Removes 3 calls to compound_head().

Link: https://lkml.kernel.org/r/20220905214557.868606-1-vishal.moola@gmail.comSigned-off-by: NVishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Once upon a time, we only support accounting thrashing of page cache. 
Then Joonsoo introduced workingset detection for anonymous pages and we
gained the ability to account thrashing of them[1].

For page cache thrashing accounting, there is no suitable place to do it
in fs level likes swap_readpage().  So we have to do it in
folio_wait_bit_common().

Then for anonymous pages thrashing accounting, we have to do it in both
swap_readpage() and folio_wait_bit_common().  This likes PSI, so we should
let thrashing accounting supports re-entrance detection.

This patch is to prepare complete thrashing accounting, and is based on
patch "filemap: make the accounting of thrashing more consistent".

[1] commit aae466b0 ("mm/swap: implement workingset detection for anonymous LRU")

Link: https://lkml.kernel.org/r/20220815071134.74551-1-yang.yang29@zte.com.cnSigned-off-by: NYang Yang <yang.yang29@zte.com.cn>
Signed-off-by: NCGEL ZTE <cgel.zte@gmail.com>
Reviewed-by: NRan Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Nwangyong <wang.yong12@zte.com.cn>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Once upon a time, we only support accounting thrashing of page cache. 
Then Joonsoo introduced workingset detection for anonymous pages and we
gained the ability to account thrashing of them[1].

So let delayacct account both the thrashing of page cache and anonymous
pages, this could make the codes more consistent and simpler.

[1] commit aae466b0 ("mm/swap: implement workingset detection for anonymous LRU")

Link: https://lkml.kernel.org/r/20220805033838.1714674-1-yang.yang29@zte.com.cnSigned-off-by: NYang Yang <yang.yang29@zte.com.cn>
Signed-off-by: NCGEL ZTE <cgel.zte@gmail.com>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

All callers of find_get_pages_contig() have been removed, so it is no
longer needed.

Link: https://lkml.kernel.org/r/20220824004023.77310-8-vishal.moola@gmail.comSigned-off-by: NVishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: David Sterba <dsterb@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Patch series "Convert to filemap_get_folios_contig()", v3.

This patch series replaces find_get_pages_contig() with
filemap_get_folios_contig().


This patch (of 7):

This function is meant to replace find_get_pages_contig().

Unlike find_get_pages_contig(), filemap_get_folios_contig() no longer
takes in a target number of pages to find - It returns up to 15 contiguous
folios.

To be more consistent with filemap_get_folios(),
filemap_get_folios_contig() now also updates the start index passed in,
and takes an end index.

Link: https://lkml.kernel.org/r/20220824004023.77310-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20220824004023.77310-2-vishal.moola@gmail.comSigned-off-by: NVishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Sterba <dsterb@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Replace three calls to compound_head() with one.

Link: https://lkml.kernel.org/r/20220809023256.178194-1-shaoqin.huang@intel.comSigned-off-by: NShaoqin Huang <shaoqin.huang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Restructure the logic in filemap_write_and_wait_range to simplify the code
and make it more consistent with file_write_and_wait_range. No functional
change intended.

Link: https://lkml.kernel.org/r/20220627132351.55680-1-linmiaohe@huawei.comSigned-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NMuchun Song <songmuchun@bytedance.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

If we're creating a page cache page with FGP_CREAT but FGP_NOWAIT is
set, we should dial back the gfp flags to avoid frivolous blocking
which is trivial to hit in low memory conditions:

[   10.117661]  __schedule+0x8c/0x550
[   10.118305]  schedule+0x58/0xa0
[   10.118897]  schedule_timeout+0x30/0xdc
[   10.119610]  __wait_for_common+0x88/0x114
[   10.120348]  wait_for_completion+0x1c/0x24
[   10.121103]  __flush_work.isra.0+0x16c/0x19c
[   10.121896]  flush_work+0xc/0x14
[   10.122496]  __drain_all_pages+0x144/0x218
[   10.123267]  drain_all_pages+0x10/0x18
[   10.123941]  __alloc_pages+0x464/0x9e4
[   10.124633]  __folio_alloc+0x18/0x3c
[   10.125294]  __filemap_get_folio+0x17c/0x204
[   10.126084]  iomap_write_begin+0xf8/0x428
[   10.126829]  iomap_file_buffered_write+0x144/0x24c
[   10.127710]  xfs_file_buffered_write+0xe8/0x248
[   10.128553]  xfs_file_write_iter+0xa8/0x120
[   10.129324]  io_write+0x16c/0x38c
[   10.129940]  io_issue_sqe+0x70/0x1cc
[   10.130617]  io_queue_sqe+0x18/0xfc
[   10.131277]  io_submit_sqes+0x5d4/0x600
[   10.131946]  __arm64_sys_io_uring_enter+0x224/0x600
[   10.132752]  invoke_syscall.constprop.0+0x70/0xc0
[   10.133616]  do_el0_svc+0xd0/0x118
[   10.134238]  el0_svc+0x78/0xa0

Clear IO, FS, and reclaim flags and mark the allocation as GFP_NOWAIT and
add __GFP_NOWARN to avoid polluting dmesg with pointless allocations
failures. A caller with FGP_NOWAIT must be expected to handle the
resulting -EAGAIN return and retry from a suitable context without NOWAIT
set.
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

By passing ->read_folio to filemap_read_folio(), we can use
filemap_read_folio() in do_read_cache_folio().
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

If the call to filler() returns AOP_TRUNCATED_PAGE, we need to
retry the page cache lookup.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

No functionality change intended; this simply moves code around to
disentangle the function a little.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

All callers of find_get_pages_range(), pagevec_lookup_range() and
pagevec_lookup() have now been removed.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NChristian Brauner (Microsoft) <brauner@kernel.org>

This is the equivalent of find_get_pages() but fills a folio_batch
instead of an array of pages.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NChristian Brauner (Microsoft) <brauner@kernel.org>

These functions have no more users, so delete them.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NMuchun Song <songmuchun@bytedance.com>

If a read races with an invalidation followed by another read, it is
possible for a folio to be replaced with a higher-order folio.  If that
happens, we'll see a sibling entry for the new folio in the next iteration
of the loop.  This manifests as a NULL pointer dereference while holding
the RCU read lock.

Handle this by simply returning.  The next call will find the new folio
and handle it correctly.  The other ways of handling this rare race are
more complex and it's just not worth it.
Reported-by: NDave Chinner <david@fromorbit.com>
Reported-by: NBrian Foster <bfoster@redhat.com>
Debugged-by: NBrian Foster <bfoster@redhat.com>
Tested-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Fixes: cbd59c48 ("mm/filemap: use head pages in generic_file_buffered_read")
Cc: stable@vger.kernel.org
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

We had an off-by-one error which meant that we never marked the first page
in a read as accessed.  This was visible as a slowdown when re-reading
a file as pages were being evicted from cache too soon.  In reviewing
this code, we noticed a second bug where a multi-page folio would be
marked as accessed multiple times when doing reads that were less than
the size of the folio.

Abstract the comparison of whether two file positions are in the same
folio into a new function, fixing both of these bugs.
Reported-by: NYu Kuai <yukuai3@huawei.com>
Reviewed-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

After we have unlocked the mmap_lock for I/O, the file is pinned, but
the VMA is not.  Checking this flag after that can be a use-after-free.
It's not a terribly interesting use-after-free as it can only read one
bit, and it's used to decide whether to read 2MB or 4MB.  But it
upsets the automated tools and it's generally bad practice anyway,
so let's fix it.

Reported-by: syzbot+5b96d55e5b54924c77ad@syzkaller.appspotmail.com
Fixes: 4687fdbb ("mm/filemap: Support VM_HUGEPAGE for file mappings")
Cc: stable@vger.kernel.org
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

This patch still does not use pte marker in any way, however it teaches
the core mm about the pte marker idea.

For example, handle_pte_marker() is introduced that will parse and handle
all the pte marker faults.

Many of the places are more about commenting it up - so that we know
there's the possibility of pte marker showing up, and why we don't need
special code for the cases.

[peterx@redhat.com: userfaultfd.c needs swapops.h]
  Link: https://lkml.kernel.org/r/YmRlVj3cdizYJsr0@xz-m1.local
Link: https://lkml.kernel.org/r/20220405014833.14015-1-peterx@redhat.comSigned-off-by: NPeter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

All implementations now use free_folio so we can delete the callers
and the method.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

Include documentation and convert the callers to use ->free_folio as
well as ->freepage.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

All but two of the callers already have a folio; pass a folio into
try_to_free_buffers().  This removes the last user of cancel_dirty_page()
so remove that wrapper function too.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NJeff Layton <jlayton@kernel.org>

All users are now converted to release_folio
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NJeff Layton <jlayton@kernel.org>

This replaces aops->releasepage.  Update the documentation, and call it
if it exists.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NJeff Layton <jlayton@kernel.org>

Now that filler_t and aops->read_folio() have the same type, we can decide
which one to use at the top of the function, and cache ->read_folio in
the filler parameter.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

By making filler_t the same as read_folio, we can use the same function
for both in gfs2.  We can push the use of folios down one more level
in jffs2 and nfs.  We also increase type safety for future users of the
various read_cache_page() family of functions by forcing the parameter
to be a pointer to struct file (or NULL).
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAndreas Gruenbacher <agruenba@redhat.com>

With all implementations of aops->readpage converted to aops->read_folio,
we can stop checking whether it's set and remove the member from aops.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

Change all the callers of ->readpage to call ->read_folio in preference,
if it exists.  This is a transitional duplication, and will be removed
by the end of the series.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

These wrappers have no more users; remove them.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

There are no more aop flags left, so remove the parameter.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Chuck Lever reported fsx-based xfstests generic 075 091 112 127 failing
when 5.18-rc1 NFS server exports tmpfs: bisected to recent tmpfs change.

Whilst nfsd_splice_action() does contain some questionable handling of
repeated pages, and Chuck was able to work around there, history from
Mark Hemment makes clear that there might be similar dangers elsewhere:
it was not a good idea for me to pass ZERO_PAGE down to unknown actors.

Revert shmem_file_read_iter() to using ZERO_PAGE for holes only when
iter_is_iovec(); in other cases, use the more natural iov_iter_zero()
instead of copy_page_to_iter().

We would use iov_iter_zero() throughout, but the x86 clear_user() is not
nearly so well optimized as copy to user (dd of 1T sparse tmpfs file
takes 57 seconds rather than 44 seconds).

And now pagecache_init() does not need to SetPageUptodate(ZERO_PAGE(0)):
which had caused boot failure on arm noMMU STM32F7 and STM32H7 boards

Link: https://lkml.kernel.org/r/9a978571-8648-e830-5735-1f4748ce2e30@google.com
Fixes: 56a8c8eb ("tmpfs: do not allocate pages on read")
Signed-off-by: NHugh Dickins <hughd@google.com>
Reported-by: NPatrice CHOTARD <patrice.chotard@foss.st.com>
Reported-by: NChuck Lever III <chuck.lever@oracle.com>
Tested-by: NChuck Lever III <chuck.lever@oracle.com>
Cc: Mark Hemment <markhemm@googlemail.com>
Cc: Patrice CHOTARD <patrice.chotard@foss.st.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Lukas Czerner <lczerner@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can extract both the file pointer and the pos from the iocb.
This simplifies each caller as well as allowing generic_perform_write()
to see more of the iocb contents in the future.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChristian Brauner <brauner@kernel.org>
Reviewed-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>

All filesystems have now been converted to use ->readahead, so
remove the ->readpages operation and fix all the comments that
used to refer to it.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>

When part of the user buffer passed to generic_perform_write() or
iomap_file_buffered_write() cannot be faulted in for reading, the entire
write currently fails.  The correct behavior would be to write all the
data that can be written, up to the point of failure.

Commit a6294593 ("iov_iter: Turn iov_iter_fault_in_readable into
fault_in_iov_iter_readable") gave us the information needed, so fix the
page prefaulting in generic_perform_write() and iomap_write_iter() to
only bail out when no pages could be faulted in.

We already factor in that pages that are faulted in may no longer be
resident by the time they are accessed.  Paging out pages has the same
effect as not faulting in those pages in the first place, so the code
can already deal with that.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

filemap_unaccount_folio() has a WARN_ON_ONCE(folio_test_dirty(folio)).  It
is good to warn of late dirtying on a persistent filesystem, but late
dirtying on tmpfs can only lose data which is expected to be thrown away;
and it's a pity if that warning comes ONCE on tmpfs, then hides others
which really matter.  Make it conditional on mapping_cap_writeback().

Cleanup: then folio_account_cleaned() no longer needs to check that for
itself, and so no longer needs to know the mapping.

Link: https://lkml.kernel.org/r/b5a1106c-7226-a5c6-ad41-ad4832cae1f@google.comSigned-off-by: NHugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The page_mapcount_reset() when folio_mapped() while mapping_exiting() was
devised long before there were huge or compound pages in the cache.  It is
still valid for small pages, but not at all clear what's right to check
and reset on large pages.  Just don't try when folio_test_large().

Link: https://lkml.kernel.org/r/879c4426-4122-da9c-1a86-697f2c9a083@google.comSigned-off-by: NHugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The PG_waiters bit is not included in PAGE_FLAGS_CHECK_AT_FREE, and
vmscan.c's free_unref_page_list() callers rely on that not to generate
bad_page() alerts.  So __page_cache_release(), put_pages_list() and
release_pages() (and presumably copy-and-pasted free_zone_device_page())
are redundant and misleading to make a special point of clearing it (as
the "__" implies, it could only safely be used on the freeing path).

Delete __ClearPageWaiters().  Remark on this in one of the "possible"
comments in folio_wake_bit(), and delete the superfluous comments.

Link: https://lkml.kernel.org/r/3eafa969-5b1a-accf-88fe-318784c791a@google.comSigned-off-by: NHugh Dickins <hughd@google.com>
Tested-by: NYu Zhao <yuzhao@google.com>
Reviewed-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mikulas asked in "Do we still need commit a0ee5ec5 ('tmpfs: allocate
on read when stacked')?" in [1]

Lukas noticed this unusual behavior of loop device backed by tmpfs in [2].

Normally, shmem_file_read_iter() copies the ZERO_PAGE when reading
holes; but if it looks like it might be a read for "a stacking
filesystem", it allocates actual pages to the page cache, and even marks
them as dirty.  And reads from the loop device do satisfy the test that
is used.

This oddity was added for an old version of unionfs, to help to limit
its usage to the limited size of the tmpfs mount involved; but about the
same time as the tmpfs mod went in (2.6.25), unionfs was reworked to
proceed differently; and the mod kept just in case others needed it.

Do we still need it? I cannot answer with more certainty than "Probably
not".  It's nasty enough that we really should try to delete it; but if
a regression is reported somewhere, then we might have to revert later.

It's not quite as simple as just removing the test (as Mikulas did):
xfstests generic/013 hung because splice from tmpfs failed on page not
up-to-date and page mapping unset.  That can be fixed just by marking
the ZERO_PAGE as Uptodate, which of course it is: do so in
pagecache_init() - it might be useful to others than tmpfs.

My intention, though, was to stop using the ZERO_PAGE here altogether:
surely iov_iter_zero() is better for this case? Sadly not: it relies on
clear_user(), and the x86 clear_user() is slower than its copy_user() [3].

But while we are still using the ZERO_PAGE, let's stop dirtying its
struct page cacheline with unnecessary get_page() and put_page().

Link: https://lore.kernel.org/linux-mm/alpine.LRH.2.02.2007210510230.6959@file01.intranet.prod.int.rdu2.redhat.com/ [1]
Link: https://lore.kernel.org/linux-mm/20211126075100.gd64odg2bcptiqeb@work/ [2]
Link: https://lore.kernel.org/lkml/2f5ca5e4-e250-a41c-11fb-a7f4ebc7e1c9@google.com/ [3]
Link: https://lkml.kernel.org/r/90bc5e69-9984-b5fa-a685-be55f2b64b@google.comSigned-off-by: NHugh Dickins <hughd@google.com>
Reported-by: NMikulas Patocka <mpatocka@redhat.com>
Reported-by: NLukas Czerner <lczerner@redhat.com>
Acked-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Zdenek Kabelac <zkabelac@redhat.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It's unused now. Remove it and clean up the relevant comment.

Link: https://lkml.kernel.org/r/20220208134149.47299-1-linmiaohe@huawei.comSigned-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the VM_HUGEPAGE flag is set, attempt to allocate PMD-sized folios
during readahead, even if we have no history of readahead being
successful.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

do_page_cache_ra() was being exposed for the benefit of
do_sync_mmap_readahead().  Switch it over to page_cache_ra_order()
partly because it's a better interface but mostly for the benefit of
the next patch.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>