[PATCH 27/30] nfs: fix various memory recursions possible with swap over NFS.

[Xiaotian Feng]

GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate IO,
just not of any filesystem data.

The problem is that previuosly NOFS was correct because that avoids
recursion into the NFS code, it now is not, because also IO (swap) can
lead to this recursion.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Suresh Jayaraman <sjayaraman@xxxxxxx>
Signed-off-by: Xiaotian Feng <dfeng@xxxxxxxxxx>
---
 fs/nfs/pagelist.c |    2 +-
 fs/nfs/write.c    |    6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 2be94bb..c0247e9 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -27,7 +27,7 @@ static inline struct nfs_page *
 nfs_page_alloc(void)
 {
 	struct nfs_page	*p;
-	p = kmem_cache_alloc(nfs_page_cachep, GFP_KERNEL);
+	p = kmem_cache_alloc(nfs_page_cachep, GFP_NOIO);
 	if (p) {
 		memset(p, 0, sizeof(*p));
 		INIT_LIST_HEAD(&p->wb_list);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 5852b20..dfa08cb 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -50,7 +50,7 @@ static mempool_t *nfs_commit_mempool;
 
 struct nfs_write_data *nfs_commitdata_alloc(void)
 {
-	struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS);
+	struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO);
 
 	if (p) {
 		memset(p, 0, sizeof(*p));
@@ -69,7 +69,7 @@ void nfs_commit_free(struct nfs_write_data *p)
 
 struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
 {
-	struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
+	struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
 
 	if (p) {
 		memset(p, 0, sizeof(*p));
@@ -79,7 +79,7 @@ struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
 		if (pagecount <= ARRAY_SIZE(p->page_array))
 			p->pagevec = p->page_array;
 		else {
-			p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
+			p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOIO);
 			if (!p->pagevec) {
 				mempool_free(p, nfs_wdata_mempool);
 				p = NULL;
-- 
1.7.1.1

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