/*
* nfs4_alloc_slot - efficiently look for a free slot
*
* nfs4_alloc_slot looks for an unset bit in the used_slots bitmap.
* If found, we mark the slot as used, update the highest_used_slotid,
* and respectively set up the sequence operation args.
*
* Note: must be called with under the slot_tbl_lock.
*/
struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl)
{
struct nfs4_slot *ret = ERR_PTR(-EBUSY);
u32 slotid;
dprintk("--> %s used_slots=%04lx highest_used=%u max_slots=%u\n",
__func__, tbl->used_slots[0], tbl->highest_used_slotid,
tbl->max_slotid + 1);
slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);
if (slotid > tbl->max_slotid)
goto out;
ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
if (IS_ERR(ret))
goto out;
__set_bit(slotid, tbl->used_slots);
if (slotid > tbl->highest_used_slotid ||
tbl->highest_used_slotid == NFS4_NO_SLOT)
tbl->highest_used_slotid = slotid;
ret->generation = tbl->generation;
out:
dprintk("<-- %s used_slots=%04lx highest_used=%d slotid=%d \n",
__func__, tbl->used_slots[0], tbl->highest_used_slotid,
!IS_ERR(ret) ? ret->slot_nr : -1);
return ret;
}
static int nfs4_grow_slot_table(struct nfs4_slot_table *tbl,
u32 max_reqs, u32 ivalue)
{
if (max_reqs <= tbl->max_slots)
return 0;
if (!IS_ERR(nfs4_find_or_create_slot(tbl, max_reqs - 1, ivalue, GFP_NOFS)))
return 0;
return -ENOMEM;
}
/*
* nfs4_lookup_slot - Find a slot but don't allocate it
*
* Note: must be called with the slot_tbl_lock held.
*/
struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid)
{
if (slotid <= tbl->max_slotid)
return nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
return ERR_PTR(-E2BIG);
}
