From a8e3765e5178fb6a2a9f14d133d0b3c23a7c1e6d Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Thu, 19 Mar 2020 13:41:08 -0400
Subject: [PATCH] NFSv4/pNFS: Scan the full list of commit arrays when
 committing

Add support for scanning the full list of per-layout segment commit
arrays to pnfs_generic_scan_commit_lists()

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/pnfs_nfs.c | 50 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 39 insertions(+), 11 deletions(-)

diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index c8518ce3a4ef..81fd85e66fd9 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -118,10 +118,14 @@ pnfs_free_commit_array(struct pnfs_commit_array *p)
 }
 EXPORT_SYMBOL_GPL(pnfs_free_commit_array);
 
+/*
+ * Locks the nfs_page requests for commit and moves them to
+ * @bucket->committing.
+ */
 static int
-pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
-				 struct nfs_commit_info *cinfo,
-				 int max)
+pnfs_bucket_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
+				struct nfs_commit_info *cinfo,
+				int max)
 {
 	struct list_head *src = &bucket->written;
 	struct list_head *dst = &bucket->committing;
@@ -142,20 +146,44 @@ pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
 	return ret;
 }
 
+static int pnfs_bucket_scan_array(struct nfs_commit_info *cinfo,
+				  struct pnfs_commit_bucket *buckets,
+				  unsigned int nbuckets,
+				  int max)
+{
+	unsigned int i;
+	int rv = 0, cnt;
+
+	for (i = 0; i < nbuckets && max != 0; i++) {
+		cnt = pnfs_bucket_scan_ds_commit_list(&buckets[i], cinfo, max);
+		rv += cnt;
+		max -= cnt;
+	}
+	return rv;
+}
+
 /* Move reqs from written to committing lists, returning count
  * of number moved.
  */
-int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo,
-				   int max)
+int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max)
 {
-	int i, rv = 0, cnt;
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	int rv = 0, cnt;
 
-	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
-	for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
-		cnt = pnfs_generic_scan_ds_commit_list(&cinfo->ds->buckets[i],
-						       cinfo, max);
-		max -= cnt;
+	cnt = pnfs_bucket_scan_array(cinfo, fl_cinfo->buckets,
+			fl_cinfo->nbuckets, max);
+	rv += cnt;
+	max -= cnt;
+	if (!max)
+		return rv;
+	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
+		cnt = pnfs_bucket_scan_array(cinfo, array->buckets,
+				array->nbuckets, max);
 		rv += cnt;
+		max -= cnt;
+		if (!max)
+			break;
 	}
 	return rv;
 }