From fb6b53ba40a7c51a5347aeabaa32546efae7fba4 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Fri, 20 Mar 2020 19:24:19 -0400
Subject: [PATCH] NFS/pNFS: Add a helper pnfs_generic_search_commit_reqs()

Lift filelayout_search_commit_reqs() into the generic pnfs/nfs code,
and add support for commit arrays.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/filelayout/filelayout.c | 32 +--------------------
 fs/nfs/pnfs.h                  |  2 ++
 fs/nfs/pnfs_nfs.c              | 51 ++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 31 deletions(-)

diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index e3cf42c91d80..795508054a4d 100644
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -1083,36 +1083,6 @@ out_err:
 	return -EAGAIN;
 }
 
-/* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
- *				   for @page
- * @cinfo - commit info for current inode
- * @page - page to search for matching head request
- *
- * Returns a the head request if one is found, otherwise returns NULL.
- */
-static struct nfs_page *
-filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
-{
-	struct nfs_page *freq, *t;
-	struct pnfs_commit_bucket *b;
-	int i;
-
-	/* Linearly search the commit lists for each bucket until a matching
-	 * request is found */
-	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
-		list_for_each_entry_safe(freq, t, &b->written, wb_list) {
-			if (freq->wb_page == page)
-				return freq->wb_head;
-		}
-		list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
-			if (freq->wb_page == page)
-				return freq->wb_head;
-		}
-	}
-
-	return NULL;
-}
-
 static int
 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 			   int how, struct nfs_commit_info *cinfo)
@@ -1217,7 +1187,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.clear_request_commit	= pnfs_generic_clear_request_commit,
 	.scan_commit_lists	= pnfs_generic_scan_commit_lists,
 	.recover_commit_reqs	= pnfs_generic_recover_commit_reqs,
-	.search_commit_reqs	= filelayout_search_commit_reqs,
+	.search_commit_reqs	= pnfs_generic_search_commit_reqs,
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 9647045a60c2..faed9be6e479 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -388,6 +388,8 @@ void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data);
 void pnfs_generic_rw_release(void *data);
 void pnfs_generic_recover_commit_reqs(struct list_head *dst,
 				      struct nfs_commit_info *cinfo);
+struct nfs_page *pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo,
+						 struct page *page);
 int pnfs_generic_commit_pagelist(struct inode *inode,
 				 struct list_head *mds_pages,
 				 int how,
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index 5b426a090ee3..9b55919e64ac 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -375,6 +375,57 @@ void pnfs_generic_recover_commit_reqs(struct list_head *dst,
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
 
+static struct nfs_page *
+pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
+		unsigned int nbuckets, struct page *page)
+{
+	struct nfs_page *req;
+	struct pnfs_commit_bucket *b;
+	unsigned int i;
+
+	/* Linearly search the commit lists for each bucket until a matching
+	 * request is found */
+	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
+		list_for_each_entry(req, &b->written, wb_list) {
+			if (req->wb_page == page)
+				return req->wb_head;
+		}
+		list_for_each_entry(req, &b->committing, wb_list) {
+			if (req->wb_page == page)
+				return req->wb_head;
+		}
+	}
+	return NULL;
+}
+
+/* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head reqest
+ *				   for @page
+ * @cinfo - commit info for current inode
+ * @page - page to search for matching head request
+ *
+ * Returns a the head request if one is found, otherwise returns NULL.
+ */
+struct nfs_page *
+pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	struct nfs_page *req;
+
+	req = pnfs_bucket_search_commit_reqs(fl_cinfo->buckets,
+			fl_cinfo->nbuckets, page);
+	if (req)
+		return req;
+	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
+		req = pnfs_bucket_search_commit_reqs(array->buckets,
+				array->nbuckets, page);
+		if (req)
+			return req;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_search_commit_reqs);
+
 static struct pnfs_layout_segment *
 pnfs_bucket_get_committing(struct list_head *head,
 			   struct pnfs_commit_bucket *bucket,