[GIT PULL] cachefiles, afs: mm wait fixes

[David Howells]

Hi Linus,

Could you pull these patches from Matthew Wilcox to fix page
waiting-related issues in cachefiles and afs as extracted from his folio
series[1]:

 (1) In cachefiles, remove the use of the wait_bit_key struct to access
     something that's actually in wait_page_key format.  The proper struct
     is now available in the header, so that should be used instead.

 (2) Add a proper wait function for waiting killably on the page writeback
     flag.  This includes a recent bugfix[2] that's not in the afs code.

 (3) In afs, use the function added in (2) rather than using
     wait_on_page_bit_killable() which doesn't provide the aforementioned
     bugfix.

Notes:

 - I've included these together since they are an excerpt from a patch
   series of Willy's, but I can send the first separately from the other
   two if you'd prefer since they touch different modules.

 - The cachefiles patch could be deferred to the next merge window as
   whichever compiler is used probably *should* generate the same code for
   both structs, even with struct randomisation turned on.

 - AuriStor (auristor.com) have added certain of my branches to their
   automated AFS testing, hence the Tested-by kafs-testing@xxxxxxxxxxxx tag
   on the patches in this set.  Is this the best way to represent this?

David

Link: https://lore.kernel.org/r/20210320054104.1300774-1-willy@xxxxxxxxxxxxx[1]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c2407cf7d22d0c0d94cf20342b3b8f06f1d904e7 [2]
Link: https://lore.kernel.org/r/20210323120829.GC1719932@xxxxxxxxxxxxxxxxxxxx/ # v1

---
The following changes since commit 0d02ec6b3136c73c09e7859f0d0e4e2c4c07b49b:

  Linux 5.12-rc4 (2021-03-21 14:56:43 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git tags/afs-cachefiles-fixes-20210323

for you to fetch changes up to 75b69799610c2b909a18e709c402923ea61aedc0:

  afs: Use wait_on_page_writeback_killable (2021-03-23 20:54:37 +0000)

----------------------------------------------------------------
cachefiles, afs: mm wait fixes

----------------------------------------------------------------
Matthew Wilcox (Oracle) (3):
      fs/cachefiles: Remove wait_bit_key layout dependency
      mm/writeback: Add wait_on_page_writeback_killable
      afs: Use wait_on_page_writeback_killable

 fs/afs/write.c          |  3 +--
 fs/cachefiles/rdwr.c    |  7 +++----
 include/linux/pagemap.h |  2 +-
 mm/page-writeback.c     | 16 ++++++++++++++++
 4 files changed, 21 insertions(+), 7 deletions(-)