[PATCH 4.1 053/159] NFSv4/pnfs: Ensure we dont miss a file extension

Greg Kroah-Hartman
2015-09-26T21:15:17Z

From: Trond Myklebust <trond.myklebust@primarydata.com>

commit 2b83d3de4c18af49800e0b26ae013db4fcf43a4a upstream.

pNFS writes don't return attributes, however that doesn't mean that we
should ignore the fact that they may be extending the file. This patch
ensures that if a write is seen to extend the file, then we always set
an attribute barrier, and update the cached file size.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfs/write.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1383,24 +1383,27 @@ static void nfs_writeback_check_extend(s
{
struct nfs_pgio_args *argp = &hdr->args;
struct nfs_pgio_res *resp = &hdr->res;
+ u64 size = argp->offset + resp->count;

if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
+ fattr->size = size;
+ if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) {
+ fattr->valid &= ~NFS_ATTR_FATTR_SIZE;
return;
- if (argp->offset + resp->count != fattr->size)
- return;
- if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode))
+ }
+ if (size != fattr->size)
return;
/* Set attribute barrier */
nfs_fattr_set_barrier(fattr);
+ /* ...and update size */
+ fattr->valid |= NFS_ATTR_FATTR_SIZE;
}

void nfs_writeback_update_inode(struct nfs_pgio_header *hdr)
{
- struct nfs_fattr *fattr = hdr->res.fattr;
+ struct nfs_fattr *fattr = &hdr->fattr;
struct inode *inode = hdr->inode;

- if (fattr == NULL)
- return;
spin_lock(&inode->i_lock);
nfs_writeback_check_extend(hdr, fattr);
nfs_post_op_update_inode_force_wcc_locked(inode, fattr);