diff options
| author | Song Liu <songliubraving@fb.com> | 2017-08-08 22:56:52 -0700 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-08-25 10:21:46 -0700 |
| commit | a72cbf83b0cb2368568d4e78cf1687079aad4d25 (patch) | |
| tree | db55f2260db6cb8f0bff001767148adaddda81fb /drivers/md | |
| parent | 26e13043b7ea14c0b038f3f5a4af0d5cdda9e95f (diff) | |
md/r5cache: call mddev_lock/unlock() in r5c_journal_mode_show
In r5c_journal_mode_show(), it is necessary to call mddev_lock()
before accessing conf and conf->log. Otherwise, the conf->log
may change (and become NULL).
Signed-off-by: Song Liu <songliubraving@fb.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5-cache.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 2dcbafa8e66c..e357ed367140 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -2529,11 +2529,18 @@ static void r5l_write_super(struct r5l_log *log, sector_t cp) static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page) { - struct r5conf *conf = mddev->private; + struct r5conf *conf; int ret; - if (!conf->log) + ret = mddev_lock(mddev); + if (ret) + return ret; + + conf = mddev->private; + if (!conf || !conf->log) { + mddev_unlock(mddev); return 0; + } switch (conf->log->r5c_journal_mode) { case R5C_JOURNAL_MODE_WRITE_THROUGH: @@ -2551,6 +2558,7 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page) default: ret = 0; } + mddev_unlock(mddev); return ret; } |