tests: ensure we test SEEK_DATA where used

fiemap is no longer the default copy implementation,
so check for SEEK_DATA support instead as that's preferred.
This will ensure better test coverage on systems without fiemap.

* init.cfg: Replace fiemap_capable_ with seek_data_capable_.
This is best supported with python 3 so prefer that.
* tests/seek-data-capable: A new test script checking for
SEEK_DATA support on the passed file name,
called from seek_data_capable_.
* tests/fiemap-capable: Remove no longer used probing script.
* tests/cp/fiemap-perf.sh: Renamed to tests/cp/sparse-perf.sh
* tests/cp/fiemap-2.sh: Renamed to tests/cp/sparse-2.sh
* tests/cp/fiemap-extents.sh: Renamed to tests/cp/sparse-extents.sh
* tests/cp/sparse-fiemap.sh: Renamed to tests/cp/sparse-extents-2.sh
* tests/cp/fiemap-FMR.sh: Renamed to tests/cp/copy-FMR.sh
* tests/local.mk: Reference the renamed tests.

init.cfg

@@ -530,15 +530,17 @@ require_kill_group_()
 }
 
 # Return nonzero if the specified path is on a file system for
-# which FIEMAP support exists.  Note some file systems (like ext3 and btrfs)
-# only support FIEMAP for files, not directories.
-fiemap_capable_()
+# which SEEK_DATA support exists.
+seek_data_capable_()
 {
-  if ! python < /dev/null; then
-    warn_ 'fiemap_capable_: python missing: assuming not fiemap capable'
-    return 1
+  { python3 < /dev/null && PYTHON_=python3; } ||
+  { python  < /dev/null && PYTHON_=python; }
+
+  if test x"$PYTHON_" = x; then
+      warn_ 'seek_data_capable_: python missing: assuming not SEEK_DATA capable'
+      return 1
   fi
-  python "$abs_srcdir"/tests/fiemap-capable "$@"
+  $PYTHON_ "$abs_srcdir"/tests/seek-data-capable "$@"
 }
 
 # Skip the current test if "." lacks d_type support.

tests/cp/copy-FMR.sh

@@ -22,6 +22,7 @@ print_ver_ cp
 require_valgrind_
 require_perl_
 
+# Trigger FMR in fiemap logic from v8.11..v8.19
 $PERL -e 'for (1..600) { sysseek (*STDOUT, 4096, 1)' \
   -e '&& syswrite (*STDOUT, "a" x 1024) or die "$!"}' > j || fail=1
 valgrind --quiet --error-exitcode=3 cp --reflink=never j j2 || fail=1

tests/cp/sparse-2.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-# Exercise a few more corners of the fiemap-copying code.
+# Exercise a few more corners of the copying code.
 
 # Copyright (C) 2011-2021 Free Software Foundation, Inc.
 
@@ -19,10 +19,9 @@
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ cp
 
-# Require a fiemap-enabled FS.
-touch fiemap_chk # check a file rather than current dir for best coverage
-fiemap_capable_ fiemap_chk \
-  || skip_ "this file system lacks FIEMAP support"
+touch sparse_chk
+seek_data_capable_ sparse_chk \
+  || skip_ "this file system lacks SEEK_DATA support"
 
 # Exercise the code that handles a file ending in a hole.
 printf x > k || framework_failure_

tests/cp/sparse-extents-2.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-# Test cp --sparse=always through fiemap copy
+# Test cp --sparse=always through SEEK_DATA copy
 
 # Copyright (C) 2010-2021 Free Software Foundation, Inc.
 
@@ -22,11 +22,11 @@ require_perl_
 
 # The test was seen to fail on ext3 so exclude that type
 # (or any file system where the type can't be determined)
-touch fiemap_chk
-if fiemap_capable_ fiemap_chk && ! df -t ext3 . >/dev/null; then
+touch sparse_chk
+if seek_data_capable_ sparse_chk && ! df -t ext3 . >/dev/null; then
   : # Current partition has working extents.  Good!
 else
-  skip_ "current file system has insufficient FIEMAP support"
+  skip_ "current file system has insufficient SEEK_DATA support"
 
   # It's not;  we need to create one, hence we need root access.
   require_root_
@@ -50,8 +50,8 @@ else
 fi
 
 # =================================================
-# Ensure that we exercise the FIEMAP-copying code enough
-# to provoke at least two iterations of the do...while loop
+# The data below was set up to ensure that the original FIEMAP-copying code
+# was exercised enough to provoke at least two iterations of the do...while loop
 # in which it calls ioctl (fd, FS_IOC_FIEMAP,...
 # This also verifies that non-trivial extents are preserved.
 

tests/cp/sparse-extents.sh

@@ -21,10 +21,9 @@ print_ver_ cp
 
 require_sparse_support_
 
-touch fiemap_chk || framework_failure_
-fiemap_capable_ fiemap_chk ||
-  skip_ 'this file system lacks FIEMAP support'
-rm fiemap_chk
+touch sparse_chk || framework_failure_
+seek_data_capable_ sparse_chk ||
+  skip_ 'this file system lacks SEEK_DATA support'
 
 fallocate --help >/dev/null || skip_ 'The fallocate utility is required'
 touch falloc.test || framework_failure_
@@ -65,7 +64,7 @@ fi
 # Ensure we handle extents beyond file size correctly.
 # Note until we support fallocate, we will not maintain
 # the file allocation.  FIXME: amend this test if fallocate is supported.
-# Note currently this only uses fiemap logic when the allocation (-l)
+# Note currently this only uses SEEK_DATA logic when the allocation (-l)
 # is smaller than the size, thus identifying the file as sparse.
 # Note the '-l 1' case is an effective noop, and just checks
 # a file with a trailing hole is copied correctly.

tests/cp/sparse-perf.sh

@@ -19,30 +19,18 @@
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ cp
 
-# Require a fiemap-enabled FS.
-touch fiemap_chk
-fiemap_capable_ fiemap_chk ||
-  skip_ "this file system lacks FIEMAP support"
-
-# Exclude ext[23] (or unknown fs types)
-# as the emulated extent scanning can be slow
-df -t ext2 -t ext3 . >/dev/null &&
-  skip_ "ext[23] can have slow FIEMAP scanning"
+touch sparse_chk
+seek_data_capable_ sparse_chk ||
+  skip_ "this file system lacks SEEK_DATA support"
 
 # Create a large-but-sparse file.
 timeout 10 truncate -s1T f ||
   skip_ "unable to create a 1 TiB sparse file"
 
-# Disable this test on old BTRFS (e.g. Fedora 14)
-# which reports (unwritten) extents for holes.
-filefrag f || skip_ "the 'filefrag' utility is missing"
-filefrag f | grep -F ': 0 extents found' > /dev/null ||
-  skip_ 'this file system reports extents for holes'
-
 # Nothing can read (much less write) that many bytes in so little time.
 timeout 10 cp f f2 || fail=1
 
-# Ensure that the sparse file copied through fiemap has the same size
+# Ensure that the sparse file copied through SEEK_DATA has the same size
 # in bytes as the original.
 test "$(stat --printf %s f)" = "$(stat --printf %s f2)" || fail=1
 

tests/fiemap-capable

@@ -1,16 +0,0 @@
-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)

tests/local.mk

@@ -98,7 +98,7 @@ EXTRA_DIST +=			\
   tests/factor/run.sh		\
   tests/factor/create-test.sh	\
   tests/filefrag-extent-compare \
-  tests/fiemap-capable		\
+  tests/seek-data-capable	\
   tests/init.sh			\
   tests/lang-default		\
   tests/no-perl			\
@@ -113,7 +113,7 @@ all_root_tests =				\
   tests/cp/special-bits.sh			\
   tests/cp/cp-mv-enotsup-xattr.sh		\
   tests/cp/capability.sh			\
-  tests/cp/sparse-fiemap.sh			\
+  tests/cp/sparse-extents-2.sh			\
   tests/cp/cross-dev-symlink.sh			\
   tests/dd/skip-seek-past-dev.sh		\
   tests/df/problematic-chars.sh			\
@@ -481,10 +481,10 @@ all_tests =					\
   tests/cp/existing-perm-dir.sh			\
   tests/cp/existing-perm-race.sh		\
   tests/cp/fail-perm.sh				\
-  tests/cp/fiemap-extents.sh			\
-  tests/cp/fiemap-FMR.sh			\
-  tests/cp/fiemap-perf.sh			\
-  tests/cp/fiemap-2.sh				\
+  tests/cp/sparse-extents.sh			\
+  tests/cp/copy-FMR.sh				\
+  tests/cp/sparse-perf.sh			\
+  tests/cp/sparse-2.sh				\
   tests/cp/file-perm-race.sh			\
   tests/cp/into-self.sh				\
   tests/cp/link.sh				\

tests/seek-data-capable

@@ -0,0 +1,33 @@
+import sys, os, errno, platform
+
+# Pass an _empty_ file
+if len(sys.argv) != 2:
+    sys.exit(1)
+
+if not hasattr(os, 'SEEK_DATA'):
+    # Not available on python 2, or on darwin python 3
+    # Also Darwin swaps SEEK_DATA/SEEK_HOLE definitions
+    if platform.system() == "Darwin":
+        SEEK_DATA = 4
+    else:
+        SEEK_DATA = 3 # Valid on Linux, FreeBSD, Solaris
+else:
+    SEEK_DATA = os.SEEK_DATA
+
+# Even if os supports SEEK_DATA or SEEK_HOLE,
+# the file system may not, in which case it would report
+# current and eof positions respectively.
+# Therefore work with an empty file,
+# ensuring SEEK_DATA returns ENXIO (no more data)
+try:
+    fd = os.open(sys.argv[1], os.O_RDONLY)
+except:
+    sys.exit(1)
+
+try:
+    data = os.lseek(fd, 0, SEEK_DATA)
+except OSError as e:
+    if e.errno == errno.ENXIO:
+      sys.exit(0)
+
+sys.exit(1)