We seem to be assuming fscache_acquire_cookie will always succeed and will obtain a valid cookie. But, under low memory conditions kmem_cache_alloc could fail and that would leave nfsi->fscache being set to NULL. This could lead to a possibility of a page with PG_fscache flag set but cookie not set(i.e. NULL). This inconsistency could trigger a kernel BUG in nfs_fscache_release_page() and other places as we do BUG_ON(!cookie), I think. I'm aware that there are other places where we would need such checks, but wanted to validate this patch before getting on to them. Signed-off-by: Suresh Jayaraman <sjayaraman@xxxxxxx> --- fs/nfs/client.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index ee77713..7776e8a 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -155,6 +155,8 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_ clp->cl_machine_cred = cred; nfs_fscache_get_client_cookie(clp); + if (!clp->fscache) + goto error_cleanup; return clp; -- Suresh Jayaraman -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
