On 3/25/2026 3:28 PM, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
Sashiko found some real issues in patch 09 and 10, I will send v3 to fix them.
https://sashiko.dev/#/patchset/20260325072850.3997161-1-yi.zhang%40huaweicloud.com
Best Regards,
Yi.
>
> Changes since v1:
> - In patch 04, rename ext4_block_get_zero_range() to
> ext4_load_tail_bh() and drop the unused 'length' parameter as Jan
> suggested.
> - In patch 06, modify the commit message, add another reason to drop
> data=ordered mode when zeroing partial blocks in ext4_punch_hole()
> and ext4_punch_hole() as Jan pointed out.
> - In patch 10, modify the commit message, explain the race condition
> between the buffered write and mmap write that pointed out by Jan.
> - Collect reviewed tags from Jan.
>
> v1: https://lore.kernel.org/linux-ext4/20260310014101.4140698-1-yi.zhang@huaweicloud.com/
>
> Original cover letter:
>
> This patch series extracted from my iomap conversion v2 series[1]. It
> refactors the ext4 zero partial block code path in preparation for
> converting buffered I/O to the iomap infrastructure. The main changes
> are:
>
> [1] https://lore.kernel.org/linux-ext4/20260203062523.3869120-1-yi.zhang@huawei.com/
>
> 1. Introduce ext4_block_zero_eof(): Extend and rename
> ext4_block_truncate_page() to handle post-EOF partial block zeroing
> for both append writes and truncate operations.
> 2. Separate ordered data handling: Move data=ordered mode handling from
> __ext4_block_zero_page_range to ext4_block_zero_eof(). Only truncate
> and post-EOF append write/fallocate paths need ordered data mode,
> hole punching and zero range paths don't need ordered data handling.
> 3. Split journal mode handling: Extract
> ext4_block_journalled_zero_range() from
> __ext4_block_zero_page_range() for data=journal mode, leaving
> ext4_block_do_zero_range() for data=ordered/writeback modes.
> 4. Refactor ext4_alloc_file_blocks(): Change parameters to loff_t byte
> granularity to simplify callers and prepares removing the zero call
> from the allocation loop for unaligned append writes.
> 5. Remove handle parameters: Stop passing handle_t * to zero functions.
> Make ext4_block_journalled_zero_range() start its own handle, and
> move zero operations outside active handles. This is required because
> iomap uses "folio lock -> transaction start" lock ordering, opposite
> to the current lock ordering.
> 6. Centralize zeroing in ext4_write_checks(): Move all post-EOF partial
> block zeroing to ext4_write_checks() so it applies to both regular
> buffered writes and the upcoming iomap path.
>
> Thanks
> Yi.
>
> Zhang Yi (10):
> ext4: add did_zero output parameter to ext4_block_zero_page_range()
> ext4: ext4_block_truncate_page() returns zeroed length on success
> ext4: rename and extend ext4_block_truncate_page()
> ext4: factor out journalled block zeroing range
> ext4: rename ext4_block_zero_page_range() to ext4_block_zero_range()
> ext4: move ordered data handling out of ext4_block_do_zero_range()
> ext4: remove handle parameters from zero partial block functions
> ext4: pass allocate range as loff_t to ext4_alloc_file_blocks()
> ext4: move zero partial block range functions out of active handle
> ext4: zero post-EOF partial block before appending write
>
> fs/ext4/ext4.h | 5 +-
> fs/ext4/extents.c | 83 +++++++--------
> fs/ext4/file.c | 14 +++
> fs/ext4/inode.c | 255 ++++++++++++++++++++++++++++------------------
> 4 files changed, 207 insertions(+), 150 deletions(-)
>