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

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

Reviewed by:	glebius
This commit is contained in:
rwatson 2004-07-14 20:26:29 +00:00
parent 5d678afb4b
commit e9825aa42c
1 changed files with 11 additions and 1 deletions
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12
sys/netgraph/ng_eiface.c
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@ -33,8 +33,10 @@
#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/sockio.h>
#include <sys/socket.h>
@ -119,6 +121,8 @@ static int ng_units_in_use = 0;
#define UNITS_BITSPERWORD (sizeof(*ng_eiface_units) * NBBY)
static struct mtx ng_eiface_mtx;
MTX_SYSINIT(ng_eiface, &ng_eiface_mtx, "ng_eiface", MTX_DEF);
/************************************************************************
HELPER STUFF
@ -132,6 +136,7 @@ ng_eiface_get_unit(int *unit)
{
int index, bit;
mtx_lock(&ng_eiface_mtx);
for (index = 0; index < ng_eiface_units_len
&& ng_eiface_units[index] == 0; index++);
if (index == ng_eiface_units_len) { /* extend array */
@ -140,8 +145,10 @@ ng_eiface_get_unit(int *unit)
newlen = (2 * ng_eiface_units_len) + 4;
MALLOC(newarray, int *, newlen * sizeof(*ng_eiface_units),
M_NETGRAPH, M_NOWAIT);
if (newarray == NULL)
if (newarray == NULL) {
mtx_unlock(&ng_eiface_mtx);
return (ENOMEM);
}
bcopy(ng_eiface_units, newarray,
ng_eiface_units_len * sizeof(*ng_eiface_units));
for (i = ng_eiface_units_len; i < newlen; i++)
@ -157,6 +164,7 @@ ng_eiface_get_unit(int *unit)
ng_eiface_units[index] &= ~(1 << bit);
*unit = (index * UNITS_BITSPERWORD) + bit;
ng_units_in_use++;
mtx_unlock(&ng_eiface_mtx);
return (0);
}
@ -170,6 +178,7 @@ ng_eiface_free_unit(int unit)
index = unit / UNITS_BITSPERWORD;
bit = unit % UNITS_BITSPERWORD;
mtx_lock(&ng_eiface_mtx);
KASSERT(index < ng_eiface_units_len,
("%s: unit=%d len=%d", __func__, unit, ng_eiface_units_len));
KASSERT((ng_eiface_units[index] & (1 << bit)) == 0,
@ -187,6 +196,7 @@ ng_eiface_free_unit(int unit)
ng_eiface_units_len = 0;
ng_eiface_units = NULL;
}
mtx_unlock(&ng_eiface_mtx);
}
/************************************************************************