NFS: Ensure NFS writeback allocations don't recurse back into NFS.

All the allocations that we can hit in the NFS layer and sunrpc layers
themselves are already marked as GFP_NOFS, but we need to ensure that
any calls to generic kernel functionality do the right thing as well.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2019-02-18 13:06:54 -05:00
parent df3accb849
commit 875bc3fbf2
1 changed files with 6 additions and 1 deletions

View File

@ -26,6 +26,7 @@
#include <linux/iversion.h>
#include <linux/uaccess.h>
#include <linux/sched/mm.h>
#include "delegation.h"
#include "internal.h"
@ -712,11 +713,13 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
struct inode *inode = mapping->host;
struct nfs_pageio_descriptor pgio;
struct nfs_io_completion *ioc = nfs_io_completion_alloc(GFP_NOFS);
struct nfs_io_completion *ioc;
unsigned int pflags = memalloc_nofs_save();
int err;
nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
ioc = nfs_io_completion_alloc(GFP_NOFS);
if (ioc)
nfs_io_completion_init(ioc, nfs_io_completion_commit, inode);
@ -727,6 +730,8 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
nfs_pageio_complete(&pgio);
nfs_io_completion_put(ioc);
memalloc_nofs_restore(pflags);
if (err < 0)
goto out_err;
err = pgio.pg_error;