On 14/11/2024 20:07, Dave Chinner wrote:
xfs_io -c "pwrite 64k 64k" mnt/file
xfs_io -c "pwrite 8k 8k" mnt/file
If unaligned unwritten extents are not permitted, we need to zero out the
sub-allocation units for ranges [0, 8K] and [16K, 64K] to prevent stale
data. While this can be handled relatively easily in direct I/O scenarios,
it presents significant challenges in buffered I/O operations. The main
difficulty arises because the extent size (64K) is larger than the page
size (4K), and our current code base has substantial limitations in handling
such cases.
Any thoughts on this?
Large folios in the page cache solve this problem. i.e. it's the
same problem that block size > page size support had to solve.
Would that work for an extsize which is not a power-of-2?
