diff options
| -rw-r--r-- | fs/nfsd/nfs4state.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index da1093dd5016..8622d6dd45c0 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1575,14 +1575,25 @@ static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca) unsigned long avail, total_avail; spin_lock(&nfsd_drc_lock); - total_avail = nfsd_drc_max_mem - nfsd_drc_mem_used; + if (nfsd_drc_max_mem > nfsd_drc_mem_used) + total_avail = nfsd_drc_max_mem - nfsd_drc_mem_used; + else + /* We have handed out more space than we chose in + * set_max_drc() to allow. That isn't really a + * problem as long as that doesn't make us think we + * have lots more due to integer overflow. + */ + total_avail = 0; avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION, total_avail); /* * Never use more than a third of the remaining memory, - * unless it's the only way to give this client a slot: + * unless it's the only way to give this client a slot. + * Give the client one slot even if that would require + * over-allocation--it is better than failure. */ avail = clamp_t(unsigned long, avail, slotsize, total_avail/3); num = min_t(int, num, avail / slotsize); + num = max_t(int, num, 1); nfsd_drc_mem_used += num * slotsize; spin_unlock(&nfsd_drc_lock); @@ -3174,10 +3185,10 @@ static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca, struct nfs * performance. When short on memory we therefore prefer to * decrease number of slots instead of their size. Clients that * request larger slots than they need will get poor results: + * Note that we always allow at least one slot, because our + * accounting is soft and provides no guarantees either way. */ ca->maxreqs = nfsd4_get_drc_mem(ca); - if (!ca->maxreqs) - return nfserr_jukebox; return nfs_ok; } |