src/patches/suse-2.6.27.25/patches.fixes/ocfs2-1.4-git-4e8a301929bfa017e6ffe11e3cf78ccaf8492801

   1 From: Jan Kara <jack@suse.cz>
   2 Subject: ocfs2: Fix possible deadlock in ocfs2_global_read_dquot()
   3 Patch-mainline: 2.6.31
   4
   5 It is not possible to get a read lock and then try to get the same write lock
   6 in one thread as that can block on downconvert being requested by other node
   7 leading to deadlock. So first drop the quota lock for reading and only after
   8 that get it for writing.
   9
  10 Signed-off-by: Jan Kara <jack@suse.cz>
  11 ---
  12  fs/ocfs2/quota_global.c |    4 +++-
  13  1 files changed, 3 insertions(+), 1 deletions(-)
  14
  15 diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
  16 index 1ed0f7c..edfa60c 100644
  17 --- a/fs/ocfs2/quota_global.c
  18 +++ b/fs/ocfs2/quota_global.c
  19 @@ -421,6 +421,7 @@ int ocfs2_global_read_dquot(struct dquot *dquot)
  20         OCFS2_DQUOT(dquot)->dq_originodes = dquot->dq_dqb.dqb_curinodes;
  21         if (!dquot->dq_off) {   /* No real quota entry? */
  22                 /* Upgrade to exclusive lock for allocation */
  23 +               ocfs2_qinfo_unlock(info, 0);
  24                 err = ocfs2_qinfo_lock(info, 1);
  25                 if (err < 0)
  26                         goto out_qlock;
  27 @@ -435,7 +436,8 @@ int ocfs2_global_read_dquot(struct dquot *dquot)
  28  out_qlock:
  29         if (ex)
  30                 ocfs2_qinfo_unlock(info, 1);
  31 -       ocfs2_qinfo_unlock(info, 0);
  32 +       else
  33 +               ocfs2_qinfo_unlock(info, 0);
  34  out:
  35         if (err < 0)
  36                 mlog_errno(err);
  37 --
  38 1.6.0.2
  39