From c74e2f6ecc51bd08bb5b0335477dba954a50592e Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 21 Mar 2022 13:48:36 -0400 Subject: [PATCH] NFS: Avoid writeback threads getting stuck in mempool_alloc() [ Upstream commit 0bae835b63c53f86cdc524f5962e39409585b22c ] In a low memory situation, allow the NFS writeback code to fail without getting stuck in infinite loops in mempool_alloc(). Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/pagelist.c | 10 +++++----- fs/nfs/write.c | 10 ++++++++-- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 98b9c1ed366e..17fef6eb490c 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -90,10 +90,10 @@ void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos) } } -static inline struct nfs_page * -nfs_page_alloc(void) +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, nfs_io_gfp_mask()); if (p) INIT_LIST_HEAD(&p->wb_list); return p; @@ -901,7 +901,7 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, struct nfs_commit_info cinfo; struct nfs_page_array *pg_array = &hdr->page_array; unsigned int pagecount, pageused; - gfp_t gfp_flags = GFP_KERNEL; + gfp_t gfp_flags = nfs_io_gfp_mask(); pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count); pg_array->npages = pagecount; @@ -984,7 +984,7 @@ nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc, desc->pg_mirrors_dynamic = NULL; if (mirror_count == 1) return desc->pg_mirrors_static; - ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_KERNEL); + ret = kmalloc_array(mirror_count, sizeof(*ret), nfs_io_gfp_mask()); if (ret != NULL) { for (i = 0; i < mirror_count; i++) nfs_pageio_mirror_init(&ret[i], desc->pg_bsize); diff --git a/fs/nfs/write.c b/fs/nfs/write.c index a97eaf4e813c..5d07799513a6 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -94,9 +94,15 @@ EXPORT_SYMBOL_GPL(nfs_commit_free); static struct nfs_pgio_header *nfs_writehdr_alloc(void) { - struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_KERNEL); + struct nfs_pgio_header *p; - memset(p, 0, sizeof(*p)); + p = kmem_cache_zalloc(nfs_wdata_cachep, nfs_io_gfp_mask()); + if (!p) { + p = mempool_alloc(nfs_wdata_mempool, GFP_NOWAIT); + if (!p) + return NULL; + memset(p, 0, sizeof(*p)); + } p->rw_mode = FMODE_WRITE; return p; }