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authorSong Liu <songliubraving@fb.com>2017-07-31 14:52:26 -0700
committerShaohua Li <shli@fb.com>2017-08-08 07:42:36 -0700
commitb44886c54a999771060371c3a05d5fedfc7e2102 (patch)
tree6803f9f24871193e61cecde1e21132006eac6d27 /drivers/md/raid5-cache.c
parent81fe48e9aa00bdd509bd3c37a76d1132da6b9f09 (diff)
downloadlinux-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/raid5-cache.c')
-rw-r--r--drivers/md/raid5-cache.c21
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]);