OpenAFS Master Repository branch, openafs-stable-1_8_x, updated. openafs-stable-1_8_8_1-68-g6997f89

[Gerrit Code Review]

The following commit has been merged in the openafs-stable-1_8_x branch:
commit 6997f890445680ecda572778155c900ba9147b7b
Author: Cheyenne Wills <cwills@sinenomine.net>
Date:   Mon Jun 27 08:38:25 2022 -0600

    Linux-5.18: replace readpages with readahead
    
    The linux 5.18 commit 'fs: Remove ->readpages address space
    operation' (704528d8) removes the address_space_operations operation
    "readpages", which is replaced with the "readahead" operation
    that was introduced with the 5.8 commit 'mm: add readahead address
    space operation' (8151b4c8).
    
    When readahead is called, the pages in 'rac' have already been added to
    the lru caches and are locked. For each page that we get from the 'rac'
    (i.e. from 'readahead_page(rac)'), we must unlock and put_page the page;
    if we successfully populated the page with data, we also set
    PageUpToDate.  If we don't process all the pages in 'rac', the caller
    will handle cleaning up any remaining pages; we don't need to unlock/put
    them or touch them at all.
      (See Linux Documentation/filesystems/vfs.rst)
    
    Add an autoconf test to detect the presence of 'readahead' in the
    address_space_operations structure.
    
    For the implementation of readahead (which is contained in Linux's
    osi_vnodeops.c):
    
    Add new functions 'afs_linux_bypass_readahead' and 'afs_linux_readahead'
    as replacements for 'afs_bypass_readpages' and 'afs_linux_readpages'
    when the linux kernel supports the readahead operation.
    
    Notes:
      In afs_linux_bypass_readahead, the pages are already locked and are
      already in the page cache, we just need to place the page into the
      iovecp.  The page's refcount will be decremented and will be unlocked
      when processing the read request.
    
      In afs_linux_readahead, the lrupages is needed in case a page is added
      to the cachefp's mapping in afs_linux_read_cache (which also handles
      unlocking the page).
    
      In afs_linux_readahead, if there is no tdc, we must still unlock the
      page otherwise the read process will wait on that page.
    
    Reviewed-on: https://gerrit.openafs.org/14953
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Andrew Deason <adeason@sinenomine.net>
    Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
    (cherry picked from commit 7a181415db1b2142d125714f1dea32879e2ca07d)
    
    Change-Id: I2ed4f22bd2b12c76586ae5326841a23735a20af0
    Reviewed-on: https://gerrit.openafs.org/15065
    Tested-by: BuildBot <buildbot@rampaginggeek.com>
    Reviewed-by: Andrew Deason <adeason@sinenomine.net>
    Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
    Tested-by: Michael Laß <lass@mail.uni-paderborn.de>
    Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>

 src/afs/LINUX/osi_vnodeops.c  | 189 +++++++++++++++++++++++++++++++++++++++++-
 src/cf/linux-kernel-struct.m4 |   2 +
 2 files changed, 189 insertions(+), 2 deletions(-)

-- 
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