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When removing the last item from a non-empty worklist, the worklist

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tail pointer must be updated.

Reported by:	Kris Kennaway <kris@obsecurity.org>
Sponsored by:   DARPA & NAI Labs.
This commit is contained in:
Kirk McKusick 2003-02-24 07:28:41 +00:00
parent e901be8e96
commit 3bf0ed940b
1 changed files with 15 additions and 2 deletions
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17
sys/ufs/ffs/ffs_softdep.c
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@ -495,6 +495,7 @@ workitem_free(item, type)
* Workitem queue management
*/
static struct workhead softdep_workitem_pending;
static struct worklist *worklist_tail;
static int num_on_worklist; /* number of worklist items to be processed */
static int softdep_worklist_busy; /* 1 => trying to do unmount */
static int softdep_worklist_req; /* serialized waiters */
@ -552,7 +553,6 @@ static void
add_to_worklist(wk)
struct worklist *wk;
{
static struct worklist *worklist_tail;
if (wk->wk_state & ONWORKLIST) {
if (lk.lkt_held != NOHOLDER)
@ -679,7 +679,7 @@ process_worklist_item(matchmnt, flags)
struct mount *matchmnt;
int flags;
{
struct worklist *wk;
struct worklist *wk, *wkend;
struct mount *mp;
struct vnode *vp;
int matchcnt = 0;
@ -717,7 +717,20 @@ process_worklist_item(matchmnt, flags)
FREE_LOCK(&lk);
return (-1);
}
/*
* Remove the item to be processed. If we are removing the last
* item on the list, we need to recalculate the tail pointer.
* As this happens rarely and usually when the list is short,
* we just run down the list to find it rather than tracking it
* in the above loop.
*/
WORKLIST_REMOVE(wk);
if (wk == worklist_tail) {
LIST_FOREACH(wkend, &softdep_workitem_pending, wk_list)
if (LIST_NEXT(wkend, wk_list) == NULL)
break;
worklist_tail = wkend;
}
num_on_worklist -= 1;
FREE_LOCK(&lk);
switch (wk->wk_type) {