On Wed, Mar 27, 2024 at 11:27:37PM +0800, Chen Hanxiao wrote:
> Add a tracepoint for obtaining root filehandle event
>
> Signed-off-by: Chen Hanxiao <chenhx.fnst@xxxxxxxxxxx>
> ---
> fs/nfsd/export.c | 4 +---
> fs/nfsd/trace.h | 39 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 40 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
> index 7b641095a665..690721ba42f3 100644
> --- a/fs/nfsd/export.c
> +++ b/fs/nfsd/export.c
> @@ -1027,15 +1027,13 @@ exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
> }
> inode = d_inode(path.dentry);
>
> - dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
> - name, path.dentry, clp->name,
> - inode->i_sb->s_id, inode->i_ino);
> exp = exp_parent(cd, clp, &path);
> if (IS_ERR(exp)) {
> err = PTR_ERR(exp);
> goto out;
> }
>
> + trace_nfsd_exp_rootfh(name, path.dentry, clp->name, inode, exp);
Converting the above dprintk to a tracepoint seems sensible.
I'd like to hear comments from others about whether the new
tracepoint records a useful set of information. We don't need to
record the memory address of the dentry, for example. Recording the
net namespace might be useful, though.
> /*
> * fh must be initialized before calling fh_compose
> */
> diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
> index 1cd2076210b1..a11b348f5d6d 100644
> --- a/fs/nfsd/trace.h
> +++ b/fs/nfsd/trace.h
> @@ -396,6 +396,45 @@ TRACE_EVENT(nfsd_export_update,
> )
> );
>
> +TRACE_EVENT(nfsd_exp_rootfh,
> + TP_PROTO(
> + const char *name,
> + const struct dentry *dentry,
> + const char *clp_name,
> + const struct inode *inode,
> + struct svc_export *exp
> + ),
> + TP_ARGS(name, dentry, clp_name, inode, exp),
> + TP_STRUCT__entry(
> + __string(name, name)
> + __field(const void *, dentry)
> + __string(clp_name, clp_name)
> + __string(s_id, inode->i_sb->s_id)
> + __field(unsigned long, i_ino)
> + __array(unsigned char, uuid, 16)
> + __field(const void *, ex_uuid)
> + ),
> + TP_fast_assign(
> + __assign_str(name, name);
> + __entry->dentry = dentry;
> + __assign_str(clp_name, clp_name);
> + __assign_str(s_id, inode->i_sb->s_id);
> + __entry->i_ino = inode->i_ino;
> + __entry->ex_uuid = exp->ex_uuid;
> + if (exp->ex_uuid)
> + memcpy(__entry->uuid, exp->ex_uuid, 16);
> + ),
> + TP_printk(
> + "path=%s dentry=%p domain=%s sid=%s/inode=%ld uuid=%s",
> + __get_str(name),
> + __entry->dentry,
> + __get_str(clp_name),
> + __get_str(s_id),
> + __entry->i_ino,
> + __entry->ex_uuid ? __print_hex_str(__entry->uuid, 16) : "NULL"
> + )
> +);
> +
> DECLARE_EVENT_CLASS(nfsd_io_class,
> TP_PROTO(struct svc_rqst *rqstp,
> struct svc_fh *fhp,
> --
> 2.39.1
>
--
Chuck Lever
