This is an initial attempt to add support for block size > PAGE_SIZE for tmpfs. Why would you want this? It helps us experiment with higher order folio uses with fs APIS and helps us test out corner cases which would likely need to be accounted for sooner or later if and when filesystems enable support for this. Better review early and burn early than continue on in the wrong direction so looking for early feedback. I have other patches to convert shmem_write_begin() and shmem_file_read_iter() to folios too but those are not yet working. In the swap world the next thing to look at would be to convert swap_cluster_readahead() to folios. If folks want to experiment with tmpfs, brd or with things related to larger block sizes I've put a branch up with this, Hannes's brd patches, and some still work-in-progress patches on my large-block-20230421 branch [0]. Similarly you can also use kdevops with CONFIG_QEMU_ENABLE_EXTRA_DRIVE_LARGEIO support to get everything with just as that branch is used for that: make make bringup make linux [0] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/log/?h=large-block-20230421 [1] https://github.com/linux-kdevops/kdevops Luis Chamberlain (8): shmem: replace BLOCKS_PER_PAGE with PAGE_SECTORS shmem: convert to use folio_test_hwpoison() shmem: account for high order folios shmem: add helpers to get block size shmem: account for larger blocks sizes for shmem_default_max_blocks() shmem: consider block size in shmem_default_max_inodes() shmem: add high order page support shmem: add support to customize block size on multiple PAGE_SIZE include/linux/shmem_fs.h | 3 + mm/shmem.c | 146 +++++++++++++++++++++++++++++---------- 2 files changed, 114 insertions(+), 35 deletions(-) -- 2.39.2
