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authorNeilBrown <neilb@suse.de>2013-06-13 12:53:42 +1000
committerJ. Bruce Fields <bfields@redhat.com>2013-07-01 17:53:28 -0400
commit013920eb5db97e99a4c30c8400f1c616e2a8b0a2 (patch)
treef4d1e80073ac61199d898a793815ee6dd493351b /include/linux/sunrpc/cache.h
parent2a1c7f53fd31e46f51780b61eb99fffef4c3c5a6 (diff)
sunrpc/cache: ensure items removed from cache do not have pending upcalls.
It is possible for a race to set CACHE_PENDING after cache_clean() has removed a cache entry from the cache. If CACHE_PENDING is still set when the entry is finally 'put', the cache_dequeue() will never happen and we can leak memory. So set a new flag 'CACHE_CLEANED' when we remove something from the cache, and don't queue any upcall if it is set. If CACHE_PENDING is set before CACHE_CLEANED, the call that cache_clean() makes to cache_fresh_unlocked() will free memory as needed. If CACHE_PENDING is set after CACHE_CLEANED, the test in sunrpc_cache_pipe_upcall will ensure that the memory is not allocated. Reported-by: <bstroesser@ts.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'include/linux/sunrpc/cache.h')
-rw-r--r--include/linux/sunrpc/cache.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 303399b1ba59..8419f7dbdab2 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -57,6 +57,7 @@ struct cache_head {
#define CACHE_VALID 0 /* Entry contains valid data */
#define CACHE_NEGATIVE 1 /* Negative entry - there is no match for the key */
#define CACHE_PENDING 2 /* An upcall has been sent but no reply received yet*/
+#define CACHE_CLEANED 3 /* Entry has been cleaned from cache */
#define CACHE_NEW_EXPIRY 120 /* keep new things pending confirmation for 120 seconds */