NFSv2/v3: Simulate the change attribute

Use the ctime to simulate a change attribute for NFSv2 and NFSv3.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 60f7e4e..a8f8de6 100644 (file)
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -880,7 +880,7 @@ static int nfs_init_server(struct nfs_server *server,
        server->options = data->options;
        server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
                NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
-               NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME;
+               NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME|NFS_CAP_CHANGE_ATTR;
 
        if (data->rsize)
                server->rsize = nfs_block_size(data->rsize, NULL);

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 0fd1efa..1855e8f 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -493,3 +493,15 @@ unsigned int nfs_page_array_len(unsigned int base, size_t len)
                PAGE_SIZE - 1) >> PAGE_SHIFT;
 }
 
+/*
+ * Convert a struct timespec into a 64-bit change attribute
+ *
+ * This does approximately the same thing as timespec_to_ns(),
+ * but for calculation efficiency, we multiply the seconds by
+ * 1024*1024*1024.
+ */
+static inline
+u64 nfs_timespec_to_change_attr(const struct timespec *ts)
+{
+       return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
+}

diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 1f56000..c99008e 100644 (file)
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -313,6 +313,8 @@ static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
        p = xdr_decode_time(p, &fattr->atime);
        p = xdr_decode_time(p, &fattr->mtime);
        xdr_decode_time(p, &fattr->ctime);
+       fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
+
        return 0;
 out_overflow:
        print_overflow_msg(__func__, xdr);

diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 01e53e9..ee284c2 100644 (file)
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -675,6 +675,7 @@ static int decode_fattr3(struct xdr_stream *xdr, struct nfs_fattr *fattr)
        p = xdr_decode_nfstime3(p, &fattr->atime);
        p = xdr_decode_nfstime3(p, &fattr->mtime);
        xdr_decode_nfstime3(p, &fattr->ctime);
+       fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
 
        fattr->valid |= NFS_ATTR_FATTR_V3;
        return 0;
@@ -725,12 +726,14 @@ static int decode_wcc_attr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
                goto out_overflow;
 
        fattr->valid |= NFS_ATTR_FATTR_PRESIZE
+               | NFS_ATTR_FATTR_PRECHANGE
                | NFS_ATTR_FATTR_PREMTIME
                | NFS_ATTR_FATTR_PRECTIME;
 
        p = xdr_decode_size3(p, &fattr->pre_size);
        p = xdr_decode_nfstime3(p, &fattr->pre_mtime);
        xdr_decode_nfstime3(p, &fattr->pre_ctime);
+       fattr->pre_change_attr = nfs_timespec_to_change_attr(&fattr->pre_ctime);
 
        return 0;
 out_overflow:

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 6deb8f0..bc36808 100644 (file)
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -106,14 +106,14 @@ struct nfs_fattr {
                | NFS_ATTR_FATTR_FILEID \
                | NFS_ATTR_FATTR_ATIME \
                | NFS_ATTR_FATTR_MTIME \
-               | NFS_ATTR_FATTR_CTIME)
+               | NFS_ATTR_FATTR_CTIME \
+               | NFS_ATTR_FATTR_CHANGE)
 #define NFS_ATTR_FATTR_V2 (NFS_ATTR_FATTR \
                | NFS_ATTR_FATTR_BLOCKS_USED)
 #define NFS_ATTR_FATTR_V3 (NFS_ATTR_FATTR \
                | NFS_ATTR_FATTR_SPACE_USED)
 #define NFS_ATTR_FATTR_V4 (NFS_ATTR_FATTR \
-               | NFS_ATTR_FATTR_SPACE_USED \
-               | NFS_ATTR_FATTR_CHANGE)
+               | NFS_ATTR_FATTR_SPACE_USED)
 
 /*
  * Info on the file system