[PATCH] knfsd: nfsd4: delegation recovery

Allow recovery of delegations after reboot.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 30 insertions, 9 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 16c9a43218c3..0f6119714c8c 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1709,14 +1709,30 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
         int status, flag = 0;
 
         flag = NFS4_OPEN_DELEGATE_NONE;
-        if (open->op_claim_type != NFS4_OPEN_CLAIM_NULL
-             || !atomic_read(&cb->cb_set) || !sop->so_confirmed)
-                goto out;
-
-        if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
-                flag = NFS4_OPEN_DELEGATE_WRITE;
-        else
-                flag = NFS4_OPEN_DELEGATE_READ;
+        open->op_recall = 0;
+        switch (open->op_claim_type) {
+                case NFS4_OPEN_CLAIM_PREVIOUS:
+                        if (!atomic_read(&cb->cb_set))
+                                open->op_recall = 1;
+                        flag = open->op_delegate_type;
+                        if (flag == NFS4_OPEN_DELEGATE_NONE)
+                                goto out;
+                        break;
+                case NFS4_OPEN_CLAIM_NULL:
+                        /* Let's not give out any delegations till everyone's
+                         * had the chance to reclaim theirs.... */
+                        if (nfs4_in_grace())
+                                goto out;
+                        if (!atomic_read(&cb->cb_set) || !sop->so_confirmed)
+                                goto out;
+                        if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
+                                flag = NFS4_OPEN_DELEGATE_WRITE;
+                        else
+                                flag = NFS4_OPEN_DELEGATE_READ;
+                        break;
+                default:
+                        goto out;
+        }
 
         dp = alloc_init_deleg(sop->so_client, stp, fh, flag);
         if (dp == NULL) {
@@ -1750,6 +1766,10 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
                      dp->dl_stateid.si_fileid,
                      dp->dl_stateid.si_generation);
 out:
+        if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS
+                        && flag == NFS4_OPEN_DELEGATE_NONE
+                        && open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
+                printk("NFSD: WARNING: refusing delegation reclaim\n");
         open->op_delegate_type = flag;
 }
 
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0ae1467c3bc3..cfe978a72cea 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1972,7 +1972,7 @@ nfsd4_encode_open(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_open
         case NFS4_OPEN_DELEGATE_READ:
                 RESERVE_SPACE(20 + sizeof(stateid_t));
                 WRITEMEM(&open->op_delegate_stateid, sizeof(stateid_t));
-                WRITE32(0);
+                WRITE32(open->op_recall);
 
                 /*
                  * TODO: ACE's in delegations
diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h
index a1f5ad0be1bf..4d24d65c0e88 100644
--- a/include/linux/nfsd/xdr4.h
+++ b/include/linux/nfsd/xdr4.h
@@ -210,6 +210,7 @@ struct nfsd4_open {
         u32             op_share_access;    /* request */
         u32             op_share_deny;      /* request */
         stateid_t       op_stateid;         /* response */
+        u32             op_recall;          /* recall */
         struct nfsd4_change_info  op_cinfo; /* response */
         u32             op_rflags;          /* response */
         int             op_truncate;        /* used during processing */