Commit 91e1f56a authored Oct 07, 2016 by Robbie Ko Committed by Filipe Manana Feb 24, 2017

Btrfs: fix leak of subvolume writers counter



When falling back from a nocow write to a regular cow write, we were
leaking the subvolume writers counter in 2 situations, preventing
snapshot creation from ever completing in the future, as it waits
for that counter to go down to zero before the snapshot creation
starts.

Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[Improved changelog and subject]
Signed-off-by: Filipe Manana <fdmanana@suse.com>

parent 6f546216

fs/btrfs/inode.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -1331,10 +1331,16 @@ next_slot:
		* either valid or do not exist.
		*/
		if (csum_exist_in_range(fs_info, disk_bytenr,
		num_bytes))
		num_bytes)) {
		if (!nolock)
		btrfs_end_write_no_snapshoting(root);
		goto out_check;
		if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
		}
		if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
		if (!nolock)
		btrfs_end_write_no_snapshoting(root);
		goto out_check;
		}
		nocow = 1;
		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
		extent_end = found_key.offset +

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