nfsd: don't halt scanning the DRC LRU list when there's an RC_INPROG entry (1b19453d) · Commits · 戴 / test

Currently, the DRC cache pruner will stop scanning the list when it hits an entry that is RC_INPROG. It's possible however for a call to take a *very* long time. In that case, we don't want it to block other entries from being pruned if they are expired or we need to trim the cache to get back under the limit. Fix the DRC cache pruner to just ignore RC_INPROG entries. Signed-off-by:

Jeff Layton <jlayton@primarydata.com> Signed-off-by:

J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfscache.c

+8 −9

Original line number	Diff line number	Diff line
		@@ -224,13 +224,6 @@ hash_refile(struct svc_cacherep *rp)
		hlist_add_head(&rp->c_hash, cache_hash + hash_32(rp->c_xid, maskbits));
		}

		static inline bool
		nfsd_cache_entry_expired(struct svc_cacherep *rp)
		{
		return rp->c_state != RC_INPROG &&
		time_after(jiffies, rp->c_timestamp + RC_EXPIRE);
		}

		/*
		* Walk the LRU list and prune off entries that are older than RC_EXPIRE.
		* Also prune the oldest ones when the total exceeds the max number of entries.
		@@ -242,8 +235,14 @@ prune_cache_entries(void)
		long freed = 0;

		list_for_each_entry_safe(rp, tmp, &lru_head, c_lru) {
		if (!nfsd_cache_entry_expired(rp) &&
		num_drc_entries <= max_drc_entries)
		/*
		* Don't free entries attached to calls that are still
		* in-progress, but do keep scanning the list.
		*/
		if (rp->c_state == RC_INPROG)
		continue;
		if (num_drc_entries <= max_drc_entries &&
		time_before(jiffies, rp->c_timestamp + RC_EXPIRE))
		break;
		nfsd_reply_cache_free_locked(rp);
		freed++;

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