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// 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)
*
* 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:
/*
* 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:
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);
}
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