bzip2/lzma: comprehensible error messages for missing decompressor

Instead of failing to identify a compressed image with a decompressor
that we don't have compiled in, identify it and fail with a
comprehensible panic message.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
index a015e267fd17..91d0cfca5071 100644
--- a/init/do_mounts_rd.c
+++ b/init/do_mounts_rd.c
@@ -79,9 +79,12 @@ identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
         sys_read(fd, buf, size);
 
         *decompressor = decompress_method(buf, size, &compress_name);
-        if (*decompressor) {
+        if (compress_name) {
                 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
                        compress_name, start_block);
+                if (!*decompressor)
+                        printk(KERN_CRIT "RAMDISK: %s decompressor not configured!\n",
+                               compress_name);
                 nblocks = 0;
                 goto done;
         }