This is a note to let you know that I've just added the patch titled
nfsd: don't halt scanning the DRC LRU list when there's an RC_INPROG entry
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-don-t-halt-scanning-the-drc-lru-list-when-there-s-an-rc_inprog-entry.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1b19453d1c6abcfa7c312ba6c9f11a277568fc94 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
Date: Thu, 5 Jun 2014 09:45:00 -0400
Subject: nfsd: don't halt scanning the DRC LRU list when there's an RC_INPROG entry
From: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
commit 1b19453d1c6abcfa7c312ba6c9f11a277568fc94 upstream.
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@xxxxxxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfsd/nfscache.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -221,13 +221,6 @@ 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.
@@ -238,8 +231,14 @@ prune_cache_entries(void)
struct svc_cacherep *rp, *tmp;
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);
}
Patches currently in stable-queue which might be from jlayton@xxxxxxxxxxxxxxx are
queue-3.10/nfsd-don-t-halt-scanning-the-drc-lru-list-when-there-s-an-rc_inprog-entry.patch
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