linux/fs/ocfs2/dlm
Junxiao Bi b1432a2a35 ocfs2: dlm: fix race between purge and get lock resource
There is a race window in dlm_get_lock_resource(), which may return a
lock resource which has been purged.  This will cause the process to
hang forever in dlmlock() as the ast msg can't be handled due to its
lock resource not existing.

    dlm_get_lock_resource {
        ...
        spin_lock(&dlm->spinlock);
        tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
        if (tmpres) {
             spin_unlock(&dlm->spinlock);
             >>>>>>>> race window, dlm_run_purge_list() may run and purge
                              the lock resource
             spin_lock(&tmpres->spinlock);
             ...
             spin_unlock(&tmpres->spinlock);
        }
    }

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05 17:10:11 -07:00
..
dlmapi.h ocfs2/trivial: Remove trailing whitespaces 2010-01-25 19:20:51 -08:00
dlmast.c o2dlm: fix NULL pointer dereference in o2dlm_blocking_ast_wrapper 2015-02-10 14:30:30 -08:00
dlmcommon.h ocfs2/dlm: do not purge lockres that is queued for assert master 2014-06-23 16:47:45 -07:00
dlmconvert.c ocfs2: use list_for_each_entry() instead of list_for_each() 2013-09-11 15:56:36 -07:00
dlmconvert.h
dlmdebug.c ocfs2: fix snprintf format specifier in dlmdebug.c 2015-02-10 14:30:29 -08:00
dlmdebug.h ocfs2/dlm: Cleanup dlmdebug.c 2010-12-22 18:34:44 -08:00
dlmdomain.c ocfs2: dlm: dlmdomain: remove unused function 2015-02-10 14:30:29 -08:00
dlmdomain.h ocfs2: dlm: dlmdomain: remove unused function 2015-02-10 14:30:29 -08:00
dlmlock.c ocfs2: remove NULL assignments on static 2014-06-04 16:53:53 -07:00
dlmmaster.c ocfs2: dlm: fix race between purge and get lock resource 2015-05-05 17:10:11 -07:00
dlmrecovery.c ocfs2/dlm: add missing dlm_lock_put() when recovery master down 2015-02-10 14:30:28 -08:00
dlmthread.c ocfs2/dlm: do not purge lockres that is queued for assert master 2014-06-23 16:47:45 -07:00
dlmunlock.c ocfs2: fix deadlock when two nodes are converting same lock from PR to EX and idletimeout closes conn 2014-06-23 16:47:45 -07:00
Makefile ocfs2: remove versioning information 2014-01-21 16:19:41 -08:00