From: Chi Zhiling This patch prepares the iomap framework for exFAT's upcoming migration to iomap. During testing of the exFAT iomap branch with xfstests generic/299 on a VM with 8GB RAM and a 40GB disk, system unresponsiveness was observed. iomap_zero_iter() lacked dirty page throttling, which could cause memory pressure when exFAT's valid_size mechanism triggers large-scale zeroing operations during writes beyond valid_size. Align iomap_zero_iter() with iomap_write_iter() by adding balance_dirty_pages_ratelimited() to throttle dirty page generation during large zeroing operations. Also add cond_resched() to provide voluntary rescheduling points during long-running loops. Signed-off-by: Chi Zhiling Cc: Namjae Jeon --- exFAT iomap migration: https://lore.kernel.org/linux-fsdevel/20260507124238.7313-1-linkinjeon@kernel.org/ fs/iomap/buffered-io.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index d7b648421a70..f6955786c8ad 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1543,6 +1543,8 @@ static int iomap_zero_iter(struct iomap_iter *iter, bool *did_zero, size_t offset; bool ret; + balance_dirty_pages_ratelimited(iter->inode->i_mapping); + bytes = min_t(u64, SIZE_MAX, bytes); status = iomap_write_begin(iter, write_ops, &folio, &offset, &bytes); @@ -1571,6 +1573,8 @@ static int iomap_zero_iter(struct iomap_iter *iter, bool *did_zero, if (WARN_ON_ONCE(!ret)) return -EIO; + cond_resched(); + status = iomap_iter_advance(iter, bytes); if (status) break; -- 2.43.0