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authorBenjamin Coddington <bcodding@redhat.com>2017-04-19 10:11:33 -0400
committerTrond Myklebust <trond.myklebust@primarydata.com>2017-04-20 13:55:10 -0400
commitae97aa524ef495b6276fd26f5d5449fb22975d7c (patch)
tree4ce8eaec4ba166c40de18ec88f839adfbf70825b /fs/nfs
parent1f84ccdf37d0db3a70714d02d51b0b6d45887fb8 (diff)
downloadlinux-ae97aa524ef495b6276fd26f5d5449fb22975d7c.tar.bz2
NFS: Use GFP_NOIO for two allocations in writeback
Prevent a deadlock that can occur if we wait on allocations that try to write back our pages. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Fixes: 00bfa30abe869 ("NFS: Create a common pgio_alloc and pgio_release...") Cc: stable@vger.kernel.org # 3.16+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/pagelist.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 3917268961d9..7d83f3acdca1 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -29,13 +29,14 @@
static struct kmem_cache *nfs_page_cachep;
static const struct rpc_call_ops nfs_pgio_common_ops;
-static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
+static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount,
+ gfp_t gfp_flags)
{
p->npages = pagecount;
if (pagecount <= ARRAY_SIZE(p->page_array))
p->pagevec = p->page_array;
else {
- p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
+ p->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
if (!p->pagevec)
p->npages = 0;
}
@@ -681,6 +682,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
{
struct nfs_pgio_mirror *new;
int i;
+ gfp_t gfp_flags = GFP_KERNEL;
desc->pg_moreio = 0;
desc->pg_inode = inode;
@@ -700,8 +702,10 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
if (pg_ops->pg_get_mirror_count) {
/* until we have a request, we don't have an lseg and no
* idea how many mirrors there will be */
+ if (desc->pg_rw_ops->rw_mode == FMODE_WRITE)
+ gfp_flags = GFP_NOIO;
new = kcalloc(NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX,
- sizeof(struct nfs_pgio_mirror), GFP_KERNEL);
+ sizeof(struct nfs_pgio_mirror), gfp_flags);
desc->pg_mirrors_dynamic = new;
desc->pg_mirrors = new;
@@ -755,9 +759,12 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
struct list_head *head = &mirror->pg_list;
struct nfs_commit_info cinfo;
unsigned int pagecount, pageused;
+ gfp_t gfp_flags = GFP_KERNEL;
pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
- if (!nfs_pgarray_set(&hdr->page_array, pagecount)) {
+ if (desc->pg_rw_ops->rw_mode == FMODE_WRITE)
+ gfp_flags = GFP_NOIO;
+ if (!nfs_pgarray_set(&hdr->page_array, pagecount, gfp_flags)) {
nfs_pgio_error(hdr);
desc->pg_error = -ENOMEM;
return desc->pg_error;