generic/223, xfs/203: IO is not well aligned
authorDave Chinner <dchinner@redhat.com>
Tue, 26 May 2015 02:51:53 +0000 (12:51 +1000)
committerDave Chinner <david@fromorbit.com>
Tue, 26 May 2015 02:51:53 +0000 (12:51 +1000)
On certain configurations (e.g. MOUNT_OPTIONS="-o dax") we get
different allocation patterns due to the writes being done in
multiple pwrite() calls. e.g. the write is 8k, but the buffer size
is 4k, and so the filesystem sees 4k writes. If the filesytem is not
using delayed allocation, then the allocation context is a 4k write
rather than an 8k write and so they don't get appropriately aligned.

Fix this by making the write buffer the same size and the writes
being done.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
tests/generic/223
tests/xfs/203

index a67b8d5..f150dc9 100755 (executable)
@@ -69,7 +69,7 @@ for SUNIT_K in 8 16 32 64 128; do
                        $XFS_IO_PROG -f -c "falloc 0 $SIZE" \
                                $SCRATCH_MNT/file-$FILE-$SIZE-falloc \
                                        >> $seqres.full 2>&1
-                       $XFS_IO_PROG -f -c "pwrite 0 $SIZE" \
+                       $XFS_IO_PROG -f -c "pwrite -b $SIZE 0 $SIZE" \
                                $SCRATCH_MNT/file-$FILE-$SIZE-write \
                                        >> $seqres.full 2>&1
                        src/t_stripealign $SCRATCH_MNT/file-$FILE-$SIZE-falloc \
index 7e18ca3..2ac5290 100755 (executable)
@@ -38,11 +38,11 @@ _write_holes()
        let fsize=$(($writes * 0x100000))
 
        # prevent EOF preallocation from affecting results
-       xfs_io -f $file -c "truncate $fsize"
+       $XFS_IO_PROG -f $file -c "truncate $fsize"
 
        offset=0
        for i in `seq 0 $writes`; do
-               xfs_io -f $file -c "pwrite -q $offset 64k"
+               $XFS_IO_PROG -f $file -c "pwrite -b 64k -q $offset 64k"
                let offset=$offset+0x100000
        done
 }