This is a note to let you know that I've just added the patch titled

md/r5cache: move mddev_lock() out of r5c_journal_mode_set()

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: md-r5cache-move-mddev_lock-out-of-r5c_journal_mode_set.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From ff35f58e8f8eb520367879a0ccc6f2ec4b62b17b Mon Sep 17 00:00:00 2001

From: Song Liu songliubraving@fb.com Date: Sun, 19 Nov 2017 22:17:00 -0800 Subject: md/r5cache: move mddev_lock() out of r5c_journal_mode_set()

From: Song Liu songliubraving@fb.com

commit ff35f58e8f8eb520367879a0ccc6f2ec4b62b17b upstream.

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().

Signed-off-by: Song Liu songliubraving@fb.com Signed-off-by: Shaohua Li shli@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/md/raid5-cache.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)

--- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -2571,31 +2571,22 @@ static ssize_t r5c_journal_mode_show(str 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]); @@ -2608,6 +2599,7 @@ static ssize_t r5c_journal_mode_store(st { int mode = ARRAY_SIZE(r5c_journal_mode_str); size_t len = length; + int ret;

if (len < 2) return -EINVAL; @@ -2619,8 +2611,12 @@ static ssize_t r5c_journal_mode_store(st 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

Patches currently in stable-queue which might be from songliubraving@fb.com are

queue-4.14/md-r5cache-move-mddev_lock-out-of-r5c_journal_mode_set.patch