nfs4: serialize layoutcommit

Current pnfs_layoutcommit_inode can not handle parallel layoutcommit.
And as Trond suggested , there is no need for client to optimize for
parallel layoutcommit. So add NFS_INO_LAYOUTCOMMITTING flag to
mark inflight layoutcommit and serialize lalyoutcommit with it.
Also mark_inode_dirty_sync if pnfs_layoutcommit_inode fails to issue
layoutcommit.

Reported-by: Vitaliy Gusev <gusev.vitaliy@nexenta.com>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d2ae413c986a..b60fddf606f7 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5950,6 +5950,7 @@ static void nfs4_layoutcommit_release(void *calldata)
 {
         struct nfs4_layoutcommit_data *data = calldata;
         struct pnfs_layout_segment *lseg, *tmp;
+        unsigned long *bitlock = &NFS_I(data->args.inode)->flags;
 
         pnfs_cleanup_layoutcommit(data);
         /* Matched by references in pnfs_set_layoutcommit */
@@ -5959,6 +5960,11 @@ static void nfs4_layoutcommit_release(void *calldata)
                                        &lseg->pls_flags))
                         put_lseg(lseg);
         }
+
+        clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
+        smp_mb__after_clear_bit();
+        wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
+
         put_rpccred(data->cred);
         kfree(data);
 }