test: improve the cp fiemap tests

* tests/cp/fiemap-2: Enable the fiemap check for files, which
will enable the test for files on ext3.
* tests/cp/fiemap-perf: Comment why we're not enabling for ext3.
* tests/cp/sparse-fiemap: Ditto.  Also sync the files before
doing a fiemap which was needed for ext4 loop back at least.
Add a comment that FIEMAP_FLAG_SYNC is ineffective, thus
requiring the explicit syncs.
* tests/fiemap-capable: A new python script to determine
if a specified path supports fiemap.
* tests/init.cfg (fiemap_capable_): Use the new python script.
* tests/Makefile.am (EXTRA_DIST): Include the new python script.

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/fiemap-capable b/tests/fiemap-capable
new file mode 100644
index 000000000..05c6926a7
--- /dev/null
+++ b/tests/fiemap-capable
@@ -0,0 +1,16 @@
+import struct, fcntl, sys, os
+
+def sizeof(t): return struct.calcsize(t)
+IOCPARM_MASK = 0x7f
+IOC_OUT = 0x40000000
+IOC_IN = 0x80000000
+IOC_INOUT = (IOC_IN|IOC_OUT)
+def _IOWR(x,y,t): return (IOC_INOUT|((sizeof(t)&IOCPARM_MASK)<<16)|((x)<<8)|y)
+
+try:
+    fd = os.open (len (sys.argv) == 2 and sys.argv[1] or '.', os.O_RDONLY)
+    struct_fiemap = '=qqllll'
+    FS_IOC_FIEMAP = _IOWR (ord ('f'), 11, struct_fiemap)
+    fcntl.ioctl (fd, FS_IOC_FIEMAP, struct.pack(struct_fiemap, 0,~0,0,0,0,0))
+except:
+    sys.exit (1)