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| author | Joonwoo Park <joonwpark81@gmail.com> | 2007-12-26 12:09:57 +0900 |
|---|---|---|
| committer | Mark Fasheh <mark.fasheh@oracle.com> | 2008-01-25 15:05:47 -0800 |
| commit | ba611edfe406be745be95c332990c8e908c026c3 (patch) | |
| tree | c343d9dbbc86379414b7976bfbe507763d376611 | |
| parent | 02ac0499c0e3c62f2e2bf61a13870b36ea103564 (diff) | |
| download | linux-ba611edfe406be745be95c332990c8e908c026c3.tar.bz2 | |
configfs: dir.c fix possible recursive locking
configfs_register_subsystem() with default_groups triggers recursive locking.
it seems that mutex_lock_nested is needed.
=============================================
[ INFO: possible recursive locking detected ]
2.6.24-rc6 #141
---------------------------------------------
swapper/1 is trying to acquire lock:
(&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca76f>] configfs_attach_group+0x4f/0x190
but task is already holding lock:
(&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca9d5>] configfs_register_subsystem+0x55/0x130
other info that might help us debug this:
1 lock held by swapper/1:
#0: (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca9d5>] configfs_register_subsystem+0x55/0x130
stack backtrace:
Pid: 1, comm: swapper Not tainted 2.6.24-rc6 #141
[<c40053ba>] show_trace_log_lvl+0x1a/0x30
[<c4005e82>] show_trace+0x12/0x20
[<c400687e>] dump_stack+0x6e/0x80
[<c404ec72>] __lock_acquire+0xe62/0x1120
[<c404efb2>] lock_acquire+0x82/0xa0
[<c43fdad8>] mutex_lock_nested+0x98/0x2e0
[<c40ca76f>] configfs_attach_group+0x4f/0x190
[<c40caa46>] configfs_register_subsystem+0xc6/0x130
[<c45c8186>] init_netconsole+0x2b6/0x300
[<c45a75f2>] kernel_init+0x142/0x320
[<c4004fb3>] kernel_thread_helper+0x7/0x14
=======================
Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
| -rw-r--r-- | fs/configfs/dir.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 50ed691098bc..a48dc7dd8765 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -546,7 +546,7 @@ static int populate_groups(struct config_group *group) * That said, taking our i_mutex is closer to mkdir * emulation, and shouldn't hurt. */ - mutex_lock(&dentry->d_inode->i_mutex); + mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); for (i = 0; group->default_groups[i]; i++) { new_group = group->default_groups[i]; @@ -1405,7 +1405,8 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) sd = configfs_sb->s_root->d_fsdata; link_group(to_config_group(sd->s_element), group); - mutex_lock(&configfs_sb->s_root->d_inode->i_mutex); + mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex, + I_MUTEX_PARENT); name.name = group->cg_item.ci_name; name.len = strlen(name.name); |