Messages in this thread | | | From | Mike Marshall <> | Date | Sat, 25 Feb 2017 15:31:14 -0500 | Subject | Re: [RFC][PATCH 07/10] orangefs: Use RCU for destroy_inode |
| |
After looking through the code and seeing how some other filesystems use call_rcu, it seems that call_rcu has to do with consistency and waiting for stuff to complete before returning an object to the slab cache, whereas we were just calling kmem_cache_free without worrying about that kind of stuff...
Is that a "close enough" description of the error that is being fixed here?
-Mike
On Fri, Feb 24, 2017 at 6:00 PM, Mike Marshall <hubcap@omnibond.com> wrote: > Thanks Al... I was going to try and evaluate that patch next > week, now all I have to do is test it <g> ... > > -Mike > > On Fri, Feb 24, 2017 at 3:52 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: >> That, AFAICS, fixes a real bug. Applied, and it needs Cc:stable as well. >> >> >>> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> >>> --- >>> fs/orangefs/super.c | 9 ++++++++- >>> 1 file changed, 8 insertions(+), 1 deletion(-) >>> >>> --- a/fs/orangefs/super.c >>> +++ b/fs/orangefs/super.c >>> @@ -115,6 +115,13 @@ static struct inode *orangefs_alloc_inod >>> return &orangefs_inode->vfs_inode; >>> } >>> >>> +static void orangefs_i_callback(struct rcu_head *head) >>> +{ >>> + struct inode *inode = container_of(head, struct inode, i_rcu); >>> + struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode); >>> + kmem_cache_free(orangefs_inode_cache, orangefs_inode); >>> +} >>> + >>> static void orangefs_destroy_inode(struct inode *inode) >>> { >>> struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode); >>> @@ -123,7 +130,7 @@ static void orangefs_destroy_inode(struc >>> "%s: deallocated %p destroying inode %pU\n", >>> __func__, orangefs_inode, get_khandle_from_ino(inode)); >>> >>> - kmem_cache_free(orangefs_inode_cache, orangefs_inode); >>> + call_rcu(&inode->i_rcu, orangefs_i_callback); >>> } >>> >>> /* >>> >>>
| |