On 04/03/2014 09:03 AM, Dave Reisner wrote: > On the initial call to copy_internal, we must use an invalid device > number. As of linux 3.14, the mount table has shifted slightly, causing > the initramfs filesystem to have a devno of 0. This is valid, but > confuses cp when attempting to copy only a single filesystem (cp -x). > Since dev_t is defined to be an integer type, we can simply use a > negative value to identify the unknown device.
dev_t is defined as an integral type, but not necessarily a signed integral type, and not necessarily a type as wide as int. Using -1 as a sentinel might be okay, but if you do, you MUST use a cast for maximum portability. > @@ -2434,7 +2434,7 @@ copy_internal (char const *src_name, char const > *dst_name, > } > > /* Decide whether to copy the contents of the directory. */ > - if (x->one_file_system && device != 0 && device != src_sb.st_dev) > + if (x->one_file_system && device != -1 && device != src_sb.st_dev) For example, this comparison may fail to do what you want if dev_t is uint16_t (it will ALWAYS be false, since ((uint16_t)-1) != -1). -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
