nfs41: send layoutreturn in last put_lseg

If current lseg is the last lseg marked with NFS_LSEG_LAYOUTRETURN,
send layoutreturn.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

1 files changed, 37 insertions, 1 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 853b544f2efc..e9acfcfdc9a9 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -50,6 +50,10 @@ static DEFINE_SPINLOCK(pnfs_spinlock);
  */
 static LIST_HEAD(pnfs_modules_tbl);
 
+static int
+pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, nfs4_stateid stateid,
+                       enum pnfs_iomode iomode);
+
 /* Return the registered pnfs layout driver module matching given id */
 static struct pnfs_layoutdriver_type *
 find_pnfs_driver_locked(u32 id)
@@ -337,6 +341,29 @@ pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
         rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);
 }
 
+/* Return true if layoutreturn is needed */
+static bool
+pnfs_layout_need_return(struct pnfs_layout_hdr *lo,
+                        struct pnfs_layout_segment *lseg,
+                        nfs4_stateid *stateid, enum pnfs_iomode *iomode)
+{
+        struct pnfs_layout_segment *s;
+
+        if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
+                return false;
+
+        list_for_each_entry(s, &lo->plh_segs, pls_list)
+                if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
+                        return false;
+
+        *stateid = lo->plh_stateid;
+        *iomode = lo->plh_return_iomode;
+        /* decreased in pnfs_send_layoutreturn() */
+        lo->plh_block_lgets++;
+        lo->plh_return_iomode = 0;
+        return true;
+}
+
 void
 pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 {
@@ -352,11 +379,20 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
         lo = lseg->pls_layout;
         inode = lo->plh_inode;
         if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
+                bool need_return;
+                nfs4_stateid stateid;
+                enum pnfs_iomode iomode;
+
                 pnfs_get_layout_hdr(lo);
                 pnfs_layout_remove_lseg(lo, lseg);
+                need_return = pnfs_layout_need_return(lo, lseg,
+                                                      &stateid, &iomode);
                 spin_unlock(&inode->i_lock);
                 pnfs_free_lseg(lseg);
-                pnfs_put_layout_hdr(lo);
+                if (need_return)
+                        pnfs_send_layoutreturn(lo, stateid, iomode);
+                else
+                        pnfs_put_layout_hdr(lo);
         }
 }
 EXPORT_SYMBOL_GPL(pnfs_put_lseg);