Re: [PATCH] radix_tree_tag_get() is not as safe as the docs make out

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Nick Piggin <npiggin@xxxxxxx> wrote:

> Nack, just drop the BUG_ON.

I can do that.

> I don't know what you mean by "untrustworthy answer".

I was thinking that the answer you get from radix_tree_tag_get() may be invalid
if the tag chain is being modified as you read it.  So if you do:

	rcu_read_lock()
	...
	x = radix_tree_tag_get(r, i, t);
	...
	y = radix_tree_tag_get(r, i, t);
	...
	rcu_read_unlock()

Then you can't guarantee that x == y, even though you were holding the RCU read
lock.

As you suggested, I'll try and come up with a comment modification to this
effect.

David
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux