From cf86f7a97561fbdf18edd25da833419196504db2 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 21 Mar 2019 09:39:52 +0800 Subject: [PATCH] rhashtable: Still do rehash when we get EEXIST [ Upstream commit 408f13ef358aa5ad56dc6230c2c7deb92cf462b1 ] As it stands if a shrink is delayed because of an outstanding rehash, we will go into a rescheduling loop without ever doing the rehash. This patch fixes this by still carrying out the rehash and then rescheduling so that we can shrink after the completion of the rehash should it still be necessary. The return value of EEXIST captures this case and other cases (e.g., another thread expanded/rehashed the table at the same time) where we should still proceed with the rehash. Fixes: da20420f83ea ("rhashtable: Add nested tables") Reported-by: Josh Elsasser Signed-off-by: Herbert Xu Tested-by: Josh Elsasser Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- lib/rhashtable.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 30526afa8343..6410c857b048 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -416,8 +416,12 @@ static void rht_deferred_worker(struct work_struct *work) else if (tbl->nest) err = rhashtable_rehash_alloc(ht, tbl, tbl->size); - if (!err) - err = rhashtable_rehash_table(ht); + if (!err || err == -EEXIST) { + int nerr; + + nerr = rhashtable_rehash_table(ht); + err = err ?: nerr; + } mutex_unlock(&ht->mutex);