[PATCH] knfsd: nfsd4: xdr encoding for fs_locations

Encode fs_locations attribute.

Signed-off-by: Manoj Naik <manoj@almaden.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 126 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 4cfacc557b40..0589852007e6 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1223,6 +1223,119 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
                         stateowner->so_replay.rp_buflen);       \
         } } while (0);
 
+/* Encode as an array of strings the string given with components
+ * seperated @sep.
+ */
+static int nfsd4_encode_components(char sep, char *components,
+                                   u32 **pp, int *buflen)
+{
+        u32 *p = *pp;
+        u32 *countp = p;
+        int strlen, count=0;
+        char *str, *end;
+
+        dprintk("nfsd4_encode_components(%s)\n", components);
+        if ((*buflen -= 4) < 0)
+                return nfserr_resource;
+        WRITE32(0); /* We will fill this in with @count later */
+        end = str = components;
+        while (*end) {
+                for (; *end && (*end != sep); end++)
+                        ; /* Point to end of component */
+                strlen = end - str;
+                if (strlen) {
+                        if ((*buflen -= ((XDR_QUADLEN(strlen) << 2) + 4)) < 0)
+                                return nfserr_resource;
+                        WRITE32(strlen);
+                        WRITEMEM(str, strlen);
+                        count++;
+                }
+                else
+                        end++;
+                str = end;
+        }
+        *pp = p;
+        p = countp;
+        WRITE32(count);
+        return 0;
+}
+
+/*
+ * encode a location element of a fs_locations structure
+ */
+static int nfsd4_encode_fs_location4(struct nfsd4_fs_location *location,
+                                    u32 **pp, int *buflen)
+{
+        int status;
+        u32 *p = *pp;
+
+        status = nfsd4_encode_components(':', location->hosts, &p, buflen);
+        if (status)
+                return status;
+        status = nfsd4_encode_components('/', location->path, &p, buflen);
+        if (status)
+                return status;
+        *pp = p;
+        return 0;
+}
+
+/*
+ * Return the path to an export point in the pseudo filesystem namespace
+ * Returned string is safe to use as long as the caller holds a reference
+ * to @exp.
+ */
+static char *nfsd4_path(struct svc_rqst *rqstp, struct svc_export *exp)
+{
+        struct svc_fh tmp_fh;
+        char *path, *rootpath;
+        int stat;
+
+        fh_init(&tmp_fh, NFS4_FHSIZE);
+        stat = exp_pseudoroot(rqstp->rq_client, &tmp_fh, &rqstp->rq_chandle);
+        if (stat)
+                return ERR_PTR(stat);
+        rootpath = tmp_fh.fh_export->ex_path;
+
+        path = exp->ex_path;
+
+        if (strncmp(path, rootpath, strlen(rootpath))) {
+                printk("nfsd: fs_locations failed;"
+                        "%s is not contained in %s\n", path, rootpath);
+                return ERR_PTR(-EOPNOTSUPP);
+        }
+
+        return path + strlen(rootpath);
+}
+
+/*
+ *  encode a fs_locations structure
+ */
+static int nfsd4_encode_fs_locations(struct svc_rqst *rqstp,
+                                     struct svc_export *exp,
+                                     u32 **pp, int *buflen)
+{
+        int status, i;
+        u32 *p = *pp;
+        struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
+        char *root = nfsd4_path(rqstp, exp);
+
+        if (IS_ERR(root))
+                return PTR_ERR(root);
+        status = nfsd4_encode_components('/', root, &p, buflen);
+        if (status)
+                return status;
+        if ((*buflen -= 4) < 0)
+                return nfserr_resource;
+        WRITE32(fslocs->locations_count);
+        for (i=0; i<fslocs->locations_count; i++) {
+                status = nfsd4_encode_fs_location4(&fslocs->locations[i],
+                                                   &p, buflen);
+                if (status)
+                        return status;
+        }
+        *pp = p;
+        return 0;
+}
 
 static u32 nfs4_ftypes[16] = {
         NF4BAD,  NF4FIFO, NF4CHR, NF4BAD,
@@ -1334,6 +1447,11 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
                                 goto out_nfserr;
                 }
         }
+        if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
+                if (exp->ex_fslocs.locations == NULL) {
+                        bmval0 &= ~FATTR4_WORD0_FS_LOCATIONS;
+                }
+        }
         if ((buflen -= 16) < 0)
                 goto out_resource;
 
@@ -1513,6 +1631,13 @@ out_acl:
                         goto out_resource;
                 WRITE64((u64) statfs.f_files);
         }
+        if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
+                status = nfsd4_encode_fs_locations(rqstp, exp, &p, &buflen);
+                if (status == nfserr_resource)
+                        goto out_resource;
+                if (status)
+                        goto out;
+        }
         if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
                 if ((buflen -= 4) < 0)
                         goto out_resource;
diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
index 259841bb2f6c..8094142d95ea 100644
--- a/include/linux/nfsd/nfsd.h
+++ b/include/linux/nfsd/nfsd.h
@@ -292,7 +292,6 @@ static inline int is_fsid(struct svc_fh *fh, struct knfsd_fh *reffh)
 /*
  * The following attributes are currently not supported by the NFSv4 server:
  *    ARCHIVE       (deprecated anyway)
- *    FS_LOCATIONS  (will be supported eventually)
  *    HIDDEN        (unlikely to be supported any time soon)
  *    MIMETYPE      (unlikely to be supported any time soon)
  *    QUOTA_*       (will be supported in a forthcoming patch)
@@ -308,7 +307,7 @@ static inline int is_fsid(struct svc_fh *fh, struct knfsd_fh *reffh)
  | FATTR4_WORD0_ACLSUPPORT      | FATTR4_WORD0_CANSETTIME   | FATTR4_WORD0_CASE_INSENSITIVE \
  | FATTR4_WORD0_CASE_PRESERVING | FATTR4_WORD0_CHOWN_RESTRICTED                             \
  | FATTR4_WORD0_FILEHANDLE      | FATTR4_WORD0_FILEID       | FATTR4_WORD0_FILES_AVAIL      \
- | FATTR4_WORD0_FILES_FREE      | FATTR4_WORD0_FILES_TOTAL  | FATTR4_WORD0_HOMOGENEOUS      \
+ | FATTR4_WORD0_FILES_FREE      | FATTR4_WORD0_FILES_TOTAL  | FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_HOMOGENEOUS      \
  | FATTR4_WORD0_MAXFILESIZE     | FATTR4_WORD0_MAXLINK      | FATTR4_WORD0_MAXNAME          \
  | FATTR4_WORD0_MAXREAD         | FATTR4_WORD0_MAXWRITE     | FATTR4_WORD0_ACL)