diff options
| author | NeilBrown <neilb@suse.de> | 2012-04-12 16:05:06 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-22 15:38:55 -0700 |
| commit | 18d72b3c0b16b96f722f5293848369ae9eb65116 (patch) | |
| tree | 4cd4538fcc2e8b1aa79eed93ccbf8113594521de | |
| parent | 128b61db6e0319afffe5e3c87a36d27e71cd0d4d (diff) | |
| download | lwn-18d72b3c0b16b96f722f5293848369ae9eb65116.tar.gz lwn-18d72b3c0b16b96f722f5293848369ae9eb65116.zip | |
md/bitmap: prevent bitmap_daemon_work running while initialising bitmap
commit afbaa90b80b1ec66e5137cc3824746bfdf559b18 upstream.
If a bitmap is added while the array is active, it is possible
for bitmap_daemon_work to run while the bitmap is being
initialised.
This is particularly a problem if bitmap_daemon_work sees
bitmap->filemap as non-NULL before it has been filled in properly.
So hold bitmap_info.mutex while filling in ->filemap
to prevent problems.
This patch is suitable for any -stable kernel, though it might not
apply cleanly before about 3.1.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/bitmap.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 239af9a9aad1..22cb5cf39304 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -1819,7 +1819,9 @@ int bitmap_load(struct mddev *mddev) * re-add of a missing device */ start = mddev->recovery_cp; + mutex_lock(&mddev->bitmap_info.mutex); err = bitmap_init_from_disk(bitmap, start); + mutex_unlock(&mddev->bitmap_info.mutex); if (err) goto out; |