diff mbox

[11/12] nfs: Prevent page allocator recursions with swap over NFS.

Message ID 1340185081-22525-12-git-send-email-mgorman@suse.de
State Not Applicable, archived
Delegated to: David Miller
Headers show

Commit Message

Mel Gorman June 20, 2012, 9:38 a.m. UTC 
GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate
IO, just not of any filesystem data.

The problem is that previously NOFS was correct because that avoids
recursion into the NFS code. With swap-over-NFS, it is no longer
correct as swap IO can lead to this recursion.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 fs/nfs/pagelist.c |    2 +-
 fs/nfs/write.c    |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Rik van Riel June 20, 2012, 5:42 p.m. UTC | #1 
On 06/20/2012 05:38 AM, Mel Gorman wrote:
> GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate
> IO, just not of any filesystem data.
>
> The problem is that previously NOFS was correct because that avoids
> recursion into the NFS code. With swap-over-NFS, it is no longer
> correct as swap IO can lead to this recursion.
>
> Signed-off-by: Peter Zijlstra<a.p.zijlstra@chello.nl>
> Signed-off-by: Mel Gorman<mgorman@suse.de>

Acked-by: Rik van Riel<riel@redhat.com>

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 9ef8b3c..7de1646 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -70,7 +70,7 @@  void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
 static inline struct nfs_page *
 nfs_page_alloc(void)
 {
-	struct nfs_page	*p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL);
+	struct nfs_page	*p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
 	if (p)
 		INIT_LIST_HEAD(&p->wb_list);
 	return p;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f45b9ca..6f90681 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -52,7 +52,7 @@  static mempool_t *nfs_commit_mempool;
 
 struct nfs_commit_data *nfs_commitdata_alloc(void)
 {
-	struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS);
+	struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO);
 
 	if (p) {
 		memset(p, 0, sizeof(*p));
@@ -70,7 +70,7 @@  EXPORT_SYMBOL_GPL(nfs_commit_free);
 
 struct nfs_write_header *nfs_writehdr_alloc(void)
 {
-	struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
+	struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
 
 	if (p) {
 		struct nfs_pgio_header *hdr = &p->header;