+failed:;
+    // make sure we clean up on error
+    lfs_deinit(lfs);
+    return err;
 }
 
 

lfs.h

@@ -158,6 +158,11 @@ enum lfs_type {
 #define LFS_F_CKREADS   0x00000020  // Check reads via parity bits/checksums
 #endif
 
+#define LFS_F_MTREEONLY 0x00010000  // Only traverse the mtree
+#define LFS_F_COMPACT   0x00000800  // Compact metadata logs
+#define LFS_F_CKMETA    0x00001000  // Check metadata checksums
+#define LFS_F_CKDATA    0x00002000  // Check metadata + data checksums
+
 // Filesystem mount flags
 #define LFS_M_RDWR               0  // Mount the filesystem as read and write
 #define LFS_M_RDONLY             1  // Mount the filesystem as read only

tests/test_mount.toml

@@ -11,14 +11,28 @@ code = '''
     lfsr_unmount(&lfs) => 0;
 '''
 
-# test that various mount flags are returned by lfsr_fs_stat
+# test that various mount flags don't assert and are returned by
+# lfsr_fs_stat
 [cases.test_mount_flags]
 defines.RDONLY = [false, true]
 defines.CKPROGS = [false, true]
 defines.CKREADS = [false, true]
 defines.FLUSH = [false, true]
 defines.SYNC = [false, true]
-if = 'LFS_IFDEF_CKREADS(true, !CKREADS)'
+defines.MTREEONLY = [false, true]
+defines.MKCONSISTENT = [false, true]
+defines.LOOKAHEAD = [false, true]
+defines.COMPACT = [false, true]
+defines.CKMETA = [false, true]
+defines.CKDATA = [false, true]
+if = [
+    'LFS_IFDEF_CKREADS(true, !CKREADS)',
+    '!RDONLY || !MKCONSISTENT',
+    '!RDONLY || !LOOKAHEAD',
+    '!RDONLY || !COMPACT',
+    '!MTREEONLY || !LOOKAHEAD',
+    '!MTREEONLY || !CKDATA',
+]
 code = '''
     lfs_t lfs;
     lfsr_format(&lfs, LFS_F_RDWR, CFG) => 0;
@@ -27,9 +41,16 @@ code = '''
                 | ((CKPROGS) ? LFS_M_CKPROGS : 0)
                 | ((CKREADS) ? LFS_IFDEF_CKREADS(LFS_M_CKREADS, 0) : 0)
                 | ((FLUSH) ? LFS_M_FLUSH : 0)
-                | ((SYNC) ? LFS_M_SYNC : 0),
+                | ((SYNC) ? LFS_M_SYNC : 0)
+                | ((MTREEONLY) ? LFS_M_MTREEONLY : 0)
+                | ((MKCONSISTENT) ? LFS_M_MKCONSISTENT : 0)
+                | ((LOOKAHEAD) ? LFS_M_LOOKAHEAD : 0)
+                | ((COMPACT) ? LFS_M_COMPACT : 0)
+                | ((CKMETA) ? LFS_M_CKMETA : 0)
+                | ((CKDATA) ? LFS_M_CKDATA : 0),
             CFG) => 0;
 
+    // lfsr_fs_stat only returns some flags
     struct lfs_fsinfo fsinfo;
     lfsr_fs_stat(&lfs, &fsinfo) => 0;
     assert(fsinfo.flags == (
@@ -38,8 +59,8 @@ code = '''
                 | ((CKREADS) ? LFS_IFDEF_CKREADS(LFS_I_CKREADS, 0) : 0)
                 | ((FLUSH) ? LFS_I_FLUSH : 0)
                 | ((SYNC) ? LFS_I_SYNC : 0)
-                | LFS_I_CANLOOKAHEAD
+                | ((!LOOKAHEAD) ? LFS_I_CANLOOKAHEAD : 0)
-                | LFS_I_UNCOMPACTED));
+                | ((!COMPACT) ? LFS_I_UNCOMPACTED : 0)));
 
     lfsr_unmount(&lfs) => 0;
 '''
@@ -50,13 +71,24 @@ code = '''
 [cases.test_mount_format_flags]
 defines.CKPROGS = [false, true]
 defines.CKREADS = [false, true]
-if = 'LFS_IFDEF_CKREADS(true, !CKREADS)'
+defines.MTREEONLY = [false, true]
+defines.COMPACT = [false, true]
+defines.CKMETA = [false, true]
+defines.CKDATA = [false, true]
+if = [
+    'LFS_IFDEF_CKREADS(true, !CKREADS)',
+    '!MTREEONLY || !CKDATA',
+]
 code = '''
     lfs_t lfs;
     lfsr_format(&lfs,
             LFS_F_RDWR
                 | ((CKPROGS) ? LFS_F_CKPROGS : 0)
-                | ((CKREADS) ? LFS_IFDEF_CKREADS(LFS_F_CKREADS, 0) : 0),
+                | ((CKREADS) ? LFS_IFDEF_CKREADS(LFS_F_CKREADS, 0) : 0)
+                | ((MTREEONLY) ? LFS_M_MTREEONLY : 0)
+                | ((COMPACT) ? LFS_M_COMPACT : 0)
+                | ((CKMETA) ? LFS_M_CKMETA : 0)
+                | ((CKDATA) ? LFS_M_CKDATA : 0),
             CFG) => 0;
 
     lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;