// SPDX-License-Identifier: GPL-2.0 #include <linux/debugfs.h> #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);	if (!nfsd_disable_splice_read) {		/*		 * Must use buffered I/O if splice_read is enabled.		 */		nfsd_io_cache_read = NFSD_IO_BUFFERED;	}	return 0;} DEFINE_DEBUGFS_ATTRIBUTE(nfsd_dsr_fops, nfsd_dsr_get, nfsd_dsr_set, "%llu\n"); /* * /sys/kernel/debug/nfsd/io_cache_read * * Contents: *   %0: NFS READ will use buffered IO *   %1: NFS READ will use dontcache (buffered IO w/ dropbehind) *   %2: NFS READ will use direct IO * * This setting takes immediate effect for all NFS versions, * all exports, and in all NFSD net namespaces. */ static int nfsd_io_cache_read_get(void *data, u64 *val){	*val = nfsd_io_cache_read;	return 0;} static int nfsd_io_cache_read_set(void *data, u64 val){	int ret = 0; 	switch (val) {	case NFSD_IO_BUFFERED:		nfsd_io_cache_read = NFSD_IO_BUFFERED;		break;	case NFSD_IO_DONTCACHE:	case NFSD_IO_DIRECT:		/*		 * Must disable splice_read when enabling		 * NFSD_IO_DONTCACHE.		 */		nfsd_disable_splice_read = true;		nfsd_io_cache_read = val;		break;	default:		ret = -EINVAL;		break;	} 	return ret;} DEFINE_DEBUGFS_ATTRIBUTE(nfsd_io_cache_read_fops, nfsd_io_cache_read_get,			 nfsd_io_cache_read_set, "%llu\n"); /* * /sys/kernel/debug/nfsd/io_cache_write * * Contents: *   %0: NFS WRITE will use buffered IO *   %1: NFS WRITE will use dontcache (buffered IO w/ dropbehind) * * This setting takes immediate effect for all NFS versions, * all exports, and in all NFSD net namespaces. */ static int nfsd_io_cache_write_get(void *data, u64 *val){	*val = nfsd_io_cache_write;	return 0;} static int nfsd_io_cache_write_set(void *data, u64 val){	int ret = 0; 	switch (val) {	case NFSD_IO_BUFFERED:	case NFSD_IO_DONTCACHE:	case NFSD_IO_DIRECT:		nfsd_io_cache_write = val;		break;	default:		ret = -EINVAL;		break;	} 	return ret;} DEFINE_DEBUGFS_ATTRIBUTE(nfsd_io_cache_write_fops, nfsd_io_cache_write_get,			 nfsd_io_cache_write_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); 	debugfs_create_file("io_cache_read", 0644, nfsd_top_dir, NULL,			    &nfsd_io_cache_read_fops); 	debugfs_create_file("io_cache_write", 0644, nfsd_top_dir, NULL,			    &nfsd_io_cache_write_fops);#ifdef CONFIG_NFSD_V4	debugfs_create_bool("delegated_timestamps", 0644, nfsd_top_dir,			    &nfsd_delegts_enabled);#endif}