[android-common:upstream-linux-5.10.y 0/334] drivers/scsi/scsi_lib.c:321:16: warning: mixing declarations and code is a C99 extension

[android-common:upstream-linux-5.10.y 0/334] drivers/scsi/scsi_lib.c:321:16: warning: mixing declarations and code is a C99 extension

[kernel test robot]

tree:   https://android.googlesource.com/kernel/common upstream-linux-5.10.y
head:   aed5c3b77cd53ba74f66767b03bfb9177662af4b
commit: cc872e35c0df80062abc71268d690a2f749e542e [0/334] scsi: core: Wake up the error handler when final completions race against each other
config: x86_64-buildonly-randconfig-002-20260305 (https://download.01.org/0day-ci/archive/20260305/202603051152.AzF904IE-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 9a109fbb6e184ec9bcce10615949f598f4c974a9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260305/202603051152.AzF904IE-lkp@intel.com/reproduce)

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>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603051152.AzF904IE-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/scsi/scsi_lib.c:321:16: warning: mixing declarations and code is a C99 extension [-Wdeclaration-after-statement]
     321 |                 unsigned int busy = scsi_host_busy(shost);
         |                              ^
   1 warning generated.


vim +321 drivers/scsi/scsi_lib.c

392160335c798b James Bottomley   2005-06-15  296  
3bd6f43f5cb371 Bart Van Assche   2017-12-04  297  /*
6eb045e092efef Ming Lei          2019-10-25  298   * Wake up the error handler if necessary. Avoid as follows that the error
6eb045e092efef Ming Lei          2019-10-25  299   * handler is not woken up if host in-flight requests number ==
6eb045e092efef Ming Lei          2019-10-25  300   * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination
6eb045e092efef Ming Lei          2019-10-25  301   * with an RCU read lock in this function to ensure that this function in
6eb045e092efef Ming Lei          2019-10-25  302   * its entirety either finishes before scsi_eh_scmd_add() increases the
3bd6f43f5cb371 Bart Van Assche   2017-12-04  303   * host_failed counter or that it notices the shost state change made by
3bd6f43f5cb371 Bart Van Assche   2017-12-04  304   * scsi_eh_scmd_add().
3bd6f43f5cb371 Bart Van Assche   2017-12-04  305   */
6eb045e092efef Ming Lei          2019-10-25  306  static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
^1da177e4c3f41 Linus Torvalds    2005-04-16  307  {
^1da177e4c3f41 Linus Torvalds    2005-04-16  308  	unsigned long flags;
^1da177e4c3f41 Linus Torvalds    2005-04-16  309  
3bd6f43f5cb371 Bart Van Assche   2017-12-04  310  	rcu_read_lock();
6eb045e092efef Ming Lei          2019-10-25  311  	__clear_bit(SCMD_STATE_INFLIGHT, &cmd->state);
3bd6f43f5cb371 Bart Van Assche   2017-12-04  312  	if (unlikely(scsi_host_in_recovery(shost))) {
cc872e35c0df80 David Jeffery     2026-01-13  313  		/*
cc872e35c0df80 David Jeffery     2026-01-13  314  		 * Ensure the clear of SCMD_STATE_INFLIGHT is visible to
cc872e35c0df80 David Jeffery     2026-01-13  315  		 * other CPUs before counting busy requests. Otherwise,
cc872e35c0df80 David Jeffery     2026-01-13  316  		 * reordering can cause CPUs to race and miss an eh wakeup
cc872e35c0df80 David Jeffery     2026-01-13  317  		 * when no CPU sees all busy requests as done or timed out.
cc872e35c0df80 David Jeffery     2026-01-13  318  		 */
cc872e35c0df80 David Jeffery     2026-01-13  319  		smp_mb();
cc872e35c0df80 David Jeffery     2026-01-13  320  
9878c660d1f0d3 Ming Lei          2024-02-03 @321  		unsigned int busy = scsi_host_busy(shost);
9878c660d1f0d3 Ming Lei          2024-02-03  322  
74665016086615 Christoph Hellwig 2014-01-22  323  		spin_lock_irqsave(shost->host_lock, flags);
3bd6f43f5cb371 Bart Van Assche   2017-12-04  324  		if (shost->host_failed || shost->host_eh_scheduled)
9878c660d1f0d3 Ming Lei          2024-02-03  325  			scsi_eh_wakeup(shost, busy);
74665016086615 Christoph Hellwig 2014-01-22  326  		spin_unlock_irqrestore(shost->host_lock, flags);
74665016086615 Christoph Hellwig 2014-01-22  327  	}
3bd6f43f5cb371 Bart Van Assche   2017-12-04  328  	rcu_read_unlock();
3bd6f43f5cb371 Bart Van Assche   2017-12-04  329  }
3bd6f43f5cb371 Bart Van Assche   2017-12-04  330  

:::::: The code at line 321 was first introduced by commit
:::::: 9878c660d1f0d37715547668adf241b5fb171dc1 scsi: core: Move scsi_host_busy() out of host lock if it is for per-command

:::::: TO: Ming Lei <ming.lei@redhat.com>
:::::: CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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