[PATCH v2 0/2] fs/erofs: Add support for EROFS

[Yifan Zhao]

changes since v1:
   - Rename some fields and fix format issues according to reviewer's comment

Note that all 8 spaces are replaced with tabs, which is not shown in the
interdiff below.

Yifan Zhao (2):
  fs/erofs: Add support for EROFS
  fs/erofs: Add tests for EROFS in grub-fs-tester

 .gitignore                   |   1 +
 INSTALL                      |   8 +-
 Makefile.util.def            |   7 +
 docs/grub.texi               |   3 +-
 grub-core/Makefile.core.def  |   5 +
 grub-core/fs/erofs.c         | 976 +++++++++++++++++++++++++++++++++++
 grub-core/kern/misc.c        |  14 +
 include/grub/misc.h          |   1 +
 tests/erofs_test.in          |  20 +
 tests/util/grub-fs-tester.in |  32 +-
 10 files changed, 1055 insertions(+), 12 deletions(-)
 create mode 100644 grub-core/fs/erofs.c
 create mode 100644 tests/erofs_test.in

Interdiff against v1:
diff --git a/docs/grub.texi b/docs/grub.texi
index 20c119c96..60c98e931 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -361,7 +361,8 @@ blocklist notation. The currently supported filesystem 
types are @dfn{Amiga
 Fast FileSystem (AFFS)}, @dfn{AtheOS fs}, @dfn{BeFS},
 @dfn{BtrFS} (including raid0, raid1, raid10, gzip and lzo),
 @dfn{cpio} (little- and big-endian bin, odc and newc variants),
-@dfn{EROFS}, @dfn{Linux ext2/ext3/ext4}, @dfn{DOS FAT12/FAT16/FAT32},
+@dfn{EROFS} (only uncompressed support for now),
+@dfn{Linux ext2/ext3/ext4}, @dfn{DOS FAT12/FAT16/FAT32},
 @dfn{exFAT}, @dfn{F2FS}, @dfn{HFS}, @dfn{HFS+},
 @dfn{ISO9660} (including Joliet, Rock-ridge and multi-chunk files),
 @dfn{JFS}, @dfn{Minix fs} (versions 1, 2 and 3), @dfn{nilfs2},
diff --git a/grub-core/fs/erofs.c b/grub-core/fs/erofs.c
index f1366ce05..6552a3fdc 100644
--- a/grub-core/fs/erofs.c
+++ b/grub-core/fs/erofs.c
@@ -30,8 +30,6 @@
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
-#define ROUND_UP(x, y) ({ grub_divmod64 (x + (y - 1), y, NULL) * y; })
-
 #define EROFS_SUPER_OFFSET (1024)
 #define EROFS_MAGIC 0xE0F5E1E2
 #define EROFS_ISLOTBITS (5)
@@ -44,7 +42,7 @@ struct grub_erofs_super
   grub_uint32_t magic;
   grub_uint32_t checksum;
   grub_uint32_t feature_compat;
-  grub_uint8_t blkszbits;
+  grub_uint8_t log2_blksz;
   grub_uint8_t sb_extslots;
 
   grub_uint16_t root_nid;
@@ -67,7 +65,7 @@ struct grub_erofs_super
 
   grub_uint16_t extra_devices;
   grub_uint16_t devt_slotoff;
-  grub_uint8_t dirblkbits;
+  grub_uint8_t log2_dirblksz;
   grub_uint8_t xattr_prefix_count;
   grub_uint32_t xattr_prefix_start;
   grub_uint64_t packed_nid;
@@ -229,14 +227,14 @@ struct grub_erofs_data
   struct grub_fshelp_node inode;
 };
 
-#define erofs_blocksz(data) (1u << data->sb.blkszbits)
+#define erofs_blocksz(data) (1u << data->sb.log2_blksz)
 
 static inline grub_uint64_t
 erofs_iloc (grub_fshelp_node_t node)
 {
   struct grub_erofs_super *sb = &node->data->sb;
 
-  return (grub_le_to_cpu32 (sb->meta_blkaddr) << sb->blkszbits) +
+  return (grub_le_to_cpu32 (sb->meta_blkaddr) << sb->log2_blksz) +
         (node->ino << EROFS_ISLOTBITS);
 }
 
@@ -333,12 +331,12 @@ grub_erofs_map_blocks_flatmode (grub_fshelp_node_t node,
   grub_uint32_t blocksz = erofs_blocksz (node->data);
 
   file_size = erofs_inode_file_size (node);
-  nblocks = grub_divmod64 (file_size + blocksz - 1, blocksz, NULL);
+  nblocks = (file_size + blocksz - 1) >> node->data->sb.log2_blksz;
   lastblk = nblocks - tailendpacking;
 
   map->m_flags = EROFS_MAP_MAPPED;
 
-  if (map->m_la < lastblk * blocksz)
+  if (map->m_la < (lastblk * blocksz))
     {
       map->m_pa =
          grub_le_to_cpu32 (node->inode.i_u.raw_blkaddr) * blocksz + map->m_la;
@@ -347,22 +345,20 @@ grub_erofs_map_blocks_flatmode (grub_fshelp_node_t node,
   else if (tailendpacking)
     {
       map->m_pa = erofs_iloc (node) + erofs_inode_size (node) +
-                  erofs_inode_xattr_ibody_size (node) + map->m_la % blocksz;
+                 erofs_inode_xattr_ibody_size (node) + (map->m_la % blocksz);
       map->m_plen = file_size - map->m_la;
 
-      if (map->m_pa % blocksz + map->m_plen > blocksz)
+      if (((map->m_pa % blocksz) + map->m_plen) > blocksz)
        return grub_error (
            GRUB_ERR_BAD_FS,
            "inline data cross block boundary @ inode %" PRIuGRUB_UINT64_T,
            node->ino);
     }
   else
-    {
     return grub_error (GRUB_ERR_BAD_FS,
-                         "internal error: invalid map->m_la=%" 
PRIuGRUB_UINT64_T
+                      "invalid map->m_la=%" PRIuGRUB_UINT64_T
                       " @ inode %" PRIuGRUB_UINT64_T,
                       map->m_la, node->ino);
-    }
 
   map->m_llen = map->m_plen;
   return GRUB_ERR_NONE;
@@ -383,18 +379,18 @@ grub_erofs_map_blocks_chunkmode (grub_fshelp_node_t node,
   else
     unit = EROFS_BLOCK_MAP_ENTRY_SIZE;
 
-  chunkbits = node->data->sb.blkszbits +
+  chunkbits = node->data->sb.log2_blksz +
              (chunk_format & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
 
   chunknr = map->m_la >> chunkbits;
-  pos = ROUND_UP (erofs_iloc (node) + erofs_inode_size (node) +
+  pos = ALIGN_UP (erofs_iloc (node) + erofs_inode_size (node) +
                      erofs_inode_xattr_ibody_size (node),
                  unit);
   pos += chunknr * unit;
 
   map->m_la = chunknr << chunkbits;
   map->m_plen = grub_min (1ULL << chunkbits,
-                          ROUND_UP (erofs_inode_file_size (node) - map->m_la,
+                         ALIGN_UP (erofs_inode_file_size (node) - map->m_la,
                                    erofs_blocksz (node->data)));
 
   if (chunk_format & EROFS_CHUNK_FORMAT_INDEXES)
@@ -416,7 +412,7 @@ grub_erofs_map_blocks_chunkmode (grub_fshelp_node_t node,
        }
       else
        {
-          map->m_pa = blkaddr << node->data->sb.blkszbits;
+         map->m_pa = blkaddr << node->data->sb.log2_blksz;
          map->m_flags = EROFS_MAP_MAPPED;
        }
     }
@@ -438,7 +434,7 @@ grub_erofs_map_blocks_chunkmode (grub_fshelp_node_t node,
        }
       else
        {
-          map->m_pa = blkaddr << node->data->sb.blkszbits;
+         map->m_pa = blkaddr << node->data->sb.log2_blksz;
          map->m_flags = EROFS_MAP_MAPPED;
        }
     }
@@ -894,7 +890,10 @@ grub_erofs_close (grub_file_t file)
 static grub_err_t
 grub_erofs_uuid (grub_device_t device, char **uuid)
 {
-  struct grub_erofs_data *data = grub_erofs_mount (device->disk, false);
+  struct grub_erofs_data *data;
+
+  grub_errno = GRUB_ERR_NONE;
+  data = grub_erofs_mount (device->disk, false);
 
   if (data)
     *uuid = grub_xasprintf (
@@ -916,7 +915,10 @@ grub_erofs_uuid (grub_device_t device, char **uuid)
 static grub_err_t
 grub_erofs_label (grub_device_t device, char **label)
 {
-  struct grub_erofs_data *data = grub_erofs_mount (device->disk, false);
+  struct grub_erofs_data *data;
+
+  grub_errno = GRUB_ERR_NONE;
+  data = grub_erofs_mount (device->disk, false);
 
   if (data)
     *label = grub_strndup ((char *) data->sb.volume_name,
@@ -932,7 +934,10 @@ grub_erofs_label (grub_device_t device, char **label)
 static grub_err_t
 grub_erofs_mtime (grub_device_t device, grub_int64_t *tm)
 {
-  struct grub_erofs_data *data = grub_erofs_mount (device->disk, false);
+  struct grub_erofs_data *data;
+
+  grub_errno = GRUB_ERR_NONE;
+  data = grub_erofs_mount (device->disk, false);
 
   if (!data)
     *tm = 0;
-- 
2.41.0