]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
sunrpc: fix cache_head leak due to queued request
authorVasily Averin <vvs@virtuozzo.com>
Wed, 28 Nov 2018 08:45:57 +0000 (11:45 +0300)
committerJ. Bruce Fields <bfields@redhat.com>
Tue, 4 Dec 2018 20:42:08 +0000 (15:42 -0500)
commit4ecd55ea074217473f94cfee21bb72864d39f8d7
tree273aa85947dace0ad1f2a7d6dd2350e07a658719
parentf50c9d797d3df41e13265491c722d3d15b038d57
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 <ptikhomirov@virtuozzo.com>
Cc: stable@kernel.org # 2.6.35
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
net/sunrpc/cache.c