* [PATCH] Btrfs-progs: add btrfs-show-super tool
@ 2012-10-19 7:18 Stefan Behrens
2012-10-23 19:45 ` Goffredo Baroncelli
0 siblings, 1 reply; 4+ messages in thread
From: Stefan Behrens @ 2012-10-19 7:18 UTC (permalink / raw)
To: linux-btrfs
Just a small program to print the fields of a super block.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
---
Makefile | 5 +-
btrfs-show-super.c | 201 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 205 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
index fe2b432..25ac6d6 100644
--- a/Makefile
+++ b/Makefile
@@ -20,7 +20,7 @@ RESTORE_LIBS=-lz
progs = btrfsctl mkfs.btrfs btrfs-debug-tree btrfs-show btrfs-vol btrfsck \
btrfs btrfs-map-logical btrfs-image btrfs-zero-log btrfs-convert \
- btrfs-find-root btrfs-restore btrfstune
+ btrfs-find-root btrfs-restore btrfstune btrfs-show-super
# make C=1 to enable sparse
ifdef C
@@ -73,6 +73,9 @@ btrfs-debug-tree: $(objects) debug-tree.o
btrfs-zero-log: $(objects) btrfs-zero-log.o
$(CC) $(CFLAGS) -o btrfs-zero-log $(objects) btrfs-zero-log.o $(LDFLAGS) $(LIBS)
+btrfs-show-super: $(objects) btrfs-show-super.o
+ $(CC) $(CFLAGS) -o btrfs-show-super $(objects) btrfs-show-super.o $(LDFLAGS) $(LIBS)
+
btrfs-select-super: $(objects) btrfs-select-super.o
$(CC) $(CFLAGS) -o btrfs-select-super $(objects) btrfs-select-super.o $(LDFLAGS) $(LIBS)
diff --git a/btrfs-show-super.c b/btrfs-show-super.c
new file mode 100644
index 0000000..2e1a368
--- /dev/null
+++ b/btrfs-show-super.c
@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) 2012 STRATO AG. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#define _XOPEN_SOURCE 500
+#define _GNU_SOURCE 1
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include "kerncompat.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "transaction.h"
+#include "list.h"
+#include "version.h"
+#include "utils.h"
+
+
+static void print_usage(void);
+static void dump_superblock(struct btrfs_super_block *sb);
+int main(int argc, char **argv);
+static void btrfs_print_id(char *prefix, u8 *id, size_t size);
+
+
+static void print_usage(void)
+{
+ fprintf(stderr, "usage: btrfs-show-super [-i super_mirror] dev\n");
+ fprintf(stderr, "\tThe super_mirror number is between 0 and %d.\n",
+ BTRFS_SUPER_MIRROR_MAX - 1);
+ fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
+}
+
+int main(int argc, char **argv)
+{
+ int opt;
+ int ret;
+ const char *filename;
+ struct btrfs_super_block sb;
+ int fd = -1;
+ u64 sb_bytenr = btrfs_sb_offset(0);
+
+ while ((opt = getopt(argc, argv, "i:")) != -1) {
+ switch(opt) {
+ case 'i': {
+ int arg = atoi(optarg);
+
+ if (arg < 0 || arg >= BTRFS_SUPER_MIRROR_MAX) {
+ fprintf(stderr,
+ "Illegal super_mirror %d\n",
+ arg);
+ print_usage();
+ exit(1);
+ }
+ sb_bytenr = btrfs_sb_offset(arg);
+ break;
+ }
+ default:
+ print_usage();
+ exit(1);
+ }
+ }
+
+ if (argc != optind + 1) {
+ print_usage();
+ exit(1);
+ }
+
+ filename = argv[optind];
+ fd = open(filename, O_RDONLY, 0666);
+ if (fd < 0) {
+ fprintf(stderr, "Could not open %s\n", filename);
+ goto error;
+ }
+
+ ret = pread64(fd, &sb, sizeof(sb), sb_bytenr);
+ if (ret < sizeof(sb)) {
+ fprintf(stderr, "Failed to read the superblock on %s at %llu\n",
+ filename, (unsigned long long)sb_bytenr);
+ goto error;
+ }
+
+ dump_superblock(&sb);
+
+error:
+ if (fd != -1)
+ close(fd);
+
+ exit(1);
+}
+
+static void dump_superblock(struct btrfs_super_block *sb)
+{
+ printf("bytenr\t%llu\n", (unsigned long long)btrfs_super_bytenr(sb));
+ printf("flags\t0x%llx\n", (unsigned long long)btrfs_super_flags(sb));
+ printf("magic \t0x%llx (little endian)\n",
+ (unsigned long long)sb->magic);
+ btrfs_print_id("fsid\t", sb->fsid, BTRFS_FSID_SIZE);
+ btrfs_print_id("label\t", (u8 *)sb->label, BTRFS_LABEL_SIZE);
+ printf("generation\t%llu\n",
+ (unsigned long long)btrfs_super_generation(sb));
+ printf("root\t%llu\n", (unsigned long long)btrfs_super_root(sb));
+ printf("sys_array_size\t%llu\n",
+ (unsigned long long)btrfs_super_sys_array_size(sb));
+ printf("chunk_root_generation\t%llu\n",
+ (unsigned long long)btrfs_super_chunk_root_generation(sb));
+ printf("root_level\t%llu\n",
+ (unsigned long long)btrfs_super_root_level(sb));
+ printf("chunk_root\t%llu\n",
+ (unsigned long long)btrfs_super_chunk_root(sb));
+ printf("chunk_root_level\t%llu\n",
+ (unsigned long long)btrfs_super_chunk_root_level(sb));
+ printf("log_root\t%llu\n",
+ (unsigned long long)btrfs_super_log_root(sb));
+ printf("log_root_transid\t%llu\n",
+ (unsigned long long)btrfs_super_log_root_transid(sb));
+ printf("log_root_level\t%llu\n",
+ (unsigned long long)btrfs_super_log_root_level(sb));
+ printf("total_bytes\t%llu\n",
+ (unsigned long long)btrfs_super_total_bytes(sb));
+ printf("bytes_used\t%llu\n",
+ (unsigned long long)btrfs_super_bytes_used(sb));
+ printf("sectorsize\t%llu\n",
+ (unsigned long long)btrfs_super_sectorsize(sb));
+ printf("nodesize\t%llu\n",
+ (unsigned long long)btrfs_super_nodesize(sb));
+ printf("leafsize\t%llu\n",
+ (unsigned long long)btrfs_super_leafsize(sb));
+ printf("stripesize\t%llu\n",
+ (unsigned long long)btrfs_super_stripesize(sb));
+ printf("root_dir\t%llu\n",
+ (unsigned long long)btrfs_super_root_dir(sb));
+ printf("num_devices\t%llu\n",
+ (unsigned long long)btrfs_super_num_devices(sb));
+ printf("compat_flags\t0x%llx\n",
+ (unsigned long long)btrfs_super_compat_flags(sb));
+ printf("compat_ro_flags\t0x%llx\n",
+ (unsigned long long)btrfs_super_compat_ro_flags(sb));
+ printf("incompat_flags\t0x%llx\n",
+ (unsigned long long)btrfs_super_incompat_flags(sb));
+ printf("csum_type\t%llu\n",
+ (unsigned long long)btrfs_super_csum_type(sb));
+ printf("cache_generation\t%llu\n",
+ (unsigned long long)btrfs_super_cache_generation(sb));
+
+ printf("dev_item.type\t%llu\n", (unsigned long long)
+ btrfs_stack_device_type(&sb->dev_item));
+ printf("dev_item.total_bytes\t%llu\n", (unsigned long long)
+ btrfs_stack_device_total_bytes(&sb->dev_item));
+ printf("dev_item.bytes_used\t%llu\n", (unsigned long long)
+ btrfs_stack_device_bytes_used(&sb->dev_item));
+ printf("dev_item.io_align\t%u\n", (unsigned int)
+ btrfs_stack_device_io_align(&sb->dev_item));
+ printf("dev_item.io_width\t%u\n", (unsigned int)
+ btrfs_stack_device_io_width(&sb->dev_item));
+ printf("dev_item.sector_size\t%u\n", (unsigned int)
+ btrfs_stack_device_sector_size(&sb->dev_item));
+ printf("dev_item.devid\t%llu\n",
+ btrfs_stack_device_id(&sb->dev_item));
+ printf("dev_item.dev_group\t%u\n", (unsigned int)
+ btrfs_stack_device_group(&sb->dev_item));
+ printf("dev_item.seek_speed\t%u\n", (unsigned int)
+ btrfs_stack_device_seek_speed(&sb->dev_item));
+ printf("dev_item.bandwidth\t%u\n", (unsigned int)
+ btrfs_stack_device_bandwidth(&sb->dev_item));
+ printf("dev_item.generation\t%llu\n", (unsigned long long)
+ btrfs_stack_device_generation(&sb->dev_item));
+}
+
+static void btrfs_print_id(char *prefix, u8 *id, size_t size)
+{
+ int i;
+ char buf[3 * size];
+
+ for (i = 0; i < size; i++) {
+ buf[3 * i] = ((id[i] >> 4) < 10) ?
+ (id[i] >> 4) + '0' :
+ (id[i] >> 4) + 'A' - 10;
+ buf[3 * i + 1] = (id[i] & 0xf) < 10 ?
+ (id[i] & 0xf) + '0' :
+ (id[i] & 0xf) + 'A' - 10;
+ buf[3 * i + 2] = (i == size - 1) ? '\0' : ':';
+ }
+ printf("%s%s\n", prefix, buf);
+}
--
1.7.12.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] Btrfs-progs: add btrfs-show-super tool
2012-10-19 7:18 [PATCH] Btrfs-progs: add btrfs-show-super tool Stefan Behrens
@ 2012-10-23 19:45 ` Goffredo Baroncelli
[not found] ` <508E61D4.1020809@giantdisaster.de>
0 siblings, 1 reply; 4+ messages in thread
From: Goffredo Baroncelli @ 2012-10-23 19:45 UTC (permalink / raw)
To: Stefan Behrens; +Cc: linux-btrfs
Hi Stefan,
On 2012-10-19 09:18, Stefan Behrens wrote:
> Just a small program to print the fields of a super block.
>
> Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
> ---
[...]
> +
> +
> +static void print_usage(void)
> +{
> + fprintf(stderr, "usage: btrfs-show-super [-i super_mirror] dev\n");
> + fprintf(stderr, "\tThe super_mirror number is between 0 and %d.\n",
> + BTRFS_SUPER_MIRROR_MAX - 1);
What about adding a flag '-a' to show all the superblocks ?
> + fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
> +}
> +
[...]
> +static void dump_superblock(struct btrfs_super_block *sb)
> +{
> + printf("bytenr\t%llu\n", (unsigned long long)btrfs_super_bytenr(sb));
> + printf("flags\t0x%llx\n", (unsigned long long)btrfs_super_flags(sb));
> + printf("magic \t0x%llx (little endian)\n",
> + (unsigned long long)sb->magic);
I suggest to print if magic matches or not. The same if csum matches or
not. This help to understand if the superblock is valid or not.
> + btrfs_print_id("fsid\t", sb->fsid, BTRFS_FSID_SIZE);
Please, use the uuid_unparse() function, so the output is like the other
btrfs tools. Be aware that the libuuid is already linked.
> + btrfs_print_id("label\t", (u8 *)sb->label, BTRFS_LABEL_SIZE);
Does make sense to output the label as hex digits ? I prefer the ascii
value, in order to avoid garbage I suggest something like:
#include <ctype.h>
char *p;
for( p= sb->label ; *p ; p++ ) putchar(isprint(*p) ? *p : '_' );
> + printf("generation\t%llu\n",
> + (unsigned long long)btrfs_super_generation(sb));
> + printf("root\t%llu\n", (unsigned long long)btrfs_super_root(sb));
> + printf("sys_array_size\t%llu\n",
> + (unsigned long long)btrfs_super_sys_array_size(sb));
[...]
> + printf("dev_item.generation\t%llu\n", (unsigned long long)
> + btrfs_stack_device_generation(&sb->dev_item));
Could you please add also the sb->dev_item.uuid and sb->dev_item.fsid
fields ?
Moreover I suggest to align every value to the right. For example a my
test shows:
bytenr 65536
flags 0x1
magic 0x4d5f53665248425f (little endian)
fsid 1A:FD:C9:5D:3C:27:43:90:A2:C8:7A:F6:87:C8:82:B1
label
00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
generation 4
root 4214784
sys_array_size 97
chunk_root_generation 2
root_level 0
chunk_root 139264
chunk_root_level 0
log_root 0
log_root_transid 0
log_root_level 0
total_bytes 1073741824
[...]
I think that it could be more readable as
bytenr 65536
flags 0x1
magic 0x4d5f53665248425f (little endian)
generation 4
root 4214784
sys_array_size 97
chunk_root_generation 2
root_level 0
chunk_root 139264
chunk_root_level 0
log_root 0
log_root_transid 0
log_root_level 0
total_bytes 1073741824
In order to avoid to check every space, I suggest to change every printf
from
> + printf("dev_item.type\t%llu\n", (unsigned long long)
> + btrfs_stack_device_type(&sb->dev_item));
to
printf("%-50s%20llu\n",
"dev_item.type",
(unsigned long long)btrfs_stack_device_type(&sb->dev_item));
BR
G.Baroncelli
--
gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
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2012-10-19 7:18 [PATCH] Btrfs-progs: add btrfs-show-super tool Stefan Behrens
2012-10-23 19:45 ` Goffredo Baroncelli
[not found] ` <508E61D4.1020809@giantdisaster.de>
2012-10-29 17:55 ` Goffredo Baroncelli
2012-10-29 18:46 ` Stefan Behrens
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