From 1538e6c52e19175a5f4da48eb88e059d5d12d7a0 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 16 Jun 2017 00:28:47 +0200 Subject: [PATCH] btrfs: use non-RCU list traversal in write_all_supers callees We take the fs_devices::device_list_mutex mutex in write_all_supers which will prevent any add/del changes to the device list. Therefore we don't need to use the RCU variant list_for_each_entry_rcu in any of the called functions. Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index ec9aa34bb6eb..06c593775b82 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3395,9 +3395,10 @@ static int barrier_all_devices(struct btrfs_fs_info *info) int errors_wait = 0; blk_status_t ret; + lockdep_assert_held(&info->fs_devices->device_list_mutex); /* send down all the barriers */ head = &info->fs_devices->devices; - list_for_each_entry_rcu(dev, head, dev_list) { + list_for_each_entry(dev, head, dev_list) { if (dev->missing) continue; if (!dev->bdev) @@ -3410,7 +3411,7 @@ static int barrier_all_devices(struct btrfs_fs_info *info) } /* wait for all the barriers */ - list_for_each_entry_rcu(dev, head, dev_list) { + list_for_each_entry(dev, head, dev_list) { if (dev->missing) continue; if (!dev->bdev) { @@ -3509,7 +3510,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) } } - list_for_each_entry_rcu(dev, head, dev_list) { + list_for_each_entry(dev, head, dev_list) { if (!dev->bdev) { total_errors++; continue; @@ -3550,7 +3551,7 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) } total_errors = 0; - list_for_each_entry_rcu(dev, head, dev_list) { + list_for_each_entry(dev, head, dev_list) { if (!dev->bdev) continue; if (!dev->in_fs_metadata || !dev->writeable)