pnfs: add return_range method

If a layout driver keeps per-inode state outside of the layout segments it
needs to be notified of any layout returns or recalls on an inode, and not
just about the freeing of layout segments.  Add a method to acomplish this,
which will allow the block layout driver to handle the case of truncated
and re-expanded files properly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index ce5d1ea695d1..76de7f568119 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -857,6 +857,16 @@ _pnfs_return_layout(struct inode *ino)
         empty = list_empty(&lo->plh_segs);
         pnfs_clear_layoutcommit(ino, &tmp_list);
         pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
+
+        if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
+                struct pnfs_layout_range range = {
+                        .iomode         = IOMODE_ANY,
+                        .offset         = 0,
+                        .length         = NFS4_MAX_UINT64,
+                };
+                NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
+        }
+
         /* Don't send a LAYOUTRETURN if list was initially empty */
         if (empty) {
                 spin_unlock(&ino->i_lock);