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| author |   Benjamin Coddington <bcodding@redhat.com> | 2017-04-19 10:11:33 -0400 |
|---|---|---|
| committer |   Trond Myklebust <trond.myklebust@primarydata.com> | 2017-04-20 13:55:10 -0400 |
| commit | ae97aa524ef495b6276fd26f5d5449fb22975d7c (patch) | |
| tree | 4ce8eaec4ba166c40de18ec88f839adfbf70825b /fs/nfs/pagelist.c | |
| parent | NFS: Fix use after free in write error path (diff) | |
| download | linux-dev-ae97aa524ef495b6276fd26f5d5449fb22975d7c.tar.xz linux-dev-ae97aa524ef495b6276fd26f5d5449fb22975d7c.zip | |
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/pagelist.c')
| -rw-r--r-- | fs/nfs/pagelist.c | 15 |
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; |