have to protect acct_process from acctwatch closing the vnode

[unix-history] / usr / src / sys / kern / kern_acct.c

diff --git a/usr/src/sys/kern/kern_acct.c b/usr/src/sys/kern/kern_acct.c
index 66a9e8a..235c2e0 100644 (file)
--- a/usr/src/sys/kern/kern_acct.c
+++ b/usr/src/sys/kern/kern_acct.c
@@ -9,7 +9,7 @@
  *
  * %sccs.include.proprietary.c%
  *
  *
  * %sccs.include.proprietary.c%
  *

- *     @(#)kern_acct.c 8.3 (Berkeley) %G%
+ *     @(#)kern_acct.c 8.6 (Berkeley) %G%

  */
 
 #include <sys/param.h>
  */
 
 #include <sys/param.h>


@@ -98,7 +98,9 @@ acct(p, uap, retval)
 
 /*
  * Periodically check the file system to see if accounting
 
 /*
  * Periodically check the file system to see if accounting

- * should be turned on or off.
+ * should be turned on or off. Beware the case where the vnode
+ * has been vgone()'d out from underneath us, e.g. when the file
+ * system containing the accounting file has been forcibly unmounted.

  */
 /* ARGSUSED */
 void
  */
 /* ARGSUSED */
 void


@@ -108,6 +110,11 @@ acctwatch(a)
        struct statfs sb;
 
        if (savacctp) {
        struct statfs sb;
 
        if (savacctp) {

+               if (savacctp->v_type == VBAD) {
+                       (void) vn_close(savacctp, FWRITE, NOCRED, NULL);
+                       savacctp = NULL;
+                       return;
+               }

                (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0);
                if (sb.f_bavail > acctresume * sb.f_blocks / 100) {
                        acctp = savacctp;
                (void)VFS_STATFS(savacctp->v_mount, &sb, (struct proc *)0);
                if (sb.f_bavail > acctresume * sb.f_blocks / 100) {
                        acctp = savacctp;


@@ -117,6 +124,11 @@ acctwatch(a)
        } else {
                if (acctp == NULL)
                        return;
        } else {
                if (acctp == NULL)
                        return;

+               if (acctp->v_type == VBAD) {
+                       (void) vn_close(acctp, FWRITE, NOCRED, NULL);
+                       acctp = NULL;
+                       return;
+               }

                (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0);
                if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) {
                        savacctp = acctp;
                (void)VFS_STATFS(acctp->v_mount, &sb, (struct proc *)0);
                if (sb.f_bavail <= acctsuspend * sb.f_blocks / 100) {
                        savacctp = acctp;


@@ -137,18 +149,25 @@ acct_process(p)
        register struct rusage *ru;
        struct vnode *vp;
        struct timeval t, ut, st;
        register struct rusage *ru;
        struct vnode *vp;
        struct timeval t, ut, st;

-       int i, s;
+       int error, i, s;

        struct acct acctbuf;
        register struct acct *ap = &acctbuf;
 
        struct acct acctbuf;
        register struct acct *ap = &acctbuf;
 

-       if ((vp = acctp) == NULL)
+       s = splclock();
+       if ((vp = acctp) == NULL) {
+               splx(s);

                return (0);
                return (0);

+       }
+       if (vp->v_type == VBAD) {
+               (void) vn_close(vp, FWRITE, NOCRED, NULL);
+               acctp = NULL;
+               splx(s);
+               return (0);
+       }

        bcopy(p->p_comm, ap->ac_comm, sizeof(ap->ac_comm));
        ru = &p->p_stats->p_ru;
        calcru(p, &ut, &st, NULL);
        bcopy(p->p_comm, ap->ac_comm, sizeof(ap->ac_comm));
        ru = &p->p_stats->p_ru;
        calcru(p, &ut, &st, NULL);

-       s = splclock();

        t = time;
        t = time;

-       splx(s);

        ap->ac_utime = compress(ut.tv_sec, ut.tv_usec);
        ap->ac_stime = compress(st.tv_sec, st.tv_usec);
        timevalsub(&t, &p->p_stats->p_start);
        ap->ac_utime = compress(ut.tv_sec, ut.tv_usec);
        ap->ac_stime = compress(st.tv_sec, st.tv_usec);
        timevalsub(&t, &p->p_stats->p_start);


@@ -168,10 +187,12 @@ acct_process(p)
        else
                ap->ac_tty = NODEV;
        ap->ac_flag = p->p_acflag;
        else
                ap->ac_tty = NODEV;
        ap->ac_flag = p->p_acflag;

-       LEASE_CHECK(vp, p, p->p_ucred, LEASE_WRITE);
-       return (vn_rdwr(UIO_WRITE, vp, (caddr_t)ap, sizeof (acctbuf), (off_t)0,
+       VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
+       error = vn_rdwr(UIO_WRITE, vp, (caddr_t)ap, sizeof (acctbuf), (off_t)0,

                UIO_SYSSPACE, IO_UNIT|IO_APPEND, p->p_ucred, (int *)0,
                UIO_SYSSPACE, IO_UNIT|IO_APPEND, p->p_ucred, (int *)0,

-               (struct proc *)0));
+               (struct proc *)0);
+       splx(s);
+       return (error);

 }
 
 /*
 }
 
 /*