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![Trond Myklebust](/assets/img/avatar_default.png)
There may still be timers active on the session waitqueues. Make sure that we kill them before freeing the memory. Cc: stable@vger.kernel.org # 3.12+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
565 lines
14 KiB
C
565 lines
14 KiB
C
/*
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* fs/nfs/nfs4session.c
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*
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* Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
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*
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/printk.h>
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#include <linux/slab.h>
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#include <linux/sunrpc/sched.h>
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#include <linux/sunrpc/bc_xprt.h>
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#include <linux/nfs.h>
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#include <linux/nfs4.h>
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#include <linux/nfs_fs.h>
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#include <linux/module.h>
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#include "nfs4_fs.h"
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#include "internal.h"
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#include "nfs4session.h"
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#include "callback.h"
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#define NFSDBG_FACILITY NFSDBG_STATE
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static void nfs4_init_slot_table(struct nfs4_slot_table *tbl, const char *queue)
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{
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tbl->highest_used_slotid = NFS4_NO_SLOT;
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spin_lock_init(&tbl->slot_tbl_lock);
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rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, queue);
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init_completion(&tbl->complete);
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}
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/*
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* nfs4_shrink_slot_table - free retired slots from the slot table
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*/
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static void nfs4_shrink_slot_table(struct nfs4_slot_table *tbl, u32 newsize)
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{
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struct nfs4_slot **p;
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if (newsize >= tbl->max_slots)
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return;
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p = &tbl->slots;
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while (newsize--)
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p = &(*p)->next;
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while (*p) {
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struct nfs4_slot *slot = *p;
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*p = slot->next;
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kfree(slot);
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tbl->max_slots--;
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}
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}
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/**
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* nfs4_slot_tbl_drain_complete - wake waiters when drain is complete
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* @tbl - controlling slot table
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*
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*/
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void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl)
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{
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if (nfs4_slot_tbl_draining(tbl))
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complete(&tbl->complete);
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}
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/*
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* nfs4_free_slot - free a slot and efficiently update slot table.
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*
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* freeing a slot is trivially done by clearing its respective bit
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* in the bitmap.
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* If the freed slotid equals highest_used_slotid we want to update it
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* so that the server would be able to size down the slot table if needed,
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* otherwise we know that the highest_used_slotid is still in use.
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* When updating highest_used_slotid there may be "holes" in the bitmap
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* so we need to scan down from highest_used_slotid to 0 looking for the now
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* highest slotid in use.
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* If none found, highest_used_slotid is set to NFS4_NO_SLOT.
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*
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* Must be called while holding tbl->slot_tbl_lock
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*/
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void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)
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{
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u32 slotid = slot->slot_nr;
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/* clear used bit in bitmap */
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__clear_bit(slotid, tbl->used_slots);
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/* update highest_used_slotid when it is freed */
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if (slotid == tbl->highest_used_slotid) {
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u32 new_max = find_last_bit(tbl->used_slots, slotid);
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if (new_max < slotid)
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tbl->highest_used_slotid = new_max;
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else {
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tbl->highest_used_slotid = NFS4_NO_SLOT;
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nfs4_slot_tbl_drain_complete(tbl);
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}
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}
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dprintk("%s: slotid %u highest_used_slotid %u\n", __func__,
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slotid, tbl->highest_used_slotid);
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}
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static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table *tbl,
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u32 slotid, u32 seq_init, gfp_t gfp_mask)
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{
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struct nfs4_slot *slot;
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slot = kzalloc(sizeof(*slot), gfp_mask);
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if (slot) {
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slot->table = tbl;
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slot->slot_nr = slotid;
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slot->seq_nr = seq_init;
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}
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return slot;
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}
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static struct nfs4_slot *nfs4_find_or_create_slot(struct nfs4_slot_table *tbl,
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u32 slotid, u32 seq_init, gfp_t gfp_mask)
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{
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struct nfs4_slot **p, *slot;
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p = &tbl->slots;
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for (;;) {
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if (*p == NULL) {
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*p = nfs4_new_slot(tbl, tbl->max_slots,
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seq_init, gfp_mask);
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if (*p == NULL)
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break;
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tbl->max_slots++;
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}
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slot = *p;
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if (slot->slot_nr == slotid)
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return slot;
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p = &slot->next;
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}
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return ERR_PTR(-ENOMEM);
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}
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/*
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* nfs4_alloc_slot - efficiently look for a free slot
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*
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* nfs4_alloc_slot looks for an unset bit in the used_slots bitmap.
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* If found, we mark the slot as used, update the highest_used_slotid,
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* and respectively set up the sequence operation args.
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*
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* Note: must be called with under the slot_tbl_lock.
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*/
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struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl)
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{
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struct nfs4_slot *ret = ERR_PTR(-EBUSY);
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u32 slotid;
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dprintk("--> %s used_slots=%04lx highest_used=%u max_slots=%u\n",
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__func__, tbl->used_slots[0], tbl->highest_used_slotid,
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tbl->max_slotid + 1);
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slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);
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if (slotid > tbl->max_slotid)
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goto out;
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ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
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if (IS_ERR(ret))
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goto out;
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__set_bit(slotid, tbl->used_slots);
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if (slotid > tbl->highest_used_slotid ||
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tbl->highest_used_slotid == NFS4_NO_SLOT)
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tbl->highest_used_slotid = slotid;
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ret->generation = tbl->generation;
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out:
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dprintk("<-- %s used_slots=%04lx highest_used=%u slotid=%u\n",
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__func__, tbl->used_slots[0], tbl->highest_used_slotid,
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!IS_ERR(ret) ? ret->slot_nr : NFS4_NO_SLOT);
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return ret;
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}
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static int nfs4_grow_slot_table(struct nfs4_slot_table *tbl,
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u32 max_reqs, u32 ivalue)
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{
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if (max_reqs <= tbl->max_slots)
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return 0;
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if (!IS_ERR(nfs4_find_or_create_slot(tbl, max_reqs - 1, ivalue, GFP_NOFS)))
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return 0;
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return -ENOMEM;
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}
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static void nfs4_reset_slot_table(struct nfs4_slot_table *tbl,
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u32 server_highest_slotid,
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u32 ivalue)
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{
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struct nfs4_slot **p;
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nfs4_shrink_slot_table(tbl, server_highest_slotid + 1);
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p = &tbl->slots;
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while (*p) {
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(*p)->seq_nr = ivalue;
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(*p)->interrupted = 0;
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p = &(*p)->next;
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}
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tbl->highest_used_slotid = NFS4_NO_SLOT;
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tbl->target_highest_slotid = server_highest_slotid;
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tbl->server_highest_slotid = server_highest_slotid;
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tbl->d_target_highest_slotid = 0;
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tbl->d2_target_highest_slotid = 0;
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tbl->max_slotid = server_highest_slotid;
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}
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/*
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* (re)Initialise a slot table
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*/
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static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl,
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u32 max_reqs, u32 ivalue)
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{
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int ret;
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dprintk("--> %s: max_reqs=%u, tbl->max_slots %u\n", __func__,
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max_reqs, tbl->max_slots);
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if (max_reqs > NFS4_MAX_SLOT_TABLE)
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max_reqs = NFS4_MAX_SLOT_TABLE;
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ret = nfs4_grow_slot_table(tbl, max_reqs, ivalue);
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if (ret)
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goto out;
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spin_lock(&tbl->slot_tbl_lock);
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nfs4_reset_slot_table(tbl, max_reqs - 1, ivalue);
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spin_unlock(&tbl->slot_tbl_lock);
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dprintk("%s: tbl=%p slots=%p max_slots=%u\n", __func__,
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tbl, tbl->slots, tbl->max_slots);
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out:
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dprintk("<-- %s: return %d\n", __func__, ret);
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return ret;
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}
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/*
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* nfs4_release_slot_table - release all slot table entries
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*/
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static void nfs4_release_slot_table(struct nfs4_slot_table *tbl)
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{
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nfs4_shrink_slot_table(tbl, 0);
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}
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/**
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* nfs4_shutdown_slot_table - release resources attached to a slot table
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* @tbl: slot table to shut down
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*
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*/
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void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl)
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{
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nfs4_release_slot_table(tbl);
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rpc_destroy_wait_queue(&tbl->slot_tbl_waitq);
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}
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/**
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* nfs4_setup_slot_table - prepare a stand-alone slot table for use
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* @tbl: slot table to set up
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* @max_reqs: maximum number of requests allowed
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* @queue: name to give RPC wait queue
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*
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* Returns zero on success, or a negative errno.
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*/
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int nfs4_setup_slot_table(struct nfs4_slot_table *tbl, unsigned int max_reqs,
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const char *queue)
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{
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nfs4_init_slot_table(tbl, queue);
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return nfs4_realloc_slot_table(tbl, max_reqs, 0);
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}
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static bool nfs41_assign_slot(struct rpc_task *task, void *pslot)
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{
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struct nfs4_sequence_args *args = task->tk_msg.rpc_argp;
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struct nfs4_sequence_res *res = task->tk_msg.rpc_resp;
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struct nfs4_slot *slot = pslot;
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struct nfs4_slot_table *tbl = slot->table;
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if (nfs4_slot_tbl_draining(tbl) && !args->sa_privileged)
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return false;
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slot->generation = tbl->generation;
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args->sa_slot = slot;
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res->sr_timestamp = jiffies;
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res->sr_slot = slot;
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res->sr_status_flags = 0;
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res->sr_status = 1;
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return true;
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}
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static bool __nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
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struct nfs4_slot *slot)
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{
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if (rpc_wake_up_first(&tbl->slot_tbl_waitq, nfs41_assign_slot, slot))
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return true;
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return false;
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}
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bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
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struct nfs4_slot *slot)
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{
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if (slot->slot_nr > tbl->max_slotid)
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return false;
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return __nfs41_wake_and_assign_slot(tbl, slot);
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}
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static bool nfs41_try_wake_next_slot_table_entry(struct nfs4_slot_table *tbl)
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{
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struct nfs4_slot *slot = nfs4_alloc_slot(tbl);
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if (!IS_ERR(slot)) {
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bool ret = __nfs41_wake_and_assign_slot(tbl, slot);
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if (ret)
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return ret;
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nfs4_free_slot(tbl, slot);
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}
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return false;
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}
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void nfs41_wake_slot_table(struct nfs4_slot_table *tbl)
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{
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for (;;) {
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if (!nfs41_try_wake_next_slot_table_entry(tbl))
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break;
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}
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}
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#if defined(CONFIG_NFS_V4_1)
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static void nfs41_set_max_slotid_locked(struct nfs4_slot_table *tbl,
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u32 target_highest_slotid)
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{
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u32 max_slotid;
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max_slotid = min(NFS4_MAX_SLOT_TABLE - 1, target_highest_slotid);
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if (max_slotid > tbl->server_highest_slotid)
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max_slotid = tbl->server_highest_slotid;
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if (max_slotid > tbl->target_highest_slotid)
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max_slotid = tbl->target_highest_slotid;
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tbl->max_slotid = max_slotid;
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nfs41_wake_slot_table(tbl);
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}
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/* Update the client's idea of target_highest_slotid */
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static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl,
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u32 target_highest_slotid)
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{
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if (tbl->target_highest_slotid == target_highest_slotid)
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return;
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tbl->target_highest_slotid = target_highest_slotid;
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tbl->generation++;
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}
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void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
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u32 target_highest_slotid)
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{
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spin_lock(&tbl->slot_tbl_lock);
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nfs41_set_target_slotid_locked(tbl, target_highest_slotid);
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tbl->d_target_highest_slotid = 0;
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tbl->d2_target_highest_slotid = 0;
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nfs41_set_max_slotid_locked(tbl, target_highest_slotid);
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spin_unlock(&tbl->slot_tbl_lock);
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}
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static void nfs41_set_server_slotid_locked(struct nfs4_slot_table *tbl,
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u32 highest_slotid)
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{
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if (tbl->server_highest_slotid == highest_slotid)
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return;
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if (tbl->highest_used_slotid > highest_slotid)
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return;
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/* Deallocate slots */
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nfs4_shrink_slot_table(tbl, highest_slotid + 1);
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tbl->server_highest_slotid = highest_slotid;
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}
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static s32 nfs41_derivative_target_slotid(s32 s1, s32 s2)
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{
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s1 -= s2;
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if (s1 == 0)
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return 0;
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if (s1 < 0)
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return (s1 - 1) >> 1;
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return (s1 + 1) >> 1;
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}
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static int nfs41_sign_s32(s32 s1)
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{
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if (s1 > 0)
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return 1;
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if (s1 < 0)
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return -1;
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return 0;
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}
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static bool nfs41_same_sign_or_zero_s32(s32 s1, s32 s2)
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{
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if (!s1 || !s2)
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return true;
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return nfs41_sign_s32(s1) == nfs41_sign_s32(s2);
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}
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/* Try to eliminate outliers by checking for sharp changes in the
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* derivatives and second derivatives
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*/
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static bool nfs41_is_outlier_target_slotid(struct nfs4_slot_table *tbl,
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u32 new_target)
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{
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s32 d_target, d2_target;
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bool ret = true;
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d_target = nfs41_derivative_target_slotid(new_target,
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tbl->target_highest_slotid);
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d2_target = nfs41_derivative_target_slotid(d_target,
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tbl->d_target_highest_slotid);
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/* Is first derivative same sign? */
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if (nfs41_same_sign_or_zero_s32(d_target, tbl->d_target_highest_slotid))
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ret = false;
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/* Is second derivative same sign? */
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if (nfs41_same_sign_or_zero_s32(d2_target, tbl->d2_target_highest_slotid))
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ret = false;
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tbl->d_target_highest_slotid = d_target;
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tbl->d2_target_highest_slotid = d2_target;
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return ret;
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}
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void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
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struct nfs4_slot *slot,
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struct nfs4_sequence_res *res)
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{
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spin_lock(&tbl->slot_tbl_lock);
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if (!nfs41_is_outlier_target_slotid(tbl, res->sr_target_highest_slotid))
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nfs41_set_target_slotid_locked(tbl, res->sr_target_highest_slotid);
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if (tbl->generation == slot->generation)
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nfs41_set_server_slotid_locked(tbl, res->sr_highest_slotid);
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nfs41_set_max_slotid_locked(tbl, res->sr_target_highest_slotid);
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spin_unlock(&tbl->slot_tbl_lock);
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}
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static void nfs4_release_session_slot_tables(struct nfs4_session *session)
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{
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nfs4_release_slot_table(&session->fc_slot_table);
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nfs4_release_slot_table(&session->bc_slot_table);
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}
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/*
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* Initialize or reset the forechannel and backchannel tables
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*/
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int nfs4_setup_session_slot_tables(struct nfs4_session *ses)
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{
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struct nfs4_slot_table *tbl;
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int status;
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dprintk("--> %s\n", __func__);
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/* Fore channel */
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tbl = &ses->fc_slot_table;
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tbl->session = ses;
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status = nfs4_realloc_slot_table(tbl, ses->fc_attrs.max_reqs, 1);
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if (status) /* -ENOMEM */
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return status;
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/* Back channel */
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tbl = &ses->bc_slot_table;
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tbl->session = ses;
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status = nfs4_realloc_slot_table(tbl, ses->bc_attrs.max_reqs, 0);
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if (status && tbl->slots == NULL)
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/* Fore and back channel share a connection so get
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* both slot tables or neither */
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nfs4_release_session_slot_tables(ses);
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return status;
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}
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struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
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{
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struct nfs4_session *session;
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session = kzalloc(sizeof(struct nfs4_session), GFP_NOFS);
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if (!session)
|
|
return NULL;
|
|
|
|
nfs4_init_slot_table(&session->fc_slot_table, "ForeChannel Slot table");
|
|
nfs4_init_slot_table(&session->bc_slot_table, "BackChannel Slot table");
|
|
session->session_state = 1<<NFS4_SESSION_INITING;
|
|
|
|
session->clp = clp;
|
|
return session;
|
|
}
|
|
|
|
static void nfs4_destroy_session_slot_tables(struct nfs4_session *session)
|
|
{
|
|
nfs4_shutdown_slot_table(&session->fc_slot_table);
|
|
nfs4_shutdown_slot_table(&session->bc_slot_table);
|
|
}
|
|
|
|
void nfs4_destroy_session(struct nfs4_session *session)
|
|
{
|
|
struct rpc_xprt *xprt;
|
|
struct rpc_cred *cred;
|
|
|
|
cred = nfs4_get_clid_cred(session->clp);
|
|
nfs4_proc_destroy_session(session, cred);
|
|
if (cred)
|
|
put_rpccred(cred);
|
|
|
|
rcu_read_lock();
|
|
xprt = rcu_dereference(session->clp->cl_rpcclient->cl_xprt);
|
|
rcu_read_unlock();
|
|
dprintk("%s Destroy backchannel for xprt %p\n",
|
|
__func__, xprt);
|
|
xprt_destroy_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
|
|
nfs4_destroy_session_slot_tables(session);
|
|
kfree(session);
|
|
}
|
|
|
|
/*
|
|
* With sessions, the client is not marked ready until after a
|
|
* successful EXCHANGE_ID and CREATE_SESSION.
|
|
*
|
|
* Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
|
|
* other versions of NFS can be tried.
|
|
*/
|
|
static int nfs41_check_session_ready(struct nfs_client *clp)
|
|
{
|
|
int ret;
|
|
|
|
if (clp->cl_cons_state == NFS_CS_SESSION_INITING) {
|
|
ret = nfs4_client_recover_expired_lease(clp);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
if (clp->cl_cons_state < NFS_CS_READY)
|
|
return -EPROTONOSUPPORT;
|
|
smp_rmb();
|
|
return 0;
|
|
}
|
|
|
|
int nfs4_init_session(struct nfs_client *clp)
|
|
{
|
|
if (!nfs4_has_session(clp))
|
|
return 0;
|
|
|
|
clear_bit(NFS4_SESSION_INITING, &clp->cl_session->session_state);
|
|
return nfs41_check_session_ready(clp);
|
|
}
|
|
|
|
int nfs4_init_ds_session(struct nfs_client *clp, unsigned long lease_time)
|
|
{
|
|
struct nfs4_session *session = clp->cl_session;
|
|
int ret;
|
|
|
|
spin_lock(&clp->cl_lock);
|
|
if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) {
|
|
/*
|
|
* Do not set NFS_CS_CHECK_LEASE_TIME instead set the
|
|
* DS lease to be equal to the MDS lease.
|
|
*/
|
|
clp->cl_lease_time = lease_time;
|
|
clp->cl_last_renewal = jiffies;
|
|
}
|
|
spin_unlock(&clp->cl_lock);
|
|
|
|
ret = nfs41_check_session_ready(clp);
|
|
if (ret)
|
|
return ret;
|
|
/* Test for the DS role */
|
|
if (!is_ds_client(clp))
|
|
return -ENODEV;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs4_init_ds_session);
|
|
|
|
#endif /* defined(CONFIG_NFS_V4_1) */
|