Commit 6d548079 authored Sep 19, 2017 by J. Bruce Fields Committed by Greg Kroah-Hartman Aug 04, 2019

nfsd: give out fewer session slots as limit approaches



[ Upstream commit de766e570413bd0484af0b580299b495ada625c3 ]

Instead of granting client's full requests until we hit our DRC size
limit and then failing CREATE_SESSIONs (and hence mounts) completely,
start granting clients smaller slot tables as we approach the limit.

The factor chosen here is pretty much arbitrary.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent dbd040b4

fs/nfsd/nfs4state.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1507,6 +1507,11 @@ static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca)
		spin_lock(&nfsd_drc_lock);
		avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION,
		nfsd_drc_max_mem - nfsd_drc_mem_used);
		/*
		* Never use more than a third of the remaining memory,
		* unless it's the only way to give this client a slot:
		*/
		avail = clamp_t(int, avail, slotsize, avail/3);
		num = min_t(int, num, avail / slotsize);
		nfsd_drc_mem_used += num * slotsize;
		spin_unlock(&nfsd_drc_lock);