/*
* This is called to attempt to lock the dquot associated with this
* dquot log item. Don't sleep on the dquot lock or the flush lock.
* If the flush lock is already held, indicating that the dquot has
* been or is in the process of being flushed, then see if we can
* find the dquot's buffer in the buffer cache without sleeping. If
* we can and it is marked delayed write, then we want to send it out.
* We delay doing so until the push routine, though, to avoid sleeping
* in any device strategy routines.
*/
STATIC uint
xfs_qm_dquot_logitem_trylock(
xfs_dq_logitem_t *qip)
{
xfs_dquot_t *dqp;
uint retval;
dqp = qip->qli_dquot;
if (dqp->q_pincount > 0)
return (XFS_ITEM_PINNED);
if (! xfs_qm_dqlock_nowait(dqp))
return (XFS_ITEM_LOCKED);
retval = XFS_ITEM_SUCCESS;
if (! xfs_qm_dqflock_nowait(dqp)) {
/*
* The dquot is already being flushed. It may have been
* flushed delayed write, however, and we don't want to
* get stuck waiting for that to complete. So, we want to check
* to see if we can lock the dquot's buffer without sleeping.
* If we can and it is marked for delayed write, then we
* hold it and send it out from the push routine. We don't
* want to do that now since we might sleep in the device
* strategy routine. We also don't want to grab the buffer lock
* here because we'd like not to call into the buffer cache
* while holding the AIL lock.
* Make sure to only return PUSHBUF if we set pushbuf_flag
* ourselves. If someone else is doing it then we don't
* want to go to the push routine and duplicate their efforts.
*/
if (qip->qli_pushbuf_flag == 0) {
qip->qli_pushbuf_flag = 1;
ASSERT(qip->qli_format.qlf_blkno == dqp->q_blkno);
#ifdef DEBUG
qip->qli_push_owner = current_pid();
#endif
/*
* The dquot is left locked.
*/
retval = XFS_ITEM_PUSHBUF;
} else {
retval = XFS_ITEM_FLUSHING;
xfs_dqunlock_nonotify(dqp);
}
}
ASSERT(qip->qli_item.li_flags & XFS_LI_IN_AIL);
return (retval);
}
/*
* This is called to attempt to lock the dquot associated with this
* dquot log item. Don't sleep on the dquot lock or the flush lock.
* If the flush lock is already held, indicating that the dquot has
* been or is in the process of being flushed, then see if we can
* find the dquot's buffer in the buffer cache without sleeping. If
* we can and it is marked delayed write, then we want to send it out.
* We delay doing so until the push routine, though, to avoid sleeping
* in any device strategy routines.
*/
STATIC uint
xfs_qm_dquot_logitem_trylock(
struct xfs_log_item *lip)
{
struct xfs_dquot *dqp = DQUOT_ITEM(lip)->qli_dquot;
if (atomic_read(&dqp->q_pincount) > 0)
return XFS_ITEM_PINNED;
if (!xfs_qm_dqlock_nowait(dqp))
return XFS_ITEM_LOCKED;
if (!xfs_dqflock_nowait(dqp)) {
/*
* dquot has already been flushed to the backing buffer,
* leave it locked, pushbuf routine will unlock it.
*/
return XFS_ITEM_PUSHBUF;
}
ASSERT(lip->li_flags & XFS_LI_IN_AIL);
return XFS_ITEM_SUCCESS;
}
