Check the result code of all command that are executed. Without this,
if the fallocate invocation fails (this feature is not supported on ext3
filesystems for example) then a zero-length output file will be created,
and subsequent the mkfs and mount invocations will fail, which will cause
the subsequent dd invocation to attempt to fill up the host's entire free
disk space. That's not a nice user experience!
Related, if fallocate does fail, try to create the test disk image using
dd instead. That should work everywhere.
Fixes: 4a28274227 ("test: fat: add test of non-contiguous file reads")
Signed-off-by: Stephen Warren <swarren@nvidia.com>
In my patch series to replace fs/fat with "ff.c", I enhanced ff.c to
optimize file reading, so that reads of contiguous clusters are submitted
to the IO device as a single read. This test attempts to torture-test
edge-cases of that enhancement.
BTW, the only way I found to validate that this script actually does
create non-contiguous files was to manually inspect the FAT bitmap in a
hex dump of the FAT image. hdparm --fibmap doesn't work on loop-mounted
filesystems. filefrag -v -e seems to lie about files being contiguous
when they aren't.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
