This is a small (debug) program to dump the device list
in the raw format from the btrfs kernel.
here I use ioctl which was introduced in the below kernel
patch
btrfs: introduce BTRFS_IOC_GET_DEVS
Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
.gitignore | 1 +
Makefile | 4 +-
btrfs-devlist.c | 230 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
ioctl.h | 45 +++++++++++
4 files changed, 278 insertions(+), 2 deletions(-)
create mode 100644 btrfs-devlist.c
diff --git a/.gitignore b/.gitignore
index ab8b81c..0928374 100644
--- a/.gitignore
+++ b/.gitignore
@@ -34,3 +34,4 @@ libbtrfs.a
libbtrfs.so
libbtrfs.so.0
libbtrfs.so.0.1
+btrfs-devlist
diff --git a/Makefile b/Makefile
index f99ca7c..2a52c17 100644
--- a/Makefile
+++ b/Makefile
@@ -47,7 +47,7 @@ MAKEOPTS = --no-print-directory Q=$(Q)
progs = mkfs.btrfs btrfs-debug-tree btrfsck \
btrfs btrfs-map-logical btrfs-image btrfs-zero-log btrfs-convert \
- btrfs-find-root btrfstune btrfs-show-super
+ btrfs-find-root btrfstune btrfs-show-super btrfs-devlist
# external libs required by various binaries; for btrfs-foo,
# specify btrfs_foo_libs = <list of libs>; see $($(subst...)) rules below
@@ -226,7 +226,7 @@ clean: $(CLEANDIRS)
@echo "Cleaning"
$(Q)rm -f $(progs) cscope.out *.o *.o.d btrfs-convert btrfs-image
btrfs-select-super \
btrfs-zero-log btrfstune dir-test ioctl-test quick-test send-test
btrfsck \
- btrfs.static mkfs.btrfs.static btrfs-calc-size \
+ btrfs.static mkfs.btrfs.static btrfs-calc-size btrfs-devlist\
version.h $(check_defs) \
$(libs) $(lib_links)
diff --git a/btrfs-devlist.c b/btrfs-devlist.c
new file mode 100644
index 0000000..7d9ef73
--- /dev/null
+++ b/btrfs-devlist.c
@@ -0,0 +1,230 @@
+/*
+ * Copyright (C) 2014 Oracle. 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.
+ */
+
+#include <unistd.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <uuid/uuid.h>
+
+#include "ctree.h"
+#include "ioctl.h"
+#include "commands.h"
+#include "utils.h"
+
+void print_header(void)
+{
+ printf(
+ "fsid "\
+ "uuid "\
+ "name \n"\
+ "\tfs_latest_devid "\
+ "fs_latest_trans "\
+ "fs_num_devices "\
+ "fs_open_devices "\
+ "fs_rw_devices "\
+ "fs_missing_devices "\
+ "fs_total_rw_bytes "\
+ "fs_num_can_discard "\
+ "fs_total_devices \n"\
+ "\tgen "\
+ "devid "\
+ "total_bytes "\
+ "disk_total_bytes "\
+ "bytes_used "\
+ "type "\
+ "io_align "\
+ "io_width "\
+ "sector_size \n"\
+ "\tflags\n");
+}
+
+void print_dev(struct btrfs_ioctl_devlist *dev)
+{
+ char uuid[BTRFS_UUID_UNPARSED_SIZE];
+ char fsid[BTRFS_UUID_UNPARSED_SIZE];
+
+ uuid_unparse(dev->uuid, uuid);
+ uuid_unparse(dev->fsid, fsid);
+
+ printf("\n%s %s %s\n"\
+ "\t%llu %llu %llu %llu %llu %llu %llu %llu %llu\n"\
+ "\t%llu %llu %llu %llu %llu %llu %u %u %u\n"\
+ "\t%s|%s|%s\n"\
+ "\t%s|%s|%s|%s|%s|%s|%s|%s|%s\n",
+ fsid,
+ uuid,
+ dev->name,
+ dev->fs_latest_devid,
+ dev->fs_latest_trans,
+ dev->fs_num_devices,
+ dev->fs_open_devices,
+ dev->fs_rw_devices,
+ dev->fs_missing_devices,
+ dev->fs_total_rw_bytes,
+ dev->fs_num_can_discard,
+ dev->fs_total_devices,
+ dev->gen,
+ dev->devid,
+ dev->total_bytes,
+ dev->disk_total_bytes,
+ dev->bytes_used,
+ dev->type,
+ dev->io_align,
+ dev->io_width,
+ dev->sector_size,
+ dev->flags & BTRFS_FS_MOUNTED ? "fs_Mounted":"not_fs_Mounted",
+ dev->flags & BTRFS_FS_SEEDING ? "fs_Seeding":"not_fs_Seeding",
+ dev->flags & BTRFS_FS_ROTATING ?
"fs_Rotating":"not_fs_Rotating",
+ dev->flags & BTRFS_DEV_WRITEABLE ? "Writable":"not_Writable",
+ dev->flags & BTRFS_DEV_IN_FS_MD ? "MD":"not_MD",
+ dev->flags & BTRFS_DEV_MISSING ? "Missing":"not_Missing",
+ dev->flags & BTRFS_DEV_CAN_DISCARD ? "Discard":"not_Discard",
+ dev->flags & BTRFS_DEV_SUBSTITUTED ?
"Substituted":"not_Substituted",
+ dev->flags & BTRFS_DEV_RUN_PENDING ?
"Run_pending":"not_Run_pending",
+ dev->flags & BTRFS_DEV_NOBARRIERS ?
"Nobarriers":"not_Nobarriers",
+ dev->flags & BTRFS_DEV_STATS_VALID ?
"Stat_valid":"not_Stat_valid",
+ dev->flags & BTRFS_DEV_STATS_DIRTY ?
"Stat_dirty":"not_Stat_dirty");
+}
+
+int get_devlist(struct btrfs_ioctl_devlist **out_devlist, u64 *out_count)
+{
+ int ret, fd, e;
+ struct btrfs_ioctl_devlist_args *devargs;
+ struct btrfs_ioctl_devlist_args *devargs_saved = NULL;
+ struct btrfs_ioctl_devlist *devlist;
+ u64 sz;
+ int count;
+
+ fd = open("/dev/btrfs-control", O_RDWR);
+ e = errno;
+ if (fd < 0) {
+ perror("failed to open /dev/btrfs-control");
+ return -e;
+ }
+
+ /* space to hold 512 fsids, doesn't matter if small
+ * it would fail and return count so then we try again
+ */
+ count = 512;
+again:
+ sz = sizeof(*devargs) + sizeof(*devlist) * count;
+
+ devargs_saved = devargs = malloc(sz);
+ if (!devargs) {
+ close(fd);
+ return -ENOMEM;
+ }
+
+ memset(devargs, 0, sz);
+ devargs->count = count;
+
+ ret = ioctl(fd, BTRFS_IOC_GET_DEVS, devargs);
+ e = errno;
+ if (ret == 1) {
+ /* out of size so reallocate */
+ count = devargs->count;
+ free(devargs);
+ goto again;
+ } else if (ret < 0) {
+ printf("ERROR: scan_fsid ioctl failed - %s\n",
+ strerror(e));
+ ret = -e;
+ goto out;
+ }
+
+ /* ioctl returns devs count in count parameter*/
+
+ *out_count = devargs->count;
+ if (*out_count == 0) {
+ *out_devlist = NULL;
+ ret = 0;
+ goto out;
+ }
+
+ devlist = (struct btrfs_ioctl_devlist *) (++devargs);
+
+ sz = sizeof(*devlist) * *out_count;
+ *out_devlist = malloc(sz);
+ if (*out_devlist == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ memcpy(*out_devlist, devlist, sz);
+ ret = 0;
+
+out:
+ free(devargs_saved);
+ close(fd);
+ return ret;
+}
+
+static void local_usage(void)
+{
+ printf("btrfs_devlist [options]\n"\
+ " Dumps the device list from the btrfs kernel "\
+ "without altering at the user level\n"\
+ " options:\n"\
+ " -h|--help prints this usage\n");
+ exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+ int ret;
+ u64 cnt;
+ struct btrfs_ioctl_devlist *devlist;
+ struct btrfs_ioctl_devlist *tmp_devlist;
+
+ while(1) {
+ int long_index;
+ static struct option long_options[] = {
+ {"help", no_argument, NULL, 'h'},
+ { NULL, no_argument, NULL, 0 }
+ };
+
+ int c = getopt_long(argc, argv, "h", long_options,
+ &long_index);
+
+ if(c < 0)
+ break;
+
+ switch(c) {
+ case 'h':
+ default:
+ local_usage();
+ }
+ }
+
+ ret = get_devlist(&devlist, &cnt);
+ if (ret) {
+ fprintf(stderr, "get devlist failed %d\n", ret);
+ return 1;
+ }
+
+ tmp_devlist = devlist;
+
+ print_header();
+ while (cnt--) {
+ print_dev(devlist);
+ devlist++;
+ }
+ kfree(tmp_devlist);
+ return ret;
+}
diff --git a/ioctl.h b/ioctl.h
index f84300b..7343a33 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -508,6 +508,8 @@ static inline char *btrfs_err_str(enum btrfs_err_code
err_code)
/* fs flags */
#define BTRFS_FS_MOUNTED (1LLU << 0)
+#define BTRFS_FS_SEEDING (1LLU << 1)
+#define BTRFS_FS_ROTATING (1LLU << 2)
struct btrfs_ioctl_fslist {
__u64 self_sz; /* in/out */
@@ -523,6 +525,47 @@ struct btrfs_ioctl_fslist_args {
__u64 count; /* out */
};
+#define BTRFS_DEV_WRITEABLE (1LLU << 8)
+#define BTRFS_DEV_IN_FS_MD (1LLU << 9)
+#define BTRFS_DEV_MISSING (1LLU << 10)
+#define BTRFS_DEV_CAN_DISCARD (1LLU << 11)
+#define BTRFS_DEV_SUBSTITUTED (1LLU << 12)
+#define BTRFS_DEV_RUN_PENDING (1LLU << 13)
+#define BTRFS_DEV_NOBARRIERS (1LLU << 14)
+#define BTRFS_DEV_STATS_VALID (1LLU << 15)
+#define BTRFS_DEV_STATS_DIRTY (1LLU << 16)
+
+struct btrfs_ioctl_devlist {
+ __u64 sz_self;
+ __u64 fs_latest_devid;
+ __u64 fs_latest_trans;
+ __u64 fs_num_devices;
+ __u64 fs_open_devices;
+ __u64 fs_rw_devices;
+ __u64 fs_missing_devices;
+ __u64 fs_total_rw_bytes;
+ __u64 fs_num_can_discard;
+ __u64 fs_total_devices;
+ __u64 gen;
+ __u64 flags;
+ __u64 devid;
+ __u64 total_bytes;
+ __u64 disk_total_bytes;
+ __u64 bytes_used;
+ __u64 type;
+ __u32 io_align;
+ __u32 io_width;
+ __u32 sector_size;
+ __u8 fsid[BTRFS_FSID_SIZE];
+ __u8 uuid[BTRFS_UUID_SIZE];
+ __u8 name[BTRFS_PATH_NAME_MAX];
+}__attribute__ ((__packed__));
+
+struct btrfs_ioctl_devlist_args {
+ __u64 self_sz; /* in/out */
+ __u64 count; /* in/out */
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -631,6 +674,8 @@ struct btrfs_ioctl_clone_range_args {
struct btrfs_ioctl_feature_flags[2])
#define BTRFS_IOC_GET_SUPPORTED_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 57, \
struct btrfs_ioctl_feature_flags[3])
+#define BTRFS_IOC_GET_DEVS _IOWR(BTRFS_IOCTL_MAGIC, 58, \
+ struct btrfs_ioctl_devlist_args)
#ifdef __cplusplus
}
#endif
--
1.7.1
--
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