This makes it clear when we are using "mount ; umount" versus "mount
-o remount" for most file systems. The reason for this distinction is
(a) tests may want to test the difference between what happens on the
remount versus the munt paths, (b) with tmpfs, "mount ; umount" will
cause the contents of all of the files to disappear which makes many
tests sad, and (c) some mount options may not be changed using "mount
-o remount".
Currently _scratch_mount performs "_scratch_mount ; _scratch_umount"
so mechnically rename this function to _scratch_cycle_mount. This was
done mechnically using the script fragment:
git grep "_scratch_remount" | \
awk -F: '{print $1}' | sort -u | \
xargs sed -i 's/_scratch_remount/_scratch_cycle_mount/g'
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
XFS had a data corruption problem where writeback of pages to unwritten
extents would fail to run unwritten extent conversion at I/O completion.
This causes subsequent reads of written, but unconverted regions to
return zeroes. This occurs on sub-page block size filesystems when
writeback contends for the inode lock (e.g., with a file writer).
Add a test that creates the conditions to reproduce the data corruption
and detect it by looking for unwritten extents after all said extents
have been overwritten.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>