From 80d73f15d12f087f3fe074f8a4d6e5c5624f2b47 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 2 Jun 2009 14:24:02 +0200 Subject: [PATCH] ocfs2: Fix possible deadlock in quota recovery In ocfs2_finish_quota_recovery() we acquired global quota file lock and started recovering local quota file. During this process we need to get quota structures, which calls ocfs2_dquot_acquire() which gets global quota file lock again. This second lock can block in case some other node has requested the quota file lock in the mean time. Fix the problem by moving quota file locking down into the function where it is really needed. Then dqget() or dqput() won't be called with the lock held. Signed-off-by: Jan Kara Signed-off-by: Joel Becker --- fs/ocfs2/quota_local.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c index 71cf410e89f0..5a460fa82553 100644 --- a/fs/ocfs2/quota_local.c +++ b/fs/ocfs2/quota_local.c @@ -444,10 +444,6 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode, mlog_entry("ino=%lu type=%u", (unsigned long)lqinode->i_ino, type); - status = ocfs2_lock_global_qf(oinfo, 1); - if (status < 0) - goto out; - list_for_each_entry_safe(rchunk, next, &(rec->r_list[type]), rc_list) { chunk = rchunk->rc_chunk; hbh = NULL; @@ -480,12 +476,18 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode, type); goto out_put_bh; } + status = ocfs2_lock_global_qf(oinfo, 1); + if (status < 0) { + mlog_errno(status); + goto out_put_dquot; + } + handle = ocfs2_start_trans(OCFS2_SB(sb), OCFS2_QSYNC_CREDITS); if (IS_ERR(handle)) { status = PTR_ERR(handle); mlog_errno(status); - goto out_put_dquot; + goto out_drop_lock; } mutex_lock(&sb_dqopt(sb)->dqio_mutex); spin_lock(&dq_data_lock); @@ -523,6 +525,8 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode, out_commit: mutex_unlock(&sb_dqopt(sb)->dqio_mutex); ocfs2_commit_trans(OCFS2_SB(sb), handle); +out_drop_lock: + ocfs2_unlock_global_qf(oinfo, 1); out_put_dquot: dqput(dquot); out_put_bh: @@ -537,8 +541,6 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode, if (status < 0) break; } - ocfs2_unlock_global_qf(oinfo, 1); -out: if (status < 0) free_recovery_list(&(rec->r_list[type])); mlog_exit(status);