mirrors/scst
1
0
Fork 0
mirror of https://github.com/SCST-project/scst.git synced 2026-05-14 09:11:27 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merged revisions 6724,6728 via svnmerge from

Browse Source 
svn+ssh://vlnb@svn.code.sf.net/p/scst/svn/trunk

........
  r6724 | bvassche | 2015-12-09 11:18:01 -0800 (Wed, 09 Dec 2015) | 24 lines
  
  scst_main: Fix wait_event() call in scst_unregister_target()
  
  Avoid that the following kernel warning gets triggered:
  
  WARNING: CPU: 3 PID: 12967 at kernel/sched/core.c:7287 __might_sleep+0x7a/0x90()
  do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81097cfe>] prepare_to_wait_event+0x5e/0xf0
  CPU: 3 PID: 12967 Comm: scst_uid Tainted: G           O    4.0.0-debug+ #1
  Call Trace:
   [<ffffffff815f11cb>] dump_stack+0x4c/0x65
   [<ffffffff81053930>] warn_slowpath_common+0x80/0xc0
   [<ffffffff810539b1>] warn_slowpath_fmt+0x41/0x50
   [<ffffffff81079c1a>] __might_sleep+0x7a/0x90
   [<ffffffff815f5d4a>] mutex_lock_nested+0x2a/0x4d0
   [<ffffffffa035330a>] test_sess_list+0x1a/0x40 [scst]
   [<ffffffffa0355b1e>] scst_unregister_target+0x26e/0x380 [scst]
   [<ffffffffa01f6c86>] __scst_local_remove_target+0xc6/0x160 [scst_local]
   [<ffffffffa01f6ddc>] scst_local_sysfs_del_target+0xbc/0x1b0 [scst_local]
   [<ffffffffa038b315>] scst_process_tgtt_mgmt_store+0x205/0x300 [scst]
   [<ffffffffa038b424>] scst_tgtt_mgmt_store_work_fn+0x14/0x20 [scst]
   [<ffffffffa038cc1d>] scst_process_sysfs_works+0xbd/0x1f0 [scst]
   [<ffffffffa038ce0d>] sysfs_work_thread_fn+0xbd/0x310 [scst]
   [<ffffffff81073d33>] kthread+0xf3/0x110
   [<ffffffff815faf18>] ret_from_fork+0x58/0x90
........
  r6728 | vlnb | 2015-12-10 17:51:31 -0800 (Thu, 10 Dec 2015) | 3 lines
  
  scst: small addition to r6724
........


git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/3.1.x@6729 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Vladislav Bolkhovitin
2015-12-11 01:52:56 +00:00
parent a85225d5a3
commit ffdfa708e6
1 changed files with 13 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
scst/src/scst_main.c
View File

@@ -593,16 +593,6 @@ out_free_tgt:
}
EXPORT_SYMBOL(scst_register_target);
static inline int test_sess_list(struct scst_tgt *tgt)
{
int res;
mutex_lock(&scst_mutex);
res = list_empty(&tgt->sysfs_sess_list);
mutex_unlock(&scst_mutex);
return res;
}
/**
* scst_unregister_target() - unregister target.
*
@@ -655,8 +645,20 @@ again:
mutex_unlock(&scst_mutex);
#endif
/*
* Testing tgt->sysfs_sess_list below without holding scst_mutex
* is safe, because:
*
* - On the init path no attempts to create new sessions for this
* target can be done in a race with this function (see above)
*
* - On the shutdown path 'tgt' won't disappear until scst_free_tgt()
* is called below and because the mutex_lock(&scst_mutex) call below
* waits until scst_free_session() has finished accessing the 'tgt'
* object.
*/
TRACE_DBG("%s", "Waiting for sessions shutdown");
wait_event(tgt->unreg_waitQ, test_sess_list(tgt));
wait_event(tgt->unreg_waitQ, list_empty(&tgt->sysfs_sess_list));
TRACE_DBG("%s", "wait_event() returned");
scst_suspend_activity(SCST_SUSPEND_TIMEOUT_UNLIMITED);