Revision 4cdd2ad78098244c1bc9ec4374ea1c225fd1cd6f authored by Mike Snitzer on 13 May 2014, 17:49:39 UTC, committed by Mike Snitzer on 14 May 2014, 20:12:17 UTC
Commit 3e9f1be1b40 ("dm mpath: remove process_queued_ios()") did not consistently take the multipath device's spinlock (m->lock) before calling dm_table_run_md_queue_async() -- which takes the q->queue_lock. Found with code inspection using hint from reported lockdep warning. Reported-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
1 parent 85ad643
debug_locks.c
/*
* lib/debug_locks.c
*
* Generic place for common debugging facilities for various locks:
* spinlocks, rwlocks, mutexes and rwsems.
*
* Started by Ingo Molnar:
*
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/rwsem.h>
#include <linux/mutex.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/debug_locks.h>
/*
* We want to turn all lock-debugging facilities on/off at once,
* via a global flag. The reason is that once a single bug has been
* detected and reported, there might be cascade of followup bugs
* that would just muddy the log. So we report the first one and
* shut up after that.
*/
int debug_locks = 1;
EXPORT_SYMBOL_GPL(debug_locks);
/*
* The locking-testsuite uses <debug_locks_silent> to get a
* 'silent failure': nothing is printed to the console when
* a locking bug is detected.
*/
int debug_locks_silent;
EXPORT_SYMBOL_GPL(debug_locks_silent);
/*
* Generic 'turn off all lock debugging' function:
*/
int debug_locks_off(void)
{
if (__debug_locks_off()) {
if (!debug_locks_silent) {
console_verbose();
return 1;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(debug_locks_off);
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...