pnfs-obj: decode layout, alloc/free lseg

objlayout_alloc_lseg prepares an xdr_stream and calls the
raid engins objio_alloc_lseg() to allocate a private
pnfs_layout_segment.

objio_osd.c::objio_alloc_lseg() uses passed xdr_stream to
decode and store the layout_segment information in an
objio_segment struct, using the pnfs_osd_xdr.h API for
the actual parsing the layout xdr.

objlayout_free_lseg calls objio_free_lseg() to free the
allocated space.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
[gfp_flags]
[removed "extern" from function definitions]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

1 files changed, 104 insertions, 0 deletions

diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
new file mode 100644
index 000000000000..946526763d38
--- /dev/null
+++ b/fs/nfs/objlayout/objlayout.c
@@ -0,0 +1,104 @@
+/*
+ *  pNFS Objects layout driver high level definitions
+ *
+ *  Copyright (C) 2007 Panasas Inc. [year of first publication]
+ *  All rights reserved.
+ *
+ *  Benny Halevy <bhalevy@panasas.com>
+ *  Boaz Harrosh <bharrosh@panasas.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  See the file COPYING included with this distribution for more details.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the Panasas company nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <scsi/osd_initiator.h>
+#include "objlayout.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+/*
+ * Unmarshall layout and store it in pnfslay.
+ */
+struct pnfs_layout_segment *
+objlayout_alloc_lseg(struct pnfs_layout_hdr *pnfslay,
+                     struct nfs4_layoutget_res *lgr,
+                     gfp_t gfp_flags)
+{
+        int status = -ENOMEM;
+        struct xdr_stream stream;
+        struct xdr_buf buf = {
+                .pages =  lgr->layoutp->pages,
+                .page_len =  lgr->layoutp->len,
+                .buflen =  lgr->layoutp->len,
+                .len = lgr->layoutp->len,
+        };
+        struct page *scratch;
+        struct pnfs_layout_segment *lseg;
+
+        dprintk("%s: Begin pnfslay %p\n", __func__, pnfslay);
+
+        scratch = alloc_page(gfp_flags);
+        if (!scratch)
+                goto err_nofree;
+
+        xdr_init_decode(&stream, &buf, NULL);
+        xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+        status = objio_alloc_lseg(&lseg, pnfslay, &lgr->range, &stream, gfp_flags);
+        if (unlikely(status)) {
+                dprintk("%s: objio_alloc_lseg Return err %d\n", __func__,
+                        status);
+                goto err;
+        }
+
+        __free_page(scratch);
+
+        dprintk("%s: Return %p\n", __func__, lseg);
+        return lseg;
+
+err:
+        __free_page(scratch);
+err_nofree:
+        dprintk("%s: Err Return=>%d\n", __func__, status);
+        return ERR_PTR(status);
+}
+
+/*
+ * Free a layout segement
+ */
+void
+objlayout_free_lseg(struct pnfs_layout_segment *lseg)
+{
+        dprintk("%s: freeing layout segment %p\n", __func__, lseg);
+
+        if (unlikely(!lseg))
+                return;
+
+        objio_free_lseg(lseg);
+}
+