On Tue, Dec 11, 2012 at 01:44:13PM -0500, Trond Myklebust wrote:
> In preparation for the dynamic slot table allocation, convert the nfsd
> slot table to a linked list model.
Thanks! This looks OK to me. But as long this is somewhat
experimental, and we're late in the cycle, I'm going to drop this for
now.
--b.
>
> Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 151 +++++++++++++++++++++++++++++++++++++++++-----------
> fs/nfsd/state.h | 10 +++-
> 2 files changed, 129 insertions(+), 32 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index d0237f8..5717ea1 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -704,15 +704,6 @@ gen_sessionid(struct nfsd4_session *ses)
> */
> #define NFSD_MIN_HDR_SEQ_SZ (24 + 12 + 44)
>
> -static void
> -free_session_slots(struct nfsd4_session *ses)
> -{
> - int i;
> -
> - for (i = 0; i < ses->se_fchannel.maxreqs; i++)
> - kfree(ses->se_slots[i]);
> -}
> -
> /*
> * We don't actually need to cache the rpc and session headers, so we
> * can allocate a little less for each slot:
> @@ -758,29 +749,127 @@ static void nfsd4_put_drc_mem(int slotsize, int num)
> spin_unlock(&nfsd_drc_lock);
> }
>
> -static struct nfsd4_session *__alloc_session(int slotsize, int numslots)
> +static void nfsd4_free_slot(struct nfsd4_slot *slot)
> {
> - struct nfsd4_session *new;
> - int mem, i;
> + kfree(slot);
> +}
> +
> +static struct nfsd4_slot *nfsd4_new_slot(size_t slotsize, gfp_t gfp_mask)
> +{
> + return kzalloc(sizeof(struct nfsd4_slot) + slotsize, gfp_mask);
> +}
> +
> +static struct nfsd4_slot *nfsd4_find_slot_locked(const struct nfsd4_slot_table *tbl,
> + u32 slotid)
> +{
> + struct nfsd4_slot *slot;
> +
> + list_for_each_entry(slot, &tbl->slt_head, sl_list) {
> + if (slot->sl_slotid == slotid)
> + return slot;
> + }
> + return NULL;
> +}
> +
> +static struct nfsd4_slot *nfsd4_find_slot(struct nfsd4_slot_table *tbl,
> + u32 slotid)
> +{
> + struct nfsd4_slot *slot;
> +
> + spin_lock(&tbl->slt_lock);
> + slot = nfsd4_find_slot_locked(tbl, slotid);
> + spin_unlock(&tbl->slt_lock);
> + return slot;
> +}
> +
> +static struct nfsd4_slot *nfsd4_find_last_slot_locked(const struct nfsd4_slot_table *tbl)
> +{
> + if (list_empty(&tbl->slt_head))
> + return NULL;
> + return list_entry(tbl->slt_head.prev, struct nfsd4_slot, sl_list);
> +}
> +
> +static bool nfsd4_grow_slot_table_locked(struct nfsd4_slot_table *tbl,
> + u32 slotid, gfp_t gfp_mask)
> +{
> + struct nfsd4_slot *slot = NULL;
> + struct nfsd4_slot *prev;
> + u32 next_slotid;
> +
> + for (;;) {
> + prev = nfsd4_find_last_slot_locked(tbl);
> + if (prev != NULL) {
> + if (prev->sl_slotid >= slotid)
> + break;
> + next_slotid = prev->sl_slotid + 1;
> + } else
> + next_slotid = 0;
> + if (slot != NULL){
> + slot->sl_slotid = next_slotid;
> + list_add_tail(&slot->sl_list, &tbl->slt_head);
> + }
> + spin_unlock(&tbl->slt_lock);
> + slot = nfsd4_new_slot(tbl->slt_slotsize, gfp_mask);
> + spin_lock(&tbl->slt_lock);
> + if (slot == NULL)
> + return false;
> + }
> + nfsd4_free_slot(slot);
> + return true;
> +}
> +
> +static bool nfsd4_grow_slot_table(struct nfsd4_slot_table *tbl,
> + u32 slotid, gfp_t gfp_mask)
> +{
> + bool ret;
> +
> + spin_lock(&tbl->slt_lock);
> + ret = nfsd4_grow_slot_table_locked(tbl, slotid, gfp_mask);
> + spin_unlock(&tbl->slt_lock);
> + return ret;
> +}
> +
> +static void nfsd4_truncate_slot_table_locked(struct nfsd4_slot_table *tbl,
> + u32 slotid)
> +{
> + struct nfsd4_slot *slot;
> +
> + for (;;) {
> + slot = nfsd4_find_last_slot_locked(tbl);
> + if (slot == NULL || slot->sl_slotid < slotid)
> + break;
> + list_del(&slot->sl_list);
> + nfsd4_free_slot(slot);
> + }
> +}
> +
> +static void nfsd4_free_slot_table(struct nfsd4_slot_table *tbl)
> +{
> + spin_lock(&tbl->slt_lock);
> + nfsd4_truncate_slot_table_locked(tbl, 0);
> + spin_unlock(&tbl->slt_lock);
> +}
> +
> +static void nfsd4_init_slot_table(struct nfsd4_slot_table *tbl, size_t slotsize)
> +{
> + INIT_LIST_HEAD(&tbl->slt_head);
> + spin_lock_init(&tbl->slt_lock);
> + tbl->slt_slotsize = slotsize;
> +}
>
> - BUILD_BUG_ON(NFSD_MAX_SLOTS_PER_SESSION * sizeof(struct nfsd4_slot *)
> - + sizeof(struct nfsd4_session) > PAGE_SIZE);
> - mem = numslots * sizeof(struct nfsd4_slot *);
> +static struct nfsd4_session *__alloc_session(size_t slotsize, u32 highest_slotid)
> +{
> + struct nfsd4_session *new;
>
> - new = kzalloc(sizeof(*new) + mem, GFP_KERNEL);
> + new = kzalloc(sizeof(*new), GFP_KERNEL);
> if (!new)
> return NULL;
> + nfsd4_init_slot_table(&new->se_slots, slotsize);
> /* allocate each struct nfsd4_slot and data cache in one piece */
> - for (i = 0; i < numslots; i++) {
> - mem = sizeof(struct nfsd4_slot) + slotsize;
> - new->se_slots[i] = kzalloc(mem, GFP_KERNEL);
> - if (!new->se_slots[i])
> - goto out_free;
> - }
> - return new;
> -out_free:
> - while (i--)
> - kfree(new->se_slots[i]);
> + if (nfsd4_grow_slot_table(&new->se_slots, highest_slotid, GFP_KERNEL))
> + return new;
> +
> + nfsd4_free_slot_table(&new->se_slots);
> kfree(new);
> return NULL;
> }
> @@ -899,7 +988,7 @@ static void nfsd4_del_conns(struct nfsd4_session *s)
> static void __free_session(struct nfsd4_session *ses)
> {
> nfsd4_put_drc_mem(slot_bytes(&ses->se_fchannel), ses->se_fchannel.maxreqs);
> - free_session_slots(ses);
> + nfsd4_free_slot_table(&ses->se_slots);
> kfree(ses);
> }
>
> @@ -936,7 +1025,7 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fchan)
> if (numslots < 1)
> return NULL;
>
> - new = __alloc_session(slotsize, numslots);
> + new = __alloc_session(slotsize, numslots - 1);
> if (!new) {
> nfsd4_put_drc_mem(slotsize, fchan->maxreqs);
> return NULL;
> @@ -2032,11 +2121,11 @@ nfsd4_sequence(struct svc_rqst *rqstp,
> if (nfsd4_request_too_big(rqstp, session))
> goto out;
>
> + /* Note: nfsd4_find_slot checks the validity of seq->slotid */
> status = nfserr_badslot;
> - if (seq->slotid >= session->se_fchannel.maxreqs)
> + slot = nfsd4_find_slot(&session->se_slots, seq->slotid);
> + if (slot == NULL)
> goto out;
> -
> - slot = session->se_slots[seq->slotid];
> dprintk("%s: slotid %d\n", __func__, seq->slotid);
>
> /* We do not negotiate the number of slots yet, so set the
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index e036894..7d319e9a 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -128,6 +128,8 @@ static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s)
> (NFSD_CACHE_SIZE_SLOTS_PER_SESSION * NFSD_SLOT_CACHE_SIZE)
>
> struct nfsd4_slot {
> + struct list_head sl_list;
> + u32 sl_slotid;
> u32 sl_seqid;
> __be32 sl_status;
> u32 sl_datalen;
> @@ -139,6 +141,12 @@ struct nfsd4_slot {
> char sl_data[];
> };
>
> +struct nfsd4_slot_table {
> + struct list_head slt_head;
> + spinlock_t slt_lock;
> + size_t slt_slotsize;
> +};
> +
> struct nfsd4_channel_attrs {
> u32 headerpadsz;
> u32 maxreq_sz;
> @@ -195,7 +203,7 @@ struct nfsd4_session {
> struct list_head se_conns;
> u32 se_cb_prog;
> u32 se_cb_seq_nr;
> - struct nfsd4_slot *se_slots[]; /* forward channel slots */
> + struct nfsd4_slot_table se_slots;
> };
>
> extern void nfsd4_put_session(struct nfsd4_session *ses);
> --
> 1.7.11.7
>
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
