git: 3c3b906b5423 - main - fusefs: After successful F_GETLK, l_whence should be SEEK_SET

The branch main has been updated by asomers:

URL: https://cgit.FreeBSD.org/src/commit/?id=3c3b906b54236841d813fd9a01b1e090f39558ea

commit 3c3b906b54236841d813fd9a01b1e090f39558ea
Author:     Alan Somers <asomers@FreeBSD.org>
AuthorDate: 2022-10-11 23:00:07 +0000
Commit:     Alan Somers <asomers@FreeBSD.org>
CommitDate: 2022-10-17 13:09:50 +0000

    fusefs: After successful F_GETLK, l_whence should be SEEK_SET
    
    PR:             266886
    Reported by:    John Millikin <jmillikin@gmail.com>
    MFC after:      2 weeks
    Reviewed by:    emaste
    Differential Revision: https://reviews.freebsd.org/D37014
---
 sys/fs/fuse/fuse_vnops.c     |  1 +
 tests/sys/fs/fusefs/locks.cc | 69 ++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/sys/fs/fuse/fuse_vnops.c b/sys/fs/fuse/fuse_vnops.c
index 30d0e557feb5..5ad4f6bebd08 100644
--- a/sys/fs/fuse/fuse_vnops.c
+++ b/sys/fs/fuse/fuse_vnops.c
@@ -537,6 +537,7 @@ fuse_vnop_advlock(struct vop_advlock_args *ap)
 	if (err == 0 && op == FUSE_GETLK) {
 		flo = fdi.answ;
 		fl->l_type = flo->lk.type;
+		fl->l_whence = SEEK_SET;
 		if (flo->lk.type != F_UNLCK) {
 			fl->l_pid = flo->lk.pid;
 			fl->l_start = flo->lk.start;
diff --git a/tests/sys/fs/fusefs/locks.cc b/tests/sys/fs/fusefs/locks.cc
index aeb24704624b..f637c65cff24 100644
--- a/tests/sys/fs/fusefs/locks.cc
+++ b/tests/sys/fs/fusefs/locks.cc
@@ -47,9 +47,9 @@ using namespace testing;
 class Fallback: public FuseTest {
 public:
 
-void expect_lookup(const char *relpath, uint64_t ino)
+void expect_lookup(const char *relpath, uint64_t ino, uint64_t size = 0)
 {
-	FuseTest::expect_lookup(relpath, ino, S_IFREG | 0644, 0, 1);
+	FuseTest::expect_lookup(relpath, ino, S_IFREG | 0644, size, 1);
 }
 
 };
@@ -355,6 +355,71 @@ TEST_F(Getlk, lock_exists)
 	leak(fd);
 }
 
+/*
+ * F_GETLK with SEEK_CUR
+ */
+TEST_F(Getlk, seek_cur)
+{
+	const char FULLPATH[] = "mountpoint/some_file.txt";
+	const char RELPATH[] = "some_file.txt";
+	uint64_t ino = 42;
+	struct flock fl;
+	int fd;
+	pid_t pid = getpid();
+
+	expect_lookup(RELPATH, ino, 1024);
+	expect_open(ino, 0, 1);
+	EXPECT_CALL(*m_mock, process(
+		ResultOf([=](auto in) {
+			return (in.header.opcode == FUSE_GETLK &&
+				in.header.nodeid == ino &&
+				in.body.getlk.fh == FH &&
+				/*
+				 * Though it seems useless, libfuse expects the
+				 * owner and pid fields to be set during
+				 * FUSE_GETLK.
+				 */
+				in.body.getlk.owner == (uint32_t)pid &&
+				in.body.getlk.lk.pid == (uint64_t)pid &&
+				in.body.getlk.lk.start == 500 &&
+				in.body.getlk.lk.end == 509 &&
+				in.body.getlk.lk.type == F_RDLCK);
+		}, Eq(true)),
+		_)
+	).WillOnce(Invoke(ReturnImmediate([=](auto in __unused, auto& out) {
+		SET_OUT_HEADER_LEN(out, getlk);
+		out.body.getlk.lk.start = 400;
+		out.body.getlk.lk.end = 499;
+		out.body.getlk.lk.type = F_WRLCK;
+		out.body.getlk.lk.pid = (uint32_t)pid + 1;
+	})));
+
+	fd = open(FULLPATH, O_RDWR);
+	ASSERT_LE(0, fd) << strerror(errno);
+	ASSERT_NE(-1, lseek(fd, 500, SEEK_SET));
+
+	fl.l_start = 0;
+	fl.l_len = 10;
+	fl.l_pid = 42;
+	fl.l_type = F_RDLCK;
+	fl.l_whence = SEEK_CUR;
+	fl.l_sysid = 0;
+	ASSERT_NE(-1, fcntl(fd, F_GETLK, &fl)) << strerror(errno);
+
+	/*
+	 * After a successful F_GETLK request, the value of l_whence is
+	 * SEEK_SET.
+	 */
+	EXPECT_EQ(F_WRLCK, fl.l_type);
+	EXPECT_EQ(fl.l_pid, pid + 1);
+	EXPECT_EQ(fl.l_start, 400);
+	EXPECT_EQ(fl.l_len, 100);
+	EXPECT_EQ(fl.l_whence, SEEK_SET);
+	ASSERT_EQ(fl.l_sysid, 0);
+
+	leak(fd);
+}
+
 /*
  * If the fuse filesystem does not support posix file locks, then the kernel
  * should fall back to local locks.