// SPDX-License-Identifier: GPL-2.0 #include #include "nfsd.h" static struct dentry *nfsd_top_dir __read_mostly; /* * /sys/kernel/debug/nfsd/disable-splice-read * * Contents: * %0: NFS READ is allowed to use page splicing * %1: NFS READ uses only iov iter read * * The default value of this setting is zero (page splicing is * allowed). This setting takes immediate effect for all NFS * versions, all exports, and in all NFSD net namespaces. */ static int nfsd_dsr_get(void *data, u64 *val) { *val = nfsd_disable_splice_read ? 1 : 0; return 0; } static int nfsd_dsr_set(void *data, u64 val) { nfsd_disable_splice_read = (val > 0) ? true : false; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(nfsd_dsr_fops, nfsd_dsr_get, nfsd_dsr_set, "%llu\n"); void nfsd_debugfs_exit(void) { debugfs_remove_recursive(nfsd_top_dir); nfsd_top_dir = NULL; } void nfsd_debugfs_init(void) { nfsd_top_dir = debugfs_create_dir("nfsd", NULL); debugfs_create_file("disable-splice-read", S_IWUSR | S_IRUGO, nfsd_top_dir, NULL, &nfsd_dsr_fops); }