/* * 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); }