Since a mounted btrfs filesystem contains all the devices info even a
device is removed after mount(like btrfs/003 in xfstests),
we can use the info to print the known missing device if possible.
So -p/--print-missing options are added to print possible missing
devices.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
cmds-filesystem.c | 26 ++++++++++++++++++++------
man/btrfs.8.in | 4 +++-
2 files changed, 23 insertions(+), 7 deletions(-)
diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index 4c9933d..77b142c 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -360,7 +360,7 @@ static u64 calc_used_bytes(struct btrfs_ioctl_space_args
*si)
static int print_one_fs(struct btrfs_ioctl_fs_info_args *fs_info,
struct btrfs_ioctl_dev_info_args *dev_info,
struct btrfs_ioctl_space_args *space_info,
- char *label, char *path)
+ char *label, char *path, int print_missing)
{
int i;
int fd;
@@ -392,7 +392,14 @@ static int print_one_fs(struct btrfs_ioctl_fs_info_args
*fs_info,
fd = open((char *)tmp_dev_info->path, O_RDONLY);
if (fd < 0) {
missing = 1;
- continue;
+ if (print_missing)
+ printf("\tdevid %4llu size %s used %s path %s
(missing)\n",
+ tmp_dev_info->devid,
+ pretty_size(tmp_dev_info->total_bytes),
+ pretty_size(tmp_dev_info->bytes_used),
+ tmp_dev_info->path);
+ else
+ continue;
}
close(fd);
printf("\tdevid %4llu size %s used %s path %s\n",
@@ -440,7 +447,7 @@ static int check_arg_type(char *input)
return BTRFS_ARG_UNKNOWN;
}
-static int btrfs_scan_kernel(void *search)
+static int btrfs_scan_kernel(void *search, int print_missing)
{
int ret = 0, fd;
FILE *f;
@@ -477,7 +484,8 @@ static int btrfs_scan_kernel(void *search)
fd = open(mnt->mnt_dir, O_RDONLY);
if ((fd != -1) && !get_df(fd, &space_info_arg)) {
print_one_fs(&fs_info_arg, dev_info_arg,
- space_info_arg, label, mnt->mnt_dir);
+ space_info_arg, label, mnt->mnt_dir,
+ print_missing);
kfree(space_info_arg);
memset(label, 0, sizeof(label));
}
@@ -500,6 +508,7 @@ static const char * const cmd_show_usage[] = {
"Show the structure of a filesystem",
"-d|--all-devices show only disks under /dev containing btrfs
filesystem",
"-m|--mounted show only mounted btrfs",
+ "-p|--print-missing show known missing device if possible",
"If no argument is given, structure of all present filesystems is
shown.",
NULL
};
@@ -513,6 +522,7 @@ static int cmd_show(int argc, char **argv)
int ret;
int where = BTRFS_SCAN_LBLKID;
int type = 0;
+ int print_missing = 0;
char mp[BTRFS_PATH_NAME_MAX + 1];
char path[PATH_MAX];
@@ -521,9 +531,10 @@ static int cmd_show(int argc, char **argv)
static struct option long_options[] = {
{ "all-devices", no_argument, NULL, 'd'},
{ "mounted", no_argument, NULL, 'm'},
+ { "print-missing", no_argument, NULL, 'p'},
{ NULL, no_argument, NULL, 0 },
};
- int c = getopt_long(argc, argv, "dm", long_options,
+ int c = getopt_long(argc, argv, "dmp", long_options,
&long_index);
if (c < 0)
break;
@@ -534,6 +545,9 @@ static int cmd_show(int argc, char **argv)
case 'm':
where = BTRFS_SCAN_MOUNTED;
break;
+ case 'p':
+ print_missing = 1;
+ break;
default:
usage(cmd_show_usage);
}
@@ -571,7 +585,7 @@ static int cmd_show(int argc, char **argv)
goto devs_only;
/* show mounted btrfs */
- ret = btrfs_scan_kernel(search);
+ ret = btrfs_scan_kernel(search, print_missing);
if (search && !ret)
return 0;
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 8fea115..db2e355 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -25,7 +25,7 @@ btrfs \- control a btrfs filesystem
.PP
\fBbtrfs\fP \fBfilesystem df\fP\fI <path>\fP
.PP
-\fBbtrfs\fP \fBfilesystem show\fP
[\fI--mounted\fP|\fI--all-devices\fP|\fI<uuid>\fP]\fP
+\fBbtrfs\fP \fBfilesystem show\fP
[\fI--mounted\fP|\fI--all-devices\fP|\fI--print-missing\fP|\fI<uuid>\fP]\fP
.PP
\fBbtrfs\fP \fBfilesystem sync\fP\fI <path> \fP
.PP
@@ -280,6 +280,8 @@ and unmounted.
If \fB--mounted\fP is passed, it would probe btrfs kernel to list mounted
btrfs filesystem(s);
If \fB--all-devices\fP is passed, all the devices under /dev are scanned;
otherwise the devices list is extracted from the /proc/partitions file.
+If \fB--print-missing\fP is passed, btrfs will try its best to print the
missing device.
+This option is only useful if the filesystem is already mounted since mounted
filesystem may contain the device list.
.TP
\fBfilesystem sync\fR\fI <path> \fR
