[0/8] Rearrange inode locking

Message

Goldwyn Rodrigues June 22, 2020, 4:20 p.m. UTC

This series attempts to arrange inode locking and unlocking to be more
aligned to ext4 and xfs, and makes it simpler in logic. The main goal is
to have shared inode lock for direct reads and direct writes within EOF
to make sure we do not race with truncate.

The advantage is that we get rid of btrfs_inode->dio_sem in the DIO
path.

This patch is on top of btrfs-iomap-dio work and survived a run of
xfstests.

Git: https://github.com/goldwynr/linux/tree/btrfs-inode-lock

 btrfs_inode.h |   10 -
 ctree.h       |    8 +
 file.c        |  355 +++++++++++++++++++++++++++++++---------------------------
 inode.c       |   13 +-
 4 files changed, 207 insertions(+), 179 deletions(-)