[PATCH v2] btrfs-progs: fix segfault when listing column OTIME on big endian host

[Eryu Guan <guaneryu@gmail.com>]

The second btrfs command segfaults on big endian host(ppc64)

	btrfs subvolume snapshot /mnt/btrfs /mnt/btrfs/snap
	btrfs subvolume list -s /mnt/btrfs

And ltrace shows

	localtime(0x10029c482d0)                 = 0
	strftime( <no return ...>
	--- SIGSEGV (Segmentation fault) ---

The corresponding code

btrfs-list.c:
        case BTRFS_LIST_OTIME:
                if (subv->otime)
                        strftime(tstr, 256, "%Y-%m-%d %X",
                                 localtime(&subv->otime));
                else
                        strcpy(tstr, "-");
                printf("%s", tstr);
                break;

localtime() returned NULL then strftime() got SIGSEGV.

The reason is that ri->otime.sec is stored as little endian but
assigned to 't' without conversion.

Signed-off-by: Eryu Guan <guaneryu@gmail.com>
---
v1->v2:
  use btrfs_stack_timespec_sec() instead of raw convert.
  Thanks Miao Xie <miaox@cn.fujitsu.com> for pointing this out.

 btrfs-list.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/btrfs-list.c b/btrfs-list.c
index 4fab858..9deddd5 100644
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -1052,7 +1052,7 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
 				flags = btrfs_root_flags(ri);
 				if(sh.len >
 				   sizeof(struct btrfs_root_item_v0)) {
-					t = ri->otime.sec;
+					t = btrfs_stack_timespec_sec(&ri->otime);
 					ogen = btrfs_root_otransid(ri);
 					memcpy(uuid, ri->uuid, BTRFS_UUID_SIZE);
 					memcpy(puuid, ri->parent_uuid, BTRFS_UUID_SIZE);
-- 
1.8.3.1