From: Joonwoo Park Date: Wed, 26 Dec 2007 03:09:57 +0000 (+0900) Subject: configfs: file.c fix possible recursive locking X-Git-Tag: v2.6.25-rc1~1232^2~2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=116ba5d5ea1a5789a8c14b1087014007cada363b;p=linux-2.6 configfs: file.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 #145 --------------------------------------------- swapper/1 is trying to acquire lock: (&sb->s_type->i_mutex_key#3){--..}, at: [] configfs_add_file+0x2e/0x70 but task is already holding lock: (&sb->s_type->i_mutex_key#3){--..}, at: [] 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: [] configfs_register_subsystem+0x55/0x130 stack backtrace: Pid: 1, comm: swapper Not tainted 2.6.24-rc6 #145 [] show_trace_log_lvl+0x1a/0x30 [] show_trace+0x12/0x20 [] dump_stack+0x6e/0x80 [] __lock_acquire+0xe62/0x1120 [] lock_acquire+0x82/0xa0 [] mutex_lock_nested+0x98/0x2e0 [] configfs_add_file+0x2e/0x70 [] configfs_create_file+0x2c/0x40 [] configfs_attach_item+0x139/0x220 [] configfs_attach_group+0x14/0x140 [] configfs_attach_group+0xc9/0x140 [] configfs_register_subsystem+0xc6/0x130 [] init_netconsole+0x2b6/0x300 [] kernel_init+0x142/0x320 [] kernel_thread_helper+0x7/0x14 ======================= Signed-off-by: Joonwoo Park Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh --- diff --git a/fs/configfs/file.c b/fs/configfs/file.c index a3658f9a08..397cb503a1 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -320,7 +320,7 @@ int configfs_add_file(struct dentry * dir, const struct configfs_attribute * att umode_t mode = (attr->ca_mode & S_IALLUGO) | S_IFREG; int error = 0; - mutex_lock(&dir->d_inode->i_mutex); + mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_NORMAL); error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode, type); mutex_unlock(&dir->d_inode->i_mutex);