NFSv4.1 pnfs_layoutcommit_inode fixes

Test NFS_INO_LAYOUTCOMMIT before kzalloc
Mark inode dirty to retry LAYOUTCOMMIT on kzalloc failure.
Add comments.

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

1 files changed, 19 insertions, 11 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 2a08ca0dddc1..ac7112574790 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -982,6 +982,14 @@ pnfs_set_layoutcommit(struct nfs_write_data *wdata)
 }
 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
 
+/*
+ * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
+ * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
+ * data to disk to allow the server to recover the data if it crashes.
+ * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
+ * is off, and a COMMIT is sent to a data server, or
+ * if WRITEs to a data server return NFS_DATA_SYNC.
+ */
 int
 pnfs_layoutcommit_inode(struct inode *inode, int sync)
 {
@@ -994,10 +1002,18 @@ pnfs_layoutcommit_inode(struct inode *inode, int sync)
 
         dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
 
+        if (!test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
+                return 0;
+
         /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
         data = kzalloc(sizeof(*data), GFP_NOFS);
-        spin_lock(&inode->i_lock);
+        if (!data) {
+                mark_inode_dirty_sync(inode);
+                status = -ENOMEM;
+                goto out;
+        }
 
+        spin_lock(&inode->i_lock);
         if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
                 spin_unlock(&inode->i_lock);
                 kfree(data);
@@ -1014,16 +1030,8 @@ pnfs_layoutcommit_inode(struct inode *inode, int sync)
         lseg->pls_end_pos = 0;
         lseg->pls_lc_cred = NULL;
 
-        if (!data) {
-                put_lseg(lseg);
-                spin_unlock(&inode->i_lock);
-                put_rpccred(cred);
-                status = -ENOMEM;
-                goto out;
-        } else {
-                memcpy(&data->args.stateid.data, nfsi->layout->plh_stateid.data,
-                        sizeof(nfsi->layout->plh_stateid.data));
-        }
+        memcpy(&data->args.stateid.data, nfsi->layout->plh_stateid.data,
+                sizeof(nfsi->layout->plh_stateid.data));
         spin_unlock(&inode->i_lock);
 
         data->args.inode = inode;