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Introduce a new mutex, ng_iface_mtx, to protect the global unit list

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lock used to synchronize allocation of unit numbers for new netgraph
interfaces.

Reviewed by:	glebius
Tested by:	glebius
This commit is contained in:
Robert Watson 2004-07-14 20:24:21 +00:00
parent 9b7b2aeff6
commit 9a668fa4d8
1 changed files with 12 additions and 1 deletions
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13
sys/netgraph/ng_iface.c
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@ -59,8 +59,10 @@
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/errno.h>
#include <sys/random.h>
#include <sys/sockio.h>
@ -218,6 +220,9 @@ static int ng_units_in_use = 0;
#define UNITS_BITSPERWORD (sizeof(*ng_iface_units) * NBBY)
static struct mtx ng_iface_mtx;
MTX_SYSINIT(ng_iface, &ng_iface_mtx, "ng_iface", MTX_DEF);
/************************************************************************
HELPER STUFF
************************************************************************/
@ -289,6 +294,7 @@ ng_iface_get_unit(int *unit)
{
int index, bit;
mtx_lock(&ng_iface_mtx);
for (index = 0; index < ng_iface_units_len
&& ng_iface_units[index] == 0; index++);
if (index == ng_iface_units_len) { /* extend array */
@ -297,8 +303,10 @@ ng_iface_get_unit(int *unit)
newlen = (2 * ng_iface_units_len) + 4;
MALLOC(newarray, int *, newlen * sizeof(*ng_iface_units),
M_NETGRAPH_IFACE, M_NOWAIT);
if (newarray == NULL)
if (newarray == NULL) {
mtx_unlock(&ng_iface_mtx);
return (ENOMEM);
}
bcopy(ng_iface_units, newarray,
ng_iface_units_len * sizeof(*ng_iface_units));
for (i = ng_iface_units_len; i < newlen; i++)
@ -314,6 +322,7 @@ ng_iface_get_unit(int *unit)
ng_iface_units[index] &= ~(1 << bit);
*unit = (index * UNITS_BITSPERWORD) + bit;
ng_units_in_use++;
mtx_unlock(&ng_iface_mtx);
return (0);
}
@ -327,6 +336,7 @@ ng_iface_free_unit(int unit)
index = unit / UNITS_BITSPERWORD;
bit = unit % UNITS_BITSPERWORD;
mtx_lock(&ng_iface_mtx);
KASSERT(index < ng_iface_units_len,
("%s: unit=%d len=%d", __func__, unit, ng_iface_units_len));
KASSERT((ng_iface_units[index] & (1 << bit)) == 0,
@ -344,6 +354,7 @@ ng_iface_free_unit(int unit)
ng_iface_units_len = 0;
ng_iface_units = NULL;
}
mtx_unlock(&ng_iface_mtx);
}
/************************************************************************