From c146e8fdb9df3a6a3f092d1171a1d7be9c12f02d Mon Sep 17 00:00:00 2001
From: Phil Sutter <phil@nwl.cc>
Date: Mon, 12 Jul 2010 00:18:56 +0200
Subject: [PATCH] zero-copy: release src pages on error

When the second call to __get_userbuf fails, the already reserved user
pages for data input need to be released first before bailing out.
---
 cryptodev_main.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/cryptodev_main.c b/cryptodev_main.c
index dffbead..c2acec7 100644
--- a/cryptodev_main.c
+++ b/cryptodev_main.c
@@ -477,6 +477,15 @@ __crypto_run_std(struct csession *ses_ptr, struct crypt_op *cop)
 
 #ifndef DISABLE_ZCOPY
 
+static void release_user_pages(struct page **pg, int pagecount)
+{
+	while (pagecount--) {
+		if (!PageReserved(pg[pagecount]))
+			SetPageDirty(pg[pagecount]);
+		page_cache_release(pg[pagecount]);
+	}
+}
+
 /* last page - first page + 1 */
 #define PAGECOUNT(buf, buflen) \
         ((((unsigned long)(buf + buflen - 1) & PAGE_MASK) >> PAGE_SHIFT) - \
@@ -558,21 +567,13 @@ static int get_userbuf(struct csession *ses,
 		if (__get_userbuf(cop->dst, cop->len, dst_pagecount,
 					ses->pages + src_pagecount, *dst_sg)) {
 			printk(KERN_ERR "%s: failed to get user pages\n", __func__);
+			release_user_pages(ses->pages, src_pagecount);
 			return -EINVAL;
 		}
 	}
 	return 0;
 }
 
-static void release_user_pages(struct page **pg, int pagecount)
-{
-	while (pagecount--) {
-		if (!PageReserved(pg[pagecount]))
-			SetPageDirty(pg[pagecount]);
-		page_cache_release(pg[pagecount]);
-	}
-}
-
 /* This is the main crypto function - zero-copy edition */
 static int
 __crypto_run_zc(struct csession *ses_ptr, struct crypt_op *cop)
-- 
2.11.4.GIT