When I was removing dlm module,I hit in to below error.
==========================================
[ INFO: possible recursive locking detected ]
2.6.18#1
---------------------------------------------
modprobe/4501 is trying to acquire lock:
(&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24
but task is already holding lock:
(&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24
other info that might help us debug this:
1 lock held by modprobe/4501:
#0: (&inode->i_mutex){--..}, at: [<c0611e5a>] mutex_lock+0x21/0x24
stack backtrace:
[<c04051ed>] show_trace_log_lvl+0x58/0x16a
[<c04057fa>] show_trace+0xd/0x10
[<c0405913>] dump_stack+0x19/0x1b
[<c043b6f1>] __lock_acquire+0x778/0x99c
[<c043be86>] lock_acquire+0x4b/0x6d
[<c0611ceb>] __mutex_lock_slowpath+0xbc/0x20a
[<c0611e5a>] mutex_lock+0x21/0x24
[<f89c2562>] configfs_unregister_subsystem+0x3e/0xa8 [configfs]
[<f8f4263f>] dlm_config_exit+0xd/0xf [dlm]
[<f8f4db94>] exit_dlm+0x12/0x23 [dlm]
[<c0442790>] sys_delete_module+0x18d/0x1b5
[<c0403fb7>] syscall_call+0x7/0xb
===========================================================
Cause for this problem is, lock-validator validates the locks through
lock class. And by definition,a lock in struct inode considered as one
class, irrespective of number of of instances of different inode present
in the system.
Hence 2 consecutive mutex lock on d_inode->i_mutex considered as
recursive lock,eventhough both inodes are different. Thats what
happening below. Is it not a kernel design constraint ??
==============================================
void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
{
struct config_group *group = &subsys->su_group;
struct dentry *dentry = group->cg_item.ci_dentry;
if (dentry->d_parent != configfs_sb->s_root) {
printk(KERN_ERR "configfs: Tried to unregister
non-subsystem!\n");
return;
}
mutex_lock(&configfs_sb->s_root->d_inode->i_mutex);
mutex_lock(&dentry->d_inode->i_mutex);
==> problem is here
if (configfs_detach_prep(dentry)) {
printk(KERN_ERR "configfs: Tried to unregister non-empty
subsystem!\n");
}
===========================================
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
