Commit 1538e6c5 authored by David Sterba's avatar David Sterba
Browse files

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: default avatarDavid Sterba <dsterba@suse.com>
parent d03262c7

fs/btrfs/disk-io.c

+5 −4
Original line number Diff line number Diff line
@@ -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)

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