OpenZFS 7280 - Allow changing global libzpool variables in zdb and ztest through command line

Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>

OpenZFS-issue: https://www.illumos.org/issues/7280
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/0e60744
Closes #5676
This commit is contained in:
George Melikov
2017-01-31 21:13:10 +03:00
committed by Brian Behlendorf
parent 41425f79da
commit ed828c0c37
6 changed files with 95 additions and 14 deletions
+1 -1
View File
@@ -140,7 +140,7 @@ libzpool_la_LIBADD = \
$(top_builddir)/lib/libnvpair/libnvpair.la \
$(top_builddir)/lib/libicp/libicp.la
libzpool_la_LIBADD += $(ZLIB)
libzpool_la_LIBADD += $(ZLIB) -ldl
libzpool_la_LDFLAGS = -version-info 2:0:0
EXTRA_DIST = $(USER_C)
+57
View File
@@ -20,6 +20,7 @@
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2016 by Delphix. All rights reserved.
*/
#include <assert.h>
@@ -31,6 +32,7 @@
#include <sys/spa.h>
#include <sys/fs/zfs.h>
#include <sys/refcount.h>
#include <dlfcn.h>
/*
* Routines needed by more than one client of libzpool.
@@ -158,3 +160,58 @@ show_pool_stats(spa_t *spa)
nvlist_free(config);
}
/*
* Sets given global variable in libzpool to given unsigned 32-bit value.
* arg: "<variable>=<value>"
*/
int
set_global_var(char *arg)
{
void *zpoolhdl;
char *varname = arg, *varval;
u_longlong_t val;
#ifndef _LITTLE_ENDIAN
/*
* On big endian systems changing a 64-bit variable would set the high
* 32 bits instead of the low 32 bits, which could cause unexpected
* results.
*/
fprintf(stderr, "Setting global variables is only supported on "
"little-endian systems\n");
return (ENOTSUP);
#endif
if ((varval = strchr(arg, '=')) != NULL) {
*varval = '\0';
varval++;
val = strtoull(varval, NULL, 0);
if (val > UINT32_MAX) {
fprintf(stderr, "Value for global variable '%s' must "
"be a 32-bit unsigned integer\n", varname);
return (EOVERFLOW);
}
} else {
return (EINVAL);
}
zpoolhdl = dlopen("libzpool.so", RTLD_LAZY);
if (zpoolhdl != NULL) {
uint32_t *var;
var = dlsym(zpoolhdl, varname);
if (var == NULL) {
fprintf(stderr, "Global variable '%s' does not exist "
"in libzpool.so\n", varname);
return (EINVAL);
}
*var = (uint32_t)val;
dlclose(zpoolhdl);
} else {
fprintf(stderr, "Failed to open libzpool.so to set global "
"variable\n");
return (EIO);
}
return (0);
}