From: David Howells Date: Thu, 19 Nov 2009 18:11:58 +0000 (+0000) Subject: CacheFiles: Mark parent directory locks as I_MUTEX_PARENT to keep lockdep happy X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6511de33c877a53b3df545bc06c29e0f272837ff;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git CacheFiles: Mark parent directory locks as I_MUTEX_PARENT to keep lockdep happy Mark parent directory locks as I_MUTEX_PARENT in the callers of cachefiles_bury_object() so that lockdep doesn't complain when that invokes vfs_unlink(): ============================================= [ INFO: possible recursive locking detected ] 2.6.32-rc6-cachefs #47 --------------------------------------------- kslowd002/3089 is trying to acquire lock: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [] vfs_unlink+0x8b/0x128 but task is already holding lock: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles] other info that might help us debug this: 1 lock held by kslowd002/3089: #0: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles] stack backtrace: Pid: 3089, comm: kslowd002 Not tainted 2.6.32-rc6-cachefs #47 Call Trace: [] __lock_acquire+0x1649/0x16e3 [] ? inode_has_perm+0x5f/0x61 [] lock_acquire+0x57/0x6d [] ? vfs_unlink+0x8b/0x128 [] mutex_lock_nested+0x54/0x292 [] ? vfs_unlink+0x8b/0x128 [] ? selinux_inode_permission+0x8e/0x90 [] ? security_inode_permission+0x1c/0x1e [] ? inode_permission+0x99/0xa5 [] vfs_unlink+0x8b/0x128 [] ? kfree+0xed/0xf9 [] cachefiles_bury_object+0xb6/0x420 [cachefiles] [] ? trace_hardirqs_on+0xd/0xf [] ? cachefiles_check_object_xattr+0x233/0x293 [cachefiles] [] cachefiles_walk_to_object+0x4ff/0x831 [cachefiles] [] ? finish_task_switch+0x0/0xb2 [] cachefiles_lookup_object+0xac/0x12a [cachefiles] [] fscache_lookup_object+0x1c7/0x214 [fscache] [] fscache_object_state_machine+0xa5/0x52d [fscache] [] fscache_object_slow_work_execute+0x5f/0xa0 [fscache] [] slow_work_execute+0x18f/0x2d1 [] slow_work_thread+0x1c5/0x308 [] ? autoremove_wake_function+0x0/0x34 [] ? slow_work_thread+0x0/0x308 [] kthread+0x7a/0x82 [] child_rip+0xa/0x20 [] ? restore_args+0x0/0x30 [] ? kthread+0x0/0x82 [] ? child_rip+0x0/0x20 Signed-off-by: Daivd Howells --- diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index 4ce818ae39ea..3df86952ca64 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -254,7 +254,7 @@ int cachefiles_delete_object(struct cachefiles_cache *cache, dir = dget_parent(object->dentry); - mutex_lock(&dir->d_inode->i_mutex); + mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); ret = cachefiles_bury_object(cache, dir, object->dentry); dput(dir); @@ -307,7 +307,7 @@ lookup_again: /* search the current directory for the element name */ _debug("lookup '%s'", name); - mutex_lock(&dir->d_inode->i_mutex); + mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); start = jiffies; next = lookup_one_len(name, dir, nlen);