[PATCH v1 00/15] Keep track of GUPed pages in fs and block

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From: Jérôme Glisse <jglisse@xxxxxxxxxx>

This patchset depends on various small fixes [1] and also on patchset
which introduce put_user_page*() [2] and thus is 5.3 material as those
pre-requisite will get in 5.2 at best. Nonetheless i am posting it now
so that it can get review and comments on how and what should be done
to test things.

For various reasons [2] [3] we want to track page reference through GUP
differently than "regular" page reference. Thus we need to keep track
of how we got a page within the block and fs layer. To do so this patch-
set change the bio_bvec struct to store a pfn and flags instead of a
direct pointer to a page. This way we can flag page that are coming from
GUP.

This patchset is divided as follow:
    - First part of the patchset is just small cleanup i believe they
      can go in as his assuming people are ok with them.
    - Second part convert bio_vec->bv_page to bio_vec->bv_pfn this is
      done in multi-step, first we replace all direct dereference of
      the field by call to inline helper, then we introduce macro for
      bio_bvec that are initialized on the stack. Finaly we change the
      bv_page field to bv_pfn.
    - Third part replace put_page(bv_page(bio_vec)) with a new helper
      which will use put_user_page() when the page in the bio_vec is
      coming from GUP.
    - Fourth part update BIO to use bv_set_user_page() for page that
      are coming from GUP this means updating bio_add_page*() to pass
      down the origin of the page (GUP or not).
    - Fith part convert few more places that directly use bvec_io or
      BIO.

Note that after this patchset they are still places in the kernel where
we should use put_user_page*(). The intention is to separate that task
in chewable chunk (driver by driver, sub-system by sub-system).


I have only lightly tested this patchset (branch [4]) on my desktop and
have not seen anything obviously wrong but i might have miss something.
What kind of test suite should i run to stress test the vfs/block layer
around DIO and BIO ?


Note that you coccinelle [5] recent enough for the semantic patch to work
properly ([5] with git commit >= eac73d191e4f03d759957fc5620062428fadada8).

Cheers,
Jérôme Glisse

[1] https://cgit.freedesktop.org/~glisse/linux/commit/?h=gup-fs-block&id=5f67db69fd9f95d12987d2a030a82bc390e05a71
    https://cgit.freedesktop.org/~glisse/linux/commit/?h=gup-fs-block&id=b070348d0e1fd9397eb8d0e97b4c89f1d04d5a0a
    https://cgit.freedesktop.org/~glisse/linux/commit/?h=gup-fs-block&id=83691c86a6c8f560b5b78f3f57fcd62c0f3f1c7a
[2] https://lkml.org/lkml/2019/3/26/1395
[3] https://lwn.net/Articles/753027/
[4] https://cgit.freedesktop.org/~glisse/linux/log/?h=gup-fs-block
[5] https://github.com/coccinelle/coccinelle

Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-block@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Steve French <sfrench@xxxxxxxxx>
Cc: linux-cifs@xxxxxxxxxxxxxxx
Cc: samba-technical@xxxxxxxxxxxxxxx
Cc: Yan Zheng <zyan@xxxxxxxxxx>
Cc: Sage Weil <sage@xxxxxxxxxx>
Cc: Ilya Dryomov <idryomov@xxxxxxxxx>
Cc: Alex Elder <elder@xxxxxxxxxx>
Cc: ceph-devel@xxxxxxxxxxxxxxx
Cc: Eric Van Hensbergen <ericvh@xxxxxxxxx>
Cc: Latchesar Ionkov <lucho@xxxxxxxxxx>
Cc: Mike Marshall <hubcap@xxxxxxxxxxxx>
Cc: Martin Brandenburg <martin@xxxxxxxxxxxx>
Cc: devel@xxxxxxxxxxxxxxxxxx
Cc: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
Cc: v9fs-developer@xxxxxxxxxxxxxxxxxxxxx
Cc: Coly Li <colyli@xxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: linux-bcache@xxxxxxxxxxxxxxx
Cc: Ernesto A. Fernández <ernesto.mnd.fernandez@xxxxxxxxx>

Jérôme Glisse (15):
  fs/direct-io: fix trailing whitespace issues
  iov_iter: add helper to test if an iter would use GUP
  block: introduce bvec_page()/bvec_set_page() to get/set
    bio_vec.bv_page
  block: introduce BIO_VEC_INIT() macro to initialize bio_vec structure
  block: replace all bio_vec->bv_page by bvec_page()/bvec_set_page()
  block: convert bio_vec.bv_page to bv_pfn to store pfn and not page
  block: add bvec_put_page_dirty*() to replace put_page(bvec_page())
  block: use bvec_put_page() instead of put_page(bvec_page())
  block: bvec_put_page_dirty* instead of set_page_dirty* and
    bvec_put_page
  block: add gup flag to
    bio_add_page()/bio_add_pc_page()/__bio_add_page()
  block: make sure bio_add_page*() knows page that are coming from GUP
  fs/direct-io: keep track of wether a page is coming from GUP or not
  fs/splice: use put_user_page() when appropriate
  fs: use bvec_set_gup_page() where appropriate
  ceph: use put_user_pages() instead of ceph_put_page_vector()

 Documentation/block/biodoc.txt      |  7 +-
 arch/m68k/emu/nfblock.c             |  2 +-
 arch/um/drivers/ubd_kern.c          |  2 +-
 arch/xtensa/platforms/iss/simdisk.c |  2 +-
 block/bio-integrity.c               |  8 +--
 block/bio.c                         | 92 ++++++++++++++++-----------
 block/blk-core.c                    |  2 +-
 block/blk-integrity.c               |  7 +-
 block/blk-lib.c                     |  5 +-
 block/blk-merge.c                   |  9 +--
 block/blk.h                         |  4 +-
 block/bounce.c                      | 26 ++++----
 block/t10-pi.c                      |  4 +-
 drivers/block/aoe/aoecmd.c          |  4 +-
 drivers/block/brd.c                 |  2 +-
 drivers/block/drbd/drbd_actlog.c    |  2 +-
 drivers/block/drbd/drbd_bitmap.c    |  4 +-
 drivers/block/drbd/drbd_main.c      |  4 +-
 drivers/block/drbd/drbd_receiver.c  |  6 +-
 drivers/block/drbd/drbd_worker.c    |  2 +-
 drivers/block/floppy.c              |  6 +-
 drivers/block/loop.c                | 16 ++---
 drivers/block/null_blk_main.c       |  6 +-
 drivers/block/pktcdvd.c             |  4 +-
 drivers/block/ps3disk.c             |  2 +-
 drivers/block/ps3vram.c             |  2 +-
 drivers/block/rbd.c                 | 12 ++--
 drivers/block/rsxx/dma.c            |  3 +-
 drivers/block/umem.c                |  2 +-
 drivers/block/virtio_blk.c          |  4 +-
 drivers/block/xen-blkback/blkback.c |  2 +-
 drivers/block/zram/zram_drv.c       | 24 +++----
 drivers/lightnvm/core.c             |  2 +-
 drivers/lightnvm/pblk-core.c        | 12 ++--
 drivers/lightnvm/pblk-rb.c          |  2 +-
 drivers/lightnvm/pblk-read.c        |  6 +-
 drivers/md/bcache/btree.c           |  2 +-
 drivers/md/bcache/debug.c           |  4 +-
 drivers/md/bcache/request.c         |  4 +-
 drivers/md/bcache/super.c           |  6 +-
 drivers/md/bcache/util.c            | 11 ++--
 drivers/md/dm-bufio.c               |  2 +-
 drivers/md/dm-crypt.c               | 18 ++++--
 drivers/md/dm-integrity.c           | 18 +++---
 drivers/md/dm-io.c                  |  7 +-
 drivers/md/dm-log-writes.c          | 20 +++---
 drivers/md/dm-verity-target.c       |  4 +-
 drivers/md/dm-writecache.c          |  3 +-
 drivers/md/dm-zoned-metadata.c      |  6 +-
 drivers/md/md.c                     |  4 +-
 drivers/md/raid1-10.c               |  2 +-
 drivers/md/raid1.c                  |  4 +-
 drivers/md/raid10.c                 |  4 +-
 drivers/md/raid5-cache.c            |  7 +-
 drivers/md/raid5-ppl.c              |  6 +-
 drivers/md/raid5.c                  | 10 +--
 drivers/nvdimm/blk.c                |  6 +-
 drivers/nvdimm/btt.c                |  5 +-
 drivers/nvdimm/pmem.c               |  4 +-
 drivers/nvme/host/core.c            |  4 +-
 drivers/nvme/host/tcp.c             |  2 +-
 drivers/nvme/target/io-cmd-bdev.c   |  2 +-
 drivers/nvme/target/io-cmd-file.c   |  2 +-
 drivers/s390/block/dasd_diag.c      |  2 +-
 drivers/s390/block/dasd_eckd.c      | 14 ++--
 drivers/s390/block/dasd_fba.c       |  6 +-
 drivers/s390/block/dcssblk.c        |  2 +-
 drivers/s390/block/scm_blk.c        |  2 +-
 drivers/s390/block/xpram.c          |  2 +-
 drivers/scsi/sd.c                   | 25 ++++----
 drivers/staging/erofs/data.c        |  6 +-
 drivers/staging/erofs/unzip_vle.c   |  4 +-
 drivers/target/target_core_file.c   |  6 +-
 drivers/target/target_core_iblock.c |  4 +-
 drivers/target/target_core_pscsi.c  |  2 +-
 drivers/xen/biomerge.c              |  4 +-
 fs/9p/vfs_addr.c                    |  4 +-
 fs/afs/fsclient.c                   |  2 +-
 fs/afs/rxrpc.c                      |  4 +-
 fs/afs/yfsclient.c                  |  2 +-
 fs/block_dev.c                      | 10 ++-
 fs/btrfs/check-integrity.c          |  6 +-
 fs/btrfs/compression.c              | 22 +++----
 fs/btrfs/disk-io.c                  |  4 +-
 fs/btrfs/extent_io.c                | 16 ++---
 fs/btrfs/file-item.c                |  8 +--
 fs/btrfs/inode.c                    | 20 +++---
 fs/btrfs/raid56.c                   |  8 +--
 fs/btrfs/scrub.c                    | 10 +--
 fs/buffer.c                         |  4 +-
 fs/ceph/file.c                      | 20 +++---
 fs/cifs/connect.c                   |  4 +-
 fs/cifs/misc.c                      | 14 ++--
 fs/cifs/smb2ops.c                   |  2 +-
 fs/cifs/smbdirect.c                 |  2 +-
 fs/cifs/transport.c                 |  2 +-
 fs/crypto/bio.c                     |  4 +-
 fs/direct-io.c                      | 94 +++++++++++++++++++--------
 fs/ext4/page-io.c                   |  4 +-
 fs/ext4/readpage.c                  |  4 +-
 fs/f2fs/data.c                      | 20 +++---
 fs/gfs2/lops.c                      |  8 +--
 fs/gfs2/meta_io.c                   |  4 +-
 fs/gfs2/ops_fstype.c                |  2 +-
 fs/hfsplus/wrapper.c                |  3 +-
 fs/io_uring.c                       |  4 +-
 fs/iomap.c                          | 10 +--
 fs/jfs/jfs_logmgr.c                 |  4 +-
 fs/jfs/jfs_metapage.c               |  6 +-
 fs/mpage.c                          |  6 +-
 fs/nfs/blocklayout/blocklayout.c    |  2 +-
 fs/nilfs2/segbuf.c                  |  3 +-
 fs/ocfs2/cluster/heartbeat.c        |  2 +-
 fs/orangefs/inode.c                 |  2 +-
 fs/splice.c                         | 13 ++--
 fs/xfs/xfs_aops.c                   |  8 +--
 fs/xfs/xfs_buf.c                    |  2 +-
 include/linux/bio.h                 | 13 ++--
 include/linux/bvec.h                | 99 +++++++++++++++++++++++++----
 include/linux/uio.h                 | 11 ++++
 kernel/power/swap.c                 |  2 +-
 lib/iov_iter.c                      | 32 +++++-----
 mm/page_io.c                        |  8 +--
 net/ceph/messenger.c                | 10 +--
 net/sunrpc/xdr.c                    |  2 +-
 net/sunrpc/xprtsock.c               |  4 +-
 126 files changed, 628 insertions(+), 467 deletions(-)

-- 
2.20.1




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