diff options
| -rw-r--r-- | fs/nfs/nfs4proc.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index c961808..b6308f6 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -274,6 +274,42 @@ static void renew_lease(const struct nfs_server *server, unsigned long timestamp #if defined(CONFIG_NFS_V4_1) /* + * nfs4_free_slot - free a slot and efficiently update slot table. + * + * freeing a slot is trivially done by clearing its respective bit + * in the bitmap. + * If the freed slotid equals highest_used_slotid we want to update it + * so that the server would be able to size down the slot table if needed, + * otherwise we know that the highest_used_slotid is still in use. + * When updating highest_used_slotid there may be "holes" in the bitmap + * so we need to scan down from highest_used_slotid to 0 looking for the now + * highest slotid in use. + * If none found, highest_used_slotid is set to -1. + */ +static void +nfs4_free_slot(struct nfs4_slot_table *tbl, u8 free_slotid) +{ + int slotid = free_slotid; + + spin_lock(&tbl->slot_tbl_lock); + /* clear used bit in bitmap */ + __clear_bit(slotid, tbl->used_slots); + + /* update highest_used_slotid when it is freed */ + if (slotid == tbl->highest_used_slotid) { + slotid = find_last_bit(tbl->used_slots, tbl->max_slots); + if (slotid >= 0 && slotid < tbl->max_slots) + tbl->highest_used_slotid = slotid; + else + tbl->highest_used_slotid = -1; + } + rpc_wake_up_next(&tbl->slot_tbl_waitq); + spin_unlock(&tbl->slot_tbl_lock); + dprintk("%s: free_slotid %u highest_used_slotid %d\n", __func__, + free_slotid, tbl->highest_used_slotid); +} + +/* * nfs4_find_slot - efficiently look for a free slot * * nfs4_find_slot looks for an unset bit in the used_slots bitmap. |