Don't mark_inode_dirty_sync() while holding lock

mark_inode_dirty_sync() grabs the same inode lock!

race conditions between holding the lock in pnfs_set_layoutcommit() and in
mark_inode_dirty_sync() can result in a second call to pnfs_layoutcommit_inode(), but
this will be a noop as NFS_INO_LAYOUTCOMMIT won't be set in the second call

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index d9ab97269ce..ff681ab65d3 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1004,6 +1004,7 @@ pnfs_set_layoutcommit(struct nfs_write_data *wdata)
 {
         struct nfs_inode *nfsi = NFS_I(wdata->inode);
         loff_t end_pos = wdata->args.offset + wdata->res.count;
+        bool mark_as_dirty = false;
 
         spin_lock(&nfsi->vfs_inode.i_lock);
         if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
@@ -1011,13 +1012,18 @@ pnfs_set_layoutcommit(struct nfs_write_data *wdata)
                 get_lseg(wdata->lseg);
                 wdata->lseg->pls_lc_cred =
                         get_rpccred(wdata->args.context->state->owner->so_cred);
-                mark_inode_dirty_sync(wdata->inode);
+                mark_as_dirty = true;
                 dprintk("%s: Set layoutcommit for inode %lu ",
                         __func__, wdata->inode->i_ino);
         }
         if (end_pos > wdata->lseg->pls_end_pos)
                 wdata->lseg->pls_end_pos = end_pos;
         spin_unlock(&nfsi->vfs_inode.i_lock);
+
+        /* if pnfs_layoutcommit_inode() runs between inode locks, the next one
+         * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
+        if (mark_as_dirty)
+                mark_inode_dirty_sync(wdata->inode);
 }
 EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);