From: Zhang Yi The did_zero output parameter was unconditionally set after the loop, which is incorrect. It should only be set when the zeroing operation actually completes, not when IOMAP_F_STALE is set or when IOMAP_F_FOLIO_BATCH is set but !folio causes the loop to break early, or when iomap_iter_advance() returns an error. This causes did_zero to be incorrectly set when zeroing a clean unwritten extent because the loop exits early without actually zeroing any data. Fix it by using a local variable to track whether any folio was actually zeroed, and only set did_zero after the loop if zeroing happened. Signed-off-by: Zhang Yi Reviewed-by: "Darrick J. Wong" --- This is cherry picked form: https://lore.kernel.org/linux-fsdevel/20260310082250.3535486-1-yi.zhang@huaweicloud.com/ No changes. fs/iomap/buffered-io.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 876c2f507f58..27ab33edbdee 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1542,6 +1542,7 @@ static int iomap_zero_iter(struct iomap_iter *iter, bool *did_zero, const struct iomap_write_ops *write_ops) { u64 bytes = iomap_length(iter); + bool zeroed = false; int status; do { @@ -1560,6 +1561,8 @@ static int iomap_zero_iter(struct iomap_iter *iter, bool *did_zero, /* a NULL folio means we're done with a folio batch */ if (!folio) { status = iomap_iter_advance_full(iter); + if (status) + return status; break; } @@ -1570,6 +1573,7 @@ static int iomap_zero_iter(struct iomap_iter *iter, bool *did_zero, bytes); folio_zero_range(folio, offset, bytes); + zeroed = true; folio_mark_accessed(folio); ret = iomap_write_end(iter, bytes, bytes, folio); @@ -1579,10 +1583,10 @@ static int iomap_zero_iter(struct iomap_iter *iter, bool *did_zero, status = iomap_iter_advance(iter, bytes); if (status) - break; + return status; } while ((bytes = iomap_length(iter)) > 0); - if (did_zero) + if (did_zero && zeroed) *did_zero = true; return status; } -- 2.52.0