NFSv4.1: Add a helper pnfs_commit_and_return_layout
In order to be able to safely return the layout in nfs4_proc_setattr,
we need to block new uses of the layout, wait for all outstanding
users of the layout to complete, commit the layout and then return it.
This patch adds a helper in order to do all this safely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 5044142..4bdffe0 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -866,6 +866,33 @@
}
EXPORT_SYMBOL_GPL(_pnfs_return_layout);
+int
+pnfs_commit_and_return_layout(struct inode *inode)
+{
+ struct pnfs_layout_hdr *lo;
+ int ret;
+
+ spin_lock(&inode->i_lock);
+ lo = NFS_I(inode)->layout;
+ if (lo == NULL) {
+ spin_unlock(&inode->i_lock);
+ return 0;
+ }
+ pnfs_get_layout_hdr(lo);
+ /* Block new layoutgets and read/write to ds */
+ lo->plh_block_lgets++;
+ spin_unlock(&inode->i_lock);
+ filemap_fdatawait(inode->i_mapping);
+ ret = pnfs_layoutcommit_inode(inode, true);
+ if (ret == 0)
+ ret = _pnfs_return_layout(inode);
+ spin_lock(&inode->i_lock);
+ lo->plh_block_lgets--;
+ spin_unlock(&inode->i_lock);
+ pnfs_put_layout_hdr(lo);
+ return ret;
+}
+
bool pnfs_roc(struct inode *ino)
{
struct pnfs_layout_hdr *lo;
