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| author | Dmitry Monakhov <dmtrmonakhov@yandex-team.ru> | 2019-10-31 13:39:19 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-17 21:56:43 +0300 |
| commit | 1a4437076566a758f7c11565907835d7ec7a4893 (patch) | |
| tree | fadc4a81219348bf23526aa6965af7e898014879 | |
| parent | 72c7fa7466f51e6ec0d0c4b2acf5d66580dcd0cb (diff) | |
| download | linux-1a4437076566a758f7c11565907835d7ec7a4893.tar.xz | |
quota: fix livelock in dquot_writeback_dquots
commit 6ff33d99fc5c96797103b48b7b0902c296f09c05 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/quota/dquot.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 3d5f22aa28e1..7f0b39da5022 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -623,7 +623,7 @@ 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; @@ -637,9 +637,10 @@ 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)); |