NFS41: make sure sending LAYOUTRETURN before close if marked so

If layout is marked by NFS_LAYOUT_RETURN_BEFORE_CLOSE, we should always
send LAYOUTRETURN before close, and we don't need to do ROC drain if we
do send LAYOUTRETURN.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 6aabbb6540216f9d23ff54cd79fcd402b2dd6e7a..e101a491e4e7c231b9ad3a6d0f840467e4a391e2 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1064,7 +1064,7 @@ bool pnfs_roc(struct inode *ino)
        struct pnfs_layout_segment *lseg, *tmp;
        nfs4_stateid stateid;
        LIST_HEAD(tmp_list);
-       bool found = false, layoutreturn = false;
+       bool found = false, layoutreturn = false, roc = false;
 
        spin_lock(&ino->i_lock);
        lo = nfsi->layout;
@@ -1072,7 +1072,7 @@ bool pnfs_roc(struct inode *ino)
            test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
                goto out_noroc;
 
-       /* Don't return layout if we hold a delegation */
+       /* no roc if we hold a delegation */
        if (nfs4_check_delegation(ino, FMODE_READ))
                goto out_noroc;
 
@@ -1083,36 +1083,41 @@ bool pnfs_roc(struct inode *ino)
                        goto out_noroc;
        }
 
+       stateid = lo->plh_stateid;
+       /* always send layoutreturn if being marked so */
+       if (test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
+                                  &lo->plh_flags))
+               layoutreturn = pnfs_prepare_layoutreturn(lo);
+
        pnfs_clear_retry_layoutget(lo);
        list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
-               if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
+               /* If we are sending layoutreturn, invalidate all valid lsegs */
+               if (layoutreturn || test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
                        mark_lseg_invalid(lseg, &tmp_list);
                        found = true;
                }
-       if (!found)
-               goto out_noroc;
-       if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
-               goto out_noroc;
-       lo->plh_return_iomode = IOMODE_ANY;
-       pnfs_get_layout_hdr(lo); /* matched in pnfs_roc_release */
-       spin_unlock(&ino->i_lock);
-       pnfs_free_lseg_list(&tmp_list);
-       pnfs_layoutcommit_inode(ino, true);
-       return true;
+       /* pnfs_prepare_layoutreturn() grabs lo ref and it will be put
+        * in pnfs_roc_release(). We don't really send a layoutreturn but
+        * still want others to view us like we are sending one!
+        *
+        * If pnfs_prepare_layoutreturn() fails, it means someone else is doing
+        * LAYOUTRETURN, so we proceed like there are no layouts to return.
+        *
+        * ROC in three conditions:
+        * 1. there are ROC lsegs
+        * 2. we don't send layoutreturn
+        * 3. no others are sending layoutreturn
+        */
+       if (found && !layoutreturn && pnfs_prepare_layoutreturn(lo))
+               roc = true;
 
 out_noroc:
-       if (lo) {
-               stateid = lo->plh_stateid;
-               if (test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
-                                          &lo->plh_flags))
-                       layoutreturn = pnfs_prepare_layoutreturn(lo);
-       }
        spin_unlock(&ino->i_lock);
-       if (layoutreturn) {
-               pnfs_layoutcommit_inode(ino, true);
+       pnfs_free_lseg_list(&tmp_list);
+       pnfs_layoutcommit_inode(ino, true);
+       if (layoutreturn)
                pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, true);
-       }
-       return false;
+       return roc;
 }
 
 void pnfs_roc_release(struct inode *ino)