[PATCH] fstests: generic/563: use fs blocksize to do the writes

[Qu Wenruo <wqu@suse.com>]

[FALSE ALERTS]
If the system has a page size larger than 4K, and the fs block size
matches the page size, test case generic/563 will fail:

    --- tests/generic/563.out	2024-04-25 18:13:45.178550333 +0930
    +++ /home/adam/xfstests-dev/results//generic/563.out.bad	2024-09-30 09:09:16.155312379 +0930
    @@ -3,7 +3,8 @@
     read is in range
     write is in range
     write -> read/write
    -read is in range
    +read has value of 8388608
    +read is NOT in range -33792 .. 33792
     write is in range
    ...

Both Ext4 and btrfs fail with 64K block size and 64K page size

[CAUSE]
The test case writes the 8MiB file using the default block size xfs_io
pwrite, which is 4KiB.

Since the fs block size is 64K, such 4KiB write is unaligned inside a
block, causing the fs to read out the full page.

Thus the pwrite will cause the fs to read out every page, resulting the
above 8MiB+ read value.

[FIX]
Fix the test case by using the fs block size to avoid such unaligned
buffered write.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 tests/generic/563 | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/tests/generic/563 b/tests/generic/563
index 0a8129a6..e8db8acf 100755
--- a/tests/generic/563
+++ b/tests/generic/563
@@ -94,6 +94,8 @@ sminor=$((0x`stat -L -c %T $LOOP_DEV`))
 _mkfs_dev $LOOP_DEV >> $seqres.full 2>&1
 _mount $LOOP_DEV $SCRATCH_MNT || _fail "mount failed"
 
+blksize=$(_get_block_size "$SCRATCH_MNT")
+
 drop_io_cgroup=
 grep -q -w io $cgdir/cgroup.subtree_control || drop_io_cgroup=1
 
@@ -103,7 +105,7 @@ echo "+io" > $cgdir/cgroup.subtree_control || _fail "subtree control"
 echo "read/write"
 reset
 switch_cg $cgdir/$seq-cg
-$XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" -c fsync \
+$XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite -b $blksize 0 $iosize" -c fsync \
 	$SCRATCH_MNT/file >> $seqres.full 2>&1
 switch_cg $cgdir
 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
@@ -114,9 +116,9 @@ check_cg $cgdir/$seq-cg $iosize $iosize 5% 5%
 echo "write -> read/write"
 reset
 switch_cg $cgdir/$seq-cg
-$XFS_IO_PROG -c "pwrite 0 $iosize" $SCRATCH_MNT/file >> $seqres.full 2>&1
+$XFS_IO_PROG -c "pwrite -b $blksize 0 $iosize" $SCRATCH_MNT/file >> $seqres.full 2>&1
 switch_cg $cgdir/$seq-cg-2
-$XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \
+$XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite -b $blksize 0 $iosize" $SCRATCH_MNT/file \
 	>> $seqres.full 2>&1
 switch_cg $cgdir
 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
@@ -134,7 +136,7 @@ reset
 switch_cg $cgdir/$seq-cg
 $XFS_IO_PROG -c "pread 0 $iosize" $SCRATCH_MNT/file >> $seqres.full 2>&1
 switch_cg $cgdir/$seq-cg-2
-$XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \
+$XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite -b $blksize 0 $iosize" $SCRATCH_MNT/file \
 	>> $seqres.full 2>&1
 switch_cg $cgdir
 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
-- 
2.46.0