tree 8e144229b87b8daf0767efb0e688d36ddad88f7a
parent 01a36b6758e723f919420ef20cea5fca1fc06e2b
author Eric Ren <zren@suse.com> 1470171730 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1470173501 -0400

ocfs2: retry on ENOSPC if sufficient space in truncate log

The testcase "mmaptruncate" in ocfs2 test suite always fails with ENOSPC
error on small volume (say less than 10G).  This testcase repeatedly
performs "extend" and "truncate" on a file.  Continuously, it truncates
the file to 1/2 of the size, and then extends to 100% of the size.  The
main bitmap will quickly run out of space because the "truncate" code
prevent truncate log from being flushed by
ocfs2_schedule_truncate_log_flush(osb, 1), while truncate log may have
cached lots of clusters.

So retry to allocate after flushing truncate log when ENOSPC is
returned.  And we cannot reuse the deleted blocks before the transaction
committed.  Fortunately, we already have a function to do this -
ocfs2_try_to_free_truncate_log().  Just need to remove the "static"
modifier and put it into the right place.

The "unlock"/"lock" code isn't elegant, but there seems to be no better
option.

[zren@suse.com: locking fix]
  Link: http://lkml.kernel.org/r/1468031546-4797-1-git-send-email-zren@suse.com
Link: http://lkml.kernel.org/r/1466586469-5541-1-git-send-email-zren@suse.com
Signed-off-by: Eric Ren <zren@suse.com>
Reviewed-by: Gang He <ghe@suse.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>