ext4: fix reserved space counter leakage
commit 6fed8395 upstream. When ext4_insert_delayed block receives and recovers from an error from ext4_es_insert_delayed_block(), e.g., ENOMEM, it does not release the space it has reserved for that block insertion as it should. One effect of this bug is that s_dirtyclusters_counter is not decremented and remains incorrectly elevated until the file system has been unmounted. This can result in premature ENOSPC returns and apparent loss of free space. Another effect of this bug is that /sys/fs/ext4/<dev>/delayed_allocation_blocks can remain non-zero even after syncfs has been executed on the filesystem. Besides, add check for s_dirtyclusters_counter when inode is going to be evicted and freed. s_dirtyclusters_counter can still keep non-zero until inode is written back in .evict_inode(), and thus the check is delayed to .destroy_inode(). Fixes: 51865fda ("ext4: let ext4 maintain extent status tree") Cc: stable@kernel.org Suggested-by:Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by:
Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by:
Eric Whitney <enwlinux@gmail.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20210823061358.84473-1-jefflexu@linux.alibaba.com Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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