NFS: Request fh_expire_type attribute in "server caps" operation

The fh_expire_type file attribute is a filesystem wide attribute that
consists of flags that indicate what characteristics file handles
on this FSID have.

Our client doesn't support volatile file handles.  It should find
out early (say, at mount time) whether the server is going to play
shenanighans with file handles during a migration.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 281c2def2b193648f04b20b77254edeab224587f..87b9b91f76cfd687b0e5eab06e7365121d64f67d 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2220,6 +2220,7 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
                server->cache_consistency_bitmask[0] &= FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE;
                server->cache_consistency_bitmask[1] &= FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY;
                server->acl_bitmask = res.acl_bitmask;
+               server->fh_expire_type = res.fh_expire_type;
        }
 
        return status;

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index a6fb55da874cb4d26d60ca5596f648842a1c1dc8..3e0fe9f92e7cf0c69f5674df49ca90bc2c3c2ead 100644 (file)
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2676,6 +2676,7 @@ static void nfs4_xdr_enc_server_caps(struct rpc_rqst *req,
        encode_sequence(xdr, &args->seq_args, &hdr);
        encode_putfh(xdr, args->fhandle, &hdr);
        encode_getattr_one(xdr, FATTR4_WORD0_SUPPORTED_ATTRS|
+                          FATTR4_WORD0_FH_EXPIRE_TYPE|
                           FATTR4_WORD0_LINK_SUPPORT|
                           FATTR4_WORD0_SYMLINK_SUPPORT|
                           FATTR4_WORD0_ACLSUPPORT, &hdr);
@@ -3223,6 +3224,28 @@ out_overflow:
        return -EIO;
 }
 
+static int decode_attr_fh_expire_type(struct xdr_stream *xdr,
+                                     uint32_t *bitmap, uint32_t *type)
+{
+       __be32 *p;
+
+       *type = 0;
+       if (unlikely(bitmap[0] & (FATTR4_WORD0_FH_EXPIRE_TYPE - 1U)))
+               return -EIO;
+       if (likely(bitmap[0] & FATTR4_WORD0_FH_EXPIRE_TYPE)) {
+               p = xdr_inline_decode(xdr, 4);
+               if (unlikely(!p))
+                       goto out_overflow;
+               *type = be32_to_cpup(p);
+               bitmap[0] &= ~FATTR4_WORD0_FH_EXPIRE_TYPE;
+       }
+       dprintk("%s: expire type=0x%x\n", __func__, *type);
+       return 0;
+out_overflow:
+       print_overflow_msg(__func__, xdr);
+       return -EIO;
+}
+
 static int decode_attr_change(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *change)
 {
        __be32 *p;
@@ -4271,6 +4294,9 @@ static int decode_server_caps(struct xdr_stream *xdr, struct nfs4_server_caps_re
                goto xdr_error;
        if ((status = decode_attr_supported(xdr, bitmap, res->attr_bitmask)) != 0)
                goto xdr_error;
+       if ((status = decode_attr_fh_expire_type(xdr, bitmap,
+                                                &res->fh_expire_type)) != 0)
+               goto xdr_error;
        if ((status = decode_attr_link_support(xdr, bitmap, &res->has_links)) != 0)
                goto xdr_error;
        if ((status = decode_attr_symlink_support(xdr, bitmap, &res->has_symlinks)) != 0)

diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 03d0b91c2d5b683e15230acd5ba137300f78ce64..7073fc74481cb6e1d69b0278e26c87c52cbc349e 100644 (file)
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -148,6 +148,9 @@ struct nfs_server {
        u32                     acl_bitmask;    /* V4 bitmask representing the ACEs
                                                   that are supported on this
                                                   filesystem */
+       u32                     fh_expire_type; /* V4 bitmask representing file
+                                                  handle volatility type for
+                                                  this filesystem */
        struct pnfs_layoutdriver_type  *pnfs_curr_ld; /* Active layout driver */
        struct rpc_wait_queue   roc_rpcwaitq;
        void                    *pnfs_ld_data;  /* per mount point data */

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 210da5dc4f17570db9c5183b7ef9ed17d736320e..6f4c3594196562e672c05c68d03d778c84c23188 100644 (file)
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -977,6 +977,7 @@ struct nfs4_server_caps_res {
        u32                             acl_bitmask;
        u32                             has_links;
        u32                             has_symlinks;
+       u32                             fh_expire_type;
        struct nfs4_sequence_res        seq_res;
 };