Commit bc38735f authored by Benjamin Coddington's avatar Benjamin Coddington Committed by Greg Kroah-Hartman

NFS: Use GFP_NOIO for two allocations in writeback

commit ae97aa52 upstream.

Prevent a deadlock that can occur if we wait on allocations
that try to write back our pages.
Signed-off-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Fixes: 00bfa30a ("NFS: Create a common pgio_alloc and pgio_release...")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2aa6b5f2
...@@ -29,13 +29,14 @@ ...@@ -29,13 +29,14 @@
static struct kmem_cache *nfs_page_cachep; static struct kmem_cache *nfs_page_cachep;
static const struct rpc_call_ops nfs_pgio_common_ops; 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; p->npages = pagecount;
if (pagecount <= ARRAY_SIZE(p->page_array)) if (pagecount <= ARRAY_SIZE(p->page_array))
p->pagevec = p->page_array; p->pagevec = p->page_array;
else { else {
p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL); p->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
if (!p->pagevec) if (!p->pagevec)
p->npages = 0; p->npages = 0;
} }
...@@ -681,6 +682,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, ...@@ -681,6 +682,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
{ {
struct nfs_pgio_mirror *new; struct nfs_pgio_mirror *new;
int i; int i;
gfp_t gfp_flags = GFP_KERNEL;
desc->pg_moreio = 0; desc->pg_moreio = 0;
desc->pg_inode = inode; desc->pg_inode = inode;
...@@ -700,8 +702,10 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, ...@@ -700,8 +702,10 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
if (pg_ops->pg_get_mirror_count) { if (pg_ops->pg_get_mirror_count) {
/* until we have a request, we don't have an lseg and no /* until we have a request, we don't have an lseg and no
* idea how many mirrors there will be */ * 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, 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_dynamic = new;
desc->pg_mirrors = new; desc->pg_mirrors = new;
...@@ -755,9 +759,12 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, ...@@ -755,9 +759,12 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
struct list_head *head = &mirror->pg_list; struct list_head *head = &mirror->pg_list;
struct nfs_commit_info cinfo; struct nfs_commit_info cinfo;
unsigned int pagecount, pageused; unsigned int pagecount, pageused;
gfp_t gfp_flags = GFP_KERNEL;
pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count); 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); nfs_pgio_error(hdr);
desc->pg_error = -ENOMEM; desc->pg_error = -ENOMEM;
return desc->pg_error; return desc->pg_error;
......
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