NFSv4.1 mark layout when already returned

When the file layout driver is fencing a DS, _pnfs_return_layout can be
called mulitple times per inode due to in-flight i/o referencing lsegs on it's
plh_segs list.

Remember that LAYOUTRETURN has been called, and do not call it again.
Allow LAYOUTRETURNs after a subsequent LAYOUTGET.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 27 insertions, 2 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 2617831afd39..3ad768f2cef4 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -662,11 +662,11 @@ _pnfs_return_layout(struct inode *ino)
         nfs4_stateid stateid;
         int status = 0;
 
-        dprintk("--> %s\n", __func__);
+        dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
 
         spin_lock(&ino->i_lock);
         lo = nfsi->layout;
-        if (!lo) {
+        if (!lo || pnfs_test_layout_returned(lo)) {
                 spin_unlock(&ino->i_lock);
                 dprintk("%s: no layout to return\n", __func__);
                 return status;
@@ -676,6 +676,7 @@ _pnfs_return_layout(struct inode *ino)
         get_layout_hdr(lo);
         mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
         lo->plh_block_lgets++;
+        pnfs_mark_layout_returned(lo);
         spin_unlock(&ino->i_lock);
         pnfs_free_lseg_list(&tmp_list);
 
@@ -686,6 +687,7 @@ _pnfs_return_layout(struct inode *ino)
                 status = -ENOMEM;
                 set_bit(NFS_LAYOUT_RW_FAILED, &lo->plh_flags);
                 set_bit(NFS_LAYOUT_RO_FAILED, &lo->plh_flags);
+                pnfs_clear_layout_returned(lo);
                 put_layout_hdr(lo);
                 goto out;
         }
@@ -1075,6 +1077,10 @@ pnfs_update_layout(struct inode *ino,
         get_layout_hdr(lo);
         if (list_empty(&lo->plh_segs))
                 first = true;
+
+        /* Enable LAYOUTRETURNs */
+        pnfs_clear_layout_returned(lo);
+
         spin_unlock(&ino->i_lock);
         if (first) {
                 /* The lo must be on the clp list if there is any
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 592beb02c955..2c6c80503ba4 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -64,6 +64,7 @@ enum {
         NFS_LAYOUT_ROC,                 /* some lseg had roc bit set */
         NFS_LAYOUT_DESTROYED,           /* no new use of layout allowed */
         NFS_LAYOUT_INVALID,             /* layout is being destroyed */
+        NFS_LAYOUT_RETURNED,            /* layout has already been returned */
 };
 
 enum layoutdriver_policy_flags {
@@ -255,6 +256,24 @@ struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *
 bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
 void nfs4_deviceid_purge_client(const struct nfs_client *);
 
+static inline void
+pnfs_mark_layout_returned(struct pnfs_layout_hdr *lo)
+{
+        set_bit(NFS_LAYOUT_RETURNED, &lo->plh_flags);
+}
+
+static inline void
+pnfs_clear_layout_returned(struct pnfs_layout_hdr *lo)
+{
+        clear_bit(NFS_LAYOUT_RETURNED, &lo->plh_flags);
+}
+
+static inline bool
+pnfs_test_layout_returned(struct pnfs_layout_hdr *lo)
+{
+        return test_bit(NFS_LAYOUT_RETURNED, &lo->plh_flags);
+}
+
 static inline int lo_fail_bit(u32 iomode)
 {
         return iomode == IOMODE_RW ?