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author | Jeff Layton <jlayton@redhat.com> | 2008-02-11 10:00:20 -0500 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2008-02-13 23:24:04 -0500 |
commit | 8e60029f403781b8a63b7ffdb7dc1faff6ca651e (patch) | |
tree | 9eb13d36a8951ef160250bb973648426b456c46b /fs/nfs/super.c | |
parent | e760e716d47b48caf98da348368fd41b4a9b9e7e (diff) |
NFS: fix reference counting for NFSv4 callback thread
The reference counting for the NFSv4 callback thread stays artificially
high. When this thread comes down, it doesn't properly tear down the
svc_serv, causing a memory leak. In my testing on an older kernel on
x86_64, memory would leak out of the 8k kmalloc slab. So, we're leaking
at least a page of memory every time the thread comes down.
svc_create() creates the svc_serv with a sv_nrthreads count of 1, and
then svc_create_thread() increments that count. Whenever the callback
thread is started it has a sv_nrthreads count of 2. When coming down, it
calls svc_exit_thread() which decrements that count and if it hits 0, it
tears everything down. That never happens here since the count is always
at 2 when the thread exits.
The problem is that nfs_callback_up() should be calling svc_destroy() on
the svc_serv on both success and failure. This is how lockd_up_proto()
handles the reference counting, and doing that here fixes the leak.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/super.c')
0 files changed, 0 insertions, 0 deletions