Re: [patch] stop inotify from sending random DELETE_SELF event under load

[Linus Torvalds <torvalds@osdl.org>]

On Mon, 19 Sep 2005, John McCutchan wrote:
> 
> Below is a patch that fixes the random DELETE_SELF events when the
> system is under load. The problem is that the DELETE_SELF event is sent
> from dentry_iput, which is called in two code paths,
> 
> 1) When a dentry is being deleted
> 2) When the dcache is being pruned.

No no.

The problem is that you put the "fsnotify_inoderemove(inode);" in the 
wrong place, and I and Al never noticed.

iput() doesn't have anything to do with delete at all, and adding a flag 
to it would be wrong. The inode may stay around _after_ the unlink() for 
as long as it has users (or much longer, if you have hardlinks ;). 

You should probably move the "fsnotify_inoderemove(inode);" call into
generic_delete_inode() instead, just after "security_inode_delete()".  No
new flags, just a new place.

(Oh, I think you need to add it to "hugetlbfs_delete_inode()" too).

There's still a potential problem there: some network filesystems seem to
use "generic_delete_inode()" as their "drop_inode" thing. Which may mean 
that you get spurious delete messages when the reference is dropped. I 
don't see how to avoid that, though - we fundamentally don't _know_ when 
the inode actually gets deleted.

Al, do you have any comments? Anything stupid I missed?

		Linus
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