2023-09-29 14:24:13

by Ojaswin Mujoo

Subject: [PATCH 1/3] ext4: treat end of range as exclusive in ext4_zero_range()

The call to filemap_write_and_wait_range() assumes the range passed to be
inclusive, so fix the call to make sure we follow that.

Signed-off-by: Ojaswin Mujoo <[email protected]>
---
fs/ext4/extents.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e4115d338f10..c79b4c25afc4 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4522,7 +4522,8 @@ static long ext4_zero_range(struct file *file, loff_t offset,
* Round up offset. This is not fallocate, we need to zero out
* blocks, so convert interior block aligned part of the range to
* unwritten and possibly manually zero out unaligned parts of the
- * range.
+ * range. Here, start and partial_begin are inclusive, end and
+ * partial_end are exclusive.
*/
start = round_up(offset, 1 << blkbits);
end = round_down((offset + len), 1 << blkbits);
@@ -4608,7 +4609,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
* disk in case of crash before zeroing trans is committed.
*/
if (ext4_should_journal_data(inode)) {
- ret = filemap_write_and_wait_range(mapping, start, end);
+ ret = filemap_write_and_wait_range(mapping, start, end - 1);
if (ret) {
filemap_invalidate_unlock(mapping);
goto out_mutex;
--
2.39.3

2023-10-19 15:01:22

by Jan Kara

Subject: Re: [PATCH 1/3] ext4: treat end of range as exclusive in ext4_zero_range()

On Fri 29-09-23 19:40:43, Ojaswin Mujoo wrote:
> The call to filemap_write_and_wait_range() assumes the range passed to be
> inclusive, so fix the call to make sure we follow that.
>
> Signed-off-by: Ojaswin Mujoo <[email protected]>

Yes, makes sense. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> fs/ext4/extents.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index e4115d338f10..c79b4c25afc4 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -4522,7 +4522,8 @@ static long ext4_zero_range(struct file *file, loff_t offset,
> * Round up offset. This is not fallocate, we need to zero out
> * blocks, so convert interior block aligned part of the range to
> * unwritten and possibly manually zero out unaligned parts of the
> - * range.
> + * range. Here, start and partial_begin are inclusive, end and
> + * partial_end are exclusive.
> */
> start = round_up(offset, 1 << blkbits);
> end = round_down((offset + len), 1 << blkbits);
> @@ -4608,7 +4609,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
> * disk in case of crash before zeroing trans is committed.
> */
> if (ext4_should_journal_data(inode)) {
> - ret = filemap_write_and_wait_range(mapping, start, end);
> + ret = filemap_write_and_wait_range(mapping, start, end - 1);
> if (ret) {
> filemap_invalidate_unlock(mapping);
> goto out_mutex;
> --
> 2.39.3
>
--
Jan Kara <[email protected]>
SUSE Labs, CR