NFSD: Implement CB_SEQUENCE referring call lists

The slot index number of the current COMPOUND has, until now, not
been needed outside of nfsd4_sequence(). But to record the tuple
that represents a referring call, the slot number will be needed
when processing subsequent operations in the COMPOUND.

Refactor the code that allocates a new struct nfsd4_slot to ensure
that the new sl_index field is always correctly initialized.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 59a693f22452b87f3528a65bdc0208b188730643..5f5bed2a0312cd73c98b2372719ea975c507f1b1 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1987,26 +1987,30 @@ reduce_session_slots(struct nfsd4_session *ses, int dec)
        return ret;
 }
 
-/*
- * We don't actually need to cache the rpc and session headers, so we
- * can allocate a little less for each slot:
- */
-static inline u32 slot_bytes(struct nfsd4_channel_attrs *ca)
+static struct nfsd4_slot *nfsd4_alloc_slot(struct nfsd4_channel_attrs *fattrs,
+                                          int index, gfp_t gfp)
 {
-       u32 size;
+       struct nfsd4_slot *slot;
+       size_t size;
 
-       if (ca->maxresp_cached < NFSD_MIN_HDR_SEQ_SZ)
-               size = 0;
-       else
-               size = ca->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ;
-       return size + sizeof(struct nfsd4_slot);
+       /*
+        * The RPC and NFS session headers are never saved in
+        * the slot reply cache buffer.
+        */
+       size = fattrs->maxresp_cached < NFSD_MIN_HDR_SEQ_SZ ?
+               0 : fattrs->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ;
+
+       slot = kzalloc(struct_size(slot, sl_data, size), gfp);
+       if (!slot)
+               return NULL;
+       slot->sl_index = index;
+       return slot;
 }
 
 static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs,
                                           struct nfsd4_channel_attrs *battrs)
 {
        int numslots = fattrs->maxreqs;
-       int slotsize = slot_bytes(fattrs);
        struct nfsd4_session *new;
        struct nfsd4_slot *slot;
        int i;
@@ -2015,14 +2019,14 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs,
        if (!new)
                return NULL;
        xa_init(&new->se_slots);
-       /* allocate each struct nfsd4_slot and data cache in one piece */
-       slot = kzalloc(slotsize, GFP_KERNEL);
+
+       slot = nfsd4_alloc_slot(fattrs, 0, GFP_KERNEL);
        if (!slot || xa_is_err(xa_store(&new->se_slots, 0, slot, GFP_KERNEL)))
                goto out_free;
 
        for (i = 1; i < numslots; i++) {
                const gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
-               slot = kzalloc(slotsize, gfp);
+               slot = nfsd4_alloc_slot(fattrs, i, gfp);
                if (!slot)
                        break;
                if (xa_is_err(xa_store(&new->se_slots, i, slot, gfp))) {
@@ -4438,8 +4442,8 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                         * spinlock, and only succeeds if there is
                         * plenty of memory.
                         */
-                       slot = kzalloc(slot_bytes(&session->se_fchannel),
-                                      GFP_NOWAIT);
+                       slot = nfsd4_alloc_slot(&session->se_fchannel, s,
+                                               GFP_NOWAIT);
                        prev_slot = xa_load(&session->se_slots, s);
                        if (xa_is_value(prev_slot) && slot) {
                                slot->sl_seqid = xa_to_value(prev_slot);

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 7d5758faef6a85d3b368b30b9b41aa77bd4c5835..1995bca158b8b7eb7cef6aefa13bc1d5e7cf6093 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -278,6 +278,7 @@ struct nfsd4_slot {
        u32     sl_seqid;
        __be32  sl_status;
        struct svc_cred sl_cred;
+       u32     sl_index;
        u32     sl_datalen;
        u16     sl_opcnt;
        u16     sl_generation;