This patchset changes the read and write paths to be more flexible in dealing with requests that are not page aligned. Until now there was a 1:1 mapping of struct nfs_page (referred to as "nfs requests") to struct page, which limited the client to page aligned I/O in several pNFS scenarios. This patchset allows multiple requests per page, loosely following the approach taken with struct buffer_head (part of kernel bio interface). With this patchset the client now supports: - non-page-aligned O_DIRECT I/O to DSes (instead of reverting to MDS) - arbitrary pnfs layout segment boundaries - arbitrary pnfs filelayout stripe sizes This patchset also includes a lot of cleanup - notably we no longer need a separate code path to support rsize/wsize < PAGE_SIZE. This new approach opens the door to many optimizations, such as not having to flush a page on a non-contiguous write, but for the time being we are focusing on correctness -- this patchset touches the read and write path for *all* versions of NFS! This has been tested against v2, v3, v4.0 and v4.1 (no pnfs) servers with different rsize/wsize settings, and against pynfs filelayout servers hacked to have non page aligned stripe sizes. I had some code review already (with changes applied) and we've been testing this pretty extensively for the last month+ - focusing mostly on v2, v3, v4.x (no pnfs). The patchset applies against Trond's testing branch, but should also include the fix I posted earlier today: "pnfs: fix race in filelayout commit path" as the race seems to be easier to hit with this patchset applied. I'm pretty sure I didn't break anything in the object and block layouts, but some extra attention there would be helpful. I plan on sharing some performance numbers once I'm able to run some nfsometer workloads. Expect them soon. -dros Weston Andros Adamson (17): nfs: clean up PG_* flags nfs: remove unused arg from nfs_create_request nfs: modify pg_test interface to return size_t nfs: call nfs_can_coalesce_requests for every req nfs: add support for multiple nfs reqs per page nfs: page group syncing in read path nfs: page group syncing in write path nfs: page group support in nfs_mark_uptodate pnfs: clean up filelayout_alloc_commit_info nfs: allow coalescing of subpage requests nfs: chain calls to pg_test nfs: use > 1 request to handle bsize < PAGE_SIZE nfs: remove list of [rw]data from pgio header pnfs: support multiple verfs per direct req pnfs: allow non page aligned pnfs layout segments pnfs: filelayout: support non page aligned layouts nfs: support page groups in nfs_read_completion fs/nfs/blocklayout/blocklayout.c | 16 ++- fs/nfs/direct.c | 93 ++++++++++--- fs/nfs/nfs4filelayout.c | 121 +++++++++-------- fs/nfs/objlayout/objio_osd.c | 20 ++- fs/nfs/pagelist.c | 284 +++++++++++++++++++++++++++++++++------ fs/nfs/pnfs.c | 77 +++++------ fs/nfs/pnfs.h | 3 +- fs/nfs/read.c | 149 +++++++------------- fs/nfs/write.c | 217 +++++++++++++++--------------- include/linux/nfs.h | 5 +- include/linux/nfs_page.h | 32 +++-- include/linux/nfs_xdr.h | 37 ++--- 12 files changed, 650 insertions(+), 404 deletions(-) -- 1.8.5.2 (Apple Git-48) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
