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From:   David Howells <dhowells@redhat.com>
To:     Al Viro <viro@zeniv.linux.org.uk>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     David Howells <dhowells@redhat.com>, Jens Axboe <axboe@kernel.dk>,
        Christoph Hellwig <hch@lst.de>,
        Christian Brauner <christian@brauner.io>,
        David Laight <David.Laight@ACULAB.COM>,
        Matthew Wilcox <willy@infradead.org>,
        Brendan Higgins <brendanhiggins@google.com>,
        David Gow <davidgow@google.com>, linux-fsdevel@vger.kernel.org,
        linux-block@vger.kernel.org, linux-mm@kvack.org,
        netdev@vger.kernel.org, linux-kselftest@vger.kernel.org,
        kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org,
        Christian Brauner <brauner@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        John Hubbard <jhubbard@nvidia.com>
Subject: [RFC PATCH 4/9] iov_iter: Consolidate bvec pattern checking
Date:   Thu, 14 Sep 2023 23:15:21 +0100
Message-ID: <20230914221526.3153402-5-dhowells@redhat.com>
In-Reply-To: <20230914221526.3153402-1-dhowells@redhat.com>
References: <20230914221526.3153402-1-dhowells@redhat.com>
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Make the BVEC-testing functions use the consolidated pattern checking
functions to reduce the amount of duplicated code.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Christian Brauner <brauner@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: Brendan Higgins <brendanhiggins@google.com>
cc: David Gow <davidgow@google.com>
cc: linux-kselftest@vger.kernel.org
cc: kunit-dev@googlegroups.com
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
---
 lib/kunit_iov_iter.c | 42 +++++++++++-------------------------------
 1 file changed, 11 insertions(+), 31 deletions(-)

diff --git a/lib/kunit_iov_iter.c b/lib/kunit_iov_iter.c
index 4925ca37cde6..eb86371b67d0 100644
--- a/lib/kunit_iov_iter.c
+++ b/lib/kunit_iov_iter.c
@@ -107,9 +107,11 @@ static void iov_kunit_build_to_reference_pattern(struct kunit *test, u8 *scratch
 	int i, patt = 0;
 
 	memset(scratch, 0, bufsize);
-	for (; pr->page >= 0; pr++)
+	for (; pr->page >= 0; pr++) {
+		u8 *p = scratch + pr->page * PAGE_SIZE;
 		for (i = pr->from; i < pr->to; i++)
-			scratch[i] = pattern(patt++);
+			p[i] = pattern(patt++);
+	}
 }
 
 /*
@@ -124,8 +126,10 @@ static void iov_kunit_build_from_reference_pattern(struct kunit *test, u8 *buffe
 
 	memset(buffer, 0, bufsize);
 	for (; pr->page >= 0; pr++) {
+		size_t patt = pr->page * PAGE_SIZE;
+
 		for (j = pr->from; j < pr->to; j++) {
-			buffer[i++] = pattern(j);
+			buffer[i++] = pattern(patt + j);
 			if (i >= bufsize)
 				return;
 		}
@@ -287,13 +291,12 @@ static void __init iov_kunit_load_bvec(struct kunit *test,
  */
 static void __init iov_kunit_copy_to_bvec(struct kunit *test)
 {
-	const struct iov_kunit_range *pr;
 	struct iov_iter iter;
 	struct bio_vec bvec[8];
 	struct page **spages, **bpages;
 	u8 *scratch, *buffer;
 	size_t bufsize, npages, size, copied;
-	int i, patt;
+	int i;
 
 	bufsize = 0x100000;
 	npages = bufsize / PAGE_SIZE;
@@ -315,16 +318,7 @@ static void __init iov_kunit_copy_to_bvec(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, iter.count, 0);
 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
 
-	/* Build the expected image in the scratch buffer. */
-	patt = 0;
-	memset(scratch, 0, bufsize);
-	for (pr = bvec_test_ranges; pr->page >= 0; pr++) {
-		u8 *p = scratch + pr->page * PAGE_SIZE;
-
-		for (i = pr->from; i < pr->to; i++)
-			p[i] = pattern(patt++);
-	}
-
+	iov_kunit_build_to_reference_pattern(test, scratch, bufsize, bvec_test_ranges);
 	iov_kunit_check_pattern(test, buffer, scratch, bufsize);
 	KUNIT_SUCCEED();
 }
@@ -334,13 +328,12 @@ static void __init iov_kunit_copy_to_bvec(struct kunit *test)
  */
 static void __init iov_kunit_copy_from_bvec(struct kunit *test)
 {
-	const struct iov_kunit_range *pr;
 	struct iov_iter iter;
 	struct bio_vec bvec[8];
 	struct page **spages, **bpages;
 	u8 *scratch, *buffer;
 	size_t bufsize, npages, size, copied;
-	int i, j;
+	int i;
 
 	bufsize = 0x100000;
 	npages = bufsize / PAGE_SIZE;
@@ -362,20 +355,7 @@ static void __init iov_kunit_copy_from_bvec(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, iter.count, 0);
 	KUNIT_EXPECT_EQ(test, iter.nr_segs, 0);
 
-	/* Build the expected image in the main buffer. */
-	i = 0;
-	memset(buffer, 0, bufsize);
-	for (pr = bvec_test_ranges; pr->page >= 0; pr++) {
-		size_t patt = pr->page * PAGE_SIZE;
-
-		for (j = pr->from; j < pr->to; j++) {
-			buffer[i++] = pattern(patt + j);
-			if (i >= bufsize)
-				goto stop;
-		}
-	}
-stop:
-
+	iov_kunit_build_from_reference_pattern(test, buffer, bufsize, bvec_test_ranges);
 	iov_kunit_check_pattern(test, buffer, scratch, bufsize);
 	KUNIT_SUCCEED();
 }