pNFS: Don't throw out valid layout segments

It is OK for layout segments to remain hashed even if no-one holds any
references to them, provided that the segments are still valid.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index b02e32e2abeb..18aa3b7962eb 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -422,6 +422,10 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
                 pnfs_layoutreturn_before_put_lseg(lseg, lo, inode);
 
         if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
+                if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
+                        spin_unlock(&inode->i_lock);
+                        return;
+                }
                 pnfs_get_layout_hdr(lo);
                 pnfs_layout_remove_lseg(lo, lseg);
                 spin_unlock(&inode->i_lock);
@@ -462,6 +466,8 @@ pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
                 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
         if (atomic_dec_and_test(&lseg->pls_refcount)) {
                 struct pnfs_layout_hdr *lo = lseg->pls_layout;
+                if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
+                        return;
                 pnfs_get_layout_hdr(lo);
                 pnfs_layout_remove_lseg(lo, lseg);
                 pnfs_free_lseg_async(lseg);