5.10-stable review patch. If anyone has any objections, please let me know.
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From: Mark Harmstone maharmstone@fb.com
commit ae4477f937569d097ca5dbce92a89ba384b49bc6 upstream.
Each superblock contains a copy of the device item for that device. In a transaction which drops a chunk but doesn't create any new ones, we were correctly updating the device item in the chunk tree but not copying over the new bytes_used value to the superblock.
This can be seen by doing the following:
# dd if=/dev/zero of=test bs=4096 count=2621440 # mkfs.btrfs test # mount test /root/temp
# cd /root/temp # for i in {00..10}; do dd if=/dev/zero of=$i bs=4096 count=32768; done # sync # rm * # sync # btrfs balance start -dusage=0 . # sync
# cd # umount /root/temp # btrfs check test
For btrfs-check to detect this, you will also need my patch at https://github.com/kdave/btrfs-progs/pull/991.
Change btrfs_remove_dev_extents() so that it adds the devices to the fs_info->post_commit_list if they're not there already. This causes btrfs_commit_device_sizes() to be called, which updates the bytes_used value in the superblock.
Fixes: bbbf7243d62d ("btrfs: combine device update operations during transaction commit") CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Mark Harmstone maharmstone@fb.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/volumes.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3101,6 +3101,12 @@ int btrfs_remove_chunk(struct btrfs_tran device->bytes_used - dev_extent_len); atomic64_add(dev_extent_len, &fs_info->free_chunk_space); btrfs_clear_space_info_full(fs_info); + + if (list_empty(&device->post_commit_list)) { + list_add_tail(&device->post_commit_list, + &trans->transaction->dev_update_list); + } + mutex_unlock(&fs_info->chunk_mutex); }