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| author | Benjamin Coddington <bcodding@redhat.com> | 2017-04-11 12:50:12 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2017-04-21 10:45:01 -0400 |
| commit | f30cb757f680f965ba8a2e53cb3588052a01aeb5 (patch) | |
| tree | 071e925905e0931b326f5474619adb0aa645d07b /fs/nfs/file.c | |
| parent | b1ece737f44f91dca8f4829cf0b442e752e406db (diff) | |
| download | linux-f30cb757f680f965ba8a2e53cb3588052a01aeb5.tar.gz | |
NFS: Always wait for I/O completion before unlock
NFS attempts to wait for read and write completion before unlocking in
order to ensure that the data returned was protected by the lock. When
this waiting is interrupted by a signal, the unlock may be skipped, and
messages similar to the following are seen in the kernel ring buffer:
[20.167876] Leaked locks on dev=0x0:0x2b ino=0x8dd4c3:
[20.168286] POSIX: fl_owner=ffff880078b06940 fl_flags=0x1 fl_type=0x0 fl_pid=20183
[20.168727] POSIX: fl_owner=ffff880078b06680 fl_flags=0x1 fl_type=0x0 fl_pid=20185
For NFSv3, the missing unlock will cause the server to refuse conflicting
locks indefinitely. For NFSv4, the leftover lock will be removed by the
server after the lease timeout.
This patch fixes this issue by skipping the usual wait in
nfs_iocounter_wait if the FL_CLOSE flag is set when signaled. Instead, the
wait happens in the unlock RPC task on the NFS UOC rpc_waitqueue.
For NFSv3, use lockd's new nlmclnt_operations along with
nfs_async_iocounter_wait to defer NLM's unlock task until the lock
context's iocounter reaches zero.
For NFSv4, call nfs_async_iocounter_wait() directly from unlock's
current rpc_call_prepare.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs/file.c')
| -rw-r--r-- | fs/nfs/file.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c index b7f4af3483b6a..bebed885b6e49 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -697,14 +697,14 @@ do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local) if (!IS_ERR(l_ctx)) { status = nfs_iocounter_wait(l_ctx); nfs_put_lock_context(l_ctx); - if (status < 0) + /* NOTE: special case + * If we're signalled while cleaning up locks on process exit, we + * still need to complete the unlock. + */ + if (status < 0 && !(fl->fl_flags & FL_CLOSE)) return status; } - /* NOTE: special case - * If we're signalled while cleaning up locks on process exit, we - * still need to complete the unlock. - */ /* * Use local locking if mounted with "-onolock" or with appropriate * "-olocal_lock=" |