From da747de6859948e75bcaaa1019ef0f7fdaf0b867 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 21 Mar 2022 12:34:19 -0400 Subject: NFS: nfsiod should not block forever in mempool_alloc() [ Upstream commit 515dcdcd48736576c6f5c197814da6f81c60a21e ] The concern is that since nfsiod is sometimes required to kick off a commit, it can get locked up waiting forever in mempool_alloc() instead of failing gracefully and leaving the commit until later. Try to allocate from the slab first, with GFP_KERNEL | __GFP_NORETRY, then fall back to a non-blocking attempt to allocate from the memory pool. Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/internal.h | 7 +++++++ fs/nfs/pnfs_nfs.c | 8 ++++++-- fs/nfs/write.c | 24 +++++++++--------------- 3 files changed, 22 insertions(+), 17 deletions(-) (limited to 'fs') diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 66fc936834f2..7239118d98a3 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -580,6 +580,13 @@ nfs_write_match_verf(const struct nfs_writeverf *verf, !nfs_write_verifier_cmp(&req->wb_verf, &verf->verifier); } +static inline gfp_t nfs_io_gfp_mask(void) +{ + if (current->flags & PF_WQ_WORKER) + return GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; + return GFP_KERNEL; +} + /* unlink.c */ extern struct rpc_task * nfs_async_rename(struct inode *old_dir, struct inode *new_dir, diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c index 316f68f96e57..657c242a18ff 100644 --- a/fs/nfs/pnfs_nfs.c +++ b/fs/nfs/pnfs_nfs.c @@ -419,7 +419,7 @@ static struct nfs_commit_data * pnfs_bucket_fetch_commitdata(struct pnfs_commit_bucket *bucket, struct nfs_commit_info *cinfo) { - struct nfs_commit_data *data = nfs_commitdata_alloc(false); + struct nfs_commit_data *data = nfs_commitdata_alloc(); if (!data) return NULL; @@ -515,7 +515,11 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages, unsigned int nreq = 0; if (!list_empty(mds_pages)) { - data = nfs_commitdata_alloc(true); + data = nfs_commitdata_alloc(); + if (!data) { + nfs_retry_commit(mds_pages, NULL, cinfo, -1); + return -ENOMEM; + } data->ds_commit_index = -1; list_splice_init(mds_pages, &data->pages); list_add_tail(&data->list, &list); diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 0691b0b02147..a296e504e4aa 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -70,27 +70,17 @@ static mempool_t *nfs_wdata_mempool; static struct kmem_cache *nfs_cdata_cachep; static mempool_t *nfs_commit_mempool; -struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail) +struct nfs_commit_data *nfs_commitdata_alloc(void) { struct nfs_commit_data *p; - if (never_fail) - p = mempool_alloc(nfs_commit_mempool, GFP_NOIO); - else { - /* It is OK to do some reclaim, not no safe to wait - * for anything to be returned to the pool. - * mempool_alloc() cannot handle that particular combination, - * so we need two separate attempts. - */ + p = kmem_cache_zalloc(nfs_cdata_cachep, nfs_io_gfp_mask()); + if (!p) { p = mempool_alloc(nfs_commit_mempool, GFP_NOWAIT); - if (!p) - p = kmem_cache_alloc(nfs_cdata_cachep, GFP_NOIO | - __GFP_NOWARN | __GFP_NORETRY); if (!p) return NULL; + memset(p, 0, sizeof(*p)); } - - memset(p, 0, sizeof(*p)); INIT_LIST_HEAD(&p->pages); return p; } @@ -1809,7 +1799,11 @@ nfs_commit_list(struct inode *inode, struct list_head *head, int how, if (list_empty(head)) return 0; - data = nfs_commitdata_alloc(true); + data = nfs_commitdata_alloc(); + if (!data) { + nfs_retry_commit(head, NULL, cinfo, -1); + return -ENOMEM; + } /* Set up the argument struct */ nfs_init_commit(data, head, NULL, cinfo); -- cgit v1.2.3