LU-13004 ptlrpc: Allow BULK_BUF_KIOV to accept a kvec

Bulk descriptor of type PTLRPC_BULK_BUF_KIOV are comprised
of a list of page+offset+len.
If the calling code actually has a virtual-address+len, it
cannot current use BULK_BUF_KIOV and must use BULK_BUF_KVEC.

However it is quite easy to convert virtual-address+len
to a list of page+offset+len.

So we can add a ->add_iov_frag interface for KIOV descriptors, and
then we will be able to use KIOV descriptors for everything.  The
caller must ensure to allocate a large enough descriptor, taking
into account the size of each exptected kvec.

Signed-off-by: Mr NeilBrown <neilb@suse.com>
Change-Id: If8bc5dc9f6e89a196bd72d3ac9b88c4ea5da83d1
Reviewed-on: https://review.whamcloud.com/36824
Reviewed-by: James Simmons <jsimmons@infradead.org>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/ptlrpc/client.c b/lustre/ptlrpc/client.c
index cf2631a..85bb30d 100644 (file)
--- a/lustre/ptlrpc/client.c
+++ b/lustre/ptlrpc/client.c
@@ -37,6 +37,7 @@
 #include <linux/delay.h>
 #include <linux/random.h>
 
 #include <linux/delay.h>
 #include <linux/random.h>
 

+#include <lnet/lib-lnet.h>

 #include <obd_support.h>
 #include <obd_class.h>
 #include <lustre_lib.h>
 #include <obd_support.h>
 #include <obd_class.h>
 #include <lustre_lib.h>


@@ -68,6 +69,28 @@ static void ptlrpc_release_bulk_page_pin(struct ptlrpc_bulk_desc *desc)
                put_page(BD_GET_KIOV(desc, i).kiov_page);
 }
 
                put_page(BD_GET_KIOV(desc, i).kiov_page);
 }
 

+static int ptlrpc_prep_bulk_frag_pages(struct ptlrpc_bulk_desc *desc,
+                                      void *frag, int len)
+{
+       unsigned int offset = (uintptr_t)frag & ~PAGE_MASK;
+
+       ENTRY;
+       while (len > 0) {
+               int page_len = min_t(unsigned int, PAGE_SIZE - offset,
+                                    len);
+               uintptr_t vaddr = (uintptr_t) frag;
+
+               ptlrpc_prep_bulk_page_nopin(desc,
+                                           lnet_kvaddr_to_page(vaddr),
+                                           offset, page_len);
+               offset = 0;
+               len -= page_len;
+               frag += page_len;
+       }
+
+       RETURN(desc->bd_nob);
+}
+

 const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_pin_ops = {
        .add_kiov_frag  = ptlrpc_prep_bulk_page_pin,
        .release_frags  = ptlrpc_release_bulk_page_pin,
 const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_pin_ops = {
        .add_kiov_frag  = ptlrpc_prep_bulk_page_pin,
        .release_frags  = ptlrpc_release_bulk_page_pin,


@@ -77,6 +100,7 @@ EXPORT_SYMBOL(ptlrpc_bulk_kiov_pin_ops);
 const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_nopin_ops = {
        .add_kiov_frag  = ptlrpc_prep_bulk_page_nopin,
        .release_frags  = ptlrpc_release_bulk_noop,
 const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_nopin_ops = {
        .add_kiov_frag  = ptlrpc_prep_bulk_page_nopin,
        .release_frags  = ptlrpc_release_bulk_noop,

+       .add_iov_frag   = ptlrpc_prep_bulk_frag_pages,

 };
 EXPORT_SYMBOL(ptlrpc_bulk_kiov_nopin_ops);
 
 };
 EXPORT_SYMBOL(ptlrpc_bulk_kiov_nopin_ops);