debugfs: fix segfault on "stat" command with no open fs

This is a regression from commit
8fdf29117f922419bd5b3f741e5d554b1d5b8893, which attempts to access
current_fs via a feature check before we check that it's open.

Just moving the feature check below the open check should fix it.

Reported-by: Andrew Hecox <ahecox@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index 8b0965e..95781d9 100644 (file)
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -291,9 +291,6 @@ void do_show_super_stats(int argc, char *argv[])
        int     c, header_only = 0;
        int     numdirs = 0, first, gdt_csum;
 
-       gdt_csum = EXT2_HAS_RO_COMPAT_FEATURE(current_fs->super,
-                                             EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
-
        reset_getopt();
        while ((c = getopt (argc, argv, "h")) != EOF) {
                switch (c) {
@@ -321,6 +318,8 @@ void do_show_super_stats(int argc, char *argv[])
                return;
        }
 
+       gdt_csum = EXT2_HAS_RO_COMPAT_FEATURE(current_fs->super,
+                                             EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
        gdp = &current_fs->group_desc[0];
        for (i = 0; i < current_fs->group_desc_count; i++, gdp++) {
                fprintf(out, " Group %2d: block bitmap at %u, "