[PATCH] knfsd: allow admin to set nthreads per node
Add /proc/fs/nfsd/pool_threads which allows the sysadmin (or a userspace
daemon) to read and change the number of nfsd threads in each pool. The
format is a list of space-separated integers, one per pool.
Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 36e8e13..5c6a477 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -54,6 +54,7 @@
NFSD_List,
NFSD_Fh,
NFSD_Threads,
+ NFSD_Pool_Threads,
NFSD_Versions,
NFSD_Ports,
/*
@@ -78,6 +79,7 @@
static ssize_t write_getfs(struct file *file, char *buf, size_t size);
static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
static ssize_t write_threads(struct file *file, char *buf, size_t size);
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
static ssize_t write_versions(struct file *file, char *buf, size_t size);
static ssize_t write_ports(struct file *file, char *buf, size_t size);
#ifdef CONFIG_NFSD_V4
@@ -95,6 +97,7 @@
[NFSD_Getfs] = write_getfs,
[NFSD_Fh] = write_filehandle,
[NFSD_Threads] = write_threads,
+ [NFSD_Pool_Threads] = write_pool_threads,
[NFSD_Versions] = write_versions,
[NFSD_Ports] = write_ports,
#ifdef CONFIG_NFSD_V4
@@ -363,6 +366,72 @@
return strlen(buf);
}
+extern int nfsd_nrpools(void);
+extern int nfsd_get_nrthreads(int n, int *);
+extern int nfsd_set_nrthreads(int n, int *);
+
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
+{
+ /* if size > 0, look for an array of number of threads per node
+ * and apply them then write out number of threads per node as reply
+ */
+ char *mesg = buf;
+ int i;
+ int rv;
+ int len;
+ int npools = nfsd_nrpools();
+ int *nthreads;
+
+ if (npools == 0) {
+ /*
+ * NFS is shut down. The admin can start it by
+ * writing to the threads file but NOT the pool_threads
+ * file, sorry. Report zero threads.
+ */
+ strcpy(buf, "0\n");
+ return strlen(buf);
+ }
+
+ nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
+ if (nthreads == NULL)
+ return -ENOMEM;
+
+ if (size > 0) {
+ for (i = 0; i < npools; i++) {
+ rv = get_int(&mesg, &nthreads[i]);
+ if (rv == -ENOENT)
+ break; /* fewer numbers than pools */
+ if (rv)
+ goto out_free; /* syntax error */
+ rv = -EINVAL;
+ if (nthreads[i] < 0)
+ goto out_free;
+ }
+ rv = nfsd_set_nrthreads(i, nthreads);
+ if (rv)
+ goto out_free;
+ }
+
+ rv = nfsd_get_nrthreads(npools, nthreads);
+ if (rv)
+ goto out_free;
+
+ mesg = buf;
+ size = SIMPLE_TRANSACTION_LIMIT;
+ for (i = 0; i < npools && size > 0; i++) {
+ snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
+ len = strlen(mesg);
+ size -= len;
+ mesg += len;
+ }
+
+ return (mesg-buf);
+
+out_free:
+ kfree(nthreads);
+ return rv;
+}
+
static ssize_t write_versions(struct file *file, char *buf, size_t size)
{
/*
@@ -544,6 +613,7 @@
[NFSD_List] = {"exports", &exports_operations, S_IRUGO},
[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
+ [NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
#ifdef CONFIG_NFSD_V4
