sunrpc: fix cache_head leak due to queued request

After commit d202cce8963d, an expired cache_head can be removed from the
cache_detail's hash.

However, the expired cache_head may be waiting for a reply from a
previously submitted request. Such a cache_head has an increased
refcounter and therefore it won't be freed after cache_put(freeme).

Because the cache_head was removed from the hash it cannot be found
during cache_clean() and can be leaked forever, together with stalled
cache_request and other taken resources.

In our case we noticed it because an entry in the export cache was
holding a reference on a filesystem.

Fixes d202cce8963d ("sunrpc: never return expired entries in sunrpc_cache_lookup")
Cc: Pavel Tikhomirov <[email protected]>
Cc: [email protected] # 2.6.35
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: NeilBrown <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>

0 files changed, 0 insertions, 0 deletions