[PATCH v2 2/2] common/rc: Add extra check for xfs_io -c "chattr" on XFS

Xiao Yang
2020-09-14T05:22:32Z

On XFS, ioctl(FSSETXATTR)(called by xfs_io -c "chattr") maskes off unsupported
or invalid flags silently. For example,
1) With kernel v4.4 which doesn't support dax flag, try to set dax flag on a
file by the lastest xfs_io -c "chattr" command:
--------------------------------------------
# xfs_io -f -c "chattr +x" testfile;echo $?
0
# xfs_io -c "lsattr" testfile
----------------X testfile
--------------------------------------------
2) Realtime inheritance flag is only valid for a directory and try to set
realtime inheritance flag on a file:
--------------------------------------------
# xfs_io -f -c "chattr +t" testfile;echo $?
0
# xfs_io -c "lsattr" testfile
----------------X testfile
--------------------------------------------

In this case, we need to check these flags by extra ioctl(FSGETXATTR)(called
by xfs_io -c "lsattr").

Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
---
common/rc | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/common/rc b/common/rc
index 6487b9f2..807a1f6c 100644
--- a/common/rc
+++ b/common/rc
@@ -2158,6 +2158,7 @@ _require_xfs_io_command()
local param="$*"
local param_checked=""
local opts=""
+ local attr_info=""

local testfile=$TEST_DIR/$$.xfs_io
local testio
@@ -2173,9 +2174,11 @@ _require_xfs_io_command()
# 'tPnE' flags are only valid for a directory so check them on a directory.
if echo "$param" | egrep -q 't|P|n|E'; then
testio=`$XFS_IO_PROG -F -c "chattr +$param" $testdir 2>&1`
+ attr_info=`$XFS_IO_PROG -F -r -c "lsattr" $testdir | awk '{print $1}'`
$XFS_IO_PROG -F -r -c "chattr -$param" $testdir 2>&1
else
testio=`$XFS_IO_PROG -F -f -c "chattr +$param" $testfile 2>&1`
+ attr_info=`$XFS_IO_PROG -F -r -c "lsattr" $testfile | awk '{print $1}'`
$XFS_IO_PROG -F -r -c "chattr -$param" $testfile 2>&1
fi
param_checked="+$param"
@@ -2300,6 +2303,19 @@ _require_xfs_io_command()
echo $testio | grep -q "\(invalid option\|not supported\)" && \
_notrun "xfs_io $command doesn't support $param"
fi
+
+ # On XFS, ioctl(FSSETXATTR)(called by xfs_io -c "chattr") maskes off unsupported
+ # or invalid flags silently so need to check these flags by extra ioctl(FSGETXATTR)
+ # (called by xfs_io -c "lsattr").
+ # The following URL explains why we don't change the behavior of XFS.
+ # https://www.spinics.net/lists/linux-xfs/msg44725.html
+ if [ -n "$attr_info" -a "$FSTYP" = "xfs" ]; then
+ local num=${#param}
+ for i in $(seq 0 $((num-1))); do
+ echo $attr_info | grep -q "${param:$i:1}" || \
+ _notrun "xfs_io $command +${param:$i:1} support is missing (unknown flag in kernel)"
+ done
+ fi
}

# check that kernel and filesystem support direct I/O
--
2.21.0