diff mbox series

[PREEMPT_RT,1/2] block: Avoid sleeping function called from invalid context bug

Message ID 20211210204156.96336-2-wander@redhat.com
State Superseded
Headers show
Series Fix warnings in blktrace | expand

Commit Message

Wander Lairson Costa Dec. 10, 2021, 8:41 p.m. UTC
This was caught during QA test:

 BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:942
 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 243401, name: sed
 INFO: lockdep is turned off.
 Preemption disabled at:
 [<ffffffff89b26268>] blk_cgroup_bio_start+0x28/0xd0

 CPU: 2 PID: 243401 Comm: sed Kdump: loaded Not tainted 4.18.0-353.rt7.138.el8.x86_64+debug #1
 Hardware name: HP ProLiant DL380 Gen9, BIOS P89 05/06/2015
 Call Trace:
  dump_stack+0x5c/0x80
  ___might_sleep.cold.89+0xf5/0x109
  rt_spin_lock+0x3e/0xd0
  ? __blk_add_trace+0x428/0x4b0
  __blk_add_trace+0x428/0x4b0
  blk_add_trace_bio+0x16e/0x1c0
  generic_make_request_checks+0x7e8/0x8c0
  generic_make_request+0x3c/0x420
  ? membarrier_private_expedited+0xd0/0x2b0
  ? lock_release+0x1ca/0x450
  ? submit_bio+0x3c/0x160
  ? _raw_spin_unlock_irqrestore+0x3c/0x80
  submit_bio+0x3c/0x160
  ? rt_mutex_futex_unlock+0x66/0xa0
  iomap_submit_ioend.isra.36+0x4a/0x70
  xfs_vm_writepages+0x65/0x90 [xfs]
  do_writepages+0x41/0xe0
  ? rt_mutex_futex_unlock+0x66/0xa0
  __filemap_fdatawrite_range+0xce/0x110
  xfs_release+0x11c/0x160 [xfs]
  __fput+0xd5/0x270
  task_work_run+0xa1/0xd0
  exit_to_usermode_loop+0x14d/0x160
  do_syscall_64+0x23b/0x240
  entry_SYSCALL_64_after_hwframe+0x6a/0xdf

We replace the get/put_cpu() call by get/put_cpu_light to avoid this bug.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
---
 block/blk-cgroup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

kernel test robot Dec. 11, 2021, 5:21 a.m. UTC | #1
Hi Wander,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on axboe-block/for-next]
[also build test ERROR on linux/master linus/master v5.16-rc4]
[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]

url:    https://github.com/0day-ci/linux/commits/Wander-Lairson-Costa/Fix-warnings-in-blktrace/20211211-044405
base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next
config: i386-randconfig-a016-20211210 (https://download.01.org/0day-ci/archive/20211211/202112111300.2jYSEVK1-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 097a1cb1d5ebb3a0ec4bcaed8ba3ff6a8e33c00a)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/37b10b13961fb1af60139789717a018f788f714e
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Wander-Lairson-Costa/Fix-warnings-in-blktrace/20211211-044405
        git checkout 37b10b13961fb1af60139789717a018f788f714e
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> block/blk-cgroup.c:1915:8: error: implicit declaration of function 'get_cpu_light' [-Werror,-Wimplicit-function-declaration]
           cpu = get_cpu_light();
                 ^
>> block/blk-cgroup.c:1932:2: error: implicit declaration of function 'put_cpu_light' [-Werror,-Wimplicit-function-declaration]
           put_cpu_light();
           ^
   block/blk-cgroup.c:1932:2: note: did you mean 'get_cpu_light'?
   block/blk-cgroup.c:1915:8: note: 'get_cpu_light' declared here
           cpu = get_cpu_light();
                 ^
   2 errors generated.


vim +/get_cpu_light +1915 block/blk-cgroup.c

  1908	
  1909	void blk_cgroup_bio_start(struct bio *bio)
  1910	{
  1911		int rwd = blk_cgroup_io_type(bio), cpu;
  1912		struct blkg_iostat_set *bis;
  1913		unsigned long flags;
  1914	
> 1915		cpu = get_cpu_light();
  1916		bis = per_cpu_ptr(bio->bi_blkg->iostat_cpu, cpu);
  1917		flags = u64_stats_update_begin_irqsave(&bis->sync);
  1918	
  1919		/*
  1920		 * If the bio is flagged with BIO_CGROUP_ACCT it means this is a split
  1921		 * bio and we would have already accounted for the size of the bio.
  1922		 */
  1923		if (!bio_flagged(bio, BIO_CGROUP_ACCT)) {
  1924			bio_set_flag(bio, BIO_CGROUP_ACCT);
  1925			bis->cur.bytes[rwd] += bio->bi_iter.bi_size;
  1926		}
  1927		bis->cur.ios[rwd]++;
  1928	
  1929		u64_stats_update_end_irqrestore(&bis->sync, flags);
  1930		if (cgroup_subsys_on_dfl(io_cgrp_subsys))
  1931			cgroup_rstat_updated(bio->bi_blkg->blkcg->css.cgroup, cpu);
> 1932		put_cpu_light();
  1933	}
  1934	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 663aabfeba18..0a532bb3003c 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1911,7 +1911,7 @@  void blk_cgroup_bio_start(struct bio *bio)
 	struct blkg_iostat_set *bis;
 	unsigned long flags;
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	bis = per_cpu_ptr(bio->bi_blkg->iostat_cpu, cpu);
 	flags = u64_stats_update_begin_irqsave(&bis->sync);
 
@@ -1928,7 +1928,7 @@  void blk_cgroup_bio_start(struct bio *bio)
 	u64_stats_update_end_irqrestore(&bis->sync, flags);
 	if (cgroup_subsys_on_dfl(io_cgrp_subsys))
 		cgroup_rstat_updated(bio->bi_blkg->blkcg->css.cgroup, cpu);
-	put_cpu();
+	put_cpu_light();
 }
 
 static int __init blkcg_init(void)