1 files changed, 116 insertions, 0 deletions

diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
index 79b5954b8a1b..8429885bc729 100644
--- a/fs/nfs/mount_clnt.c
+++ b/fs/nfs/mount_clnt.c
@@ -29,6 +29,8 @@
  * XDR data type sizes
  */
 #define encode_dirpath_sz       (1 + XDR_QUADLEN(MNTPATHLEN))
+#define MNT_status_sz           (1)
+#define MNT_fhs_status_sz       (1)
 
 /*
  * XDR argument and result sizes
@@ -61,6 +63,65 @@ enum {
 
 static struct rpc_program       mnt_program;
 
+/*
+ * Defined by OpenGroup XNFS Version 3W, chapter 8
+ */
+enum mountstat {
+        MNT_OK                  = 0,
+        MNT_EPERM               = 1,
+        MNT_ENOENT              = 2,
+        MNT_EACCES              = 13,
+        MNT_EINVAL              = 22,
+};
+
+static struct {
+        u32 status;
+        int errno;
+} mnt_errtbl[] = {
+        { .status = MNT_OK,                     .errno = 0,             },
+        { .status = MNT_EPERM,                  .errno = -EPERM,        },
+        { .status = MNT_ENOENT,                 .errno = -ENOENT,       },
+        { .status = MNT_EACCES,                 .errno = -EACCES,       },
+        { .status = MNT_EINVAL,                 .errno = -EINVAL,       },
+};
+
+/*
+ * Defined by RFC 1813, section 5.1.5
+ */
+enum mountstat3 {
+        MNT3_OK                 = 0,            /* no error */
+        MNT3ERR_PERM            = 1,            /* Not owner */
+        MNT3ERR_NOENT           = 2,            /* No such file or directory */
+        MNT3ERR_IO              = 5,            /* I/O error */
+        MNT3ERR_ACCES           = 13,           /* Permission denied */
+        MNT3ERR_NOTDIR          = 20,           /* Not a directory */
+        MNT3ERR_INVAL           = 22,           /* Invalid argument */
+        MNT3ERR_NAMETOOLONG     = 63,           /* Filename too long */
+        MNT3ERR_NOTSUPP         = 10004,        /* Operation not supported */
+        MNT3ERR_SERVERFAULT     = 10006,        /* A failure on the server */
+};
+
+static struct {
+        u32 status;
+        int errno;
+} mnt3_errtbl[] = {
+        { .status = MNT3_OK,                    .errno = 0,             },
+        { .status = MNT3ERR_PERM,               .errno = -EPERM,        },
+        { .status = MNT3ERR_NOENT,              .errno = -ENOENT,       },
+        { .status = MNT3ERR_IO,                 .errno = -EIO,          },
+        { .status = MNT3ERR_ACCES,              .errno = -EACCES,       },
+        { .status = MNT3ERR_NOTDIR,             .errno = -ENOTDIR,      },
+        { .status = MNT3ERR_INVAL,              .errno = -EINVAL,       },
+        { .status = MNT3ERR_NAMETOOLONG,        .errno = -ENAMETOOLONG, },
+        { .status = MNT3ERR_NOTSUPP,            .errno = -ENOTSUPP,     },
+        { .status = MNT3ERR_SERVERFAULT,        .errno = -ESERVERFAULT, },
+};
+
+struct mountres {
+        int errno;
+        struct nfs_fh *fh;
+};
+
 struct mnt_fhstatus {
         u32 status;
         struct nfs_fh *fh;
@@ -179,6 +240,61 @@ static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
         return 0;
 }
 
+/*
+ * RFC 1094: "A non-zero status indicates some sort of error.  In this
+ * case, the status is a UNIX error number."  This can be problematic
+ * if the server and client use different errno values for the same
+ * error.
+ *
+ * However, the OpenGroup XNFS spec provides a simple mapping that is
+ * independent of local errno values on the server and the client.
+ */
+static int decode_status(struct xdr_stream *xdr, struct mountres *res)
+{
+        unsigned int i;
+        u32 status;
+        __be32 *p;
+
+        p = xdr_inline_decode(xdr, sizeof(status));
+        if (unlikely(p == NULL))
+                return -EIO;
+        status = ntohl(*p);
+
+        for (i = 0; i <= ARRAY_SIZE(mnt_errtbl); i++) {
+                if (mnt_errtbl[i].status == status) {
+                        res->errno = mnt_errtbl[i].errno;
+                        return 0;
+                }
+        }
+
+        dprintk("NFS: unrecognized MNT status code: %u\n", status);
+        res->errno = -EACCES;
+        return 0;
+}
+
+static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
+{
+        unsigned int i;
+        u32 status;
+        __be32 *p;
+
+        p = xdr_inline_decode(xdr, sizeof(status));
+        if (unlikely(p == NULL))
+                return -EIO;
+        status = ntohl(*p);
+
+        for (i = 0; i <= ARRAY_SIZE(mnt3_errtbl); i++) {
+                if (mnt3_errtbl[i].status == status) {
+                        res->errno = mnt3_errtbl[i].errno;
+                        return 0;
+                }
+        }
+
+        dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
+        res->errno = -EACCES;
+        return 0;
+}
+
 static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
                                 struct mnt_fhstatus *res)
 {