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Conditionalize locking of Giant for VFS in acct(2). We already

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conditionally acquired Giant in the other parts of the accounting code.
This commit is contained in:
John Baldwin 2006-03-28 21:26:59 +00:00
parent a08d2e7fe1
commit 11178ee4c1
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=157232
1 changed files with 20 additions and 17 deletions
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37
sys/kern/kern_acct.c
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@ -159,7 +159,7 @@ int
acct(struct thread *td, struct acct_args *uap)
{
struct nameidata nd;
int error, flags;
int error, flags, vfslocked;
/* Make sure that the caller is root. */
error = suser(td);
@ -168,38 +168,38 @@ acct(struct thread *td, struct acct_args *uap)
/*
* If accounting is to be started to a file, open that file for
* appending and make sure it's a 'normal'. While we could
* conditionally acquire Giant here, we're actually interacting with
* vnodes from possibly two file systems, making the logic a bit
* complicated. For now, use Giant unconditionally.
* appending and make sure it's a 'normal'.
*/
mtx_lock(&Giant);
if (uap->path != NULL) {
NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->path, td);
NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_USERSPACE,
uap->path, td);
flags = FWRITE | O_APPEND;
error = vn_open(&nd, &flags, 0, -1);
if (error)
goto done;
return (error);
vfslocked = NDHASGIANT(&nd);
NDFREE(&nd, NDF_ONLY_PNBUF);
#ifdef MAC
error = mac_check_system_acct(td->td_ucred, nd.ni_vp);
if (error) {
VOP_UNLOCK(nd.ni_vp, 0, td);
vn_close(nd.ni_vp, flags, td->td_ucred, td);
goto done;
VFS_UNLOCK_GIANT(vfslocked);
return (error);
}
#endif
VOP_UNLOCK(nd.ni_vp, 0, td);
if (nd.ni_vp->v_type != VREG) {
vn_close(nd.ni_vp, flags, td->td_ucred, td);
error = EACCES;
goto done;
VFS_UNLOCK_GIANT(vfslocked);
return (EACCES);
}
VFS_UNLOCK_GIANT(vfslocked);
#ifdef MAC
} else {
error = mac_check_system_acct(td->td_ucred, NULL);
if (error)
goto done;
return (error);
#endif
}
@ -216,15 +216,18 @@ acct(struct thread *td, struct acct_args *uap)
* enabled.
*/
acct_suspended = 0;
if (acct_vp != NULL)
if (acct_vp != NULL) {
vfslocked = VFS_LOCK_GIANT(acct_vp->v_mount);
error = acct_disable(td);
VFS_UNLOCK_GIANT(vfslocked);
}
if (uap->path == NULL) {
if (acct_state & ACCT_RUNNING) {
acct_state |= ACCT_EXITREQ;
wakeup(&acct_state);
}
sx_xunlock(&acct_sx);
goto done;
return (error);
}
/*
@ -245,20 +248,20 @@ acct(struct thread *td, struct acct_args *uap)
error = kthread_create(acct_thread, NULL, NULL, 0, 0,
"accounting");
if (error) {
vfslocked = VFS_LOCK_GIANT(acct_vp->v_mount);
(void) vn_close(acct_vp, acct_flags, acct_cred, td);
VFS_UNLOCK_GIANT(vfslocked);
crfree(acct_cred);
acct_vp = NULL;
acct_cred = NULL;
acct_flags = 0;
sx_xunlock(&acct_sx);
log(LOG_NOTICE, "Unable to start accounting thread\n");
goto done;
return (error);
}
}
sx_xunlock(&acct_sx);
log(LOG_NOTICE, "Accounting enabled\n");
done:
mtx_unlock(&Giant);
return (error);
}