Re: [PATCH v4 14/16] bcachefs: add pre-content fsnotify hook to fault

[Jan Kara <jack@suse.cz>]

On Wed 14-08-24 17:25:32, Josef Bacik wrote:
> bcachefs has its own locking around filemap_fault, so we have to make
> sure we do the fsnotify hook before the locking.  Add the check to emit
> the event before the locking and return VM_FAULT_RETRY to retrigger the
> fault once the event has been emitted.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>

Looks good to me. Would be nice to get ack from bcachefs guys. Kent?

								Honza

> ---
>  fs/bcachefs/fs-io-pagecache.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/bcachefs/fs-io-pagecache.c b/fs/bcachefs/fs-io-pagecache.c
> index a9cc5cad9cc9..1fa1f1ac48c8 100644
> --- a/fs/bcachefs/fs-io-pagecache.c
> +++ b/fs/bcachefs/fs-io-pagecache.c
> @@ -570,6 +570,10 @@ vm_fault_t bch2_page_fault(struct vm_fault *vmf)
>  	if (fdm == mapping)
>  		return VM_FAULT_SIGBUS;
>  
> +	ret = filemap_maybe_emit_fsnotify_event(vmf);
> +	if (unlikely(ret))
> +		return ret;
> +
>  	/* Lock ordering: */
>  	if (fdm > mapping) {
>  		struct bch_inode_info *fdm_host = to_bch_ei(fdm->host);
> -- 
> 2.43.0
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR