r5c_journal_mode_set() is called by r5c_journal_mode_store() and raid_ctr() in dm-raid. We don't need mddev_lock() when calling from raid_ctr(). This patch fixes this by moves the mddev_lock() to r5c_journal_mode_store().

Cc: stable@vger.kernel.org (v4.13+) Signed-off-by: Song Liu songliubraving@fb.com --- drivers/md/raid5-cache.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index f1c86d9..39f31f0 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -2577,31 +2577,22 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page) int r5c_journal_mode_set(struct mddev *mddev, int mode) { struct r5conf *conf; - int err;

if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH || mode > R5C_JOURNAL_MODE_WRITE_BACK) return -EINVAL;

- err = mddev_lock(mddev); - if (err) - return err; conf = mddev->private; - if (!conf || !conf->log) { - mddev_unlock(mddev); + if (!conf || !conf->log) return -ENODEV; - }

if (raid5_calc_degraded(conf) > 0 && - mode == R5C_JOURNAL_MODE_WRITE_BACK) { - mddev_unlock(mddev); + mode == R5C_JOURNAL_MODE_WRITE_BACK) return -EINVAL; - }

mddev_suspend(mddev); conf->log->r5c_journal_mode = mode; mddev_resume(mddev); - mddev_unlock(mddev);

pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n", mdname(mddev), mode, r5c_journal_mode_str[mode]); @@ -2614,6 +2605,7 @@ static ssize_t r5c_journal_mode_store(struct mddev *mddev, { int mode = ARRAY_SIZE(r5c_journal_mode_str); size_t len = length; + int ret;

if (len < 2) return -EINVAL; @@ -2625,8 +2617,12 @@ static ssize_t r5c_journal_mode_store(struct mddev *mddev, if (strlen(r5c_journal_mode_str[mode]) == len && !strncmp(page, r5c_journal_mode_str[mode], len)) break; - - return r5c_journal_mode_set(mddev, mode) ?: length; + ret = mddev_lock(mddev); + if (ret) + return ret; + ret = r5c_journal_mode_set(mddev, mode); + mddev_unlock(mddev); + return ret ?: length; }

struct md_sysfs_entry