On 09/18/2014 03:05 AM, Nicholas A. Bellinger wrote: > On Wed, 2014-09-17 at 14:01 -0600, Lee Duncan wrote: >> Hi Nicholas: >> >> >> Apologies for the top-post, but my current mail agent sucks. :) >> >> >> No problem on the delay. >> >> >> What about handling "NULL" and "" as meaning "clear the current value? >> I could supply a patch ... >> >> > > While writing the earlier response, I was trying to remember why "" was > deemed insufficient in the first place for clearing the current value, > but alas the original reasoning escapes me atm. Perhaps the reason for this is that writing an empty string from the shell is not easy. Trying to do an 'echo -n "" > some_file" gets optimized into not writing anything out. I had to use something like: 'echo -n "\0" > some_file" to get it to write an empty string. > > It could very well have to do with some early user-space (eg: lio-utils) > during state re-creation had a distinction between an empty value and > explicitly clearing a value, but I still don't recall exactly why this > mattered. > > That said, there was some reasoning behind this, and I'd like to > remember why first before making a change that could negatively effect > user-space. If you remember please let me know, as I've patched our kernel to accept these NULL values. > > --nab > > -- Lee Duncan SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
