features/locks: fcntl(3) on F_GETLK must return first conflicting lock

- Added test program, getlk_owner.c to capture the bug when regressed.

Change-Id: Ic2a0f6fa8d094c0f2e9f4a6febd278d4a2948223
BUG: 869724
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/4164
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 120 insertions, 0 deletions

diff --git a/tests/bugs/getlk_owner.c b/tests/bugs/getlk_owner.c
new file mode 100644
index 000000000..619c2e32d
--- /dev/null
+++ b/tests/bugs/getlk_owner.c
@@ -0,0 +1,120 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+
+#define GETLK_OWNER_CHECK(f, cp, label)                     \
+    do {                                                    \
+        switch (f.l_type) {                                 \
+            case F_RDLCK:                                   \
+            case F_WRLCK:                                   \
+                ret = 1;                                    \
+                goto label;                                 \
+            case F_UNLCK:                                   \
+                if (!are_flocks_sane (&f, &cp)) {           \
+                    ret = 1;                                \
+                    goto label;                             \
+                }                                           \
+                break;                                      \
+        }                                                   \
+    } while (0)
+
+void
+flock_init (struct flock *f, short int type, off_t start, off_t len)
+{
+    f->l_type = type;
+    f->l_start = start;
+    f->l_len = len;
+}
+
+int
+flock_cp (struct flock *dst, struct flock *src)
+{
+    memcpy ((void *) dst, (void *) src, sizeof (struct flock));
+}
+
+int
+are_flocks_sane (struct flock *src, struct flock *cpy)
+{
+    return ((src->l_whence == cpy->l_whence) &&
+            (src->l_start == cpy->l_start) &&
+            (src->l_len == cpy->l_len));
+}
+
+/*
+ * Test description:
+ * SETLK (0,3), F_WRLCK
+ * SETLK (3,3), F_WRLCK
+ *
+ * the following GETLK requests must return flock struct unmodified
+ * except for l_type to F_UNLCK
+ * GETLK (3,3), F_WRLCK
+ * GETLK (3,3), F_RDLCK
+ *
+ * */
+
+int main (int argc, char **argv)
+{
+    int fd = -1;
+    int ret = 1;
+    char *fname = NULL;
+    struct flock f = {0,};
+    struct flock cp = {0,};
+
+    if (argc < 2)
+        goto out;
+
+    fname = argv[1];
+    fd = open (fname, O_RDWR);
+    if (fd == -1) {
+        perror ("open");
+        goto out;
+    }
+
+    flock_init (&f, F_WRLCK, 0, 3);
+    flock_cp (&cp, &f);
+    ret = fcntl (fd, F_SETLK, &f);
+    if (ret) {
+        perror ("fcntl");
+        goto out;
+    }
+    if (!are_flocks_sane (&f, &cp)) {
+        ret = 1;
+        goto out;
+    }
+
+    flock_init (&f, F_WRLCK, 3, 3);
+    flock_cp (&cp, &f);
+    ret = fcntl (fd, F_SETLK, &f);
+    if (ret) {
+        perror ("fcntl");
+        goto out;
+    }
+    if (!are_flocks_sane (&f, &cp)) {
+        ret = 1;
+        goto out;
+    }
+
+    flock_init (&f, F_WRLCK, 3, 3);
+    flock_cp (&cp, &f);
+    ret = fcntl (fd, F_GETLK, &f);
+    if (ret) {
+        perror ("fcntl");
+        return 1;
+    }
+    GETLK_OWNER_CHECK (f, cp, out);
+
+    flock_init (&f, F_RDLCK, 3, 3);
+    flock_cp (&cp, &f);
+    ret = fcntl (fd, F_GETLK, &f);
+    if (ret) {
+        perror ("fcntl");
+        return 1;
+    }
+    GETLK_OWNER_CHECK (f, cp, out);
+
+out:
+    if (fd != -1)
+        close (fd);
+    return ret;
+}