Messages in this thread | | | Date | Tue, 15 Jan 2008 19:41:58 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: [PATCH 2.6.24-rc7 2/2] sysfs: fix bugs in sysfs_rename/move_dir() |
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On Wed, 16 Jan 2008, Tejun Heo wrote: > > * sysfs_move_dir() has an extra dput() on success path.
Are you sure? How did this ever work?
Also, looking at this, I think the "how did this ever work" question is answered by "it didn't", but I also think there are still serious problems there. Look at
again: mutex_lock(&old_parent->d_inode->i_mutex); if (!mutex_trylock(&new_parent->d_inode->i_mutex)) { mutex_unlock(&old_parent->d_inode->i_mutex); goto again; }
and wonder what happen sif old_parent == new_parent. Is that trying to avoid an ABBA deadlock? Normally you'd do it by ordering the locks, or by taking a third lock to guarantee serialization at a higher level (ie the "s_vfs_rename_mutex" on the VFS layer)
I'd like to apply these two patches, but I really want to get more of an ack for them from somebody like Al, or at least more of an explanation for why it's all the right thing.
Linus
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