libblkid: add erofs filesystem support
Enhanced Read-Only File System (EROFS) has been included in Linux
kernel, many Linux distributions, buildroot and Android AOSP for
a while. Plus, nowadays, it's known that EROFS has been commercially
used by several Android vendors for their system partitions.
This patch adds support for detecting EROFS filesystem to libblkid.
Since util-linux/util-linux@cd129b7 introduced blkid_probe_set_block_size
function to report filesystem block size, TWRP is using blkid 2.25.0, which
means blkid_probe_set_block_size wasn't supported and required, so remove
the blkszbits judgement and blkid_probe_set_block_size for fixing building.
Test: Add erofs mount point to twrp.flags, build and boot
OP4A7A:/ # logcat | grep erofs
I (6)[571:recovery]erofs: (device dm-0): mounted with opts: , root inode @ nid 58.
I (6)[571:recovery]erofs: (device dm-9): mounted with opts: , root inode @ nid 43.
I (6)[571:recovery]erofs: (device dm-1): mounted with opts: , root inode @ nid 52.
I (6)[571:recovery]erofs: (device dm-10): mounted with opts: , root inode @ nid 45.
I (6)[571:recovery]erofs: (device dm-8): mounted with opts: , root inode @ nid 42.
I (0)[571:recovery]erofs: (device dm-12): mounted with opts: , root inode @ nid 38.
I (3)[571:recovery]erofs: (device dm-0): mounted with opts: , root inode @ nid 58.
I (3)[571:recovery]erofs: (device dm-1): mounted with opts: , root inode @ nid 52.
I (3)[571:recovery]erofs: (device dm-0): mounted with opts: , root inode @ nid 58.
I (3)[571:recovery]erofs: (device dm-0): mounted with opts: , root inode @ nid 58.
I (3)[571:recovery]erofs: (device dm-9): mounted with opts: , root inode @ nid 43.
I (2)[571:recovery]erofs: (device dm-1): mounted with opts: , root inode @ nid 52.
I (2)[571:recovery]erofs: (device dm-10): mounted with opts: , root inode @ nid 45.
I (2)[571:recovery]erofs: (device dm-8): mounted with opts: , root inode @ nid 42.
I (2)[571:recovery]erofs: (device dm-12): mounted with opts: , root inode @ nid 38.
I (6)[571:recovery]erofs: (device dm-0): mounted with opts: , root inode @ nid 58.
I (6)[571:recovery]erofs: (device dm-0): mounted with opts: , root inode @ nid 58.
OP4A7A:/ # cat /tmp/recovery.log | grep erofs
Current_File_System: erofs
Fstab_File_System: erofs
Current_File_System: erofs
Fstab_File_System: erofs
Fstab_File_System: erofs
Current_File_System: erofs
Fstab_File_System: erofs
Current_File_System: erofs
Fstab_File_System: erofs
Current_File_System: erofs
Fstab_File_System: erofs
Current_File_System: erofs
Fstab_File_System: erofs
Now TWRP can recognize the EROFS filesystem perfectly after setting fs in twrp.flags
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
[@pomelohan: Adapt for TWRP's libblkid version and add erofs.c to build]
Co-authored-by: GarfieldHan <2652609017@qq.com>
Signed-off-by: GarfieldHan <2652609017@qq.com>
Change-Id: I00263757b5b6ed881165e65795ef849d86763165
diff --git a/libblkid/src/superblocks/erofs.c b/libblkid/src/superblocks/erofs.c
new file mode 100644
index 0000000..0bf1591
--- /dev/null
+++ b/libblkid/src/superblocks/erofs.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2020 Gao Xiang
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License
+ */
+#include <stddef.h>
+#include <string.h>
+
+#include "superblocks.h"
+
+#define EROFS_SUPER_OFFSET 1024
+#define EROFS_SB_KBOFF (EROFS_SUPER_OFFSET >> 10)
+
+#define EROFS_SUPER_MAGIC_V1 "\xe2\xe1\xf5\xe0"
+#define EROFS_MAGIC_OFF 0
+
+/* All in little-endian */
+struct erofs_super_block {
+ uint32_t magic;
+ uint32_t checksum;
+ uint32_t feature_compat;
+ uint8_t blkszbits;
+ uint8_t reserved;
+
+ uint16_t root_nid;
+ uint64_t inos;
+
+ uint64_t build_time;
+ uint32_t build_time_nsec;
+ uint32_t blocks;
+ uint32_t meta_blkaddr;
+ uint32_t xattr_blkaddr;
+ uint8_t uuid[16];
+ uint8_t volume_name[16];
+ uint32_t feature_incompat;
+ uint8_t reserved2[44];
+};
+
+static int probe_erofs(blkid_probe pr, const struct blkid_idmag *mag)
+{
+ struct erofs_super_block *sb;
+
+ sb = blkid_probe_get_sb(pr, mag, struct erofs_super_block);
+ if (!sb)
+ return errno ? -errno : BLKID_PROBE_NONE;
+
+ if (sb->volume_name[0])
+ blkid_probe_set_label(pr, (unsigned char *)sb->volume_name,
+ sizeof(sb->volume_name));
+
+ blkid_probe_set_uuid(pr, sb->uuid);
+
+ return BLKID_PROBE_OK;
+}
+
+const struct blkid_idinfo erofs_idinfo =
+{
+ .name = "erofs",
+ .usage = BLKID_USAGE_FILESYSTEM,
+ .probefunc = probe_erofs,
+ .magics =
+ {
+ {
+ .magic = EROFS_SUPER_MAGIC_V1,
+ .len = 4,
+ .kboff = EROFS_SB_KBOFF,
+ .sboff = EROFS_MAGIC_OFF,
+ }, { NULL }
+ }
+};