From 5e3a98883e7ebdd1440f829a9e9dd5c3d2c5903b Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 17 Jun 2016 16:48:24 -0400 Subject: [PATCH] pnfs_nfs: fix _cancel_empty_pagelist pnfs_generic_commit_cancel_empty_pagelist calls nfs_commitdata_release, but that is wrong: nfs_commitdata_release puts the open context, something that isn't valid until nfs_init_commit is called, which is never the case when pnfs_generic_commit_cancel_empty_pagelist is called. This was introduced in "nfs: avoid race that crashes nfs_init_commit". Signed-off-by: Weston Andros Adamson Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/pnfs_nfs.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c index 0dfc476da3e1..b38e3c0dc790 100644 --- a/fs/nfs/pnfs_nfs.c +++ b/fs/nfs/pnfs_nfs.c @@ -247,7 +247,11 @@ void pnfs_fetch_commit_bucket_list(struct list_head *pages, } /* Helper function for pnfs_generic_commit_pagelist to catch an empty - * page list. This can happen when two commits race. */ + * page list. This can happen when two commits race. + * + * This must be called instead of nfs_init_commit - call one or the other, but + * not both! + */ static bool pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages, struct nfs_commit_data *data, @@ -256,7 +260,11 @@ pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages, if (list_empty(pages)) { if (atomic_dec_and_test(&cinfo->mds->rpcs_out)) wake_up_atomic_t(&cinfo->mds->rpcs_out); - nfs_commitdata_release(data); + /* don't call nfs_commitdata_release - it tries to put + * the open_context which is not acquired until nfs_init_commit + * which has not been called on @data */ + WARN_ON_ONCE(data->context); + nfs_commit_free(data); return true; }