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| author | NeilBrown <neilb@suse.de> | 2014-12-15 04:56:59 +0300 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2015-02-06 01:32:55 +0300 |
| commit | b7b17c9b67e5984210c83d50d2c8117d3bd50ea0 (patch) | |
| tree | 072e63fa9cd1e1c314d9d99d0ae77d9e955d1a38 /drivers/md/bitmap.c | |
| parent | 7b1485bab9c49b0d3811d72beb0de60c7b8b337d (diff) | |
| download | linux-b7b17c9b67e5984210c83d50d2c8117d3bd50ea0.tar.xz | |
md: remove mddev_lock() from md_attr_show()
Most attributes can be read safely without any locking.
A race might lead to a slightly out-dated value, but nothing wrong.
We already have locking in some places where needed.
All that remains is can_clear_show(), behind_writes_used_show()
and action_show() which are easily fixed.
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/bitmap.c')
| -rw-r--r-- | drivers/md/bitmap.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 3424b1915fc4..3a5767968ba0 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -2211,11 +2211,13 @@ __ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store); static ssize_t can_clear_show(struct mddev *mddev, char *page) { int len; + spin_lock(&mddev->lock); if (mddev->bitmap) len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ? "false" : "true")); else len = sprintf(page, "\n"); + spin_unlock(&mddev->lock); return len; } @@ -2240,10 +2242,15 @@ __ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store); static ssize_t behind_writes_used_show(struct mddev *mddev, char *page) { + ssize_t ret; + spin_lock(&mddev->lock); if (mddev->bitmap == NULL) - return sprintf(page, "0\n"); - return sprintf(page, "%lu\n", - mddev->bitmap->behind_writes_used); + ret = sprintf(page, "0\n"); + else + ret = sprintf(page, "%lu\n", + mddev->bitmap->behind_writes_used); + spin_unlock(&mddev->lock); + return ret; } static ssize_t |