If you do something like:
# touch foo
# tail -f foo &
# rm foo
# <take snapshot>
# <mount snapshot>
you'll panic, because ext3/4 tries to do orphan list processing on the
readonly snapshot device, and:
kernel: journal commit I/O error
kernel: Assertion failure in journal_flush_Rsmp_e2f189ce() at journal.c:1356: "!journal->j_checkpoint_transactions"
kernel: Kernel panic: Fatal exception
for a truly readonly underlying device, it's reasonable and necessary
to just skip orphan list processing.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
a8f48a9561