1 files changed, 44 insertions, 16 deletions

diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index 4aaed890048f..0dfc476da3e1 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -61,7 +61,7 @@ EXPORT_SYMBOL_GPL(pnfs_generic_commit_release);
 
 /* The generic layer is about to remove the req from the commit list.
  * If this will make the bucket empty, it will need to put the lseg reference.
- * Note this must be called holding the inode (/cinfo) lock
+ * Note this must be called holding i_lock
  */
 void
 pnfs_generic_clear_request_commit(struct nfs_page *req,
@@ -98,7 +98,7 @@ pnfs_generic_transfer_commit_list(struct list_head *src, struct list_head *dst,
 		if (!nfs_lock_request(req))
 			continue;
 		kref_get(&req->wb_kref);
-		if (cond_resched_lock(cinfo->lock))
+		if (cond_resched_lock(&cinfo->inode->i_lock))
 			list_safe_reset_next(req, tmp, wb_list);
 		nfs_request_remove_commit_list(req, cinfo);
 		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
@@ -119,7 +119,7 @@ pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
 	struct list_head *dst = &bucket->committing;
 	int ret;
 
-	lockdep_assert_held(cinfo->lock);
+	lockdep_assert_held(&cinfo->inode->i_lock);
 	ret = pnfs_generic_transfer_commit_list(src, dst, cinfo, max);
 	if (ret) {
 		cinfo->ds->nwritten -= ret;
@@ -142,7 +142,7 @@ int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo,
 {
 	int i, rv = 0, cnt;
 
-	lockdep_assert_held(cinfo->lock);
+	lockdep_assert_held(&cinfo->inode->i_lock);
 	for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
 		cnt = pnfs_generic_scan_ds_commit_list(&cinfo->ds->buckets[i],
 						       cinfo, max);
@@ -161,16 +161,16 @@ void pnfs_generic_recover_commit_reqs(struct list_head *dst,
 	struct pnfs_layout_segment *freeme;
 	int i;
 
-	lockdep_assert_held(cinfo->lock);
+	lockdep_assert_held(&cinfo->inode->i_lock);
 restart:
 	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
 		if (pnfs_generic_transfer_commit_list(&b->written, dst,
 						      cinfo, 0)) {
 			freeme = b->wlseg;
 			b->wlseg = NULL;
-			spin_unlock(cinfo->lock);
+			spin_unlock(&cinfo->inode->i_lock);
 			pnfs_put_lseg(freeme);
-			spin_lock(cinfo->lock);
+			spin_lock(&cinfo->inode->i_lock);
 			goto restart;
 		}
 	}
@@ -186,7 +186,7 @@ static void pnfs_generic_retry_commit(struct nfs_commit_info *cinfo, int idx)
 	LIST_HEAD(pages);
 	int i;
 
-	spin_lock(cinfo->lock);
+	spin_lock(&cinfo->inode->i_lock);
 	for (i = idx; i < fl_cinfo->nbuckets; i++) {
 		bucket = &fl_cinfo->buckets[i];
 		if (list_empty(&bucket->committing))
@@ -194,12 +194,12 @@ static void pnfs_generic_retry_commit(struct nfs_commit_info *cinfo, int idx)
 		freeme = bucket->clseg;
 		bucket->clseg = NULL;
 		list_splice_init(&bucket->committing, &pages);
-		spin_unlock(cinfo->lock);
+		spin_unlock(&cinfo->inode->i_lock);
 		nfs_retry_commit(&pages, freeme, cinfo, i);
 		pnfs_put_lseg(freeme);
-		spin_lock(cinfo->lock);
+		spin_lock(&cinfo->inode->i_lock);
 	}
-	spin_unlock(cinfo->lock);
+	spin_unlock(&cinfo->inode->i_lock);
 }
 
 static unsigned int
@@ -238,14 +238,31 @@ void pnfs_fetch_commit_bucket_list(struct list_head *pages,
 	struct pnfs_commit_bucket *bucket;
 
 	bucket = &cinfo->ds->buckets[data->ds_commit_index];
-	spin_lock(cinfo->lock);
+	spin_lock(&cinfo->inode->i_lock);
 	list_splice_init(&bucket->committing, pages);
 	data->lseg = bucket->clseg;
 	bucket->clseg = NULL;
-	spin_unlock(cinfo->lock);
+	spin_unlock(&cinfo->inode->i_lock);
 
 }
 
+/* Helper function for pnfs_generic_commit_pagelist to catch an empty
+ * page list. This can happen when two commits race. */
+static bool
+pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages,
+					  struct nfs_commit_data *data,
+					  struct nfs_commit_info *cinfo)
+{
+	if (list_empty(pages)) {
+		if (atomic_dec_and_test(&cinfo->mds->rpcs_out))
+			wake_up_atomic_t(&cinfo->mds->rpcs_out);
+		nfs_commitdata_release(data);
+		return true;
+	}
+
+	return false;
+}
+
 /* This follows nfs_commit_list pretty closely */
 int
 pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
@@ -280,6 +297,11 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 	list_for_each_entry_safe(data, tmp, &list, pages) {
 		list_del_init(&data->pages);
 		if (data->ds_commit_index < 0) {
+			/* another commit raced with us */
+			if (pnfs_generic_commit_cancel_empty_pagelist(mds_pages,
+				data, cinfo))
+				continue;
+
 			nfs_init_commit(data, mds_pages, NULL, cinfo);
 			nfs_initiate_commit(NFS_CLIENT(inode), data,
 					    NFS_PROTO(data->inode),
@@ -288,6 +310,12 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 			LIST_HEAD(pages);
 
 			pnfs_fetch_commit_bucket_list(&pages, data, cinfo);
+
+			/* another commit raced with us */
+			if (pnfs_generic_commit_cancel_empty_pagelist(&pages,
+				data, cinfo))
+				continue;
+
 			nfs_init_commit(data, &pages, data->lseg, cinfo);
 			initiate_commit(data, how);
 		}
@@ -874,12 +902,12 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
 	struct list_head *list;
 	struct pnfs_commit_bucket *buckets;
 
-	spin_lock(cinfo->lock);
+	spin_lock(&cinfo->inode->i_lock);
 	buckets = cinfo->ds->buckets;
 	list = &buckets[ds_commit_idx].written;
 	if (list_empty(list)) {
 		if (!pnfs_is_valid_lseg(lseg)) {
-			spin_unlock(cinfo->lock);
+			spin_unlock(&cinfo->inode->i_lock);
 			cinfo->completion_ops->resched_write(cinfo, req);
 			return;
 		}
@@ -896,7 +924,7 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
 	cinfo->ds->nwritten++;
 
 	nfs_request_add_commit_list_locked(req, list, cinfo);
-	spin_unlock(cinfo->lock);
+	spin_unlock(&cinfo->inode->i_lock);
 	nfs_mark_page_unstable(req->wb_page, cinfo);
 }
 EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);