From: Anand Jain <anand.j...@oracle.com>
btrfs inspect dump-tree picks the disk with the largest generation
to read the root tree by scanning for the required devices by default.
But in 2 or more disks RAID1/5/6 you may need to know what's in the
disks individually, so this option --noscan indicates to use only the
given disk to dump.
For example:
mkfs.btrfs -fq -draid1 -mraid1 /dev/sd[b-d]
btrfs in dump-tree --noscan /dev/sdb /dev/sdc
However as usual without noscan option it works as it scans for the
devices by its own. And if minimum required number of devices are
not provided then when --noscan option is used, it errors out as
shown below.
btrfs in dump-tree --noscan /dev/sdb
check arg type : /dev/sdbbtrfs-progs v4.14.1
warning, device 3 is missing
warning, device 2 is missing
bytenr mismatch, want=22036480, have=0
ERROR: cannot read chunk root
ERROR: unable to open /dev/sdb
Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
v2->v3: make it scalable for more than two disks in noscan mode
v1->v2: rename --degraded to --noscan
cmds-inspect-dump-tree.c | 60 ++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 53 insertions(+), 7 deletions(-)
diff --git a/cmds-inspect-dump-tree.c b/cmds-inspect-dump-tree.c
index 0802b31e9596..8625cd608ad0 100644
--- a/cmds-inspect-dump-tree.c
+++ b/cmds-inspect-dump-tree.c
@@ -21,6 +21,7 @@
#include <unistd.h>
#include <uuid/uuid.h>
#include <getopt.h>
+#include <fcntl.h>
#include "kerncompat.h"
#include "radix-tree.h"
@@ -183,6 +184,46 @@ static u64 treeid_from_string(const char *str, const char
**end)
return id;
}
+static int scan_args(char **argv, int argc, int tmpind, int noscan)
+{
+ int fd;
+ int ret;
+ u64 num_devices;
+ struct btrfs_fs_devices *tmp_devices;
+
+ while (tmpind < argc) {
+ ret = check_arg_type(argv[tmpind]);
+ if (ret != BTRFS_ARG_BLKDEV && ret != BTRFS_ARG_REG) {
+ error("not a block device or regular file: %s",
+ argv[tmpind]);
+ return -EINVAL;
+ }
+
+ if (!noscan) {
+ tmpind++;
+ continue;
+ }
+
+ fd = open(argv[tmpind], O_RDONLY);
+ if (fd < 0) {
+ error("cannot open %s: %m", argv[tmpind]);
+ return -EINVAL;
+ }
+ ret = btrfs_scan_one_device(fd, argv[tmpind],
+ &tmp_devices, &num_devices,
+ BTRFS_SUPER_INFO_OFFSET,
+ SBREAD_DEFAULT);
+ close(fd);
+ if (ret) {
+ error("cannot scan %s: %s",
+ argv[tmpind], strerror(-ret));
+ return ret;
+ }
+ tmpind++;
+ }
+ return 0;
+}
+
const char * const cmd_inspect_dump_tree_usage[] = {
"btrfs inspect-internal dump-tree [options] device",
"Dump tree structures from a given device",
@@ -199,6 +240,7 @@ const char * const cmd_inspect_dump_tree_usage[] = {
"-b|--block <block_num> print info from the specified block only",
"-t|--tree <tree_id> print only tree with the given id (string or
number)",
"--follow use with -b, to show all children tree blocks
of <block_num>",
+ "--noscan only uses the devices provided as the argument",
NULL
};
@@ -213,7 +255,7 @@ int cmd_inspect_dump_tree(int argc, char **argv)
struct btrfs_disk_key disk_key;
struct btrfs_key found_key;
char uuidbuf[BTRFS_UUID_UNPARSED_SIZE];
- int ret;
+ int ret = 0;
int slot;
int extent_only = 0;
int device_only = 0;
@@ -225,10 +267,12 @@ int cmd_inspect_dump_tree(int argc, char **argv)
struct btrfs_root *tree_root_scan;
u64 tree_id = 0;
bool follow = false;
+ bool noscan = false;
while (1) {
int c;
- enum { GETOPT_VAL_FOLLOW = 256 };
+ enum { GETOPT_VAL_FOLLOW = 256,
+ GETOPT_VAL_NOSCAN = 257};
static const struct option long_options[] = {
{ "extents", no_argument, NULL, 'e'},
{ "device", no_argument, NULL, 'd'},
@@ -238,6 +282,7 @@ int cmd_inspect_dump_tree(int argc, char **argv)
{ "block", required_argument, NULL, 'b'},
{ "tree", required_argument, NULL, 't'},
{ "follow", no_argument, NULL, GETOPT_VAL_FOLLOW },
+ { "noscan", no_argument, NULL, GETOPT_VAL_NOSCAN },
{ NULL, 0, NULL, 0 }
};
@@ -293,19 +338,20 @@ int cmd_inspect_dump_tree(int argc, char **argv)
case GETOPT_VAL_FOLLOW:
follow = true;
break;
+ case GETOPT_VAL_NOSCAN:
+ open_ctree_flags |= OPEN_CTREE_NO_DEVICES;
+ noscan = true;
+ break;
default:
usage(cmd_inspect_dump_tree_usage);
}
}
- if (check_argc_exact(argc - optind, 1))
+ if (check_argc_min(argc - optind, 1))
usage(cmd_inspect_dump_tree_usage);
- ret = check_arg_type(argv[optind]);
- if (ret != BTRFS_ARG_BLKDEV && ret != BTRFS_ARG_REG) {
- error("not a block device or regular file: %s", argv[optind]);
+ if (scan_args(argv, argc, optind, noscan))
goto out;
- }
printf("%s\n", PACKAGE_STRING);
--
2.15.0
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