Commit Graph

754 Commits

Author SHA1 Message Date
Ira Weiny 5dc21f0c0b mm/shmem: ensure proper fallback if page faults
The kernel test robot flagged a recursive lock as a result of a conversion
from kmap_atomic() to kmap_local_folio()[Link]

The cause was due to the code depending on the kmap_atomic() side effect
of disabling page faults.  In that case the code expects the fault to fail
and take the fallback case.

git archaeology implied that the recursion may not be an actual bug.[1]
However, depending on the implementation of the mmap_lock and the
condition of the call there may still be a deadlock.[2] So this is not
purely a lockdep issue.  Considering a single threaded call stack there
are 3 options.

	1) Different mm's are in play (no issue)
	2) Readlock implementation is recursive and same mm is in play
	   (no issue)
	3) Readlock implementation is _not_ recursive (issue)

The mmap_lock is recursive so with a single thread there is no issue.

However, Matthew pointed out a deadlock scenario when you consider
additional process' and threads thusly.

"The readlock implementation is only recursive if nobody else has taken a
write lock.  If you have a multithreaded process, one of the other threads
can call mmap() and that will prevent recursion (due to fairness).  Even
if it's a different process that you're trying to acquire the mmap read
lock on, you can still get into a deadly embrace.  eg:

process A thread 1 takes read lock on own mmap_lock
process A thread 2 calls mmap, blocks taking write lock
process B thread 1 takes page fault, read lock on own mmap lock
process B thread 2 calls mmap, blocks taking write lock
process A thread 1 blocks taking read lock on process B
process B thread 1 blocks taking read lock on process A

Now all four threads are blocked waiting for each other."

Regardless using pagefault_disable() ensures that no matter what locking
implementation is used a deadlock will not occur.  Add an explicit
pagefault_disable() and a big comment to explain this for future souls
looking at this code.

[1] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/
[2] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/

Link: https://lkml.kernel.org/r/20221025220108.2366043-1-ira.weiny@intel.com
Link: https://lore.kernel.org/r/202210211215.9dc6efb5-yujie.liu@intel.com
Fixes: 7a7256d5f5 ("shmem: convert shmem_mfill_atomic_pte() to use a folio")
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: kernel test robot <yujie.liu@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:23 -07:00
Jason A. Donenfeld a251c17aa5 treewide: use get_random_u32() when possible
The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake
Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Acked-by: Helge Deller <deller@gmx.de> # for parisc
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:58 -06:00
Linus Torvalds f721d24e5d tmpfile API change
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Merge tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs tmpfile updates from Al Viro:
 "Miklos' ->tmpfile() signature change; pass an unopened struct file to
  it, let it open the damn thing. Allows to add tmpfile support to FUSE"

* tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fuse: implement ->tmpfile()
  vfs: open inside ->tmpfile()
  vfs: move open right after ->tmpfile()
  vfs: make vfs_tmpfile() static
  ovl: use vfs_tmpfile_open() helper
  cachefiles: use vfs_tmpfile_open() helper
  cachefiles: only pass inode to *mark_inode_inuse() helpers
  cachefiles: tmpfile error handling cleanup
  hugetlbfs: cleanup mknod and tmpfile
  vfs: add vfs_tmpfile_open() helper
2022-10-10 19:45:17 -07:00
Zach O'Keefe 7c6c6cc4d3 mm/shmem: add flag to enforce shmem THP in hugepage_vma_check()
Patch series "mm: add file/shmem support to MADV_COLLAPSE", v4.

This series builds on top of the previous "mm: userspace hugepage
collapse" series which introduced the MADV_COLLAPSE madvise mode and added
support for private, anonymous mappings[2], by adding support for file and
shmem backed memory to CONFIG_READ_ONLY_THP_FOR_FS=y kernels.

File and shmem support have been added with effort to align with existing
MADV_COLLAPSE semantics and policy decisions[3].  Collapse of shmem-backed
memory ignores kernel-guiding directives and heuristics including all
sysfs settings (transparent_hugepage/shmem_enabled), and tmpfs huge= mount
options (shmem always supports large folios).  Like anonymous mappings, on
successful return of MADV_COLLAPSE on file/shmem memory, the contents of
memory mapped by the addresses provided will be synchronously pmd-mapped
THPs.

This functionality unlocks two important uses:

(1)	Immediately back executable text by THPs.  Current support provided
	by CONFIG_READ_ONLY_THP_FOR_FS may take a long time on a large
	system which might impair services from serving at their full rated
	load after (re)starting.  Tricks like mremap(2)'ing text onto
	anonymous memory to immediately realize iTLB performance prevents
	page sharing and demand paging, both of which increase steady state
	memory footprint.  Now, we can have the best of both worlds: Peak
	upfront performance and lower RAM footprints.

(2)	userfaultfd-based live migration of virtual machines satisfy UFFD
	faults by fetching native-sized pages over the network (to avoid
	latency of transferring an entire hugepage).  However, after guest
	memory has been fully copied to the new host, MADV_COLLAPSE can
	be used to immediately increase guest performance.

khugepaged has received a small improvement by association and can now
detect and collapse pte-mapped THPs.  However, there is still work to be
done along the file collapse path.  Compound pages of arbitrary order
still needs to be supported and THP collapse needs to be converted to
using folios in general.  Eventually, we'd like to move away from the
read-only and executable-mapped constraints currently imposed on eligible
files and support any inode claiming huge folio support.  That said, I
think the series as-is covers enough to claim that MADV_COLLAPSE supports
file/shmem memory.

Patches 1-3	Implement the guts of the series.
Patch 4 	Is a tracepoint for debugging.
Patches 5-9 	Refactor existing khugepaged selftests to work with new
		memory types + new collapse tests.
Patch 10 	Adds a userfaultfd selftest mode to mimic a functional test
		of UFFDIO_REGISTER_MODE_MINOR+MADV_COLLAPSE live migration.
		(v4 note: "userfaultfd shmem" selftest is failing as of
		Sep 22 mm-unstable)

[1] https://lore.kernel.org/linux-mm/YyiK8YvVcrtZo0z3@google.com/
[2] https://lore.kernel.org/linux-mm/20220706235936.2197195-1-zokeefe@google.com/
[3] https://lore.kernel.org/linux-mm/YtBmhaiPHUTkJml8@google.com/
[4] https://lore.kernel.org/linux-mm/20220922222731.1124481-1-zokeefe@google.com/
[5] https://lore.kernel.org/linux-mm/20220922184651.1016461-1-zokeefe@google.com/


This patch (of 10):

Extend 'mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()' to
shmem, allowing callers to ignore
/sys/kernel/transparent_hugepage/shmem_enabled and tmpfs huge= mount.

This is intended to be used by MADV_COLLAPSE, and the rationale is
analogous to the anon/file case: MADV_COLLAPSE is not coupled to
directives that advise the kernel's decisions on when THPs should be
considered eligible.  shmem/tmpfs always claims large folio support,
regardless of sysfs or mount options.

[shy828301@gmail.com: test shmem_huge_force explicitly]
  Link: https://lore.kernel.org/linux-mm/CAHbLzko3A5-TpS0BgBeKkx5cuOkWgLvWXQH=TdgW-baO4rPtdg@mail.gmail.com/
Link: https://lkml.kernel.org/r/20220922224046.1143204-1-zokeefe@google.com
Link: https://lkml.kernel.org/r/20220907144521.3115321-2-zokeefe@google.com
Link: https://lkml.kernel.org/r/20220922224046.1143204-2-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:33 -07:00
Jeff Layton 36f05cab0a tmpfs: add support for an i_version counter
NFSv4 mandates a change attribute to avoid problems with timestamp
granularity, which Linux implements using the i_version counter. This is
particularly important when the underlying filesystem is fast.

Give tmpfs an i_version counter. Since it doesn't have to be persistent,
we can just turn on SB_I_VERSION and sprinkle some inode_inc_iversion
calls in the right places.

Also, while there is no formal spec for xattrs, most implementations
update the ctime on setxattr. Fix shmem_xattr_handler_set to update the
ctime and bump the i_version appropriately.

Link: https://lkml.kernel.org/r/20220909130031.15477-1-jlayton@kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:06 -07:00
Matthew Wilcox (Oracle) 923e2f0e7c shmem: remove shmem_getpage()
With all callers removed, remove this wrapper function.  The flags are now
mysteriously called SGP, but I think we can live with that.

Link: https://lkml.kernel.org/r/20220902194653.1739778-34-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:50 -07:00
Matthew Wilcox (Oracle) 7459c149ae khugepaged: call shmem_get_folio()
shmem_getpage() is being removed, so call its replacement and find the
precise page ourselves.

Link: https://lkml.kernel.org/r/20220902194653.1739778-32-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:50 -07:00
Matthew Wilcox (Oracle) e4b57722d0 shmem: convert shmem_get_link() to use a folio
Symlinks will never use a large folio, but using the folio API removes a
lot of unnecessary folio->page->folio conversions.

Link: https://lkml.kernel.org/r/20220902194653.1739778-31-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:50 -07:00
Matthew Wilcox (Oracle) 7ad0414bde shmem: convert shmem_symlink() to use a folio
While symlinks will always be < PAGE_SIZE, using the folio APIs gets rid
of unnecessary calls to compound_head().

Link: https://lkml.kernel.org/r/20220902194653.1739778-30-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:49 -07:00
Matthew Wilcox (Oracle) b0802b22a9 shmem: convert shmem_fallocate() to use a folio
Call shmem_get_folio() and use the folio APIs instead of the page APIs. 
Saves several calls to compound_head() and removes assumptions about the
size of a large folio.

Link: https://lkml.kernel.org/r/20220902194653.1739778-29-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:49 -07:00
Matthew Wilcox (Oracle) 4601e2fc8b shmem: convert shmem_file_read_iter() to use shmem_get_folio()
Use a folio throughout, saving five calls to compound_head().

Link: https://lkml.kernel.org/r/20220902194653.1739778-28-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:49 -07:00
Matthew Wilcox (Oracle) eff1f906c2 shmem: convert shmem_write_begin() to use shmem_get_folio()
Use a folio throughout this function, saving a couple of calls to
compound_head().

Link: https://lkml.kernel.org/r/20220902194653.1739778-27-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:49 -07:00
Matthew Wilcox (Oracle) a7f5862cc0 shmem: convert shmem_get_partial_folio() to use shmem_get_folio()
Get rid of an unnecessary folio->page->folio conversion.

Link: https://lkml.kernel.org/r/20220902194653.1739778-26-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:49 -07:00
Matthew Wilcox (Oracle) 4e1fc793ad shmem: add shmem_get_folio()
With no remaining callers of shmem_getpage_gfp(), add shmem_get_folio()
and reimplement shmem_getpage() as a call to shmem_get_folio().

Link: https://lkml.kernel.org/r/20220902194653.1739778-25-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:49 -07:00
Matthew Wilcox (Oracle) a3a9c39704 shmem: convert shmem_read_mapping_page_gfp() to use shmem_get_folio_gfp()
Saves a couple of calls to compound_head().

Link: https://lkml.kernel.org/r/20220902194653.1739778-24-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:48 -07:00
Matthew Wilcox (Oracle) 68a541001a shmem: convert shmem_fault() to use shmem_get_folio_gfp()
No particular advantage for this function, but necessary to remove
shmem_getpage_gfp().

[hughd@google.com: fix crash]
  Link: https://lkml.kernel.org/r/7693a84-bdc2-27b5-2695-d0fe8566571f@google.com
Link: https://lkml.kernel.org/r/20220902194653.1739778-23-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:48 -07:00
Matthew Wilcox (Oracle) fc26babbc7 shmem: convert shmem_getpage_gfp() to shmem_get_folio_gfp()
Add a shmem_getpage_gfp() wrapper for compatibility with current users.

Link: https://lkml.kernel.org/r/20220902194653.1739778-22-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:48 -07:00
Matthew Wilcox (Oracle) 5739a81cf8 shmem: eliminate struct page from shmem_swapin_folio()
Convert shmem_swapin() to return a folio and use swap_cache_get_folio(),
removing all uses of struct page in this function.

Link: https://lkml.kernel.org/r/20220902194653.1739778-21-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:48 -07:00
Matthew Wilcox (Oracle) 0d698e2572 shmem: convert shmem_replace_page() to shmem_replace_folio()
The caller has a folio, so convert the calling convention and rename the
function.

Link: https://lkml.kernel.org/r/20220902194653.1739778-19-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:47 -07:00
Matthew Wilcox (Oracle) 7a7256d5f5 shmem: convert shmem_mfill_atomic_pte() to use a folio
Assert that this is a single-page folio as there are several assumptions
in here that it's exactly PAGE_SIZE bytes large.  Saves several calls to
compound_head() and removes the last caller of shmem_alloc_page().

Link: https://lkml.kernel.org/r/20220902194653.1739778-18-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:47 -07:00
Matthew Wilcox (Oracle) 4081f7446d mm/swap: convert put_swap_page() to put_swap_folio()
With all callers now using a folio, we can convert this function.

Link: https://lkml.kernel.org/r/20220902194653.1739778-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:46 -07:00
Matthew Wilcox (Oracle) a4c366f01f mm/swap: convert add_to_swap_cache() to take a folio
With all callers using folios, we can convert add_to_swap_cache() to take
a folio and use it throughout.

Link: https://lkml.kernel.org/r/20220902194653.1739778-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:46 -07:00
Matthew Wilcox (Oracle) 907ea17eb2 shmem: convert shmem_replace_page() to use folios throughout
Introduce folio_set_swap_entry() to abstract how both folio->private and
swp_entry_t work.  Use swap_address_space() directly instead of
indirecting through folio_mapping().  Include an assertion that the old
folio is not large as we only allocate a single-page folio to replace it. 
Use folio_put_refs() instead of calling folio_put() twice.

Link: https://lkml.kernel.org/r/20220902194653.1739778-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:45 -07:00
Matthew Wilcox (Oracle) 4cd400fd1f shmem: convert shmem_delete_from_page_cache() to take a folio
Remove the assertion that the page is not Compound as this function now
handles large folios correctly.

Link: https://lkml.kernel.org/r/20220902194653.1739778-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:45 -07:00
Matthew Wilcox (Oracle) f530ed0e2d shmem: convert shmem_writepage() to use a folio throughout
Even though we will split any large folio that comes in, write the code to
handle large folios so as to not leave a trap for whoever tries to handle
large folios in the swap cache.

Link: https://lkml.kernel.org/r/20220902194653.1739778-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:45 -07:00
Matthew Wilcox (Oracle) d788f5b374 mm: add split_folio()
This wrapper removes a need to use split_huge_page(&folio->page).  Convert
two callers.

Link: https://lkml.kernel.org/r/20220902194653.1739778-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:02:45 -07:00
Miklos Szeredi 863f144f12 vfs: open inside ->tmpfile()
This is in preparation for adding tmpfile support to fuse, which requires
that the tmpfile creation and opening are done as a single operation.

Replace the 'struct dentry *' argument of i_op->tmpfile with
'struct file *'.

Call finish_open_simple() as the last thing in ->tmpfile() instances (may
be omitted in the error case).

Change d_tmpfile() argument to 'struct file *' as well to make callers more
readable.

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-09-24 07:00:00 +02:00
Matthew Wilcox (Oracle) 9dfb3b8d65 shmem: update folio if shmem_replace_page() updates the page
If we allocate a new page, we need to make sure that our folio matches
that new page.

If we do end up in this code path, we store the wrong page in the shmem
inode's page cache, and I would rather imagine that data corruption
ensues.

This will be solved by changing shmem_replace_page() to
shmem_replace_folio(), but this is the minimal fix.

Link: https://lkml.kernel.org/r/20220730042518.1264767-1-willy@infradead.org
Fixes: da08e9b793 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-28 14:02:43 -07:00
Hugh Dickins 76d36dea02 mm/shmem: shmem_replace_page() remember NR_SHMEM
Elsewhere, NR_SHMEM is updated at the same time as shmem NR_FILE_PAGES;
but shmem_replace_page() was forgetting to do that - so NR_SHMEM stats
could grow too big or too small, in those unusual cases when it's used.

Link: https://lkml.kernel.org/r/cec7c09d-5874-e160-ada6-6e10ee48784@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Radoslaw Burny <rburny@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20 15:17:45 -07:00
Hugh Dickins 15f242bb65 mm/shmem: tmpfs fallocate use file_modified()
5.18 fixed the btrfs and ext4 fallocates to use file_modified(), as xfs
was already doing, to drop privileges: and fstests generic/{683,684,688}
expect this.  There's no need to argue over keep-size allocation (which
could just update ctime): fix shmem_fallocate() to behave the same way.

Link: https://lkml.kernel.org/r/39c5e62-4896-7795-c0a0-f79c50d4909@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Radoslaw Burny <rburny@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20 15:17:45 -07:00
Hugh Dickins cb241339b9 mm/shmem: fix chattr fsflags support in tmpfs
ext[234] have always allowed unimplemented chattr flags to be set, but
other filesystems have tended to be stricter.  Follow the stricter
approach for tmpfs: I don't want to have to explain why csu attributes
don't actually work, and we won't need to update the chattr(1) manpage;
and it's never wrong to start off strict, relaxing later if persuaded. 
Allow only a (append only) i (immutable) A (no atime) and d (no dump).

Although lsattr showed 'A' inherited, the NOATIME behavior was not being
inherited: because nothing sync'ed FS_NOATIME_FL to S_NOATIME.  Add
shmem_set_inode_flags() to sync the flags, using inode_set_flags() to
avoid that instant of lost immutablility during fileattr_set().

But that change switched generic/079 from passing to failing: because
FS_IMMUTABLE_FL and FS_APPEND_FL had been unconventionally included in the
INHERITED fsflags: remove them and generic/079 is back to passing.

Link: https://lkml.kernel.org/r/2961dcb0-ddf3-b9f0-3268-12a4ff996856@google.com
Fixes: e408e695f5 ("mm/shmem: support FS_IOC_[SG]ETFLAGS in tmpfs")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Radoslaw Burny <rburny@google.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20 15:17:45 -07:00
Linus Torvalds f30adc0d33 iov_iter stuff, part 2, rebased
* more new_sync_{read,write}() speedups - ITER_UBUF introduction
 * ITER_PIPE cleanups
 * unification of iov_iter_get_pages/iov_iter_get_pages_alloc and
   switching them to advancing semantics
 * making ITER_PIPE take high-order pages without splitting them
 * handling copy_page_from_iter() for high-order pages properly
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull more iov_iter updates from Al Viro:

 - more new_sync_{read,write}() speedups - ITER_UBUF introduction

 - ITER_PIPE cleanups

 - unification of iov_iter_get_pages/iov_iter_get_pages_alloc and
   switching them to advancing semantics

 - making ITER_PIPE take high-order pages without splitting them

 - handling copy_page_from_iter() for high-order pages properly

* tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
  fix copy_page_from_iter() for compound destinations
  hugetlbfs: copy_page_to_iter() can deal with compound pages
  copy_page_to_iter(): don't split high-order page in case of ITER_PIPE
  expand those iov_iter_advance()...
  pipe_get_pages(): switch to append_pipe()
  get rid of non-advancing variants
  ceph: switch the last caller of iov_iter_get_pages_alloc()
  9p: convert to advancing variant of iov_iter_get_pages_alloc()
  af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages()
  iter_to_pipe(): switch to advancing variant of iov_iter_get_pages()
  block: convert to advancing variants of iov_iter_get_pages{,_alloc}()
  iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()
  iov_iter: saner helper for page array allocation
  fold __pipe_get_pages() into pipe_get_pages()
  ITER_XARRAY: don't open-code DIV_ROUND_UP()
  unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() guts
  unify xarray_get_pages() and xarray_get_pages_alloc()
  unify pipe_get_pages() and pipe_get_pages_alloc()
  iov_iter_get_pages(): sanity-check arguments
  iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper
  ...
2022-08-08 20:04:35 -07:00
Al Viro fcb14cb1bd new iov_iter flavour - ITER_UBUF
Equivalent of single-segment iovec.  Initialized by iov_iter_ubuf(),
checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC
ones.

We are going to expose the things like ->write_iter() et.al. to those
in subsequent commits.

New predicate (user_backed_iter()) that is true for ITER_IOVEC and
ITER_UBUF; places like direct-IO handling should use that for
checking that pages we modify after getting them from iov_iter_get_pages()
would need to be dirtied.

DO NOT assume that replacing iter_is_iovec() with user_backed_iter()
will solve all problems - there's code that uses iter_is_iovec() to
decide how to poke around in iov_iter guts and for that the predicate
replacement obviously won't suffice.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08 22:37:15 -04:00
Linus Torvalds 6614a3c316 - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
 
 - Some kmemleak fixes from Patrick Wang and Waiman Long
 
 - DAMON updates from SeongJae Park
 
 - memcg debug/visibility work from Roman Gushchin
 
 - vmalloc speedup from Uladzislau Rezki
 
 - more folio conversion work from Matthew Wilcox
 
 - enhancements for coherent device memory mapping from Alex Sierra
 
 - addition of shared pages tracking and CoW support for fsdax, from
   Shiyang Ruan
 
 - hugetlb optimizations from Mike Kravetz
 
 - Mel Gorman has contributed some pagealloc changes to improve latency
   and realtime behaviour.
 
 - mprotect soft-dirty checking has been improved by Peter Xu
 
 - Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
2022-08-05 16:32:45 -07:00
Linus Torvalds f00654007f Folio changes for 6.0
- Fix an accounting bug that made NR_FILE_DIRTY grow without limit
    when running xfstests
 
  - Convert more of mpage to use folios
 
  - Remove add_to_page_cache() and add_to_page_cache_locked()
 
  - Convert find_get_pages_range() to filemap_get_folios()
 
  - Improvements to the read_cache_page() family of functions
 
  - Remove a few unnecessary checks of PageError
 
  - Some straightforward filesystem conversions to use folios
 
  - Split PageMovable users out from address_space_operations into their
    own movable_operations
 
  - Convert aops->migratepage to aops->migrate_folio
 
  - Remove nobh support (Christoph Hellwig)
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Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache

Pull folio updates from Matthew Wilcox:

 - Fix an accounting bug that made NR_FILE_DIRTY grow without limit
   when running xfstests

 - Convert more of mpage to use folios

 - Remove add_to_page_cache() and add_to_page_cache_locked()

 - Convert find_get_pages_range() to filemap_get_folios()

 - Improvements to the read_cache_page() family of functions

 - Remove a few unnecessary checks of PageError

 - Some straightforward filesystem conversions to use folios

 - Split PageMovable users out from address_space_operations into
   their own movable_operations

 - Convert aops->migratepage to aops->migrate_folio

 - Remove nobh support (Christoph Hellwig)

* tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits)
  fs: remove the NULL get_block case in mpage_writepages
  fs: don't call ->writepage from __mpage_writepage
  fs: remove the nobh helpers
  jfs: stop using the nobh helper
  ext2: remove nobh support
  ntfs3: refactor ntfs_writepages
  mm/folio-compat: Remove migration compatibility functions
  fs: Remove aops->migratepage()
  secretmem: Convert to migrate_folio
  hugetlb: Convert to migrate_folio
  aio: Convert to migrate_folio
  f2fs: Convert to filemap_migrate_folio()
  ubifs: Convert to filemap_migrate_folio()
  btrfs: Convert btrfs_migratepage to migrate_folio
  mm/migrate: Add filemap_migrate_folio()
  mm/migrate: Convert migrate_page() to migrate_folio()
  nfs: Convert to migrate_folio
  btrfs: Convert btree_migratepage to migrate_folio
  mm/migrate: Convert expected_page_refs() to folio_expected_refs()
  mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()
  ...
2022-08-03 10:35:43 -07:00
Matthew Wilcox (Oracle) 541846502f mm/migrate: Convert migrate_page() to migrate_folio()
Convert all callers to pass a folio.  Most have the folio
already available.  Switch all users from aops->migratepage to
aops->migrate_folio.  Also turn the documentation into kerneldoc.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
2022-08-02 12:34:04 -04:00
Theodore Ts'o e408e695f5 mm/shmem: support FS_IOC_[SG]ETFLAGS in tmpfs
This allows userspace to set flags like FS_APPEND_FL, FS_IMMUTABLE_FL,
FS_NODUMP_FL, etc., like all other standard Linux file systems.

[akpm@linux-foundation.org: fix CONFIG_TMPFS_XATTR=n warnings]
Link: https://lkml.kernel.org/r/20220715015912.2560575-1-tytso@mit.edu
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 18:07:15 -07:00
ZhaoLong Wang 0c98c8e1e1 tmpfs: fix the issue that the mount and remount results are inconsistent.
An undefined-behavior issue has not been completely fixed since commit
d14f5efadd ("tmpfs: fix undefined-behaviour in shmem_reconfigure()"). 
In the commit, check in the shmem_reconfigure() is added in remount
process to avoid the Ubsan problem.  However, the check is not added to
the mount process.  It causes inconsistent results between mount and
remount.  The operations to reproduce the problem in user mode as follows:

If nr_blocks is set to 0x8000000000000000, the mounting is successful.

  # mount tmpfs /dev/shm/ -t tmpfs -o nr_blocks=0x8000000000000000

However, when -o remount is used, the mount fails because of the
check in the shmem_reconfigure()

  # mount tmpfs /dev/shm/ -t tmpfs -o remount,nr_blocks=0x8000000000000000
  mount: /dev/shm: mount point not mounted or bad option.

Therefore, add checks in the shmem_parse_one() function and remove the
check in shmem_reconfigure() to avoid this problem.

Link: https://lkml.kernel.org/r/20220629124324.1640807-1-wangzhaolong1@huawei.com
Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>
Cc: Luo Meng <luomeng12@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhihao Cheng <chengzhihao1@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-18 15:07:51 -07:00
Matthew Wilcox (Oracle) 75fa68a5d8 mm/swap: convert delete_from_swap_cache() to take a folio
All but one caller already has a folio, so convert it to use a folio.

Link: https://lkml.kernel.org/r/20220617175020.717127-22-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:48 -07:00
Matthew Wilcox (Oracle) 105c988f5d shmem: Convert shmem_unlock_mapping() to use filemap_get_folios()
This is a straightforward conversion.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-06-29 08:51:06 -04:00
Matthew Wilcox (Oracle) 2bb876b58d filemap: Remove add_to_page_cache() and add_to_page_cache_locked()
These functions have no more users, so delete them.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
2022-06-29 08:51:05 -04:00
Matthew Wilcox (Oracle) 6ffcd825e7 mm: Remove __delete_from_page_cache()
This wrapper is no longer used.  Remove it and all references to it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-06-29 08:51:05 -04:00
Miaohe Lin 833de10ff5 mm/shmem.c: clean up comment of shmem_swapin_folio
shmem_swapin_folio has changed to use folio but comment still mentions
page.  Update the relevant comment accordingly as suggested by Naoya.

Link: https://lkml.kernel.org/r/20220530115841.4348-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16 19:48:28 -07:00
Linus Torvalds 8291eaafed Two followon fixes for the post-5.19 series "Use pageblock_order for cma
and alloc_contig_range alignment", from Zi Yan.
 
 A series of z3fold cleanups and fixes from Miaohe Lin.
 
 Some memcg selftests work from Michal Koutný <mkoutny@suse.com>
 
 Some swap fixes and cleanups from Miaohe Lin.
 
 Several individual minor fixups.
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Merge tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - Two follow-on fixes for the post-5.19 series "Use pageblock_order for
   cma and alloc_contig_range alignment", from Zi Yan.

 - A series of z3fold cleanups and fixes from Miaohe Lin.

 - Some memcg selftests work from Michal Koutný <mkoutny@suse.com>

 - Some swap fixes and cleanups from Miaohe Lin

 - Several individual minor fixups

* tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (25 commits)
  mm/shmem.c: suppress shift warning
  mm: Kconfig: reorganize misplaced mm options
  mm: kasan: fix input of vmalloc_to_page()
  mm: fix is_pinnable_page against a cma page
  mm: filter out swapin error entry in shmem mapping
  mm/shmem: fix infinite loop when swap in shmem error at swapoff time
  mm/madvise: free hwpoison and swapin error entry in madvise_free_pte_range
  mm/swapfile: fix lost swap bits in unuse_pte()
  mm/swapfile: unuse_pte can map random data if swap read fails
  selftests: memcg: factor out common parts of memory.{low,min} tests
  selftests: memcg: remove protection from top level memcg
  selftests: memcg: adjust expected reclaim values of protected cgroups
  selftests: memcg: expect no low events in unprotected sibling
  selftests: memcg: fix compilation
  mm/z3fold: fix z3fold_page_migrate races with z3fold_map
  mm/z3fold: fix z3fold_reclaim_page races with z3fold_free
  mm/z3fold: always clear PAGE_CLAIMED under z3fold page lock
  mm/z3fold: put z3fold page back into unbuddied list when reclaim or migration fails
  revert "mm/z3fold.c: allow __GFP_HIGHMEM in z3fold_alloc"
  mm/z3fold: throw warning on failure of trylock_page in z3fold_alloc
  ...
2022-05-27 11:40:49 -07:00
Andrew Morton fa020a2b87 mm/shmem.c: suppress shift warning
mm/shmem.c:1948 shmem_getpage_gfp() warn: should '(((1) << 12) / 512) << folio_order(folio)' be a 64 bit type?

On i386, so an unsigned long is 32-bit, but i_blocks is a 64-bit blkcnt_t.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Jessica Clarke <jrtc27@jrtc27.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-27 09:33:47 -07:00
Miaohe Lin 6cec2b95da mm/shmem: fix infinite loop when swap in shmem error at swapoff time
When swap in shmem error at swapoff time, there would be a infinite loop
in the while loop in shmem_unuse_inode().  It's because swapin error is
deliberately ignored now and thus info->swapped will never reach 0.  So we
can't escape the loop in shmem_unuse().

In order to fix the issue, swapin_error entry is stored in the mapping
when swapin error occurs.  So the swapcache page can be freed and the user
won't end up with a permanently mounted swap because a sector is bad.  If
the page is accessed later, the user process will be killed so that
corrupted data is never consumed.  On the other hand, if the page is never
accessed, the user won't even notice it.

Link: https://lkml.kernel.org/r/20220519125030.21486-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reported-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-27 09:33:46 -07:00
Linus Torvalds 98931dd95f Yang Shi has improved the behaviour of khugepaged collapsing of readonly
file-backed transparent hugepages.
 
 Johannes Weiner has arranged for zswap memory use to be tracked and
 managed on a per-cgroup basis.
 
 Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime
 enablement of the recent huge page vmemmap optimization feature.
 
 Baolin Wang contributes a series to fix some issues around hugetlb
 pagetable invalidation.
 
 Zhenwei Pi has fixed some interactions between hwpoisoned pages and
 virtualization.
 
 Tong Tiangen has enabled the use of the presently x86-only
 page_table_check debugging feature on arm64 and riscv.
 
 David Vernet has done some fixup work on the memcg selftests.
 
 Peter Xu has taught userfaultfd to handle write protection faults against
 shmem- and hugetlbfs-backed files.
 
 More DAMON development from SeongJae Park - adding online tuning of the
 feature and support for monitoring of fixed virtual address ranges.  Also
 easier discovery of which monitoring operations are available.
 
 Nadav Amit has done some optimization of TLB flushing during mprotect().
 
 Neil Brown continues to labor away at improving our swap-over-NFS support.
 
 David Hildenbrand has some fixes to anon page COWing versus
 get_user_pages().
 
 Peng Liu fixed some errors in the core hugetlb code.
 
 Joao Martins has reduced the amount of memory consumed by device-dax's
 compound devmaps.
 
 Some cleanups of the arch-specific pagemap code from Anshuman Khandual.
 
 Muchun Song has found and fixed some errors in the TLB flushing of
 transparent hugepages.
 
 Roman Gushchin has done more work on the memcg selftests.
 
 And, of course, many smaller fixes and cleanups.  Notably, the customary
 million cleanup serieses from Miaohe Lin.
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Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Almost all of MM here. A few things are still getting finished off,
  reviewed, etc.

   - Yang Shi has improved the behaviour of khugepaged collapsing of
     readonly file-backed transparent hugepages.

   - Johannes Weiner has arranged for zswap memory use to be tracked and
     managed on a per-cgroup basis.

   - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
     runtime enablement of the recent huge page vmemmap optimization
     feature.

   - Baolin Wang contributes a series to fix some issues around hugetlb
     pagetable invalidation.

   - Zhenwei Pi has fixed some interactions between hwpoisoned pages and
     virtualization.

   - Tong Tiangen has enabled the use of the presently x86-only
     page_table_check debugging feature on arm64 and riscv.

   - David Vernet has done some fixup work on the memcg selftests.

   - Peter Xu has taught userfaultfd to handle write protection faults
     against shmem- and hugetlbfs-backed files.

   - More DAMON development from SeongJae Park - adding online tuning of
     the feature and support for monitoring of fixed virtual address
     ranges. Also easier discovery of which monitoring operations are
     available.

   - Nadav Amit has done some optimization of TLB flushing during
     mprotect().

   - Neil Brown continues to labor away at improving our swap-over-NFS
     support.

   - David Hildenbrand has some fixes to anon page COWing versus
     get_user_pages().

   - Peng Liu fixed some errors in the core hugetlb code.

   - Joao Martins has reduced the amount of memory consumed by
     device-dax's compound devmaps.

   - Some cleanups of the arch-specific pagemap code from Anshuman
     Khandual.

   - Muchun Song has found and fixed some errors in the TLB flushing of
     transparent hugepages.

   - Roman Gushchin has done more work on the memcg selftests.

  ... and, of course, many smaller fixes and cleanups. Notably, the
  customary million cleanup serieses from Miaohe Lin"

* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
  mm: kfence: use PAGE_ALIGNED helper
  selftests: vm: add the "settings" file with timeout variable
  selftests: vm: add "test_hmm.sh" to TEST_FILES
  selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
  selftests: vm: add migration to the .gitignore
  selftests/vm/pkeys: fix typo in comment
  ksm: fix typo in comment
  selftests: vm: add process_mrelease tests
  Revert "mm/vmscan: never demote for memcg reclaim"
  mm/kfence: print disabling or re-enabling message
  include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
  include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
  mm: fix a potential infinite loop in start_isolate_page_range()
  MAINTAINERS: add Muchun as co-maintainer for HugeTLB
  zram: fix Kconfig dependency warning
  mm/shmem: fix shmem folio swapoff hang
  cgroup: fix an error handling path in alloc_pagecache_max_30M()
  mm: damon: use HPAGE_PMD_SIZE
  tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
  nodemask.h: fix compilation error with GCC12
  ...
2022-05-26 12:32:41 -07:00
Hugh Dickins e384200e70 mm/shmem: fix shmem folio swapoff hang
Shmem swapoff makes no progress: the index to indices is not incremented. 
But "ret" is no longer a return value, so use folio_batch_count() instead.

Link: https://lkml.kernel.org/r/c32bee8a-f0aa-245-f94e-24dd271924fa@google.com
Fixes: da08e9b793 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-25 10:47:47 -07:00
Luo Meng d14f5efadd tmpfs: fix undefined-behaviour in shmem_reconfigure()
When shmem_reconfigure() calls __percpu_counter_compare(), the second
parameter is unsigned long long.  But in the definition of
__percpu_counter_compare(), the second parameter is s64.  So when
__percpu_counter_compare() executes abs(count - rhs), UBSAN shows the
following warning:

================================================================================
UBSAN: Undefined behaviour in lib/percpu_counter.c:209:6
signed integer overflow:
0 - -9223372036854775808 cannot be represented in type 'long long int'
CPU: 1 PID: 9636 Comm: syz-executor.2 Tainted: G                 ---------r-  - 4.18.0 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack home/install/linux-rh-3-10/lib/dump_stack.c:77 [inline]
 dump_stack+0x125/0x1ae home/install/linux-rh-3-10/lib/dump_stack.c:117
 ubsan_epilogue+0xe/0x81 home/install/linux-rh-3-10/lib/ubsan.c:159
 handle_overflow+0x19d/0x1ec home/install/linux-rh-3-10/lib/ubsan.c:190
 __percpu_counter_compare+0x124/0x140 home/install/linux-rh-3-10/lib/percpu_counter.c:209
 percpu_counter_compare home/install/linux-rh-3-10/./include/linux/percpu_counter.h:50 [inline]
 shmem_remount_fs+0x1ce/0x6b0 home/install/linux-rh-3-10/mm/shmem.c:3530
 do_remount_sb+0x11b/0x530 home/install/linux-rh-3-10/fs/super.c:888
 do_remount home/install/linux-rh-3-10/fs/namespace.c:2344 [inline]
 do_mount+0xf8d/0x26b0 home/install/linux-rh-3-10/fs/namespace.c:2844
 ksys_mount+0xad/0x120 home/install/linux-rh-3-10/fs/namespace.c:3075
 __do_sys_mount home/install/linux-rh-3-10/fs/namespace.c:3089 [inline]
 __se_sys_mount home/install/linux-rh-3-10/fs/namespace.c:3086 [inline]
 __x64_sys_mount+0xbf/0x160 home/install/linux-rh-3-10/fs/namespace.c:3086
 do_syscall_64+0xca/0x5c0 home/install/linux-rh-3-10/arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x6a/0xdf
RIP: 0033:0x46b5e9
Code: 5d db fa ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b db fa ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f54d5f22c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000077bf60 RCX: 000000000046b5e9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 000000000077bf60 R08: 0000000020000140 R09: 0000000000000000
R10: 00000000026740a4 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd1fb1592f R14: 00007f54d5f239c0 R15: 000000000077bf6c
================================================================================

[akpm@linux-foundation.org: tweak error message text]
Link: https://lkml.kernel.org/r/20220513025225.2678727-1-luomeng12@huawei.com
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19 14:08:54 -07:00
Yang Shi 613bec092f mm: mmap: register suitable readonly file vmas for khugepaged
The readonly FS THP relies on khugepaged to collapse THP for suitable
vmas.  But the behavior is inconsistent for "always" mode
(https://lore.kernel.org/linux-mm/00f195d4-d039-3cf2-d3a1-a2c88de397a0@suse.cz/).

The "always" mode means THP allocation should be tried all the time and
khugepaged should try to collapse THP all the time.  Of course the
allocation and collapse may fail due to other factors and conditions.

Currently file THP may not be collapsed by khugepaged even though all the
conditions are met.  That does break the semantics of "always" mode.

So make sure readonly FS vmas are registered to khugepaged to fix the
break.

Register suitable vmas in common mmap path, that could cover both readonly
FS vmas and shmem vmas, so remove the khugepaged calls in shmem.c.

Still need to keep the khugepaged call in vma_merge() since vma_merge() is
called in a lot of places, for example, madvise, mprotect, etc.

Link: https://lkml.kernel.org/r/20220510203222.24246-9-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastmil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Song Liu <song@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19 14:08:50 -07:00