[PATCH 4/4] pNFS: Handle RPC size limit for layoutcommits

[Sergey Bashirov <sergeybashirov@gmail.com>]

When there are too many block extents for a layoutcommit, they may not
all fit into the maximum-sized RPC. This patch allows the generic pnfs
code to properly handle -ENOSPC returned by the block/scsi layout driver
and trigger additional layoutcommits if necessary.

Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
---
 fs/nfs/pnfs.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 3adb7d0dbec7..48dc22916f06 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -3338,6 +3338,7 @@ pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 	struct nfs_inode *nfsi = NFS_I(inode);
 	loff_t end_pos;
 	int status;
+	bool mark_as_dirty = false;
 
 	if (!pnfs_layoutcommit_outstanding(inode))
 		return 0;
@@ -3389,19 +3390,23 @@ pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 	if (ld->prepare_layoutcommit) {
 		status = ld->prepare_layoutcommit(&data->args);
 		if (status) {
-			put_cred(data->cred);
+			if (status != -ENOSPC)
+				put_cred(data->cred);
 			spin_lock(&inode->i_lock);
 			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
 			if (end_pos > nfsi->layout->plh_lwb)
 				nfsi->layout->plh_lwb = end_pos;
-			goto out_unlock;
+			if (status != -ENOSPC)
+				goto out_unlock;
+			spin_unlock(&inode->i_lock);
+			mark_as_dirty = true;
 		}
 	}
 
 
 	status = nfs4_proc_layoutcommit(data, sync);
 out:
-	if (status)
+	if (status || mark_as_dirty)
 		mark_inode_dirty_sync(inode);
 	dprintk("<-- %s status %d\n", __func__, status);
 	return status;
-- 
2.43.0