zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/app/busybox/src/util-linux/volume_id/btrfs.c b/ap/app/busybox/src/util-linux/volume_id/btrfs.c
new file mode 100644
index 0000000..ee71d2e
--- /dev/null
+++ b/ap/app/busybox/src/util-linux/volume_id/btrfs.c
@@ -0,0 +1,108 @@
+/*
+ * volume_id - reads filesystem label and uuid
+ *
+ * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2009 Vladimir Dronnikov <dronnikov@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "volume_id_internal.h"
+
+#define BTRFS_UUID_SIZE 16
+#define BTRFS_LABEL_SIZE 256
+#define BTRFS_CSUM_SIZE 32
+#define BTRFS_FSID_SIZE 16
+
+#define BTRFS_MAGIC "_BHRfS_M"
+
+struct btrfs_dev_item {
+ uint64_t devid;
+ uint64_t total_bytes;
+ uint64_t bytes_used;
+ uint32_t io_align;
+ uint32_t io_width;
+ uint32_t sector_size;
+ uint64_t type;
+ uint64_t generation;
+ uint64_t start_offset;
+ uint32_t dev_group;
+ uint8_t seek_speed;
+ uint8_t bandwidth;
+ uint8_t uuid[BTRFS_UUID_SIZE];
+ uint8_t fsid[BTRFS_UUID_SIZE];
+} PACKED;
+
+struct btrfs_super_block {
+ uint8_t csum[BTRFS_CSUM_SIZE];
+ uint8_t fsid[BTRFS_FSID_SIZE]; // UUID
+ uint64_t bytenr;
+ uint64_t flags;
+ uint8_t magic[8];
+ uint64_t generation;
+ uint64_t root;
+ uint64_t chunk_root;
+ uint64_t log_root;
+ uint64_t log_root_transid;
+ uint64_t total_bytes;
+ uint64_t bytes_used;
+ uint64_t root_dir_objectid;
+ uint64_t num_devices;
+ uint32_t sectorsize;
+ uint32_t nodesize;
+ uint32_t leafsize;
+ uint32_t stripesize;
+ uint32_t sys_chunk_array_size;
+ uint64_t chunk_root_generation;
+ uint64_t compat_flags;
+ uint64_t compat_ro_flags;
+ uint64_t incompat_flags;
+ uint16_t csum_type;
+ uint8_t root_level;
+ uint8_t chunk_root_level;
+ uint8_t log_root_level;
+ struct btrfs_dev_item dev_item;
+ uint8_t label[BTRFS_LABEL_SIZE]; // LABEL
+ // ...
+} PACKED;
+
+int FAST_FUNC volume_id_probe_btrfs(struct volume_id *id /*,uint64_t off*/)
+{
+ // btrfs has superblocks at 64K, 64M and 256G
+ // minimum btrfs size is 256M
+ // so we never step out the device if we analyze
+ // the first and the second superblocks
+ struct btrfs_super_block *sb;
+ unsigned off = 64;
+
+ while (off < 64*1024*1024) {
+ off *= 1024;
+ dbg("btrfs: probing at offset 0x%x", off);
+
+ sb = volume_id_get_buffer(id, off, sizeof(*sb));
+ if (sb == NULL)
+ return -1;
+
+ if (memcmp(sb->magic, BTRFS_MAGIC, 8) != 0)
+ return -1;
+ }
+
+ // N.B.: btrfs natively supports 256 (>VOLUME_ID_LABEL_SIZE) size labels
+ volume_id_set_label_string(id, sb->label, VOLUME_ID_LABEL_SIZE);
+ volume_id_set_uuid(id, sb->fsid, UUID_DCE);
+ IF_FEATURE_BLKID_TYPE(id->type = "btrfs";)
+
+ return 0;
+}