svn commit: r300339 - projects/zfsd/head/cddl/usr.sbin/zfsd

[Alan Somers]

Author: asomers
Date: Sat May 21 00:43:10 2016
New Revision: 300339
URL: https://svnweb.freebsd.org/changeset/base/300339

Log:
  Fix a crash bug in zfsd when destroying a pool with I/O errors
  
  cddl/usr.sbin/zfsd/case_file.cc
  	CaseFile::ReEvaluateByGuid was calling std::for_each on a std::list
  	of CaseFiles.  However, the functor would sometimes remove a
  	CaseFile from the list, which caused a segfault in std::for_each.
  	The solution is to remove the use of for_each.  Instead, manually
  	iterate through the list, taking care not to access potentially
  	invalid iterators.
  
  Sponsored by:	Spectra Logic Corp

Modified:
  projects/zfsd/head/cddl/usr.sbin/zfsd/case_file.cc

Modified: projects/zfsd/head/cddl/usr.sbin/zfsd/case_file.cc
==============================================================================
--- projects/zfsd/head/cddl/usr.sbin/zfsd/case_file.cc	Sat May 21 00:34:54 2016	(r300338)
+++ projects/zfsd/head/cddl/usr.sbin/zfsd/case_file.cc	Sat May 21 00:43:10 2016	(r300339)
@@ -89,36 +89,6 @@ using DevdCtl::EventList;
 using DevdCtl::Guid;
 using DevdCtl::ParseException;
 
-/*-------------------------- File-scoped classes ----------------------------*/
-/**
- * \brief Functor that operators on STL collections of CaseFiles
- *
- * Selectively calls ReEvaluate on the casefile, based on its pool GUID.
- */
-class CaseFileReEvaluator : public std::unary_function<CaseFile, bool>
-{
-public:
-	CaseFileReEvaluator(Guid guid, const ZfsEvent &event);
-
-	void operator() (CaseFile *casefile);
-
-private:
-	Guid		m_poolGUID;
-	const ZfsEvent &m_event;
-};
-
-CaseFileReEvaluator::CaseFileReEvaluator(Guid guid, const ZfsEvent &event)
- : m_poolGUID(guid), m_event(event)
-{
-}
-
-void
-CaseFileReEvaluator::operator() (CaseFile *casefile)
-{
-	if (m_poolGUID == casefile->PoolGUID())
-		casefile->ReEvaluate(m_event);
-}
-
 /*--------------------------------- CaseFile ---------------------------------*/
 //- CaseFile Static Data -------------------------------------------------------
 CaseFileList  CaseFile::s_activeCases;
@@ -170,8 +140,13 @@ CaseFile::Find(const string &physPath)
 void
 CaseFile::ReEvaluateByGuid(Guid poolGUID, const ZfsEvent &event)
 {
-	CaseFileReEvaluator reevaluator(poolGUID, event);
-	std::for_each(s_activeCases.begin(), s_activeCases.end(), reevaluator);
+	CaseFileList::iterator casefile;
+	for (casefile = s_activeCases.begin(); casefile != s_activeCases.end();){
+		CaseFileList::iterator next = std::next(casefile);
+		if (poolGUID == (*casefile)->PoolGUID())
+			(*casefile)->ReEvaluate(event);
+		casefile = next;
+	}
 }
 
 CaseFile &