1ca52fcfac
For a failing smc_listen_rdma_finish() smc_listen_decline() is called. If fallback is possible, the new socket is already enqueued to be accepted in smc_listen_decline(). Avoid enqueuing a second time afterwards in this case, otherwise the smc_create_lgr_pending lock is released twice: [ 373.463976] WARNING: bad unlock balance detected! [ 373.463978] 4.18.0-rc7+ #123 Tainted: G O [ 373.463979] ------------------------------------- [ 373.463980] kworker/1:1/30 is trying to release lock (smc_create_lgr_pending) at: [ 373.463990] [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc] [ 373.463991] but there are no more locks to release! [ 373.463991] other info that might help us debug this: [ 373.463993] 2 locks held by kworker/1:1/30: [ 373.463994] #0: 00000000772cbaed ((wq_completion)"events"){+.+.}, at: process_one_work+0x1ec/0x6b0 [ 373.464000] #1: 000000003ad0894a ((work_completion)(&new_smc->smc_listen_work)){+.+.}, at: process_one_work+0x1ec/0x6b0 [ 373.464003] stack backtrace: [ 373.464005] CPU: 1 PID: 30 Comm: kworker/1:1 Kdump: loaded Tainted: G O 4.18.0-rc7uschi+ #123 [ 373.464007] Hardware name: IBM 2827 H43 738 (LPAR) [ 373.464010] Workqueue: events smc_listen_work [smc] [ 373.464011] Call Trace: [ 373.464015] ([<0000000000114100>] show_stack+0x60/0xd8) [ 373.464019] [<0000000000a8c9bc>] dump_stack+0x9c/0xd8 [ 373.464021] [<00000000001dcaf8>] print_unlock_imbalance_bug+0xf8/0x108 [ 373.464022] [<00000000001e045c>] lock_release+0x114/0x4f8 [ 373.464025] [<0000000000aa87fa>] __mutex_unlock_slowpath+0x4a/0x300 [ 373.464027] [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc] [ 373.464029] [<0000000000197a68>] process_one_work+0x2a8/0x6b0 [ 373.464030] [<0000000000197ec2>] worker_thread+0x52/0x410 [ 373.464033] [<000000000019fd0e>] kthread+0x15e/0x178 [ 373.464035] [<0000000000aaf58a>] kernel_thread_starter+0x6/0xc [ 373.464052] [<0000000000aaf584>] kernel_thread_starter+0x0/0xc [ 373.464054] INFO: lockdep is turned off. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.