Re: warning in ext4_journal_start_sb on filesystem freeze

[Christoph Hellwig <hch@infradead.org>]

On Tue, Mar 04, 2014 at 02:04:42PM -0500, J. Bruce Fields wrote:
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 6d7be3f..eea5ad1 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -404,6 +404,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
>  	umode_t		ftype = 0;
>  	__be32		err;
>  	int		host_err;
> +	bool		get_write_count;
>  	int		size_change = 0;
>  
>  	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
> @@ -411,10 +412,18 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
>  	if (iap->ia_valid & ATTR_SIZE)
>  		ftype = S_IFREG;
>  
> +	/* Callers that do fh_verify should do the fh_want_write: */
> +	get_write_count = !fhp->fh_dentry;

Eww, this is nasty.  Given that there are only 6 callers of nfsd_setattr
in total, and only half of these might cause size changes I'd rather
deal with this properly, e.g. by taking both the fh_verify into the
callers.