NFSv4/pnfs: Support a list of commit arrays in struct pnfs_ds_commit_info

When we have multiple layout segments with different lists of mirrored
data, we need to track the commits on a per layout segment basis.
This patch adds a list to support this tracking in struct
pnfs_ds_commit_info.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/direct.c

@@ -305,6 +305,7 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
 	kref_get(&dreq->kref);
 	init_completion(&dreq->completion);
 	INIT_LIST_HEAD(&dreq->mds_cinfo.list);
+	pnfs_init_ds_commit_info(&dreq->ds_cinfo);
 	dreq->verf.committed = NFS_INVALID_STABLE_HOW;	/* not set yet */
 	INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);
 	spin_lock_init(&dreq->lock);

fs/nfs/filelayout/filelayout.c

@@ -1140,7 +1140,10 @@ filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
 	struct nfs4_filelayout *flo;
 
 	flo = kzalloc(sizeof(*flo), gfp_flags);
-	return flo != NULL ? &flo->generic_hdr : NULL;
+	if (flo == NULL)
+		return NULL;
+	pnfs_init_ds_commit_info(&flo->commit_info);
+	return &flo->generic_hdr;
 }
 
 static void

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -48,6 +48,7 @@ ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
 
 	ffl = kzalloc(sizeof(*ffl), gfp_flags);
 	if (ffl) {
+		pnfs_init_ds_commit_info(&ffl->commit_info);
 		INIT_LIST_HEAD(&ffl->error_list);
 		INIT_LIST_HEAD(&ffl->mirrors);
 		ffl->last_report_time = ktime_get();

fs/nfs/pnfs.h

@@ -462,6 +462,12 @@ pnfs_get_ds_info(struct inode *inode)
 	return ld->get_ds_info(inode);
 }
 
+static inline void
+pnfs_init_ds_commit_info(struct pnfs_ds_commit_info *fl_cinfo)
+{
+	INIT_LIST_HEAD(&fl_cinfo->commits);
+}
+
 static inline void
 pnfs_generic_mark_devid_invalid(struct nfs4_deviceid_node *node)
 {
@@ -759,6 +765,11 @@ pnfs_get_ds_info(struct inode *inode)
 	return NULL;
 }
 
+static inline void
+pnfs_init_ds_commit_info(struct pnfs_ds_commit_info *fl_cinfo)
+{
+}
+
 static inline bool
 pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
 			 struct nfs_commit_info *cinfo, u32 ds_commit_idx)

include/linux/nfs_xdr.h

@@ -1280,6 +1280,7 @@ struct pnfs_commit_array {
 };
 
 struct pnfs_ds_commit_info {
+	struct list_head commits;
 	unsigned int nwritten;
 	unsigned int ncommitting;
 	unsigned int nbuckets;