[PATCH 3/5] nfs: new tracepoints around write handling

[Jeff Layton <jlayton@xxxxxxxxxx>]

New start and done tracepoints for:

nfs_update_folio()
nfs_write_begin()
nfs_write_end()
nfs_try_to_update_request()

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 fs/nfs/file.c     | 16 +++++++++++++---
 fs/nfs/nfstrace.h | 13 +++++++++++++
 fs/nfs/write.c    | 10 +++++++++-
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 1e89801abed626ea64cd79722fad8720b2485d32..058cb545ab8a2974e08810c0309e5a2040f82cc2 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -356,6 +356,8 @@ static int nfs_write_begin(const struct kiocb *iocb,
 	int once_thru = 0;
 	int ret;
 
+	trace_nfs_write_begin(file_inode(file), pos, len);
+
 	dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
 		file, mapping->host->i_ino, len, (long long) pos);
 
@@ -363,8 +365,10 @@ static int nfs_write_begin(const struct kiocb *iocb,
 start:
 	folio = __filemap_get_folio(mapping, pos >> PAGE_SHIFT, fgp,
 				    mapping_gfp_mask(mapping));
-	if (IS_ERR(folio))
-		return PTR_ERR(folio);
+	if (IS_ERR(folio)) {
+		ret = PTR_ERR(folio);
+		goto out;
+	}
 	*foliop = folio;
 
 	ret = nfs_flush_incompatible(file, folio);
@@ -379,6 +383,8 @@ static int nfs_write_begin(const struct kiocb *iocb,
 		if (!ret)
 			goto start;
 	}
+out:
+	trace_nfs_write_begin_done(file_inode(file), pos, len, ret);
 	return ret;
 }
 
@@ -392,6 +398,7 @@ static int nfs_write_end(const struct kiocb *iocb,
 	unsigned offset = offset_in_folio(folio, pos);
 	int status;
 
+	trace_nfs_write_end(file_inode(file), pos, len);
 	dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
 		file, mapping->host->i_ino, len, (long long) pos);
 
@@ -420,13 +427,16 @@ static int nfs_write_end(const struct kiocb *iocb,
 	folio_unlock(folio);
 	folio_put(folio);
 
-	if (status < 0)
+	if (status < 0) {
+		trace_nfs_write_end_done(file_inode(file), pos, len, status);
 		return status;
+	}
 	NFS_I(mapping->host)->write_io += copied;
 
 	if (nfs_ctx_key_to_expire(ctx, mapping->host))
 		nfs_wb_all(mapping->host);
 
+	trace_nfs_write_end_done(file_inode(file), pos, len, copied);
 	return copied;
 }
 
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index d7d25cdf0060b3fa7c5889752a1bd193d0e8ca92..b90eed094e639a532463cb5a3f6ba32c64431a6a 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -1045,6 +1045,19 @@ DEFINE_NFS_FOLIO_EVENT_DONE(nfs_writeback_folio_done);
 DEFINE_NFS_FOLIO_EVENT(nfs_invalidate_folio);
 DEFINE_NFS_FOLIO_EVENT_DONE(nfs_launder_folio_done);
 
+DEFINE_NFS_FOLIO_EVENT(nfs_try_to_update_request);
+DEFINE_NFS_FOLIO_EVENT_DONE(nfs_try_to_update_request_done);
+
+DEFINE_NFS_FOLIO_EVENT(nfs_update_folio);
+DEFINE_NFS_FOLIO_EVENT_DONE(nfs_update_folio_done);
+
+DEFINE_NFS_FOLIO_EVENT(nfs_write_begin);
+DEFINE_NFS_FOLIO_EVENT_DONE(nfs_write_begin_done);
+
+DEFINE_NFS_FOLIO_EVENT(nfs_write_end);
+DEFINE_NFS_FOLIO_EVENT_DONE(nfs_write_end_done);
+
+
 DECLARE_EVENT_CLASS(nfs_kiocb_event,
 		TP_PROTO(
 			const struct kiocb *iocb,
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 374fc6b34c7954ef781026e5114cf5411f366ecd..60138026053b992434c6fadc7bc53ebb5d8e8545 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1068,11 +1068,12 @@ static struct nfs_page *nfs_try_to_update_request(struct folio *folio,
 	unsigned int end;
 	int error;
 
+	trace_nfs_try_to_update_request(folio_inode(folio), offset, bytes);
 	end = offset + bytes;
 
 	req = nfs_lock_and_join_requests(folio);
 	if (IS_ERR_OR_NULL(req))
-		return req;
+		goto out;
 
 	rqend = req->wb_offset + req->wb_bytes;
 	/*
@@ -1094,6 +1095,9 @@ static struct nfs_page *nfs_try_to_update_request(struct folio *folio,
 	else
 		req->wb_bytes = rqend - req->wb_offset;
 	req->wb_nio = 0;
+out:
+	trace_nfs_try_to_update_request_done(folio_inode(folio), offset, bytes,
+					     PTR_ERR_OR_ZERO(req));
 	return req;
 out_flushme:
 	/*
@@ -1104,6 +1108,7 @@ static struct nfs_page *nfs_try_to_update_request(struct folio *folio,
 	nfs_mark_request_dirty(req);
 	nfs_unlock_and_release_request(req);
 	error = nfs_wb_folio(folio->mapping->host, folio);
+	trace_nfs_try_to_update_request_done(folio_inode(folio), offset, bytes, error);
 	return (error < 0) ? ERR_PTR(error) : NULL;
 }
 
@@ -1341,6 +1346,8 @@ int nfs_update_folio(struct file *file, struct folio *folio,
 
 	nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
 
+	trace_nfs_update_folio(inode, offset, count);
+
 	dprintk("NFS:       nfs_update_folio(%pD2 %d@%lld)\n", file, count,
 		(long long)(folio_pos(folio) + offset));
 
@@ -1360,6 +1367,7 @@ int nfs_update_folio(struct file *file, struct folio *folio,
 	if (status < 0)
 		nfs_set_pageerror(mapping);
 out:
+	trace_nfs_update_folio_done(inode, offset, count, status);
 	dprintk("NFS:       nfs_update_folio returns %d (isize %lld)\n",
 			status, (long long)i_size_read(inode));
 	return status;

-- 
2.50.1