From: Mr NeilBrown <neilb@suse.com>
Date: Sun, 5 Jan 2020 16:11:30 +0000 (-0500)
Subject: LU-13004 ptlrpc: Allow BULK_BUF_KIOV to accept a kvec
X-Git-Tag: 2.13.52~106
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=917655fc2938b90a9c246dd2d58408c42aa1658d;hp=4b0f0164c6ed761897409186376e9edc989323c9

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
--- a/lustre/ptlrpc/client.c
+++ b/lustre/ptlrpc/client.c
@@ -37,6 +37,7 @@
 #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>
@@ -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);
 }
 
+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,
@@ -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,
+	.add_iov_frag	= ptlrpc_prep_bulk_frag_pages,
 };
 EXPORT_SYMBOL(ptlrpc_bulk_kiov_nopin_ops);