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- Fix two obvious locking bugs; 1) returning with lock held when it needed

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to be dropped, 2) attempting to lock acct_mtx while already holding it.
  Sorry to those who experienced pain.
- Added two comments referring to two areas in which acct_mtx is held over
  vnode operations that might sleep.  Patch in the works for this.
This commit is contained in:
Andrew R. Reiter 2002-09-12 05:00:32 +00:00
parent 3080733f2e
commit b4dcc46af5
1 changed files with 16 additions and 3 deletions
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19
sys/kern/kern_acct.c
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@ -157,6 +157,10 @@ acct(td, uap)
* close the file, and (if no new file was specified, leave).
*/
/*
* XXX arr: Should not hold lock over vnode operation.
*/
mtx_lock(&acct_mtx);
if (acctp != NULLVP || savacctp != NULLVP) {
callout_stop(&acctwatch_callout);
@ -167,8 +171,10 @@ acct(td, uap)
crfree(acctcred != NOCRED ? acctcred : savacctcred);
acctcred = savacctcred = NOCRED;
}
if (SCARG(uap, path) == NULL)
if (SCARG(uap, path) == NULL) {
mtx_unlock(&acct_mtx);
goto done2;
}
/*
* Save the new accounting file vnode, and schedule the new
@ -178,9 +184,9 @@ acct(td, uap)
acctcred = crhold(td->td_ucred);
acctflags = flags;
callout_init(&acctwatch_callout, 0);
mtx_unlock(&acct_mtx);
acctwatch(NULL);
done2:
mtx_unlock(&acct_mtx);
mtx_unlock(&Giant);
return (error);
}
@ -342,6 +348,11 @@ acctwatch(a)
mtx_lock(&acct_mtx);
/*
* XXX arr: Need to fix the issue of holding acct_mtx over
* the below vnode operations.
*/
if (savacctp != NULLVP) {
if (savacctp->v_type == VBAD) {
(void) vn_close(savacctp, savacctflags, savacctcred,
@ -361,8 +372,10 @@ acctwatch(a)
log(LOG_NOTICE, "Accounting resumed\n");
}
} else {
if (acctp == NULLVP)
if (acctp == NULLVP) {
mtx_unlock(&acct_mtx);
return;
}
if (acctp->v_type == VBAD) {
(void) vn_close(acctp, acctflags, acctcred, NULL);
acctp = NULLVP;