From: Chuck Lever Date: Sun, 9 Nov 2014 01:14:45 +0000 (-0500) Subject: xprtrdma: Re-write rpcrdma_flush_cqs() X-Git-Tag: omap-for-v3.19/fixes-rc1~150^2~2^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c166bef4fa138da45d756dc77a8cb29fced1714;p=pandora-kernel.git xprtrdma: Re-write rpcrdma_flush_cqs() Currently rpcrdma_flush_cqs() attempts to avoid code duplication, and simply invokes rpcrdma_recvcq_upcall and rpcrdma_sendcq_upcall. 1. rpcrdma_flush_cqs() can run concurrently with provider upcalls. Both flush_cqs() and the upcalls were invoking ib_poll_cq() in different threads using the same wc buffers (ep->rep_recv_wcs and ep->rep_send_wcs), added by commit 1c00dd077654 ("xprtrmda: Reduce calls to ib_poll_cq() in completion handlers"). During transport disconnect processing, this sometimes resulted in the same reply getting added to the rpcrdma_tasklets_g list more than once, which corrupted the list. 2. The upcall functions drain only a limited number of CQEs, thanks to the poll budget added by commit 8301a2c047cc ("xprtrdma: Limit work done by completion handler"). Fixes: a7bc211ac926 ("xprtrdma: On disconnect, don't ignore ... ") BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=276 Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- Reading git-diff-tree failed