4.4-stable review patch. If anyone has any objections, please let me know.
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From: Waiman Long longman@redhat.com
commit 1dbd449c9943e3145148cc893c2461b72ba6fef0 upstream.
The nr_dentry_unused per-cpu counter tracks dentries in both the LRU lists and the shrink lists where the DCACHE_LRU_LIST bit is set.
The shrink_dcache_sb() function moves dentries from the LRU list to a shrink list and subtracts the dentry count from nr_dentry_unused. This is incorrect as the nr_dentry_unused count will also be decremented in shrink_dentry_list() via d_shrink_del().
To fix this double decrement, the decrement in the shrink_dcache_sb() function is taken out.
Fixes: 4e717f5c1083 ("list_lru: remove special case function list_lru_dispose_all." Cc: stable@kernel.org Signed-off-by: Waiman Long longman@redhat.com Reviewed-by: Dave Chinner dchinner@redhat.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/dcache.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
--- a/fs/dcache.c +++ b/fs/dcache.c @@ -1155,15 +1155,11 @@ static enum lru_status dentry_lru_isolat */ void shrink_dcache_sb(struct super_block *sb) { - long freed; - do { LIST_HEAD(dispose);
- freed = list_lru_walk(&sb->s_dentry_lru, + list_lru_walk(&sb->s_dentry_lru, dentry_lru_isolate_shrink, &dispose, 1024); - - this_cpu_sub(nr_dentry_unused, freed); shrink_dentry_list(&dispose); cond_resched(); } while (list_lru_count(&sb->s_dentry_lru) > 0);