From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [PATCH md 0 of 2] Introduction Date: Fri, 03 Sep 2004 12:27:31 +1000 Sender: linux-raid-owner@vger.kernel.org Message-ID: <20040903122034.15346.patches@notabene> Return-path: To: Andrew Morton Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Two patches for md in 2.6.9-rc1-mm2 The first adds support for notifying user-space of events in md. The mechanism is very simple. A reader of /proc/mdstat can select for "exceptional" events. When select/poll indicates one of these, the reader should re-read /proc/mdstat from the top looking for changes, and then select again. If the reader opens for write as well (O_RDWR) (only root can do this), then it indicates that it is prepared to take remedial action. This is currently only relevant for multipath. On last-drive-failure, if there is a reader of /proc/mdstat that has an open for write, then multipath will wait for that reader to add a new drive or take other action before resubmitting the failed requests. The second patch just fixes a counter in raid5/6 which could get out-by-one, and so produce confusing messages. (I think I sent a single item of junk just before this, sorry about that. Please ignore it). NeilBrown