diff options
| author | Song Liu <songliubraving@fb.com> | 2017-07-31 14:52:26 -0700 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-08-08 07:42:36 -0700 |
| commit | b44886c54a999771060371c3a05d5fedfc7e2102 (patch) | |
| tree | 6803f9f24871193e61cecde1e21132006eac6d27 /drivers/md | |
| parent | 81fe48e9aa00bdd509bd3c37a76d1132da6b9f09 (diff) | |
| download | linux-b44886c54a999771060371c3a05d5fedfc7e2102.tar.bz2 | |
md/r5cache: call mddev_lock/unlock() in r5c_journal_mode_set
In r5c_journal_mode_set(), it is necessary to call mddev_lock()
before accessing conf and conf->log. Otherwise, the conf->log
may change (and become NULL).
Shaohua: fix unlock in failure cases
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5-cache.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index bfa1e907c472..ce98414a6e34 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -2540,23 +2540,32 @@ 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 = mddev->private; - struct r5l_log *log = conf->log; - - if (!log) - return -ENODEV; + 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); + return -ENODEV; + } + if (raid5_calc_degraded(conf) > 0 && - mode == R5C_JOURNAL_MODE_WRITE_BACK) + mode == R5C_JOURNAL_MODE_WRITE_BACK) { + mddev_unlock(mddev); 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]); |