On Tue, Oct 08, 2024 at 10:59:17AM +0200, Christoph Hellwig wrote:
> All XFS callers of iomap_zero_range and iomap_file_unshare already hold
> invalidate_lock, so we can't take it again in
> iomap_file_buffered_write_punch_delalloc.
>
> Use the passed in flags argument to detect if we're called from a zero
> or unshare operation and don't take the lock again in this case.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Thanks for fixing the bug I reported,
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> fs/xfs/xfs_iomap.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index 4fa4d66dc37761..17170d9b9ff78a 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -1239,10 +1239,18 @@ xfs_buffered_write_iomap_end(
> if (start_byte >= end_byte)
> return 0;
>
> - filemap_invalidate_lock(inode->i_mapping);
> - iomap_write_delalloc_release(inode, start_byte, end_byte, flags, iomap,
> - xfs_buffered_write_delalloc_punch);
> - filemap_invalidate_unlock(inode->i_mapping);
> + /* For zeroing operations the callers already hold invalidate_lock. */
> + if (flags & (IOMAP_UNSHARE | IOMAP_ZERO)) {
> + rwsem_assert_held_write(&inode->i_mapping->invalidate_lock);
> + iomap_write_delalloc_release(inode, start_byte, end_byte, flags,
> + iomap, xfs_buffered_write_delalloc_punch);
> + } else {
> + filemap_invalidate_lock(inode->i_mapping);
> + iomap_write_delalloc_release(inode, start_byte, end_byte, flags,
> + iomap, xfs_buffered_write_delalloc_punch);
> + filemap_invalidate_unlock(inode->i_mapping);
> + }
> +
> return 0;
> }
>
> --
> 2.45.2
>
>
