[kbuild-all] Re: [linux-next:master 6373/10489] fs/xfs/xfs_log_cil.c:897:1-10: second lock on line 900 (fwd)

On Thu, Jun 17, 2021 at 07:59:00PM +0100, Matthew Wilcox wrote: > On Thu, Jun 17, 2021 at 11:50:44AM -0700, Darrick J. Wong wrote: > > On Thu, Jun 17, 2021 at 08:28:24PM +0200, Julia Lawall wrote: > > > cocci warnings: (new ones prefixed by >>) > > > >> fs/xfs/xfs_log_cil.c:897:1-10: second lock on line 900 > > > > > > 5fd9256ce156ef Dave Chinner 2021-06-03 891 /* > > > 5fd9256ce156ef Dave Chinner 2021-06-03 892 * If the checkpoint spans multiple iclogs, wait for all previous > > > cb1acb3f324636 Dave Chinner 2021-06-04 893 * iclogs to complete before we submit the commit_iclog. In this case, > > > cb1acb3f324636 Dave Chinner 2021-06-04 894 * the commit_iclog write needs to issue a pre-flush so that the > > > cb1acb3f324636 Dave Chinner 2021-06-04 895 * ordering is correctly preserved down to stable storage. > > > 5fd9256ce156ef Dave Chinner 2021-06-03 896 */ > > > 5fd9256ce156ef Dave Chinner 2021-06-03 @897 spin_lock(&log->l_icloglock); > > > cb1acb3f324636 Dave Chinner 2021-06-04 898 if (ctx->start_lsn != commit_lsn) { > > > 5fd9256ce156ef Dave Chinner 2021-06-03 899 xlog_wait_on_iclog(commit_iclog->ic_prev); > > > cb1acb3f324636 Dave Chinner 2021-06-04 @900 spin_lock(&log->l_icloglock); > > > > xlog_wait_on_commit drops l_icloglock, either directly or via xlog_wait. > > It looks odd (perhaps there should be a comment?) but at least in theory > > the functions are annotated so I guess that means the static checking > > doesn't know that commit_iclog->ic_log == log? > > I think it's hard for a tool to reach into fs/xfs/xfs_log.c and look for > the __releases annotation on the definition of xlog_wait_on_commit(). > Should we also annotate the prototype in fs/xfs/xfs_log_priv.h ? > > For example, > > void wbc_attach_and_unlock_inode(struct writeback_control *wbc, > struct inode *inode) > __releases(&inode->i_lock); That depends on whether or not amending the declaration in that manner actually satisfies the checking tool? Ah, I see, __releases is a macro that only expands to anything if __CHECKER__, which is probably why the actual checker tool doesn't see this, and possibly why gcc can't complain about the mismatch between declaration and definition.