[PATCH 3/4] nfsd: add some stub tracepoints around key vfs functions

From: Jeff Layton
Date: Thu Mar 06 2025 - 07:40:30 EST


Sargun set up kprobes to add some of these tracepoints. Convert them to
simple static tracepoints. These are pretty sparse for now, but they
could be expanded in the future as needed.

Cc: Sargun Dillon <sargun@xxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfsd/nfs3proc.c | 3 +++
fs/nfsd/nfs4proc.c | 2 ++
fs/nfsd/nfsproc.c | 2 ++
fs/nfsd/trace.h | 35 +++++++++++++++++++++++++++++++++++
fs/nfsd/vfs.c | 26 ++++++++++++++++++++++++++
5 files changed, 68 insertions(+)

diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 372bdcf5e07a5c835da240ecebb02e3576eb2ca6..2a56cae4c78a7ca66d569637e9f0e7c0fdcfb826 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -14,6 +14,7 @@
#include "xdr3.h"
#include "vfs.h"
#include "filecache.h"
+#include "trace.h"

#define NFSDDBG_FACILITY NFSDDBG_PROC

@@ -69,6 +70,8 @@ nfsd3_proc_getattr(struct svc_rqst *rqstp)
struct nfsd_fhandle *argp = rqstp->rq_argp;
struct nfsd3_attrstat *resp = rqstp->rq_resp;

+ trace_nfsd_getattr(rqstp, &argp->fh);
+
dprintk("nfsd: GETATTR(3) %s\n",
SVCFH_fmt(&argp->fh));

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index c20f1abcb94f131b1ec898860ba2c394b22e61e1..87d241ff91920317e0122a58bf0cf71c5b28d264 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -876,6 +876,8 @@ nfsd4_getattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
struct nfsd4_getattr *getattr = &u->getattr;
__be32 status;

+ trace_nfsd_getattr(rqstp, &cstate->current_fh);
+
status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
if (status)
return status;
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 6dda081eb24c00b834ab0965c3a35a12115bceb7..9563372f0826b9580299144069f57664dbd2a079 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -54,6 +54,8 @@ nfsd_proc_getattr(struct svc_rqst *rqstp)
struct nfsd_fhandle *argp = rqstp->rq_argp;
struct nfsd_attrstat *resp = rqstp->rq_resp;

+ trace_nfsd_getattr(rqstp, &argp->fh);
+
dprintk("nfsd: GETATTR %s\n", SVCFH_fmt(&argp->fh));

fh_copy(&resp->fh, &argp->fh);
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 117f7e1fd66a4838a048cc44bd5bf4dd8c6db958..d4a78fe1bab24b594b96cca8611c439da9ed6926 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -2337,6 +2337,41 @@ DEFINE_EVENT(nfsd_copy_async_done_class, \
DEFINE_COPY_ASYNC_DONE_EVENT(done);
DEFINE_COPY_ASYNC_DONE_EVENT(cancel);

+DECLARE_EVENT_CLASS(nfsd_vfs_class,
+ TP_PROTO(struct svc_rqst *rqstp, struct svc_fh *fhp),
+ TP_ARGS(rqstp, fhp),
+ TP_STRUCT__entry(
+ __field(u32, xid)
+ __field(u32, fh_hash)
+ ),
+ TP_fast_assign(
+ __entry->xid = be32_to_cpu(rqstp->rq_xid);
+ __entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+ ),
+ TP_printk("xid=0x%08x fh_hash=0x%08x",
+ __entry->xid, __entry->fh_hash)
+);
+
+#define DEFINE_NFSD_VFS_EVENT(name) \
+ DEFINE_EVENT(nfsd_vfs_class, nfsd_##name, \
+ TP_PROTO(struct svc_rqst *rqstp, struct svc_fh *fhp), \
+ TP_ARGS(rqstp, fhp))
+
+DEFINE_NFSD_VFS_EVENT(lookup);
+DEFINE_NFSD_VFS_EVENT(lookup_dentry);
+DEFINE_NFSD_VFS_EVENT(create_locked);
+DEFINE_NFSD_VFS_EVENT(create);
+DEFINE_NFSD_VFS_EVENT(access);
+DEFINE_NFSD_VFS_EVENT(create_setattr);
+DEFINE_NFSD_VFS_EVENT(readlink);
+DEFINE_NFSD_VFS_EVENT(symlink);
+DEFINE_NFSD_VFS_EVENT(link);
+DEFINE_NFSD_VFS_EVENT(rename);
+DEFINE_NFSD_VFS_EVENT(unlink);
+DEFINE_NFSD_VFS_EVENT(readdir);
+DEFINE_NFSD_VFS_EVENT(statfs);
+DEFINE_NFSD_VFS_EVENT(getattr);
+
#define show_ia_valid_flags(x) \
__print_flags(x, "|", \
{ ATTR_MODE, "MODE" }, \
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index d755cc87a8670c491e55194de266d999ba1b337d..772a4d32b09a4bd217a9258ec803c06618cf13c8 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -244,6 +244,8 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct dentry *dentry;
int host_err;

+ trace_nfsd_lookup(rqstp, fhp);
+
dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);

dparent = fhp->fh_dentry;
@@ -313,6 +315,8 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
struct dentry *dentry;
__be32 err;

+ trace_nfsd_lookup(rqstp, fhp);
+
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
if (err)
return err;
@@ -794,6 +798,8 @@ nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *suppor
u32 query, result = 0, sresult = 0;
__be32 error;

+ trace_nfsd_create(rqstp, fhp);
+
error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
if (error)
goto out;
@@ -1401,6 +1407,8 @@ nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct iattr *iap = attrs->na_iattr;
__be32 status;

+ trace_nfsd_create_setattr(rqstp, fhp);
+
/*
* Mode has already been set by file creation.
*/
@@ -1467,6 +1475,8 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
__be32 err;
int host_err;

+ trace_nfsd_create_locked(rqstp, fhp);
+
dentry = fhp->fh_dentry;
dirp = d_inode(dentry);

@@ -1557,6 +1567,8 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
__be32 err;
int host_err;

+ trace_nfsd_create(rqstp, fhp);
+
if (isdotent(fname, flen))
return nfserr_exist;

@@ -1609,6 +1621,8 @@ nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
DEFINE_DELAYED_CALL(done);
int len;

+ trace_nfsd_readlink(rqstp, fhp);
+
err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
if (unlikely(err))
return err;
@@ -1657,6 +1671,8 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
__be32 err, cerr;
int host_err;

+ trace_nfsd_symlink(rqstp, fhp);
+
err = nfserr_noent;
if (!flen || path[0] == '\0')
goto out;
@@ -1725,6 +1741,8 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
__be32 err;
int host_err;

+ trace_nfsd_link(rqstp, ffhp);
+
err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
if (err)
goto out;
@@ -1842,6 +1860,8 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
int host_err;
bool close_cached = false;

+ trace_nfsd_rename(rqstp, ffhp);
+
err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
if (err)
goto out;
@@ -2000,6 +2020,8 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
__be32 err;
int host_err;

+ trace_nfsd_unlink(rqstp, fhp);
+
err = nfserr_acces;
if (!flen || isdotent(fname, flen))
goto out;
@@ -2222,6 +2244,8 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
loff_t offset = *offsetp;
int may_flags = NFSD_MAY_READ;

+ trace_nfsd_readdir(rqstp, fhp);
+
err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
if (err)
goto out;
@@ -2288,6 +2312,8 @@ nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, in
{
__be32 err;

+ trace_nfsd_statfs(rqstp, fhp);
+
err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
if (!err) {
struct path path = {

--
2.48.1