This is a note to let you know that I've just added the patch titled pnfs_nfs: fix _cancel_empty_pagelist to the 4.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pnfs_nfs-fix-_cancel_empty_pagelist.patch and it can be found in the queue-4.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5e3a98883e7ebdd1440f829a9e9dd5c3d2c5903b Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson <dros@xxxxxxxxxx> Date: Fri, 17 Jun 2016 16:48:24 -0400 Subject: pnfs_nfs: fix _cancel_empty_pagelist From: Weston Andros Adamson <dros@xxxxxxxxxx> commit 5e3a98883e7ebdd1440f829a9e9dd5c3d2c5903b upstream. 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 <dros@xxxxxxxxxxxxxxx> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/nfs/pnfs_nfs.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/fs/nfs/pnfs_nfs.c +++ b/fs/nfs/pnfs_nfs.c @@ -247,7 +247,11 @@ void pnfs_fetch_commit_bucket_list(struc } /* 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_pagelis 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; } Patches currently in stable-queue which might be from dros@xxxxxxxxxx are queue-4.6/pnfs_nfs-fix-_cancel_empty_pagelist.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html