[GIT PULL] configfs fixes for 5.3

[Christoph Hellwig]

Hi Linus,

please pull these late configfs fixe from Al that fix pretty nasty
removal vs attribute access races.

The following changes since commit 089cf7f6ecb266b6a4164919a2e69bd2f938374a:

  Linux 5.3-rc7 (2019-09-02 09:57:40 -0700)

are available in the Git repository at:

  git://git.infradead.org/users/hch/configfs.git tags/configfs-for-5.3

for you to fetch changes up to b0841eefd9693827afb9888235e26ddd098f9cef:

  configfs: provide exclusion between IO and removals (2019-09-04 22:33:51 +0200)

----------------------------------------------------------------
configfs fixes for 5.3

 - fix removal vs attribute read/write races (Al Viro)

----------------------------------------------------------------
Al Viro (4):
      configfs: stash the data we need into configfs_buffer at open time
      configfs_register_group() shouldn't be (and isn't) called in rmdirable parts
      configfs: new object reprsenting tree fragments
      configfs: provide exclusion between IO and removals

 fs/configfs/configfs_internal.h |  15 ++-
 fs/configfs/dir.c               | 137 +++++++++++++++-----
 fs/configfs/file.c              | 280 ++++++++++++++++++++--------------------
 3 files changed, 257 insertions(+), 175 deletions(-)