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authorDmitry Monakhov <dmtrmonakhov@yandex-team.ru>2019-10-31 10:39:19 +0000
committerJan Kara <jack@suse.cz>2019-10-31 19:07:11 +0100
commit6ff33d99fc5c96797103b48b7b0902c296f09c05 (patch)
treee31ff65aa111de1f52bfcbfc1c9c5b75fcfd352e /fs/quota
parent30ef0e4085070312101be26c015f36277f02e12b (diff)
downloadlinux-6ff33d99fc5c96797103b48b7b0902c296f09c05.tar.bz2
quota: fix livelock in dquot_writeback_dquots
Write only quotas which are dirty at entry. XFSTEST: https://github.com/dmonakhov/xfstests/commit/b10ad23566a5bf75832a6f500e1236084083cddc Link: https://lore.kernel.org/r/20191031103920.3919-1-dmonakhov@openvz.org CC: stable@vger.kernel.org Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/quota')
-rw-r--r--fs/quota/dquot.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 26812a67ed77..b492b9ea829a 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -622,7 +622,7 @@ EXPORT_SYMBOL(dquot_scan_active);
/* Write all dquot structures to quota files */
int dquot_writeback_dquots(struct super_block *sb, int type)
{
- struct list_head *dirty;
+ struct list_head dirty;
struct dquot *dquot;
struct quota_info *dqopt = sb_dqopt(sb);
int cnt;
@@ -636,9 +636,10 @@ int dquot_writeback_dquots(struct super_block *sb, int type)
if (!sb_has_quota_active(sb, cnt))
continue;
spin_lock(&dq_list_lock);
- dirty = &dqopt->info[cnt].dqi_dirty_list;
- while (!list_empty(dirty)) {
- dquot = list_first_entry(dirty, struct dquot,
+ /* Move list away to avoid livelock. */
+ list_replace_init(&dqopt->info[cnt].dqi_dirty_list, &dirty);
+ while (!list_empty(&dirty)) {
+ dquot = list_first_entry(&dirty, struct dquot,
dq_dirty);
WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags));