diff options
Diffstat (limited to 'fs/btrfs/extent_io.c')
| -rw-r--r-- | fs/btrfs/extent_io.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index ca765d62324f..90ad3006ef3a 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -902,7 +902,30 @@ static void submit_extent_page(struct btrfs_bio_ctrl *bio_ctrl, size -= len; pg_offset += len; disk_bytenr += len; - bio_ctrl->len_to_oe_boundary -= len; + + /* + * len_to_oe_boundary defaults to U32_MAX, which isn't page or + * sector aligned. alloc_new_bio() then sets it to the end of + * our ordered extent for writes into zoned devices. + * + * When len_to_oe_boundary is tracking an ordered extent, we + * trust the ordered extent code to align things properly, and + * the check above to cap our write to the ordered extent + * boundary is correct. + * + * When len_to_oe_boundary is U32_MAX, the cap above would + * result in a 4095 byte IO for the last page right before + * we hit the bio limit of UINT_MAX. bio_add_page() has all + * the checks required to make sure we don't overflow the bio, + * and we should just ignore len_to_oe_boundary completely + * unless we're using it to track an ordered extent. + * + * It's pretty hard to make a bio sized U32_MAX, but it can + * happen when the page cache is able to feed us contiguous + * pages for large extents. + */ + if (bio_ctrl->len_to_oe_boundary != U32_MAX) + bio_ctrl->len_to_oe_boundary -= len; /* Ordered extent boundary: move on to a new bio. */ if (bio_ctrl->len_to_oe_boundary == 0) |