Re: [PATCH 05/14] drbd: Make the lock context annotations compatible with Clang

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20260304194843.760669-6-bvanassche@acm.org>
References: <20260304194843.760669-6-bvanassche@acm.org>
TO: Bart Van Assche <bvanassche@acm.org>
TO: Jens Axboe <axboe@kernel.dk>
CC: Christoph Hellwig <hch@lst.de>
CC: Damien Le Moal <dlemoal@kernel.org>
CC: Marco Elver <elver@google.com>
CC: linux-block@vger.kernel.org
CC: Bart Van Assche <bvanassche@acm.org>
CC: Philipp Reisner <philipp.reisner@linbit.com>
CC: Lars Ellenberg <lars.ellenberg@linbit.com>
CC: "Christoph Böhmwalder" <christoph.boehmwalder@linbit.com>
CC: Nathan Chancellor <nathan@kernel.org>

Hi Bart,

kernel test robot noticed the following build warnings:

[auto build test WARNING on axboe/for-next]
[also build test WARNING on bpf-next/net bpf-next/master bpf/master linus/master v7.0-rc2 next-20260305]
[cannot apply to ceph-client/testing ceph-client/for-linus hch-configfs/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Bart-Van-Assche/drbd-Balance-RCU-calls-in-drbd_adm_dump_devices/20260305-035510
base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git for-next
patch link:    https://lore.kernel.org/r/20260304194843.760669-6-bvanassche%40acm.org
patch subject: [PATCH 05/14] drbd: Make the lock context annotations compatible with Clang
:::::: branch date: 33 hours ago
:::::: commit date: 33 hours ago
config: openrisc-randconfig-r053-20260306 (https://download.01.org/0day-ci/archive/20260306/202603061238.WbZr6WGt-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 15.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Julia Lawall <julia.lawall@inria.fr>
| Closes: https://lore.kernel.org/r/202603061238.WbZr6WGt-lkp@intel.com/

cocci warnings: (new ones prefixed by >>)
>> drivers/block/drbd/drbd_bitmap.c:132:16-25: ERROR: b is NULL but dereferenced.
   drivers/block/drbd/drbd_bitmap.c:159:16-25: ERROR: b is NULL but dereferenced.

vim +132 drivers/block/drbd/drbd_bitmap.c

b411b3637fa71fc Philipp Reisner     2009-09-25  123  
b30ab7913b0a7b1 Andreas Gruenbacher 2011-07-03  124  void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags)
9c640e625a48df2 Bart Van Assche     2026-03-04  125  	__acquires(&device->bitmap->bm_change)
b411b3637fa71fc Philipp Reisner     2009-09-25  126  {
b30ab7913b0a7b1 Andreas Gruenbacher 2011-07-03  127  	struct drbd_bitmap *b = device->bitmap;
b411b3637fa71fc Philipp Reisner     2009-09-25  128  	int trylock_failed;
b411b3637fa71fc Philipp Reisner     2009-09-25  129  
b411b3637fa71fc Philipp Reisner     2009-09-25  130  	if (!b) {
d01801710265cfb Andreas Gruenbacher 2011-07-03  131  		drbd_err(device, "FIXME no bitmap in drbd_bm_lock!?\n");
9c640e625a48df2 Bart Van Assche     2026-03-04 @132  		__acquire(&b->bm_change);
b411b3637fa71fc Philipp Reisner     2009-09-25  133  		return;
b411b3637fa71fc Philipp Reisner     2009-09-25  134  	}
b411b3637fa71fc Philipp Reisner     2009-09-25  135  
8a03ae2a5baed3d Thomas Gleixner     2010-01-29  136  	trylock_failed = !mutex_trylock(&b->bm_change);
b411b3637fa71fc Philipp Reisner     2009-09-25  137  
b411b3637fa71fc Philipp Reisner     2009-09-25  138  	if (trylock_failed) {
c60b0251d9d3501 Andreas Gruenbacher 2011-08-10  139  		drbd_warn(device, "%s[%d] going to '%s' but bitmap already locked for '%s' by %s[%d]\n",
c60b0251d9d3501 Andreas Gruenbacher 2011-08-10  140  			  current->comm, task_pid_nr(current),
b411b3637fa71fc Philipp Reisner     2009-09-25  141  			  why, b->bm_why ?: "?",
c60b0251d9d3501 Andreas Gruenbacher 2011-08-10  142  			  b->bm_task->comm, task_pid_nr(b->bm_task));
8a03ae2a5baed3d Thomas Gleixner     2010-01-29  143  		mutex_lock(&b->bm_change);
b411b3637fa71fc Philipp Reisner     2009-09-25  144  	}
20ceb2b22edaf51 Lars Ellenberg      2011-01-21  145  	if (BM_LOCKED_MASK & b->bm_flags)
d01801710265cfb Andreas Gruenbacher 2011-07-03  146  		drbd_err(device, "FIXME bitmap already locked in bm_lock\n");
20ceb2b22edaf51 Lars Ellenberg      2011-01-21  147  	b->bm_flags |= flags & BM_LOCKED_MASK;
b411b3637fa71fc Philipp Reisner     2009-09-25  148  
b411b3637fa71fc Philipp Reisner     2009-09-25  149  	b->bm_why  = why;
b411b3637fa71fc Philipp Reisner     2009-09-25  150  	b->bm_task = current;
b411b3637fa71fc Philipp Reisner     2009-09-25  151  }
b411b3637fa71fc Philipp Reisner     2009-09-25  152  

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