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| author |   Andreas Dilger <andreas.dilger@intel.com> | 2016-06-20 16:55:52 -0400 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-20 14:28:39 -0700 |
| commit | 9936913e549bca6721157418bb5014118c3786e0 (patch) | |
| tree | b29ba5f83cc49189b7b1fa128dad3c90ff606f54 /drivers/staging/lustre/lustre/mgc | |
| parent | staging/lustre/libcfs: Do not call kthread_run in wrong state (diff) | |
| download | linux-dev-9936913e549bca6721157418bb5014118c3786e0.tar.xz linux-dev-9936913e549bca6721157418bb5014118c3786e0.zip | |
staging: lustre: quiet lockdep recursive lock warning
Lockdep complains about potential recursive locking during mount
because the client configuration log is holding a lock on the MGC
obd_device to prevent it from being torn down, while also getting
mutexes on the MDC and OSC devices as they are instantiated:
Lustre: Mounted myth-client
=============================================
[ INFO: possible recursive locking detected ]
4.7.0-rc2-vm-nfs+ #127 Tainted: G C
---------------------------------------------
May be due to missing lock nesting notation
2 locks held by ll_cfg_requeue/5928:
#0: (&cli->cl_sem){.+.+.+}, at: mgc_requeue_thread+0x15d/0x730 [mgc]
#1: (&cld->cld_lock){+.+.+.}, at: mgc_process_log+0x5e/0xf80 [mgc]
CPU: 0 PID: 5928 Comm: ll_cfg_requeue
Call Trace:
[<ffffffff814a0855>] dump_stack+0x86/0xc1
[<ffffffff810e7766>] __lock_acquire+0x726/0x1210
[<ffffffff810e86be>] lock_acquire+0xfe/0x1f0
[<ffffffff81888171>] down_read+0x51/0xa0
[<ffffffffa04a8477>] sptlrpc_conf_client_adapt+0x47/0x150 [ptlrpc]
[<ffffffffa0186b16>] mdc_set_info_async+0x2b6/0x470 [mdc]
[<ffffffffa0294090>] class_notify_sptlrpc_conf+0x190/0x360 [obdclass]
[<ffffffffa01a9e85>] mgc_process_log+0x925/0xf80 [mgc]
[<ffffffffa01abafa>] mgc_requeue_thread+0x1fa/0x730 [mgc]
[<ffffffff810af331>] kthread+0x101/0x120
[<ffffffff8188ad6f>] ret_from_fork+0x1f/0x40
Add a separate lock class for the MGC callpath, since it will always
be held first, and none of the other obd_device locks should ever
be held concurrently.
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/lustre/lustre/mgc')
| -rw-r--r-- | drivers/staging/lustre/lustre/mgc/mgc_request.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/staging/lustre/lustre/mgc/mgc_request.c b/drivers/staging/lustre/lustre/mgc/mgc_request.c index fbbf2762ac84..9d0bd4745865 100644 --- a/drivers/staging/lustre/lustre/mgc/mgc_request.c +++ b/drivers/staging/lustre/lustre/mgc/mgc_request.c @@ -496,7 +496,9 @@ static void do_requeue(struct config_llog_data *cld) * export which is being disconnected. Take the client * semaphore to make the check non-racy. */ - down_read(&cld->cld_mgcexp->exp_obd->u.cli.cl_sem); + down_read_nested(&cld->cld_mgcexp->exp_obd->u.cli.cl_sem, + OBD_CLI_SEM_MGC); + if (cld->cld_mgcexp->exp_obd->u.cli.cl_conn_count != 0) { int rc; |