Implement metadata dump tool

src/dump_meta.cpp

@@ -0,0 +1,173 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+#define _LARGEFILE64_SOURCE
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <malloc.h>
+#include <linux/fs.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <stdio.h>
+
+#include "object_id.h"
+#include "osd_id.h"
+
+// "VITAstor"
+#define BLOCKSTORE_META_MAGIC_V1 0x726F747341544956l
+#define BLOCKSTORE_META_VERSION_V1 1
+
+#define DIRECT_IO_ALIGNMENT 512
+#define MEM_ALIGNMENT 4096
+
+struct __attribute__((__packed__)) clean_disk_entry_v0_t
+{
+    object_id oid;
+    uint64_t version;
+    uint8_t bitmap[];
+};
+
+struct __attribute__((__packed__)) blockstore_meta_header_v1_t
+{
+    uint64_t zero;
+    uint64_t magic;
+    uint64_t version;
+    uint32_t meta_block_size;
+    uint32_t data_block_size;
+    uint32_t bitmap_granularity;
+};
+
+struct meta_dumper_t
+{
+    char *meta_device;
+    uint32_t meta_block_size;
+    uint64_t meta_offset;
+    uint64_t meta_len;
+    uint64_t meta_pos;
+    int fd;
+};
+
+int main(int argc, char *argv[])
+{
+    meta_dumper_t self = { 0 };
+    int b = 1;
+    if (argc < b+4)
+    {
+        printf("USAGE: %s <meta_file> <meta_block_size> <offset> <size>\n", argv[0]);
+        return 1;
+    }
+    self.meta_device = argv[b];
+    self.meta_block_size = strtoul(argv[b+1], NULL, 10);
+    self.meta_offset = strtoull(argv[b+2], NULL, 10);
+    self.meta_len = strtoull(argv[b+3], NULL, 10);
+    if (self.meta_block_size % DIRECT_IO_ALIGNMENT)
+    {
+        printf("Invalid metadata block size\n");
+        return 1;
+    }
+    self.fd = open(self.meta_device, O_DIRECT|O_RDONLY);
+    if (self.fd == -1)
+    {
+        printf("Failed to open metadata device\n");
+        return 1;
+    }
+    // Read all metadata into memory
+    void *data = memalign(MEM_ALIGNMENT, self.meta_len);
+    if (!data)
+    {
+        printf("Failed to allocate %lu MB of memory\n", self.meta_len/1024/1024);
+        close(self.fd);
+        return 1;
+    }
+    while (self.meta_pos < self.meta_len)
+    {
+        int r = pread(self.fd, data+self.meta_pos, self.meta_len-self.meta_pos, self.meta_offset+self.meta_pos);
+        assert(r > 0);
+        self.meta_pos += r;
+    }
+    close(self.fd);
+    // Check superblock
+    blockstore_meta_header_v1_t *hdr = (blockstore_meta_header_v1_t *)data;
+    if (hdr->zero == 0 &&
+        hdr->magic == BLOCKSTORE_META_MAGIC_V1 &&
+        hdr->version == BLOCKSTORE_META_VERSION_V1)
+    {
+        // Vitastor 0.6-0.7 - static array of clean_disk_entry_v0_t with bitmaps
+        if (hdr->meta_block_size != self.meta_block_size)
+        {
+            printf("Using block size %u bytes based on information from the superblock\n", hdr->meta_block_size);
+            self.meta_block_size = hdr->meta_block_size;
+        }
+        uint64_t clean_entry_bitmap_size = hdr->data_block_size / hdr->bitmap_granularity / 8;
+        uint64_t clean_entry_size = sizeof(clean_disk_entry_v0_t) + 2*clean_entry_bitmap_size;
+        uint64_t block_num = 0;
+        printf(
+            "{\"version\":\"0.6\",\"meta_block_size\":%u,\"data_block_size\":%u,\"bitmap_granularity\":%u,\"entries\":[\n",
+            hdr->meta_block_size, hdr->data_block_size, hdr->bitmap_granularity
+        );
+        bool first = true;
+        for (uint64_t meta_pos = self.meta_block_size; meta_pos < self.meta_len; meta_pos += self.meta_block_size)
+        {
+            for (uint64_t ioff = 0; ioff < self.meta_block_size-clean_entry_size; ioff += clean_entry_size, block_num++)
+            {
+                clean_disk_entry_v0_t *entry = (clean_disk_entry_v0_t*)(data + meta_pos + ioff);
+                if (entry->oid.inode)
+                {
+                    printf(
+#define ENTRY_FMT "{\"block\":%lu,\"pool\":%u,\"inode\":%lu,\"stripe\":%lu,\"version\":%lu,\"bitmap\":\""
+                        (first ? (",\n" ENTRY_FMT) : ENTRY_FMT),
+#undef ENTRY_FMT
+                        block_num, INODE_POOL(entry->oid.inode), INODE_NO_POOL(entry->oid.inode),
+                        entry->oid.stripe, entry->version
+                    );
+                    first = false;
+                    for (uint64_t i = 0; i < clean_entry_bitmap_size; i++)
+                    {
+                        printf("%02x", entry->bitmap[i]);
+                    }
+                    printf("\",\"ext_bitmap\":\"");
+                    for (uint64_t i = 0; i < clean_entry_bitmap_size; i++)
+                    {
+                        printf("%02x", entry->bitmap[clean_entry_bitmap_size + i]);
+                    }
+                    printf("\"}");
+                }
+            }
+        }
+        printf("]}\n");
+    }
+    else
+    {
+        // Vitastor 0.4-0.5 - static array of clean_disk_entry_v0_t
+        uint64_t clean_entry_size = sizeof(clean_disk_entry_v0_t);
+        uint64_t block_num = 0;
+        printf("{\"version\":\"0.5\",\"meta_block_size\":%u,\"entries\":[\n", self.meta_block_size);
+        bool first = true;
+        for (uint64_t meta_pos = 0; meta_pos < self.meta_len; meta_pos += self.meta_block_size)
+        {
+            for (uint64_t ioff = 0; ioff < self.meta_block_size-clean_entry_size; ioff += clean_entry_size, block_num++)
+            {
+                clean_disk_entry_v0_t *entry = (clean_disk_entry_v0_t*)(data + meta_pos + ioff);
+                if (entry->oid.inode)
+                {
+                    printf(
+#define ENTRY_FMT "{\"block\":%lu,\"pool\":%u,\"inode\":%lu,\"stripe\":%lu,\"version\":%lu}"
+                        (first ? (",\n" ENTRY_FMT) : ENTRY_FMT),
+#undef ENTRY_FMT
+                        block_num, INODE_POOL(entry->oid.inode), INODE_NO_POOL(entry->oid.inode),
+                        entry->oid.stripe, entry->version
+                    );
+                    first = false;
+                }
+            }
+        }
+        printf("]}\n");
+    }
+    free(data);
+}