pnfs: add a new mechanism to select a layout driver according to an ordered list

[karo-tx-linux.git] / fs / nfs / nfs4xdr.c

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 7bd3a5c09d3185856e85bbe8c5484fccfee3651f..17b4e059c588f727388d705532d4b3a2e1e83b6e 100644 (file)
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4725,34 +4725,37 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
 }
 
 /*
- * Decode potentially multiple layout types. Currently we only support
- * one layout driver per file system.
+ * Decode potentially multiple layout types.
  */
-static int decode_first_pnfs_layout_type(struct xdr_stream *xdr,
-                                        uint32_t *layouttype)
+static int decode_pnfs_layout_types(struct xdr_stream *xdr,
+                                   struct nfs_fsinfo *fsinfo)
 {
        __be32 *p;
-       int num;
+       uint32_t i;
 
        p = xdr_inline_decode(xdr, 4);
        if (unlikely(!p))
                goto out_overflow;
-       num = be32_to_cpup(p);
+       fsinfo->nlayouttypes = be32_to_cpup(p);
 
        /* pNFS is not supported by the underlying file system */
-       if (num == 0) {
-               *layouttype = 0;
+       if (fsinfo->nlayouttypes == 0)
                return 0;
-       }
-       if (num > 1)
-               printk(KERN_INFO "NFS: %s: Warning: Multiple pNFS layout "
-                       "drivers per filesystem not supported\n", __func__);
 
        /* Decode and set first layout type, move xdr->p past unused types */
-       p = xdr_inline_decode(xdr, num * 4);
+       p = xdr_inline_decode(xdr, fsinfo->nlayouttypes * 4);
        if (unlikely(!p))
                goto out_overflow;
-       *layouttype = be32_to_cpup(p);
+
+       /* If we get too many, then just cap it at the max */
+       if (fsinfo->nlayouttypes > NFS_MAX_LAYOUT_TYPES) {
+               printk(KERN_INFO "NFS: %s: Warning: Too many (%u) pNFS layout types\n",
+                       __func__, fsinfo->nlayouttypes);
+               fsinfo->nlayouttypes = NFS_MAX_LAYOUT_TYPES;
+       }
+
+       for(i = 0; i < fsinfo->nlayouttypes; ++i)
+               fsinfo->layouttype[i] = be32_to_cpup(p++);
        return 0;
 out_overflow:
        print_overflow_msg(__func__, xdr);
@@ -4764,7 +4767,7 @@ out_overflow:
  * Note we must ensure that layouttype is set in any non-error case.
  */
 static int decode_attr_pnfstype(struct xdr_stream *xdr, uint32_t *bitmap,
-                               uint32_t *layouttype)
+                               struct nfs_fsinfo *fsinfo)
 {
        int status = 0;
 
@@ -4772,10 +4775,9 @@ static int decode_attr_pnfstype(struct xdr_stream *xdr, uint32_t *bitmap,
        if (unlikely(bitmap[1] & (FATTR4_WORD1_FS_LAYOUT_TYPES - 1U)))
                return -EIO;
        if (bitmap[1] & FATTR4_WORD1_FS_LAYOUT_TYPES) {
-               status = decode_first_pnfs_layout_type(xdr, layouttype);
+               status = decode_pnfs_layout_types(xdr, fsinfo);
                bitmap[1] &= ~FATTR4_WORD1_FS_LAYOUT_TYPES;
-       } else
-               *layouttype = 0;
+       }
        return status;
 }
 
@@ -4856,7 +4858,7 @@ static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo)
        status = decode_attr_time_delta(xdr, bitmap, &fsinfo->time_delta);
        if (status != 0)
                goto xdr_error;
-       status = decode_attr_pnfstype(xdr, bitmap, &fsinfo->layouttype);
+       status = decode_attr_pnfstype(xdr, bitmap, fsinfo);
        if (status != 0)
                goto xdr_error;