| Message ID | 20221212073724.12637-2-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/7] btrfs: use file_offset to limit bios size in calc_bio_boundaries | expand |
On Mon, Dec 12, 2022 at 08:37:18AM +0100, Christoph Hellwig wrote: > btrfs_ordered_extent->disk_bytenr can be rewritten by the zoned I/O > completion handler, and thus in general is not a good idea to limit I/O > size. But the maximum bio size calculation can easily be done using the > file_offset fields in the btrfs_ordered_extent and btrfs_bio structures, > so switch to that instead. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Can you add a comment to the code as well? I'm going to see this in a year or two and spend a little bit scratching my head as to why we're using the file_offset here. With that done you can add Reviewed-by: Josef Bacik <josef@toxicpanda.com> Thanks, Josef
On Mon, Dec 12, 2022 at 01:54:14PM -0500, Josef Bacik wrote: > Can you add a comment to the code as well? Sure. > I'm going to see this in a year or two > and spend a little bit scratching my head as to why we're using the file_offset > here. With that done you can add Heh. I hope the code in this form is actually gone in a year, as the concept of first creating the ordered extents and inserting them into a tree, and then doing a lookup a few lines down in writepages is not exactly very efficient and we should be able to just pass a pointer down. But that is several series down in my queue.
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a65a1629d3356d..1fcb55e549717f 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -944,8 +944,8 @@ static void calc_bio_boundaries(struct btrfs_bio_ctrl *bio_ctrl, ordered = btrfs_lookup_ordered_extent(inode, file_offset); if (ordered) { bio_ctrl->len_to_oe_boundary = min_t(u32, U32_MAX, - ordered->disk_bytenr + - ordered->disk_num_bytes - logical); + ordered->file_offset + + ordered->disk_num_bytes - file_offset); btrfs_put_ordered_extent(ordered); return; }
btrfs_ordered_extent->disk_bytenr can be rewritten by the zoned I/O completion handler, and thus in general is not a good idea to limit I/O size. But the maximum bio size calculation can easily be done using the file_offset fields in the btrfs_ordered_extent and btrfs_bio structures, so switch to that instead. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/btrfs/extent_io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)