From: Jeff Layton Date: Tue, 4 Mar 2014 15:30:23 +0000 (-0500) Subject: locks: require that flock->l_pid be set to 0 for file-private locks X-Git-Tag: v3.15-rc1~98^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=90478939dce096ed5b239cad16237dca0a59d66f;p=pandora-kernel.git locks: require that flock->l_pid be set to 0 for file-private locks Neil Brown suggested potentially overloading the l_pid value as a "lock context" field for file-private locks. While I don't think we will probably want to do that here, it's probably a good idea to ensure that in the future we could extend this API without breaking existing callers. Typically the l_pid value is ignored for incoming struct flock arguments, serving mainly as a place to return the pid of the owner if there is a conflicting lock. For file-private locks, require that it currently be set to 0 and return EINVAL if it isn't. If we eventually want to make a non-zero l_pid mean something, then this will help ensure that we don't break legacy programs that are using file-private locks. Cc: Neil Brown Signed-off-by: Jeff Layton --- Reading git-diff-tree failed