[PATCH 3.19 099/175] nfs41: .init_read and .init_write can be called with valid pg_lseg

Greg Kroah-Hartman
2015-03-04T06:35:03Z

From: Peng Tao <tao.peng@primarydata.com>

commit cb5d04bc39e914124e811ea55f3034d2379a5f6c upstream.

With pgio refactoring in v3.15, .init_read and .init_write can be
called with valid pgio->pg_lseg. file layout was fixed at that time
by commit c6194271f (pnfs: filelayout: support non page aligned
layouts). But the generic helper still needs to be fixed.

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

---
fs/nfs/pnfs.c | 41 ++++++++++++++++++++---------------------
1 file changed, 20 insertions(+), 21 deletions(-)

--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1445,19 +1445,19 @@ pnfs_generic_pg_init_read(struct nfs_pag
{
u64 rd_size = req->wb_bytes;

- WARN_ON_ONCE(pgio->pg_lseg != NULL);
-
- if (pgio->pg_dreq == NULL)
- rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
- else
- rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
-
- pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
- req->wb_context,
- req_offset(req),
- rd_size,
- IOMODE_READ,
- GFP_KERNEL);
+ if (pgio->pg_lseg == NULL) {
+ if (pgio->pg_dreq == NULL)
+ rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
+ else
+ rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
+
+ pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+ req->wb_context,
+ req_offset(req),
+ rd_size,
+ IOMODE_READ,
+ GFP_KERNEL);
+ }
/* If no lseg, fall back to read through mds */
if (pgio->pg_lseg == NULL)
nfs_pageio_reset_read_mds(pgio);
@@ -1469,14 +1469,13 @@ void
pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
struct nfs_page *req, u64 wb_size)
{
- WARN_ON_ONCE(pgio->pg_lseg != NULL);
-
- pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
- req->wb_context,
- req_offset(req),
- wb_size,
- IOMODE_RW,
- GFP_NOFS);
+ if (pgio->pg_lseg == NULL)
+ pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+ req->wb_context,
+ req_offset(req),
+ wb_size,
+ IOMODE_RW,
+ GFP_NOFS);
/* If no lseg, fall back to write through mds */
if (pgio->pg_lseg == NULL)
nfs_pageio_reset_write_mds(pgio);